WO2024075857A1 - Epdm rubber composition with surface embossing effect on glass run corner molding using uhmwpp and glass run product for vehicle using same - Google Patents

Abstract

The present embodiments relate to an EPDM rubber composition using UHMWPP and having a surface embossing effect on a glass run corner molding, and a glass run product for a vehicle, using same. Specifically, the EPDM rubber composition using UHMWPP and having a surface embossing effect on a glass run corner molding, according to an embodiment, comprises ethylene propylene diene monomer (EPDM), a reinforcing agent, a softener, a high-functional olefinic resin, a vulcanization activator, a processing aid, an anti-foaming agent, a vulcanizing agent, and a vulcanization accelerator, and the high-functional olefinic resin may have a weight average molecular weight (Mw) in the range of 500,000-2,500,000 as measured by gel permeation chromatography (GPC).

Description

EPDM rubber composition with surface embossing effect on glass run corner molding using UHMWPP and glass run products for automobiles using the same

These examples relate to an EPDM rubber composition that has an embossing effect on the surface of a glass run corner molded part using UHMWPP, and more specifically, is used in a corner molded part of a glass run channel product, which is a sealing part for automobiles. It relates to a rubber composition.

The Glass Run Channel is mounted on the edge of the window of a car door and serves as a guide (prevention of separation) when raising/lowering the window and blocks wind, rainwater, noise, and dust that may enter the interior from the outside. It is a sealing part that blocks. Therefore, considering the installation location of the product, it is a part that must satisfy the characteristics of the exterior material and the interior material at the same time because it is installed on the borderline between the automobile interior and exterior materials.

Recently, there is a trend to require emotional quality even in functional parts, and uniqueness, which is an emotional requirement for interior materials, is also required as an important exterior quality for glass run products.

In particular, the glass run product includes an extruded rubber profile formed by an extrusion method and a corner molding part where the extruded cross section is molded to fit the corner of the car window. At this time, a unique feeling is created due to the difference in the molding method. do.

However, this unique color reduces the appearance quality and aesthetics of the product, causing a significant decrease in marketability.

In this embodiment, in order to improve the appearance quality of the corner molding part of the glass run channel (hereinafter referred to as glass run) product, which is an automobile part, UHMWPP was used to minimize the discoloration of the extruded cross section and corner molding part constituting the glass run part. The purpose of this study is to provide an EPDM rubber composition that has an embossing effect on the surface of a glass run corner molding area and a glass run product for automobiles using the same.

An EPDM rubber composition having an effect of embossing the surface of a glass run corner molded part using UHMWPP according to an embodiment includes ethylene propylene diene monomer (EPDM), reinforcing agent, softener, high-performance olefin resin, vulcanization activator, anti-foaming agent, vulcanizing agent, and a vulcanization accelerator, and the high-functional olefin resin may have a weight average molecular weight (Mw) in the range of 500,000 to 2,500,000, as measured by gel permeation chromatography (GPC).

The high-functional olefin resin may have a melting point in the range of 110°C to 200°C, as measured by differential scanning calorimetry (DSC).

The high-functional olefin resin may have a melt index (MI) of 0.05 to 20 g/10 min as measured by ASTM D1238.

The high-performance olefin-based resin may include ultra high molecular weight polypropylene (UHMWPP).

The content of the high-functional olepine resin may range from 6 parts by weight to 24 parts by weight based on the weight parts of the ethylene propylene diene monomer (EPDM).

The ethylene propylene diene monomer (EPDM) may have a pattern viscosity (ML1+4, 125°C) of 60 mu or less.

The ethylene propylene diene monomer (EPDM) may have an ethylidene norbornene (ENB) content of 7% by weight or more and an ethylene (Ethylene) content of 60.0% by weight or less.

The rubber composition includes 75 to 100 parts by weight of the reinforcing agent, 35 to 45 parts by weight of the softener, and 5 to 10 parts by weight of the vulcanization activator, based on 100 parts by weight of the ethylene propylene diene monomer (EPDM). It may include 2 to 5 parts by weight of the processing aid, 3 to 5 parts by weight of the anti-foaming agent, 1 to 2 parts by weight of the vulcanizing agent, and 2 to 5 parts by weight of the vulcanization accelerator.

The reinforcing agent may include at least one of carbon black and silica.

The reinforcing agent may have an average particle diameter ranging from 40 to 48 nm.

The vulcanization activator may include zinc oxide and stearic acid.

The vulcanizing aid may include polyethylene glycol (PEG#4000: molecular weight 4,000) and a metal salt.

The vulcanization accelerator is at least one of 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc di-n-butyl dithiocarbamate (ZnBDC), tetramethylthiuram disulfide (TMTD), and N-cyclohexyl-2-benzothiazyl sulfonamide (CBS). may include.

A glass run product for automobiles according to another embodiment may be manufactured using an EPDM rubber composition that has an embossing effect on the surface of the glass run corner molded part using the UHMWPP.

The surface roughness of the corner molded portion of the glass run product may be 1.0 Ra or more.

