JP2009067825A - Damping and reinforcing composition, damping and reinforcing sheet, and damping and reinforcing method of thin plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damping and reinforcing composition enhancing both reinforcing and damping properties of a thin plate without increasing weight (basis weight), a damping and reinforcing sheet obtained using the composition with high productivity and excellent in handleability, and a damping and reinforcing method of a thin plate. <P>SOLUTION: The damping and reinforcing composition is prepared by blending rubber including acrylonitrile-butadiene rubber and butyl rubber, in which the acrylonitrile-butadiene rubber occupies 30-70 wt.% of the total amount of those, with a crosslinking agent. The damping and reinforcing sheet 1 is obtained by stacking a damping and reinforcing layer 2 of the composition formed in a sheet shape and a constraint layer 3 on one surface of the damping and reinforcing layer 2. The damping and reinforcing sheet 1 is stuck on a thin plate 5 and then the damping and reinforcing layer 2 is heated and cured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping reinforcing composition, a vibration damping reinforcing sheet, and a method for damping and reinforcing a thin plate.

  2. Description of the Related Art Conventionally, thin plates used for structures such as automobiles and home appliances have been required to have enhanced reinforcing properties in order to prevent deformation due to external stress. For this reason, a reinforcing sheet formed from an epoxy-based or rubber-based thermosetting resin layer and a glass cloth or aluminum foil constraining layer is attached to a thin plate and heated to cure the thermosetting resin layer. It is known to increase the reinforcement of the thin plate.

Further, since the thin plate generates vibration noise when used in automobiles, home appliances, etc., it is necessary to improve the vibration damping property in order to prevent the generation of the vibration noise. Therefore, it is known that a damping sheet formed from a viscoelastic resin layer such as rubber or asphalt and a constraining layer is attached to a thin plate to improve the damping performance of the thin plate.
In general, since reinforcing properties and vibration damping properties are contradictory properties, a reinforcing sheet is attached to a portion of a thin plate that requires reinforcing properties, and a portion that requires vibration damping properties is controlled. A vibration sheet is attached. However, when sticking a reinforcing sheet and a damping sheet, respectively, it is difficult to achieve both a reinforcing property and a damping property because it is limited by the area of the thin plate and the weight increase due to the bonding of multiple sheets. It is.

Therefore, three layers of a spacer layer containing a liquid epoxy resin, a methacrylic resin and a curing agent, a damping material sheet layer containing butyl rubber, and a metal sheet are provided in order to improve both reinforcement and damping properties. Has been proposed (see, for example, Patent Document 1). When this foamable thermosetting resin sheet is affixed to a thin plate, the spacer layer acts to enhance the reinforcing property (rigidity), and the damping material sheet layer acts to enhance the damping property.
JP-A-6-170997

However, the reinforcing property and vibration damping property of the foamable thermosetting resin sheet described in Patent Document 1 are both inferior to the case where the reinforcing sheet and the vibration damping sheet are individually attached.
Moreover, since the foamable thermosetting resin sheet described in Patent Document 1 has two layers of a spacer layer and a damping material sheet layer laminated on a metal sheet, there is a problem that the weight and thickness increase. is there.

In addition, the foamable thermosetting resin sheet has an interface between the spacer layer and the damping sheet layer and an interface between the damping sheet layer and the metal sheet. When arranged along, they are liable to cause inconveniences such as deviation, peeling or dropping at these interfaces.
Moreover, when manufacturing the foamable thermosetting resin sheet described in Patent Document 1, two layers having different properties such as thickness, viscosity, and elasticity are laminated on the metal sheet. It is necessary to adjust the lamination method accordingly. As a result, the manufacturing method becomes complicated and the productivity is reduced. Moreover, the handleability of the obtained foamable thermosetting resin sheet may fall.

  An object of the present invention is obtained with high productivity by using a vibration-damping reinforcement composition capable of enhancing both the reinforcing property and vibration-damping property of a thin plate without increasing the weight (basis weight), An object of the present invention is to provide a vibration-damping / reinforcing sheet having excellent handling properties and a vibration-damping / reinforcing method for thin plates.

