JP5660985B2 - Adhesive damping material - Google Patents

Description

  The present invention relates to a sticking type vibration damping material, and more particularly to a sticking type vibration damping material used in various industrial fields.

  Conventionally, a thin plate is used as a part of a part in a car or home appliance, and a vibration sound of the thin plate is generated when the car is operated or when the home appliance is operated. Therefore, in order to prevent the generation of this vibration sound, it is known to improve the damping performance of the thin plate, for example, by sticking a damping sheet having a resin layer (viscoelastic body) to the thin plate.

  In addition, a thin plate disposed in the vicinity of a motor of an automobile engine room or a home appliance is likely to be high in temperature, and therefore, a damping sheet (damping material) that can exhibit a damping effect even at high temperatures is desired. .

  In order to cause the damping material to exhibit a damping effect at a high temperature, for example, it is conceivable that the glass transition temperature of the viscoelastic body used in the damping material is made higher than room temperature. For example, by setting the glass transition temperature of the viscoelastic body used for the damping material to, for example, about room temperature to about 100 ° C., the damping effect can be expressed in the engine room of the automobile.

  However, such a vibration damping material is excellent in vibration damping properties at high temperatures, but is inferior in adhesiveness at room temperature. Therefore, there is a problem that heating is required for sticking the vibration damping material and workability is poor.

  As a vibration damping material that ensures vibration damping properties at high temperatures and can be stuck at room temperature, for example, a high elastic constraining layer and an intermediate composed of a vulcanized rubber admixture containing a hot melt adhesive and a reinforcing agent There has been proposed a vibration-damping sheet that includes a constraining layer and a low-elasticity adhesive layer that has adhesiveness to a braking body and has adhesiveness (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 5-220883

  However, the vibration damping effect of the above vibration damping sheet under high temperature is effectively expressed against low-frequency vibrations, but cannot sufficiently cope with vibrations in a wide frequency range including high frequencies. In the industrial field, there is a demand for a vibration damping sheet having vibration damping performance superior to that of the above vibration damping sheet.

  An object of the present invention is to provide a sticking type vibration damping material having further improved vibration damping properties.

  In order to achieve the above object, an adhesive vibration damping material of the present invention includes a constraining layer, a first viscoelastic layer laminated on the constraining layer, and a second viscoelastic layer laminated on the first viscoelastic layer. An elastic layer, wherein the first viscoelastic layer has a glass transition point at 0 ° C. or higher, and the second viscoelastic layer has a glass transition point below 0 ° C.

  Moreover, in the sticking type | mold damping material of this invention, the difference of the said glass transition temperature of a said 1st viscoelastic layer and the said glass transition temperature of a said 2nd viscoelastic layer is 20-100 degreeC. Is preferred.

  Moreover, in the sticking type | mold damping material of this invention, the storage shear elastic modulus G 'of the said 1st viscoelastic layer with respect to the storage shear elastic modulus G' of the said 2nd viscoelastic layer in all 20-80 degreeC. The ratio is preferably 1 to 500.

Moreover, in the sticking type | mold damping material of this invention, it is suitable that the tensile elasticity modulus of the said constrained layer is 10 < ⁹ > Pa or more.

  The sticking type damping material of the present invention has a first viscoelastic layer having a glass transition point at 0 ° C. or higher and a second viscoelastic layer laminated on the first viscoelastic layer and having a glass transition point below 0 ° C. Because it is provided with a layer, it can be attached at room temperature with the second viscoelastic layer, and can exhibit excellent vibration damping properties against vibrations in a wide frequency range including high frequencies even at high temperatures. it can.

It is sectional drawing of one Embodiment of the sticking type | mold damping material of this invention. It is sectional drawing of other embodiment of the sticking type | mold damping material of this invention. The dynamic viscoelasticity measurement chart of the 1st viscoelastic layer in the comparative example 4 is shown. The dynamic viscoelasticity measurement chart of the 1st viscoelastic layer in Example 2 is shown. The dynamic viscoelasticity measurement chart of the 1st viscoelastic layer in the comparative example 1 is shown. The dynamic viscoelasticity measurement chart of the 1st viscoelastic layer in the comparative example 2 is shown. Showing the dynamic viscoelasticity measurement chart of the second viscoelastic layer in a ratio Comparative Examples 1, 2, 4. The dynamic viscoelasticity measurement chart of the 2nd viscoelastic layer in Example 2 is shown.

