JP3217646B2 - Ceramic sound absorbing material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound absorbing material used for roads, houses, buildings, and the like, and more particularly to a sound absorbing material which does not deteriorate in sound absorbing performance even when it is subjected to rapid heat or quenching such as fire.

[0002]

2. Description of the Related Art A conventional method for producing a ceramic sound-absorbing material without a firing step generally involves adding a resin-based binder to ceramic particles, mixing the mixture well, filling the mixture into a press mold, and press-molding the mixture. Thereafter, it is taken out and dried at room temperature for one day or more to exhibit strength (FIG. 3).

[0003]

A conventional ceramic sound-absorbing material using a resin-based binder, which is not fired at a high temperature, burns out the resin-based binder in a high-temperature atmosphere such as a fire. Only the pressing force in the pressing step causes the ceramic particles to adhere to each other, resulting in a significant decrease in the strength of the sound absorbing material. In some cases, the ceramic particles on the surface of the sound absorbing material also partially fall off. (In Table 1). An object of the present invention is to solve the problems of the prior art and to provide an improved sound absorbing material in which the strength is not reduced and the ceramic particles are not dropped even when the water falls in a high temperature atmosphere such as a fire. .

[0004]

The present inventors have conducted various studies to overcome the above-mentioned drawbacks of the prior art. As a result, the ceramic particles fall off the surface of the sound absorbing material even when exposed to a sudden high-temperature atmosphere such as a fire. In order to prevent this, it has been found that it is effective to add not only a conventional resin binder but also an inorganic binder as a binder (FIG. 1). Here, the inorganic binder used is
It must be in a molten or semi-molten state at a fire temperature of about 500 to 800 ° C. and have a sticky, glue-like state having a certain viscosity (FIG. 2).

[0005] That is, the present invention is a ceramic sound absorbing material obtained by pressing an admixture obtained by adding a resin binder and an inorganic binder to an oxide ceramic granule as an aggregate, and integrally forming the aggregate . The above inorganic binder
Over the PbO by weight _{ratio: 35~65% SiO 2: 20~35%} B 2 O 3: 5~20% ZnO, Al 2 O 3, other: having the composition and the balance, and volume expansion coefficient of 300 × 10 ^-7
It is the gist of the following lead borosilicate glass .
The oxide ceramic particles used as the aggregate include, for example, mullite, and the resin binder is generally preferably a thermosetting resin such as an epoxy resin.

When a sound-absorbing material to which both a resin-based binder and an inorganic-based binder are added encounters a fire, a sharp rise in temperature occurs and the material is heated to 500 to 800 ° C. for a short time. Extinguished or extinguished within a short time. The resin binder disappears during this short temperature rise, but the inorganic binder becomes molten or semi-molten,
At this time, although the strength of itself is not high, it becomes so-called glue-like (or molten glass-like) and plays a role of preventing ceramic particles from falling off the surface of the sound absorbing material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As low-melting inorganic binders, phosphoric acid (P ₂ O ₅ ) and boric acid (B ₂ O ₃₎
), Lead (PbO) and mixtures thereof. First, a phosphoric acid system, for example, SM-5 (trade name, manufactured by Nippon Frit Co., containing 35 to 40% of P ₂ O ₅ as a main component) has a high body expansion number (450 × 10 ⁻⁷ ), and is particularly rapidly cooled. In such a case, cracks are formed in the material and the strength is remarkably reduced, so that it is not suitable as a binder.

Next, in a boric acid system, for example, PR520
3 (Japan frit Co., trade name, B ₂ as a main component
35 to 40% of O ₃ , other than Al ₂ O ₃ and SiO ₂ ) have a slightly higher body expansion coefficient (350 × 1).
0 ^-7 ), since the melting temperature is as high as about 800 ° C, it does not form a glue in the case of fire and does not serve as a binder. Even if it is melted, cracks easily occur during rapid cooling, so it is not suitable as a binder. .

In the lead system, for example, XM-735L
(Product name made by Nippon Frit Co., Ltd., PbO as main component
(40-45%, other containing SiO ₂ and Al ₂ O ₃ ) has a low body expansion coefficient of 170 × 10 ^−7, and no crack is observed during quenching after melting. However, when the melting temperature is 800-90
Since the temperature is as high as 0 ° C, it does not fulfill its purpose in case of fire. Therefore, various tests were conducted on a lead-based material having a low body expansion coefficient and a component having a low melting temperature. As a result, the body expansion coefficient is 300 × 10 ⁻⁷ or less and the softening temperature is 350 ° C.
It has been found that a material having a melting temperature of 400 to 600 ° C. has an effect as a materialless binder in the case of rapid heat or rapid cooling such as fire.

