TPV (thermoplastic vulcanizate) material special for external water cutting and capable of eliminating apparent shock marks and preparation method of TPV material

Abstract

The invention discloses a TPV (thermoplastic vulcanizate) material special for external water cutting and capable of eliminating apparent shock marks as well as a preparation method and application of the TPV material, and the TPV material special for external water cutting and capable of eliminating apparent shock marks is prepared by taking ethylene propylene diene monomer, paraffin oil, polypropylene, talcum powder, polyethylene, a vulcanizing agent, an auxiliary vulcanizing agent, zinc oxide and a processing aid as preparation raw materials through melting and mixing. The invention provides a material-level solution for solving the problem that the TPV external water cutting material with shock marks for the automobile is degraded for use or scrapped in the prior art, and solves the problem that the time cost and the material cost are wasted in the existing production.

Description

Technical Field

[0001] The invention belongs to the modified material technology and relates to a TPV material, in particular to a TPV material specially used for external water shearing and capable of eliminating apparent chatter marks and a preparation method thereof. Background Art

[0002] Thermoplastic vulcanizate (TPV) is abbreviated as TPV. TPV has the elasticity of rubber at room temperature and can be processed and formed at high temperature like plastic, and has the characteristics of being reusable. At present, the thermoplastic vulcanizates successfully prepared by dynamic vulcanization technology include EPDM / polypropylene (PP), PP / nitrile rubber (NBR), and PP / hydrogenated styrene-butadiene block copolymer (SEBS). TPV materials are widely used in automotive parts, especially water-cut materials. CN117186558A discloses a TPV material for a window glass guide and a water-cut strip. The TPV material for the window glass guide and the water-cut strip is obtained by a unique formula material and ratio to obtain a high-performance, low compression permanent deformation TPV material, which is used in the window glass guide and the water-cut strip. CN219076977U discloses a tightly fitting inner water-cut, including a main frame, which is an "n"-shaped bending structure as a whole, and the main frame is set to a TPV rubber material. CN113276647B discloses a high-gloss black outer water-cut structure, wherein the outer water-cut lip edge is made of TPV material with a hardness of Shore A 65±5.

[0003] At present, the external water-cutting materials for automobiles are generally composed of steel strips and TPV. TPV is extruded on the steel strip. Since the TPV attached to the steel strip is very thin, surface vibration marks will appear under the flow of TPV. Since the steel strip cannot be reused, the cost of scrapping after vibration marks is very high. For minor vibration marks, it will be downgraded. After searching, there is no literature or report in the prior art that studies the solution to this phenomenon from the material level. Summary of the invention

[0004] With regard to automotive TPV external water-cut materials with chatter marks, the existing technology either downgrades them for use or scraps them; the present invention provides a material-level solution to solve the problem of wasting time and material costs in existing production.

[0005] The present invention adopts the following technical scheme.

[0006] A special TPV material for external water cutting for eliminating apparent chatter marks, comprising EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids.

[0007] The present invention discloses a method for preparing the above-mentioned TPV material specially used for external water cutting and eliminating apparent chatter marks, comprising the following steps: melting and mixing the preparation raw materials to obtain the TPV material specially used for external water cutting and eliminating apparent chatter marks; the preparation raw materials include ethylene propylene diene monomer rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids.

[0008] Preferably, the present invention uses EPDM rubber, paraffin oil, polypropylene, talc, polyethylene, vulcanizer, co-vulcanizer, zinc oxide, and processing aids as raw materials for preparation, and melt-mixes them to prepare a special TPV material for external water shearing that eliminates apparent chatter marks.

[0009] Further preferably, taking the mass percentage of the raw materials as 100%, the mass percentages of EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids are as follows: EPDM Residue Paraffin oil 30-45% Polypropylene 10-20% Talc 10-17% Polyethylene 5-10% Vulcanizing agent 0.2-1% Vulcanizing agent 0.2-1% Zinc oxide 0.5-2% Processing aids 0.5-3% Further preferably, taking the mass percentage of the raw materials as 100%, the mass percentages of EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids are as follows: EPDM Residue Paraffin oil 25-40% Polypropylene 12-18% Talc 10-15% Polyethylene 7-9% Vulcanizing agent 0.5-1% Vulcanizing agent 0.2-0.8% Zinc oxide 0.5-1% Processing aids 1-2% Further preferably, taking the mass percentage of the raw materials as 100%, the mass percentages of EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids are as follows: EPDM Residue Paraffin oil 30-35% Polypropylene 13-17% Talc 10-13% Polyethylene 6-9% Vulcanizing agent 0.6-1% Vulcanizing agent 0.3-0.6% Zinc oxide 0.5-0.9% Processing aids 1-1.5% In the present invention, the Mooney viscosity of the EPDM rubber is 55-95, the test condition is ML (1+4) 125° C., the ethylene content is 65%-75%, the third monomer is ethylidene norbornene, and the third monomer content is 3%-8%.

