JPH0475935B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a vibration damping material, and more specifically, it has a large dynamic elastic modulus and a large loss coefficient, and is used as a core or intermediate layer of a vibration damping composite laminate, and is made by adding a filler. The present invention relates to a vibration damping material that exhibits excellent vibration damping performance and also has excellent heat resistance when used as a vibration damping composite composition. (Prior Art) Conventionally, various resin compositions have been developed that utilize internal friction caused by shear deformation of viscoelastic substances in order to suppress or prevent noise and vibration generated from various mechanical devices, electrical devices, structures, etc. Damping materials made of materials have been proposed or put into practical use. Typical thermoplastic resins such as polyethylene and polypropylene are already known as such damping materials. A vibration damping material has been disclosed, and also published in
No. 43251 and JP-A No. 54-43252 disclose vibration damping materials containing polyisobutylene as a main component and blending this with a diene hydrocarbon polymer or cyclic olefin polymer and an inorganic filler. has been done. However, all of these conventional damping materials do not have sufficient damping performance and have poor heat resistance, making it difficult to use them as vibration damping laminates at high temperatures, or for baking-painted materials. There is a problem that it cannot withstand high temperature processing such as (Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems in vibration damping materials, and provides a vibration damping material that has excellent vibration damping performance and excellent heat resistance. The purpose is to provide (Summary of the Invention) The damping material according to the present invention comprises 3 to 30% of a viscous to semisolid hydrocarbon having a number average molecular weight in the range of 200 to 2,000 per 100 parts by weight of a 4-methyl-1-pentene polymer. It consists of a composition containing 30 parts by weight, and has a heat distortion temperature of 160°C or higher and a temperature of 25°C.
The loss coefficient is 0.08 or more, and the dynamic elastic modulus is 1×10 ⁹ dyn/cm ² or more. (Means and effects for solving the problems) The 4-methyl-1-pentene polymer used in the present invention includes a homopolymer of 4-methyl-1-pentene, and a 4-methyl-1-pentene homopolymer. Contains a copolymer with a small amount of other α-olefin components, and such copolymer has an intrinsic viscosity [η] measured in decalin at 135°C in the range of 1 to 5 dl/g. Preferably, especially 1.5 to 3 dl/g
It is preferable that it is in the range of . The above α-olefins include α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, Examples include 1-hexadecene and 1-octadecene. The content of these α-olefin components in the 4-methyl-1-pentene polymer is usually
It is in the range of 0.5 to 4 mol%. Next, the viscous hydrocarbons used in the present invention include viscous hydrocarbons and semisolid hydrocarbons having a number average molecular weight at 25°C in the range of 200 to 2000, preferably 300 to 1500. Specific examples include relatively low molecular weight ethylene/propylene copolymers, ethylene/α-olefin copolymers such as ethylene/1-butene copolymers, relatively low molecular weight butadiene polymers, isobutylene polymers, Examples include isoprene polymers, decene polymers, hydrides thereof, squalane, squalene, low polymers thereof, and liquid paraffin. When the number average molecular weight of the above-mentioned viscous to semi-solid hydrocarbon is larger than 2000, the vibration damping performance is insufficient.On the other hand, when it is smaller than 200, it is used as a 4-methyl-1-pentene polymer. melting,
It will volatilize during kneading. The damping material according to the present invention has the above-mentioned 4-methyl-1-
It consists of a composition containing 3 to 30 parts by weight of the above-mentioned viscous to semi-solid hydrocarbon per 100 parts by weight of the pentene polymer. When the content of slimy or semi-solid hydrocarbons in the damping material is less than the above range, its damping performance is still insufficient, while when the content exceeds the above range, the heat distortion temperature As a result, the hydrocarbons in the form of viscous or semi-solid bleed out onto the surface of the composition, resulting in a decrease in handling properties. Furthermore, the damping material made of the composition as described above is
Its heat distortion temperature is over 160℃ and 25℃
The loss coefficient (tan δ) is required to be 0.08 or more, and the dynamic elastic modulus (E') is required to be 1×10 ⁹ dyn/cm ² or more. Here, the heat distortion temperature refers to the temperature when the sample is penetrated 0.1 mm when the sample is heated at a temperature increase rate of 5°C/min with a load of 49 g according to the penetration test method, for example,
It can be measured by a Dupont 990TMA device. When this heat distortion temperature is lower than 160℃,
