JP2011038069A - Rubber composition for high damping laminate and high damping laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a high damping laminate excellent in workability, which attains a high damping laminate having a high damping property and an excellent shear modulus, and a high damping laminate prepared using the same. <P>SOLUTION: The rubber composition for a high damping laminate includes 100 pts.mass of a crosslinkable rubber component, 10-60 pts.mass of an inorganic filler having a silanol group and 0.1-30 pts.mass of a polylactic acid-based resin. There is also provided a high damping laminate obtained by alternately laminating the rubber composition for a high damping laminate and a rigid plate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber composition for a high attenuation laminate and a high attenuation laminate.

  In recent years, anti-vibration devices, vibration isolation devices, seismic isolation devices, and the like are rapidly spreading as vibration energy absorbing devices. In such an apparatus, a rubber composition having vibration energy damping performance is used.

  For example, laminated rubber for seismic isolation used in bridge bearings and building seismic isolation devices has high damping (attenuates vibration energy by converting vibration into more heat) and the desired shear elasticity The rate is required to develop.

  As a rubber composition used for such a seismic isolation laminated rubber, the present applicant described in Patent Document 1 “100 parts by mass of a diene rubber, 40 to 75 parts by mass of carbon black, and 5 to 35 parts by mass of silica. , A rubber composition for a high attenuation laminate including 5 to 55 parts by mass of an inorganic filler and 5 to 50 parts by mass of a petroleum resin.

  Further, 5 to 100 parts by weight of silica, 2 to 20% by weight of silane coupling agent, and water or an acidic aqueous solution are blended and kneaded with 100 parts by weight of the rubber component obtained by solution polymerization. A method for producing a rubber composition has been proposed (Patent Document 2).

JP 2006-143849 A JP 2000-290431 A

However, the present inventor examined the compounding amount of carbon black, silica, etc. in order to achieve further improvement in the damping property of the rubber composition for a high damping laminated body described in Patent Document 1 described above. Even if it can be improved, it has been clarified that the viscosity at the time of unvulcanization increases and the processability is inferior, or the shear modulus after vulcanization may decrease.
Further, when a rubber composition containing an inorganic filler having a silanol group with respect to a rubber component and not containing a polylactic acid resin is stored, and the rubber composition absorbs moisture over time, the rubber composition after storage The present inventors have found that although the vulcanization time is shortened compared to the rubber composition before storage, the damping property is lowered.
In the past, the present inventors have found that a rubber composition containing a crosslinkable rubber component, a polylactic acid resin and a filler having a silanol group has been useful as a high-damping rubber, and the rubber composition is vulcanized. Then, when further heating was continued, the torque was increased during vulcanization, and the torque was further increased during heating after vulcanization (the torque increased in two stages during vulcanization and during heating).
This will be described with reference to the accompanying drawings. FIG. 5 is based on JIS K6300-2: 2001 “How to Obtain Vulcanization Characteristics Using a Vibrating Vulcanization Tester”, using a rotorless vulcanization tester as a rheometer, and at a predetermined test temperature (150 ° C.) It is a graph which shows the outline of the vulcanization curve obtained by making the obtained torque into a vertical axis | shaft and making a vulcanization time into a horizontal axis. In FIG. 5, the rubber composition (rubber composition 1) containing a filler having a silanol group relative to the rubber component and not containing a polylactic acid resin has a dotted vulcanization curve with only one stage of torque increase. Show. On the other hand, when a rubber composition (rubber composition 2) containing a crosslinkable rubber component, a polylactic acid and a filler having a silanol group is vulcanized and then further heated, the torque is the same as that at the time of vulcanization. A dashed vulcanization curve that sometimes rises in two stages is shown.
Furthermore, in the vulcanization curve (broken line) in which the torque increases in two stages, the inventors do not increase tan δ when the torque during vulcanization increases, whereas tan δ increases when the torque during heating increases. It confirmed that it soared.
Accordingly, an object of the present invention is to provide a rubber composition for a high-damping laminate excellent in processability and a method for producing the same, which can realize a high-damping laminate having high damping properties and excellent shear modulus. To do.
In addition, the present invention significantly reduces the vulcanization time when vulcanizing a rubber composition for a high-damping material containing a polylactic acid resin and an inorganic filler having a silanol group with respect to the rubber component, An object of the present invention is to provide a rubber composition for a highly attenuated laminate that does not reduce the attenuation, and a method for producing the same.

As a result of diligent studies to solve the above problems, the present inventor has processed rubber components by using a rubber composition in which a specific amount of an inorganic filler having a silanol group and a polylactic acid resin is blended. The present invention was completed by discovering that a highly damped laminate having excellent properties, damping properties and shear modulus can be obtained.
In addition, the inventors of the present application have found that a rubber composition containing a specific amount of an inorganic filler having a silanol group and a polylactic acid resin in a rubber component contains an appropriate amount of water, thereby vulcanizing time. The present invention was completed by discovering that the damping property was further improved while greatly shortening the length.
That is, FIG. 5 shows a rubber composition (rubber composition 3, FIG. 5) containing a specific amount of a silanol group-containing inorganic filler and a polylactic acid resin and further containing an appropriate amount of water. The solid vulcanization curve in Fig. 5 is a rubber composition 1 containing an inorganic filler having a silanol group with respect to the rubber component and not containing a polylactic acid resin (the increase in torque in Fig. 5 is only one stage) When the rubber composition 2 containing a crosslinkable rubber component, a polylactic acid, and a filler having a silanol group is vulcanized and then further heated (the torque in FIG. It shows that the productivity is higher than the dashed vulcanization curve that rises in two stages during heating.
That is, this invention provides the following 1-16.

1. A rubber composition for a high attenuation laminate comprising 100 parts by mass of a crosslinkable rubber component, 10 to 150 parts by mass of an inorganic filler having a silanol group, and 0.1 to 30 parts by mass of a polylactic acid resin.
2. 2. The rubber composition for a high attenuation laminate according to 1 above, further containing 5 to 50 parts by mass of a petroleum resin with respect to 100 parts by mass of the rubber component.
3. 3. The rubber composition for a high attenuation laminate according to the above 1 or 2, further comprising a metal compound.
4). 4. The rubber composition for a high attenuation laminate according to 3 above, wherein the amount of the metal compound is 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.
5). The rubber composition for a high attenuation laminate according to any one of the above 1 to 4, further comprising 5-55 parts by mass of an inorganic filler other than the inorganic filler having a silanol group with respect to 100 parts by mass of the rubber component. object.
6). 6. The rubber composition for a high attenuation laminate according to any one of 1 to 5 above, wherein the rubber component is a diene rubber.
7). 7. The rubber composition for a high damping laminate according to any one of 1 to 6 above, wherein the rubber component contains natural rubber and vinyl-cis butadiene rubber.
8). 8. The rubber composition for a high attenuation laminate according to the above 7, wherein the rubber component contains 10% by mass or more of the vinyl-cis butadiene rubber.
9. 9. The rubber composition for a high attenuation laminate according to any one of 1 to 8 above, wherein the polylactic acid resin has a melting point of 150 ° C. or lower.
10. 10. The rubber composition for a high attenuation laminate according to any one of 1 to 9 above, wherein the polylactic acid resin has a number average molecular weight of 1,000 to 10,000.
11. High in any one of said 1-10 whose mass ratio (inorganic filler / polylactic acid-type resin) of the inorganic filler which has the said silanol group, and the said polylactic acid-type resin is 1 / 1-1 / 10/1. Rubber composition for damping laminate.
12 The high-attenuation laminate according to any one of 1 to 11 above, wherein the inorganic filler having a silanol group and the polylactic acid-based resin are contained as an inorganic filler / polylactic acid master batch obtained by mixing them in advance. Rubber composition.
13. The inorganic filler having the silanol group and the polylactic acid-based resin are mixed as a polylactic acid surface-treated inorganic filler obtained by removing the solvent and drying the mixture after previously mixing them in a solvent. 11. The rubber composition for a high attenuation laminate according to any one of 11 above.
14 The high attenuation laminate according to any one of 1 to 13 above, which contains water and has a moisture content X (% by mass) in the rubber composition for a high attenuation laminate before crosslinking satisfies the following formula (1): Body rubber composition.
{(C / 5b) / (Total amount of rubber composition for highly attenuated laminate)} × 100 ≦ X ≦ 3 (1)
(In the formula, c / 5b represents an approximate value of moisture contained in the rubber composition for a high attenuation laminate, c is the amount of the inorganic filler having the silanol group, and b is the amount of the polylactic acid-based resin. Amount.)
15. The rubber composition for a high-damping laminate according to any one of 1 to 14 above, which is vulcanized.
16. A high attenuation laminate obtained by alternately laminating the rubber composition for a high attenuation laminate according to any one of 1 to 15 above and a hard plate.

