An automobile weather strip corner connecting material, an automobile weather strip assembly and a preparation method

Abstract

The application relates to the technical field of rubber products, and particularly discloses a car sealing strip joint material, a car sealing strip assembly and a preparation method. The car sealing strip joint material provided by the application uses specific low-mooney EPDM (ethylene propylene diene monomer) and high-ENB high-resistance EPDM in combination, uses high-resistance carbon black BC1004 as a reinforcing material, uses liquid EPDM Trilene 67 as a plasticizer, uses nano reinforcing agent PF81S as a filler, and adds modified lignin to improve the bonding effect of the joint material, so that the prepared sealing strip joint material has the performance requirements of high resistance, vulcanization process, hardness, strength and the like, no paraffin oil is added in the whole system, the processing process performance of the joint material is ensured, the rapid vulcanization of the joint material and stable production are facilitated, in addition, the whole system does not contain nitrosamine substances, is more environmentally friendly, and has a high application prospect in the field of car sealing strip joint materials.

Description

Technical Field

[0001] This invention relates to the field of rubber products technology, and in particular to an automotive sealing strip corner material, an automotive sealing strip assembly, and a preparation method thereof. Background Technology

[0002] Automotive window sealing strips are key components that ensure accurate positioning of the car door and glass, and guide the window's movement. They provide waterproofing, dustproofing, and airtight sealing. Installed in the car door rails, the window sealing strip works in conjunction with the glass to create a seal when the car door is closed. It also reduces glass vibration during driving, thus improving the user experience.

[0003] Due to the structural differences in various parts of the automotive body sheet metal, the cross-sectional materials of automotive sealing strips vary, especially in the moving and fixed parts of automotive doors and windows, as well as corners, bends, and straight sections. To achieve the desired assembly effect, corner materials with different cross-sectional grooves are bonded together through heat vulcanization to form a complete sealing strip, ensuring airtightness. The corner material for groove sealing strips is generally ethylene propylene diene monomer (EPDM) rubber. EPDM rubber's non-polar characteristics give it good electrical insulation. However, to ensure the strength and other properties of the corner material, a large amount of carbon black is usually added to the formulation. Carbon black can form conductive channels in the corner adhesive, severely affecting the electrical insulation of the corner material and failing to meet the requirements for high-resistance groove corner products. Reducing the amount of carbon black results in insufficient strength, vulcanization performance, and corner processability. Therefore, developing a high-resistance sealing strip corner material that can be rapidly vulcanized and has high strength is of great significance for improving the structural stability and performance quality of sealing strips. Summary of the Invention

[0004] To address the problem that existing corner materials for grooved sealing strips cannot simultaneously meet the requirements of high resistance, vulcanization processability, and strength performance, this invention provides a corner material for automotive sealing strips, an automotive sealing strip assembly, and a preparation method thereof.

[0005] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] A corner joint material for automotive sealing strips comprises the following components in parts by weight: 35-45 parts of EPDM rubber K2470C, 50-60 parts of EPDM rubber 9097M, 10-20 parts of EPDM rubber K9720B, 2-4 parts of activator, 1.5-3.5 parts of flow aid, 1.5-2.5 parts of silane coupling agent, 8-12 parts of hydroxymethylated modified lignin, 40-60 parts of carbon black BC1004, 40-60 parts of EPDM rubber Trilene 67, 80-120 parts of nano-reinforcing agent PF81S, 1-2 parts of vulcanizing agent, 3.6-7.6 parts of environmentally friendly accelerator system, and 0.6-1.2 parts of accelerator XLA.

[0007] Compared to existing technologies, the automotive sealing strip corner material provided by this invention utilizes a combination of specific low Mooney EPDM rubber and high ENB high resistance EPDM rubber, along with high resistance carbon black BC1004 as a reinforcing material, liquid EPDM rubber Trilene 67 as a plasticizer, nano-reinforcing agent PF81S as a filler, and modified lignin to improve the bonding effect of the corner material. This results in a sealing strip corner material that meets the requirements for high resistance, vulcanization processability, hardness, and strength. Furthermore, the entire system does not contain paraffin oil, ensuring the processing performance of the corner material and facilitating rapid vulcanization and stable production. In addition, the overall system does not contain nitrosamines, making it more environmentally friendly and showing high application prospects in the field of automotive sealing strip corner materials.

