JP2006143860A - Rubber vibration insulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber vibration insulator which is excellent in heat resistance (heat ageing resistance) and durability, has a low dynamic-to-static modulus ratio and is excellent also in attenuation performances. <P>SOLUTION: The rubber vibration insulator is equipped with a rubber member comprised of a rubber composition comprising a rubber component comprised of a blended material of natural rubber with a butyl rubber, one or more hydrazine derivatives represented by general formulae (I)-(III), a large particle size high-structure carbon black, an alkylphenol disulfide, and sulfur. In the formulae, A is a single bond, a bivalent group derived from an aromatic ring, a bivalent group derived from an optionally substituent-bearing hydantoin ring, or a bivalent group derived from a 1-18C saturated or unsaturated linear hydrocarbon; B is a monovalent group derived from an aromatic ring and has a substituent X; X is a hydroxy group or an amino group; Y is a pyridyl group or a hydrazino group; and R<SP>1</SP>-R<SP>4</SP>are each independently hydrogen, a 1-18C alkyl group, a cycloalkyl group or a monovalent aromatic ring group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an anti-vibration rubber, and in particular, to a rubber component obtained by blending natural rubber and butyl rubber, a hydrazine derivative and a large particle size / high structure carbon black (hereinafter referred to as “large particle size • HS and CB ") and an alkylphenol disulfide and sulfur as a crosslinking agent (vulcanizing agent) and a high heat resistance, high durability, low dynamic magnification, and high damping vibration-proof rubber.

  Industrial anti-vibration pads, anti-vibration mats, rail slab mats, pads, automotive engine mounts, strut mounts, bushing and other anti-vibration rubbers, especially automotive anti-vibration rubbers, weights to support A vibration-proof function that absorbs and suppresses vibrations of objects and strength characteristics that support heavy objects are required. In other words, vibration-proof rubber is required to have improved dynamic characteristics, particularly lower dynamic magnification (lower dynamic magnification). On the other hand, in order to support a vibrating body such as an engine, a certain degree of fatigue resistance is required. It is necessary to ensure the property (static elastic modulus).

  Conventionally, anti-vibration rubber is generally blended with diene rubber components such as natural rubber and carbon black as a filler, and in order to achieve both dynamic characteristics and fatigue resistance of anti-vibration rubber, It has been proposed to use a large particle size / HS / CB having a large particle size (small specific surface area) and a developed structure.

  In the anti-vibration rubber, high damping and low dynamic magnification are in a trade-off relationship. In order to overcome this problem, conventionally, a rubber component obtained by blending a diene rubber and an isobutylene-brominated paramethylstyrene copolymer is used (JP-A-8-134269), or a rubber having a low dynamic magnification. Techniques have been proposed in which materials exhibiting high attenuation in a matrix are dispersed in a sea-island structure.

In addition, it is known that low exothermic property is expressed by blending a hydrazine derivative into a rubber composition (Japanese Patent Laid-Open No. 10-139934), and as a blending effect of the hydrazine derivative, ozone resistance is improved, Although the improvement of the green strength has been reported, there has been no report on the low doubling action in the vibration-proof rubber.
JP-A-8-134269 JP-A-10-139934

  In the anti-vibration rubber compounded with carbon black, if the blending amount of carbon black is increased in order to increase the damping performance and the static elastic modulus, the dynamic magnification increases, and, for example, the ride comfort deteriorates in the anti-vibration rubber for automobiles. The use of large particle size, HS, and CB as carbon black can achieve low dynamic multiplication, but the low dynamic multiplication effect cannot be said to be sufficient, and there is a problem of deterioration in physical properties of rubber, particularly durability. is there. In addition, there is a problem that the damping performance is lowered by reducing the dynamic multiplication.

  In addition, in the past, there has not yet been provided a material that can sufficiently satisfy both high attenuation and low dynamic magnification, and in particular, a material exhibiting high attenuation in a rubber matrix having a low dynamic magnification has a sea-island structure. In the method of dispersing in a state, there is still a production problem that it is necessary to prepare a masterbatch of a material exhibiting high attenuation in order to exhibit characteristics.

