JPS62158777A - Panel damping material - Google Patents

Abstract

PURPOSE:To obtain a panel damping material which has excellent damping properties, good workability in applying to a panel to be damped and good adhesion to the panel, and also has excellent sound insulating properties, by incorporating two kinds of inorganic filters having different particle diameters into a resin. CONSTITUTION:A panel damping material obtained by incorporating at least 30pts.wt. inorganic fillers (e.g., calcium carbonate, talc, silica sand, silica, or iron oxide) into 100pts.wt. of one or more resins (e.g., an epoxy resin, a xylene resin, or a PVC). The inorganic fillers shall consist of two kinds of fillers comprising a powdered filler of which at least 90% passes through a 200-mesh sieve and a particulate filler of which 10% or less passes through a 200-mesh sieve, the weight ratio of the former to the latter being 10:90-90:10. As compared with the case in which either a powdered filler or a particulate filler is used alone, the damping properties can be improved, the application to a panel to be damped can be facilitated, even the incorporation of larger quantities of fillers will not impair the conformability to the shape of the panel, and the sound insulating properties can also be improved remarkably.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention has excellent vibration damping characteristics, and has good workability when applied to a damped panel and good adhesion to the damped panel. The present invention relates to a panel damping material that also has excellent sound insulation properties.

(Prior art) Conventionally, in panel structures such as vehicle bodies such as automobiles and railway vehicles, prime movers such as engines and motors, housings of electrical equipment, and ducts for flow and body axis, panel surfaces have been A damping material is placed in close contact with the

Such panel vibration damping materials are required to have a large composite yarn loss coefficient (η) [Noise Countermeasures Handbook, edited by Japan Acoustic Material μ Association, p. 21] evaluated in a composite system with the damped panel. There is. In order to obtain a panel damping material with a large composite yarn loss coefficient (η), the material needs to be an excellent material as a damping material and also be able to be easily adhered to the damped panel. For example, if the panel to be damped is a car floor panel,
It has a complex surface shape by adding beads, embossing, curved surfaces, etc. If the surface becomes complex in this way, the damping material will not be able to follow the shape of the damping material, and the adhesion to the damping panel will be insufficient, resulting in gaps being formed between the panel and the damping material, or easily peeling off. If this is the case, the vibration damping characteristics will deteriorate, which is not preferable. Further, if it takes a considerable amount of time to uniformly adhere the damping material to the surface of the damping panel, there will be problems in terms of work.

Furthermore, since such a damping material is used to cover the surface of a panel, it is often expected to have a sound insulation function in addition to vibration damping. Sound insulation properties are expressed by transmittance or transmission loss, which is the ratio of the sound energy transmitted through the material to the sound energy incident on the material. It is a well-known fact that the more the material, the better the sound insulation properties. In other words, it is sufficient to apply a thick material with a high specific gravity. However, increasing the thickness of the covering material is not preferable due to space constraints, and there is a demand for a sound insulating material that is made of a material with as high a specific gravity as possible and can be applied thinly.

Under such circumstances, for example, vibration damping materials for 70 Abanel in automobiles have been made using thermoplastic resins such as asphalt (for example, manufactured by Nippon Tokushu Toyo Co., Ltd. under the trade name "Melsheet"). Also, engineering? Products containing thermosetting resins such as xyl resin (for example, patent application 1986-210)
A large number of vibration damping materials such as No. 55) have been proposed, each of which has a different temperature range in which it exhibits its damping effect.

Such automobile damping materials are manufactured using thermosetting paint for painting the car body in the car manufacturing process, so the car body is heated to a temperature of 140°C or higher for 80 minutes or more to harden the paint film. undergo heating. These damping materials utilize this heat to adhere to the vehicle body panels. When a worker temporarily places the damping material sheet on the vehicle body panel, the sheet melts due to the heat and its own weight is removed. It is a vibration damping material that is excellent not only in vibration damping performance but also in terms of adhesion and workability, as it follows the complex shape of the damped panel and is fused, bonded, and hardened.

