JP4978983B2 - Damper working medium and damper device - Google Patents

Description

  The present invention relates to a working medium having a unique rheological characteristic, and a damper device using the characteristic by filling the working medium in a closed system. Especially for building damping oil dampers that control shaking caused by earthquakes and winds in high-rise buildings, door closers that relieve shocks when opening and closing doors, shock absorbers and rotary dampers used in transportation and industrial machinery systems, etc. The present invention relates to an optimum working medium and a damper device using the working medium.

High-rise buildings such as high-rise buildings, towers, and bridges are constantly subject to wind swaying and encounter large shaking due to earthquakes. In addition, transportation machines such as automobiles and railroads also shake during travel. Furthermore, various industrial machines such as machine tools also need to control vibrations and vibrations when high-precision machining is performed or when a large force is immediately relieved. Conventionally, a damper system is known as a system that enables control of these vibrations and vibrations. These include seismic dampers used in buildings, shock absorbers used in transportation and industrial machinery systems, rotary dampers and door closers. In either case, kinetic energy such as shaking and vibration is absorbed by the compressibility and flow resistance of the working medium filled in the closed system.
So far, these damper systems typically use a working fluid that is liquid at the use temperature of mineral oil or synthetic oil in consideration of safety, comfort, and responsiveness (Patent Document 1). ).

In recent years, high reliability and long life have been cited as performance required for damper systems. In particular, as a problem of a damper system filled with a liquid working medium, there are problems and performance degradation due to leakage of the liquid working medium from the seal part and the fitting part. If the working medium does not leak from the system to the outside and the initial filling state can be maintained for a long time, high reliability and long life of the damper system can be realized. Although the leakage of working medium can be suppressed to some extent by optimizing the shape and material of the seal / fitting part, thermal expansion / contraction due to fluctuations in temperature causes a physical gap, which causes operation. Causes media leakage. Although there is a means to suppress oil leakage to the outside rather than a seal mechanism by dealing with hardware in consideration of these, for example, oil repellency treatment of the seal sliding surface, it is correspondingly cost and labor . For this reason, the working medium that has leaked and is insufficient at present must be supplied to the damper system or replaced with a new damper. In particular, the dampers installed at the time of construction, such as seismic dampers for high-rise buildings, are not only easy to maintain, but there is also a concern of causing contamination around the leaked working medium.
JP 2000-119672 A

  The present invention relates to a damper working medium and a damper working medium that do not leak from a gap such as a seal part or a fitting part of the damper, and that reliably hold a desired damper operation for a long period of time. It is an object to provide a damper device used.

  The present inventors have used a semi-solid material that is not fluid in a state where mechanical shear is not substantially applied and fluid in a state where mechanical shear is applied as a working medium for a damper in a conventional damper system. Even when used as it is, the present inventors have found that the above problems can be solved, and have completed the present invention.

That is, the working medium for a damper according to the present invention is:
It is characterized by comprising a semi-solid substance that exhibits no fluidity in a state where an external force (mechanical shear) is not substantially applied and exhibits fluidity in a state where an external force (mechanical shear) is applied. The semi-solid substance preferably includes a semi-solid component composed of a compound forming a three-dimensional network structure and a liquid base oil component composed of a liquid oily compound.
Further, the compound forming the three-dimensional network structure is a compound containing one or more amide groups, and the content thereof is preferably 0.05 to 5% by mass of the working medium for the damper, and the liquid oily compound Is preferably a hydrocarbon or a hydrocarbon derivative having an ester group or an ether group.

Moreover, this invention is a damper apparatus using said working medium for dampers.
Furthermore, the present invention is a method of operating a damper device using such a working medium. When the damper device is stopped, the working medium is not fluid, and when the damper device starts to move, the working medium flows. After that, when the damper device stops, the working medium is in a state in which the working medium is not fluid, and when the damper device starts to move, the working medium is in a state in which the working medium exhibits fluidity.