In order to achieve the above object, the vibration-damping reinforcement composition of the present invention contains acrylonitrile-butadiene rubber and butyl rubber, and the content of the acrylonitrile-butadiene rubber in the total amount thereof is 30 to 70% by weight. It is characterized by containing an agent.
Further, it is preferable that the vibration-damping reinforcement composition of the present invention further contains a foaming agent.

Further, the vibration-damping reinforcement sheet of the present invention comprises a vibration-damping reinforcement layer in which the above-described vibration-damping reinforcement composition is formed in a sheet shape, and a constraining layer laminated on one side of the vibration-damping reinforcement layer. It is said.
The thin plate vibration damping reinforcement method of the present invention is characterized in that the vibration damping reinforcing layer is heated and cured after the vibration damping reinforcing sheet is disposed on the thin plate.

According to the vibration-damping / reinforcing composition, the vibration-damping / reinforcing sheet, and the vibration-damping / reinforcing method of the thin plate according to the present invention, both the reinforcing property and the vibration-damping property of the thin plate can be improved without increasing the weight (basis weight). .
Moreover, the vibration-damping reinforcement sheet of the present invention can be obtained with high productivity and is excellent in handleability.

The vibration-damping reinforcement composition of the present invention contains rubber and a crosslinking agent.
Rubbers include acrylonitrile butadiene comb and butyl rubber.
Acrylonitrile butadiene rubber is a synthetic rubber obtained by copolymerization of acrylonitrile and butadiene. The acrylonitrile-butadiene rubber also includes, for example, a three-dimensional copolymer into which a carboxyl group or the like is introduced.

The acrylonitrile-butadiene rubber has an acrylonitrile content of, for example, 15 to 50% by weight, and a Mooney viscosity of, for example, 25 to 80 (ML1 + 4, at 100 ° C.).
Acrylonitrile butadiene rubber can be used alone or in combination of two or more different physical properties.

Butyl rubber is a synthetic rubber obtained by copolymerization of isobutene (isobutylene) and isoprene.
Butyl rubber has an unsaturation degree of, for example, 0.8 to 2.0, and a Mooney viscosity of, for example, 30 to 90 (ML1 + 8, at 125 ° C.).
Butyl rubber can be used alone or in combination of two or more different physical properties.

  In the rubber, the content of acrylonitrile-butadiene rubber is 30 to 70% by weight, preferably 35 to 65% by weight, based on the total amount of acrylonitrile-butadiene rubber and butyl rubber. When the content ratio of acrylonitrile-butadiene rubber is less than the above range, although the vibration damping property of the vibration damping reinforcing composition after heating is improved, the improvement of the reinforcing property is insufficient. On the other hand, when the content ratio of the acrylonitrile-butadiene rubber exceeds the above range, although the reinforcing property of the vibration-damping reinforcing composition after heating is improved, the improvement of the vibration-damping property is insufficient.

  The crosslinking agent is not particularly limited as long as it can crosslink acrylonitrile-butadiene rubber and / or butyl rubber. For example, sulfur, metal oxides (for example, magnesium oxide, lead monoxide), oximes (for example, p -Quinone dioxime, p, p'-dibenzoylquinone dioxime), alkylphenols (for example, alkylphenol-formaldehyde resin) and the like. Preferably, sulfur is used. The crosslinking agents can be used alone or in combination of two or more.

Examples of sulfur include powdered sulfur (fine powdered sulfur), insoluble sulfur, surface-treated sulfur, precipitated sulfur, and colloidal sulfur. Preferably, sulfur powder is used.
The content of the cross-linking agent depends on the required reinforcing properties, but is, for example, 1 to 50 parts by weight with respect to 100 parts by weight of rubber, and preferably 5 to 5% from the viewpoint of a balance between reinforcing properties and vibration damping properties. 30 parts by weight.

