KR20100029799A - Weather strip composition for car and the weather strip for car prepared therefrom - Google Patents

Abstract

PURPOSE: A weather strip composition for vehicle is provided to improve properties such as strength and durability, and to improve production rate compared with existing products. CONSTITUTION: A weather strip(100) composition for vehicle comprises a hard part and a soft part. The hard part is a thermoplastic elastomer composition containing 80~90 parts by weight of a ethylene propylene diene monomer, 40~60 parts by weight of polypropylene, 70~90 parts by weight of high viscosity paraffin oil, 0.7~0.9 parts by weight of peroxide cross-linking agent, 0.3~0.5 parts by weight of antioxidant, 20~25 parts by weight of inorganic filler, and .3~0.5 parts by weight of additives.

Description

Weather strip composition for car and weather strip for car using same {Weather strip composition for car and the weather strip for car prepared therefrom}

The present invention relates to an automotive weather strip composition and an automotive weather strip using the same. Vulcanizate (TPV) The present invention relates to a vehicle weather strip thermoplastic elastomer composition and a vehicle weather strip using the same, which can be improved by replacing with a rigid and thermoplastic elastomer soft material.

Weather strip for automobile is also called window frame rubber for automobile.It is installed on the vehicle body, door, etc., to prevent leakage inside and outside of the vehicle body, and to provide sealing property from external noise and dust, and vibration of the vehicle body. It is a functional product of a car that prevents the fluctuation of glass and the glass and imparts a cushioning effect to the car body to impart comfort and comfort to the car.

Weather strips mounted on automobiles have been manufactured by applying ethylene propylene diene monomer rubber (Ethylene Propylene Diene Monomer rubber) in the past, and designing and developing products for various shapes of weather strips in consideration of rubber's unique elastic resilience and sealing properties This has been generalized.

However, in recent years, the demand for the development of new technologies and materials for the purpose of customer's various emotional needs, high quality, eco-friendliness, light weight, etc. is gradually rising. In view of this, thermoplastic elastomer as an alternative material of ethylene propylene diene monomer (Thermoplastic Vulcanizate) is being applied to some products.

The inventors of the present invention have found that the use of a thermoplastic elastomer instead of the ethylene propylene diene monomer rubber used as the weather strip material can improve the physical properties of the product and improve the working efficiency.

Accordingly, an object of the present invention is to provide a weatherstrip thermoplastic elastomer composition and a weatherstrip using the same which improves physical properties such as strength and durability and is recyclable.

In order to achieve the above object, the present invention is a vehicle weather strip composition comprising a hard portion and a soft portion, the hard portion 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 40 to 60 parts by weight of polypropylene, It is a thermoplastic elastomer composition containing 70 to 90 parts by weight of high viscosity paraffin oil, 0.7 to 0.9 parts by weight of peroxide crosslinking agent, 0.3 to 0.5 parts by weight of antioxidant, 20 to 25 parts by weight of inorganic filler and 0.3 to 0.5 parts by weight of other additives, Part is 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 20 to 40 parts by weight of polypropylene, 180 to 200 parts by weight of styrene ethylene butadiene styrene copolymer (SEBS), 140 to 160 parts by weight of high viscosity paraffin oil, 0.6 peroxide crosslinking agent Weather strip composition for automobiles, which is a thermoplastic elastomer composition containing ˜0.9 parts by weight, 0.5 to 0.8 parts by weight of antioxidant, 20 to 25 parts by weight of inorganic filler, and 0.3 to 0.5 parts by weight of other additives. Provided.

The present invention also provides an automotive weather strip prepared from the composition.

The weather strip composition of the present invention can improve the physical properties such as strength, durability, etc. of the product, it is possible to reduce the weight of the product, and also to increase the production speed than the existing product. In addition, the thermoplastic elastomer is a recyclable material, thereby protecting the environment and reducing costs.

1 shows an exemplary structure of a body weather strip.

The weather strip composition of this invention consists of a thermoplastic elastomer composition for a hard part and a soft part.

In particular, the weather strip composition of the present invention is used for body seal weather strip of automobiles.

