Modified plastic composite master batch and production process thereof

Abstract

The invention relates to the technical field of materials, and discloses a modified plastic composite master batch and a production process thereof.The modified plastic composite master batch is prepared from ethylene propylene diene monomer and chlorinated polyethylene as main raw materials and modified additives as additives through mixing and extrusion granulation processes. Wherein the modified additive is prepared by modifying the surface of pyrophyllite with a macromolecular modifier, and due to the existence of the macromolecular modifier, the interface affinity of the pyrophyllite and the ethylene propylene diene monomer can be improved, so that the pyrophyllite can give full play to the reinforcing effect of the pyrophyllite as an inorganic additive, and the mechanical strength of the plastic is improved. Besides, the macromolecular modifier can promote rapid formation of an expanded carbon layer structure on the surface of the material during combustion to effectively prevent heat and oxygen, and meanwhile, pyrophyllite can form a layer of stable and high-temperature-resistant ceramic barrier during combustion to cooperate with a carbon layer, so that the flame retardant property of the material is greatly enhanced.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to a modified plastic composite masterbatch and its production process. Background Technology

[0002] Plastic composite masterbatch is an elastomer prepared by blending plastics and rubber, obtained through extrusion granulation or crushing granulation. Its technological development has evolved from single-color masterbatch to multifunctional composite masterbatch, especially in high-end fields such as new energy vehicles, 5G communications, and building waterproofing, where higher functional requirements are placed on masterbatch. Ethylene propylene diene monomer (EPDM) rubber, as a non-polar saturated rubber, occupies an important position in plastic composites due to its unique molecular structure (ethylene-propylene backbone with a small amount of non-conjugated diene side chains). Benefiting from its unique molecular structure, plastic composites made with EPDM as the base material have excellent UV resistance, thermal stability, and electrical insulation properties, meeting the application requirements of various fields such as building waterproof membranes, sealing strips, and electronic component packaging. However, EPDM itself has a limiting oxygen index (LOI) of only 17%, making it a flammable material. When burning, it produces molten droplets, easily causing the fire to spread, thus failing to meet the safety standards of some industries. Therefore, modifying plastic composites based on EPDM is of great significance.

[0003] Currently, flame retardant modification by adding flame retardants is a common method. However, both inorganic and organic flame retardants have significant problems in practical applications. Inorganic flame retardants require large amounts to be added, organic halogen-based flame retardants cause environmental pollution, and phosphorus-based flame retardants have poor flame retardant effects. Based on this, the present invention provides a plastic composite masterbatch that can solve the problems existing in the prior art. Summary of the Invention

[0004] In order to solve the problems mentioned in the background art, the purpose of this invention is to provide a modified plastic composite masterbatch and its production process.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A modified plastic composite masterbatch, comprising the following raw materials measured in parts by weight:

[0007] 68-75 parts of ethylene propylene diene monomer (EPDM) rubber, 10-18 parts of chlorinated polyethylene, 1-2 parts of lubricant, 5-12 parts of compatibilizer, 2-5.5 parts of modifying additives, and 0.1-0.5 parts of antioxidant;

[0008] The modified additive is pyrophyllite with an organically modified surface.

[0009] As a further embodiment of the present invention, the lubricant is any one of polyethylene wax, paraffin wax, or vinyl bis-stearamide; the compatibilizer is maleic anhydride-grafted EPDM rubber.

[0010] As a further aspect of the present invention, the preparation method of the modified additive includes the following steps:

[0011] Step A: Add pyrophyllite to an ethanol aqueous solution with a volume fraction of 50-70%. After the addition is complete, disperse it evenly by ultrasonication. Then, add the functionalized organic modifier to the formed uniform dispersion, adjust the pH to 3-4, raise the temperature to 60-70℃, and continue to stir for 4-8 hours. After that, stop heating, cool down and discharge the material. The crude product is washed and vacuum dried to obtain functionalized pyrophyllite.

[0012] Step B: Functionalized pyrophyllite is ultrasonically dispersed in 1,4-dioxane, followed by the addition of a phosphorus-containing phenylenedialdehyde derivative and a catalyst. After the addition is complete, the temperature is raised to 60-70℃ and stirred for 3-6 hours. Then, aminoethyl sulfide is added. After the addition is complete, the temperature is further raised to 70-80℃ and stirred for 12-18 hours. The product is then cooled and discharged. The crude product is washed and vacuum dried to obtain the modified additive.

[0013] As a further aspect of the present invention, the functionalized organic modifier is KH-550 or KH-551.

