JP6880445B2 - Method for manufacturing high damping composition and method for manufacturing viscoelastic damper - Google Patents

Description

The present invention uses a method for producing a high damping composition which is a source of a high damping member for relaxing or absorbing vibration energy transmission, and a high damping composition produced by the manufacturing method for viscoelasticity. It relates to a method of manufacturing a viscoelastic damper including a step of forming an elastic body.

For example, high damping members are used in a wide range of fields such as buildings such as buildings and bridges, industrial machinery, aircraft, automobiles, railroad vehicles, computers and their peripherals, household electrical equipment, and automobile tires. .. By using the high damping member, it is possible to relax or absorb the transmission of vibration energy, that is, to perform seismic isolation, vibration control, vibration control, vibration control, and the like.
The high damping member is mainly formed of a high damping composition containing a crosslinkable rubber such as natural rubber.

The high damping composition is filled with inorganic materials such as carbon black and silica in order to increase the hysteresis loss when vibration is applied and to improve the performance of efficiently and quickly damping the energy of the vibration, that is, the damping performance. It is common to add an agent or a tackifier such as rosin or petroleum resin (see, for example, Patent Documents 1 to 3).
However, with these conventional configurations, the damping performance of the high damping member cannot be sufficiently enhanced, and in order to further enhance the damping performance from the current level, the blending ratio of the inorganic filler, the tackifier, etc. should be increased from the current level. It is conceivable to further increase the number.

However, the high-damping composition containing a large amount of inorganic filler becomes difficult to knead, and the high-damping composition containing a large amount of tackifier becomes too sticky at the time of kneading. There is a problem that it is lowered and it becomes difficult to knead or mold to produce a high damping member having a desired three-dimensional shape.
In particular, when mass-producing high damping members at the factory level, low workability greatly reduces the productivity, increases the energy required for production, and further increases the production cost, which is not desirable.

Therefore, in order to improve the damping performance without lowering the workability, in Patent Document 4, a crosslinkable rubber having no polar side chain such as natural rubber, silica, an adhesive imparting agent having two or more polar groups, etc. It is being considered to combine with.
However, when the compounding ratio of the tackifier is increased in order to further improve the damping performance from the current state, the tackifier blooms on the surface of the high damping member, resulting in poor adhesion to metal or the like. Is a concern.

In Patent Document 5, it is studied to further improve the damping performance by using a rosin derivative having a specific softening point as a tackifier.
However, when the compounding ratio of the rosin derivative is increased in order to further improve the damping performance from the current state, there is a problem that the adhesiveness at the time of kneading becomes too high and the processability is lowered.

In Patent Document 6, it is studied to further improve the damping performance by blending imidazole and a hindered phenolic compound as an damping agent.
However, even with such a configuration, the current situation is that it is becoming difficult to sufficiently meet the demand for even higher attenuation in recent years.
In Patent Document 7, high rigidity and good results are obtained by using a diene rubber, a 1,2-polybutadiene polymer, a novolac-type phenol resin, and a silane coupling agent in a predetermined ratio together with silica and a silylating agent. It is being studied to satisfy both excellent damping performance and good workability.

Further, in Patent Document 8, a 1,2-polybutadiene elastomer, silica, an alkyl silylating agent, a phenyl silylating agent, and a silane coupling agent are further added to the polyisoprene rubber and the polybutadiene rubber as the diene rubber. By doing so, it has been studied to suppress the deterioration of damping performance when large deformation is repeatedly applied due to an earthquake or the like.

Japanese Unexamined Patent Publication No. 2003-3014 Japanese Unexamined Patent Publication No. 2007-63425 Japanese Unexamined Patent Publication No. 07-41603 Japanese Unexamined Patent Publication No. 2009-138053 Japanese Unexamined Patent Publication No. 2010-189604 Japanese Unexamined Patent Publication No. 2011-116931 Japanese Unexamined Patent Publication No. 2013-53251 Japanese Unexamined Patent Publication No. 2015-129251

However, as described in Patent Documents 7 and 8, when a 1,2-polybutadiene polymer (1,2-polybutadiene elastomer) is blended in the high damping composition, the damping performance of the high damping member depends on the temperature. There is a problem that the sex becomes large.
An object of the present invention is a method for producing a high damping composition capable of forming a high damping member having excellent damping performance and rigidity and a small temperature dependence of the damping performance, and a high damping composition produced by the manufacturing method. It is an object of the present invention to provide a method for producing a viscoelastic damper provided with a viscoelastic body.

The present invention is a crosslinkable rubber having two types of polyisoprene rubber and polybutadiene rubber, and the compounding ratio of the polybutadiene rubber is 40 parts by mass or more and 80 parts by mass or less in the total amount of 100 parts by mass of both rubbers. , 100 parts by mass or more and 150 parts by mass or less of silica, 1 part by mass or more and 10 parts by mass or less of an alkyl-type silylating agent, 15 parts by mass or more and 30 parts by mass, per 100 parts by mass of the total amount of the two types of crosslinkable rubber. A method for producing a high damping composition, which comprises a step of kneading a phenyl type silylating agent of 1 part or less and a silane coupling agent of 1 part by mass or more and 10 parts by mass or less at a temperature of 145 ° C. or higher and 175 ° C. or lower. ..

Further, the present invention is a method for producing a viscoelastic damper, which comprises a step of forming a viscoelastic body using the high damping composition produced by the above-mentioned production method of the present invention.

According to the present invention, a method for producing a high damping composition capable of forming a high damping member having excellent damping performance and rigidity and a small temperature dependence of the damping performance, and a high damping composition produced by the manufacturing method are used. It is possible to provide a method for producing a viscoelastic damper provided with a viscoelastic body.

