JPH06198802A - Composite type damping material with excellent workability - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a composite vibration damping material having excellent vibration damping performance near room temperature, specifically in the range of 20 to 40 ° C, and having good moldability. Has an aim. [Composition] A composite vibration damping material in which a resin composition for composite vibration damping material is sandwiched between two metal plates as an intermediate resin layer,
A reaction-curable resin layer whose main component is a reaction product of the intermediate resin layer with a polyester and a polyvalent isocyanate compound,
Characterized by forming a two-layer structure of an unreacted resin layer containing polyester as a main component

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping material such as a composite type damping steel sheet formed by forming a resin layer between two steel sheets, and particularly at room temperature and a wide temperature range in the vicinity thereof. The present invention relates to a composite type vibration damping material having an excellent vibration damping action and good workability.

[0002]

2. Description of the Related Art A composite type vibration damping steel sheet has a viscoelastic resin (hereinafter referred to as an intermediate resin) layer interposed between two steel sheets, and the vibration applied to the steel sheet by the intermediate resin layer is converted into heat energy. It is a noise prevention material. This composite type vibration damping steel plate responds to the recent needs for noise regulation, and is used for building materials such as automobile oil pans, stairs, doors, floor materials, motors,
It is being used or is being considered for compressor covers.

Generally, the damping performance of such a composite damping material depends on the performance of the intermediate resin layer. When this damping performance is represented by a loss coefficient (η), this damping performance shows a characteristic that shows a peak at a certain temperature, and it is known that it is most effective to use near this peak characteristic temperature. ing.

Conventionally, as an intermediate resin for this damping steel plate,
Polyurethane (JP-A 47-19277), polyester (JP-A 50-143880), polyamide (JP-A 51-79146), polyisobutylene (JP-A 54-43251), ethylene / α-olefin (JP-A-55-84655), EVA (JP-A-57-34)
949), cross-linked polyolefin (JP-A-59-152)
No. 847), polyvinyl acetal (JP-A-60-88).
No. 149) has been studied, and it is known that asphalt, synthetic rubber, acrylic pressure-sensitive adhesive, epoxy resin and the like also have vibration damping performance. Among these, acrylic-based adhesives, synthetic rubber (isobutylene rubber), EVA, and other resins that are flexible at room temperature have relatively damping properties at temperatures near room temperature, but because the cohesive force of the resin at room temperature is weak, adhesion Because of its low strength, vibration-damping steel plates made of the resin cannot withstand molding and have no heat resistance, so these vibration-damping steel plates are only used for building materials that are used in a state close to a flat plate. It was

Further, polyolefin resins modified by copolymerization, blending, etc., such as ethylene / α-olefin resins, have relatively excellent vibration damping properties on the high temperature side of 50 to 100 ° C. as compared with the former, and at room temperature. Since the resin has a strong cohesive force and is compatible with molding processing, it is said that the vibration-damping steel plate using the resin is suitable for the vibration-damping steel plate used for high temperatures such as oil pans of automobiles.

[0006]

However, even if both of them are limited in their use, they cannot be said to have reached sufficiently satisfactory levels in terms of vibration damping performance and adhesive performance. No resin has yet been found that can simultaneously satisfy the high vibration damping performance required at around room temperature for home electric appliances and the molding processability such as deep drawing and bending.

The present invention solves the above-mentioned problems,
Specifically, it is an object of the present invention to provide a composite type vibration damping material having excellent vibration damping performance in the range of 20 to 40 ° C and having good moldability.

[0008]

In order to achieve the above object, according to the present invention, a composite type vibration damping material in which a resin composition for a composite type vibration damping material is sandwiched as an intermediate resin layer between two metal plates. The intermediate resin layer has a two-layer structure of a reaction-curable resin layer containing a reaction product of polyester and a polyvalent isocyanate compound as a main component and an unreacted resin layer containing polyester as a main component. A composite type vibration damping material having excellent workability, which is characterized by being provided. Here, it is preferable that the intermediate resin layer further contains a conductive substance.
Hereinafter, the present invention will be described in more detail.