(Problems to be Solved by the Invention) However, in order for conventional damping materials to satisfy the shape followability of the damped panel, the heating temperature ( 140 for cars
For "C grade)", the material must have sufficient fluidity, and generally, as the amount of filler mixed increases, the shape followability of the damping material deteriorates, so it is necessary to use a filler that can be mixed with the resin naturally. There was a limit to the total amount.

In the case of non-constrained damping material, the loss coefficient (tan δ) of the damping material
.

[
Noise Countermeasures Handbook, edited by Japan Acoustic Materials Association, No. 448
page〕. The mixing effect of fillers can be expected to increase the elastic modulus of the material and further increase its specific gravity. Therefore, in order to improve vibration damping and sound insulation properties, it is possible to increase the amount of conventional fillers contained in vibration damping materials. However, there has been a problem in that the shape followability is decreased, and in some cases, the fusion strength and adhesive strength are decreased, resulting in a loss of vibration damping properties.

(Means for solving the problem) This invention is achieved by blending two or more types of inorganic fillers with different particle sizes with one or more types of resin that can be used as a resin for vibration damping materials. The object of the present invention is to provide a panel vibration damping material that has excellent not only vibration damping properties but also sound insulation properties without impairing shape followability, that is, adhesion, to a damped panel.

The resin used in this invention can be a thermoplastic resin, a thermosetting resin, or a combination of two or more thereof. As a vibration damping material, resin is expected to have a vibration damping function that utilizes its viscoelastic properties, and since it covers the damped panel, it improves rigidity and reduces vibration amplitude due to a considerable increase in mass. There is a reduction function. It is well known that this function and the viscoelastic physical property region of the resin are closely related. For example, a resin region with a large vibration damping function has a glass transition region between a glassy region and a rubbery region. Alternatively, the flow region is at a higher temperature than the rubber-like region, and the amplitude reduction function due to improved rigidity is most suitable for the region where the elastic modulus of the resin is high, that is, the glass-like region. Naturally, the effects of increasing the number of pawnbrokers will be felt regardless of the field. When selecting a resin, select a resin that has a viscoelastic region that can exhibit the necessary function within the temperature range in which a damping effect is expected, and is not influenced by the type of resin. This also includes resins whose viscoelastic properties have been modified by adding, for example, a softening agent.

The damping material of this invention uses the heating history of the damping panel to conform to complex shapes, and in order to adhere tightly, the resin must exhibit fluidity at the highest temperature the damping material is exposed to. There is a need. In other words, the resin used in this invention has a softening temperature below the maximum temperature that the damping material is exposed to (Rikagaku Dictionary, Co., Ltd.).
For thermosetting resins, it is the softening temperature before curing. In the present invention, it is preferable that the softening temperature of one or more resins is 140° C. or lower.

Furthermore, since the damping material of the present invention is formed into a sheet and is fused or adhered to the damping panel, it is preferable that the resin used for the damping material be self-adhesive. When using a resin with poor adhesion, you can apply a known adhesive, hot-melt adhesive, etc. to the surface of the damping material formed into a sheet or the surface of the damping material panel, or apply it to the resin used. A tackifier such as rosin resin, petroleum resin, etc. may be added. Typical examples of these resins include epoxy resin, xylene resin, phenolic resin,
Examples include asphalt, polyvinyl chloride, ethylene vinyl acetate copolymer, polyamide, and polyester.

In this invention, the inorganic filler may be either granular or powdery, including mineral fillers such as calcium carbonate, talc, clay, silica sand, and silica, as well as metal fillers such as lead, lead oxide, and iron oxide. However, it is necessary to use two types of fillers: a powder filler with a capacity of 90 inches or more that passes through 200 meshes, and a granular filler with a capacity of 10% or less that passes through 200 meshes. The powdery filler and the granular filler may be used alone or in combination, and the powdery and granular fillers may be of the same type.

