KR102248501B1 - Vibration-damping material - Google Patents

Abstract

The vibration damping material includes a resin layer and a restraint layer laminated on the resin layer. The resin layer is formed of a resin composition containing a butyl rubber, a softener and a filler, the number average molecular weight of the softener is 1000 or more, and the content ratio of the filler is 10 to 100 parts by mass per 100 parts by mass of the butyl rubber, and the filler is It contains clay minerals and/or organic bentonite.

Description

Vibration damping material{VIBRATION-DAMPING MATERIAL}

The present invention relates to a vibration damping material, specifically, to a vibration damping material used by bonding to a vibration member used in various industrial products.

Conventionally, various parts used in fields such as automobiles, railroad vehicles, home appliances, office equipment, residential facilities, and machine tools are liable to generate a vibration sound during their operation. Therefore, in order to prevent the occurrence of such a vibration sound, it is known to improve the vibration damping property of the component by, for example, bonding a vibration damping sheet to the component (vibration member).

For example, in order to obtain good vibration damping properties under a temperature of about 40°C, a vibration damping sheet containing 100 parts of butyl rubber and 1600 parts of calcium carbonate has been proposed (for example, see Japanese Patent Laid-Open No. Hei 9-136998). ).

In Japanese Unexamined Patent Application Publication No. Hei 9-136998, the vibration damping properties of the vibration damping sheet under normal temperature (about 20° C.) and at a temperature of about 40° C. are evaluated.

However, in the vibration damping material of Japanese Unexamined Patent Application Publication No. Hei 9-136998, the specific gravity of the vibration damping material is large, and weight reduction is desired. Further, since the vibration suppression sheet is used by adhering to a component, good adhesion is also desired for the vibration suppression sheet.

Furthermore, with respect to a wall with good sliding properties (a member installed vertically in the vertical direction), in order to improve the adhesiveness, the vibration damping sheet is adhered (baked) at a high temperature in some cases. In this case, the vibration suppression sheet may be drooped off due to heat or may fall off the wall. Therefore, improvement of thermal sagging is also desired.

An object of the present invention is to provide a vibration damping material having good vibration damping properties, adhesiveness and light weight, and suppressing thermal sagging.

The vibration damping material of the present invention includes a resin layer and a restraining layer laminated on the resin layer, the resin layer is formed of a resin composition containing butyl rubber, a softener and a filler, and the number average molecular weight of the softener is 1000 or more. And the content ratio of the filler is 10 to 100 parts by mass with respect to 100 parts by mass of the butyl rubber, and the filler contains a clay mineral and/or organic bentonite.

In addition, in the vibration damping material of the present invention, it is preferable that the resin layer has a content ratio of 30 to 150 parts by mass per 100 parts by mass of the butyl rubber.

Further, in the vibration damping material of the present invention, it is preferable that the softener is polybutene.

Further, in the vibration damping material of the present invention, it is preferable that the resin layer contains 5 to 150 parts by mass of the tackifier with respect to 100 parts by mass of the butyl rubber.

Further, in the vibration damping material of the present invention, it is preferable that the specific gravity of the resin layer is 1.20 or less.

The vibration damping material of the present invention comprises a constraining layer and a resin layer containing a specific amount of a butyl rubber, a softener having a number average molecular weight of 1000 or more, and a filler containing clay minerals and/or organic bentonite.

Therefore, the vibration damping material of the present invention is excellent in vibration damping properties, adhesiveness, and light weight in a room temperature region (20 to 40°C). In addition, thermal sagging is also suppressed. Therefore, the vibration damping material of the present invention can be reliably adhered to the vibration member, and vibration vibration can be sufficiently suppressed without weighting the vibration member.

1A to 1B are explanatory diagrams showing a method of adhering a vibration damping material according to an embodiment of the present invention to a vibration member, FIG. 1A is a process of preparing a vibration damping material and peeling a release paper, and FIG. 1B is a vibration damping material. The process of adhering to the member is shown.

As shown in FIG. 1A, the vibration damping material 1 of the present invention includes a resin layer 2 and a restraining layer 3 laminated on the resin layer 2.

