JP2015057319A - Vibration damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damper having excellent adhesiveness at a normal temperature, and improved vibration damping performance at a wide range of temperatures from a normal temperature to a high temperature.SOLUTION: A vibration damper 1 has a resin layer 2, and a constraint layer 3 put on the resin layer 2. The resin layer 2 is formed of a resin composition comprising butyl rubber and softener, where a weight average molecular weight of the softener is 1500 or more, and the content ratio of the softener is 30-90 pts.mass relative to the butyl rubber 100 pts.mass.

Description

  The present invention relates to a vibration damping material, and more particularly to a vibration damping material used by being attached to a vibration member used in various industrial products.

  Conventionally, various parts used in fields such as automobiles, railway vehicles, home appliances, office equipment, housing equipment, and machine tools are likely to generate vibration noise during operation. Therefore, in order to prevent the generation of such vibration noise, for example, it is known to improve the vibration damping property of the component by sticking a vibration damping sheet to the component (vibrating member).

  For example, a vibration damping sheet containing 100 parts of butyl rubber and 1600 parts of calcium carbonate has been proposed in order to obtain good vibration damping characteristics at a temperature of about 40 ° C. (see, for example, Patent Document 1).

JP-A-9-136998

  In Patent Document 1, the vibration damping performance of the vibration damping sheet at normal temperature (about 20 ° C.) and at a temperature of about 40 ° C. is evaluated.

  On the other hand, in recent years, parts used at high temperatures exceeding 40 ° C. (high-temperature parts), specifically, heat-generating parts such as motors, heaters, engines, etc., and further used under a wide range of temperatures from room temperature to high temperature. It is desired to improve vibration damping properties for parts and the like.

  However, in the vibration damping sheet of Patent Document 1, it may be difficult to sufficiently improve the vibration damping properties of the above components under a wide range of temperatures from the normal temperature to the high temperature.

  Further, the damping material is also required to have adhesiveness that can be easily attached to a part at room temperature from the viewpoint of workability.

  An object of the present invention is to provide a vibration damping material that has good adhesiveness at room temperature and further improved vibration damping properties in a wide range of temperatures from room temperature to high temperature.

  In order to achieve the above object, the vibration damping material of the present invention comprises a resin layer and a constraining layer laminated on the resin layer, and the resin layer is formed from a resin composition containing butyl rubber and a softening agent. The weight average molecular weight of the softening agent is 1500 or more, and the content ratio of the softening agent to 100 parts by mass of the butyl rubber is 30 to 90 parts by mass.

  In the vibration damping material of the present invention, the resin layer may further contain 5 to 150 parts by mass of a tackifier and 100 to 350 parts by mass of a filler with respect to 100 parts by mass of the butyl rubber. Is preferred.

  In the vibration damping material of the present invention, it is preferable that the softening agent is polybutene.

In the vibration damping material of the present invention, it is preferable that the flow viscosity of the resin composition when measured under the conditions of a temperature of 60 ° C. and a load pressure of 20 kgf / cm ² is 6000 to 30000 Pa · s.

  The vibration damping material of the present invention includes a resin layer containing a specific amount of a butyl rubber and a softening agent having a weight average molecular weight of 1500 or more.

  Therefore, the vibration damping material of the present invention has good adhesiveness at room temperature. Further, if the vibration damping material of the present invention is attached to the vibration member, the vibration member can be sufficiently vibration-damped even when used in a wide range of temperatures from room temperature to high temperature.

FIG. 1 is an explanatory view showing a method of sticking a vibration damping material according to an embodiment of the present invention to a vibration member, and FIG. 1A is a step of preparing the vibration damping material and peeling the release paper, FIG. 1B shows a process of sticking the vibration damping material to the vibration member.

  As shown in FIG. 1A, the vibration damping material 1 of the present invention includes a resin layer 2 and a constraining layer 3 laminated on the resin layer 2.

  The resin layer 2 is formed from a resin composition into a sheet shape.

  The resin composition contains butyl rubber and a softening agent.

