JPH0550985B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a vibration damping adhesive sheet, and more specifically, it can be applied to vehicles such as automobiles, trains, airplanes, office equipment, home appliances, work equipment, building materials, etc. at -20°C. ~80℃, especially at around room temperature, to reduce noise from vibrating parts,
This invention relates to a vibration damping adhesive sheet that exhibits excellent vibration damping properties.

(Prior art) In recent years, (a) vehicles such as automobiles, trains and airplanes, (b) building floors, roofs, stairs, walls and pillars, etc., (c) office equipment, and (d)
Countermeasures against the vibrations of electrical products and the noise caused by them are being highlighted as an urgent issue. To date, many vibration damping materials have been proposed and put on the market as countermeasures. In addition, many construction methods have been proposed.

Broadly speaking, there are two methods. That is, one method is to manufacture the vibration generator itself from a damping steel plate with a viscoelastic composition sandwiched between two steel plates, and to control the generated vibration itself.
One method is to attach a damping material to the vibration noise source in post-processing to damp the generated vibrations.

The present invention pertains to the latter method of attaching a damping material to a noise source in post-processing.

(Problems to be Solved by the Invention) In the conventional vibration damping method using post-processing, a vibration damping material made of a blended composition of asphalt or vinyl chloride resin, and a filler such as mica, molded into a sheet, is used to produce vibration noise. Methods such as bonding to the source with an adhesive or adhesive, or mechanically bonding with bolts or the like are used.

The problems with this conventional technology are: (1) The damping performance of the damping material is closely related to the weight of the damping material, and in order to achieve high performance with this method, it is necessary to increase the weight of the damping material. This increases the weight of the entire structure.

(2) The post-processing method of mounting uses adhesive or adhesive, which not only makes it difficult to align the mounting position, but also tends to contaminate the surrounding area.

(Means for Solving the Problems) The present invention improves the conventional drawbacks as described above, and provides a vibration damping adhesive sheet that is a damping material that is lightweight, easy to install, and has excellent vibration damping ability. There is a particular thing.

That is, the present invention has a two-layer structure of a sheet-like pressure-sensitive adhesive vibration damping composition layer A and a restraining plate B that adhesively restrains the layer, and the layer A is rubber-based, acrylic-based, or rubber-acrylic-based. and B of layer A
This is a vibration-damping adhesive sheet that has an uneven pattern on the surface opposite to the plate and further on the bonding side of the A layer to the B plate, and is easy to attach to the vibration generator.
Since the surface of the layer is provided with an uneven pattern, an air circulation path exists between the A layer and the vibration generator, and furthermore, an air circulation path may exist between the restraining plate and the A layer. Therefore, such a path space greatly improves vibration damping performance.

In addition, although the vibration-damping adhesive sheet according to the present invention is an extremely lightweight vibration-damping sheet, it has a large vibration-damping effect, and since there is a point adhesive between the sheet and the vibration generator, it has excellent installation workability. ing.

The vibration damping composition layer A used in the present invention has a flexible pressure-sensitive adhesive property at room temperature, and has viscoelastic properties such as loss angle tangent (Tan δ) in the temperature range of -20°C to 80°C. has a peak value of 0.5 or more, and the storage modulus (E′) at that time is
It is preferable to use a viscoelastic adhesive having a value of 5×10 ⁶ to 5×10 ⁹ dyne/cm ² , and rubber-based adhesives, acrylic-based adhesives, and rubber-acrylic combination adhesives are preferred.

As the rubber adhesive material, natural rubber, styrene/butadiene copolymer, isoprene polymer,
Synthetic rubbers such as butadiene polymers, chloroprene polymers, isobutylene-isoprene copolymers, halogenated isobutylene-isoprene copolymers, acrylonitrile/butadiene copolymers are used as base polymers, and natural resins such as rosin, terpene resins, or petroleum tackifying resins such as resins, coumaron indene, oil-soluble phenolic resins, xylene resins, alkyd resins, and epoxy resins, or plasticizers such as phthalate esters, phosphate esters, chlorinated paraffin, polybutene, and polyisobutylene,
Alternatively, oils and fats such as animal oils, vegetable oils, and mineral oils, as well as various fillers, crosslinking agents, accelerators, anti-aging agents, etc., are mixed and used.