Since the damping material has poor heat resistance, it is difficult to use it as a vibration damping laminate at high temperatures, and it also has the problem of not being able to withstand high-temperature treatments such as baking painting. The loss coefficient refers to tan δ at a frequency of 110 Hz and a dynamic displacement of 1.6 × 10 ^-3 cm according to the Vibron method. If the loss coefficient is smaller than 0.1 at 25°C, the damping performance is not sufficient. In addition, the dynamic elastic modulus refers to the storage elastic modulus (E') at a frequency of 110 Hz and a dynamic displacement of 1.6 x 10 ^-3 cm using the Vibron method, and the dynamic elastic modulus at 25°C is 1 x 10 ⁹
When it is smaller than dyn/ ^cm2 , for example, when this damping material is laminated between metal plates to form a composite laminate, the damping performance against vibrations, especially in the high frequency range, is insufficient, and furthermore, The shape retention of such a composite is reduced, and the deep drawability when producing a vibration damping material by press working is reduced. The damping material according to the present invention can be used, for example, as a core or an intermediate layer in a composite laminate for vibration damping, and
It can be suitably used as a vibration damping composite composition containing a filler. First, the use as a core in a vibration damping composite laminate will be explained. When used as a core, the structure of the composite laminate is not limited in any way, but a preferred example is a composite laminate having a structure in which the damping material is interposed between opposing metal plates. I can do it. When used as such a core, the thickness of the core is usually preferably in the range of 0.05 to 0.5 mm. In addition, as the metal plate in the composite laminate, iron, steel,
Examples include copper, aluminum, stainless steel, brass, etc. The thickness of these metal plates is not particularly limited, but is usually in the range of 0.1 to 2 mm, preferably 0.2 to 0.5 mm. The damping material according to the invention may contain modified polyolefin, for example to improve adhesion to metals. Such modified polyolefins include, for example, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, citraconic acid, bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid, or the like. A copolymer obtained by graft copolymerizing an unsaturated carboxylic acid derivative consisting of an acid anhydride, salt, or ester with a polyolefin can be suitably used. Here, the above-mentioned polyolefin includes, for example, polyethylene,
Homopolymers of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, etc. and copolymers thereof. The grafting ratio of the unsaturated carboxylic acid derivative component units in these modified polyolefins is usually in the range of 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the polyolefin. Further, the content of the modified polyolefin in the vibration damping material is as follows:
Usually 5 parts by weight per 100 parts by weight of the pentene polymer.
-20 parts by weight, preferably 5-10 parts by weight. Further, the vibration damping material according to the present invention may contain an inorganic filler, if necessary, in order to improve vibration damping properties and rigidity, or to suppress flow-out of the polymer during baking coating. Examples of such inorganic fillers include graphite, mica, titanium oxide, zinc white, clay, calcium carbonate, magnesium carbonate, and carbon black. The blending amount of such an inorganic filler is usually in the range of 10 to 400 parts by weight per 100 parts by weight of the 4-methyl-1-pentene polymer. Various methods of manufacturing such vibration-damping composite laminates are already known. For example, a vibration-damping composite laminate can be obtained by thermocompression-bonding a sheet-like damping material between metal plates, or by adhesively laminating the sheet-like damping material between metal plates using an appropriate adhesive. Next, use as a vibration damping composite composition made by blending an inorganic filler with the vibration damping material according to the present invention will be explained. As the inorganic filler, as mentioned above, graphite, mica, titanium oxide, zinc white, clay, calcium carbonate, magnesium carbonate, lead, carbon black, etc. are preferably used.
Similarly to the above, the amount is usually 10 to 400 parts by weight, preferably 10 to 200 parts by weight, per 100 parts by weight of the 4-methyl-1-pentene polymer. If necessary, other polymers, e.g. ethylene/α
- Olefin copolymer, propylene/α-olefin copolymer, 1-butene/α-olefin copolymer, ethylene/propylene/diene copolymer,
Polyisobutylene, butyl rubber, NBR, ethylene/vinyl acetate copolymer, the above-mentioned unsaturated carboxylic acid-modified polyolefin, etc. can also be blended. In this way, when the unsaturated carboxylic acid-modified polyolefin is blended into the damping material according to the present invention,
The adhesion and affinity between the 4-methyl-1-pentene polymer and the inorganic filler are improved, and the adhesion of the composite composition to metals is also improved. The amount of the other polymer containing the modified polyolefin is usually 5 to 20 parts by weight, preferably 5 parts by weight, based on 100 parts by weight of the 4-methyl-1-pentene polymer.
