JP2009179717A - Restrained type vibration control sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a restrained type vibration control sheet having effective vibration control performance from a low temperature to a high temperature. <P>SOLUTION: The restrained type vibration control sheet includes a vibration control material layer, the layer being formed by using (A) a butyl rubber aqueous emulsion, (B) an acrylic emulsion including an acrylic polymer consisting essentially of 2-ethyl-hexyl acrylate and having ≤-50°C Tg and (C) mica including a particle diameter component (c-1) having ≤30 μm average particle diameter and a particle diameter component (c-2) having 50 to 200 μm average particle diameter, a mass ratio ((a)/(b)) of a solid content (a) of (A) the butyl rubber aqueous emulsion to a solid content (b) of (B) the acrylic emulsion is 30/70 to 70/30, a mass ratio ((c-1)/(c-2)) of the particle diameter component (c-1) to the particle diameter component (c-2) is 20/80 to 80/20, and a sum total amount of the particle diameter components (c-1) and (c-2) is 80 to 200 pts.mass to 100 pts.mass sum total of the solid contents (a) and (b). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a constrained vibration damping sheet including a constraining layer, a vibration damping material layer, and an adhesive layer. More specifically, the present invention attenuates vibrations generated from automobiles, railway vehicles, home appliances, office equipment, housing equipment, and the like. In order to reduce noise, the present invention relates to a constrained vibration damping sheet that is used by being attached to a vibration part.

  In recent years, the use of vibration damping materials has become popular as a noise countermeasure for automobiles, railway vehicles, home appliances, office equipment, housing facilities, and the like. In particular, a vibration damping sheet of a type that is directly attached to a vibration site is widely used because it is excellent in terms of work simplicity and weight reduction.

  Conventionally, as a method of attaching a vibration damping sheet, a method of attaching a pressure-sensitive adhesive layer to a vibration-damping material in the form of a sheet of asphalt, rubber, resin, or the like, a method of attaching using an adhesive, and tackiness A method of giving and pasting is known. Moreover, the constraining layer which consists of aluminum foil, a hard resin sheet, etc. is provided, and the improvement of a damping performance is aimed at.

  As a vibration damping material, for example, a material that is less dependent on temperature of the loss coefficient and exhibits pressure-sensitive adhesiveness is disclosed (for example, see Patent Document 1). The vibration damping material disclosed in Patent Document 1 is formed by blending mica having an average particle diameter of 50 μm or more into butyl rubber. A vibration damping material produced by blending mica having an average particle size of less than 50 μm with butyl rubber cannot reduce the temperature dependence of the loss factor, and may make it difficult to develop pressure-sensitive adhesiveness.

  Further, a damping material having excellent damping performance at a temperature from room temperature to 80 ° C. is disclosed (for example, see Patent Document 2). The damping material disclosed in Patent Document 2 is composed of a constraining layer, a damping material layer, and an adhesive layer. Ultrafine powder silica and other inorganic fillers are added to butyl rubber constituting the damping material layer. It will be. However, Patent Document 2 does not mention how to select other inorganic fillers.

  Furthermore, a damping material having damping performance even at a temperature of 40 ° C. or higher is disclosed (for example, see Patent Document 3). The vibration damping material disclosed in Patent Document 3 is obtained by blending 200 to 500 parts by weight of an inorganic filler with 100 parts by weight of a mixture of butyl rubber, C5 petroleum resin, and asphalt.

Japanese Patent No. 3295914 Japanese Patent No. 1914045 JP-A-9-136998

  However, even though the conventional damping material that has been disclosed has damping performance near room temperature or at a relatively high temperature from room temperature, a damping material that has effective damping performance from low temperature to high temperature is disclosed. There wasn't.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to provide a constrained vibration damping sheet having effective vibration damping performance from low temperature to high temperature. is there.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved by providing a predetermined vibration damping material layer on the constrained vibration-damping sheet. It came to be completed.

  That is, according to the present invention, the following constraint type vibration damping sheet is provided.