As an acrylic adhesive, (1) the number of carbon atoms is 4 to 10;
acrylic acid alkyl esters of alkyl groups,
(2) Copolymerizable monomers such as acrylic acid acrylic esters or methacrylic acid alkyl esters with lower alkyl groups, vinyl acetate, vinylidene chloride, styrene or acrylonitrile, and (3) monomers containing carboxylic acid groups such as acrylic acid and methacrylic acid. Alternatively, a copolymer of three components such as a hydroxyl group-containing monomer or an acid amide is preferably used.

Furthermore, rubber/acrylic adhesives, which are intermediate adhesive compositions between rubber adhesives and acrylic adhesives, use natural rubber or synthetic rubber as a base polymer, and contain lower alkyl acrylates or alkyl methacrylates. A monomer capable of copolymerizing ester with acrylic acid or methacrylic acid,
Furthermore, tackifier resin, plasticizer, animal oil,
It is used by mixing vegetable oil, mineral oil, filler, crosslinking agent, accelerator, anti-aging agent, etc.

Note that the vibration damping composition layer A, which is an adhesive composition,
is in the form of a sheet, and after the surface is given an uneven pattern so that the cross section becomes an irregular cross section, heat, moisture, electromagnetic waves, especially electron beams, etc. are applied to maintain the uneven pattern.
A crosslinked structure was introduced by irradiation with ultraviolet light, etc. Note that the thickness of layer A is preferably 0.02 mm to 1.20 mm.

The restraining plate B is preferably made of metal, plastic, paper, etc., with a storage modulus (E') of 5 x 10 ¹⁰ dyne/cm ² or more in the temperature range of -30°C to 100°C, and in the case of metal, iron, aluminum, Examples of materials include nickel, stainless steel, zinc-treated steel sheets, copper, and brass; plastic materials include polyethylene terephthalate, polyamide, polycarbonate, and vinyl chloride; paper materials include cardboard, cardboard, etc., and foil with a thickness of 0.05 mm to 1.20 mm. Alternatively, a film is preferably used.

The vibration damping adhesive sheet according to the present invention is manufactured by directly applying layer A to a metal plate or plastic sheet as a restraining plate using a coating device such as a roll coater or a knife coater, or an extrusion coating device, and then forming an embossed pattern. Pressure molded using rolls, etc.
Alternatively, plastic sheets that have been subjected to release treatment with an embossed pattern are laminated and molded using a pressure roll or the like to impart an uneven pattern to the surface of the adhesive sheet.

In addition, when applying adhesive material in the form of ribbons or islands, it is impossible to apply the adhesive material using the above-mentioned normal methods.
It is necessary to apply printing and dyeing techniques such as the silk screen method, plate method, and gravure method. In addition, when coating in parallel stripes, a comb-shaped doctor blade method can also be used, which is convenient.

The uneven pattern of the pressure-sensitive adhesive A layer makes it easy to attach to the vibration source, and it is necessary to maintain the surface shape of the A layer in order to maintain vibration damping performance. It is preferable to prevent the shape from deforming.

Furthermore, by making the A layer and the B plate as thin as possible, more characteristic vibration damping can be achieved.

(Example) The present invention will be described in further detail with reference to Examples below, but first a test method for evaluating the performance of the vibration damping adhesive sheet according to the present invention will be briefly described.

As a test sample, a vibration-damping adhesive sheet consisting of a vibration-damping composition layer 1 and a restraint plate 2 as shown in attached FIG. 1 was attached to a cold-rolled steel plate 3 with a thickness of 8 mm as shown in FIG. The workability of mounting to the vibration source, adhesion, and vibration damping properties were measured.

