JPH0220529A - Sound-insulating rubber sheet - Google Patents

Abstract

PURPOSE:To provide a sound-insulating rubber sheet having a high gravimetric surface density and an excellent sound insulation effect and being of a low cost by using a rubbery compd. of a high specific gravity obtd. by kneading a rubber material such as a natural or synthetic rubber etc., with a dried iron powder of a specified particle size. CONSTITUTION:A rubbery compd. having a specific gravity of 1.7 or higher is prepd. by kneading a mixture of a natural or synthetic rubber or a mixture thereof with a reclaimed rubber together with a dried iron powder having a particle size of 200-mesh pass of 80% or higher. Then, a sound-insulating rubber sheet is prepd. by molding the obtd. rubber compd. In addition, it is possible to prepare an odorless sound-insulating rubber sheet by adding and kneading furthermore active carbon to said rubber compd. Furthermore, by constituting the rubber sheets consisting of said rubber compd. as a multi-layered sheet, it is possible to improve furthermore the sound insulating effect.

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to a sound insulating rubber sheet that can be used as a wall material for walls and floors of buildings, audio equipment, etc. to prevent the transmission of noise. In recent years, the problem of neighborhood noise has become a social problem that harms the residential environment due to the overcrowding of housing due to the progress of urbanization, the spread of audio equipment, etc., and countermeasures are required to prevent it. Characteristics required for sound insulation materials include: ■ No air permeability ■ High internal viscosity ■ Weight surface density (g/cd)
There are three important points. Generally, rubber materials have no air permeability and high internal viscosity, so they have been used as sound insulating materials, but they have the disadvantage of not having a large surface density by weight, so the desired sound insulating effect cannot be obtained. The present invention is a sound insulating rubber sheet that increases the weight surface density while making use of the characteristics of conventional rubber.Since the weight surface density is proportional to the specific gravity when the thickness is constant, the specific gravity of the rubber compound is increased. To provide a sound insulating rubber sheet which can reliably enhance a desired sound insulating effect by kneading dry iron powder into a rubber sheet and which can be manufactured at low cost. Another object of the present invention is to provide an odorless sound-insulating rubber sheet by kneading activated carbon with the above-mentioned rubber compound. Furthermore, another object of the present invention is to provide a sound insulating rubber sheet that can further improve the sound insulating effect by using the sound insulating rubber sheet made of the above-mentioned rubber compound as a multilayer structure. The present invention is a sound insulation material made of a rubber compound with a specific gravity of 1.7 or more, which is obtained by kneading dry iron powder with a particle size of 250 mesh passing through a mesh of 80% or more into a compound mainly made of natural rubber, synthetic rubber, or these and recycled rubber. Regarding rubber sheets, they can be formed by a simple process of kneading inexpensive dry iron powder with inexpensive rubber materials, and in particular, they can increase the weight surface density and exhibit the desired sound insulation effect. be. In addition, the present invention can achieve the desired deodorization by a simple operation of kneading an appropriate amount of activated carbon into the rubber compound, and furthermore, by configuring the rubber sheet as a multilayer, the sound insulation effect can be synergized. It is something that can be improved. The present invention will be explained in detail below. In the first example, as shown in Table 1, natural rubber, CaC0° carbon black (SRF), softener, vulcanization aid, vulcanization accelerator, sulfur, and dry iron powder were blended and pressurized by a conventional method. A sound-insulating rubber sheet made by vulcanizing and forming into a sheet (
1), T-1 is a comparative example that does not contain dry iron powder. As for the dry iron powder, one manufactured by Mitomi Metal Co., Ltd. was used. Product Name CS Flower F (Particle size) 28-35 Meth 35-48〃 48-65〃 65-100〃 100-150〃 150-200〃 200-250〃 250-350〃 (χ ) 0.2 0.6 0.8 1.0 1.2 1.4 5.8 Total 100.0 T-2 to T5 are examples in which appropriate amounts of dry iron powder were blended, respectively. These sample pieces (4) were measured using the simple sound insulation performance measuring device shown in FIG. 1, and the sound insulation performance measurement results are shown in Table 2. The sound source is 84-86db. The simple sound insulation performance measuring device shown in Figure 1 is vertical. A sample piece of this example was prepared in which a flange (3) was provided at the opening of an iron cylinder (2) with a width of 100 m/m and a length of 200 m/m, and was laminated to a plywood board large enough to cover the opening. 4) is fixed by the fixing piece (5), and the opening is sealed. A new TAN I TA buzzer (6) is housed inside the iron tube (2) as a sound source. A microphone (7) is placed in front of the sample piece (4) at a distance of approximately loam, and the microphone (7) is connected to a sound level meter (8). This example is a sound insulation rubber sheet kneaded with dry iron powder (350 mesh is approximately 89χ) as shown in Table 1, and the sound insulation performance measurement results of these sheets were measured using the simple sound insulation performance measuring device shown in FIG. 1. As shown in Figure 2, it has a sound insulation effect of 14 to 21 db compared to a normal rubber sheet, and this effect increases as the specific gravity increases. table table