In addition, when sulfur is used as the crosslinking agent, for example, a vulcanization aid, a vulcanization accelerator, and the like are further included in the vibration damping reinforcement composition.
Examples of the vulcanization aid include zinc oxide (for example, zinc white) and magnesium oxide. Vulcanization aids can be used alone or in combination, and the content of the vulcanization aid depends on the vulcanization temperature and vulcanization time, but is, for example, 0.5 to 30 weights with respect to 100 parts by weight of rubber. Part.

  Examples of the vulcanization accelerator include sulfenamides, aldehyde ammonias, aldehyde amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, xanthates, and the like. Vulcanization accelerators can be used alone or in combination. The content of the vulcanization accelerator depends on the vulcanization temperature and vulcanization time, but is, for example, 0.5 to 30 wt. Part.

Moreover, the vibration-damping reinforcement composition of the present invention can further contain a foaming agent.
A foaming agent is mix | blended when foaming the damping reinforcement layer after the heating mentioned later. Examples of the foaming agent include heat-decomposable foaming agents such as inorganic foaming agents and organic foaming agents. Examples of the inorganic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, azides and the like.

  Examples of organic foaming agents include N-nitroso compounds (N, N′-dinitrosopentamethylenetetramine, N, N′-dimethyl-N, N′-dinitrosotephthalamide, etc.), azo compounds, and the like. (Eg, azobisisobutyronitrile, azodicarboxylic acid amide, barium azodicarboxylate, etc.), fluorinated alkanes (eg, trichloromonofluoromethane, dichloromonofluoromethane, etc.), hydrazine compounds (eg, p-toluenesulfonyl) Hydrazide, diphenylsulfone-3,3′-disulfonylhydrazide, 4,4′-oxybis (benzenesulfonylhydrazide) (OBSH), allylbis (sulfonylhydrazide), etc.), semicarbazide compounds (for example, p-toluylenesulfonyl semicarbazide, 4 4'such oxybis (benzenesulfonyl semicarbazide)), triazole compound (e.g., 5-morpholyl-1,2,3,4-thiatriazole, etc.) and the like.

  Examples of the foaming agent include gas-filled microcapsule foaming agents, and more specifically, heat-expandable substances (eg, isobutane, pentane, etc.) are microcapsules (eg, vinylidene chloride, acrylonitrile). And thermally expandable fine particles encapsulated in a microcapsule made of a thermoplastic resin such as acrylic acid ester or methacrylic acid ester. As such thermally expandable fine particles, for example, commercially available products such as microspheres (trade name, manufactured by Matsumoto Yushi Co., Ltd.) are used.

These foaming agents can be used alone or in combination of two or more. Of these foaming agents, a heat decomposable foaming agent is preferable, and OBSH is more preferable.
The blending ratio of the foaming agent is, for example, 20 parts by weight or less, preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the rubber, although it depends on the curing temperature and the curing time. If the blending ratio of the foaming agent is within the above range, the foaming ratio during heating of the vibration-damping reinforcement composition can be set to 5 times or less.

In addition to the above-mentioned components, the vibration-damping reinforcement composition of the present invention may optionally contain fillers, lubricants, softeners, tackifiers, and, if necessary, additives such as anti-aging agents. Can be included.
Examples of the filler include talc, calcium carbonate, carbon black, titanium oxide, silica, aluminum hydroxide (alumina), and magnesium hydroxide. These fillers can be used alone or in combination. The blending ratio of the filler is, for example, 300 parts by weight or less with respect to 100 parts by weight of the rubber.

Examples of the lubricant include stearic acid and a metal salt of stearic acid. The lubricant can be used alone or in combination, and is contained in an appropriate ratio.
Examples of the softening agent include oils such as vegetable oil, fatty oil, tall oil (pine tree oil), mineral oil, and liquid resins such as liquid polybutene and liquid isoprene, such as paraffinic resins. These softeners can be used alone or in combination, and the content thereof is, for example, 100 parts by weight or less with respect to 100 parts by weight of rubber. If the content of the softening agent exceeds the above range, the strength may decrease excessively.

