JP2000345038A - Vibration-proofing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in vibration-proofness and small in an influence by a temperature change, which composition comprises a matrix component comprising a silicone oil and an organic polymer having a pour point in a specified temperature range and a fine solid powder which does not soften at a specified temperature or lower. SOLUTION: This composition comprises a matrix component containing a silicone oil (A) and an organic polymer (B) such as a polyisobutylene having a pour point in the range of 30-200 deg.C in an A/B weight ratio of 99/1 to 5/95, 5-75 wt.% fine solid particles which do not soften at 20 deg.C or below such as a fine silica powder of a mean particle diameter of 0.01-300 μm, and 0. 1-50 wt.% metal soap such as zinc stearate. The composition may optionally contain an antioxidant, a rust inhibitor, a flame retardancy improver, a pigment, etc. Component A desirably has a kinematic viscosity at 25 deg.C in the range of 100-1,000,000 mm2/s and is exemplified by trimethylsiloxy-blocked dimethylpolysiloxane, or dimethylvinylsiloxy-blocked dimethylpolysiloxane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration composition, and more particularly, to an anti-vibration composition having a small effect of temperature change and having stable anti-vibration characteristics.

[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 powder (Japanese Patent Laid-Open No. Sho 62-62) No. 113932), a vibration damping composition comprising a viscous liquid such as silicone oil and a solid powder such as silica powder, glass powder and silicone resin powder (see JP-A-63-308241); 2. Description of the Related Art A vibration damping composition (see JP-A-63-308242) comprising an organic resin powder having a glass transition point of a liquid and an acrylic resin within a use temperature range is known. However, these vibration damping compositions change their vibration damping properties due to temperature changes and do not have stable vibration damping properties.

[0003]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention.
That is, an object of the present invention is to provide an anti-vibration composition having excellent anti-vibration properties, being less affected by a change in temperature, and having stable anti-vibration properties.

[0004]

The present invention provides (A) and (a)
The present invention relates to a vibration damping composition comprising a silicone oil, (b) a matrix component composed of an organic polymer having a pour point in a temperature range of 30 ° C. to 200 ° C., and (B) a solid fine powder that does not liquefy at a temperature of 200 ° C. or lower.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The component (A) of the composition of the present invention is a matrix component comprising (a) a silicone oil and (b) an organic polymer having a pour point in a temperature range of 30 ° C to 200 ° C,
It is a medium for dispersing the solid fine powder of the component (B).

As the silicone oil (a) constituting the component (A), there can be mentioned an organopolysiloxane which is liquid at normal temperature. In the organopolysiloxane, a group bonded to a silicon atom includes an alkyl group such as a methyl group, an ethyl group and a propyl group; an alkenyl group such as a vinyl group, an allyl group and a butenyl group; and an aryl group such as a phenyl group and a tolyl group. A substituted or unsubstituted monovalent hydrocarbon group such as a halogenated alkyl group such as a 3,3,3-trifluoropropyl group, and a small amount of an alkoxy group such as a hydroxyl group, a methoxy group or an ethoxy group. Among these, an alkyl group is preferable, and a methyl group is particularly preferable, because the temperature dependency of the change in viscosity is small and the storage stability of the composition of the present invention is good. Examples of the molecular structure of the silicone oil include linear, partially branched linear, branched, and cyclic, and a linear structure is preferable. Preferably the kinematic viscosity at 25 ° C. of the silicone oil is in the range of 100~1,000,000mm ² / s, more preferably in the range of 500~500,000mm ² / s. This is because the kinematic viscosity at 25 ° C. is 100 mm ² /
If it is less than s, the solid fine powder of the component (B) tends to be unable to be maintained in a dispersed state, while
If it exceeds 0 mm ² / s, the handling workability decreases (B)
This is because it tends to be difficult to disperse the solid fine powder of the component. Examples of such silicone oil include trimethylsiloxy group-blocked dimethylpolysiloxane, dimethylvinylsiloxy group-blocked dimethylpolysiloxane, silanol group-blocked dimethylpolysiloxane, and trimethylsiloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer.

