JPH0699540A - Composite type vibration-damping metal plate - Google Patents

Abstract

PURPOSE:To provide a material having improved vibration absorption of a composite type vibration-damping material of a three-layer structure having a metal plate/a thermoplastic resin sheet/a metal plate. CONSTITUTION:Thermal reactive adhesive is interposed between connecting surfaces of a metal plate and a thermoplastic resin sheet to set its shearing adhesive strength to 120kg/cm<2> or more. As the resin, saturated copolymer polyester is used, its melting point is 220 deg.C or higher and its glass transition point is 50-100 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite type vibration damping material, particularly a vibration damping metal plate, and more particularly to a composite type vibration damping metal plate having excellent vibration damping properties at high temperatures.

[0002]

2. Description of the Related Art In recent years, the problems of noise and vibration have become a social problem as pollution due to the development of transportation facilities and the approach of houses to factories. In addition, noise and vibration are suppressed in living spaces and comfortable living is achieved. The environment tends to improve. Corresponding to such a tendency, it is required to add vibration damping performance to a metal material that is a noise source or a vibration source and to improve the vibration damping performance.

[0003] Therefore, as one of the materials exhibiting damping performance, a composite damping material having a three-layer structure in which an intermediate layer made of a resin having viscoelastic behavior is sandwiched between two metal layers has been proposed. Considered, for example, in automobile oil pans, engine covers or rocker covers, hopper chute parts, home appliance exterior panels, motor covers, and other vibration reduction parts of processing machines and structural members of precision machinery where vibration prevention is desired. Has been adopted.

The metal material forming the two metal layers may be any material that can form a composite vibration damping material by sandwiching a resin in the middle, and the shape and material are not particularly specified. Usually, the metal layer referred to here is a surface coated with iron, aluminum, copper, lead, or an alloy containing one of these, and further, a metal material plated with zinc, tin, chromium, or the like, and an epoxy resin, a melamine resin, or the like. It may be treated, and examples thereof include a metal plate, a metal tube, a metal molded body and the like which can be superposed on each other and which can have a three-layer structure.

As a resin constituting the intermediate layer of such a composite type vibration damping material, polyester alone (Japanese Patent Laid-Open No. 50-1) is used.
No. 43880), polyamide resin (JP-A-51-791)
No. 46) and the like are known, but the workability is deteriorated because the resin alone has low adhesiveness. Therefore, in order to improve the adhesiveness, a method of adding a cross-linking agent to the resin and thermosetting is adopted (JP-A-63-278988, JP-A-64-4).
8813, JP-A-4-243339).

However, the method of heat curing by adding a cross-linking agent has a problem that workability is poor because the working time is limited by the pot life of the resin and the resin form is a solution type. In addition, since the resin has a three-dimensional structure after cross-linking, viscoelastic performance is lost and the vibration damping property deteriorates.

A characteristic required of the composite type damping material is a loss tangent (tan δ) which is a substitute characteristic of damping performance.
Alternatively, the loss coefficient (η) is large and the temperature range in which the vibration damping performance is exhibited is wide. Further, in the application of the composite type vibration damping material, there is a case where a baking coating step in which the material is overheated to about 200 ° C. may be performed, so that it is also required that the intermediate layer exhibiting viscoelasticity near the above temperature does not decompose and flow.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems in a composite type vibration damping material, particularly a vibration damping metal plate (steel plate), and is excellent in vibration damping property and adhesiveness at high temperature. Further, the present invention provides a vibration-damping steel plate having excellent workability during manufacturing.

[0009]

Means for Solving the Problems As a result of earnest studies, the inventor of the present invention has prepared a composite vibration-damping steel plate with a heat-reactive crosslinking agent on at least one joint surface between two metal plates and a thermoplastic sheet. By installing and thermocompression bonding, both excellent adhesiveness due to thermosetting at the adhesive interface and excellent vibration damping at the center of the resin layer are compatible, and the resin form can be supplied in sheet form, and vibration damping is possible. The present invention has been achieved based on the knowledge that workability in the production of wood is improved.

That is, the present invention is a composite type vibration-damping metal plate obtained by applying a heat-reactive cross-linking agent to the bonding surface between a metal plate and a thermoplastic resin sheet, and then heating and pressing to bond them. .

