JP2969999B2 - Anti-vibration rubber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration rubber. In particular, rubber parts such as engine mounts (FIG. 1), strut mounts (FIG. 2), bumper rubbers (FIG. 3), and bush rubbers (FIG. 4) which are attached to an automobile chassis for vibration damping and cushioning purposes. This is a preferred invention.

[0002]

2. Description of the Related Art Anti-vibration rubber is required to have excellent dynamic characteristics, that is, excellent anti-vibration performance.

[0003] Conventional anti-vibration rubbers for automobiles are mainly made of natural rubber (NR) having excellent anti-vibration properties (NR is a rubber component or a rubber main component).

[0004] On the other hand, with the recent trend toward higher temperatures and narrower interiors of automobile engine rooms, rubber materials for anti-vibration rubber for automobiles have been required to have higher heat resistance than ever before.

[0005]

However, as far as the present inventors know, there is no technique for improving the heat resistance of the above-mentioned NR rubber without significantly lowering the vibration-proof performance.

[0006] In view of the above, the present invention provides
Compared to R-made anti-vibration rubber, the anti-vibration performance does not decrease ,
Moreover, an object of the present invention is to provide an anti-vibration rubber which can be expected to greatly improve heat resistance.

[0007]

SUMMARY OF THE INVENTION The vibration-proof rubber of the present invention solves the above-mentioned problems by the following constitution.

[0008] In a vibration-isolating rubber obtained by molding and vulcanizing a rubber compound of a conjugated diene rubber, the compounding recipe of an auxiliary material in the rubber compound is 3 to 10 ph.
r, sulfur 0.1-1 phr , and the carbon black is SRF black
High structure and carbon black
And a coupling agent for rubber and rubber .

[0009]

[Detailed Description of Means] (1) The vibration-proof rubber of the present invention is premised on being molded and vulcanized from a rubber compound of a conjugated diene rubber.

Here, the conjugated diene rubber is NR.
In addition, synthetic rubbers having an unsaturated bond in the main chain, such as styrene-butadiene rubber (SBR), isoprene rubber (IR), butadiene rubber (BR), and nitrile rubber (NBR) can be mentioned. Among these, NR, SBR, IR, and BR are desirable from the viewpoint of vibration damping performance.

In the vulcanization molding method of the vibration isolating rubber, a metal part (normally, the contact surface side with the rubber part is treated with an adhesive) 1 prepared in advance is set in a mold, and the rubber part is formed by insert molding. 3 is integrated with the metal part 1 (usually by vulcanization bonding). Further, the metal part 1 and the rubber part 3 are separately prepared, and the adhesive and the press-fitting (mechanical connection) are used together or integrated by only one means.

(2) The first feature of the present invention is that the compounding formulation of the auxiliary material in the rubber compound is an antioxidant 3-1.
0 phr and 0.1 to 1 phr of sulfur.

Here, when the antioxidant is less than 3 phr,
Heat resistance cannot be improved, and if it exceeds 10 phr, heat resistance cannot be further improved, and mold contamination,
Problems such as blooming of the molded product and coating film contamination are likely to occur.

The anti-aging agent is preferably used in combination, and in particular, three types of amine ketone type, aromatic secondary amine type and benzimidazole type are preferably used.

Specifically, the following can be mentioned. Amine ketone type: 2,2,4-trimethyl-1,2-dihydroquinoline (polymer), 6-ethoxy-2,2,2
4-trimethyl-1,2-dihydroquinoline, condensates of acetone and diphenylamine, condensates of acetone and N-phenyl-2-naphthylamine, and the like.

Aromatic secondary amine type: N, N'-diphenyl-p-phenylenediamine, N, N'-dinaphthyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N -(1,3-dimethyl-butyl) -N'-phenyl-
p-phenylenediamine, N-octyl-N'-phenyl-p-phenylenediamine, N, N'-di (1,4-dimethylpentyl) -p-phenylenediamine, N, N'-diallyl-p-phenylenediamine ,etc.

Benzimidazole type: 2-mercaptobenzimidazole and its zinc salt.

If the amount of sulfur is less than 0.1 phr, it is difficult to obtain a predetermined vulcanization strength. If it exceeds 1 phr, it is difficult to expect a significant improvement in heat resistance of the vulcanized rubber.

(3) A second feature of the present invention is that carbon black (CB) is a high structure of SRF black (SRF-HS), and a coupling agent of CB and rubber is used in combination. It is characterized by the following.

Here, other than SRF-HS, the more desirable effects of the present invention and the effect of compensating for the decrease in the vibration isolation performance are small. Specific physical properties of CB are described in JP-A-59-47.
No. 263, the following range described in the claims.