  FIG. 1 is a cross-sectional view of an embodiment of the sticking type vibration damping material of the present invention, and FIG. 2 is a cross sectional view of another embodiment of the sticking type vibration damping material of the present invention.

  In FIG. 1 and FIG. 2, the sticking type damping material 1 includes a constraining layer 2, a first viscoelastic layer 3 laminated on the constraining layer 2, and a second viscoelasticity laminated on the first viscoelastic layer 3. Layer 4.

  The constraining layer 2 constrains and retains the first viscoelastic layer 3 (and the second viscoelastic layer 4 laminated on the first viscoelastic layer 3), and the first viscoelastic layer 3 (and the first viscoelastic layer). Toughness is imparted to the second viscoelastic layer 4), which is laminated to 3 to improve the strength.

  In addition, the constraining layer 2 is formed of a sheet-like material that is lightweight and thin and can be closely integrated with the first viscoelastic layer 3. Examples of such materials include glass cloth, resin-impregnated glass cloth, metal foil, synthetic resin nonwoven fabric, and carbon fiber.

  The glass cloth is made of glass fiber and includes a known glass cloth.

  The resin-impregnated glass cloth is obtained by impregnating the above-described glass cloth with a synthetic resin such as a thermosetting resin or a thermoplastic resin, and includes known ones. In addition, as a thermosetting resin, an epoxy resin, a urethane resin, a melamine resin, a phenol resin etc. are mentioned, for example. Examples of the thermoplastic resin include vinyl acetate resin, ethylene-vinyl acetate copolymer (EVA), vinyl chloride resin, EVA-vinyl chloride resin copolymer, and the like. Moreover, the above-mentioned thermosetting resin and thermoplastic resin can be used alone or in combination, respectively.

  Examples of the metal foil include known metal foils such as an aluminum foil and a steel foil.

  The synthetic resin nonwoven fabric is a nonwoven fabric made of a synthetic resin such as an olefin resin, a polyethylene terephthalate resin, or a polyester resin, and includes known ones.

  The carbon fiber is a fiber made of carbon as a main component, and includes known ones.

Among these constraining layers 2, in consideration of weight, adhesion, strength, and cost, glass cloth is preferably used. The thickness of the constraining layer 2 is, for example, 50 μm to 2 mm. In particular, when a glass cloth is used as the constraining layer 2, the thickness is preferably 300 μm or less, and when a metal foil is used as the constraining layer 2, the thickness is 100 μm or less from the viewpoint of handling. .

Further, the tensile elastic modulus (measurement method: conforming to JIS K 7164) of the constraining layer 2 is, for example, 10 ⁹ Pa or more, preferably 5 × 10 ⁹ Pa or more, more preferably 8 × 10 ⁹ Pa or more. 10 ¹¹ Pa or less.

When the tensile elastic modulus of the constraining layer 2 is 10 ⁹ Pa or more, the vibration damping property by the constraining layer 2 can be sufficiently exhibited, and the vibration damping property of the sticking type vibration damping material 1 can be improved. .

  As will be described in detail later, the first viscoelastic layer 3 has a glass transition point at 0 ° C. or higher, and is made of, for example, rubber (hereinafter referred to as first rubber).

  The first rubber is not particularly limited, and a known rubber can be used. Specific examples of the rubber include styrene / butadiene rubber such as styrene / butadiene copolymer and hydrogenated styrene / butadiene copolymer (hydrogenated styrene / butadiene rubber), such as styrene / isoprene copolymer (3 , 4-isoprene-styrene copolymer, etc.) and styrene rubber such as styrene-isoprene rubber, and nitrile rubber, for example.

  These first rubbers can be used alone or in combination of two or more.

  From the viewpoint of the glass transition temperature (described later) of the first viscoelastic layer 3, the first rubber is preferably a styrene rubber, more preferably a styrene / butadiene rubber or a styrene / isoprene rubber.