[0008] The formulation mechanism of the automotive sealing strip corner material provided by this invention is as follows:

[0009] The poor insulation of current sealing strip corner materials is mainly due to the formation of conductive circuits by conductive materials such as carbon black within the system. The formation of a conductive circuit requires three factors: dispersion of the conductive material, the formation of a conductive pathway, and the formation of a continuous energy conduction pathway within the polymer. Therefore, reducing the interconnection of conductive materials within the polymer to prevent the formation of conductive pathways is key to improving the insulation of sealing strip corner materials.

[0010] I. Raw Rubber System: This invention uses a combination of low Mooney EPDM rubbers K2470C and K9720B with high ENB high resistance EPDM rubber 9097M. The low Mooney EPDM rubbers K2470C and K9720B ensure the low Mooney viscosity and processing performance of the compound, giving the corner joint material good flowability during the bonding process, and guaranteeing suitable hardness and high strength. The high ENB high resistance EPDM rubber 9097M increases the vulcanization speed of the corner joint material, ensuring the degree of crosslinking and meeting the requirements of rapid vulcanization bonding processes, thus improving the product's appearance. Furthermore, the high ENB high resistance EPDM rubber 9097M effectively improves the dispersion of carbon black in the system, coating the carbon black surface with EPDM rubber 9097M to form individually coated carbon black particles, preventing the carbon black from forming conductive pathways in the polymer, thereby effectively improving the insulation of the corner joint material.

[0011] II. Reinforcing System: In existing technologies, high-structure carbon black is generally chosen as the reinforcing material to reduce the viscosity of the adhesive and ensure good processing performance. This invention selects a specific high-resistivity carbon black, BC1004, as the reinforcing material. It features low surface area and medium structure, which can significantly improve the volume resistivity of the corner material and enhance the smoothness of the corner surface, thereby improving the product's appearance quality.

[0012] III. Plasticizing System: This invention selects a specific liquid ethylene propylene diene rubber, Trilene 67, as a plasticizer. It is a low molecular weight ethylene-propylene-conjugated diene terpolymer with an average molecular weight of about 7200 and an ENB content of 9.5%. Its low molecular weight and viscosity can significantly reduce the viscosity of the rubber compound, improve processing performance, and at the same time increase the degree of crosslinking, ensuring the vulcanization speed and the performance of the vulcanized rubber.

[0013] IV. Filler System: This invention uses PF81S, a special nano-reinforcing agent with dehydroxylated surface activation treatment, as a filler, which can effectively improve the strength of the corner joint material. At the same time, it has good dispersibility in the rubber system and can also improve the resilience of the corner joint material.

[0014] V. Vulcanization System: This invention adopts a nitrosamine-free vulcanization system. In particular, by adding the accelerator XLA, the vulcanization speed of the corner joint material can be effectively improved, enabling the corner joint material to meet the process requirements of rapid vulcanization, while ensuring the processing stability of the corner joint material.

[0015] VI. Other materials: This invention improves the bonding performance of corner joint materials by adding modified lignin to the system, thereby enhancing the structural stability of the finished sealing strip after corner jointing. Furthermore, the hydroxymethylated modified lignin has good compatibility with the rubber system in this invention and has no adverse effects on the insulation and strength of the corner joint materials.

[0016] Preferably, the environmentally friendly accelerator system comprises: 1-2 parts of accelerator MBT-75, 0.4-1.0 parts of accelerator CBS-80, 0.6-1.2 parts of accelerator TP-50, 0.6-1.2 parts of accelerator ZAT-70, 0.4-1.0 parts of accelerator TBzTD-70, and 0.6-1.2 parts of accelerator HSPD-50.

[0017] The preferred environmentally friendly accelerator system of this invention, combined with accelerator XLA, can effectively improve the vulcanization speed, enabling the corner material to meet the process requirements of rapid vulcanization. Furthermore, the accelerator does not contain nitrosamines, making it more environmentally friendly.

[0018] Preferably, the activator is zinc oxide.

[0019] Preferred activators can effectively improve the activity of accelerators and the vulcanization speed of rubber compounds.

[0020] Preferably, the vulcanizing agent is sulfur S-80.

[0021] Preferably, the flow aid comprises 1-2 parts stearic acid and 0.5-1.5 parts polyethylene glycol.

[0022] In this invention, stearic acid and polyethylene glycol are added as flow aids, which can effectively improve the dispersibility of the rubber compound during the mixing process and enhance the mixing uniformity of each component.

[0023] Preferably, the silane coupling agent is silane coupling agent Si-69.

