JP4399043B2 - Anti-vibration silicone composition - Google Patents

Description

【００３０】
【表２】

【００３１】
【表３】

【００３２】
【発明の効果】
本発明の防振性シリコーン組成物は、防振特性の温度依存性が小さいという特徴がある。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anti-vibration silicone composition, and more particularly to an anti-vibration silicone composition having low temperature dependence of anti-vibration properties.
[0002]
[Prior art]
Anti-vibration silicone compositions comprising silicone oil and solid powders such as silica powder, glass powder, and silicone resin powder are known, for example, from JP-A 63-308241 and JP-A 63-308242. Yes.
However, these anti-vibration silicone compositions have a problem that their anti-vibration properties are likely to change with temperature.
[0003]
[Problems to be solved by the invention]
As a result of intensive studies on the above problems, the present inventors have reached the present invention.
That is, an object of the present invention is to provide a vibration-proof silicone composition having a small temperature dependency of vibration-proof characteristics.
[0004]
[Means for Solving the Problems]
The vibration-proof silicone composition of the present invention comprises: (A) a dimethylpolysiloxane having a viscosity at 25 ° C. in the range of 100 to 5,000 mPa · s, or a dimethylpolysiloxane or methyl group blocked at both ends with a trimethylsiloxy group. A diorganopolysiloxane partially substituted with an aryl group , (B) having a viscosity of 10 times or more of the viscosity of the component (A) at 25 ° C., completely compatible with the component (A) Since the solubility or solubility in the component (A) increases as the temperature rises , the light rays of the silicone oil composition comprising the component (A) and the component (B) measured by a spectrophotometer Permeability (%) increases with increasing temperature. Trimethylsiloxy group-capped dimethylpolysiloxane or both ends of a molecular chain silanol group-capped dimethylsiloxane methyl E vinylsiloxane copolymer, and (C) an average particle diameter of Ri Do from the solid powder is 0.1 to 200 [mu] m, the weight ratio of component (A) and component (B) 50: 50 to 99: it is 1 It is characterized by. However , the component (B) is a silicone oil or silicone gum having a group different from the component (A), or a silicone oil or silicone gum having the same group as the component (A) but having a different content.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The vibration-proof silicone composition of the present invention will be described in detail. Component (A) of the silicone oil is the main components of the composition, at 25 ° C., the viscosity of Ru der range of 1 00~5,000mPa · s. The molecular structure of the component (A) is not limited, and examples thereof include a straight chain, a partially branched straight chain, and a branched chain, and preferably a straight chain. Examples of the component (A) of the silicone oil, dimethylpolysiloxane with both molecular chain terminals blocked with trimethylsiloxy groups, a part of the full Eniru group methyl group of the dimethyl polysiloxane, a tolyl group, a xylyl group or the like The diorganopolysiloxane substituted by the aryl group is exemplified. However, the component (A) is a silicone oil having a group different from that of the component (B), or a silicone oil having the same group as that of the component (B) but having a different content.
[0006]
On the other hand, the component (B) has a viscosity of 10 times or more of the viscosity of the component (A) at 25 ° C. and does not completely dissolve or dissolve in the component (A). In addition, since the compatibility or solubility in the component (A) increases , the light transmittance (%) of the silicone oil composition comprising the component (A) and the component (B) measured with a spectrophotometer increases in temperature. This is a trimethylsiloxy group-capped dimethylpolysiloxane or a molecular chain both-end silanol group-capped dimethylsiloxane / methylphenylsiloxane copolymer, which increases with temperature, and reduces the temperature dependence of the anti-vibration properties of this composition. Is a component for. This is because the viscosity of component (B) at 25 ° C. is less than 10 times the viscosity of component (A) at 25 ° C., or component (B) is completely compatible or dissolved in component (A). This is because the vibration-proof characteristics of the resulting vibration-proof silicone composition are likely to change depending on the temperature. In the present composition, the component (B) is not completely compatible or dissolved in the component (A), and the compatibility or solubility in the component (A) increases as the temperature rises. A part or all of the components are dissolved or dissolved in the component (A) to be in an equilibrium state, and the temperature dependence of the vibration-proof characteristics of the composition can be reduced. In particular, since the temperature dependency of the