Conventional weather strip composition is composed of ethylene propylene diene monomer (EPDM) rubber and ethylene propylene diene monomer sponge (sponge) in order to be able to change the application of each part to improve the sealing properties In general, the material to be compressed by the vehicle body is applied in the form of a sponge and the other parts are applied to the solid ethylene propylene diene monomer rubber. On the other hand, the composition of the present invention is applied by replacing the conventional ethylene propylene diene monomer rubber and ethylene propylene diene monomer sponge with the thermoplastic elastomer (Thermoplastic Vulcanizate, hereinafter 'TPV') hard and TPV soft material. 1 shows an exemplary weatherstrip structure to which the composition of the present invention is applied.

1. Hard part

The hard part of the composition of the present invention 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 40 to 60 parts by weight of polypropylene, 70 to 90 parts by weight of high viscosity paraffin oil, 0.7 to 0.9 parts by weight of peroxide crosslinking agent, 0.3 to 0.5 antioxidant It is a thermoplastic elastomer composition containing 20 parts by weight to 20 parts by weight of inorganic filler, and 0.3 to 0.5 parts by weight of other additives.

More preferably, the hard part of the composition of the present invention 80 parts by weight of ethylene propylene diene mono (EPDM), 50 parts by weight of polypropylene, 80 parts by weight of high viscosity paraffin oil, 0.8 parts by weight of peroxide crosslinking agent, 0.4 parts by weight of antioxidant, inorganic 20 parts by weight of the filler and 0.4 parts by weight of other additives.

The ethylene propylene diene monomer (EPDM) used in the hard part of this invention is contained in the amount of 80-90 weight part. If the content is less than 80 parts by weight, the elasticity of the product is lowered and durability is lowered, and if the content is greater than 90 parts by weight it will interfere with the weight of the product. In addition, the ethylene propylene diene monomer has a pattern viscosity of 80 or more at 125 ℃, it is preferable to use a product having a content of 5-ethylidene-2-norbornene (ENB) 8% or more. Do.

The polypropylene used for the hard part of this invention is contained in the quantity of 40-60 weight part. If the content is less than 40 parts by weight, it is difficult to mold due to the surface crack phenomenon according to the take-up speed during extrusion molding, and if it is more than 60 parts by weight when the body seal is mounted due to the increase in the hardness of the finished product. The task is difficult. Also, in the present invention, the polypropylene has a high crystalline block nose having a melt flow index of 0.5 or less at 230 ° C. and 2.16 kg in order to improve the weather strip's excellent extrudability and sealability. Preference is given to using polymers.

The high viscosity paraffin oil used in the hard part of the present invention promotes workability in preparing thermoplastic elastomers and promotes dispersion of carbon black or pigments and fillers for filling. In addition, it serves to reduce the hardness of the thermoplastic elastomer, thereby increasing plasticity and formability. In the composition of the present invention, the high viscosity paraffin oil is contained in an amount of 70 to 90 parts by weight. If the content is less than 70 parts by weight, the flowability is poor during extrusion molding, which causes mold failure and poor work. If the content is more than 90 parts by weight, the flowability increases, resulting in poor extrusion shape and cooling time. This takes a lot. In addition, the high viscosity paraffin oil is preferably in the range of 40 ℃ kinematic viscosity (Kinematic Viscosity) 170 or more.

The peroxide crosslinking agent used in the hard part of the present invention serves to crosslink the rubber part to exhibit the physical properties of the thermoplastic elastomer. Thermoplastic elastomer material is manufactured to have the same viscosity and elasticity as rubber by dynamic crosslinking by adding a crosslinking agent to crosslink the rubber segment, which is basically a soft segment, and using a twin screw extruder. In this case, phenolic resin crosslinking agent, peroxide crosslinking agent and silane crosslinking agent are mainly used for crosslinking agent for thermoplastic elastomer crosslinking. In the case of phenolic resin crosslinking agent, chemicals are sensitive to moisture and cause problems due to moisture absorption in summer. In the present invention, a peroxide crosslinking agent is used because there are less problems due to water absorption than the resin. In the composition of the present invention, the peroxide crosslinking agent is contained in an amount of 0.7 to 0.9 parts by weight. If the content is less than 0.7 parts by weight, the crosslinking is not sufficient, and the physical properties and elasticity of the finished product are lowered. If the content is more than 0.9 parts by weight, too much crosslinking occurs, resulting in foreign matter such as fish-eye. This may be observed and may be a cause of poor appearance and poor moldability of the extruder. In the present invention, the peroxide crosslinking agent may be selected from 2,5-dimethyl-2,5-di-tertiary butyl peroxy hexane (2,5-Dimethyl-2,5-di- (tert-butylperoxy) -hexane). It is preferable to use a product having a structure, having a half-life temperature of 170 ° C., and having a molecular weight of 290 or more.

