JP4618014B2 - Rubber laminate - Google Patents

Description

  The present invention relates to a rubber laminate, and more particularly to a rubber laminate that has good vibration energy absorption performance and can improve durability and tensile performance.

  Various rubber laminates that are installed on the foundation of a structure and serve as a support have been proposed, and rubber laminates using lead as a damping material are known in order to improve damping performance. As illustrated in FIG. 5, the structure includes a rubber laminate 1 in which thin steel plates 5 and rubber layers 4 are alternately laminated between a metal upper plate 2 and a lower plate 3, and the upper plate 2 to the lower plate 3. An insertion hole 8 penetrating up to is provided, and a lead plug 7 is inserted into the insertion hole 8 to form an attenuation material. The upper plate 2 is provided with a boss hole B used for installing a structure or the like.

  The excellent damping performance of the lead plug 7 can provide good vibration energy absorption performance. However, since lead does not stretch and is not integrated with rubber, the upper plate 2 and the lower plate 3 are relatively When the shear displacement is caused by shifting to the side, as shown in FIG. 6, there is a problem that the constriction occurs and breaks, and the durability becomes insufficient because the use becomes impossible.

  The rubber laminate 1 is normally used in a compressive stress state, but is designed on the assumption that the upper plate 2 and the lower plate 3 are subjected to tensile stress that is relatively separated in the vertical direction. Therefore, it is necessary to secure a certain pressure receiving area and reduce the tensile stress.

  However, lead is a material that is difficult to bond, and the lead plug 7 and the plates 2 and 3 cannot be integrated by bonding. Therefore, the adhesion area between the rubber layer 4 and the plates 2 and 3 has to be increased, and there is a problem that it is difficult to reduce the size of the rubber laminate 1.

On the other hand, what is used as an attenuation material by filling with a plastic material instead of the lead plug 7 has been proposed (see Patent Document 1). However, even in this proposal, since the damping material and the upper and lower plates are not integrated, there is a problem in improving the tensile performance and reducing the size of the rubber laminate.
Japanese Patent Laid-Open No. 11-210902

  An object of the present invention is to provide a rubber laminate that has good vibration energy absorption performance and that can be improved in durability and tensile performance and can be reduced in size.

In order to achieve the above object, the rubber laminate of the present invention is a rubber laminate in which steel plates and rubber layers are alternately laminated between an upper plate and a lower plate, wherein the damping material made of transpolyisoprene is used as the upper plate, It is bonded and integrated with the lower plate, steel plate and rubber layer, and is interposed between both plates . The damping material is blended with diene rubber and carbon black, and this damping material is composed of transpolyisoprene and diene rubber. A composition in which 40 parts by mass or more and 100 parts by mass or less of carbon black is blended with respect to 100 parts by mass of the resulting polymer, and the mass blending ratio of transpolyisoprene in the polymer is 50% or more .

  According to the rubber laminate of the present invention, by providing a damping material made of trans polyisoprene between the upper plate and the lower plate, it is possible to obtain good vibration energy absorption performance, and at the time of shear deformation, The constriction that occurs in the lead damping material does not occur, and durability is improved.

  Trans polyisoprene is a material that can be bonded to metal, etc., and by adhering the damping material to the upper plate, the lower plate, the steel plate, and the rubber layer, the rubber layer and the It is possible to bear the tensile stress together with the steel sheet, it is possible to improve the tensile performance of the rubber laminate, and it is not necessary to increase the bonding area between both plates and the rubber layer in order to cope with the tensile stress, The rubber laminate can be miniaturized.

  Hereinafter, the rubber laminate of the present invention will be described based on the embodiments shown in the drawings. In addition, the same code | symbol is attached | subjected and demonstrated to the same component as a prior art example. As shown in a longitudinal section in FIG. 1, the rubber laminate 1 of this embodiment is configured by alternately laminating steel plates 5 and rubber layers 4 between an upper plate 2 and a lower plate 3. Attenuating material 6 having upper and lower ends bonded and fixed is interposed between both plates 2 and 3.

  The damping material 6 is made of transpolyisoprene, is columnar and is vertically installed through the steel plate 5 and the rubber layer 4 at the center, and is bonded to the steel plate 5 and the rubber layer 4 together with the plates 2 and 3. It has become.