  [1] It has a constraining layer, a damping material layer, and an adhesive layer, and the damping material layer comprises (A) an aqueous emulsion dispersion of butyl rubber, and (B) 2-ethyl-hexyl acrylate as the main components. An acrylic emulsion containing an acrylic polymer having a Tg of −50 ° C. or less, (C) a particle size component having an average particle size of 30 μm or less, and (c-2) particles having an average particle size of 50 to 200 μm And (a) a solid content of the aqueous emulsion dispersion of (A) butyl rubber, and (b) of the acrylic emulsion (b). ) The mass ratio of solids ((a) / (b)) is 30/70 to 70/30, and the mass ratio of (c-1) particle size component to (c-2) particle size component (( c-1) / (c-2)) is 20/80 to 80/20, Constraint that the total content of the (c-1) particle size component and the (c-2) particle size component is 80 to 200 parts by mass with respect to a total of 100 parts by mass of the shape and the (b) solid content Mold damping sheet.

  The constrained vibration damping sheet of the present invention has an effect of having effective vibration damping performance from a low temperature to a high temperature.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

(1) Restraint type damping sheet The restraint type vibration damping sheet of the present invention has a restraining layer, a damping material layer, and an adhesive layer. The details will be described below.

(Restricted layer)
The constraining layer has an effect of improving the vibration damping performance of the constraining vibration damping sheet. As the constraining layer, for example, a foil such as aluminum, SUS, or a steel plate, or a hard resin thin sheet such as FPR can be used. Among these, a soft aluminum foil having a thickness of 50 to 200 μm is preferable because it is excellent in the cutability and bendability of the constrained vibration damping sheet.

(Damping material layer)
The damping material layer has an effect of imparting damping performance to the constrained damping sheet. The damping material layer is composed of (A) an aqueous emulsion dispersion of butyl rubber (hereinafter also referred to as “component (A)”) and (B) 2-ethyl-hexyl acrylate, and Tg is −50 ° C. or less. An aqueous mixture containing an acrylic emulsion containing the acrylic polymer (hereinafter also referred to as “component (B)”) and (C) mica (hereinafter also referred to as “component (C)”) is applied and dried. It is a sheet.

Component (A) Component (A) is an aqueous emulsified dispersion of butyl rubber. For example, those disclosed in Japanese Patent Application Laid-Open No. 2006-219609 by the present inventors can be suitably used. More specifically, an anionic emulsifier is mixed and stirred in a rubber solution prepared by dissolving butyl rubber in an organic solvent such as toluene, hexane, or cyclohexane, and further diluted with water. It is obtained by leaving.

Component (B) The component (B) is an acrylic emulsion containing 2-ethyl-hexyl acrylate as a main component and an acrylic polymer having a Tg of −50 ° C. or lower. By including the component (B) in the vibration damping material layer, it is possible to impart adhesiveness to the sheet of the vibration damping material layer without impairing the vibration damping performance of the vibration damping material layer. Moreover, the adhesiveness of a damping material layer, a constraining layer, and an adhesive layer can be improved.

  As the component (B), specifically, trade name “AE610H” (manufactured by JSR, solid content 45%, Tg = −62 ° C.), trade name “E-03H” (manufactured by Soken Chemical Co., Ltd., solid content 62%) , Tg = −58 ° C.) and the like.

Component (C) The component (C) includes a particle size component having an average particle size of 30 μm or less (hereinafter also referred to as “(c-1) particle size component”) and a particle size component having an average particle size of 50 to 200 μm (hereinafter referred to as “c”). (Also referred to as “(c-2) particle size component”). By including (c-1) a particle size component as mica, a constrained vibration damping sheet having effective vibration damping performance from a low temperature to a high temperature can be produced. Further, by including (c-2) a particle size component as mica, a constrained vibration damping sheet having effective vibration damping performance from a relatively low frequency to a high frequency can be produced.

  (C-2) If the average particle size of the particle size component is less than 50 μm, the loss factor may be small at 100 Hz, which is a relatively low frequency. On the other hand, if the average particle size of the (c-2) particle size component is more than 200 μm, the peel strength may be inferior as the peak temperature of the loss coefficient is lowered.

  (C-1) Specific examples of the mica particle size component include trade name “Mica S-325” (manufactured by Repco, average particle size of 27 μm).

  (C-2) Specifically, as the mica of the particle size component, the product name “Mica S-200HG” (manufactured by Repco, average particle size 55 μm), the product name “Mica SC-80” (manufactured by Repco, average Particle diameter 150 μm), trade name “Mica S-150H” (manufactured by Repco, average particle diameter 160 μm), trade name “Mica S-60H” (manufactured by Repco, average particle diameter 185 μm), and the like.