The resin layer 2 is formed in a sheet shape from a resin composition.

The resin composition contains butyl rubber, a softener, and a filler.

Butyl rubber is a synthetic rubber obtained by copolymerization of isobutene (isobutylene) and isoprene.

The Mooney viscosity (at ML 1+4, 100°C) of the butyl rubber is, for example, 25 or more, preferably 30 or more, and, for example, 90 or less, preferably 60 or less. Mooney viscosity is measured according to JIS K 6300.

The specific gravity of the butyl rubber is, for example, 0.8 or more, preferably exceeds 1.0, and is, for example, 1.5 or less, preferably 1.3 or less.

The content ratio of the butyl rubber is, for example, 5% by mass or more, preferably 10% by mass or more, and, for example, 50% by mass or less, preferably 40% by mass or less with respect to the resin composition.

The softener is formulated to impart plasticity to the vibration damping material 1 and improve the handling properties of the vibration damping material 1. For example, liquid rubber such as polybutene, liquid isoprene rubber, and liquid butadiene rubber, such as paraffin. Oils such as oil and naphthenic oil, for example, esters such as phthalic acid ester and phosphoric acid ester, etc. may be mentioned.

These softening agents may be used alone or in combination.

Among these softening agents, preferably, liquid rubber is used, and more preferably, polybutene is used. As a result, the vibration damping material 1 is excellent in vibration damping property and adhesiveness.

In particular, the resin composition contains a softener having a number average molecular weight of 1000 or more. The number average molecular weight of the softener is preferably 1100 or more, and more preferably 1200 or more. By setting the quantity average molecular weight of the softener contained in the resin composition (that is, the vibration damping material 1) to the above range, good vibration damping properties can be imparted to the vibration damping material 1. Further, since the softener is generally low in specific gravity compared to the filler and can be blended into the resin composition without lowering the viscosity of the resin composition, the blending amount can be increased. As a result, the weight reduction of the vibration damping material 1 can be achieved. Furthermore, it becomes favorable also in the point of suppression of thermal sagging, adhesion, and workability.

The upper limit of the yield average molecular weight is, for example, 4000 or less, and preferably 3500 or less.

The number average molecular weight is determined by gel permeation chromatography (GPC). GPC is measured in terms of standard polystyrene in the following apparatus and measurement conditions.

GPC device: HLC-8120GPC (Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000, column size: 6.0mmI.D.×150mm), detector: differential refractive index detector (RI), manufactured by Tosoh Corporation

GPC measurement conditions: mobile phase tetrahydrofuran, flow rate 0.6ML/min, column temperature 40°C, sample concentration 1.0g/L, injection volume 20µl

The kinematic viscosity (100°C) at 100°C of the softener is, for example, 100 mm 2 /s or more, preferably 350 mm 2 /s or more, and, for example, 800 mm 2 /s or less, preferably 700 mm 2 /s or less to be. Kinematic viscosity is measured according to JIS K 2283 or ASTM D-445.

The specific gravity of the softener is, for example, 0.5 or more, preferably 0.7 or more, and, for example, 1.2 or less, preferably less than 1.0.

The content ratio of the softener having a yield average molecular weight of 1000 or more is 30 parts by mass or more, and preferably 50 parts by mass or more with respect to 100 parts by mass of the butyl rubber. Moreover, it is 150 mass parts or less, Preferably it is 120 mass parts or less. When the content ratio of the softener is within the above range, the vibration damping material 1 can sufficiently exhibit vibration damping properties.

In addition, the resin composition may contain a softener having a low molecular weight (number average molecular weight is less than 1000) in addition to the softener described above. In the case of containing a low molecular weight softener, from the viewpoint of preventing contamination of the operator's hands due to excessive increase in stickiness of the resin layer 2, the low molecular weight softener content ratio is based on 100 parts by mass of butyl rubber, eg For example, it is 80 parts by mass or less, preferably 50 parts by mass or less, and more preferably 10 parts by mass or less.

