JP2013043912A - High damping composition and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high damping composition that is excellent in productivity, processability when a high damping member is formed, and the like and besides forms a high damping member exhibiting more excellent damping performance than the present members.SOLUTION: The high damping composition comprises at least a base polymer and, incorporated therewith, wet process silica having its moisture percentage adjusted to 6 mass% or lower. The moisture percentage is preferably 3 mass% or lower. Preferably, the wet process silica has its moisture percentage adjusted by low-humidity storage treatment or high-temperature storage treatment.

Description

  The present invention relates to a highly damped composition that is a source of a highly damped member that relaxes or absorbs transmission of vibration energy, and a method for manufacturing the same.

For example, in a wide range of fields such as buildings and bridges, industrial machinery, aircraft, automobiles, railway vehicles, computers and peripheral equipment, household electrical equipment, and automobile tires, vibration energy transmission is alleviated. In order to absorb or absorb, that is, to perform seismic isolation, vibration control, vibration control, vibration isolation, etc., a high damping member containing rubber or the like as a base polymer is used.
The high damping member includes the base polymer in order to increase the hysteresis loss when vibration is applied to improve damping performance, i.e., to efficiently and quickly attenuate the energy of the vibration. In general, it is formed by a high attenuation composition adjusted so that the peak of tan δ falls within the operating temperature range of the high attenuation member.

The high attenuation composition is formed into a predetermined three-dimensional shape, and when the base polymer is rubber, a high attenuation member is formed by vulcanization.
Examples of the high attenuation composition include those prepared by adding silica and a silane compound (silylating agent) as an attenuation imparting agent to a base polymer, kneading and reacting the silica and the silane compound. (See Patent Documents 1-3).

Further, as silica, wet method silica that can be manufactured at low cost with less energy is widely used because it does not require such a combustion step as compared with dry method silica that requires a high temperature combustion step.
However, the conventional high damping composition cannot sufficiently enhance the damping performance of the high damping member.

  In order to further improve the damping performance of the high damping member, it is conceivable to further increase the blending ratio of a filler, a tackifier, and the like. However, the high attenuation composition containing a large amount of filler and tackifier is deteriorated in workability, and the high attenuation composition is kneaded to produce a high attenuation member having a desired three-dimensional shape, There is a problem that it is not easy to form and process the three-dimensional shape.

Particularly when mass-producing high-attenuation members at the factory level, the low workability is desirable because it greatly reduces the productivity of high-attenuation members, increases the energy required for production, and further increases production costs. Absent.
In Patent Document 4, it is studied to mix silica as a filler and an attenuating agent having two or more polar groups into a base polymer having no polar side chain. According to such a configuration, it is possible to reduce the temperature dependence of characteristics near room temperature by using a base polymer that does not have a polar group while maintaining good attenuation performance by using silica together. .

  However, it is necessary to use a special and expensive material as the attenuating agent having two or more polar groups, and the blending ratio of the attenuating agent is increased in order to further improve the attenuating performance as compared with the current situation. In such a case, there is a problem that the workability is lowered because the adhesiveness of the highly attenuating composition is increased.

JP 7-41603 A JP 2009-30016 A JP-A-6-32945 JP 2009-138053 A

  An object of the present invention is to provide a high attenuation composition capable of forming a high attenuation member that is superior in productivity and workability when forming a high attenuation member, and more excellent in attenuation performance than the current state, and a method for producing the same. It is to provide.

The present invention is a highly attenuating composition containing at least a base polymer, and is characterized in that a wet process silica having a moisture content adjusted to 6% by mass or less is blended.
In the present invention, the wet process silica whose water content is not adjusted is selected by blending the wet process silica whose water content is adjusted to 6% by mass or less into the high attenuation composition containing at least the base polymer. Compared with the case where it mix | blends, while being able to obtain a higher attenuation | damping performance with an equivalent compounding quantity, the compounding quantity of the wet process silica for obtaining an equivalent attenuation | damping performance can be decreased.

