JP2639291B2 - Resin composition for manufacturing composite damping material and 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 resin composition for producing a composite vibration damping material and a composite vibration damping material obtained by laminating a plurality of metal plates using the resin composition as a bonding layer.
The vibration damping material exhibits an excellent vibration damping effect when used as a component or a part of a building, a machine, or the like, and is therefore useful as a noise prevention material accompanying vibration.

[0002]

2. Description of the Related Art In recent years, with the development of transportation systems or the proximity of dwellings to factories and business establishments, measures to prevent noise generated from various transportation systems and various machinery and equipment have been taken from the viewpoint of environmental preservation in residential areas. Is a major issue. Especially, in the oil pan, dash panel, chute of hopper, general-purpose engine cover, outer plate of electric washing machine or other various metal processing machines of automobiles, noise accompanying vibration has become a big social problem. Various vibration damping materials have been put to practical use in order to reduce or eliminate such problems.

[0003] By the way, a composite damping material is a damping metal plate,
A plurality of sheets are laminated with an intermediate resin layer also serving as a bonding agent interposed therebetween, and the intermediate resin layer includes polyurethane resin (JP-A-47-19277) and polyester resin (JP-A- No. 50-143880), polyamide resin (JP-A-51-79146), ethylene / α-olefin resin (JP-A-55-84665), ethylene / vinyl acetate resin (JP-A-57-84665). No. 34949) and cross-linked polyolefin-based resins (JP-A-59-152847). Other than these, asphalt, synthetic rubber,
It has been confirmed that an acrylic pressure-sensitive adhesive or the like is effective as a resin constituting an intermediate layer for producing a composite vibration damping material.

Among these resins, flexible resins at normal temperature (10 to 40 ° C.), such as acrylic adhesives and ethylene / vinyl acetate resins, are laminated with a metal plate mainly by a hot melt lamination method to obtain vibration damping. The material exhibits a relatively high vibration damping effect and end bending workability at temperatures around room temperature. However, these resins have low adhesive strength due to low cohesion at room temperature, and are baked (usually 180 ° C x
It does not have enough heat resistance to withstand 30 minutes to 230 ° C x 30 minutes).

Therefore, recently, thermosetting polyurethane resins (JP-A-63-202613) have been used as joining resins that can withstand baking coating.
JP-A-63-75056) and the like, which are used in a solvent method in which a resin is dissolved in a solvent,
After removing the solvent, it is laminated together with the metal plate.

[0006] Comparing the features of the manufacturing methods developed so far including the above technology, the hot melt lamination method meets social demands such as labor saving, energy saving, and pollution reduction. The heat resistance of the obtained vibration damping material is not sufficient. In addition, the film lamination method has good heat resistance, but has a high degree of adhesion to the metal plate during edge bending, so the flange bending phenomenon (commonly called "gull") is likely to occur. This is disadvantageous in terms of cost because an expensive film with high precision must be used. Further, the solvent method requires a solvent removal facility because a solvent is used, and does not satisfy social demands such as non-pollution.

[0007] Thus, the known resin for producing a composite vibration damping material is as follows.
It cannot be said that the vibration damping property, heat resistance, bending workability, or handling properties have reached a sufficiently satisfactory level, and it has high vibration damping properties at room temperature and high heat resistance even at high temperatures. There are few known bonding resins having sufficient performance for manufacturing required damping materials.

[0008] As a new use of the vibration damping material, application to building materials such as steel stairs and steel doors of general houses and apartment houses has been actively promoted recently. Since baking or rubber coating is performed, heat resistance at high temperatures is required. Therefore, the conventional thermoplastic resin used in the hot melt lamination method or the like is unsuitable for such applications, and therefore has a long pot life in the normal / medium temperature range (10 to 60 ° C) and has a long pot life in the high temperature range (150 to 180 ° C). The development of a new solvent-free thermosetting resin having fast curing properties has been desired.

[0099]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to take advantage of the advantages of the hot melt lamination method.
It has improved heat resistance, which is a drawback, and can be firmly laminated and joined to a vibration-damping metal plate in a solvent-free type. It exhibits high vibration-damping effect and bending workability at room temperature, and has a high resistance to baking coating. An object of the present invention is to provide a resin composition for producing a composite vibration damping material having heat resistance, and a high-performance composite vibration damping material using the resin composition as a resin for joining a vibration damping metal plate.