Next, the blending amount of the above inorganic filler is such that the total amount of the granular and powder fillers is 30 parts by weight or more per 100 parts by weight of the resin, and the granular and powder fillers are the total amount of the inorganic filler. Of these, at least 10 or more shall be included.

If the total amount of the inorganic fillers is less than aomm part, it is unsuitable because the filling effect of increasing the elastic modulus of the vibration damping material is hardly obtained. Further, the maximum total amount of inorganic fillers can be blended up to the maximum amount that can be physically mixed, which can be calculated from the oil absorption determined by the type of filler. However, as the total amount of inorganic filler increases, the ability to follow the shape of the damped panel tends to deteriorate, so an upper limit should be set depending on the complexity of the shape of the damped panel to which the damping material is applied. is preferred. For example, when applied to an automobile floor panel, the upper limit is preferably about 500 parts by weight. Furthermore, if the powdery filler is less than 10% by weight with respect to the total amount of inorganic fillers, the vibration damping properties will deteriorate;
On the other hand, if the particulate filler is less than 10's by weight, it is unsuitable because the shape followability, that is, the adhesion is reduced.

The panel vibration damping material of the present invention is usually used as a sheet (an uncured sheet if a thermosetting resin is used) formed from a composition to a desired thickness using an extruder or sheeting roll, By simply placing the sheet temporarily on the damped panel, the sheet melts using the heat applied to the panel structure for the purpose of drying or curing the paint film, and its own weight creates a controlled material with a complex surface shape. Even in the case of a vibration panel, the material follows the shape of the vibration panel and is then fused or bonded and hardened, so it is a panel vibration damping material that has excellent workability and adhesion when attached to the vibration damped panel.

(Function) The panel vibration damping material of the present invention exhibits excellent vibration damping properties and shape/followability due to the synergistic effect of the powdery filler and granular filler blended into the resin.

Although a vibration damping material containing only a powder filler mixed with a resin can improve the damping characteristics to some extent, the shape followability deteriorates rapidly as the amount of filler is increased.

Furthermore, a damping material containing only a granular filler does not significantly deteriorate shape followability, but its damping properties are unsatisfactory. On the other hand, in the panel vibration damping material of the present invention, the powdery and granular fillers form a complicated filling form, and in the region where the resin modulus is high near the practical temperature of the vibration damping material, the fillers and fillers and The vibration damping properties are improved by increasing the frictional resistance between the filler and the resin, and in the flow region above the softening temperature of the resin, the frictional resistance between the resin and the filler is reduced by adding a part of the granular filler. It is thought that this will lead to a rapid decrease in shape followability. Furthermore, even when a large amount of filler is mixed, the specific gravity of the mixed material can be increased without impairing the shape followability, so the sound insulation properties can be improved.

(Example) This invention will be explained by the following examples and comparative examples.

The method for evaluating the damping characteristics of the panel damping material and the ability to follow the shape of the damped panel is as follows.

Evaluation method 1 [Vibration damping characteristics] A panel damping material with the same length and width and a thickness of 4 mm was placed on one side of a general automobile exterior panel A plate with a length of 250 mm, a width of 1011 mm, and a thickness of QJIm. Thereafter, heating is performed at 140° C. for 80 minutes to obtain a fused or bonded, hardened test piece for evaluating damping characteristics. This test piece was measured using the cantilever resonance method to obtain the composite image loss coefficient (η) at the secondary resonance point of bending vibration.
was measured in an air-conditioned room at 26°C.

Evaluation method 2 [Shape followability] As shown in Fig. 1, two steel plates 2 are fixed horizontally on a support base 3 with a parallel spacing l = 80 fl, and on top of that, a plate with a length l, )xoojn, A panel damping material 1 with a width (W) of 3 o IIm and a thickness of 1) 4 is placed and heated at 140'c for 80 minutes. After cooling down to the room, the sag m (a) of the panel damping material was measured as shown in FIG.

The sagging ml (d) for following the shape of an automobile floor panel and achieving sufficient adhesion was 2.5 u or more.

