KR101491166B1 - Weather strip compositions - Google Patents

Abstract

The present invention relates to a weather strip composition, and more particularly, to a weather strip composition comprising a polymer containing at least one selected from EPDM (ethylene propylene diene) rubber or Thermoplastic Elastomer (TPE); Fillers; A crosslinking agent; A crosslinking accelerator; And a processing oil. The weather strip prepared from such a weather strip composition is superior to conventional weather strips in sound absorption, permanent deformation, heat resistance and light weight.

Weather Strip, Glass Bubble

Description

Weather strip compositions

The present invention relates to a weather strip composition in which a glass bubble is introduced to improve the sound absorption, permanent deformation, heat resistance and light weight of a weather strip.

Weather Strip is a functional part that attaches to the car body and door to give the comfort and comfort of the automobile by preventing leakage to the inside of the car body and sealing from external noise. The weather strip consists of an extruded portion and a joint portion connecting the extruded portion. The required performance of the weather strip component is heat resistance, permanent deformation resistance, weather resistance, ozone resistance and the like.

The types of weather strips are classified into door side seals, body side seals and glass run. Among them, the door side seals and the glass run connect the extruded part to the joint part The joint portion of the door side seal is a sponge-like foam, but the glass run is a solid without foam.

Most of the composition of the weatherstrip contains filler, vulcanizing agent and the like in the base polymer. In recent years, wind noise reduction technology has been increasing in importance in terms of providing comfort and comfort of the vehicle occupant. However, the existing sound-absorbing performance of the weatherstrip does not satisfy the requirement level of the customer, Permanent deformation occurs, which increases the penetration of wind sound. Also. There is a problem that the temperature of the vehicle is higher than the use temperature of the base polymer depending on the region or season, and is rapidly deformed. Particularly, in the joint part, there is a problem that it is particularly vulnerable to heat resistance and permanent deformation because a polymer having a low viscosity, that is, a low molecular weight is used in order to improve workability.

Accordingly, there is an increasing demand for a new weather strip that can solve the problems of existing automotive weather strips in the automobile business.

The present inventors have found that when glass bubbles are used as a main filler instead of carbon black as a composition of a weather strip, the glass bubble itself has low deformability, low heat transfer characteristics, It has been found that heat resistance of the weather strip can be ensured due to the simple performance. That is, an object of the present invention is to provide a weather strip composition which is excellent in mechanical properties, particularly in permanent deformation.

The present invention relates to a weather strip composition, which comprises a polymer containing at least one selected from EPDM rubber or TPE; Fillers containing glass bubbles; A crosslinking agent; A crosslinking accelerator; And a processing oil.

The weather strip produced by the weather strip composition of the present invention is excellent in mechanical properties such as negative impact noise, heat resistance and permanent deformation, and is excellent in chemical properties such as weather resistance and ozone resistance, and can be lightweight.

Hereinafter, the present invention described above will be described in more detail.

The above-described invention will be described in terms of composition ratio. With respect to 100 phr (parts per hundred rubber by weight) of a polymer containing at least one selected from ethylene propylene diene (EPDM) rubber or thermoplastic carbon polymer (TPE) , 0.5 to 3 phr of a crosslinking agent, 0.5 to 2 phr of a crosslinking accelerator, and 2.5 to 10 phr of a processing oil.

The present invention may further comprise at least one selected from the group consisting of carbon black, a foaming agent, a crosslinking activator, an antioxidant and an ozone antioxidant as additives in addition to the composition described above, 0.5 to 5 phr of the carbon black, 0.5 to 7 phr of the crosslinking activator, 0.1 to 2 phr of the antioxidant and 0.1 to 2 phr of the ozone antioxidant, respectively. The amount of the foaming agent used varies depending on the use place of the weather strip composition.

Each of the above compositions will be described in more detail.

In the present invention, EPDM rubber or TPE is used as a main component as a main component. EPDM rubber and TPE are excellent in heat resistance, and have an excellent adhesive strength at the time of extrusion and molding with the joint part of the weather strip have. The EPDM rubber preferably has a weight average molecular weight of 20,000 to 100,000. And the TPE uses a dynamically crosslinked material.