In general, when manufacturing a thermoplastic elastomer material using a twin screw extruder (Twin Screw Extruder) is produced through the dynamic cross-linking, in this case the processing temperature is 200 ℃ or more and high shear force occurs. At this time, an antioxidant is used for the purpose of preventing oxidation of the rubber part of the soft segment of the thermoplastic elastomer material. In addition, in the case of finished products, antioxidants are used to prevent decomposition by heat.

The antioxidant used for the hard part of this invention is contained in the quantity of 0.3-0.5 weight part. If the content is less than 0.3 parts by weight, the physical properties of the composition are lowered and performance is reduced when the finished product is used for a long time. If the content is more than 0.5 parts by weight, the manufacturing cost of the product is increased, and the unreacted antioxidants bloom on the surface of the product. It will cause a problem. In addition, the antioxidant in the present invention has a structure of pentaerythrithol tetrakis- (3-dodecylthiopropionate), the melting point of 120 ℃ or more, the product has a whiteness of 95% or more Preference is given to using.

The inorganic filler used in the hard part of the present invention is used to lower the role of the filler and the unit cost of the material, and is contained in an amount of 20 to 25 parts by weight. If the content is less than 20 parts by weight, the material cost rises and the role as a filler is insignificant, and if it exceeds 25 parts by weight it is difficult to extrude due to the rise in hardness and material flow problems. As the inorganic filler used in the present invention, it is preferable to use a product having a particle size of 10 μm or less and a whiteness of 95% or more, and especially calcium carbonate.

The other additive used for the hard part of this invention is contained in the quantity of 0.3-0.5 weight part. In addition, the other additives, but it is preferable to use a polypropylene wax to improve the surface slip properties and increase the wear resistance of the weather strip product, but is not limited thereto. In particular, the polypropylene wax has a specific gravity of 0.90 or less, and a melting point of 160 ° C. or more is preferable.

2. Soft part

The soft part of the composition of the present invention is 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 20 to 40 parts by weight of polypropylene, 180 to 200 parts by weight of styrene ethylene butadiene styrene block copolymer (SEBS), high viscosity It is a thermoplastic elastomer composition containing 140-160 weight part of paraffin oils, 0.6-0.9 weight part of peroxide crosslinking agents, 0.5-0.8 weight part of antioxidants, 20-25 weight part of inorganic fillers, and 0.3-0.5 weight part of other additives.

More preferably, the soft part of the composition of the present invention 80 parts by weight of ethylene propylene diene monomer (EPDM), 30 parts by weight of polypropylene, 190 parts by weight of styrene ethylene butadiene styrene block copolymer (SEBS) high viscosity paraffin 150 parts by weight of oil, 0.7 parts by weight of peroxide crosslinking agent, 0.7 parts by weight of antioxidant, 20 parts by weight of inorganic filler, and 0.4 parts by weight of other additives.

The ethylene propylene diene monomer (EPDM) used in the soft portion of the present invention is contained in an amount of 80 to 90 parts by weight. If the content is less than 80 parts by weight, the elasticity of the product is lowered and durability is lowered, and if the content is greater than 90 parts by weight it will interfere with the weight of the product. In addition, the ethylene propylene diene monomer (EPDM) is a pattern viscosity of 80 or more at 125 ℃, the product of the content of 5-ethylidene-2-norbornene (5-ethylidene-2-norbornene, ENB) 8% or more It is desirable to.