The composite type damping material (hereinafter referred to as damping material) of the present invention is basically constituted by disposing an intermediate resin layer between metal plates such as steel plates. The metal plate applied to the damping material of the present invention is not particularly limited, cold-rolled steel plate, chromate-treated steel plate, zinc-based plated steel plate, surface-treated steel plate such as phosphate-treated steel plate, copper plate, aluminum plate, stainless steel. It may be a plate, a titanium plate, or the like, and may be a coiled original plate or a cut plate. The plate thickness is not particularly limited, but considering molding processability and shape retention,
It is preferably 0.2 to 2 mm.

The intermediate resin layer arranged between such metal plates is a reaction-curable resin layer obtained by crosslinking a saturated copolyester (hereinafter referred to as polyester) with a polyvalent isocyanate compound (hereinafter referred to as isocyanate compound). And a two-layer structure of an unreacted resin layer is formed.

Conventionally, saturated copolyester has a narrow temperature at which the resin itself exhibits viscoelasticity due to its sharp melting behavior, so that the temperature at which good vibration damping performance is exhibited is also limited to a specific narrow temperature range. In addition, since the cohesive force is insufficient in the temperature range where the viscoelasticity is exhibited, the adhesive strength is weak even at the temperature at which the vibration damping property is practically obtained. Therefore, at a temperature higher than that, sufficient strength was not obtained. The inventors have made a good control at room temperature by forming the intermediate resin layer composed of a specific polyester and a polyvalent isocyanate compound into a two-layer structure of a reaction-cured resin layer with a curing agent and an unreacted resin layer. It was possible to obtain a vibration damping material having a large value of vibration performance, that is, a loss coefficient, and having extremely excellent moldability.

Further, the resin used in the present invention is a two-component polyurethane or a curable epoxy composed of a low-molecular weight normal liquid polyester or polyether and an isocyanate compound even when laminated with two metal plates. Does not require a long heating time like reactive resins such as resins,
There is no problem of resin flowing out during lamination processing, and a melting point above the temperature exposed during use is essential, as in the case of bonding using the thermoplasticity of the resin itself such as polyurethane resin or modified polyolefin resin. It does not require the indispensable high lamination temperature and lamination pressure, and even at a lamination temperature below the practical temperature, high adhesive strength can be obtained, and it has excellent working effects such as having extremely good workability. is there.

Of these intermediate resin layers, the first essential constituent component forming the reaction-cured resin layer and the essential constituent component forming the unreacted resin layer are the main components (saturated copolymerization).
It is polyester.

The polyester used in the present invention has a glass transition temperature of 40 as measured by a viscoelastic spectrometer.
It is preferably below ℃. Those having a glass transition temperature of higher than 40 ° C. often have not only low vibration damping performance at around room temperature but also insufficient adhesive performance (hereinafter referred to as adhesiveness). More preferably, it is 20 ° C. or less.

Considering the processability during the production of the vibration damping material, the polyester used in the present invention is preferably one which is soluble in a general-purpose solvent such as toluene, MEK or ethyl acetate. When a polyester soluble in a general-purpose solvent is used as the polyester, the polyester is dissolved in the solvent to form a liquid in the manufacturing process of the vibration damping material, which facilitates coating on a metal plate, resulting in an intermediate resin. Gas entrapment in the layer is eliminated. Further, it becomes easy to add and mix the conductive powder and the filler, and various additives to be added to the intermediate resin layer for imparting the spot weldability when processing the composite type vibration damping material.

