Low odor TPV material and method of making same

Abstract

The application belongs to the technical field of new materials, and particularly relates to a low-odor TPV material and a preparation method thereof. EPDM rubber, PP resin, a processing aid, color masterbatch and white oil are mixed and granulated to obtain a masterbatch; the masterbatch is dynamically vulcanized in the presence of a vulcanizing agent and a vulcanization accelerator to obtain the low-odor TPV material; the vulcanization accelerator comprises one or both of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate. In the prior art, a method of adsorption treatment is mostly used to reduce the odor of TPV, and obvious defects exist. The application develops a new formula on the basis of the TPV system, effectively reduces the odor, and maintains good mechanical properties of the material. The application uses di-tert-butyl peroxide isopropyl phenyl (BIBP) in combination with trimethylolpropane trimethacrylate and trimethylolpropane triacrylate for EPDM rubber / PP resin / white oil, and extrusion granulation is performed to obtain the low-odor TPV material. Conventional detection finds that the odor grade of the TPV material is as low as 1, and the problem of odor emission of the TPV material is solved.

Description

Technical Field

[0001] The present invention belongs to new material technology, and specifically relates to a low-odor TPV material and a preparation method thereof. Background Art

[0002] As the industry has evolved, the processing and manufacturing of automotive parts has become increasingly sophisticated, including the widespread and mature methods of extruding and injection molding TPV materials. TPV materials offer advantages such as environmental friendliness, a wide hardness range, excellent processing properties, and recyclability. However, TPVs can produce a pungent odor during processing. With automakers now demanding low-odor automotive parts, low-odor TPV materials have become a future trend. Existing technologies for reducing the odor of TPVs primarily rely on adsorption treatment. For example, CN113980397A discloses a low-odor, low-VOC automotive TPV material and its preparation method. The addition of an adsorbent further reduces the odor and VOC content of the elastomer material, while maintaining an odor rating of 3 or higher. CN117209903A discloses a low-odor TPV material and its preparation method. PP, EPDM, paraffin oil, talc, and a lubricating agent are first mixed with a compatibilizer and masterbatch using a twin-screw extruder to form a semi-finished masterbatch. The semi-finished masterbatch is then mixed with a vulcanizer and two deodorizers and granulated using a twin-screw extruder to produce finished particles. While adsorbents can be effective, they have significant drawbacks: increased cost, poor compatibility with plastic components, which can affect the performance of plastic products, and inconsistent deodorization. Therefore, new formulations based on the TPV system are needed that maintain the material's good mechanical properties. Summary of the Invention

[0003] Most existing technologies attempt to improve the odor of TPV materials through the use of adsorbents. However, this treatment method, which only treats the symptoms, is difficult to fundamentally remove the odor from the material. The present invention overcomes the technical bias of the existing technology that believes in using adsorbents for odor removal. Starting from the material formula, it creatively proposes a low-odor TPV material and a preparation method thereof. By combining the ingredients and proportions, the prepared product has a very low odor level while maintaining the conventional mechanical properties of the TPV material.

[0004] The present invention adopts the following technical solutions:

[0005] A low-odor TPV material, the preparation method of which comprises the following steps:

[0006] (1) EPDM rubber, PP resin, processing aids, masterbatch and white oil are mixed and granulated to obtain masterbatch;

[0007] (2) The masterbatch is dynamically vulcanized in the presence of a vulcanizing agent and a vulcanizing accelerator to obtain a low-odor TPV material;

[0008] The vulcanizing agent includes one or both of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate.

[0009] Preferably, the vulcanization accelerating agent is trimethylolpropane trimethacrylate and trimethylolpropane triacrylate.

[0010] More preferably, the mass ratio of trimethylolpropane trimethacrylate to trimethylolpropane triacrylate is 1:(1-3), such as 1:2.

[0011] In the present invention, the processing aid includes one or more of a weathering agent, an antioxidant, and a lubricant.

[0012] In the present invention, the vulcanizing agent is a peroxide, including one or more of di-tert-butyl peroxide isopropylphenyl (BIBP), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (BIBP), and tert-butyl peroxyisopropyl carbonate (C75).

[0013] In the present invention, the mass ratio of EPDM rubber, PP resin, white oil, processing aid, masterbatch, vulcanizing agent and vulcanizing accelerator is (25-50): (10-25): (25-35): (1-2): (2-2.5): (1-3): (1-3).

