Method for preparing phenolic aldehyde system TPV (thermoplastic vulcanizate) material by one-step method and product

Abstract

The invention belongs to a material modification technology, relates to a preparation method of a TPV (Thermoplastic Vulcanizate) system, and particularly relates to a method for preparing a phenolic aldehyde system TPV material by a one-step method and a product. An existing TPV production system is a two-step method, namely, in the first step, rubber and plastic are blended through an internal mixer or double screws to prepare master batches, in the second step, a vulcanization system is added, and a TPV product is obtained through double-screw dynamic vulcanization. According to the invention, the prejudice in the prior art is overcome, the conventional TPV two-step production is changed into one-step production, the process is simplified, many intermediate links are reduced, and particularly, the performance of the obtained product is improved, and the stability is very good and exceeds the imagination of people.

Description

Technical Field

[0001] The invention belongs to material modification technology and relates to a method for preparing a TPV system, specifically a method for preparing a phenolic system TPV material in one step and a product. Background Art

[0002] TPV is the abbreviation of thermoplastic dynamic vulcanized rubber. Its essence is that EPDM is vulcanized in molten PP, and EPDM is sheared into micron-level particles to form a sea-island structure. This gives TPV both the elasticity of vulcanized rubber and the thermoplasticity of plastic. The vulcanization systems adopted by commercial TPV are peroxide vulcanization system and phenolic vulcanization system. The former has a low degree of vulcanization and low performance, but is easier to process and has good production stability; the latter has a high degree of vulcanization and high performance, but is more difficult to process and has poor production stability. However, the production processes of both are two-step methods, that is, the first step is to use a mixer or a twin-screw extruder to mix rubber and plastic to make a masterbatch, and the second step is to mix the masterbatch and the vulcanizer and then feed it into the twin screw to obtain the TPV product through dynamic vulcanization. The existing TPV production system is a two-step method. Such a process has high energy consumption, low efficiency, and poor stability, especially the TPV prepared by the phenolic resin vulcanization system, which has a high degree of vulcanization, lower controllability, and worse stability. Summary of the invention

[0003] The existing TPV production system is a two-step process, that is, the first step is to use an internal mixer or a twin-screw extruder to mix rubber and plastic to make masterbatch, and the second step is to add a vulcanization system to obtain TPV products through twin-screw dynamic vulcanization. The present invention overcomes the prejudice of the prior art, changes the conventional TPV two-step production process into a one-step production process, simplifies the process, reduces many intermediate links, and in particular, improves the performance of the obtained product, especially the stability is very good, beyond people's imagination.

[0004] The present invention adopts the following technical scheme.

[0005] A one-step method for preparing a phenolic system TPV material comprises the following steps: (1) Mixing phenolic resin and paraffin oil to obtain a mixed oil; mixing fillers and processing aids to obtain a mixture; (2) EPDM, PP, mixture, mixed oil, and paraffin oil are fed into a twin-screw extruder respectively, and then granulated to obtain a phenolic system TPV material.

[0006] In the present invention, the filler includes talc.

[0007] In the present invention, in the mixed oil, the mass percentage of the phenolic resin is 20-50%, preferably, the mass percentage of the phenolic resin is 25-40%, and more preferably, the mass percentage of the phenolic resin is 30-35%.

[0008] In the present invention, step (2) is to feed EPDM, PP and the mixture into the twin-screw extruder through the main feeding port, feed paraffin oil into the third barrel to the fifth barrel, and feed the mixed oil into the sixth barrel to the seventh barrel.

[0009] Preferably, step (2) is to feed EPDM, PP and the mixture into the twin-screw extruder through the main feed port, feed the paraffin oil into the third barrel and the fifth barrel respectively, and feed the mixed oil into the sixth barrel.

[0010] Preferably, the mass ratio of paraffin oil fed into the third barrel section and the fifth barrel section is (5-7): (3-5).

[0011] In the present invention, each raw material is fed by a loss-in-weight scale, and the specific feeding method is conventional technology. As common sense, a twin-screw extruder is an existing device, which has a multi-section barrel, and a main feeding port is provided in the first section of the barrel.

[0012] In the present invention, the processing aids include catalysts, flow aids, antioxidants, weathering agents, and colorants; preferably, the catalyst includes tin compounds, the flow aids include zinc compounds and stearic acid compounds, the weathering agents include light stabilizers and ultraviolet absorbers, and the colorants include masterbatches.