(1) Adhesion test (a) Shear adhesion was measured at a tensile speed of 5 mm/min.

(b) Peel adhesion force was measured at a pulling speed of 50 mm/min.

(2) Vibration damping property The loss coefficient η, which is a measure of vibration damping ability, was measured using the mechanical impedance method.

(3) Installation workability A damping adhesive sheet with a width of 80 mm and a length of 1000 mm is
After attaching it to a 0.8 mm cold-rolled steel plate, the state of air entering the bonded surface was observed.

(4) Viscoelastic properties The storage modulus (E') and loss angle tangent (Tan δ) of the sheet-like test piece containing only layer A were measured using a Vibron tester in the temperature range of -100°C to 120°C.

The maximum value of Tan δ at a frequency of 100 Hz and (E′) at that temperature were measured.

Example 1 (1) As a vibration damping composition, the materials shown in Table 1 below were kneaded in a kneader to obtain a rubber-based adhesive composition.

Table 1 - Brominated butyl rubber (bromobutyl 2255 manufactured by Nippon Gosei Co., Ltd.) 30 parts by weight - Polybdenum, 2000H (manufactured by Idemitsu Petrochemical Co., Ltd.)
60 〃 ・ Silica, Nipsil VN3 (manufactured by Nippon Silica Co., Ltd.) 12 〃 ・ Alcon M-100 (manufactured by Arakawa Chemical Co., Ltd.) 30 〃 ・ Trimethylolpropane-triacrylate 3 〃 ・ Benzoin isopropyl ether
0.4〃・2,6-di-t-butyl-p-cresol
0.4 〃 (2) A galvanized steel plate with a thickness of 80μ was used as the restraining plate B.

The rubber adhesive composition shown in Table 1 was directly applied to a galvanized steel plate of a restraining plate using a ConAvar roll coating device so that the coating layer had a thickness of 300 μm.
After that, one side was subjected to mold release treatment, and a 38μ thick polyethylene terephthalate film with a tortoise-shell pattern embossed shape was laminated with the above coated surface, and pressure molded with Nitpro rolls to form the heights of the peaks and valleys on the uneven surface. A sheet with an uneven surface pattern with a difference in thickness of about 150 μm was obtained.

In addition, a 4KW high-pressure mercury lamp eliminates 55% of ultraviolet rays.
A rubber vibration damping adhesive sheet was obtained by irradiating for seconds to introduce a partial crosslinked structure into the rubber vibration damping adhesive composition layer.

To evaluate the performance of the vibration-damping adhesive sheet obtained as described above, adhesion, vibration damping properties, installation workability, and viscoelastic properties of the adhesive were measured by the methods described above. The results were as follows.

・ Adhesion test Shear adhesion force (Kgf/cm ² ) 1.80 Peel adhesion force (Kgf/cm) 1.20 ・ Vibration damping loss coefficient (25℃, 700Hz) 0.35 ・ Installation workability Very good, no air inclusions ・ Viscoelastic properties (Tan δ peak temperature 25°C) Tan δ 1.20 E′ 7.0×10 ⁷ dyne/cm ² Example 2 (1) As a vibration damping composition, the materials shown in Table 2 below were kneaded in a kneader, and rubber An acrylic adhesive composition was obtained.

Table 2 ・ SIS block copolymer rubber (Ciel Chemical Co., Ltd., Califrex TR1111) 50 parts by weight ・ Methyl methacrylate 25 〃 ・ Cyclohexyl methacrylate 25 〃 ・ Zinc acrylate (manufactured by Asano Chemical Co., Ltd.) 10 〃 ・ Alcon M100 (Arakawa Chemical Co., Ltd.) 40〃 ・Dicumyl peroxide (manufactured by NOF Corporation)
1 (2) As the restraining plate B, a galvanized steel plate with a thickness of 80μ was used.