  When the styrene / butadiene rubber and the styrene / isoprene rubber are used in combination as the first rubber, the blending ratio thereof is 100 parts by mass with respect to the total amount of the styrene / butadiene rubber and the styrene / isoprene rubber. The styrene / butadiene rubber is, for example, 25 to 75 parts by mass, preferably 40 to 60 parts by mass, and the styrene / isoprene rubber is, for example, 25 to 75 parts by mass, preferably 40 to 60 parts by mass.

  Moreover, a thermoplastic resin can be mix | blended with said 1st rubber | gum.

  It does not restrict | limit especially as a thermoplastic resin, A well-known thermoplastic resin can be used.

  Preferred examples of the thermoplastic resin include resins having a melting point higher than the glass transition temperature (described later) of the first viscoelastic layer 3, and specific examples thereof include ethylene / vinyl acetate copolymer and ethylene / ethyl acrylate. Examples thereof include ethylene-based copolymers such as copolymers.

  Moreover, when a thermoplastic resin is mix | blended, the compounding ratio is 10-300 mass parts with respect to 100 weight part of 1st rubber | gum, Preferably, it is 20-250 mass part.

  The first viscoelastic layer 3 can further contain, for example, a filler, a tackifier, a softener, a plasticizer and the like in order to adjust the glass transition temperature.

  It does not restrict | limit especially as a filler, A well-known filler can be used. Specific examples of the filler include inorganic fillers such as talc, calcium carbonate, clay and mica, metal oxides such as zinc oxide and magnesium oxide, reinforcing fillers such as carbon black and silica, and water. Examples include flame retardants such as aluminum oxide and magnesium hydroxide.

  These fillers can be used alone or in combination of two or more.

  The blending ratio of the filler is, for example, 300 parts by mass or less with respect to 100 parts by mass of the first rubber (the total amount of the first rubber and the thermoplastic resin when the thermoplastic resin is compounded), 25 to 250 parts by mass.

  It does not restrict | limit especially as a tackifier, A well-known tackifier can be used. Specific examples of the tackifier include petroleum resins, terpene resins, rosin resins (such as hydrogenated rosin esters), phenol resins, and coumarone resins.

  These tackifiers can be used alone or in combination of two or more.

  The blending ratio of the tackifier is, for example, 200 parts by mass or less, preferably 100 parts by mass or less with respect to 100 parts by mass of the first rubber (the total amount of the first rubber and the thermoplastic resin when the thermoplastic resin is compounded). 10 to 150 parts by mass.

  The softening agent is not particularly limited, and a known softening agent can be used. Specific examples of the softening agent include process oil, naphthenic oil, polybutene (polybutene rubber), and the like.

  These softeners can be used alone or in combination of two or more.

  The blending ratio of the softening agent is, for example, 100 parts by mass or less, preferably 100 parts by mass or less with respect to 100 parts by mass of the first rubber (when the thermoplastic resin is compounded, the total amount of the first rubber and the thermoplastic resin). 1 to 50 parts by mass.

  It does not restrict | limit especially as a plasticizer, A well-known plasticizer can be used. Specific examples of the plasticizer include phthalic acid esters, adipic acid esters, oils, and the like.

  These plasticizers can be used alone or in combination of two or more.

  The blending ratio of the plasticizer is, for example, 100 parts by mass or less, preferably 100 parts by mass or less with respect to 100 parts by mass of the first rubber (the total amount of the first rubber and the thermoplastic resin when the thermoplastic resin is compounded). 1 to 50 parts by mass.

  In addition to the above components, the first viscoelastic layer 3 may include, for example, an anti-aging agent, an antioxidant, an ultraviolet absorber, a stabilizer, a lubricant, a scorch inhibitor, a pigment, a colorant, Known additives such as an antifungal agent can be blended in an appropriate ratio.

  The method for forming the first viscoelastic layer 3 is not particularly limited. For example, the above components are mixed at, for example, 80 to 150 ° C. and pressure-formed at, for example, 0.01 to 10 MPa (for example, press molding, A known method such as roll molding or extrusion molding may be employed.