The resin composition contains clay mineral and/or organic bentonite as a filler. Since these fillers have high thixotropic properties, they can impart a high viscosity to the resin composition, and as a result, the vibration damping property and adhesiveness of the vibration damping material 1 can be effectively suppressed, as they are good, and thermal sagging can be effectively suppressed.

Examples of clay minerals include kaolinite, smectite, montmorillonite, sericite, iriite, gloconite, chlorite, talc, zeolite, and the like. Preferably, talc is used.

Organic bentonite is a hydrophobic compound obtained by surface-treating montmorillonite, a clay mineral, with organic cations such as quaternary ammonium salts.

Examples of the quaternary ammonium salt include alkyltrimethyl ammonium salts such as trimethyloctyl ammonium salt, trimethyldodecyl ammonium salt, trimethyloctadecyl ammonium salt, and trimethylstearyl ammonium salt, such as dimethyldioctyl ammonium salt, dimethyldidodecyl ammonium salt, dimethyldioctadecyl Dimethyldialkyl ammonium salts such as ammonium salts, trialkylmethyl ammonium salts such as trioctylmethyl ammonium salts and tridodecylmethyl ammonium salts, tetraalkyl ammonium salts such as tetramethyl ammonium salts and tetrabutyl ammonium salts, such as oleylbis (2-hydroxyethyl) methyl ammonium salt, etc. are mentioned.

These organic bentonites may be used alone or in combination.

Preferably, a tetraalkyl ammonium salt is used.

Specific examples of the organic bentonite include the Oruganaito series, S-ben series, S-ben N series, and the like manufactured by Hojun Corporation.

In addition to clay minerals and organic bentonite, the resin composition can also use other fillers in combination. As other fillers, for example, calcium carbonate (e.g., heavy calcium carbonate, light calcium carbonate, Hakuenka (colloidal calcium carbonate), etc.), carbon black (e.g., acetylene black, furnace black, etc.), silica, alumina , Aluminum silicate, titanium oxide, metal powder (eg, aluminum powder, iron powder, etc.), resin powder (eg, acrylic resin powder, plastic beads such as styrene resin powder), glass powder (glass powder), boron nitride powder , Metal hydroxides (eg, aluminum hydroxide, magnesium hydroxide, etc.), and the like. These fillers may be used alone or in combination.

As other fillers to be used in combination, preferably, calcium carbonate and carbon black are exemplified.

The total content of the filler is 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 60 parts by mass or more, and 100 parts by mass or less, preferably 90 parts by mass or less based on 100 parts by mass of the butyl rubber. to be.

When the content ratio of the filler is within the above range, the specific gravity of the resin layer 2 is reduced, and the light weight of the vibration damping material 1 is improved.

In particular, in the case of containing organic bentonite among the above fillers, calcium carbonate and carbon black are preferably used in combination. Thereby, it is excellent in light weight, vibration damping property, and adhesiveness.

When containing organic bentonite, the content of organic bentonite in the filler is, for example, 1% by mass or more, preferably 5% by mass or more, and 15% by mass or less, preferably 30% by mass or less. The content of calcium carbonate in the filler is, for example, 50% by mass or more, preferably 60% by mass or more, and, for example, 95% by mass or less, preferably 85% by mass or less. The content of the carbon black in the filler is, for example, 1% by mass or more, preferably 5% by mass or more, and, for example, 20% by mass or less, preferably 15% by mass or less.

In the case of containing a clay mineral, preferably, the filler contains only a clay mineral, or a clay mineral and an organic bentonite are used in combination.

When the filler uses a clay mineral and an organic bentonite together, the content ratio of the clay mineral in the filler is, for example, 70% by mass or more, preferably 80% by mass or more, and, for example, 99% by mass or less, preferably Is 95% by mass or less. The content ratio of organic bentonite in the filler is, for example, 1% by mass or more, preferably 5% by mass or more, and, for example, 30% by mass or less, preferably 20% by mass or less.

In addition, when the amount of carbon black in the resin composition increases, the resin composition preferably does not contain carbon black from the viewpoint of black contamination of the operator who handles the vibration damping material 1 or members around the vibration damping material. In the case of containing carbon black, the content of carbon black is preferably less than 20 parts by mass, more preferably less than 15 parts by mass, and still more preferably less than 10 parts by mass, based on 100 parts by mass of the butyl rubber.