The polypropylene used for the soft portion of the present invention is contained in an amount of 20 to 40 parts by weight. If the content is less than 20 parts by weight, the matrix effect of polypropylene is drastically reduced, resulting in surface unevenness during extrusion molding, which is difficult to mold, and when it is more than 40 parts by weight, the body seal is increased due to the increase in the hardness of the finished product. It is disadvantageous to restore shape when opening and closing the door after installation. Also, in the present invention, the polypropylene has a high crystalline block nose having a melt flow index of 0.5 or less at 230 ° C. and 2.16 kg in order to improve the weather strip's excellent extrudability and sealability. Preference is given to using polymers.

Styrene ethylene butadiene styrene copolymer (Styrene Ethylene Butylene Styrene Block Copolymer, SEBS) used in the soft portion of the present invention is contained in an amount of 180 to 200 parts by weight. If the content is less than 180 parts by weight, the shape restoration is disadvantageous when opening and closing the door seal.If the content is more than 200 parts by weight, the sealing property is good due to the rigidity of the material itself, but the tearing or the wear resistance is poor. Disadvantageous durability.

The high viscosity paraffin oil used in the soft part of the present invention promotes workability in preparing thermoplastic elastomers and promotes dispersion of carbon black or pigments and fillers for filling. In addition, it serves to reduce the hardness of the thermoplastic elastomer, thereby increasing plasticity and formability. In the composition of the present invention, the high viscosity paraffin oil is contained in an amount of 140 to 160 parts by weight. If the content is less than 140 parts by weight, the flowability is poor during extrusion molding, which causes mold failure and poor work. If the content is more than 160 parts by weight, the flowability increases, resulting in extrusion shape defect and cooling time. This takes a lot. In addition, the high viscosity paraffin oil is preferably in the range of 40 ℃ kinematic viscosity (Kinematic Viscosity) 170 or more.

The peroxide used in the soft part of the present invention serves to crosslink the rubber part to exhibit the physical properties of the thermoplastic elastomer. Thermoplastic elastomer material is manufactured to have the same viscosity and elasticity as rubber by dynamic crosslinking by adding a crosslinking agent to crosslink the rubber segment, which is basically a soft segment, and using a twin screw extruder. In this case, phenolic resin crosslinking agent, peroxide crosslinking agent and silane crosslinking agent are mainly used for crosslinking agent for thermoplastic elastomer crosslinking. In the case of phenolic resin crosslinking agent, chemicals are sensitive to moisture and cause problems due to moisture absorption in summer. In the present invention, a peroxide crosslinking agent is used because there are less problems due to water absorption than the resin. In the composition of the present invention, the peroxide crosslinking agent is contained in an amount of 0.6 to 0.9 parts by weight. If the content is less than 0.6 parts by weight, the crosslinking is not sufficiently made, and the physical properties and viscoelastic properties of the finished product are lowered. If the content is more than 0.9 parts by weight, too much crosslinking occurs and foreign matters such as fish-eye appear on the appearance. This may be observed and may be a cause of poor appearance and poor moldability of the extruder. In the present invention, the peroxide crosslinking agent may be selected from 2,5-dimethyl-2,5-di-tertiary butyl peroxy hexane (2,5-Dimethyl-2,5-di- (tert-butylperoxy) -hexane). It is preferred to use a product having a structure, having a half-life temperature of 170 ° C. and a molecular weight of 290 or more.

In general, when manufacturing a thermoplastic elastomer material using a twin screw extruder (Twin Screw Extruder) is produced through the dynamic cross-linking, in this case the processing temperature is 200 ℃ or more and high shear force occurs. At this time, an antioxidant is used for the purpose of preventing oxidation of the rubber part of the soft segment of the thermoplastic elastomer material. In addition, in the case of finished products, antioxidants are used to prevent decomposition by heat.

The antioxidant used for the hard part of this invention is contained in the quantity of 0.5-0.8 weight part. If the content is less than 0.5 parts by weight, the physical properties of the composition is lowered and performance is reduced when the finished product is used for a long time. If the content is more than 0.8 parts by weight, the manufacturing cost of the product is increased, and the unreacted antioxidants bloom on the surface of the product. It will cause a problem. In addition, the antioxidant in the present invention has a structure of pentaerythrithol tetrakis- (3-dodecylthiopropionate), the melting point of 120 ℃ or more, the product has a whiteness of 95% or more Preference is given to using.