An exploded perspective view of a test piece as a model of the high damping member produced for evaluating the damping performance of the high damping member made of the high damping composition produced in Examples and Comparative Examples of the present invention. Is. FIGS. (A) and (b) are diagrams illustrating an outline of a testing machine for displacing the test body and obtaining the relationship between the displacement amount 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, which is obtained by displacing a test body using the above-mentioned test machine.

<< Manufacturing method of high damping composition >>
The method for producing the high damping composition of the present invention is two kinds of polyisoprene rubber and polybutadiene rubber, and the compounding ratio of the polybutadiene rubber is 40 parts by mass or more in 100 parts by mass of the total amount of both rubbers, 80 parts by mass. parts by mass or less in a cross-linkable rubber, the total amount per 100 parts by weight of the two cross-linkable rubber, 100 parts by mass or more, 150 parts by mass of silica, 1 part by mass or more, 10 parts by weight or less of alkyl type silylating agent , 15 parts by mass or more and 30 parts by mass or less, and 1 part by mass or more and 10 parts by mass or less of the silane coupling agent are kneaded at a temperature of 145 ° C. or higher and 175 ° C. or lower. It is characterized by.

According to the present invention, the 1,2-polybutadiene polymer is not blended, and instead, the crosslinkable rubber is mixed with silica, an alkyl-type silylating agent, a phenyl-type silylating agent, and a silane coupling in the above-mentioned predetermined ratios. By setting the temperature at the time of blending and kneading the agent in the above range, the reactivity of the silane coupling agent with the crosslinkable rubber or silica can be enhanced as compared with the present state.

That is, when producing a conventional high-damping composition such as Patent Documents 1 to 8, the temperature of the kneading is generally set to less than 145 ° C., usually about 135 ° C., but this kneading By setting the temperature to 145 ° C. or higher, the silane coupling agent can react with the crosslinkable rubber or silica even better than at present.
Therefore, even if the 1,2-polybutadiene polymer is not blended, the damping performance and rigidity of the high damping member made of the high damping composition can be improved as much as or more than the case where the polymer is blended.

Moreover, by not blending (excluding) the 1,2-polybutadiene polymer, it is possible to reduce the temperature dependence of the damping performance.
However, when the kneading temperature exceeds 175 ° C., the rubber is likely to be burnt during kneading. Therefore, the kneading temperature must be 175 ° C. or lower in order to suppress the burning.

Considering that the damping performance and rigidity of the high damping member are further improved while more effectively suppressing the occurrence of burning, the kneading temperature is preferably 150 ° C. or higher even in the above range. It is preferably 170 ° C. or lower.
<Crosslinkable rubber>
As the crosslinkable rubber, two types of rubber, polyisoprene rubber and polybutadiene rubber, are used. The term "two types" as used herein includes the case where two or more types of polyisoprene rubber and two or more types of polybutadiene rubber are used in combination.

(Polyisoprene rubber)
Examples of the polyisoprene-based rubber include natural rubber and / or polyisoprene rubber, and natural rubber is particularly preferable because it has an advantage that it is easily available and a high-damping composition can be produced at low cost.
(Polybutadiene rubber)
As the polybutadiene rubber, any of various polybutadiene rubbers having crosslinkability can be used.

As is well known, the polybutadiene rubber referred to here refers to a polybutadiene rubber as a general-purpose synthetic rubber excluding 1,2-polybutadiene polymer.
Examples of such polybutadiene rubber include cis 1,4-polybutadiene rubber and trans 1,4-polybutadiene rubber. The former cis 1,4-polybutadiene rubber has a cis-1,4 bond ratio of 90% by mass or more. It is classified into high cis polybutadiene rubber and low cis polybutadiene rubber having a cis-1,4 bond ratio of about 35% by mass.

Any polybutadiene rubber can be used, but the change in physical properties due to temperature is particularly small, and the decrease in elastic modulus due to heat generation is suppressed, and the decrease in damping performance when a large deformation is repeatedly applied to the high damping member is suppressed. A high cis-polybutadiene rubber having an excellent function and having a cis-1,4 bond ratio of 90% by mass or more, particularly 95% by mass or more is preferable.
Specific examples of such high cis polybutadiene rubber include UBEPOL (registered trademark) BR150 manufactured by Ube Kosan Co., Ltd. [Moony viscosity (ML _{1 + 4} , 100 ° C.): 43, cis-1,4 bond content: 98% by mass]. , BR150B [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 40, cis-1,4 bond content: 97% by mass], BR130B [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 29, cis-1,4 bond content: 96% by mass], BR150L [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 43, cis-1,4 bond content: 98% by mass], BR360L [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 51, cis-1, cis-1, 4 bond content: 98% by mass], BR230 [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 38, cis-1,4 bond content: 98% by mass], BR710 [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 44, Cis-1,4 bond content: 98% by mass], BR133P [Moonie viscosity (ML _{1 + 4} , 100 ° C.): 35, cis-1,4 bond content: 98% by mass], etc. ..

(Mixing ratio)
The blending ratio of the polybutadiene rubber needs to be 40 parts by mass or more and 80 parts by mass or less in the total amount of 100 parts by mass of the polyisoprene rubber and the polybutadiene rubber as the crosslinkable rubber.
If the blending ratio is less than this range, the effect of blending the polybutadiene rubber to suppress the deterioration of the damping performance when the high damping member is repeatedly subjected to large deformation may not be sufficiently obtained.

On the other hand, if the blending ratio of the polybutadiene rubber exceeds the above range, the processability of the high damping composition may decrease.
On the other hand, by setting the compounding ratio of the polybutadiene rubber in the above range, the damping performance when the high damping member is repeatedly subjected to large deformation while suppressing the deterioration of the workability of the high damping composition is achieved. The decrease can be suppressed more effectively.

