CN118878956A - Wear-resistant self-lubricating thermoplastic elastomer in automobile sealing strip and its processing method - Google Patents

Abstract

The invention discloses a wear-resistant self-lubricating thermoplastic elastomer in an automobile sealing strip and a processing method thereof, and specifically relates to the technical field of thermoplastic elastomer sealing materials. The thermoplastic elastomer is composed of hydrogenated nitrile rubber (HNBR), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), POE elastomer, nano-scale filler, plasticizer, cross-linking agent, and auxiliary agent; the mass percentages of the thermoplastic elastomer are: hydrogenated nitrile rubber (HNBR) 20-35%, polycarbonate (PC) 5-15%, acrylonitrile-butadiene-styrene copolymer (ABS) 5-15%, POE elastomer 2-10%, nano-scale filler 1-5%, plasticizer 0.1-10%, cross-linking agent 0.1-5%, and auxiliary agent 1-5%. The invention has the advantages of high temperature resistance, aging resistance, environmental protection and wear resistance, and improves the service life of the thermoplastic elastomer.

Description

Wear-resistant self-lubricating thermoplastic elastomer in automobile sealing strip and its processing method

Technical Field

The invention relates to the technical field of thermoplastic elastomer sealing materials, and more specifically to a wear-resistant self-lubricating joint thermoplastic elastomer in automobile sealing strips and a processing method thereof.

Background Art

Automobile sealing strips are widely used in doors, windows, car bodies, sunroofs and other parts. They play important roles such as waterproofing, sealing, sound insulation, dustproofing, shock absorption and energy saving. In recent years, the country has attached great importance to the management of automobile lightweight, low VOC, energy conservation and emission reduction, noise reduction, etc. Traditional sealing strip production mainly uses soft PVC and EPDM (EPDM) raw materials. Although the sealing strips made of EPDM synthetic rubber have good extrusion process performance, strong anti-weathering and aging performance, and excellent comprehensive performance, a large amount of powder, vulcanizer and vulcanizing auxiliaries need to be added during the production process. There are problems such as cumbersome process, pollution, and non-recyclability. They need to be processed by rubber refining and vulcanization, with high energy consumption, non-recyclability and high VOC. TPV sealing strips are modified by blending EPDM and PP plastics, which can be quickly extruded and molded without vulcanization. They have excellent ozone resistance and weathering resistance, but poor elasticity, contain VOC, and ultra-low temperature performance are affected to a certain extent. TPEE sealing strips contain block copolymers of polyester hard segments and polyether soft segments. Compared with rubber, they have better processing performance and longer service life, and compared with engineering materials, they have high strength, flexibility and dynamic mechanical properties.

At present, the domestic automotive sealing strip materials basically use ethylene propylene diene monomer rubber (EPDM) and thermoplastic elastomer (TPV). The corner joints of the sealing strips can only be guaranteed by injection molding with the same material. Thermoplastic elastomer (TPV) sealing strips and their thermoplastic elastomer (TPV) corner materials have been widely used, which are easy to process, environmentally friendly and cost-saving.

However, the service life of existing thermoplastic elastomers is still not high. Therefore, in order to further improve the high temperature resistance, aging resistance, environmental protection and wear resistance of thermoplastic elastomers, a wear-resistant self-lubricating joint thermoplastic elastomer in an automobile sealing strip and a processing method thereof are proposed.

Summary of the invention

In order to overcome the above defects of the prior art, the present invention provides a wear-resistant self-lubricating thermoplastic elastomer for automobile sealing strips and a processing method thereof to solve the problems raised in the above background technology.

To achieve the above object, the present invention provides the following technical solution: a wear-resistant self-lubricating joint thermoplastic elastomer in an automobile sealing strip, which is composed of hydrogenated nitrile rubber (HNBR), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), POE elastomer, nano-scale filler, plasticizer, cross-linking agent, and additives;

The mass percentages of the thermoplastic elastomer are: hydrogenated nitrile rubber (HNBR) 20-35%, polycarbonate (PC) 5-15%, acrylonitrile-butadiene-styrene copolymer (ABS) 5-15%, POE elastomer 2-10%, nano-scale filler 1-5%, plasticizer 0.1-10%, cross-linking agent 0.1-5%, and auxiliary agent 1-5%.

Preferably, the hydrogenated nitrile rubber (HNBR) is made of rubber particles or rubber blocks containing 50-65% of hydrogenated nitrile rubber body, 25-35% of carbon black, 1-3% of vulcanizer and 1-2% of plasticizer in a mass ratio.

