JPS62196143A - Weldable vibration-damping material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is an allocating material that damps vibrations when they are transmitted, and in particular, exhibits excellent allocating performance even when the material temperature becomes high, and has good allocating properties. This invention relates to vibration damping materials with welding performance.

(Prior Art) In recent years, there has been an increasing demand for vibration-damping materials that destroy vibrations in order to prevent noise pollution caused by vibrations.

Conventionally, this type of material has been made by laminating metal plates such as aluminum plates or steel plates as outer layers on both sides of an intermediate layer made of an insulating polymer material such as butyl rubber or ethylene vinyl acetate copolymer. In addition, most of its applications were at room temperature and did not require welding for fixing, but recently it has been used in a wide range of temperatures, such as in automobile gouche springs and engine oil pans, and it has become difficult to fix. It has also come to be used in applications that use electric resistance welding (hereinafter simply referred to as welding) such as spot welding.

However, conventional damping materials exhibit considerable damping performance when the material temperature is close to room temperature, but as the material temperature increases during use, the vibration damping performance deteriorates. Also, because the intermediate layer is made of an insulating polymer material, it cannot be directly welded.
When welding, an auxiliary electrode had to be used.

For this reason, there has been a demand for the development of a damping material that exhibits excellent vibration allocation performance even when the material temperature exceeds room temperature, and that can be directly welded.

(Problems to be Solved by the Invention) In order to meet such demands, the present invention provides a vibration-damping material that solves the problems of a decrease in allocation performance and welding performance due to an increase in the temperature of the material.

(Means for Solving the Problems) In order to solve the above problems, the present inventors manufactured materials in which graphite powder was mixed as a conductive filler with various polymeric materials as intermediate layers, and used them. As a result of investigating the vibration damping performance and welding performance due to temperature rise of the vibration damping material, it was found that when graphite powder is added to the intermediate layer, vibration damping performance does not deteriorate even when the material temperature rises compared to when graphite powder is not added. They also discovered that by appropriately adjusting the blending amount, particle size, and specific surface area of graphite powder, a short circuit can be formed in the intermediate layer to conduct current through the out-of-plane layer, and welding performance can be imparted.

The present invention was made based on such knowledge, and
On both sides of the intermediate layer of a composition consisting of three components: a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound, and a polyol compound, and graphite powder blended in an amount of 5 to 70 parts by weight based on a total of 100 parts by weight of these three components. Metal plates are laminated as the outer layer, and the graphite powder in the middle layer has an average particle size of 172 or more and 3/2 or less of the thickness of the middle layer, and a specific surface area of 1.
( )lI is 12/9 or less.

The present invention will be explained in detail below.

In the present invention, as described above, the composition is made of a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound, a polyol compound, and graphite powder. , preferably has a hydroxyl group at the molecular end and has a number average molecular weight of 300 to 25.
000, preferably 500 to 10,000, and has a hydroxyl group content of 0.1 to 10 vne.
q/9, preferably about 0.3 to 10 meq/9 is suitable.

Such liquid diene polymers include, for example, diene polymers and diene copolymers having 4 to 12 carbon atoms, and combinations of these diene monomers and α-old fin type addition-polymerizable moamers having 2 to 22 carbon atoms. Copolymers include butadiene homopolymer, imbrene homopolymer, butanoene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate fuborimer, butadiene- Examples include n-octadecyl acrylate copolymer.

These liquid diene polymers can be produced, for example, by subjecting a conjugated diene monomer to a heating reaction in the presence of hydrogen peroxide in a liquid reaction medium.

The polyisocyanate compound is an organic compound having two or more isocyanate groups in one molecule, and has inocyanate groups that are reactive with the hydroxyl groups of the hydroxyl group-containing liquid diene polymer.

Examples of such polyisocyanate compounds include the usual aromatic, III-aliphatic and cycloaliphatic ones, such as tolylene diisocyanate, hexamethylene diisocyanate, nophenylmethane diisocyanate (MDI), liquid Modified diphenylmethane diisocyanate, polymethylene polyphenylisocyanate,
~Silylene diisocyanate, cyclohexylnoisocyanate, cyclohexanephenylene diisocyanate, naphthalene-1,5-diisocyanate, isopropylbenzene-2,4-diisocyanate, polypropylene glycol and tolylene diisocyanate addition reaction products, and the like.

Particularly preferred are MDI, liquid modified nophenylmethanoisocyanate, and tolylene diisocyanate.

Furthermore, as a polyol compound, the molecular weight is 200 to 5.
00, specifically N,N-bis-2-hydroxypropylaniline, N.

Examples include N'-bishydroxyisopropyl-2-methylbiperazine and a propylene oxide adduct of bisphenol A.

Next is graphite powder, which has an average particle size of 172 or more and 372 or less, which is the thickness of the intermediate layer, and a specific surface area of 101112/
9 or less. The reason why the average particle size and specific surface area of the graphite powder are limited in this way is that if the average particle size is less than 172 mm, which is the thickness of the intermediate layer, the composition will not thicken during the production of the intermediate layer composition. This is because it is difficult to form a short circuit between the amphoteric layers by the intermediate layer at a blending amount of 1/2, and when it exceeds 3/2, the graphite powder becomes an obstacle, making it difficult to control the thickness of the intermediate layer. Moreover, if the specific surface area exceeds 101112/9, the composition will thicken during production of the intermediate layer composition. This graphite powder improves the conductivity of the intermediate layer, so
It is preferable to use highly oriented ones.