  The thickness of the 1st viscoelastic layer 3 is 100-5000 micrometers, for example, Preferably, it is 500-3000 micrometers.

  And the 1st viscoelastic layer 3 has a glass transition point in 0 degreeC or more.

  The glass transition point of the first viscoelastic layer 3 is a peak of the loss shear elastic modulus G ″ measured by a dynamic viscoelasticity measuring apparatus (measurement conditions: shear mode, temperature rising rate 5 ° C./min, frequency 1 Hz). Defined. The glass transition temperature of the first viscoelastic layer 3 is a temperature at which the glass transition point is confirmed.

  The difference between the glass transition temperature of the first viscoelastic layer 3 and the glass transition temperature (described later) of the second viscoelastic layer 4 is, for example, 20 to 100 ° C., preferably 25 to 90 ° C. Specifically, as described above, it is 0 ° C. or higher, preferably 2 ° C. or higher, and usually 80 ° C. or lower. The specific temperature range is, for example, 0 to 80 ° C., preferably 2 to 70 ° C. It is.

  Note that the first viscoelastic layer 3 may have a plurality of glass transition points. In such a case, the glass transition temperature of at least one glass transition point should just be 0 degreeC or more, and the glass transition temperature of other glass transition points may be less than 0 degreeC, for example.

  In addition, when the first viscoelastic layer 3 has a plurality of glass transition points, when a plurality of glass transition temperatures are recognized at 0 ° C. or higher, preferably all the glass transition points recognized at 0 ° C. or higher. The difference between the glass transition temperature of the second viscoelastic layer 4 and the glass transition temperature (described later) of the second viscoelastic layer 4 is, for example, 20 to 100 ° C, preferably 25 to 90 ° C.

The first viscoelastic layer 3 has a storage shear modulus G ′ in the range of, for example, 10 ⁴ to 10 ⁹ Pa, preferably 10 ⁵ to 10 ⁸ Pa at all temperatures of 20 to 80 ° C.

  Specifically, the storage shear modulus G ′ of the first viscoelastic layer 3 is in the above range at any of 20 ° C., 40 ° C., 60 ° C., and 80 ° C. The storage shear modulus G ′ is considered to be in the above range.

  The storage shear modulus G ′ of the first viscoelastic layer 3 is measured by a dynamic viscoelasticity measuring device (measurement conditions: shear mode, temperature rising rate 5 ° C./min, frequency 1 Hz).

  Although described in detail later, the second viscoelastic layer 4 has a glass transition point below 0 ° C., and is made of, for example, a known pressure-sensitive adhesive.

  Although it does not restrict | limit especially as an adhesive, For example, rubber | gum (henceforth a 2nd rubber | gum) etc. are mentioned.

  Examples of the second rubber include acrylic resin rubber.

  The acrylic resin rubber can be obtained by polymerizing a monomer component mainly composed of (meth) acrylic acid ester.

  The (meth) acrylic acid ester which is the main component of the monomer component is a methacrylic acid ester and / or an acrylic acid ester, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate Isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, (meth) Neopentyl acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate , Isononyl (meth) acrylate, decyl (meth) acrylate, (meth) Acrylic acid isodecyl, (meth) acrylate, lauryl (meth) bornyl acrylate, (meth) acrylic acid isobornyl (meth) acrylate, myristyl (meth) acrylate, pentadecyl, and the like (meth) stearyl acrylate.

  These (meth) acrylic acid esters can be used alone or in combination of two or more.

  The (meth) acrylic acid ester is preferably a (meth) acrylic acid ester having 2 to 14 carbon atoms in the alkyl group, more preferably a (meth) acrylic acid ester having 2 to 8 carbon atoms in the alkyl group. More preferably, (meth) acrylic acid ester having 4 to 6 carbon atoms in the alkyl group may be mentioned.

  Moreover, as a monomer component, you may use together the monomer copolymerizable with (meth) acrylic acid ester other than above-described (meth) acrylic acid ester. Examples of such a copolymerizable monomer include a functional group-containing monomer containing a functional group.