[Example 2] As shown in Table 3, the sample pieces of this example were natural rubber for T-6゜7-8, and synthetic rubber (SBR-1502 for T-7 and 7-9). ) is used, and T-10 is natural rubber. Synthetic rubber and recycled rubber are used, and T-6 and T-7 each contain 100 parts by weight of dry iron powder (same as in Table 1), and T-6 and T-7 contain 100 parts by weight of dry iron powder (same as Table 1).
8, T-9, and T-IQ were each mixed with 400 parts by weight. The other parts are formed in accordance with the first embodiment. Table 4 shows the results of sound insulation performance measurements with veneer plywood with a thickness of 4 m/+. In this example, the sound insulation effect was compared between a comparative piece of veneer plywood with a thickness of 4n+m and a sample piece with a thickness of 1 fin. ~44.8
db) was found to have a higher sound insulation effect (7.7 to 12.1 db) than 4-fin thick veneer plywood (52.5 db) alone. However, the difference in sound insulation effect between natural rubber and synthetic rubber (SBR-1502) is not very clear, and when recycled rubber is mixed, the sound insulation effect is slightly better. table

[Example 3] In this example, as shown in T-12 to T-15 in Table 5,
Activated carbon C was added to a rubber sheet material almost similar to T-5 in Example 1.
B is kneaded in a range of 2.5 to 10.0 parts by weight. Activated carbon CB was not kneaded in T-11 in Table 5. Rubber, rubber chemicals added to rubber, iron powder, etc. emit a characteristic odor, which is a nuisance to users. Therefore, from the point of view of odor, kneaded materials are not desirable as building materials, so it is desirable that the characteristic odor emitted from them be deodorized. It was found that the odor emitted from the rubber compound used in this example was suppressed by the adsorption effect of activated carbon. The activated carbon used is Nyukaku activated carbon CB from Nimura Chemical Industry Co., Ltd.
As the dry iron powder, CS Flower F manufactured by Tapi Kosan Co., Ltd. is used. In this example, when the amount of activated carbon CB was 7.0 PIIR or more, the deodorizing effect increased and it was effective. However, it goes without saying that the amount added varies depending on the nine brands of activated carbon.