Moreover, this invention provides the manufacturing method of the rubber composition for the following highly attenuated laminated bodies.
17. Kneading an unvulcanized rubber composition containing 100 parts by mass of the rubber component, 10 to 150 parts by mass of the inorganic filler having a silanol group, and 0.1 to 30 parts by mass of the polylactic acid resin. The manufacturing method of the rubber composition for high attenuation | damping laminated bodies in any one of said 1-14 obtained by.
18. 18. The method for producing a rubber composition for a high attenuation laminate according to the above 17, wherein the unvulcanized rubber composition further contains 5 to 50 parts by mass of the petroleum resin with respect to 100 parts by mass of the rubber component.
19. 19. The method for producing a rubber composition for a high attenuation laminate according to the above 17 or 18, wherein the unvulcanized rubber composition further contains a metal compound.
20. 20. The method for producing a rubber composition for a high attenuation laminate according to the above 19, wherein the amount of the metal compound is 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.
21. The unvulcanized rubber composition further includes 5 to 55 parts by mass of an inorganic filler other than the inorganic filler having a silanol group with respect to 100 parts by mass of the rubber component. The manufacturing method of the rubber composition for high attenuation | damping laminated bodies of description.
22. High in any one of said 17-21 whose mass ratio (inorganic filler / polylactic acid-type resin) of the inorganic filler which has the said silanol group, and the said polylactic acid-type resin is 1 / 1-10 / 1. A method for producing a rubber composition for a damping laminate.
23. The high attenuation laminate according to any one of the above 17 to 22, wherein the inorganic filler having a silanol group and the polylactic acid-based resin are blended as an inorganic filler / polylactic acid master batch obtained by mixing them in advance. For producing a rubber composition for use.
24. The above-mentioned inorganic filler having silanol groups and the polylactic acid resin are blended as a polylactic acid surface-treated inorganic filler obtained by mixing these in advance in a solvent, removing the solvent, and drying. The manufacturing method of the rubber composition for highly attenuated laminated bodies in any one of -22.
25. The unvulcanized rubber composition contains moisture, and the moisture content X (mass%) in the rubber composition for highly attenuated laminate before crosslinking satisfies the following formula (1): The manufacturing method of the rubber composition for highly attenuated laminated bodies in any one of these.
{(C / 5b) / (Total amount of rubber composition for highly attenuated laminate)} × 100 ≦ X ≦ 3 (1)
(In the formula, c / 5b represents an approximate value of moisture contained in the rubber composition for a high attenuation laminate, c is the amount of the inorganic filler having the silanol group, and b is the amount of the polylactic acid-based resin. Amount.)
26. 26. The method for producing a rubber composition for a high attenuation laminate according to any one of 25 above, wherein water is added to the unvulcanized rubber composition.
27. The rubber composition for a high attenuation laminate according to any one of 1 to 14 above or the rubber composition for a high attenuation laminate obtained by the method for producing a rubber composition for a high attenuation laminate according to any of the above 17 to 26. 16. The method for producing a rubber composition for a high attenuation laminate according to the above 15, obtained by vulcanizing a product.

As described below, according to the present invention, there is provided a rubber composition for a high-damping laminate having excellent workability and capable of realizing a high-damping laminate having high damping properties and excellent shear modulus. can do.
In addition, when the rubber composition for a high damping laminate of the present invention contains a specific amount of moisture, not only the vulcanization time is greatly shortened and the productivity is improved, but also the damping property, the horizontal rigidity (= shear elastic modulus). ) Is even better.

FIG. 1 is a schematic cross-sectional view of a highly attenuated laminate that represents an example of an embodiment of the laminate of the present invention. FIG. 2 is a schematic side view of a sample for a lap shear type shear test. FIG. 3 is a graph showing an example of a hysteresis curve obtained by a lap shear type shear test. FIG. 4 is a graph showing a stress-strain curve during an autograph tensile test. FIG. 5 shows the torque obtained at a predetermined test temperature using a rotorless vulcanization tester as a rheometer in accordance with JIS K6300-2: 2001 “How to obtain vulcanization characteristics using a vibration vulcanization tester”. It is a graph which shows the outline of the vulcanization curve obtained by making a vertical axis | shaft and making a vulcanization time a horizontal axis. FIG. 6 is a graph showing vulcanization curves measured in the examples of the present invention.

The present invention is described in detail below.
The rubber composition for highly attenuated laminates of the present invention (hereinafter also simply referred to as “the rubber composition of the present invention”) has 100 parts by mass of a crosslinkable rubber component and 10 to 60 parts by mass of an inorganic filler having a silanol group. Part and a rubber composition for a high-damping laminate comprising 0.1 to 30 parts by mass of a polylactic acid resin.
Next, the crosslinkable rubber component, the inorganic filler having a silanol group and the polylactic acid resin contained in the rubber composition of the present invention will be described in detail.

<Crosslinkable rubber component>
The rubber component contained in the rubber composition of the present invention is not particularly limited as long as it is a rubber component that can be crosslinked with a sulfur compound or a peroxide. Specific examples thereof include a diene rubber and a heat having a double bond. Examples thereof include a plastic elastomer.

Specific examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), vinyl-cis butadiene rubber (VCR), and styrene-butadiene copolymer rubber (SBR). ), Acrylonitrile-butadiene copolymer rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (Br-IIR, Cl-IIR), chloroprene rubber (CR) and the like.
Specific examples of the thermoplastic elastomer having a double bond include ethylene-propylene-diene rubber (EPDM), styrene-butadiene-styrene block copolymer (SBS), and hydrogenation (hydrogenation) thereof. Product (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-isoprene-styrene block copolymer (SIS), styrene-isobutylene-styrene block copolymer (SIBS), and the like.
These crosslinkable rubber components may be used alone or in combination of two or more.