"Nitrogen adsorption specific surface area (N ₂ BA) 34 m ² /
g or less, dibutyl phthalate oil absorption (DBP) 136 ml
/ 100g or less, and aggregate distribution (Ds
t) Carbon black for rubber compounding having a selective property whose mode diameter is equal to or less than the value obtained by the equation [0.60 (DBP) -9.96 (N ₂ BA) +270]. Unless a coupling agent is blended, improvement in vibration isolation performance cannot be expected. The amount of the coupling agent is usually
1 to 10 phr. As the coupling agent, N-
Nitroso type such as (2-methyl-2-nitropropyl) -4-nitrosoaniline and N-methyl-4, N-dinitrosoaniline may be used, but from the viewpoint of working environment, non-nitroso type N, N ' -Bis (2-methyl-1,2
-Nitropropyl) -1,6-diaminohexane and the like are desirable.

(4) In addition to the aging inhibitor, sulfur, CB and coupling agent, zinc rubber, stearic acid, A process oil, a vulcanization accelerator and other auxiliary materials are appropriately blended and kneaded to obtain a rubber material for vibration-proof rubber.

[0023]

Effects and Effects of the Invention The vibration-proof rubber of the present invention has the above-described structure, and as shown in the test examples described later,
R manufactured rubber cushion without reducing the vibration isolation performance as compared with the (conventional example), it is possible to greatly improve heat resistance (Examples).

[0024]

EXAMPLES In the following basic compounding recipe, a rubber material was prepared from each rubber compound in which the CB, antioxidant and coupling agent were of the kind and amount indicated in Table 1 and each test piece was prepared from each rubber material. Was prepared and tested for the following items.

NR Basic Formulation NR 100 parts Stearic acid 1 part CB 30 parts Zinc white 5 parts Antioxidant variable wax 2 parts vulcanization accelerator 2 parts sulfur variable (1) Normal physical properties: JIS K 6301 : in accordance with No. 3 dumbbell), spring hardness; H _S (JIS a), tensile ^{_{strength; T B (kgf / cm 2}} ), elongation at break; was measured for each item of the E _B (%) .

(2) Anti-vibration performance: Evaluated by the ratio of dynamic elastic modulus (E'100HZ) to (G _S ) measured by the following method.

Dynamic elastic modulus: Measured with a viscoelastic spectrometer manufactured by Iwamoto Seisakusho under the following conditions.

Specimen: 5 mm strip, frequency: 100 Hz, dynamic strain: 0.5%, static shear modulus: low elongation stress test (test piece: 5 mm strip) was measured based on JISK 6301 and determined by the following formula. Was.

G _S = 1.639 × σ ₂₅ (elastic modulus at 25% elongation) (3) Heat resistance: According to JIS K 6301 (test piece: No. 3 dumbbell-shaped), under the conditions of 100 ° C. × 70 h: The items were subjected to an air heating aging test.

Tensile strength: ΔT _B (%), elongation at break: ΔE _B (%) (4) Compression set resistance: A compression set test was performed according to JIS K6301.
00 are performed by the heat treatment conditions of ℃ × 70h, compression set;
CS (%) was determined. From Table 1 showing the test results, the first characteristic of the present invention (the combination of the antioxidant and sulfur is within a specific range)
The second feature (combination of specific CB and coupling agent)
It can be seen that, in the combined example , the heat resistance is significantly improved as compared with the anti-vibration rubbers of the conventional example and Comparative Example 1 , and that the anti-vibration performance is not reduced as compared with the conventional example. Also book
Second feature of the invention (combination of specific CB and coupling agent)
Even formulation having a use), compared inhibitor and sulfur formulation aging does not have the first feature not within the scope of the present invention Example 1
It can be seen that although the anti-vibration performance is improved, the heat resistance is not improved. Conversely, the first feature of the present invention (the anti-aging agent and sulfur
Even if the composition has a specific CB).
Not combined with coupling agent and does not have secondary features
In Comparative Example 2, the heat resistance is improved, but the vibration isolation performance is reduced.
You can see that.

[0031]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a sectional view of an engine mount showing an example of an application example of the present invention.

FIG. 2 is a cross-sectional view of a strut mount showing another example.

FIG. 3 is a sectional view of a bumper rubber showing still another example.

FIG. 4 is a sectional view of a bush rubber showing still another example.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F16F 15/00-15/328 B60G 7/02 C08K 3/06 C08K 5/16 F16F 1/00-6 / 00

Claims (3)

(57) [Claims] 1. An anti-vibration rubber molded and vulcanized from a rubber composition of a co-projected diene rubber, wherein the compounding composition of an auxiliary material in the rubber composition is 3 to 10 phr of anti-aging material and 0.1 to 1 phr of sulfur. Haisutoraku along with satisfying the requirements, carbon black is, of SRF black
Charcoal and a combination of carbon black and rubber.
An anti-vibration rubber characterized by using a pulling agent in combination . 2. An anti-vibration rubber according to claim 1 , wherein said anti-aging agent is a combination of three types of amine ketone type, aromatic secondary amine type and benzimidazole type. Wherein the coupling agent, N, N'-bis (2-methyl-2-nitro-propyl) -1,6 claim 1 or 2, wherein the a-diaminohexane
Of anti-vibration rubber.