It is also possible to use carbon black or metal powder instead of graphite powder as the conductive 74, but the former has a very large specific surface area of about 1000II12/9, so it has poor dispersibility, and the latter has poor composition. Dispersion is difficult because there is a large difference in specific gravity with other components of the product.

There are no particular restrictions on the blending ratio of the four components, especially in the case of the three components: the hydroxyl group-containing liquid diene polymer, the polyisocyanate compound, and the polyol compound. However, when blending a polyisocyanate compound with a hydroxyl group-containing liquid diene polymer, the molar ratio of the former hydroxyl group (011> to the latter incyanate group (NGO)) is usually NC01011.
= 0.2 to 2.01, preferably 0.3 to 1.5. This means that this ratio is less than 0.2 or 2.
This is because if it exceeds 0, a cured product cannot be obtained, which is not preferable. The polyol compound is blended in an amount of 5 to 200 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the hydroxyl group-containing liquid diene polymer.

On the other hand, the blending ratio of graphite powder is 5 to 70 parts by weight based on the total of 100 parts by weight of the three components. This blending ratio is 5
If it is less than 7 parts by weight, no short circuit will be formed in the intermediate layer;
If it exceeds 0 part by weight, a short circuit will be formed and the welding performance will be good, but since graphite powder is usually blended with a hydroxyl group-containing liquid diene polymer or polyisocyanate compound during the production of the intermediate layer, the amount of these particles will increase. Sticky and undesirable.

The raw trapping layer of the present invention basically consists of the above four components, but various additives and fillers can be added as necessary.

In particular, polyamine compounds are preferred as the reinforcing agent.

This polyamine compound is not particularly limited and may be any of diamine, triamine, and tetramine. Furthermore, any of primary polyamine, secondary polyamine, and tertiary polyamine can be used. These polyamine compounds include, for example, aliphatic amines such as hexamethylene diamine, alicyclic amines such as 3゜3'-dimethyl 4,4'-diaminodicyclohexylmethane, and aromatic amines such as 4,4'-noamino diphenyl. Examples include amines, tetramines such as 2,4.6-)su(dimethylami7methyl)7enol, and the like. The amount of reinforcing agent added is usually 1 to 10 parts by weight per 100 parts by weight of the hydroxyl group-containing liquid diene Mff1 combination.
00 parts by weight, preferably 3 to 200 parts by weight.

Adding plasticizers such as Nooctyl 7 Talate as a viscosity modifier to the pond, adding softeners such as aromatic, naphthenic, and paraffinic oils, and adding adhesive and adhesive strength.
For i4 adjustment, alkyl 7 ether resin, terpene I (
1lllF, terpene 727-l fat, xylene formaldehyde resin, rosin, hydrogenated rosin, coumaron resin,
Tackifying U4 fats such as aliphatic and aromatic petroleum resins can be added.

It is also possible to add curing accelerators such as dibutyltinnolaurate, stannous octoate, and polyethylenediamine. Furthermore, an anti-aging agent can be added to improve weather resistance, and a silicon compound or the like can be added as an antifoaming agent.

As fillers, mica, vermiculite, calcium carbonate, slate powder, feldspar, silicic acid, white glaze, etc. can also be added.

The intermediate layer of the present invention is manufactured by measuring the blending amount, mixing graphite powder in advance with a hydroxyl group-containing liquid diene polymer or polyisocyanate compound, and then kneading it with the other two components.

The kneading may be carried out by a commonly used method, such as a mixing type casting machine. When using a mixing type casting machine, the crosstalk conditions are a temperature of 0 to 150°C, preferably 10 to 120°C.
C for 0.1 seconds to 1 hour, preferably 0.5 minutes to 10 minutes.

Next, regarding the outer layer metal plate, there are no particular restrictions on the metal plate, such as cold-rolled steel plate, stainless steel plate, or plated steel plate plated with metal or alloy (for example, zinc-plated steel plate, aluminum-plated steel plate).・ Steel plates such as coated steel plates, copper-based plated steel plates, chrome-plated steel plates) and painted steel plates,
Alternatively, it can be made of a non-ferrous metal plate such as a copper plate or an aluminum plate. Even if there is a chemical conversion film such as a phosphate film or a chromate film, a paint film such as a coated chromate film, or a paint film such as a primer on the laminated side of the metal plate, good.

In the present invention, outer layers are laminated on both sides of the intermediate layer as described above, but various lamination methods are suitable for application. The most common method is to inject the composition as an intermediate layer between the metal plates that will be the outer layer, or to supply the composition to one metal plate and then press the other metal plate sequentially from one side. This is a method in which both layers are laminated in advance, pressure is applied between a pair of pressure rolls set at a predetermined interval, and then the material is cured.

