JP3383995B2 - Vibration energy absorber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention improves the operation response speed and measurement accuracy by controlling vibrations in various transportation equipment, precision electronic equipment, audio equipment and the like. The present invention relates to a polyolefin-based vibration energy absorber excellent in vibration energy absorption performance used for improving sound quality. [0002] Conventionally, butyl rubber is most often used as a vibration energy absorbing material. Also, recently, polynorbornene and special urethane-based elastomers have been found to have higher performance and have attracted attention. [0003] The primary evaluation of these vibration energy-absorbing materials is based on storage elastic modulus (E ') and loss coefficient (tan δ = loss elastic modulus (E ") / obtained by measuring the viscoelasticity of the material.
(Storage modulus (E ')). In order to design as a vibration energy absorbing material, the larger the loss coefficient is, the more the storage modulus has an optimum value depending on the form used. [0004] These two factors are usually highly temperature dependent. That is, the storage elastic modulus gradually decreases as the temperature increases, and sharply decreases from a temperature range usually exceeding the glass transition point. Further, the loss coefficient shows the highest value in a temperature range exceeding the glass transition point, but generally tends to decrease in a temperature range around the glass transition point. [0005] Therefore, conventionally, as a criterion required for such a vibration energy absorbing material, a high loss coefficient is firstly obtained in a temperature range in which the material is used. [0006] In this respect, since the polyolefin resin is a crystalline resin, the contribution of the micro-Brownian motion of the amorphous portion in the glass transition region is small. And a very low loss factor peak value. On the other hand, polyolefin resins can be used in a wide range of applications such as films, sheets and molds in various industrial fields because of their excellent performance / price ratio and moldability. In particular, polyolefin resins having high crystallinity, such as polypropylene, have high rigidity and are therefore often used for various industrial parts, automobiles, home appliances, and OA / FA. In these fields, texture, reliability,
Although there is a strong demand for suppression of vibration from the demand for improvement of response speed and the like, as described above, only a low loss coefficient is obtained at present, so that it is widely used. [0007] Also, many attempts have been made to impart vibration energy absorption performance by adding various fillers typified by mica / graphite to a polyolefin-based resin. However, the improvement effect is small. Also, a number of compositions containing a plasticizer represented by a polycarboxylic acid ester have been studied. You will lose. [0008] Therefore, it is desired to impart vibration energy absorption performance to a polyolefin-based resin while maintaining characteristics such as high rigidity, and to increase the loss coefficient in the operating temperature range. SUMMARY OF THE INVENTION The present invention relates to a polypropylene
While taking advantage of the high rigidity characteristic of len-based resins ,
An object of the present invention is to provide a polyolefin-based vibration energy absorber having excellent vibration energy absorption performance. Means for Solving the Problems In view of the above situation, the present inventors have made intensive studies and as a result have completed the present invention. [0011] That is, the present invention relates to a glass transition region.
Having a Young's modulus of at least 1 × 10 ⁸ Pa
Alicyclic hydrogenated petroleum resin 5
Vibration energy absorbing material obtained by adding up to 70 parts by weight, having a peak value of a loss coefficient (tan δ) of 0.1 or more and a Young's modulus at a peak temperature of 5 × 10 ⁸ Pa or more. About materials . Hereinafter, the details will be described. The polypropylene resin used in the present invention has a Young's modulus in the glass transition region of 1 × 10 ⁸ Pa.
Polypropylene resin having the above, such a
Examples of polypropylene resins include Tosoh Polypro
J5040B (trade name; manufactured by Tosoh Corporation) is marketed
I have. On the other hand, the alicyclic hydrogenated petroleum tree used in the present invention
Fat is a tackifier resin, and a polyolefin resin.
Compatibility with the resin, and also taking into account the weather resistance of the resulting shaped body of a material obtained by adding the resin to the polyolefin resin
It is. Particularly preferred is an ester of tetrahydroabietic acid or an alicyclic hydrogenated petroleum resin having a hydrogenation ratio of 95% or more. The temperature showing a high loss factor by the softening point, the addition amount of the resin is different, softening point in order to express the loss factor near 10 to 100 ° C. is preferably 140 ° C. or less, more preferably 40 ° C. to 100 It is below ° C.
The addition amount is 5 parts per 100 parts by weight of the polypropylene resin.
