WO2001071707A1

WO2001071707A1 - Sound absorbing film

Info

Publication number: WO2001071707A1
Application number: PCT/JP2000/001720
Authority: WO
Inventors: Mitsuo Hori; Kazuhiro Yoshikawa
Original assignee: Shishiai-Kabushikigaisha
Priority date: 2000-03-21
Filing date: 2000-03-21
Publication date: 2001-09-27

Abstract

A sound absorbing film which comprises a polymer material and, incorporated therein, an active agent which increases a dipole moment, characterized as comprising further an anti-blocking agent comprising calcium carbonate in an amount of 1 to 20 wt %. The sound absorbing film is extremely easy to handle and can be used in a variety of applications such as a precision device, for example, a sound recording/playback system using a magnetic medium such as a tape recorder, a MD recorder or a digital audio taperecorder (DAT) and a picture recording/playback system such as a video recorder or a video camera; a soundproofing cover applied for a pipe in a building; a liner for a household electrical appliance or a vehicle; and an interior material.

Description

Itoda sound absorption technical field

INDUSTRIAL APPLICABILITY The present invention is applicable to precision equipment such as a recording / reproducing apparatus using a magnetic medium such as a tape recorder, an MD recorder, and a digital audio tape recorder (DAT recorder), and a video recording / reproducing apparatus such as a video recorder and a video camera. The present invention relates to a sound-absorbing film that can be applied to a wide range of applications, such as soundproof covers applied to automobiles, other linings for home appliances and vehicles, and interior materials for homes. Background art

Conventionally, as a sound absorbing material, rock wool, glass wool, an open-cell foamed polyurethane molded product, or a material obtained by attaching a film material to the surface of such a material has been known. With these sound absorbing materials, the sound was consumed as frictional heat when passing through the fiber surface or inside the open cell while colliding, and the attenuation was measured.

In these conventional sound-absorbing materials, sound absorption was enhanced by increasing the surface resistance on the fiber surface or in the open cells. However, these sound-absorbing materials required a certain thickness in order to ensure sufficient sound-absorbing properties.

On the other hand, in precision equipment such as a recording / reproducing apparatus and a video recording / reproducing apparatus, there was a problem that a recording section inside the apparatus itself picked up noise. In order to solve this problem, it is conceivable to place a sound absorbing material inside the equipment body.However, the space for placing the sound absorbing material inside the equipment body is extremely small, and a bulky sound absorbing material with sufficient sound absorbing properties can be placed. Did not.

Also, in soundproof covers applied to pipes in buildings, sound-absorbing materials were used as one of the components of the soundproofing par. However, in order to ensure sufficient sound absorption, a certain amount of thickness is required, and when it is applied to a soundproof cover, the thickness of the soundproof cover becomes thicker, and the pipes conform to the pipe standard (size). There was a problem that there was no.

As described above, conventional sound-absorbing materials have many limitations due to the fact that they require a certain thickness in order to ensure sufficient sound-absorbing properties, and further compactness has been required.

To meet such demands, sound-absorbing films made of polymer materials formed into films have been proposed. This sound-absorbing film has a sound-absorbing mechanism that vibrates in response to the transmitted sound and consumes the energy of the sound as internal frictional resistance, and can be applied to the precision equipment and soundproof cover described above. It is a compact one. However, this sound-absorbing film had low sound-absorbing properties, and did not solve the problem sufficiently.

In addition to this technical problem of improving sound absorbing properties, this sound absorbing film, for example, in the case of a film made of a polyolefin such as polyethylene or polypropylene, has a high adhesiveness, as is well known, causing blocking. This not only impaired the workability in the production of the film and its high-order processing, but also caused various troubles such as sticking of the stacked films to each other during use.

An object of the present invention is to propose a sound-absorbing film that is compact, has sufficient sound absorbing properties, hardly causes blocking, has good workability during manufacturing and processing, and has extremely good handleability during use. Things. Disclosure of the invention

The sound-absorbing film of the present invention can be used as a recording / reproducing apparatus using a magnetic medium such as a tape recorder, an MD recorder, or a digital audio tape recorder (DAT recorder), or a video recording / reproducing apparatus such as a video recorder or a video camera. It can be applied to a wide range of applications, such as precision equipment, soundproofing pars applied to piping in buildings, linings of home appliances and vehicles, and interior materials of houses.

This sound-absorbing film is a film in which an active ingredient that increases the amount of dipole moment is blended with a polymer material, and contains an antiblocking agent composed of calcium carbonate at a ratio of 1 to 20% by weight. It is characterized by the following. Examples of the polymer material constituting the sound absorbing film include polyvinyl chloride, polyethylene, chlorinated polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polyvinylidene fluoride, polyisoprene, polystyrene, and styrene. 1-butadiene-acrylonitrile copolymer, styrene-acrylonitrile

1. Ryl copolymer, acrylonitrile-butadiene rubber (NBR), styrene butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), isoprene rubber (IR), and other polymer materials, blends of these, etc. Can be mentioned.

