JPH0434227A - Vibrationproof material - Google Patents

Abstract

PURPOSE:To obtain vibrationproof material which has anisotropy of high elastic modulus by determining orientation rate of staple according to the predetermined equation and constituting orientation rate in the S1 direction, the S2 direction which is at right angle to the S1 direction, and the S3 direction which is at right angle to the S1 and S2 directions to the predetermined %. CONSTITUTION:Orientation of staple 11 of staple composite elastomer which constitutes vibrationproof material is done by well-known calender, extrusion molding, and injection molding. As constituent member or a part of constituent member of vibrationproof material which has spring constant having anisotropy, when orientation rate Hi is defined by Hi={(1/Vi)/(1/V1+1/V2+1/V3)}X100i =1,2,3(V1, V2, V3: coefficient of solvent linear expansion in S1, S2, S3 directions), orientaion rate H1 in S1 direction is 45 to 100%, orientation rate H2 in S2 direc tion which is at right angle to S1 direction is (100-H1)X(50-100)%, and orienta tion rate H3 in S3 direction which is at right angle to S1, S2, directions is {100-(H1+H2)}%. Thus, orientation condition of staple 11 is set with consider ably high degree of freedom in vibrationproof material, and it has different elastic modulus in three and two dimensional directions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vibration damping material constructed using a short fiber composite elastomer.

(Conventional technology) Conventionally, in order to develop an anisotropic spring constant, ■
A method of imparting anisotropy to the shape of vibration-proof rubber, and a method of combining it with a metal plate are widely adopted. As method (2), a method is known in which a plurality of metal plates and rubber layers are laminated to have a high spring constant in the direction perpendicular to the laminated surface and a low spring constant in the shear direction.

(Problem to be solved by the invention) However, according to the method (■), since anisotropy is imparted depending on the shape, there are limitations in essential parts, including restrictions on mounting space and shape, and it is difficult to meet the requirements. It may not be possible. Furthermore, stress concentration may occur depending on the shape, resulting in a shortened lifespan.

On the other hand, according to method (2), since it is a composite with a metal member, the manufacturing process is complicated, and there are problems in terms of reliability such as stability of the quality of the adhesive interface and interface fatigue. Also,
It is actually difficult to develop three-dimensional anisotropy.

The present invention has been made in view of these points, and it is an object to solve the above-mentioned problems and to provide a vibration isolating material having a higher degree of anisotropy in elastic modulus (spring constant).

(Means for Solving the Problem) The invention as claimed in claim (1) uses a short fiber composite elastomer containing 0.5 to 65% by volume of short fibers as a constituent member or a part of the constituent member. In the short fiber composite elastomer, the orientation ratio H1 of the short fibers is determined by the following formula, and S
The orientation ratio H in one direction is 45 to 100%, and the orientation ratio H2 in the S2 direction perpendicular to the S1 direction is ((100-Hl)X
(50-100))%, S, , S perpendicular to the S2 direction,
The configuration is such that the orientation ratio H3 in the direction is (100(H1+H2)) 1%.

H, -((1/V, )/(1/Vl 41/V2 +
l/V3) IX1001-1.2.8 Here, V+, V2, V3; S+, 82,
S3 direction solvent linear expansion coefficient The invention of claim (2) is one in which a short fiber composite elastomer containing 0.5 to 65% by volume of short fibers is used as a constituent member or a part of the constituent member, and the above-mentioned The short fibers are mainly oriented in a concentric direction with respect to one axis.

The invention of claim (3) uses a short fiber composite elastomer containing 0.5 to 65% by volume of short fibers as a constituent member or a part of the constituent member, wherein the constituent member has an orientation direction and an orientation direction. It is constructed by laminating the same or different types of short fiber composite elastomers with different ratios. Further, the invention of claim (4) is the invention of claim (3), and is constructed by laminating short fiber composite elastomers having different short fiber contents.

In the invention of claim (5), in claim (1), claim (2), claim (3), or claim (4), a metal member is used as a part of the constituent member.

(Function) According to the invention of claim (1), the short fibers of the short fiber composite elastomer as a constituent member are three-dimensionally oriented, and anisotropy in elastic modulus can be obtained. Therefore, the greater the difference in the orientation rate in each direction, the greater the anisotropy of the elastic modulus.

