JP3343401B2 - Composite for vibration damping material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material for vibration damping materials, and more particularly to a vehicle, an electric component, a component of a machine or a structure, or a part thereof, which is used when used at room temperature. The present invention relates to a vibration damping material composite having high vibration absorption performance capable of reducing the vibration of the material and reducing noise.

[0002]

2. Description of the Related Art In recent years, with the development of transportation systems and the proximity of dwellings to factories, noise and vibration problems have become social problems as pollution, and noise has also been raised at workplaces in order to improve the working environment. And tend to regulate vibration. In response to such a trend, there is a demand for providing a vibration-suppressing performance to a substrate having high rigidity, which is a noise source and a vibration source, and to improve the vibration-suppressing performance.

[0003] Therefore, as one of the materials exhibiting such vibration damping performance, a composite vibration damper having a three-layer structure in which a viscoelastic intermediate layer made of a viscoelastic resin is interposed between two rigid substrates. Materials have been proposed. For example, when the rigid substrate is made of metal, oil pans for automobiles, engine covers, dashboard panels and floors, chute parts for hoppers, stoppers for transport equipment, home appliances,
In addition, various studies have been made and adopted for vibration reduction members of metal working machines and components of precision machines for which vibration prevention is desired.

As a viscoelastic resin constituting the viscoelastic intermediate layer of such a composite for vibration damping materials, a polyester resin or a resin composition comprising a polyester resin and a polyolefin resin (Japanese Patent Laid-Open No. 61-89,842) No.)
A resin composition comprising an amorphous polyester resin and a low-crystalline polyester resin (JP-A-62-18160); and an acrylonitrile-butadiene copolymer (JP-A-60-245,5).
No. 50) or a composition comprising a hydroxyl group-containing liquid diene polymer (JP-A-60-190,350, JP-A-61-207,746, JP-A-61-261,020, JP-A-62-167,042). Publications),
Compositions comprising ethylene / maleic anhydride copolymer and / or terpolymer of ethylene / maleic anhydride / alkyl (meth) acrylate (JP-A-62-46,638, JP-A-62-46,639) And a composition comprising a styrene-based copolymer and an olefin-based copolymer (JP-A-62-64844). In addition, the inventors have disclosed a composition comprising a block copolymer of a conjugated diene and a vinyl aromatic hydrocarbon / a tackifier resin / a cross-linking agent (Japanese Patent Laid-Open No. 3-69,444) and a conjugated diene and a vinyl aromatic hydrocarbon / vinyl. A composition comprising a polymer of an aromatic hydrocarbon and a vinyl compound having a functional group / tackifying resin (JP-A-3-69,445) has also been proposed.

The characteristics required of such a composite for vibration damping materials include, first, high vibration damping performance, which is generally expressed by the magnitude of a loss coefficient. And secondly, the composite material for vibration damping material is used as a structural member, and the bonding strength between the viscoelastic intermediate layer composed of a viscoelastic resin and the secondary processing such as pressing is also performed, especially High shear adhesive strength is mentioned. Third, the composite for vibration damping material may be heated to about 200 ° C. during processing or coating, and the intermediate layer resin composition does not flow out around this temperature, and Is required to have water resistance such that the intermediate layer resin composition is not damaged by water or the like when used for practical use and the adhesive strength is not significantly reduced.

In particular, in the case of a vibration damping material exhibiting excellent vibration damping performance in a normal temperature range of 0 to 60 ° C., the glass transition region of the viscoelastic intermediate layer resin composition needs to be around normal temperature or lower, At room temperature, the composition has a low elastic modulus. on the other hand,
Compositions exhibiting a high modulus of elasticity generally have better shear bond strength. That is, the vibration-damping performance required for the vibration-damping material composite and the shear adhesive strength related to the press workability are conflicting requirements with respect to the elastic modulus of the viscoelastic intermediate layer resin, and also in durability. The durability against water is also a very strict required characteristic.