In consideration of further improving the effect, the compounding ratio of the polybutadiene rubber is preferably 50 parts by mass or more, preferably 70 parts by mass or less, based on 100 parts by mass of the total amount of the crosslinkable rubber even in the above range. Is preferable.
<silica>
As the silica, either wet method silica or dry method silica classified according to the production method may be used. As the silica, considering that further enhance the effect of improving the damping performance of the high damping member, preferably a BET specific surface area used as a 100 to 400 m ² / g, especially 200~250m ² / g .. The BET specific surface area is represented by a value measured by a vapor phase adsorption method using nitrogen gas as an adsorption gas using, for example, a rapid surface area measuring device SA-1000 manufactured by Shibata Chemical Instruments Co., Ltd.

Examples of silica include NipSil KQ manufactured by Tosoh Silica Co., Ltd.
The blending ratio of silica needs to be 100 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
If the blending ratio of silica is less than this range, good damping performance cannot be imparted to the high damping member.

On the other hand, when the compounding ratio of silica exceeds the above range, the processability of the high attenuation composition is lowered.
On the other hand, by setting the blending ratio of silica in the above range, it is possible to impart the best possible damping performance to the high damping member while suppressing the deterioration of the workability of the high damping composition.
In consideration of further improving the effect, the blending ratio of silica is preferably 110 parts by mass or more and 140 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber even in the above range. Is preferable.

<Alkyl-type silylating agent>
The alkyl-type silylating agent functions to allow silica to smoothly penetrate into the crosslinkable rubber during kneading to further improve the processability of the high damping composition.
As an alkyl type silylating agent, the formula (1):

Examples thereof include various compounds represented by, in which R ¹ is an alkyl group having 1 to 3 carbon atoms and n is 2 to 9.
The reason why n is 2 to 9 in the formula (1) is that an alkyl-type silylating agent having n less than 2 may not sufficiently obtain the above-mentioned effect of improving the processability of the high attenuation composition. Because there is.

On the other hand, with an alkyl-type silylating agent having n of more than 9, the elastic modulus of the high damping member may decrease and good damping performance may not be imparted.
On the other hand, by using an alkyl-type silylating agent in which n in the formula (1) is in the above range, the high damping composition is given as good workability as possible, and the high damping member is as good as possible. Attenuation performance can be added.

Considering that the effect is further improved, n in the formula (1) is preferably 3 or more, and preferably 7 or less even in the above range.
Specific examples of the alkyl-type silylating agent include propyltriethoxysilane (R ¹ = ethyl group, n = 2), hexyltrimethoxysilane (R ¹ = methyl group, n = 5), and hexyltriethoxysilane (R 1 = methyl group, n = 5). R ¹ = ethyl, n = 5), decyl trimethoxysilane ^{(R 1} = methyl group, n = 9), decyl triethoxysilane ^{(R 1} = ethyl, n = 9) 1 or more kinds of such Can be mentioned. In particular, ^{at least one of hexyltrimethoxysilane (R 1} = methyl group, n = 5) and hexyltriethoxysilane (R ¹ = ethyl group, n = 5) is preferable.

The blending ratio of the alkyl-type silylating agent needs to be 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
Since the alkyl-type silylating agent is easily compatible with the crosslinkable rubber, it is effective to improve the workability with such a small amount of compounding. However, if the blending ratio is less than this range, the effect of improving the processability of the high attenuation composition by blending the alkyl type silylating agent cannot be obtained.

On the other hand, when the blending ratio of the alkyl-type silylating agent exceeds the above range, a large amount of the alkyl-type silylating agent is too familiar with the crosslinkable rubber, and even if a phenyl-type silylating agent or the like is used in combination, it is high. The damping performance of the damping member is reduced. In addition, the temperature dependence of the damping performance of the high damping member may increase.
On the other hand, by setting the blending ratio of the alkyl type silylating agent in the above range, the high damping composition is imparted with as good workability as possible, and the high damping member is provided with good damping performance and is damped. The temperature dependence of performance can be reduced.

In consideration of further improving the effect, the blending ratio of the alkyl-type silylating agent is preferably 3 parts by mass or more per 100 parts by mass of the total amount of the crosslinkable rubber even in the above range, preferably 7 parts by mass. It is preferably less than or equal to a portion.
<Phenyl-type silylating agent>
The phenyl-type silylating agent functions to impart a high elastic modulus to the high damping member and improve the damping performance of the high damping member.

The phenyl-type silylating agent, like the alkyl-type silylating agent described above, also functions to smoothly allow silica to smoothly enter the crosslinkable rubber during kneading to further improve the processability of the high damping composition. To do.
As a phenyl-type silylating agent, the formula (2):

^{Examples thereof include various compounds in which R 2} in the formula is an alkyl group having 1 to 3 carbon atoms.
Specific examples of such a phenyl-type silylating agent include at least one such as ^{phenyltrimethoxysilane (R 2} = methyl group) and phenyltriethoxysilane (R ^{2 = ethyl group).}
The blending ratio of the phenyl-type silylating agent needs to be 15 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.

If the blending ratio is less than this range, the effect of blending the phenyl-type silylating agent to smoothly penetrate silica into the crosslinkable rubber during kneading to improve the workability of the high damping composition and the high damping member. The effect of improving the damping performance of silica cannot be obtained.
On the other hand, when the blending ratio of the phenyl-type silylating agent exceeds the above range, the processability of the high damping composition is rather lowered, and the damping performance of the high damping member is lowered.

On the other hand, by setting the blending ratio of the phenyl type silylating agent in the above range, it is possible to impart good damping performance to the high damping member while maintaining good workability of the high damping composition. ..
In consideration of further improving the effect, the blending ratio of the phenyl-type silylating agent is preferably 18 parts by mass or more, and preferably 22 parts by mass or less, even in the above range.