[Example 4] This example is a rubber sheet made of a mixture of recycled tire rubber and natural rubber as shown in Table 6, and the other ingredients are almost the same as in Example 3. The rubber content of recycled tire rubber is 50%.
The vulcanization conditions were 155-b direct hot air vulcanization. Sample pieces T-16 and T-17 were formed as the sample pieces of this example, and a comparison piece T-18 was prepared. The dimensions of the T-16 sound insulating rubber sheet are 1760 x 910 x 1 + u thickness and the areal density is 2.8 kg/m, and the T-17 sample piece is 1820 x 910 x 9 thick between two pieces of plasterboard. 1 B 20 x 910 x 1 thick sound insulating rubber sheets are sandwiched between them, and the surface density is 16.3 kg/n. A double-sided adhesive tape with a width of 5 Q + im is pasted on the outer periphery of the mating surfaces, and a cross-shaped tape is placed in the center. A 30 mm I+II double-sided adhesive tape with both ends extending to the outer periphery is pasted, and the above-mentioned plasterboard, sound insulation rubber sheet, and plasterboard are laminated in this order. Also, a comparison of T-18. The pieces are 1820 x 910 x 9 pieces of gypsum board with a surface density of 13.5 kg/m and are pasted together using double-sided adhesive tape as described above.Table 6 Figure 2 shows the sample pieces ( 4), etc. As shown in FIG.
(4) is attached to one side of a wooden frame (9), and the periphery of the wooden frame (9) is filled with oil clay (10). The method for installing it is to fit 3 polished steel bars (11) of 12φ x 8351m at intervals of 420 bars in the longitudinal direction on the top surface of the wooden frame (9), and to prevent tension from being applied with a wire mesh (12) stretched over the bars. Support sample piece T-16, width of 4 sides around 35++n
It was held down with a 4-thick plywood board and nailed (1,9 medium x 32 mm) at 10c+n intervals. As the test specimen 2, sample piece T17 (
4) on both sides of the wooden frame (9), and cover the surrounding area with oil clay (1).
0). The mounting method is the sample piece (4
) nails (l, 9Φ x 32 fl) were driven at 10 cm intervals at 2.5 cm from the edge. The thickness of the middle air layer is 95 mm. As a test specimen 3, comparative specimen T-18 (4-1) was attached to both sides of a wooden frame (9) as shown in FIG. 2(b) above, and the surrounding area was filled with oil clay (10). The mounting method was to drive nails (1.9 Φ x 32 mm) at 1Q cm intervals on the four sides of the comparison piece (4-1) at 2.5 cm from the edge. The thickness of the middle air layer is 95 mm. The measurement facility and measurement method are shown below.

[Measurement facility]

Reverberation chamber for sound source: Volume = 98 rrr Surface area = 128
Reverberation room for sound reception: Volume: 179n? Surface area・188
Ho