[0007] In the composite for vibration damping materials manufactured with the above-mentioned conventional viscoelastic composition, both the characteristics of the vibration damping performance and the shearing adhesive strength and the water resistance cannot be sufficiently satisfied. It is insufficient as a viscoelastic composition. For example,
Among the above-described conventional techniques, Japanese Patent Application Laid-Open No. 62-46,638
JP-A-62-4663 and JP-A-62-4639 have excellent vibration damping performance in a high temperature range, but have low vibration damping performance at room temperature, and have a composite composition for a vibration damping material. Is not fully satisfactory. Further, Japanese Patent Application Laid-Open No. 62-1
In the case of the composition composed of the polyester resin No. 8,160, the water resistance is insufficient due to its hydrophilicity, and the composition for vibration damping material is not sufficiently satisfactory.

[0008]

The inventors of the present invention have conducted intensive studies to obtain a composite material for a vibration damping material exhibiting a vibration damping performance in the vicinity of room temperature, which does not have the above-mentioned problems. Composed of a cross-linked block copolymer and a composite material for vibration damping material having at least a three-layer structure composed of two rigid layers on both sides, exhibit high vibration damping performance and excellent balance of adhesive strength The present invention has been found to have excellent water resistance. Accordingly, an object of the present invention is to provide a composite for a vibration damping material that exhibits excellent vibration damping performance particularly at around normal temperature.

[0009]

That is, the present invention provides:
A composite material for a vibration damping material having at least a three-layer structure composed of two damping resin layers and two rigid layers disposed on both sides thereof, wherein the rigid layer has a flexural modulus at 20 ° C. A material having 2.0 × 10 ⁴ kgf / cm ² or more, and the vibration-damping resin layer has the following hard segment B1
And soft segment B2 hard segment B1: 20 of polymer obtained by polymerization
A structural unit obtained from one or a mixture of two or more radically polymerizable compounds having a flexural modulus at 1.5 ° C. of 1.5 × 10 ⁴ kgf / cm ² or more. Soft segment B2: weight obtained by polymerization One or more (meth) acrylic acid esters 9 having a glass transition temperature of −40 to 40 ° C. and a loss tangent (tan δ) at the glass transition temperature of 0.1 or more;
A block copolymer obtained from 9.99 to 90 mol% and 0.01 to 10 mol% of a vinyl compound having a functional group, and containing a structural unit in which all or a part of the functional group is cross-linked. It is a composite material for vibration damping material. Hereinafter, the present invention will be described in detail.

First, the composite for vibration damping material according to the present invention is, as described above, at least three composite layers each composed of one damping resin layer and two rigid layers disposed on both sides thereof.
It is a composite for vibration damping materials having a layer structure. In this specification, the glass transition temperature is defined as the temperature at which the loss tangent (tan δ) obtained by the dynamic viscoelasticity measurement by the shearing method has a maximum value, and the value of tan δ at that time is defined as tan δ at the glass transition temperature. Is defined as

The material used as the rigid layer has a flexural modulus at 20 ° C. of 2.0 × 10 ⁴ kgf / cm ² or more, preferably 3.0 × 10 ⁴ kgf / cm ² or more, more preferably 5 × 10 ⁴ kgf / cm ² or more. It is a material of 0.0 × 10 ⁴ kgf / cm ² or more. Flexural modulus at 20 ° C. is 2.0 × 10 ⁴ kgf / c
When it is smaller than m ² , the vibration damping effect when laminated with the block copolymer to form a composite is small. Such materials include metal materials such as steel plates, copper plates, and aluminum plates, PS,
Resins such as PA, PC, and PMMA, glass, and wood are exemplified.

The component forming the vibration-damping resin layer must be a block copolymer containing at least the following two types of structural units, a hard segment B1 and a soft segment B2. The radical polymerizable compound constituting the hard segment B1 has a flexural modulus at 20 ° C. of 1.5 × 10 ⁴ kgf / cm ² or more, preferably 2.0 × 10 ⁴ kgf / cm ² or more. There is no particular limitation as long as coalescence can be obtained, for example,
Styrene, o-methylstyrene, p-methylstyrene,
Examples thereof include aromatic vinyl compounds such as 1,3-dimethylstyrene, α-methylstyrene, and vinylnaphthalene, and unsaturated cyanide compounds such as (meth) acrylates such as methyl methacrylate and ethyl methacrylate, and acrylonitrile. Any of these may be used alone, or two or more of them may be used in combination. An aromatic vinyl compound is preferred because a particularly large elastic modulus can be obtained.