[0010] In the present invention, the polypropylene is extrusion-grade polypropylene with a melt index of 1 to 5, including one or more of homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene.

[0011] In the present invention, the particle size of talc is 1000-3000 meshes.

[0012] In the present invention, polyethylene is one or more of high-density polyethylene, ultra-high molecular weight polyethylene, low-density polyethylene, and linear low-density polyethylene.

[0013] In the present invention, the vulcanizing agent is a peroxide vulcanizing agent, including one or two of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and tert-butylperoxyisopropyl carbonate. Preferably, the vulcanizing agent is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and tert-butylperoxyisopropyl carbonate; more preferably, the mass ratio of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane to tert-butylperoxyisopropyl carbonate is 1: (0.8-1.2), such as 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2 and any ratio within the range thereof.

[0014] In the present invention, the co-vulcanizing agent is trimethylolpropane trimethacrylate.

[0015] In the present invention, the processing aids include one or more of lubricants, antioxidants, light stabilizers, and ultraviolet absorbers.

[0016] The invention discloses the application of the above-mentioned TPV material specially used for external water shearing for eliminating apparent chatter marks in the preparation of TPV products.

[0017] The invention discloses the application of the above-mentioned TPV material specially used for external water shearing for eliminating apparent chatter marks in the preparation of TPV automobile products.

[0018] The present invention discloses the application of the above-mentioned TPV material for external water cutting that eliminates apparent chatter marks in the preparation of TPV automotive water cutting products. In particular, the present invention discloses the application of the above-mentioned TPV material for external water cutting that eliminates apparent chatter marks in the preparation of TPV automotive external water cutting products.

[0019] The present invention discloses the application of the above-mentioned TPV material specially used for external water cutting for eliminating apparent chatter marks in improving chatter marks of TPV automobile water cutting products, especially external water cutting products.

[0020] An automobile component is prepared from the above-mentioned TPV material specially used for external water cutting for eliminating apparent chatter marks.

[0021] Due to the characteristics of TPV materials and their thinness, chatter marks will appear during the process of extrusion and attachment to the steel belt. Water-cut materials with this defect can only be downgraded for use. If the chatter marks are obvious, they can only be scrapped. The obvious disadvantage is increased cost and reduced efficiency. In view of the chatter mark problem of existing TPV materials, the present invention adopts a new formula system to improve the chatter mark problem, significantly improve production efficiency, and also make the external water-cut products have a high application rate of high quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the product photo of Example 5.

[0023] Figure 2 This is a product photo of Example 4.

[0024] Figure 3 This is the product photo of Example 2. DETAILED DESCRIPTION

[0025] Existing literature and reports do not study the identification method and solution of external water cut chatter marks from the TPV material level. When the client who sends the material to the product factory finds this problem during the external water cut, it will produce a lot of uncontrollable risks, waste time and material costs. The present invention aims to provide a solution to chatter marks at the material level.

[0026] The present invention uses EPDM rubber, paraffin oil, polypropylene, talc, polyethylene, vulcanizer, co-vulcanizer, zinc oxide, and processing aids as raw materials for preparation, and melts and mixes them to prepare a special TPV material for external water shearing that eliminates apparent chatter marks. The mass percentage of the raw materials is 100%, and the formula is as follows: EPDM Residue Paraffin oil 30-35% Polypropylene 13-17% Talc 10-15% Polyethylene 5-10% Vulcanizing agent 0.5-1% Vulcanizing agent 0.3-0.6% Zinc oxide 0.5-1% Other processing aids 1-2% In the present invention, specific raw materials are all commercially available products.

[0027] The Mooney viscosity of EPDM rubber is 55-95 under the test condition ML (1+4) 125°C, the ethylene content is 65%-75%, the third monomer is ethylidene norbornene, and the third monomer content is 3%-8%. In the examples and comparative examples, EPDM rubber was purchased from Sinopec Mitsui with a grade of 3092.