  The semi-solid substance constituting the damper working medium according to the present invention does not have fluidity unless it receives external force (mechanical shearing) and maintains its shape, so that it does not leak out from the seal portion or the like. By a slight external force (mechanical shearing), the liquid instantly becomes liquid and exhibits fluidity, thereby exhibiting desired characteristics as a damper system. When the external force is removed again, it is easily recovered to a semi-solid state and has a characteristic of not leaking. As a result, the operation medium can be stably operated for a long time without leakage of the working medium from the gap of the damper system.

[Semi-solid material]
The semi-solid substance constituting the damper working medium according to the present invention is not fluid in a state where mechanical shear is not substantially applied, and exhibits fluidity in a state where mechanical shear is applied. In order to exhibit fluidity when subjected to shear, this semi-solid substance has a characteristic that the viscosity decreases as the shearing force (shear rate) increases, that is, a so-called non-Newtonian property (thixotropic property). Specifically, a medium shear rate, for example, a viscosity _{V M} at ^{5s -1,} a low shear rate, for example, the ratio of the viscosity _{V L} at ^{_{0.1s -1 (V L / V M}} ), 2 or more, In particular, 5 to 100,000, more preferably 10 to 1,000 are preferable.

The working medium of the present invention has a property that once the fluidity is obtained, the fluidity is lost again by being left at the operating temperature to lose the external force. Specifically, after 5 minutes of mechanical shearing in a high shear rate region (5 s ^-1 or more) and sufficiently reducing the viscosity, the viscosity is preferably increased by 30% or more in 30 minutes, particularly 50% or more. It is preferable to increase.
This semi-solid substance can be composed of a compound (a semi-solid component, also referred to as a gelling agent) that forms a three-dimensional network structure described later and a liquid base oil component.

[Semi-solid component]
The semi-solidifying component is preferably a compound that forms a three-dimensional network structure, and in particular, one in which this three-dimensional network structure is formed by hydrogen bonds or van der Waals bonds between the compounds.
Examples of the semi-solidifying component (gelling agent) include paraffin wax and beeswax that form van der Waals force, and alcohol compounds, fatty acid compounds, amine compounds, and amide compounds that form hydrogen bonds. These can be used alone or in combination of two or more. Of these, a gelling agent capable of forming a hydrogen bond is preferably used.
Particularly preferred semi-solidifying components are compounds containing one or more amide groups, in particular compounds containing one amide group (monoamide), compounds containing two amide groups (bisamide) or compounds containing three amide groups. (Triamide). The liquid base oil is retained in the three-dimensional (stereo) network structure of the amide compound formed by hydrogen bonding, and in particular, bisamide and triamide can make the liquid base oil semi-solid even with a relatively small amount, and It has thermoreversibility, is chemically stable, and has the advantage of reducing the frictional resistance of the sliding portion, and is most preferable.

ここで、Ｒ^１、Ｒ^２は、それぞれ独立して、炭素数５〜２５の飽和又は不飽和の鎖状炭化水素基であり、Ａ^１は、炭素数１〜１０のアルキレン基、フェニレン基又はアルキルフェニレン基、あるいはこれらが組み合わされたかたちである炭素数１〜１０の２価の炭化水素基である。 The bisamide, which is a compound containing two amide groups, may be either a diamine acid amide or a diacid acid amide. The bisamide preferably used has a melting point of 80 to 180 ° C., particularly preferably 100 to 170 ° C., and a molecular weight of 242 to 932, particularly preferably 298 to 876.
The acid amide of diamine that is preferably used is a compound represented by the following general formula (1).

Here, R ¹ and R ² are each independently a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms, and A ¹ is an alkylene group having 1 to 10 carbon atoms, a phenylene group, or It is an alkylphenylene group or a divalent hydrocarbon group having 1 to 10 carbon atoms in the form of a combination thereof.

ここで、Ｒ^３、Ｒ^４は、それぞれ独立して、炭素数５〜２５の飽和又は不飽和の鎖状炭化水素基であり、Ａ^２は、炭素数１〜１０のアルキレン基、フェニレン基又はアルキルフェニレン基、あるいはこれらが組み合わされたかたちである炭素数１〜１０の２価の炭化水素基である。 The acid amide of diacid preferably used is a compound represented by the following general formula (2).

Here, R ³ and R ⁴ are each independently a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms, and A ² is an alkylene group having 1 to 10 carbon atoms, a phenylene group, or It is an alkylphenylene group or a divalent hydrocarbon group having 1 to 10 carbon atoms in the form of a combination thereof.