[0010]

Means for Solving the Problems A resin composition for producing a composite vibration damping material according to the present invention, which can solve the above-mentioned problems, is composed of a plurality of metal plates overlapped with a joining resin composition interposed therebetween. The bonding resin composition in a vibration damping material comprising: an epoxy resin having two or more epoxy groups in a molecule, a liquid rubber having a carboxyl group in a molecule, an acid anhydride, and imidazole or imidazole or the like. Derivatives have a gist where they are blended, and their preferred blending ratio is 100 to 100 parts by weight of epoxy resin, 10 to 100 parts by weight of liquid rubber, 10 to 80 parts by weight of acid anhydride, imidazole or Its derivatives range from 1 to 10 parts by weight. Then, a composite vibration damping material having excellent vibration damping properties, bending workability and heat resistance is obtained by laminating a plurality of metal plates through a resin layer having a thickness of 30 to 300 μm made of this resin composition. be able to.

[0011]

The resin composition according to the present invention is used as an intermediate resin composition for a composite vibration damping material comprising a plurality of metal plates and an intermediate resin layer for joining the metal plates, and comprises a specific epoxy resin. It contains a resin, a liquid rubber having a carboxyl group, an acid anhydride, and imidazole or a derivative thereof as essential components.

The epoxy resin used in the present invention is a main component of a material for forming an intermediate layer having excellent adhesiveness and heat resistance, and has two or more epoxy groups in one molecule. Any one can be used as long as it is used. Preferred examples thereof include polypropylene glycol diglycidyl ether, diglycidyl ether of an alkylene oxide adduct of bisphenol A, diglycidyl ether of bisphenol A and a polymerized fatty acid, polymerized fatty acid polyglycidyl ester, and liquid rubber. Diglycidyl ether. These epoxy resins can be used alone or
It can be used in combination of more than one species.

The liquid rubber mainly has an effect of increasing the elasticity of the resin constituting the intermediate layer to enhance the vibration damping action, and has a carboxyl group in the molecule in order to have reactivity with the epoxy resin. Is selected. Specific examples include acid-terminated liquid NBR, acid-terminated liquid polybutadiene [“Hiker CTBN” manufactured by Ube Industries, Ltd.]
Etc.], acid-terminated liquid chloroprene rubber [Electrical Chemical Industry Co., Ltd.], acid-terminated polyester polyol [Kuraray Co., Ltd.] and the like. These liquid rubbers can be used alone or in combination of two or more.

The acid anhydride is used as a curing agent. For example, aromatic anhydrides such as phthalic anhydride, trimellitic anhydride, ethylene glycol bis (trimellitate anhydride) and glycerol tris (trimellitate anhydride) are used. , Pyromellitic anhydride, 3,3 ', 4,4'-
Benzophenone tetracarboxylic anhydride and the like; cyclic aliphatic anhydrides such as maleic anhydride, succinic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, alkenylsuccinic anhydride,
Hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhexenetetracarboxylic anhydride, etc .;
Examples thereof include aliphatic acid anhydrides such as polyadipic anhydride and polyazeleic anhydride. These acid anhydrides can be used alone or as a mixture.

The imidazole or a derivative thereof is used mainly for exhibiting a function as a curing accelerator, and is preferably 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole or 2-ethylimidazole.
Undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl- Examples thereof include 2-methylimidazole and 1-cyanoethyl-2-undecylimidazole, and these imidazoles can be used alone or as a mixture.

Next, preferred amounts of the respective raw materials will be described. First, the compounding amount of the liquid rubber having a carboxyl group is preferably selected from the range of 10 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin. Alternatively, the damping action may not be sufficiently exerted. A more preferred amount of the liquid rubber is 50 to 100 parts by weight based on 100 parts by weight of the epoxy resin.

The compounding amount of the acid anhydride is preferably set in the range of 10 to 80 parts by weight, more preferably 20 to 60 parts by weight, based on 100 parts by weight of the epoxy resin. In some cases, the adhesive strength of the layer becomes insufficient, and a satisfactory vibration damping effect may not be exhibited. Further, imidazoles are used in an amount of 1 to 10 based on 100 parts by weight of the epoxy resin.
Parts by weight, more preferably in the range of 4 to 8 parts by weight, and if it is out of this range, not only the curability and the curing speed of the resin composition are reduced, but also the strength of the cured product tends to be insufficient. Become. The essential components in the present invention are the above four types, but if necessary, various conductive materials such as carbon black, graphite, metal powder, etc. may be used to impart conductivity for the purpose of improving the weldability of the vibration damping material. A conductive filler can be blended.

In the resin composition having the above composition according to the present invention, a carboxyl group in the liquid rubber, a carboxyl group generated by a reaction between an acid anhydride and an imidazole, or an alkoxy anion formed by a reaction between an imidazole and an epoxy group. It is considered that such a compound reacts with an epoxy group in an epoxy resin to be cross-linked and cured, and exhibits various properties such as vibration damping property, workability, adhesive strength, and heat resistance at high temperatures.