  Examples of the tackifier include coumarone indene resin, phenol formalin resin, xylene formalin resin, terpene resin (polyterpene resin), petroleum resin, rosin resin (rosin ester), and the like. These tackifiers can be used alone or in combination, and are contained in an appropriate ratio. If a tackifier is contained, the adhesiveness of the vibration-damping reinforcement sheet can be increased when a vibration-damping reinforcement sheet to be described later is attached to a thin plate.

Examples of the anti-aging agent include amine-ketone series, aromatic secondary amine series, phenol series, benzimidazole series, and phosphorous acid series. These antioxidants can be used alone or in combination, and are contained in an appropriate ratio.
In order to prepare the vibration-damping reinforcement composition of the present invention, rubber, a crosslinking agent, if necessary, a foaming agent, and an additive that is optionally blended are blended in the above-described content ratios. Mix evenly. In addition, the vibration-damping reinforcement composition can be prepared by kneading the above-described components with, for example, a mixing roll, a pressure kneader, an extruder, or the like.

And the vibration damping reinforcement sheet of this invention is equipped with the vibration damping reinforcement layer in which the above-mentioned vibration damping reinforcement composition was formed in the sheet form, and the constraining layer laminated | stacked on the single side | surface of a vibration damping reinforcement layer.
In order to form the vibration damping reinforcement layer into a sheet shape, the vibration damping reinforcement composition is rolled by a molding method such as calendar molding, extrusion molding or press molding.
In the formation of the vibration-damping reinforcement layer, the temperature condition is not particularly limited. However, when the vibration-damping reinforcement composition contains a cross-linking agent and, if necessary, a foaming agent, a temperature condition that does not substantially decompose (for example, , 60-100 ° C.).

The thickness of the vibration damping reinforcing layer formed in this way is, for example, 0.5 to 5.0 mm.
The constraining layer constrains the vibration damping reinforcement layer and imparts toughness to the vibration damping reinforcement layer to improve the strength. In addition, the constraining layer is in the form of a sheet, and is made of a material that is lightweight and thin, and can be closely integrated with the heated vibration damping reinforcement layer. Examples of such materials include metal foils such as aluminum foil and stainless steel foil, for example, glass nonwoven fabric (glass cloth) or glass woven fabric formed from glass, for example, carbon fiber woven fabric or carbon formed from carbon fiber. A fiber nonwoven fabric etc. are mentioned. Preferably, aluminum foil and glass cloth are used.

Moreover, the thickness of a constrained layer is 0.05-2 mm, for example. Further, when the constraining layer is formed from a metal foil, the thickness thereof is preferably 100 μm or less from the viewpoint of handling. Further, when the constraining layer is formed of glass cloth, the thickness thereof is preferably 300 μm or less from the viewpoint of handling.
And the vibration-damping reinforcement sheet of the present invention is 1.0 to 6.0 mm by bonding the vibration-damping reinforcement layer and the constraining layer.

The vibration-suppressing reinforcing sheet thus obtained has a bending strength of 1 mm displacement in reinforcing properties evaluated in Examples described later, for example, 20 N or more, and usually 50 N or less. If the bending strength is less than the above range, the thin plate may not be sufficiently reinforced.
Further, the vibration-damping reinforcing sheet has a loss coefficient of 0 ° C., 20 ° C., 40 ° C., and 60 ° C. in vibration damping evaluated in Examples described later, for example, 0.05 or more, and is generally 0.30. It is as follows. If the loss coefficient is less than the above range, the thin plate may not be sufficiently damped.