[0013] In the present invention, the mass ratio of EPDM, paraffin oil, PP, filler, phenolic resin and processing aid is (30-45): (30-45): (10-15): (10-15): (2-8): (1-10); preferably, the mass ratio of EPDM, paraffin oil, PP, filler, phenolic resin and processing aid is (30-40): (35-45): (12-14): (10-13): (4-7): (3-7).

[0014] Preferably, among the processing aids, the mass ratio of the catalyst, the flow aid, the antioxidant, the weathering agent and the colorant is (0.1-3): (0.1-3): (0.1-3): (0.1-3): (0-3), and more preferably, the mass ratio of the catalyst, the flow aid, the antioxidant and the weathering agent is (1-2): (1-2): (0.5-1): (0.5-2): (0-2).

[0015] In the present invention, the rotation speed of the twin-screw extruder is 200-1000 rpm, and the maximum temperature is 210-230°C; preferably, the rotation speed of the twin-screw extruder is 300-500 rpm, and the maximum temperature is 215-220°C.

[0016] The invention discloses a phenolic system TPV material prepared by the one-step method for preparing a phenolic system TPV material.

[0017] The invention discloses application of the phenolic system TPV material in preparing TPV products.

[0018] The invention discloses application of the phenolic system TPV material in preparing automobile products.

[0019] The invention discloses the application of the phenolic system TPV material in preparing stable TPV products.

[0020] A TPV product, the raw materials for its preparation include the above-mentioned TPV product.

[0021] Preferably, the TPV product is an automotive part.

[0022] The present invention adopts a phenolic formula system (mainly a vulcanization system) combined with a preparation process, and through high-temperature vulcanization and shearing, the crosslinking rate and crosslinking density of the rubber are matched with the size of the mixed shear rate to form a thermoplastic elastomer with a certain crosslinking degree and particle size range and with rubber particles as the dispersed phase. The two-step process of the prior art is reduced to a one-step process, while maintaining the same performance, simplifying the production process, improving efficiency, and greatly reducing production costs; unexpectedly, the one-step process of the present invention significantly improves the stability of the final material. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the oil filling port of the twin-screw extruder of the present invention.

[0024] Figure 2 This is a photo of a conventional extruded product of the particles of the present invention.

[0025] Figure 3 This is a photo of a conventional extruded product of the particles of the present invention.

[0026] Figure 4 This is a photo of a conventional extrusion product of existing commercially available particles. DETAILED DESCRIPTION

[0027] The one-step TPV preparation process of the present invention, which only needs to be processed once by a twin-screw extruder, overcomes the technical prejudice of the prior art that vulcanized TPV requires two granulation times. For the first time, a process of dissolving phenolic resin in oil is combined with a process of segmented oil feeding, and oil is added at three points. Under the temperature and speed of the twin-screw extruder, the stability of the product obtained by granulation is significantly improved, and the comprehensive performance is improved compared with the prior art.

[0028] Based on 100% of the total amount of raw materials, the formula and mass percentage adopted by the present invention are as follows: EPDM Residue Paraffin oil 30-45% Polypropylene 10-15% Talc 10-15% Phenolic resin 2-8% Stannous chloride dihydrate 0.1-3% Zinc oxide 0.1-3% Stearic acid 0.1-3% Other processing additives 0.1-3% Preferably, based on 100% of the total amount of raw materials, the formula and mass percentage used in the present invention are as follows: EPDM Residue Paraffin oil 35-45% Polypropylene 12-14% Talc 10-13% Phenolic resin 4-7% Stannous chloride dihydrate 1-2% Zinc oxide 1-2% Stearic acid 0.5-1% Other processing aids 0.5-2% Among them, 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 experiment, EPDM was purchased from SABIC, brand 756.

[0029] Polypropylene (PP) is common extrusion grade homopolymer polypropylene with a melt index of 1-5. In the experiment, PP was purchased from Zhenhai Refining and Chemical, with the brand name PPH-T03.

[0030] The talcum powder was 2000 mesh, a common commercial brand, purchased from Heshan Chemical Industry, brand CMS-777.

[0031] The phenolic resin is an octyl thermal reactive phenolic resin purchased from SI Group with the brand number 1045KH.

[0032] Paraffin oil is ordinary paraffin oil, and its kinematic viscosity (40℃) is 90~120mm 2 / S, open cup flash point ≥ 267°C, purchased from Zhengxin Petroleum, brand C-02-T108.

