WO2014002990A1

WO2014002990A1 - Viscous composition

Info

Publication number: WO2014002990A1
Application number: PCT/JP2013/067343
Authority: WO
Inventors: 誠村中
Original assignee: 株式会社ニフコ
Priority date: 2012-06-25
Filing date: 2013-06-25
Publication date: 2014-01-03
Also published as: JP6027831B2; JP2014028909A

Abstract

A viscous composition which comprises a dispersion medium and composite particles each comprising a core capable of absorbing the dispersion medium and a coating layer covering the core, and which has a viscosity of 90 to 410 inclusive at 25˚C.

Description

Viscous composition

The present invention relates to a viscous composition.

A rotary damper having a mechanism using a viscous fluid is known as a damper that is used in various opening / closing mechanisms and applies torque to the opening / closing operation of the opening / closing member. As a viscous fluid used in the rotary damper of this mechanism, for example, Japanese Patent Application Laid-Open No. 2010-281425 discloses a liquid in which solid particles are dispersed in a liquid such as silicone oil.
However, in the rotary damper of the mechanism using a viscous fluid, the viscosity of the viscous fluid changes depending on the temperature. Therefore, the torque tends to increase in the low temperature region and decrease in the high temperature region. Accordingly, there is a problem that the damper function also varies depending on the temperature.

In order to solve the above problems, a rotary damper having a mechanism that does not use a viscous fluid has been proposed. For example, JP 2009-133372 A discloses a rotary damper having an annular ring portion made of an elastomer or soft rubber and a sliding portion that slides along the circumferential direction thereof. JP-A-2001-187933 discloses a rotary damper using a viscous solid made of silicon gel.

Also, improvement of viscous fluids has been attempted as another means for solving the above problems. For example, Japanese Patent Laid-Open No. 2005-68849 discloses a magnetorheological fluid in which magnetic particles are dispersed in a liquid such as silicone oil, and a rotary damper that is filled with the magnetorheological fluid and can be adjusted in viscosity by applying a magnetic field. ing. Also, for example, Japanese Patent Application Laid-Open No. 2007-211070 discloses an adhesive grease composition in which an inorganic filler is added to a silicone oil having a specific molecular structure.

Various rotary dampers have been proposed as described above, but the technology that shows the torque value that is practically desired at room temperature and that can suppress torque fluctuations in the low temperature range is the rotation of a mechanism that does not use viscous fluid. The current situation is that neither a mechanical damper nor a rotary damper with a mechanism using viscous fluid has been obtained yet.

The present invention was made under the above situation. The problem to be solved by the present invention is to provide a viscous composition that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region.

Specific means for solving the above-described problems are as follows.
<1> A viscous composition comprising a dispersion medium and a composite particle having a core that absorbs the dispersion medium and a coating layer that covers the core, and has a consistency at 25 ° C. of 90 to 410.
<2> The viscous composition according to <1>, wherein the composite particle is a particle in which the core includes silicone rubber, and the coating layer is a layer including a polyorganosilsesquioxane resin.
<3> The viscous composition according to <1> or <2>, wherein the composite particles have an average particle size of 0.5 μm or more and 50 μm or less.
<4> The viscous composition according to any one of <1> to <3>, wherein the dispersion medium is silicone oil.
<5> The viscous composition according to any one of <1> to <4>, wherein the dispersion medium has a kinematic viscosity at 25 ° C. of 10,000 cSt or less.

According to the present invention, a viscous composition that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided.

It is a top view which shows an example of the rotary damper with which the viscous composition of this invention is filled. It is a side view of the rotary damper shown in FIG. It is a disassembled perspective view of the rotary damper shown in FIG.

Embodiments of the present invention will be described below. However, these descriptions and examples illustrate the present invention and do not limit the scope of the present invention.
In the present specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

<Viscous composition>
The viscous composition of the present invention includes a dispersion medium, and a composite particle having a core that absorbs the dispersion medium and a coating layer that covers the core, and has a consistency of 90 to 410 at 25 ° C. Here, the consistency is a value measured under non-mixing conditions with a 1/4 consistency meter according to JIS K2220: 2003.
The viscous composition having such a configuration exhibits a practically desired torque value at room temperature (for example, 23 ° C. to 25 ° C.), and the change in torque value due to temperature is small in a low temperature region.
The viscous composition of the present invention is used for a torque generating mechanism such as a rotary damper.

