JPH0328234A - Vibration-damping material - Google Patents

Abstract

PURPOSE:To obtain a vibration-damping material decreased in a temperature shift and improved in vibration-damping properties by mixing a resin based on a room temperature curing liquid epoxy resin with mica and chopped glass strands. CONSTITUTION:A vibration-damping material prepared by mixing a resin based on a room temperature curing liquid epoxy resin with mica and chopped glass strands. An example of the resin used is a mixture comprising a room temperature curing liquid epoxy resin such as bisphenol A epoxy resin or bisphenol F epoxy resin, a polyamideamine and a polyamine. The mixing ratio of the resin to mica and chopped glass strands is desirably such that 25-200 pts.wt. total of mica and chopped glass strands is used per 100 pts.wt. resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration damping material that reduces temperature shift and improves vibration damping performance.

[Conventional technology]

Conventionally, vibration damping materials have been used as parts of automobiles and the like to absorb sound and vibration.

This damping material is made of powdered mica (mica) added to the resin.
This is achieved by blending it as a filler.

However, damping materials containing mica in this way have the disadvantage of a large temperature shift ΔT. In other words, as shown in Figure 2, mica? The mixture has a maximum value η of loss coefficient η representing vibration damping performance. 18 at temperature T1, but at temperature T. At the required temperature T0, which is usually lower than η,
, 8, if you want to achieve temperature shift material $4 (
For example, add a diluent) and adjust the temperature to △T (=TT0).
only have to be lowered. In this case, η. (2) decreases by Δη and becomes η say. Therefore, when the temperature shift ΔT is large, Δη becomes large, and as a result,
There is a problem that vibration damping performance deteriorates.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a damping material in which the temperature shift ΔT is reduced and the absolute value of −Δη generated at that time is made as small as possible.

[Means to solve the problem]

The vibration damping material of the present invention is characterized in that it is made by blending mica and chopped glass strands into a resin that is mainly a liquid epoxy resin that hardens at room temperature.

This means will be explained in detail below.

The resin used in the present invention is mainly a liquid epoxy resin that hardens at room temperature, and may be one that is normally used as a component of vibration damping materials, such as bisphenol A.
It is a mixed resin consisting of a room temperature curing liquid epoxy resin such as type epoxy resin or bisphenol F type epoxy resin, polyamide amine, and polyamine.

In the present invention, the mica blended into this resin may be a powdered type commonly used for vibration damping materials (mica powder).
. Further, the glass chopped strand is made of an aggregate of a plurality of cut glass fibers. For example, the glass fiber has a filament diameter of 5 to 12 μm and a length of 3 to 2 μm.
It is of size 51 and has an anosilane-based cassophage ring surface treatment.

Although the blending ratio of mica and glass strands to the resin is not specified, the resin is 100%
The total amount of mica and glass chopped strands may be about 50 parts by weight based on the weight of the mica and glass chopped strands. The total amount of land is preferably 25 parts by weight to 200 parts by weight. If it is less than 25 parts by weight, it will not be possible to obtain a sufficiently large damping performance η, and the performance as a damping material will not be exhibited. On the other hand, if it exceeds 200 parts by weight, there will be problems with mixability and the strength of the cured product will be reduced. decreases,
Becomes vulnerable. Further, the respective blending amounts of mica and glass chopped strands are preferably 20 parts by weight to 150 parts by weight of mica and 5 parts by weight to 50 parts by weight of glass chopped strands, based on 10 parts by weight of resin.

In addition to these mica and glass chopped strands, additives such as colorants and diluents may be appropriately blended as necessary.

As shown in FIG. 1, the distributed material of the present invention made in this way has a difference ΔT' (=T, '-70') between the temperature T at which η■8 is reached and the required temperature T0'. It is smaller than the above ΔT (ΔT′ minus ΔT). Therefore, the difference Δη between η■8 at temperature T1' and η″■ at the required temperature T0'
' becomes smaller than the above-mentioned Δη (Δη′<Δη).

Examples are shown below.