[0014] As a further aspect of the present invention, the phosphorus-containing phenylenedialdehyde derivative is prepared by the following method:

[0015] Pentaerythritol phosphate was added to N,N-dimethylformamide and stirred until homogeneous. Then, an aqueous hydroxide solution was added. After the addition was complete, the mixture was stirred at 50-60°C for 1-2 hours. Then, 5-bromoisophenylenedialdehyde was added. After the addition was complete, the temperature was raised to 75-85°C and the mixture was stirred for 4-8 hours. The solvent was then evaporated to remove the solvent. The crude product was purified to obtain a phosphorus-containing phenylenedialdehyde derivative.

[0016] As a further aspect of the present invention, the molar ratio of pentaerythritol phosphate to 5-bromoisobenzoic acid is 1:1.

[0017] As a further embodiment of the present invention, the hydroxide aqueous solution is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, with a mass fraction of 10-20%.

[0018] As a further aspect of the present invention, the catalyst is glacial acetic acid.

[0019] It should be noted that in the above technical solution, firstly, a functionalized organic modifier is used to modify the surface of pyrophyllite, so that the surface of pyrophyllite carries active amino functional groups, thus obtaining functionalized pyrophyllite. Then, under the action of a catalyst, the active amino group of the functionalized pyrophyllite reacts with the aldehyde functional group in the structure of the phosphorus-containing phenylenedialdehyde derivative in a Schiff base reaction. At the same time, the phosphorus-containing phenylenedialdehyde derivative that does not participate in the reaction in the system can act as an intermediate linker to continuously react with aminoethyl sulfide in a Schiff base reaction, thereby producing the effect of in-situ polymerization of phosphorus-containing phenylenedialdehyde derivative and aminoethyl sulfide on the surface of pyrophyllite with the amino group of the functionalized pyrophyllite as the active initiation site. A macromolecular modifier with an alternating linkage structure linked by Schiff base is modified on the surface of pyrophyllite to obtain a modified additive.

[0020] The phosphorus-containing phenylenedialdehyde derivatives are prepared by using pentaerythritol phosphate and 5-bromoisophenylenedialdehyde as raw materials, and by the substitution reaction of the active hydroxyl functional groups in their structures with halogen substituents under the action of alkaline hydroxide.

[0021] As a further embodiment of the present invention, the antioxidant is a mixture of lignin and antioxidant 168 in a mass ratio of 1:0.2-0.4.

[0022] A production process for modified plastic composite masterbatch includes the following steps:

[0023] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0024] Step 2: Add all raw materials to a high-speed mixer, control the speed to 300-500 r / min, and mechanically mix for 30-60 min. Then feed the resulting mixture into a twin-screw extruder through a feed hopper, control the extrusion temperature to 200-240℃, and granulate it through melt extrusion.

[0025] The beneficial effects of this invention are:

[0026] This invention modifies pyrophyllite by applying macromolecular modifiers to its surface to create a modified additive. Firstly, the macromolecular modifiers act as a transition layer between pyrophyllite and EPDM rubber, transforming the pyrophyllite surface from hydrophilic to oleophilic, thus enhancing interfacial affinity and promoting relatively uniform dispersion of pyrophyllite in the plastic. This allows pyrophyllite to fully exert its reinforcing effect as an inorganic additive, improving the mechanical strength of the plastic. Secondly, the macromolecular modifiers contain abundant phosphorus, nitrogen, and sulfur. Phosphorus and sulfur act as acid sources, rapidly catalyzing carbonization during combustion, leading to the rapid formation of a dense carbon layer on the material surface. The nitrogen combustion gases are encapsulated within the carbon layer, forming an expanded carbon layer that effectively blocks heat and oxygen. Simultaneously, pyrophyllite itself forms a stable, high-temperature-resistant ceramic barrier during combustion, synergistically enhancing the flame-retardant properties of the material.

[0027] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is an infrared analysis test image of a phosphorus-containing phenylenedialdehyde derivative. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Preparation Example

[0032] Preparation of modified additives:

[0033] Step A: Add 2.6g of pyrophyllite to a 50% (v / v) ethanol aqueous solution. After the addition is complete, disperse the mixture evenly by ultrasonication. Then, add 0.5g of KH-550 to the formed uniform dispersion, adjust the pH to 3, raise the temperature to 65℃, and continue stirring for 6 hours. After that, stop heating, cool down and discharge the material. The crude product is washed and vacuum dried to obtain functionalized pyrophyllite.