Therefore, according to the present invention, it is possible to form a high-damping member that is excellent in productivity and workability when forming a high-damping member, and more excellent in damping performance than the current state.
In consideration of further improving the effect, it is preferable that the wet silica is adjusted to 3% by mass or less even in the above range.
In addition, the wet-process silica saves man-hours and labor required for adjusting the moisture content, and considering that the moisture content is constantly supplied in a constant state, the temperature is 15 ° C. or less and the relative humidity is 15% or less. It is preferable to use a product whose moisture content is adjusted within the above range by a low humidity storage treatment for 3 days or more in an environment or a high temperature storage treatment for 3 days or more in an environment at a temperature of 85 ° C. or more.

When a high-damping composition according to the present invention is used as a forming material to form a damping damper for a building as a high-damping member, the damping damper is excellent in damping performance. It is possible to reduce the number of the vibration dampers incorporated therein.
The present invention is a method for producing a highly attenuated composition comprising a step of blending at least a base polymer with a wet process silica, wherein the wet process silica prior to the blending is in an environment at a temperature of 15 ° C. or less and a relative humidity of 15% or less. Including a process of adjusting the moisture content to 6% by mass or less in advance by performing low humidity storage processing for 3 days or more, or high temperature storage processing for 3 days or more in an environment at a temperature of 85 ° C. or higher. It is characterized by.

In the present invention, the high attenuation of the present invention is obtained by blending with the base polymer and the like in a state where the moisture content of the wet process silica is adjusted to 6% by mass or less through the low humidity storage process or the high temperature storage process. The composition can be stably produced with fewer man-hours.
In the present invention, the moisture content of the wet process silica is expressed by a moisture content (mass%) based on mass measured using a heat drying moisture meter.

  According to the present invention, a high attenuation composition capable of forming a high attenuation member that is superior in productivity and workability when forming a high attenuation member, and more excellent in attenuation performance than the current state, and a method for producing the same. Can be provided.

It is a disassembled perspective view which decomposes | disassembles and shows the test body as a model of the said high attenuation member produced in order to evaluate the attenuation performance of the high attenuation member which consists of the high attenuation composition of the Example of this invention, and a comparative example. FIGS. 4A and 4B are diagrams for explaining the outline of a testing machine for displacing the test body and obtaining the relationship between the displacement and the load. It is a graph which shows an example of the hysteresis loop which shows the relationship between the displacement amount and a load calculated | required by displacing a test body using the said testing machine.

<High damping composition>
The present invention is a highly attenuating composition containing at least a base polymer, and is characterized in that a wet process silica having a moisture content adjusted to 6% by mass or less is blended.
(Base polymer)
As the base polymer, any of various base polymers that can exhibit high damping performance by blending wet process silica can be used, and rubber is particularly preferable.

  Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, norbornene rubber, ethylene propylene rubber, ethylene propylene diene rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, acrylonitrile butadiene rubber, epichlorohydrin rubber, chloro One type or two or more types such as sulfonated polyethylene and polysulfide rubber may be mentioned.

In particular, considering that the temperature dependence of the damping performance is reduced to provide a high damping member that exhibits stable damping performance over a wide temperature range, among these, natural rubber, isoprene rubber, butadiene rubber, and styrene butadiene rubber are used. At least one diene rubber selected from the group consisting of
Two or more types of rubber may be used in combination, but it is considered to improve the productivity of the high damping composition and the high damping member by simplifying the composition of the high damping composition and further reduce the production cost. Then, it is preferable to use any one of them alone.

(Wet process silica)
The reason why the moisture content of the wet process silica to be blended in the high attenuation composition is limited to 6% by mass or less is that the moisture content is higher at the same blending amount than when the wet process silica exceeding the above range is blended. This is because the damping performance can be obtained and the blending amount of the wet process silica for obtaining the equivalent damping performance can be reduced.

In consideration of further improving the effect, the moisture content of the wet process silica is preferably adjusted to 3% by mass or less even within the above range.
In addition, it does not specifically limit about the minimum of a moisture content, When the said effect is considered, a moisture content is so preferable that it is small.
However, the moisture content of the wet process silica is preferably 0.1% by mass or more. When adjusting the moisture content of the wet process silica to less than the above range, not only the effect is not obtained, but also when adjusting the moisture content by, for example, a low humidity storage process or a high temperature storage process described below. In addition, these treatments require a long time, and the productivity of the high damping member may be reduced, resulting in an increase in production cost.