The condition satisfying this condition is Pb
Lead borosilicate glass composed of O, B ₂ O ₃ , SiO ₂ or the like is preferable. P ₂ O ₅ is not preferable because of its high expansion coefficient. Lead borosilicate glass with a body expansion coefficient of 3
In order to reduce the melting temperature to 00 × 10 ⁻⁷ or less, it is necessary to reduce B ₂ O _{3 to} 20% or less.
It is necessary that O is 35% or more, B ₂ O _{3 is} 5% or more, and further, SiO ₂ and ZnO are appropriately blended.

The compounding amount of the lead borosilicate glass is preferably in the range of 100: 3 to 20: 2 to 10 by weight of ceramic particles: lead borosilicate glass: resin binder. When the content of lead borosilicate glass is 3% or less, the effect of increasing the strength after quenching cannot be expected, and the effect of the binder at high temperatures is low. Further, the strength can be expected to increase as the amount is increased, but the porosity decreases, which has a great influence on the sound absorbing performance. The resin binder is
It is added to ensure strength at low temperatures, which is an atmosphere that is always used as a sound absorbing material. However, 2 to 10% is preferable, strength is insufficient at 2% or less, and porosity decreases when it exceeds 10%. Has been found to affect sound absorption performance.

[0012]

The present invention will be described in more detail with reference to the following examples. (Example 1) Production of ceramic sound absorbing material (i) Ceramic particles (crushed mullite particles having a diameter of about 0.5 to 1 mm) ... 5000 g (ii) Epoxy resin adhesive ... 100 g (iii) Lead borosilicate glass (# 4370) 500 g (produced by Nippon Hollow Glaze Co., Ltd.) was well mixed with a mixer for about 20 minutes. The obtained mixture was filled in a press die (450 mm × 900 mm) and press-molded under a pressure of about 200 tons to obtain a sample having a size of 450 × 900 × 9 mm.
This was taken out of the mold and dried at room temperature for one day or more to cure the adhesive, and a sound absorbing material having considerable strength was obtained. The flexural strength (of Table 1) was 140 kg / cm ² . FIG. 4 shows the sound absorption coefficient of this composition. Next, 750 ° C
After heating for 30 minutes, the sample was quenched and returned to room temperature, and the strength was measured. As a result, it was found to be 80 kg / cm ² (Table 1).
of). In FIG. 4, the solid line indicates the sound absorption coefficient of the sample before heating, and the dotted line indicates the sound absorption coefficient of the sample cooled after the heat treatment at 750 ° C. for 30 minutes.

(Comparative Example 1) The flexural strength of a sample obtained by treating in the same manner as in Example 1 except that no borosilicate glass was blended is shown in Table 1 and in Table 1.

[0014]

[Table 1]

[0015]

By using lead borosilicate glass as the inorganic binder, it is possible to prevent the sound-absorbing material which has not been subjected to the sintering step from falling off of the ceramic particles even in the case of rapid heating such as a fire. In addition, when cooled after extinguishing, the molten material solidifies, and the lead borosilicate glass acts as a bonding agent for the ceramic particles, has an appropriate strength, and has an effect that it can be reused as a sound absorbing material. .

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of the ceramic sound absorbing material of the present invention.

FIG. 2 is a schematic view showing a state in which an inorganic binder used in the ceramic sound absorbing material of the present invention is molten.

FIG. 3 is a schematic view showing an example of a conventional ceramic sound absorbing material using a resin binder.

FIG. 4 is a graph showing a reverberation chamber method sound absorption coefficient before and after heating of the sound absorbing material of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G10K 11/16-11/175 C08J 9/32

Claims (1)

(57) [Claims] 1. A oxide-based ceramics and granular material a ceramic sound absorbing material comprising this mixture of resin binder and an inorganic binder was obtained by adding pressurized integrally molded as an aggregate, the inorganic binder There PbO by weight _{ratio: 35~65% SiO 2: 20~35%} B 2 O 3: 5~20% ZnO, Al 2 O 3, other: having the composition and the balance, and volume expansion coefficient of 300 × 10 ^-7
A ceramic sound absorbing material characterized by the following lead borosilicate glass .