JPH07168577A - Sound absorber and its installation method - Google Patents
Sound absorber and its installation methodInfo
- Publication number
- JPH07168577A JPH07168577A JP5311584A JP31158493A JPH07168577A JP H07168577 A JPH07168577 A JP H07168577A JP 5311584 A JP5311584 A JP 5311584A JP 31158493 A JP31158493 A JP 31158493A JP H07168577 A JPH07168577 A JP H07168577A
- Authority
- JP
- Japan
- Prior art keywords
- sound
- particles
- sound absorbing
- resin
- frequency
- 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.)
- Granted
Links
Landscapes
- Building Environments (AREA)
- Duct Arrangements (AREA)
- Molding Of Porous Articles (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は樹脂発泡粒子を用いた吸
音体およびその施工方法に関する。詳しくは、土木、建
築、空調機器、及び、産業用機器の騒音防止に有効な樹
脂発泡粒子の成形体を用いた吸音体およびその施工方法
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing body using resin foam particles and a method of constructing the same. More specifically, the present invention relates to a sound absorbing body using a molded body of resin foam particles which is effective for noise prevention of civil engineering, construction, air conditioning equipment, and industrial equipment, and a construction method thereof.
【0002】[0002]
【従来の技術】吸音材料としては、音のエネルギーが細
孔状の材料内部で空気を振動させ、細孔内壁面との摩擦
により熱損失することを利用する多孔質体、板や膜の振
動へと変換することを利用する板状体や膜状体、共鳴現
象を利用した穴あき板体等の種々の材料が利用されてい
る。中でも多孔質成形体、即ち、具体的にはグラスウー
ルやロックウール等の繊維集合体や連続気泡構造を有す
る軟質ポリウレタン発泡成形体、或いは、セラミック粉
砕粒子を固めて焼成した多孔質成形体は吸音効果が得ら
れ易い点でその利用は多い。2. Description of the Related Art As a sound-absorbing material, the vibration of a porous body, plate, or membrane that utilizes the fact that the energy of sound vibrates air inside the pore-shaped material and causes heat loss due to friction with the inner wall surface of the pore Various materials such as a plate-shaped body and a film-shaped body that utilize the conversion into a hole, and a perforated plate that utilizes the resonance phenomenon are used. Among them, a porous molded article, specifically, a fiber aggregate such as glass wool or rock wool, a soft polyurethane foam molded article having an open cell structure, or a porous molded article obtained by solidifying and firing ceramic crushed particles has a sound absorbing effect. It is often used because it is easy to obtain.
【0003】しかしながら、これらのうちセラミック多
孔質成形体は軽量性や価格上の点で不利なため高温や環
境条件上の耐久性が求められる特殊な用途に限定されて
いる。また、軟質ポリウレタン発泡成形体は、その製造
条件により気泡膜の破壊状態が変化するため安定した吸
音効果を得られ難い。そのため最も一般的には、安価性
や軽量性に優れるグラスウールやロックウールが汎用さ
れている。However, among these, the ceramic porous molded body is disadvantageous in terms of lightness and price, and is therefore limited to special applications requiring durability under high temperature and environmental conditions. Further, in the flexible polyurethane foam molded article, it is difficult to obtain a stable sound absorbing effect because the broken state of the cell membrane changes depending on the manufacturing conditions. Therefore, most commonly, glass wool or rock wool, which is inexpensive and lightweight, is widely used.
【0004】ところで、こうした多孔質成形体は高音、
即ち高周波数領域の音に対しては優れた吸音効果を持つ
ものであるが、低音、即ち低周波数の音に対しては吸音
効果が薄く、吸音材料の厚みを大きく取ったり、或いは
音波を反射する壁(以下、剛壁と呼ぶ)と吸音材料との
間に背後空気層を大きく設けて対応せざるを得なかっ
た。通常、剛壁から騒音の1/4波長の所に多孔質成形
体を置くと最も大きい吸音率が得られる。例えば、20
0Hz、100Hzの騒音に対しては、それぞれ43
0、860mmの空間厚みが必要となる。そのため多大
な空間容積を必要とするものであり、低音の騒音防止対
策としては実用性に薄れるものであった。By the way, such a porous molded body is
In other words, it has an excellent sound absorption effect for sounds in the high frequency range, but it has a low sound absorption effect for low sounds, that is, low frequency sounds, and the sound absorbing material is thickened or sound waves are reflected. A large back air layer has to be provided between the sound absorbing wall (hereinafter referred to as a rigid wall) and the sound absorbing material. Usually, the largest sound absorption coefficient is obtained when the porous molded body is placed at a position of ¼ wavelength of noise from the rigid wall. For example, 20
43 for each of 0 Hz and 100 Hz noise
A space thickness of 0,860 mm is required. Therefore, a large space volume is required, which is not practical as a measure for preventing low-pitched noise.
【0005】一方、グラスウール等の繊維集合体では壁
の内外に温度差がある場合には結露現象による吸水や、
雨水の侵入による吸水によって吸音性能が劣化する。さ
らにこれら繊維集合体自体では柔軟なため、所望の形状
に施工する場合にはパンチングメタルや治具等の副資材
を用いて取付施工を行う必要があり、その上、作業時に
皮膚を刺激したり、吸入による人体に有害な悪影響を及
ぼす等の問題を有するものであった。On the other hand, in the case of a fiber aggregate such as glass wool, when there is a temperature difference between the inside and outside of the wall, water absorption due to the dew condensation phenomenon,
Sound absorption performance deteriorates due to water absorption due to intrusion of rainwater. Furthermore, since these fiber aggregates themselves are flexible, it is necessary to perform installation work using auxiliary materials such as punching metal and jigs when performing work in a desired shape. , Had a problem such as having a harmful adverse effect on the human body by inhalation.
【0006】[0006]
【発明が解決しようとする課題】本発明の目的は、騒音
の発生源に対して、吸音性能、施工に必要な空間容積、
及び施工の作業性の面から効率的な騒音防止対策を計る
こと、具体的には低周波数領域の吸音性能を高めること
で背後空気層を含めた吸音施工に必要な空間寸法を縮小
すること、施工時の作業を簡略化し作業性を高めるこ
と、環境条件の影響(特に吸水現象)による吸音性能の
低下問題を排除すること等を可能にする吸音体の施工方
法を提供することにある。DISCLOSURE OF THE INVENTION The object of the present invention is to reduce the noise absorption source, the sound absorption performance, the space volume required for construction,
And to take effective noise prevention measures from the viewpoint of workability of construction, specifically, to reduce the space size necessary for sound absorbing construction including the back air layer by enhancing sound absorbing performance in the low frequency region, It is an object of the present invention to provide a method of constructing a sound absorbing body that simplifies work during construction, improves workability, and eliminates a problem of deterioration in sound absorbing performance due to influence of environmental conditions (particularly water absorption phenomenon).
【0007】[0007]
【課題を解決するための手段】本発明は樹脂発泡粒子の
多数個が粒子間に空隙を残して互いに一体化した成形体
を用いることにより、従来の吸音体が持つ上記欠点を改
善するものである。すなわち、本発明の第1は100〜
3000Hzの周波数領域に吸音率30%以上のピーク
周波数を有する樹脂発泡粒子の多孔質成形体からなる吸
音体であり、その第2は100〜3000Hzの周波数
領域に吸音率30%以上のピーク周波数を有する樹脂発
泡粒子の多孔質成形体をからなる吸音体を施工するに際
し、該吸音体の肉厚みと背後空気層の厚みとの和d
(m)と騒音源の周波数f(Hz)とが、下記(1)式
及び(2)式を満たす条件で該吸音体を設置することを
特徴とする吸音体の施工方法である。DISCLOSURE OF THE INVENTION The present invention is to improve the above-mentioned drawbacks of a conventional sound absorbing body by using a molded body in which a large number of expanded resin particles are integrated with each other with a gap between the particles. is there. That is, the first aspect of the present invention is 100-
A sound absorbing body made of a porous molded body of resin foam particles having a peak frequency of 30% or more in a frequency range of 3000 Hz, and the second one has a peak frequency of 30% or more in a frequency range of 100 to 3000 Hz. The sum of the thickness of the sound absorbing body and the thickness of the back air layer when constructing the sound absorbing body made of the porous molded body of resin foamed particles
(M) and the frequency f (Hz) of the noise source are the sound absorbing body construction methods characterized in that the sound absorbing body is installed under the condition that the following formulas (1) and (2) are satisfied.