[0024] The preferred silane coupling agent of this invention can effectively improve the dispersibility of the nano-reinforcing agent PF81S in rubber systems.

[0025] Preferably, the hydroxymethylated modified lignin is modified lignin LIN150 from Guangzhou Lingge Polymer Materials Co., Ltd.

[0026] The present invention also provides a method for preparing the above-mentioned automotive sealing strip corner material, which includes at least the following steps:

[0027] Step a: Weigh each component according to the design ratio, mix the weighed components other than the environmentally friendly accelerator system, accelerator XLA and vulcanizing agent evenly, and then perform intensive mixing, degassing, debinding, compounding, and sheeting to obtain the film.

[0028] Step b: Place the film for more than 12 hours, mix it with the weighed environmentally friendly accelerator system, accelerator XLA and vulcanizing agent, perform intensive mixing, discharge the glue, and thin out the sheet to obtain the automotive sealing strip corner material.

[0029] The above preparation method is simple to operate, has no complicated procedures, does not require special equipment, is low in cost, and is suitable for large-scale industrial production.

[0030] Preferably, in step a, other components besides the environmentally friendly accelerator system, accelerator XLA, and vulcanizing agent are added when the internal mixer temperature is 65-75℃.

[0031] Preferably, in step a, the exhaust temperature is 105-115℃, the glue discharge temperature is 140-150℃, and the mixing time is 240-250s.

[0032] Preferably, in step b, the glue discharge temperature is 75-85℃.

[0033] In another aspect, the present invention provides an automotive sealing strip assembly, comprising a sealing strip and the automotive sealing strip corner material described in any of the above claims, wherein the automotive sealing strip corner material is connected to the sealing strip.

[0034] Furthermore, in conjunction with the above, the present invention also provides an automobile, including the aforementioned automobile sealing strip assembly.

[0035] The automotive sealing strip corner material provided by this invention combines specific low Mooney EPDM rubber and high ENB high resistance EPDM rubber with high resistance carbon black BC1004, liquid EPDM rubber Trilene 67, nano-reinforcing agent PF81S, hydroxymethylated modified lignin, and accelerator XLA. This results in a sealing strip corner material that meets the requirements for high resistance, vulcanization processability, hardness, and strength. Furthermore, the entire system does not contain paraffin oil, ensuring the processing performance of the corner material and facilitating rapid vulcanization and stable production. In addition, the overall system is free of nitrosamines, making it more environmentally friendly and possessing high application value in the field of automotive sealing strip corner materials. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] In the following examples and comparative examples, the manufacturer of EPDM rubber K2470C is Arlan Newtech; the manufacturers of EPDM rubber 9097M and EPDM rubber K9720B are Mitsui Chemicals; the manufacturer of silane coupling agent Si-69 is Dongying Hengyi Chemical; the manufacturer of hydroxymethylated modified lignin LIN150 is Guangzhou Lingge Polymer Materials Co., Ltd.; the manufacturer of carbon black BC1004 is Bora Group (Shandong); the manufacturer of EPDM rubber Trilene 67 is Lion Chemicals (USA); the manufacturer of nano-reinforcing agent PF81S is Shanghai Xuanluo New Materials; the manufacturers of sulfur S-80, accelerator MBT-75, accelerator CBS-80, accelerator ZAT-70, accelerator TBzTD-70, and accelerator XLA are Rhein Chemicals; and the manufacturer of accelerator TP-50 is Ningbo Aikem New Materials.

[0038] Example 1

[0039] This embodiment provides a corner joint material for automotive sealing strips, comprising the following components in parts by weight: 40 parts of EPDM K2470C, 55 parts of EPDM 9097M, 15 parts of EPDM K9720B, 3 parts of zinc oxide, 1.5 parts of stearic acid, 1 part of polyethylene glycol, 2 parts of silane coupling agent Si-69, 10 parts of hydroxymethylated modified lignin LIN150, 50 parts of carbon black BC1004, 50 parts of EPDM Trilene 67, 100 parts of nano-reinforcing agent PF81S, 1.2 parts of sulfur S-80, 1.2 parts of accelerator MBT-75, 0.7 parts of accelerator CBS-80, 0.7 parts of accelerator TP-50, 0.8 parts of accelerator ZAT-70, 0.6 parts of accelerator TBzTD-70, and HSPD-50. 0.9 parts and 1 part of accelerator XLA.