An EPDM rubber composition that has a surface embossing effect on glass run corner molding parts using UHMWPP according to one embodiment is used in corner joints of glass run products. Specifically, by being used for the joint of an extruded rubber profil and an extruded cross section, the product's marketability can be significantly improved by minimizing the discoloration of the appearance of products with differences in molding methods.

Currently, the corner molding parts of glass run products are generally manufactured using the surface corrosion method of a transfer mold. However, this surface corrosion method has the problem of deteriorating the exterior quality of the product due to wear of the corroded surface and adsorption of rubber oil vapor on the surface during the product manufacturing process.

However, when manufacturing glass run products for automobiles using an EPDM rubber composition with a surface embossing effect on the glass run corner molding area using UHMWPP of this example, it is possible to improve the appearance quality of the product and at the same time ensure uniformity of quality. You can.

Figure 1 is a schematic diagram of an apparatus for illustrating a transfer type molding method.

Figure 2 shows a surface photograph of a specimen manufactured using the rubber composition prepared according to Example 1 and Comparative Examples 1 to 2.

Figure 3 shows the equipment used to measure surface roughness in this example.

Figures 4a and 4b show poor dispersion of the rubber composition of Reference Example 2.

Figure 5 shows surface photographs of specimens manufactured using the rubber compositions prepared according to Reference Example 1, Example 2, and Example 3.

Figure 6a shows a sample using the existing glass run corner joint rubber.

Figure 6b shows a sample using the glass run corner joint rubber prepared using the rubber composition prepared according to Example 3.

Terms such as first, second, and third are used to describe, but are not limited to, various parts, components, regions, layers, and/or sections. These terms are used only to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first part, component, region, layer or section described below may be referred to as the second part, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is only intended to refer to specific embodiments and is not intended to limit the invention. As used herein, singular forms include plural forms unless phrases clearly indicate the contrary. As used in the specification, the meaning of "comprising" refers to specifying a particular characteristic, area, integer, step, operation, element and/or ingredient, and the presence or presence of another characteristic, area, integer, step, operation, element and/or ingredient. This does not exclude addition.

When a part is referred to as being “on” or “on” another part, it may be directly on or on the other part or may be accompanied by another part in between. In contrast, when a part is said to be "directly on top" of another part, there is no intervening part between them.

Although not defined differently, all terms including technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

An EPDM rubber composition having an effect of embossing the surface of a glass run corner molded part using UHMWPP according to an embodiment includes ethylene propylene diene monomer (EPDM), reinforcing agent, softener, high-performance olefin resin, vulcanization activator, anti-foaming agent, vulcanizing agent, and a vulcanization accelerator.

Hereinafter, each component constituting the EPDM rubber composition that has the effect of embossing the surface of the glass run corner molded part using UHMWPP according to the present invention will be described in more detail.

(One) Highly functional olefin resin

In the EPDM rubber composition that has the effect of embossing the surface of the glass run corner molded part using UHMWPP according to this embodiment, the high-functional olefin resin is used to ensure the surface corrosion effect.

Specifically, the high-functional olefin resin may have a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) in the range of 500,000 to 2,500,000, more specifically, in the range of 2,500,000. If the weight average molecular weight of the high-functional olefin resin satisfies the above range, a glass run product with excellent tensile strength and wear resistance can be produced.

In addition, the high-functional olefin resin may have a melting point measured by differential scanning calorimetry (DSC) in the range of 110°C to 200°C, more specifically 130°C to 180°C or 150°C to 175°C. .

The high-functional olefin resin may have a melt index (MI; melt index) of 0.05 to 20 g/10 min, more specifically 0.05 to 5 g/10 min, or 0.5 to 5 g/10 min, as measured by ASTM D1238. there is.

If the melting point and melt index satisfy the above range, a glass run product with excellent tensile strength and wear resistance can be produced. In addition, it is very advantageous to ensure an embossing effect in glass run products to which the rubber composition of this example is applied. In this way, if the embossing effect, that is, the surface roughness above a certain level is secured, the discoloration of the extruded cross-section and corner molding part of the glass run product can be minimized.

In this embodiment, the high-functional olefin resin may include, for example, ultra high molecular weight polypropylene (UHMWPP).

In addition, the content of the high-functional olefin resin may range from 6 parts by weight to 24 parts by weight, more specifically, from 10 parts by weight to 20 parts by weight, based on the weight parts of the ethylene propylene diene monomer (EPDM). If the content of the high-functional olefin-based resin is less than 6 parts by weight, there is a problem of insufficient embossing effect, and if the content of the high-functional olefin-based resin exceeds 24 parts by weight, dispersion failure may occur during the kneading process for manufacturing the high-performance composition. .

When manufacturing rubber compositions, LDPE is sometimes used to reinforce rigidity. This is to incorporate the high hardness and physical properties of poly-olefin elastomer (POE: Poly Olefin Elastomer) into rubber compounding.