On the other hand, the (meth) acrylic acid ester for constituting the soft segment B2 has a glass transition temperature (Tg) of -40 ° C. to 40 ° C. and a loss tangent (tan δ) at that Tg of 0.1. 1 or more, preferably 0.2
It is not particularly limited as long as it is a compound from which the above polymer can be obtained, and examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and the like. Or two or more of them may be used in combination. Ethyl acrylate and butyl acrylate are particularly preferred in that Tg is in an optimal range and a high tan δ is obtained.

Examples of the vinyl compound having a functional group copolymerized with the soft segment B2 include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and cis-4-cyclohexane-1,2-carboxylic acid. Α, β-unsaturated carboxylic acids and the like, alicyclic unsaturated carboxylic acids and anhydrides thereof, esters, amides, imides,
Derivatives such as metal salts are exemplified. Further, vinyl triethoxysilane, vinyl group-containing silane compounds such as γ-methacryloxypropyl triethoxysilane, and N-vinyl caprolatum, vinyl group-containing organic nitrogen compounds such as N-vinyl succinimide, and the like, Particularly preferred functional group-containing vinyl compounds are unsaturated carboxylic acids.

In the present invention, the vinyl compound having a functional group in the soft segment B2 is copolymerized because the bonding structure derived from the vinyl compound having the functional group is present, whereby the adhesiveness to the outer rigid layer is reduced. In addition to remarkable improvement, by further cross-linking the functional group, the soft segment B2 changes from thermoplastic to thermosetting, and heat resistance and oil resistance are remarkably improved, and the cross-linking further increases the adhesive strength. is there.

In the soft segment B2, the ratio of the (meth) acrylate to the vinyl compound copolymerized with the (meth) acrylate is 99.9% for the (meth) acrylate.
~ 90 mol%, and the vinyl compound is 0.01 ~ 1
0 mol%. 0.01mol of vinyl compound
%, The heat resistance is not improved by the crosslinking described later. Conversely, if it is more than 10 mol%, the vibration-damping resin layer becomes hard and the vibration-damping performance decreases.

In the present invention, the soft segment B2 needs to be crosslinked. This cross-link
It is obtained by reacting a functional group derived from a vinyl compound having a functional group that is a constituent component of the soft segment B2 with a predetermined crosslinking agent. By this crosslinking reaction, the heat resistance of the composition is significantly improved, The fluidity at high temperatures can be significantly reduced, and the oil resistance can be significantly improved as compared to a state in which crosslinking is not performed. In addition, the adhesive strength (T
Peeling and shearing) can be further improved, and a very preferable resin can be obtained.

The crosslinking agent used for such a purpose may be any compound capable of reacting under a specific condition with a functional group derived from the above functional group-containing vinyl compound. A salt, a metal oxide, a metal chloride, a metal compound such as a metal alcoholate compound, an epoxy compound, an amine compound, an isocyanate compound, a guanamine / melamine compound, an aziridyl compound and any one compound selected from oxazoline compounds or Mixtures of two or more can be mentioned. When the functional group is a carboxylic acid or a carboxylic acid anhydride, a metal compound highly reactive therewith, an isocyanate compound, and an epoxy compound such as a bisphenol A type epoxy resin are particularly preferable. Further, a metal compound is more preferable in consideration of heat resistance of crosslinking and workability of the resin. The term “crosslinking” used herein means that the compound is a compound in which the above-mentioned compounds are bonded between different molecules of a polymer, and may be a compound soluble in a solvent.

In the present invention, the hard segment B
The ratio of 1 to the soft segment B2 is such that the hard segment B1 is 5 to 50 in the total amount of B1 and B2 of 100 parts by weight.
Parts by weight, and the remaining 95 to 50 parts by weight are soft segments B2. If the hard segment B1 is less than 10 parts by weight, the cohesive force of the vibration damping resin is reduced and the adhesive strength with the outer rigid layer is reduced so that the resin cannot withstand use. The layer becomes hard, the value of tan δ becomes small, and the vibration damping performance is not so expressed, which is not preferable.

The molecular weight of the block copolymer of the present invention containing the hard segment B1 and the soft segment B2 is not particularly limited as long as it satisfies the above performance. Considering processability, the weight average molecular weight is generally 10,000 to 300,
A range of 000 is preferred.