vibration damping characteristics of the composition becomes smaller, most groups bonded to the silicone oil of component (A) is a methyl group, whereas, (B) groups attached to Ingredients As the compatibility or solubility is easy to control, and the resulting vibration-proof silicone composition has excellent heat resistance and can be used in a high temperature range, so that at least a phenyl group is bonded. Is preferred. Such (B) Ingredient is a both molecular chain terminals blocked by trimethylsiloxy groups dimethylpolysiloxane or both molecular chain terminals blocked with silanol groups dimethylsiloxane-methylphenylsiloxane copolymers, in fact, the component (A) A silicone oil or silicone gum having a different group, or a silicone oil or silicone gum having the same group as that of the component (A) but having a different content .
[0007]
In the present composition, (B) The amount of component, (A) component and (B) weight ratio of component 50 to 99: Ri der 1, especially in the range, the weight ratio is 70:30 It is preferable to be within the range of ~ 95: 5. This is because when the blending amount of the component (B) is less than the lower limit of the above range with respect to the weight of the component (A), the temperature dependency of the vibration-proof property of the resulting vibration-proof silicone composition tends to increase. On the other hand, if the upper limit of the above range is exceeded, when the resulting vibration-proof silicone composition is subjected to repeated temperature changes, its stability tends to decrease.
[0008]
The solid powder of component (C) is a component for imparting vibration-proof properties to the present composition, and the average particle size thereof is in the range of 0.1 to 200 μm, preferably 0.1 to It is in the range of 100 μm, and particularly preferably in the range of 10 to 40 μm. Further, the solid powder of the component (C) has a content of solid powder having a particle size of 10 μm or less of 1% by weight or more and a content of solid powder having a particle size of 30 μm or more of 10% by weight or more. It is preferable to have a particle size distribution. Examples of the solid powder of component (C) include inorganic powders such as silica powder, calcium carbonate powder, and glass powder (beads); organic resin powders such as polyethylene resin powder, acrylic resin powder, and fluororesin powder; silicone resin powder Is exemplified.
[0009]
In the present composition, the amount of component (C) is not limited, but is preferably within the range of 5 to 200 parts by weight with respect to the total of 100 parts by weight of component (A) and component (B). It is preferably within the range of 10 to 150 parts by weight. When the blending amount of the component (C) is less than the lower limit of the above range with respect to the total of 100 parts by weight of the component (A) and the component (B), the resulting vibration-proof silicone composition is vibration-proof. This is because the properties tend to be insufficient, and even if the upper limit of the above range is exceeded, the vibration-proof properties of the resulting vibration-proof silicone composition tend to be insufficient.
[0010]
The method for producing the vibration-proof silicone composition of the present invention is not limited. For example, the method of mixing the component (A), the component (B), and the component (C) with a mixing device, or the component (A) and (B) The component can be dissolved in an organic solvent that can be dissolved together, and then the (C) component is mixed with the silicone oil composition from which the organic solvent has been removed. The latter method is preferable because separation hardly occurs.
[0011]
In the former production method, the mixing device for mixing the component (A), the component (B), and the component (C) is not limited. For example, a known mixing device such as a planetary mixer, a Henschel mixer, or a Hobart mixer may be used. Illustrated.
[0012]
In the latter production method, examples of the organic solvent that can dissolve both the component (A) and the component (B) include aromatic organic solvents such as toluene and xylene; ketones such as acetone and methyl isobutyl ketone. Organic organic solvents; aliphatic hydrocarbon organic solvents such as hexane, heptane and cyclohexane; and chlorinated organic solvents such as chloroform, 1,1,1-trichloroethane and 1,1,1-trichloroethylene.
[0013]
In the latter method, the amount of the organic solvent is not limited, but the amount can completely dissolve the component (A) and the component (B). In this case, the dissolution of these components should be promoted by heating. Can do. In this way, the component (A) and the component (B) are dissolved in the organic solvent, and then the organic solvent is removed, so that the component (A) is compatible with the component (A). A silicone oil composition in which the component (B) that has not been dissolved is uniformly dispersed can be prepared. In particular, even when the obtained vibration-proof silicone composition is subjected to repeated temperature changes, the temperature dependence of its vibration-proof characteristics can be kept small. Therefore, in component (A), It is preferable to use a silicone oil composition in which the component (B) that is compatible or not dissolved is dispersed in the form of particles having an average particle diameter of 0.01 to 500 μm.