[0034] Step B: 1.8g of functionalized pyrophyllite was ultrasonically dispersed in 1,4-dioxane, followed by the addition of 0.5g of phosphorus-containing phenylenedialdehyde derivative and 0.3g of glacial acetic acid. After the addition was complete, the temperature was raised to 65℃ and stirred for 3 hours. Then, 0.2g of aminoethyl sulfide was added. After the addition was complete, the temperature was further raised to 75℃ and stirred for 16 hours. The product was then cooled and discharged. The crude product was washed and vacuum dried to obtain the modified additive.

[0035] The phosphorus-containing phenylenedialdehyde derivatives were prepared using the following method:

[0036] 0.8 g of pentaerythritol phosphate was added to N,N-dimethylformamide and stirred until homogeneous. Then, 2 mL of 15% sodium hydroxide aqueous solution was added. After the addition was complete, the mixture was stirred at 55°C for 1 h. Then, 0.95 g of 5-bromoisophenylenedialdehyde was added. After the addition was complete, the temperature was raised to 80°C and the mixture was stirred for 6 h. The solvent was then evaporated to remove the solvent. The crude product was purified to obtain a phosphorus-containing phenylenedialdehyde derivative.

[0037] Figure 1 The infrared analysis results for phosphorus-containing phenylenedialdehyde derivatives are shown, with the 3000–3100 cm⁻¹ range being the most significant. -1 The characteristic absorption peak appearing at 1692 cm⁻¹ is attributed to the characteristic absorption peak of CH on the benzene ring. -1 The characteristic absorption peak appearing at 1032 cm⁻¹ is attributed to the C=O characteristic absorption peak of the aldehyde group. -1 The characteristic absorption peak appearing at this point is attributed to the CO characteristic absorption peak of the ether bond.

[0038] Example 1

[0039] A modified plastic composite masterbatch, comprising the following raw materials measured in parts by weight:

[0040] 68 parts of EPDM rubber, 10 parts of chlorinated polyethylene, 1 part of polyethylene wax, 5 parts of maleic anhydride-grafted EPDM rubber, 2 parts of modifying additives, and 0.1 parts of antioxidant.

[0041] The preparation method of the plastic composite masterbatch includes the following steps:

[0042] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0043] Step 2: Add all raw materials to a high-speed mixer, control the speed at 300 r / min, and mechanically mix for 60 min. Then feed the resulting mixture into a twin-screw extruder through a feed hopper, control the extrusion temperature at 200℃, and granulate it through melt extrusion.

[0044] The preparation method of the modified additive is shown in the preparation example. The antioxidant is a mixture of lignin and antioxidant 168 in a mass ratio of 1:0.3. The same applies to the following.

[0045] Example 2

[0046] A modified plastic composite masterbatch, comprising the following raw materials measured in parts by weight:

[0047] 70 parts of ethylene propylene diene monomer (EPDM) rubber, 15 parts of chlorinated polyethylene, 1.5 parts of vinyl bis-stearamide, 10 parts of maleic anhydride-grafted EPDM rubber, 5 parts of modifying additives, and 0.3 parts of antioxidant.

[0048] The preparation method of the plastic composite masterbatch includes the following steps:

[0049] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0050] Step 2: Add all raw materials to a high-speed mixer, control the speed to 400 r / min, and mechanically mix for 40 min. Then feed the resulting mixture into a twin-screw extruder through a feed hopper, control the extrusion temperature to 220℃, and granulate it through melt extrusion.

[0051] Example 3

[0052] A modified plastic composite masterbatch, comprising the following raw materials measured in parts by weight:

[0053] 75 parts of EPDM rubber, 18 parts of chlorinated polyethylene, 2 parts of vinyl bis-stearamide, 12 parts of maleic anhydride-grafted EPDM rubber, 5.5 parts of modifying additives, and 0.5 parts of antioxidant.

[0054] The preparation method of the plastic composite masterbatch includes the following steps:

[0055] Step 1: Weigh out each ingredient according to the specified weight proportions and set aside.

[0056] Step 2: Add all raw materials to a high-speed mixer, control the speed at 500 r / min, and mechanically mix for 30 minutes. Then feed the resulting mixture into a twin-screw extruder through a feed hopper, control the extrusion temperature at 240℃, and granulate it through melt extrusion.

[0057] Comparative Example 1

[0058] A modified plastic composite masterbatch differs from Example 2 in that the modified additive is replaced with pyrophyllite, while the rest are the same.