The inorganic filler used in the soft portion of the present invention is used to lower the role of the filler and the unit cost of the material, and is contained in an amount of 20 to 25 parts by weight. If the content is less than 20 parts by weight, the material cost rises and the role as a filler is insignificant, and if it exceeds 25 parts by weight it is difficult to extrude due to the rise in hardness and material flow problems. As the inorganic filler used in the present invention, it is preferable to use a product having a particle size of 10 μm or less and a whiteness of 95% or more, and especially calcium carbonate.

The other additive used for the soft part of this invention is contained in the quantity of 0.3-0.5 weight part. In addition, the other additives, but it is preferable to use a polypropylene wax to improve the surface slip properties and increase the wear resistance of the weather strip product, but is not limited thereto. In particular, the polypropylene wax has a specific gravity of 0.90 or less, and a melting point of 160 ° C. or more is preferable.

The thermoplastic elastomer composition according to the present invention is prepared for automotive weather strips, in particular for automotive body seal weather strips, and automotive weather strips using the composition of the present invention are injection molding, extrusion molding, etc. Without particular limitation, the molding method may be selected and manufactured, and preferably, an extrusion molding method may be used. Conventional automotive weatherstrip is made of ethylene propylene diene monomer (EPDM) rubber, so it is generally manufactured by extrusion molding. However, when the product is manufactured using ethylene propylene diene monomer (EPDM) rubber, there is a problem that a vulcanization process is necessary to secure the physical properties of the product, such as elasticity, and work efficiency decreases due to long vulcanization time during extrusion. In addition, it is impossible to recycle the molding defects generated during the manufacture of the product, and also has the disadvantage of relatively low heat resistance and low temperature embrittlement.

On the other hand, since the weather strip of the present invention is manufactured using TPV, a separate compounding and vulcanization process is not required, and the product can be produced directly at an extrusion facility, so that the process can be shortened, thereby improving work efficiency and reducing costs, and handling. It is easy to use, and recycling of defective molding can provide environmental protection and cost savings. In particular, the soft TPV material has an excellent wear resistance of 10-20% compared to the ethylene propylene diene monomer (EPDM) sponge.

In addition, thermoplastic elastomers generally have a lower specific gravity than rubber. In the case of ethylene propylene diene monomer (EPDM) rubber material, the specific gravity is generally 1 or more, while in the case of thermoplastic elastomer material, it has a specific gravity between 0.95 and 0.96. It is lightening effect of about%. In addition, the physical properties of the product can be improved, thereby improving strength, durability, and the like.

REFERENCE EXAMPLE 1 Preparation of Examples 1-2 and Comparative Examples 1-3

To the compositions of Tables 1 and 2 and Comparative Examples 1 to 3 of the composition of the body seal weatherstrip (hard body seal weatherstrip) for the hard part was prepared.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 EPDM 70 80 100 80 80 Polypropylene 60 40 50 50 50 High Viscosity Paraffin Oil 100 60 50 80 80 Peroxide crosslinking agent 0.6 0.8 1.0 0.8 0.9 Antioxidant 0.3 0.4 0.6 0.4 0.5 Inorganic filler 25 20 25 20 20 Other additives 0.4 0.4 0.3 0.4 0.4

The composition was prepared by an extrusion molding method according to a general manufacturing method known in the art, and the following materials were used to prepare the composition.

-EPDM: Ethylene Propylene Diene Monomer, KHP KEP-2480, 125 ℃ Moony Viscosity 80

-Polypropylene: SMT BP2000, Melt Index 0.5g / min (230 ℃, 2.16kg) Density 0.91g / ㎠

-Paraffinic oil: SJC KL1100, density 0.84g / ㎠, kinematic viscosity (40 ℃) 200.9

-Peroxide Crosslinker: Atochem Luperox 101-50D, Purity 50%, Specific Gravity 1.08

-Antioxidant: Songwon Industry S1010, Molecular Weight 1,100, Melting Point 110 ℃ or higher

-Inorganic filler: OMY calcium carbonate, density 2.5g / ㎠, whiteness 95% or more

-Polypropylene Wax: Lion Chemtech 500 Series, Density 0.89g / ㎠

[Test Example 1] Evaluation of product properties, ozone resistance and durability of Examples 1 to 2 and Comparative Examples 1 to 3

The basic physical properties, heat resistance, oil resistance, ozone resistance, extrusion moldability and durability of the body seal weatherstrip hard parts of Examples 1 to 2 and Comparative Examples 1 to 3 prepared in the Reference Examples were evaluated.