The viscous composition of the present invention has a consistency at 25 ° C. of 90 or more and 410 or less. In the viscous composition of the present invention in this consistency range, most of the dispersion medium is present in the state of being absorbed by the core of the composite particle, and part of the dispersion medium is present on the surface of the composite particle without being absorbed. It is considered that the slipperiness between the composite particles is improved while dispersing the composite particles. If this torque composition is filled in the torque generating mechanism, a practically desired torque value can be generated at room temperature.
In general, the viscosity of the dispersion medium for the torque generating mechanism varies depending on the temperature, and the rate of increase in viscosity increases as the temperature decreases. On the other hand, in the viscous composition of the present invention, most of the dispersion medium is present in a state absorbed by the core of the composite particle, and a part of the dispersion medium is present on the surface of the composite particle. The dispersion medium hardly exhibits temperature-dependent viscosity fluctuations. As a result, even when the viscous composition of the present invention is used in a low temperature region (eg, −30 ° C. or more and 0 ° C. or less), the change in torque value due to temperature is small. it is conceivable that.
When the viscosity of the viscous composition is less than 90, the composite particles are in a state close to powder, and it is difficult to obtain a practically desired torque value at any temperature.
On the other hand, if the viscosity of the viscous composition is more than 410, it is considered that the dispersion medium that is not absorbed by the composite particles is excessively present around the composite particles, and the dispersion medium exhibits temperature-dependent viscosity fluctuations. It is difficult to obtain a torque value desired in practice.

Furthermore, in the viscous composition of the present invention, since the composite particles absorb most of the dispersion medium and the consistency at 25 ° C. is 90 or more and 410 or less, the sedimentation of the particles due to the specific gravity difference between the dispersion medium and the particles, Of the dispersion state, aggregation between particles, and leakage of the dispersion medium can be suppressed.

[Dispersion medium]
The type of the dispersion medium contained in the viscous composition of the present invention is not particularly limited, but a liquid exhibiting fluidity in a wide temperature range (for example, −30 ° C. to 80 ° C.) is desirable. For example, a composition for a rotary damper is used. The liquid conventionally used is mentioned. Specific examples include silicone oil, polybutene, poly-α-olefin, alkylbenzene, polyalkylene glycol, and polyol ester. These may be used alone or in combination of two or more.

Examples of the silicone oil include dimethyl silicone, cyclic dimethyl silicone, methylphenyl silicone, phenyl silicone, methyl hydrogen silicone, fluorine-modified silicone, polyether-modified silicone, polyglycerin-modified silicone, amino-reactive silicone, and epoxy-reactive. Examples include silicone, mercapto reactive silicone, carbinol reactive silicone, carboxyl reactive silicone, methacrylic silicone, alkyl nonreactive silicone, aralkyl reactive silicone, and the like.
Among the above, non-reactive silicone is preferable from the viewpoint of long-term stability and low hygroscopicity.
The molecular weight of the silicone constituting the silicone oil is preferably 500 or more and 50000 or less.

Polybutene (including hydrogenated polybutene) is preferably one having a molecular weight of 5000 or less from the viewpoint of viscosity.

Examples of the poly-α-olefin include poly (1-hexene), poly (1-octene), poly (1-decene) and the like. These are preferably those having a molecular weight of 5000 or less from the viewpoint of viscosity.

Examples of the alkylbenzene include those having 1 to 6 linear or branched alkyl groups having 6 to 16 carbon atoms.
Even an alkylbenzene having a melting point of more than −30 ° C. (solid alkylbenzene at temperatures below −30 ° C.) exhibits fluidity at a temperature of −30 ° C. when mixed with other types of alkylbenzene. If present, it can be used as a dispersion medium.

Examples of the polyalkylene glycol include so-called pluronic nonionic surfactants synthesized by addition polymerization of alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) to alcohols.

Examples of the polyol ester include dioctyl adipate; dioctyl sebacate; trimethylolpropane trifatty acid esters such as trimethylolpropane trioleate; pentaerythritol tetraheptanoate;

As the dispersion medium, silicone oil, polybutene, alkylbenzene, and polyol ester are preferable, and silicone oil and polybutene are more preferable. Among these, silicone oils that are excellent in heat resistance, cold resistance, low volatility, and chemical stability are particularly preferable.

When the dispersion medium has a kinematic viscosity (cSt, centistokes) at 25 ° C. of 10,000 cSt or less, the effect of the configuration of the present invention is remarkable. When a dispersion medium with a kinematic viscosity in the above range is applied alone to a torque generating mechanism (for example, a rotary damper), the required torque value cannot be achieved for each application at room temperature (for example, 23 ° C to 25 ° C). There is. Such a dispersion medium can realize a torque value required for various applications at room temperature by using the configuration of the present invention, and a change in torque value due to temperature is small in a low temperature region.
Further, it is preferable that the dispersion medium has a kinematic viscosity at 25 ° C. of 10,000 cSt or less because it is easily absorbed by the composite particles.
The dispersion medium preferably has a kinematic viscosity at 25 ° C. of 20 cSt or more in that it is difficult to volatilize.
In the present invention, the kinematic viscosity of the dispersion medium is measured with a viscoelasticity measuring apparatus (manufactured by Anton Paar) under the condition of 2 Hz using a parallel plate as a measuring jig.