[0040] The manufacturing process of the aforementioned automotive sealing strip corner material is as follows:

[0041] Step a: Weigh each component according to the design ratio. Put the weighed components other than the accelerator and vulcanizing agent into the internal mixer. The internal mixer temperature is 70℃. Mix the components, exhaust the air at 110℃, and discharge the rubber at 145℃. Then, use a fully automatic open mill to pound the rubber for 240 seconds before feeding it into the sheeting open mill. Sheet the rubber compound according to the specifications to obtain rubber sheets.

[0042] Step b: Place the film for more than 12 hours, add it together with the weighed accelerator and sulfur into a mixer, discharge the glue at 80°C, then pass it through a two-roll mill 1.5mm thin pass 3 times, 4mm tamping for 120s, and cut it into strips according to the size requirements to obtain the automotive sealing strip corner material.

[0043] The corner joining process can be completed by subsequent steps of precision cutting, mold insertion, glue injection, bonding, demolding, and trimming.

[0044] Example 2

[0045] This embodiment provides a corner material for automotive sealing strips, comprising the following components in parts by weight: 35 parts of EPDM K2470C, 60 parts of EPDM 9097M, 10 parts of EPDM K9720B, 4 parts of zinc oxide, 1 part of stearic acid, 0.5 parts of polyethylene glycol, 1.5 parts of silane coupling agent Si-69, 12 parts of hydroxymethylated modified lignin LIN150, 40 parts of carbon black BC1004, 60 parts of EPDM Trilene 67, 120 parts of nano-reinforcing agent PF81S, 1 part of sulfur S-80, 2 parts of accelerator MBT-75, 0.4 parts of accelerator CBS-80, 1.2 parts of accelerator TP-50, 0.6 parts of accelerator ZAT-70, 1.0 part of accelerator TBzTD-70, and HSPD-50. 0.6 parts and 1.2 parts of accelerator XLA.

[0046] The manufacturing process of the aforementioned automotive sealing strip corner material is as follows:

[0047] Step a: Weigh each component according to the design ratio. Put the weighed components other than the accelerator and vulcanizing agent into the internal mixer. The internal mixer temperature is 70℃. Mix the components, exhaust the air at 110℃, and discharge the rubber at 145℃. Then, use a fully automatic open mill to pound the rubber for 250 seconds before feeding it into the sheeting open mill. Sheet the rubber compound according to the specifications to obtain rubber sheets.

[0048] Step b: Place the film for more than 12 hours, add it together with the weighed accelerator and sulfur into a mixer, discharge the glue at 80°C, then pass it through a two-roll mill 1.5mm thin pass 3 times, 4mm tamping for 120s, and cut it into strips according to the size requirements to obtain the automotive sealing strip corner material.

[0049] Example 3

[0050] This embodiment provides a corner joint material for automotive sealing strips, comprising the following components in parts by weight: 45 parts of EPDM K2470C, 50 parts of EPDM 9097M, 20 parts of EPDM K9720B, 2 parts of zinc oxide, 2 parts of stearic acid, 1.5 parts of polyethylene glycol, 2.5 parts of silane coupling agent Si-69, 8 parts of hydroxymethylated modified lignin LIN150, 60 parts of carbon black BC1004, 40 parts of EPDM Trilene 67, 80 parts of nano-reinforcing agent PF81S, 2 parts of sulfur S-80, 1 part of accelerator MBT-75, 1 part of accelerator CBS-80, 0.6 parts of accelerator TP-50, 1.2 parts of accelerator ZAT-70, 0.4 parts of accelerator TBzTD-70, 1.2 parts of accelerator HSPD-50, and 1.2 parts of accelerator XLA. 0.6 copies.

[0051] The manufacturing process of the aforementioned automotive sealing strip corner material is as follows:

[0052] Step a: Weigh each component according to the design ratio. Put the weighed components other than the accelerator and vulcanizing agent into the internal mixer. The internal mixer temperature is 70℃. Mix the components, exhaust the air at 110℃, and discharge the rubber at 145℃. Then, use a fully automatic open mill to pound the rubber for 240 seconds before feeding it into the sheeting open mill. Sheet the rubber compound according to the specifications to obtain rubber sheets.

[0053] Step b: Place the film for more than 12 hours, add it together with the weighed accelerator and sulfur into a mixer, discharge the glue at 80°C, then pass it through a two-roll mill 1.5mm thin pass 3 times, 4mm tamping for 120s, and cut it into strips according to the size requirements to obtain the automotive sealing strip corner material.