Specifically, the heat resistance physical properties were measured after elapse of 70 hours at 120 ℃. In addition, ozone resistance was confirmed for the presence of external cracks after 100 hours at 50pphm, 40 ℃ ozone concentration. The results were evaluated as very good (◎), good (○), normal (△), and poor (×). In addition, the durability evaluation confirmed the presence of product rupture after a 1,000 times wear evaluation of the finished product. The oil resistance evaluation method is ASTM NO. The volume change was measured after immersion at 120 ° C. and 70 hours in 3 OIL.

The evaluation results are shown in Table 2 below.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Basic properties Shore A 73 71 78 70 72 Tensile Strength (kgf / ㎠) 78 69 65 75 78 Elongation at Break (%) 470 410 410 430 410 Tear strength (kgf / cm) 32 29 34 29 28 Heat resistance Hardness change rate (%) +3 +2 +2 +1 +1 Tensile Strength Change Rate (%) -11 -8 -5 -6 -5 Elongation rate of change (%) -15 -9 -8 -10 -9 Oil resistance (% volume change) +2 +7 +3 +3 +3 Ozone resistance ○ × ○ ◎ ◎ Extrusion moldability ○ × × ◎ △ Durability rating NG NG NG OK OK

As can be seen in Table 2, Examples 1 to 2 according to the present invention can be confirmed in particular excellent in ozone resistance, extrusion moldability, and excellent durability.

Reference Example 2 Preparation of Examples 3 to 4 and Comparative Examples 4 to 6

The composition of Examples 3 to 4 and Comparative Examples 4 to 6 of the body seal weatherstrip soft part for automobiles was prepared using the composition of Table 3 below.

division Comparative Example 4 Comparative Example 5 Comparative Example 6 Example 3 Example 4 EPDM 70 80 100 80 80 Polypropylene 40 20 30 30 30 SEBS 180 170 190 190 200 High Viscosity Paraffin Oil 170 130 120 150 140 Peroxide crosslinking agent 0.5 0.7 0.9 0.7 0.8 Antioxidant 0.6 0.7 0.9 0.7 0.8 Inorganic filler 25 20 25 20 20 Other additives 0.4 0.4 0.5 0.4 0.4

The composition was prepared by an extrusion molding method according to a general manufacturing method known in the art, and the following materials were used to prepare the composition.

-EPDM: Ethylene Propylene Diene Monomer, KHP KEP-2480, 125 ℃ Moony Viscosity 80

-Polypropylene: SMT BP2000, Melt Index 0.5g / min (230 ℃, 2.16kg) Density 0.91g / ㎠

-SEBS: Styrene Ethylene Butadiene Styrene Copolymer, KS 35HF, Melt Index 6g / min (230 ℃, 2.16kg), Density 0.98g / ㎠

-Paraffinic oil: SJC KL1100, density 0.84g / ㎠, kinematic viscosity (40 ℃) 200.9

-Peroxide Crosslinker: Atochem Luperox 101-50D, Purity 50%, Specific Gravity 1.08

-Antioxidant: Songwon Industry S1010, Molecular Weight 1,100, Melting Point 110 ℃ or higher

-Inorganic filler: OMY calcium carbonate, density 2.5g / ㎠, whiteness 95% or more

-Polypropylene Wax: Lion Chemtech 500 Series, Density 0.89g / ㎠, Softening Point 161 ~ 163 ℃

[Test Example 2] Evaluation of product properties, ozone resistance and durability of Examples 3 to 4 and Comparative Examples 4 to 6

Evaluation of basic physical properties, heat resistance, compressive permanent shrinkage, ozone resistance, extrusion moldability and durability of the body seal weatherstrip soft parts of Examples 3 to 4 and Comparative Examples 4 to 6 prepared in the above reference example It was.