<Silane coupling agent>
The silane coupling agent has a good affinity between silica and the crosslinkable rubber, and functions to improve the damping performance of the high damping member and to improve the rigidity of the high damping member.
Examples of the silane coupling agent include one or more types of sulfur-containing silane coupling agents, mercapto-based silane coupling agents, and other silane coupling agents.

Examples of the sulfur-containing silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, and bis ( 2-Trimethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-trimethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-tri) Methoxysilylpropyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N, N -Dimethylthiocarbamoyltetrasulfide, 2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazolyltetrasulfide, 3-triethoxysilylpropylbenzothiazoletetrasulfide, 3- One or more of triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl methacrylate monosulfide and the like can be mentioned.

Examples of the mercapto-based silane coupling agent include one or more types such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, and 2-mercaptoethyltriethoxysilane. Can be mentioned.
Further examples of the silane coupling agent include vinyl-based compounds such as vinyltriethoxysilane and vinyltrimethoxysilane; 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and 3- (2-aminoethyl) amino. Amino systems such as propyltriethoxysilane and 3- (2-aminoethyl) aminopropyltrimethoxysilane; γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyl Glysidoxy-based products such as diethoxysilane and γ-glycidoxypropylmethyldimethoxysilane; nitro-based products such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; 3-chloropropyltrimethoxysilane and 3-chloropropyl Examples thereof include one or more of various silane coupling agents such as chloro-based silane coupling agents such as triethoxysilane, 2-chloroethyltrimethoxysilane, and 2-chloroethyltriethoxysilane.

Of these, a sulfur-containing silane coupling agent is preferable in terms of interaction with silane, two types of silylating agents, and the like.
The blending ratio of the silane coupling agent needs to be 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
If the blending ratio is less than this range, the effect of improving the damping performance and rigidity of the high damping member by blending the silane coupling agent cannot be obtained.

On the other hand, when the blending ratio of the silane coupling agent exceeds the above range, the damping performance of the high damping member is rather lowered.
On the other hand, by setting the blending ratio of the silane coupling agent within the above range, good damping performance and rigidity can be imparted to the high damping member.
In consideration of further improving the effect, the blending ratio of the silane coupling agent is preferably 3 parts by mass or more per 100 parts by mass of the total amount of the crosslinkable rubber, preferably 7 parts by mass, even in the above range. It is preferably as follows.

<Other ingredients>
In addition to the above components, the high damping composition may further contain an inorganic filler other than silica, a cross-linking component for cross-linking the cross-linking rubber, or the like in an appropriate ratio.
(Other inorganic fillers)
Among the above, examples of other inorganic fillers include carbon black and the like.

Further, as the carbon black, one or more of the various carbon blacks classified according to the production method and the like, which can function as a filler, can be used.
The blending ratio of carbon black is preferably 1 part by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.

(Crosslink component)
As the cross-linking component, various cross-linking components capable of cross-linking two types of cross-linking rubber can be used.
Among them, as the cross-linking component, a combination of a sulfur-based cross-linking agent and a cross-linking accelerator having an action of promoting cross-linking of rubber by the sulfur-based cross-linking agent is preferably adopted.
Among these, sulfur-based cross-linking agents include, for example, sulfur such as powdered sulfur, oil-treated powdered sulfur, precipitated sulfur, colloidal sulfur, and dispersible sulfur, or organic sulfur-containing agents such as tetramethylthiuram disulfide and N, N-dithiobismorpholine. Examples thereof include compounds, and sulfur is particularly preferable.

Examples of the cross-linking accelerator include sulfenamide-based accelerators and thiuram-based accelerators. Since the mechanism of vulcanization promotion differs depending on the type of the cross-linking accelerator, it is preferable to use two or more types in combination.
Examples of the sulfenamide-based accelerator include Noxeller (registered trademark) NS [N-tert-butyl-2-benzothiazolyl sulfenamide] manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Examples of the thiuram-based accelerator include Noxeller TBT [tetrabutyl thiuram disulfide] manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.

The blending ratio of the sulfur-based cross-linking agent and the cross-linking accelerator is not particularly limited, and may be appropriately adjusted according to the characteristics such as damping performance and rigidity, which differ depending on the application of the high damping member and the like.
However, the blending ratio of sulfur as the sulfur-based cross-linking agent is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
When, for example, powdered sulfur containing oil, dispersible sulfur, or the like is used as the sulfur, the above-mentioned compounding ratio is the ratio of sulfur itself as an active ingredient contained therein.

The blending ratio of the sulfenamide-based accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
Further, the blending ratio of the thiuram-based accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
(Other)
If necessary, various additives such as an accelerator, a softener, a tackifier, and an anti-aging agent may be added to the high damping composition in an appropriate ratio.

Among these, examples of the accelerator include metal compounds such as zinc oxide, fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid, and one or more of other conventionally known accelerators. Usually, it is preferable to use a metal compound and a fatty acid in combination as a promoter aid.
For example, when zinc oxide and stearic acid are used in combination, the blending ratio of zinc oxide is preferably 1 part by mass or more and 5 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.

The mixing ratio of stearic acid is preferably 1 part by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
The softener is a component for further improving the processability of the high damping composition and lowering the rigidity of the high damping composition, and the softening agent is, for example, liquid at room temperature (2 to 35 ° C.). Liquid rubber exhibiting. Examples of the liquid rubber include one or more types such as liquid polyisoprene rubber, liquid nitrile rubber (liquid NBR), and liquid styrene butadiene rubber (liquid SBR).