【Measuring method】

Measurement method According to JISA1416 (method for measuring acoustic transmission loss in a laboratory). Measurement points For each test specimen, reverberation time was measured at 5 points in the sound receiving reverberation room, and sound pressure level difference was measured at 5 points each in both the sound source and sound receiving reverberation rooms. Measurement week wave number 12511z ~ 6.3KIlz
The 1/3 octave bass measurement device and block diagram are shown in FIG. Test specimens are in the shaded area (13)
Fixed to. The calculation formula is as follows.・The average sound pressure level is calculated for each of the sound source reverberation room and the sound reception reverberation room using the following formula. L: Average sound pressure level (d(1) P + - P s: Effective value of sound pressure at each of the five points in the room (Pa) Po Two standard sound pressure (2X 10-'Pa) of the reverberation room for sound reception Sound absorption is calculated from the average value of the measured reverberation times using the following formula: A: Sound absorption power of the reverberation room for sound reception (rtr) T: Reverberation time of the reverberation room for sound reception (seconds) V: Volume of the reverberation room for sound reception (rrr) C: Speed of sound in air (m/sec) C・331.5 + 0.61t t: Temperature of air (°C) The sound transmission loss of the test specimen is determined by the reverberation chamber for the sound source and the reverberation chamber for the sound receiver. It is calculated from the average sound pressure level of each and the sound absorption power of the sound receiving reverberation room using the following formula: TL=D+10 log (S/A) D=L, -L2 TL: Sound transmission loss (dB) D : Sound pressure level difference between rooms (dB) S: Area of sound transmission part of test specimen (1.36m) Sound absorption power of reverberation room for Az sound reception (n?) Ll: Average sound pressure level of reverberation room for sound source (dB) L2: Average sound pressure level (dB) transmission loss measurement and calculation results for sound receiving reverberation chamber are shown in Table 7. Mugi unit dll Figure 4 shows a comparison of the transmission of test specimens 1 and 2.3 between the lighting conditions. 7
It is displayed based on. The results of the test of this example will be discussed. The transmission loss of test specimen 1 (sound insulating rubber sheet only) is 12
In the range of 511z to 50011z, it is about a dozen dB, but at high frequencies above 50011z, it decreases almost linearly to 4 dB.
It increases at a rate of ~5 dllloct, which clearly shows the general sound insulation characteristics of soft sound insulation rubber sheets. Test specimen 2 (a sand inch panel with a sound-insulating rubber sheet sandwiched between two plasterboards attached to both sides of a wooden frame) has a transmission loss that is not significantly different from that of test specimen 3 in the 250 to 50011z band, but The drop in i3 excess loss in the 16011z and 4Ktlz bands that was seen in 2011 has disappeared, and especially in the high frequency range of 4Ktlz or higher, the transmission loss has increased by about 10 dB. Also, about 6 dBlo for 25011z ~ 2 K11z
The transmission loss is increasing at a rate of ct. In test specimen 3 (two sheets of gypsum board attached to both sides of a wooden frame), a drop in transmission was observed in the 160,112 and 4 KHz bands. This dip in the 1601Iz band is considered to be due to resonance of the vibration system constituted by the gypsum board and the intermediate air layer. 4K
The decrease in transmission loss in the Ilz band is due to the coincidence effect caused by the wavelength of the bending wave of the test object determined by the bending rigidity of the test object and the wavelength of the obliquely incident sound wave. The present invention is a sound insulating rubber sheet made of a rubber compound with a specific gravity of 1.7 or more, which is obtained by kneading dry iron powder with a particle size of 250 meshes or more with a passing rate of 80% or more into a mixture of natural rubber, synthetic rubber, or a mixture of these and recycled rubber as main materials. Therefore, by increasing the weight surface density, the sound insulation effect can be enhanced, and moreover, it can be produced at low cost. In addition, the present invention was able to absorb the odor of the rubber compound and make it odorless by simply kneading an appropriate amount of activated carbon into the rubber compound. Furthermore, the present invention can be achieved by configuring the thin sound insulating rubber sheet as a multilayer sheet. We were able to demonstrate the synergistic effect of LH.

[Brief explanation of the drawing]

Figure 1 shows a simple sound insulation performance measuring device according to an embodiment of the present invention;
The figure is a cross-sectional view showing the mounting state of a sample piece for measuring sound insulation performance, Figure 3 is a block diagram of the measuring device, and Figure 4 is a fold line diagram comparing the transmission loss of test specimens 1 and 2.3. It is. 1. Sound insulating rubber sheet, 2...iron tube, 3. collar, 4. sample piece, 5-. fixed piece, 6- buzzer 7.. micro, ton, 8- sound level meter, 9.. wood Frame, 10--oil particle size, 11-polished iron mesh, 12--wire mesh, 13 diagonal line area. Patent applicant Tsuchiya Rubber Co., Ltd.? 2 Figure CCL') Rod + Figure (Hiroshi Criticism) Dangrain

Claims (3)

[Claims] (1) Particle size 250 mesh passing amount 8 for a mixture mainly made of natural rubber, synthetic rubber, or these and recycled rubber
A sound-insulating rubber sheet made of a rubber compound with a specific gravity of 1.7 or more mixed with 0% or more of dry iron powder. (2) The sound insulating rubber sheet according to claim 1, which is made odorless by kneading activated carbon into the rubber compound. (3) The sound insulating rubber sheet according to claim 1 or 2, which is constructed of a multi-layered rubber sheet made of the above-mentioned compound.