[0014]
Next, the component (C) is mixed with the silicone oil composition in which the component (B), which has not been dissolved or dissolved in the component (A), is uniformly dispersed in the component (A). Examples of the method of mixing the component (C) with the silicone oil composition include a method of mixing with the exemplified mixing apparatus.
[0015]
The anti-vibration silicone composition of the present invention is suitable as an anti-vibration material in a severe place where the anti-vibration property is subject to temperature changes because of its small temperature dependence.
[0016]
【Example】
The vibration-proof silicone composition of the present invention will be described in detail with reference to examples. In addition, the viscosity in an Example is the value measured in 25 degreeC. In addition, in order to confirm the change in compatibility or solubility of the component (B) with respect to the component (A) due to temperature rise, the light transmittance of the silicone oil composition comprising the components (A) and (B) is measured. It was measured with a photometer (UV-265FW manufactured by Shimadzu Corporation; wavelength 500 nm; optical path width 1 mm). Further, the average particle size (number average particle size) of the component (B) dispersed in the component (A) was determined by an image processing apparatus connected to an optical microscope. Furthermore, the anti-vibration property of the anti-vibration silicone composition was measured by a rheometric dynamic analyzer RDA-700 (plate method) manufactured by RHEOMETRICS, and indicated by its loss coefficient (tan δ). The measurement conditions are as follows.
Plate diameter: 20mm
Frequency: 10Hz
Strain: 20%
Sample thickness: 1mm
[0017]
[Example 1]
Into a 500 ml three-necked flask equipped with a stirrer, 200 g of toluene, and a dimethylsiloxane / methylphenylsiloxane copolymer blocked with silanol groups at both ends of a molecular chain having a plasticity defined by JISK 6249 of 100 (dimethylsiloxane units and methylphenylsiloxane) Unit weight ratio = 92: 8) 20 g was added and heated under stirring to completely dissolve this copolymer. Next, 180 g of trimethylsiloxy group-capped dimethylpolysiloxane having a molecular chain viscosity of 1,000 mPa · s was charged into the flask and stirred uniformly, and then heated to 150 ° C. under reduced pressure to remove toluene. Then it was cooled to room temperature. The obtained silicone oil composition had a viscosity of 3,560 mPa · s and was a translucent suspension viscous liquid. The average particle diameter of the dimethylsiloxane / methylphenylsiloxane copolymer dispersed in a granular form was 2 μm.
[0018]
The temperature-viscosity characteristics of this silicone oil composition were measured with a rotational viscometer manufactured by Brookfields, and the results are shown in Table 1. Further, the change in the compatibility or solubility of the dimethylsiloxane / methylphenylsiloxane copolymer and dimethylpolysiloxane when this silicone oil composition was heated was observed by the change in the light transmittance. The change in light transmittance is shown in Table 2.
[0019]
Into a Hobart mixer manufactured by Hobart, 100 g of the above silicone oil composition, 162 g of calcium carbonate having an average particle size of 20 μm, and 36 g of glass beads having an average particle size of 90 μm are added, stirred at a low speed, and scraped off every 30 minutes. The mixture was kneaded for 1 hour to prepare a vibration-proof silicone composition. Measure tan δ at −20 ° C., 25 ° C., and 60 ° C. of the vibration-proof silicone composition, and determine the ratio of tan δ at −20 ° C. and 60 ° C. to tan δ at 25 ° C., and the results Are shown in Table 3.
[0020]
[Example 2]
In Example 1, the blending amount of the dimethylsiloxane / methylphenylsiloxane copolymer blocked with both ends of silanol groups having a degree of plasticity defined in JIS K 6249 of 100 is 30 g, and the viscosity is 1,000 mPa · s. A silicone oil composition was prepared in the same manner as in Example 1 except that the amount of trimethylsiloxy group-blocked dimethylpolysiloxane at both chain ends was 170 g. The obtained silicone oil composition had a viscosity of 5,720 mPa · s and was a translucent suspension viscous liquid. The average particle size of the dimethylsiloxane / methylphenylsiloxane copolymer dispersed in a granular form was 2 μm.
[0021]