When sound collides with a film composed of these polymer materials, vibration is generated. At this time, a displacement occurs in the dipole 12 existing inside the film 11 as shown in FIG. The displacement of the dipoles 12 means that each dipole 12 in the film 11 rotates or shifts in phase.

It can be said that the arrangement state of the dipoles 12 inside the film 11 before the sound energy is applied as shown in FIG. 1 is in a stable state. However, as shown in Fig. 2, when energy is applied to the film by the impact of sound and the dipoles 12 existing inside the film are displaced, each dipole 1 2 inside the film 11 becomes unstable. And each dipole 12 tries to return to the stable state shown in FIG.

At this time, energy is consumed. It is thought that excellent sound absorption is produced through the displacement of the dipole inside the film, the energy consumption due to the dipole restoring action, and the generation of frictional heat on the film surface.

When considering such a sound absorbing mechanism, the sheet resistance per unit area of the film and the amount of the dipole moment inside the film 11 as shown in Figs. It can be seen that it is greatly involved in sound absorption. According to the experiments by the present inventors, the larger the amount of the dipole moment in the film 11 is, the higher the performance of absorbing the sound energy (sound absorption) of the film 11 is. I understand.

The amount of the dipole moment inside the film composed of the above-mentioned polymer material varies depending on the type of the polymer material. The same polymer material for the film Even if is used, the amount of dipole moment generated inside the film changes depending on the temperature when the sound is applied and the frequency of the sound. The amount of dipole moment also changes depending on the magnitude of the sound energy applied to the film. For this reason, it is desirable to select and use a polymer material that has the largest amount of dipole moment in consideration of the temperature, frequency, energy level, etc. when applied as a sound absorbing material for a certain application. No.

However, when selecting the polymer material that constitutes the film, not only the amount of dipole moment inside the film, but also the handling properties, moldability, availability, etc., according to the application and use form of the sound absorbing material. It is desirable to consider ease, temperature performance (heat resistance and cold resistance), weather resistance, and price.

In the sound absorbing film of the present invention, an active ingredient capable of dramatically increasing the amount of dipole moment in the film is incorporated in the polymer material constituting the film. The active component is a component that dramatically increases the amount of dipole moment inside the film. The active component itself has a large dipole moment, or the active component itself has a small dipole moment. It means a component that can dramatically increase the amount of dipole moment inside the film by blending the active component.

For example, the amount of dipole moment generated inside film 11 under the given temperature conditions, sound frequency, and energy level is the same as shown in Fig. 3 by adding the active ingredient to this. Under these conditions, the amount will increase by a factor of three or ten. Along with this, the energy consumption due to the dipole restoring action when the above-mentioned energy is added will also increase dramatically, and the sound absorption effect due to the friction of the material surface will be added, and the prediction will be much farther. It is considered that a sound absorption effect exceeding this will occur.

Examples of active ingredients that induce such effects include N, N-dicyclohexylbenzothiazyl-2-sulfenamide (DCHBSA), 21-mercaptobenzothiazole (MBT), dibenzothiazyl sulfide (MBTS), and the like. N-cyclohexinolevenzothiazirulu 2-sulfenamide (CBS), N-tert

'―2-sulfenamide (BBS), N-oxyxeti One or more compounds selected from compounds containing a benzothiazyl group, such as' _2-sulfenamide (OBS), N, N-diisopropylbenzothiazyl-2-sulfenamide (DPBS),

Benzotriazole with an azole group bonded to the benzene ring as the mother nucleus, and a phenyl group bonded to the nucleus 2— {2,1-hydroxy-13 '— (3, “, 5”, 6 ”tetrahydrophthalimide Methyl) 1-5'-Methylphenyl} Benzotriazole (2HPMMB), 2- {2'-Hydrox-xy 5'-Methylphenyl} Benzotriazole (2HMPB), 2- {2'-Hydrox-oxy 1 3'-t-butyl 5 '—methinolephen 2} 1-5—black benzotriazo mono (2 HBMP CB), 2— {2'—hide mouth 3', 5 ' One or more compounds selected from compounds having a benzotriazole group such as benzotriazole (2-HDBPCB)

One or more compounds selected from compounds having a diphenyl acrylate group, such as ethyl 2-cyano 3, 3-diphenyl acrylate;

Alternatively, a compound having a benzophenone group, such as 2-hydroxy-1-methoxybenzophenone (HMBP) and 2-hydroxy-4-methoxybenzophenone-5-snorrephonic acid (HMBPS). One or more selected ones can be mentioned.

The amount of the active ingredient is preferably 10 to 300 parts by weight based on 100 parts by weight of the polymer material. For example, if the amount of the active ingredient is less than 10 parts by weight, the effect of adding the active ingredient to increase the amount of the dipole moment cannot be obtained, and the amount of the active ingredient is 300 parts by weight. If the ratio exceeds, it may not be fully compatible.