The glass bubble serves as a filler. In the present invention, glass bubbles are used instead of carbon black used in conventional weather strips. Although the shape of the carbon black is irregular, the shape of the glass bubble is spherical as shown in FIG. 1, so that it is not only deformed in shape, but also has a low heat transfer characteristic of glass and excellent heat- It is possible to secure the heat resistance of the battery. In addition, since the average specific gravity of the glass bubble is 0.125 to 0.6 and the hollow shape is formed, the weight of the weather strip for improving automobile fuel efficiency is made smaller than that of carbon black having an average specific gravity of 1.64, There is a sound absorption effect. The proper blending of the glass bubble is 0.2 to 15 phr with respect to 100 phr of the polymer. If less than 0.2 phr is used, it is difficult to realize the physical properties of the weather strip. When the use exceeds 15 phr, whitening of the weather strip occurs Or the elongation may be deteriorated. Therefore, it is preferable to use within the above range.

In the present invention, the crosslinking agent, which is one of the compositions of the present invention, plays a role of linking the chain-like EPDM polymers to a three-dimensional network structure, and it is preferable to use sulfur instead of peroxide for reducing odor. The crosslinking agent may be used in an amount of 0.5 to 3 phr per 100 phr of the polymer. If the crosslinking agent is used in an amount less than 0.5 phr, the crosslinking density may be lowered and the elasticity of the weatherstrip may be insufficient. , Crosslinking density becomes too high and overcure may occur. Therefore, it is preferable to use it within the above range.

The crosslinking accelerator, which is one of the compositions of the present invention, serves to shorten the crosslinking time. The crosslinking accelerator may be a crosslinking accelerator used in the art. Although not specifically limited in the present invention, the crosslinking accelerator may be selected from 1-mercaptobenzothiazole (MBT) and diphenylguanidine (DPG) More preferably, it is preferable to use the above-mentioned MBT, which is a non-polluting accelerator, and the DPG, which has an effect of improving the crosslinking density, in order to prevent contamination of automobile painting. When the amount of the crosslinking accelerator used is less than 0.5 phr, the 90% vulcanization time (T90) is too short as 2 minutes or less, which makes it difficult to process the vulcanization accelerator. If the amount is more than 2 phr, T90 may be more than 60 minutes, resulting in a problem that the processing time becomes rather long, the torque is low and the elasticity becomes small. .

The processing oil, which is a composition of the present invention, plays a role in improving the workability of the weatherstrip composition. Although not specifically limited in the present invention, it is preferable to use at least one selected from paraffinic processing oil and naphthalene- desirable. In the present invention, it is preferable to use 2.5 to 10 phr of the processing oil, which is less than the amount of processing oil used in the conventional weather strip production. This is because in the present invention, glass bubbles are used as a filler, the glass bubble serves as a ball bearing, so that the viscosity of the weather strip composition is lowered and the flow during processing is improved. Therefore, it is preferable to use the processing oil within the above range.

As described above, the present invention may further comprise at least one additive selected from the group consisting of carbon black, a foaming agent, a crosslinking activator, an antioxidant and an ozone antioxidant, in addition to the above-described composition.

In the present invention, the carbon black may be added as a reinforcing filler for enhancing affinity with rubber and reinforcing strength. The carbon black is not particularly limited, but it is preferable to use at least one selected from FEF (particle diameter: 40 to 48 nm) and HAF (particle diameter: 26 to 30 nm). The amount of the carbon black to be used is preferably 0.5 to 5 phr of the carbon black per 100 phr of the polymer. If the amount of the carbon black is less than 0.5 phr, the reinforcement effect due to the addition of carbon black can not be observed. If the carbon black is used in an amount exceeding 5 phr, the hardness of the weather strip becomes too high and the compressive load increases, , It is preferable to use it within the above range.

The blowing agent, which is one of the additives, is used and used depending on the use of the weather strip produced using the composition of the present invention. For example, when used in a door side seal, a foaming agent is added. When used in a glass run, a foaming agent is not added to the weather strip composition of the present invention. The amount of the foaming agent is determined depending on the use of the weather strip, so that the foaming agent is not particularly limited in the present invention.

Among the additives, the crosslinking activator serves to further accelerate the reaction by activating the crosslinking accelerator. Although not particularly limited, it is preferable to use at least one selected from zinc oxide (ZnO) and stearic acid, more preferably zinc oxide and stearic acid in combination. When the amount of the crosslinking activator used is less than 0.5 phr, the amount of the crosslinking activator to be added is insufficient and the activity of the crosslinking accelerator is insufficient. When the amount of the crosslinking activator is less than 7 phr, , Blooming may occur. Therefore, it is preferable to use within the above range.