The adhesive used in the present invention may be an organic peroxide, an azo compound, an isocyanate compound, an epoxy compound or the like, but the isocyanate compound is preferable for the saturated copolyester. The isocyanate compound is
Compounds having at least two or more isocyanate groups in the molecule, specifically 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (commonly called TD
I), methylene-bis (4-phenylisocyanate)
(Commonly known as MDI) Commercially available MDI such as Millionate MT (manufactured by Nippon Polyurethane Company), polymethylene polyphenyl polyisocyanate, or polyol-modified MDI.
Derivative, hexamethylene diisocyanate (commonly called HD
I) and its derivatives, block type isocyanate commercial product Millionate MS (manufactured by Nippon Polyurethane Co.) whose isocyanate group is masked with phenol, caprolactam or the like for the purpose of preventing reaction with moisture in the air can be used.

The thermoplastic resin used in the present invention is not limited as long as it can be adhered by an adhesive, but preferably has a melting point (Tm) of 220 ° C. or higher and a glass transition point (Tg) of 50 to 100 ° C. Which is a thermoplastic resin or a thermoplastic resin composition. Preferred thermoplastic resins are, for example, saturated copolyester resins, aromatic dibasic acids such as dimethylphthalic acid, terephthalic acid, isophthalic acid and phthalic acid, succinic acid, glutaric acid, adipic acid, β-methyladipic acid, Aliphatic dibasic acids such as pimelic acid, 1,6-hexanedicarboxylic acid, azelaic acid and sebacic acid, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1 , 4-butanediol, 1,2-pentadiol, 1,5-pentadiol, 3-methylpentadiol, 1,3-hexanediol, 1,6-hexanediol, 1,4-cyclohexanediol, hydrogenated bisphenol A, diethylene glycol, triethylene glycol, polyethylene glycol, dipropyi Glycol, polypropylene glycol, which has been polymerized random and / or block copolymer from glycols or derivatives thereof, such as polytetramethylene glycol.

The saturated copolyester resin used in the present invention is preferably 70 mol% or more and 90 mol% or more of the acid component.
Less than mol% is terephthalic acid residue. A polyester resin having a terephthalic acid residue content of 70 mol% or less has a Tm of 200 ° C. or less, and the resin layer melts away during baking. On the other hand, those of 90 mol% or more are not preferable because they have high crystallinity and may reduce the vibration damping property. Examples of the dibasic acid used in combination when the terephthalic acid residue is used in the above range include the above-mentioned aromatic or aliphatic dibasic acids, preferably isophthalic acid, sebacic acid, and adipic acid. .

The glycol component is preferably such that 70 mol% or more is an ethylene glycol residue. As the glycol component used in combination when the ethylene glycol residue is used in the above range, cyclohexane glycols,
Examples include neopentyl glycol.

More specifically, the saturated copolyester resin according to the present invention has a Tg of 60 to 70 ° C. in order to obtain vibration damping properties around 100 ° C. and a Tm of 200 ° C. in order to have heat resistance up to 200 ° C. Since the above is desired,
It is necessary to select the type and molar ratio of the above-mentioned dibasic acid and glycol.

In addition, the resin and the resin composition used in the present invention may contain known additives such as coloring agents, inorganic fillers, fibrous reinforcing agents, etc. within a range that does not impair vibration damping performance and heat resistance.
A conductivity imparting agent, a stabilizer, a plasticizer and the like can be added.

Further, by adding a conductive solid substance as an additive to the resin and resin composition used in the present invention, conductivity can be imparted. As a conductive material used for such a purpose, for example, a metal substance obtained by processing a metal such as iron, stainless steel, zinc, tin, or nickel into a powder, flakes, or fibers, or a conductive metal plating is applied. Inorganic substances, conductive carbon substances such as carbon black, graphite and carbon fibers can be mentioned. It is also possible to surface-treat the above conductive solid substance with a silane coupling agent or the like.

Regarding the method of forming the resin composition used in the present invention into a sheet, known equipment and methods generally used, that is, the composition and components constituting the present invention are fed to an extruder and passed through a slit-shaped die. It is obtained by extruding, cooling and solidifying on a casting drum to form a sheet. Examples of the method for supplying the composition and components of the present invention to the extruder include, for example, 1) after mixing the components,
A method of melt-kneading and extruding with an extruder to prepare pellets, and then supplying the pellets to an extruder equipped with a slit die to prepare a sheet, 2) once preparing pellets having different compositions, and then arranging the pellets Any method such as a method of quantitatively mixing and supplying to an extruder for making a sheet to obtain a sheet, 3) a method of directly charging one or more of each component to the extruder for making a sheet, and the like can be used. In addition, a sheet that has been once created or a piece that has been crushed into scraps generated during sheet formation can be used as one of the materials or components for sheet formation in 1) to 3). . It is preferable that the pellets and the components are dried before being fed to the extruder.