Here, in the present invention, the polyester means the following compounds. That is, dimethyl terephthalic acid, terephthalic acid, isophthalic acid, aromatic dibasic acids such as phthalic acid, succinic acid, glutaric acid, adipic acid,
one or more of aliphatic dibasic acids such as β-methyladipic acid, pimelic acid, 1,6-hexanedicarboxylic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, and hexadecanedicarboxylic acid; Ethylene glycol, 1,2-propanediol, 1,3-
Propanediol, 1,3-butanediol, 1,4-
Butanediol, 1,2-pentanediol, 1,5-
Pentanediol, 3-methylpentanediol, 1,
3-hexanediol, 1,6-hexanediol,
1 of glycols such as 1,4-cyclohexanediol, hydrogenated bisphenol A, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol, or a residue-forming derivative thereof A saturated copolyester synthesized from one or more kinds,
Alternatively, it is a saturated copolyester synthesized from caprolactone.

The polyester used in the present invention is preferably an acid component having a terephthalic acid residue of 30 to 9
It is 0 mol%. Among the acid components, a saturated copolyester having a terephthalic acid residue of less than 30 mol% has insufficient cohesive force and weak adhesive strength, and it is difficult to obtain strength immediately after laminating adhesion, resulting in problems during processing. May be. Further, if it exceeds 90 mol%, the adhesive property may be similarly deteriorated, which is not preferable. Examples of the dibasic acid used together when the terephthalic acid residue is used in the above range as the acid component include the above-mentioned aromatic dibasic acids or aliphatic dibasic acids, but preferred are one or more. Aliphatic dibasic acids, especially adipic acid and sebacic acid.

The polyester used in the present invention is preferably one having an ethylene glycol residue of 30 to 80 mol% in the glycol component. Among the glycol components, a saturated copolyester having an ethylene glycol residue of less than 30 mol% has low adhesiveness, and a glycol copolymer of more than 80 mol% has not only low adhesiveness but also good control. Vibration performance may not be obtained. As the glycol component, examples of the glycol component used in combination when the ethylene glycol residue is used in the above range include the glycols described above, but more preferable ones are:
Hexanediol glycols having 6 carbon atoms or polyoxyalkylene glycols such as polyethylene glycol and polytetramethylene glycol.

As the polyester, for example, unsaturated fatty acids such as maleic acid, fumaric acid and dimer acid,
Copolymers of fatty acids such as trimellitic acid that have more than two functional groups, trimethylolpropane, pentaerythritol and other compounds that have more than two functional groups of hydroxyl groups can also be used, but these monomers have low adhesiveness. Since the adhesion durability is poor or the vibration damping performance itself is low, it is preferable to use such a polyester within a range that does not impair the characteristics of the present invention.

The polyester applied to the present invention may be one synthesized by a usual method. As an example, the synthesis method is as follows. Synthesized by the esterification reaction of the above-mentioned dibasic acid or polybasic acid with glycol or the like, and the subsequent transesterification while distilling off excess glycol under high temperature and reduced pressure, or pre-synthesized polyethylene. It may be synthesized by depolymerizing terephthalate, polybutylene terephthalate or the like in the presence of a desired dibasic acid or the like and excess glycol or the like, and similarly performing a transesterification reaction.

More specifically, for example, by using dibasic acid and glycol as the main raw materials and heating at 150 to 220 ° C., under normal pressure, in the presence of a catalyst mainly composed of a metal salt, an oligo-esterification reaction is carried out. Esterification,
Subsequently, the polyester having a high molecular weight can be synthesized by heating at 200 to 270 ° C. under normal pressure or reduced pressure to distill off excess glycol. When synthesizing the polyester, it is preferable to add 1.5 to 2.0 times the amount of glycol in the desired polyester composition. The composition of the polyester produced at this time can be adjusted by measuring the molar ratio of the monomer residues by ¹ H-NMR. The polymerization catalyst is appropriately selected from ordinary catalysts composed of metal salts such as tetra-n-butoxytitanium, zinc acetate, antimony trioxide and potassium titanate oxalate.

The second essential component forming the reaction-cured resin layer of the intermediate resin layer is an isocyanate compound.
Examples of the isocyanate compound used in the present invention include various known isocyanate compounds having at least two or more isocyanate groups in the molecule, and are not particularly limited.