  Furthermore, in recent years, the temperature in the engine room tends to increase with the increase in the output of the automobile and the space saving in the engine room, and the requirements for the heat resistance and heat aging resistance of the anti-vibration rubber for automobiles have become severe. In the prior art, heat aging resistance important as a vibration-proof rubber property is not taken into consideration.

  Accordingly, an object of the present invention is to provide an anti-vibration rubber having excellent heat resistance (heat aging resistance) and durability, low dynamic magnification and excellent damping performance.

  The anti-vibration rubber of the present invention (Claim 1) is a rubber component made of a blend material of natural rubber and butyl rubber, and one or two hydrazine derivatives represented by the following general formulas (I) to (III): It is characterized by comprising a rubber member made of a rubber composition containing seeds or more, large particle size / high structure carbon black, alkylphenol disulfide and sulfur.

（上記式中、
Ａは、単結合、芳香族環由来の２価の基、置換基を有していても良いヒダントイン環由来の２価の基、或いは、炭素数１〜１８の飽和又は不飽和直鎖状炭化水素由来の２価の基であり、
Ｂは、芳香族環由来の１価の基であり、置換基Ｘを有し、
Ｘは、ヒドロキシル基又はアミノ基であり、
Ｙは、ピリジル基又はヒドラジノ基であり、
Ｒ^１〜Ｒ^４は、各々独立に、水素、炭素数１〜１８のアルキル基、シクロアルキル基、１価の芳香族環基
である。）

(In the above formula,
A is a single bond, a divalent group derived from an aromatic ring, a divalent group derived from a hydantoin ring which may have a substituent, or a saturated or unsaturated linear carbon atom having 1 to 18 carbon atoms. A divalent group derived from hydrogen,
B is a monovalent group derived from an aromatic ring, has a substituent X,
X is a hydroxyl group or an amino group,
Y is a pyridyl group or a hydrazino group,
R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, or a monovalent aromatic ring group. )

  The anti-vibration rubber according to claim 2 is characterized in that, in claim 1, natural rubber 80 to 20 phr and butyl rubber 20 to 80 phr are included.

  The anti-vibration rubber according to claim 3 is characterized in that, in claim 1 or 2, the hydrazine derivative is an aromatic carboxylic acid hydrazide, and the blending amount in the rubber composition is 0.01 to 5 phr.

  The vibration-proof rubber according to claim 4 is characterized in that, in claim 3, the hydrazine derivative is isophthalic acid dihydrazide and / or 2-naphthalenic acid-3-hydroxy (1-methylethylidene) hydrazide.

The vibration-proof rubber according to claim 5 is the vibration-proof rubber according to any one of claims 1 to 4, wherein the iodine adsorption amount of the large particle size / high structure carbon black is 15 to 45 g / kg, and the DBP oil absorption amount is 120 to 180 × 10. ^{It is −5} m ³ / kg, and the blending amount of the large particle size and high structure in the rubber composition is 10 to 100 phr.

  The anti-vibration rubber according to claim 6 is the anti-vibration rubber according to any one of claims 1 to 5, wherein the compounding amount of alkylphenol disulfide in the rubber composition is 0.1 to 10 phr, and the compounding amount of sulfur is 0.1 to 1. 0.0 phr.

  ADVANTAGE OF THE INVENTION According to this invention, the anti-vibration rubber which is excellent in heat resistance (heat aging resistance) and durability, is low dynamic magnification, and is excellent also in damping performance is provided.

  The mechanism of the effect of improving various characteristics in the present invention is as follows.

