JPH0635573B2 - Sheet-shaped panel damping material with excellent damping and sound insulation characteristics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has excellent vibration damping properties, and has good workability for application to a vibration-damped panel and good adhesion to the vibration-damped panel. The present invention also relates to a panel damping material having excellent sound insulation characteristics.

(Prior Art) Conventionally, in a panel structure such as a vehicle body of an automobile or a railroad vehicle, a prime mover such as an engine or a motor, a housing of an electric device, a duct for fluid transportation, etc., a damping material is applied to the panel surface for the purpose of reducing vibration. Are closely attached.

Such a panel damping material is required to have a large composite system loss coefficient (η) evaluated on the composite system with the vibration-damped panel [Noise Countermeasure Handbook, edited by Japan Society for Acoustic Materials, page 21]. . In order to obtain a panel damping material having a large composite loss factor (η), it is necessary that the material is an excellent damping material and that it can easily adhere to the panel to be damped. For example, when the vibration-damped panel is an automobile floor panel, it has a complicated surface shape due to the addition of beads, embossments, curved surfaces, and the like. When the surface becomes complicated in this way, the shape-following property of the damping material is poor, the adhesion between the panel to be damped becomes insufficient, and a gap is formed between the panel and the damping material, and it easily peels off. If so, it is not preferable because the vibration damping property is deteriorated. Further, if it takes a great deal of time to uniformly attach the damping material to the surface of the vibration-damped panel, there is a problem in working.

Further, since such a vibration damping material is used to cover the surface of the panel, it is often expected that a sound insulation function is expected together with the vibration damping. The sound insulation property is expressed by the transmittance or the transmission loss, which is the energy ratio of the sound transmitted through the material to the energy of the sound incident on the material. It is a well known fact that the higher the value, the better the sound insulation characteristics. That is, a material having a large specific gravity may be applied thickly. However, thickening the coating material is not preferable because of space limitations, and there is a demand for a sound insulating material that can be applied thinly with a material having a large specific gravity.

Under such a situation, conventionally, for example, as a damping material for a floor panel of an automobile, one containing a thermoplastic resin typified by asphalt (for example, manufactured by Nippon Special Coating Co., Ltd.,
(Product name “Melsheet”) In addition, those containing thermosetting resin such as epoxy resin as a component (for example, Japanese Patent Application No. 60-2105).
No. 5), etc., a large number of vibration damping materials having different temperature ranges exhibiting a vibration damping effect have been proposed. Since such a vibration damping material for automobiles uses a thermosetting paint for coating the vehicle body in the automobile manufacturing process, the vehicle body is heated at a temperature of 140 ° C. or more for 30 minutes or more due to curing of the coating film. Receive. These damping materials use this heat to adhere to the vehicle body panel, and the worker only temporarily puts the damping material sheet on the vehicle body panel, and the sheet melts due to the heat and only the self-weight is applied. Since it follows the complicated shape of the vibration-damped panel and is fused, bonded, or cured, it is a vibration-damping material excellent not only in vibration damping but also in adhesion and workability.

(Problems to be Solved by the Invention) However, since the conventional damping material satisfies the shape-following property with respect to the vibration-damped panel, the heating temperature received after the vibration-damping material is temporarily placed on the vibration-damped panel ( 140 for cars
At about (° C), the material must have sufficient fluidity, and generally the shape-following property of the damping material deteriorates as the amount of filler mixed increases, so the total amount of filler that can be naturally mixed with the resin There was a limit.

It is a well-known fact that in the case of non-restraint type vibration damping material, not only the loss coefficient (tan δ) of the vibration damping material is large, but also the elastic modulus is large, so that good damping characteristics can be obtained. Noise Countermeasure Handbook, edited by Japan Society for Acoustic Materials, No. 443
page〕. As the mixing effect of the filler can be expected to increase the elastic modulus of the material and further increase the specific gravity, in order to improve the vibration damping properties and sound insulation properties, if the conventional filler contained in the damping material is added in an increased amount, However, there is a problem in that the shape following property is deteriorated, and in some cases, the fusion force and the adhesive force are deteriorated, and as a result, the vibration damping property is impaired.