  Butyl rubber is a synthetic rubber obtained by copolymerization of isobutene (isobutylene) and isoprene.

  The Mooney viscosity (ML1 + 4, at 100 ° C.) of butyl rubber is, for example, 25 or more, preferably 30 or more, and for example, 90 or less, preferably 60 or less. Mooney viscosity is measured in accordance with JIS K 6300.

  The content ratio of butyl rubber is, for example, 5% by mass or more, preferably 10% by mass or more, and for example, 50% by mass or less, preferably 30% by mass or less with respect to the resin composition.

  The softening agent is blended to impart plasticity to the vibration damping material 1 and improve the handleability of the vibration damping material 1. For example, liquid rubber such as polybutene, liquid isoprene rubber, liquid butadiene rubber, paraffin oil, Examples thereof include oils such as naphthenic oil, and esters such as phthalic acid esters and phosphoric acid esters.

  These softeners may be used alone or in combination.

  Among these softeners, liquid rubber is preferable, and polybutene is more preferable. Thereby, the damping property and adhesiveness of the damping material 1 are excellent.

  In particular, the resin composition contains a softening agent having a weight average molecular weight of 1500 or more. The weight average molecular weight of the softening agent is preferably 1800 or more, more preferably 2500 or more. By setting the weight average molecular weight of the softener contained in the resin composition (that is, the vibration damping material 1) within the above range, the vibration damping material 1 can exhibit excellent vibration damping properties in a wide temperature range. .

  The upper limit of the weight average molecular weight is, for example, 4000 or less, and preferably 3500 or less.

  The number average molecular weight of the softening agent is, for example, 1350 or less, preferably 1300 or less, and for example, 700 or more. By setting the number average molecular weight of the softening agent in the above range, the molecular weight distribution of the softening agent is widened, and the vibration damping material 1 can more reliably exhibit vibration damping properties in a wide temperature range.

  The weight average molecular weight is measured by gel permeation chromatography (GPC) using standard polystyrene equivalent values with the following apparatus and measurement conditions.

GPC apparatus: HLC-8120 GPC (column: TSKgel SuperHZM-H / HZ4000 / HZ3000 / HZ2000, column size: 6.0 mm ID × 150 mm), detector: differential refractive index detector (RI), GPC measurement manufactured by Tosoh Corporation Conditions: mobile phase tetrahydrofuran, flow rate 0.6 mL / min, column temperature 40 ° C., sample concentration 1.0 g / L, injection amount 20 μL
The number average molecular weight is measured by a vapor pressure osmotic pressure method (VPO method) or GPC.

The kinematic viscosity (100 ° C.) of the softening agent at 100 ° C. is, for example, 100 mm ² / s or more, preferably 150 mm ² / s or more, and for example, 800 mm ² / s or less, preferably 700 mm ² / s. It is as follows. The kinematic viscosity is measured according to JIS K 2283 or ASTM D-445.

  The content rate of the softening agent whose weight average molecular weight is 1500 or more is 30 parts by mass or more with respect to 100 parts by mass of butyl rubber, preferably 40 parts by mass or more, and more preferably 50 parts by mass or more. Moreover, it is 90 mass parts or less, Preferably, it is 85 mass parts or less, More preferably, it is 80 mass parts or less. When the content ratio of the softening agent is within the above range, the vibration damping material 1 can sufficiently exhibit excellent vibration damping properties in a wide range. Moreover, the adhesiveness at normal temperature (23 ° C.) becomes good.

  Further, the vibration damping material 1 can be used in combination with a softening agent having a low molecular weight (weight average molecular weight of less than 1500) in addition to the softening agent.

  The resin composition preferably contains a tackifier and / or a filler, and more preferably contains a tackifier and a filler. When the resin composition contains these, the flow viscosity of the resin layer 2 can be set in a desired range (described later), and the adhesiveness, vibration damping property, workability, and the like of the resin layer 2 can be improved. .