The above-mentioned cross-linking reaction is carried out in order to secure an appropriate reaction rate in accordance with the actual operating conditions in the production line.
The types and amounts of the epoxy resin, liquid rubber, acid anhydride and imidazoles used are appropriately combined. in this case,
Considering the manufacturing conditions of the vibration damping material, the resin composition of the present invention comprising an epoxy resin, a liquid rubber, an acid anhydride and imidazoles has a coating property on a metal plate, prevention of gas entrapment in a laminated portion, and processing. In order to impart spot weldability, it is desired to use a low viscosity material of about 10 to 200 poise at room temperature in consideration of the ease of mixing or addition of a conductive filler or an additive.

The resin composition of the present invention comprises a so-called main agent and a curing agent which are used separately by storing the above epoxy resin, liquid rubber, acid anhydride and imidazole separately and mixing them immediately before the production of a vibration damping material. It may be used like a two-part adhesive, but since the stability of this resin composition at room temperature is quite good, it is also possible to mix all of the above-mentioned raw materials and use it as a one-part adhesive. it can. The two-pack type or the one-pack type is appropriately selected according to the resin composition and the actual operating conditions of the production line, etc. , And supplied to the production line. From the viewpoint of operation, the one-pack type is preferred.

As a method for producing a vibration damping plate using the resin composition of the present invention, for example, a batch method in which the above-mentioned resin composition layer is formed on one or both sides of a cut metal plate to be laminated and heated and pressed. Should be adopted. As a method of laminating a metal plate and a resin composition layer, a method of applying a paint-like resin composition to a metal plate, laminating the other metal plate thereon, bonding by heating and pressing, and the like. Can be adopted.

The cured product of the resin composition preferably has a glass transition temperature (Tg) of -70 to -10 ° C. That is, the application of the vibration damping material is mainly in a normal temperature range such as a staircase, a door, a floor, a dash panel of an automobile, a floor, an outer plate of an electric washing machine, a chute of a hopper, a general-purpose engine cover, etc. In most cases, a resin composition whose Tg of the cured product is between -70 and -10 ° C is excellent at room temperature by using this as a resin constituting the intermediate layer. This is because a damping material exhibiting an improved damping effect is provided.

The type of metal plate is not particularly limited, and these metal plates may be the same or different. As such a metal plate, for example, a steel plate (including a surface-treated steel plate, a stainless steel plate or the like), an aluminum plate, a steel plate, a titanium plate, or a surface-treated plate thereof may be selected according to the use and purpose of use. The thickness of the resin composition layer interposed between the metal plates as the intermediate resin layer should be set within the range of 30 to 300 μm.If the intermediate resin layer is too thin, the vibration damping action is sufficiently exerted. If it is too thick, the workability such as bending will deteriorate. The thickness of the intermediate resin layer, which is more preferable for more effectively exhibiting the vibration damping action and workability, is 50.
100100 μm.

[0024]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to the following Examples. The methods for measuring the physical properties of the resin composition, the lamination / adhesion method, and the methods for measuring the characteristics of the vibration damping plate, etc. employed in the following Examples are as follows.

1) Viscosity "Reomat 3" is a rotary type high temperature viscometer manufactured by Contrabass.
Using "0", the measurement was performed at a shear rate of 100 sec ^-1 . 2) Pot life Evaluation was made by the time required for the viscosity of the resin to become twice the initial viscosity at a predetermined temperature, and those having a pot life of 12 hours or more were indicated by ○, and those having a pot life of less than 12 hours were indicated by x.

3) Glass transition temperature (Tg) Measured at a heating rate of 10 ° C./min using a heat flux type differential scanning calorimeter manufactured by Seiko Instruments Inc. 4) Used metal plate A 0.8 mm thick galvanized steel plate was degreased before use.

5) Lamination / adhesion method The resin composition of the present invention (viscosity of 50 to 100 poises) was heated at a predetermined temperature (25 ° C. in Examples 1 to 3 and Comparative Example 2; 60 ° C. in Comparative Example 1).
C) using a bar coater to apply evenly on a galvanized steel sheet on which a spacer with a thickness of 100 μm is fixed.
Then, the resin-coated surfaces of the two steel plates were overlapped and heated and bonded at 160 ° C. for 2 minutes at a surface pressure of 5 kg / cm ² using a compression molding machine, and evaluated.

6) Adhesive strength The above laminated and adhered steel sheet is cut into a width of 25 mm, and is subjected to JIS K 6854.
The T peel strength was measured at room temperature according to the above. 7) Vibration damping properties A strip-shaped sample (20 mm wide x 200 m
m length), and using the complex elastic modulus measuring device manufactured by B & K (Bruel and Kjeaer Ltd.), the measurement frequency is determined by the resonance method.
A vibration damping test was performed at 250 Hz.

8) Heat resistance The laminated and bonded steel sheet is cut into a width of 20 mm and a length of 200 mm.
The resin was kept in a dryer at 180 ° C. for 30 minutes, and the state of “bleeding of the resin” from the end was observed.

