JPH10251517A - Vibration isolating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having excellent vibration isolating characteristic even under the variation of the vibration frequency and useful as a cushioning material for electrical equipment by compounding a viscous liquid and a specific solid powder. SOLUTION: This composition is composed of (A) 100 pts.wt. of a viscous liquid (preferably a silicone oil) and (B) 5-200 pts.wt. of a solid powder having an average particle diameter of 0.1-100μm and containing <=1wt.% of fraction having particle diameter of <=10μm and >=10wt.% of fraction having particle diameter of >=30μm. The composition is producible e.g. by kneading the component A with the component B using a kneader such as a ball mill. The composition may be incorporated with other component such as clay.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping composition comprising a viscous liquid and a solid powder, and more particularly, to a vibration damping composition having good vibration damping characteristics even when the frequency of vibration changes.

[0002]

2. Description of the Related Art As a vibration damping composition comprising a viscous liquid and a solid powder, for example, a vibration damping composition comprising a liquid polymer such as water, diethylene glycol, glycerin, polybutadiene and a clay mineral (Japanese Patent Laid-Open No. 62-113933). No., a viscous liquid such as silicone oil and silica powder,
Vibration-damping compositions composed of solid powders such as glass powder and silicone resin powder (see JP-A-63-308241), viscous liquids such as silicone oil, and glass transition points of acrylic resins and the like are within the operating temperature range. 2. Description of the Related Art An anti-vibration composition comprising a resin powder (see JP-A-63-308242) is known.

[0003] However, these vibration damping compositions do not have good vibration damping properties depending on changes in the frequency of vibration.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have intensively studied the above-mentioned problems, and as a result, have reached the present invention. That is, an object of the present invention is to provide a vibration damping composition having good vibration damping properties even when the frequency of vibration changes.

[0005]

The anti-vibration composition of the present invention comprises (A) 100 parts by weight of a viscous liquid, and (B) an average particle diameter of 0.1 to 100 μm, and a particle diameter of 10 μm or less. It is characterized in that the powder is 1% by weight or more, and the powder having a particle diameter of 30 μm or more is 5 to 200 parts by weight of a solid powder of 10% by weight or more.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The vibration damping composition of the present invention will be described in detail. The viscous liquid of the component (A) is a main component of the present composition, and is a medium for dispersing the component (B). Examples of such a component (A) include mineral oil, vegetable oil, synthetic oil, and silicone oil. Particularly, because of its high compressibility, small temperature dependence of viscosity change, and excellent heat resistance, And silicone oil.
Examples of the group bonded to the silicon atom of the silicone oil include an alkyl group such as a methyl group, an ethyl group, and a propyl group;
Alkenyl groups such as vinyl group, allyl group and butenyl group; aryl groups such as phenyl group and tolyl group; substituted or unsubstituted monovalent hydrocarbons such as halogenated alkyl groups such as 3,3,3-trifluoropropyl group Group; a small amount of hydroxyl group,
Examples of the alkoxy group such as a methoxy group and an ethoxy group,
Almost all of these groups are preferably alkyl groups, and particularly preferably methyl groups, because the temperature dependency of the viscosity change is small and the storage stability of the present composition is good. Examples of the molecular structure of the silicone oil include linear, partially branched linear, branched, and cyclic, and the linear structure is particularly preferable. The viscosity of the component (A) at 25 ° C. is 100
It is preferably in the range of 1 to 1,000,000 centistokes, and particularly preferably in the range of 500 to 500,000 centistokes. this is,
If the viscosity of the component (A) at 25 ° C. is less than this range, the component (B) tends to be unable to be maintained in a dispersed state, while if the viscosity exceeds this range, handling workability deteriorates, This is because the component (B) tends to be difficult to disperse.

[0007] The solid powder of the component (B) is a component dispersed in the component (A) to give the composition an anti-vibration property, and has an average particle diameter in the range of 0.1 to 100 µm. And
Preferably, the powder is in the range of 10 to 40 μm. Further, the component (B) has a particle size distribution, and powder having a particle size of 10 μm or less is 1% by weight or more, and powder having a particle size of 30 μm or more is 10% by weight or more. It is characterized by the following. Examples of the component (B) include inorganic powders such as silica powder and glass powder; organic resin powders such as polyethylene resin powder and acrylic resin powder;
Silicone resin powder is exemplified, and when silicone oil is used as the component (A), it is particularly preferable to use silicone resin powder because of its excellent affinity for it. As this silicone resin powder, R
Silicone resin powder that the SiO _3/2 units and / or SiO _4/2 units as the main skeleton is exemplified further, as any other unit, R ₃ SiO _1/2 units and / or R
_Although a silicone resin powder having ₂ SiO _2/2 units is exemplified, a silicone resin powder consisting of only RSiO _3/2 units is particularly preferable. R in this unit formula
As alkyl groups such as methyl group, ethyl group and propyl group; alkenyl groups such as vinyl group, allyl group and butenyl group; aryl groups such as phenyl group and tolyl group;
-A substituted or unsubstituted monovalent hydrocarbon group such as a halogenated alkyl group such as a trifluoropropyl group; and a small amount of a hydroxyl group, a methoxy group, an alkoxy group such as an ethoxy group, and the like, in particular, a methyl group, an ethyl group, It is preferably an alkyl group such as a propyl group, a vinyl group, or a phenyl group.