  Examples of the tackifier include rosin resins, terpene resins (for example, terpene-aromatic liquid resins), coumarone indene resins, phenol resins, phenol formalin resins, xylene formalin resins, petroleum resins. Examples thereof include resins (for example, C5 petroleum resin, C9 petroleum resin, C5 / C9 petroleum resin, etc.).

  These tackifiers may be used alone or in combination.

  Among these tackifiers, a petroleum resin is preferable.

  The softening point of the tackifier is, for example, 50 ° C. or higher, preferably 80 ° C. or higher, and for example, 200 ° C. or lower, preferably 150 ° C. or lower. The softening point is measured according to the test method of TSTM4027.

  The content of the tackifier is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, and for example, 150 parts by mass or less, preferably 90 parts by mass or less with respect to 100 parts by mass of butyl rubber. is there. When the content ratio of the tackifier is within the above range, the resin layer 2 is excellent in adhesiveness at room temperature.

  Examples of the filler include calcium carbonate (for example, heavy calcium carbonate, light calcium carbonate, white luster), carbon black (for example, acetylene black, furnace black), talc, mica, clay, mica powder, bentonite (organite). ), Silica, alumina, aluminum silicate, titanium oxide, metal powder (for example, aluminum powder and iron powder), resin powder (for example, plastic beads such as acrylic resin powder and styrene resin powder), glass powder (powder) ), Boron nitride powder, metal hydroxides (eg, aluminum hydroxide, magnesium hydroxide, etc.).

  These fillers can be used alone or in combination.

  Among these fillers, calcium carbonate and carbon black are preferable, and a combination of calcium carbonate and carbon black is more preferable.

  The content ratio of the filler is, for example, 100 parts by mass or more, preferably 120 parts by mass or more, and, for example, 350 parts by mass or less, preferably 250 parts by mass or less with respect to 100 parts by mass of butyl rubber. . When the content ratio of the filler is within the above range, the vibration damping material 1 is excellent in vibration damping properties, reinforcing properties, workability, cost, and the like.

  In addition to the above components, the resin composition further includes, for example, a crosslinking agent, a crosslinking accelerator, a foaming agent, a lubricant, an anti-aging agent, a thixotropic agent (for example, montmorillonite), and fats and oils (for example, animal fats and oils, Vegetable oils and fats, mineral oils, etc.), pigments, scorch inhibitors, stabilizers, plasticizers, ultraviolet absorbers, fungicides, flame retardants, and other known additives can be contained in appropriate proportions.

  The resin composition is prepared as a kneaded product by blending the above-described components in the above-described content ratios, and kneading with a kneader such as a mixing roll, a pressure kneader, a Banbury mixer, or an extruder.

The flow viscosity of the kneaded product (resin composition, and hence resin layer 2) when measured under the conditions of a temperature of 60 ° C. and a load pressure of 20 kgf / cm ² is, for example, 6000 Pa · s or more, preferably 10,000 Pa · s or more. In addition, for example, it is 30000 Pa · s or less, preferably 20000 Pa · s or less. By setting the flow viscosity within the above range, the vibration damping material 1 can sufficiently exhibit excellent vibration damping properties in a wide range. Moreover, the adhesiveness at normal temperature becomes favorable.

  Thereafter, the obtained kneaded product is compressed and stretched by, for example, calendar molding, extrusion molding, press molding, or the like, thereby forming the resin layer 2 into a sheet shape (that is, forming into a sheet).

  Thereby, the resin layer 2 is formed.

  The thickness of the resin layer 2 is 0.5 mm or more, for example, is 6.0 mm or less, for example, Preferably, it is 3.0 mm or less.

  When the thickness of the resin layer 2 is less than the above lower limit value, the vibration damping property may be low. Further, when the thickness of the resin layer 2 exceeds the above upper limit value, although the vibration damping property is recognized, the effect of increasing the thickness may be hardly recognized.

  The constraining layer 3 is laminated on the resin layer 2 in order to constrain the resin layer 2 and impart toughness to the resin layer 2 to improve strength. The constraining layer 3 is in the form of a sheet and is formed of a material that is lightweight and thin and can be tightly integrated with the resin layer 2, for example, glass cloth, resin-impregnated glass cloth, synthetic resin nonwoven fabric, metal foil, carbon fiber, Examples include synthetic resin films.

