JP4741829B2 - Restraint type damping material - Google Patents

Description

  The present invention relates to a housing structure such as a house, an apartment, an office building, various structures such as a high-speed railway, a viaduct, and a railroad track, various vehicles such as an automobile, a railway vehicle, and a construction vehicle, as well as a home electric device and an acoustic device. The present invention relates to a vibration damping material used for reducing vibrations and noise generated in the field, and more particularly to a restrained vibration damping material in an acoustic device.

  As a constrained damping material, a damping resin composition comprising a base polymer material having a polar side chain, such as chlorinated polyethylene or nitrile butadiene rubber, blended with chlorinated paraffin, a sulfenamide dielectric material, liquid rubber, or the like. The thing of the structure which bonded together the damping resin layer which consists of, and the constrained layer which consists of a steel plate, aluminum, etc. was proposed.

However, if the loss tangent (tan δ) peak used as a performance index of the damping material is to appear near room temperature, the glass transition temperature (hereinafter referred to as “Tg”) of the damping material resin is also near room temperature. For this reason, there is a problem that sufficient adhesive strength cannot be obtained at low temperatures, and that construction cannot be performed outdoors in winter, for example.

  As a result of repeated investigations to solve this problem, the inventors of the present invention provided an adhesive resin layer having a glass transition temperature lower than that of the vibration damping resin layer, thereby maintaining the peak temperature of vibration damping performance near room temperature. It was found that high tackiness was obtained even at low temperatures.

  That is, a first one according to the present invention includes a constraining layer, a vibration damping resin layer, and an adhesive resin layer, wherein the difference between the Tg of the vibration damping resin layer and the Tg of the adhesive resin layer is 10 ° C. or more. It is a restraint type damping material.

  If the difference between the Tg of the damping resin layer and the Tg of the adhesive resin layer is less than 10 ° C., the adhesive resin layer cannot exhibit sufficient adhesive strength at low temperatures. This Tg difference is preferably 15 ° C. or more, and more preferably 20 ° C. or more.

  In the constrained vibration damping material according to the present invention, the constraining layer may be made of a steel plate or aluminum.

  The damping resin layer is composed of a damping resin composition in which chlorinated paraffin, sulfenamide-based dielectric material, liquid rubber, etc. are blended with a base polymer material having a polar side chain such as chlorinated polyethylene or nitrile butadiene rubber. It may be. For example, a resin containing a chlorine-containing thermoplastic resin having a chlorine content of 20 to 70% by weight, such as chlorinated polyethylene, polyvinyl chloride, or vinyl chloride-vinyl acetate copolymer, and a chlorinated paraffin having a chlorine content of 30 to 75% by weight. What consists of a composition is used preferably. The composition may contain a stabilizer such as a tin-based heat stabilizer as necessary.

  The loss tangent (tan δ) of the damping resin layer is preferably 1 or more, more preferably 1.5 or more.

  The adhesive resin layer is preferably composed of a resin composition based on acrylic, polyolefin, butyral, urethane, rubber, silicone or the like.

  The adhesive strength of the adhesive resin layer is preferably 2.0 N / cm or more, more preferably 5.0 N / cm in a 180 ° C. peel test in accordance with JIS Z 0237. The thickness of the adhesive resin layer is preferably 2 mm or less, more preferably 1.5 mm or less in order to reduce the influence of the loss factor ((η)) on the peak temperature.

  When the solubility parameters of the vibration damping resin layer and the adhesive resin layer (hereinafter referred to as SP values) are close, the liquid components contained in these resin layers migrate, and therefore the vibration damping resin layer and the adhesive are assumed under actual use conditions. It is desirable to sandwich a film having an SP value that is one or more away from the SP value of the low melting point component among the constituent components of the resin layer.

Also , a plasticizer migration prevention film is interposed between the vibration damping resin layer and the adhesive resin layer so as to separate these layers, and the SP value of the film and the melting point of the constituent components of the vibration damping resin layer and the adhesive resin layer are 2. The constrained vibration damping material according to claim 1, wherein the difference between the SP values of all components at 80 ° C. or less is 1 or more.

  When the difference between the SP value of the plasticizer migration prevention film and the SP value of the liquid component in the vibration damping resin layer and the adhesive resin layer is less than 1, the plasticizer contained in the vibration damping resin layer and the adhesive resin layer migrates There is a fear. The difference in SP value is preferably 1.5 or more, and more preferably 1.8 or more. A PET film is preferable as the film having such SP value. The thickness of the plasticizer migration prevention film is preferably 5 μm or more, and more preferably 12 μm or more.

  The restraint type damping material according to the present invention is a housing structure such as a house, a condominium, an office building, various structures such as a high-speed railroad, a viaduct, a railroad track, various vehicles such as an automobile, a railcar, and a construction vehicle, and a home. Although it can be used to reduce vibration and noise generated in electrical equipment, acoustic equipment, etc., use in acoustic equipment is particularly effective.

According to a second aspect of the present invention, there is provided a vibration damping structure for an acoustic device, wherein the restraint type damping material according to claim 1 or 2 is bonded to at least a part of the acoustic device.

  According to the first invention, the adhesive resin layer can exhibit sufficient adhesive force even at a low temperature while keeping the peak temperature of vibration damping performance near room temperature. For example, the construction can be performed without hindrance outdoors in winter. .