Among the additives, the antioxidant and the ozone antioxidant may be used to prevent aging which causes deterioration of physical properties such as hardening, softening, ignition, cracking, or loss of elasticity, and the antioxidant may be 2-mercapto N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD) is used as the ozone antioxidant. It is good to use. The amount of the antioxidant or ozone antioxidant is preferably 0.1 to 2 phr per 100 phr of the polymer. When the amount of the antioxidant or ozone antioxidant is less than 0.1 phr, The physical properties of the weather strip may be deteriorated and whitening may occur. Therefore, it is preferable to use within the above range.

Such a weather strip composition of the present invention can be used in the manufacture of weather strips of moving means, in particular weather strips for automobiles.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples.

Examples 1 to 5 and Comparative Examples 1 and 2: Manufacture of Weather Strip for Automobile

The weather strip compositions for automobiles having the compositions shown in Table 1 below were prepared and Examples and Comparative Examples were conducted.

division
(Unit: phr) Example
One Example
2 Example
3 Example
4 Example
5 Comparative Example
One Comparative Example
2
Polymer
EPDM rubber ⁽¹⁾ 100 100 - 100 100 100 100 TPE ⁽²⁾ - - 100 - - - - Glass bubble ⁽³⁾ 3 5 5 10 12 - 23 Oils for processing ⁽⁴⁾ 3 3 3 4 2.5 10 - Cross-linking agent sulfur One One One One 2 One One
Crosslinking accelerator MBT ⁽⁵⁾ 1.0 One One 1.5 0.5 One One DPG ⁽⁶⁾ 0.5 0.5 0.5 - 0.5 0.5 0.5 Carbon black FEF ⁽⁷⁾ 3 - - - 0.5 3 3 Crosslinking activator Zinc oxide One One One 3 3 One One Antioxidant MBI ⁽⁸⁾ 1.5 1.5 1.5 0.5 One 1.2 1.5 Ozone antioxidant IPPD ⁽⁹⁾ 2 2 2 0.5 One 1.5 2 (1) ethylene propylene diene rubber: Kumho Polychem VISTALON-8600.
(2) Thermoplastic Elastomer: Santoprene hardness 65
(3) Glass bubble: average specific gravity 0.60, 3M, S60HS
(4) Processing oil: naphthalene oil, Felexon, 84.
(5) 2-Mercaptobenzothiazole: Flexys, Perkacit MBT.
(6) Diphenylguaidine: Ouchi Shinko, NOCCELER D.
(7) FEF: average particle diameter of 40 to 45 nm,
(8) 2-mercaptobenzoimidazole: Ouchi Shinko, Nocrac MB.
(9) N-isopropyl-N'-phenyl-p-phenylenediamine: Flexys, Santoflex IPPD.

Experimental Example

In order to measure the physical properties of the compositions prepared in Examples and Comparative Examples, physical properties were evaluated under the evaluation conditions shown in Table 2 below, and the results are shown in Table 3 below. When the evaluation range of Table 2 is satisfied, it indicates that it is excellent as a weather strip composition for automobiles.

According to the results shown in Table 3, the case of charging compared to the carbon black filled formulation showed excellent values of both tensile strength and elongation after aging. It can be seen that the heat resistance is better. Also, there is a large difference in the compressive permanent band tone. The excellent heat resistance and permanent deformation performance shown in the examples are possible due to the characteristics of the glass bubble, which is hollow spherical glass. This is a physical property indicating the wind noise sealing force, which means that even after running the vehicle for a long time, the permanent deformation is small and the wind noise is less influxed. It can be confirmed that the indoor sound evaluation result is reduced by 2 dB or more.

1 is an electron micrograph of a glass bubble.

Claims (7)

Ethylene propylene diene rubber 100 phr; An average specific gravity of 0.125 to 0.6, a hollow glass bubble of 0.2 to 15 phr; 0.5 to 3 phr of a crosslinking agent; 0.5 to 2 phr of a crosslinking accelerator; And 2.5 to 10 phr of processing oil; Wherein the negative electrode is a negative electrode. The method according to claim 1, Carbon black, carbon black, a foaming agent, a crosslinking activator, an antioxidant and an ozone antioxidant. The method according to claim 1, And 3 to 12 phr of said glass bubble. delete delete The method according to claim 1, Wherein the crosslinking accelerator comprises at least one member selected from 2-mercaptobenzothiazole and diphenyl guanidine. A door side seal or a body side seal of a weather strip produced using the composition of any one of claims 1, 2, 3 or 6.

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