  Here, FIG. 4 illustrates the tensile properties of lead, general natural rubber (NR), and trans polyisoprene (TPI). As shown in FIG. 4, lead has a high tensile yield stress of about 13 MPa, but the elongation at break is small and about 30%, and natural rubber (NR) is not clearly shown in FIG. Is low and the elongation at break is about 500%. On the other hand, trans polyisoprene (TPI) has a physical property that the tensile yield stress is as high as 10 MPa or more and the elongation at break is about 400%.

  As described above, by using transisoprene having a tensile yield stress close to that of lead in the damping material 6 as a substitute for lead, the rubber laminate 1 can obtain good vibration energy absorption performance.

  Further, as shown in FIG. 2, when the upper structure 9a and the lower structure 9b fixed to the plates 2 and 3 are relatively laterally displaced, they are shear-deformed, but the damping material 6 made of transpolyisoprene has an elongation at break. Is large like rubber and adheres to the rubber layer 4, the steel plate 5, and both the plates 2 and 3, so that it will not be constricted and damaged like the lead plug 7, and it will follow the shear deformation and have sufficient durability. Will have.

  As shown in FIG. 3, when the upper structure 9a fixed to the upper plate 2 is greatly inclined, the rubber laminate 1 may be subjected to tensile stress. In this case, since the damping member 6 and the plates 2 and 3 are bonded and fixed and integrated, the damping member 6 can bear the tensile stress together with the rubber layer 4 and the steel plate 5, and the tensile strength of the rubber laminate 1 can be increased. Performance is improved.

  Accordingly, in order to cope with the tensile stress, it is not necessary to increase the bonding area between the plates 2 and 3 and the rubber layer 4 as in the conventional rubber laminate 1 using the lead plug 7, The rubber laminate 1 can be downsized.

  In order to manufacture the rubber laminate 1, for example, the rubber layer 4 and the steel plate 5 having a shape in which the central portion is cut out in advance are alternately laminated, and then the damping material 6 is inserted in the central portion. The damping material 6 and both the plates 2 and 3, the rubber layer 4, and the steel plate 5 are bonded and fixed by vulcanization in a state of being sandwiched by 3. Without being limited to this manufacturing method, a manufacturing method capable of adhering and fixing the damping material 6 to both the plates 2 and 3, the rubber layer 4, and the steel plate 5 can be used.

  When the tensile yield stress of the damping material 6 is 5 MPa or more and the elongation at break is 150% or more, durability can be improved without constriction and breakage during shear deformation while obtaining particularly good vibration energy absorption performance. . The upper limit values of tensile yield stress and elongation at break are about 15 MPa and about 550%, respectively, as the physical property limit values of transpolyisoprene.

  In the embodiment, the damping material 6 is disposed at the central portion of the rubber layer 4 and the steel plate 5, but the present invention is not limited to this, and the arrangement and the number of the damping materials 6 are appropriately determined according to the required performance. For example, like the lead plug 7 in the conventional rubber laminate 1 shown in FIG. 5, a plurality of damping materials 6 are evenly arranged around the center in the plane direction of the rubber laminate 1.

  As the shape of the damping material 6, various columnar bodies such as a cylindrical body and a prismatic body, and a cylindrical body can be adopted. For example, when only one cylindrical member or cylindrical damping member 6 is used for the rubber laminate 1, and the rubber layer 4 and the steel plate 5 are concentrically formed with the damping member 6, the vibration energy absorbing performance has no directivity. In addition, vibration energy absorption performance without variation in all directions in the plane direction can be obtained.

The occupation area ratio of the damping material 6 in the cross section of the component member interposed between the plates 2 and 3 can be determined as appropriate according to the required performance, but is, for example, about 20% to 40%. .
Further, when a composition in which carbon black is mixed with trans polyisoprene at a predetermined ratio is used as the damping material 6, a high tensile yield stress can be easily obtained due to the reinforcing effect of the carbon black, and vibration energy absorption performance is improved. Can be achieved. Specifically, as a reference form , it is preferable to mix 40 parts by mass or more and 100 parts by mass or less of carbon black with respect to 100 parts by mass of transpolyisoprene.

This carbon black has a nitrogen adsorption specific surface area of 25 m ² / g or more and 260 m ² / g or less, preferably 70 m ² / g or more and 250 m ² / g or less, more preferably 190 m ² / g or more and 215 m ² / g or less. The oil absorption is 65 ml / 100 g or more and 150 ml / 100 g or less, preferably 70 ml / 100 g or more and 135 ml / 100 g or less, more preferably 95 ml / 100 g or more and 130 ml / 100 g or less.