【0008】 1.03・(1/d)1.7 ≦f≦17.16・(1/d)1.7 (1) 100≦f≦285・(1/d)0.48 (2) まず、本発明の第1について説明する。本発明で用いら
れる吸音体は100〜3000Hz領域に吸音率が30
%以上のピーク周波数を有する樹脂発泡粒子の多孔質成
形体であることが肝要である。ピーク周波数が3000
Hzを越えるものは低音の吸音性が低下し本発明の目的
に適さない。また、ピーク周波数が100Hz未満のも
のは得ることが難しい。ここに吸音率とは、剛体壁に吸
音体が密着した状態で、JIS A1405に規定され
た垂直入射吸音率を言い、背後空気層を有する場合、つ
まり、音波を反射する剛体壁と吸音体との間に空気層を
設定して測定された値ではない。本発明の吸音体では背
後空気層を設けることにより吸音率のピーク周波数は低
周波数側に移行し、ピーク吸音率は増加する傾向にあ
る。また、本発明の吸音体は、これまで吸音体として樹
脂発泡粒子の多孔質成形体を用いたものがなかったのに
対し、吸音体として樹脂発泡粒子の多孔質成形体を用い
たことを特徴とする。1.03 · (1 / d) 1.7 ≦ f ≦ 17.16 · (1 / d) 1.7 (1) 100 ≦ f ≦ 285 · (1 / d) 0.48 (2) First, the first aspect of the present invention 1 will be described. The sound absorber used in the present invention has a sound absorption coefficient of 30 in the 100 to 3000 Hz region.
It is essential that the molded product is a porous molded product of expanded resin particles having a peak frequency of at least%. Peak frequency is 3000
Those having a frequency exceeding Hz are not suitable for the purpose of the present invention because the sound absorbing property of low sound is deteriorated. Further, it is difficult to obtain a peak frequency of less than 100 Hz. Here, the sound absorption coefficient refers to a normal incident sound absorption coefficient specified in JIS A1405 in a state where the sound absorbing body is in close contact with the rigid body wall, and has a back air layer, that is, the sound absorbing body reflects the rigid body wall and the sound absorbing body. It is not the value measured by setting the air layer between. In the sound absorber of the present invention, by providing the back air layer, the peak frequency of the sound absorption coefficient shifts to the low frequency side, and the peak sound absorption coefficient tends to increase. Further, the sound absorbing body of the present invention is characterized by using a porous molded body of resin foamed particles as the sound absorbing body, while there has been no one using a porous molded body of resin foamed particles as the sound absorbing body until now. And
【0009】上記の樹脂発泡粒子の多孔質成形体を用い
ることによる効果について、図を用いて説明すると以下
のとおりである。まず、図1は本発明で用いる多孔質成
形体の断面構造例の一つを示す拡大様式図である。1は
発泡粒子の部分、2は空隙部分を示す。本発明で用いる
樹脂発泡粒子の多孔質成形体は上記要件を満たすた
め、樹脂発泡粒子1の多数個が隣接する粒子表面の一部
で面接合して一体成形されており、その粒子間に空隙部
分2が形成されている。この空隙部分2は成形体厚み方
向には一定形状を有してはおらず、次の断面ではその面
積が広く、狭く、或いはその形状を違えた状態で連な
り、または屈曲して連なり、この空隙部分2が成形体内
部の多方向に道幅の割には急激な凹凸状、或いはジグザ
グ状に入り組んだいわゆるサウンドストリーム形構造の
通路を形成することになる。このため入射した音波は上
記音道を通過する際に多重反射や干渉による減衰効果を
も発現することになる。The effect of using the above-mentioned porous molded body of resin foamed particles will be described below with reference to the drawings. First, FIG. 1 is an enlarged stylistic view showing one example of a sectional structure of a porous molded body used in the present invention. Reference numeral 1 indicates a foamed particle portion, and 2 indicates a void portion. In order to satisfy the above requirements, the porous molded body of resin foamed particles used in the present invention is formed integrally by surface-joining a large number of resin foamed particles 1 at a part of adjacent particle surfaces, and voids between the particles. The part 2 is formed. This void portion 2 does not have a constant shape in the thickness direction of the molded body, and the area is wide and narrow in the next cross section, or the void portions 2 are connected in a state where the shape is different, or are bent and connected. 2 forms a path of a so-called sound stream type structure in which a sharp uneven shape or a zigzag shape is intertwined in many directions in the inside of the molded body for the width of the road. For this reason, the incident sound wave also exhibits an attenuation effect due to multiple reflection and interference when passing through the sound path.
【0010】本発明に用いる樹脂発泡粒子の多孔質成形
体も多孔質体の基本的性質を有しており、音波が細孔状
の吸音体内に侵入すると空隙内の空気が振動し、その際
に空気と空隙の内壁面との間で摩擦を生じ、熱損失とな
って音のエネルギーが消費される。加えるに本発明では
空隙を形成する内壁材料が多数の独立気泡構造からなる
樹脂発泡粒子で構成され、内壁表面は非常に薄い膜を形
成しているため音圧エネルギーを受けて膜の振動へと変
換する機能を有し、即ち、低周波数の吸音性に優れた効
果を持つことになる。しかも極めて多数個の樹脂発泡粒
子からなる成形体であるため相乗的に低音域の吸音性が
向上される。The porous molded body of expanded resin particles used in the present invention also has the basic properties of a porous body. When a sound wave enters the sound absorbing body having a pore shape, the air in the void vibrates. At the same time, friction is generated between the air and the inner wall surface of the void, resulting in heat loss and consumption of sound energy. In addition, in the present invention, the inner wall material forming the void is composed of resin foam particles having a large number of closed cell structures, and since the inner wall surface forms a very thin film, it receives sound pressure energy to cause vibration of the film. It has a converting function, that is, it has an excellent effect of absorbing low-frequency sound. In addition, since it is a molded product composed of an extremely large number of expanded resin particles, the sound absorption in the low sound range is synergistically improved.
【0011】また、本発明の吸音体で用いられる樹脂発
泡粒子の成形体においては、平均粒子径が1.5〜5.
5mmの樹脂発泡粒子の多数個が隣接する粒子表面の一
部で面接合し、全体容積に対して15〜40%の容積空
隙率を有して一体化していることが好ましい。以下これ
らの要件について説明する。発泡粒子における空隙の形
状を規定する第一の因子は、その空隙を形成する粒子の
大きさであり、樹脂発泡粒子の成形体の平均粒子径は
1.5〜5.5mmの範囲であることが好ましい。これ
により、サウンドストリーム形の通路、即ち音道の幅が
決定される。粒子径が5.5mmを越えると吸音体とし
て受音する単位面積当たりの細孔空隙の個数が低下する
と共に、全容積中の空隙の内壁総面積が低下し、音圧エ
ネルギーを摩擦損失に変換する機能が低下し吸音性能が
損なわれる。粒子径が1.5mm未満であると後述する
製造方法との関係から吸音体の空隙率が低下し、吸音性
能が低下すると共に、吸音体の芯部の粒子を熱接着する
ことが難しく肉厚みの厚い成形体の製造が困難となる。
こうした点から本発明の樹脂発泡粒子の平均粒子径は
1.5〜5.5mmが好ましい。更に好ましくは2〜4
mmである。Further, in the molded product of the resin expanded particles used in the sound absorbing body of the present invention, the average particle size is 1.5 to 5.
It is preferable that a large number of resin foam particles having a diameter of 5 mm are surface-bonded at a part of the adjacent particle surfaces and have a volume porosity of 15 to 40% with respect to the entire volume and are integrated. These requirements will be described below. The first factor that determines the shape of the voids in the foamed particles is the size of the particles that form the voids, and the average particle size of the molded resin foamed particles is in the range of 1.5 to 5.5 mm. Is preferred. Thereby, the width of the sound stream type passage, that is, the sound path is determined. If the particle size exceeds 5.5 mm, the number of pores per unit area that the sound absorber receives will decrease, and the total inner wall area of the voids in the entire volume will decrease, converting sound pressure energy into friction loss. Function is reduced and sound absorption performance is impaired. If the particle diameter is less than 1.5 mm, the porosity of the sound absorber is reduced due to the relationship with the manufacturing method described later, the sound absorbing performance is reduced, and it is difficult to thermally bond the particles of the core of the sound absorber to the wall thickness. It becomes difficult to manufacture a thick molded body.
From such a point, the average particle diameter of the resin expanded particles of the present invention is preferably 1.5 to 5.5 mm. More preferably 2 to 4
mm.