Specifically, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (commonly called TD
I), MDI derivatives such as methylene-bis-4-phenyl isocyanate (common name MDI), polymethylene polyphenyl polyisocyanate or polyol modified MDI, hexamethylene diisocyanate (common name HDI) and its derivatives, isophorone diisocyanate. (Aka I
PDI) and its derivatives, and TDI-based adduct polyisocyanate obtained by adding TDI to trimethylolpropane, for example, commercially available products such as Coronate L, Coronate HL (all manufactured by Nippon Polyurethane Industry Co., Ltd.), Dismofen L, Dismodur N (Sumitomo Bayer Urethane). Made),
Pre-reacted polymerized polyisocyanate, for example, commercially available products such as Suprasec 3240, 3250, Coronate 2030, 2031 (manufactured by Nippon Polyurethane Industry Co., Ltd.), Dismodur IL, HL (manufactured by Sumitomo Bayer Urethane), and isocyanate masked with caprolactam or the like. Examples thereof include blocked isocyanates and terminal isocyanate prepolymers obtained by previously reacting a low molecular weight polyether with the above-mentioned polyvalent isocyanates, and any of them can be used, but it improves the adhesiveness. Therefore, adduct polyisocyanate and polymerized polyisocyanate are preferable for the present invention.

The amount of the polyvalent isocyanate compound added to the saturated copolyester is 1% of the hydroxyl group in the saturated copolyester calculated from the weight average molecular weight of the resin on the side of the intermediate resin layer which is the reaction-curable resin layer. 0.1 to 10.0 equivalents are preferable relative to the equivalents. When the amount of the polyvalent isocyanate compound added is less than 0.1 equivalent, the adhesive strength of the entire resin layer is extremely low, which causes problems such as peeling and misalignment during molding, and resin outflow during baking coating. Further, if the amount of addition of the polyvalent isocyanate compound exceeds 10.0 equivalents, the vibration damping performance in the vicinity of room temperature is significantly reduced.

The polyvalent isocyanate compound is not added to the unreacted resin layer side of the intermediate resin.

The reaction-curable resin layer has a viscoelastic resin obtained by crosslinking the above polyester with an isocyanate compound in the intermediate resin layer. The viscoelastic resin contains a polyester and an isocyanate compound. It is produced by subjecting the resin composition to a heat treatment and reacting the hydroxyl group of the polyester with the isocyanate group of the isocyanate compound.

The crosslink density of the reaction-curable resin layer is not particularly limited and may be freely set according to the required characteristics in the application. Generally, the lower the crosslink density is, the better the vibration damping property is.
On the contrary, the higher ones have excellent adhesiveness and heat resistance.

From the viewpoint of satisfactorily exhibiting the characteristics of the reaction-curable resin layer, one equivalent of the hydroxyl group of the saturated copolyester when converted to the weight average molecular weight is equivalent to one equivalent of the isocyanate group in the isocyanate compound. It is preferably about 5 equivalents. By setting the amount of the isocyanate group of the isocyanate compound to the hydroxyl group of the saturated copolyester to 1 equivalent or more, good cohesive force can be imparted to the reaction-cured resin layer, and excellent adhesive force can be obtained.
No displacement or peeling between layers occurs during molding of the vibration damping material. On the other hand, similarly, by setting the amount of the isocyanate group to 5 equivalents or less, good vibration damping performance is exhibited, and deterioration of characteristics over time due to reaction between the excess isocyanate group and moisture in the air, particularly, It is possible to obtain a vibration damping material having excellent durability without deterioration of vibration damping performance or spot weldability.

The molecular weight of the reaction-curable resin layer is not particularly limited and may be appropriately set according to the required characteristics, but is usually about 10,000 to 50,000 in weight average molecular weight. If the molecular weight is too small, the vibration damping property and the adhesiveness are deteriorated, and if the molecular weight is too large, handling and synthesis become difficult.

