Acrylic rubber composition

Abstract

An acrylic rubber composition comprising 5 to 80 parts by weight, preferably 10 to 60 parts by weight, more preferably 20 to 40 parts by weight, of a styrene-based resin, based on 100 parts by weight of acrylic rubber. A vibration insulation member having an excellent tan value at a high temperature and improved vibration insulation properties can be molded by adding a specific ratio of a styrene-based resin to acrylic rubber. This acrylic rubber composition can be effectively used as a molding material for a mount, a grommet, or the like in the vicinity of an automobile engine used in a high temperature environment.

Claims

1. An acrylic rubber composition comprising 5 to 80 parts by weight of a styrene-based resin and 0.1 to 5 parts by weight of a vulcanization agent that consists of sulfur, based on 100 parts by weight of a reactive halogen group-containing acrylic rubber or an epoxy group-containing acrylic rubber.

2. A vibration insulation member obtained by vulcanizing molding of the acrylic rubber composition according to claim 1.

3. The vibration insulation member according to claim 2, which is used as a mount or a grommet in the vicinity of an automobile engine.

Description

EXAMPLES

(1) The following describes the present invention with reference to Examples.

Example 1

(2) TABLE-US-00001 Active chlorine group-containing acrylic rubber 100 parts by weight (Noxtite PA401-L, produced by Unimatec Co., Ltd.) Styrene resin A (YS resin SX100, produced by 20 parts by weight Yasuhara Chemical Co., Ltd.) Sulfur 0.2 parts by weight
The above components were kneaded by a pressurizing kneader, and then subjected to roll processing using an open roll. The resultant was vulcanized at 190 C. for 8 minutes, followed by oven vulcanization (secondary vulcanization) at 175 C. for 5 hours, thereby forming a sheet-like material (thickness: 2 mm).

(3) Kneading properties, roll processability, and vulcanization molding properties were evaluated. In addition, dynamic properties (tan ) were measured.

(4) Kneading Properties:

(5) (1) No bridge (rubber block) in the gap between a rotor and a weight during kneading by a pressurizing kneader, and stable progress of the kneading process

(6) (2) No contamination in the kneader after the discharge of a compound

(7) When both (1) and (2) were satisfied, the result was evaluated as ; and when at least one of (1) and (2) was not satisfied, the result was evaluated as X

(8) Roll Processability:

(9) (1) Low tackiness on the surface of the rubber compound

(10) (2) No cessation due to tackiness in the cutback operation for improving dispersibility; and the sheeting operation for sheet feeding, and excellent roll processability

(11) When both (1) and (2) were satisfied, the result was evaluated as ; and when at least one of (1) and (2) was not satisfied, the result was evaluated as X

(12) Vulcanization Molding Properties:

(13) (1) No compound burning, poor compound flow, foaming, etc., under the above vulcanization conditions, and stable vulcanization molding properties

(14) (2) No bleeding etc. on the surface of the vulcanized sheet, and low surface tackiness

(15) When both (1) and (2) were satisfied, the result was evaluated as ; and when at least one of (1) and (2) was not satisfied, the result was evaluated as X

(16) Dynamic Properties (Tan ):

(17) The test was carried out referring to JIS K6394 corresponding to ISO 4664-1

(18) The tensile method and the form and size of test pieces were as follows: strip-like materials (width: 6 mm and thickness: 2 mm), holder interval: 20 mm, average strain: 10%, strain amplitude: 0.1%, frequency: 100 Hz, and test temperature: 23 C., 70 C., or 100 C.

(19) In each temperature range, a tan of 0.2 or more was evaluated as excellent, and a tan of 0.3 or more was evaluated as more preferable

Example 2

(20) In Example 1, the same amount of styrene resin B (ARUFON UH-1150, produced by Toagosei Co., Ltd.) was used in place of the styrene resin A.

Example 3

(21) In Example 1, the amount of the styrene resin A was changed to 40 parts by weight.

Comparative Example 1

(22) In Example 1, no styrene resin A was used.

Comparative Example 2

(23) In Example 1, the same amount of carboxyl group-containing acrylic resin (ARUFON UC-3000, produced by Toagosei Co., Ltd.) was used in place of the styrene resin A.

Comparative Example 3

(24) In Example 1, the same amount of carboxyl group-containing styrene acrylic resin (ARUFON UF-5041, produced by Toagosei Co., Ltd.; containing long chain alkyl group) was used in place of the styrene resin A.

Comparative Example 4

(25) In Example 1, the same amount of aromatic modified terpene resin (YS RESIN TO105, produced by Yasuhara Chemical Co., Ltd.) was used in place of the styrene resin A.

Comparative Example 5

(26) In Example 1, the same amount of aromatic modified, hydrogenated terpene resin (CLEARON K4100, produced by Yasuhara Chemical Co., Ltd.) was used in place of the styrene resin A.

(27) Results of measurement or evaluation obtained in the foregoing Examples and Comparative Examples are shown in the following Table.

(28) TABLE-US-00002 TABLE Measurement Example Comparative Example evaluation item 1 2 3 1 2 3 4 5 [KneadingProcessing properties] kneader X X X kneading properties roll processability X X X vulcanization X X molding properties [Dynamic properties] tan (23 C.) 1.4 0.99 1.1 1.0 0.90 0.88 tan (70 C.) 0.30 0.22 0.27 0.24 0.20 0.20 tan (100 C.) 0.21 0.23 0.42 0.14 0.17 0.26