  That is, the hydrazine derivative used in the present invention has a functional group having an interaction with both the carbon black and the natural rubber and butyl rubber as a matrix. The dispersibility of the carbon black can be improved, and the increase in the dynamic elastic modulus due to the interaction between the carbon blacks can be suppressed to further reduce the dynamic multiplication. In addition, the rubber strength is increased by increasing the interaction between the carbon black and the matrix rubber, while fully demonstrating the low dynamics due to the use of large particle size, HS, and CB as carbon black. , Improve durability.

  In order to achieve low dynamics, the damping performance generally declines in systems with large particle sizes, HS, and CB as fillers, but in the present invention, natural rubber is blended with butyl rubber as the rubber component. By using this, sufficient damping capacity is secured.

  In addition, sulfur is generally used as a rubber cross-linking agent. In the present invention, by using alkylphenol disulfide together with sulfur as a cross-linking agent, the amount of sulfur is reduced and heat resistance is improved while ensuring the cross-linking density. Can be made.

Hereinafter, embodiments of the vibration-proof rubber of the present invention will be described in detail.
[Rubber component]
In the present invention, a natural rubber and a butyl rubber such as butyl rubber or a blend of one or more halogenated butyl rubbers such as brominated butyl rubber and chlorinated butyl rubber are used as the rubber component. If the content of natural rubber in the rubber component is too high, the amount of butyl rubber will be relatively reduced, and the effect of improving the damping performance due to the butyl rubber cannot be obtained sufficiently. The durability is inferior. Accordingly, it is preferable to mix and use natural rubber at a blending ratio of 80 to 20 phr, particularly 70 to 30 phr, and butyl rubber at a blending ratio of 20 to 80 phr, particularly 30 to 70 phr. If it is this range, the rubber strength and durability improvement effect by natural rubber can be obtained together with the improvement effect of damping performance by butyl rubber, and a good anti-vibration rubber can be obtained.

（上記式中、
Ａは、単結合、芳香族環由来の２価の基、置換基を有していても良いヒダントイン環由来の２価の基、或いは、炭素数１〜１８の飽和又は不飽和直鎖状炭化水素由来の２価の基であり、
Ｂは、芳香族環由来の１価の基であり、置換基Ｘを有し、
Ｘは、ヒドロキシル基又はアミノ基であり、
Ｙは、ピリジル基又はヒドラジノ基であり、
Ｒ^１〜Ｒ^４は、各々独立に、水素、炭素数１〜１８のアルキル基、シクロアルキル基、１価の芳香族環基
である。） [Hydrazine derivatives]
The hydrazine derivative used in the present invention is represented by any one of the following general formulas (I) to (III).

(In the above formula,
A is a single bond, a divalent group derived from an aromatic ring, a divalent group derived from a hydantoin ring which may have a substituent, or a saturated or unsaturated linear carbon atom having 1 to 18 carbon atoms. A divalent group derived from hydrogen,
B is a monovalent group derived from an aromatic ring, has a substituent X,
X is a hydroxyl group or an amino group,
Y is a pyridyl group or a hydrazino group,
R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, or a monovalent aromatic ring group. )

  In the above general formula (I), the divalent linking group A is a single bond; a phenylene group, a naphthylene group, a pyridylene group, or a quinolylene group in which any of the ortho, para, and meta positions is the linking position. An aromatic ring group such as: a hydantoin ring group which may have a substituent; a hydrocarbon group in which carbons at both ends of a saturated or unsaturated linear hydrocarbon having 1 to 18 carbon atoms are linked positions, for example, Examples thereof include an ethylene group, a tetramethylene group, a heptamethylene group, an octamethylene group, an octadecamethylene group, and a 7,11-octadecadienylene group.

  In the above general formula (II), B is a monovalent aromatic group such as a phenyl group or a naphthyl group, and the substitution position of the hydroxyl group or amino group which is X as the substituent of B is ortho-position, Either the meta position or the para position may be used, but the ortho position is particularly preferable.

  In general formula (III), Y is a pyridyl group or a hydrazino group, and the bonding position is preferably the 2-position or 3-position in the pyridyl group.