However, in general, when high hardness rubber of EPDM compound, that is, product physical properties of Shore 85A or higher in hardness are required, there is a problem in that it is very difficult to secure the physical properties using EPDM and carbon black.

In particular, when hardness is increased by increasing the amount of carbon black, the mooney viscosity of EPDM increases, so processability and formability may be significantly reduced.

In this example, instead of using POE for the effect of reinforcing rigidity, a POE product with a high molecular weight was used. This improves the self-shape retention capacity of POE resin with high molecular weight during the rubber molding process. This is to secure the embossing (surface unevenness) effect. For this purpose, the above-mentioned high molecular weight and high MP (Melting Point) products are essential.

Unlike general-purpose polypropylene (PP: Poly Propylene), UHMWPP material is difficult to process using the existing P.P polymer material processing method due to maximization of molecular weight and high viscosity, so a new method is needed in rubber compounding. .

In other words, due to the M.P. characteristics due to the high molecular weight, the above-mentioned LDPE achieves plasticization through sufficient softening in the rubber mixture, but UHMWPP exists in a state in which the shape of UHMWPP itself is maintained in the rubber mixture.

This UHMWPP maintains its particle shape at high molding temperatures and can maintain its shape even after vulcanization of the corner molding part of the glass run product, thereby producing a surface embossing effect.

(2) Ethylene propylene diene monomer (EPDM)

Glass run is a type of sealing part for automobiles and requires weather ability. Therefore, in order to secure high weather resistance performance, EPDM, which has excellent weather resistance performance among synthetic rubbers, is used, and this is a common issue among not only domestic but also global weather strip manufacturers.

EPDM was also used as the base polymer in the present invention.

Generally, the corner molding part of glass run products is done by transfer molding, and transfer molding requires excellent flow of rubber. Therefore, products with relatively low pattern viscosity are preferred.

Among the structural factors of EPDM, various characteristics appear depending on Mooney Viscosity, ENB content, and ethylene/propylene content ratio (EP Ratio).

The ethylene propylene diene monomer (EPDM) used in this example preferably has a fringe viscosity (ML1+4, 125°C) of 60 mu or less, more specifically 20 mu or more and 30 mu or less. If the pattern viscosity of EPDM satisfies the above range, a low pattern viscosity of the EPDM rubber composition with an embossing effect on the surface of the glass run corner molded part using UHMWPP according to an embodiment can be secured, and thus excellent rubber flow is achieved. ), the molding workability of glass run products is excellent, which can improve productivity and ensure uniform product quality.

In addition, ENB, 1, 4-Hexadiene, and DCPD (Dicyclopentadiene) are used as third components of EPDM. In this example, EPDM containing ethylidene norbornene (ENB) was used. This is advantageous not only in terms of crosslinking properties, but also in securing productivity and high product properties due to fast crosslinking performance.

Specifically, in this embodiment, the ethylene propylene diene monomer (EPDM) has an ethylidene norbornene (ENB) content of 7% by weight or more, more specifically 7.5 to 9.0% by weight, based on the EPDM. It is desirable. When the ENB content included in EPDM satisfies the above range, the vulcanization reaction is activated and the productivity of glass run products can be improved.

In addition, the ethylene propylene diene monomer (EPDM) preferably has an ethylene content of 60.0% by weight or less, more specifically 55 to 60% by weight, based on EPDM. When the ethylene content included in EPDM satisfies the above range, crystallinity is excellent, so when a product is manufactured using the rubber composition of this example, automobile assembly workability is excellent.

(3) Reinforcement agent

In this embodiment, the reinforcing agent may include at least one of carbon black and silica.

Among these, the carbon black is classified into N100 to N900 according to ASTM standards according to particle size. However, N200 ~ N300 products with small particle sizes are generally used for tire products that require high durability, and N700 ~ N900 products are generally used for products that require high dynamic characteristics.

In this embodiment, it is preferable to use N550, that is, FEF (Fast Extrusion Furnace) carbon black, as the reinforcing agent. This is because the reinforcing agent is advantageous in terms of securing flowability in the molding process and securing the rigidity of the glass run product.

Additionally, the reinforcing agent may be included in the range of 75 parts by weight to 100 parts by weight based on 100 parts by weight of ethylene propylene diene monomer (EPDM). If the content of reinforcing agent is less than 75 parts by weight, mechanical properties may be significantly reduced.

In addition, when the reinforcing agent content exceeds 100 parts by weight, transfer molding becomes difficult because high hardness and flowability in the extrusion process are reduced.

(4) Softener

Although glass run products are functional parts, they also require high emotional quality, that is, appearance quality. Therefore, since the softener used in this embodiment may cause emotional quality issues such as discoloration and discoloration, paraffin oil, for example, rubber compounding oil (process oil), which is relatively excellent in discoloration, discoloration, and heat aging, can be used.

In this embodiment, the softener may be included in the range of 35 parts by weight to 45 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM).

If the content of the softener is less than 35 parts by weight, dispersibility and processability are poor when manufacturing the rubber composition, and hardness increases, making molding difficult.