  Examples of the functional group-containing monomer include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, and crotonic acid, such as (meth) acrylic acid-2-hydroxyethyl and (meth) acrylic acid-2. -Hydroxypropyl, hydroxyl group-containing monomers such as (meth) acrylic acid-2-hydroxybutyl, such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl ( Amide group-containing monomers such as (meth) acrylamide and N-butoxymethyl (meth) acrylamide, for example, amino group-containing monomers such as diaminoethyl (meth) acrylate, for example, glycidyl group-containing monomers such as glycidyl (meth) acrylate, Others, (meta) Ronitoriru, N- (meth) acryloyl morpholine, N- vinyl-2-Pirodorin the like.

  These functional group-containing monomers can be used alone or in combination of two or more.

  As the functional group-containing monomer, a carboxyl group-containing monomer is preferable.

  Further, as other copolymerizable monomers, for example, vinyl esters such as vinyl acetate, aromatic vinyl compounds such as styrene and vinyl toluene, for example, cyclopentyl di (meth) acrylate, isobornyl (meth) acrylate, etc. (Meth) acrylic esters of cyclic alcohols such as neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol And (meth) acrylic acid esters of polyhydric alcohols such as methanetri (meth) acrylate and dipentaerythritol hexa (meth) acrylate.

  These other copolymerizable monomers can be used alone or in combination of two or more.

  As other copolymerizable monomers, vinyl esters are preferably used.

  When these functional group-containing monomers (preferably carboxyl group-containing monomers) and / or other copolymerizable monomers (preferably vinyl esters) are used in combination, their blending ratio is (meta ) The functional group-containing monomer is, for example, 0.1 to 20 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the total amount of acrylic acid ester, and other copolymerizable monomers. For example, it is 0.1-15 mass parts, Preferably, it is 1-10 mass parts.

  The method for synthesizing the second rubber is not particularly limited, and for example, the above components are radically polymerized by a known method such as solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization and the like.

  Further, in order to further adjust the glass transition temperature, for example, the above-mentioned filler, tackifier, cross-linking agent, softener (plasticizer) and the like can be blended in the pressure-sensitive adhesive. Add agent.

  The compounding ratio of the tackifier is, for example, 150 parts by mass or less, preferably 5 to 100 parts by mass with respect to 100 parts by mass of the second rubber.

  In addition to the above-mentioned components, the pressure-sensitive adhesive includes, for example, an anti-aging agent, an antioxidant, an ultraviolet absorber, a stabilizer, a lubricant, an anti-scorch agent, a pigment, a colorant, and an antifungal agent. These known additives can be blended at an appropriate ratio.

  And it does not restrict | limit especially as a method of forming the 2nd viscoelastic layer 4, For example, well-known methods, such as cast-molding the adhesive prepared as mentioned above, are employable.

  Moreover, the 2nd viscoelastic layer 4 can also be formed, for example as an adhesive tape etc. with which said adhesive was laminated | stacked on the surface and back surface of a base material (for example, refer FIG. 2).

  Specifically, as shown in FIG. 2, the second viscoelastic layer 4 as an adhesive tape has a multilayer (3) by laminating an adhesive layer 4b on each of the front surface and the back surface of the substrate 4a. Layer) as a structure.

  The substrate 4a is not particularly limited. For example, a polyester film such as a polyethylene terephthalate (PET) film, a polyolefin film such as a polyethylene film or a polypropylene film, a plastic film such as polyvinyl chloride or polystyrene, for example, , Paper such as kraft paper, for example, cloth such as cotton cloth, sufu cloth, for example, woven cloth such as manila hemp, pulp, rayon, acetate fiber, for example, non-woven cloth such as polyester non-woven cloth, vinylon non-woven cloth, for example metal Examples include foil.

  The substrate 4a is preferably paper.

  The thickness of the base material 4a is, for example, 5 to 200 μm, or preferably 10 to 150 μm.

  Moreover, the thickness of each adhesive layer 4b laminated | stacked on the base material 4a is 10-500 micrometers, for example, Preferably, it is 20-300 micrometers.