[0008] The amount of component (B) to be added is in the range of 5 to 200 parts by weight, preferably 10 to 150 parts by weight, and particularly preferably 100 parts by weight of component (A). Is in the range of 30 to 150 parts by weight. this is,
This is because a composition in which the addition amount of the component (B) is out of this range tends to deteriorate vibration damping properties.

As a method for preparing the present composition, the components (A) and (B) are mixed with a ball mill, a vibration mill, a kneader mixer, a screw extruder, a paddle mixer,
A kneading method using a well-known kneading device such as a ribbon mixer, a Henschel mixer, a flow jet mixer, a Hobart mixer, or a roll mixer may be used. In addition, the present composition contains clay, bentonite, silica fine powder, thickeners such as metal soaps, antioxidants, rust inhibitors, flame retardants, pigments, and dyes as other optional components. You may.

The present composition is sealed in a container made of an elastic material to form a buffer, and the buffer is used for electric equipment such as a compact disc player, a compact disc changer, a mini disc player, and a car navigation device. It can be used as a buffer.

[0011]

EXAMPLES The vibration damping composition of the present invention will be described in more detail with reference to examples. The characteristics in the examples are values at 25 ° C. Further, the vibration-proofing properties of the vibration-proofing composition were evaluated by tan δ measured by a plate method under the following measurement conditions using a dynamic viscoelasticity tester (Dynamic Analyzer RDA-700 manufactured by Rheometrics). [Measurement conditions] Plate diameter: 20 mm Frequency: 0.1 Hz, 1.0 Hz, 10 Hz Strain: 10% Sample thickness: 0.6 mm

Example 1 Using a Hobart mixer, 1100 g of a silicone oil composed of dimethylpolysiloxane capped at both ends of a molecular chain with a viscosity of 3,000 centistokes and having an average particle diameter of 20 μm
And 9% by weight of powder having a particle diameter of 10 μm or less, and 26% by weight of powder having a particle diameter of 30 μm or more.
Silicone resin powder 9 consisting of H ₃ SiO _3/2 units only
00 g was kneaded at room temperature for 2 hours to prepare a vibration-proof composition. Table 1 shows the vibration damping properties of the vibration damping composition.

Example 2 Using a Hobart mixer, 1100 g of a silicone oil composed of dimethylpolysiloxane capped at both ends of a molecular chain having a viscosity of 10,000 centistokes and having an average particle diameter of 20 μm.
m, powder having a particle diameter of 10 μm or less is 9% by weight, and powder having a particle diameter of 30 μm or more is 26% by weight.
H ₃ silicone resin powder 9 comprising only SiO _3/2 units
00 g was kneaded at room temperature for 2 hours to prepare a vibration-proof composition. Table 1 shows the vibration damping properties of the vibration damping composition.

Example 3 Using a Hobart mixer, 1100 g of a silicone oil composed of dimethylpolysiloxane capped at both ends of a molecular chain with a viscosity of 10,000 centistokes and having an average particle size of 30 μm.
m, and a 12 wt% powder of size not larger than 10 [mu] m, the powder particle size of at least 30μm is 17 wt% C ₆ H ₅ SiO _3/2 units and _{n-C 3 H 6 SiO 3} / consists of _two units, the molar ratio of the units 7: silicone resin powder 900g is 3 to prepare a vibration damping composition was kneaded for 2 hours at room temperature. Table 1 shows the vibration damping properties of the vibration damping composition.

Comparative Example 1 Using a Hobart mixer, 1100 g of a silicone oil composed of dimethylpolysiloxane having a viscosity of 10,000 centistokes and capped at both ends of a molecular chain with a trimethylsiloxy group, and an average particle diameter of 0.1%.
A vibration-proof composition was prepared by kneading 900 g of calcium carbonate powder having a particle size of 04 μm and a maximum particle size of 5 μm at room temperature for 2 hours. Table 1 shows the vibration damping properties of the vibration damping composition.

Comparative Example 2 1860 g of a silicone oil composed of dimethylpolysiloxane having a trimethylsiloxy group at both ends of a molecular chain having a viscosity of 10,000 centistokes and a mean particle size of 0.1 centistokes was measured by Hobart Misaki.
140 g of fumed titanium oxide powder having a maximum particle diameter of 5 μm and a particle diameter of 01 μm was kneaded at room temperature for 2 hours to prepare a vibration-proof composition. Table 1 shows the vibration damping properties of the vibration damping composition.

Comparative Example 3 Using a Hobart mixer, 1100 g of a silicone oil composed of dimethylpolysiloxane capped at both ends of a molecular chain having a viscosity of 10,000 centistokes and having an average particle diameter of 12
900 g of glass powder having a particle size of 0 μm and a minimum particle size of 75 μm was kneaded at room temperature for 2 hours to prepare a vibration-proof composition. Table 1 shows the vibration damping properties of the vibration damping composition.

[0018]

[Table 1]

[0019]

The vibration damping composition of the present invention is characterized by having good vibration damping properties even when the frequency of vibration changes.

Claims (3)

[Claims] (A) 100 parts by weight of a viscous liquid; and (B) a powder having an average particle diameter of 0.1 to 100 μm and a particle diameter of 10 μm or less is 1% by weight or more and 30 μm or more. A vibration damping composition comprising 5-200 parts by weight of a solid powder having a particle diameter of 10% by weight or more. 2. The vibration damping composition according to claim 1, wherein the component (A) is a silicone oil. 3. The vibration damping composition according to claim 2, wherein the component (B) is a silicone resin powder.