The resin composition preferably contains a tackifier. Thereby, the adhesiveness, vibration damping property, workability, etc. of the vibration damping material 1 can be improved.

As tackifier, for example, rosin resin, terpene resin (for example, terpene-aromatic liquid resin, etc.), coumarone indene resin, phenol resin, phenol formalin resin, xylene formalin resin, petroleum resin Resins (for example, C5 type petroleum resin, C9 type petroleum resin, C5/C9 type petroleum resin, etc.), etc. are mentioned.

These tackifiers may be used alone or in combination.

Among these tackifiers, preferably, a petroleum resin is used.

The softening point of the tackifier is, for example, 50°C or more, preferably 80°C or more, and for example, 200°C or less, preferably 150°C or less. The softening point is measured according to the test method of TSTM4027.

The specific gravity of the adsorption imparting agent is, for example, 0.6 or more, preferably 0.8 or more, and, for example, 1.3 or less, preferably less than 1.0.

The content ratio of the tackifier is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, and, for example, 150 parts by mass or less, preferably 90 parts by mass or less, based on 100 parts by mass of the butyl rubber. When the content ratio of the tackifier is within the above range, the resin layer 2 is excellent in tackiness and the like.

In the resin composition, in addition to the above components, for example, a crosslinking agent, a crosslinking accelerator, a foaming agent, a lubricant, an anti-aging agent, oils and fats (e.g., animal fats, vegetable fats, mineral oils, etc.), pigments, antiscorch agents, stabilizers, plasticizers, ultraviolet absorbers , A mold inhibitor, a flame retardant, and other known additives may be further contained in an appropriate ratio.

In addition, the resin composition is prepared as a kneaded product by blending each of the components in the above content ratio and kneading by a kneader such as a mixing roll, a pressure kneader, a Banbury mixer, or an extruder.

The flow viscosity when measured under the conditions of the kneaded product (resin composition, furthermore the resin layer 2) at a temperature of 60° C. and a load pressure of 20 kgf/cm 2 is, for example, 3000 Pa·s or more, preferably 5300 Pa·s. It is more, more preferably 6000 Pa·s or more, and, for example, 30000 Pa·s or less, preferably 10000 Pa·s or less. By making the flow viscosity within the above range, the vibration damping material 1 can sufficiently exhibit excellent vibration damping properties.

Thereafter, the obtained kneaded product is compression stretched by, for example, calender molding, extrusion molding, press molding, or the like to form the resin layer 2 in a sheet shape (that is, to form a sheet).

Thereby, the resin layer 2 is formed.

The thickness of the resin layer 2 is, for example, 0.5 mm or more, for example 6.0 mm or less, and preferably 3.0 mm or less.

When the thickness of the resin layer 2 is less than the above lower limit, the vibration damping property may be low. In addition, when the thickness of the resin layer 2 exceeds the above-described upper limit value, although the vibration damping property is seen, the effect of increasing the thickness may hardly be seen.

The specific gravity of the resin layer 2 is, for example, 1.20 or less, preferably 1.18 or less, more preferably 1.16 or less, and for example 1.10 or more. When the specific gravity of the resin layer 2 exceeds the above-described upper limit, weight reduction of the vibration damping material 1 becomes insufficient.

Specific gravity is measured by, for example, a dimensional method.

The 90 degree peel adhesion of the resin layer 2 at 23° C. is, for example, 10 N/25 mm or more, preferably 50 N/25 mm or more, more preferably 65 N/25 mm or more, for example 500 N/ It is also less than 25mm.

In addition, the 90 degree peel adhesion was obtained by cutting the resin layer 2 into a width of 25 mm and a length of 100 mm to prepare a sample, and after bonding the sample to a stainless steel plate, a speed of 300 mm / at 23°C was performed at 90 degrees to the stainless steel plate. It is measured by peeling the sample using a universal tensile tester in minutes.

