JPH02107435A - Resin composition for vibration damping metal - Google Patents

Abstract

PURPOSE:To reduce melting viscosity, to enhance coating properties and to improve vibration damping performance at a low temperature by forming of vinyl ester copolymer or unsaturated carboxylate copolymer, and incorporating vinyl ester of branched fatty acid in the copolymer. CONSTITUTION:When vinyl ester copolymer, unsaturated carboxylate copolymer or copolymer of vinyl ester and unsaturated carboxylic acid contains the vinyl ester of branched fatty acid as the component of the copolymer, its melting viscosity is remarkably reduced, or vibration damping performance at a low temperature is enhanced. The unsaturated carboxylic acid includes one or more selected from acrylic acid, methacrylic acid, maleic acid, fumaric acid, itacoinc acid, crotonic acid, maleic anhydride, and the ratio occupying in the copolymer is desirably 1 - 6mol%. The vinyl ester, i.e., the vinyl ester except the vinyl ester of branched fatter acid includes desirably vinyl carboxylate, and the monopolymer of the vinyl carboxylate has high vibration damping properties.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a vibration-damping metal resin composition, and more particularly to a vibration-damping metal plate composed of a plurality of metal plates and an intermediate layer joining them. The present invention relates to a vibration-damping metal resin composition used for an intermediate layer.

(Prior art) In recent years, measures to reduce noise generated by vibrations in various machines and transportation systems have become an important issue, and as a countermeasure, metal plates with vibration damping properties, that is, vibration damping metal plates, are used for noise sources. It has started to be done.

For example, vibration-damping metal plates have been used in automobile oil pans, dash panels, chutes of boosters, general-purpose engine covers, vibration reduction members of metal processing machines, and the like.

A vibration-damping metal plate consists of multiple metal plates and an intermediate layer (
The required characteristics vary depending on the application, but in any case, it is necessary that the vibration damping performance (hereinafter referred to as vibration damping performance) be good at the usage environment temperature.

Methods for producing such vibration-damping metal plates, that is, bonding methods, include a hot melt lamination method using a true melt adhesive, a dry lamination method using a resin dissolved in a solvent as an adhesive, and a film lamination method using a heat adhesive film. be.

Among these methods, according to the film lamination method, the obtained vibration-damping metal plate has excellent adhesion between the metal plate and the resin layer and ductility of the resin layer, but has poor vibration damping performance.

In the case of the dry lamination method, the damping performance is relatively high, but the adhesion is not sufficient, and the resin layer may peel or break during deep drawing of the damping metal plate.

On the other hand, the hot melt lamination method has the best vibration damping performance. In addition, this method is suitable for high-speed mass production because it is instant adhesive, and since it is solvent-free, there is no risk of poisoning the human body or fire, and it can be bonded to a wide range of metal plates, and it is also possible to re-bond it. It has various advantages. However, since the base resin of conventional hot melt adhesives alone has a high melt viscosity, there is a drawback that special coating equipment (such as an extrusion coater) is required during coating. Furthermore, when used at relatively low temperatures, there is a drawback that the damping performance is lowered.

Therefore, a technique has been developed in which a plasticizer is added to the resin to lower the melt viscosity and improve the coating properties, as well as to improve the vibration damping performance at low temperatures (0 to 60° C.). For example, Japanese Patent Publication No. 46-17582 discloses a vibration-damping metal resin composition in which a plasticizer is added to a vinyl acetate resin.
Japanese Patent No. 8700 proposes a vibration-damping metal resin composition in which a plasticizer is added to a low molecular weight polyamide resin.

(Problem to be Solved by the Invention) However, in the vibration-damping metal resin composition to which a plasticizer has been added as described above, the plasticizer evaporates when it is melted and applied to a metal plate. There is a problem that a predetermined resin composition cannot be obtained. Furthermore, since the evaporated plasticizer is generally harmful, there is a drawback that safety and hygiene measures are required during the coating operation.

Furthermore, when the obtained damping metal is used in a high-temperature environment such as in a place exposed to direct sunlight or in a heat-generating cover, the plasticizer tends to volatilize from the resin composition.

The present invention has been made in view of these circumstances, and its purpose is to solve the above-mentioned problems of the conventional ones, and to provide a plasticizer-added vibration-damping metal resin composition. A vibration-damping resin composition for metals that does not cause problems such as plasticizer evaporation during melt coating or plasticizer volatilization when used in high-temperature environments as in In addition, the present invention aims to provide a vibration-damping metal resin composition that can improve vibration-damping performance at low temperatures.