In addition, in the obtained vibration-damping reinforcement sheet, a separator (until the actual use) on the surface of the vibration-damping reinforcement layer (the surface opposite to the back surface on which the constraining layer is laminated), if necessary. Release paper) can also be attached.
The vibration-damping reinforcing sheet of the present invention is used for damping and reinforcing a thin plate.
Thin plates are used in various industries, and are used, for example, in automobiles and home appliances. More specifically, examples of thin plates used in automobiles include automobile pillars, roofs, fenders, hoods, trunks, quarter panels, doors, door handles, door mirrors, and the like. Moreover, as a thin plate used for household appliances, the case of a computer, a computer display, a television, a mobile phone, a game device, a refrigerator, a vacuum cleaner, etc. are mentioned, for example.

FIG. 1 shows an embodiment of a method for damping and reinforcing a thin plate according to the present invention. A damping and reinforcing sheet is disposed on a thin plate, and the damping and reinforcing layer is heated and cured, thereby damping the thin plate. It is explanatory drawing which shows the method to reinforce.
Next, with reference to FIG. 1, one embodiment of the vibration damping reinforcement method of the thin plate of this invention is demonstrated.
As shown in FIG. 1A, the vibration damping sheet 1 has a vibration damping reinforcing layer 2 laminated on a constraining layer 3, and a release paper 6 is attached to the surface of the vibration damping reinforcing layer 2 as necessary. The vibration damping reinforcement layer 2 is curable, and the vibration damping reinforcement composition does not contain a foaming agent.

In use, the release paper 6 is peeled off from the surface of the vibration damping reinforcement layer 2 as shown by phantom lines, and the surface of the vibration damping reinforcement layer 2 is removed from the thin plate 5 (see FIG. 1B). Adhere to the thin plate 5) before heating.
Then, as shown in FIG.1 (c), the damping reinforcement sheet 1 is heated. In order to heat the vibration-damping reinforcement sheet 1, for example, heat at the time of painting and drying the thin plate 5 is used. Although heating temperature is based also on the kind and content rate of a crosslinking agent, it is 130-220 degreeC, for example, and heating time is 10 to 60 minutes, for example.

Then, the vibration damping reinforcement layer 2 is cured by heating, and the strength is increased to become the cured layer 4. As a result, the vibration-damping reinforcing sheet 1 can enhance the reinforcing property of the thin plate 5 and can improve the vibration-damping property of the thin plate 5.
Moreover, since only one layer of the vibration damping reinforcement layer 2 is cured, the cured layer 4 is lightweight and thin, and effectively suppresses the weight (basis weight) increase of the vibration damping reinforcement sheet 1. Can do.

Further, since the vibration damping reinforcing sheet 1 has only one layer of the vibration damping reinforcing layer 2 laminated on the constraining layer 3, it can be obtained with high productivity and is excellent in handling.
FIG. 2 shows a vibration damping and reinforcing method for a thin plate according to another embodiment of the present invention, in which a vibration damping reinforcing sheet is disposed on the thin plate and the vibration damping reinforcing layer is heated and foamed, thereby damping the thin plate. It is explanatory drawing which shows the method of reinforcing. In addition, about the member corresponding to each above-mentioned part, the same referential mark is attached | subjected in FIG. 2, and the detailed description is abbreviate | omitted.

Next, with reference to FIG. 2, another embodiment of the method for damping and reinforcing a thin plate of the present invention will be described.
The damping reinforcement composition of the damping reinforcement layer 2 contains a foaming agent, and the damping reinforcement layer 2 can be foamed.
As shown in FIG. 2A, the vibration damping sheet 1 has a vibration damping reinforcing layer 2 laminated on a constraining layer 3. And in use, as shown in FIG.2 (b), the surface of the damping reinforcement layer 2 is stuck on the thin plate 5 (thin plate 5 before a heating).

Then, as shown in FIG.2 (c), the damping reinforcement sheet 1 is heated. Although heating temperature is based also on the kind and content rate of a foaming agent and a crosslinking agent, it is 130-220 degreeC, for example, and heating time is 10 to 60 minutes, for example.
Then, the vibration-damping reinforcement layer 2 is cured while being foamed by heating. Thereby, the vibration damping reinforcement layer 2 becomes the foam layer 7.