The silicone oil as the dispersion medium has a kinematic viscosity at 25 ° C. of preferably 10,000 cSt or less, more preferably 5000 cSt or less, from the viewpoint of easy absorption by the composite particles.
Since the silicone oil as the dispersion medium tends to be absorbed by the composite particles as the kinematic viscosity is lower, the lower limit value of the kinematic viscosity at 25 ° C. is not particularly limited. For example, commercially available silicone oils include silicone oils having a kinematic viscosity (25 ° C.) of 100 cSt, 10 cSt, 1 cSt, and the like, and silicone oils having a relatively low kinematic viscosity (25 ° C.) can be used in the present invention. In terms of being less volatile, the silicone oil preferably has a kinematic viscosity at 25 ° C. of 20 cSt or more.

[Composite particles]
In the present invention, particles having a nucleus and a coating layer covering the nucleus are referred to as composite particles. The composite particles contained in the viscous composition of the present invention are configured so that the core contains a substance that can absorb the dispersion medium. The coating layer may be configured to include a substance that can absorb the dispersion medium, or may be configured to include no substance that can absorb the dispersion medium.

The shape of the composite particles is arbitrary and may be spherical, elliptical, rod-shaped, plate-shaped, or indefinite. The composite particles are preferably spherical from the viewpoint of keeping the torque value within a good range.

The composite particles only need to cover at least a part of the surface of the nucleus with the coating layer, and may cover the entire surface of the nucleus.
The composite particles preferably have a path through which the dispersion medium passes in the coating layer so that the core absorbs the dispersion medium. In the case where the coating layer covers the entire surface of the nucleus, it is preferable that the coating layer includes a substance that can absorb the dispersion medium or that the coating layer has a hole through which the dispersion medium passes. When the coating layer covers a part of the surface of the nucleus, the dispersion medium can be absorbed by the nucleus from the gap where the coating layer does not cover the nucleus.

From the viewpoint of the dispersion medium absorbability of the nucleus and the permeability of the coating layer through the dispersion medium, the composite particle is preferably composed of both the nucleus and the coating layer.
The resin contained in the core and the resin contained in the coating layer may be a natural product or a synthetic product, and are preferably resins that do not react with or dissolve in the dispersion medium.

In the composite particles, the coating layer is preferably harder than the core from the viewpoint of the shape stability of the composite particles. If the coating layer is harder than the core, for example, even if there is a temperature drop or increase that causes the volume of the dispersion medium absorbed by the core or the core itself, the composite particles will undergo a temperature-dependent shape change. Hateful. And when a composite particle is excellent in shape stability, the viscous composition of this invention will have a smaller change of the torque value by temperature.
As a method for making the coating layer harder than the core, for example, the crosslinking density of the resin contained in the coating layer is made higher than the crosslinking density of the resin contained in the core.

The surface of the composite particles may be subjected to surface treatment (for example, hydrophobization treatment or hydrophilization treatment) for the purpose of increasing the affinity with the dispersion medium or for improving the dispersibility in the dispersion medium. .

The average particle size of the composite particles depends on the application to which the viscous composition of the present invention is applied and the size of the apparatus, but is preferably 0.5 μm or more and 50 μm or less. When it is 0.5 μm or more, the absorbability of the dispersion medium is good, and when it is 50 μm or less, the dispersibility with respect to the dispersion medium is good.
From the above viewpoint, the average particle diameter of the composite particles is more preferably 1 μm or more and 40 μm or less, still more preferably 2 μm or more and 30 μm or less, still more preferably 3 μm or more and 20 μm or less, and particularly preferably 4 μm or more and 15 μm or less. Or less, and most preferably 5 μm or more and 12 μm or less.
The average particle diameter of the composite particles means a 50% diameter (center diameter) when a cumulative curve is obtained with the total volume of a group of particles as 100%, and is measured by a particle size analyzer.

The composite particles may be used alone or in combination of two or more.

-Nuclear-
In the composite particles contained in the viscous composition of the present invention, the nucleus absorbs the dispersion medium. In order to obtain the property of absorbing the dispersion medium, the nucleus includes, for example, a resin having a low crosslinking density.
When a resin having a low crosslink density is applied to the core, the core is formed using, for example, rubber hardness as an index. When the rubber hardness of the core is in the range of 20 or more and 90 or less, the dispersion medium absorbability desirable as the core of the composite particle is easily developed. Here, the rubber hardness is a value measured according to JIS K6253: 2006.