  Examples of diamine acid amides include ethylene bis stearic acid amide, ethylene bisisostearic acid amide, ethylene bisoleic acid amide, methylene bislauric acid amide, hexamethylene bisoleic acid amide, hexamethylene bishydroxystearic acid amide, and m-xylylene. Bistearic acid amide or the like is preferable, and the acid amide of diacid is preferably N, N′-distearyl sebacic acid amide or the like. Among these, ethylene bis stearamide is particularly preferable.

ここで、
Ｒ^５は炭素数５〜２５の飽和又は不飽和の鎖状炭化水素基、Ｒ^６は水素、炭素数５〜２５の飽和又は不飽和の鎖状炭化水素基である。 As the monoamide which is a compound containing one amide group, a compound represented by the following general formula (3) is preferably used.

here,
R ⁵ is a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms, and R ⁶ is hydrogen, a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms.

Specifically, saturated fatty acid amides such as lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxy stearic acid amide, unsaturated fatty acid amides such as oleic acid amide and erucic acid amide, and stearyl stearic acid amide Or a long-chain fatty acid such as oleyl oleic acid amide and a substituted amide with a long-chain amine (in the above general formula, R ⁶ is not a hydrogen monoamide). However, considering that it is used at a high temperature, a substituted amide having a molecular weight close to that of bisamide is preferred. Monoamides preferably used have a melting point of 30 to 130 ° C., particularly preferably 50 to 120 ° C., and a molecular weight of 115 to 745, particularly preferably 157 to 689.

ここで、Ｒ^７、Ｒ^８、Ｒ^９は、それぞれ独立して、炭素数２〜２５の飽和又は不飽和の鎖状炭化水素基であり、Ｍはアミド基（−ＣＯ−ＮＨ−）、Ａ^３、Ａ^４、Ａ^５は、それぞれ独立して、単結合又は炭素数５以下のアルキレン基である。 Moreover, as a triamide which is a compound containing three amide groups, what is represented by following General formula (4) is used preferably.

Here, R ⁷ , R ⁸ and R ⁹ are each independently a saturated or unsaturated chain hydrocarbon group having 2 to 25 carbon atoms, M is an amide group (—CO—NH—), A ³ , A ⁴ and A ⁵ are each independently a single bond or an alkylene group having 5 or less carbon atoms.

  Specifically, N-acylamino acid diamide compounds are preferred. The N-acyl group of this compound is a linear or branched saturated or unsaturated aliphatic acyl group or aromatic acyl group having 1 to 30 carbon atoms, particularly a caproyl group, a capryloyl group, a lauroyl group, a myristoyl group, Preferred are those comprising a stearoyl group, and preferred amino acids are those comprising aspartic acid and glutamic acid, and the amine of the amide group is a linear or branched saturated or unsaturated aliphatic amine or aromatic having 1 to 30 carbon atoms. Preference is given to amines or cycloaliphatic amines, in particular those consisting of butylamine, octylamine, laurylamine, isostearylamine, stearylamine cyclahexylamine, benzylamine and the like. In particular, N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide is preferable.

A preferable blending amount of the semi-solid component is 0.05 to 20% by mass, particularly 0.2 to 10% by mass, and more preferably 0.2 to 10% by mass of the damper working medium. In particular, when triamide is used as a semi-solidifying component, the liquid base oil can be semi-solidized in a smaller amount, and the viscosity when fluidity is exhibited by external force (at high shear) is also in the liquid base oil. Not big compared. The blending amount of the triamide compound is desirably 0.01 to 10%, more preferably 0.05 to 5% in consideration of semi-solidification and thickening width at the time of flow.
The method for preparing the semi-solid substance serving as the damper working medium is not particularly limited, but a predetermined amount of the liquid base oil component and the semi-solid component (gelling agent) are weighed and exceed the melting point of the gelling agent. After heating and dissolving uniformly, it can be cooled to a semi-solid state. Alternatively, a semi-solid working medium can be obtained by dissolving a gelling agent in an alcohol-based, ketone-based, hydrocarbon-based solvent or the like, and blending the solution into a liquid base oil.