The constraining layer 3 is laminated on the resin layer 2 in order to constrain the resin layer 2 and impart toughness to the resin layer 2 to improve strength. The constraining layer 3 has a sheet shape, and is lightweight and thin, and is formed of a material that can be closely integrated with the resin layer 2, for example, glass fiber, resin-impregnated glass fiber, synthetic resin nonwoven fabric, metal foil, Carbon fiber, synthetic resin film, etc. are mentioned.

The glass fiber is made of a cloth made of glass fiber, and a known glass fiber may be mentioned.

The resin-impregnated glass fibers are those in which the above-described glass fibers are impregnated with a synthetic resin such as a thermosetting resin or a thermoplastic resin, and a known one is exemplified. Moreover, as a thermosetting resin, an epoxy resin, a urethane resin, a melamine resin, a phenol resin, etc. are mentioned, for example. Further, examples of the thermoplastic resin include vinyl acetate resin, ethylene-vinyl acetate copolymer (EVA), vinyl chloride resin, and EVA-vinyl chloride resin copolymer. In addition, the above-described thermosetting resin and thermoplastic resin may be used alone or in combination.

Examples of the synthetic resin nonwoven fabric include polypropylene resin nonwoven fabric, polyethylene resin nonwoven fabric, and polyester resin nonwoven fabric.

As a metal foil, an aluminum foil, a steel foil, etc. are mentioned, for example.

The carbon fiber is a fabric made of a fiber containing carbon as a main component, and known ones are exemplified.

As a synthetic resin film, polyester films, such as a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, and a polybutylene terephthalate (PBT) film, etc. are mentioned, for example. Preferably, a PET film is used.

Among these restraining layers 3, from the viewpoint of adhesiveness, strength, and cost, preferably, glass fibers and resin-impregnated glass fibers are exemplified.

In addition, the thickness of the constraining layer 3 is, for example, 0.05 mm or more, preferably 0.1 mm or more, and, for example, 2.0 mm or less, preferably 1.0 mm or less.

The total thickness of the resin layer 2 and the constraining layer 3 (that is, the thickness of the vibration damping material 1) is, for example, 0.55 to 8.0 mm.

In order to manufacture the vibration damping material 1, the resin layer 2 and the restraining layer 3 are bonded, for example, by compression bonding or thermal compression bonding.

In addition, in the vibration damping material 1, a known release paper 4 may be adhered to the surface of the resin layer 2 opposite to the lamination side of the constraining layer 3, if necessary. In that case, the release paper 4 is laminated on the resin layer 2 when forming the resin layer 2 into a sheet.

Further, the vibration damping material 1 has a loss coefficient of 0°C, 20°C, and 40°C, for example, 0.05 or more, preferably 0.10 or more, and, for example, 1.00 or less.

When the loss factor of the vibration damping material 1 is more than the above-described lower limit, the vibration damping member 5 can be sufficiently damped by bonding the vibration damping material 1 to the vibration member 5.

In particular, at 20°C, the loss factor is, for example, 0.30 or more, preferably 0.40 or more, more preferably 0.50 or more, and 1.00 or less, for example.

In addition, as for the loss factor, a sample was prepared by cutting the resin layer 2 into a width of 10 mm and a length of 250 mm, and the sample was adhered to an SPCC steel plate of 0.8 mm x 10 mm x 250 mm as an adherend, and a loss factor measuring device Using, the loss factor of the secondary resonance point is measured by the central excitation method.

The vibration damping material 1 thus obtained is adhered to various parts used in fields such as automobiles, railroad vehicles, home appliances, office equipment, residential equipment, machine tools, and the like, and thereby dampens the various parts.

Examples of various parts include parts that are expected to be lightweight, such as a steel door plate for a vehicle, a panel for a home appliance, and the like.

More specifically, in the vibration damping material 1, when the release paper 4 is adhered to the surface of the resin layer 2, in use, as shown by the imaginary line in Fig. 1A, the resin layer 2 The release paper 4 is peeled off from the surface of, and then, as shown in Fig. 1B, the surface of the resin layer 2 is adhered to a vibration member 5 such as a component to be adhered. Thereby, the vibration damping material 1 vibrates the vibration member 5.

