JP2000313806A - Vibration-proof silicone composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anti-vibration silicone composition which is excellent in anti-vibration properties and has stable anti-vibration properties which are less affected by temperature changes. SOLUTION: The vibration-proof silicone composition comprises (A) silicone oil, (B) silicone resin powder and (C) boron compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-damping silicone composition, and more particularly to a vibration-damping silicone composition having stable vibration-damping properties which is less affected by temperature changes.

[0002]

2. Description of the Related Art Conventionally, as an anti-vibration silicone composition, an anti-vibration composition comprising a silicone oil and a solid powder such as a silica powder, a glass powder, a silicone resin powder and the like has been known (Japanese Patent Application Laid-Open (JP-A) No. Sho. JP-A-63-308241, JP-A-10-251517 and JP-A-10-251517
-281202). Further, there is known a vibration damping composition comprising an organic resin powder having a glass transition point such as a silicone oil and an acrylic resin within a use temperature range (see JP-A-63-308242). However, these vibration damping silicone compositions have a problem that fluctuations in vibration damping characteristics due to temperature changes are large.

[0003]

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

[0004]

Means for Solving the Problems The present invention comprises (A) 100 parts by weight of silicone oil, (B) 5 to 200 parts by weight of silicone resin powder, and (C) 0.001 to 10 parts by weight of a boron compound. The present invention relates to a vibration-proof silicone composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the vibration-proof silicone of the present invention will be described.
The composition will be described in detail. Used in the composition of the present invention
The silicone oil of the component (A) is used in the composition of the present invention.
A matrix component, wherein component (B) and component (C)
Is a medium for dispersing. Used silicone
As an oil, organopolysiloxane that is liquid at room temperature
Sun. In this organopolysiloxane,
Groups bonded to an iodine atom include a methyl group, an ethyl group,
Alkyl groups such as propyl group; vinyl group, allyl group, bute
Alkenyl groups such as a phenyl group;
Reel group; halogen such as 3,3,3-trifluoropropyl group
Or unsubstituted monovalent hydrocarbons such as alkylated alkyl groups
Groups; other small amounts of hydroxyl, methoxy, ethoxy, etc.
An alkoxy group is exemplified. Among these, viscosity change
Has low temperature dependence, and the storage stability of the composition of the present invention is good.
Because it is good, it is desirable that it is an alkyl group,
Particularly, it is preferably a methyl group. The molecular structure
The structure is straight-chain, partially branched straight-chain, branched-chain
And cyclic, but it is desirable that it be linear.
No. The kinematic viscosity of this silicone oil at 25 ° C is 10
0-1,000,000mm ^Two/ S, preferably 5
00-500,000mm^Two/ S range is more preferable.
No. This is because the kinematic viscosity at 25 ° C is 100mm^TwoLess than / s
If there is, the component (B) and the component (C) are kept in a dispersed state.
And 1,000,000mm^Two/
If it exceeds s, the handling workability decreases, and the component (B)
(C) Does component tend to be difficult to disperse?
It is. Such silicone oils include
Methylsiloxy-blocked dimethylpolysiloxane, dimethyl
Divinylsiloxy-blocked dimethylpolysiloxane, sila
Nol-blocked dimethylpolysiloxane, trimethylsilo
Xyl-blocked dimethylsiloxane / methylphenylsiloxy
An example is a sun copolymer.

The composition of the component (B) used in the composition of the present invention
Silicone resin powder improves the anti-vibration properties of the composition of the present invention
It is a component to make it. Used silicone resin
The powder has the formula: RSiO_3/2Up to the siloxane unit
Or formula: SiO_4/2A siloxane unit represented by
Organopolysiloxane, which is liquid at 30 ° C. or lower.
Any solid powder that does not form may be used. In addition, this silicone
The resin powder has an optional siloxane unit of the formula:
R_ThreeSiO_1/2And a siloxane unit represented by the formula: R _TwoSi
O_2/2May contain a siloxane unit represented by
No. R in the above formula is a methyl group, an ethyl group,
Alkyl group such as phenyl group; vinyl group, allyl group, butenyl group
Alkenyl groups such as phenyl; aryl such as phenyl and tolyl
A halogenated amino group such as a 3,3,3-trifluoropropyl group;
Substituted or unsubstituted monovalent hydrocarbon groups such as alkyl groups; water
Examples include alkoxy groups such as acid groups, methoxy groups, and ethoxy groups
Is done. Among them, methyl group, ethyl group, propyl group
Alkyl group such as phenyl group; vinyl group, phenyl group and hydroxyl
It is preferably a group. In particular, silicone of component (B)
Resin powder has the formula: R¹SiO_3/2(Where R¹Also replace
Or an unsubstituted monovalent hydrocarbon group. )
Loxane unit as a main constituent, and a small amount of formula: R¹(OH)
SiO_2/2Silanol group-containing siloxane unit represented by
Is preferably an organopolysiloxane having
No. This is because (B) component has a silanol group.
Of silanol groups on the surface of silicone resin powder and (C)
A pseudo-crosslink is formed between the component boric acid,
This is because the anti-vibration properties of the composition of the present invention are further improved.
You. The content of the silanol group is 0.01 to 5.00.
% By weight, preferably from 0.02 to 5.0.
More preferably, it is in the range of 0% by weight. Also this
The silicone resin powder has an average particle size of 0.1 to 300 μm
Is preferably in the range of 1 to 300 μm.
More preferably, it is in the range of 1 to 200 μm.
More preferred. (B) Component of silicone resin powder
The compounding amount is 5 to 20 parts by weight based on 100 parts by weight of the component (A).
0 parts by weight, and 10 to 180 parts by weight.
Preferably. This is the anti-vibration property when less than 5 parts by weight
Is reduced, and if it exceeds 200 parts by weight, handleability is reduced.
That's why.