The organic polymer (b) constituting the component (A) may be a high molecular compound having a pour point in the temperature range of 30 ° C. to 200 ° C. Those having a pour point in the temperature range below the upper limit are preferred. Specifically, those having a pour point of 150 ° C. or lower are preferable, and those having a pour point in the range of 30 ° C. to 120 ° C. are more preferable. The organic polymer having a pour point in such a specific temperature range has an effect of remarkably reducing the temperature dependence of the vibration damping properties of the composition of the present invention. Examples of the organic polymer include paraffin wax, polyisobutylene, polybutene, other polyolefins, and copolymers of polyolefin and silicone. Among them, polyisobutylene is preferable because of its excellent vibration isolation.

The matrix component (A) is a mixture of the above-mentioned (a) silicone oil and (b) an organic polymer, and the mixing ratio thereof is in the range of 99: 1 to 5: 95% by weight. And preferably 99: 1 to 10: 9.
More preferably, it is in the range of 0% by weight. In addition to the (a) silicone oil and the (b) organic polymer, a non-silicone organic polymer having fluidity at 25 ° C. can be added to the component (A). Examples of the organic polymer include low molecular weight polyolefins such as an isobutylene polymer. The addition amount is 50 parts by weight based on 100 parts by weight of the total of (a) the silicone oil and (b) the organic polymer.
It is preferable that the amount is not more than part by weight.

The solid fine powder of the component (B) used in the composition of the present invention is a component for improving the vibration-proofing properties of the composition of the present invention. It is not particularly limited. Examples of the solid fine powder of the component (B) include inorganic fine powders such as dry silica fine powder, wet silica fine powder, calcium carbonate fine powder, glass fine powder, clay, bentonite, diatomaceous earth, and quartz powder. Fillers such as organic resin fine powder such as acrylic resin fine powder, fluororesin fine powder, and silicone resin fine powder. Among these, silicone resin fine powder or inorganic fine powder is preferable. The silicone resin fine powder refers to an organopolysiloxane containing a siloxane unit represented by the formula: RSiO _3/2 (where R is a monovalent hydrocarbon group) or a siloxane unit represented by the formula: SiO _4/2 . A siloxane, specifically having the formula: CH
Silicone resin fine powder composed of only siloxane unit represented by ₃ SiO _3/2 , silicone resin composed of siloxane unit represented by formula (CH ₃ ) ₃ SiO _1/2 and siloxane unit represented by formula SiO _4/2 Fine powder is exemplified. When an inorganic fine powder is used, silane,
It is preferable that the surface is hydrophobized with silicone, a surfactant or the like. The solid fine powder of the component (B) preferably has an average particle size in the range of 0.01 to 300 μm, and more preferably in the range of 0.01 to 200 μm. Examples of the shape include a spherical shape, a flat shape, and an irregular shape. Further, the solid fine powder of the component (B)
A mixture of two or more types of solid fine powders having different materials may be used. In this case, a combination of two or more types of solid fine powders having different average particle diameters is preferable. As such a combination, the average particle size is 0.01 to 50 μm.
And a solid fine powder having an average particle diameter of 20 to 200 μm. The content of the component (B) in the composition of the present invention is preferably in the range of 5 to 75% by weight, more preferably in the range of 9 to 70% by weight, and more preferably in the range of 20 to 70% by weight. It is more preferred that there be. This is because if the amount of the component (B) is out of this range, the vibration-proofing properties of the composition of the present invention tend to decrease.