In addition, if the softener content exceeds 45 parts by weight, dispersibility is poor, and physical properties are reduced due to a decrease in hardness, which may lead to a decrease in sealing performance.

In addition, calcium carbonate can be used as needed to improve appearance quality and secure cost competitiveness, and can be used in the range of 0 to 20 parts by weight based on 100 parts by weight of ethylene propylene diene monomer (EPDM). If the content of calcium carbonate exceeds 20 parts by weight, poor dispersion and deterioration of physical properties may occur.

However, calcium carbonate was not used in this example.

(5) Vulcanization activators and processing aids

Vulcanization activator is a rubber raw material to improve the acceleration ability of vulcanization accelerator.

In this example, zinc oxide (ZnO: ZinC Oxide), a metal oxide, and stearic acid (fatty acid) are used as vulcanization activators.

Processing aids are added in a small amount to the rubber mixture to improve processability such as mixing and dispersion of rubber raw materials, and polyethylene glycol (PEG#4000: molecular weight 4,000) and metal salt are added to ensure smooth molding process through lubricating effect. ) is used.

The vulcanization activator may include 5 to 10 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM).

The steel processing aid may include 2 to 5 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM).

If the content of the vulcanization activator and processing aid exceeds the above range, unreacted fatty acid salts may migrate to the surface, causing a whitening phenomenon (also called blooming) that may deteriorate the appearance quality. This is a fatal quality deterioration factor in glass run products that require excellent exterior quality.

(6) Anti-foaming agent

Moisture that may exist inside the rubber is evaporated during the molding process, forming pores inside. Pores formed inside the product may affect the outside in the form of protrusions, and durability may be reduced in some cases. CaO is used as an anti-foaming agent to remove moisture in advance, which is the cause of pore formation. In particular, it must be used in the extrusion process.

H ₂ O + CaO → Ca(OH) ₂

Moisture and calcium oxide react to produce calcium hydroxide, which has the same effect as the inorganic filler dispersed inside the rubber, so it can suppress the creation of pores.

The anti-foaming agent may be used in an amount of 3 to 5 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM).

(7) Vulcanizing agent

In general, the crosslinking method for the rubber composition includes, for example, sulfur crosslinking, peroxide crosslinking, and resin crosslinking, but in this embodiment, it can be manufactured by the sulfur crosslinking method.

Sulfur crosslinks are formed when sulfur is combined in the double bond structure of the base polymer, and sulfur must be used to provide elasticity to the rubber compound.

At this time, the vulcanizing agent used, sulfur, has a cyclic S8 molecular structure, and at 159°C, the cyclic structure is converted into a chain structure, thereby activating the vulcanization reaction in which the viscous force of the rubber is converted to elastic force.

Additionally, when sulfur is added to rubber and heat is applied, individual polymer chains are formed into a three-dimensional network through a chemical reaction caused by sulfur, which is called vulcanization. At this time, using a vulcanization accelerator can increase the vulcanization speed and enable efficient vulcanization at a relatively low temperature.

The vulcanizing agent may be included in an amount of 1 to 2 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM). When the content of the vulcanizing agent satisfies the above range, vulcanization can be performed efficiently.

(8) Vulcanization accelerator

A vulcanization accelerator may be used to accelerate the vulcanization reaction.

The vulcanization accelerator is at least one of 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc di-n-butyl dithiocarbamate (ZnBDC), tetramethylthiuram disulfide (TMTD), and N-cyclohexyl-2-benzothiazyl sulfonamide (CBS). may include.

The MBT (2-mercaptobenzothiazole) is generally less prone to contamination, exhibits smooth vulcanization, and has excellent aging resistance and physical properties. Facilitative ability has quasi-facilitative ability.

MBTS (dibenzothiazyl disulfide) has similar performance to MBS, but has a tendency to slow the initial vulcanization speed, making it advantageous for securing molding operation stability.

In addition, ZnBDC (zinc di-n-butyl dithiocarbamate) has a very strong stimulating ability and affects the activation of MBT/MBTS. It is known to have very little or no contamination.

TMTD (tetramethylthiuram disulfide) is called a super accelerator because it has a very strong vulcanization accelerator, is non-contaminating, and can secure high tensile strength and modulus.

CBS (N-cyclohexyl-2-benzothiazyl sulfonamide) is a sustained-acting accelerator, which is advantageous in securing the initial flowability of transfer molding by slowing down the initial vulcanization speed.

The vulcanization accelerator may include 2 to 5 parts by weight based on 100 parts by weight of the ethylene propylene diene monomer (EPDM).

That is, in this embodiment, the EPDM rubber composition that has an effect of embossing the surface of the glass run corner molded part using UHMWPP contains 75 to 100 parts by weight of the reinforcing agent and the softener, based on 100 parts by weight of the ethylene propylene diene monomer (EPDM). 35 to 45 parts by weight, 5 to 10 parts by weight of the vulcanization activator, 2 to 5 parts by weight of the processing aid, 3 to 5 parts by weight of the anti-foaming agent, 1 to 2 parts by weight of the vulcanizing agent. parts, and may include 2 to 5 parts by weight of the vulcanization accelerator.