Preferably, the polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS) form a PC/ABS alloy powder, and its melt index is 33-85 g/min.

Preferably, the melt index of the POE elastomer is 10-80 g/10 min.

Preferably, the nanoscale filler is one or more of nano-silicon dioxide and nano-calcium carbonate.

Preferably, the plasticizer is epoxidized soybean oil.

Preferably, the crosslinking agent is one of organic dicumyl peroxide (DCP), tert-butyl cumyl peroxide, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, and dibenzoyl peroxide.

Preferably, the auxiliary agent is an ultra-high molecular weight polysiloxane, a compatibilizer, an antioxidant, an ultraviolet light blocking agent or the like.

A thermoplastic elastomer processing method comprises the following steps:

S1: adding chemically modified nitrile rubber (HNBR), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), POE elastomer, nano-scale filler, plasticizer, cross-linking agent and additives into a high-speed kneading machine according to the mass ratio, and kneading for 3-8 minutes to obtain a mixture A;

S2: Add mixed material A into the hopper of the twin-screw extruder, heat the main machine, and the main machine heating zone is 10 sections. Add plasticizer in the fourth to sixth heating zones at a ratio of 0 to 100% to fully melt, disperse, mix and extrude the mixed material. The time to obtain melt A is 4-5 minutes;

S3: The extruded melt A is formed into a wire bundle through a die, and then water-cooled and granulated. The water temperature is controlled below 70 °C.

S4: Dehydrating and separating the output water and particles through a vibrating screen to obtain a semi-finished product;

S5: Add the semi-finished product into a high-speed kneading machine, add a cross-linking agent and knead for 4-6 minutes to obtain a pre-cross-linked masterbatch;

S6: Add the additives according to the mass fraction into a high-speed kneader and knead for 2-5 minutes to obtain a mixture B;

S7: Add the mixed material B into the hopper of the twin-screw extruder, heat the main machine, and the main machine heating zone is 10 sections. In the fourth and sixth zones, add the pre-crosslinked masterbatch from the side feed in proportion, so that the pre-crosslinked masterbatch and the mixed particle B are fully melted, sheared, dispersed, and dynamically vulcanized and extruded to obtain the melt A. The time is: 4-5 minutes;

S8: The extruded melt B is formed into a strand through a die, and water-cooled and granulated, with the water temperature being controlled below 70°C.

S9: Finally, the output water and particles are dehydrated, separated, dried and packaged through a vibrating screen to obtain the finished product.

The wear-resistant self-lubricating thermoplastic elastomer in the automobile sealing strip and the processing method thereof provided by the present invention have the following beneficial effects: by adopting hydrogenated nitrile rubber, compared with the traditionally used EPDM rubber, it has higher high temperature resistance and aging resistance, thereby being able to improve the high temperature resistance and aging resistance of the thermoplastic elastomer;

The PC/ABS alloy powder is composed of polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS), which can improve the hot melt index, so that the fluidity is higher during the processing, so that the various components can be mixed more evenly, thereby improving the stable rigidity and processing performance;

Using epoxidized soybean oil as a plasticizer not only has the advantages of high efficiency, but also can reduce environmental pollution and improve environmental protection;

And by adding a small amount of nano-silicon dioxide and nano-calcium carbonate, the mechanical properties and wear resistance of thermoplastic elastomers can be improved;

In summary, it can be seen that the thermoplastic elastomer of the present invention has the advantages of high temperature resistance, aging resistance, environmental protection and wear resistance, and improves the service life of the thermoplastic elastomer.

DETAILED DESCRIPTION

Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

The wear-resistant self-lubricating thermoplastic elastomer for automobile sealing strip and its processing method are prepared by hydrogenated nitrile rubber (HNBR), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), POE elastomer, nano-scale filler, plasticizer, cross-linking agent and auxiliary agent.

The mass percentages of the thermoplastic elastomer are: hydrogenated nitrile rubber (HNBR) 20-35%, polycarbonate (PC) 5-15%, acrylonitrile-butadiene-styrene copolymer (ABS) 5-15%, POE elastomer 2-10%, nano-scale filler 1-5%, plasticizer 0.1-10%, cross-linking agent 0.1-5%, and auxiliary agent 1-5%.

The hydrogenated nitrile rubber (HNBR) is made of rubber particles or rubber blocks containing 50-65% of hydrogenated nitrile rubber body, 25-35% of carbon black, 1-3% of vulcanizer and 1-2% of plasticizer in a mass ratio.