Of these, liquid polyisoprene rubber is preferable. Examples of the liquid polyisoprene rubber include Kuraray (registered trademark) LIR-30 (number average molecular weight: 28000) and LIR-50 (number average molecular weight: 54000) manufactured by Kuraray Co., Ltd.
The blending ratio of the liquid polyisoprene rubber is preferably 5 parts by mass or more, and preferably 50 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.

Examples of other softeners include kumaron indene resin and the like.
Examples of the marron indene resin include various marron indene resins which are mainly composed of a polymer of marron and indene, have a relatively low molecular weight of about 1000 or less, and can function as a softener.
Examples of the Kumaron inden resin include Knit Resin (registered trademark) Kumaron G-90 manufactured by Nikko Kagaku Co., Ltd. [Average molecular weight: 770, softening point: 90 ° C., acid value: 1.0 KOHmg / g or less, hydroxyl value : 25KOHmg / g, bromine value 9g / 100g], G-100N [average molecular weight: 730, softening point: 100 ° C., acid value: 1.0KOHmg / g or less, hydroxyl value: 25KOHmg / g, bromine value 11g / 100g] , V-120 [average molecular weight: 960, softening point: 120 ° C., acid value: 1.0 KOHmg / g or less, hydroxyl value: 30 KOHmg / 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 kumaron inden resin is preferably 3 parts by mass or more, and preferably 20 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
Examples of the tackifier include petroleum resins and rosin derivatives.
Of these, as the petroleum resin, for example, Maruzen Petrochemical Co., Ltd.'s Marukaletz (registered trademark) M890A [dicyclopentadiene petroleum resin, softening point: 105 ° C.] and the like are preferable.

The blending ratio of the petroleum resin is preferably 3 parts by mass or more, and preferably 30 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
Examples of the rosin derivative include MSR-4 (softening point: 127 ° C.), DS-130 (softening point: 135 ° C.), and AD-130 (softening point: softening point:) in the Harima Chemicals Co., Ltd. brand name Hariester series. 135 ° C), DS-816 (softening point: 148 ° C), DS-822 (softening point: 172 ° C), 145P (softening point: 138 ° C), 135GN of the Harima Mac series trade name manufactured by Harima Chemicals, Inc. (Softening point: 139 ° C.), AS-5 (softening point: 165 ° C.) and the like, one kind or two or more kinds can be mentioned.

The blending ratio of the rosin derivative is preferably 3 parts by mass or more, and preferably 30 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber.
Examples of the anti-aging agent include one or more of various anti-aging agents such as benzimidazole-based, quinone-based, polyphenol-based, and amine-based. In particular, it is preferable to use a benzimidazole-based anti-aging agent and a quinone-based anti-aging agent in combination.

Among these, examples of the benzimidazole-based antiaging agent include Nocrack (registered trademark) MB [2-mercaptobenzimidazole] manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. Examples of the quinone-based antiaging agent include Antigen FR [aromatic ketone-amine condensate] manufactured by Maruishi Chemicals Co., Ltd.
The blending ratio of both anti-aging agents is preferably 0.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber of the benzimidazole-based anti-aging agent. The quinone-based antiaging agent is preferably 0.5 parts by mass or more per 100 parts by mass of the total amount of the crosslinkable rubber, and preferably 5 parts by mass or less.

<Manufacturing method of high damping composition>
In the method for producing a high damping composition of the present invention, as described above, silica, an alkyl type silylating agent, a phenyl type silylating agent, and a silane coupling agent are mixed with a crosslinkable rubber in a predetermined ratio and kneaded. It can be carried out in the same manner as in the conventional case except that the temperature at the time of the operation is set to 145 ° C. or higher and 175 ° C. or lower.

That is, first, while kneading two types of crosslinkable rubber, polyisoprene rubber and polybutadiene rubber, at a predetermined ratio using a closed kneader or the like, silica, two types of silylating agents, and a silane cup The ring agent is blended in a predetermined ratio and kneaded at a temperature of 145 ° C. or higher and 175 ° C. or lower as described above.
Next, while continuing kneading, each component other than the cross-linking component is first mixed and kneaded, and finally the cross-linking component is mixed and further kneaded to produce a high attenuation composition.

Of the above steps, the temperature at which silica, two types of silylating agents, and a silane coupling agent are mixed and kneaded, and then each component other than the cross-linking component is further mixed and kneaded is 145 ° C. or higher. Is preferable, and the temperature is preferably 175 ° C. or lower. Further, the temperature at the time of blending and kneading the cross-linking component is preferably 125 ° C. or lower.
Examples of the high damping member that can be manufactured by using the high damping composition manufactured by the manufacturing method of the present invention include a seismic isolation damper incorporated in the foundation of a building such as a building, and a control incorporated in the structure of the building. Vibrating damping dampers for vibrations, vibration damping members for cables such as suspension bridges and cable-stayed bridges, vibration damping members for industrial machinery, aircraft, automobiles, railway vehicles, computers and their peripheral equipment, or household electricity Examples include vibration damping members for equipment and the like, and treads for automobile tires.

<Manufacturing method of viscoelastic damper>
In particular, when a viscoelastic body of a viscoelastic damper of a building as a high-damping member is formed by using the high-damping composition produced by the production method of the present invention as a forming material, the viscoelastic body has high damping. Since it has performance, even if the damping performance of the viscoelastic damper including such a viscoelastic body is improved to reduce the overall size or the number to be incorporated in one building, it is equal to or higher than the conventional one. Seismic control performance can be obtained.

In addition, two types of crosslinkable rubber, polyisoprene rubber and polybutadiene rubber, are used in combination, and the 1,2-polybutadiene polymer is omitted, so that the temperature dependence such as the rigidity of the viscoelastic body can be reduced. For example, a viscoelastic damper can be installed near the outer wall of a building having a large temperature difference.
Therefore, it is possible to expand the degree of freedom in designing the seismic control performance by the viscoelastic damper in a building or the like, or omit the design for increasing the strength of the peripheral steel material, which leads to cost reduction.