Specifically, the heat resistance physical properties were measured after elapse of 70 hours at 120 ℃. In addition, ozone resistance was confirmed for the presence of external cracks after 100 hours at 50pphm, 40 ℃ ozone concentration. The results were evaluated as very good (◎), good (○), normal (△), and poor (×). In addition, the durability evaluation confirmed the presence of product rupture after 3,000 times the wear evaluation of the finished product. The compressive permanent shrinkage was measured for restoring force after 168 hours at 70 ℃. The evaluation results are shown in Table 4 below.

division Comparative Example 4 Comparative Example 5 Comparative Example 6 Example 3 Example 4 Basic properties Shore A 41 39 43 38 39 Tensile Strength (kgf / ㎠) 44 36 32 40 42 Elongation at Break (%) 510 480 470 490 470 Tear strength (kgf / cm) 12 11 13 11 10 Heat resistance Hardness change rate (%) +4 +3 +4 +3 +3 Tensile Strength Change Rate (%) -19 -21 -19 -17 -18 Elongation rate of change (%) -15 -9 -8 -22 -9 Compressed permanent reduction rate (%) 29 26 31 25 26 Ozone resistance × ○ × ◎ ◎ Extrusion moldability × × ○ ◎ ○ Durability rating NG NG NG OK OK

As can be seen in Table 4, Examples 3 to 4 in accordance with the present invention can be confirmed in particular excellent in ozone resistance, extrusion moldability, and excellent durability.

2: body flange
11: retainer
12: seal
13: grip lip
14: sealing lip
15: metal reinforcement
16: foam rubber adhesive layer
17: Thermoplastic Elastomer (TPE) Sheet
100: weather strip
D: exterior decoration

Claims (11)

In the automotive weather strip composition comprising a hard portion and a soft portion,
The hard part 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 40 to 60 parts by weight of polypropylene, 70 to 90 parts by weight of high viscosity paraffin oil, 0.7 to 0.9 parts by weight of peroxide crosslinking agent, 0.3 to 0.5 parts by weight of antioxidant, It is a thermoplastic elastomer composition containing 20 to 25 parts by weight of the inorganic filler and 0.3 to 0.5 parts by weight of other additives,
The soft part 80 to 90 parts by weight of ethylene propylene diene monomer (EPDM), 20 to 40 parts by weight of polypropylene, 180 to 200 parts by weight of styrene ethylene butadiene styrene copolymer (SEBS), 140 to 160 parts by weight of high viscosity paraffin oil, peroxide The automotive weatherstrip composition which is a thermoplastic elastomer composition containing 0.6-0.9 weight part of crosslinking agents, 0.5-0.8 weight part of antioxidants, 20-25 weight part of inorganic fillers, and 0.3-0.5 weight part of other additives. The method of claim 1, wherein the ethylene propylene diene monomer (EPDM) has a pattern viscosity of 80 or more at 125 ℃, the content of 5-ethylidene-2-norbornene (ENB) is 8 Automotive weather strip composition, characterized in that more than%. The weather strip composition of claim 1, wherein the polypropylene is a high crystalline block copolymer having a melt flow index of 0.5 or less at 230 ° C. and 2.16 kg. The weather strip composition of claim 1, wherein the high viscosity paraffin oil has a Kinematic Viscosity range of 170 or higher. The weather strip composition of claim 1, wherein the peroxide crosslinking agent has a half-life temperature of 170 ° C. and a molecular weight of 290 or more. The weather strip composition of claim 1, wherein the antioxidant has a melting point of 120 ° C. or more and a whiteness of 95% or more. The weather strip composition of claim 1, wherein the inorganic filler has a particle size of 10 μm or less and a whiteness of 95% or more. 8. The weatherstrip composition for automobiles according to claim 7, wherein the inorganic filler is calcium carbonate. The weather strip composition of claim 1, wherein the other additive is a polypropylene wax. 10. The weather strip composition for automobile according to claim 9, wherein the polypropylene wax has a middle weight of 0.90 or less and a melting point of 160 ° C or more. A weather strip for automobiles prepared from the composition of any one of claims 1 to 10.

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