[Liquid base oil component]
The liquid base oil component is preferably a hydrocarbon or a hydrocarbon derivative having an ester group or an ether group. A kinematic viscosity at 40 ° C. of ^{2 to} 10,000 mm ² / s can be suitably used, but a kinematic viscosity in the range of 5 to 5000 mm ² / s can be more suitably used. Furthermore, the viscosity index is 90 or more, preferably 95 to 250, the pour point is −10 ° C. or less, preferably −15 to −70 ° C., and the flash point is preferably 150 ° C. or more. The hydrocarbon derivative may be a so-called silicone oil in which a part of the carbon element is replaced with a silicon element, or a so-called fluorinated ether oil in which a part of the hydrogen element is replaced with a halogen element such as fluorine.

Examples of the hydrocarbon include mineral oil and synthetic oil such as poly-α-olefin and ethylene-α-olefin oligomer.
Mineral oil is generally used as a base oil from a lubricating oil fraction obtained by subjecting crude oil to atmospheric distillation or further distillation under reduced pressure, and refined by various refining processes. Prepared by blending additives and the like. Examples of the purification process include hydrorefining, solvent extraction, solvent dewaxing, hydrodewaxing, sulfuric acid washing, and clay treatment. These processes can be combined and processed in an appropriate order to obtain a mineral oil-based lubricating base oil suitable for the present invention. A mixture of a plurality of refined oils having different properties obtained by using different crude oils or distillate oils in different process combinations and sequences can also be used as a suitable base oil.

  The synthetic oil can be used as a base oil having high heat resistance, for example, poly-α-olefin (PAO), low molecular weight ethylene / α-olefin copolymer, alkylnaphthalene or the like alone or in combination. Further, these are prepared as they are or by blending various additives and the like.

In particular, the liquid base oil preferably contains a hydrocarbon derivative having an ester group or an ether group. The proportion of such hydrocarbon derivatives in the liquid base oil is preferably 5% by mass or more, particularly 10% by mass or more, and more preferably 20% by mass or more. By doing so, the fluid medium that has obtained fluidity quickly loses fluidity and recovers to a semi-solid state.
As the hydrocarbon derivative having an ester group or an ether group, the following polyol ester, diester or polyether is preferably used.

[Polyol ester]
As the polyol ester, an ester of a polyol having 3 to 20 diols or hydroxyl groups and a fatty acid having 6 to 20 carbon atoms is preferably used.
Here, as the diol, specifically, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1, 3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12- And dodecanediol.

  Specific examples of the polyol having 3 to 20 hydroxyl groups include trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, -(Pentaerythritol), tri- (pentaerythritol), glycerin, polyglycerin (glycerin 2-20 mer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabitol, xylitol , Polyhydric alcohols such as mannitol, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, Yukurosu, raffinose, gentianose, sugars and their partial etherification such as melezitose, and methyl glucoside (glycoside) and the like.

  Among these diols and polyols, neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol, di- (pentaerythritol) Hindered alcohols such as tri- (pentaerythritol) are preferred.

  In the fatty acid used in the polyol ester, the carbon number is not particularly limited, but those having 1 to 24 carbon atoms are usually used. Among the fatty acids having 1 to 24 carbon atoms, those having 3 or more carbon atoms are preferable from the viewpoint of lubricity, those having 4 or more carbon atoms are more preferable, those having 5 or more carbon atoms are further preferable, and those having 7 or more carbon atoms. Is particularly preferred. The fatty acid may be a linear fatty acid or a branched fatty acid, and may be a fatty acid (neoic acid) in which the α carbon atom is a quaternary carbon atom. From the viewpoint of lubricity, straight chain fatty acids are preferable, and from the viewpoint of hydrolysis stability, branched fatty acids are preferable.

  Specific examples of fatty acids include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid , Nonadecanoic acid, icosanoic acid, oleic acid and the like. Among these, valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n-nonanoic acid), caprin Acid (n-decanoic acid), oleic acid (cis-9-octadecenoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid and 3,5,5 5-Trimethylhexanoic acid is preferably used.