The EPDM rubber composition, which has an embossing effect on the surface of a glass run corner molded part using UHMWPP according to an embodiment, can secure excellent tensile strength and abrasion resistance because it contains the above-mentioned high-performance olefin resin. In addition, an embossing effect can be implemented on glass run products, thereby ensuring excellent exterior quality and uniformity of exterior quality by minimizing discoloration between the extruded cross section and corner molding section.

According to another embodiment, a glass run product for automobiles manufactured using an EPDM rubber composition having a surface embossing effect on a glass run corner molded portion using the above-described UHMWPP can be provided.

It is preferable that the surface roughness of the corner molded part of the glass run product is 1.0Ra or more. If the surface roughness is 1.0 Ra or more, the discoloration of the extruded cross section can be minimized, and excellent external quality of the product can be secured.

At this time, corner molding of glass run products is generally produced by transfer molding.

Transfer molding is a compression mold that is applied when it is difficult to manufacture with an injection mold. Rubber is injected into the pot at the top of the upper mold and the glass run corners are formed with the force of closing the upper and lower molds.

In general, it is often applied when dimensional precision is required for small products.

This method is widely used because it is suitable for glass run corner molding, which is an automobile part where dimensional stability is most important. Therefore, it is most important that the weight of the input rubber is kept constant. If the weight of the rubber is large, the weight overflows from inside the molding space to the outside, causing the contact area with the extruded surface to be pushed, and if the input weight is small, the weight overflows from inside the molding space to the outside. , short shots occur.

Figure 1 is a schematic diagram of an apparatus for illustrating a transfer type molding method. The transfer molding method is the most commonly used method for manufacturing glass run corner molding parts, and almost all glass runs are manufactured using the transfer molding method.

Referring to Figure 1, a certain weight of rubber is injected into a hole at the top of the mold called a POT, and as the prize mold mounted on the press descends, the injection rod is pressed into the hole, and the injected rubber is released into the glass run space. Molding takes place by injecting it into the body.

The mold temperature is set in the range of 180-200°C, and the vulcanization time is maintained at around 2 minutes (120 seconds) to 3 minutes (180 seconds) depending on the vulcanization characteristics of the rubber material in the injected state.

Depending on the size of the molded part, a vulcanization time of 4 to 5 minutes may be necessary.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

Experimental Example 1

Rubber compositions according to Examples 1 to 2 and Comparative Examples 1 to 2 were prepared by mixing at the composition ratio shown in Table 1 below.

Specifically, the kneading process for each rubber composition was performed in a Banbury Mixer for CMB rubber and in a Kneader for FMB rubber.

In addition, the EPDM polymer used to manufacture CMB was KEP-330 (Kumho Polychem), and the carbon black was HS-45 from Orion Engineering Carbons. Additionally, ZnO (Zinc Oxide), Stearic Acid, and ZnO were used as vulcanization activators and processing aids. PEG#4000 (Poly Ethylene Glycol MW 4000) was used. Specific information on the EPDM polymer used in this example is shown in Table 2 below.

The softener used was a paraffin-based rubber compounding oil.

Since the moisture content inside the rubber is a factor that can form pores inside the molded product, to prevent this, CaO (Calcium Oxide) was added to remove moisture in advance as shown below.

CaO (calcium oxide) + H ₂ O (moisture) → Ca(OH) ₂

Additionally, a processing aid (process acid) was used to ensure the stability of the glass run corner molding. The processing aid is a blend of fatty acid derivatives (Mainly zinc soaps), and is used because it is efficient in filling every corner of the molded part with high flowability when the rubber composition is filled into the mold.

division			Example 1	Comparative Example 1	Comparative Example 2	Comparative Example 3
CMB	polymer	EPDM	100	100	100	100
	adjuvant	Carbon Black	85	90	85	85
	softener	Process Oil	40	40	40	40
	High functionality Olefin type profit		LDPE			10
		UHMWPE				10
		UHMWPP	10
	vulcanization activator & processing aids	Zinc Oxide	8	8	8	8
		Stearic Acid	1.5	1.5	1.5	1.5
		PEG#4000	2	2	2	2
		Process Aid	2	2	2	2
	anti-foam agent	Calcium Oxide	5	5	5	5
	CMB Subtotal		253.5	248.5	253.5	253.5
FMB	vulcanizing agent	Sulfur	1.5	1.5	1.5	1.5
	Vulcanization accelerator	Accelerator MBT	0.7	0.7	0.7	0.7
		Accelerator MBTS	0.3	0.3	0.3	0.3
		Accelerator ZnBDC	One	One	One	One
		Accelerator TMTD	0.5	0.5	0.5	0.5
		AcceleratorCBS	1.2	1.2	1.2	1.2
	Total (CMB + FMB)		258.7	253.7	258.7	258.7

division	KEP-330
Mooney Viscosity (ML1+4,125℃)	28mu
Ethylene Cont.(%)	57%
3rd Monomer type &Cont.(%)	ENB (7.9%)

In Table 1 above, the chemical names and chemical formulas of the vulcanization accelerator are as follows.