【0012】なお、吸音体を構成する樹脂発泡粒子の粒
子径分布も空隙率に影響し、吸音性能に影響してくる。
粒子径の大きな粒子と小さな粒子が混在すると大きな粒
子の間隙に小さな粒子が取り込まれるため上記サウンド
ストリーム形の通路を塞ぐことがあったり、容積空隙率
が低下することがある。特に、大粒子と小粒子の径の比
が小さな値の場合、加えるにその存在割合が特定の関係
にある場合(大粒子/小粒子=6/4)にはこの現象が
著しく、吸音率の低下が起こる。The particle size distribution of the resin foam particles constituting the sound absorbing body also affects the porosity and the sound absorbing performance.
When particles having a large particle diameter and particles having a small particle diameter are mixed, the small particles are taken into the gaps between the large particles, so that the sound stream type passage may be blocked or the volume porosity may decrease. In particular, when the ratio of the size of large particles to small particles is small, and when the abundance ratio also has a specific relationship (large particles / small particles = 6/4), this phenomenon is remarkable and A decline occurs.
【0013】本発明では使用に供する粒子群内で最大粒
子径と最小粒子径との比の値が0.3〜0.9に取るこ
とが好ましい。すべての粒子径が同一であれば型内に充
填された場合に細密充填となり、隣接する粒子同士が面
接合して形成される空隙の割合が低くなり、吸音性能に
とって好ましくない。また、本発明で用いられる吸音体
において、音波の反射や干渉を効果的に発現させるには
道幅が周期的に増減した導波路が三次元的に入り組み連
通した構造となることが好ましく、粒子間の接合が点状
ではなく面状の接合を成し、かつ、粒子間に形成される
空隙を全容積に対して15〜40%の容積空隙率とする
ことが好ましい。In the present invention, it is preferable that the ratio of the maximum particle size to the minimum particle size in the particle group used is 0.3 to 0.9. If all the particles have the same diameter, the particles are closely packed when they are filled in the mold, and the proportion of voids formed by surface-bonding adjacent particles is reduced, which is not preferable for sound absorbing performance. Further, in the sound absorbing body used in the present invention, in order to effectively express the reflection and interference of sound waves, it is preferable that the waveguides whose path width is periodically increased and decreased are three-dimensionally interdigitated and communicated with each other. It is preferable that the bonding between the particles is not a dot-shaped bonding but a planar bonding, and the voids formed between the particles have a volume porosity of 15 to 40% with respect to the total volume.
【0014】空隙の形状を規定する第二の因子は、樹脂
発泡粒子が互いに隣接する粒子と面接合することであ
る。これは隣接する粒子間の接着強度を高め成形体とし
ての機械的強度を発現させるために重要なことである
が、吸音性能の面からも好ましいと考えられる。空隙に
侵入した音波は種々な方向に進行し、反射散乱を繰り返
して減衰していくが、空隙を形成する粒子間が点状に接
合している場合には面接合している場合と比べ音波が反
射される確率は低くなる。多重反射の頻度は粒子間が面
状に接合することで増加する。これは、種々の方向から
入射してくる音波を受け、壁表面を形成している樹脂発
泡粒子の表皮膜が振動エネルギーに変換する確率も高ま
り、また、多重反射の頻度が増加することにより減衰効
果も発現される。つまり、互いに連通する空隙ではある
が進行する音波にとって袋小路となる通路を多数形成さ
せるためである。The second factor that determines the shape of the voids is that the resin foam particles are surface-bonded to the particles adjacent to each other. This is important in order to increase the adhesive strength between adjacent particles and to express the mechanical strength as a molded body, but it is considered preferable from the viewpoint of sound absorbing performance. Sound waves that have entered the voids propagate in various directions and are repeatedly reflected and scattered to be attenuated.However, when the particles forming the voids are joined in a point shape, the sound waves are Is less likely to be reflected. The frequency of multiple reflection increases when particles are joined in a plane. This is because the probability that the surface film of the resin foam particles forming the wall surface will be converted into vibration energy upon receiving sound waves that are incident from various directions, and that the frequency of multiple reflections will increase the attenuation. The effect is also expressed. That is, it is for forming a large number of passages that are voids that communicate with each other, but that are blind alleys for traveling sound waves.
【0015】本発明では、このような粒子間の面接合の
度合いが容易に調整できることも特徴である。即ち、吸
音体を成形する際に膨張能を有する樹脂発泡粒子を用い
ることにあり、これらを金型に充填し、加熱して接合す
る際に発泡粒子が元の容積の1.08〜1.41倍の容
積となるよう加熱膨張させることにより型内の粒子が互
いに押し合いながら面接合に至り、上記空隙形状を持つ
吸音体が得られる。The present invention is also characterized in that the degree of such surface bonding between particles can be easily adjusted. That is, the resin expanded particles having expandability are used when molding the sound absorbing body, and when these are filled in a mold and heated and joined, the expanded particles have a volume of 1.08 to 1. By heat-expanding so as to have a volume of 41 times, particles in the mold are pressed against each other to reach surface bonding, and a sound absorbing body having the above void shape is obtained.
【0016】また、吸音性能に大きな影響を与えるもの
として空隙率がある。多孔質吸音体の空隙率も吸音性能
に影響を及ぼすが、本発明においては樹脂発泡粒子の多
数個が接合してなる吸音体であるため、15〜40%の
容積空隙率にすることが好ましい。空隙率が40%を越
えると吸音成形体しての機械的強度が低下し、実質的に
成形体としての使用が難しくなる。空隙率が15%未満
であると吸音率が30%未満となり、吸音性能が劣化す
る。吸音性、及び機械強度の点から20〜35%にとる
こがより好ましい。The porosity has a great influence on the sound absorbing performance. The porosity of the porous sound absorbing body also affects the sound absorbing performance, but in the present invention, since it is a sound absorbing body in which a large number of resin foam particles are joined, it is preferable to set the volume porosity of 15 to 40%. . If the porosity exceeds 40%, the mechanical strength of the sound-absorbing molded product is lowered, and it becomes substantially difficult to use it as a molded product. If the porosity is less than 15%, the sound absorption rate will be less than 30%, and the sound absorption performance will deteriorate. From the viewpoint of sound absorption and mechanical strength, it is more preferably 20 to 35%.
【0017】次に、上述してきた本発明で用いる多孔質
成形体の製造方法について説明する。本発明では樹脂発
泡粒子の表面に該粒子の軟化発泡温度よりも低い温度で
熱接着し得る接着用樹脂を添着することが隣接する粒子
間の接着を容易にし、多孔質成形体の空隙率を高めるこ
と、及び特定の空隙構造を有する多孔質成形体を得るた
めに有利である。樹脂発泡粒子は加熱により発泡、膨張
する性質を有し、金型に充填して加熱された場合、個々
の粒子自体が膨張し互いに隣接する粒子同士が押圧し合
うため、表面の熱接着用樹脂を介して十分に強固な接着
強度を得ることができるため本発明の目的には極めて好
適である。更に、使用する樹脂の量を低減でき軽量性や
断熱性も付加された多孔質成形体を得る点からも好まし
い。Next, a method for manufacturing the above-mentioned porous molded body used in the present invention will be described. In the present invention, by adhering an adhesive resin that can be heat-bonded at a temperature lower than the softening and foaming temperature of the resin foamed particles to the surface of the resin foamed particles, adhesion between adjacent particles is facilitated and the porosity of the porous molded article is increased. It is advantageous to increase and obtain a porous molded body having a specific void structure. Resin foam particles have the property of expanding and expanding when heated, and when filled in a mold and heated, the individual particles themselves expand and the particles that are adjacent to each other press against each other. It is extremely suitable for the purpose of the present invention because it is possible to obtain a sufficiently strong adhesive strength through the. Further, it is preferable from the viewpoint that the amount of resin used can be reduced and a porous molded body having added weight and heat insulating properties can be obtained.
【0018】樹脂発泡粒子の表面に上記熱接着性樹脂を
添着することは、樹脂発泡粒子が熱軟化し高度に膨張す
るに至る前、即ち、元の容積の1.08〜1.41倍の
容積となる温度で熱接着でき、その結果として発泡粒子
の熱膨張が低減され高い空隙率を維持させることが可能
となり、前述のような発泡粒子間の面状接合が容易とな
りサウンドストリーム形の空隙形状が形成され、吸音性
に優れた多孔質成形体が得られる。また、上記製法を用
いれば、エネルギー消費を低減でき、短時間での成形が
可能となり、生産性にも優れた効果をもたらすものとな
る。The above-mentioned heat-adhesive resin is attached to the surface of the expanded resin particles before the expanded resin particles are thermally softened and highly expanded, that is, 1.08 to 1.41 times the original volume. It can be heat-bonded at the temperature of volume, and as a result, the thermal expansion of the foamed particles can be reduced and a high porosity can be maintained. A porous molded body having a formed shape and excellent sound absorption can be obtained. Further, by using the above-mentioned manufacturing method, energy consumption can be reduced, molding can be carried out in a short time, and excellent productivity can be obtained.