  The polyol ester may be a partial ester that remains without being esterified, as long as it has two or more ester groups, and all the hydroxyl groups are esterified. It may be a complete ester, or a mixture of a partial ester and a complete ester, but is preferably a complete ester. When the residual amount of carboxyl groups is large, undesirable phenomena such as the formation of metal soap and precipitation due to the reaction with the metal used inside the damper occur, so that the total acid value is 3 mgKOH / g or less. Preferably, 0.1 mgKOH / g or less is more preferable. In addition, if the residual amount of hydroxyl groups is large, the ester becomes cloudy at low temperature and undesired phenomena such as blocking the damper device occur. Therefore, the hydroxyl value is preferably 50 mgKOH / g or less, and 10 mgKOH / g or less. Is more preferable.

[Diester]
As the diester, an ester of a polybasic acid having 4 to 14 carbon atoms and an alcohol having 5 to 18 carbon atoms is preferably used. Specific examples of the polybasic acid include adipic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and the like, and adipic acid, azelaic acid, and sebacic acid are preferable.
Specific examples of the alcohol include 2-ethylhexanol, 3,5,5-trimethylhexanol, decyl alcohol, lauryl alcohol, oleyl alcohol and the like, and monohydric alcohols and 6 to 6 carbon atoms. Those having branches in 12 and particularly 8 to 10 hydrocarbon groups are preferred. Specifically, 2-ethylhexanol and 3,5,5-trimethylhexanol are preferable.

[Polyether]
The polyether is an organic compound having a plurality of ether bonds, and a preferred polyether is represented by the following general formula (5) or (6).

In formulas (5) and (6), R ^{10 to} R ¹⁴ each independently represent hydrogen or an alkyl group having 1 to 8 carbon atoms, and A ^{6 to} A ⁹ each independently represent one or more carbon atoms. A polymer chain composed of 5 to 300 alkylene oxide units of 2 to 4 is shown.
R ^{10 to} R ¹⁴ are each preferably hydrogen, a methyl group, an iso-propyl group, an iso-butyl group, or a tert-butyl group, and particularly preferably all of them are methyl groups. In A ^{6 to} A ⁹ , the alkylene oxide unit is preferably an ethylene oxide unit or a propylene oxide unit, and the polymer chain may be a block copolymer chain, a random copolymer chain, or an alternating copolymer chain. The number of alkylene oxide units in the polymer chain is set so that the viscosity of the polyether falls within a predetermined range.

Specific examples of the polyether include polyalkylene glycol or a derivative thereof, polyvinyl ether, and the like, and a polyalkylene glycol derivative or polyvinyl ether in which both ends are alkyl groups is preferable.
As other liquid base oils, silicone oils having a —O— bond in the molecular structure, fluorinated ether oils, and the like can be used.

[Other additives]
In addition, in order to give performance as a normal working medium to liquid base oil, antioxidant, rust preventive agent, antiwear agent, extreme pressure agent, oiliness agent, antifoaming agent, metal deactivator, etc. You may mix | blend suitably.

[Damper]
The damper to which the present invention can be applied is not particularly dependent on the purpose, application, and shape as long as it is a damper device in which a working medium is filled in a hermetic system and the compressibility and flow resistance of the working medium are utilized. For example, the present invention can be applied to a vibration control oil damper for a building that controls shaking of a high-rise building, a door closer that softens a shock at the time of opening and closing the door, various shock absorbers and rotary dampers used in a transportation machine system and an industrial machine system.

[Example]
Examples of the present invention are shown below, but the present invention is not limited thereto.

[Liquid base oil]
As the liquid base oil (liquid base oil component), three kinds of liquids of polyol ester, polyalkylene glycol and poly-α-olefin having the properties shown in Table 1 were used. The polyol ester is mainly composed of neopentyl glycol (NPG) isostearate. Polyalkylene glycol has ethylene propylene monool as a main component. As the poly-α-olefin, a poly-α-olefin synthetic base oil (SPECTRASYN 8 manufactured by EXXONMOBIL), which is a 1-decene polymer, was used.