[0033] Stannous chloride dihydrate, zinc oxide, and stearic acid are common commercially available brands.

[0034] Other processing aids include lubricant polyethylene wax; antioxidant 1010, antioxidant 168; light stabilizer UV-234, ultraviolet absorber UV-P, all of which are common commercial brands; and may further include colorants, such as masterbatches.

[0035] The following is an explanation of the technical progress of the present invention through specific experiments, and the specific preparation operations and performance tests are all conventional techniques.

[0036] The specific formulas used in the embodiments and comparative examples are as follows: EPDM Residue Paraffin oil 35% Polypropylene 13% Talc 12% Phenolic resin 6% Stannous chloride dihydrate 1.5% Zinc Oxide 1% Stearic acid 0.5% Other processing aids 2% The total amount of the above raw materials is 100%.

[0037] Among them, lubricant polyethylene wax is 0.6%; antioxidant 1010 and antioxidant 168 are 0.2% each; light stabilizer UV-234 and ultraviolet absorber UV-P are 0.5% each.

[0038] Embodiment Processing method: (1) Heat paraffin oil to 120°C, take all the phenolic resin and melt it into the oil to make a 30% mixed oil, 70% oil and 30% phenolic resin; (2) talc, processing aids (stannous chloride dihydrate, zinc oxide, stearic acid, polyethylene wax, antioxidant 1010, antioxidant 168, light stabilizer UV-234, ultraviolet absorber UV-P) were conventionally mixed in a mixer and recorded as a mixture; (3) EPDM, PP, mixture, mixed oil and paraffin oil are fed into a twin-screw extruder in proportion through a loss-in-weight scale for extrusion and granulation; the oil is injected at multiple points, and a refueling port is set on each of the third, fifth and sixth barrels of the twin-screw, marked as ①②③. The structure is as follows: Figure 1 As shown, pure paraffin oil is injected into the oil injection ports ① and ② (the mass ratio of the paraffin oil injected into the oil injection ports ① and ② is shown in Table 3), and the mixed oil is injected into the oil injection port ③; the twin-screw extruder has a diameter of 58 mm, an output of 200 kg / h, a rotation speed of 300-500 rpm, and an extrusion temperature of see Table 1.

[0039] Embodiment Processing method: (1) Making phenolic resin into 50% phenolic masterbatch: adding EPDM and all phenolic resin in a weight ratio of 1:1 into an internal mixer, mixing at a temperature of 170°C for 20 minutes, and then extruding and granulating through a single screw extruder to produce phenolic masterbatch for later use; (2) Put corresponding weight parts of EPDM rubber, paraffin oil, polypropylene, talc processing aids (zinc oxide, stearic acid, polyethylene wax, antioxidant 1010, antioxidant 168, light stabilizer UV-234, ultraviolet absorber UV-P) into an internal mixer for mixing, the internal mixer rotor speed is 50r / min, the internal mixing temperature is 170°C, and the internal mixing is carried out for 20 minutes; then, the master batch is produced by a single screw extruder for granulation and set aside; (3) The masterbatch obtained in step (2), the phenolic masterbatch obtained in step (1) and stannous chloride dihydrate are mixed, and dynamically vulcanized and extruded into granules through a twin-screw extruder; the twin-screw extruder has a diameter of 58 mm, a speed of 300-500 r / min, an extrusion temperature as shown in Table 1, and an output of 200 kg / h.

[0040] Table 1 Extrusion temperature of examples and comparative examples

[0041] The testing methods for materials are conventional techniques, which are briefly described as follows: Tensile strength: According to ISO 37:2017, tested with a dumbbell specimen, tensile speed 500mm / min, unit MPa; Compression set: Tested according to ISO815-1, method A, experimental conditions 70℃*22h, unit %, this is the key performance, the lower the value, the better the performance; Melt Index: Tested according to ISO 1133-2 Method A, Condition 10kg*230℃.

[0042] Melt Index Standard Deviation: Calculated by formula, the specific calculation is conventional technology, which is a statistic that describes the degree of dispersion of data, indicating the degree of deviation of each value in the data set from the mean value of the data set. The standard deviation is the arithmetic square root of the variance.