In the present invention, among these crosslinkable rubber components, the resulting rubber composition of the present invention has good physical properties such as tensile strength after vulcanization and elongation at break, and the rubber composition of the present invention. In the high attenuation laminate of the present invention (hereinafter also referred to as “laminate of the present invention”) obtained by alternately laminating and hard plates, a rubber composition and a hard plate (for example, general structural steel plate, A diene rubber is preferred for the reason that the adhesiveness with a rolled steel sheet or the like is good.
Among these, a diene rubber containing natural rubber and vinyl-cisbutadiene rubber is more preferable, and a diene rubber containing 10% by mass or more of vinyl-cisbutadiene rubber is more preferable.

Here, vinyl - and cis-butadiene rubber, in an inert organic solvent mainly composed of C ₄ fraction, polybutadiene rubber composite comprising the cis-1,4 polymerization and syndiotactic-1,2 polymerization It is.
Specific examples of the vinyl-cis butadiene rubber include, for example, 97 to 80% by mass of cis-1,4-polybutadiene rubber having a cis 1,4-bond content of 90% or more, and syndiotactic-1,2-polybutadiene. Examples include composites composed of 3 to 20% by mass.

  In the present invention, as such a vinyl-cis butadiene rubber, for example, a commercially available product such as UBEPOL-VCR manufactured by Ube Industries, Ltd. can be used.

<Inorganic filler having silanol group>
The inorganic filler having a silanol group contained in the rubber composition of the present invention is not particularly limited as long as it is an inorganic filler having a silanol group (Si—OH) on at least a part of the surface.
Examples of the inorganic filler having a silanol group include silica, clay, talc and the like, and these may be used alone or in combination of two or more.

Specific examples of silica include fumed silica, calcined silica, precipitated silica, pulverized silica, fused silica, and colloidal silica.
Silica preferably has an average aggregate particle diameter of 5 to 50 μm, more preferably 5 to 30 μm.

  Specific examples of the clay include T-clay, kaolin clay, wax stone clay, sericite clay, calcined clay, and silane-modified clay.

  In the present invention, the content of the inorganic filler having a silanol group is 10 to 150 parts by mass, preferably 10 to 60 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component described above. More preferably, it is 15-50 mass parts, and it is especially preferable that it is 20-40 mass parts.

<Polylactic acid resin>
The polylactic acid resin contained in the rubber composition of the present invention is a homopolymer of lactic acid and / or a copolymer of lactic acid.
Here, the homopolymer of lactic acid is polylactic acid.
The lactic acid copolymer is a copolymer of lactic acid and one kind of monomer selected from the group consisting of hydroxy acids other than lactic acid, lactones and diene compounds copolymerizable with lactic acid.

Specific examples of hydroxy acids other than lactic acid include hydroxyacetic acid (glycolic acid), hydroxybutyric acid, malic acid, citric acid, ricinoleic acid, shikimic acid, salicylic acid, and coumaric acid.
Specific examples of the lactone include ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, γ-valerolactone, δ-valerolactone, β-butyrolactone, γ-butyrolactone, β -Propiolactone and the like are exemplified.
Specific examples of the diene compound copolymerizable with lactic acid include butadiene and isoprene.
The copolymer of these and lactic acid may be a block copolymer, a random block copolymer, a random copolymer, or a graft polymer as long as lactic acid is a main component. Preferably there is.

In the present invention, among these polylactic acid-based resins, the resulting rubber composition of the present invention has good melting point, vulcanized tensile strength, elongation and other properties such as elongation at break. It is preferable that it is 135 degrees C or less.
For the same reason, the number average molecular weight is preferably 1000 to 10000, more preferably 2000 to 8000.
Here, the melting point is a value measured at a heating rate of 10 ° C./min by differential scanning calorimetry (DSC-Differential Scanning Calorimetry).
The number average molecular weight is a number average molecular weight (polystyrene conversion) measured by gel permeation chromatography (GPC). Tetrahydrofuran (THF), N, N-dimethylformamide (DMF) is used for measurement. ), Chloroform is preferably used as a solvent.

  Moreover, in this invention, content of the said polylactic acid-type resin is 0.1-30 mass parts with respect to 100 mass parts of crosslinkable rubber components mentioned above, and it is more preferable that it is 1-20 mass parts. Preferably, it is 3-15 mass parts.

  Furthermore, in the present invention, as such a polylactic acid resin, for example, LACEA H-440 (melting point: 155 ° C., number average molecular weight: 78000, weight average molecular weight: 150,000) manufactured by Mitsui Chemicals, Shimadzu Corporation Commercially available products such as Lacti # 1012 (melting point: 170 ° C., number average molecular weight: 180000) can be used.

In the present invention, by containing the above-described inorganic filler having a silanol group and a polylactic acid resin within the above-described content range, the rubber composition of the present invention obtained is excellent in processability, The laminate of the invention has high damping properties and good shear modulus.
Although the detailed mechanism is unknown, the inorganic filler having a silanol group forms a crosslink by a siloxane bond, and due to the interaction between the remaining silanol group or the siloxane bond and the ester bond of the polylactic acid resin, This is probably because the polylactic acid resin collects around the crosslinked filler and crystallizes.
Further, as is apparent from the results shown in Comparative Examples 2 to 4 described later, this is an extremely excellent effect that cannot be obtained even if the content of carbon black, silica, and petroleum resin is adjusted with respect to Comparative Example 1. It is.

  Further, in the present invention, the processability of the rubber composition of the present invention to be obtained becomes better, the damping property of the laminate of the present invention is higher, and the shear elastic modulus is better, as described above. The mass ratio of the inorganic filler having a silanol group and the polylactic acid resin (inorganic filler / polylactic acid resin) is preferably 1/1 to 10/1, more preferably 8/1 to 4/1. Is more preferable.

Furthermore, in the present invention, when the polylactic acid-based resin described above is contained in an amount of about 10 parts by mass or more with respect to 100 parts by mass of the crosslinkable rubber component described above, the resulting rubber composition of the present invention is cut after vulcanization The reason why the above-mentioned inorganic filler and polylactic acid resin having a silanol group are contained as an inorganic filler / polylactic acid masterbatch obtained by mixing them in advance for the reason that the reduction in time elongation and tear strength can be suppressed. Is preferred.
Here, the manufacturing method of the said inorganic filler / polylactic acid masterbatch is not specifically limited, A conventionally well-known method is employable. Specific examples include a method of mixing the above-mentioned inorganic filler having a silanol group and a polylactic acid resin and then pelletizing with a pelletizer.
For the same reason, the inorganic filler having a silanol group and the polylactic acid resin described above are mixed in advance in a solvent (for example, toluene, acetone, chloroform, etc.), and then the solvent is removed and dried. It is preferable to contain it as a polylactic acid surface-treated inorganic filler.

<Petroleum resin>
The rubber composition of the present invention preferably contains a petroleum resin from the viewpoint of improving physical properties such as tensile strength after vulcanization and elongation at break, and further increasing the damping property of the laminate of the present invention. .
As the petroleum resin, conventionally known ones can be used, for example, C5 aliphatic unsaturated hydrocarbon polymer, C9 aromatic unsaturated hydrocarbon polymer, C5 aliphatic unsaturated polymer. Copolymers of saturated hydrocarbons and C9 aromatic unsaturated hydrocarbons can be used.

Specific examples of the C5 aliphatic unsaturated hydrocarbon include, for example, 1-pentene, 2-pentene, 2-methyl-1-butene contained in a C5 fraction obtained by thermal decomposition of naphtha, Olefinic hydrocarbons such as 3-methyl-1-butene and 2-methyl-2-butene; 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 3-methyl-1 , 2-olefin hydrocarbons such as 2-butadiene;
These can be polymerized or copolymerized in the presence of a suitable catalyst. Here, the C5 aliphatic unsaturated hydrocarbon polymer is a co-polymer of a single C5 aliphatic unsaturated hydrocarbon homopolymer and two or more C5 aliphatic unsaturated hydrocarbons. It refers to any polymer.