There are various methods for obtaining such a block copolymer, and there is no particular limitation. For example, one of the hard segment B1 and the soft segment B2 (for example, the hard segment B
When radically polymerizing a monomer for forming 1),
Polymerization is performed in the presence of a compound containing a thioester and a thiol group in a molecule such as thiolcarboxylic acid or 2-acetylthioethylthiol, 10-acetylthiodecanethiol, and the obtained polymer is subjected to sodium hydroxide, ammonium or the like. To obtain a polymer having a thiol group at one end, and subjecting the monomer for forming the other (for example, soft segment B2) to radical polymerization in the presence of this polymer to obtain a target block. The method for obtaining the copolymer is simple and highly efficient and is most preferable.
In this case, a block copolymer in which the hard segment B1 and the soft segment B2 are bonded via a sulfur atom is obtained.

In the present invention, the resin composition constituting the vibration-damping resin layer contains the above block copolymer,
For the purpose of further improving the vibration damping performance, a tackifier resin can be blended. Examples of such tackifying resins include terpene resins such as terpenes and hydrogenated terpenes, rosin resins such as rosin, rosin ester and hydrogenated rosin ester, aliphatic petroleum resins, aromatic petroleum resins, and polydicyclopentadiene. Among them, terpene or hydrogenated terpene resin is particularly preferable.

In the present invention, an inorganic filler may be further added in order to further improve the adhesive strength (T peeling, shearing) of the resin composition. The inorganic filler used for this purpose must be one that does not thermally decompose even when heated to about 250 ° C., for example, talc, clay,
Examples include titanium oxide, silica, alumina, mica, zinc white, carbon black, graphite and the like. Of these, talc, clay, silica, or one or more of carbon black is preferably used because it has a particularly large effect of improving the shear adhesive strength.

The modified resin composition of the present invention has the same properties as the modified block copolymer in order to improve the vibration damping performance or the elastic modulus within a range that does not impair the overall performance as a vibration damping material. You may mix and use resin other than union. These resins include, for example, polystyrene, AS
Resins, ABS resins, styrene resins such as SBR (block or random) resins, ethylene / α-olefin copolymers, ethylene / vinyl acetate copolymers, propylene / ethylene copolymers, propylene / butene copolymers, etc. Olefin resin, natural rubber, polyisoprene rubber (I
R), rubber resins such as butyl rubber (IIR), and resins such as elastomers such as polyester elastomers and polyamide elastomers.

In order to shift the glass transition temperature of the resin composition to a desired value, a plasticizer may be added. Examples of the plasticizer used for this purpose include polyester plasticizers, polyetherester plasticizers, phosphate esters, epoxy plasticizers, ester plasticizers such as phthalic diester sebacic diester, and trimellitic acid. Examples thereof include a plasticizer, chlorinated paraffin, and the like, which are appropriately selected and used according to the types of the modified block copolymer A, the vinyl aromatic hydrocarbon-based polymer B, and the tackifier resin to be used.

Further, a coupling agent such as silane or titanium may be added to the resin composition forming the vibration damping resin layer in order to improve the adhesion to the outer rigid layer. Then, in order to improve heat resistance, a phenol-based, phosphorus-based, or sulfur-based antioxidant may be added.

Further, when the rigid layer is made of a metal material, conductivity is imparted by blending a conductive solid substance as a filler into the above-mentioned vibration damping resin layer, and the obtained vibration damping material can be spot-welded. It can also be a material. Conductive materials used for such purposes include stainless steel, zinc,
Examples thereof include metal substances obtained by processing a metal such as tin, copper, brass, and nickel into powder, flake, fiber, wire, and the like. These conductive substances may be used alone or in combination of two or more. At this time, in order to obtain better spot weldability, when the conductive substance is in a powder form, its maximum particle size is determined, and when the conductive substance is in a flake form, its maximum thickness is determined. Further, in the case of a fibrous shape, when the maximum diameter is represented by the respective representative lengths (L), the representative length (L) and the vibration-damping resin layer serving as the intermediate resin layer in the composite for vibration-damping material are determined. The ratio (L / T) to the thickness (T) is 0.5 or more, preferably 0.8 or more, and more preferably 1.0 or more.