[0014] Preferably, the mass ratio of EPDM rubber, PP resin, white oil, processing aid, masterbatch, vulcanizing agent, and vulcanizing accelerator is (30-50): (15-25): (30-35): (1-2): (2-2.5): (1-2): (1-2).

[0015] Further preferably, the mass ratio of EPDM rubber, PP resin, white oil, processing aid, masterbatch, vulcanizing agent, and vulcanizing accelerator is (35-45): (17-23): (30-35): (1-2): (2-2.5): (1-2): (1-2).

[0016] More preferably, the ratio of the amount of the vulcanizing agent to the amount of the vulcanizing accelerator is 1:(0.8-1.2), such as 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, etc.

[0017] The present invention discloses the application of the low-odor TPV material in the preparation of TPV products.

[0018] The present invention discloses the application of the low-odor TPV material in the preparation of TPV automobile products.

[0019] The present invention discloses the application of the low-odor TPV material in the preparation of TPV automobile interior products.

[0020] The present invention discloses the application of the low-odor TPV material in improving the odor of TPV products.

[0021] The invention discloses an automobile component, and the raw materials for preparing the automobile component include the low-odor TPV material disclosed in the invention.

[0022] Existing technologies for reducing TPV odor primarily rely on adsorption treatment, which presents significant drawbacks: increased costs, poor compatibility of the adsorbent with plastic components, which can affect the performance of plastic products, and inconsistent deodorization. Therefore, the present invention, based on the TPV system, has developed a new formulation that effectively reduces odor while maintaining the material's excellent mechanical properties. This invention combines di-tert-butyl peroxyisopropyl (BIBP) with trimethylolpropane trimethacrylate and trimethylolpropane triacrylate in an EPDM rubber / PP resin / white oil system. Extrusion granulation produces a low-odor TPV material. Conventional testing reveals an odor rating as low as Class 1, thus resolving the odor issue associated with TPV. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a photo of the actual appearance of the conventional sample preparation of the product in Example 1. DETAILED DESCRIPTION

[0024] A drawback of existing TPVs is the pungent odor of their particles. Currently, most car interiors are made of TPV materials, which produce a pungent odor after injection molding. As people's living conditions improve, their expectations for cars are also gradually increasing. The first thing they notice when they open their car is the odor, and more and more customers are demanding low-odor cars. This has led to the emergence of low-odor TPVs. However, existing technologies all use adsorbents to improve odor, which leads to production and cost issues, and also affects the performance of the TPV system. The present invention addresses the odor issue of TPV by creatively adjusting the material formula.

[0025] The method for preparing the low-odor TPV material of the present invention comprises the following steps:

[0026] The first step is to make masterbatch: EPDM, PP resin, processing aids and masterbatch are fully mixed in a mixer and then put into a twin-screw extruder for processing. White oil is added to the extruder separately through a loss-in-weight scale. The speed is 350-400 rpm and the temperature is 180-220℃ to make masterbatch.

[0027] The second step is dynamic vulcanization: the masterbatch, vulcanizing agent and vulcanizing accelerator are mixed evenly and put into the twin-screw extruder at a speed of 380-400 rpm and a temperature of 160-190°C to form the product.

[0028] In the preparation method of the low-odor TPV material of the present invention, the formula composition is as follows in terms of mass percentage:

[0029] EPDM rubber remainder

[0030] PP resin 10-25%

[0031] White oil 25-35%

[0032] Processing aids 1-2%

[0033] Masterbatch 2-2.5%

[0034] Curing agent (BIPB) 1-2%

[0035] Vulcanizing agent (TMPTMA / PL400) 1-2%

[0036] EPDM (ethylene propylene diene monomer) is a terpolymer with different Mooney viscosities formed by the polymerization of ethylene, propylene and non-conjugated dienes; 3092PM was used in the experiment.

[0037] The PP resin is a block copolymer polypropylene with a melt flow rate of 1 to 5 g / 10 min and a flexural modulus of ≥1300 MPa; K8003 was used in the experiment.

[0038] White oil: liquid hydrocarbon mixture, open flash point: 250~290℃; KP-100B is used for experiments.

[0039] Processing aids: A combination of commonly used weathering agents, antioxidants, and lubricants. The experimental weathering agents used were equal parts 5590 and UV-234, the antioxidants were equal parts 1010 and 168, and the lubricants were equal parts PE wax and erucamide. The weight ratio of weathering agent: antioxidant: lubricant was 1:1:1.

[0040] Masterbatch: Colorant for polymer materials; 3050E for experiments.