【0019】本発明でいう樹脂発泡粒子とは汎用の熱可
塑性樹脂、例えば、ポリスチレン、ハイインパクトポリ
スチレン、ABS樹脂、ポリエチレン(高密度、低密
度)、ポリプロピレン、ポリメチルチタアクリレート、
ポリ塩化ビニリデン共重合樹脂、ナイロンー6、ナイロ
ンー6,6、ポリエチレンテレフタレート等の樹脂に有
機揮発性発泡剤や熱分解性発泡剤を含有さしめたもので
ある。こうした膨張性を有する粒子として好ましくは、
ポリスチレン、ポリエチレン、ポリプロビレン、ポリメ
チルメタアクリレート、塩化ビニリデン系樹脂、ポリフ
ェニレンエーテルーポリスチレンアロイ等を素材樹脂と
する発泡性樹脂粒子や発泡粒子があり、工業的に生産さ
れている。The expanded resin particles referred to in the present invention are general-purpose thermoplastic resins such as polystyrene, high-impact polystyrene, ABS resin, polyethylene (high density and low density), polypropylene, polymethyl titaacrylate,
It is a resin such as polyvinylidene chloride copolymer resin, nylon-6, nylon-6,6, polyethylene terephthalate, and the like, which contains an organic volatile foaming agent and a thermally decomposable foaming agent. As the particles having such expandability, preferably,
There are expandable resin particles and expanded particles made of polystyrene, polyethylene, polypropylene, polymethylmethacrylate, vinylidene chloride resin, polyphenylene ether-polystyrene alloy, etc. as raw materials, and are industrially produced.
【0020】もちろん、過度の加熱を行えば樹脂粒子の
膨張が大きくなり粒子間の空隙が消失するため、これら
発泡性粒子の膨張する温度と粒子表面に添着された接着
用樹脂が熱接着する温度との関係を適切にした組み合わ
せを選択することが重要である。従って、発泡性樹脂粒
子としては、スチーム等の熱媒加熱により緩慢な膨張速
度を取るものは目的の空隙率を達成するために加熱条件
を厳密に管理する必要もないため発泡性塩化ビニリデン
系樹脂粒子は特に好適な素材粒子である。Of course, if the heating is performed excessively, the expansion of the resin particles becomes large and the voids between the particles disappear, so that the temperature at which the expandable particles expand and the temperature at which the adhesive resin attached to the surface of the particles adheres thermally. It is important to select a combination that has an appropriate relationship with. Therefore, as the expandable resin particles, those that take a slow expansion rate by heating the heating medium such as steam do not require strict control of the heating conditions to achieve the target porosity, and thus the expandable vinylidene chloride resin. Particles are particularly suitable material particles.
【0021】発泡性塩化ビニリデン系樹脂粒子とは、塩
化ビニリデン、及び、これと共重合可能なビニルモノマ
ー1種以上とからなり、塩化ビニリデンが30重量%以
上を含み、ガラス転移点が85℃以上の塩化ビニリデン
共重合体に有機揮発性発泡剤を含有せしめた未発泡の樹
脂粒子、及び、それを加熱発泡することにより得られる
独立気泡構造の発泡粒子の両者を善い、共に加熱により
膨張し、詳細には特開昭63ー170433号公報、特
開昭63ー170434号公報に記載されるもので、発
泡性粒子は含有する発泡剤の量を調整すること、あるい
は予備発泡粒子の熟成条件、即ち、処理温度やその時間
を調整することにより容易に得られる。The expandable vinylidene chloride resin particles are composed of vinylidene chloride and one or more vinyl monomers copolymerizable therewith, containing 30% by weight or more of vinylidene chloride and having a glass transition point of 85 ° C. or more. Non-expanded resin particles obtained by adding an organic volatile foaming agent to the vinylidene chloride copolymer of, and both of the expanded particles having a closed cell structure obtained by heat-expanding it are expanded by heating. The details are described in JP-A-63-170433 and JP-A-63-170434, in which the expandable particles contain the amount of the foaming agent contained therein, or the aging conditions of the pre-expanded particles, That is, it can be easily obtained by adjusting the processing temperature and the processing time.
【0022】また、発泡断熱材として使用される空隙の
ない成形体を裁断した発泡破砕片を本発明の原料として
供することもできる。次に、本発明の樹脂発泡粒子の表
面に添着される熱溶着可能な接着用樹脂を説明する。該
接着用樹脂としては、軟化温度が70℃以上で、かつ使
用する合成樹脂素材粒子の軟化温度以下のものを選択す
ることが好ましい。軟化温度が70℃未満のものでは粘
着性を帯び易く表面に添着された合成樹脂素材粒子の流
動性が悪く、製造過程での取扱いや金型への充填性が不
良となる。また、成形された製品の使用環境によっては
熱を受ける場合に変形したりして不都合を生じる。一
方、接着用樹脂の軟化温度が合成樹脂素材粒子の軟化温
度を越えると、成形加工時の加熱により素材粒子の熱変
形が大きくなり、空隙率の高い多孔質成形体を得ること
が難しくなる。Further, a crushed foamed piece obtained by cutting a molded body having no voids used as a foamed heat insulating material may be used as the raw material of the present invention. Next, the heat-sealable adhesive resin attached to the surface of the expanded resin particles of the present invention will be described. As the adhesive resin, it is preferable to select one having a softening temperature of 70 ° C. or higher and a softening temperature of the synthetic resin material particles to be used or lower. If the softening temperature is less than 70 ° C., it tends to be sticky and the synthetic resin material particles attached to the surface have poor fluidity, resulting in poor handling in the manufacturing process and filling in the mold. Further, depending on the usage environment of the molded product, it may be deformed when receiving heat, which causes inconvenience. On the other hand, when the softening temperature of the adhesive resin exceeds the softening temperature of the synthetic resin material particles, thermal deformation of the material particles increases due to heating during the molding process, making it difficult to obtain a porous molded article having a high porosity.
【0023】上記接着用樹脂としては、例えば熱可塑性
接着剤として分類されるビニル系の酢酸ビニル系接着
剤、アクリル系接着剤、エチレンー酢酸ビニル共重合接
着剤やポリアミド系接着剤、ポリエステル系接着剤、熱
か塑性ポリウレタン系接着剤、及び、極性基を有する熱
可塑性樹脂として、ポリ塩化ビニル、アクリロニトリル
ースチレン共重合体(AS)、アクリロニトリル−ブタ
ジエン−スチレン共重合体(ABS)、スチレンー無水
マレイン酸共重合体、スチレンーアクリル酸共重合体、
アクリル系樹脂等がある。Examples of the adhesive resin include vinyl-based vinyl acetate adhesives, acrylic adhesives, ethylene-vinyl acetate copolymer adhesives, polyamide-based adhesives, polyester-based adhesives, which are classified as thermoplastic adhesives. Polyvinyl chloride, acrylonitrile-styrene copolymer (AS), acrylonitrile-butadiene-styrene copolymer (ABS), styrene-maleic anhydride, as a thermoplastic polyurethane-based adhesive and a thermoplastic resin having a polar group Copolymer, styrene-acrylic acid copolymer,
There are acrylic resins and the like.
【0024】本発明に好適な粒子素材である発泡性ポリ
塩化ビニリデン系樹脂粒子の場合に好ましい熱接着用樹
脂ものとしては、極性基を有するビニルモノマーが共重
合された樹脂、即ち、ハロゲン基、カルボン酸基、エス
テル基、シアノ基、ニトロ基等を置換基として有するビ
ニルモノマーが少なくとも5重量%以上共重合された樹
脂であり、ASTM D 1525で測定されるビカッ
ト軟化点が70〜115℃のものが使用できる。これら
熱接着用樹脂は溶剤溶液、エマルジョン、或いはホット
メルトの形で使用に供され、目的に応じて使い分けるこ
とができる。勿論、接着用樹脂の溶液中に種々な機能を
付加させるための添加剤を加えることも可能であり、付
加機能向上のためにも優れた製法である。例えば、有
機、無機系の各種難燃剤、顔料や染料の着色剤、導電性
物質、帯電防止剤、熱安定剤等のものが使用できる。In the case of the expandable polyvinylidene chloride-based resin particles which are the particle material suitable for the present invention, the preferred resin for thermal bonding is a resin in which a vinyl monomer having a polar group is copolymerized, that is, a halogen group, A resin obtained by copolymerizing at least 5% by weight or more of a vinyl monomer having a carboxylic acid group, an ester group, a cyano group, a nitro group or the like as a substituent, and having a Vicat softening point of 70 to 115 ° C. measured by ASTM D 1525. Things can be used. These heat-bonding resins are used in the form of a solvent solution, an emulsion, or a hot melt, and can be used properly according to the purpose. Of course, it is possible to add additives for adding various functions to the solution of the adhesive resin, which is an excellent manufacturing method for improving the additional functions. For example, various organic and inorganic flame retardants, colorants such as pigments and dyes, conductive substances, antistatic agents, heat stabilizers and the like can be used.