Specific examples of the wet process silica include one or more of Nipsil (registered trademark) KQ, VN3, AQ, ER and the like manufactured by Tosoh Silica Co., Ltd.
Since all wet-process silicas have high hygroscopicity as is well known, according to the inventors' investigation, conventionally, the moisture content after production has been provided to the market in a state where the moisture content exceeds 6%, and remains as it is. In general, it was blended into a highly attenuated composition.

For example, wet-process silica with a water content of about 7% by mass due to crystallization water usually has a total moisture content exceeding 8% by moisture absorption after production. It was used as a raw material for producing the composition.
Still, it has been thought that there is no problem because the water is removed by heating at the time of kneading with the base polymer, or by heating at the time of crosslinking the rubber as the base polymer. By adjusting the moisture content of wet-process silica as a raw material used for the preparation of a highly attenuated composition in advance to 6% by mass or less in advance, as described above, higher attenuation performance can be achieved with an equivalent compound amount. It has become clear that the amount of the wet process silica for obtaining the same damping performance can be reduced.

In order to adjust the moisture content of the wet process silica to 6% by mass or less, for example, a normal wet process silica in which the moisture content is not controlled,
(i) Low-humidity storage treatment for storage for 3 days or more in an environment where the temperature is 15 ° C or lower and the relative humidity is 15% or lower, or
(ii) It is preferable to carry out a high temperature storage treatment for storing for 3 days or more in an environment at a temperature of 85 ° C. or higher. By performing these treatments, it is possible to stably supply wet-process silica in which the moisture content is always adjusted within a certain range while omitting the man-hours and labor required for adjusting the moisture content.

It is preferable that the temperature of the low-humidity storage treatment (i) is 15 ° C. or less and the relative humidity is 15% or less. This is because it takes a long time to adjust the mass% or less, the productivity of the high damping member is lowered, and the production cost may be increased.
In addition, it is preferable that temperature is 5 degreeC or more also in the said range. If the temperature is lower than the above range, the temperature is too low to reduce the moisture content of the wet process silica efficiently, and it takes a long time for the treatment, resulting in a decrease in productivity of the high attenuation member and an increase in production cost. There is a risk.

Moreover, it is preferable that relative humidity is 5% or more also in the said range. Even if the relative humidity is less than the above range, the effect of efficiently reducing the moisture content of the wet process silica can not be expected, and the amount of energy for maintaining the low humidity state increases. Productivity may decrease and production costs may increase.
Furthermore, the time of the low humidity storage treatment (i) is preferably 5 days or less even within the above range. Even if the treatment time exceeds the above range, the effect of efficiently reducing the moisture content of the wet process silica can not be expected, and it takes a long time for the treatment, resulting in a decrease in the productivity of the high attenuation member. Cost may increase.

The temperature of the high-temperature storage treatment (ii) is preferably 85 ° C. or higher. When the temperature is lower than the above range, it takes a long time to adjust the moisture content of the wet process silica to 6% by mass or less. This is because the productivity of the high damping member is lowered and the production cost may be increased.
In addition, it is preferable that temperature is 95 degrees C or less also in the said range. When the temperature exceeds the above range, the amount of energy for maintaining the temperature increases, so that the productivity of the high attenuation member may decrease and the production cost may increase.

Further, the high temperature storage treatment time (ii) is preferably 5 days or less even within the above range. Even if the treatment time exceeds the above range, the effect of efficiently reducing the moisture content of the wet process silica can not be expected, and it takes a long time for the treatment, resulting in a decrease in the productivity of the high attenuation member. Cost may increase.
In particular, the high temperature storage treatment (ii) is preferable. Compared with the low-humidity storage process (i), the high-temperature storage process (ii) can reduce the moisture content more efficiently and largely by the process at almost the same time.

The blending ratio of the wet process silica is preferably 80 parts by mass or more, particularly 120 parts by mass or more, more preferably 180 parts by mass or less, and particularly preferably 150 parts by mass or less, per 100 parts by mass of the base polymer.
If the blending ratio is less than the above range, the effect of improving the damping performance of the high damping member by blending the wet process silica may not be sufficiently obtained. On the other hand, when the blending ratio exceeds the above range, the workability of the high attenuation composition is lowered, and the high attenuation composition is kneaded or molded into an arbitrary shape to produce a high attenuation member. May not be easy.