  The mass ratio of (c-1) particle size component to (c-2) particle size component ((c-1) / (c-2)) is preferably 20/80 to 80/20, 40 / 60 to 80/20 is more preferable, and 50/50 to 75/25 is particularly preferable. If the mass ratio is less than 20/80, it may be difficult to reduce temperature dependency. On the other hand, if the mass ratio exceeds 80/20, the loss factor may be small at a relatively low frequency of 100 Hz.

  The mass ratio ((a) / () of the solid content of the component (A) (hereinafter also referred to as “(a) solid content”) and the solid content of the component (B) (hereinafter also referred to as “(b) solid content”). b)) is preferably 30/70 to 70/30, more preferably 40/60 to 60/40. If the mass ratio is less than 30/70, as the peak temperature of the loss factor decreases, the vibration damping performance may decrease at a temperature of room temperature or higher. On the other hand, if the mass ratio is more than 70/30, the adhesion between the vibration damping material layer and the constraining layer becomes weak, and the peel strength may be inferior.

  The total content of (c-1) particle size component and (c-2) particle size component with respect to 100 mass parts in total of (a) solid content and (b) solid content is 80 to 200 mass parts. It is preferably 100 to 180 parts by mass, more preferably 130 to 170 parts by mass. When the total content is less than 80 parts by mass, the peak temperature of the loss factor is lowered, and therefore, the vibration damping performance may be inferior at a temperature of room temperature or higher, or the interface may be broken during peeling. On the other hand, if the total content exceeds 200 parts by mass, the peel strength may be inferior.

  Moreover, it is preferable that a damping material layer is a sheet | seat which further contains (D) other additives (henceforth "(D) component").

(D) component (D) A component is another additive. Examples of other additives include tackifiers and softeners. In addition, an inorganic filler other than mica, a viscosity modifier, a plasticizer, a colorant, an acrylic emulsion containing an acrylic polymer having a Tg of −50 ° C. or higher, a rubber latex such as SBR, EVA, etc. A resin emulsion or the like can also be added.

  Examples of the tackifier include terpene resins, aromatic modified terpene resins, aromatic modified hydrogenated terpene resins, alicyclic saturated hydrocarbon resins, hydrogenated C5 / aromatic copolymer resins, and the like. Further, as a tackifier commercially available as an aqueous emulsion, specifically, the trade name “Nanolet R1510” (manufactured by Yashara Chemical Co., Ltd., 50% aqueous emulsion of aromatic modified terpene resin), the trade name “AM-1002” ( Arakawa Chemical Industries, Ltd., 45% aqueous emulsion of alicyclic saturated hydrocarbon resin). Among these, a tackifier having a Tg of around room temperature is preferable because it increases the peak value of the loss coefficient around room temperature or improves the adhesion of the constrained vibration damping sheet.

  The addition amount of the tackifier is preferably 30 to 80 parts by mass and more preferably 40 to 60 parts by mass with respect to 100 parts by mass in total of (a) solid content and (b) solid content. . When the addition amount of the tackifier is less than 30 parts by mass, the effect of increasing the peak value of the loss coefficient near room temperature may be small. On the other hand, if the addition amount of the tackifier is more than 80 parts by mass, the temperature dependency of the loss factor may increase.

  Examples of the softener include terpene low polymer and polybutene. Specific examples of the softener commercially available as an aqueous emulsion include the trade name “Emauret 10E” (manufactured by NOF Corporation, 50% aqueous emulsion of polybutene).

  The addition amount of the softening agent is preferably 10 to 50 parts by mass, and more preferably 10 to 30 parts by mass with respect to 100 parts by mass in total of (a) the solid content and (b) the solid content. When the addition amount of the softening agent is less than 10 parts by mass, the effect of increasing the adhesion of the vibration damping material layer may be small. On the other hand, if the addition amount of the softening agent exceeds 50 parts by mass, the vibration damping performance may be inferior at a temperature of room temperature or higher as the peak of the loss factor is lowered.

  The thickness of the damping material layer is preferably 1 to 3 times the thickness of the vibration-damping member, and is 1 to 3 mm after drying, depending on the thickness of the target vibration-damping member. It is preferable. If the thickness of the damping material layer is less than 1 mm, sufficient damping performance may not be obtained. On the other hand, if the thickness of the damping material layer is more than 3 mm, it may not be economical.

