JPH0287198A - Silencing structure and manufacture thereof - Google Patents

Abstract

PURPOSE: To simplify the structure and to obtain an excellent silencing effect by using foamed moldings composed mainly of polyvinyl chloride(PVC) resin and inorg. packing material and superposing a plate-like foam provided with many cavity parts and a plate-like foam provided with many through-hole path parts on each other, thereby constituting a silencing structural body. CONSTITUTION: The plate-like foams A, B are formed by expansion molding of the compsn. composed mainly of PVC resin and an inorg. packing material. These plate-like foams A, B are superposed on each other and are integrally coupled by an adhesive. The one planar foam A thereof is provided with the many cavity parts 1 scattered at required intervals on the superposition surface thereof. The other plate-like form B is provided with the many through-hole path parts 2 scattered at regard intervals. The respective through-hole path parts 2 and the cavity parts 1 are concentrically connected to etch other. As a result, the constitution of the structural body by the simple means is made possible and the excellent sound absorptivity, weatherability, etc., are obtd. by the material to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a sound-absorbing structure used in railways, vehicles, tunnels, buildings, etc., and a manufacturing method thereof.

[Prior Art] Conventionally, this type of sound-absorbing structure has been made from a mixed material made by kneading porous lightweight fireproof aggregate such as perlite, vermiculite, asbestos, rock wool, and glass wool with an inorganic binder added.
A substrate with many cavity recesses on its surface is molded, and a cylindrical body made of the same type of material is fixed in each recess on the surface of the substrate, so that sound energy (sound waves) that enters from the outside through the cylindrical body is absorbed. A soundproofing board (see Japanese Utility Model Publication No. 51-20725) is known that mutes sound by converting it into thermal energy within a recess on the substrate side.

[Problems to be Solved by the Invention] The above-mentioned sound deadening structure includes a number of cylindrical bodies made in addition to the substrate,
Since the cylindrical body is adhesively fixed by applying it to each of the many recesses provided on the surface of the substrate, it not only takes a lot of time and effort to bond the many cylindrical bodies, but also the adhesive surface is small. The cylindrical body attached to it is likely to fall off.

[Object of the invention] The present invention has been made in view of the above problems, and includes:
It can be configured with extremely simple means.

Moreover, the materials used not only have sound absorption properties, light weight, and weather resistance, but also
The object of the present invention is to provide a sound-absorbing structure having excellent properties such as nonflammability, heat insulation, processability, and adhesiveness, and a method for manufacturing the same.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention is made by laminating plate-shaped foams formed by foam-molding a composition mainly consisting of a vinyl chloride resin and an inorganic filler. The board is integrally formed with a large number of cavities provided in a dotted manner on one of the foamed plates and a large number of through-hole passages provided in a scattered manner on the other foamed plate. The above-mentioned problem is solved by a configuration in which the two are connected to each other by overlapping surfaces.

Furthermore, as a method for manufacturing the sound-absorbing structure, a composition mainly composed of the vinyl chloride resin and an inorganic filler is poured into a mold, and a plate-shaped foam having a large number of cavities scattered therein is formed. , a plate-shaped foam having a large number of through-hole passages in a scattered manner are molded separately, and both plate-shaped foams are overlapped and integrated so that the cavity and the through-hole passage are in communication with each other. The gist of this is to

[Function] In the sound-absorbing structure having the above configuration, the plate-shaped foam having the through-hole passage is bonded to the plate-shaped foam having the cavity over the entire board surface, so a strong bond is obtained and peeling is prevented. There is no risk of it happening.

In addition, since both of the plate-shaped foams are formed by foaming a composition mainly composed of vinyl chloride resin and an inorganic filler, they have good sound deadening (sound absorption), weather resistance, and nonflammability. It exhibits excellent performance in all aspects of heat resistance, heat insulation, processability, and adhesion.

