JP2000007922A - Asphalt-based low specific gravity vibration-damping material and damping vibration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vibration-damping material of a low specific gravity which is lightweight and excellent in vibration-damping property and can be efficiently manufactured and easily recycled by compounding a specific inorganic expanded particle as a part of a filler. SOLUTION: The objective vibration-damping material comprises, as a part of a filler, highly strong, low specific gravity inorganic expanded particles obtained by coating the surfaces of inorganic expanded particles with a skin layer of porcelain, where at least 80% of the aggregate constituting the inorganic expandable particles has particle sizes ranging from 0.1 to 4.0 mm. The highly strong, low specific gravity inorganic expanded particles are contained in the low specific gravity vibration-damping material composition preferably in an amount of around 5-50 wt.% thereof. The kind of asphalt employed for the vibration- damping material is not particularly limited. As methods to apply the low specific gravity vibration-damping material on a surface to be treated, there can be exemplified (1) a method comprising laying the vibration-damping material on a surface to be treated such as metal or the like and heating thereby melt bonding to unify them, and (2) a method comprising adhering the vibration-damping material to a surface to be treated by means of one properly selected from pressure sensitive adhesives, hot melt type adhesives and double-sided adhesive tapes and melt bonding, if necessary, to unify them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping material mainly used for structural materials such as floors, walls and ceilings of vehicles and ships and floor and outer wall materials of buildings, and a vibration damping treatment using the vibration damping resin. About the method.

[0002]

2. Description of the Related Art Materials such as iron and aluminum are generally used for floors, walls and ceilings of automobiles, railcars, ships and the like and floors and outer walls of some buildings. These have the advantage of high heat resistance, high mechanical strength, and high elastic modulus, but on the other hand, they often have problems with sound resonance or metal-specific vibration noise.

[0003] Conventionally, in order to improve the livability of the room by blocking the external sound and suppressing the vibration of the structural member itself,
Various studies have been made to form a damping structure.

For example, there is a method in which a bituminous substance such as asphalt is melted, and a flaky filler such as mica or graphite is mixed with this. Also, studies have been made to use a heavy material as a filler material to form a part that is heavier and a part that is lighter so as to broaden the peak of the frequency at which vibration suppression is exhibited.

[0005] However, taking various measures to improve the vibration damping property is accompanied by an increase in the weight of a transport machine such as an automobile or a railcar, which is a resource saving and resource saving technique which has been recently said. It will be in the opposite direction to energy saving. Therefore, development of a vibration-damping material and a vibration-damping treatment method which are as light as possible and exhibit excellent vibration-damping properties at the same time is awaited.

[0006]

In order to solve the above-mentioned problems, a patent application filed by the present applicant (Japanese Patent Laid-Open No. 19405/1990).
No. 7) disclosed a lightweight sheet-like vibration damping material containing asphalt as a binder, a hollow plastic filler, and surface-treated calcium carbonate as a filler.

[0007] According to the above invention, even a plastic hollow filler which is difficult to disperse and mix into asphalt, is uniformly dispersed well by the surface-treated calcium carbonate, and the vibration damping material is lightweight and low due to the plastic hollow filler. The specific gravity was obtained, and the vibration damping property was exhibited to the same degree as that of the conventional asphalt-based vibration damping material, and the effect was achieved that the weight was reduced.

However, when a plastic hollow filler is used to reduce the weight and specific gravity, the following problems remain.

[0009] Since the plastic hollow filler does not have a very high strength as a filler, in the step of kneading and dispersing with the asphalt as a binder, if a large force acts, the plastic hollow filler is crushed. Must be operated at a low speed, resulting in poor production efficiency.

[0010] Further, in the step of processing into a sheet shape convenient for using the vibration damping material, and further trimming to a desired shape,
Parts other than the standard width, so-called ears, and trimmings are generated. These are collected, returned to the melting, kneading and dispersing step, and recycled.However, since the plastic filler has the above-mentioned disadvantages, the crushing of the plastic filler gradually progresses when recycling is repeated. However, when the percentage of recycled products in the raw material increases, the percentage of crushed filler in the sheet-like vibration damping material also increases, resulting in a higher specific gravity of the vibration damping material and a smaller light weight effect, In some cases, only a certain percentage of recycled products could be mixed into raw materials.