~10 parts by weight. Such a vibration-damping composite composition is obtained by melt-kneading a mixture consisting of the above-mentioned components, and is used, for example, in printer housings, speaker boxes, transportation equipment, and other various office equipment such as electronic computers. Used for forming products and parts that require vibration damping properties, such as soundproof sheets. (Effects of the Invention) As described above, the vibration damping material according to the present invention is a composition containing a 4-methyl-1-pentene polymer and a slimy to semisolid hydrocarbon having the above-mentioned predetermined properties. As a result, its damping performance is significantly improved compared to conventional damping materials, and it also has excellent heat resistance. (Example) The vibration damping material according to the present invention will be described below with reference to Examples. Example 1 Squalane and (manufactured by Wako Pure Chemical Industries, Ltd.) 10
Add parts by weight and mix with a Brabender mixer.
A 4-methyl-1-pentene polymer composition was prepared by mixing at 250°C. The heat distortion temperature of a press-formed sheet made of this composition is 188°C, the loss coefficient (tan δ) at room temperature is 0.165, and the dynamic elastic modulus (E') is 2.43×
It was ¹⁰⁹ dyn/ ^cm2 . (Manufacture and evaluation of composite laminate for vibration damping) In order to evaluate the vibration damping properties of a laminate using the above polymer composition, a laminate (galvanized iron plate/polymer composition/galvanized iron plate = 450μ/ 500μ/450μ) were produced. For adhesion between the galvanized iron plate and the polymer composition, a 20μ thick film made of a copolymer obtained by graft copolymerizing maleic anhydride to a 4-methyl-1-pentene polymer was attached to the iron plate and the polymer composition. This was done by laminating an adhesive film between the objects. Evaluation of vibration damping performance is given in the Journal of Japan Rubber Association, Volume 51.
As described on page 222 (1978), we constructed a device capable of measuring the two-suspended resonance damping method and determined the logarithmic damping ratio at various frequencies. The attenuation rate is
"Noise Handbook" (edited by the Japan Acoustic Materials Association, 1968)
It was determined according to the method described in page 433 (published by Gihodo Co., Ltd.). The test piece was a laminate with a length of 300 mm, a width of 30 mm, and a thickness of 1.4 mm. 100Hz and
The logarithmic attenuation rate at 1000Hz is 0.017 and 0.129, respectively.
It was hot. Examples 2 to 7 As shown in the table, various viscous to semisolid hydrocarbons were blended with the 4-methyl-1-pentene polymer, and sheets and composite laminates were prepared in the same manner as in Example 1. I got it. The heat distortion temperature, loss coefficient (tan δ), and dynamic elastic modulus (E') of each sheet are shown in the table. In addition, the vibration damping performance of the composite laminate is shown in the table. Comparative Example 1 A sheet and a composite laminate were obtained using only the same 4-methyl-1-pentene polymer as in Example 1. Heat distortion temperature and loss coefficient (tanδ) of this sheet
and dynamic elastic modulus (E′) are shown in the table. In addition, the vibration damping performance of the composite laminate is shown in the table. Comparative Examples 2 to 4 The 4-methyl-1-pentene polymer shown in the table was blended with a slimy to semi-solid hydrocarbon in an amount outside the range specified by the present invention, and the same procedure as in Example 1 was carried out. A sheet and a composite laminate were obtained. Heat distortion temperature, loss coefficient (tanδ) and dynamic elastic modulus (E′) of each sheet
are shown in the table. In addition, the vibration damping performance of the composite laminate is shown in the table. Example 8 Same polymer composition as Example 1 with 50% lead powder by weight
A press plate with a thickness of 10 mm was prepared.

【table】

[Table] The transmission loss of this press plate for 1KHz sound is
It was 42dB. Comparative Example 5 50% by weight of lead powder was blended with the same 4-methyl-1-pentene polymer as in Example 1, and a 10 mm thick press plate was produced in the same manner as in Example 8. The transmission loss of this press board for 1KHz sound was 31dB.

Claims (1)

[Claims] 1 A composition containing 3 to 30 parts by weight of a viscous to semisolid hydrocarbon having a number average molecular weight in the range of 200 to 2,000 per 100 parts by weight of a 4-methyl-1-pentene polymer; Deformation temperature is 160℃
In addition to the above, the loss coefficient is 0.08 at 25℃
A damping material having the above characteristics and having a dynamic elastic coefficient of 1×10 ⁹ dyn/cm ² or more.