[Example 1] Figures 1 and 2 show a sound-absorbing structure according to an example of the present invention, and A and B are compositions whose main materials are a vinyl chloride resin and an inorganic filler, respectively. It is a plate-shaped foam formed by foam molding, and among these plate-shaped foams A and B, which are overlapped and bonded together with an adhesive, one of the plate-shaped foams A has the overlapped A large number of cavities 1 on the surface
are provided in a dotted manner at a required interval, and on the other plate-shaped foam B, a large number of through-hole passages 2 are provided in a dotted manner at a required interval, and each through-hole passage 2 and It is concentrically connected to the cavity 1.

FIGS. 3 and 4 show an example of a method for manufacturing the plate-shaped foams A and B. That is, 3.4 is a mold, and in molding, the plate-shaped foam A is obtained by pouring the composition into the mold 3 having a hemispherical convex portion 3a on the surface and performing foam molding. For molding, the plate-shaped foam B is obtained by pouring the composition into a mold 4 having a truncated conical convex portion 4a on its surface and performing foam molding. By applying an adhesive to the plate-shaped foams A and B obtained in this manner and overlapping them, the sound-absorbing structure shown in FIG. 1 is obtained.

Therefore, in the sound-absorbing structure having the above configuration, as shown in FIG. (sound waves) change into thermal energy in the cavity, silencing (
sound absorption). That is, the through-hole passage portion 2 functions as a sound-muffling tube, and the cavity portion 1 functions as a sound-muffling cavity, but the muffling tube and the sound-damping cavity are mainly made of the above-mentioned vinyl chloride resin and inorganic filler. Since it is composed of a plate-shaped foam formed by foam-molding a composition of Excellent effects are also exhibited.

For example, an inorganic filler such as stone powder or calcium ash and a vinyl chloride resin (mixing weight ratio of 95:50 to 50:50)
, a melt viscosity modifier and an internal lubricant for vinyl chloride resin are mixed in a kneading device (with a compressibility of 2.5 at the point where shear force is generated).
or more, shear force is 10'dyne or more, shear stress is 1
After grinding and melting and dispersing the material using 0'dyne/al, which has a cross-wire capacity of 15,000 times or more of displacement action, a crosslinking agent and a foaming agent are added and a crosslinking/foaming reaction is carried out within a specified temperature range. The foam material (specific gravity of 0.1 or less) is most suitable as the foam material for the sound-absorbing structure.

Next, preferred examples of the foam are shown below.

(First step) Suspension polymerized vinyl chloride resin with p=12()O 20 parts by weight Calcium carbonate 55 Hydrous aluminum silicate (kaolinite) 25 Polyacrylate 10 Glycerol monostearate 2n Decyl alcohol 3 3 Basic lead sulfate
3. After mixing the raw materials that will become the foaming matrix in a mixer, the compression ratio is 3.5. shear force 235
B860dyne, shear stress 21440dyne/
a! The mixture was placed in a mixing device having a kneading capacity of 24,480 displacement operations, the kneading temperature was set at 180 to 200° C., and the mixture was mixed at a screw rotation speed of 6 Orpm to obtain a molten dispersion.

(Second step) Melt dispersion of the first step 115 parts by weight dicumyl peroxide 2.0 Azobisisobutyronitrile 2.0 Dinitrosopentamethylenetetramine 2. O Urea-based foaming aid
2. O Triallyl cyanurate 0.5 Toluene
10.0# In the second step, the crosslinking agent and blowing agent reactants were added to the melted dispersion obtained in the first step, moistened with a small amount of toluene, and mixed uniformly.

(Reaction step) The mixture obtained in this second step is heated at 50°C to 220°C.
The crosslinking and foaming reactions were carried out in the reactor at temperatures in the range of , and the toluene was recovered.

(Product) Specific gravity 80kg/bo, thermal conductivity 0.030kc at 25℃
A homogeneous foam of al/m-hr·°C was obtained.

Next, the characteristics of the foam will be specifically described.