[0054] Comparative Example 1

[0055] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that EPDM 9097M in Example 1 is replaced with 45 parts of EPDM 9090M, and all other parts are exactly the same.

[0056] Comparative Example 2

[0057] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that the carbon black BC1004 in Example 1 is replaced with an equal amount of carbon black N550. All other aspects are exactly the same.

[0058] Comparative Example 3

[0059] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that the liquid EPDM rubber Trilene 67 in Example 1 is replaced with an equal amount of paraffin oil 2158. All other aspects are exactly the same.

[0060] Comparative Example 4

[0061] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that the nano-reinforcing agent PF81S in Example 1 is replaced with an equal amount of talc powder, and all other aspects are exactly the same.

[0062] Comparative Example 5

[0063] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that the accelerator XLA in Example 1 is replaced with an equal amount of accelerator HSPD-50. All other aspects are exactly the same.

[0064] Comparative Example 6

[0065] This comparative example provides an automotive sealing strip corner material, whose formulation and preparation method are exactly the same as those in Example 1. The only difference is that the hydroxymethylated modified lignin LIN150 in Example 1 is omitted, and all other aspects are exactly the same.

[0066] The performance of the automotive sealing strip corner materials prepared in Example 1 and Comparative Examples 1-6 was tested, and the specific results are shown in Table 1.

[0067] Table 1

[0068]

[0069] Note: The test standard for Mooney viscosity is GB / T1232.1-2016 "Determination of Uncured Rubber by Disk Shear Viscometer - Part 1: Determination of Mooney Viscosity"; the test standard for hardness is GB / T531.1-2008 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber - Part 1: Shore Hardness Tester Method (Shore Hardness)"; the test standards for T10, T90, ML, and MH are GB / T9869-2014 "Determination of Vulcanization Characteristics of Rubber Compounds by Disk Oscillating Vulcanizer Method"; the test standard for tensile strength / elongation at break is GB / T528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber"; and the test standard for volume resistivity is GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials".

[0070] 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 or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A corner joint material for automotive sealing strips, characterized in that, It is composed of the following components in parts by weight: 35-45 parts of EPDM K2470C, 50-60 parts of EPDM 9097M, 10-20 parts of EPDM K9720B, 2-4 parts of activator, 1.5-3.5 parts of flow aid, 1.5-2.5 parts of silane coupling agent, 8-12 parts of hydroxymethylated modified lignin, 40-60 parts of carbon black BC1004, 40-60 parts of EPDM Trilene 67, 80-120 parts of nano-reinforcing agent PF81S, 1-2 parts of vulcanizing agent, 3.6-7.6 parts of environmentally friendly accelerator system and 0.6-1.2 parts of accelerator XLA; The environmentally friendly accelerator system consists of the following components in parts by weight: 1-2 parts of accelerator MBT-75, 0.4-1.0 parts of accelerator CBS-80, 0.6-1.2 parts of accelerator TP-50, 0.6-1.2 parts of accelerator ZAT-70, 0.4-1.0 parts of accelerator TBzTD-70, and 0.6-1.2 parts of accelerator HSPD-50.

2. The automotive sealing strip corner material as described in claim 1, characterized in that, The activator is zinc oxide.

3. The automotive sealing strip corner material as described in claim 1, characterized in that, The vulcanizing agent is sulfur S-80.

4. The automotive sealing strip corner material as described in claim 1, characterized in that, The flow aid is composed of 1-2 parts stearic acid and 0.5-1.5 parts polyethylene glycol.

5. The automotive sealing strip corner material as described in claim 1, characterized in that, The silane coupling agent is silane coupling agent Si-69.

6. A method for preparing the corner material of an automotive sealing strip according to any one of claims 1-5, characterized in that, Includes the following steps: Step a: Weigh each component according to the design ratio, mix the weighed components other than the environmentally friendly accelerator system, accelerator XLA and vulcanizing agent evenly, and then perform intensive mixing, degassing, debinding, compounding, and sheeting to obtain the film. Step b: Place the film for more than 12 hours, mix it with the weighed environmentally friendly accelerator system, accelerator XLA and vulcanizing agent, perform intensive mixing, discharge the glue, and thin out the sheet to obtain the automotive sealing strip corner material.

7. An automotive sealing strip assembly, characterized in that, It includes a sealing strip and the automotive sealing strip corner material as described in any one of claims 1-5, wherein the automotive sealing strip corner material is connected to the sealing strip.

8. A car, characterized in that, Includes the automotive sealing strip assembly as described in claim 7.

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