The resin layer 2 and the vibrating member 5 can be bonded, for example, by compression bonding or thermal compression bonding (baking).

In the case of thermocompression bonding, the heating temperature is, for example, 100°C or higher, preferably 150°C or higher, and, for example, 250°C or lower, preferably 200°C or lower. The heating time is, for example, 1 minute or more, preferably 5 minutes or more, and for example, 2 hours or less, preferably 1 hour or less.

And this vibration damping material 1 is equipped with the resin layer 2 containing butyl rubber, a softener having a specific range of water-average molecular weight, and a specific filler in a specific content ratio.

In particular, since the butyl rubber contains a softener having a water quantity average molecular weight of 1000 or more, the peak of the loss factor of the vibration damping material 1 can be shifted to the high temperature side (normal temperature region). As a result, vibration can be sufficiently suppressed for parts used at 0°C to 40°C (especially 20°C). In addition, since clay minerals or organic bentonite are contained as a filler, deformation of the vibration damping material 1 due to heat can be suppressed as long as good adhesion and vibration damping properties are improved in a specific amount. Further, since the filler is in a specific amount, the specific gravity of the resin layer 2 is reduced, and the vibration damping material 1 can be reduced in weight.

As a result, the vibration damping material 1 can be reliably adhered, and vibration damping can be performed without weighting the vibration member 5. In addition, when the vibration damping material 1 is attached to the surface extending in the vertical direction of the member at high temperature, the vibration damping material 1 is slackened and it is difficult for the vibration damping material 1 to fall off the surface. Also, it is possible to easily control vibration even on a vertical surface.

Furthermore, it is possible to reduce contaminant fillers such as carbon black, and the workability is also excellent.

Hereinafter, the present invention will be described in more detail by giving examples and comparative examples, but the present invention is not limited thereto at all. In addition, the numerical values of the examples disclosed below may replace the numerical values (ie, upper or lower limit values) described in the above embodiments.

Examples 1 to 4 and Comparative Examples 1 to 4

In the formulation shown in Table 1, each component was blended and kneaded with a mixing roll to prepare a kneaded product (resin composition).

Subsequently, the obtained kneaded product was compression stretched into a sheet shape by press molding, and laminated on the surface of a release paper to form a resin layer having a thickness of 2.0 mm.

Thereafter, on the surface opposite to the lamination side of the release paper in the resin layer, a constraining layer containing 0.2 mm thick glass fibers is bonded by thermocompression, and the total thickness of the resin layer and the constraining layer is 2.2 mm. A vibration damping material was produced.

(Measurement of number average molecular weight)

The number average molecular weight of the softener was measured in terms of standard polystyrene in the following apparatus and measurement conditions.

GPC device: HLC-8120GPC (Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000, column size: 6.0mmI.D.×150mm), detector: differential refractive index detector (RI), manufactured by Tosoh Corporation

GPC measurement conditions: mobile phase tetrahydrofuran, flow rate 0.6ML/min, column temperature 40°C, sample concentration 1.0g/L, injection volume 20µl

(Ratio of resin layer)

The specific gravity of the resin layer prepared in each Example and each Comparative Example was measured by the dimensional method. That is, the mass of the resin layer was measured with an electronic balance, and then the dimension of the resin layer was measured with a vernier caliper to calculate the volume of the resin layer. Then, the specific gravity of the resin layer was calculated by dividing the mass of the resin layer by the volume of the resin layer.

(Flow viscosity)

Using a solidification flow tester (manufactured by Shimadzu Corporation, "CFT-500D"), a nozzle length of 1.0 mm and a nozzle diameter of 1.0 mm were used, and a temperature of 60°C and a load pressure of 20 kgf/cm 2 (about 0.98 MPa) were used. Under the conditions, the flow viscosity of the resin composition prepared in each Example and each Comparative Example was measured. Table 1 shows the results.

(Adhesiveness)

A sample was prepared by cutting the resin layer prepared in each example and each comparative example into a width of 25 mm and a length of 100 mm, and after bonding the sample to a stainless steel plate, the speed was 300 mm at 23°C and 90 degrees to the stainless steel plate. By peeling the sample using a universal tensile tester at /min, the 90 degree peel adhesion to each resin layer was measured. Table 1 shows the results.