(Means for Solving the Problems) In order to achieve the above-mentioned problems, the present invention provides a vibration-damping metal resin composition having the following configuration.

That is, the vibration-damping metal resin composition of the first aspect is a vibration-damping metal resin composition comprising a vinyl ester copolymer or an unsaturated carboxylic acid copolymer, wherein the copolymer is a branched fatty acid. A vibration-damping metal resin composition according to the second claim, which is characterized in that it contains a vinyl ester, is a vibration-damping metal resin composition comprising a copolymer of a vinyl ester and an unsaturated carboxylic acid. This is a resin composition for vibration-damping metal, wherein the copolymer contains a vinyl ester of a branched fatty acid.

In the damping metal resin composition according to the third aspect, the unsaturated carboxylic acid is one or two selected from acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, and maleic anhydride. The l4Jlft M oxide teal for vibration damping metals according to the first and second claims.

The vibration-damping metal resin composition according to the fourth aspect is the vibration-damping metal resin composition according to the first, second, and third claims, wherein the vinyl ester is vinyl carboxylate.

(Function) The inventors focused on vinyl ester copolymers and unsaturated carboxylic acid copolymers and conducted various studies on their properties. When a copolymer with an unsaturated carboxylic acid contains a branched fatty acid vinyl ester as a component of the copolymer, the melt viscosity decreases significantly;
We have obtained the knowledge that vibration damping performance is improved at low temperatures. The present invention is based on these findings.

As mentioned above, the damping metal resin composition according to the present invention is a vinyl ester copolymer, an unsaturated carboxylic acid copolymer, or a copolymer of a vinyl ester and an unsaturated carboxylic acid. Since it always contains a vinyl ester of a branched fatty acid, the melt viscosity is low based on the above, and therefore the coating properties can be excellent. Therefore, using the resin composition as a true melt adhesive,
If vibration-damping metal is manufactured, special coating equipment during coating becomes unnecessary. Moreover, if the resin composition is used as an adhesive,
A damping metal with high damping performance at low temperatures can now be obtained.

The melt viscosity is thus significantly reduced and the damping performance at low temperatures is high (this is because the homopolymer of branched fatty acid vinyl ester has a low glass transition temperature (3°C)).

Furthermore, since the resin composition for damping metals according to the present invention does not contain a plasticizer, it is difficult to prevent plasticizer evaporation during melt coating and high-temperature environments, such as in plasticizer-added resin compositions for vibration-damping metals. Basically, there are no problems such as plasticizer volatilization when used under conditions.

The unsaturated carboxylic acid is preferably one or more selected from acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, and maleic anhydride. This is because by doing so, the adhesive strength to the metal plate is further improved. Further, the proportion of unsaturated carboxylic acid in the copolymer is preferably 1 to 6 mol%. When it is less than 1 mol%, adhesive strength decreases,
This is because if the content exceeds 6 mol%, the damping performance will decrease.

Vinyl esters other than vinyl esters of branched fatty acids include vinyl carboxylates such as vinyl acetate, vinyl propionate, and vinyl butyrate, or methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Acrylic esters such as, or methacrylic esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate can be used. Among these, it is particularly desirable to use vinyl carboxylate. This is because the homopolymer of vinyl carboxylate has high vibration damping properties.

As the branched fatty acid vinyl ester, Beoba 10
or Beoba 9 (all product names; Shell Chemical Co., Ltd.)
can be used.

Copolymerization can be carried out by a conventional method, for example, a solution polymerization method using methyl alcohol, acetone, or the like.

In order to improve the heat resistance and stability of the resin composition, antioxidants such as high molecular weight hindered phenols, stabilizers such as zinc-based liquid stabilizers and phosphite-based stabilizers are added, and the melt viscosity is adjusted and controlled. In order to improve the adhesive strength of the shaken metal plate, a viscosity modifier such as high-purity ultrafine particle anhydrous silica may be added as necessary. When added, the proportion to the resin composition is
The amount of antioxidants and stabilizers added is preferably 1 to 4 wt%, and the amount of viscosity modifiers is preferably 0.5 to 5 wt%.