9) Bendability The laminated and bonded steel sheet is cut into a width of 20 mm and a length of 200 mm.
Using a die having a V width of 25 mm, an end bending test was performed at a position 35 mm from both ends with a hydraulic press brake.
(Refer to Fig. 1 (a).) During processing, the occurrence of processing defects such as flange bending defect phenomenon (see Fig. 1 (b)) and peeling of upper and lower steel plates were visually confirmed, and occurrence of processing defects was recognized. The test results were indicated by x, and the test results were not indicated by ○.

Examples 1 to 3 The resin compositions having the composition and properties shown in Table 1 were used as intermediate resin layer constituents for bonding, and after heating and bonding to two galvanized steel sheets according to the lamination and bonding method described above. The characteristics (adhesive strength, vibration damping properties, heat resistance and bending workability) of each obtained test damping plate were examined. The results are collectively shown in Table 1. The resin composition of the present invention has a good pot life and good workability for lamination with a steel sheet. It turns out that it is excellent in both adhesiveness and bending workability.

[0032]

[Table 1]

Comparative Examples 1 and 2 The pot life is relatively long in a normal / medium temperature range (10 to 60 ° C.)
A peroxide-curable urethane acrylate or polyurethane, which is known as a resin having fast-setting properties in a high temperature range (150 to 180 ° C.), is used as a joining resin. Created. Table 2 shows the composition and properties of the resin composition and the properties of the obtained comparative damping plate.
Are shown together.

[0034]

[Table 2]

As is clear from Table 2, Comparative Examples 1 and 2
Each of the resin compositions of No. 2 has a short pot life, and the obtained vibration damping plate has good heat resistance, but has low vibration damping properties and poor lamination adhesion as compared with the above-mentioned examples.

Comparative Examples 3 and 4 Hot-melt type resins [vinyl acetate, n-butyl acrylate, acrylic acid and Veova 10 (vinyl manufactured by Shell Chemical Co., Ltd.), which are known as resins which are easy to handle and have relatively excellent vibration damping properties, Of Ester Monomer) and a film type resin (Dima Chemical Japan, Primacol 14)
10) was used as a joining resin. Hot-melt resin is a galvanized steel sheet with a 100-μm-thick spacer fixed, heated to about 100 ° C and evenly applied on it. Film-type resin is a 100-μm-thick film coated with a galvanized steel sheet. A damping steel plate was manufactured on the upper part. Table 3 collectively shows the loss coefficient, heat resistance, and bending workability of the obtained comparative damping plate.

[0037]

[Table 3]

As is clear from Table 3, Comparative Example 3,
All of the damping materials of No. 4 were inferior in heat resistance, and Comparative Example 4 was also inferior in bending workability.

[0039]

The resin composition of the present invention is constituted as described above. It is applied to a metal plate in a solvent-free type at room temperature, then laminated, heated and pressed, and firmly adheres to the damping metal plate. It is possible to obtain a composite vibration damping plate that can be composited and has excellent vibration damping properties and bending workability. Moreover, since the resin composition has excellent heat resistance enough to withstand baking coating and the like in a cured state, the obtained composite vibration damping material is used for automobiles, various transportation systems, industrial machines, apartment houses, factory buildings, etc. It can be widely used as an anti-noise material accompanying the vibration of metal stairs, metal doors, home appliances and the like.

[Brief description of the drawings]

FIG. 1A is a schematic view showing an edge bending test method;
(B) is a schematic diagram showing a flange bending failure phenomenon.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Kobayashi 1 Kanazawacho, Kakogawa City Inside Kobe Steel Works Kakogawa Works (72) Inventor Seiji Kawano 1 Kanazawacho Kakogawa City Kobe Steel Works Kakogawa Inside the steelworks

Claims (3)

(57) [Claims] 1. A bonding resin composition in a composite vibration damping material comprising a plurality of metal plates superposed via a bonding resin composition, the epoxy resin having two or more epoxy groups in a molecule. A resin composition for producing a composite vibration damping material, comprising a resin, a liquid rubber having a carboxyl group in a molecule, an acid anhydride, imidazole or a derivative thereof. 2. 100 to 100 parts by weight of an epoxy resin having two or more epoxy groups in a molecule, 10 to 100 parts by weight of a liquid rubber having a carboxyl group in a molecule and 10 to 100 parts by weight of an acid anhydride.
80 parts by weight and 1 to 10 parts of imidazole or a derivative thereof
The resin composition according to claim 1, wherein the resin composition is blended by weight. 3. A composite vibration damping material comprising a plurality of metal plates laminated via a resin layer having a thickness of 30 to 300 μm comprising the resin composition according to claim 1 or 2. .