The amount is from 70 to 70 parts by weight, preferably from 5 to 50 parts by weight, particularly preferably from 5 to 30 parts by weight. If the amount is less than 5 parts by weight, the effect of improving the loss coefficient is low, and if it exceeds 70 parts by weight, the tackiness becomes remarkable, and the workability and post-process workability are undesirably impaired. The above composition has a loss coefficient peak value of 0.1 or more, and a Young's modulus at a temperature at which the peak value is attained is 5 × 10 ⁸ Pa or more. When the loss coefficient at the operating temperature is less than 0.1, the effect is low, and when the Young's modulus is less than 5 × 10 ⁸ Pa, the rigidity is hardly high. The workability can be improved by compounding the tackifier resin with the polyolefin resin,
The effect of improving heat sealability has been found. However, the effect of improving the vibration energy absorbing performance as shown in the present invention has not been found, and the vibration energy absorbing material of the present invention does not significantly impair the rigidity of the polypropylene resin . Further, in addition to the above substances, the vibrational energy absorbing material of the present invention may further include, if necessary, an inorganic filler such as calcium carbonate, talc, clay, silica, mica, carbon black, and an antioxidant. A fuel, a lubricant and the like may be added to such an extent that the performance is not extremely reduced. The vibration energy absorbing material according to the present invention is made of poly
May also be directly molded that the alicyclic hydrogenated petroleum resin in the propylene resin by dry blending, a high concentration of fat
Polypropylene master batch containing alicyclic system hydrogenated petroleum resin
It may be molded by blending with a pyrene-based resin . The molding method is a conventional polyolefin resin molding method such as an inflation method, a T-die processing method, an extrusion lamination method such as an extrusion lamination method, an injection molding method, a blow molding method, a vacuum molding method or the like. It can be molded freely. The vibration energy-absorbing material obtained according to the present invention is used for supporting members of equipment such as precision electronic equipment and precision measuring equipment, etc., whose accuracy is affected by vibration, fixing members such as packing and gaskets, and sound. In addition to being used for laminated members and chassis of equipment and the like, it can also be used for flywheels and gears. In addition, it can be directly attached to highly vibrating parts such as automobiles and industrial equipment to suppress vibration,
Used for the legs of precision equipment to prevent transmission of vibration from the floor, and used in combination with other materials such as metal materials such as stainless steel plates and aluminum plates, wood, inorganic materials, etc. You can also. EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples. Example 1 Polypropylene (Tosoh Polypro J5040B, manufactured by Tosoh Corporation), Young's modulus at peak loss factor 3.3
× 10 ⁹ Pa ) 100 parts by weight and 10 parts by weight of an alicyclic hydrogenated petroleum resin (Alcon P-90, manufactured by Arakawa Chemical Industry Co., Ltd.) with a twin-screw kneader (Laboplast Mill, Toyo Seiki Co., Ltd.)
Was mixed at 190 ° C. for 5 minutes to obtain a mixture. This was pressed for 10 minutes with a press molding machine at 190 ° C., and cooled for 5 minutes at 30 ° C. to obtain a target sheet-like vibration energy absorbing material. Example 2 The same operation as in Example 1 was carried out except that 30 parts by weight of the alicyclic hydrogenated petroleum resin was used to obtain an intended sheet-like vibration energy absorbing material. Comparative Example 1 Only the polypropylene used in Example 1 was processed in exactly the same manner as in Example 1 to obtain a sheet-like molded product. [Evaluation of Loss Factor (tan δ)]
Using the sheet (thickness 1 mm) obtained in the comparative example, the rate of temperature rise was measured by a viscoelastic analyzer RSAII (manufactured by Rheometrics Fast-East), which is a measuring device based on the non-resonant forced vibration method. 2 ° C / min, measurement frequency 10Hz
Was used to measure the loss factor. Table 1 shows the peak value of the loss coefficient at this time, and the temperature and Young's modulus at that time. [ Table 1] As is apparent from the above invention, according to the present invention, the Young's modulus in the glass transition region is 1 × 10 ^8.
Alicyclic hydrogenation on polypropylene resin having Pa or more
By compounding petroleum resin , a vibration energy absorbing material having a high loss coefficient can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 23/02-23/24 F16F 15/02 WPI (DIALOG)

Claims (1)

(57) [Claims 1] A Young's modulus in a glass transition region is 1 × 1.
100 weight of polypropylene resin having 0 ⁸ Pa or more
Of the alicyclic hydrogenated petroleum resin per part by weight to a vibration energy absorbing material, and a loss coefficient (t
a vibration energy absorbing material having a peak value of an δ) of 0.1 or more and a Young's modulus at a peak temperature of 5 × 10 ⁸ Pa or more.