  The method for forming the second viscoelastic layer 4 as an adhesive tape is not particularly limited. For example, the adhesive (adhesive layer 4b) formed as described above is bonded to the front surface and the back surface of the substrate 4a. For example, a known method can be adopted.

  In addition, as the 2nd adhesive layer 4, a commercially available double-sided adhesive tape etc. can also be used.

  The thickness of the 2nd viscoelastic layer 4 is 10-500 micrometers, for example, Preferably, it is 20-300 micrometers.

  And the 2nd viscoelastic layer 4 has a glass transition point in less than 0 degreeC.

  Similarly to the first viscoelastic layer 3, the glass transition point of the second viscoelastic layer 4 is a loss measured by a dynamic viscoelasticity measuring device (measuring conditions: shear mode, heating rate 5 ° C./min, frequency 1 Hz). It is defined as the peak of shear modulus G ″. The glass transition temperature of the second viscoelastic layer 4 is a temperature at which the glass transition point is confirmed.

  The difference between the glass transition temperature of the second viscoelastic layer 4 and the glass transition temperature of the first viscoelastic layer 3 is, for example, 20 to 100 ° C., preferably 25 to 90 ° C. Specifically, as described above, it is less than 0 ° C., preferably less than −10 ° C., usually −60 ° C. or more, and the specific temperature range is, for example, −60 to −10 ° C., preferably − 55--15 ° C.

  If the glass transition temperature difference between the first viscoelastic layer 3 and the second viscoelastic layer 4 is 20 to 100 ° C., each of the first viscoelastic layer 3 and the second viscoelastic layer 4 has excellent vibration damping properties. As a result, the damping performance of the sticking type damping material 1 can be improved.

Further, the second viscoelastic layer 4 has a storage shear modulus G ′ of, for example, 5 × 10 ^{3 to} 5 × 10 ⁶ Pa, preferably 10 ⁴ to 10 ⁶ Pa in all of 20 to 80 ° C. It is a range.

  Specifically, the storage shear modulus G ′ of the second viscoelastic layer 4 is in the above range at any of 20 ° C., 40 ° C., 60 ° C., and 80 ° C. The storage shear modulus G ′ is considered to be in the above range.

  The storage shear modulus G ′ of the second viscoelastic layer 4 is a dynamic viscoelasticity measuring device (measurement conditions: shear mode, temperature rising rate 5 ° C./min, frequency 1 Hz), similar to the first viscoelastic layer 3. Measured by.

  And in order to form the sticking type | mold damping material 1, although it does not restrict | limit in particular, For example, the 1st viscoelastic layer 3 is laminated | stacked on the surface of the constrained layer 2, and after that, the 1st viscoelastic layer 3 is formed on the surface of the 1st viscoelastic layer 3. Two viscoelastic layers 4 may be laminated.

  Thus, the thickness of the sticking type | mold damping material 1 formed is 1.0-6.0 mm, for example, Preferably, it is 1.5-4.0 mm.

  In the sticking type damping material 1, the storage shear modulus G ′ (measurement frequency: 1 Hz) of the first viscoelastic layer 3 with respect to the storage shear modulus G ′ (measurement frequency: 1 Hz) of the second viscoelastic layer 4. The ratio is, for example, 1 to 500, preferably 3 to 300 in all of 20 to 80 ° C.

  Specifically, the ratio of the storage shear modulus G ′ (measurement frequency: 1 Hz) of the first viscoelastic layer 3 to the storage shear modulus G ′ (measurement frequency: 1 Hz) of the second viscoelastic layer 4 is 20 It is the said range in any of 40 degreeC, 40 degreeC, 60 degreeC, and 80 degreeC, and, thereby, the ratio of storage shear modulus G 'is considered to be the said range in all 20-80 degreeC.

  If the ratio of the storage shear modulus G ′ of the first viscoelastic layer 3 to the storage shear modulus G ′ of the second viscoelastic layer 4 is 1 to 500 in the entire temperature range of 20 to 80 ° C., Excellent vibration damping properties can be expressed in the entire temperature range.