(Other ingredients)
The high attenuation composition of the present invention may further contain a filler other than the wet process silica, or a crosslinking component for crosslinking the rubber when the base polymer is rubber, in an appropriate ratio. Good.
Examples of the other fillers include calcium carbonate and carbon black.

Among these, as the calcium carbonate, any of powdered calcium carbonate that can function as a filler among synthetic calcium carbonate, heavy calcium carbonate, and the like classified according to the production method thereof can be used. In addition, as calcium carbonate, a surface-treated one may be used in order to improve the affinity to the base polymer and the dispersibility.
As the carbon black, any of various carbon blacks that can function as a filler among various carbon blacks classified according to the production method thereof can be used.

The blending ratio of carbon black is not particularly limited, but is preferably 1 part by mass or more per 100 parts by mass of the base polymer, preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less.
As the crosslinking component, various crosslinking components capable of crosslinking the base polymer can be used. For example, when the base polymer is a diene rubber, it is preferable to use a sulfur vulcanized crosslinking component. Examples of the sulfur-vulcanized crosslinking component include a combination of a vulcanizing agent, a vulcanization accelerator, and a vulcanization acceleration aid. In particular, it is preferable to combine a vulcanizing agent, a vulcanization accelerator, and a vulcanization acceleration aid that hardly cause the problem that the rubber elasticity of the high damping member increases and the damping performance decreases.

Examples of the vulcanizing agent include sulfur and sulfur-containing organic compounds. In particular, sulfur is preferable.
Examples of the vulcanization accelerator include a sulfenamide vulcanization accelerator and a thiuram vulcanization accelerator. It is preferable to use two or more vulcanization accelerators in combination because the vulcanization acceleration mechanism varies depending on the type.

Among them, examples of the sulfenamide-based vulcanization accelerator include Noxeller (registered trademark) NS [N-tert-butyl-2-benzothiazolylsulfenamide] manufactured by Ouchi Shinsei Chemical Industry Co., Ltd. . Examples of the thiuram vulcanization accelerator include Noxeller TBT [tetrabutyl thiuram disulfide] manufactured by Ouchi Shinsei Chemical Co., Ltd.
Examples of the vulcanization acceleration aid include zinc white and stearic acid. Usually, it is preferable to use both as a vulcanization acceleration aid.

The blending ratio of the vulcanizing agent, vulcanization accelerator, and vulcanization accelerating agent may be appropriately adjusted according to characteristics such as damping performance and rubber hardness that differ depending on the use of the high damping member.
In the high attenuation composition of the present invention, various additives such as a silane compound, a softening agent, a tackifier, and an anti-aging agent may be further blended at an appropriate ratio as necessary.
Among these, as the silane compound, the formula (a):

[Wherein, at least one of R ¹ , R ² , R ³ , and R ⁴ represents an alkoxy group. However, R ¹ , R ² , R ³ , and R ⁴ are not simultaneously an alkoxy group, and the other represents an alkyl group or an aryl group. ]
And various silane compounds that can function as a dispersant for wet-process silica, such as silane coupling agents and silylating agents.

In particular, alkoxysilanes such as hexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and diphenyldimethoxysilane are preferred.
Examples of the silane compound include KBE-103 (phenyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.
Although the blending ratio of the silane compound is not particularly limited, it is preferably 5 parts by mass or more and preferably 25 parts by mass or less per 100 parts by mass of the wet process silica.

Examples of the softening agent include one or more of coumarone indene resin and liquid rubber.
Among these, the coumarone indene resin includes various coumarone indene resins which are mainly composed of a polymer of coumarone and indene, have a relatively low molecular weight of about 1000 or less in average molecular weight, and can function as a softening agent.

  As the coumarone indene resin, for example, Knit Resin (registered trademark) Coumarone G-90 manufactured by Nikko Chemical Co., Ltd. [average molecular weight: 770, softening point: 90 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl group] Value: 25 KOH mg / g, bromine value 9 g / 100 g], G-100N [average molecular weight: 730, softening point: 100 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl value: 25 KOH mg / g, bromine value 11 g / 100 g V-120 [average molecular weight: 960, softening point: 120 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl value: 30 KOH mg / g, bromine value 6 g / 100 g], V-120S [average molecular weight: 950, Softening point: 120 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl value: 30 KOH mg / g, bromine value 7 g / 100 g] and the like.