In the present invention, the reaction-cured resin layer is for the purpose of imparting strong adhesion and heat resistance to the metal plate, and the unreacted resin layer is an extremely good vibration damping performance at around room temperature and a resin layer during molding. The purpose is to give a shear deformation amount (shear elongation) sufficient to withstand the shear deformation of the.

The ratio of both layers is not particularly limited, but the ratio of the unreacted resin layer is increased when the processability is emphasized (when the drawing ratio is large), and the ratio of the reaction-cured resin layer is increased when the heat resistance is emphasized. It is desirable to do.

The layer thickness of such an intermediate resin layer is not particularly limited and may be appropriately set according to the use of the vibration damping material, but is usually about 20 to 150 μm, preferably 20 to 5 μm.
It is about 0 μm.

The essential constituent components of the intermediate resin layer of the vibration damping material of the present invention are as described above, but various additives can be used in combination with such an intermediate resin layer, if necessary.

Examples of additives that can be used in combination include polyesters other than saturated copolyester, acrylic resins having terminal hydroxyl groups, epoxy resins such as bisphenol epoxy resins, cresol novolac epoxy resins, and the like.
Styrene resin such as styrene and α-methylstyrene, terpene resin, terpene phenol resin, rosin resin, hydrocarbon resin, aromatic resin, tackifying resin such as phenol resin, polyalkylene glycol polyester plastic Agents, melamine resins, organofunctional silanes (commonly called silane coupling agents), crosslinking agents such as peroxides, metal salts such as n-butyltin dilaurate, amine-based and glycol-based isocyanate curing catalysts, chain extenders, etc. There is.

As the filler, inorganic fillers such as calcium carbonate, talc and hard seal can be used.

Further, as the solvent, toluene, ME
K, acetone, xylene, chloroform, MIBK, ethyl acetate, etc. can be used.

The intermediate resin layer (viscoelastic resin layer) of the vibration damping material of the present invention is provided with conductivity by blending a conductive solid substance as a filler so that the composite vibration damping material can be spot-welded. It can also be a material.

Examples of the conductive substance used for such a purpose include metal substances obtained by processing metals such as stainless steel, zinc, copper, tin, nickel and brass into powder, flakes, fibers and wires. , Iron-based metal plated with copper or nickel, carbon black,
Conductive carbon materials such as graphite and carbon fiber can be used. These conductive materials are
They can be used alone or in combination of two or more. In addition, as the conductive substance, it is preferable to select a metal substance in order to exhibit good conductivity.

By the way, the conductive substance has a maximum particle size when it is in the form of powder, a maximum thickness when it is in the form of flakes, and a maximum particle size when it is in the form of fibers or wires. Letting the maximum diameter be the respective representative length (L), in order to develop better conductivity, the ratio of the representative length (L) to the thickness (T) of the resin layer containing the conductive substance (T) L / T) is 0.5 or more, preferably 0.
It is preferable to use one that is 8 or more. The L / T ratio is 0.
When it is less than 5, the spot welding performance of the composite type vibration damping material having such a resin layer deteriorates.

Further, the filling amount of the conductive material is preferably such that it accounts for 0.5 to 10% by volume of the intermediate resin layer. If it is less than 0.5% by volume, the spot welding performance of the composite vibration damping material containing such an intermediate resin layer is low, and 10
When the content exceeds the volume%, the spot weldability is sufficiently satisfied, but the adhesiveness between the metal plate and the intermediate resin layer and the vibration damping performance of the intermediate resin layer deteriorate, which is not preferable. A more preferable range is about 1 to 5% by volume.

Next, a suitable method for producing the vibration damping material of the present invention will be described. The resin composition used for producing the intermediate resin layer used in the present invention, the polyester and the isocyanate compound are stored separately, and both are used in the case of producing the damping material, the so-called main agent and curing It is generally used like a two-component adhesive consisting of an agent.