The composition of the present invention comprises the above components (A) and (B). In addition to these components,
When a metal soap or a higher fatty acid amide is added and blended as the component (C), the composition of the present invention having excellent anti-vibration properties and storage stability can be obtained. Examples of the metal soap include metal salts of higher fatty acids and metal salts of naphthenic acid. Specifically, zinc stearate, calcium stearate,
Examples thereof include calcium 2-hydroxystearate, magnesium stearate, barium stearate, lithium stearate, zinc oleate, zinc laurate, zinc myristate, aluminum monostearate, aluminum distearate, and aluminum tristearate. Examples of higher fatty acid amides include ethylenebisstearic acid amide, erucic acid monoamide, oleic acid monoamide, stearic acid monoamide, ethylenebisoleic acid amide, ethylenebiserucic acid amide, and ethylenebislauric acid amide. Among these,
Preference is given to zinc stearate, calcium stearate, lithium stearate and zinc oleate.
The content of the component (C) in the composition of the present invention is 0.1 to 5%.
It is preferably in the range of 0% by weight, and more preferably in the range of 0.2 to 30% by weight.

The composition of the present invention comprises the above components (A) and (B), or components (A) to (C). Other optional components include antioxidants, rust inhibitors, Flame retardants, pigments, dyes and the like may be added. The composition of the present invention is usually a viscous liquid or semi-solid at room temperature.

The composition of the present invention is produced by uniformly mixing the above components (A) and (B), or components (A) to (C). Examples of the mixing means include well-known kneading devices such as a ball mill, a vibration mill, a kneader mixer, a screw extruder, a paddle mixer, a ribbon mixer, a Banbury mixer, a loss mixer, a Henschel mixer, a flow jet mixer, a Hobart mixer, and a roll mixer. . The mixture may be heated at the time of mixing, and the heating temperature is preferably a temperature equal to or higher than the pour point of the organic polymer (b) in the component (A).

The composition of the present invention as described above has the characteristics that it is excellent in vibration damping properties and has a very small influence on temperature due to its small temperature dependency. For this reason, the composition of the present invention has an advantage that it can be used as a buffer by enclosing the composition in an elastic container such as a rubber bag or a rubber cylinder. In particular, it is suitable as a buffer for electric equipment and electronic equipment used in an environment with a large temperature change, such as a compact disc player, a compact disc changer, a mini disc player, and a car navigation device.

[0014]

Next, the composition of the present invention will be described in detail with reference to examples. In the examples, viscosity and kinematic viscosity are measured values at 25 ° C. The pour point is measured according to the method specified in JIS K 2269, and the anti-vibration property of the anti-vibration composition is −
Loss tangent coefficients at 20 ° C, 25 ° C and 65 ° C (tan
It was evaluated by measuring δ). Note that tan δ is “Dynamic Analyzer RDA-
700 "by the plate method. The measurement conditions were as follows: plate diameter: 20 mm, frequency: 10 Hz, strain: 20%, and sample thickness: 1 mm. From these results, the ratio of tan δ to tan δ at 25 ° C. [tan δ / ta
nδ (25 ° C.)].

[0015]

Example 1 80 g of a dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped with trimethylsiloxy groups at both ends was mixed in a mixer.
20 g of polyisobutylene having a pour point of 67 ° C. and a viscosity average molecular weight of 30,000, and an irregularly shaped calcium carbonate having an average particle size of 20 μm 1
62 g (no surface treatment) and average particle size of 110 to 80 μ
Then, 36 g of spherical glass beads having a diameter of m were charged and kneaded for 1 hour at a low speed (150 rpm) while scraping them every 30 minutes, and further kneaded at 100 ° C. for 1 hour to prepare a vibration damping compound composition. The vibration damping properties of the composition thus obtained were measured, and the results are shown in Table 1.

[0016]

Example 2 80 g of dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped with trimethylsiloxy groups at both ends was added to a mixer.
20 g of polyisobutylene having a pour point of 112 ° C. and a viscosity average molecular weight of 60,000, 162 g of irregularly shaped calcium carbonate having an average particle size of 20 μm (no surface treatment), and an average particle size of 110 to 80
36 g of spherical glass beads having a diameter of μm were charged, and the glass beads were scraped off at a low speed (150 rpm) every 30 minutes.
After kneading for 1 hour, the mixture was further kneaded at 130 ° C. for 1 hour to prepare a vibration-proof compound composition. The vibration damping properties of the composition thus obtained were measured, and the results are shown in Table 1.