The method for producing a composite for a vibration damping material using the resin composition of the present invention is not particularly limited, and a vibration is applied to a plate-shaped or coil-shaped rigid body forming a rigid layer. A method of dissolving a resin in a solvent to form a paint, applying and bonding, a method of forming an intermediate layer of a vibration damping resin on a rigid material using a T-die extruder, or a film produced offline A method of sandwiching the vibration damping resin as an intermediate layer between the rigid materials and bonding them by hot melt bonding. When the rigid body is a resin material, various methods such as multilayer extrusion molding, multilayer inflation molding, multilayer blow molding, and double injection are used. Any method can be adopted according to the purpose such as the properties of the resin composition or the type of the obtained composite for vibration damping material.

[0029]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the scope of the present invention is not limited by these Examples and Comparative Examples.

Examples 1 to 4 and Comparative Examples 1 to 8 The block copolymers used in Examples and Comparative Example 8 were prepared from ethyl acrylate or a mixture of ethyl acrylate / butyl acrylate in the presence of polystyrene having a thiol group at one end. Radical polymerization of acrylic acid and
Alternatively, it was obtained by ion crosslinking with Zn ions.

In Comparative Example 1, a homopolymer obtained by radical polymerization of ethyl acrylate was used as the resin, and in Comparative Example 2, a resin obtained by radical polymerization of a mixture of styrene and ethyl acrylate was used. Comparative Example 6 is the same as the above method, except that acrylic acid was not used and ionic crosslinking was not performed, and Comparative Example 7 was that only ionic crosslinking was not performed. Comparative Example 5 is the same as Comparative Example 6, but using methyl methacrylate instead of styrene. In Comparative Examples 3 and 4,
In order to confirm the effect as a composite, rigid PC and P
The performance of P alone was measured.

These polymers are dissolved in a solvent (xylene and / or cyclohexanone) to form a coating material. The composition is applied on a cold-rolled steel sheet using a bar coater and dried at a temperature of 180 ° C. for 3 minutes. They were superposed and heated and pressed at 180 ° C. for 3 minutes to prepare a composite for vibration damping materials having a viscoelastic resin intermediate layer having a thickness of about 50 μm. Tables 1 and 2 show the structures of the obtained composites for vibration damping materials of Examples 1 to 4 and Comparative Examples 1 to 8.

In the resin compositions for forming the vibration-damping resin layers in the vibration-damping material composites of Examples 1 to 4 and Comparative Examples 5 to 8, they were used to form the hard segments B1. The flexural modulus at 20 ° C. of the polymer of the radically polymerizable compound and the copolymer of the (meth) acrylate ester and the vinyl compound having a functional group used to constitute the soft segment B2 were obtained. Glass transition temperature (Tg) and loss tangent (ta)
nδ). Table 3 shows the results.

Further, Example 1 thus prepared was prepared.
With respect to the composites for damping materials of Comparative Examples 1 to 4 and Comparative Examples 1 to 8, the adhesive strength (T-peel adhesive strength and shear adhesive strength) and the damping performance were measured. Table 4 shows the results. The T-peel adhesive strength was 50 m based on the JIS-K-6854 test method.
evaluated at a tensile speed of m / min.
Evaluation was made at a tensile speed of 5 mm / min based on the -K-6850 test method. The vibration damping performance is measured by a mechanical impedance method by measuring a loss coefficient (η) representing a vibration absorbing ability at each temperature, and obtaining a maximum value of the loss coefficient and a temperature (T
p) was evaluated. The heat resistance of the block copolymer was 0.5 mm with a Shimadzu Corporation descending flow tester.
φ × 1.0mm long die, 100 ℃ to 5 ℃ / mi
n was measured at a heating rate of n, and the melt viscosity was 1.0 × 10 ⁴ p
The evaluation was performed at a temperature at which the oise was reached.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

Examples using a steel sheet as the rigid layer (Comparative Examples 1 and 2)
2 and 5 to 7 and Examples 1 to 3) will be described. In Comparative Example 1 using only the soft segment B2 of the present invention as a resin, the maximum loss coefficient is 0.40, which is a high value, but the adhesive strength is low and the heat fluidity is poor. Next, hard segment B1
Comparative Example 2, in which the compound used for the soft segment B2 was randomly copolymerized, had unsatisfactory vibration damping performance, adhesive strength, and thermal fluidity. Further, in Comparative Example 6 having no vinyl compound having a functional group contained in the soft segment B2 of the present invention and Comparative Example 7 in which acrylic acid was used as the compound but no crosslinking was performed, the vibration damping performance was at a sufficient level. Although slightly improved, the adhesive strength is still low and the heat fluidity is poor. Comparative Example 5 using methyl methacrylate instead of styrene also did not satisfy the performance.