(Means for Solving Problems) The present invention is achieved by mixing two or more kinds of inorganic fillers having different particle sizes with one or more kinds of resins that can be used as a resin for a vibration damping material. The present invention provides a panel damping material which is excellent not only in vibration damping characteristics but also in sound insulation characteristics without impairing the shape following property with respect to the vibration-damped panel, that is, the adhesiveness.

The resin used in the present invention may be a thermoplastic resin, a thermosetting resin, or a combination of two or more thereof. The expected effects of resin as a damping material are the vibration damping function that uses its viscoelastic properties, and the vibration damping panel is covered to improve the rigidity and decrease the vibration amplitude due to a considerable increase in mass. There is a function. It is known that this function and the viscoelastic property region of the resin are closely related to each other. For example, the resin region having a large vibration damping function is a glass transition region between the glass-like region and the rubber-like region, Alternatively, the region where the resin has a high elastic modulus, that is, the glass-like region is the most suitable for the amplitude reducing function by improving the rigidity, which is a flow region corresponding to a temperature higher than the rubber-like region. The effect of increasing the mass is naturally exhibited regardless of the region. In selecting a resin, a resin having a viscoelastic region capable of exhibiting a required function in a temperature range where a vibration damping effect is expected is selected, and is not influenced by the type of resin. Further, for example, a resin in which a viscoelastic property is modified by adding a plasticizer or the like corresponds to this.

The vibration damping material of the present invention follows the complicated shape by utilizing the heating history received by the vibration-damped panel, so that the resin exhibits fluidity at the maximum temperature that the vibration damping material receives in order to adhere to it. There is a need. That is, the resin used in the present invention needs to have a softening temperature (Rikagaku Dictionary, Iwanami Shoten Co., Ltd.) at a temperature equal to or lower than the maximum temperature that the damping material receives, and a thermosetting resin has a softening temperature before curing. And in this invention, it is preferable that the softening temperature of 1 type or 2 types or more of resin is 140 degreeC or less.

Further, since the damping material of the present invention is formed into a sheet and is fused or adhered to the panel to be damped, it is preferable that the resin used for the damping material is self-adhesive. When using a resin having poor adhesiveness, the surface of the damping material formed into a sheet shape, or the surface of the damping material panel, a method of applying a known adhesive, a hot melt adhesive or the like, or a resin to be used, A tackifier such as a rosin resin or a petroleum resin may be added. Typical of these resins are epoxy resin, xylene resin, phenol resin,
Examples include asphalt, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyamide and polyester.

In the present invention, as the inorganic filler, in addition to calcium carbonate, talc, clay, minerals such as silica sand, lead, and metal oxides such as lead oxides, both granular and powdery can be used. It is necessary to use two kinds of filler, that is, a powdery filler having a passage rate of 200 mesh of 90% or more and a granular filler having a passage rate of 200 mesh of 10% or less. The powdery filler and the granular filler are used individually or as a mixture of a plurality of them, and the powdery and granular fillers may be of the same type.

Next, the compounding amount of the above-mentioned inorganic filler is 30 parts by weight or more as the total amount of the granular and powdery fillers relative to 100 parts by weight of the resin, and the granular and powdery fillers are the total amount of the inorganic fillers. Of these, at least 10% by weight is contained.

If the total amount of the above-mentioned inorganic fillers is less than 30 parts by weight, the filling effect of increasing the elastic modulus of the vibration damping material is hardly obtained, which is unsuitable. Further, the maximum total amount of the inorganic fillers that can be physically mixed can be calculated from the oil absorption determined by the type of the fillers. However, as the total amount of inorganic filler increases, the shape followability with respect to the shape of the damping panel tends to deteriorate, so the upper limit is set according to the complexity of the damping panel shape to which damping material is applied. Preferably. For example, when applied to a floor panel of an automobile, it is preferable that the upper limit is about 500 parts by weight. Further, when the powdery filler is less than 10 wt% with respect to the total amount of the inorganic filler, the damping property is deteriorated, while when the granular filler is less than 10 wt%, the shape-following property, That is, it is not suitable because the adhesiveness decreases.