  Moreover, the sticking type damping material 1 can be stuck to a desired installation location by the second viscoelastic layer 4, and its adhesive strength (90-degree peel test on stainless steel plate (conforming to JIS Z0237), peeling speed of 300 mm / Min., 23 ° C.) is, for example, 0.1 N / 25 mm or more, preferably 1 N / 25 mm or more.

  And such a sticking type | mold damping material 1 is laminated | stacked on the 1st viscoelastic layer 3 which has a glass transition point above 0 degreeC, and the 1st viscoelastic layer 3, and has a glass transition point below 0 degreeC. Since the second viscoelastic layer 4 has the second viscoelastic layer 4, the second viscoelastic layer 4 can be attached at room temperature and has excellent control against vibrations in a wide frequency range including high frequencies even at high temperatures. Can exhibit tremor.

  The application temperature of the sticking type vibration damping material 1 is, for example, 20 to 80 ° C., and the vibration frequency to be damped thereby is, for example, 500 to 5000 Hz.

  Note that the application temperature of the sticking type damping material 1 is, for example, a loss factor measuring device or the like, and the loss coefficient of the sticking type damping material 1 at a desired frequency is calculated by the central excitation method (the central excitation method of JIS G0602). This can be determined by measuring by the vibration method (based on the central support steady vibration method).

  Specifically, if the loss coefficient of the sticking type damping material 1 at a desired frequency is 0.1 or more under a specific temperature condition, the damping property under the temperature condition is good and sticking. It is determined that the applied temperature and frequency of the vibration damping material 1.

  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.

Example 2 and Comparative Examples 1 to 4
(Formation of the first viscoelastic layer)
In the formulation shown in Table 1, each component was blended on a mass part basis, mixed at 120 ° C., and then pressure-formed by a press so that the thickness became 1.8 mm.

(Formation of second viscoelastic layer)
In the formulation shown in Table 1, each component was blended on a mass part basis, polymerized by a known radical polymerization method, and then dissolved in toluene. Next, the obtained toluene solution was cast to a molding thickness of 35 μm, and the obtained adhesive was bonded to the front and back surfaces of 80 μm thick paper (23 g / m ² ).

(Manufacture of adhesive damping material)
A thickness of 2.2 mm is obtained by thermally bonding the first viscoelastic layer to the surface of the constraining layer shown in Table 1 at 100 ° C., and then bonding the second viscoelastic layer to the surface of the first viscoelastic layer. The sticking type damping material was obtained.

  In Comparative Example 3, a vibration damping material was obtained without forming the second viscoelastic layer.

なお、表１中の成分またはその略号の詳細を以下に示す。

In addition, the detail of the component in Table 1 or its abbreviation is shown below.

EVA: ethylene / vinyl acetate copolymer (thermoplastic resin, vinyl acetate content 25 mass%, MFR = 15)
SIS: Styrene / isoprene copolymer (first rubber, 3,4-isoprene-styrene copolymer (trade name HIBLER 5127, manufactured by Kuraray))
SBR: Styrene-butadiene copolymer (first rubber (trade name Asaprene 6500P, manufactured by Asahi Kasei))
Polybutene: Polybutene rubber (softener)
Tackifier A: Petroleum resin (softening point 115 ° C.)
BA: Butyl acrylate VAc: Vinyl acetate AA: Acrylic acid Tackifier B: Hydrogenated rosin ester (softening point 80 ° C.)
(Evaluation)
1) Measurement of dynamic viscoelasticity Examples 1 to 2 and a dynamic viscoelasticity measurement apparatus (apparatus name ARES (manufactured by Rheometric Co., Ltd.), measurement conditions: shear mode, heating rate 5 ° C./min, frequency 1 Hz) The storage shear modulus G ′ and the loss shear modulus G ″ of the first viscoelastic layer and the second viscoelastic layer in Comparative Examples 1 and 2 were measured, and the elastic modulus ratio tan δ (= G ″ / G ′). )

Moreover, the glass transition temperatures of the first viscoelastic layer and the second viscoelastic layer in Example 2 and Comparative Examples 1, 2, and 4 were determined from the peak of the loss shear modulus G ″. The results are shown in Table 1.