[0028] The polypropylene is extrusion grade polypropylene with a melt index of 1-5. The polypropylene is purchased from Zhenhai Refining and Chemical, and is homopolymer polypropylene with a grade of PPH-T03.

[0029] Filler A is talcum powder with a mesh size of 2000, a common commercial grade, purchased from Heshan Chemical Industry, with a grade of CMS-777; Filler B is calcium carbonate with a mesh size of 2000, a common commercial grade, purchased from Guangxi Kelong, with a grade of 918.

[0030] Polyethylene A is high-density polyethylene, brand 5000S purchased from Sinopec; polyethylene B is ultra-high molecular weight polyethylene, brand 9300CG purchased from Sinopec; polyethylene C is low-density polyethylene, brand 2426H purchased from Sinopec.

[0031] The vulcanizing agent is a peroxide vulcanizing agent, vulcanizing agent A: 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; vulcanizing agent B: tert-butyl peroxyisopropyl carbonate; domestic common commercial products.

[0032] The co-vulcanizing agent is trimethylolpropane trimethacrylate, which is a common commercial product in China.

[0033] The paraffin oil is ordinary paraffin oil, with a kinematic viscosity (40°C) of 110 mm2 / S and a flash point of 275°C. Zinc oxide is used as an acid absorbent.

[0034] Other processing aids include lubricant polyethylene wax, added at 0.6%, antioxidant 1010, added at 0.1%, antioxidant 168, added at 0.1%, light stabilizer UV-234, added at 0.1%, ultraviolet absorber UV-P, added at 0.1%, all of which are common commercial brands in the experiment.

[0035] The formula of the embodiment of the present invention is shown in Table 1, and the formula of the comparative example is shown in Table 2. The processing technology is as follows: 1: Put the raw materials (except vulcanizer and co-vulcanizer) of corresponding weight parts into an internal mixer for mixing. The internal mixer rotor speed is 50r / min, the internal mixing temperature is 170℃, and the internal mixing is carried out for 20 minutes. Then, the raw materials are pelletized by a single screw extruder to produce master batches for standby use. The single screw extruder has a diameter of 75mm, an aspect ratio of 44 / 1, a speed of 400r / min, a temperature of 180~210℃, and an output of 300kg / h. 2: The masterbatch obtained in step 1 is mixed with corresponding weight portions of vulcanizing agent and co-vulcanizing agent, and dynamically vulcanized and extruded into granules through a twin-screw extruder. The twin-screw extruder has a diameter of 58 mm, an aspect ratio of 56 / 1, a speed of 400 r / min, a temperature of 200-230° C., and an output of 200 kg / h.

[0036] Compression set is tested according to GB / T 7759.1, method A, experimental conditions 70℃*22h, unit %, which represents elasticity. The lower the value, the better the elasticity. Generally, automobile manufacturers require it to be less than 40%.

[0037] Chatter Identification Method For each solution, 10kg of material is taken and extruded onto steel strips at the customer's site (existing production process) to evaluate the severity of the chatter marks: divided into three levels: no chatter marks, slight chatter marks, and severe chatter marks. The definitions are as follows: slight chatter marks refer to chatter marks with a width less than 1mm and a chatter mark concentration of less than 3 / 10 cm long steel strip; obvious chatter marks refer to chatter marks with a width greater than or equal to 1mm or a chatter mark concentration greater than or equal to 3 / 10 cm long steel strip. Among them, the chatter mark width is the largest value among all chatter marks. The chatter marks and their number are observed by the naked eye, and the width is measured with a ruler.

[0038] Table 1 Example formulation, Kg

[0039] Note: In Example 7, the amount of lubricant added is 0.5%.

[0040] Table 2 Comparative Example Formula, Kg

[0041] Figure 1 This is a photo of the product of Example 5, and no vibration marks were observed.

[0042] Figure 2 This is a photo of the product of Example 4, and slight shock marks were observed.

[0043] Figure 3 This is a photo of the product of Example 2, and severe chatter marks were observed.

[0044] In the above examples, although the products of Comparative Examples 1 to 4 are classified as slight chatter marks in production, in reality, the chatter marks of the products containing polyethylene are slightly better than those without polyethylene. The compression permanent deformation of the product of Comparative Example 5 without filler and polyethylene is about 35%, and the compression permanent deformation of the products of Examples 2 to 7 are all below 38%, among which the compression permanent deformation of Example 5 is as low as 34.5%, while the compression permanent deformation of the product of Example 1 is about 48%; in addition, the compression permanent deformation of the products of Comparative Examples 2 and 4 exceeds 50%.