  The glass cloth is made of glass fiber and includes a known glass cloth.

  The resin-impregnated glass cloth is obtained by impregnating the above-described glass cloth with a synthetic resin such as a thermosetting resin or a thermoplastic resin, and includes known ones. In addition, as a thermosetting resin, an epoxy resin, a urethane resin, a melamine resin, a phenol resin etc. are mentioned, for example. Examples of the thermoplastic resin include vinyl acetate resin, ethylene-vinyl acetate copolymer (EVA), vinyl chloride resin, EVA-vinyl chloride resin copolymer, and the like. Moreover, the above-described thermosetting resin and thermoplastic resin may be used alone or in combination.

  Examples of the synthetic resin nonwoven fabric include a polypropylene resin nonwoven fabric, a polyethylene resin nonwoven fabric, and a polyester resin nonwoven fabric.

  Examples of the metal foil include aluminum foil and steel foil.

  The carbon fiber is a fiber made of carbon as a main component, and includes known ones.

  Examples of the synthetic resin film include polyester films such as a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, and a polybutylene terephthalate (PBT) film. Preferably, a PET film is used.

  Among these constrained layers 3, glass cloth and resin-impregnated glass cloth are preferable from the viewpoint of adhesion, strength, and cost.

  The thickness of the constraining layer 3 is, for example, 0.05 mm or more, preferably 0.1 mm or more, and, for example, 2.0 mm or less, preferably 1.0 mm or less.

  The total thickness of the resin layer 2 and the constraining layer 3 (that is, the thickness of the damping material 1) is, for example, 0.55 to 8.0 mm.

  In order to produce the vibration damping material 1, the resin layer 2 and the constraining layer 3 are attached by, for example, pressure bonding or thermocompression bonding.

  In addition, in the damping material 1, the well-known release paper 4 can also be affixed on the surface on the opposite side to the lamination | stacking side of the constrained layer 3 in the resin layer 2, if necessary. In that case, the release paper 4 is laminated on the resin layer 2 when the resin layer 2 is formed into a sheet.

  Moreover, the damping material 1 has a loss coefficient of, for example, 0.05 or more, preferably 0.10 or more, and more preferably 0.15 or more at each of 0 ° C., 20 ° C., 40 ° C. and 60 ° C. For example, it is 1.00 or less.

  In particular, over 20 to 40 ° C., for example, 0.10 or more, preferably 0.20 or more, more preferably 0.30 or more, for example, 1.00 or less.

  Further, the loss coefficient of the damping material 1 is, for example, 0.03 or more, preferably 0.05 or more, and, for example, 1.00 or less at 80 ° C.

  Moreover, the loss factor of the damping material 1 is, for example, 0.01 or more, preferably 0.02 or more, more preferably 0.03 or more, and, for example, 1.00 or less at 100 ° C.

  The loss factor is measured by measuring the loss factor by cutting the resin layer 2 into a width of 10 mm and a length of 250 mm to prepare a sample, and sticking the sample to an adherend 0.8 mm × 10 mm × 250 mm SPCC steel plate. Using the apparatus, the loss factor of the secondary resonance point is measured by the central excitation method.

  When the loss factor of the damping material 1 is equal to or greater than the above lower limit value, the vibration member 5 can be sufficiently damped if the damping material 1 is attached to the vibrating member 5.

  The adhesive strength of the damping material 1 at 23 ° C. is, for example, 10 N / 25 mm or more, preferably 50 N / 25 mm or more, more preferably 95 N / 25 mm or more, and for example, 500 N / 25 mm or less.

  In addition, adhesive strength cuts the damping material 1 (laminated body of the resin layer 2 and the constraining layer 3) into 25 mm in width and 150 mm in length, produces a sample, and affixes the resin layer 2 side of a sample to a stainless steel plate. After that, the sample is peeled off from the stainless steel plate at an angle of 90 degrees and a speed of 300 mm / min with respect to the stainless steel plate at 23 ° C. using a universal tensile tester.