In the general formulas (I) to (III), R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, or a monovalent aromatic ring group, Examples thereof include hydrogen, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, and a phenyl group.

  Specific compounds represented by the above general formula (I) include isophthalic acid dihydrazide, isophthalic acid di (1-methylethylidene) hydrazide, which is a derivative of adipic acid hydrazide, adipic acid di (1-methylethylidene) hydrazide, isophthalic acid. Acid di (1-methylpropylidene) hydrazide, adipic acid di (1-methylpropylidene) hydrazide, isophthalic acid di (1,3-dimethylpropylidene) hydrazide, adipic acid di (1,3-dimethylpropylidene) hydrazide , Di (1-phenylethylidene) hydrazide, isophthalic acid, di (1-phenylethylidene) hydrazide, and the like, but the following dihydrazide compound derivatives are the same in addition to these isophthalic acid dihydrazide and adipic acid dihydrazide derivatives. Effective It is. For example, terephthalic acid dihydrazide, azelaic acid dihydrazide, succinic acid dihydrazide, icosanoic dicarboxylic acid dihydrazide and the like. Among these, isophthalic acid dihydrazide is preferable because of its excellent effect of reducing the doubling rate.

  Specific compounds represented by the general formula (II) include 2-naphthalenic acid-3-hydroxy (1-methylethylidene) hydrazide, 2-naphthalenic acid-3-hydroxy (1-methylpropylidene) hydrazide, 2 In addition to derivatives of 2-naphthalenic acid-3-hydroxyhydrazide such as -naphthalenic acid-3-hydroxy (1,3-dimethylpropylidene) hydrazide, 2-naphthalenic acid-3-hydroxy (1-phenylethylidene) hydrazide, Examples include salicylic acid hydrazide, 4-hydroxybenzoic acid hydrazide, anthranilic acid hydrazide, and 1-hydroxy-2-naphthalic acid hydrazide derivatives. Among them, in particular, a derivative of 2-naphthalene-3-hydroxyhydrazide, particularly 2-naphthalene-3-hydroxy (1-methylethylidene) hydrazide is preferable because it has an excellent effect of reducing the doubling rate.

  Specific compounds represented by the general formula (III) include isonicotinic acid (1-methylethylidene) hydrazide, isonicotinic acid (1-methylpropylidene) hydrazide, isonicotinic acid (1,3-dimethylpropylidene). In addition to derivatives of isonicotinic acid hydrazide such as hydrazide and isonicotinic acid (1-phenylethylidene) hydrazide, derivatives of carbonic acid dihydrazide can be mentioned.

  In addition, the synthesis | combining method of the hydrazide compound represented by said formula (I)-(III) is Pant, UC; Ramchandran, Reena; Joshi, BCRev.Roum.Chim. (1979) 24 (3), 471-82. It is described in the literature.

  The hydrazine derivatives represented by the general formulas (I) to (III) may be used singly or in combination of two or more.

  The blending amount of such a hydrazine derivative in the rubber composition is preferably 0.01 to 5 phr, particularly preferably 0.1 to 3.0 phr. If the blending amount of the hydrazine derivative is less than this range, the above-mentioned doubling effect and strength improvement effect due to the hydrazine derivative cannot be sufficiently obtained, and no more effect can be obtained at most, and the anti-vibration rubber Other physical properties tend to decrease, which is not preferable.

[Large particle size / High structure carbon black (Large particle size / HS / CB)]
The large particle size / HS / CB used in the present invention has an iodine adsorption of 15 to 45 g / kg, particularly 20 to 40 g / kg, and a DBP oil absorption of 120 to 180 × 10 ⁻⁵ m ³ / kg, particularly 140 to. It is preferable that it is 180 * 10 < ^-5 > m < ³ > / kg. If the amount of iodine adsorbed is less than 15 g / kg, the physical properties of the rubber are deteriorated and the durability is inferior, and if it exceeds 45 g / kg, the increase in dynamic magnification becomes significant. Further, if the DBP oil absorption is less than 120 × 10 ⁻⁵ m ³ / kg, the physical properties of the rubber deteriorate and the durability becomes inferior, and if it exceeds 180 × 10 ⁻⁵ m ³ / kg, the durability improving effect is saturated. , Rubber properties will not change.