Specific examples of the resin contained in the core include natural rubber, silicone rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, ethylene propylene rubber, urethane rubber, fluorine rubber, nitrile rubber, acrylic rubber, and butyl rubber. , Epichlorohydrin rubber, chlorosulfonated polyethylene rubber and the like.
The molecular species and crosslinking density of the resin may be selected from the viewpoints of affinity with the dispersion medium and absorbability of the dispersion medium.

As the core, particles containing silicone rubber (referred to as “silicone rubber particles”) are most preferable from the standpoints of absorption of the dispersion medium, heat resistance, cold resistance and the like.

Confirmation that the nucleus absorbs the dispersion medium is performed, for example, by the following method.
After immersing the nuclei in the dispersion medium, the nuclei are taken out from the dispersion medium, the mass is measured, and the nuclei absorb the dispersion medium by increasing the mass of the nuclei before immersion, which was measured in advance. Make sure you do.

-Coating layer-
The composite particle has a coating layer covering the nucleus. Here, the coating means a state in which the coating layer covers at least a part of the surface of the nucleus. The coverage (the ratio of the surface covered by the coating layer to the entire surface of the nucleus) is not particularly limited. From the viewpoint of the shape stability, wear resistance, smoothness of the composite particles, and slipperiness with the contacting member (for example, the rotor inside the rotary damper), the coverage is preferably 1% or more and 100% or less, preferably 10%. It is more preferably 95% or less and further preferably 30% or more and 90% or less.

The covering layer includes, for example, a resin. Specific examples of the resin contained in the coating layer include polyorganosilsesquioxane resin, polyurethane, epoxy resin, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polymethyl acrylate, and polymethyl methacrylate. And methyl methacrylate-styrene copolymer, polystyrene, polyester, polyamide, polyimide and the like.

The resin contained in the coating layer preferably has a higher crosslinking density than the resin contained in the core. Due to the high crosslinking density of the resin contained in the coating layer, the composite particles are excellent in shape stability. As a result, the viscosity composition of the present invention has a smaller change in torque value due to temperature.
In order to realize the above, a resin having more crosslinking points than the resin contained in the core may be selected as the resin contained in the coating layer.

The coating layer is most preferably a layer composed of a polyorganosilsesquioxane resin in terms of shape stability, wear resistance, smoothness, slipperiness with a contacting member, and the like.

The composite particles have a core containing any of silicone rubber, urethane rubber, nitrile rubber, and acrylic rubber, and a coating layer is made of polyorganosilsesquioxane resin, polymethyl methacrylate, methyl methacrylate-styrene copolymer, It is preferable to contain either polystyrene or polyamide.

-Silicone composite particles-
The composite particles include particles containing silicone rubber in terms of excellent dispersion medium absorbability, shape stability, heat resistance, cold resistance, wear resistance, smoothness, slipperiness with contacting members, etc. ( Particles (referred to as “silicone composite particles”) in which the coating layer is a layer containing a polyorganosilsesquioxane resin are suitable.

The silicone rubber particles are preferably made of a silicone cured product having a linear organopolysiloxane block represented by the following formula (1) in the molecular structure, and preferably have a crosslinked structure from the stability of the shape.
Formula (1):-(R ¹ ₂ SiO) _n-

In the formula (1), R ¹ represents an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group; an aryl group such as a phenyl group or a tolyl group; an alkenyl group such as a vinyl group or an allyl group; Group, aralkyl group such as β-phenylpropyl group; monovalent halogenated hydrocarbon group such as chloromethyl group, 3,3,3-trifluoropropyl; epoxy group, amino group, mercapto group, acryloxy group, methacryloxy group, etc. It is preferable that the monovalent organic group having 1 to 20 carbon atoms, which is selected from one or two or more kinds selected from the group consisting of the above-mentioned reactive groups, 90% by mole or more of which is a methyl group.
In the formula (1), n is an integer of 5 to 5000, preferably an integer of 10 to 1000. When n is 5 or more, the characteristics of the linear organopolysiloxane are sufficiently exhibited, and when n is 5000 or less, the production of silicone rubber particles is easy.

The shape of the silicone rubber particles is not particularly limited, but is, for example, spherical.
The silicone rubber particles may contain organosilane, inorganic particles, and organic particles within a range that does not impair the effects of the present invention.