On the other hand, in Examples 1 and 2 in which ionic crosslinking was carried out with Na and Zn, the adhesive strength was improved, the thermal fluidity was suppressed, and the performance was sufficiently satisfied. In Example 3 in which the soft segment B2 was ethyl acrylate / butyl acrylate, Tp was 20 ° C., and the vibration damping performance in a lower temperature range was improved.

On the other hand, the case where a resin is used as the rigid layer (Comparative Examples 3, 4, 8 and Example 4) will be described. The rigid body has a flexural modulus at 20 ° C. of 2.3 × 10 ⁴ kgf / cm
^{In the case} of a PC with a value of ² , the maximum loss factor for a single PC is 0.0
When the composite was formed by laminating the same resin as in Example 3 but low as 1, it was remarkably improved to 0.18. However, as a rigid body 2
When PP having a flexural modulus at 0 ° C. of 1.3 × 10 ⁴ kgf / cm ² is used, the PP alone has a maximum loss coefficient of 0.05, which is higher than that of PC. 1
0, not much improved.

[0042]

According to the composite for a vibration damping material of the present invention, the vibration damping resin layer sandwiched between the two rigid layers exhibits excellent vibration damping performance especially at around normal temperature, and the outer rigid layer is hardened. It has excellent adhesion and excellent durability (high-temperature outflow resistance, water resistance), and is extremely useful in industry.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazutoshi Terada 1621 Sazu, Kurashiki City, Okayama Prefecture, inside Kuraray Co., Ltd. Inventor Toshiaki Sato 1621 Sazu, Kurashiki City, Okayama Prefecture, Kuraray Co., Ltd. (56) References JP-A-4-218554 (JP, A) JP-A-5-295054 (JP, A) JP-A-3-3 287652 (JP, A) JP-A-62-187022 (JP, A) JP-A-6-287253 (JP, A) JP-A-2-196848 (JP, A) JP-A-63-314223 (JP, A) JP-A-56-67380 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 F16F 15/00-15/36 C08F 293/00

Claims (6)

(57) [Claims] 1. A composite material for a vibration damping material having at least a three-layer structure composed of one vibration-damping resin layer and two rigid layers disposed on both sides thereof, wherein the rigid layer is composed of 20
A material having a flexural modulus at 2.0 ° C. of 2.0 × 10 ⁴ kgf / cm ² or more, and the vibration-damping resin layer has the following hard segment B1 and soft segment B2. 20 of united
A structural unit obtained from one or a mixture of two or more radically polymerizable compounds having a flexural modulus at 1.5 ° C. of 1.5 × 10 ⁴ kgf / cm ² or more. Soft segment B2: weight obtained by polymerization One or more (meth) acrylic acid esters 9 having a glass transition temperature of −40 to 40 ° C. and a loss tangent (tan δ) at the glass transition temperature of 0.1 or more;
A block copolymer obtained from 9.99 to 90 mol% and 0.01 to 10 mol% of a vinyl compound having a functional group, and containing a structural unit in which all or a part of the functional group is cross-linked. A composite material for a vibration damping material, comprising: 2. The soft segment B1 of the vibration-damping resin layer
2. The composite for vibration damping materials according to claim 1, wherein is obtained by polymerizing one or more kinds of radically polymerizable compounds selected from an aromatic vinyl compound, a (meth) acrylate ester and an unsaturated cyanide compound. body. 3. The hard segment B1 of the vibration-damping resin layer
3. The composite for a vibration damping material according to claim 1, wherein the compound is obtained by polymerizing a radically polymerizable compound composed of at least one of styrene and a styrene derivative. 4. The soft segment B2 of the vibration-damping resin layer
The composite for vibration damping materials according to any one of claims 1 to 3, wherein the crosslinking in (1) is ionic crosslinking. 5. The soft segment B2 of the vibration-damping resin layer
The composite material for a vibration damping material according to any one of claims 1 to 4, wherein the vinyl compound having a functional group is a vinyl compound having a carboxyl group. 6. The hard segment B1 of the vibration-damping resin layer
And the ratio of soft segment B2 is 5/90 or more and 50 /
The composite material for a vibration damping material according to any one of claims 1 to 5, wherein the number is 50 or less.