The step of forming the viscoelastic body using the high damping composition can be carried out in the same manner as before. For example, a viscoelastic body can be formed by filling a high-damping composition formed in an arbitrary shape such as a sheet into a mold corresponding to the shape of the viscoelastic body, and then cross-linking the crosslinkable rubber.

Hereinafter, the present invention will be further described based on Examples and Hidden, but the configuration of the present invention is not limited to such Examples and Comparative Examples.
<Example 1>
(Preparation of high damping composition)
As the crosslinkable rubber, 40 parts by mass of natural rubber [SMR (Standard Marysian Rubber) -CV60] and polybutadiene rubber [UBEPOL BR150 manufactured by Ube Industries, Ltd., Mooney viscosity (ML _{1 + 4} , 100 ° C.): 43, cis- 1,4 bond content: 98% by mass] 60 parts by mass was used.

The compounding ratio of the polybutadiene rubber in the total amount of 100 parts by mass of the crosslinkable rubber was 60 parts by mass.
The total amount of 100 parts by mass of the crosslinkable rubber was kneaded using a closed kneader to mix the components shown in Table 1 below, and the kneading temperature was set to 160 ° C. for kneading.

Each component in Table 1 is as follows. The parts by mass in Table 1 are parts by mass per 100 parts by mass of the total amount of the crosslinkable rubber.
Silica: NipSil (nip seal) KQ manufactured by Tosoh Silica Co., Ltd., BET specific surface area: 230 m ² / g
Alkyl-type silylating agent: KBE-3063 manufactured by Shin-Etsu Chemical Co., Ltd., hexyltriethoxysilane, R ¹ = ethyl group in formula (1), n = 5
Phenyl-type silylating agent: KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd., phenyltriethoxysilane, R ² = ethyl group silane coupling agent in formula (2): Si 266 manufactured by Ebony Industries, bis (tri) Ethoxysilylpropyl) disulfide, sulfur-based silane coupling agent Next, using a closed-type kneader, each component other than the cross-linking component among the components shown in Table 2 below was mixed and kneaded at 160 ° C, and then closed-type. After taking out from the kneader and cooling, the crosslinked component was added again in the closed kneader and kneaded at 100 ° C. to prepare a high damping composition.

Each component in Table 2 is as follows. The parts by mass in Table 2 are parts by mass per 100 parts by mass of the total amount of the crosslinkable rubber.
Liquid polyisoprene rubber: LIR-50 manufactured by Kuraray Co., Ltd., number average molecular weight: 54000
Carbon Black: Tokai Carbon Co., Ltd. Seest 3, HAF
Benzimidazole-based anti-aging agent: Nocrack MB manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., 2-Mercaptobenzimidazole Quinone-based anti-aging agent: Antigen FR manufactured by Maruishi Chemical Co., Ltd.
Zinc oxide 2 types: Mitsui Mining & Smelting Co., Ltd. Stearic acid: NOF Corporation "Tsubaki"
Kumaron resin: Knit resin (registered trademark) Kumaron G-90 manufactured by Nikko Kagaku Co., Ltd., softening point 90 ° C.
Dicyclopentadiene petroleum resin: Maruzen Petrochemical Co., Ltd. Marcaretz (registered trademark) M890A, softening point 105 ° C.
5% oil-treated powder Sulfur: Sulfenamide accelerator manufactured by Tsurumi Chemical Industry Co., Ltd .: Noxeller (registered trademark) NS, N-tert-butyl-2-benzothiazolylsul made by Ouchi Shinko Chemical Industry Co., Ltd. Fenamide Sulfur-based vulcanization accelerator: Noxeller TBT-N, Tetrabutyl Sulfur Disulfide manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. <Example 2>
A high damping composition was prepared in the same manner as in Example 1 except that the blending ratio of the natural rubber was 60 parts by mass and the blending ratio of the polybutadiene rubber was 40 parts by mass.

<Example 3>
A high damping composition was prepared in the same manner as in Example 1 except that the blending ratio of the natural rubber was 20 parts by mass and the blending ratio of the polybutadiene rubber was 80 parts by mass.
<Comparative example 1>
A high damping composition was prepared in the same manner as in Example 1 except that the polybutadiene rubber was not blended with the blending ratio of the natural rubber being 100 parts by mass.

<Comparative example 2>
When the blending ratio of polybutadiene rubber was 100 parts by mass without blending natural rubber, kneading could not be performed, so the subsequent work was abandoned.
<Examples 4 and 5, Comparative Examples 3 and 4>
90 parts by mass (Comparative Example 3), 100 parts by mass (Example 4), 150 parts by mass (Example 5), 160 parts by mass (Example 6) of the compounding ratio of silica per 100 parts by mass of the total amount of the crosslinkable rubber. A high attenuation composition was prepared in the same manner as in Example 1 except for the above.

<Comparative Examples 5 and 6>
High attenuation in the same manner as in Example 1 except that the blending ratio of the phenyl-type silylating agent per 100 parts by mass of the total amount of the crosslinkable rubber was 10 parts by mass (Comparative Example 5) and 35 parts by mass (Comparative Example 6). The composition was prepared.
<Comparative Example 7>
A high attenuation composition was prepared in the same manner as in Example 1 except that the alkyl type silylating agent was not blended.

<Comparative Example 8>
A high damping composition was prepared in the same manner as in Example 1 except that the blending ratio of the alkyl type silylating agent per 100 parts by mass of the total amount of the crosslinkable rubber was 15 parts by mass.
<Example 6>
Implemented except that 5 parts by mass of propyltriethoxysilane [Dynasilan (registered trademark) PTEO manufactured by Evonik Industries, Inc., R ^{1 = ethyl group, n = 2] in the formula (1) was blended as an alkyl-type silylating agent.} A high attenuation composition was prepared in the same manner as in Example 1.