〔Example〕

The following distribution materials were produced, and the relationship between temperature and loss coefficient η was measured for these distribution materials by the following method. The results are shown in FIGS. 3 to 6.

of, operation: 9 mm thick iron $iss41 (dimensions 500 mta
A damping material/vibration member composite sample is prepared by applying the damping material to 16 mta of the damping material (30 IIn).

This sample is placed in a constant temperature bath maintained at a constant temperature T7, and the center of the sample is subjected to sine wave vibration using a vibrator. The impedance head detects the response acceleration and load at this time, and the FTP analyzer determines the transfer function. From this transfer function, the loss coefficient η is determined by the half-width at the resonance point f7.
seek.

■ Conventional allocation material 1.

Bisphenol A type epoxy resin (manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent: 180-200) 100 parts by weight? Contains 56 parts by weight of mica powder.

The measurement results are shown in Figure 3. As can be seen from FIG. 3, the peak temperature (temperature T,) at which the maximum value η,%ax=0.18 of the loss coefficient η is achieved is 32°C.

■ Damping material 1 of the present invention.

Bisphenol A type epoxy resin (manufactured by Asahi Denka Kogyo Co., Ltd., il 180-200” per epoxy) 100 fft
38 parts by weight of mica powder and 18 parts by weight of glass chopped strands (total amount: 56 parts by weight).

The measurement results are shown in Figure 4. As can be seen from FIG. 4, the peak temperature (temperature T1') at which the maximum value η■Eo,18 of the loss coefficient η is achieved is 30"C.

■ Conventional allocation material 2.

84 parts by weight of mica powder was mixed with 100 parts by weight of bisphenol A type epoxy resin (manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent: 180-200).

The measurement results are shown in Figure 5. As can be seen from FIG. 5, the maximum value η■ of the loss coefficient η. The peak temperature (temperature T,) that achieves =0.22 is 35°C.

■ Damping material 2 of the present invention.

? Sphenol A type epoxy resin (manufactured by Asahi Denka Kogyo Co., Ltd., epoxy equivalent: 180-200) 56 parts by weight of mica powder and 28 parts by weight of glass chosoplast strands were mixed with 100 parts by weight of ffl (total amount: 84 parts by weight).

The measurement results are shown in Figure 6. As can be seen from FIG. 6, the maximum value η of the loss coefficient η. ．． ．． The peak temperature (temperature T,') at which T = 0.22 is achieved is 31°C.

As can be seen from FIGS. 3 to 6, the peak temperature at which the damping material of the present invention reaches the maximum value η■ is lower than that of the conventional damping material containing only mica powder as a filler. Therefore, since the temperature shift is reduced, vibration damping performance can be improved.

〔Effect of the invention〕

As explained above, since the distribution material of the present invention is made by blending both the resin and the glass chopped strand into the resin, it can exhibit the following effects.

(1) Since the temperature shift becomes smaller, vibration damping performance can be improved.

? 2) Good filling efficiency eliminates the need for high loading.

That is, in order to achieve a certain target value of η■U, if mica powder is used alone, 56 parts by weight of mica powder must be filled into 100 parts by weight of epoxy resin. On the other hand, when glass chosopdo strands and mica powder are used together, the total amount is 56 parts by weight (38 parts by weight of mica powder, 18 parts by weight of glass chosopdo strands and 1-land), but the filling efficiency is lower than that of glass. Chosopdo strands are more expensive than mica powder, so they are essentially 56X0.7-0.8 (based on mica alone). = 39 to 45 parts by weight of filler can be added to the same viscosity. Therefore, the processability of the finished material is better than that of a material containing mica powder alone.

(3) Since the temperature shift is small, the formulation can be simplified, making it easier to maintain η■8.

[Brief explanation of drawings]

1 to 6 are relationship diagrams between temperature and loss coefficient for vibration damping materials.

Claims (1)

[Claims] A damping material made by blending mica and chopped glass strands with a resin that is mainly a liquid epoxy resin that hardens at room temperature.