The temperature-viscosity characteristics of this silicone oil composition were measured with a rotational viscometer manufactured by Brookfields, and the results are shown in Table 1. In addition, a change in the compatibility or solubility of the dimethylsiloxane / methylphenylsiloxane copolymer and dimethylpolysiloxane when the silicone oil composition was heated was observed by a change in light transmittance. The change in light transmittance is shown in Table 2.
[0022]
Into a Hobart mixer manufactured by Hobart, 100 g of the above silicone oil composition, 162 g of calcium carbonate having an average particle size of 20 μm, and 36 g of glass beads having an average particle size of 90 μm are added, stirred at a low speed, and scraped off every 30 minutes. The mixture was kneaded for 1 hour to prepare a vibration-proof silicone composition. The anti-vibration silicone composition was measured for tan δ at −20 ° C., 25 ° C., and 60 ° C., and the ratio of each tan δ at −20 ° C. and 60 ° C. with respect to tan δ at 25 ° C. was determined. Are shown in Table 3.
[0023]
[Example 3]
A 500 ml three-necked flask equipped with a stirrer is charged with 200 g of toluene and 10 g of dimethylpolysiloxane blocked with trimethylsiloxy group-blocked dimethylpolysiloxane having a plasticity specified by JISK 6249 of 160, and this is heated under stirring. Was completely dissolved. Next, 190 g of a trimethylsiloxy group-blocked dimethylsiloxane / methylphenylsiloxane copolymer (molar ratio of methyl group to phenyl group = 5: 95) having a viscosity of 500 mPa · s was added to the flask. After stirring, the mixture was heated to 150 ° C. under reduced pressure to remove toluene, and then cooled to room temperature. The obtained silicone oil composition had a viscosity of 850 mPa · s and was a translucent suspension viscous liquid. The average particle size of the dimethylsiloxane / methylphenylsiloxane copolymer dispersed in a granular form was 30 μm.
[0024]
The temperature-viscosity characteristics of this silicone oil composition were measured with a rotational viscometer manufactured by Brookfields, and the results are shown in Table 1. In addition, a change in the compatibility or solubility of the dimethylsiloxane / methylphenylsiloxane copolymer and dimethylpolysiloxane when the silicone oil composition was heated was observed by a change in light transmittance. The change in light transmittance is shown in Table 2.
[0025]
Into a Hobart mixer manufactured by Hobart, 100 g of the above silicone oil composition, 162 g of calcium carbonate having an average particle diameter of 20 μm, and 360 g of glass beads having an average particle diameter of 90 μm are added, stirred at a low speed, and scraped off every 30 minutes. The mixture was kneaded for 1 hour to prepare a vibration-proof silicone composition. The anti-vibration silicone composition was measured for tan δ at −20 ° C., 25 ° C., and 60 ° C., and the ratio of tan δ at −20 ° C. and 60 ° C. with respect to tan δ at 25 ° C. was determined. Indicated.
[0026]
[Example 4]
In a Hobart mixer manufactured by Hobart, a dimethylsiloxane / methylphenylsiloxane copolymer having both ends of a molecular chain blocked with a silanol group having a plasticity defined by JIS K 6249 of 100 (weight ratio of dimethylsiloxane units to methylphenylsiloxane units = 92) : 8) 8 g, viscosity of 1,000 mPa · s molecular chain both ends trimethylsiloxy group-blocked dimethylpolysiloxane 92 g, average particle size 20 μm calcium carbonate 162 g, average particle size 90 μm glass beads 36 g, and stirred at low speed The anti-vibration silicone composition was prepared by kneading for 1 hour while scraping off every 30 minutes. The anti-vibration silicone composition was measured for tan δ at −20 ° C., 25 ° C., and 60 ° C., and the ratio of tan δ at −20 ° C. and 60 ° C. with respect to tan δ at 25 ° C. was determined. Indicated.
[0027]
[Comparative Examples 1-3]
Molecular chain both ends trimethylsiloxy group-capped dimethylpolysiloxane having a viscosity of 5,000 mPa · s, molecular chain both ends trimethylsiloxy group-capped dimethylpolysiloxane having a viscosity of 12,500 mPa · s, and molecular chain both ends trimethylsiloxy having a viscosity of 500 mPa · s For the blocked dimethylsiloxane / methylphenylsiloxane copolymer (molar ratio of methyl group to phenyl group = 5: 95), the respective temperature-viscosity characteristics were measured with a rotational viscometer manufactured by Brookfields, and the results were obtained. It is shown in Table 1.
[0028]
100 g of these silicone oils, 162 g of calcium carbonate having an average particle diameter of 20 μm, and 36 g of glass beads having an average particle diameter of 90 μm are put into a Hobart mixer manufactured by Hobart, stirred at a low speed, and scraped off every 30 minutes. By kneading for a period of time, three types of vibration-proof silicone compositions were prepared. These vibration-proof silicone compositions were measured for tan δ at −20 ° C., 25 ° C., and 60 ° C., and the ratios of tan δ at −20 ° C. and 60 ° C. with respect to tan δ at 25 ° C. were determined. It was shown to.
[0029]
[Table 1]

