JPH03131900A - Sound absorbing material - Google Patents

Abstract

PURPOSE:To improve touch resistance, weatherability, heat resistance, and sound absorbing characteristic and to prevent color shading occurring by coating the surface of an aluminum porous material with a coating agent containing specific tetraalkoxide silane, titanium tetraalkoxide, and its hydrolytic matter, or the subclass condensate of the hydrolytic matter, inorganic color pigment, and a solvent. CONSTITUTION:The surface of the aluminum porous material is coated with the coating agent containing tetraalkoxide silane with 1-5 carbon of alkoxide group, hydrolytic matter or the subclass condensate of the hydrolytic matter, the titanium alkoxide with 1-5 carbon of alkoxide group, hydrolytic matter or the subclass condensate, and the inorganic color pigment. In other words, when hydrolysis, condensation, high polymerization occurs in each of the tetraalkoxide silane and the titanium tetraalkoxide by using them simultaneously, a coating film goes to the one in which an SiO2 and a TiO2 are coupled, and a generated coating film consists of a stable inorganic matter. Thereby, it is possible to improve the touch resistance, the weatherability, the heat resistance, and the sound absorbing characteristic, and to prevent the color shading occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to an air-absorbing f material, specifically for expressways, bridges,
This relates to @sound materials that are useful for use in soundproof walls attached to general roads, railways, and other outdoor structures, or indoor soundproof walls in public halls, music halls, gymnasiums, theaters, etc.

(Prior Art) Aluminum porous materials in the form of plates or blocks (hereinafter sometimes abbreviated as porous aluminum materials) are used as outdoor soundproof walls and indoor soundproof walls as described above. When using this porous aluminum material, paint, enamel, or enamel lacquer made by mixing an organic color vehicle with a coloring pigment is applied to the surface of the porous material.
It is applied relatively thickly to impart corrosion resistance and weather resistance to the surface of the porous material.

Oil-based paints, synthetic resin paints, and cellulose-based paints are mainly used as paints using organic color vehicles, and as coloring pigments, Wi-based or non-film types with a particle size of 1μ or less are used. The paint consisting of is applied to the surface to be coated by brushing or spraying with a spray gun, and is dried and cured to form a coating film.

(Problems to be solved by the invention) As mentioned above, conventionally used paints, etc. do not have problem B if the surface to be coated is flat, but the surface of porous aluminum material is not flat and is in a porous state. It has been found that the density is not uniform throughout the entire area, and that various problems occur when painting porous materials with non-uniform density using conventional techniques such as Bain F.

That is, since the above-mentioned paints used in the past generally have a slow curing speed, there is a risk that the paint may penetrate into the interior of the porous material due to capillary action, and this and the non-uniform density of the porous material. This causes color unevenness, and furthermore, the pores are partially blocked by the paint that has entered the porous interior, resulting in a decrease in sound absorption coefficient.

<Means for Solving Problem a) The present invention solves the above-mentioned problems and provides a sound absorbing material made of porous aluminum material without deterioration in sound absorbing performance and without uneven appearance. 0, and its gist is that the surface of the porous aluminum material is treated with (a) tetraalkoxysilane whose alkoxy group has 1 to 5 carbon atoms, its hydrolyzate, or its hydrated Partial polycondensate of decomposition products, (b) Titanium tetraalkoxide whose alkoxy group has 1 to 5 carbon atoms, its hydrolyzate or partial polycondensate of this hydrolyzate, (c) jIlli mechanical coloring pigment It consists in a sound-absorbing material coated with a coating material containing a colored pigment (molten M).

The aluminum porous material in the present invention is manufactured, for example, as follows.

■By powder metallurgy method.

The aluminum porous material produced by this method is (
It is commercially available from NDC Co., Ltd. under the trade name 1.

■Make aluminum fibers and intertwine them to make a non-woven fabric. This nonwoven fabric can be used in various densities, from high density to low density (high and low porosity). Additionally, since this non-woven fabric can be deformed under high stress, it may be subjected to a sintering process to create bonds between the intertwined fibers, or it may be coated with a metal mesh, preferably aluminum. It may be used by sandwiching the aluminum fiber nonwoven fabric from both sides with a mesh made of expanded metal made of aluminum, or by applying pressure to only one side of the fabric and applying pressure through the rolls to form the fabric. This expant metal made of aluminum is molded into a nonwoven fabric as a shape-retaining material, and is commercially available from Unix Co., Ltd. under the trade name [Boal 1].

Note that this aluminum fiber nonwoven fabric is not limited to a thin one such as a nonwoven fabric for clothing, but a thicker one may also be used depending on the use as a sound absorbing material.

■By foaming method. The molten aluminum is process rolled to form open pores.

Foamed aluminum is commercially available from Shindo Steel Wire Co., Ltd. under the trade name Lalboran.

The salt is eluted with water to form pores.

The porous aluminum material in the present invention includes those made of aluminum alone, as well as those made of aluminum alloys.