Further, since the plastic hollow filler does not have high heat resistance, it cannot withstand heating at 200 ° C. or more for several hours at a temperature of 200 ° C. There was a risk that the structure would break and the specific gravity would increase. Further, since the plastic hollow filler itself does not have a high Young's modulus, even if it is effective in reducing the weight and the specific gravity of the vibration damping material by mixing, it hardly contributes to the improvement of the vibration damping property.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have invented a vibration damping material containing a specific filler and a vibration damping processing method using the vibration damping material. It was done.

According to the first aspect of the invention, there is provided a high-strength, low-specific-gravity inorganic aggregate having a particle size distribution of 80% or more of the aggregate in the range of 0.1 to 4.0 mm covered with a porcelain skin layer. An asphalt-based low-specific-gravity damping material characterized by containing inorganic foam particles as a part of a filler. "

According to a second aspect of the present invention, it is provided that the low-specific-gravity damping material according to the first aspect is placed on a surface to be damped such as a metal, and is fused and integrated by heating. Characteristic vibration suppression processing method. "

According to a third aspect of the invention, there is provided a vibration damping material according to the first aspect of the present invention, wherein the low specific gravity damping material is subjected to vibration damping by a method appropriately selected from a pressure-sensitive adhesive, a hot melt adhesive, and a double-sided adhesive tape. A vibration damping treatment method, wherein the vibration damping method is affixed to a surface and, if necessary, fused and integrated by heating. "

[0016] The high-strength inorganic foamed granules, which are essential components in the invention according to claim 1, are a porcelain skin layer whose surface is formed using a vitreous mineral and a kaolinite-containing mineral as main raw materials. The inside is foamed particles in which minute bubbles are distributed countlessly in an independent state. The high-strength inorganic foamed particles are the same as those disclosed by some of the present inventors in JP-A-8-333819.

The formation of the inorganic foamed particles into high-strength inorganic foamed particles having the above-mentioned skin layer can be achieved, for example, by firing the inorganic foamed particles. Because of the foamed particles having such a configuration, the strength of the foamed particles is significantly higher than that of a conventionally used plastic hollow filler, and an open kneader used for mixing and dispersing with molten asphalt.
It can withstand repeated mixing without being crushed in a normal mixing and dispersing step using a pressure kneader. Furthermore, it has been found that the foamed particles have a high Young's modulus, and that the use of particles having a particle size distribution described later contributes to remarkable improvement in vibration damping properties. In the present invention, as a result of further study, it has been found that the object of the present invention can be achieved by using expanded particles having a specific particle size distribution.

[0018] The high-strength inorganic expanded granules are produced by the following method.
Various particle sizes are manufactured, but in order to use it for asphalt vibration damping material, use inorganic foam particles having a particle size distribution of 80% or more of the aggregate in the range of 0.1 to 4.0 mm. Things are desirable. More preferably, it is desirable to use inorganic foamed particles in the range of 0.1 to 3.0 mm. 0.1
If the particle size distribution is less than mm, the effect of reducing the specific gravity and weight cannot be expected. In the case of a particle size distribution exceeding 4.0 mm, the thickness is 4.0.
When an attempt is made to manufacture a sheet-shaped vibration damping material having a thickness of 0 mm or less, the inorganic foamed particles are exposed, and not only the appearance is reduced, but also the continuity of the sheet is deteriorated.

The high-strength inorganic foamed particles are desirably blended in the composition of the low specific gravity damping material of the present invention in a range of 5% to 50% (weight percentage, the same applies hereinafter), more preferably 20% to 40%. Of the range. If the amount is less than 5%, sufficient light weight and low specific gravity effect, and the effect of improving vibration damping properties cannot be expected, and if more than 50%, it becomes difficult to disperse and mix with asphalt. Problems such as difficulty in processing into a sheet shape may occur.

The type of asphalt used for the low-specific-gravity damping material according to the present invention is not particularly limited, and examples thereof include straight asphalt, blown asphalt, semi-blown asphalt, rubber-modified asphalt, and asphalt appropriately mixed with these. Conventionally known asphalt can be used.