MBT: 2-Mercaptobenzothiazole (C ₇ H ₅ NS ₂ )

MBTS: Mercaptobenzothiazole disulfide (C ₁₄ H ₈ N ₂ S ₄ )

ZnBDC: Zinc dibutyl dithiocarbamate ([(C ₄ H ₉ ) ₂ NCS ₂ ] ₂ Zn)

TMTD: Tetramethyl thiuram disulfide ([(CH ₃ ) ₂ NCS ₂ -] ₂ )

CBS: N-cyclohexyl-2-benzothiazylesulfenamide (C ₁₃ H ₁₆ N ₂ S ₂ )

The manufacturing process of the EPDM rubber composition with the surface embossing effect of the glass run corner molding part using UHMWPP in this embodiment can be largely divided into CMB (Carbon Master Batch) and FMB (Final Master Batch) processes.

The manufacturing process of CMB rubber is a process in which the pulverized base polymer and raw materials are mixed by adding reinforcing agents, softeners, high-functional olefin resins, vulcanizing activators, processing aids, and anti-foaming agents after first pulverizing the base polymer. am.

CMB rubber produced through this process is a material that does not undergo a vulcanization reaction even when heat is applied, so it cannot be molded into a product and can be stored for a long time. Optionally, CMB rubber can be subjected to a process called aging for a certain period of time to stabilize the base polymer against the high mechanical stress experienced during the manufacturing process.

Next, the FMB process is a process of mixing CMB rubber with a fixed amount of vulcanizing agent (sulfur) and vulcanization accelerator. These raw materials must be mixed to create a finished rubber composition.

In Experimental Example 1, the physical properties of each rubber composition for Examples 1 to 2 and Comparative Examples 1 to 2 are shown in Tables 3 and 4 below.

division			Example 1	Comparative Example 1	Comparative Example 2	Comparative Example 3
Basic properties of unvulcanized rubber	scorch (Scorch at 125℃)	VMs	25.5	21.5	21.2	23.6
		T5	9'41	11'16	10'09	10'23
	rheometer (180℃×6 minutes)	Tmax	40.5	37.4	36.9	38.5
		Tmin	4.9	4.5	4.4	4.7
		ts1	0'46	0'48	0'46	0'47
		ts5	0'59	1'04	1'00	1'03
		T10	0'56	0'58	0'56	0'59
		T90	3'03	3'33	3'38	3'28

division				Example 1	Comparative Example 1	Comparative Example 2	Comparative Example 3
vulcanized rubber basic properties	Basic physical properties	Hardness	KS M 6518	72	70	69	71
		tensile strength		149.3	127.3	124.2	131.8
		elongation rate		265.5	287.6	302.3	299.3
	Aging properties (70℃×72Hrs)	Hardness change		+1	+1	+1	+1
		Tensile strength change		0	+2	0	+1
		Elongation rate change		-2	-5	-4	-3
	Compression permanent shrinkage rate (%) (70℃×22Hrs)	C/Set	JIS K 6301	10.5	13.7	12.1	12.3
	NBS wear performance	Wear index	KS M 6625	128	109	115	127

The rubber composition according to this example was designed with a focus on hardness (Shore) 70A, which is a general required property for glass run corner molded parts.

Referring to Tables 3 and 4, the rubber composition according to Example 1 has tensile strength and abrasion resistance compared to the rubber composition prepared according to Comparative Example 1 in which high-performance olefin resin was not used and Comparative Example 2 in which LDPE resin was used. You can confirm this excellence.

Table 5 and Figure 2 show surface roughness measurement results and surface photographs of specimens manufactured using the rubber compositions prepared according to Example 1 and Comparative Examples 1 to 3. That is, the surface embossing effect of the rubber compositions according to Example 1 and Comparative Examples 1 to 2 was compared and evaluated by measuring surface roughness.

division	Example 1	Comparative Example 1	Comparative Example 2	Comparative Example 3
surface roughness	1.109 Ra	0.045Ra	0.037Ra	0.529 R

Figure 3 shows the equipment used to measure surface roughness in this example. Specifically, the tip of the illuminance needle, indicated by a yellow circle in Figure 3, moves to measure surface roughness.

Referring to Table 5 and Figure 2, in Example 1, the surface embossing effect could be confirmed with the naked eye. In the case of Comparative Example 2 using LDPE resin, a POE product, it can be confirmed that the surface roughness is lower than in the case of Comparative Example 1 without adding POE. It is believed that sufficient melting occurred during the specimen molding process, and this plasticization resulted in relatively good surface smoothness and low surface roughness.

In addition, in the case of Comparative Example 3 using a UHMWPE product with a similar molecular weight as UHMWPP, it has a relatively low molecular weight and melting point compared to UHMWPP, so a slight melting phenomenon occurs at a high molding temperature and does not form surface roughness. It is judged as not possible.