The volume expansion ratio at the time of foaming of the vibration-damping reinforcing layer 2 (foam layer 7) after foaming is, for example, 5.0 times or less, and preferably 0.1 to 3 times.
As a result, the damping and reinforcing sheet 1 can further improve the reinforcing properties and damping properties of the thin plate 5 as the thickness of the damping and reinforcing sheet 1 increases due to the formation of the foam layer 7.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the examples and comparative examples.
Examples 1-4 and Comparative Examples 1-2
(Preparation of vibration damping reinforcement composition)
In the formulation shown in Table 1, each component was blended on the basis of parts by weight and kneaded with a mixing roll to prepare a vibration damping reinforcing composition.

  In this preparation, first, rubber, filler, lubricant, tackifier and softener are kneaded with a mixing roll heated to 120 ° C., and after cooling, this kneaded product is further mixed with a crosslinking agent and a foaming agent (implementation). Example 2 only), a vulcanization aid and a vulcanization accelerator were added and kneaded with a mixing roll.

なお、表１中の成分またはその略号の詳細を以下に示す。
ＮＢＲ※１：アクリロニトリル・ブタジエンゴム（アクリロニトリル含量３３．５重量%、ムーニー粘度４６（ＭＬ１＋４、ａｔ１００℃）、商品名「ニッポール１０５２Ｊ」、日本ゼオン社製
ブチルゴム※２：不飽和度１．６、ムーニー粘度５１（ＭＬ１＋８、ａｔ１２５℃）、商品名「ＪＳＲブチル６８」、ＪＳＲ社製
ＯＢＳＨ※３：４，４’−オキシビス（ベンゼンスルホニルヒドラジド）
スルフェンアミド類※４：ノクセラーＣＺ（加硫促進剤）、大内新興化学工業社製
テルペン系樹脂※５：ＹＳレジンＰｘ１１５０（粘着付与剤）、ヤスハラケミカル社製
石油系樹脂※６：クイントンＵ１８５（粘着付与剤）、日本ゼオン社製
パラフィン系樹脂※７：ダイナプロセスオイルＰＷ−９０（軟化剤）、出光興産社製
（制振補強シートの作製）
次いで、調製した制振補強組成物を、プレス成形により圧延して硬化可能な制振補強層（実施例１、３、４および比較例１〜２）および発泡可能な制振補強層（実施例２）をそれぞれ形成し、この制振補強層に、拘束層として、厚さ０．２ｍｍのガラスクロスを貼り合わせることにより、厚さ２ｍｍの制振補強シートを作製した（図１（ａ）および図２（ａ）参照）。

In addition, the detail of the component in Table 1 or its abbreviation is shown below.
NBR * 1: Acrylonitrile butadiene rubber (acrylonitrile content 33.5% by weight, Mooney viscosity 46 (ML1 + 4, at100 ° C), trade name "Nippol 1052J", Nippon Zeon butyl rubber * 2: Unsaturation 1.6, Mooney Viscosity 51 (ML1 + 8, at 125 ° C.), trade name “JSR butyl 68”, OBSH * 3: 4,4′-oxybis (benzenesulfonylhydrazide) manufactured by JSR
Sulfenamides * 4: Noxeller CZ (vulcanization accelerator), terpene resin manufactured by Ouchi Shinsei Chemical Industry * 5: YS Resin Px1150 (tackifier), Petroleum resin manufactured by Yashara Chemical * 6: Quinton U185 ( (Tackifier), paraffinic resin manufactured by Nippon Zeon Co., Ltd. * 7: Dyna Process Oil PW-90 (softener), manufactured by Idemitsu Kosan Co., Ltd.
Next, the prepared vibration-damping reinforcement composition was rolled and cured by press molding to be cured (Examples 1, 3, 4 and Comparative Examples 1 to 2) and foamable vibration-damping reinforcement layer (Examples) 2) was formed, and a vibration-damping reinforcement sheet having a thickness of 2 mm was produced by bonding a glass cloth having a thickness of 0.2 mm as a constraining layer to the vibration-damping reinforcement layer (FIG. 1 (a) and (See FIG. 2 (a)).