(1) Sound deadening properties Results of a sound deadening test conducted in accordance with the Reverberation Soho Sound Absorption Measurement Method specified in J I 5-A-1409.

It is recognized that it has a noise reduction effect of 70% or more.

(2) Weather resistance In outdoor natural exposure tests, there were no phenomena such as cracking, aging, or shrinkage, and it was recognized that there is a significant difference in aging resistance performance when compared with other organic insulation materials. In particular, there is an extremely large difference between urethane-based, styrene-based, and polyethylene-based, and they are also chemically stable.

(3-insulation property: It has excellent insulation properties not only at room temperature, but especially at low temperatures (-
195℃ 20 years). Because it has a completely closed cell structure, the gas in the cells remains independent, reducing heat transfer.

(4) Water resistance Since it is a completely closed-cell foam, it does not permeate water even in a pressure test. Water was absorbed for 24 hours at a water temperature of 23°C, and 24°C9
The thermal conductivity when left for 24 hours at 0% RH is negligible.

(5) Moisture resistance It has low moisture permeability, making it difficult for water vapor to pass through.

Can be used even in humid places.

(6) Processability/Workability Since vinyl chloride resin is used as a binder, the material is sticky and installation is easy. Can be easily cut with a utility knife. Curved surfaces can be easily processed at approximately 80°C for 15 minutes. By applying baking liquid,
It can be easily bent by 180''.

(7) Toxic gas generation status The toxic gas test for semi-noncombustible materials is 172, which is the standard value, and the oxygen index value is 26 or higher, which is the standard value for noncombustible materials.

[Effects of the Invention] As described above, the sound deadening structure according to the present invention uses a foamed molded product of a composition mainly composed of a vinyl chloride resin and an inorganic filler, and has a large number of cavities. The structure is extremely simple, and it is not only easy to manufacture, but also has an excellent sound deadening effect. is obtained,
It also has excellent weather resistance, heat insulation, water resistance, moisture resistance, etc., so it can be widely used for exterior walls.

In addition, the sound-deadening structure of the present invention is lightweight, bendable, cutable,
Since adhesive processing is easy, it can be effective in large-scale construction work.

Furthermore, according to the method of the present invention, a composition mainly composed of a vinyl chloride resin and an inorganic filler is poured into a mold, and a plate-shaped foam having a large number of cavities dotted therein and a large number of through holes are formed. This is because a plate-shaped foam having hole passages scattered therein is molded separately, and both plate-shaped foams are integrated by overlapping each other so that the cavity and the through-hole passage are in communication with each other. , the silencing structure can be manufactured extremely simply and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a silencing structure showing an embodiment of the present invention;
FIG. 2 is an enlarged longitudinal cross-sectional view, FIGS. 3 and 4 are cross-sectional views of a molding frame for a plate-shaped foam constituting the sound-absorbing structure, and FIG. 5 is an explanatory view of the sound-absorbing structure. A, B...Plate foam, 1...
...Cavity part, 2......Through hole passage part, 3,
４・・・・・・・・・Formwork.

Claims (2)

[Claims] (1) Plate-shaped foams formed by foam-molding a composition mainly composed of vinyl chloride resin and an inorganic filler are stacked together to form a single body, and one of the plate-shaped foams is provided in a dotted manner. A sound-absorbing structure characterized in that a large number of hollow portions provided in the foam plate and a large number of through-hole passage portions provided in a scattered manner in the other plate-shaped foam are connected to each other at the overlapping surface of the plate. . (2) A composition mainly composed of vinyl chloride resin and an inorganic filler is poured into a formwork to form a plate-shaped foam having a large number of cavities dotted therein and a number of through-holes dotted therein. Manufacturing a sound-absorbing structure characterized by separately molding a plate-shaped foam having a shape, and integrating both plate-shaped foams by overlapping them so that the cavity and the through-hole passage communicate with each other. Law.