【0025】次に、本発明の樹脂発砲粒子の成形体の具
体的な製造方法の一態様を説明する。発泡性樹脂粒子1
00重量部に対して接着用樹脂固形分が5〜15重量部
となるように接着用樹脂2〜10重量%の溶剤溶液、或
いは、20〜60重量%のエマルジョン溶液を混合す
る。混合に際しては一般に粒体の混合として使用される
混合機が使用でき、例えば、リボンブレンダー等を用い
て接着用樹脂溶液を添加、またはスプレーして素材粒子
の表面に被覆添着させる。Next, one embodiment of a specific method for producing the molded resin foam particles of the present invention will be described. Expandable resin particles 1
A solvent solution of 2 to 10 wt% of the adhesive resin or an emulsion solution of 20 to 60 wt% is mixed so that the solid content of the adhesive resin is 5 to 15 parts by weight with respect to 00 parts by weight. For mixing, a mixer generally used for mixing particles can be used. For example, a resin blending solution is added or sprayed by using a ribbon blender or the like to coat and adhere to the surface of the material particles.
【0026】接着用樹脂固形分が5重量部未満では上記
素材粒子が接着用樹脂を介して接合した成形体としての
接着強度が不十分であり、15重量部を越えても強度的
に有効には作用しなくて経済的に不利となる。接着用樹
脂溶液の固形分濃度は目的に応じて適宜選択できるが、
溶剤溶液の場合は2〜10重量%、水性エマルジョンの
場合には20〜60重量%のものが好ましく使用でき
る。If the solid content of the adhesive resin is less than 5 parts by weight, the adhesive strength as a molded body in which the above material particles are bonded via the adhesive resin is insufficient, and even if it exceeds 15 parts by weight, the strength is effectively improved. Does not work and is economically disadvantageous. The solid content concentration of the adhesive resin solution can be appropriately selected according to the purpose,
A solvent solution of 2 to 10% by weight and an aqueous emulsion of 20 to 60% by weight can be preferably used.
【0027】上記混合を完了したら、必要に応じて乾燥
し、加熱発泡して発泡倍率を調整する予備発泡工程に供
したり、或いは、直接成形工程に供する。特に、形状の
複雑な型物の成形に供する場合は発泡、乾燥処理して軽
量性、流動性を持たした上で金型への充填性を向上させ
ることは好ましい。こうした処理を行った樹脂発泡粒子
は汎用の型内発泡自動成形機に供給され、金型充填後、
接着用樹脂の軟化温度以上で、樹脂発泡粒子の発泡温度
以下で加熱し、冷却の工程を経て成形体を得る。こうし
て高い空隙率を維持し、粒子間の空隙構造が制御された
本発明の吸音性に優れる多孔質成形体が得られる。After the above mixing is completed, it is dried, if necessary, and subjected to a preliminary foaming step of foaming by heating to adjust the expansion ratio, or directly to a molding step. Particularly, when it is used for molding a mold having a complicated shape, it is preferable to perform foaming and drying treatment so as to have lightness and fluidity and then to improve the filling property into the mold. The resin foamed particles that have undergone such treatment are supplied to a general-purpose in-mold foaming automatic molding machine, and after filling the mold,
It is heated above the softening temperature of the adhesive resin and below the foaming temperature of the resin expanded particles, and a molding is obtained through a cooling step. Thus, the porous molded article of the present invention, which maintains a high porosity and has a controlled void structure between particles, is obtained.
【0028】次に、本発明の第2について説明する。吸
音施工においては、吸音材料を設置するために必要な空
間寸法をできるだけ縮小して、吸音性能を最大限に発現
させることが最も重要である。このためには本発明の多
孔質吸音体の吸音率が最大ピークとなる周波数と騒音源
の周波数とを一致させることが好ましい。Next, the second aspect of the present invention will be described. In sound absorbing construction, it is most important to reduce the space size required for installing the sound absorbing material as much as possible to maximize the sound absorbing performance. For this purpose, it is preferable to match the frequency at which the sound absorption coefficient of the porous sound absorbing body of the present invention has a maximum peak with the frequency of the noise source.
【0029】本発明の多孔質成形体の吸音特性を用い、
この具体的な内容を図2を用いて説明する。図2は、多
孔質成形体の肉厚みと背後空気層厚みとの和dがその時
の吸音率のピーク周波数Fに与える影響を解析したもの
である。直線は多孔質成形体を従来の多孔質体が最も
大きい吸音効果を発現するところである騒音源の1/4
波長のところに設置した場合(d=λ/4=344/4
f、すなわちf=344/4d:ただし、音速は344
m/分とする)を示し、直線はその1/2の空間厚み
となる、多孔質成形体を従来の多孔質体が最も大きい吸
音効果を発現するところである騒音源の(1/8)波長
を示す。◎印は吸音率のピーク周波数において60%以
上の吸音率を有し、且つ、dが(1/8)波長以下とな
る点であり、○印は上記吸音率が30%以上で60%未
満で、かつ、dが(1/8)波長を越えて(1/4)波
長以下となる点であり、×印は吸音率が30%未満であ
るか、またはdが(1/4)波長を越える点である。Using the sound absorption characteristics of the porous molded article of the present invention,
The specific content will be described with reference to FIG. FIG. 2 is an analysis of the influence of the sum d of the wall thickness of the porous molded body and the back air layer thickness on the peak frequency F of the sound absorption coefficient at that time. The straight line indicates that the porous molded body is 1/4 of the noise source where the conventional porous body exhibits the greatest sound absorbing effect.
When installed at the wavelength (d = λ / 4 = 344/4
f, that is, f = 344 / 4d: However, the speed of sound is 344
m / min), and the straight line has a space thickness of ½ of that, and the porous molded body is a (1/8) wavelength of the noise source where the conventional porous body exhibits the greatest sound absorbing effect. Indicates. The ⊚ mark indicates that the sound absorption coefficient is 60% or more at the peak frequency of the sound absorption coefficient, and d is not more than (1/8) wavelength, and the ○ mark indicates that the sound absorption coefficient is 30% or more and less than 60%. And d is a point that exceeds (1/8) wavelength and is (1/4) wavelength or less, and x indicates that the sound absorption coefficient is less than 30%, or d is (1/4) wavelength. Is a point that exceeds.
【0030】まず、本発明においては多孔質成形体の肉
厚みと背後空気層の厚みとの和d(m)と騒音源の周波
数f(Hz)とが、下記(1)式及び(2)式を満たす
条件で該成形体を設置することが必要である。 1.03・(1/D)1.7 ≦f≦17.16・(1/D)1.7 (1) 100≦f≦285・(1/D)0.48 (2) f<1.03・(1/D)1.7 では吸音率が逐次低下
し、また多孔質成形体の肉厚みが小さくなりすぎ成形困
難であるため適当でない。一方、f>17.16・(1
/d)1.7 を越えても吸音率は徐々に低下し30%未満
の吸音率となり、また、所望の吸音性能を出そうとすれ
ば従来の多孔質体と較べてdが厚くなるため長所が発現
できない。First, in the present invention, the sum d (m) of the thickness of the porous molded body and the thickness of the back air layer and the frequency f (Hz) of the noise source are expressed by the following equations (1) and (2). It is necessary to install the molded body under conditions that satisfy the formula. 1.03 ・ (1 / D) 1.7 ≦ f ≦ 17.16 ・ (1 / D) 1.7 (1) 100 ≦ f ≦ 285 ・ (1 / D) 0.48 (2) f <1.03 ・ (1 / D) 1.7 is not suitable because the sound absorption coefficient gradually decreases and the wall thickness of the porous molded body becomes too small, which makes molding difficult. On the other hand, f> 17.16 · (1
/ D) The sound absorption coefficient gradually decreases to less than 30% even if it exceeds 1.7 , and if the desired sound absorption performance is to be achieved, d is thicker than the conventional porous body, which is an advantage. Cannot be expressed.