When a solvent is not used, the resin composition in which all the constituents are mixed is formed into an extruded film by, for example, heat melting and mixing, and when a solvent is used, it is formed into a release sheet. After coating, the solvent is distilled off to give a so-called casting film.

It is also possible to laminate it between two metal plates and bond them by heating roll, hot press bonding or subsequently cooling roll or cooling press, but preferably the following method is used. That is, a predetermined polyester in a solvent, after mixing the isocyanate and the other additives as necessary, directly applied to one of the metal plate, also to the other metal plate a mixed solution or polyester of polyester and solvent Then, a mixed solution of the above-mentioned other additives and a solvent is applied, and the solvent is distilled off by heating at room temperature or preferably at a temperature of 100 to 200 ° C., followed by standing or standing, followed by heat lamination adhesion to manufacture.

At this time, the thickness of the resin layer is preferably 20 to 150 μm in terms of the total thickness of the intermediate resin layer. If the total thickness of the intermediate resin layer is less than 20 μm, the vibration damping performance and the adhesive strength are reduced, and if it exceeds 150 μm, the front and back metal plates may be displaced or cracked during the molding process.

As the solvent, as described above, toluene, MEK, acetone, xylene, chloroform, M
IBK, ethyl acetate, etc. can be used.

The method of applying the resin composition to the metal plate is not particularly limited, but a roll coater, spray, curtain flow coater, doctor knife coater and the like are preferable. The lamination adhesion temperature is usually 120 to 26 for the resin composition.
It suffices that heating at 0 ° C. be applied, and for a heating press, it is about 2 seconds to 2 minutes, and for a heating roll, it is 0.
The contact time may be about 5 to 10 seconds. Alternatively, the metal plates may be preheated to the same temperature and laminated and bonded by a cooling press or a cooling roll.

As described above, the intermediate resin of the present invention is characterized in that it has heat resistance equal to or higher than the adhesion temperature under the same processing conditions as the thermoplastic resin, and a predetermined adhesion performance can be obtained immediately after the lamination and adhesion. It also has a feature that the pot life of a coated product on a metal plate is a length that causes no practical problems. Also, when the resin can be applied in solution during lamination processing, the adhesion between the metal plate and the resin can be enhanced, and not only the gas layer can be prevented from being entrained, but spot welding of the formed metal plate is also possible. It is most preferable for the present invention because it facilitates the addition of conductive metal powder, carbon, etc., which is added for the purpose of imparting properties, and the saturated copolymerized polyester of the present invention can easily achieve this.

The composite damping material of the present invention has been described above in detail. However, the present invention is not limited to this, and various modifications and improvements can be made without departing from the gist of the present invention. Of course, it is good.

[0049]

EXAMPLES The present invention will be described in more detail with reference to specific examples of the present invention.

(Examples 1 to 6) The followings were prepared as the polyester and the isocyanate compound for obtaining the intermediate resin layer. Polyester: Synthesized by a conventional method using terephthalic acid, isophthalic acid, sebacic acid, ethylene glycol and neopentyl glycol as raw materials. (Weight average molecular weight:
20,000, glass transition temperature: -15 ° C) Polyester: synthesized by a conventional method using terephthalic acid, sebacic acid, ethylene glycol and propylene glycol as raw materials. (Weight average molecular weight: 20,000, glass transition temperature: + 5 ° C.) Isocyanate compound (Nippon Polyurethane Industry Co., Ltd., Coronate L and Coronate 2030)

The glass transition temperature (Tg) of the above polyester is shown below. 1 mm of polyester
Thick sheet and viscoelastic spectrometer (10H
The dynamic elastic modulus (E ′) was measured by z) and the temperature at which the elastic modulus started to decrease was displayed.