  Furthermore, the storage shear modulus G ′ of the first viscoelastic layer and the second viscoelastic layer was determined for each of 20 ° C., 40 ° C., 60 ° C., and 80 ° C., and the ratio of the storage shear modulus G ′ was calculated. . The results are shown in Table 1.

  Moreover, the measurement chart by a dynamic viscoelasticity measuring apparatus is shown to FIGS.

3 is a chart of the first viscoelastic layer in Comparative Example 4 , FIG. 4 is a chart of the first viscoelastic layer in Example 2, and FIG. 5 is a chart of the first viscoelastic layer in Comparative Example 1. Figure 6 is a chart of the first viscoelastic layer in Comparative example 2, FIG. 7, the chart of the second viscoelastic layer in a ratio Comparative examples 1, 2, 4, 8, the second viscoelastic layer in example 2 Each chart is shown.
2) Loss coefficient The sticking type damping material having a thickness of 2.2 mm obtained in each example and each comparative example was cut into a size of 10 × 250 mm, and this was cut into a size of 0.8 × 10 × 250 mm. A test piece was obtained by sticking to one side of the cold rolled steel sheet. In addition, since the damping material of the comparative example 3 cannot be stuck at room temperature, it was heat-sealed to one side of a cold-rolled steel plate at 100 ° C.

  Then, the loss coefficient of the sticking type damping material at each temperature of 20 ° C., 40 ° C., 60 ° C. and 80 ° C. was measured by the central vibration method at 500 Hz and 5000 Hz, respectively. The results are shown in Table 1.

If the loss factor of the sticking type damping material is 0.1 or more, it is judged that the damping property under the temperature condition is good and that it is the adaptive temperature and frequency of the sticking type damping material. The
3) Adhesive strength The sticking type damping material of each example and each comparative example was cut out with a width of 25 mm, and bonded to a stainless steel plate at 1 MPa in a 23 ° C. atmosphere, and the adhesive strength (N / 25 mm) was 90 ° peel test. (Tensile speed 300 mm / min). The results are shown in Table 1.
(Discussion)
Comparative Example 4 and Example 2 comprising a first viscoelastic layer having a glass transition point at 0 ° C. or higher and a second viscoelastic layer laminated on the first viscoelastic layer and having a glass transition point below 0 ° C. The sticking type damping material has excellent damping properties against vibrations in a wide frequency range (specifically, 500 to 5000 Hz) at room temperature to high temperature (specifically, 20 to 80 ° C.). Can be expressed.

  On the other hand, when a layer having no glass transition point at 0 ° C. or higher is used as the first viscoelastic layer as in Comparative Examples 1 and 2, the vibration damping performance in the high temperature range is inferior even if it is highly elastic.

  Further, in the case of only the first viscoelastic layer as in Comparative Example 3, adhesion at normal temperature cannot be performed, and workability is inferior.

DESCRIPTION OF SYMBOLS 1 Adhesive type damping material 2 Constrained layer 3 1st viscoelastic layer 4 2nd viscoelastic layer

Claims (4)

A constraining layer, a first viscoelastic layer laminated on the constraining layer, and a second viscoelastic layer laminated on the first viscoelastic layer,
The first viscoelastic layer contains a styrene / isoprene copolymer and a styrene / butadiene copolymer, and has a glass transition point at 0 ° C. or higher.
The sticking type vibration damping material, wherein the second viscoelastic layer contains an acrylic resin rubber and has a glass transition point below 0 ° C.   The sticking mold according to claim 1, wherein a difference between the glass transition temperature of the first viscoelastic layer and the glass transition temperature of the second viscoelastic layer is 20 to 100 ° C. Damping material.   The ratio of the storage shear modulus G ′ of the first viscoelastic layer to the storage shear modulus G ′ of the second viscoelastic layer is 1 to 500 at all temperatures of 20 to 80 ° C. The sticking type | mold damping material of Claim 1 or 2. The sticking type | mold damping material as described in any one of Claims 1-3 whose tensile elasticity modulus of the said constrained layer is 10 < ⁹ > Pa or more.

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