[0045] in conclusion: The most important step in the preparation process of TPV is the cross-linking of the rubber phase. After dynamic vulcanization, the size of the cross-linked EPDM particles gradually becomes regular and the distribution gradually becomes uniform. When no vulcanizer is added, the rubber does not produce cross-linking, the rubber phase in the blended elastomer is the continuous phase, the plastic phase is the dispersed phase, and the mechanical properties of TPV are poor. After adding the vulcanizer, the rubber produces cross-linking, and a phase transition occurs during the dynamic vulcanization process. At this time, the rubber phase is dispersed in the plastic phase as a dispersed phase. The linear macromolecular chain of the rubber forms a three-dimensional network structure through chemical cross-linking, and a phase transition occurs after dynamic vulcanization. The cross-linked rubber phase is dispersed in the plastic continuous phase as a dispersed phase. Since the rubber phase is transformed from a continuous phase to a dispersed phase, the damping factor of the blended elastomer decreases after the addition of a vulcanizer. The vulcanization of the rubber phase in olefins has a significant effect on the performance of the TPV system. The present invention explores an experimental scheme from the formulation level to eliminate the shock marks of the TPV material without reducing the elasticity of the material. Experiments show that adding talcum powder and polyethylene to the main TPV system, combined with the vulcanization system, can solve the chatter mark problem caused by steel strip extrusion, and unexpectedly, the material still maintains the qualified elasticity. The TPV material formula of the present invention has an unexpected technical effect, and is applied to the preparation of automobile external water cutting, which significantly improves the chatter mark problem and solves the waste problem of existing products caused by chatter marks.

Claims

1. A TPV material specially used for external water cutting for eliminating apparent chatter marks, comprising EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids.

2. The method for preparing the special TPV material for external water cutting that eliminates apparent chatter marks as described in claim 1 comprises the following steps: melt-mixing the raw materials to obtain the special TPV material for external water cutting that eliminates apparent chatter marks; the raw materials include ethylene propylene diene monomer rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizer, co-vulcanizer, zinc oxide, and processing aids.

3. The method for preparing a TPV material for external water shearing that eliminates apparent chatter marks according to claim 2, characterized in that: Taking the mass percentage of the raw materials as 100%, the mass percentages of EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids are as follows: EPDM Residue Paraffin oil 20-45% Polypropylene 10-20% Talc 10-17% Polyethylene 5-10% Vulcanizing agent 0.2-1% Vulcanizing agent 0.2-1% Zinc oxide 0.5-2% Processing aids 0.5-3%.

4. The method for preparing a TPV material for external water cutting for eliminating apparent chatter marks according to claim 3, characterized in that: Taking the mass percentage of the raw materials as 100%, the mass percentages of EPDM rubber, paraffin oil, polypropylene, talcum powder, polyethylene, vulcanizing agent, co-vulcanizing agent, zinc oxide, and processing aids are as follows: EPDM Residue Paraffin oil 25-40% Polypropylene 12-18% Talc 10-15% Polyethylene 7-9% Vulcanizing agent 0.5-1% Vulcanizing agent 0.2-0.8% Zinc oxide 0.5-1% Processing aids 1-2%.

5. The method for preparing a TPV material for external water cutting that eliminates apparent chatter marks according to claim 2, characterized in that: Polypropylene includes one or more of homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene; polyethylene includes one or more of high-density polyethylene, ultra-high molecular weight polyethylene, and low-density polyethylene.

6. The method for preparing a TPV material for external water cutting that eliminates apparent chatter marks according to claim 2, characterized in that: The vulcanizing agent is a peroxide vulcanizing agent; the co-vulcanizing agent is trimethylolpropane trimethacrylate; and the processing aids include one or more of a lubricant, an antioxidant, a light stabilizer, and an ultraviolet absorber.

7. The method for preparing a TPV material for external water cutting for eliminating apparent chatter marks according to claim 6, characterized in that: The vulcanizing agent includes one or both of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and tert-butyl peroxyisopropyl carbonate.

8. Use of the TPV material for external water shearing for eliminating apparent chatter marks as claimed in claim 1 in the preparation of TPV products.

9. Use of the TPV material for external water shearing for eliminating apparent chatter marks as claimed in claim 1 in the preparation of TPV automobile products.

10. An automobile part, prepared from the TPV material specially used for external water cutting for eliminating apparent chatter marks as claimed in claim 1.

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