[0030]
[Table 2]

[0031]
[Table 3]

[0032]
【The invention's effect】
The vibration-proof silicone composition of the present invention is characterized in that the temperature dependence of the vibration-proof characteristics is small.

Claims (4)

(A) Dimethylpolysiloxane having both ends of a molecular chain blocked with a trimethylsiloxy group having a viscosity at 25 ° C. in the range of 100 to 5,000 mPa · s, (B) The viscosity of the component (A) at 25 ° C. Spectrophotometer, because it has a viscosity of 10 times or more of the above and does not completely dissolve or dissolve in the component (A), and the compatibility or solubility in the component (A) increases with increasing temperature. The light transmittance (%) of the silicone oil composition comprising the component (A) and the component (B) measured by the method increases with increasing temperature. (C) an average particle size of 0.1 to 200 μm, and a solid powder selected from inorganic solid powder, organic resin solid powder, and silicone resin powder; And the weight ratio of the component (B) is 50:50 to 99: 1, and the blending amount of the component (C) is 5 to 200 weights with respect to a total of 100 parts by weight of the components (A) and (B). Antivibration silicone composition which is part. (A) a diorganopolysiloxane in which both ends of a molecular chain having a viscosity at 25 ° C. in the range of 100 to 5,000 mPa · s are blocked with a trimethylsiloxy group and a part of the methyl group is substituted with an aryl group; B) At 25 ° C., the viscosity of the component (A) is 10 times or more, and the component (A) is not completely compatible or dissolved in the component (A). Since the compatibility or solubility increases, the light transmittance (%) of the silicone oil composition comprising the component (A) and the component (B) measured by a spectrophotometer increases as the temperature rises. And (C) an average particle size of 0.1 to 200 μm, selected from inorganic solid powder, organic resin solid powder, and silicone resin powder. The weight ratio of the component (A) to the component (B) is 50:50 to 99: 1, and the amount of the component (C) is the sum of the components (A) and (B). The vibration-proof silicone composition which is 5-200 weight part with respect to 100 weight part. The anti-vibration silicone composition is prepared by dissolving the component (A) and the component (B) in an organic solvent that can be dissolved together, and then mixing the component (C) in the silicone oil composition from which the organic solvent has been removed. The anti-vibration silicone composition according to claim 1 or 2, wherein A silicone oil composition obtained by dissolving the component (A) and the component (B) in an organic solvent that can be dissolved together, and then removing the organic solvent is contained in the component (A) at 25 ° C. characterized in that (a) is not compatible or soluble in the component the component (B) in which are dispersed in the form of particles having an average particle diameter 0.01～500Myuemu, any of claims 1 to 3 A vibration-proof silicone composition according to claim 1.