(Evaluation)
1) Reinforcing property Damping sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were cut into a size of 25 × 150 mm, and this was cut into a test steel plate having a size of 0.8 × 25 × 150 mm. (Refer to FIG. 1 (b) and FIG. 2 (b)). Next, these are heated at 180 ° C. for 20 minutes to cure the vibration-damping reinforcement layers of Examples 1, 3, 4 and Comparative Examples 1-2, and the vibration-damping reinforcement layer of Example 2 is foamed. And it was made to harden and the test piece was obtained (refer FIG.1 (c) and FIG.2 (c)). In addition, the thickness of the vibration-damping reinforcement sheet of Example 2 was 3 mm.

Thereafter, with the test steel plate facing upward, each test piece is supported at a span of 100 mm, and at the center in the longitudinal direction, the test bar is lowered from above in the vertical direction at a compression speed of 1 mm / min. The bending strength when the foamed layer or the hardened layer was displaced by 1 mm after contact was evaluated as the reinforcing property. The results are shown in Table 2.
2) Vibration control (loss factor)
The vibration damping sheets obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were cut into a size of 10 × 250 mm, and this was attached to a steel plate having a size of 0.8 × 10 × 250 mm (see FIG. 1 (b) and FIG. 2 (b)). Subsequently, these were heated at 180 ° C. for 20 minutes, respectively, to cure the vibration-damping reinforcing layers of Examples 1, 3, 4 and Comparative Examples 1 to 2 to form a cured layer. The vibration-damping reinforcing layer was foamed and cured to form a foamed layer, and test pieces corresponding to the examples and the comparative examples were obtained (see FIGS. 1C and 2C). In addition, the thickness of the vibration-damping reinforcement sheet of Example 2 was 3 mm.

  Then, the damping coefficient of the secondary resonance point at each temperature of 0 ° C., 20 ° C., 40 ° C., and 60 ° C. was measured by the central vibration method. The results are shown in Table 2.

FIG. 1 shows an embodiment of a method for damping and reinforcing a thin plate according to the present invention. A damping and reinforcing sheet is disposed on a thin plate, and the damping and reinforcing layer is heated and cured, thereby damping the thin plate. It is explanatory drawing which shows the method to reinforce, Comprising: (a) is a process which prepares a damping reinforcement sheet and peels release paper, (b) is a process which arranges a damping reinforcement sheet on a thin plate, (c) These show the process of heating and hardening a damping reinforcement layer. A method for damping and reinforcing a thin plate by disposing a damping reinforcing sheet on a thin plate and heating and foaming the damping reinforcing layer as another embodiment of the method for damping and reinforcing a thin plate of the present invention (A) is a step of preparing a vibration damping reinforcement sheet and peeling off the release paper, (b) is a step of arranging the vibration damping reinforcement sheet on a thin plate, and (c) is a damping step. The process of heating and vibrating the vibration reinforcing layer is shown.

Explanation of symbols

1 Damping and reinforcing sheet 2 Damping and reinforcing layer 3 Constraining layer 5 Thin plate

Claims (4)

A rubber containing acrylonitrile-butadiene rubber and butyl rubber, wherein the content of the acrylonitrile-butadiene rubber in the total amount thereof is 30 to 70% by weight;
A vibration-damping / reinforcing composition comprising a crosslinking agent.   Furthermore, the damping reinforcement composition of Claim 1 containing the foaming agent. A damping reinforcement layer in which the damping reinforcement composition according to claim 1 or 2 is formed into a sheet shape;
A vibration damping reinforcement sheet comprising a constraining layer laminated on one side of the vibration damping reinforcement layer.   A method for damping and reinforcing a thin plate, comprising: arranging the damping and reinforcing sheet according to claim 3 on a thin plate; and heating and curing the damping and reinforcing layer.

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