Next, the tetraalkoxysilane in the present invention is represented by the general formula S + (OR)+. In this formula, R is a furkyl group with i''-5 carbon atoms.This silane compound rapidly hydrolyzes when it encounters moisture. The silica compound produced by hydrolysis undergoes polycondensation to form a partial polycondensate.This product further increases in molecular weight and hardens to form a coating film.This curing proceeds even at room temperature. 6. In the present invention, two or more types of tetraalkoxysilane can be used.
May be used in combination with H.

The titanium tetraalkoxide in the present invention is represented by the general formula T + (OR-. In this formula, R is a furkyl group having 1 to 5 carbon atoms. Like the above-mentioned silane compound, this titanium tetraalkoxide is in contact with moisture. When applied to a surface, it is immediately hydrolyzed by moisture in the air.

The titanium compound produced by hydrolysis undergoes polycondensation to produce a partial polycondensate. This material was further developed into a polymer,
It hardens and becomes a coating film. This curing proceeds even at room temperature, but when heated, curing proceeds more quickly.

In the present invention, this titanium tetraalkoxide is
Two or more species can be used together (turtle).

In the present invention, when tetraalkoxysilane and titanium tetraalkoxide are used together, each of them is hydrolyzed, polycondensed, and polymerized. It is thought that it will become. Since the coating film thus produced is made of stable inorganic material, it has excellent corrosion resistance, weather resistance, and heat resistance.

Inorganic colored pigments (including white pigments) used in the present invention
As such, those with colors depending on the purpose are selected and used as appropriate.

The solvent used in the present invention is used to adjust the viscosity so that the coating work can proceed smoothly and easily when the paint used in the present invention is applied by brushing or spraying with a spray gun. It is used in a suitable proportion.Although aliphatic monohydric alcohols having 1 to 8 carbon atoms are suitable for this solvent, it is preferable that they evaporate and volatilize quickly after painting, so it is preferable to use aliphatic monohydric alcohols having 4 carbon atoms. The following alcohols are suitable. In addition to monohydric lower alcohols, toluene, xylene, mineral spirits, etc. can also be used.

To manufacture the sound absorbing material of the present invention, an aluminum porous material obtained as described above is prepared.

On the other hand, a coating material consisting of tetraalkoxysilane, titanium tetraalkoxide, an inorganic coloring pigment, and a solvent as described above was prepared, and applied with a brush to the surface of the porous aluminum material.
Or spray it on with a spray gun. Tetraalkoxysilane and titanium tetraalkoxide are hydrolyzed as described above, which causes partial polycondensation and further increases in molecular weight.

Then, the solvent in the coating material evaporates and volatilizes.

In this way, curing progresses and a strong coating film is formed on the surface of the porous aluminum material.In order to accelerate this curing, it is necessary to heat the coating at a temperature of, for example, 100 to 300°C for 10 to 30 minutes after painting.
It is preferable to perform the heat treatment for about 60 minutes.

On the surface of the aluminum porous material obtained in this way, S
; A coating film made of a substance in which 02 and T i Ot are combined forms a strong coating, and since this coating film is made of an inorganic chemically stable oxide, it has excellent heat resistance, corrosion resistance, and weather resistance. It will be excellent.

When the sound absorbing material of the present invention obtained in this way is used for applications where corrosion resistance is desired mainly for the interior of the porous aluminum material, it may be immersed in a silicic acid solution after the surface coating treatment according to the present invention. Then, take it out, drain it, and let it cool for 18 minutes.
Temperatures from 0 to 200°C (one specific example is approximately 180°C)
℃ for 1 hour) when drying inside the ly! Internal corrosion resistance can be improved without causing any inconvenience to the wood.

(Example) Various physical properties were evaluated for the products obtained in the following Examples and Comparative Examples, and the evaluations were performed using the following methods.

(i) Color unevenness of colored coating film: Visually inspect the appearance of the colored coating.

i) Thickness of the colored coating film on the surface layer: Measured using an electromagnetic film thickness meter 6 (iii)'M adhesion: Adhesively press Sellotape with a width of 18 mm and a length of 50 mm onto the surface of the colored coating film. Peel it off rapidly and check the peeling condition.

(iv) Hardness: Conforms to JIS K-5400614.

(Ma) Heat resistance: The temperature was maintained at 400°C for 1 hour, and the state of the colored coating film was observed.

. (vi) Boiling water resistance: Hold in boiling tap water for 120 hours and observe the state of the colored coating.

(vli) It salt water sprayability: Maintained for 336 hours in accordance with JIS Z-2371.

(Cancer) Sound absorption characteristics: Based on the normal incidence sound absorption coefficient measurement method of JIS A-1405, measurement is performed with a rear air layer 50-.

Example 1 The following material was used as an aluminum porous material. i.e. 100μ
Both sides of a nonwoven fabric made of aluminum fibers with a diameter of about 100 yen are held between expanded metals made of aluminum (the size of each diamond-shaped opening is 4 rings on the long axis and 3 rings on the short axis) and pressed. It is molded to obtain a product with dimensions of 500-1 x 500-1.6 rings (thickness).