Carbon black, graphite,
Various conductive fillers such as metal powder can be blended.

The type of metal of the damping metal plate is not particularly limited.

In order to manufacture a damping metal plate using the resin composition according to the present invention, the composition is melted at, for example, 120 to 180°C,
After coating the surface of the metal plate to a thickness of about 30-100 μ-, layer another metal plate on top of it and heat it at 120-180°C, 15-20°C.
The above composition may be bonded by thermocompression at a pressure of 30 to 400 g/cm" on the metal plate surface by dissolving the above composition in a solvent such as acetone.
It may be applied to a thickness of 1/1 m, preferably 60 to 200 μm, and after removing the solvent, it may be bonded by thermocompression.

(Example) Examples of the present invention will be described below.

Mishin Itsu 1 Add acetone (polymerization solution) to a 500 ml three-ring flask.
;100ml, vinyl acetate, n-butyl acrylate (
vinyl ester), Beoba 10; 115g; 0
．． 58++ol (vinyl ester of branched fatty acid), acrylic acid i5g: 0.0694 mol (unsaturated carboxylic acid) and azobisisobutyronitrile (polymerization initiator)
;O, 5g was added, and copolymerization was carried out under normal pressure at a water bath temperature of 700C while acetone was refluxed and the polymerization solution was stirred to obtain a quaternary copolymer.

Here, vinyl acetate is 10 to 40 g (0.12 to 0.4
6■ol), n-butyl acrylate ranges from 13.6 to
It was varied in the range of 54.4 g (0.11 to 0.42*ol). The composition of the obtained quaternary copolymer is shown in Table 1.

In Table 1, No. 4 is a terpolymer prepared for comparison.

The obtained polymer was measured at 180'C and a shear rate of 1 using a high-temperature viscometer (Rheomat 30) manufactured by Contrapass.
The melt viscosity was measured under the conditions of 0.00 (1/sec).

As a result, Beoba 10 (vinyl ester of branched fatty acids)
The melt viscosity of the copolymer (No. 4) not containing was extremely high and could not be measured. On the other hand, Heoba 1
The melt viscosity of the quaternary copolymers (Nos. 1 to 3) containing 0 was low, ranging from 29 to 31 voids.

The above polymer was applied to a thickness of 100 μm on the surface of a cold-rolled steel plate measuring 200 x 250 m², and after the solvent was removed in a vacuum dryer, another steel plate was placed on top of it and heated at 160'C.

A damping steel plate was obtained by thermocompression bonding at 20 kg/cm'' for 5 minutes.

This application was extremely easy and did not require any special application equipment.

A rectangular sample was made from this damping steel plate, and measured at a frequency of 250 using the resonance method using a complex elastic modulus measuring device manufactured by BAK.
A vibration damping test was conducted at 11z, and the relationship between the ambient temperature during the test and the loss coefficient of the damping steel plate was determined. The results are shown in Figure 1. In Figure 1, O is No, 1, ・ is No, 2, Δ is No,
3 and × indicate the results in the case of No and 4. 1st
As can be seen from the figure, compared to No. 4, No. 1
In the case of ~3, vibration damping performance at relatively low temperatures is excellent. N
Regarding cases 1 to 3, the higher the amount of n-butyl acrylate added, the more the maximum temperature shifts to the lower temperature side. However, it is clear that the vibration damping performance can be improved.

In addition, the adhesive strength was measured using a strip sample according to JIS N68.
It was carried out according to the method of No. 54. As a result, the T-direction peel strength was 0.9 to 1.2 Kgf/+m+s. This shows that with this level of strength, processing such as shirring can be performed without peeling, and therefore the vibration-damping resin composition for metals according to the present invention can provide sufficient adhesive strength.

Backyard■) By the same method as in Example 1, vinyl acetate (vinyl ester), Beoba 10, acrylic acid (unsaturated carboxylic acid)
; 5 g: 0.0694 mol of a terpolymer was obtained. Here, vinyl acetate is 10 to 40 g (0.12 to 0.4
6*ol) range, Beoba 10 is 119-206g (
0.60 to 1.04*ol). The composition of the obtained terpolymer is shown in Table 2.

A vibration damping steel plate was made using the obtained polymer in the same manner as in Example 1, and a vibration damping test and adhesive force measurement were performed.

As in Example 1, the application of the polymer was extremely easy.

