JPH0615660B2 - Viscoelastic composition for damping material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a viscoelastic composition for vibration damping materials, and more specifically, as a structural member of various structures such as machines, buildings, vehicles, or a part thereof. The present invention relates to a viscoelastic composition for a damping material used as an intermediate layer in a damping material having a multi-layer structure.

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, etc. It tends to regulate vibration. In response to these trends, the vibration damping performance of metal materials that are noise sources and vibration sources, that is, the vibration energy of the members that generate noise is absorbed and exchanged for thermal energy, and vibration speed or vibration amplitude It has been demanded to add a function of attenuating and reducing the acoustic emission and to improve the function.

Based on such a demand, as one of the vibration damping materials exhibiting such performance, a composite vibration damping material having a multilayer structure in which an intermediate layer having viscoelasticity is sandwiched between metal layers has been conventionally proposed. And, this composite type vibration damping material is used for automobile oil pans, engine covers, hopper chute parts, transport equipment stoppers, home appliances, and other vibration reduction members for metal working machines and structural members for precision machinery where vibration prevention is desired. Etc. have been examined and adopted.

Generally, the damping performance of such a composite damping material depends on the performance of the viscoelastic intermediate layer constituting the intermediate layer.
This damping performance is expressed as a loss factor (a quantity related to mechanical hysteresis loss due to vibration, which is a measure of the exchange of vibration energy from the outside into thermal energy due to internal friction), and this damping performance has a peak characteristic at a certain temperature. Indicates
It is known that it is most effective to use in the vicinity of this peak characteristic temperature.

Conventionally, as a viscoelastic composition constituting the viscoelastic intermediate layer of such a composite type vibration damping material, polyester alone (Japanese Patent Application Laid-Open
50-143880) or a polyester added with a plasticizer (JP-A-51-93770), polyurethane foam alone (JP-A-51-91981), polyamide alone (JP-A-56-159160). Gazette), ethylene-vinyl acetate copolymer simple substance (JP-A-57-34949), polyvinyl butyral or a composition of polyvinyl butyral and polyvinyl acetate mixed with a plasticizer and a tackifier (JP-B-55). -27975), a copolymer of an isocyanate prepolymer and a vinyl monomer (JP-B-52-26554).
Japanese Patent Publication No. 39-12451, Japanese Patent Publication No. 45-3
The copolymer and the like shown in Japanese Patent No. 4703 are known.

Problems to be Solved by the Invention By the way, as characteristics required for the composite vibration damping material,
First, it is required that the value of the loss coefficient is high and the adhesive strength between the viscoelastic intermediate layer composed of the viscoelastic composition and the metal layer is high. The composite type vibration damping material produced from the above-mentioned materials has a problem in any of its performances and is not sufficiently satisfactory.

Means for Solving the Problems That is, the present invention, the following amorphous polyester resin (A) and (B)
Is (A) 5 to 95% by weight, and (B) 95 to 5 relative to the composition.
A viscoelastic composition for a vibration damping material, characterized in that the viscoelastic composition is blended in a range of wt%.

However: (A) 90 mol% or more of aromatic dicarboxylic acid and 10
Consists of a dicarboxylic acid component in which less than mol% is an aliphatic dicarboxylic acid and / or an alicyclic dicarboxylic acid, an alkylene glycol having 2 to 9 carbon atoms and / or an alkylene oxide adduct of a bisphenol compound, and / or an alicyclic glycol. Amorphous polyester resin composed of glycol component.

(B): 40 to 89 mol% of aromatic dicarboxylic acid, 60 to 11 mol% of dicarboxylic acid component of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid, and alkylene glycol having 2 to 9 carbon atoms and / or Alternatively, it is an amorphous polyester resin composed of a glycol component composed of an alkylene oxide adduct of a bisphenol compound and / or a polyether glycol.

Action The present invention is described in detail below. First, in the present invention,
The damping material is a composite damping material in which a viscoelastic intermediate layer that joins these metal layers to each other is sandwiched between metal layers. Any material may be used as long as the vibration-damping material is formed by sandwiching the viscoelastic composition between the two, for example, a metal plate, a concentric metal tube, a shaped steel, a molded body that can be overlapped with each other, a metal molded body and a contact plate, and other Examples thereof include those having a layered structure. And as the metal said here, iron,
Steel, aluminum, etc. can be mentioned, and generally widely used materials include steel materials and aluminum and their alloys. Further, these metal materials may be surface-treated like plated steel sheets.

Next, the viscoelastic composition of the present invention will be described in detail.

First, the amorphous polyester resin referred to in the present invention is, for example,
This refers to a polyester resin that does not have a clear melting endothermic peak of a crystal part in a thermal analysis by DSC. Further, both the amorphous polyester resins (A) and (B) in the present invention preferably have a reduced viscosity of 0.4 or more.

Next, the aromatic dicarboxylic acid referred to in the present invention is, for example,
Terephthalic acid, isophthalic acid, orthophthalic acid, 2,6
-Naphthalenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, etc. or their esterified products, acid anhydrides, etc. are used, and one kind or two or more kinds are appropriately selected and used. As the aromatic dicarboxylic acid component, one or both of isophthalic acid and orthophthalic acid are preferably copolymerized at least 30 mol% of the aromatic dicarboxylic acid component.

Next, the aliphatic dicarboxylic acid referred to in the present invention is, for example,
Examples thereof include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid and the like, and their esterified products and acid anhydrides. One kind or two or more kinds are appropriately selected and used.

The alicyclic dicarboxylic acid referred to in the present invention means, for example, 1,
Examples thereof include 4-cyclohexanedicarboxylic acid and the like, esterified products thereof, acid anhydrides and the like, and one kind or two or more kinds are appropriately selected and used.

The alkylene glycol having 2 to 9 carbon atoms in the present invention means, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3-methylpentanediol, 1,6- Hexane diol, 1,9-nonane diol and the like can be mentioned, and one kind or two or more kinds are appropriately selected and used.

Next, the alicyclic glycol referred to in the present invention means, for example, 1,
4-cyclohexane diol, 1, 4-cyclohexane dimethanol, etc. are mentioned, and 1 type (s) or 2 or more types are selected and used suitably.

The alkylene oxide adduct of bisphenol compound referred to in the present invention includes bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, bisphenol S ethylene oxide adduct, hydroquinone ethylene oxide adduct, and hydroquinone propylene oxide adduct. There are things.

The polyether glycol referred to in the present invention includes diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol and the like, and one or more of these are appropriately selected and used. Is.

In the present invention, it is desirable to use a glycol having an alkyl group in the side chain for at least 30 mol% of all glycol components. Preferred glycols having an alkyl group in the side chain include propylene glycol and neopentyl. Mention may be made of glycol and 3-methyl-1,5-pentanediol.

Next, in the present invention, the dicarboxylic acid component and glycol component as described above constitute the following two types of amorphous polyester resins (A) and (B), and these (A)
The blending amount is in the range of 5 to 95% by weight and (B) 95 to 5% by weight for the following reason.

First, the amorphous polyester resin (A) is composed of the composition described below, and the tensile breaking strength of the resin according to ASTM D638-61T is 250 kgf / cm ² or more, preferably 300 kgf / cm ² or more,
A hardness of 45 Shore D or more, preferably 50 Shore D or more, while an amorphous polyester resin (B)
Has a composition as described below, and the tensile breaking strength of the resin according to ASTM D638-61T is less than 250 kgf / cm ² , preferably
Those having a hardness of 200 kgf / cm ² or less and a hardness of less than 45 Shore D, preferably 40 Shore D or less,
Resins (A) and (B) are added in a total amount of 100, one of which is 5 to 95% by weight, and the other of which is the rest of the ingredients, the resin (A) is less than 5% by weight, that is, the resin (B) is 95% by weight. JIS K 6850 to be super
If the resin (A) exceeds 95% by weight, that is, the resin (B) is less than 5% by weight, JIS K 685
This is because the T-shaped peel strength due to 4 is significantly reduced.

Next, the resin (A) has an aromatic dicarboxylic acid content of 90 mol% or more as a dicarboxylic acid component, but when the aromatic dicarboxylic acid content is less than 90 mol%, the resin (A) has a tensile breaking strength. Because it will decrease. Further, as the glycol component, an alkylene glycol having 2 to 9 carbon atoms and / or an alkylene oxide adduct of a bisphenol compound and / or an alicyclic glycol is used. This is to give some flexibility.

By polycondensing such a dicarboxylic acid component and a glycol component, the tensile breaking strength of the resin is 250 kgf /
An amorphous polyester resin having a property of cm ² or more and a hardness of 45 Shore D or more can be obtained.

On the other hand, the resin (B) is one in which 40 to 89 mol% of the dicarboxylic acid component is an aromatic dicarboxylic acid, and the remaining 11 to 60 mol% is one or both of an aliphatic or alicyclic dicarboxylic acid. However, when the aromatic dicarboxylic acid is less than 40 mol%, the resin becomes fluid, and when it exceeds 89 mol%, the resin becomes hard. Further, the aliphatic or alicyclic dicarboxylic acid is selected as the balance for the purpose of enhancing the non-crystallinity. If one or both of them is less than 11 mol%, the resin becomes hard and T
This is because the peel strength is reduced, and if it exceeds 60 mol%, the resin becomes fluid.

As the glycol component, an alkylene glycol having 2 to 9 carbon atoms and / or an alkylene oxide adduct of a bisphenol compound and / or a polyether glycol is used. This is to improve the vibration performance.

By polycondensing such a dicarboxylic acid component and a glycol component, an amorphous polyester resin having a tensile breaking strength of less than 250 kgf / cm ² and a hardness of less than 45 Shore D can be obtained.

Next, both resins (A) and (B) are mixed in the above-mentioned predetermined range to obtain the viscoelastic mixture of the present invention. In this case, the resins (A) and (B) are dicarboxylic acid monomer and glycol monomer in a reaction vessel equipped with a thermometer, a stirrer and a partial reflux condenser, respectively, and a small amount of zinc acetate as a catalyst, antimony trioxide, etc. After carrying out the transesterification reaction at 140 to 220 ° C for about 3 hours, the reaction system is heated to 220 to 250
While increasing the temperature to ℃, the pressure in the system takes 1 to 5 mm over about 60 minutes.
It can be obtained by reducing the pressure to Hg and then performing a polycondensation reaction at 270 ° C. for about 90 minutes under a reduced pressure of 0.1 to 0.3 mmHg. These are dissolved in a solvent such as cyclohexanone and xylene solvent having a weight ratio of 1: 1 or a solvent such as methyl ethyl ketone and toluene solvent having a weight ratio of 1: 1 and stirred and mixed in a container equipped with a stirrer to volatilize the solvent before use. .

When the mixture of the present invention is used as the intermediate layer of the vibration damping material, it goes without saying that the above mixture can be used as it is, but in addition to this, glass fiber for the purpose of increasing the resin strength,
Various fibers such as polyester fiber and carbon fiber, various particles such as calcium carbonate and magnesium carbonate, and various metal powders and metal fibers such as stainless powder and aluminum powder for the purpose of imparting point contact weldability, or carbon black and graphite. One or more of various coupling agents for the purpose of improving the adhesion between the conductive particles such as the above and other mixed inorganic substances and the resin, and various leveling agents for the purpose of improving the coating property can be appropriately selected and used.

The viscoelastic mixture of the present invention having such a constitution exhibits a marked effect as compared with the conventional viscoelastic substance having a polyester resin as a base material. That is, with the conventional polyester resin alone, it is difficult to satisfy both good vibration damping performance and adhesive strength, but as in the present invention, the amorphous polyester resin (A) and the amorphous polyester resin (B) The use of the mixture with and improves the vibration damping performance and, at the same time, significantly improves the adhesive strength. In addition, it is generally known that the composite steel sheet having a three-layer structure exhibits an extreme value of the vibration damping performance at about 30 to 40 ° C. above the glass transition temperature of the resin, and the resin (A) and the resin (B The temperature at which the vibration damping performance is maximized can be changed without lowering the vibration damping performance and the adhesive strength by changing the compounding ratio of) and changing the glass transition temperature of the resin mixture.

For example, since the glass transition temperature of the resin (B) can be changed by changing the aromatic component of the dicarboxylic acid component in the resin (B) within the range of 40 to 89 mol%, the resin ( By adjusting the component (B) and adjusting the mixing ratio of the resin (A) and the resin (B), it is possible to continuously change the temperature at which the vibration damping performance becomes maximum over a wider temperature range. It is possible to obtain the most effective viscoelastic mixture with respect to the use temperature without decreasing the adhesive strength.

Example Hereinafter, the effect of the present invention will be described more specifically based on an example.

Table 1 shows the amorphous polyester resin (A) and the amorphous polyester resin constituting the mixed polyester resin of the present invention.
(B) and the ratio of the constitutional units of the polyester resin (C) as a comparative material and the reduced viscosity of each resin are shown in Table 2.
The compounding ratio of (A) and resin (B) and the temperature (vibration peak temperature) at which the vibration absorption performance of the vibration-damping steel sheet using the same is maximized, T-type peel strength, and shear adhesive strength are shown.

In addition, in Table 3, the temperature and T-type peeling at which the vibration absorption performance of the vibration-damping steel plate is maximized when (A), (B), (C) are used individually and when (C) is used in combination. The strength and the shear adhesive strength are shown as comparative examples.

The measurement of vibration absorption performance is indicated by the loss coefficient η,
The relationship between the loss factor and the temperature at a vibration frequency of 500 Hz was determined for a damping steel plate consisting of a 0.8 mm thick bonded steel plate and a 0.05 mm thick viscoelastic mixture layer.

For each of 1 to 17- in Table 2, one of the five resins (A) and one of the five resins (B) listed in Table 1 was selected and the mixing ratio was 1: 3, 1. The temperature, the T-type peel strength, and the shear adhesive strength at which the vibration of the vibration-damping steel sheet using each mixed resin when changed to 1: 1, 3: 1 are maximized are shown.

In each of 1 to 17-in Table 2 in which the resin (A) and the resin (B) in Table 1 are mixed, the maximum loss coefficient η is
A high value of 0.5 or more and a temperature range of η = 0.1 or more
50 ℃ or more.

On the other hand, if resin (A) and resin (B) are used alone,
As shown in Comparative Examples 17 to 26 in the table, the temperature range of η = 0.1 or more is narrower and the operating temperature range is narrower than in the case of mixed use.
Also, by changing the mixing ratio of resin (A) and resin (B),
The maximum loss coefficient value ηMAX can be adjusted to the operating temperature of the damping steel plate.

Also, regarding T-type peel strength and shear adhesive strength,
It is shown that by mixing (A) and the resin (B), the T-type peel strength and the shear adhesive strength are superior to those when the resin (A) or the resin (B) is used alone.

Further, among the comparative polyester resins shown in Table 1, the resins C-1 and C-2 in which the aromatic dicarboxylic acid component is less than 40 mol% among the dicarboxylic acid components of the constituent monomers are
As shown in Comparative Examples 25 and 26 of Table 3, when used alone, the maximum loss coefficient η of both was 0.3 or less, and the adhesive strength was T-type peel strength of less than 10 kgf / 25 mm and shear adhesive strength of 60 kgf /. It is less than cm ² , but C-like C-3
When 1 and C-2 are used in a 1: 1 mixture, as shown in Example 27, loss factor is 0.2 or less, T-type peel strength is 10 kgf /
The adhesive strength is less than 25 kg and the shear adhesive strength is less than 30 kgf / cm ² , and when the aromatic dicarboxylic acid component in the dicarboxylic acid component of the constituent monomers is less than 40 mol%, sufficient adhesive strength and vibration damping performance cannot be obtained.

EFFECTS OF THE INVENTION As is clear from the above examples, the viscoelastic mixture of the present invention is sandwiched between two metal plates, and thus has a high vibration damping performance which cannot be achieved by a single resin composition and is excellent. Since it forms an intermediate layer exhibiting adhesiveness, it is extremely useful as a viscoelastic composition for a composite vibration damping material.

Front Page Continuation (72) Inventor Nobuo Kadowaki 5-10-1 Fuchinobe, Sagamihara-shi, Kanagawa Inside Nippon Steel Co., Ltd. 2nd Technical Research Center (72) Inventor Takeshi Yatsuka 2-1-1 Katata, Otsu, Shiga Prefecture Toyobo Co., Ltd. Inside the Research Center Research Institute (72) Inventor Hiroshi Nagai 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. Research Center (72) Inventor Yu Mizumura 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Institute

Claims (1)

[Claims] 1. The following amorphous polyester resins (A) and (B)
(A) 5 to 95% by weight and (B) 95 to 5% by weight with respect to the composition, and a viscoelastic composition for a vibration damping material. However, (A): a dicarboxylic acid component in which 90 mol% or more is an aromatic dicarboxylic acid, and less than 10 mol% is an aliphatic dicarboxylic acid and / or an alicyclic dicarboxylic acid, and a carbon number of 2
9 to 9, and / or an amorphous polyester resin composed of a glycol component composed of an alkylene oxide adduct of a bisphenol compound and / or an alicyclic glycol. (B): 40-89 mol% of aromatic dicarboxylic acid, and 60-
A dicarboxylic acid component in which 11 mol% is an aliphatic dicarboxylic acid and / or an alicyclic dicarboxylic acid, and a carbon number of 2 to 9
An amorphous polyester resin composed of a glycol component consisting of an alkylene glycol of alkylene glycol and / or an alkylene oxide adduct of a bisphenol compound and / or a polyether glycol.