  The blending amount of such a large particle size / HS / CB rubber composition is preferably 10 to 100 phr, more preferably 15 to 80 phr. When the blending amount of large particle size / HS / CB is less than 10 phr, the dynamic characteristics and fatigue resistance can be improved sufficiently by blending large particle size / HS / CB. In addition, the rubber physical properties required as a vibration-proof rubber cannot be ensured, and if it exceeds 100 phr, the dynamic magnification increases, and the rubber physical properties deteriorate and the durability becomes inferior.

[Alkylphenol disulfide and sulfur]
Examples of the alkyl group of the alkylphenol disulfide include an amyl group.

  In the present invention, the compounding amount of the alkylphenol disulfide in the rubber composition is 0.1 to 10 phr, particularly 1.0 to 5.0 phr, and the compounding amount of sulfur is preferably 0.1 to 1.0 phr, The total amount of alkylphenol disulfide and sulfur is preferably about 0.2 to 10 phr, particularly about 1.0 to 5.0 phr. In either case, the crosslink density of the vibration-proof rubber obtained is less than the lower limit, the rubber physical properties are remarkably deteriorated, and the heat resistance is deteriorated if the upper limit is exceeded.

[Other ingredients]
In addition to the rubber component, hydrazine derivative, large particle size / HS / CB, and alkylphenol disulfide and sulfur as a crosslinking agent (vulcanizing agent), the rubber composition constituting the vibration-proof rubber of the present invention is necessary. Accordingly, usual rubber additives such as process oil and vulcanization accelerator can be blended.

  Examples of the process oil that can be used in the present invention include paraffinic, naphthenic, and aromatic oils. Aromatic oils are preferred for applications that place importance on durability, and the amount used is 0 to 100 phr, and if it exceeds 100 phr, the durability of the vibration-proof rubber is remarkably deteriorated.

  The vulcanization accelerator that can be used in the present invention is not particularly limited, but preferably CZ (N-cyclohexyl-2-benzothiazolesulfenamide), MBT (2-mercaptobenzothiazole), DM ( Examples include thiazole vulcanization accelerators such as dibenzothiazyl disulfide) and CBS (N-cyclohexyl-2-benzothiazylsulfenamide), and guanidine vulcanization accelerators such as DPG (diphenylguanidine). The amount used is 0.1 to 5 phr, preferably 0.2 to 3 phr.

  In the present invention, besides these, RD (polymerized 2,2,4-trimethyl-1,2-dihydroquinoline), 6C (N-1,3-dimethylbutyl-N′-), which is usually used in the rubber industry. Additives such as anti-aging agents such as phenyl-p-phenylenediamine), zinc white (ZnO), stearic acid, wax, antioxidants, ozone degradation inhibitors, and silane coupling agents can also be blended.

[Anti-vibration rubber]
The anti-vibration rubber of the present invention is a kneading machine such as a roll or an internal mixer containing the above rubber component, hydrazine derivative, large particle size / HS / CB, alkylphenol disulfide and sulfur, and various additives blended as necessary. The rubber composition obtained by kneading using can be vulcanized after molding.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

In the following examples and comparative examples, carbon black, hydrazine derivative and alkylphenol disulfide blended in the rubber composition are as follows.
Carbon black A: iodine adsorption 24 (g / kg), DBP oil absorption 152 (10 ^-5 m ³ / kg)
Carbon black B: iodine adsorption 26 (g / kg), DBP oil absorption 170 (10 ^-5 m ³ / kg)
Carbon black C: iodine adsorption 60 (g / kg), DBP oil absorption 100 (10 ^-5 m ³ / kg)
Hydrazine derivative A: Isophthalic acid dihydrazide Hydrazine derivative B: 2-Naphthalenic acid-3-hydroxy (1-methylethylidene)
Hydrazide Alkylphenol disulfide: Product name “Vultac5” by ATOFINA