In deciding the active ingredient contained in the polymer material, it is preferable to take into consideration the easiness of the compatibility between the active ingredient and the polymer material, that is, the SP value, and to select one having a similar value.

The amount of the dipole moment in the active ingredient varies depending on the type of the active ingredient, similarly to the amount of the dipole moment inside the film. Also, even if the same active ingredient is used, the temperature at the time when sound energy is applied causes the film to be generated inside the film. The amount of the dipole moment changes. Also, the amount of dipole moment changes depending on the magnitude of the sound energy applied to the film. For this reason, it is desirable to select and use the active component having the largest amount of dipole moment in consideration of the magnitude of temperature and energy when applied as a sound absorbing material for a certain application.

The sound absorbing film also has an anti-blocking agent made of calcium carbonate.

It is contained at a ratio of 1 to 20% by weight. The calcium carbonate used as the anti-blocking agent may be either heavy calcium carbonate or light calcium carbonate. The shape of the calcium carbonate is arbitrary, such as spherical, cubic, spindle-shaped, and elliptical, and may be appropriately determined according to the type and use of the above-described polymer material. The fineness of the carbonated calcium is also arbitrary, and may be appropriately determined according to the type and use of the above-mentioned polymer material, but is preferably in the range of 0.01 to 10 / im. Desirably.

This calcium carbonate is contained in a proportion of 1 to 20% by weight. When the content of calcium carbonate is less than 1% by weight, it is not possible to sufficiently prevent the booking, and when the content is more than 20% by weight, the transparency of the film is impaired or white powder is generated. Troubles such as failures to occur.

The sound-absorbing film of the present invention is obtained by mixing the above-mentioned polymer material with the above-mentioned anti-blocking agent comprising the above-mentioned active ingredient and calcium carbonate, and further adding a corrosion inhibitor or a dye as necessary. Can be obtained by molding into a film. The polymer material and the active ingredient are blended, and the blend is formed into a film by a conventionally known molding method.

The sound absorbing film thus obtained has excellent sound absorbing properties that cannot be predicted from the sound absorbing properties of conventional sound absorbing films, but the thinner the performance, the more sensitive it is to sound. Vibrates in response to excellent sound absorption. In addition, since this sound absorbing film contains an anti-blocking agent made of carbonic acid lucium, the workability in the production and higher-order processing of the film is good. Various troubles such as sticking of the films that have been set are unlikely to occur. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram showing dipoles inside a film.

Figure 2 is a schematic diagram showing the state of the dipole inside the film when vibration energy is applied.

FIG. 3 is a schematic diagram showing a dipole state inside a film when an active ingredient is blended.

FIG. 4 is a graph showing the normal incidence sound absorption coefficient of each film of Examples 1 and 2 and Comparative Examples 1 to 3. Example

Table 1 (% by weight)

The components blended in the proportions shown in Table 1 above were kneaded by a kneading roll machine, and then hot pressed by a press machine to produce a sound absorbing film (0.2 mm thick).

The obtained films of Examples 1 and 2 and Comparative Examples 1 to 3 were evaluated for sound absorption and blocking.

Measurement of normal incidence sound absorption coefficient Each of the films obtained in Examples 1 and 2 and Comparative Examples 1 to 3 was punched into a test piece having a size of 1101.4 mmΦ (for A tube) and 49πιπιΦ (for 、 tube). Using a vertical incidence sound absorption coefficient measuring device (Al17C, manufactured by Ono Sokki Co., Ltd.), the vertical incidence sound absorption coefficient of tube A (100 to 2000 Hz) and tube B (800 to 5000 Hz) was measured automatically. result of the base surface product connecting the graph line and graphs of the measurement results from the graph, determined whether strikes many ^_0/0 of the total area of the graph, indicated this was the absorption area ratio. the results are shown in FIG 4 .

From FIG. 4, it was confirmed that each of the films of Examples 1 and 2 and Comparative Examples 1 to 3 had excellent sound absorbing properties.

Procking evaluation

For each of the films of Examples 1 and 2, and Comparative Examples 1 to 3, blocking was evaluated by tentacles. In Table 2, 〇 indicates that the film surface was loose and no blocking occurred, △ indicates that the film surface was slightly sticky, and ベ indicates that the film surface was sticky. X indicates that locking occurred.

Table 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2

X X X Δ 〇

Claims

Scope of word blue

1. A film in which an active ingredient that increases the amount of dipole moment is added to a polymer material, and contains an antiblocking agent composed of carbonated calcium at a ratio of 1 to 20% by weight. A sound absorbing film characterized by the following.

2. The sound-absorbing film according to claim 1, wherein the active ingredient is blended in an amount of 10 to 300 parts by weight with respect to 100 parts by weight of the polymer material.

3. The active ingredient is one or more selected from a compound having a benzothiazyl group, a compound having a benzotriazole group, a compound having a diphenyl atalylate group, and a compound having a benzophenone group. The sound-absorbing film according to claim 1, wherein: