KR20120040845A - Rubber composite for bearing oil seal - Google Patents

Abstract

PURPOSE: A rubber composition for bearing oil seal is provided to improve sealability of bearing seal because of excellent heat resistance, and to be able to manufacture a bearing seal having a color. CONSTITUTION: A rubber composition for bearing oil sea comprise: 100.0 parts by weight of a polymer consisting of nitrile butadiene rubber; 80-100 parts by weight of a filling reinforcing agent with white color or colorless, consisting of silica-based material; pigment coloring the polymer; and a vulcanizer consisting of peroxide or sulfur. The peroxide is dicumyl peroxide, and the content of the dicumyl peroxide is 1-2 parts by weight on the basis of 100 parts by weight of the polymer.

Description

Rubber composition of bearing seal {RUBBER COMPOSITE FOR BEARING OIL SEAL}

The present invention relates to a rubber composition of a bearing seal, and more particularly, to a rubber composition of a bearing seal used in a bearing applied to a vehicle.

A bearing is a device that transmits or moves a force in various types of movements such as rotation, reciprocation, side pressure, angular swing operation by using self-lubricating property or sliding property of a vibrating body under a load and power of a vehicle.

The bearing includes a bearing seal. The bearing seal functions to prevent oil leakage, external dust intrusion, and the rod lubricating surface.

An example of the bearing may include an inner ring, an outer ring, and a plurality of balls. In this case, the inner ring is engaged to move integrally with the rod. The outer ring is fixed to a frame that is radially opposed to the inner ring. A plurality of balls are inserted in the circumferential direction so as to make rolling contact between the inner ring and the outer ring. Through this, a bearing supports the rod by allowing relative movement between the outer ring and the inner ring by the rolling contact of the ball.

Lubricating oil is filled between the outer ring and the inner ring so that the rolling resistance of the ball is minimized, and a bearing seal is installed to seal the oil to prevent leakage of the lubricant and foreign matters into the lubricant.

Typically, the bearing seal is black, mainly using nitrile butadiene rubber (NBR).

By the way, since the oil contacting the bearing in the vehicle rises up to 100 ° C, the bearing seal should have excellent heat resistance along with oil resistance. Moreover, in recent years, along with the extension of the quality assurance period of vehicle parts, the required physical properties in the harsh conditions of finished car manufacturers are becoming more demanding, and the heat resistance standards of bearing seals are becoming more demanding.

In addition, conventional bearing seals have a black color. However, in connection with the diversification of the product, in order to distinguish it from other products, a bearing seal having a color (有色) is required, but when NBR rubber is colored, there is a problem in that technical properties including heat resistance of the rubber are deteriorated.

[Issue to solve]

The present invention has been made in view of the above problems, and an object of the present invention is to provide a rubber composition of a bearing seal having color and excellent heat resistance.

[Measures to solve the problem]

 Therefore, the rubber composition of the bearing seal according to the preferred embodiment of the present invention includes a polymer, a filler reinforcing agent, and a pigment. The polymer consists of nitrile butadiene rubber (NBR). Filling reinforcing agent has 80 to 100 parts by weight with respect to 100 parts by weight of the polymer, made of a silica-based material, it is colorless or white. Pigments color the polymer. The vulcanizing agent consists of peroxide and sulfur.

The dicumyl peroxide may have 1 to 2 parts by weight based on 100 parts by weight of the polymer.

 In addition, the filling reinforcing agent, Nipsil E74P having 35 parts by weight with respect to 100 parts by weight of the polymer, Dixie Clay having 45 parts by weight with respect to 100 parts by weight of the polymer, Aerosil 200 having 10 parts by weight with respect to 100 parts by weight of the polymer Can be made.

 On the other hand, the present invention, consisting of Suntight R and AOF, having an antioxidant of 1 to 5 parts by weight based on 100 parts by weight of the polymer, zinc oxide (zinc oxide), stearic acid, silane coupling additive (Silane coupling agent) ), A vulcanization aid having 7 to 11 parts by weight based on 100 parts by weight of the polymer, tetramethythiuram disulfide and N-cyclohexyl-2-benzothiazole sulfenamide (N-cyclohexyl -2-benzothianole Sulfenamide), and further comprises an accelerator having 1 to 3 parts by weight based on 100 parts by weight of the polymer, and a plasticizer having a diester system and having 7 to 13 parts by weight based on 100 parts by weight of the polymer. Can be.

The pigment may be any one of phthalocyanine, anthraquinone red, disazo orange, titanium chromium yellow and chromium oxide.

[Effects of the Invention]

According to the present invention having the above configuration, the bearing seal has better heat resistance when compared with the existing bearing seal. This improves the sealability of the bearing seals.

In addition, since the bearing seal is colored, it is easy to distinguish it from other products, thereby increasing the assembly speed of the operator.

[Details for carrying out the invention]

EMBODIMENT OF THE INVENTION Hereinafter, the preferable Example of the rubber composition of the bearing seal of this invention is described in detail.

In this case, as described above, the bearing transmits the force in various movement forms such as rotation, reciprocation, side pressure, angular swing operation by using the self-lubricating property or the sliding property of the vibrating body under the load and power of the vehicle. It is a moving device, the bearing seal is included in the bearing, and serves to prevent oil leakage, external dust intrusion, and the rod lubrication surface.

The rubber composition of the brake seal according to a preferred embodiment of the present invention comprises a polymer, a filler reinforcing agent, a pigment, and a vulcanizing agent.

The polymer consists of nitrile butadiene rubber (NBR). The nitrile butadiene rubber has good oil resistance, abrasion resistance, and aging resistance to prevent oil leakage, prevent intrusion of external dust, and protect the lubricating surface of the rod.

Filling reinforcing agents are intended to improve the adhesion of the polymer, while improving processability and reinforcement. In the present invention, a silica-based material is used as a filler reinforcing agent. Silica-based materials have a colorless or white color. Accordingly, by selecting and blending an appropriate pigment, the bearing seal may be colored.

Conventionally, in order to satisfy the mechanical properties, carbon black is applied as a filler reinforcing agent, but in this case, the rubber cannot be colored even when the carbon black is mixed with a pigment.

According to the present invention, the rubber becomes colored by using a silica-based filler as a filler. In this case, the filling reinforcing agent is more preferably silicon dioxide (SiO ₂ ), because the silicon dioxide is not only easy to give a color, but also excellent mechanical properties reinforcement.

In this case, the filling reinforcing agent preferably has 80 to 100 parts by weight based on 100 parts by weight of the polymer. If the weight part exceeds 100, the compound compounding process is difficult, the dispersibility is deteriorated, and if the weight part is less than 80, the mechanical properties are inferior.

The filler reinforcement may be made of Nipsil E74P, Dixie Clay, and Aerosil 200.

Nipsil E74P is a silicon dioxide (SiO ₂ ) material produced and sold by Silica Japan. Dixie Clay is a brand name for kaolin clay produced and sold by Dixie Clay Company, and has a fine particle size in kaolin clay having a molecular formula of Al ₂ Si ₂ O ₂ (OH) ₄ used in rubber compounds. It is a hard clay. Aerosil 200 is a silicon dioxide (SiO ₂ ) material produced and sold by Evoinc.

In this case, Nipsil E74P may have 35 parts by weight with respect to 100 parts by weight of the polymer, Dixie Clay may have 45 parts by weight with respect to 100 parts by weight of the polymer, and Aerosil 200 may have 10 parts by weight with respect to 100 parts by weight of the polymer.

Pigments express the rubber colored. The pigment may be a material having no chemical effect on the rubber. The pigment may be any one of phthalocyanine, anthraquinone red, disazo orange, titanium chromium yellow, and chromium oxide (green), depending on the color to be expressed. In this case, the content of the pigment is preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the polymer. If the weight part is 0.5 or less, the coloring power and physical properties of the rubber do not appear, and when the weight part exceeds 3, the rubber softens. There is a problem that the strength decreases.

The vulcanizing agent functions to crosslink the monomers constituting the polymer when the kneaded rubber is heated to an appropriate temperature. The vulcanizing agent may be applied to a peroxide-based vulcanizing agent together with sulfur. The peroxide based vulcanizing agent exhibits better thermal aging than conventional sulfur vulcanizing agents.

More preferably, the vulcanizing agent may include dicumyl peroxide. In this case, the content of the dicumyl peroxide is preferably 1 to 2 parts by weight with respect to 100 parts by weight of the polymer. There is a risk of occurrence.

Meanwhile, the bearing seal of the present invention may further include an anti-aging agent, a vulcanization aid, an accelerator, and a plasticizer.

Antioxidants serve to prevent aging of organic polymeric materials. Antioxidants are also called antioxidants because they often have the same effect as antioxidants. Antioxidants act to stop the chain reaction, which is automatically oxidized by oxygen, a major factor in aging.

In the present invention, the anti-aging agent may be composed of Suntight R and A.O.F. Suntight R is produced by SEICO CHEM, Inc. and is a mix of synthetic wax and higher fatty amide. The synthetic wax also serves to spray the pigment well.

AOF is produced and sold by Daenae Shinheung Co., Ltd. and is based on N, N'-Di-2-Naphthyl-P-Phenylene-Diamine. .

In this case, the anti-aging agent preferably has 1 to 5 parts by weight based on 100 parts by weight of the polymer.

Vulcanization aids are intended to increase the crosslinking rate of the polymer while preventing side chain reactions to increase the crosslinking density. As the crosslinking aid, zinc oxide, stearic acid, and a silane coupling additive may be included.

In this case, the silane coupling additive means that one end has an organic functional group (Organic Functional Group) and the other has a methoxy group or an ethoxy group. Silane is basically polymerized by condensation reaction with water at room temperature. The ethoxy group at one end is hydrolyzed by water and ethanol is dropped and becomes Si-OH group. The Si-OH group is unstable to bond with Si-O-Si, which is a Siloxane bond, and the silane is crosslinked and gelated. The content of the vulcanization aid may have 7 to 11 parts by weight based on 100 parts by weight of the polymer.

Plasticizers serve to soften the polymer. For example, the plasticizer is a simple description of a long string of string-like molecules, the harder the pull between each other. In this case, when the plasticizer is inserted between the molecules, the direct pulling force between the plastic molecules is weakened, which causes the plastic to bend well. It is therefore advantageous for the plasticizer to be well mixed, i.e., blendable, with the polymer.

In the present invention, the plasticizer is made of diester, and may have 7 to 13 parts by weight based on 100 parts by weight of the polymer.

Accelerators lower the vulcanization temperature and shorten the vulcanization time, as well as improve the properties of the vulcanized product.

In the present invention, the accelerator may be composed of tetramethythiuram disulfide and N-cyclohexyl-2-benzothianole Sulfenamide.

The use of tetramethylthiuram disulfide has the advantage of low scorch tendency. N-cyclohexyl-2-benzothiazole sulfenamide is an sustained release accelerator and is excellent in tensile strength. The content of the accelerator may have 1 to 3 parts by weight based on 100 parts by weight of the polymer.

According to the present invention, by applying a silica-based filling reinforcing agent and adding a pigment, the bearing seal can be colored. In addition, by using a vulcanizing agent together with sulfur and a peroxide system, and applying an appropriate material and content to additives such as plasticizers, accelerators, and vulcanizing aids, heat resistance and mechanical properties are excellent.

Hereinafter, the properties of the rubber composition (hereinafter referred to as "example" for convenience) according to the embodiment of the present invention as described above between the rubber composition (hereinafter referred to as "comparative example" for convenience) of the conventional bearing seal. Various effects are tested and compared with each other, and the above effects will be described more clearly.

Table 1 is a table comparing the components of the Examples and Comparative Examples applied to the various tests.

Ingredients (parts by weight) Comparative example Example Polymer NBR ^{1 )} 100 100 Filling reinforcement SRF ^{2 )} 55 0 Nipsil E74P ^{3 )} 0 35 Dixie Clay ^{4 )} 0 54 Aerosil 200 ⁵⁾ 0 10 Antioxidant Suntight R ^{6 )} 2 One AO F ⁷⁾ 3 One Vulcanization ZnO2 ^{8 )} 10 10 Stearic Acid ^{9 )} One 1.5 A-172 ¹⁰⁾ 0 8 Vulcanizing agent Sulfur ^{11 )} 0.6 0.6 DCP ^{12 )} 0 One accelerant TMTD ^{13 )} 2.5 2.5 CBS ^{14 )} 3 0 Plasticizer TP-95 ¹⁵⁾ 5 10 Pigment For Blue3300 ^{16 )} 0 One 1) NBR: ACN (33%) NBR, JSR
2) SRF: N-774, DCC
3) Nipsil E74P: SiO2, 日本 SILICA
4) Dixie Clay: SiO2.Al2O3, RTVanderbilt
5) Aerosil200: SiO2, Evoinc
6) Suntight R: Mixture of synthetic wax and higher fatty amide, SEIKO CHEM
7) AO F: N, N'-Di-2-Naphthyl-P-Phenylene-Diamine, Daenae Shinheung
8) ZnO: Zinc oxide, SBC
9) Stearic Acid: Stearic Acid, NATOLEO
10) A-172: Silane Coupling Agent, Taehwa Co., Ltd.
11) Sulfur: Hwang, Miwon Corporation
12) DCP: Dicumyl Peroxide, NOF
13) TMTD: Tetramethylthiuram Disulfide, Flexsys
14) CBS: N-cyclohexyl-2-benzothiazole Sulfenamide, Flexsys
15) TP-95: Diester series, ROHM & HAAS
16) Korea Blue 3300: Cu-Phthalocyanine, Korea Swiss Chemical

Table 2 is a table comparing the heat resistance, hardness and tensile strength of the Examples and Comparative Examples results of the basic physical property test and the heat resistance test.

In this case, the heat test was observed for 1000 hours in an ambient atmosphere of 100 ℃ and then observed the change in hardness. In this case, the heat resistance test, hardness test, and tensile strength test satisfied the specifications of KS M 6518, respectively.

As a result, the Example was blue, and the Comparative Example was black. That is, the embodiment has a color.

In addition, the hardness and tensile strength of the Examples are 77 Shore A and 195 Kgf / cm ² , respectively, almost the same level or higher than 76 Shore A and 182 Kgf / cm ^{2 of the} comparative example.

In addition, in the heat resistance test, the hardness change was +14 in the comparative example, whereas the hardness change was +10 in the example, and it was found that the example was better.

As described above, in the case of the embodiment, it is possible to manufacture a colored bearing seal, and it can be seen that mechanical properties and heat resistance are also superior to those of the comparative example.

Item Required Property Comparative example Example Related Standard Basic property color Colored black blue Shore A - 77 76 KS M 6518 Tensile strength (kgf / cm ² ) - 195 182 Heat resistance
100 ℃ × 1000H Hardness change (pts) - +14 +10

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (5)

Polymer made of Nitrile Butadiene Rubber (NBR)
80 to 100 parts by weight based on 100 parts by weight of the polymer, made of a silica-based material, a colorless or white filling filler
Pigments that color-express the polymer; and
A vulcanizing agent consisting of peroxide and sulfur
Rubber composition of the bearing seal comprising a. The method of claim 1,
The peroxide system is dicumyl peroxide,
The dicumyl peroxide rubber composition of the bearing seal, characterized in that 1 to 2 parts by weight based on 100 parts by weight of the polymer. The method of claim 1,
The filling adjuvant. Nipsil E74P having 35 parts by weight with respect to 100 parts by weight of the polymer, Dixie Clay having 45 parts by weight with respect to 100 parts by weight of the polymer, Aerosil 200 having 10 parts by weight with respect to 100 parts by weight of the polymer Rubber composition of the seal. The method of claim 1,
An anti-aging agent consisting of Suntight R and AOF and having 1 to 5 parts by weight based on 100 parts by weight of the polymer;
A vulcanization aid consisting of zinc oxide, stearic acid, a silane coupling agent, and having 7 to 11 parts by weight with respect to 100 parts by weight of the polymer;
Tetramethythiuram Disulfide and N-cyclohexyl-2-benzothianole Sulfenamide, consisting of 1 to 3 parts by weight based on 100 parts by weight of the polymer With accelerator to have
Plasticizer made of diester, having 7 to 13 parts by weight based on 100 parts by weight of the polymer
Rubber composition of the bearing seals further comprising. The method of claim 1,
The pigment is a rubber composition of a bearing seal, characterized in that any one of phthalocyanine, anthraquinone red, disazo orange, titanium chromium yellow and chromium oxide.