The polyorganosilsesquioxane resin is a resinous polymer having an organosilsesquioxane unit represented by the following formula (2) as a constituent unit, and has a crosslinked structure from the stability of its shape. preferable.
Equation ^(2): R ² SiO _3/2

In the formula (2), R ² represents an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group; an aryl group such as a phenyl group or a tolyl group; an alkenyl group such as a vinyl group or an allyl group; β-phenylethyl Group, aralkyl group such as β-phenylpropyl group; monovalent halogenated hydrocarbon group such as chloromethyl group, 3,3,3-trifluoropropyl; epoxy group, amino group, mercapto group, acryloxy group, methacryloxy group, etc. It is preferable that the monovalent organic group having 1 to 20 carbon atoms, which is selected from one or two or more kinds selected from the group consisting of reactive groups, is a methyl group.

The polyorganosilsesquioxane resin may contain R ² ₂ SiO _2/2 units, R ² ₃ SiO _1/2 units, and SiO ₂ units as long as the coverage of the silicone rubber particles is not impaired.

In the silicone composite particles, the polyorganosilsesquioxane resin covers at least a part of the surface of the silicone rubber particles. From the viewpoints of shape stability, heat resistance, cold resistance, abrasion resistance, smoothness, and slipperiness with the contacting member of the silicone composite particles, polyorganosilsesquioxane resin is the entire surface of the silicone rubber particles. It is preferable to coat.

The amount of the polyorganosilsesquioxane resin is 100 masses of silicone rubber particles from the viewpoint of the shape stability, heat resistance, cold resistance, wear resistance, smoothness, slipperiness with the contacting member, etc. of the silicone composite particles. 0.5 parts by mass to 500 parts by mass is preferable with respect to parts. More preferably, it is 0.5 to 100 parts by mass.

The average particle size of the silicone composite particles is preferably 0.5 μm or more and 50 μm or less in terms of excellent absorbability of the dispersion medium, dispersibility in the dispersion medium, and the like. More preferably, they are 1 micrometer or more and 40 micrometers or less, More preferably, they are 2 micrometers or more and 30 micrometers or less, More preferably, they are 3 micrometers or more and 20 micrometers or less, Especially preferably, they are 4 micrometers or more and 15 micrometers or less, Most preferably, they are 5 micrometers or more and 12 micrometers or less .

Silicone composite particles can be produced, for example, by the following method.
That is, an alkaline substance or an aqueous alkali solution and an organotrialkoxysilane are added to an aqueous dispersion of silicone rubber particles having an average particle size of, for example, 0.5 μm or more and 50 μm or less, and hydrolysis and condensation reactions are performed in the presence of a catalyst or the like. Let After completion of the reaction, the aqueous dispersion is concentrated by a method such as heat dehydration, filtration, and centrifugation, and then washed with water as necessary to remove moisture by heating and drying to obtain silicone composite particles as a powder. . When the obtained powder has agglomeration, it may be pulverized by a pulverizer such as a jet mill or a ball mill, and further classified by a sieve or the like as necessary to adjust the particle size distribution. For details of the production method, the method described in JP-A-7-196815 may be employed.

Specific examples of the silicone composite particles include commercially available products such as KMP-600, KMP-601, KMP-602, KMP-605 and X-52-7030 manufactured by Shin-Etsu Chemical Co., Ltd.

The viscous composition of the present invention is preferably a combination in which the dispersion medium is silicone oil and the composite particles are silicone composite particles. Viscous composition using silicone oil and silicone composite particles has low torque fluctuation rate in a wide temperature range, and also has low volatility, chemical stability, heat resistance, cold resistance, abrasion resistance, Excellent slipperiness with contacting members.

In the viscous composition of the present invention, the mixing ratio of the dispersion medium and the composite particles is not particularly limited, and the consistency at 25 ° C. is 90 or more and 410 or less for each combination of the type of dispersion medium and the type of composite particles. To be mixed. For the torque generating mechanism, the mixing ratio of the dispersion medium and the composite particles may be selected so that a desired torque value is obtained for each torque generating mechanism at room temperature (for example, 23 ° C. to 25 ° C.).
The ratio of the composite particles in the total amount of the dispersion medium and the composite particles is, for example, 80% by mass or less for achieving a consistency of 90 or more, and for example, 20% by mass or more for achieving a consistency of 410 or less. The proportion of the composite particles may be adjusted to 75 mass% or less, 70 mass% or less, or 65 mass% or less, or 25 mass% or more, 30 mass% or more, 35 depending on the combination of the type of dispersion medium and the type of composite particles. Adjust to more than mass%.