  By making the nitrogen adsorption specific surface area and the DBP oil absorption amount within the above ranges, the reinforcing effect of carbon black can be further enhanced. The nitrogen adsorption specific surface area is a value measured according to ASTM D3037-89, and the DBP oil absorption is a value measured according to JIS K-6221.

  Trans polyisoprene is softened at about 60 ° C, and a composition in which carbon black is blended with it can be mixed, rolled, and extruded in the same manner as a normal rubber composition, and easily formed into a predetermined shape, for example, a cylindrical shape. It can be processed to a high degree, has excellent mixing processability, and can be bonded to metal and rubber.

As in the present invention, when a predetermined proportion of diene rubber is blended with the damping material 6 in which carbon black is blended with trans polyisoprene, the temperature dependence on the shear modulus (modulus) of the composition can be reduced, Stable performance can be exhibited without being greatly affected by the temperature environment in which the rubber laminate 1 is installed.

Specifically, trans polyisoprene and the polymer 100 mass parts consisting of a diene rubber, a composition containing carbon black 40 parts by mass or more 100 mass parts or less and dampening material 6, the transformer in the polymer the mass proportion of polyisoprene by 50% or more, while obtaining a reinforcing effect for excellent carbon black described above, the performance stably less susceptible to temperature can be ensured.

  Diene rubbers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile- Examples include butadiene copolymer rubber (NBR, NIR, NBIR), butyl rubber (IIR), halogenated butyl rubber (Br-IIR, C1-IIR), chloroprene rubber (CR), ethylene propylene diene rubber (EPDM), and the like. Two or more types may be used in combination. In addition, if BR with a low glass transition point is used, the temperature dependence of the modulus can be further reduced.

Trans polyisoprene, butadiene rubber, and carbon black (nitrogen adsorption specific surface area 202 m ² / g, DBP oil absorption 126 ml / 100 g) were blended in the proportions shown in Table 1, and B-type Banbury mixer (1.8 L, manufactured by Kobe Steel) ) For 5 minutes, and a small proportion of sulfur and vulcanization accelerator (N-cyclohexyl-2-benzothiazolesulfenamide (CBS)) that does not affect the characteristics of the present invention are added to the kneaded product. The mixture was kneaded with an 8-inch kneading roll for 4 minutes, and press vulcanized at 148 ° C. for 45 minutes to obtain seven types of compositions ( Examples 1-2, Reference Examples 1-4 , Comparative Example 1). The following performance was evaluated for each composition, and the results are shown in Table 1.

[Mixed workability]
The materials of each blending ratio are kneaded to show the unity of the unvulcanized composition after kneading, ○ when it can be summarized without problems, × when it can not be sufficiently kneaded and is not organized Indicated.

[Tensile yield stress] [Elongation at break]
A tensile test was performed based on JIS K-6251. Since the yield stress and the 50% modulus obtained from the tensile test in Examples 1 and 2 and Reference Examples 1 to 4 are close to each other, the 50% modulus is taken as the tensile yield stress. Moreover, elongation at the time of fracture | rupture by a tensile test was made into the fracture | rupture elongation of each of Examples 1-2 and Reference Examples 1-4 .

[Shear yield stress] [History loop area]
As shown in FIG. 7, the composition 10a after kneading was rolled to a size of width 25 mm × length 25 mm × thickness 4.8 mm, and steel plate 10b (width 25 mm) coated with a metal adhesive by sandblasting the surface. X length 100 mm × thickness 20 mm) was laminated and then press vulcanized at 130 ° C. for 120 minutes for integration to produce test sample 10.

  The test sample 10 was subjected to a lap shear shear test under the following conditions using a vibrator, an input signal oscillator, and an output signal processor. Each test sample 10 was subjected to 175% strain excitation under a deformation frequency of 0.5 Hz and a measurement temperature of 23 ° C. using a biaxial shear tester, and the shear yield stress Psr and the hysteresis loop area ΔW shown in FIG. 8 were measured. . It shows that damping performance (vibration energy absorption performance) is so good that both measured value Psr and (DELTA) W are large. In Comparative Example 1, test sample 10 could not be prepared due to insufficient kneading, and measurement was impossible.