This material had a bulk specific gravity of 1.5 g/cm', a porosity of 44.4%, and an average pore diameter of 80 μm.

The paint to be applied to this is the product name rset = 7! made by Nichiita Research Institute Co., Ltd. TTS-100Jl 00fxj
A heartless green pigment with a particle size of 0.5 to 1.2μ.
Dainichiseika Chemical Co., Ltd. S! ! As the Green #93 10% component, 10 parts by weight of 1, which is Ti0z-ZnON1O-CoO, was added, and the mixture was mixed in a ball mill for 40 minutes to prepare a uniform colored coating liquid.

This coating liquid was applied to one side of the aluminum porous material using a spray gun [manufactured by Iwata Paint Industry Co., Ltd., W-17-IG type, nozzle diameter 1.0-Ugly] at a coating pressure of 2-Okg/c.
Spray evenly at m2. The amount of spraying is such that the thickness of the colored coating formed on the surface of the porous aluminum material after painting, drying and curing is 5 μm.

The Ceramic Force TS-100 consists of an isopropyl alcohol solution of tetraethoxysilane and titanium tetra-n-butoxide, and the nonvolatile content is 25% by weight.

After spraying the aluminum porous material sprayed with the coating solution as described above, it was kept at room temperature for 1 hour to air dry.
It was kept in a dryer at 150° C. for 1 hour to cure, and a coated product was obtained.

Table 1 shows the results of physical property evaluation conducted on this product.

Comparative Example 1 An aluminum porous material manufactured in the same manner as in Example 1 was used.

As a coating material, the standard baking material containing green pigment, which is commercially available for coating industrial machinery parts, is type melamine-alkyd 0.
Add 20 parts by weight of No. 1 petroleum synthetic resin paint thinner to 100 parts by weight of No. 1 oil paint and mix uniformly to prepare an organic P and colored paint liquid. Spray the mixture onto one side of the above porous aluminum material with a spray gun. (of the same type as used in Example 1) at a coating pressure of 2.5 kg/cm''.

This spraying is performed so that the coating thickness on the coated surface formed after application, drying, and curing is 5 μm in one spraying. Bake for a minute. In the obtained product, due to the dripping phenomenon of the colored paint that occurred in the darkness from the application stage to the curing, and the capillary phenomenon of the porous aluminum material, the paint material penetrated into the pores, and as described later in plS1.
As shown in the table, the thickness of the coating film became thinner, uneven coloring occurred, and pores were partially blocked, resulting in a decrease in sound absorption properties. The results of evaluating the physical properties of this product are shown in Table 1. When the coating was further coated in order to thicken the surface coating, the clogging of the pores became even worse.

No. table The measurement results of the sound absorption properties in Table 1 are shown in FIG.

In the figure, 1 is a curve showing the sound absorption characteristics measured for the same porous aluminum material used in Example 1, but without any coating, and 2 is a curve of the porous aluminum material coated in Example 1. Curve 3 represents the sound absorption characteristics of the porous material coated in Comparative Example 1. According to this chart, there is virtually no difference in sound absorption properties between the material of Example 1 and the unpacked aluminum porous material, but it is clear that the sound absorption properties of Comparative Example 1 have significantly changed. be.

This indicates that substantially no pore clogging occurred in the product of Example 1, while pore clogging occurred in the product of Comparative Example 1.

(Effect of the invention) The colored coated sound absorbing material of the present invention has a surface that is corrosion resistant and
In addition to being excellent in weather resistance and heat resistance, there is no change in sound absorption properties due to colored coating, and there is no color unevenness in appearance, making it extremely useful for use in indoor and outdoor soundproof walls.

[Brief explanation of the drawing]

FIG. 1 is a chart showing the sound absorption properties of the products of the present invention and comparative examples. In the figure, 1 is a curve showing the sound absorption characteristics of the same aluminum porous material used in the present invention product and comparative example product, but without surface coating, and 2 is a curve showing the sound absorption characteristics of the same aluminum porous material used in the present invention product and the comparative example product, and 2 is the curve showing the sound absorption characteristics of the same aluminum porous material used for the present invention product and the comparative example product, and 2 is the curve showing the sound absorption characteristics of the same aluminum porous material used for the present invention product and the comparative example product, 2 is the present invention JIII book Example 1 3 is a curve showing the sound absorption properties of the porous material coated in Comparative Example 1. Diagram

Claims (1)

[Claims] (1) The surface of the porous aluminum material is made of (a) tetraalkoxysilane whose alkoxy group has 1 to 5 carbon atoms, its hydrolyzate, or a partial polycondensate of this hydrolyzate; Sound absorbing material coated with a coating material containing a titanium tetraalkoxide having 1 to 5 carbon atoms, a hydrolyzate thereof, or a partial polycondensate of the hydrolyzate, (c) an inorganic coloring pigment, and (d) a solvent. material