The viscous composition of the present invention has a consistency at 25 ° C. of 90 or more and 410 or less. You may adjust the said consistency within the said range for every various uses.
When the viscous composition of the present invention is applied to a torque generation mechanism, the lower limit of the consistency at 25 ° C. is from the viewpoint of easily realizing a practically desired torque value at room temperature and further suppressing a change in torque value due to temperature. 100 or more is preferred, 110 or more is more preferred, 120 or more is more preferred, 150 or more is even more preferred, and the upper limit of the consistency at 25 ° C. is preferably 400 or less, more preferably 350 or less, even more preferably 320 or less, 300 The following are even more preferred:

[Other ingredients]
The viscous composition of the present invention may contain various additives as long as the use and effect of the present invention are not impaired. Examples of the additive include an antioxidant, an antigelling agent, a dye, a pigment, a thickener, a thickener, a metal deactivator, and a surfactant. The additive may be selected in accordance with the purpose, for example, from those conventionally used in a rotary damper composition.

[Method for producing viscous composition]
The viscous composition of the present invention is obtained by mixing a dispersion medium, composite particles, and an additive to be added as necessary. The mixing means is not particularly limited, and for example, a mixing means in which a gas such as air is difficult to mix into the viscous composition or a mixing means capable of degassing a mixed gas such as air is desirable. For example, a stirring kneader equipped with a deaeration device is suitable as the mixing means.

<Rotary damper>
A rotary damper will be described as an example of a torque generation mechanism to which the viscous composition of the present invention is applied.
The rotary damper includes at least a housing filled with the viscous composition of the present invention, a shaft body rotatably accommodated in the housing, and a torque plate (rotor) to which a rotational force is transmitted from the outside. The rotary damper having such a configuration has a small variation in torque value due to temperature in a low temperature region, and has a high temperature stability of the damper function.
The rotary damper is used in various door opening and closing mechanisms, various cover opening and closing mechanisms, hooks, holders and shelf rotating mechanisms, and provides torque to the opening and closing operations of the opening and closing members and the rotating operations of the rotating members. Demonstrate the damper function.

1 to 3 are schematic views showing an example of a rotary damper filled with the viscous composition of the present invention. FIG. 1 is a plan view of the rotary damper, FIG. 2 is a side view of the rotary damper, and FIG. FIG. 3 is an exploded perspective view of a rotary damper.
The rotary damper 1 includes a housing 5 in which a housing main body 4 and a cover 2 are integrated, a shaft body 3 rotatably accommodated in the housing 5, and a shaft body 3 provided in the housing 5. The brake plate (rotor) 6 accommodated is provided.
The shaft body 3 is attached to a portion protruding from the housing 5 with a gear, a cam or the like (not shown) for braking the movable portion (driven portion) of the opening / closing mechanism. The housing body 4 includes a mounting portion 4a. A mounting hole 4b is formed in the mounting portion 4a, and a screw or the like is fitted into the mounting hole 4b, so that the housing body 4 is attached to a fixing portion or the like in the opening / closing mechanism. Fixed. The housing 5 is filled with the viscous composition of the present invention.

When the shaft body 3 is rotated with respect to the housing 5, the rotary damper 1 causes friction between the brake plate 6 and the rotary damper composition inside the housing 5, thereby causing torque to the shaft body 3. Occurs, and the damper function is demonstrated.
The rotary damper having the configuration illustrated in FIGS. 1 to 3 is used, for example, in an opening / closing mechanism of a lid of a cup holder that is provided in a room of a vehicle such as an automobile and holds a container such as a cup or can. In this application, it is desirable that the torque value at 23 ° C. is, for example, in the range of 1.5 mN · m to 23 mN · m (preferably 2.5 mN · m to 23 mN · m).
The rotary damper filled with the viscous composition of the present invention can also be used to open and close an accessory case and an ashtray provided in the interior of a vehicle such as an automobile; an assist grip for an automobile; an electronic and electrical device such as a printer or a DVD deck; Can be used for mechanism.

<Application>
The viscous composition of the present invention is suitable as a composition for a torque generating mechanism that is used by being filled in the torque generating mechanism.
Examples of the torque generating mechanism include a piston damper, a free stop hinge, a liquid seal damper and the like in addition to the rotary damper.

You may apply the viscous composition of this invention for uses other than a torque generation mechanism. Applications other than the torque generating mechanism include, for example, an encapsulating material; a sealing material; a cushion material; a seismic isolation material; In the viscous composition of the present invention, the composite particles absorb most of the dispersion medium, and the consistency at 25 ° C. is in the range of 90 to 410. Therefore, the viscous composition is excellent in resilience even when pressurization and depressurization are repeated. Therefore, it is suitable for the above application.
The encapsulant is used by being encapsulated in various devices. Examples of such devices include limited slip differentials and viscous couplings mounted on vehicles such as automobiles; traction drives and clutches in vehicles such as automobiles and other power transmission mechanisms. In addition, as the encapsulating material, substitution of silicone rubber in a device such as a push-type button mounted on a vehicle such as an automobile or various devices can be given.
The sealing material is used by being sealed or applied between various devices and building members, and specifically includes, for example, a dust seal and a soundproof seal.
As a cushioning material or a seismic isolation material, it is used by being enclosed or applied between various devices and building members.