In specific implementation, by adding carbon black to hydrogenated nitrile rubber, the hardness and wear resistance can be improved, and by inducing a cross-linking reaction between rubber molecular chains through a vulcanizer, combined with an appropriate amount of plasticizer, the softness and hardness of the final hydrogenated nitrile rubber can be adjusted, thereby complying with the selection of thermoplastic elastomer materials and improving the high temperature resistance and aging resistance of the thermoplastic elastomer.

The polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS) form PC/ABS alloy powder, and its melt index is 33-85g/min, so as to improve the melt index, thereby improving the fluidity and processing performance, thereby improving the processing efficiency and the uniformity of the combination between the materials.

The melt index of the POE elastomer is 10-80 g/10 min.

The nano-scale filler is one or more of nano-silicon dioxide and nano-calcium carbonate, so as to improve the mechanical properties and wear resistance of the elastomer.

The plasticizer is epoxidized soybean oil. Using epoxidized soybean oil as a plasticizer can firstly meet environmental protection requirements and be compatible with the polymer substrate. At the same time, it also has a certain cold resistance, so that the elastomer can be well used in a low temperature environment. It also has good thermal stability and light stability, and is not easy to decompose and discolor, thereby increasing the service life of the elastomer.

The crosslinking agent is one of organic diisopropylbenzene peroxide (DCP), tert-butyl cumene peroxide, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane and dibenzoyl peroxide.

The auxiliary agents are ultra-high molecular weight polysiloxane, compatibilizer, antioxidant, UV protection agent and other auxiliary agents.

A thermoplastic elastomer processing method comprises the following steps:

S1: Add 20-35% of hydrogenated nitrile rubber (HNBR), 5-15% of polycarbonate (PC), 5-15% of acrylonitrile-butadiene-styrene copolymer (ABS), 2-10% of POE elastomer, 1-5% of nano-scale filler, 0.1-10% of plasticizer, 0.1-5% of cross-linking agent and 1-5% of auxiliary agent into a high-speed kneader according to mass ratio, and knead for 3-8 minutes to obtain a mixture A;

Specifically, 35% of hydrogenated nitrile rubber (HNBR) consisting of 60% hydrogenated nitrile rubber body, 35% carbon black, 3% vulcanizer and 2% plasticizer can be selected;

30% PC/ABS alloy powder composed of 60% polycarbonate (PC) and 40% acrylonitrile-butadiene-styrene copolymer (ABS) by mass ratio;

POE elastomer 10%;

Nano silicon dioxide and nano calcium carbonate 5%;

Epoxidized soybean oil 10%;

Dicumyl peroxide (DCP) 5%;

5% of a mixed additive consisting of 25% ultra-high molecular weight polysiloxane, 25% of a compatibilizer, 25% of an antioxidant, and 25% of an anti-ultraviolet agent;

S2: Add mixed material A into the hopper of the twin-screw extruder, heat the main machine, and the heating temperature is 200-1800℃. The main machine heating zone is 10 sections. Add plasticizer in the fourth to sixth heating zones at a ratio of 0-100% to fully melt, disperse, mix and extrude the mixed material. The time to obtain melt A is 4-5 minutes;

S3: The extruded melt A is formed into a wire bundle through a die, and then water-cooled and granulated. The water temperature is controlled below 70 °C.

S4: Dehydrating and separating the output water and particles through a vibrating screen to obtain a semi-finished product;

S5: Add the semi-finished product into a high-speed kneading machine, add a cross-linking agent and knead for 4-6 minutes to obtain a pre-cross-linked masterbatch;

S6: Add the additives according to the mass fraction into a high-speed kneader and knead for 2-5 minutes to obtain a mixture B;

S7: Add the mixed material B into the hopper of the twin-screw extruder, heat the main machine, and the main machine heating zone is 10 sections. In the fourth and sixth zones, add the pre-crosslinked masterbatch from the side feed in proportion, so that the pre-crosslinked masterbatch and the mixed particle B are fully melted, sheared, dispersed, and dynamically vulcanized and extruded to obtain the melt A. The time is: 4-5 minutes;

S8: The extruded melt B is formed into a wire bundle through a die, and water-cooled and granulated, and the water temperature is controlled below 70°C;

S9: Finally, the output water and particles are dehydrated, separated, dried and packaged through a vibrating screen to obtain the finished product.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. The wear-resistant self-lubricating corner thermoplastic elastomer in the automobile sealing strip is characterized by being formed by combining Hydrogenated Nitrile Butadiene Rubber (HNBR), polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), POE elastomer, nanoscale filler, plasticizer, cross-linking agent and auxiliary agent;

The thermoplastic elastomer comprises the following components in percentage by mass: 20-35% of Hydrogenated Nitrile Butadiene Rubber (HNBR), 5-15% of Polycarbonate (PC), 5-15% of acrylonitrile-butadiene-styrene copolymer (ABS), 2-10% of POE elastomer, 1-5% of nano filler, 0.1-10% of plasticizer, 0.1-5% of cross-linking agent and 1-5% of auxiliary agent.