Moreover , the migration of the plasticizer contained in the vibration damping resin layer and the adhesive resin layer can be reliably prevented, and the vibration damping performance and the adhesive performance can be maintained for a long time.

According to the second invention, vibration and noise in the acoustic device can be effectively reduced.

The present invention will be specifically described based on examples.
Example 1
100 parts by weight of chlorinated polyethylene (made by Showa Denko Co., Ltd., trade name “Elaslene 402NA”, SP value = 9.2, melting point 140 ° C. or higher (cannot be measured due to lower decomposition temperature)) and chlorinated paraffin (Tosoh) Product name “Toyoparax 150”, SP value = 9.3, melting point = −35 ° C. 250 parts by weight, chlorinated paraffin (Ajinomoto Fine Techno Co., Ltd., product name “Empara 70”, SP 200 parts by weight of a value = 10.6, melting point = 105 ° C. were put into a 6-inch roll (manufactured by Irie Iron Works Co., Ltd.) and kneaded at 100 ° C. The Tg after kneading was 15 ° C. In this way, a vibration damping resin composition was prepared. This damping resin composition is soft aluminum foil (manufactured by Sun Aluminum Industry Co., Ltd., trade name “8079”, thickness = 0.2 mm) and PET film (thickness = 0.012 mm, SP value = 10.8) at 120 ° C. A damping resin layer having a thickness of 1.5 mm sandwiched between a soft aluminum foil and a PET film was formed. At least one surface of the soft aluminum foil was primer-treated, and a vibration-damping resin layer was bonded to the treated surface. Furthermore, an adhesive sheet (manufactured by Sekisui Chemical Co., Ltd., trade name “Doubletack # 5762”, thickness = 0.12 mm, Tg = 0 ° C., SP value = 9.5, melting point 140 on the other side of the PET film at room temperature. More than ℃ (measurement is impossible because the decomposition temperature is lower)). A release paper was bonded to the other surface of the adhesive resin layer. The constrained damping material thus obtained is shown in FIG. In the figure, 1 is a soft aluminum foil, 2 is a damping resin layer, 3 is a PET film, 4 is an adhesive resin layer, and 5 is a release paper.
Comparative Example 1
In Example 1, the PET film was not used, and the other operations were performed in the same manner as in Example 1 to obtain a constrained vibration damping material (soft aluminum foil / damping resin layer / adhesive resin layer / release paper). .
Comparative Example 2
Separately, 100 parts by weight of acrylic acid ester copolymer (Mitsubishi Rayon Co., Ltd., trade name “P-501A”, melting point 140 ° C. or higher (cannot be measured due to lower decomposition temperature)) and chlorinated paraffin (Tosoh Corporation) ) Made by the company, trade name "Toyoparax 150", melting point = -35 ° C) 300 parts by weight, and chlorinated paraffin (Ajinomoto Fine Techno Co., Ltd., trade name "Empara 70", melting point = 105 ° C) 100 parts by weight Were put into a 6 inch roll (manufactured by Irie Iron Works Co., Ltd.) and kneaded at 140 ° C. The Tg after kneading was 15 ° C. Thus, an adhesive resin composition was prepared. This pressure-sensitive adhesive resin composition was formed into a film with a thickness of 0.12 mm to obtain a pressure-sensitive adhesive sheet.

In Example 1, instead of the product name “Double Tack # 5762” manufactured by Sekisui Chemical Co., Ltd., an adhesive sheet prepared separately as described above was used as the adhesive sheet. The same operation was performed to obtain a constrained vibration damping material.
Performance test The performance test of the following item was done about the restraint type damping material sample obtained by the Example and the comparative example.
a) Adhesive performance A sample is cut into a strap with a width of 20 mm, the cut piece is bonded to an SPC steel plate, and the resulting bonded body is 23 ° C. (normal temperature) using a universal tester (model number UCT-5T manufactured by Orientec Co., Ltd.). A 90 ° C. peel test was conducted at 300 mm / min at 0 ° C. (adhesive strength) and 0 ° C. (low temperature adhesive strength).
b) Migration of liquid components
The above sample was placed in an 80 ° C. oven for 2 weeks, and the liquid component on the adhesive surface was visually observed.

  The test results obtained are shown in Table 1.

FIG. 1 is a cross-sectional view showing a layer structure of a constrained vibration damping material obtained in Example 1. FIG.

1 is soft aluminum foil 2 is damping resin layer 3 is PET film 4 is adhesive resin layer 5 is release paper

Claims (2)

Including a constraining layer, a damping resin layer, and an adhesive resin layer, and a plasticizer migration prevention film is interposed between the damping resin layer and the adhesive resin layer so as to separate the layers, and the glass of the damping resin layer the difference between the Tg of the transition temperature (hereinafter "Tg") and the adhesive resin layer is Ri der 10 ° C. or higher, the components of the SP value and the damping resin layer and the adhesive resin layer of the plasticizer migration inhibiting film constrained damping material difference between the SP values of all the components of which has a melting point of 80 ° C. or less and wherein the der Rukoto 1 or more. Damping of acoustic devices constrained damping material of claim 1 Symbol mounting is characterized in that it is bonded to at least a portion of the audio equipment.

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