Example 1 Epoxy resin (manufactured by Yuka Shell Epixy Co., Ltd., trade name [
1001J) 85 Juhirobe, epoxy resin (manufactured by Yuka Ciel Egoxy Co., Ltd., trade name: ``Epicoat 8'')
71J) were mixed for 30 minutes in a Banbury mixer heated to 1500°C to fully dissolve them. The softening temperature of this mixed resin was 45°C or less. After cooling this to 60°C, dicyandiamide 8 electromagnetic part, 8-(p-chlorophenyl)-1,1
- dimethyl urea quadruplex, and talc (Kunimine Kogyo Co., Ltd. tllll, product name "TAJ, 2" as a powder filler)
00 mesh passing 99 inches or more) 150 weight part, silica sand (manufactured by Yotetsu Mining Co., Ltd., product name "Nikko 6
No. 150 (8% or less passing through 200 mesh) was added and kneaded at 60°C for 1 hour. Next, it was formed into a sheet with a thickness of 4 μm using a calendar roll. The results of evaluating this sheet according to evaluation methods 1 and 2 are shown in the first
Shown in the table.

Example 2 Among the formulations shown in Example 1, the powdered filler talc (rT
AJ) was changed to 270 parts by weight, and the granular filler silica sand (Nikko No. 6) was changed to 80 parts by weight. Comparative Example 1 Among the formulations shown in Example 1, no granular filler was added.
Sheets were obtained in the same manner as in Example 1, except that the powdered filler talc ((TAJ) was changed to 800 parts of phosphorous) in increasing thickness.

The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Example 8 Xylene resin (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Nikanol HHJ") 70-layer plate part, epoxy resin (manufactured by Yuka Shell Epixy Co., Ltd., trade name "Epicor" 1004J)
80 parts by weight were mixed in a Banbury mixer heated to 150"C for 45 minutes to fully dissolve the resin. The softening temperature of this mixed resin was 50°C or less.
After cooling to 0°C, the same curing agent as in Example 1 was added to the same fjj.
In addition, as a powder filler, lead oxide powder (
Added silica sand (manufactured by Yotetsu Mining Co., Ltd., trade name "Nikko No. 5", 200 mesh passed 2 inches or less) as a granular filler, The mixture was kneaded for 1 hour at a temperature of 60'C. Next, a sheet with a thickness of 4 mm was obtained using a calendar roll. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Example 4 Among the formulations shown in Example 8, the powder filler was talc (manufactured by Kunimine Kogyo Co., Ltd., trade name r-G T A, J, 20).
A sheet with a thickness of 4M was obtained in the same manner as in Example 8, except that the weight of the granular filler silica sand ("Nikko No. 5") was changed to 250 parts by weight in the 250 parts (0 mesh passing 99 inches or more). . The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Comparative Example 2 All of the formulations shown in Example 3 were the same except that no particulate filler was added, and in the same manner as Example 8,
A sheet with a thickness of 4 mm was obtained. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Among the formulations shown in Example 8, the powdered filler was calcium carbonate (manufactured by Nitto Funka Kogyo Co., Ltd., trade name: NS-400J).
, 15 parts by weight of granular filler (passed through 20G mesh, 99 inches or more), 1 part by weight of metal lead particles (passed through 200 mesh, 5 inches or less)
5 parts by weight, and the thickness was 4f in the same manner as in Example 8.
I got a sheet of i. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Comparative Example 3 Among the formulations shown in Example 8, the powdered filler calcium carbonate (rNs+400J) was changed to the 5-type dish part, and the same metal lead particles used in Example 5 were changed to the 5-layer part, In the same manner as in Example 8, a 4-thick sheet was obtained. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Example 6 Straight asphalt (manufactured by Nippon Oil Co., Ltd., product name:
60 parts by weight of straight asphalt (manufactured by Nippon Oil Co., Ltd., product name "0-2ONY Asphalt"), 10ffiJIt parts, flattened asphalt (manufactured by Nippon Oil Co., Ltd., product name "0-2ONY Asphalt"),
ao-4osp blown asphalt) J) 30 stacked parts were mixed for 30 minutes in a Banbury mixer heated to 150°C. The softening temperature of this mixed asphalt is 65
It was below ゛C. Thereafter, while maintaining the temperature at 150°C, 80 parts by weight of powdery filler talc (rGTAJ) and 100 parts by weight of granular filler silica sand ("Nikko No. 6") were added and kneaded for 1 hour. Next, a sheet with a thickness of 4 u was obtained using a calender roll. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