The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Preparation of materials]
The dispersion media and resin particles used in the examples, comparative examples, and reference examples are as follows.

-Dispersion medium-
Silicone oil (1): KF-96 manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.) 200 cSt.
Silicone oil (2): KF-96 manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.) 1000 cSt.
Silicone oil (3): KF-96 manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.) 5000 cSt.
Silicone oil (4): KF-96 manufactured by Shin-Etsu Chemical Co., Ltd., kinematic viscosity (25 ° C.) 300000 cSt.
-Hydrogenated polyisobutene (1): Pearl Oil 6 manufactured by NOF Corporation, kinematic viscosity (25 ° C.) 35 cSt.
Hydrogenated polyisobutene (2): Pearl Ream 18 manufactured by NOF Corporation, kinematic viscosity (25 ° C.) 30000 cSt.

-Resin particles-
Silicone composite particles (A): KMP-600 manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 5 μm, specific gravity 0.99. Composite particles in which the core is a silicone rubber particle and the coating layer is a layer made of a polyorganosilsesquioxane resin.
Silicone composite particles (B): KMP-601 manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 12 μm, specific gravity 0.98. Composite particles in which the core is a silicone rubber particle and the coating layer is a layer made of a polyorganosilsesquioxane resin.
Silicone rubber particles (C): KMP-597 manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 5 μm, specific gravity 0.97.
Silicone resin particles (D): X52-1621 manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 5 μm, specific gravity 1.30.

Silicone composite particles (A) and silicone composite particles (B) were each immersed in silicone oil (2) for 2 hours, then taken out from the oil and measured for mass. It was confirmed that the silicone composite particles (A) and the silicone composite particles (B) absorbed the silicone oil (2) by increasing the mass of the composite particles before immersion, which had been measured in advance.
Moreover, it confirmed that a silicone rubber particle absorbed the silicone oil (2) similarly to the above about the silicone rubber particle of the same material as the core of the silicone composite particle (A) and the silicone composite particle (B).

<Examples 1 to 4, Comparative Examples 1 to 3, Reference Examples 1 and 2>
[Preparation of composition]
Table 1 shows the materials and composition ratios used in Examples 1 to 4 and Comparative Examples 1 to 3. By the following operation, a composition containing a predetermined amount of silicone oil and resin particles was obtained.
Resin particles were added to silicone oil in several batches, and each time it was added, the mixture was stirred using a vacuum stirring / defoaming mixer (V-mini300 manufactured by EME). For example, in Example 3, 600 mg of silicone oil (2) and 150 mg of silicone composite particles (A) were placed in a 10 cc glass sample tube and stirred (1550 rpm, 10 minutes), followed by silicone composite particles (A ) Was added in an amount of 150 mg each and stirred (1550 rpm, 10 minutes) was repeated 5 times.

[Measurement of consistency]
The temperature of the compositions of Examples 1 to 4 and Comparative Example 1 was adjusted to 25 ° C., and the consistency was measured under non-mixing conditions with a 1/4 consistency meter according to JIS K2220: 2003. The results are shown in Table 1.
Comparative Example 1 is in a state close to powder, that is, in a state where the consistency is less than 90, and the consistency could not be actually measured.

[Measurement of torque value]
Using each composition obtained above, a rotary damper (rotor material: polyacetal, rotor diameter: 11.2 mm, clearance: 200 μm) as shown in FIGS. 1 to 3 was prepared, and this was used as the torque of the composition. The value was used for measurement.
When the rotary damper is used, for example, in a lid opening / closing mechanism of a cup holder that is provided in a vehicle interior such as an automobile and holds a container such as a cup or can, the torque value at 23 ° C. is 1.5 mN · m. It is desirable to be in the range of ˜23 mN · m.

The produced rotary damper was rotated at room temperature at a rotation speed of 120 rpm for 5 seconds, and then allowed to stand for 2 hours in an environment of ambient temperature of 80 ° C., 23 ° C., or −30 ° C.
After that, the rotating damper is rotated at a rotation speed of 20 rpm under the ambient temperature at the time of standing, and the torque value is measured using a torque measuring device (manufactured by Nifco), and the torque value between 6 seconds and 9 seconds from the start of rotation. The average value of was obtained. And the ratio of the torque value between each temperature was calculated | required. The results are shown in Table 1.