The boron compound of the component (C) used in the composition of the present invention, in combination with the silicone resin powder of the component (B), further improves the vibration-proofing properties. The boron compound to be used is not particularly limited as long as it is a compound containing a boron atom. For example, trialkyl borate such as trimethyl borate, triethyl borate and tributyl borate; lithium borate anhydride, sodium borate anhydride, lithium borate trihydrate Borate such as hydrate, sodium borate decahydrate, potassium borate tetrahydrate, barium borate, lead borate, zinc borate, aluminum borate, ammonium borate, lead borate; potassium boride, sodium boride, borate Examples thereof include ammonium fluoride, copper borofluoride, hydrofluoric acid, boric acid, and boron. Among these, boric acid and the above-mentioned borates are preferred. In addition, its properties are usually solid powder at normal temperature, but it may be blended after use in the form of a master batch with silicone oil or an aqueous solution. In the master batch, the mixing ratio of the boron compound to the silicone oil is preferably such that the boron compound: silicone oil is 10 to 80:90 to 20% by weight. As the silicone oil, those similar to the above component (A) can be used, and among them, dimethylpolysiloxane is preferable. The compounding amount of the boron compound as the component (C) is in the range of 0.001 to 10 parts by weight with respect to 100 parts by weight of the component (A).
It is preferably in the range of 8 to 8 parts by weight. This is 0.
If the amount is less than 001 parts by weight, the synergistic effect on the vibration isolating property is reduced, and if it exceeds 10 parts by weight, the workability is reduced.

The composition of the present invention comprises the above components (A) to (C). In addition to these components,
It is preferable to add a silica fine powder as the component (D) in order to further improve the vibration isolation characteristics. Examples of the silica fine powder to be used include silica fine powder synthesized by a wet method and silica fine powder synthesized by a dry method. Examples of the wet method include a method of directly decomposing sodium silicate with a mineral acid such as sulfuric acid, and examples of the dry method include a method of hydrolyzing silicon tetrachloride at high temperature in an oxyhydrogen flame. The specific surface area of such silica fine powder is 30 to 60.
0 m ² / g, preferably 40 to 500 m ² / g.
More preferably, it is in the range of m ² / g. The surface may be untreated or may be subjected to a hydrophobic treatment. Examples of the hydrophobic treatment agent include chlorosilanes such as dimethyldichlorosilane and trimethylchlorosilane, hexamethyldisilazane, various alkylalkoxysilanes, and silicones. Oil and the like. The amount of the fine silica powder of the component (D) is 0.1 to 100 parts by weight based on 100 parts by weight of the component (A), and 0.5 to 50 parts by weight.
It is preferably in the range of parts by weight. This is because if it is less than 0.1 part by weight, the effect of improving the vibration isolating properties is poor, and if it exceeds 100 parts by weight, the workability is reduced.

The composition of the present invention may further contain, as optional components, an antioxidant, a rust inhibitor, a flame retardant, a pigment, and a dye. The shape of 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) to (C) or components (A) to (D). Examples of the mixing means include well-known mixing 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. Can be Heating is preferably performed at the time of mixing, and the heating temperature at that time is usually 5
The range is from 0 to 200 ° C. The heating time is optional, but is preferably in the range of 10 minutes to 10 hours.

The composition of the present invention as described above is excellent in anti-vibration properties, and in particular, has a feature that the influence of a temperature change is extremely small because of its low temperature dependency. Therefore, the composition of the present invention can be used as a buffer by enclosing it in an elastic container such as a rubber bag or a rubber cylinder. Therefore, in particular, compact disc players, compact disc changers, mini disc players,
It is suitable as a buffer for electric equipment and electronic equipment used in an environment with a large temperature change such as a car navigation device.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. In the examples, “parts” means “parts by weight” and the viscosity is 25 parts.
It is a measured value at ° C. The anti-vibration properties of the anti-vibration composition are as follows:
Loss tangent coefficients at -20 ° C, 25 ° C, and 65 ° C (tan
It was evaluated by measuring δ). This tanδ is
Rheometrics Dynamic Analyzer RD
A-700 "was measured 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 [tanδ to tanδ at 25 ° C.
/ Tan δ (25 ° C)].