【0031】f<100では音波の波長が上記dに比べ
て大きくなるため、吸音率は急激に低下し、30%以上
の吸音率を確保することは困難となり、一方、285・
(1/D)0.48<fでは、背後空気層がない場合、即ち
本発明の多孔質成形体の厚みだけで吸音施工する場合に
相当し、吸音率のピ−ク周波数を超えた孔周波数側の音
波に対しての吸音となるため、吸音性能は徐々に低下す
ることとなる。When f <100, the wavelength of the sound wave becomes larger than that of d, so that the sound absorption coefficient sharply decreases and it becomes difficult to secure a sound absorption coefficient of 30% or more.
(1 / D) 0.48 <f corresponds to the case where there is no back air layer, that is, the case where sound absorbing construction is performed only by the thickness of the porous molded body of the present invention, and the hole frequency side exceeds the peak frequency of sound absorbing coefficient. Since the sound is absorbed by the sound wave, the sound absorbing performance gradually decreases.
【0032】fとDの関係において、従来の吸音体では
(1/d)の一次式で支配されることに対して本発明
の多孔質吸音体では(1/d)のべき剰で支配されるこ
とに最も大きな特徴がある。換言すれば、本発明の多孔
質成形体は背後空気層の厚みが薄くても特に低周波数の
騒音に対して有効な吸音効果を示すことが大きな特徴で
あり、吸音のための必要空間容積を大きく低減させるこ
とができるものである。さらに、吸音率が60%以上
で、かつ、施工空間厚みが従来の多孔質吸音体より半減
できる(dが1/8波長以下となる)条件を付加させ、
吸音性能と必要空間容積が低減されたより優れた施工と
するには図2における◎印で囲まれる多角形EFCGH
の領域を満足することが好ましい。ここに、直線EFは
吸音率が60%以上となるに必要な多孔質成形体の下限
の肉厚みでの背後空気層厚みと吸音率のピーク周波数と
の関係を表し、直線HGはD=(波長)/8を示す。多
角形EFCGHを座標(D,F)で示せば、点E(0.
014,2195)、点F(0.087,100)、点
C(0.35,100)、点G(0.32,135)、
点H(0.026,1630)となる。Regarding the relationship between f and D, the conventional sound absorber is governed by a linear expression of (1 / d), whereas the porous sound absorber of the present invention is governed by a power of (1 / d). It has the greatest feature. In other words, the porous molded article of the present invention is characterized in that it exhibits an effective sound absorbing effect particularly for low frequency noise even if the thickness of the back air layer is thin. It can be greatly reduced. Furthermore, a condition that the sound absorption coefficient is 60% or more and that the construction space thickness can be reduced to half that of the conventional porous sound absorber (d becomes 1/8 wavelength or less) is added,
For better construction with reduced sound absorption performance and required space volume, polygonal EFCGH enclosed by ⊚ in Fig. 2
It is preferable to satisfy the area of. Here, the straight line EF represents the relationship between the back air layer thickness and the peak frequency of the sound absorption coefficient at the lower limit wall thickness of the porous molded body required for the sound absorption coefficient to be 60% or more, and the straight line HG is D = ( Wavelength) / 8. If the polygon EFCGH is indicated by coordinates (D, F), the point E (0.
014, 2195), point F (0.087,100), point C (0.35,100), point G (0.32,135),
It becomes the point H (0.026, 1630).
【0033】ここに本発明で言う吸音率とは垂直入射法
による測定値で定義されるものであるが、実際の騒音で
は音源周波数も幅を持つものであり、種々の角度からの
入射音があるため、施工仕様を一義的に決定できるもの
ではなく実用評価に臨んで決定することが望ましいが、
騒音の周波数領域内で音圧レベルが最大となる周波数を
f(Hz)とし、このfに関して少なくとも上記関係を
満足することが必要である。The sound absorption coefficient referred to in the present invention is defined by a measured value by the vertical incidence method. However, in actual noise, the sound source frequency also has a width, and the incident sound from various angles is present. Therefore, it is desirable to decide on the practical evaluation, not the one that can uniquely determine the construction specifications.
It is necessary that the frequency at which the sound pressure level is maximum in the frequency range of noise is f (Hz), and at least the above relationship is satisfied with respect to this f.
【0034】本発明により従来技術では困難であった空
隙率や空隙の大きさのコントロールが容易になり、使用
目的に応じてこれらを制することで吸音性能を変化させ
たり、種々の形状に加工でき各種産業機器に装着可能な
吸音成形体として好適なものが得られる。発泡性粒子を
用いることにより、特に静音化が求められるエアコン、
換気扇等の空調機器、ダクト等の風路を形成する部分で
断熱性、軽量性の機能と吸音性を併せて持つ新規な工業
部材として展開できる。また、建築分野においても特異
な素材としての展開が期待できる。According to the present invention, it becomes easy to control the porosity and the size of the void, which was difficult in the prior art, and by controlling them according to the purpose of use, the sound absorbing performance can be changed or processed into various shapes. Thus, it is possible to obtain a suitable sound absorbing molded body that can be mounted on various industrial equipment. By using expandable particles, an air conditioner that is especially required to reduce noise,
It can be developed as a new industrial member that has both heat insulating and lightweight functions and sound absorption in the parts that form air passages such as air conditioners such as ventilation fans and ducts. In addition, it can be expected to develop as a unique material in the construction field.
【0035】[0035]
【実施例】以下、実施例により本発明を説明する。な
お、本発明で用いた評価方法は次の通りである。 (1)平均粒子径 100gの樹脂発泡粒子をJISZ8801で規定され
る、呼び寸法が5.6、4.75.4、3.35、2.
36、1.7、1.4、1mmである標準ふるいを用い
分級をを行う。di 目を通過して、かつdi+1 で止まる
粒子の平均粒子径di 、重量割合Xi であれば、各分級
品の平均粒子径は di = (di ・di+1 )1/2 で与えられる。EXAMPLES The present invention will be described below with reference to examples. The evaluation method used in the present invention is as follows. (1) Foamed resin particles having an average particle diameter of 100 g are specified by JIS Z8801 and have nominal dimensions of 5.6, 4.75.4, 3.35, 2.
Classify using a standard sieve of 36, 1.7, 1.4, 1 mm. If the average particle diameter d i of the particles passing through the d i eye and stopping at d i +1 and the weight ratio X i , the average particle diameter of each classified product is d i = (d i · d i + 1 ) It is given by 1/2 .
【0036】全粒子の平均粒子径ds は次式により求め
る。 ds = ΣXi di (2)粒子径分布 前項の測定で分級して得た各群の内、最小粒子径dmin
を最大粒子径dmaxで除した値で定義する。 (3)引張強度 JISA9511に基づき測定する。 (4)空隙率 見かけのかさ容積(V1 )の多孔質成形体を一定量の水
を張ったメスシリンダー中に浸漬し、その時の増加容積
(V2 )を測定し、次式により求める。The average particle diameter d s of all particles is calculated by the following equation. d s = ΣX i d i (2) Particle size distribution Minimum particle size d min of each group obtained by classification in the measurement in the previous section
Is divided by the maximum particle diameter d max . (3) Tensile strength Measured according to JIS A9511. (4) Porosity A porous molded body having an apparent bulk volume (V 1 ) is immersed in a graduated cylinder filled with a fixed amount of water, and the increased volume (V 2 ) at that time is measured and calculated by the following formula.
【0037】{(V1 −V2 )/V1 }× 100 (5)吸音率 JISA1405に基づき垂直入射吸音率(定在波法)
を測定する。 吸音体材料を特定する際の吸音率は背後空気層のな
い状態、つまり、剛壁に密着した状態で各周波数につい
て測定する。{(V 1 -V 2 ) / V 1 } × 100 (5) Sound absorption coefficient Normal incident sound absorption coefficient (standing wave method) based on JISA1405
To measure. The sound absorption coefficient when specifying the sound absorbing material is measured at each frequency in the state without the back air layer, that is, in the state of being in close contact with the rigid wall.
【0038】 背後空気層を設定した際の吸音率の上
昇値、 背後空気層を設けた場合の吸音率値から項の方法で測
定された吸音率値をそれぞれの周波数において差し引い
た値を言う。 吸水処理後の吸音率低下値、 項で測定した吸音率から、吸音体試料にその全体積の
50%の容積の水を吸水させた後に項と同様にして測
定した値を差し引いた値を各周波数について求める。It is a value obtained by subtracting the sound absorption coefficient value measured by the method described above from the sound absorption coefficient increase value when the back air layer is set and the sound absorption coefficient value when the back air layer is provided at each frequency. The value obtained by subtracting the value measured in the same manner as in the above item after absorbing 50% of the total volume of water in the sound absorber sample from the sound absorption reduction value after water absorption treatment and the sound absorption factor measured in Find the frequency.