According to the invention of claim (2), the elastic modulus is high in two directions,
It becomes lower in one direction, indicating anisotropy.

According to the inventions of claims (3) and (4), products having various anisotropies are produced by combining the same or different types of short fiber composite elastomers with different orientation directions, orientation ratios, contents, etc. can get.

According to the invention of claim (5), the anisotropy of the elastic modulus can be increased by the combination with the metal member.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

The vibration isolating material according to the present invention can be formed into any shape,
There are 0.5 to 6 short fibers in the elastic base material made of elastomer.
A short fiber composite elastomer mixed and dispersed at 5% by volume is used as a component or a part of the component, and is formed to have an anisotropic spring constant (elastic modulus). Here, the mixing amount of short fibers is set to 0.5 to 65% by volume because if it is less than 0.5% by volume, sufficient anisotropy of elastic modulus cannot be obtained, and if it exceeds 65% by volume, molding process This is because it becomes difficult.

The short fibers of the short fiber composite elastomer constituting the above-mentioned vibration damping material can be oriented by a well-known calender, extrusion molding, injection molding, etc. For some of the constituent members, the orientation rate H1 is expressed as H-=1(1/V-)/(1/Vl +l/V2 +l
/V3) IXlool 1 i=1.2.3 Here, V+, V2, V3: St, S2
, 83 direction solvent linear expansion coefficient (Sll 82.Ss force direction linear expansion coefficient when the material is immersed in a solvent and reaches equilibrium swelling), the orientation ratio H0 in the S1 direction is 45~
100%, the orientation ratio H2 in the S2 direction perpendicular to the S1 direction is ((100-Ht)X (50-100))%, Sl
, the orientation rate H1 in the S, direction perpendicular to the S2 direction is (100
-(Hl +H2) 1% is effective.

As a result, in the vibration damping material, the orientation state of the short fibers can be set with a considerably high degree of freedom, and the vibration damping material has different elastic moduli in three or two dimensions.

Examples of the elastomer constituting the elastic base material include crosslinked elastomers such as natural rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, ethylene-propylene rubber, and urethane rubber, as well as polyolefin-based, polyester-based, and polyether-based elastomers. It is appropriately selected from thermoplastic elastomers such as polyamide and polyurethane. In addition, reinforcing agents, fillers, softening agents,
Common elastomer formulations and additives such as crosslinking agents, crosslinking accelerators, crosslinking accelerators, antiaging agents, tackifiers, antistatic agents, and kneaded adhesives can be selected as desired.

Short fibers include aliphatic polyamide, aromatic polyamide, polyester, acrylic, acetylated polyvinyl alcohol, synthetic fibers such as cotton, silk, wool, bulb, rayon, natural fibers, and semi-synthetic fibers, as well as steel, stainless steel,
It is appropriately selected from metal fibers such as copper. Further, if necessary, the fiber surface is adhesively treated with epoxy, isocyanate, resorcin formalin latex, chlorinated rubber adhesive, or the like.

Although the shape of the short fibers is arbitrary, if the fiber length/fiber diameter ratio (L/D) is too large, it is difficult to disperse the fibers into the elastomer, and if it is too small, the elastic modulus becomes anisotropic. The effect on From this point, L/D is 10
The fiber length is preferably between 1,000 and 1,000, and the fiber length is 50+n or less.

Function and life can be improved by combining the short fiber composite elastomer having an anisotropic spring constant with an elastomer that does not composite short fibers as part of a component of a vibration isolating material.

For example, in a columnar vibration damping material made by alternately laminating sheets of short fiber composite elastomer and sheets of elastomer without short fiber composite, the compression spring constant is It is possible to set a high ratio to the shear spring constant. Furthermore, by using an elastomer that does not combine short fibers in areas where cracks are likely to occur due to its shape, it is possible to improve the lifespan of the vibration damping material compared to a vibration isolating material made of a single short fiber composite elastomer.

In addition, by using a short fiber composite form in which the short fibers are mainly oriented concentrically with respect to one axis, a vibration isolating material having different spring constants in the axial direction and in the direction orthogonal to the axial direction can be created. can be formed.

In this way, by combining various members with different short fiber types, contents, orientation directions, orientation ratios, etc., it is possible to satisfy the restricted space or overall shape and achieve the required anisotropy of the spring constant. It is possible to manufacture a vibration isolating material having the following properties.