[Gelling agent]
The following gelling agents (amide A and amide B) were used as semisolid components to be blended with a liquid base oil to form a semisolid gel.
Amide A: N-lauroyl-L-glutamic acid-α, γ-di-n-butyramide [Ajinomoto, GP-1], melting point 151 ° C.
Amide B: Ethylene bis stearic acid amide [Nippon Kasei Co., Sripacks E], melting point 145 ° C.

[Preparation method]
The working medium was prepared by the following procedure using the above liquid base oil and gelling agent (semi-solidifying component). In a stainless steel beaker, measure a predetermined amount of liquid base oil and gelling agent in the proportions (parts by weight) shown in the upper part of Table 2, Table 3, and Table 4, respectively, and use a tabletop electromagnetic heater to exceed the melting point of the gelling agent (Melting point + 20 ° C.) (temperature was measured with a thermocouple). After visually observing the appearance of uniform dissolution, about 100 mL of the uniform solution was transferred to a heat resistant glass container (inner diameter 60 mm × height 90 mm) and allowed to cool.

〔Evaluation methods〕
The following performance evaluation test was implemented and evaluated about the working medium (Examples 1-8 and Comparative Examples 1-2) prepared as mentioned above. The evaluation results are shown in Table 2, Table 3, and Table 4.

[Evaluation 1: Confirmation of semi-solid state]
When the prepared working medium is dropped at about 1 mL with a pipette onto a glass plate set at an inclination angle of 15 degrees at room temperature (room temperature, about 25 ° C.) Judgment was made and the liquid that immediately flowed was defined as liquid. Moreover, about the working medium of Examples 1-8 and Comparative Examples 1-2 which were prepared with the said preparation method and were moved to the heat-resistant glass container, a liquid base oil and a gelatinizer isolate | separate or precipitate on appearance, or it is uniform. It was confirmed visually. As a result, even if the container was tilted, it did not flow, there was no separation or precipitation in appearance, and a uniform one was judged as “uniform / semi-solid”.

[Evaluation 2: Hardness recovery after fluidization]
In order to qualitatively grasp the rheological characteristics of the working medium in the evaluation 1, the stirring rod (cross-type propeller having a diameter of 50 mm) was placed in the glass container containing the working medium of Examples 1 to 8 evaluated as semi-solid. Was inserted and rotated at 50 rpm for 5 minutes to give mechanical shear to break and fluidize the gel, and whether the glass container was tilted was judged visually. The working media of Examples 1 to 8 all showed fluidity. After confirming the fluidity, the glass container was allowed to stand at room temperature to observe whether it became semi-solid again. The evaluation criteria are “fast” if the number of days that have become semi-solid is within 2 days, and “slow” if it is more than 2 days.

[Evaluation 3: Viscosity characteristics]
Since the physical properties of the working medium, such as hardness and semi-solid, are related to viscosity (viscosity characteristics), the rheological characteristics of the working medium were determined quantitatively. The hardness, non-Newtonian property (relationship between shear rate and viscosity) and hardness recovery rate of the working medium were measured using a B-type rotational viscometer (manufactured by Toki Sangyo Co., Ltd .: Model No. DVM-B-HMDB). That is, a predetermined amount of an evaluation sample (working medium) was put in a stainless steel sample container, and then a rotor was inserted, and the viscosity of the sample was measured while changing the rotational speed of the rotor. The experiment was performed at room temperature (about 25 ° C.).

First, the hardness of the sample was evaluated by obtaining a ratio (viscosity ratio at the time of low shear) between the viscosity of the sample at a low shear rate (0.1 s ⁻¹ ) and the viscosity of the corresponding liquid base oil.
Next, the rotational speed was increased (shear rate was increased), and it was determined whether the viscosity changed and decreased (non-Newtonian) or the viscosity did not change (Newtonian). That is, the sample in which the viscosity at a high shear rate (10 s ⁻¹ ) is reduced to ½ or less of the viscosity at a low shear rate (0.1 s ⁻¹ ) has non-Newtonian properties.
Next, after further applying mechanical shear for 5 minutes at a high shear rate (20 s ⁻¹ ), the rotational speed was immediately lowered to a low shear rate (0.1 s ⁻¹ ), and the change in viscosity at that shear rate was measured over time. The degree of recovery of hardness (whether there is a viscosity recovery property) was determined. When the time required for the viscosity to increase by 50% or more immediately after reaching the low shear rate (0.1 s ⁻¹ ) is within 30 minutes, the viscosity recovery property is “fast”, and when the viscosity is 30 minutes or more, the viscosity The recoverability was “None”.