Typically, when the surface roughness of the corner molding part of a glass run product is 1.0 Ra or more, the discoloration with the extruded cross section can be minimized.

Experimental Example 2

Rubber compositions were prepared according to Examples 2 to 3 and Reference Examples 1 to 2 for each high-functional olefin resin (UHMWPP) content by mixing at the composition ratio shown in Table 6 below.

Specifically, in Experimental Example 2, the rubber kneading method was the same as that in Experimental Example 1. That is, CMB rubber was kneaded in a Banbury Mixer, and FMB rubber was kneaded in a Kneader.

The raw materials used were the same as those in Experimental Example 1. EPDM polymer was KEP-330 (Kumho Polychem), and carbon black was Orion Engineering Carbons' HS-45.

Additionally, ZnO (Zinc Oxide), Stearic Acid, and PEG#4000 (Poly Ethylene Glycol MW 4000) were used as vulcanization activators and processing aids.

The softener used was a paraffin-based rubber compounding oil.

division			Reference example 1	Example 2	Example 3	Reference example 2
CMB	polymer	EPDM	100	100	100	100
	adjuvant	Carbon Black	85	85	80	80
	softener	Process Oil	40	40	40	40
	High functionality Olefin type profit	UHMWPP	5	10	20	25
	Vulcanizing activator & Processing aid	Zinc Oxide	8	8	8	8
		Stearic Acid	1.5	1.5	1.5	1.5
		PEG#4000	2	2	2	2
		Process Aid	2	2	2	2
	anti-foam agent	Calcium Oxide	5	5	5	5
	CMB Subtotal		248.5	253.5	258.5	263.5
FMB	vulcanizing agent	Sulfur	1.5	1.5	1.5	1.5
	Vulcanization accelerator	Accelerator MBT	0.7	0.7	0.7	0.7
		Accelerator MBTS	0.3	0.3	0.3	0.3
		Accelerator ZnBDC	One	One	One	One
		Accelerator TMTD	0.5	0.5	0.5	0.5
		AcceleratorCBS	1.2	1.2	1.2	1.2
	Total (CMB + FMB)		253.7	258.7	263.7	268.7

In Experimental Example 2, the physical properties of each rubber composition for Examples 2 to 3 and Reference Examples 1 to 2 are shown in Tables 7 and 8 below.

division			Reference example 1	Example 2	Example 3
Unvulcanized rubber Basic physical properties	scorch (Scorch at 125℃)	VMs	24.3	25.5	26.8
		T5	10’03	9'41	9’12
	rheometer (180℃×6 minutes)	Tmax	39.2	40.5	41.8
		Tmin	4.7	4.9	4.8
		ts1	0’47	0'46	0’45
		ts5	1’03	0'59	0’57
		T10	0’57	0'56	0’55
		T90	3’28	3'03	2’57

division				Reference example 1	Example 2	Example 3
vulcanized rubber basic properties	Basic physical properties	Hardness	KS M 6518	71	72	73
		tensile strength		131.3	149.3	135.6
		elongation rate		273.2	265.5	255.1
	Aging properties (70℃×72Hrs)	Hardness change		+1	+1	+1
		Tensile strength change		+1	0	+1
		Elongation rate change		-3	-2	-2
	Compression permanent shrinkage rate (%) (70℃×22Hrs)	C/Set	JIS K 6301	13.3	10.5	13.1

In Table 8, the physical properties of each rubber composition for Reference Example 2 could not be measured due to UHMWPP dispersibility problems.

Specifically, in Reference Example 2, in which 25 parts by weight of high-functional olefin resin was added based on 100 parts by weight of polymer, the CMB rubber was found to be very dry.

Figures 4a and 4b show the poor dispersion state of the rubber composition of Reference Example 2. UHMWPP particles were visually confirmed on the surface (Figure 4a). In severe cases, white UHMWPP particles separated and fell off (Figure 4b). This is believed to be a phenomenon that occurs because excessively added UHMWPP was not sufficiently dispersed in the rubber compound.

Table 9 and Figure 5 show surface roughness measurement results and surface photos of specimens manufactured using the rubber compositions prepared according to Reference Example 1, Example 2, and Example 3.

division	Reference example 1	Example 2	Example 3
surface roughness	0.125Ra	1.109 Ra	1.313Ra

Referring to Table 9 and Figure 5, Reference Example 1, in which 5 parts by weight of UHMWPP was added based on 100 parts by weight of polymer, showed a surface embossing effect, but the embossing effect was significantly low. This is because UHMWPP was not sufficient to form surface roughness.

On the other hand, in Examples 2 and 3, in which 10 parts by weight and 20 parts by weight of UHMWPP were added, respectively, based on 100 parts by weight of polymer, the surface roughness was measured in the range of 1.1 Ra to 1.4 Ra. In addition, referring to Figure 5, it can be seen that the surface of the specimens of Examples 2 and 3 showed a greater embossing effect compared to Reference Example 1.