Furthermore, it is also possible to enhance the anisotropy by combining the short fiber composite elastomer with a metal member (metal restraint) or a plastic member.

Next, performance tests conducted on the above-mentioned vibration isolating material will be explained.

Table 1 The formulations in Table 1 above were mixed in a closed mixer, and then 31
A mixture prepared by mixing a predetermined amount of meta-based polyamide fibers cut into lengths was rolled with a roll, laminated with the grain direction aligned, and then vulcanized with a press. After vulcanization, a cube of 15 mm on a side was cut out from the vulcanized block along the grain direction to obtain a block-shaped sample 12 in which short fibers 11 were three-dimensionally oriented as shown in FIG. x, y of sample 12 shown in FIG.

The relationship between the 5% compressive stress in the Z direction and the short fiber content is
As shown in the figure.

From FIG. 2, it can be seen that the ratio of the elastic modulus in the X direction to the elastic modulus in the Y and Z directions is at most 5:1, indicating anisotropy.

Next, 15% by volume of nylon 6.6 fibers cut into 3-1 lengths were mixed with the formulation shown in Table 1 above, and the mixture was dyed according to the manufacturing method described in, for example, JP-A No. 58-29231. By varying the channel diameter and expansion ratio, three types of extruded sheets with different three-dimensional orientation ratios were manufactured. Similarly to the case described above, a cube having a side of 15 m5+ was cut out from a vulcanized block laminated and vulcanized with the extrusion direction aligned to create a block-shaped sample.

For this sample, the short fiber orientation rate, 5% compressive stress, and mechanical loss in the Z direction were determined from the toluene swelling rate in each direction when the extrusion direction is the X direction, the width direction is the X direction, and the thickness direction is the Z direction. (tan δ) was measured.

The results are shown in Table 2 below.

From Table 2 above, Comparative Example 2 with a fiber orientation rate of 38% in the Z direction
In this case, there is no large difference in the compressive modulus in the x, y, and z directions, but in the present invention examples of 51% or more, the greater the difference in the orientation ratio in the three directions, the greater the anisotropy of the elastic modulus. .

Furthermore, it is inferred that the higher the orientation ratio in the Z direction, the greater the tan δ during compressive deformation in the Z direction, and the greater the contribution of the energy elasticity of the fibers.

In addition, 15% by volume of nylon 6.6 fibers cut to an average length of 3 mm were mixed in the formulation shown in Table 1 above, separated using a calender roll, and then cut into lengths as shown in Figure 3 (a). A sheet 22 having a thickness of 1 mm and having short fibers 21 oriented in the transverse direction was prepared. The sheet 22 is rolled up into a cylindrical shape in the length direction as shown in FIG. 3(b), and after vulcanization and pressure is applied in that state, one side is 15 mm as shown in FIG. 3(e).
A block-shaped sample 23 was prepared by cutting out a cube of 1-, and the same measurements as described above were performed.

The results are shown in Table 3 below.

Table 3 From Table 3 above, it can be seen that the elastic modulus is high in two directions and low in one direction, indicating anisotropy.

Unvulcanized sheet of Invention Example 1.2 shown in Table 2 and Comparative Example 1
unvulcanized sheets were alternately laminated and vulcanized under pressure to create sample 31, which is a laminate shown in FIG. That is, the sample 31 has a layer 3 in which short fibers are oriented in two directions from the top.
A layer 31b in which short fibers 1a1 are not mixed at all, a layer 31c in which short fibers are oriented in the X direction, and a layer 31d in which short fibers are not mixed at all are repeatedly laminated in this order. This sample 31 has a compressive modulus of elasticity in the Z direction of about 3.1 times, a shear modulus of elasticity in the X direction of about 1.8 times, and a shear modulus of elasticity in the Shear modulus is approximately 1
．． It has increased four times. That is, the vibration isolating material has anisotropy in that it is rigid in the Z direction, which is the compression direction, but flexible in the X and X directions, which are the shear directions.

In a similar manner, as shown in FIG. 5, a sample 41 in which a short fiber composite rubber 41a in which short fibers are oriented in two directions is covered with a rubber 41b in which no short fibers are mixed is produced with the same shape. Z of 6±3% compared to short fiber composite rubber alone.
It showed approximately three times the lifespan (430,000 cycles compared to 140,000 cycles) in the directional compression fatigue test.