As a method for drying the pellets and flakes, for example, air or nitrogen gas heated to a temperature in the range of 100 ° C. or higher and 30 ° C. lower than the melting point of the resin, more preferably 120 to 130 ° C. is used. Depending on the situation, a method of dehumidifying and drying, a method of drying using electromagnetic waves, or the like is applied.

During casting, a film or sheet having excellent flatness can be obtained by applying static electricity to the film or sheet so that the film or sheet is brought into close contact with the cooling drum.

To provide an adhesive layer on a metal plate (hereinafter sometimes abbreviated as (A)) and a sheet made of a thermoplastic resin (hereinafter sometimes abbreviated as (B)), for example, joining of (A) and (B) is performed. The adhesive is made into a solution on the surface to be coated, and dried and solidified if necessary. Further, a film or sheet made of an adhesive may be extruded or dry laminated on the joint surface of (A) or (B) in advance.

The surfaces on which the adhesive layer is provided are (A) and (B).
You should select at least one of the surfaces where and are to be joined. By providing the adhesive layer in this way, (A) and (B) can be strongly bonded, and the vibration damping metal plate is excellent.

As a method for producing the composite type vibration damping metal plate, any method such as a batch method using a cutting plate or a continuous method using a coil can be adopted, but at least one of the surfaces to be joined is to be joined. As a method of joining a metal plate having an adhesive layer on one surface and an intermediate layer using a sheet made of a thermoplastic resin, a method of thermocompression bonding is generally adopted.

[0024]

EXAMPLES Hereinafter, the composite type vibration damping steel plate of the present invention will be described based on Examples and Comparative Examples.

Steel Plate Joining Method An isocyanate compound (Millimate MT: manufactured by Nippon Polyurethane Company) was adjusted to 40% (w / w) in a toluene / MEK (50/50) solvent. The isocyanate solution is applied to the joint surface of a steel plate preheated to 80 ° C., the solvent is dried, and then a sheet (thickness 0.1 mm) made of a thermoplastic resin and a thermoplastic resin composition is sandwiched between the steel plates at 240 ° C. After that, they were thermocompression bonded for 45 seconds and laminated.

Evaluation of Damping Property In order to measure the damping performance of the damping steel plate, a 0.1 mm hot sheet made of a thermoplastic resin and a resin composition was cold-rolled steel plate (thickness 0.5 mm, width 25 mm, A composite type vibration-damping steel plate was obtained by laminating with a length of 100 mm and sandwiching it from both sides. After fixing one end of the damping steel plate to a clamp, a spherical steel ball having a mass of 14 g and a diameter of 15 mm is fixed at the other end at a height of 3
The sound pressure generated by dropping from 0 cm was measured. To measure the sound pressure, a microphone was installed at a position 30 cm away from the drop point.

Evaluation of Adhesiveness Heat composed of thermoplastic resin and thermoplastic resin composition
A 1 mm sheet was sandwiched between cold-rolled steel plates (thickness 1 mm, width 25 mm, length 100 mm) from both sides, and laminated by this bonding method to obtain an adhesion test piece having an adhesion area of about 5 cm ² . Shear adhesion was measured using test pieces.

[0028]

[Comparative Example] A resin sheet was sandwiched between steel sheets without coating a cross-linking agent on the steel sheet and the resin sheet, and they were laminated by thermocompression bonding at 240 ° C for 45 seconds.

The above results are shown in Table 1.

[0030]

[Table 1]

[0031]

The composite vibration-damping metal plate of the present invention exhibits excellent vibration-damping property and adhesiveness in a wide temperature range in the high-temperature range which has been difficult in the past. In addition, since the vibration-damping steel sheet uses a sheet of a thermoplastic resin or a thermoplastic resin composition, it is excellent in workability and various workability, and therefore, noise-generating automobiles, electric / electronic equipment, OA equipment,
It can be effectively used as a material for forming mechanical tools.

Claims (3)

[Claims] 1. A composite vibration-damping metal in which an adhesive layer made of a heat-reactive adhesive is provided on the joint surface between a thermoplastic resin sheet and a metal plate, and the shear adhesive strength of the adhesive layer is at least 120 kg / cm ^2. Board. 2. The composite vibration-damping metal plate according to claim 1, wherein the thermoplastic resin is a saturated copolyester, has a melting point of 220 ° C. or higher, and has a glass transition temperature of 50 to 100 ° C. 3. The composite vibration-damping metal plate according to claim 1, wherein the adhesive is made of a polyvalent isocyanate compound.