The blending ratio of the coumarone indene resin is not particularly limited, but it is preferably 5 parts by mass or more and preferably 50 parts by mass or less per 100 parts by mass of the base polymer.
Examples of the liquid rubber include various rubbers that are liquid at room temperature (3-35 ° C.). Examples of the liquid rubber include one or more of liquid polyisoprene rubber, liquid nitrile rubber (liquid NBR), liquid styrene butadiene rubber (liquid SBR), and the like.

Of these, liquid polyisoprene rubber is preferred. Examples of the liquid polyisoprene rubber include Claprene (registered trademark) LIR-50 manufactured by Kuraray Co., Ltd.
The blending ratio of the liquid polyisoprene rubber is not particularly limited, but is preferably 5 parts by mass or more and preferably 80 parts by mass or less per 100 parts by mass of the base polymer.
Examples of the tackifier include petroleum resins. As the petroleum resin, for example, Marcaretz (registered trademark) M890A [dicyclopentadiene-based petroleum resin, softening point: 105 ° C.] manufactured by Maruzen Petrochemical Co., Ltd. is preferable.

The blending ratio of the petroleum resin is not particularly limited, but it is preferably 3 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the base polymer.
As an anti-aging agent, 1 type, or 2 or more types of various anti-aging agents, such as a benzimidazole type, a quinone type, a polyphenol type, and an amine type, are mentioned, for example. In particular, it is preferable to use a benzimidazole antioxidant and a quinone antioxidant together.

Among them, examples of the benzimidazole-based anti-aging agent include NOCRACK (registered trademark) MB [2-mercaptobenzimidazole] manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Examples of the quinone anti-aging agent include Antigen FR [aromatic ketone-amine condensate] manufactured by Cobblestone Chemical Co., Ltd.
The blending ratio of both anti-aging agents is not particularly limited, but the benzimidazole anti-aging agent is preferably 0.5 parts by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the base polymer. The quinone anti-aging agent is preferably 0.5 parts by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the base polymer.

<Method for producing highly attenuated composition>
The highly attenuating composition of the present invention is produced by blending the above-described components at an arbitrary ratio and kneading using an arbitrary kneader or the like.
Prior to the blending, in the production method of the present invention, the wet silica before blending is subjected to the low humidity storage treatment of (i) or the high temperature storage treatment of (ii), so that the moisture content is 6 mass in advance. The process of adjusting to% or less is performed.

Thereby, the highly attenuating composition of the present invention can be stably produced with fewer man-hours.
It should be noted that the wet-process silica after the completion of the process has a tendency to immediately start moisture absorption and increase the moisture content when the storage process environment is shifted from the storage environment to the normal environment. Therefore, it is preferable to mix with other components as soon as possible after completion of the step.

<High damping member>
The high attenuation composition of the present invention is molded into a desired three-dimensional shape, and when the base polymer is rubber, the rubber is crosslinked to produce a high attenuation member having a predetermined attenuation performance.
The high damping member that can be manufactured using the high damping composition of the present invention includes, for example, a seismic isolation damper that is incorporated in the foundation of a building such as a building, and a damping damper that is incorporated in the structure of the building. Damping members for cables such as suspension bridges and cable-stayed bridges, anti-vibration members for industrial machines, aircraft, automobiles, railway vehicles, etc., anti-vibration members for computers and their peripheral devices, household electric appliances, etc. Examples include treads for automobile tires.

According to the present invention, a high damping member having excellent damping performance suitable for each application can be obtained by adjusting the base polymer, wet process silica and other various component types and their combinations and blending ratios. Can do.
In particular, when a damping damper to be incorporated into a structure of a building is formed using the high damping composition of the present invention, the damping damper is excellent in damping performance, so that it is incorporated into one building. The quantity of damping dampers can be reduced.