The panel vibration-damping material of the present invention is usually used as a sheet formed into a desired thickness with an extruder or a sheeting roll (an uncured sheet when a thermosetting resin is used), Just by temporarily placing it on the vibration-damped panel, the sheet is melted using the heat applied to the panel structure for the purpose of drying and curing the coating film, for example. Even in the vibration panel, the panel vibration damping material follows the shape of the vibration panel, and then is fused, adhered, or cured, so that it is a panel vibration damping material having excellent workability and adhesion to the vibration-damped panel.

(Operation) The panel vibration damping material of the present invention exhibits excellent vibration damping characteristics and shape conformability due to the synergistic effect of the powdery filler and the granular filler compounded in the resin. The damping material in which only the powdery filler is mixed with the resin can improve the damping characteristics to some extent, but the shape-following property deteriorates sharply due to the increased amount of the filler. Further, the damping material containing only the granular filler does not deteriorate the shape following property so much, but the damping characteristic is not good. On the other hand, the panel damping material of the present invention forms a complicated filling form with powdery and granular fillers,
In a region where the resin elastic modulus is high near the practical temperature of the damping material, the damping characteristics can be improved by increasing the friction resistance between the filler and the filler and the resin, and the temperature above the softening temperature of the resin can be achieved. In the flow region, it is considered that the frictional resistance between the resin and the filler is drastically reduced by partially blending the granular filler, and the shape followability can be improved. Even when a large amount of the filler is blended, the specific gravity can be increased with the mixed material without impairing the shape following property, so that the sound insulation property can be improved.

(Example) This invention is demonstrated with the following example and a comparative example.

The vibration damping characteristics of the panel vibration damping material in the examples and the shape following ability of the panel to be damped are evaluated as follows.

Evaluation method 1 [Vibration damping characteristics] A panel damping material of length 250 mm, width 10 mm, and thickness 0.8 mm, which is the same in length and width, and 4 mm in thickness, is placed on one side of a general automobile exterior steel plate, and then Then, heating is performed at 140 ° C. for 30 minutes to obtain a test piece for vibration damping characteristic evaluation that is fused, adhered, or cured. This test piece was subjected to a cantilever beam resonance method to obtain a composite loss factor (η) at the secondary resonance point of bending vibration of 25 ° C.
The measurement was performed in an air-conditioned room.

Evaluation method 2 [Shape-following property] As shown in FIG. ₁ , two steel plates 2 are horizontally fixed on a support base 3 at a parallel interval of 1 ₁ = 30 mm, and a length (l ₂ ) of 100 mm is set on the steel plate 2. A panel damping material 1 having a width (W) of 30 mm and a thickness (t) of 4 mm is placed and heated at 140 ° C. for 30 minutes. After cooling to room temperature, the amount of sag (d) of the panel damping material 4 was measured as shown in FIG. The amount of sagging (d) for following the shape of the floor panel of the automobile and sufficiently adhering was 2.5 mm or more.

Example 1 35 parts by weight of epoxy resin (Yukaka Shell Epoxy Co., Ltd., trade name "Epicoat 1001"), epoxy resin (Okaka Shell Epoxy Co., Ltd., trade name "Epicoat 871")
65 parts by weight were mixed for 30 minutes with a Banbury mixer heated to 150 ° C. to be sufficiently compatible. The softening temperature of this mixed resin was 45 ° C. or lower. After allowing to cool to 60 ° C., 8 parts by weight of dicyandiamide, 4 parts by weight of 3- (p-chlorophenyl) -1,1-dimethylurea as a curing agent, and talc as a powdery filler (manufactured by Kunimine Industries Co., Ltd.) , Product name "TA", 200% passing through mesh
150 parts by weight), as a granular filler, 150 parts by weight of silica sand (Kawatetsu Mining Co., Ltd., trade name "Nikko No. 6", 200% passing through 3 mesh or less) are added, and the mixture is kneaded at a temperature of 60 ° C for 1 hour. did. Then, it was formed into a sheet having a thickness of 4 mm with a calendar roll. The results of evaluation of this sheet according to Evaluation Methods 1 and 2 are shown in Table 1.