(Adhesive layer)
The pressure-sensitive adhesive layer has an effect of imparting adhesiveness to the constrained vibration damping sheet. The pressure-sensitive adhesive layer is obtained by applying and drying an aqueous emulsion mainly composed of the component (A) and the component (B). As (A) component and (B) component, the thing similar to what was illustrated in the above-mentioned "(damping material layer)" can be mentioned. In addition, although the (A) component and (B) component used for a damping material layer and the (A) component and (B) component used for an adhesive layer may respectively be the same or different. Are preferably the same.

  In the pressure-sensitive adhesive layer, the mass ratio of (a) solid content and (b) solid content ((a) / (b)) is preferably 30/70 to 70/30, and 30/70 to 50/50. More preferably. If the mass ratio is less than 30/70, the vibration damping performance may be inferior at temperatures above room temperature as the peak temperature of the loss factor decreases. On the other hand, if the mass ratio is more than 70/30, the adhesive strength is insufficient and the practicality may be inferior.

  Moreover, in order to improve the adhesive force of an adhesive layer, it is also preferable to add a tackifier and a softening agent to an aqueous emulsion. In this case, the solid content (a) is preferably 30 to 70% by mass, and more preferably 40 to 60% by mass with respect to the total solid content in the aqueous emulsion. (A) If the solid content is less than 30% by mass, the peak temperature of the loss factor may be lowered. On the other hand, if (a) the solid content is more than 70% by mass, the adhesive strength is insufficient and the practicality may be inferior. In addition, as a tackifier and a softening agent, the thing similar to what was illustrated in the above-mentioned "(damping material layer)" can be mentioned.

  Furthermore, an inorganic filler can also be added as needed. Note that other rubber-based adhesives and acrylic-based adhesives may be added as long as the vibration damping performance is not adversely affected.

  The thickness of the pressure-sensitive adhesive layer is preferably 25 to 200 μm. If the thickness of the pressure-sensitive adhesive layer is less than 25 μm, sufficient adhesive strength may not be obtained. On the other hand, when the thickness of the pressure-sensitive adhesive layer exceeds 200 μm, the peak of the loss factor shifts to a low temperature, and the vibration damping performance near room temperature may deteriorate.

(2) Manufacturing method of constraining type damping sheet The constraining type damping sheet of the present invention can be manufactured, for example, as follows.

(Production method of damping material layer sheet)
First, a damping material layer sheet is prepared. An aqueous emulsion dispersion of butyl rubber can be prepared by the method disclosed in Japanese Patent Application Laid-Open No. 2006-219609 by the present inventors. More specifically, emulsification is carried out by adding an aqueous solution of an anionic emulsifier having a rosin soap and an alkyl group having 6 to 30 carbon atoms to a rubber solution prepared by dissolving butyl rubber in an organic solvent, and stirring. Thereafter, it is diluted with water and the organic solvent is distilled off, whereby an aqueous emulsion dispersion of butyl rubber can be prepared.

  Here, when adding a tackifier or a softening agent to the vibration damping material layer, the tackifier or softener is dissolved in an organic solvent together with butyl rubber. When the tackifier or softener is an aqueous emulsion, it is added by diluting with water and before distilling off the organic solvent.

  An acrylic emulsion containing 2-ethyl-hexyl acrylate as a main component and an acrylic polymer having a Tg of −50 ° C. or less, (c-1) mica having a particle size component, and (c -2) An aqueous mixture can be prepared by blending mica having a particle size component. The prepared aqueous mixture can be applied to release paper or the like and dried to prepare a vibration damping material layer sheet.

(Method for producing sheet having constraining layer and damping material layer)
Next, a sheet having a constraining layer and a damping material layer is produced. A sheet having a constraining layer and a damping material layer can be produced by bonding the restraining layer and the damping material layer to the produced damping material layer sheet using an adhesive or an adhesive. The pressure-sensitive adhesive used here is preferably the same as that constituting the pressure-sensitive adhesive layer. In addition, when preparing the sheet | seat of a damping material layer, the sheet | seat which has a restricted layer and a damping material layer can also be produced by apply | coating the prepared aqueous mixture directly to a constraining layer, and drying.