[0017]

Example 3 92 g of dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped with trimethylsiloxy groups at both ends was added to a mixer.
8 g of polyisobutylene having a pour point of 67 ° C. and a viscosity average molecular weight of 30,000, _consisting of only a siloxane unit represented by the formula: CH ₃ SiO _3/2 and having an average particle size of 20 μm which does not liquefy even at 250 ° C.
82 g of the silicone resin fine powder was added and kneaded at a low speed (150 rpm) for 2 hours while scraping every 30 minutes, and further kneaded at 100 ° C. for 1 hour to prepare a vibration damping compound composition. The vibration damping properties of the composition thus obtained were measured, and the results are shown in Table 1.

[0018]

EXAMPLE 4 80 g of dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped at both ends with a trimethylsiloxy group,
20 g of polyisobutylene having a pour point of 67 ° C. and a viscosity average molecular weight of 30,000, and an irregularly shaped calcium carbonate having an average particle size of 20 μm 1
62 g (no surface treatment), 36 g of spherical glass beads having an average particle size of 110 to 80 μm and 3 g of zinc stearate were charged, and these were kneaded for 1 hour while being scraped off at a low speed (150 rpm) every 30 minutes. 1 in ° C
The mixture was kneaded for a period of time to prepare an anti-vibration compound composition. The vibration damping properties of the composition thus obtained were measured, and the results are shown in Table 1. Further, when the anti-vibration compound composition was allowed to stand at room temperature for one month and the appearance and the anti-vibration characteristics after one month were measured, no change was observed from immediately after the production.

[0019]

Comparative Example 1 The procedure of Example 1 was repeated except that polyisobutylene 20 was used.
g was not added, and instead of 100 g, a dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped with trimethylsiloxy groups at both ends was prepared in the same manner as in Example 1 to prepare a vibration damping compound composition. . The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0020]

Comparative Example 2 In Example 3, 8 g of polyisobutylene was used.
Was prepared in the same manner as in Example 3, except that 100 g of a dimethylpolysiloxane having a viscosity of 10,000 mPa · s and capped with a trimethylsiloxy group at both terminals was used instead. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0021]

[Table 1]

[0022]

The anti-vibration composition of the present invention comprises the above components (A) and (B). In particular, as the matrix component of the component (A), (a) silicone oil and (b) a pour point of 30 are used. Since a mixture with an organic polymer having a temperature of up to 200 ° C. is used, it is characterized by having excellent vibration damping properties and having stable vibration damping properties with little influence of temperature changes.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/16 C08L 101/00 (72) Inventor Masayuki Hayashi 2-2 Chikusa Kaigan, Ichihara City, Chiba Prefecture Toray Dow Corning Silicone Co., Ltd. Research and Development Division F-term (reference) 4J002 AE03X BB01X BB17X BB18X CP03W CP03X EG036 EG046 EP016 EP026 FD036

Claims (6)

[Claims] (A) (a) a silicone oil,
(B) a matrix component composed of an organic polymer having a pour point in a temperature range of 30 ° C. to 200 ° C .;
An anti-vibration composition comprising a solid fine powder that does not liquefy at 0 ° C. or lower. 2. The vibration damping composition according to claim 1, wherein the component (b) is polyisobutylene. 3. The vibration damping composition according to claim 1, further comprising a metal soap or a higher fatty acid amide added as component (C). 4. An average particle diameter of the component (B) is from 0.01 to 30.
The vibration damping composition according to any one of claims 1 to 3, which is within a range of 0 µm. 5. The vibration damping composition according to claim 1, wherein the component (B) is a silicone resin fine powder. 6. The vibration damping composition according to claim 1, wherein the component (B) is a mixture of two or more different solid fine powders.