[0041] Curing agent: di-tert-butyl peroxide isopropylbenzene (BIBP), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (BIBP) or tert-butyl peroxyisopropyl carbonate (C75).

[0042] Vulcanizing agent: TMPTMA (trimethylolpropane trimethacrylate), PL400 (trimethylolpropane triacrylate).

[0043] The formulas of the comparative examples and embodiments are shown in Table 1 and Table 2, and the specific processing methods are as follows:

[0044] The first step is to make masterbatch: EPDM, PP resin, processing aids and masterbatch are mixed in a conventional mixer and then put into a twin-screw extruder for processing. White oil is added to the extruder separately through a loss-in-weight scale. The masterbatch is produced at a speed of 400 rpm, a temperature of 180-220°C and a production capacity of 200 kg / h.

[0045] The second step is dynamic vulcanization: the masterbatch, vulcanizer and vulcanizing agent are mixed evenly and put into a twin-screw extruder with a speed of 400 rpm, a temperature of 160-190 ° C and a production capacity of 180 kg / h to produce the product.

[0046] Material testing method: Shore hardness: ISO868:2023, 15-second reading; required to be greater than 65A; the example materials are all greater than 67A.

[0047] Tensile strength: ISO 37:2017, dumbbell-shaped specimen, test speed: 500 mm / min; required to be greater than 6 MPa; all examples of materials are greater than 6 MPa.

[0048] The odor level adopts the conventional test method of automobile manufacturers. The test methods of various automobile manufacturers are not exactly the same, but they are comparable to each other. The experiment of the present invention adopts: Q / BYDQ-A1901.404-2015. The lower the better. Sensoryly, the odor level of 1-1.5 is considered to be almost odorless.

[0049] Table 1: Formulas and properties of Examples and Comparative Examples, Kg

[0050]

[0051] Table 2 Example formulations and properties, Kg

[0052]

[0053] Control Example

[0054] The mechanical properties and odor level tests of similar products currently available on the market are as follows:

[0055]

[0056] During the dynamic vulcanization reaction, crosslinking prevents the rubber particles from reuniting into ribbons. Simultaneously, the ribbons are sheared and continuously re-fractionated, ultimately forming vulcanized rubber particles uniformly dispersed within the continuous PP phase. The most critical step in TPV production is crosslinking the rubber phase. After dynamic vulcanization, the crosslinked EPDM particles gradually become more uniformly sized and evenly distributed. Without the addition of a vulcanizing agent, the rubber does not crosslink, resulting in the continuous rubber phase and the dispersed plastic phase in the blended elastomer. Consequently, the mechanical properties of the TPV are poor. Experimental results show that the odor rating of three currently used external water-cut materials does not reach Level 1, and their tensile strength is low. Vulcanizing agents affect the mechanical properties of the products. Comparative Example 3 has a hardness of 65A and a tensile strength of 5MP. The combination of vulcanizing agent and vulcanizing accelerator significantly affects the odor level of TPV. The combination of the vulcanizing agent and the vulcanizing accelerator, added to the basic TPV formulation, and extruded and granulated to produce a product with excellent performance, reduces vehicle odor, is beneficial to human health, and does not alter the original properties of the material.

Claims

1. A method for preparing a low-odor TPV material, characterized in that: The following steps are involved: (1) EPDM rubber, PP resin, processing aid, masterbatch and white oil are mixed and granulated to obtain masterbatch; (2) the masterbatch is dynamically vulcanized in the presence of a vulcanizing agent and a vulcanizing accelerator to obtain a low-odor TPV material; wherein the vulcanizing agent is di-tert-butyl peroxide isopropylbenzene; the vulcanizing accelerator is trimethylolpropane trimethacrylate and trimethylolpropane triacrylate in a mass ratio of 1:(1-3); the mass ratio of EPDM rubber, PP resin, white oil, processing aid, masterbatch, vulcanizing agent and vulcanizing accelerator is (25-50):(10-25):(25-35):(1-2):(2-2.5):(1-3):(1-3).

2. The method for preparing the low-odor TPV material according to claim 1, characterized in that: The ratio of the amount of vulcanizing agent to the amount of vulcanizing accelerator is 1: (0.8~1.2).

3. The low-odor TPV material prepared according to the method for preparing the low-odor TPV material according to claim 1.

4. Use of the low-odor TPV material according to claim 3 in the preparation of TPV products.

5. Use of the low-odor TPV material according to claim 3 in the preparation of TPV automotive products.

6. An automotive component, wherein the raw materials for its preparation include the low-odor TPV material according to claim 3.

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