The above polyester was previously mixed with toluene,
Dissolve in MEK mixed solvent to make a solution with a solid content of 30%,
The above-mentioned isocyanate compound was mixed and applied to one surface of the steel sheet so as to have a predetermined film thickness by using a roll coater (layer A). Further, a polyester solution in which the polyvalent isocyanate compound was not mixed was applied to one surface of another steel plate (layer B). After applying to two steel plates, oven (150 ℃ ×
The solvent was distilled off in 1 minute). Thereafter, the coated surfaces of the resin-coated steel sheets were superposed on each other and heat-bonded with a hot press (200 ° C. × 1 minute, pressure 20 Kgf / cm ² ), and the following various tests were performed on the obtained laminated steel sheets.

[TPS (T-peel strength)] A sample of the obtained composite vibration damping material was cut into a width of 25 mm, and a pulling speed was 20.
It was measured according to JIS K-6854 at 0 mm / min and room temperature of 23 ° C.

[Workability] Similarly, the above laminated and adhered pieces were cut into 25 mm width × 100 mm length and bent into 4 mmφ, and those with a floating portion were marked with x, and those without change were marked with ◯. (Normal). Similarly, the bent products were left in an oven at 150 ° C. for 24 hours, and those immersed in boiling water for 24 hours were taken out. Those with floating were marked with x, and those without change were marked with ◯.

[Η] To evaluate the vibration damping performance, each composite vibration damping material sample was processed into a size of 20 mm × 300 mm,
The loss coefficient (η) was measured by the mechanical impedance method, and the loss coefficient at 20 ° C. and 1000 Hz was investigated.

The results are shown in Table 1. The steel plate is
A cold rolled steel plate (SPCC-SD) having a thickness of 0.5 mm was degreased and used. Table 1 shows the thickness of each resin tank (A and B layers), the addition amount of the curing agent, the equivalent amount, and the Tg (glass transition temperature) of the polyester used.

The addition amount and equivalent amount of the curing agent are shown below. The equivalent number of isocyanate groups was calculated based on the terminal hydroxyl groups measured from the amount of isocyanate added to 100 parts by weight of polyester and the weight average molecular weight of polyester.

[0058]

[Table 1]

[Table 2]

From the results shown in Table 1 above, according to the composite type vibration damping material of the present invention, by setting the intermediate resin layer according to the use, the required performance can be satisfactorily exhibited, and the wide range of uses can be achieved. It can be seen that it can be suitably applied to.

[0060]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, the damping material of the present invention has a specific saturated copolyester and a polyvalent isocyanate as an intermediate resin layer for exhibiting a damping effect. By using a compound in combination, the intermediate resin layer has a two-layer structure of a reaction-cured product layer with a curing agent and an unreacted resin layer, so that excellent vibration damping is achieved at around room temperature, specifically at a temperature of 20 ° C to 40 ° C. And has good moldability. Therefore, as a noise prevention material, it can be used not only for building materials such as stairs, doors and floor materials, but also for oil pans of automobiles, dash panels around bodies, floor panels, roof panels, etc., which have been difficult to use in the past, or motors. It is possible to provide damping materials that can be widely used in the automobile industry, civil engineering and construction industry, electrical industry, etc. for parts used near room temperature, such as compressor covers and home appliances, and the effects on those industries are It's a very big one.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F16F 15/02 Q 9138-3J // B23K 11/16 320 9265-4E (72) Inventor Sakamoto Seiji, 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Pref., Technical Research Division, Kawasaki Steel Co., Ltd. (72) Inventor, Hidetaka Suganabe 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Pref., Technical Research Division, Kawasaki Steel Co., Ltd.

Claims (2)

[Claims] 1. A composite type vibration damping material in which a resin composition for a composite type vibration damping material is sandwiched between two metal plates as an intermediate resin layer, wherein the intermediate resin layer comprises a polyester and a polyvalent isocyanate compound. A composite type vibration damping material with excellent processability, characterized in that it has a two-layer structure of a reaction-cured resin layer containing the reaction product as a main component and an unreacted resin layer containing a polyester as a main component. 2. The composite vibration damping material according to claim 1, wherein the intermediate resin layer further contains a conductive substance.