Furthermore, as shown in FIG. 6(a), a layer 51a in which short fibers are oriented in the Z direction and a layer 5 in which short fibers are oriented in the X direction.
Sample 51 in which 1b and 1b are alternately stacked, FIG. 6(b)
As shown, a rubber layer 52 in which short fibers are oriented in two directions
A sample 52 formed by alternately stacking metal plates 52a and 52b,
As shown in FIG. 6(C), a cylindrical center layer 53a in which short fibers are oriented in the circumferential direction, an intermediate JW 53b disposed outside the cylindrical center layer 53a in which short fibers are oriented in the radial direction, and further therein. The sample 53, which consists of an outer layer 53c disposed on the outside and in which short fibers are oriented in the circumferential direction, is also a product of the same shape consisting of a single rubber with no short fibers mixed therein or a single type of short fiber composite rubber. The comparison showed different anisotropy of elastic modulus.

As described above, all of the above examples exhibit high anisotropy of elastic modulus, have a high tan δ in the deformation mode in which the fiber bends, and have anisotropy in the spring constant. It can be seen that it functions extremely effectively as a material.

Note that the present invention is not limited to the above embodiments,
Needless to say, countless variations are possible.

(Effects of the Invention) According to the invention of claim (1), the short fibers are oriented three-dimensionally, and anisotropy of elastic modulus over a wide range can be obtained. In particular, the greater the difference in the orientation rate in each direction, the greater the anisotropy of the elastic modulus.

According to the invention of claim (2), the elastic modulus is high in two directions,
Short fibers can be oriented three-dimensionally such that they are lower in one direction, thereby exhibiting anisotropy in the elastic modulus.

According to the inventions of claims (3) and (4), short fiber composite elastomers of the same type or different types with different short fiber orientation directions, orientation ratios, contents, etc. are arbitrarily combined, and Accordingly, materials having various anisotropy of elastic modulus can be obtained.

According to the invention of claim (5), it becomes possible to obtain even higher anisotropy of elastic modulus by combining with a metal member.

[Brief explanation of the drawing]

The present invention shows examples of the drawings, in which FIG. 1 is a perspective view of a block-shaped sample, FIG. 2 is a diagram showing the relationship between short fiber content and 5% compressive stress, and FIGS. C) is an explanatory diagram of the method for manufacturing the sample, FIGS. 4 and 5 are perspective views of other samples, and FIG. 6(a) is a perspective view of another sample. 11.21...Short fiber 52b...Metal plate (metal member) to (e) are further 11.21...Short fiber 52b...Metal plate (Metal member) Fig. 1 γmm gold content pHR) Fig. 2

Claims (5)

[Claims] (1) A short fiber composite elastomer containing 0.5 to 65% by volume of short fibers is used as a component or a part of the component, and the short fiber composite elastomer has short fibers oriented according to the following formula. The orientation ratio H_i is determined, and the orientation ratio H_1 in the S_1 direction is 45.
~100%, the orientation rate H_2 in the S_2 direction perpendicular to the S_1 direction is {(100-H_1)×(50-100)}%
, the orientation rate H in the S_3 direction perpendicular to the S_1 and S_2 directions
A vibration isolating material characterized in that _3 is {100-(H_1+H_2)}%. H_i={(1/V_i)/(1/V_1+1/V_2
+1/V_3)}×1001=1, 2, 3 Here, V_1, V_2, V_3; Solvent linear expansion coefficient in S_1, S_2, S_3 directions (2) A component in which a short fiber composite elastomer containing 0.5 to 65% by volume of short fibers is used as a component or a part of the component, wherein the short fibers of the short fiber composite elastomer are mainly oriented along one axis. A vibration isolating material characterized in that it is oriented in a concentric direction with respect to. (3) A short fiber composite elastomer containing 0.5 to 65% by volume of short fibers is used as a component or a part of the component, and the component is of the same or different type with different orientation directions and orientation ratios. A vibration isolating material characterized by being constructed by laminating short fiber composite elastomers. (4) The vibration damping material according to claim (3), which is constructed by laminating short fiber composite elastomers having different short fiber contents. (5) The vibration isolating material according to claim (1), claim (2), claim (3), or claim (4), wherein a metal member is used as a part of the component.