Specific examples of the C9 aromatic unsaturated hydrocarbon include, for example, α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p contained in a C9 fraction obtained by thermal decomposition of naphtha. -Vinyl-substituted aromatic hydrocarbons such as vinyltoluene.
These can be polymerized or copolymerized in the presence of a suitable catalyst. Here, the C9 aromatic unsaturated hydrocarbon polymer is a co-polymer of a single C9 aromatic unsaturated hydrocarbon homopolymer and two or more C9 aromatic unsaturated hydrocarbons. It refers to any polymer.

In addition, a copolymer of a C5 aliphatic unsaturated hydrocarbon and a C9 aromatic unsaturated hydrocarbon is a C9 aromatic unsaturated hydrocarbon in that the softening point of the copolymer is high. What a unit is 60 mol% or more is preferable, and what is 90 mol% or more is more preferable.
A copolymer of a C5 aliphatic unsaturated hydrocarbon and a C9 aromatic unsaturated hydrocarbon can be copolymerized in the presence of a suitable catalyst.

  The petroleum resin affects the physical properties of the above-mentioned crosslinkable rubber component (particularly diene rubber) due to its molecular weight and double bond reactivity, so the softening point (JIS K2207) is 100 ° C. or higher. The thing of 120 degreeC or more is more preferable.

  In the present invention, the content in the case of containing a petroleum resin as desired is preferably 5 to 50 parts by mass, and 10 to 45 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component described above. Is more preferable.

<Inorganic filler>
The rubber composition of the present invention contains an inorganic filler other than the above-mentioned inorganic filler having a silanol group from the viewpoint of higher damping properties of the laminate of the present invention and better shear modulus. preferable.
Specific examples of such inorganic fillers include calcium carbonate, heavy calcium carbonate, magnesium carbonate, aluminum hydroxide, barium sulfate, aggregates of quartz and kaolinite, and diatomaceous earth. .

  In the present invention, among these inorganic fillers, an agglomerate of quartz and kaolinite is preferable because the damping property and stability against long-term shear deformation can be kept particularly high.

  In the present invention, the content in the case of containing an inorganic filler as desired is preferably 5 to 55 parts by mass, and 10 to 50 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component described above. More preferably, it is 15 to 40 parts by mass.

  In the present invention, the total amount of the inorganic filler having a silanol group and the inorganic filler other than the inorganic filler having a silanol group is 20 to 75 with respect to 100 parts by mass of the crosslinkable rubber component. It is preferable that it is a mass part, and 30-65 mass parts is more preferable. When the total amount is in such a range, the rubber composition for a high-damping laminate having an excellent balance, in which the damping property is higher and the damping property and the shear elastic modulus against long-term repeated shear deformation are more stable. Is obtained.

  The mass ratio of the inorganic filler having a silanol group and the inorganic filler other than the inorganic filler having a silanol group is preferably 1/1 to 1 / 2.5, and 1/1 to 1/2. 0.0 is more preferable. When the mass ratio is within this range, good workability can be obtained.

<Carbon black>
The rubber composition of the present invention has good physical properties such as tensile strength after vulcanization, elongation at break, etc., and the damping properties of the laminate of the present invention are higher. It is preferable to contain.

In the present invention, carbon black having a CTAB adsorption specific surface area of 100 m ² / g or more is preferably used, and carbon black of 110 to 370 m ² / g is more preferably used.
When the CTAB adsorption specific surface area is in the range of 100 m ² / g or more, the damping property of the obtained laminate of the present invention can be maintained higher.
Here, the CTAB adsorption specific surface area is a value obtained by measuring the surface area that carbon black can be used for adsorption with rubber molecules by adsorption of CTAB (cetyltrimethylammonium bromide).
Examples of such carbon black include SAF, ISAF, and HAF. The CATB adsorption specific surface area can be measured by the method described in ASTM D3765-80.

  Further, in the present invention, the content when carbon black is optionally contained is preferably 40 to 75 parts by mass, and 50 to 75 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component described above. It is more preferable that

<Metal compound>
The rubber composition of the present invention contains a metal compound from the viewpoint of accelerating the decomposition of the polylactic acid resin and increasing the number of sites where the polylactic acid resin and the inorganic filler having a silanol group interact. Is preferred.
As said metal compound, a zinc compound, an aluminum compound, a copper compound etc. are mentioned, for example.
Of these, zinc compounds are preferable, and specifically zinc oxide, organic zinc phosphate, and fatty acid zinc are more preferable. Of these, zinc oxide is more preferable.

  In the present invention, the content in the case of containing a metal compound as desired is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the crosslinkable rubber component described above. More preferably, it is part by mass.

<Silane coupling agent>
The rubber composition of the present invention preferably contains a silane coupling agent from the viewpoint of improving physical properties such as tensile strength after vulcanization and elongation at break of the rubber composition of the present invention to be obtained.
Specific examples of the silane coupling agent include bis- [3- (triethoxysilyl) -propyl] tetrasulfide, bis- [3- (trimethoxysilyl) -propyl] tetrasulfide, and bis- [ 3- (triethoxysilyl) -propyl] disulfide, mercaptopropyl-trimethoxysilane, mercaptopropyl-triethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl-tetrasulfide, trimethoxysilylpropyl-mercapto Benzothiazole tetrasulfide, triethoxysilylpropyl-methacrylate-monosulfide, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl-tetrasulfide and the like may be mentioned, and these may be used alone. It may be used in combination with more species.

  In the present invention, the content in the case of containing a silane coupling agent as desired is preferably 0.1 to 10% by mass of the content of the inorganic filler having a silanol group described above, and 1 to 8% by mass. % Is more preferred.

  The rubber composition for a highly damped laminate of the present invention further contains moisture, not only is the vulcanization time significantly shortened and the productivity is improved, but also the damping property and horizontal rigidity (= shear elastic modulus) are further increased. It is preferable because it is excellent.

Furthermore, when the moisture content X (mass%) in the rubber composition for high attenuation laminate (unvulcanized rubber composition) before crosslinking satisfies the following formula (1), the vulcanization time is greatly increased. This is preferable because it is not only shortened and excellent in productivity, but also has excellent damping properties and horizontal rigidity (= shear elastic modulus).
{(C / 5b) / (Total amount of rubber composition for highly attenuated laminate)} × 100 ≦ X ≦ 3 (1)
(Wherein c / 5b represents an approximate value of moisture contained in the rubber composition for a highly attenuated laminate of the present invention, c is the amount of the inorganic filler having a silanol group, and b is the polylactic acid type) The amount of resin.)
In the above formula (1), c / 5b represents an approximate value of moisture contained in the rubber composition for a high attenuation laminate according to the present invention. The inventors of the present application have experimentally obtained that c / 5b represents an approximate value of moisture contained in the rubber composition for a highly attenuated laminate according to the present invention. The reason why the molecule is c in c / 5b is that the inorganic filler having a silanol group contains a lot of moisture and easily absorbs the moisture, so the amount of moisture in the composition is the amount of the inorganic filler having a silanol group. This is because it is considered to be proportional to.
The inventors of the present application have inferred that not only the damping property but also the horizontal rigidity become higher due to hydrolysis of the polylactic acid resin. The reason for the presence of b in the denominator (5b) in c / 5b is that the amount of polylactic acid resin in the unvulcanized rubber composition increases, so that water in the composition is consumed by hydrolysis and This is because moisture is considered to decrease. Here, b is a relative value with respect to moisture in the composition and has no unit.