2. The wear-resistant self-lubricating joint thermoplastic elastomer in an automobile sealing strip according to claim 1, wherein the hydrogenated nitrile rubber (HNBR) is selected from rubber particles or block rubber comprising 50-65% of hydrogenated nitrile rubber body, 25-35% of carbon black, 1-3% of vulcanizing agent and 1-2% of plasticizer according to mass ratio.

3. The wear resistant, self-lubricating, corner thermoplastic elastomer in automotive weatherstrip according to claim 2, characterized in that the Polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS) constitute PC/ABS alloy powder with a melt index of 33-85g/min.

4. The wear resistant, self-lubricating, corner thermoplastic elastomer in automotive weatherstrip according to claim 3, characterized in that the POE elastomer has a melt index of 10-80g/10min.

5. The wear resistant self-lubricating joint thermoplastic elastomer in automotive weatherstrip according to claim 4, wherein said nanoscale filler is one or more of nanosilicon dioxide and nanosilicon calcium carbonate.

6. The wear-resistant self-lubricating corner thermoplastic elastomer in an automobile sealing strip and the processing method thereof according to claim 5, wherein the plasticizer is epoxidized soybean oil.

7. The wear resistant self-lubricating corner thermoplastic elastomer in automotive weatherstrip according to claim 6, wherein the cross-linking agent is one of organic dicumyl peroxide (DCP), t-butylcumyl peroxide, 2, 5-bis (t-butylperoxy) -2, 5-dimethylhexane, dibenzoyl peroxide.

8. The wear-resistant self-lubricating corner thermoplastic elastomer in the automobile sealing strip according to claim 7, wherein the auxiliary agents are auxiliary agents such as ultra-high molecular weight polysiloxane, compatilizer, antioxidant and ultraviolet inhibitor.

9. A method for processing the wear-resistant self-lubricating joint thermoplastic elastomer in the automobile sealing strip according to claim 8, which is characterized by comprising the following steps:

S1: adding the butadiene-acrylonitrile rubber (HNBR), the Polycarbonate (PC), the acrylonitrile-butadiene-styrene copolymer (ABS), the POE elastomer, the nanoscale filler, the plasticizer, the cross-linking agent and the auxiliary agent into a high-speed kneader according to mass ratio, and kneading for 3-8 minutes to obtain a mixture A;

s2: adding the mixture A into a hopper of a double-screw extruder, heating by a host machine, wherein the heating area of the host machine is 10 sections, adding plasticizer into the fourth-sixth heating area according to the proportion of 0-100%, fully melting, dispersing and mixing the mixture A for extrusion, and obtaining the solution A with the time of: 4-5 minutes;

s3: the extruded melt A is formed into a wire bundle through a die, water cooling and granulation are carried out, and the water temperature is controlled below 70 ℃;

S4: dewatering and separating the output water and particles through a vibrating screen to obtain a semi-finished product;

S5: adding the semi-finished product into a high-speed kneader, adding a cross-linking agent, and kneading for the following time: 4-6 minutes to obtain pre-crosslinked master batch;

s6: adding the auxiliary agent into a high-speed kneader according to mass fraction, and kneading for the following time: 2-5 minutes to obtain a mixture B;

S7: adding the mixture B into a hopper of a double-screw extruder, heating by a host machine, wherein the heating area of the host machine is 10 sections, adding the pre-crosslinked master batch into the mixture B from side feeding in a fourth zone and a sixth zone according to a proportion, and fully melting, shearing, dispersing and dynamically vulcanizing the pre-crosslinked master batch and the mixture B for reaction extrusion to obtain a solution A, wherein the time is as follows: 4-5 minutes;

s8: forming the extruded solution B into a wire bundle through a die, performing water cooling and granulation, and controlling the water temperature below 70 ℃;

s9: finally, the output water and particles are dehydrated, separated, dried and packaged by a vibrating screen to obtain the finished product.