【0039】[0039]
【実施例1】塩化ビニリデン、Nーフェニルマレイミ
ド、アクリロニトリル、及びスチレンをそれぞれ42,
2.4,44.3,11.3モル%の組成比の混合物1
00重量部に対して0.02重量部のジビニルベンゼン
を加えて懸濁重合法により共重合体樹脂粒子を得た。こ
れにHCFC−142bを70℃にて24時間かけて含
浸処理を行った。得られた発泡性樹脂粒子は10重量%
のHCFC142bを含有していた。Example 1 Vinylidene chloride, N-phenylmaleimide, acrylonitrile, and styrene were respectively added to 42,
Mixture 1 with a composition ratio of 2.4, 44.3, 11.3 mol%
Copolymer resin particles were obtained by the suspension polymerization method by adding 0.02 parts by weight of divinylbenzene to 100 parts by weight. This was impregnated with HCFC-142b at 70 ° C. for 24 hours. The expandable resin particles obtained were 10% by weight.
Of HCFC 142b.
【0040】この発泡性樹脂粒子100重量部をリボン
ブレンダーに投入し、アクリル系エマルジョン(コニ
シ、SP−210)20重量部を撹絆混合しながらスプ
レー添加し15分間混合し、その後35℃の温風を通気
して乾燥して表面にアクリル系熱接着剤が添着された発
泡性樹脂粒子を得た。この発泡性樹脂粒子を0.2kg
/cm2-Gのスチームにより発泡した予備発泡粒子を得
た。この予備発泡粒子を標準ふるいを用いて分級し、表
1に示すような粒子径分布、及び、平均粒子径を有する
5つのグループに配分した。100 parts by weight of the expandable resin particles were placed in a ribbon blender, 20 parts by weight of an acrylic emulsion (Konishi, SP-210) was added by spraying while stirring and mixing, and mixed for 15 minutes, and then at a temperature of 35 ° C. By blowing air and drying, expandable resin particles having an acrylic thermal adhesive attached to the surface were obtained. 0.2 kg of this expandable resin particle
Pre-expanded particles were obtained which were expanded with steam of / cm 2 -G. The pre-expanded particles were classified using a standard sieve and distributed into five groups having a particle size distribution as shown in Table 1 and an average particle size.
【0041】それぞれのグループの予備発泡粒子を汎用
の発泡スチロール用自動成形機にて300×300×2
5mmの成形金型に投入し、一方加熱を0.1kg/c
m2のスチームで10秒間、続いて両面加熱を表1に示
すスチーム圧で10秒間行って、水冷し離型した。得ら
れた空隙を有する成形体の空隙率、剛壁に密着した状態
でのピーク吸音率とその周波数、及び、引張強度を測定
した結果を合わせて表1に示す。The pre-expanded particles of each group were 300 × 300 × 2 by a general-purpose Styrofoam automatic molding machine.
Put into a 5 mm molding die, while heating 0.1 kg / c
m 2 steam was applied for 10 seconds, followed by double-sided heating at the steam pressure shown in Table 1 for 10 seconds, followed by water cooling and mold release. Table 1 shows the porosity of the obtained molded article having voids, the peak sound absorption coefficient and the frequency thereof in the state of being closely adhered to the rigid wall, and the results of measuring the tensile strength.
【0042】表1の結果から明らかなように、本発明の
樹脂発泡粒子による多孔質成形体は剛壁密着状態で10
0〜3000Hzの領域に高い吸音率を示し、空隙率の
増加に伴い吸音率の値も上昇していることが分かる。As is clear from the results shown in Table 1, the porous molded article made of the resin foamed particles of the present invention has a rigid wall adhesion state of 10 or less.
It can be seen that a high sound absorption coefficient is shown in the region of 0 to 3000 Hz, and the value of the sound absorption coefficient also rises as the void ratio increases.
【0043】[0043]
【表1】 [Table 1]
【0044】[0044]
【実施例2】上記実験No.1、2、3と同一の予備発
泡粒子を用いて、同様の成形条件により、肉厚みがそれ
ぞれ100、50、25、15、10mmの多孔質成形
体を得、空隙率を測定するとそれぞれ30、33、2
5、28、15%であった。こうして得た多孔質成形体
について、背後空気層の厚みを変化させて吸音率の周波
数依存性を測定し、吸音率が最大となるピーク周波数を
求めた結果を表2に示す。Example 2 The above experiment No. Using the same pre-expanded particles as 1, 2, 3 and under similar molding conditions, porous molded bodies having wall thicknesses of 100, 50, 25, 15, 10 mm were obtained, respectively, and the porosity was measured to be 30, respectively. 33, 2
It was 5, 28 and 15%. With respect to the porous molded body thus obtained, the frequency dependence of the sound absorption coefficient was measured by changing the thickness of the back air layer, and the peak frequency at which the sound absorption coefficient was maximized was obtained.
【0045】[0045]
【表2】 [Table 2]
【0046】次に、上記の結果を吸音率のピーク周波数
Fと多孔質成形体の肉厚みと背後空気層厚みとの和Dに
ついて両対数プロットして図示すると図2となる。図中
の直線、はそれぞれD=λ/4、D=λ/8を示
す。ここにλは音波の各周波数における波長を表す。ま
た、◎印は吸音率のピーク周波数における吸音率が60
%以上で、かつ、Dがλ/8以下であることを満足する
点、○印は吸音率が30%以上で60%未満であり、か
つ、Dがλ/8を越えてλ/4以下となる点、×印は吸
音率が30%未満であるか、または、Dがλ/4を越え
る点である。Next, FIG. 2 shows the above results in a logarithmic plot of the sum D of the peak frequency F of the sound absorption coefficient, the wall thickness of the porous molded body and the back air layer thickness. The straight lines in the figure indicate D = λ / 4 and D = λ / 8, respectively. Here, λ represents the wavelength at each frequency of the sound wave. Also, ◎ indicates that the sound absorption coefficient at the peak frequency of the sound absorption coefficient is 60.
%, And D satisfies λ / 8 or less, and ○ indicates that the sound absorption coefficient is 30% or more and less than 60%, and D exceeds λ / 8 and λ / 4 or less. The point x indicates that the sound absorption coefficient is less than 30% or D exceeds λ / 4.
【0047】さらに、ピーク周波数における吸音率が6
0%以上で、かつ、従来の多孔質吸音体に較べ施工空間
厚みが半減できる条件は多角形EFCGHの領域であ
る。Further, the sound absorption coefficient at the peak frequency is 6
The condition in which the construction space thickness is 0% or more and the construction space thickness can be reduced to half as compared with the conventional porous sound absorber is in the area of the polygonal EFCGH.
【0048】[0048]
【実施例3】多孔質成形体として、実施例1の実験N
o.2の成形体を用いて吸音率の周波数依存性を下記の
条件で評価した。 背後空気層を25mmに設定した際の吸音率値か
ら、剛壁密着状態の測定値を差し引いた値が30%以上
の上昇を示す場合を○、30%未満の場合を×とした。 背後空気層の距離を変化させて吸音率を測定し、各
周波数における吸音率が50%を越える為に必要な空間
厚み、即ち、多孔質成形体の肉厚み(25mm)と背後
空気層の厚みとの和Dが100mm以内の場合を○、1
00mmを越える場合を×とした。 吸水処理後の吸音率が処理前に比べて10%を越え
て低下する場合を×、10%以内を○とした。[Example 3] As a porous molded body, Experiment N of Example 1
o. The frequency dependence of the sound absorption coefficient was evaluated using the molded body of No. 2 under the following conditions. The case where the value obtained by subtracting the measured value of the rigid wall contact state from the sound absorption value when the back air layer was set to 25 mm showed an increase of 30% or more was marked with ◯, and the case of less than 30% was marked with x. The sound absorption coefficient was measured by changing the distance of the back air layer, and the space thickness required for the sound absorption coefficient at each frequency to exceed 50%, that is, the thickness of the porous molded body (25 mm) and the back air layer thickness. When the sum D of and is within 100 mm, ○, 1
The case where it exceeds 00 mm was marked with x. When the sound absorption coefficient after the water absorption treatment decreased by more than 10% as compared with that before the treatment, x was designated as ×, and 10% or less was marked as ◯.