According to Tables 2 to 4, the working media of Examples 1 to 8 containing the gelling agent were all in a uniform semi-solid state before mechanical shearing, and by applying mechanical shearing, Fluidize. In addition, all of the working media of Examples 1 to 8 have non-Newtonian properties in which the viscosity decreases as the shear rate is increased. Furthermore, even if the viscosity is temporarily decreased by applying high shear, the working medium is sheared. By reducing the viscosity, the viscosity can be recovered in a short time.
On the other hand, the samples of Comparative Example 1 and Comparative Example 2 in which no gelling agent is blended are uniform liquid Newtonian fluids, and their viscosity does not change even when shear is applied.

  As is clear from the above, the semi-solid working medium according to the present invention filled in the damper does not show fluidity under static conditions where no external force is applied, and does not leak out from the seal portion. When an external force is applied, it fluidizes and functions as a working medium for the damper. Therefore, it is used as a working medium for various dampers, and is useful for a longer life, maintenance-free operation, and prevention of oil leakage.

It is a graph which shows the relationship between the shear rate and the viscosity used for evaluation of the presence or absence of non-Newtonian property in the samples of Examples 1, 2, 3 and Comparative Example 1 (see Tables 2 and 4). It is a graph which shows the time-dependent change of the load log | history of the low shear rate-> high shear rate-> low shear rate used for evaluation of the viscosity recovery property and recovery time about the sample of Example 4, and a low shear rate (refer Table 2).

Claims (6)

No fluidity in the state machine械的allowed shear is not pressurized straw, in a state that joined the cross-sectional does not machine械的a semi-solid substance having a fluidity, the semi-solid material is represented by the following general formula (1) to (4) A semi-solid component composed of a compound that forms a three-dimensional network structure represented by any one of the above and a liquid base oil component composed of a hydrocarbon or a hydrocarbon derivative having an ester group or an ether group. A working medium for a damper characterized by.

(In the above formula, R ¹ and R ² are each independently a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms, and A ¹ is an alkylene group having 1 to 10 carbon atoms, phenylene. Or a divalent hydrocarbon group having 1 to 10 carbon atoms in the form of a group, an alkylphenylene group, or a combination thereof.)

(In the above formula, R ³ and R ⁴ are each independently a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms, and A ² is an alkylene group having 1 to 10 carbon atoms, phenylene. Or a divalent hydrocarbon group having 1 to 10 carbon atoms in the form of a group, an alkylphenylene group, or a combination thereof.)

(In the above formula, R ⁵ is a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms , and R ⁶ is hydrogen and a saturated or unsaturated chain hydrocarbon group having 5 to 25 carbon atoms.)

(In the above formula, R ⁷ , R ⁸ and R ⁹ are each independently a saturated or unsaturated chain hydrocarbon group having 2 to 25 carbon atoms, and M is an amide group (—CO—NH—). , A ³ , A ⁴ and A ⁵ are each independently a single bond or an alkylene group having 5 or less carbon atoms.) The damper working medium according to claim 1, wherein the content of the semi- solid component is 0.05 to 5% by mass of the damper working medium. The damper working medium according to claim 1 or 2 , wherein the semi-solidifying component is N-acylamino acid diamide or acid amide of diamine . 4. The damper working medium according to claim 1 , wherein the liquid base oil component has a kinematic viscosity at 40 ° C. of 5 to 5000 mm ² / s and a pour point of −15 ° C. to −70 ° C. 5 . A damper device using the damper working medium according to any one of claims 1 to 4.   6. The operation method of a damper device according to claim 5, wherein the working medium is not fluid when the damper device is stopped, and the working medium exhibits fluidity when the damper device starts to move, and then the damper device is stopped. Then, the operation | movement method of a damper apparatus which repeats the state in which a working medium does not have fluidity, and the state in which a working medium shows fluidity when a damper apparatus starts a motion.

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