  If the adhesive force of the damping material 1 is equal to or greater than the above lower limit value, the vibration member 5 can be sufficiently damped by being firmly adhered to the adherend even at room temperature. Further, the vibration damping material 1 can be prevented from falling off during conveyance and use.

  In particular, from the viewpoint of efficiently transmitting vibration to the damping material 1, in the measurement of the adhesive force, the peeling mode between the damping material 1 (resin layer 2) and the adherend is preferably cohesive failure.

  The vibration damping material 1 obtained in this way is attached to various parts used in the fields of automobiles, railway vehicles, home appliances, office equipment, housing equipment, machine tools, etc., and the various parts are damped. .

  As various parts, for example, parts used at a high temperature exceeding 40 ° C. (high-temperature parts), for example, heat-generating parts such as motors, heaters, and engines, and further, for example, from normal temperature (20 ° C.) to high temperature (eg, 100 Parts used under a wide range of temperatures up to (° C.).

  More specifically, in the vibration damping material 1, when the release paper 4 is adhered to the surface of the resin layer 2, during use, from the surface of the resin layer 2 as shown by the phantom line in FIG. 1A. The release paper 4 is peeled off, and then, as shown in FIG. 1B, the surface of the resin layer 2 is attached to a vibration member 5 such as a part to be adhered. Thereby, the damping material 1 dampens the vibration member 5.

  The resin layer 2 and the vibration member 5 can be attached by, for example, pressure bonding or thermocompression bonding.

  And this damping material 1 is equipped with the resin layer 2 which contains butyl rubber and the softening agent whose weight average molecular weight is a specific range with a specific content rate.

  In general, a rubber-based vibration damping material is blended with a softening agent that imparts plasticity to the vibration damping material in order to improve processability and handleability. However, the softening agent generally has a glass transition point lower than that of rubber, and has an effect of lowering the peak temperature of the loss factor of the damping material. However, according to the damping material 1, the peak of the loss factor of the damping material 1 can be shifted to the high temperature side by adding a specific amount of a softening agent having a specific weight average molecular weight to the butyl rubber.

  Therefore, if the vibration damping material 1 is stuck to the vibration member 5, even if the vibration member 5 is used under a wide range of temperatures from room temperature to high temperature, vibration can be sufficiently suppressed. Specifically, it is possible to sufficiently dampen components used at normal temperatures (20 ° C.) to high temperatures of 40 ° C. or more and 100 ° C. or less.

  In the embodiment of FIGS. 1A and 1B, in the vibration damping material 1, the constraining layer 3 is laminated on the resin layer 2. For example, although not shown, only the resin layer 2 is provided without providing the constraining layer 3. It can also be set as the damping material 1 provided with.

  Also according to this embodiment, the same effects as those of the embodiment of FIGS. 1A and 1B can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these. Moreover, the numerical value of the Example shown below can be substituted for the numerical value (namely, upper limit value or lower limit value) described in said embodiment.

Examples 1-3 and Comparative Examples 1-3
In the formulation shown in Table 1, each component was blended and kneaded with a mixing roll to prepare a kneaded product (resin composition).

  Next, the obtained kneaded product was compressed and stretched into a sheet shape by press molding and laminated on the surface of the release paper to form a resin layer having a thickness of 2.0 mm.

  Thereafter, a constraining layer made of a glass cloth having a thickness of 0.2 mm is attached to the surface of the resin layer by thermocompression bonding, and a damping material having a total thickness of the resin layer and the constraining layer of 2.2 mm is obtained. Produced.

  In addition, the weight average molecular weight (Mw) of the softening agent was measured by the standard polystyrene conversion value with the following apparatus and measurement conditions. The results are shown in Table 1.

