JP2006143859A - Rubber vibration insulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further lower the dynamic-to-static modulus ratio and enhance strength thereby to enhance durability of a rubber vibration insulator of a low dynamic-to-static modulus ratio which comprises a large particle size high-structure carbon black. <P>SOLUTION: The rubber vibration insulator is equipped with a rubber member comprised of a rubber composition comprising a diene rubber component, one or more hydrazine derivatives represented by general formulae (I)-(III), and the large particle size high-structure carbon black. 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 more particularly to a specific anti-vibration rubber compounded with an anti-vibration rubber containing a large particle size / high structure carbon black (hereinafter sometimes abbreviated as “large particle size / HS / CB”). It is related with the vibration-proof rubber which mix | blended and aimed at the low dynamic multiplication.

  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. And, in order to further reduce the dynamic magnification of the vibration-proof rubber, an improvement such as using a larger particle size / HS / CB or controlling the surface state of the larger particle size / HS / CB. Has also been reported.

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-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.

  Therefore, the present invention solves the above-mentioned conventional problems, and in the low dynamic vibration-proof rubber comprising a large particle size, HS, and CB, further lowering the dynamic speed and increasing the strength and durability An object of the present invention is to provide an anti-vibration rubber having improved properties.

  The anti-vibration rubber of the present invention (Claim 1) includes a diene rubber component, one or more hydrazine derivatives represented by the following general formulas (I) to (III), a large particle size and a high structure. A rubber member made of a rubber composition containing carbon black is provided.

（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, the rubber component is natural rubber or a blend material of natural rubber and styrene-butadiene rubber and / or butadiene rubber.

  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 15-50 g / kg and the DBP oil absorption amount is 100-180 × 10. It is characterized by being ⁻⁵ m ³ / kg.

  The anti-vibration rubber according to claim 6 is characterized in that, in any one of claims 1 to 5, the blending amount of the large particle size and high structure in the rubber composition is 20 to 150 phr.

  According to the present invention, an anti-vibration rubber having an excellent balance between dynamic characteristics and fatigue resistance, particularly good damping characteristics due to an excellent low dynamic multiplication effect, and high strength and excellent durability is provided. Is done.

  The working mechanism of the low dynamic multiplication effect and the durability improvement effect 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 diene rubber as a matrix. And the increase in the dynamic elastic modulus due to the interaction between the carbon blacks can be suppressed to further reduce the dynamic ratio. 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.

Hereinafter, embodiments of the vibration-proof rubber of the present invention will be described in detail.
[Diene rubber component]
In the present invention, a diene rubber is used as the rubber component. Examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), etc. Rubber materials containing NR as an essential component, such as NR, a blend of NR and BR, or a blend of NR and SBR, are more suitably employed, thereby exhibiting even better vibration isolation characteristics. The

  In the case of a blend of NR and another diene synthetic rubber, the content of NR in the rubber component is preferably 20% by weight or more, particularly preferably 40% by weight or more.

（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 15-50 g / kg, particularly 20-45 g / kg, and a DBP oil absorption of 100-180 × 10 ⁻⁵ m ³ / kg, particularly 120- It is preferable that it is 180 * 10 < ^-5 > m < ³ > / kg. If the iodine adsorption amount is less than 15 g / kg, the physical properties of the rubber deteriorate and the durability becomes inferior, and if it exceeds 50 g / kg, the increase in dynamic magnification becomes significant. Further, if the DBP oil absorption is less than 100 × 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 20 to 150 phr, more preferably 25 to 100 phr. When the blending amount of large particle size / HS / CB is less than 20 phr, the dynamic characteristics and fatigue resistance can be improved sufficiently by blending large particle size / HS / CB. However, if it exceeds 150 phr, the dynamic magnification increases, and the physical properties of the rubber deteriorate and the durability deteriorates.

[Other ingredients]
In addition to the rubber component, hydrazine derivative and large particle size / HS / CB, the rubber composition constituting the vibration-proof rubber of the present invention includes a vulcanizing agent, a process oil, a vulcanization accelerator, and the like as necessary. The usual rubber additives can be blended.

  Examples of the vulcanizing agent that can be used in the present invention include sulfur and the like. The amount of these used is 0.1 to 5 phr, preferably 1 to 2 phr as a sulfur content. When the blending amount of the vulcanizing agent is less than 0.1 phr, the durability of the vibration isolating rubber is lowered, and when it exceeds 5 phr, the vibration isolating property tends to be lost.

  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 prepared by kneading the rubber component, hydrazine derivative, large particle size / HS / CB, and various additives blended as necessary, using a kneader such as a roll or an internal mixer. The rubber composition obtained by doing so can be obtained by molding and then vulcanizing.

  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 and hydrazine derivatives 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 30 (g / kg), DBP oil absorption 150 (10 ^-5 m ³ / kg)
Carbon black D: iodine adsorption 35 (g / kg), DBP oil absorption 90 (10 ^-5 m ³ / kg)
Carbon black E: iodine adsorption 27 (g / kg), DBP oil absorption 28 (10 ^-5 m ³ / kg)
Carbon black F: 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

Examples 1-5, 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.
Elongation fatigue durability N: 200% at room temperature for test piece (JIS No. 4 type dumbbell)
The extension was repeated and the number of times (N) to break was examined.
Static spring constant Ks: Conforms to JIS K 6385.
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, it can be seen that by blending a large particle size / HS / CB and a hydrazine derivative, a rubber rubber having good rubber properties, excellent dynamic characteristics and low dynamic magnification can be obtained.

Claims (6)

A diene rubber component;
One or more hydrazine derivatives represented by the following general formulas (I) to (III),
An anti-vibration rubber comprising a rubber member made of a rubber composition containing a large particle size and high structure carbon black.

(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. )   2. The anti-vibration rubber according to claim 1, wherein the rubber component is natural rubber or a blend material of natural rubber and styrene-butadiene rubber and / or butadiene rubber.   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. 5. The iodine adsorption amount of the large particle size / high structure carbon black is 15 to 50 g / kg and the DBP oil absorption amount is 100 to 180 × 10 ⁻⁵ m ³ / kg according to claim 1. Anti-vibration rubber characterized by   6. The anti-vibration rubber according to any one of claims 1 to 5, wherein a blending amount of the large particle size and high structure in the rubber composition is 20 to 150 phr.