, Example 7 Among the formulations shown in Example 6, the powdered filler talc ("G
10 parts by weight of granular filler silica sand (Nikko 6)
A sheet with a thickness of 4fi was obtained in the same manner as in Example 6, except that the amount of 100% by weight was changed to 90 parts by weight. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Comparative Example 4 Among the formulations shown in Example 6, no powder filler was added,
A sheet with a thickness of 4 silk was obtained in the same manner as in Example 6 except that the granular filler silica sand (Nikko No. 6) was changed to 100 parts by weight. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Example 8 50 parts by weight of polyvinyl chloride (manufactured by Nippon Zeon Co., Ltd., trade name "Zeon 121"), plasticizer dioctyl phthalate)
Add 50 parts by weight and a small amount of stabilizer and heat to 1 at 105"C.
The mixture was mixed in a Banbury mixer for an hour. The softening temperature of this mixed resin was 60°C or less. Powdered filler clay (manufactured by Kunimine Kogyo Co., Ltd., trade name "Kunimine Clay", passing through 200 meshes of 90 inches or more)5.
0 parts by weight and 50 parts by weight of granular filler silica sand (Nikko No. 5) were added, and the mixture was kneaded in an extruder heated to 150°C and pelletized. Furthermore, a sheet having a thickness of 4IIjI was obtained using a hot roll. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Comparative Example 5 A sheet with a thickness of 4 mm was obtained in the same manner as in Example 8 using the same formulation as in Example 8 except that no powdery filler was added. The results of evaluation using evaluation methods 1 and 2 are shown in Table 1.

Example 9 To 100 parts by weight of ethylene vinyl acetate copolymer (manufactured by Mitsubishi Yuka Co., Ltd., trade name "Yukalon Eva EvA50M"),
100 parts by weight of powdered filler talc (rGTAJ) and 100 parts by weight of granular filler silica sand (Nikko No. 6 J) were added and kneaded in an extruder heated to 180°C to form pellets. The softening temperature was 50° C. or less.Furthermore, a sheet with a thickness of 4 mm was obtained using a hot roll.Table 1 shows the results of the evaluation using evaluation methods 1 and 2.

Next, the transmission loss of the sheets of Example 8 and Comparative Example 2 was measured by the reverberation chamber method, and the sheet of Example 1 had better sound insulation characteristics by 2.6 dB than the sheet of Comparative Example 2 at a frequency of 500 Hz. showed that.

(Effects of the Invention) Since the panel vibration damping material of the present invention uses a mixture of appropriate amounts of powdered filler and granular filler as the inorganic filler, the damping material contains only powder or granular filler. It has improved vibration damping characteristics and shape followability compared to the previous model, and has high vibration damping characteristics that are easy to install on the damped panel.
Even when a large amount of filler is mixed, the shape followability is not impaired, so it has the advantage of being a vibration damping material with a high specific gravity and significantly improving the noise characteristics.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the state of the panel damping material before heating in evaluation method 2, and FIG. 2 is a sectional view showing the state of the panel damping material after heating in evaluation method 2. 1... Panel damping material (before heating) 2... Steel plate 8... Support base 4... Panel damping material (after heating) Patent applicant Nissan Motor Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. One or more types of resin and 30 parts by weight or more of an inorganic filler per 100 parts by weight of the resin are mixed,
The above-mentioned inorganic filler consists of two types: a powder filler with 90% or more passing through 200 mesh, and a granular filler with 10% or less passing through 200 mesh. ) is 10:90 to 90:10.