From this result, it can be confirmed that Examples 1 and 2 and Reference Examples 1 to 4 have good mixing workability, the shear yield stress Psr and the hysteresis loop area ΔW are sufficiently large, and have good vibration energy absorption performance. It was. In particular, it has been clarified that a more excellent vibration absorbing performance can be obtained by setting the mixing ratio of carbon black within a specific range .

Next, five kinds of miniature rubber laminates ( Examples 3 to 4 and Comparative Examples 2 to 4) were prepared using the rubber layer and the damping material shown in Table 2. This rubber laminate is obtained by alternately laminating each of the unvulcanized rubber layers shown in Table 2 and a metal plate (130 mm × 130 mm × 3.0 mm) coated with a metal adhesive. The plate was molded so as to have three layers. An end steel plate (130 mm x 130 mm x 30 mm) coated with a metal adhesive after sandblasting is laminated on the surface of the uppermost and lowermost rubber layers, and press vulcanized at 130 ° C for 275 minutes. A rubber laminate of 3.0 mm was obtained.

In the rubber laminates of Examples 3 to 4 and Comparative Example 4, damping materials shown in Table 2 were interposed between the end steel plates as shown in FIG. The damping material of Examples 3-4 is a composition which consists of a compounding ratio of previous Example 1 . In Example 3 , in the cross section of the rubber laminate, the ratio of the area occupied by the damping material was 30%, Example 4 was 40%, and Comparative Example 4 was 7%. Comparative Examples 2 to 3 are each composed only of a high damping rubber and an ultra high damping rubber, and no damping material is interposed. In Examples 3 to 4 and Comparative Examples 2 to 3, the rubber layer or the damping material is bonded and integrated with each member to form a rubber laminate. In Comparative Example 4, the damping material (lead) is not It is a rubber laminate that is not integrated in a bonded state.

  For each rubber laminate, an equivalent damping constant was determined by a biaxial shear tester under conditions of a deformation frequency of 0.5 Hz and a strain of 175%. The larger the equivalent damping constant, the better the damping performance (vibration energy absorption performance).

From these results, Examples 3 and 4 are vibrations equivalent to or higher than those of Comparative Example 2 which is a high damping rubber laminate, Comparative Example 3 which is an ultra high damping rubber laminate and Comparative Example 4 which uses lead as a damping material. In particular, it was confirmed that Example 4 had excellent vibration absorbing performance over that of Comparative Example 3 of the ultrahigh damping rubber laminate.

It is a longitudinal cross-sectional view which shows embodiment of the rubber laminated body of this invention. It is a longitudinal cross-sectional view which illustrates the state which the rubber laminated body of this invention is carrying out the shear deformation. It is a longitudinal cross-sectional view which illustrates the state in which the rubber laminated body of this invention is receiving the tensile stress. It is a graph which illustrates the tensile characteristic of natural rubber, trans polyisoprene, and lead. It is a perspective view which illustrates the conventional rubber laminated body. It is a longitudinal cross-sectional view which illustrates the state which the conventional rubber laminated body is carrying out the shear deformation. It is a side view which shows the test sample of a lap shear shear test. It is a graph which illustrates the hysteresis loop area and shear yield stress by a lap shear test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rubber laminated body 2 Upper plate 3 Lower plate 4 Rubber layer 5 Steel plate 6 Damping material 7 Lead plug 8 Insertion hole 9a Upper structure 9b Lower structure 10 Test sample (for lap shear test)
10a Composition 10b Steel plate

Claims (3)

In a rubber laminate in which steel plates and rubber layers are alternately laminated between an upper plate and a lower plate, a damping material made of transpolyisoprene is bonded and integrated with the upper plate, lower plate, steel plate, and rubber layer. The diene rubber and carbon black are blended in the damping material, and 40 parts by mass of carbon black is added to 100 parts by mass of the polymer composed of transpolyisoprene and diene rubber. A rubber laminate comprising a composition containing 100 parts by mass or less and a mass proportion of trans polyisoprene in the polymer of 50% or more .   The rubber laminate according to claim 1, wherein the damping material has a tensile yield stress of 5 MPa or more and an elongation at break of 150% or more. The rubber laminate according to claim 1 or 2 , wherein the carbon black has a nitrogen adsorption specific surface area of 25 m ² / g to 260 m ² / g and a DBP oil absorption of 65 ml / 100 g to 150 ml / 100 g.

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