【0049】上記結果と施工性の評価とを合わせて表3
に示した。なお、施工性の評価は空調用ファンの吸音を
想定した場合の吸音体の取付作業の難易度、そのために
必要な治具、副資材の要否で判断した。本発明の多孔質
成形体では金型を作成しておけば所望の形状の成形体が
量産できること、また、そのまま装置に組み込むだけで
良いため施工性に優れる。The above results and the evaluation of workability are shown in Table 3 together.
It was shown to. The workability was evaluated based on the difficulty level of the work of mounting the sound absorber assuming sound absorption of the air-conditioning fan, and the necessity of jigs and auxiliary materials for that purpose. With the porous molded article of the present invention, molded articles having a desired shape can be mass-produced if a mold is prepared, and since it can be assembled in the apparatus as it is, the workability is excellent.
【0050】[0050]
【表3】 [Table 3]
【0051】[0051]
【比較例1】密度が24kg/m3 であり、肉厚みが2
5mmのガラスウールの吸音体を用いて実施例3と同様
な評価を行った結果を表4に示す。この場合には空気流
によるガラス繊維の飛散を防ぐために綿布で包み縫製す
る必要があり、背後空気層を設けるためにはそれを支持
するための部材や治具を必要とするため施工性に劣る。[Comparative Example 1] Density is 24 kg / m 3 and wall thickness is 2
Table 4 shows the results of the same evaluations as in Example 3 using a 5 mm glass wool sound absorber. In this case, it is necessary to wrap and sew with a cotton cloth to prevent the glass fibers from scattering due to the air flow, and in order to provide the back air layer, members and jigs for supporting it are required, and the workability is poor. .
【0052】[0052]
【表4】 [Table 4]
【0053】[0053]
【発明の効果】本発明の樹脂発泡粒子を用いた吸音体及
びその施工方法は吸音効果に優れ、特に低周波数の騒音
防止に少ない空間容積で施工できる経済的にも優れた吸
音体および施工方法である。EFFECT OF THE INVENTION The sound absorbing body using the resin foamed particles of the present invention and the method for constructing the same are excellent in sound absorbing effect, and particularly economically excellent sound absorbing body and construction method which can be constructed in a small space volume to prevent low frequency noise. Is.
【図1】本発明の多孔質成形体の断面構造を示す模式図
である。FIG. 1 is a schematic view showing a cross-sectional structure of a porous molded body of the present invention.
【図2】本発明の多孔質成形体の厚みと背後空気層との
和dと吸音率のピーク周波数との相関を示す解析図であ
る。FIG. 2 is an analysis diagram showing the correlation between the thickness d of the porous molded article of the present invention and the back air layer, and the peak frequency of the sound absorption coefficient.
1 樹脂発泡粒子 2 空隙部分 1 resin foam particles 2 voids
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 F24F 13/02 H // B29K 105:04 B29L 31:00 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification number Office reference number FI technical display location F24F 13/02 H // B29K 105: 04 B29L 31:00
Claims (3)
音率30%以上のピーク周波数を有する樹脂発泡粒子の
多孔質成形体からなる吸音体。1. A sound absorbing body made of a porous molded body of resin foam particles having a peak frequency of a sound absorbing rate of 30% or more in a frequency range of 100 to 3000 Hz.
子径が1.5〜5.5mmの樹脂発泡粒子の多数個が隣
接する粒子表面の一部で面接合し、全体容積に対して1
5〜40%の容積空隙率を有して一体化していることを
特徴とする請求項1記載の吸音体。2. A porous molded article of expanded resin particles, wherein a large number of expanded resin particles having an average particle size of 1.5 to 5.5 mm are surface-bonded at a part of the surface of the particles adjacent to each other, with respect to the entire volume. 1
The sound absorbing body according to claim 1, wherein the sound absorbing body has a volume porosity of 5 to 40% and is integrated.
音率30%以上のピーク周波数を有する樹脂発泡粒子の
多孔質成形体からなる吸音体を施工するに際し、該吸音
体の肉厚みと背後空気層の厚みとの和d(m)と騒音源
の周波数f(Hz)とが、下記(1)式及び(2)式を
満たす条件で該吸音体を設置することを特徴とする吸音
体の施工方法。 1.03・(1/d)1.7 ≦f≦17.16・(1/d)1.7 (1) 100≦f≦285・(1/d)0.48 (2)3. When constructing a sound absorber made of a porous molded body of expanded resin particles having a peak frequency of a sound absorption coefficient of 30% or more in the frequency range of 100 to 3000 Hz, the wall thickness of the sound absorber and the back air layer A sound absorbing body construction method, characterized in that the sound absorbing body is installed under the condition that the sum of the thickness d (m) and the frequency f (Hz) of the noise source satisfy the following expressions (1) and (2). . 1.03 · (1 / d) 1.7 ≦ f ≦ 17.16 · (1 / d) 1.7 (1) 100 ≦ f ≦ 285 · (1 / d) 0.48 (2)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP31158493A JP3268094B2 (en) | 1993-12-13 | 1993-12-13 | Sound absorber and method of construction |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP31158493A JP3268094B2 (en) | 1993-12-13 | 1993-12-13 | Sound absorber and method of construction |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH07168577A true JPH07168577A (en) | 1995-07-04 |
JP3268094B2 JP3268094B2 (en) | 2002-03-25 |
Family
ID=18019003
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP31158493A Expired - Lifetime JP3268094B2 (en) | 1993-12-13 | 1993-12-13 | Sound absorber and method of construction |
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998043797A1 (en) * | 1997-04-01 | 1998-10-08 | Jsp Corporation | Molded body of thermoplastic resin having sound absorption characteristics |
US6818161B2 (en) | 1997-04-01 | 2004-11-16 | Jsp Corporation | Molded body of thermoplastic resin having sound absorption characteristics |
WO2005116990A1 (en) * | 2004-05-27 | 2005-12-08 | Kawasaki Jukogyo Kabushiki Kaisha | Sound absorbing device for ultra-low frequency sound |
US7938228B2 (en) | 2005-03-07 | 2011-05-10 | Prime Polymer Co., Ltd. | Process for producing sound absorber and produced by the process, sound absorber and sound absorbing structure |
GB2493169A (en) * | 2011-07-26 | 2013-01-30 | Silentair Group Ltd | Sound insulated ducted unit and an air conditioner incorporating the same |
WO2018147464A1 (en) | 2017-02-13 | 2018-08-16 | 旭化成株式会社 | Resin foamed particles, resin foam molded body, and laminated body |
JP2018131620A (en) * | 2017-02-13 | 2018-08-23 | 旭化成株式会社 | Resin foamed particle and resin foam molded body |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4079851B2 (en) * | 2003-07-25 | 2008-04-23 | トヨタ車体株式会社 | Soundproof material |
JP6322999B2 (en) * | 2013-12-25 | 2018-05-16 | 株式会社ジェイエスピー | Foam molding |
-
1993
- 1993-12-13 JP JP31158493A patent/JP3268094B2/en not_active Expired - Lifetime
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1998043797A1 (en) * | 1997-04-01 | 1998-10-08 | Jsp Corporation | Molded body of thermoplastic resin having sound absorption characteristics |
US6818161B2 (en) | 1997-04-01 | 2004-11-16 | Jsp Corporation | Molded body of thermoplastic resin having sound absorption characteristics |
WO2005116990A1 (en) * | 2004-05-27 | 2005-12-08 | Kawasaki Jukogyo Kabushiki Kaisha | Sound absorbing device for ultra-low frequency sound |
US7938228B2 (en) | 2005-03-07 | 2011-05-10 | Prime Polymer Co., Ltd. | Process for producing sound absorber and produced by the process, sound absorber and sound absorbing structure |
GB2493169A (en) * | 2011-07-26 | 2013-01-30 | Silentair Group Ltd | Sound insulated ducted unit and an air conditioner incorporating the same |
WO2013014442A1 (en) | 2011-07-26 | 2013-01-31 | Silentair Group Limited | Improved air conditioning units |
WO2018147464A1 (en) | 2017-02-13 | 2018-08-16 | 旭化成株式会社 | Resin foamed particles, resin foam molded body, and laminated body |
JP2018131620A (en) * | 2017-02-13 | 2018-08-23 | 旭化成株式会社 | Resin foamed particle and resin foam molded body |
KR20190099312A (en) | 2017-02-13 | 2019-08-26 | 아사히 가세이 가부시키가이샤 | Resin foamed particles, resin foamed molded product, and laminated body |
US10882970B2 (en) | 2017-02-13 | 2021-01-05 | Asahi Kasei Kabushiki Kaisha | Resin foam particles, resin foam shaped product, and laminate |
Also Published As
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