[0059] Comparative Example 2

[0060] A modified plastic composite masterbatch differs from Example 2 in that the modified additives are removed, while the rest are the same.

[0061] Test case

[0062] The plastic composite masterbatches from the examples and comparative examples were injection molded into test samples that met the test specifications, and the following performance tests were performed:

[0063] Mechanical properties were tested according to standard GB / T 528-2009;

[0064] According to standard GB / T 2406.2-2009, the limiting oxygen index test was conducted to evaluate the flame retardant performance.

[0065] The test results are recorded in Table 1:

[0066] Table 1 - Test Results

[0067] Analysis of the test results shows that the plastic composite material prepared in the embodiments of the present invention has good mechanical properties and flame retardant properties. After replacing the modified additive with pyrophyllite, the pyrophyllite may not be able to exert a high-efficiency reinforcing effect due to interface problems. At the same time, the loss of macromolecular modifiers leads to a significant decrease in the various properties of the material.

[0068] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified plastic composite masterbatch, characterized in that, Includes the following raw materials measured in parts by weight: 68-75 parts of ethylene propylene diene monomer (EPDM) rubber, 10-18 parts of chlorinated polyethylene, 1-2 parts of lubricant, 5-12 parts of compatibilizer, 2-5.5 parts of modifier additives, and 0.1-0.5 parts of antioxidant; The modified additive is pyrophyllite with an organically modified surface.

2. The modified plastic composite masterbatch according to claim 1, characterized in that, The lubricant is any one of polyethylene wax, paraffin wax, or vinyl bis-stearamide; the compatibilizer is maleic anhydride-grafted EPDM rubber.

3. The modified plastic composite masterbatch according to claim 1, characterized in that, The preparation method of the modified additive includes the following steps: Step A: Add pyrophyllite to an ethanol aqueous solution with a volume fraction of 50-70%. After the addition is complete, disperse it evenly by ultrasonication. Then, add the functionalized organic modifier to the formed uniform dispersion, adjust the pH to 3-4, raise the temperature to 60-70℃, and continue to stir for 4-8 hours. After that, stop heating, cool down and discharge the material. The crude product is washed and vacuum dried to obtain functionalized pyrophyllite. Step B: Functionalized pyrophyllite is ultrasonically dispersed in 1,4-dioxane, followed by the addition of a phosphorus-containing phenylenedialdehyde derivative and a catalyst. After the addition is complete, the temperature is raised to 60-70℃ and stirred for 3-6 hours. Then, aminoethyl sulfide is added. After the addition is complete, the temperature is further raised to 70-80℃ and stirred for 12-18 hours. The product is then cooled and discharged. The crude product is washed and vacuum dried to obtain the modified additive.

4. The modified plastic composite masterbatch according to claim 3, characterized in that, The functionalized organic modifier is KH-550 or KH-551.

5. The modified plastic composite masterbatch according to claim 3, characterized in that, The phosphorus-containing phenylenedialdehyde derivative was prepared using the following method: Pentaerythritol phosphate was added to N,N-dimethylformamide and stirred until homogeneous. Then, an aqueous hydroxide solution was added. After the addition was complete, the mixture was stirred at 50-60°C for 1-2 hours. Then, 5-bromoisophenylenedialdehyde was added. After the addition was complete, the temperature was raised to 75-85°C and the mixture was stirred for 4-8 hours. The solvent was then evaporated to remove the solvent. The crude product was purified to obtain a phosphorus-containing phenylenedialdehyde derivative.

6. The modified plastic composite masterbatch according to claim 5, characterized in that, The molar ratio of pentaerythritol phosphate to 5-bromoisobenzoic acid is 1:

1.

7. The modified plastic composite masterbatch according to claim 5, characterized in that, The hydroxide aqueous solution is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, with a mass fraction of 10-20%.

8. The modified plastic composite masterbatch according to claim 3, characterized in that, The catalyst is glacial acetic acid.

9. The modified plastic composite masterbatch according to claim 1, characterized in that, The antioxidant is a mixture of lignin and antioxidant 168 in a mass ratio of 1:0.2-0.

4.

10. A production process for the modified plastic composite masterbatch as described in claim 1, characterized in that, Includes the following steps: Step 1: Weigh out each ingredient according to the specified weight proportions and set aside. Step 2: Add all raw materials to a high-speed mixer, control the speed to 300-500 r / min, and mechanically mix for 30-60 min. Then feed the resulting mixture into a twin-screw extruder through a feed hopper, control the extrusion temperature to 200-240℃, and granulate it through melt extrusion.

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