(Manufacturing method of constrained vibration damping sheet having constraining layer, vibration damping material layer, and adhesive layer)
An aqueous emulsion is prepared by blending an aqueous emulsion dispersion of butyl rubber prepared separately with an acrylic emulsion containing 2-ethyl-hexyl acrylate as a main component and an acrylic polymer having a Tg of −50 ° C. or lower. The prepared water-based emulsion is directly applied to a sheet having a constraining layer and a vibration damping material layer and dried to produce a constrained vibration damping sheet. Moreover, a water-based emulsion is applied to a release paper or the like, and a pressure-sensitive adhesive layer is produced by drying, and the produced pressure-sensitive adhesive layer is transferred to a sheet having a constraining layer and a vibration damping material layer. Can be manufactured. The transfer method is not particularly limited, and for example, transfer can be performed using a roll.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

  [Loss coefficient]: A 0.8 mm × 25 mm × 300 mm galvanized steel sheet was pasted with a constrained vibration damping sheet cut to 25 mm × 300 mm to obtain a test piece for measuring the loss coefficient. The measurement was performed in accordance with method B of JIS K 7244-3: 1999.

  [Peel strength]: A galvanized steel plate of 0.8 mm × 25 mm × 300 mm was bonded with 100 mm of a constrained vibration damping sheet cut to 25 mm × 300 mm, and a 180 ° peel test was performed according to JIS Z0237: 2000 at a peel rate of 300 mm / min. Conducted in compliance.

(Synthesis Example 1)
100 parts (600 g) of butyl rubber (manufactured by JSR, trade name “JSR Butyl268”) and 400 parts (2400 g) of toluene are charged into an emulsifier (Special Machine Industries, TK combination type), and then 90 ° C. The rubber solution was prepared by dissolving the butyl rubber in toluene. Separately, rosin soap (Arakawa Chemical Industries, trade name “Longis K-80”) 45 g (active ingredient 36 g) and anionic emulsifier (Daiichi Kogyo Seiyaku, trade name “Neogen S-20F”) 30 g (effective) Component 6g) was dissolved in water (45 g) at 50 ° C. to prepare an anionic emulsifier. While maintaining the internal temperature at 50 ° C., the prepared anionic emulsifier was added to the rubber solution to carry out emulsification. Next, 250 parts (1500 g) of water was added dropwise over 60 minutes for dilution. As a thickener, 20 parts (120 g) of a 1% aqueous solution of a trade name “KELDENT” (Dainippon Pharmaceutical Co., Ltd., xanthan gum) was added and mixed for 10 minutes. Toluene was distilled off at 50 ° C. and 720 to 640 mmHg (96.0 to 85.3 kPa) using a rotary evaporator (Tokyo Rika Kikai Co., Ltd., N-11 type) to make the residual toluene amount 0.05%. Thus, an aqueous emulsion dispersion of 50% butyl rubber was prepared.

Example 1
To the aqueous emulsion dispersion of 50% butyl rubber prepared in Synthesis Example 1, mica (1) (manufactured by Repco) with an acrylic emulsion (manufactured by Soken Chemical Co., Ltd., trade name “E-03H”) solid content of 50 parts and an average particle size of 27 μm. , Trade name "Mica S-325") and 100 parts of mica (2) (manufactured by Repco, trade name "Mica S-200HG") having an average particle diameter of 55 µm were prepared to prepare an aqueous mixture. The prepared aqueous mixture was applied to a 0.1 mm thick soft aluminum foil to a thickness of 3.3 mm, dried at room temperature, and then heated at 80 ° C. for 1 hour to produce a sheet having a constraining layer and a damping material layer. . Separately, an acrylic emulsion (manufactured by Soken Chemical Co., Ltd., trade name “E-03H”) was added to the aqueous emulsion dispersion of 50% butyl rubber prepared in Synthesis Example 1 so as to have a solid content mass ratio of 50/50. Was prepared. The prepared aqueous emulsion was applied to a release paper with a thickness of 0.1 mm, and heated at 80 ° C. for 30 minutes to prepare an adhesive layer. The produced pressure-sensitive adhesive layer was transferred to a sheet having a constraining layer and a vibration damping material layer with a roll to produce a constrained vibration damping sheet. The graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature is shown in FIGS. 1-5 and FIG. Moreover, the peel strength test of the restraining type vibration damping sheet was performed. The results are shown in Table 2.