Example 2 Of the formulations shown in Example 1, powdered talc (“T
A ") to 270 parts by weight and granular filler silica sand (" Nikko 6
No. ”) was changed to 30 parts by weight, and a sheet having a thickness of 4 mm was obtained in the same manner as in Example 1. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Comparative Example 1 Of the formulations shown in Example 1, without adding the granular filler,
A powder filler talc ((TA)) was changed to 300 parts by weight, and a sheet having a thickness of 4 mm was obtained in the same manner as in Example 1. The results of evaluation by Evaluation Methods 1 and 2 are shown in Table 1. Show.

Example 3 70 parts by weight of xylene resin (manufactured by Mitsubishi Gas Chemical Co., Inc., trade name "Nikanol HH"), 30 parts by weight of epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., trade name "Epicoat 1004") The mixture was mixed for 45 minutes with a Banbury mixer heated to 0 ° C. to make them sufficiently compatible. The softening temperature of this mixed resin was 50 ° C. or lower. After allowing to cool to 60 ° C., the same curing agent as in Example 1 was added in the same part by weight, and a lead oxide powder (200 mesh pass 95%) was added as a powdery filler.
%) 250 parts by weight, as a granular filler, 150 parts by weight of silica sand (Kawatetsu Mining Co., Ltd., trade name "Nikko No. 5", 200% passing 2% or less) are added, and the temperature is 60 ° C for 1 hour. Kneaded Then, a calendar roll was used to obtain a sheet having a thickness of 4 mm. The first is the result of the evaluation according to the evaluation methods 1 and 2.
Shown in the table.

Example 4 In the composition shown in Example 3, 250 parts by weight of powdered filler of talc (trade name "GTA" manufactured by Quemine Industries, Inc., 99% or more through 200 mesh) was added to granular filler silica sand. (“Nikko No. 5”) was changed to 250 parts by weight, and a sheet having a thickness of 4 mm was obtained in the same manner as in Example 3. Table 1 shows the results of the evaluation method and the evaluation by 2.

Comparative Example 2 Of the formulations shown in Example 3, all were the same except that no granular filler was blended, and in the same manner as in Example 3,
A sheet having a thickness of 4 mm was obtained. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Example 5 Among the formulations shown in Example 3, calcium carbonate was used as a powdery filler (trade name “NS ≠ 400” manufactured by Nitto Koka Kogyo Co., Ltd.,
15 parts by weight of the metallic lead particles (passage of 200 mesh or less 5% or less) 15
By changing to parts by weight, a sheet having a thickness of 4 mm was obtained in the same manner as in Example 3. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Comparative Example 3 Of the formulation shown in Example 3, the powdered filler calcium carbonate (“NS ≠ 400”) was changed to 5 parts by weight, and the same metallic lead particles used in Example 5 were changed to 5 parts by weight. Example 3
A sheet having a thickness of 4 mm was obtained by the same method as described above. Evaluation method 1
Table 1 shows the results of the evaluations according to 2 and 2.