<Example 1>
(Adjustment of moisture content of wet silica)
As the wet method silica, NipSil (nip seal) KQ [moisture content (catalog value): 7.0% by mass] manufactured by Tosoh Silica Co., Ltd. was used. When the moisture content of the wet process silica was measured using a heat drying moisture meter [MX-50 manufactured by A & D Co., Ltd.], it was 8.4% by mass before the treatment.

Prior to the preparation of the highly attenuated composition described below, the wet process silica was subjected to low humidity storage treatment for 3 days in an environment at a temperature of 10 ° C. and a relative humidity of 10% or less. It was 5% by mass.
(Preparation of highly attenuated composition)
100 parts by mass of natural rubber [SMR (Standard Malaysian Rubber) -CV60] as a base polymer is blended with 135 parts by mass of wet-process silica immediately after the low-humidity storage treatment and each component shown in Table 1 below, and sealed A highly attenuated composition was prepared by kneading using a kneader.

Each component in the table is as follows.
Carbon Black: FEF, Sea Toe SO manufactured by Tokai Carbon Co., Ltd.
Silane compound: Phenyltriethoxysilane, KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.
Liquid polyisoprene rubber: softener, LIR50 manufactured by Kuraray Co., Ltd.
Dicyclopentadiene-based petroleum resin: softening point 105 ° C., Marukaretsu (registered trademark) M890A manufactured by Maruzen Petrochemical Co., Ltd.
Coumarone resin: softening point 90 ° C., Nikko Chemical Co., Ltd. Escron (registered trademark) G-90
Benzimidazole anti-aging agent: 2-mercaptobenzimidazole, NOCRACK MB manufactured by Ouchi Shinsei Chemical Co., Ltd.
Quinone anti-aging agent: Antigen FR manufactured by Maruishi Chemical Co., Ltd.
Two types of zinc oxide: manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: "Tsubaki" manufactured by NOF Corporation
5% oil-treated powder sulfur: vulcanizing agent, manufactured by Tsurumi Chemical Industry Co., Ltd. Sulfenamide vulcanization accelerator: N-tert-butyl-2-benzothiazolylsulfenamide, Ouchi Shinsei Chemical Industry Co., Ltd. Noxeller (registered trademark) NS
Thiuram-based vulcanization accelerator: Noxeller TBT-N manufactured by Ouchi Shinsei Chemical Co., Ltd.
<Example 2>
(Adjustment of moisture content of wet silica)
As the wet method silica, NipSil (nip seal) KQ manufactured by Tosoh Silica Co., Ltd. was used. The moisture content of the wet process silica was 8.4% by mass before the treatment as described above.

Prior to the preparation of the high-damping composition, the wet process silica was subjected to high-temperature storage treatment for 3 days in an environment at a temperature of 90 ° C., and the moisture content was measured again to be 2.2% by mass.
(Preparation of highly attenuated composition)
A highly attenuating composition was prepared in the same manner as in Example 1 except that the same amount (135 parts by mass) of the wet process silica immediately after completion of the high-temperature storage treatment was blended.

<Comparative example 1>
High in the same manner as in Example 1 except that the same amount (135 parts by mass) of wet-process silica having a moisture content of 8.4% by mass without being subjected to low-humidity storage treatment or high-temperature storage treatment was blended. A damping composition was prepared.
<Attenuation characteristic test>
(Preparation of test specimen)
The high attenuation compositions prepared in Examples 1 and 2 and Comparative Example 1 were extruded into a sheet and then punched to produce a disk 1 (thickness 5 mm × diameter 25 mm) as shown in FIG. A rectangular plate-like steel plate 2 having a thickness of 6 mm × length 44 mm × width 44 mm is overlapped on both front and back surfaces of 1 and heated to 150 ° C. while pressing in the laminating direction to form a disk 1. While vulcanizing the high-damping composition, the disk 1 was vulcanized and bonded to the two steel plates 2 to produce a specimen 3 for evaluating damping characteristics as a model of a high-damping member.

(Displacement test)
As shown in FIG. 2 (a), two test bodies 3 are prepared, and the two test bodies 3 are fixed to one central fixing jig 4 with bolts via one steel plate 2. One left and right fixing jig 5 was fixed to the other steel plate 2 of each test body 3 with bolts. The center fixing jig 4 is fixed to the upper fixing arm 6 of the testing machine (not shown) with a bolt via a joint 7, and the two left and right fixing jigs 5 are connected to the lower movable platen of the testing machine. 8 was fixed with bolts through a joint 9.