<Example 7>
Implemented except that 5 parts by mass of decyltriethoxysilane [KBE-3103 manufactured by Shin-Etsu Chemical Co., Ltd., R ^{1 = ethyl group, n = 9] in the formula (1) was blended as an alkyl-type silylating agent.} A high attenuation composition was prepared in the same manner as in Example 1.
<Comparative Example 9>
A high attenuation composition was prepared in the same manner as in Example 1 except that the silane coupling agent was not blended.

<Examples 8 and 9, Comparative Example 10>
Implementation except that the compounding ratio of the silane coupling agent per 100 parts by mass of the total amount of the crosslinkable rubber was 1 part by mass (Example 8), 10 parts by mass (Example 9), and 12 parts by mass (Comparative Example 10). A high damping composition was prepared in the same manner as in Example 1.
<Comparative Example 11>
Further, high attenuation in the same manner as in Example 1 except that 10 parts by mass of a 1,2-polybutadiene polymer [JSR (registered trademark) RB830 manufactured by JSR Corporation, 1,2-bond: 93%] was blended. The composition was prepared.

<Examples 10 and 11, Comparative Example 12>
The kneading temperature after blending silica, two silylating agents, and a silane coupling agent with two types of crosslinkable rubber was 135 ° C. (Comparative Example 12), 145 ° C. (Example 10), and 175 ° C. (Example). A high damping composition was prepared in the same manner as in Example 1 except that it was set in Example 11) and kneaded.
<Comparative Example 13>
After blending two types of crosslinkable rubber with silica, two types of silylating agents, and a silane coupling agent, the kneading temperature was set to 180 ° C. and kneading caused burning, so the subsequent work was abandoned. did.

<Evaluation of workability>
When each component was kneaded in order to prepare a high damping composition in Examples and Comparative Examples, it was not possible to knead or burned as described above, or kneading was possible for 120 minutes. The workability was evaluated as a product that took more than the above time as defective (x), a product that was easily kneaded and kneaded within the above time as a good product (◯).

<Attenuation characteristic test>
(Preparation of test piece)
The high-damping compositions prepared in Examples and Comparative Examples were extruded into a sheet and then punched to form a flat plate 1 (thickness 5 mm × length 25 mm × width 25 mm) having a rectangular planar shape as shown in FIG. A rectangular flat plate 2 having a thickness of 6 mm, a length of 44 mm, and a width of 44 mm is laminated on both the front and back surfaces of the flat plate 1 via a vulcanizing adhesive, and heated to 150 ° C. while pressurizing in the stacking direction to heat the flat plate 1 to 150 ° C. The high damping composition to be formed was crosslinked and the flat plate 1 was vulcanized and adhered to two steel plates 2 to prepare a test body 3 for evaluating damping characteristics as a model of a viscoelastic body.

(Displacement test)
As shown in FIG. 2A, two test specimens 3 are prepared, and the two test specimens 3 are fixed to one central fixing jig 4 via one steel plate 2, and both are fixed. One left and right fixing jig 5 was fixed to the other steel plate 2 of the test body 3. Then, the central fixing jig 4 is fixed to the upper fixing arm 6 of the testing machine (not shown) via the joint 7, and the two left and right fixing jigs 5 are jointed to the movable plate 8 on the lower side of the testing machine. It was fixed via 9.

Both test bodies 3 were fixed as described above in a state where two parallel sides of the flat plate 1 were aligned in parallel with the following displacement directions.
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 shown by the white arrow in FIG. 2A under an environment of a temperature of 23 ° C., and the flat plate 1 is displaced in FIG. As shown in (b), the state is distorted and deformed in the direction perpendicular to the thickness direction, and then the movable board 8 is moved from this state to the fixed arm 6 as shown by the white arrow in FIG. 2 (b). the operation is displaced to lowering in the opposite direction to the direction to return to the state shown in FIG. 2 (a) as one cycle, the strain deformation repeatedly plate 1, i.e. at the time of vibrated, the direction perpendicular to the thickness direction of the plate 1 The hysteresis loop H (see FIG. 3) showing the relationship between the displacement amount (mm) and the load (N) of the above was obtained.

For the measurement, the above operation was carried out for 3 cycles, and the value in the 3rd cycle was obtained. The maximum displacement amount in each cycle was set so that the amount of displacement of the two steel plates 2 sandwiching the flat plate 1 in the direction orthogonal to the thickness direction of the flat plate 1 was 200% of the thickness of the flat plate 1.
(Evaluation of rigidity and damping performance)
Then, connecting the maximum displacement point and the minimum displacement point of the hysteresis loop H shown in FIG. 3 obtained by the above measurement, determine the slope Keq (N / mm) of the straight line L ₁ shown by a thick solid line in the figure, From this inclination Keq (N / mm), the thickness T (mm) of the flat plate 1, and the cross-sectional area A (mm ² ) of the flat plate 1, the equation (a):

The equivalent shear modulus Geq (N / mm ² ) was determined by.
Then, when the equivalent shear elastic modulus Geq (N / mm ² ) in Comparative Example 1 is set to 100, the relative value of the equivalent shear elastic modulus Geq (N / mm ² ) of each example is obtained, and the relative value is less than 111. The rigidity was evaluated as defective (x), 111 or more and less than 120 as good (◯), and 120 or more as particularly good (⊚).