Example 6 Straight asphalt (manufactured by Nippon Oil Co., Ltd., trade name "6"
0-80 straight asphalt ") 60 parts by weight, straight asphalt (manufactured by Nippon Oil Co., Ltd., trade name" 0-2 "
10 parts by weight of 0NY asphalt ”) and 30 parts by weight of blown asphalt (manufactured by Nippon Oil Co., Ltd., trade name“ 30-40SP blown asphalt ”) were mixed with a Banbury mixer heated to 150 ° C. for 30 minutes. The softening temperature of this mixed asphalt was 65 ° C or lower. Then, at 150 ° C, powder filler talc (“GTA”)
80 parts by weight, granular filler silica sand ("Nikko No. 6") 100
A part by weight was added and the mixture was kneaded for 1 hour. Next, a calender roll was used to obtain a sheet having a thickness of 4 mm. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Example 7 Of the formulations shown in Example 6, powdered filler talc (“G
TA ") to 10 parts by weight of granular filler silica sand (" Nikko 6
No. ”) was changed to 90 parts by weight, and a sheet having a thickness of 4 mm was obtained in the same manner as in Example 6. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Comparative Example 4 Of the formulations shown in Example 6, the powdery filler was not incorporated,
The particulate filler silica sand (“Nikko No. 6”) was changed to 100 parts by weight, and a sheet having a thickness of 4 mm was obtained in the same manner as in Example 6. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Example 8 Polyvinyl chloride (manufactured by Nippon Zeon Co., Ltd., trade name "Zeon 1"
21 ") 50 parts by weight of plasticizer dioctyl phthalate 5
0 parts by weight and a small amount of stabilizer were added, and the mixture was mixed with a Banbury mixer at 105 ° C. for 1 hour. The softening temperature of this mixed resin was 60 ° C. or lower. In addition, 5.0 parts by weight of powdery filler clay (Kunimine Industry Co., Ltd., trade name "Kunimine clay", 99% or more through 200 mesh), 50 parts by weight of granular filler silica sand ("Nikko No. 5") Parts were added, and the mixture was kneaded with an extruder heated to 150 ° C. to form a pellet. Further, a sheet having a thickness of 4 mm was obtained with a hot roll.
Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Comparative Example 5 A sheet having a thickness of 4 mm was obtained in the same manner as in Example 8 except that the powdery filler was not mixed among the formulations shown in Example 8. Table 1 shows the results of the evaluations according to Evaluation Methods 1 and 2.

Example 9 100 parts by weight of ethylene vinyl acetate copolymer (Mitsubishi Yuka Co., Ltd., trade name "Yukaron EVA EVA50M"), 100 parts by weight of powdery filler talc ("GTA"), and granular filler silica sand ( "Nikko No. 6") 100 parts by weight, 130 ° C
The mixture was kneaded with an extruder heated to 1, and pelletized. The softening temperature of this resin was 50 ° C. or lower. Further, a sheet having a thickness of 4 mm was obtained with a hot roll. Table 1 shows the evaluation results of Evaluation Methods 1 and 2.

Next, the transmission loss of the sheets of Example 3 and Comparative Example 2 was measured by the reverberation chamber method. The sheet of Example 3 was 2.6 dB superior to the sheet of Comparative Example 2 at a frequency of 500 Hz. And exhibited sound characteristics.

(Effect of the invention) Since the panel vibration damping material of the present invention uses an appropriate amount of the powdery filler and the granular filler as the inorganic filler, it is a vibration damping material containing only the powdery or granular filler. Compared with the above, it has improved vibration damping characteristics and shape followability, and has high vibration damping characteristics that make it easy to attach to the panel to be damped.
Even if a large amount of the filler is blended, the shape-following property is not impaired, so that it is a vibration damping material having a large specific gravity, and the advantages that the flexural characteristics and sound characteristics are remarkably improved are obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state of the panel damping material before heating in the evaluation method 2, and FIG. 2 is a sectional view showing a state of the panel damping material after heating in the evaluation method 2. 1 ... Panel damping material (before heating) 2 ... Steel plate 3 ... Support base 4 ... Panel damping material (after heating)

Front page continuation (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F16F 15/02 Q 9138-3J G10K 11/16 A 7406-5H // B60R 13/08

Claims (1)

[Claims] 1. 1 to 3 kinds of resins and 2 or more parts selected from calcium carbonate, talc, clay, silica sand, lead and lead oxide as an inorganic filler in an amount of 30 parts by weight or more based on 100 parts by weight of the resin. The above-mentioned inorganic filler is composed of two kinds, that is, a powdery filler having a flow rate of 200 mesh of 90% or more and a particulate filler having a flow rate of 200 mesh of 10% or less. Mixing ratio of filler (weight ratio) is 1
A sheet-shaped panel vibration-damping material having excellent vibration-damping properties and sound-insulating properties, which is obtained by molding a composition of 0:90 to 90:10 into a sheet.