As a result, it can be confirmed that in order to implement the embossing effect to reduce the discoloration of the glass run joint molded part, it is appropriate to include the high-performance olefin resin in the range of 10 to 20 parts by weight based on 100 parts by weight of EPDM.

Figure 6a is a sample using the glass run corner joint rubber manufactured using the rubber composition prepared according to Comparative Example 1 of Experimental Example 1, and Figure 6b is a glass run manufactured using the rubber composition prepared according to Example 2. This shows a sample using corner joint rubber.

Referring to Figures 6a and 6b, it can be seen that when using the rubber composition prepared according to Example 2, a glass run product with excellent surface quality without heterochromatic feeling can be implemented.

The present invention is not limited to the above-mentioned embodiments, but can be manufactured in various different forms, and those skilled in the art will be able to form other specific forms without changing the technical idea or essential features of the present invention. You will be able to understand that this can be implemented. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

Claims (15)

1. Contains ethylene propylene diene monomer (EPDM), reinforcing agent, softener, high-functional olefin resin, vulcanization activator, processing aid, anti-foaming agent, vulcanizing agent, and vulcanization accelerator,

   The high-functional olefin resin is an EPDM rubber composition that has a surface embossing effect on the glass run corner molding part using UHMWPP, which has a weight average molecular weight (Mw) in the range of 500,000 to 2,500,000 as measured by gel permeation chromatography (GPC).
2. According to paragraph 1,

   The high-functional olefin resin is an EPDM rubber composition that has a surface embossing effect on the glass run corner molding part using UHMWPP, which has a melting point in the range of 110 ℃ to 200 ℃ as measured by differential scanning calorimetry (DSC).
3. According to paragraph 1,

   The high-functional olefin resin is an EPDM rubber composition that has a surface embossing effect on the glass run corner molded part using UHMWPP, which has a melt index (MI) of 0.05 to 20 g/10 min as measured by ASTM D1238.
4. According to paragraph 1,

   The high-functional olefin resin is an EPDM rubber composition that has an embossing effect on the surface of the glass run corner molding area using UHMWPP, which includes ultra high molecular weight polypropylene (UHMWPP).
5. According to paragraph 1,

   The content of the high-functional olefin resin is,

   An EPDM rubber composition having an embossing effect on the surface of a glass run corner molded part using 6 to 24 parts by weight of UHMWPP based on the ethylene propylene diene monomer (EPDM).
6. According to paragraph 1,

   The ethylene propylene diene monomer (EPDM) is an EPDM rubber composition that has a surface embossing effect on the glass run corner molded part using UHMWPP with a pattern viscosity (ML1+4, 125°C) of 60mu or less.
7. According to paragraph 1,

   The ethylene propylene diene monomer (EPDM) has an ethylidene norbornene (ENB) content of 7% by weight or more and has an ethylene (Ethylene) content of 60.0% by weight or less. The surface embossing effect of the glass run corner molding part using UHMWPP is achieved. EPDM rubber composition.
8. According to paragraph 1,

   Based on 100 parts by weight of the ethylene propylene diene monomer (EPDM),

   75 to 100 parts by weight of the reinforcing agent,

   35 to 45 parts by weight of the softener,

   5 to 10 parts by weight of the vulcanization activator,

   2 to 5 parts by weight of the processing aid,

   3 to 5 parts by weight of the anti-foaming agent,

   1 to 2 parts by weight of the vulcanizing agent, and

   An EPDM rubber composition having a surface embossing effect on a glass run corner molded part using UHMWPP containing 2 to 5 parts by weight of the vulcanization accelerator.
9. According to paragraph 1,

   An EPDM rubber composition having a surface embossing effect on a glass run corner molded part using UHMWPP, wherein the reinforcing agent includes at least one of carbon black and silica.
10. According to paragraph 1,

    The reinforcing agent is an EPDM rubber composition that has an embossing effect on the surface of the glass run corner molded part using UHMWPP with an average particle diameter in the range of 40 to 48 nm.
11. According to paragraph 1,

    An EPDM rubber composition having a surface embossing effect on a glass run corner molded part using UHMWPP, wherein the vulcanization activator includes zinc oxide and stearic acid.
12. According to paragraph 1,

    An EPDM rubber composition having a surface embossing effect on a glass run corner molded part using UHMWPP, wherein the vulcanizing aid contains polyethylene glycol (PEG#4000: molecular weight 4,000) and a metal salt.
13. According to paragraph 1,

    The vulcanization accelerator is at least one of 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc di-n-butyl dithiocarbamate (ZnBDC), tetramethylthiuram disulfide (TMTD), and N-cyclohexyl-2-benzothiazyl sulfonamide (CBS). EPDM rubber composition with surface embossing effect on glass run corner molding using UHMWPP containing.
14. A glass run product for automobiles manufactured using an EPDM rubber composition having a surface embossing effect on a glass run corner molded part using UHMWPP according to any one of claims 1 to 13.
15. According to clause 14,

    A glass run product for automobiles in which the surface roughness of the corner molded portion of the glass run product is 1.0 Ra or more.

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