GPC apparatus: HLC-8120 GPC (column: TSKgel SuperHZM-H / HZ4000 / HZ3000 / HZ2000, column size: 6.0 mm ID × 150 mm), detector: differential refractive index detector (RI), GPC measurement manufactured by Tosoh Corporation Conditions: mobile phase tetrahydrofuran, flow rate 0.6 mL / min, column temperature 40 ° C., sample concentration 1.0 g / L, injection amount 20 μL
(Evaluation)
(1) Flow Viscosity Using a Koka type flow tester (manufactured by Shimadzu Corporation, “CFT-500D”), the nozzle length is adjusted to 1.0 mm, the nozzle diameter is 1.0 mm, the temperature is 60 ° C., the load pressure is 20 kgf / cm 2 Under the condition of about 0.98 MPa), the flow viscosities of the resin compositions of the examples and comparative examples were measured. The results are shown in Table 1.

(2) Vibration control (loss factor)
The loss factor at the secondary resonance point of the damping material at 0, 20 ° C., 40 ° C., 60 ° C., 80 ° C., and 100 ° C. is measured by the central excitation method using the loss factor measuring device under the following measurement conditions. did. Specifically, the damping material was cut into a width of 10 mm and a length of 250 mm, a sample was prepared, and the loss coefficient was measured by sticking the sample to an adherend. The results are shown in Table 1.
Substrate: 0.8 mm x 10 mm x 250 mm SPCC steel plate Frequency: 500 Hz (500 Hz is calculated from the resonance point)
(3) Adhesiveness The damping material manufactured in each example and each comparative example was cut into a width of 25 mm and a length of 150 mm to prepare a sample. The resin layer side of the sample was attached to a stainless steel plate, and the sample was pressed against the stainless steel plate by reciprocating a 2 kg roller over the constraining layer. Thirty minutes later, the sample was peeled from the stainless steel plate at 23 ° C. using a universal tensile tester at an angle of 90 ° with respect to the stainless steel plate and at a speed of 300 mm / min. The peel adhesion was measured. The results are shown in Table 1.

The numerical value in each component of Table 1 indicates the number of parts by mass unless otherwise specified. The abbreviations in Table 1 are shown below.
S butyl reclaimed rubber: Mooney viscosity 44 ± 6 (ML1 + 4 (100 ° C.)), manufactured by Gogo Co., Ltd. KVIS10: Trade name “PBKVIS-10”, liquid polybutene, Mn: 950, kinematic viscosity 230 ± 30 mm ² / s ( 100 ° C), manufactured by M / s Kothari Petrochemicals, KVIS30: trade name “PBKVIS-30”, liquid polybutene, Mn: 1300, kinematic viscosity 660 ± 30 mm ² / s (100 ° C.), manufactured by M / s Kothari Petrochemicals HV15: trade name “polybutene HV-15”, liquid polybutene, Mn: 630, kinematic viscosity 31 ± 2 mm ² / s (100 ° C.), manufactured by JX Nippon Mining & Energy Corporation, heavy calcium carbonate: calcium carbonate, Maruo calcium Made of carbon black: trade name "Asahi Carbon # 50", flat Uniform particle size 80 nm, Asahi Carbon Co., Ltd./Escollet 1202: Trade name, petroleum resin, softening point 100 ± 5 ° C., manufactured by Exxon

1 Damping material 2 Resin layer 3 Constrained layer

Claims (4)

A resin layer and a constraining layer laminated on the resin layer;
The resin layer is formed from a resin composition containing butyl rubber and a softening agent,
The softener has a weight average molecular weight of 1500 or more;
A damping material, wherein a content ratio of the softening agent with respect to 100 parts by mass of the butyl rubber is 30 to 90 parts by mass.   The said resin layer further contains 5-150 mass parts tackifier and 100-350 mass parts filler with respect to 100 mass parts of the said butyl rubbers. Damping material.   The vibration damping material according to claim 1 or 2, wherein the softening agent is polybutene. 4. The flow viscosity of the resin composition when measured under conditions of a temperature of 60 ° C. and a load pressure of 20 kgf / cm ² is 6000 to 30000 Pa · s, according to claim 1. The damping material described.

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