[0013]

Example 1 100 parts of a dimethylpolysiloxane having a kinematic viscosity of 10,000 mm ² / s and capped with trimethylsiloxy groups at both ends, a siloxane unit represented by the formula: CH ₃ SiO _3/2 and a formula: CH ₃ (HO ) 86 parts of a silicone resin powder (silanol group content: 0.1% by weight) _consisting of a silanol group-containing siloxane unit represented by SiO _2/2 and having a mean particle size of 20 μm which is solid at 100 ° C., and boric acid and silicone Master batch with oil [mixture obtained by kneading 100 parts by weight of boric acid powder (crystalline white powder) and 100 parts by weight of dimethylpolysiloxane capped at both ends with trimethylsiloxy groups having a viscosity of 10,000 mPa · s using three rolls] 3
The mixture was kneaded at a low speed (150 rpm) for 1 hour, and further mixed at 170 ° C. under reduced pressure for 2 hours to obtain a compound-like vibration-proof silicone composition. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0014]

Comparative Example 1 A vibration-proof silicone composition was prepared in the same manner as in Example 1, except that the masterbatch of boric acid and silicone oil was not added and blended. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0015]

Comparative Example 2 A vibration-proof silicone composition was prepared in the same manner as in Example 1, except that the silicone resin powder was not added and blended. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0016]

Example 2 100 parts of a dimethylpolysiloxane having a kinematic viscosity of 10,000 mm ² / s and capped with a trimethylsiloxy group at both ends, a siloxane unit of the formula: CH ₃ SiO _3/2 and a compound of the formula: CH ₃ (HO ) 86 parts of a silicone resin powder (silanol group content 0.1% by weight) having a silanol group-containing siloxane unit represented by SiO _2/2 and having a mean particle size of 20 μm which is solid at 100 ° C., and has a specific surface area of 2
Both ends of 00m ² / g and is pH wet process silica fine powder 5 parts of a 6, a master batch of the boric acid and the silicone oil [boric acid powder (crystalline white powder) 100 parts by weight of viscosity 10,000 mPa · s 3 parts of a mixture obtained by kneading 100 parts by weight of trimethylsiloxy group-blocked dimethylpolysiloxane using a three-roll mill,
rpm) for 1 hour, and further mixed under reduced pressure at 170 ° C. for 2 hours to obtain a compound-like anti-vibration silicone composition. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0017]

Comparative Example 3 A vibration-proof silicone composition was prepared in the same manner as in Example 2, except that the master batch of boric acid and silicone oil was not added and blended. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0018]

Example 3 100 parts of a dimethylpolysiloxane having a kinematic viscosity of 10,000 mm ² / s and capped with a trimethylsiloxy group at both ends, a siloxane unit represented by the formula: CH ₃ SiO _3/2 and a formula: CH ₃ (HO ) 86 parts of a silicone resin powder (silanol group content 0.1% by weight) having a silanol group-containing siloxane unit represented by SiO _2/2 and having a mean particle size of 20 μm which is solid at 100 ° C., and ammonium tetraborate ( A mixture of 1.5 parts of white powder (2 parts) and 2 parts of water was charged and kneaded at a low speed (150 rpm) for 1 hour.
The mixture was further mixed at 170 ° C. under reduced pressure for 2 hours to obtain a compound-like vibration-proof silicone composition. The anti-vibration properties of the obtained composition were measured, and the results are shown in Table 1.

[0019]

[Table 1]

[0020]

The anti-vibration silicone composition of the present invention comprises the above components (A) to (C), and particularly contains (B) a silicone resin powder and (C) a boron compound in predetermined amounts. It is characterized by excellent vibration damping properties and stable vibration damping properties that are less affected by temperature changes.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayuki Hayashi 2-2 Chigusa Coast, Ichihara City, Chiba Prefecture Toray Dow Corning Silicone Co., Ltd. Research and Development Headquarters F-term (reference) 4J002 CP031 CP061 DJ017 DK006 FA081 GM00 GR00

Claims (6)

[Claims] An anti-vibration silicone composition comprising (A) 100 parts by weight of silicone oil, (B) 5 to 200 parts by weight of silicone resin powder, and (C) 0.001 to 10 parts by weight of a boron compound. 2. (A) 100 parts by weight of silicone oil, (B) 5 to 200 parts by weight of silicone resin powder, (C) 0.001 to 10 parts by weight of boron compound, and (D) fine powder of silica 0.1 1 to 100 parts by weight. 3. The vibration damping silicone composition according to claim 1, wherein the component (A) is dimethylpolysiloxane oil. 4. The silicone resin powder of component (B) has an average particle size of 0.1 to 300 μm.
3. The vibration damping silicone composition according to item 1. 5. The vibration-damping silicone composition according to claim 1, wherein the silicone resin powder of the component (B) contains a silanol group. 6. The vibration damping silicone composition according to claim 1, wherein the boron compound as the component (C) is boric acid or a borate.