Also hatched in FIG. 3, and the absorbed energy amount ΔW represented by the total surface area of the hysteresis loop H, was denoted by the Amisen in the figure, the straight line L _1, the horizontal chart From the elastic strain energy W represented by the surface area of the region surrounded by the _{axis and the perpendicular line L 2} drawn from the intersection of the straight line L ₁ and the hysteresis loop H to the horizontal axis, the equation (b):

The equivalent attenuation constant Heq was obtained by.
Then, when the equivalent attenuation constant Heq in Comparative Example 1 is set to 100, the relative value of the equivalent attenuation constant Heq of each embodiment is obtained, and those having such a relative value of less than 85 are defective (x), 85 or more, and less than 87. The damping performance was evaluated with the ones as good (◯) and the ones with 87 or more as particularly good (⊚).

(Evaluation of temperature dependence of damping performance)
^{The equivalent shear elastic modulus Geq (0 ° C.) (N / mm 2} ) was obtained from the hysteresis loop H shown in FIG. 3 obtained by performing a displacement test under the same conditions as above in an environment of a temperature of 0 ° C., and the same sample was obtained. The ratio Geq (0 ° C.) / Geq (23 ° C.) to the equivalent shear elastic modulus Geq (23 ° C.) (N / mm ^{2) obtained in the above-mentioned environment of 23 ° C. was determined.}

Then, when the ratio Geq (0 ° C.) / Geq (23 ° C.) in Comparative Example 1 is set to 100, the relative values of the ratio Geq (0 ° C.) / Geq (23 ° C.) of each Example and Comparative Example are obtained, and the relative values are obtained. The temperature dependence of the damping performance was evaluated with a value of 88 or less as particularly good (⊚), a value of more than 88 and 92 or less as good (◯), and a value of more than 92 as defective (x).
The above results are shown in Tables 3 to 7.

From the results of Examples 1 to 11 and Comparative Examples 11 to 13 in Tables 3 to 7, the 1,2-polybutadiene polymer was not blended, and instead, the crosslinkable rubber was mixed with silica and two kinds of silylating agents. By setting the temperature at the time of blending and kneading the silane coupling agent to the range of 145 ° C. or higher and 175 ° C. or lower, the reactivity between the silane coupling agent and the crosslinkable rubber or silica is made higher than the current state. It has been found that a high damping composition capable of forming a high damping member having excellent damping performance and rigidity and having a small temperature dependence of the damping performance can be prepared.

Further, from the results of Examples 1, 10 and 11, considering that the effect is further improved, the temperature of the kneading is preferably 150 ° C. or higher, preferably 170 ° C. or lower even in the above range. It turned out to be preferable.
Further, from the results of Examples 1 to 3 and Comparative Examples 1 and 2, it is necessary to use two kinds of polyisoprene rubber such as natural rubber and polybutadiene rubber together as the crosslinkable rubber, and the compounding ratio of the polybutadiene rubber. Must be 40 parts by mass or more and 80 parts by mass or less in the total amount of 100 parts by mass of the crosslinkable rubber, particularly preferably 50 parts by mass or more, and preferably 70 parts by mass or less. understood.

From the results of Examples 1, 4, 5 and Comparative Examples 3 and 4, the blending ratio of silica needs to be 100 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber, and 110 parts by mass in particular. It was found that the amount is preferably 4 parts or more, and preferably 140 parts by mass or less.
From the results of Examples 1 and Comparative Examples 5 and 6, the blending ratio of the phenyl-type silylating agent needs to be 15 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber, and 18 parts by mass in particular. It was found that the amount is preferably 2 parts or more, and preferably 22 parts by mass or less.

From the results of Examples 1 and Comparative Examples 7 and 8, the blending ratio of the alkyl-type silylating agent needs to be 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber, and 3 parts by mass in particular. It was found that it is preferably more than 7 parts by mass, and more preferably 7 parts by mass or less.
Further, from the results of Examples 1, 6 and 7, as the alkyl-type silylating agent, a compound represented by the formula (1) in which n in the formula (1) is 2 to 9, especially 3 to 7, is preferable. I found out.

Further, from the results of Examples 1, 8 and 9, and Comparative Examples 9 and 10, the blending ratio of the silane coupling agent needs to be 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the total amount of the crosslinkable rubber. Among them, it was found that it is preferably 3 parts by mass or more, and preferably 7 parts by mass or less.

1 Flat plate 2 Steel plate 3 Specimen 4 Central fixing jig 5 Left and right fixing jig 6 Fixed arm 7 Joint 8 Movable board 9 Joint H Hysteresis loop L ₁ Straight line L ₂ Perpendicular line W Energy ΔW Absorbed energy amount

Claims (3)

Two types of polyisoprene rubber and polybutadiene rubber , and the compounding ratio of the polybutadiene rubber is 40 parts by mass or more and 80 parts by mass or less in the total amount of 100 parts by mass of both rubbers, the above two types. 100 parts by mass or more and 150 parts by mass or less of silica, 1 part by mass or more and 10 parts by mass or less of an alkyl-type silylating agent, and 15 parts by mass or more and 30 parts by mass or less of phenyl per 100 parts by mass of the total amount of the crosslinkable rubber. A method for producing a high damping composition, which comprises a step of kneading a mold silylating agent and a silane coupling agent of 1 part by mass or more and 10 parts by mass or less at a temperature of 145 ° C. or higher and 175 ° C. or lower. The alkyl-type silylating agent has the formula (1):

[In the formula, R ¹ represents an alkyl group having 1 to 3 carbon atoms, and n represents a number of 2 to 9. ]
The phenyl-type silylating agent is a compound represented by the formula (2) :.

[In the formula, R ² represents an alkyl group having 1 to 3 carbon atoms. ]
The method for producing a high attenuation composition according to claim 1, which is a compound represented by. A method for producing a viscoelastic damper, which comprises a step of forming a viscoelastic body using the high damping composition produced by the production method according to claim 1 or 2.

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