  In the present invention, when 100 parts by mass of the crosslinkable rubber component contains 10 to 150 parts by mass of an inorganic filler having a silanol group and 0.1 to 30 parts by mass of a polylactic acid resin, the moisture content X is Formula (1) can be satisfied. In addition, when 100 parts by mass of the crosslinkable rubber component in the present invention contains 10 to 150 parts by mass of an inorganic filler having a silanol group and 0.1 to 30 parts by mass of a polylactic acid resin, c / 5b can be c / 25.

In the following cases where the upper limit of the moisture content X is 3% by mass, vulcanization inhibition is unlikely to occur and the torque is unlikely to decrease, which is preferable from the viewpoint of excellent damping properties and excellent horizontal rigidity.
When the lower limit value of the moisture content X is [{(c / 5b) / (total amount of rubber composition for highly attenuated laminate)} × 100] mass% or more, from the viewpoint of excellent damping properties and excellent horizontal rigidity. preferable.
The moisture content X is 0.5 ≦ X ≦ 1.5 from the viewpoint that not only the vulcanization time is greatly shortened and the productivity is improved, but also the damping property and the horizontal rigidity (= shear elastic modulus) are further improved. It is preferable that there is 0.6 ≦ X ≦ 1.2.

  Examples of the moisture contained in the rubber composition for high attenuation laminate (unvulcanized rubber composition) before crosslinking include, for example, the moisture originally contained in the unvulcanized rubber composition, and the unvulcanized rubber composition. Moisture absorbed, and water when water is added to the unvulcanized rubber composition.

<Other additives>
The rubber composition of the present invention can contain other additives as necessary within a range not impairing the object of the present invention.
Examples of the additive include a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a plasticizer, a softening agent, a vulcanization aid, a flame retardant, a weathering agent, and a heat resistance agent.
Specific examples of the vulcanizing agent include sulfur; organic sulfur-containing compounds such as TMTD; organic peroxides such as dicumyl peroxide; and the like.
Specific examples of the vulcanization accelerator include sulfenamides such as N-cyclohexyl-2-benzothiazole sulfenamide (CBS); thiazoles such as mercaptobenzothiazole; tetramethylthiuram monosulfide and the like. Thiurams; stearic acid; and the like.
Specific examples of the antiaging agent include ketone / amine condensates such as TMDQ; amines such as DNPD; monophenols such as styrenated phenol; and the like.
Specific examples of the plasticizer include phthalic acid derivatives (for example, DBP, DOP and the like), sebacic acid derivatives (for example, DBS and the like) monoesters, and the like.
Specific examples of the softening agent include paraffinic oil (process oil).

The method for producing the rubber composition of the present invention is not particularly limited. For example, an unvulcanized rubber composition containing 100 parts by mass of the rubber component, 10 to 150 parts by mass of the inorganic filler having a silanol group, and 0.1 to 30 parts by mass of the polylactic acid resin is kneaded. The manufacturing method of the rubber composition for highly attenuated laminated bodies obtained by doing is mentioned. Further, for example, an unvulcanized rubber composition containing the above-described components can be prepared by kneading using a known method and apparatus (for example, a Banbury mixer, a kneader, a roll, etc.).
In addition, as described above, when the polylactic acid-based resin described above is contained in an amount of about 10 parts by mass or more with respect to 100 parts by mass of the crosslinkable rubber component described above, among the components described above, the above-described silanol group is included. It is preferable to prepare an inorganic filler / polylactic acid master batch or a polylactic acid surface-treated inorganic filler by previously mixing the inorganic filler and the polylactic acid resin.

When the rubber composition for a highly attenuated laminate of the present invention contains water, for example, a method of adding water to the composition, a method of absorbing the composition, a filler containing a lot of water in the composition (for example, silanol group) The composition can be produced by a method of containing an inorganic filler having
When the rubber composition for a high attenuation laminate according to the present invention contains moisture, the moisture content X (% by mass) in the rubber composition for a high attenuation laminate before crosslinking satisfies the following formula (1). This is preferable because not only the vulcanization time is greatly shortened and the productivity is improved, but also the damping property and the horizontal rigidity (= shear elastic modulus) are further improved.
{(C / 5b) / (Total amount of rubber composition for highly attenuated laminate)} × 100 ≦ X ≦ 3 (1)
(In the formula, c / 5b represents an approximate value of moisture contained in the rubber composition for a high attenuation laminate, c is the amount of the inorganic filler having the silanol group, and b is the amount of the polylactic acid-based resin. Amount.)
Formula (1) is synonymous with the above.

The vulcanization conditions (primary crosslinking) of the rubber composition of the present invention are not particularly limited, and vulcanization can be performed under conventionally known vulcanization conditions using a sulfur compound or a peroxide.
In the present invention, the primary cross-linking temperature is preferably 130 to 200 ° C. from the viewpoint of superior horizontal rigidity.

In the present invention, it is preferable to heat-treat the rubber composition of the present invention that has undergone primary crosslinking.
The temperature condition of the heat treatment is not particularly limited as long as it is the same temperature as the primary crosslinking temperature, but is preferably in the range of a temperature 10 ° C. to 10 ° C. higher than the temperature of the primary crosslinking. More preferably, the temperature is in the range of 5 ° C. to 5 ° C., more preferably in the range of 2 ° C. to 2 ° C. higher than the temperature of primary crosslinking.

The heat treatment time is obtained from a vulcanization curve obtained from a rheometer torque defined in JIS K6300-2: 2001 using the rubber composition of the present invention before primary crosslinking (unvulcanized). Is preferably 0.5 to 3 times, more preferably 0.5 to 2 times.
Here, the vulcanization curve is based on JIS K6300-2: 2001 “How to obtain vulcanization characteristics by vibration vulcanization tester”, using a rotorless vulcanization tester as a rheometer at a predetermined test temperature. The obtained torque is on the vertical axis and the vulcanization time is on the horizontal axis. The rheometer test temperature is the above-described primary crosslinking temperature.
In such a vulcanization curve, when the torque is clear that you have reached the maximum value M _H from the minimum value M _L is required vulcanized start until the torque reaches 95% of the width of the minimum and maximum values The vulcanization time is T95.
When the torque continues to increase as the vulcanization time elapses and does not show a clear maximum value _MH , JIS K6300-2: 2001 states that “the vulcanization curve continues to rise and the vulcanization curve has a stable slope. Therefore, in the present invention, t _c (max) = 30 minutes from the time listed as the specific time, and the torque at that time is expressed as _MH . To do.

  By performing such heat treatment, it is possible to further improve the damping property of the laminate of the present invention and to ensure excellent vibration damping properties in a wide temperature range. This is considered to be because the network of the inorganic filler grows by interacting with the inorganic filler having a silanol group by promoting the decomposition of the polylactic acid-based resin described above.

  The laminate of the present invention is a high-attenuation laminate obtained by alternately laminating the rubber composition of the present invention and the hard plate described above, and is a structure used for bridge support, building base isolation, etc. is there.

  In FIG. 1, the cross-sectional schematic of the high attenuation | damping laminated body showing an example of the embodiment of the laminated body of this invention is shown. In FIG. 1, the code | symbol 1 represents a high attenuation | damping laminated body (seismic isolation laminated body), the code | symbol 2 represents a hard board, and the code | symbol 3 represents the rubber composition for high attenuation | damping laminated bodies of this invention.