As other fillers used in the low specific gravity damping material according to the present invention, calcium carbonate, barium sulfate, clay, talc, mica, graphite, defibrated fiber, ground waste paper and the like can be used if necessary. However, a vibration damping material can be manufactured without using these materials.

Other compounds used in the low specific gravity vibration damping material according to the present invention include petroleum resins, thermoplastic resins, thermosetting resins, synthetic rubbers, antioxidants, ultraviolet absorbers, moisture absorbers and the like. Can be mentioned.

The low specific gravity damping material according to the present invention can be manufactured by a conventionally known method for manufacturing an asphalt damping material. That is, the asphalt is heated and melted, and other components such as high-strength inorganic foamed particles are added to the asphalt and mixed and kneaded by a disperser. As the disperser, an open kneader, a pressure kneader, a mixing roll, various mixers and the like can be used.
After kneading, it is processed into a sheet having a desired uniform thickness by a calender roll. The thickness of the sheet is not particularly limited, but is often manufactured in a thickness range of 1 to 5 mm. Further, if necessary, it is trimmed to a desired shape by a punching die and a press machine.

As a first method of applying the low-specific-gravity damping material of the present invention to a surface to be damped, the damping material is placed on a required surface, and the asphalt component of the damping material is softened by heating. There is a method of integrating the surface to be damped by fusion. For example, in a coating line of an automobile, since the paint after the coating passes through a heating and drying furnace in order to dry the coating, it is possible to perform fusion by utilizing heat at the time of passing through the heating and drying furnace.

As a second method of applying the low-specific-gravity damping material of the present invention to a surface to be damped, a pressure-sensitive adhesive, a hot-melt type adhesive, a double-sided adhesive tape is applied to the low-specific-gravity damping material. A method that is integrated with the surface to be damped by sticking by a method appropriately selected from the above. The adhesive may be applied on the damping material side or on the damped surface. When applying to the vibration damping material side in advance, it is preferable that the release paper is pasted after the application, and the release paper is peeled off and pasted immediately before the adhering work, so that the work efficiency is good. Further, if necessary, after these are attached, heating may be further performed to perform integration by heat fusion.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments will be described to facilitate understanding of the present invention. Needless to say, the present invention is not limited to the following examples.

[0027]

[Example] Straight / bron mixed rubber modified asphalt: [1] Synthetic rubber: [2] Synthetic resin: [3] Fiber: [4] Mica: [5] The surface of the inorganic foam particles was covered with a porcelain skin layer. High-strength low-specific-gravity inorganic foamed particles: [6] Calcium carbonate: [7] The above-mentioned composition was weighed according to the following table, kneaded with a pressure kneader, and processed into a sheet having a thickness of 2 mm with a calender roll. . (Unit in the table is% by weight)

[0028]

[Test method] The dispersibility of the filler in the binder was observed and evaluated as sheet workability. The specific gravity was measured by a water displacement method. The loss coefficient at 20 ° C. was determined by the resonance method.

[0029]

【result】

[0030]

The low specific gravity vibration damping material of the present invention realizes a light weight and low specific gravity as compared with the conventional asphalt vibration damping material. By comparison, 1) high damping effect, 2) good manufacturing efficiency,
3) It has excellent effects such as easy recycling.
Further, the vibration control method is easy, and the vibration control effect is high. For this reason, it can be widely applied to various transport machines, building structural materials, building members, and the like, and can meet needs such as high speed of transport machines, resource saving and fuel saving.

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Claims (3)

[Claims] (1) The particle size distribution of 80% or more of the aggregate is 0.1 to
An asphalt-based low-specific-gravity damping material comprising as a part of a filler a high-strength low-specific-gravity inorganic foam in which the surface of an inorganic foam within a range of 4.0 mm is covered with a porcelain skin layer. 2. The vibration damping process according to claim 1, wherein the low-specific-gravity damping material according to claim 1 is placed on a surface to be damped, such as a metal, and fused by heating to be integrated. Method. 3. The low-specific-gravity damping material according to claim 1 is adhered to a surface to be damped by a method appropriately selected from a pressure-sensitive adhesive, a hot-melt adhesive, and a double-sided adhesive tape.
If necessary, a vibration damping method characterized by being fused and integrated by heating.