Reference Example 1 shows the torque value at 23 ° C. of the silicone oil (2) itself used in Example 1 and the like. The silicone oil (2) alone does not satisfy the torque value at 23 ° C. of 1.5 mN · m to 23 mN · m.
In Reference Example 2, silicone oil (4) having a kinematic viscosity of 300,000 cSt, which has been conventionally used for a rotary damper as shown in FIGS. 1 to 3, is used alone. As shown in Table 1, the silicone oil (4) has a torque value at 23 ° C. in the range of 1.5 mN · m to 23 mN · m, and the ratio of the torque value at −30 ° C. to the torque value at 23 ° C. ( −30 ° C./23° C.) is 1.8.

As can be seen from Table 1, in Examples 1 to 4, the torque value at 23 ° C. is in the range of 1.5 mN · m to 23 mN · m, and a torque value of −30 ° C. and a torque value of 23 ° C. The ratio (−30 ° C./23° C.) was closer to 1 than in Reference Example 2, Comparative Example 2 and Comparative Example 3. From this, it can be seen that the viscous composition of the present invention shows a practically desired torque value at room temperature and a small change in torque value due to temperature in a low temperature region. Note that Comparative Example 1 did not show a practically desired torque value at room temperature.
Therefore, according to the viscous composition of the present invention, a viscous composition that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided. In addition, by using the viscous composition of the present invention, a torque generating mechanism that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided.

<Examples 5 to 8>
Except for changing the materials and mixing ratio as shown in Table 2, compositions of Examples 5 to 8 were obtained in the same manner as in Example 3, and the consistency and torque values were measured in the same manner as described above. The results are shown in Table 2. Table 2 shows the consistency and torque values of Example 3.

As can be seen from Table 2, in Examples 5 to 8, the torque value at 23 ° C. is in the range of 1.5 mN · m to 23 mN · m, and the torque value of −30 ° C. and the torque value of 23 ° C. The ratio (−30 ° C./23° C.) was closer to 1 than in Reference Example 2, Comparative Example 2 and Comparative Example 3. From this, it can be seen that the viscous composition of the present invention shows a practically desired torque value at room temperature and a small change in torque value due to temperature in a low temperature region.
Therefore, according to the viscous composition of the present invention, a viscous composition that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided. In addition, by using the viscous composition of the present invention, a torque generating mechanism that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided.

<Example 9, Reference Example 3>
A composition of Example 9 was obtained in the same manner as in Example 3 except that the materials and the mixing ratio were changed as shown in Table 3, and the consistency and torque values were measured in the same manner as described above. However, the torque value was measured at an ambient temperature of 80 ° C., 23 ° C., and 0 ° C. The results are shown in Table 3.

In Reference Example 3, hydrogenated polyisobutene (2) having a kinematic viscosity of 30000 cSt, which has been conventionally used in a rotary damper as shown in FIGS. 1 to 3, is used alone. As shown in Table 3, the hydrogenated polyisobutene (2) has a torque value at 23 ° C. in the range of 1.5 mN · m to 23 mN · m, and the ratio of the torque value at 0 ° C. to the torque value at 23 ° C. ( 0 ° C / 23 ° C) is 3.2.

As can be seen from Table 3, in Example 9, the torque value at 23 ° C. is in the range of 1.5 mN · m to 23 mN · m, and the ratio between the torque value at 0 ° C. and the torque value at 23 ° C. (0 (° C./23° C.) was closer to 1 than in Reference Example 3. From this, it can be seen that the viscous composition of the present invention shows a practically desired torque value at room temperature and a small change in torque value due to temperature in a low temperature region.
Therefore, according to the viscous composition of the present invention, a viscous composition that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided. In addition, by using the viscous composition of the present invention, a torque generating mechanism that exhibits a practically desired torque value at room temperature and has a small change in torque value due to temperature in a low temperature region is provided.

The disclosures of Japanese Application No. 2012-142164 filed on June 25, 2012 and Japanese Application No. 2012-207444 filed on September 20, 2012 are incorporated herein by reference in their entirety. It is.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims

A viscous composition comprising a dispersion medium and a composite particle having a core that absorbs the dispersion medium and a coating layer that covers the core, and has a consistency at 25 ° C. of 90 to 410.
The viscous composition according to claim 1, wherein the composite particle is a particle in which the core contains silicone rubber, and the coating layer is a layer containing a polyorganosilsesquioxane resin.
The viscous composition according to claim 1 or 2, wherein the composite particles have an average particle size of 0.5 µm or more and 50 µm or less.
The viscous composition according to any one of claims 1 to 3, wherein the dispersion medium is silicone oil.
The viscous composition according to any one of claims 1 to 4, wherein the dispersion medium has a kinematic viscosity at 25 ° C of 10,000 cSt or less.