This curing is performed by leaving it at room temperature for 0.1 to 24 hours. After curing 30-150°C1 preferably 40-1
Heat curing is performed at 20° C. for 0.1 to 24 hours, preferably 0.5 to 10 hours.

The thickness of the intermediate layer and outer layer of the damping material may be determined as appropriate depending on the purpose of use, but generally the thickness of the intermediate layer is 20 to 300 μm.
, preferably 30-200μ, and both outer layers each have a thickness of 0.0μ.
1-10 mm, preferably 0.5-5II11. Note that both outer layers may have the same thickness or may have different thicknesses.

Next, the present invention will be explained with reference to examples.

(Example) First, each component shown in Table 1 was blended in a predetermined amount and kneaded under the conditions shown in Table 1 using a mixing type casting stone to produce a composition that would become an intermediate layer. In addition, 78 parts by weight of graphite powder is a total of 3 components: hydroxyl-terminated liquid polybutadiene, diphenylmethane twin doanate, and polyol compound.
When converted to the blending amount for 00 parts by weight, the amount is 26.1 parts by weight, and 10 parts by weight is 3.3 parts by weight.

This composition was applied to a dog at a temperature of 25°C with a thickness of 0.8 mm.
After injecting the mixture between two steel plates of m, the mixture was passed between a pair of pressure rolls at a predetermined interval to give an intermediate layer thickness of 100 μm.

Thereafter, the resulting laminate was left to stand at room temperature for 2 hours to harden, and was further heated and cured at 70° C. for 15 hours.

The resonant performance of the resonant material manufactured in the manner described above was evaluated using a loss coefficient measurement method using the resonance method.

The results are first shown in FIG.

Next, a steel plate of the same thickness as the outer layer was applied to the lower side of the vibration-damping material, and the welding current was 10,000 A, the welding time was 15 cycles, and the welding force was 250 kg%, and the tip diameter was 5 m + as shown in Figure 2.
Direct spot welding was performed under the conditions of a, and the maximum tensile shear load of the weld was measured. This result! @1 Shown below the table. In FIG. 2, 1 is a damping material, 2 is a steel plate, and 3 is a chip.

Note 1 to Table 1: Idemitsu Petrochemical Co., Ltd. II, rR-45HTJ
Number average molecular weight 2800, hydroxyl group content i 0.79Iae
q/9 Note 2... Incyanate group content 28.2% by weight Note 3... Propylene oxide adduct of bis7er7-A (manufactured by Nippon Nyukazai Co., Ltd., rB A P-3J)
Note 4...N,N-bis-2-hydroxypropylaniline (manufactured by Kasei Upzidine Co., Ltd., 1lsonol C-1
00J) Note 5--Nooctyl 7 tallate Note 6 ・2,2'-methylenebis(4-methyl-6
-t-butylphenol) Note 7... Pentaerythrityl-tetrakis [(3,5
-di-t-butyl-4-hydroxy7enyl)propionate 1 Note 8...2-(,3,5-not-t-butyl-2-hydroxyphenyl)-5-chloropenttriazole Note 9...・Nobutyltin dilaurate Note 10: Made by Kyowa Carbon Co., Ltd., highly oriented graphite [POG200J, average particle size 64 μm, specific surface area 3,0I6279 attention...
・Highly oriented graphite 1-PO manufactured by Kyowa Carbon Co., Ltd.
20J average particle size 9μm, specific surface area 5. O+n2/9 Note 12 ・
・・Manufactured by Japan Synthetic Rubber Co., Ltd., [JSRButye 05
As is clear from Figure 1 of 6J, even if the composition of the intermediate layer is made up of only three components, such as the hydroxyl group-containing liquid diene polymer, the polyisocyanate compound, and the polyol compound, as in Comparative Example 3, it is more resistant to temperature rise than the conventional material in Comparative Example 4. The damping performance is considerably improved, but it is further improved when graphite powder is added as in the present invention.

Furthermore, as is clear from Table 1, even if the average particle size of the graphite powder blended into the composition of the intermediate layer is within the range of the present invention as in Comparative Example 1, if the blended amount is out of range, welding will not be possible and the same will occur. Even if the blending amount is within the range of the present invention as in Comparative Example 2, welding cannot be performed if the average grain size is out of range.

(Effects) As described above, the damping performance of the vibration damping material of the present invention does not deteriorate compared to conventional materials even when the temperature rises, and welding is also possible. Therefore, it can be used for parts such as automobile parts whose temperature tends to rise easily.

[Brief explanation of drawings]

FIG. 1 is a graph showing the allocation performance of the damping material as a result of temperature rise, and FIG. 2 shows the method of welding the damping material in the example.

Claims (1)

[Claims] On both sides of the intermediate layer of a composition consisting of three components: a hydroxyl group-containing liquid diene polymer, a polyisocyanate compound, and a polyol compound, and graphite powder blended in an amount of 5 to 70 parts by weight based on a total of 100 parts by weight of these three components. Metal plates are laminated as the outer layer, and the graphite powder in the middle layer has an average particle size of 1/2 or more and 3/2 or less of the thickness of the middle layer, and a specific surface area of 1.
A weldable vibration damping material characterized by having a vibration damping property of 0m^2/g or less.