[0043] Note: The standard deviation of the melt index is used to characterize the stability of the material processing process. When the material changes, the melt index is most affected and fluctuates the most, so the standard deviation of the melt index is used to characterize the stability of the process. The specific method is to make three batches for each scheme, each batch is made for 90 minutes, and the material is taken every 30 minutes to test the performance, a total of 9 data, and the standard deviation of the 9 data is calculated to characterize the stability. The smaller the standard deviation, the higher the stability.

[0044] Table 2 Experimental design of the comparison group

[0045] It can be seen that under the existing two-step method, no matter how the specific process parameters are adjusted, the prepared particles have poor processing stability and a large standard deviation of the melt index.

[0046] Table 3 Experimental plan of the implementation group

[0047] Implementation Group 10 On the basis of implementing group 3, the mixed oil was added from the 4th section of the cylinder, and the refueling port of the 6th section of the cylinder was closed. Other things were the same, and the compression permanent set was slightly reduced to 33.

[0048] Comparison example Take 9 packages (from different production batches) of commercially available phenolic TPV particles with good application performance, each package is 25 kg, take a sample from each package, test the melt index and calculate the standard deviation, which is 7.8.

[0049] Application Examples On the basis of Example 3, the amount of polypropylene is reduced by 1%, and 1% masterbatch (3050E) is added. The rest is the same, and the standard deviation of the melt index is 1.6. The TPV particles and the existing TPV are used to make automotive door and window sealing strips in the client. Figure 2 , Figure 3 as well as Figure 4 , can achieve the same effect as the conventional two-step TPV on the market, can be normally applied in the client, and because the fluctuation of the melt index is small (the standard deviation of the melt index is small), the client production process is more stable.

[0050] The existing TPV production system is a two-step process, that is, the first step is to use an internal mixer or a twin-screw to mix rubber and plastic to make a masterbatch, and the second step is to add a vulcanization system to obtain a TPV product through a twin-screw dynamic vulcanization. This process has high energy consumption, low efficiency, and poor stability, especially the TPV prepared by the phenolic resin vulcanization system, which has a high degree of vulcanization, lower controllability, and worse stability. The process of the present invention is simplified, and the traditional two-step method is changed into a one-step method, and the efficiency and energy consumption are improved; the performance of the product prepared by the present invention is even slightly improved compared with the traditional two-step method (as reflected in tensile strength and compression permanent deformation); unexpectedly, the stability of the one-step method is greatly improved compared with the traditional two-step method (as can be seen from the standard deviation of the melt index).

Claims

1. A one-step method for preparing a phenolic system TPV material, comprising the following steps: (1) Mixing phenolic resin and paraffin oil to obtain a mixed oil; mixing fillers and processing aids to obtain a mixture; (2) EPDM, PP, mixture, mixed oil, and paraffin oil are fed into a twin-screw extruder respectively, and then granulated to obtain a phenolic system TPV material.

2. The method for preparing phenolic system TPV material in one step according to claim 1, characterized in that: The filler includes talc powder; the processing aids include catalysts, flow aids, antioxidants and weathering agents.

3. The method for preparing phenolic system TPV material in one step according to claim 1, characterized in that: In the mixed oil, the mass percentage of phenolic resin is 20-50%.

4. The method for preparing phenolic system TPV material in one step according to claim 1, characterized in that: Step (2) is to feed EPDM, PP and the mixture into the twin-screw extruder through the main feeding port, feed the paraffin oil into the third barrel to the fifth barrel, and feed the mixed oil into the sixth barrel to the seventh barrel.

5. The method for preparing phenolic system TPV material in one step according to claim 4, characterized in that: Step (2) is to feed EPDM, PP and the mixture into the twin-screw extruder through the main feeding port, feed the paraffin oil into the third barrel and the fifth barrel respectively, and feed the mixed oil into the sixth barrel.

6. The method for preparing phenolic system TPV material in one step according to claim 1, characterized in that: The mass ratio of EPDM, paraffin oil, PP, filler, phenolic resin and processing aid is (30-45): (30-45): (10-15): (10-15): (2-8): (1-10).

7. A phenolic system TPV material prepared by the one-step preparation method of a phenolic system TPV material according to claim 1.

8. Use of the phenolic system TPV material according to claim 7 in the preparation of TPV products.

9. Use of the phenolic system TPV material according to claim 7 in the preparation of automobile products.

10. A TPV product, wherein the raw materials for preparing the TPV product include the TPV product according to claim 7.

Images