  Next, in this state, the movable platen 8 is displaced so as to be pushed up in the direction of the fixed arm 6 as indicated by the white arrow in the figure, and the disk 1 of the test body 3 is moved to the position shown in FIG. As shown in the figure, the test body 3 is strained and deformed in a direction orthogonal to the stacking direction, and from this state, the movable platen 8 is moved in a direction opposite to the direction of the fixed arm 6 as indicated by a white arrow in the figure. The operation of the test body 3 when the disk 1 of the test body 3 is repeatedly distorted or deformed, that is, vibrated, with the operation of displacing it down and returning to the state shown in FIG. A hysteresis loop H (see FIG. 3) indicating the relationship between the displacement (mm) of the disk 1 in the direction perpendicular to the stacking direction and the load (N) was obtained.

For the measurement, the above operation was performed for 3 cycles to obtain the third value. The maximum amount of displacement was set so that the amount of deviation of the two steel plates 2 sandwiching the disc 1 in the direction perpendicular to the stacking direction was 100% of the thickness of the disc 1.
Then, connecting the inner and the maximum displacement point and the minimum displacement point of the hysteresis loop H shown in FIG. 3 obtained by the measurement, a straight line L ₁ shown by a thick solid line in the figure, the horizontal axis of the graph, the straight line The elastic strain energy W expressed by the surface area of the region indicated by the halftone line in the figure surrounded by the perpendicular line L ₂ drawn from the intersection of L ₁ and the hysteresis loop H to the horizontal axis of the graph. When,
The amount of absorbed energy ΔW represented by the total surface area of the hysteresis loop H, indicated by hatching in FIG.
From equation (1):

Thus, an equivalent damping constant Heq was obtained. It can be determined that the greater the equivalent damping constant Heq is, the better the specimen 3 is in damping performance.
Therefore, when the equivalent attenuation constant Heq in Comparative Example 1 is set to 1.00, the relative value of the equivalent attenuation constant Heq in each Example and Comparative Example is obtained, and the relative value is 1.10 or more. The improvement effect was evaluated as very good (◎), 1.05 or higher as good (◯), 1.00 or higher as conventional level (-), and less than 1.00 as poor (x).

  The results are shown in Table 2.

  From the results of Examples 1 and 2 in Table 2, it was found that the damping performance of the high damping member can be improved as compared with the current situation by blending the wet process silica whose water content is adjusted to 6% by mass or less. From the results of Examples 1 and 2, it was also found that the damping performance of the high damping member can be further improved by adjusting the moisture content of the wet process silica to 3% by mass or less.

DESCRIPTION OF SYMBOLS 1 Disc 2 Steel plate 3 Specimen 4 Center fixed jig 5 Left and right fixed jig 6 Fixed arm 7 Joint 8 Movable platen 9 Joint H Hysteresis loop L ₁ Straight line L ₂ perpendicular W Energy ΔW Absorbed energy amount

Claims (5)

  A highly attenuating composition comprising at least a base polymer, wherein a wet process silica having a moisture content adjusted to 6% by mass or less is blended.   The high attenuation composition according to claim 1, wherein a moisture content of the wet process silica is 3% by mass or less.   The wet-process silica is subjected to a low-humidity storage treatment in which the temperature is 15 ° C. or less and a relative humidity is 15% or less for 3 days or more, or a high-temperature storage treatment in which the temperature is 85 ° C. or more for 3 days or more. The highly attenuating composition according to claim 1 or 2, wherein the moisture content is adjusted within the range.   The high-damping composition according to any one of claims 1 to 3, which is used as a material for forming a damper for vibration control of a building.   A method for producing a highly attenuated composition comprising a step of blending at least a base process polymer with a wet process silica, wherein the preprocessed wet process silica is used for 3 days or more in an environment of a temperature of 15 ° C. or less and a relative humidity of 15% or less. It includes a step of adjusting the moisture content to 6% by mass or less in advance by performing low-humidity storage processing for storage or high-temperature storage processing for storage for 3 days or more in an environment at a temperature of 85 ° C. or higher. Method for producing a highly attenuated composition.

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