The rubber-acrylic adhesive composition shown in Table 2 was directly coated on a galvanized steel plate of a restraining plate using a ConAvar roll coating device to a coating layer thickness of 100 μm. Thickness after which mold release treatment is applied to one side
A sheet was obtained by laminating a 38μ polyethylene terephthalate film with the above coated surface.

Furthermore, with a 50-mesh wire mesh placed on top of the polyethylene terephthalate film for molding purposes, it was crimped using a flat press as a crimping machine at a temperature of 150℃ and a pressure of 10Kg/ ^cm2 .
By heating under pressure for 10 minutes, a cross-linked structure was partially introduced into the rubber-acrylic damping adhesive layer, and the surface shape became a wire mesh pattern, and the height difference between the peaks and valleys of the uneven surface was adjusted to approximately 50μ. A rubber-acrylic damping adhesive sheet was obtained.

The same measurements as in Example 1 were performed under the same conditions as in Example 1 to evaluate the performance of the vibration damping adhesive sheet obtained as described above. The results were as follows.

・ Adhesion test Shear adhesion (Kgf/cm ² ) 0.75 Peel adhesion (Kgf/cm) 0.60 ・ Vibration damping loss coefficient (25℃, 300Hz) 0.43 ・ Installation workability Very good, no air inclusions ・ Viscoelastic properties (Tan δ peak temperature 35°C) Tan δ 1.35 E′ 5.0×10 ⁸ dyne/cm ² (Effects of the invention) (1) The vibration damping adhesive sheet according to the present invention can be attached to a vibration generator to achieve the desired results as shown in Figure 3 of the attached drawings. As shown in Figure 2, it exhibited excellent vibration damping properties (loss coefficient) over a wide range of vibration frequencies.

(2) The vibration-damping adhesive sheet according to the present invention is lightweight, and can be easily attached to a vibration generator.
Moreover, it is also easy to wear.

(3) Therefore, it is expected to be used as a damping material for vibration sources in many fields, and also as a soundproofing material.

[Brief explanation of the drawing]

In the accompanying drawings, FIG. 1 is a longitudinal cross-sectional view of a vibration-damping adhesive sheet according to the present invention, and FIG. 2 is a longitudinal cross-sectional view showing the vibration-damping adhesive sheet of FIG. 1 attached to a vibration source.
FIG. 3 is a graph showing the relationship between vibration frequency and vibration damping property (loss coefficient) of the vibration damping composition layer according to the present invention. DESCRIPTION OF SYMBOLS 1... Vibration damping composition layer, 2... Restraint plate, 3... Vibration source (cold rolled steel plate).

Claims (1)

[Scope of Claims] 1 Consists of a two-layer structure of a sheet-like pressure-sensitive adhesive vibration damping composition layer A and a restraining plate B that adhesively restrains the layer, and the layer A is rubber-based, acrylic-based, or rubber-based. A vibration-damping adhesive sheet that is made of acrylic and has an uneven pattern on the surface of the A layer opposite to the B plate. 2. The vibration-damping adhesive sheet according to claim 1, wherein an uneven pattern is further provided on the surface of the A layer on the side where the B plate is bonded. 3 In the vibration damping adhesive sheet according to claim 1, the peak temperature of the loss angle tangent (Tan δ) of the A layer is -20°C to 80°C, the peak value is 0.5 or more, and the storage modulus (E') is A sheet with 5×10 ⁶ to 5×10 ⁹ dyne/cm ² . 4. A vibration-damping adhesive sheet according to claim 1, in which layer A has a crosslinked structure. 5. The vibration damping adhesive sheet according to claim 1, wherein the A layer has a thickness of 0.02 mm to 1.20 mm. 6. The vibration damping adhesive sheet according to claim 1, wherein the thickness of plate B is 0.05 mm to 1.20 mm.