(Heat sagging property)

Oil was applied to the surface of a 0.8 mm×80 mm×200 mm SPCC steel plate, and left to stand for 1 day to obtain an adherend.

Samples were prepared by cutting the vibration damping material prepared in each example and each comparative example into a width of 50 mm and a length of 150 mm. This sample was pressed against an adherend with a 2 kg roller, aged for 1 hour, and then installed vertically and baked at 180° C. for 20 minutes, and the amount of shift (mm) or the presence or absence of dropping was confirmed at that time. Table 1 shows the results.

(Workability)

The surface of the resin layer of the vibration damping material prepared in each example and each comparative example was lightly touched by hand, and whether or not the hand became black and dirty was measured. The case where the hand was not black and dirty was evaluated as ○, and the case where the hand was black and dirty was evaluated as x. Table 1 shows the results.

(Vibration isolation (loss factor))

The loss coefficients of the secondary resonance points at 0, 20° C. and 40° C. of the vibration damping material prepared in each Example and each Comparative Example were measured under the following measurement conditions by the central excitation method using a loss coefficient measuring device. Specifically, a sample was prepared by cutting the vibration damping material into a width of 10 mm and a length of 250 mm, and the loss factor was measured by adhering the sample to an adherend. Table 1 shows the results.

Attachment: 0.8mm×10mm×250mm SPCC steel plate

Frequency: 500Hz (500Hz is calculated from the resonance point)

Numerical values in each component in Table 1 represent parts by mass unless otherwise specified. Abbreviated reference numerals in Table 1 and the like are disclosed below.

S-butyl recycled rubber: Mooney viscosity 44±6 (ML 1+4 (100℃)), specific gravity 1.16, manufactured by Agata Rubber

Polybutene HV-15: brand name, liquid polybutene, number average molecular weight 630, kinematic viscosity 31±2mm2/s (100℃), specific gravity 0.83, manufactured by JX Nikko-Niseki Energy

Polybutene HV-300: brand name, liquid polybutene, number average molecular weight 1400, kinematic viscosity 590 mm2/s (100°C), specific gravity 0.87, manufactured by JX Nikko-Niseki Energy

Calcium carbonate: heavy calcium carbonate, specific gravity 2.7, manufactured by Maruo Calcium

Carbon black: Brand name "Asahi Carbon #50", specific gravity 1.8, manufactured by Asahi Carbon

Talc: ``Imported talc'', specific gravity 2.7, manufactured by Sove Ecre Co., Ltd.

Organic bentonite: brand name ``organite'', hydrophobic compound surface-treated montmorillonite with quaternary ammonium salt (tetrabutyl ammonium salt, etc.), specific gravity 1.7, manufactured by Hojun

Escorets 1202: brand name, petroleum resin, softening point 100±5℃, specific gravity 0.98, manufactured by Exxon

In addition, although the above description has been provided as an exemplary embodiment of the present invention, this is only a mere illustration and should not be interpreted limitedly. Modification examples of the present invention that are apparent by those skilled in the art are included in the claims to be described later.

Claims (5)

A resin layer and a restraint layer laminated on the resin layer,
The resin layer is formed of a resin composition containing butyl rubber, a softener and a filler,
The number average molecular weight of the softener is 1000 or more,
With respect to 100 parts by mass of the butyl rubber, the content ratio of the filler is 10 to 100 parts by mass,
The vibration damping material, characterized in that the filler contains only organic bentonite, calcium carbonate, and carbon black. The vibration damping material according to claim 1, wherein the content ratio of the softener is 30 to 150 parts by mass based on 100 parts by mass of the butyl rubber. The vibration damping material according to claim 1, wherein the softening agent is polybutene. The vibration damping material according to claim 1, wherein the resin layer contains 5 to 150 parts by mass of a tackifier with respect to 100 parts by mass of the butyl rubber. The vibration damping material according to claim 1, wherein the resin layer has a specific gravity of 1.20 or less.

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