As shown in FIG. 1 as an example, the high attenuation laminate 1 of the present invention includes a rubber composition 3 for a high attenuation laminate of the present invention and a hard plate 2 (for example, a general structural steel plate, a cold rolled steel plate, etc.). Are alternately stacked.
The high attenuation laminate 1 may be configured by providing an adhesive layer between the rubber composition 3 for the high attenuation laminate of the present invention and the hard plate 2, or directly without providing the adhesive layer. It may be configured by vulcanization.

In FIG. 1, the high attenuation laminate 1 of the present invention is shown in a state where the rubber composition 3 for the high attenuation laminate of the present invention and the hard plate 2 are alternately laminated. The body rubber composition 3 may have a structure in which two or more layers are laminated.
Moreover, in FIG. 1, although the example of a total of 13 layers of 6 layers about the rubber composition 3 for high attenuation laminated bodies of this invention and 7 layers about the hard board 2 is shown, the high attenuation laminated body 1 of this invention is shown. The number of laminated layers of the rubber composition 3 for a highly attenuated laminate of the present invention and the hard plate 2 is not limited to this, and can be arbitrarily set according to the intended use, required characteristics, and the like.
Furthermore, the size of the high attenuation structure 1 of the present invention, the overall thickness, the layer thickness of the rubber composition 3 for the high attenuation laminate of the present invention, the thickness of the hard plate, etc. It can be set arbitrarily according to the required characteristics.

  In order to produce the laminate of the present invention, the rubber composition for a highly attenuated laminate of the present invention is molded into a sheet and then vulcanized to obtain a sheet-like rubber composition, and then a layer containing an adhesive May be laminated alternately with the hard plate, or the rubber composition for the highly damped laminate of the present invention that has not been vulcanized in advance is formed into a sheet shape and laminated alternately with the hard plate, and then heated. Then, vulcanization and adhesion may be performed simultaneously.

Since the laminated body of the present invention uses the above-described rubber composition of the present invention, it has an effect of high damping and excellent shear modulus.
Specifically, an equivalent damping constant (Heq) that is an index of damping performance measured by a lap shear shear test described later is 0.21 or more, and a shear elastic modulus (Geq) that is similarly measured is 0.78 to 0.00. 96.

The equivalent damping constant (Heq) and shear modulus (Geq) are measured by a lap shear shear test.
FIG. 2 is a schematic side view of a sample for a lap shear type shear test. In FIG. 2, the code | symbol 4 represents the sample for a lap shear type shear test, the code | symbol 5 represents the rolled unvulcanized rubber composition, and the code | symbol 6 represents a steel plate.
The unvulcanized rubber composition 5 is an unvulcanized rubber composition of the rubber composition of the present invention that has been rolled to a size of 25 mm wide × 25 mm long × 5 mm thick. The steel plate 6 is a steel plate (width 25 mm × length 100 mm × thickness 20 mm) having a surface sandblasted and coated with a metal adhesive.
The sample 4 for lap shear type shear test is obtained by placing (stacking) the unvulcanized rubber composition 5 and the steel plate 6 as shown in FIG. 2 and then press vulcanizing at 130 ° C. for 120 minutes.

The lap shear shear test is performed under the following conditions using a vibrator (manufactured by Saginomiya), an input signal oscillator, and an output signal processor.
Using the lap shear type shear test sample prepared as described above, each time when a 175% strain was applied 10 times at a deformation frequency of 0.5 Hz by a biaxial shear tester at a measurement temperature of 23 ° C. Obtain the average shear characteristic value.
Specifically, using the Xmax and Qmax indicated by the hysteresis curve obtained in the lap shear type shear test, the equivalent damping constant (Heq) and shear modulus (Geq) are determined according to the following formulas (1) and (2). calculate. FIG. 3 shows an example of a hysteresis curve obtained by a lap shear type shear test.

In equation (1), ΔW is the area of the hysteresis loop (the shaded area in FIG. 3).
In the formula (2), Keq is represented by the following formula (3), H represents the total thickness of the rubber layer laminated in the high attenuation laminate, and A is the cross-sectional area of the rubber layer.

  The use, application conditions, and the like of the high attenuation laminate are not particularly limited as long as the high attenuation laminate is used as a vibration energy absorber. Among these, since it has the above-described excellent characteristics, it is preferably used as a vibration energy absorption device for buildings. For example, various vibration energy absorption devices for vibration isolation, vibration isolation, vibration isolation, etc. Is suitably used for, for example, support of road bridges, bridges, building base isolation, and detached base isolation applications).

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely according to an Example, this invention is not limited to the following Example.

(Examples 1 to 11, Comparative Examples 1 to 4: Preparation of samples for lap shear type shear test)
First, each compound was blended so as to have the composition shown in Table 1 below (unit: parts by mass) and kneaded for 5 minutes with a B-type Banbury mixer to prepare an unvulcanized rubber composition.
Next, the prepared unvulcanized rubber composition was rolled into a size of width 25 mm × length 25 mm × thickness 5 mm.
An unvulcanized rubber composition after rolling (5 in FIG. 2) and a steel plate (25 mm wide × 100 mm long × 20 mm thick, 6 in FIG. 2) coated with a metal adhesive by sandblasting the surface. 2 was placed (laminated) as shown in the side view of the lap shear type shear test sample 4 in FIG. 2, and then press vulcanized at 130 ° C. for 120 minutes to prepare a lap shear type shear test sample.

<Mooney viscosity>
About the obtained unvulcanized rubber composition, Mooney viscosity was measured according to JIS K6300-1: 2001 using an L-shaped rotor under the conditions of a preheating time of 1 minute and a test temperature of 125 ° C.

<Tensile properties>
The obtained unvulcanized rubber composition was vulcanized for 45 minutes under a pressure of 3.0 MPa using a press molding machine at 148 ° C. to prepare a vulcanized sheet having a thickness of 2 mm. A JIS No. 3 dumbbell-shaped test piece was punched from this sheet, and a tensile test at a tensile speed of 500 mm / min was conducted in accordance with JIS K6251-2004. Tensile strength (T _B ) [MPa], elongation at break (E _B ) [%] And 150% modulus (M ₁₅₀ ) [MPa] were measured at room temperature. The results are shown in Table 1.

<Lap shear test>
A lap shear shear test was performed on the lap shear type shear test sample using a vibrator (manufactured by Saginomiya), an input signal oscillator, and an output signal processor. The number of lap shear type shear test samples used in each example was ten.
Specifically, the shear characteristics of each time when 175% strain was applied 10 times at a deformation frequency of 0.5 Hz by a biaxial shear tester and a measurement temperature of 23 ° C. with respect to the lap shear type shear test sample. The average of the values was obtained.
Using Xmax and Qmax indicated by the hysteresis curve obtained by this lap shear shear test, average shear characteristic values (Geq, Heq) were determined according to the above formulas (1) and (2). The results are shown in Table 1.