Examples 1-7, Comparative Examples 1-4
The rubber composition was kneaded with the formulation shown in Table 1, vulcanized at 150 ° C. for 20 minutes, and then evaluated by the following test method. The results are shown in Table 1.
Mooney viscosity: Conforms to JIS K 6300.
Rubber hardness Hs: Conforms to JIS K 6253 (type A).
Tensile strength Tb: compliant with JIS K 6251.
Tensile elongation Eb: compliant with JIS K 6251.
Heat resistance ΔEb: Under the condition of heat aging at 100 ° C. and 100 hours, the tensile elongation Eb
Change rate of ΔEb ≦ 30%, “◯”, ΔEb> 30%
Evaluated as “x”.
Elongation change rate ΔEb
= {1- (Eb (after heat aging) / Eb (before heat aging))} × 100
Static spring constant Ks: Conforms to JIS K 6385.
Loss coefficient tan δ: Conforms to JIS K 6385. (15Hz)
Dynamic spring constant Kd ₁₀₀ : Conforms to JIS K 6385. (100Hz)
Dynamic magnification Kd ₁₀₀ / Ks: Conforms to JIS K 6385.
Riding comfort: Anti-vibration rubber is mounted on the passenger car, and the vehicle interior vibration transmitted from engine vibration
Measures the sound of murmur, and “○” indicates that there is almost no vibration or murmur.
The thing was evaluated as “△” and the larger one as “×”.

  From Table 1, blending natural rubber and butyl rubber with a large particle size, HS, CB, hydrazine derivative, alkylphenol disulfide and sulfur gives excellent heat resistance (heat aging resistance) and durability. It can be seen that an anti-vibration rubber having low dynamic magnification and excellent damping performance can be obtained.

Claims (6)

A rubber component made of a blend material of natural rubber and butyl rubber;
One or more hydrazine derivatives represented by the following general formulas (I) to (III),
Large particle size, high structure carbon black,
An anti-vibration rubber comprising a rubber member made of a rubber composition containing an alkylphenol disulfide and sulfur.

(In the above formula,
A is a single bond, a divalent group derived from an aromatic ring, a divalent group derived from a hydantoin ring which may have a substituent, or a saturated or unsaturated linear carbon atom having 1 to 18 carbon atoms. A divalent group derived from hydrogen,
B is a monovalent group derived from an aromatic ring, has a substituent X,
X is a hydroxyl group or an amino group,
Y is a pyridyl group or a hydrazino group,
R ^{1 to} R ⁴ are each independently hydrogen, an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, or a monovalent aromatic ring group. )   The anti-vibration rubber according to claim 1, comprising natural rubber 80 to 20 phr and butyl rubber 20 to 80 phr.   3. The vibration-proof rubber according to claim 1, wherein the hydrazine derivative is an aromatic carboxylic acid hydrazide, and a blending amount in the rubber composition is 0.01 to 5 phr.   4. The anti-vibration rubber according to claim 3, wherein the hydrazine derivative is isophthalic acid dihydrazide and / or 2-naphthalenic acid-3-hydroxy (1-methylethylidene) hydrazide. In any one of Claims 1 thru | or 4, the iodine adsorption amount of large particle size and high structure carbon black is 15-45 g / kg, and DBP oil absorption is 120-180 * 10 < ^-5 > m < ³ > / kg, An anti-vibration rubber characterized in that the compounding amount of large particle size and high structure in the rubber composition is 10 to 100 phr.   6. The rubber composition according to claim 1, wherein the amount of alkylphenol disulfide in the rubber composition is 0.1 to 10 phr, and the amount of sulfur is 0.1 to 1.0 phr. Anti-vibration rubber.