JPH0521147B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to vibration damping materials, and more specifically, the present invention relates to vibration damping materials that utilize a novel polymer composition that has large dynamic elastic modulus and loss coefficient, as well as excellent heat resistance and high elastic modulus. Regarding vibration damping materials. (Prior Art) Conventionally, various resin compositions have been developed that utilize internal friction caused by shear deformation of viscoelastic materials 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 low heat resistance, making it difficult to use them as vibration damping laminates at high temperatures, or they cannot be used with baked-on coatings. There is a problem that it cannot withstand high temperature processing such as Furthermore, there is also the problem of poor workability due to the small elastic modulus. (Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems in vibration damping materials, and has not only excellent vibration damping performance but also excellent heat resistance and workability. The purpose is to provide excellent vibration damping materials. (Summary of the invention) The damping material according to the present invention has an isobutylene content of 90 mol% or more based on 100 parts by weight of the 4-methyl-1-pentene polymer, and the vibration damping material was measured in diisobutylene at 20°C. Polyisobutylene elastic polymer with an intrinsic viscosity in the range of 0.6 to 4 dl/g 20~
It consists of a composition containing 200 parts by weight, has a heat distortion temperature of 100°C or higher, a loss coefficient of 0.06 or higher at 25°C, and a dynamic elastic modulus of 1×
It is characterized by being 10 ⁹ dyn/cm ² or more. (Means and effects for solving the problems) The 4-methyl-1-pentene polymer used in the damping material according to the present invention includes 4-methyl-1-
Contains a homopolymer of pentene and a copolymer of 4-methyl-1-pentene and a small amount of other α-olefin components, and has an intrinsic viscosity [η] of 1.0 to 1.0 when measured in decalin at 135°C. It is necessary to be in the range of 5.0 dl/g, and preferably in the range of 1.5 to 3.0 dl/g. 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, 1-hexadecene, 1-octadecene, etc. can be mentioned. 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%. The polyisobutylene-based elastic polymer used in the present invention must have an isobutylene content of 90 mol% or more, and an intrinsic viscosity measured in isobutylene at 20° C. in the range of 0.6 to 3 dl/g.
The polyisobutylene elastic polymer having such an intrinsic viscosity is an elastic solid polymer having a number average molecular weight exceeding 2,000 and a weight average molecular weight in the range of approximately 20,000 to 500,000. Therefore,
Specific examples of such polyisobutylene-based elastic polymers include isobutylene homocopolymers, isobutylene/diene copolymers, and the like. The 4-methyl-1-pentene polymer composition composition used in the vibration damping material according to the present invention is
- For 100 parts by weight of methyl-1-pentene polymer, 20 to 20 parts of the above polyisobutylene elastic polymer
Contains 200 parts by weight. When the content of the polyisobutylene elastomer in the polymer composition is less than the above range, the damping performance of the damping material made of such a polymer composition is still low; on the other hand, when the content exceeds the above range When, the heat distortion temperature decreases. Furthermore, in the damping material according to the present invention, the polymer composition has a heat distortion temperature of 100°C or higher and a loss coefficient (tan δ) of 0.06 at 25°C.
The dynamic elastic modulus (E') is 1×
¹⁰⁹ dyn/ ^cm2 or more. Here, the heat distortion temperature refers to the temperature when the sample is penetrated by 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 990 TMA instrument. When this heat distortion temperature is lower than 100°C, the vibration damping material does not have sufficient heat resistance. The loss factor is a frequency of 110Hz and a dynamic displacement of 1.6 using the Vibron method.
It refers to tan δ at ×10 ^-3 cm, and if this loss coefficient is smaller than 0.06 at 25°C, vibration damping performance is not sufficient. Furthermore, 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 this dynamic elastic modulus at 25°C is 1 x 10 ⁹ dyn. When it is smaller than / ^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. . In addition, deep drawability when manufacturing the 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 50 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 It is also possible to blend unsaturated carboxylic acid-modified polyolefins and the like. 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 made of a 4-methyl-1-pentene polymer and a polyisobutylene elastic body having the above-mentioned predetermined properties, and is similar to the conventional vibration damping material. In addition to its vibration damping performance being significantly improved compared to that of steel, it also has excellent heat resistance and workability.Thus, due to its excellent workability, it is now possible to perform deep drawing processing, which was previously difficult. Furthermore, due to its excellent heat resistance, it is suitable for vibration damping materials used at high temperatures and vibration damping materials that require high temperature treatment. (Example) The vibration damping material according to the present invention will be described below with reference to Examples. Example 1 (Preparation of polymer composition) 1.5 mol% of α-olefin having 16 to 18 carbon atoms was contained as a copolymer component, and the intrinsic viscosity [η] was
The isobutylene content is 98 parts by weight for 100 parts by weight of 4-methyl-1-pentene polymer, which is 2.1 dl/g.
150 parts by weight of a polyisobutylene polymer (JSR Butyl (registered trademark) 365 manufactured by Japan Synthetic Rubber Co., Ltd.) having a mole% and intrinsic viscosity [η] of 1.21 was blended and mixed at 250°C using a Brabender mixer. , a polymer composition was prepared. This polymer composition was hot press molded at 250℃,
It was rapidly cooled using a cold press to obtain a sheet with a thickness of 1 mm. The heat distortion temperature of this sheet is 105℃, the loss coefficient (tan δ) at room temperature is 0.15, and the dynamic elastic modulus (E')
was 1.0×10 ⁹ dyn/cm ² . (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 material and the object. 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 factors at 1000Hz were 0.06 and 0.25, respectively. Examples 2 to 5 Example 1 was carried out using the 4-methyl-1-pentene polymer and polyisobutylene polymer shown in the table.
A sheet and a vibration damping composite laminate were obtained in the same manner as above. The heat distortion temperature, loss coefficient (tan δ), and dynamic elastic modulus (E') of the sheet are shown in the table. Furthermore, the vibration damping performance of the composite laminate is shown in the table. Comparative Examples 1 to 3 Polymer compositions were prepared by adding the same 4-methyl-1-pentene polymer as in Example 1 to the same 4-methyl-1-pentene polymer without adding the polyisobutylene polymer, or adding an amount outside the range specified by the present invention. was prepared, from which sheets and laminates were manufactured in the same manner as in Example 1. The sheet thermal deformation temperature, loss coefficient (tan δ), and dynamic elastic modulus (E') are shown in the table. Furthermore, the vibration damping performance of the composite laminate is shown in the table.

[Table] Example 6 (Preparation of composite composition and evaluation of sound insulation properties) 50% by weight of lead powder was blended with the 4-methyl-1-pentene polymer composition prepared in Example 1, and a 10 mm
The transmission loss for 1KHz sound was measured to be 42dB. Comparative Example 4 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 6. The transmission loss of this press plate for 1KHz sound was 31dB.

Claims (1)

[Claims] 1 Intrinsic viscosity measured in decalin at 135℃ is 1.0
For 100 parts by weight of 4-methyl-1-pentene polymer in the range of ~5.0 dl/g, the isobutylene content is 90 mol% or more, and the intrinsic viscosity measured in diisobutylene at 20°C is 0.6 Polyisobutylene elastic polymer in the range of ~3dl/g20~
It consists of a composition containing 200 parts by weight, has a heat distortion temperature of 100°C or higher, a loss coefficient of 0.06 or higher at 25°C, and a dynamic elastic modulus of 1×
A damping material characterized by having a vibration resistance of 10 ⁹ dyn/cm ² or more.