The following were used for each component in Table 1.
・ Natural rubber: STR20, manufactured by SIAM INDO RUBBER ・ Vinyl-cis butadiene rubber: UBEPOL-VCR412, manufactured by Ube Industries, Ltd. ・ Carbon black: Diamond Black I, manufactured by Mitsubishi Chemical Corporation ・ Silica: Nip Seal VN3, manufactured by Tosoh Silica Clay: SUPREX PLAY, manufactured by Kentucky Tennessee Clay Company ・ Petroleum resin: High Resin # 120S (softening point 120 ° C., manufactured by Toho Chemical Co., Ltd.)
-Zinc oxide: Zinc Hana 3 manufactured by Shodo Chemical Industry Co., Ltd.-Polylactic acid 1: LACEA H-440 (melting point: 155 ° C, number average molecular weight: 78000, weight average molecular weight: 150,000, manufactured by Mitsui Chemicals)
Polylactic acid 2: A polymer obtained by the following synthesis (melting point: 116 ° C., number average molecular weight: 2500, weight average molecular weight: 3500) was used. First, 1 g of n-dodecanol was added as an initiator to 80 g of LL-lactide and stirred at 150 ° C. for 3 hours under a nitrogen atmosphere. Thereafter, the portion melted at 150 ° C. was dropped into methanol to form a precipitate, and a white powdery polymer was recovered.
・ Sulfur: Sulfur powder, manufactured by Hosoi Chemical Co., Ltd. ・ Vulcanization accelerator: Noxeller CZ, manufactured by Ouchi Shinsei Chemical Co., Ltd.

As is apparent from Table 1, rubber compositions prepared by changing the blending amounts of carbon black, petroleum resin, and silica with respect to the rubber composition for highly attenuated laminates prepared in Comparative Example 1 (Comparative Examples 2 to 2) 4) It was found that although the damping property was improved as compared with Comparative Example 1, the viscosity increased and the workability deteriorated and the shear modulus was inferior.
On the other hand, the rubber compositions for highly attenuated laminates prepared in Examples 1 to 11 all have the same level of viscosity (workability) as Comparative Example 1, while increasing the damping property, and the shear modulus. Was also found to be excellent.

(Example 12)
First, 150 g of silica (Nipseal VN3, manufactured by Tosoh Silica Co., Ltd.) is added to 300 g of polylactic acid (LACEA H-440 (melting point: 155 ° C., number average molecular weight: 78000, weight average molecular weight: 150,000, manufactured by Mitsui Chemicals)). After adding and mixing at 200 ° C. for 5 minutes, pellets (silica / polylactic acid master batch) were prepared with a pelletizer.
Next, together with 15 g of the obtained pellets (silica: 5 g, polylactic acid: 10 g), the respective compounds were blended so as to have the composition shown in Table 2 below (unit: parts by mass), and 5 in a B-type Banbury mixer. The mixture was kneaded for a minute to prepare an unvulcanized rubber composition.
About the obtained unvulcanized rubber composition, the elongation at break after vulcanization was measured by the same method as described above, the tear strength was measured by the method shown below, and the damping property was evaluated.

<Tear strength>
A vulcanized sheet having the same tensile properties as described above was prepared, and a crescent-shaped test piece was punched out according to JIS K6252-2007, and the tear strength (N / mm) was measured.

<Attenuation>
A vulcanized sheet having the same tensile physical properties as described above was prepared, and a strip-shaped test piece having a width of 10 mm and a thickness of 2 mm was prepared. The hysteresis loss [%] for the fifth time was calculated when the produced test piece was stretched 150% five times at a crosshead speed of 500 mm / min with an autograph tensile tester. The hysteresis loss was calculated by multiplying 100 by the ratio (ABCDA / ABCEA) between the area corresponding to ABCDA and the area corresponding to ABCEA in the stress-strain curve diagram shown in FIG. Energy attenuation was evaluated from hysteresis loss. The results are shown in Table 2.

(Example 13)
First, 100 g of polylactic acid (LACEA H-440 (melting point: 155 ° C., number average molecular weight: 78000, weight average molecular weight: 150,000, manufactured by Mitsui Chemicals)) was dissolved in 1 L of toluene, and then silica (Nip seal VN3, Tosoh 50 g) (manufactured by Silica) was added and stirred at 70 ° C. for 3 hours. Subsequently, after removing toluene by filtration, it was dried to prepare polylactic acid surface-treated silica.
Here, when the obtained polylactic acid surface-treated silica was subjected to thermogravimetry (TGA) from room temperature to 600 ° C. under a temperature rising rate of 20 ° C./min, the organic content (polylactic acid) was 50% by mass. I found out that
Next, together with the obtained polylactic acid surface-treated silica 20 g (silica: 10 g, polylactic acid: 10 g), each compound was blended so as to have the composition shown in Table 2 below (units are parts by mass), and B-type Banbury The mixture was kneaded for 5 minutes to prepare an unvulcanized rubber composition.
About the obtained unvulcanized rubber composition, the elongation at break and tear strength after vulcanization were measured by the same method as described above, and the damping property was evaluated.

Each component in Table 2 is the same as each component in Table 1 except for the following.
Silica / polylactic acid master batch: prepared in Example 12.
Polylactic acid surface-treated silica: prepared in Example 13.

  As is apparent from Table 2, when polylactic acid is contained in an amount of about 10 parts by mass or more with respect to 100 parts by mass of natural rubber, it is more effective to contain it as a silica / polylactic acid master batch or polylactic acid surface-treated silica. It was found that the elongation at break and the decrease in tear strength can be suppressed while maintaining the properties.

Example II
<Manufacture of rubber composition for highly attenuated laminate>
The components shown in Table 3 below were blended in the amounts (parts by mass) shown in the same table and kneaded for 5 minutes with a B-type Banbury mixer to obtain an unvulcanized rubber composition (compound). The obtained compound is made into compounding 1-4.

Details of each component shown in Table 3 are as follows.
・ Natural rubber: STR20, manufactured by SIAM INDO RUBBER ・ Vinyl-cis butadiene rubber: UBEPOL-VCR412, manufactured by Ube Industries, Ltd. ・ Carbon black: Diamond Black I, manufactured by Mitsubishi Chemical Corporation ・ Silica 1: inorganic filler having a silanol group, Nip seal VN3, manufactured by Tosoh Silica Co., Ltd. ・ Clay: inorganic filler having silanol group, SUPREX PLAY, manufactured by Kentucky Tennessee Clay Company ・ Petroleum resin: High Resin # 120S (softening point 120 ° C., manufactured by Toho Chemical Co., Ltd.)
-Zinc oxide: Zinc Hana 3 manufactured by Shodo Chemical Industry Co., Ltd.-Polylactic acid 1: LACEA H-440 (melting point: 155 ° C, number average molecular weight: 78000, weight average molecular weight: 150,000, manufactured by Mitsui Chemicals)
・ Aqueous solution: An aqueous solution containing 8% by mass of sodium dihydrogen phosphate (manufactured by Wako Pure Chemical Industries, Ltd.) as an acidic component ・ Sulfur: Sulfur powder, manufactured by Hosoi Chemical Co., Ltd. ・ Vulcanization accelerator: Noxeller CZ, Ouchi Shinsei Chemical Industry Made by company

  The water content in the unvulcanized rubber composition was changed by placing the treatments shown in Table 4 under the treatment conditions shown in Table 4 below (room temperature 23 ° C., moist heat, drying). For Formulation 3, the water content in the unvulcanized rubber composition was changed by adding water as shown in Table 3 and placing the treatment time shown in the same table under the treatment conditions shown in Table 4 below. Wet heat was performed by putting the unvulcanized rubber composition to be used in a wet heat oven (humidity: 95% RH, temperature: 60 ° C.). Drying was performed by putting the unvulcanized rubber composition to be used in a vacuum oven (temperature: 80 ° C.).