(Examples 2-7, Comparative Examples 1-6)
A constrained vibration damping sheet was produced in the same manner as in Example 1 except that the formulation shown in Table 1 was used. The graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Examples 2-7 and Comparative Examples 1, 4, and 5 is shown in FIGS. FIG. 6 shows a graph (frequency: 100 Hz) in which the loss coefficient is plotted with respect to the temperature for the constraint type vibration damping sheets of Example 6 and Comparative Example 3. In addition, a peel strength test was performed on the constrained vibration damping sheets of Comparative Examples 2, 5, and 6. The results are shown in Table 2.

(Example 8)
A constrained vibration damping sheet was produced in the same manner as in Example 1 except that the vibration damping material layer further contained 50 parts of a tackifier (trade name “Nanolet R1510” manufactured by Yasuhara Chemical Co., Ltd.). FIG. 4 shows a graph (frequency: 500 Hz) in which the loss coefficient is plotted against the temperature. In addition, a peel strength test of the constrained vibration damping sheet was performed. The results are shown in Table 2.

Example 9
Implementation, except that the damping material layer further contains 35 parts of a tackifier (trade name “Nanolet R1510” manufactured by Yashara Chemical Co., Ltd.) and 15 parts of a softening agent (trade name “Emauret 10E” manufactured by Nippon Oil & Fats Co., Ltd.) A restrained vibration damping sheet was produced in the same manner as in Example 1. FIG. 4 shows a graph (frequency: 500 Hz) in which the loss coefficient is plotted against the temperature. In addition, a peel strength test of the constrained vibration damping sheet was performed. The results are shown in Table 2.

(Comparative Example 7)
As an acrylic emulsion, the product name “AE337” (manufactured by JSR, Tg = −30 ° C.) was used instead of the product name “E-03H” (manufactured by Soken Chemical Co., Ltd., Tg = −58 ° C.). A constrained vibration damping sheet was produced in the same manner as in Example 1. FIG. 5 shows a graph (frequency 500 Hz) in which the loss coefficient is plotted against the temperature. In addition, a peel strength test of the constrained vibration damping sheet was performed. The results are shown in Table 2.

(Comparative Example 8)
Instead of mica (2) having an average particle size of 55 μm (trade name “Mica S-200HG” manufactured by Repco), mica (3) having an average particle size of 550 μm (trade name “SC-30” manufactured by Repco) was used. A constrained vibration damping sheet was produced in the same manner as in Example 1 except that it was used. FIG. 7 shows a graph (frequency 500 Hz) in which the loss coefficient is plotted against the temperature. In addition, a peel strength test of the constrained vibration damping sheet was performed. The results are shown in Table 2.

  The present invention is a constrained vibration damping sheet having effective vibration damping performance from a low temperature to a high temperature, and is suitable for practical use.

It is the graph (frequency 500Hz) which plotted the loss factor with respect to temperature about the restraint type damping sheet of Examples 1, 2, 3 and Comparative Example 1. It is the graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Examples 1, 4, 5 and Comparative Example 5. It is the graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Examples 1, 6, 7 and Comparative Example 4. It is the graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Examples 1, 8, and 9. It is the graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Example 1 and Comparative Example 7. It is the graph (frequency 100Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Example 6 and Comparative Example 3. It is the graph (frequency 500Hz) which plotted the loss coefficient with respect to temperature about the restraint type damping sheet of Example 1 and Comparative Example 8.

Claims (1)

Having a constraining layer, a damping material layer, and an adhesive layer;
The damping material layer is
(A) an aqueous emulsion dispersion of butyl rubber;
(B) an acrylic emulsion containing an acrylic polymer mainly composed of 2-ethyl-hexyl acrylate and having a Tg of −50 ° C. or lower;
(C) mica containing (c-1) particle size component having an average particle size of 30 μm or less and (c-2) particle size component having an average particle size of 50 to 200 μm;
Is a sheet formed by applying and drying an aqueous mixture containing
The mass ratio ((a) / (b)) of (a) solid content of the aqueous emulsion dispersion of (A) butyl rubber and (b) solid content of (B) acrylic emulsion is 30/70 to 70/30. And
The mass ratio ((c-1) / (c-2)) of the (c-1) particle size component and the (c-2) particle size component is 20/80 to 80/20,
The total content of the (c-1) particle size component and the (c-2) particle size component with respect to 100 mass parts in total of the (a) solid content and the (b) solid content is 80 to 200 mass. Restraint type damping sheet that is a part.

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