The adhesive strength (peel strength) was also the same as in Example 1.

The relationship between the ambient temperature and the loss coefficient of the damping steel plate is shown in Figure 2. In Figure 2, O is N005, . is N016, Δ is 7, and the results are shown. From Figure 2, the maximum temperature of the loss coefficient is low in both cases (and, as the amount of vinyl acetate added decreases, the maximum temperature shifts to the lower temperature side, so depending on the amount of addition added, the temperature ranges from 0 to 20°C) It can be seen that excellent vibration damping performance can be obtained even at such low temperatures.

Fuchi 11 By the same method as in Example 1, vinyl acetate; 30 g: o
, 35sol, n-butyl acrylate; 27.2g
: 0.211Ilo1, Beoba 10; 115g
:0.58 sol of a terpolymer was obtained. A vibration damping steel plate was made using the obtained polymer in the same manner as in Example 1, and a vibration damping test was conducted.

As in Example 1, the application of the polymer was extremely easy.

The adhesive strength (peel strength) was also the same as in Example 1.

Figure 3 shows the relationship between the ambient temperature and the loss coefficient of the damping steel plate. From FIG. 3, it can be seen that the maximum temperature of the loss coefficient is low, and excellent vibration damping performance can be obtained even at relatively low temperatures.

XJJU soil Example 1: Beoba 10 and/or Beoba 9, acrylic acid (unsaturated carboxylic acid); 5g:0
．． A ternary copolymer of 0694+*ol and a binary copolymer of Iha were obtained. Here, Beoba 10 is 115-206g (0
, 58 to 1.04 sol), Beoba 9 is 43 to 1
0.7 g (0.234 to 0.58 sol). The composition of the obtained copolymer is shown in Table 3.

A vibration damping steel plate was made using the obtained polymer in the same manner as in Example 1, and a vibration damping test was conducted.

As in Example 1, the application of the polymer was extremely easy.

The relationship between the ambient temperature and the loss coefficient of the damping steel plate is shown in Figure 4. The middle part of Figure 0 is No, 8, . is No, 9, Δ is No.

Table 2 Table 3 Table 1 (Hereafter, margin) lOlO indicates the result for No. 11.

From Figure 4, the loss coefficient and maximum temperature are both low: 0
It can be seen that it exhibits high vibration damping performance of 0.1 or higher in the temperature range of ~80°C.

(Effects of the Invention) According to the vibration-damping metal resin composition according to the present invention, the melt viscosity is lowered and coating properties can be improved, so that it can be easily controlled without requiring special coating equipment. It becomes possible to manufacture shaken metal plates.

Furthermore, since damping performance at low temperatures can be improved, a damping metal with excellent damping performance over a wide temperature range can be obtained.

Furthermore, problems such as plasticizer evaporation during coating and plasticizer volatilization when used in high-temperature environments, which occur with plasticizer-added resin compositions, do not occur, so safety and health during coating work can be ensured, and , it becomes possible to achieve long-term stabilization of vibration damping performance.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the ambient temperature and the loss coefficient of the damping steel plate according to Example 1, and FIG. 2 is a diagram showing the relationship between the ambient temperature and the loss coefficient of the vibration damping steel plate according to Example 2. FIG. 3 is a diagram showing the relationship between the ambient temperature and the loss coefficient of the damping steel plate according to Example 3, and FIG. 4 is a diagram showing the relationship between the ambient temperature and the loss coefficient of the vibration damping steel plate according to Example 4. be. Patent applicant: Kobe Steel, Ltd. Representative Patent attorney: Akira Kanemaru - Figure 1 Figure 2 Ambient temperature (0C)

Claims (4)

[Claims] (1) A resin composition for damping metals comprising a vinyl ester copolymer or an unsaturated carboxylic acid copolymer, wherein the copolymer contains a branched fatty acid vinyl ester. Resin composition. (2) A vibration-damping metal resin composition comprising a copolymer of a vinyl ester and an unsaturated carboxylic acid, wherein the copolymer contains a vinyl ester of a branched fatty acid. Composition. (3) the unsaturated carboxylic acid is acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid,
The vibration-damping metal resin composition according to claim 1 or 2, wherein the resin composition is one or more selected from maleic anhydride. (4) The vibration-damping metal resin composition according to the first, second, and third claims, wherein the vinyl ester is vinyl carboxylate.