<Evaluation>
After placing the formulations 1 to 4 under the processing conditions shown in Table 4 below, productivity, equivalent damping constant, horizontal stiffness constant (horizontal stiffness), and moisture content were measured according to the following methods. The results are shown in Table 4. In addition, Table 4 shows the lower limit value of the moisture content X represented by the above formula (1) of each example.

1. Productivity Productivity was evaluated based on the vulcanization time obtained from the vulcanization curve until the torque reached T95 defined below.
In vulcanization curve, when the torque is clear that you have reached the maximum value M _H from the minimum value M _L is vulcanization torque is minimum from the start and maximum vulcanization time taken to reach 95% of the width Is T95.
When the torque continues to increase as the vulcanization time elapses and does not show a clear maximum value _MH , JIS K6300-2: 2001 states that “the vulcanization curve continues to rise and the vulcanization curve has a stable slope. Therefore, in the present invention, t _c (max) = 30 minutes from the time listed as the specific time, and the torque at that time is expressed as _MH . To do.
The vulcanization curve conforms to JIS K6300-2: 2001 “How to obtain vulcanization characteristics using a vibration vulcanization tester” and uses a rotorless vulcanization tester as a rheometer at a predetermined test temperature (150 ° C.). The obtained torque was plotted on the vertical axis and the vulcanization time was plotted on the horizontal axis.
A test piece of unvulcanized rubber used for evaluating the vulcanization curve is prepared by cutting out a rubber mass of about 8 cm ³ each from an unvulcanized rubber sheet having a thickness of 3 mm in accordance with JIS K 6300. It was done.
The result of the obtained vulcanization curve is shown in FIG. FIG. 6 is a graph showing vulcanization curves measured in the examples of the present invention.

2. Equivalent damping constant, horizontal stiffness constant In the same manner as in Example 1, a sample for a lap shear type shear test was prepared and a lap shear shear test was performed. Using Xmax and Qmax indicated by the hysteresis curve obtained by the lap shear shear test, average shear characteristic values [equivalent damping constant (Heq), horizontal stiffness constant (Geq)] were determined according to the above formulas (1) and (2). . The horizontal stiffness constant (Geq) was calculated according to the above formula (2) in the same manner as the shear modulus (Geq).

3. Moisture content X
The actual water content contained in each formulation was measured by the Karl Fischer method (a method using a Karl Fischer reagent that reacts selectively and quantitatively with water). The water content contained in each formulation is measured according to a coulometric titration method using an electrolytic solution (trade name: Aquamicron CXU, manufactured by API Corporation) containing, as a Karl Fischer reagent, iodide ions, sulfur dioxide, and alcohol as main components. This was performed using a moisture measuring device (manufactured by Okura Riken).

As is apparent from the results shown in Table 4, Comparative Example II-2 absorbed moisture over time and the moisture content was higher than that of Comparative Example II-1, resulting in increased productivity. However, Comparative Examples II-1 and 2 did not contain a polylactic acid resin and had low productivity, damping property, and horizontal rigidity. Further, Comparative Example II-2 was lower in damping property and horizontal rigidity than Comparative Example II-1. Comparative Example II-3 containing an acidic aqueous solution had low productivity. Low molecular acid components such as sodium dihydrogen phosphate and glycolic acid have the disadvantage of inhibiting vulcanization and speeding up scorching.
On the other hand, Examples II-1 to 5 are excellent in damping property, horizontal rigidity, and productivity. Examples II-2, 3, and 5 satisfying the formula (1) had higher productivity than Examples II-1 and 4.
Further, as is clear from the results shown in FIG. 6, Comparative Examples II-1 to III-3 containing no polylactic acid resin had only one stage of torque increase, and the maximum value of torque was low.
In contrast, in Examples II-1 and 4, two stages of torque increase were observed, and the vulcanization time at the first stage of torque increase was comparable to that of Comparative Examples II-1 to III, but the torque The highest value is remarkably high at 20 dN · m or more, and it has excellent damping and horizontal rigidity. Examples II-2 and 3 in which the moisture content satisfies the formula (1) are excellent in productivity, and the maximum value of torque is as high as 25 dN · m or more, and is excellent in damping property and horizontal rigidity.

1 High attenuation laminate (Seismic isolation laminate)
2 Hard plate 3 Rubber composition for high attenuation laminate of the present invention 4 Sample for lap shear type shear test 5 Rolled unvulcanized rubber composition 6 Steel plate

Claims (16)

  A rubber composition for a high attenuation laminate comprising 100 parts by mass of a crosslinkable rubber component, 10 to 150 parts by mass of an inorganic filler having a silanol group, and 0.1 to 30 parts by mass of a polylactic acid resin.   The rubber composition for a high attenuation laminate according to claim 1, further comprising 5 to 50 parts by mass of a petroleum resin with respect to 100 parts by mass of the rubber component.   The rubber composition for a high attenuation laminate according to claim 1 or 2, further comprising a metal compound.   The rubber composition for a high attenuation laminate according to claim 3, wherein the amount of the metal compound is 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.   The rubber for high attenuation laminates according to any one of claims 1 to 4, further comprising 5-55 parts by mass of an inorganic filler other than the inorganic filler having a silanol group with respect to 100 parts by mass of the rubber component. Composition.   The rubber composition for a high attenuation laminate according to any one of claims 1 to 5, wherein the rubber component is a diene rubber.   The rubber composition for a high attenuation laminate according to any one of claims 1 to 6, wherein the rubber component contains natural rubber and vinyl-cisbutadiene rubber.   The rubber composition for a high attenuation laminate according to claim 7, wherein the rubber component contains 10% by mass or more of the vinyl-cis butadiene rubber.   The melting point of the polylactic acid resin is 150 ° C. or less, The rubber composition for a high attenuation laminate according to claim 1.   The number average molecular weight of the said polylactic acid-type resin is 1000-10000, The rubber composition for highly attenuated laminated bodies in any one of Claims 1-9.   The mass ratio (inorganic filler / polylactic acid resin) between the inorganic filler having a silanol group and the polylactic acid resin is 1/1 to 10/1. Rubber composition for highly attenuated laminates.   The highly attenuated laminate according to any one of claims 1 to 11, wherein the inorganic filler having a silanol group and the polylactic acid-based resin are contained as an inorganic filler / polylactic acid master batch obtained by mixing them in advance. Rubber composition.   The inorganic filler having the silanol group and the polylactic acid-based resin are contained as a polylactic acid surface-treated inorganic filler obtained by previously mixing these in a solvent, then removing the solvent and drying. The rubber composition for highly attenuated laminates according to any one of -11. The high attenuation | damping in any one of Claims 1-13 which contains a water | moisture content and the moisture content X (mass%) in the said rubber composition for highly attenuated laminated bodies before bridge | crosslinking satisfy | fills following formula (1). Rubber composition for laminate.
{(C / 5b) / (Total amount of rubber composition for highly attenuated laminate)} × 100 ≦ X ≦ 3 (1)
(In the formula, c / 5b represents an approximate value of moisture contained in the rubber composition for a high attenuation laminate, c is the amount of the inorganic filler having the silanol group, and b is the amount of the polylactic acid-based resin. Amount.)   The rubber composition for a high attenuation laminate according to any one of claims 1 to 14, which has been vulcanized.   A high attenuation laminate obtained by alternately laminating the rubber composition for a high attenuation laminate according to any one of claims 1 to 15 and a hard plate.