Preparation process of an anti-aging and flame-retardant plastic particle

Abstract

The present invention provides a preparation process of anti-aging flame-retardant plastic particles, belonging to the technical field of plastic preparation; the preparation process includes the following steps: preparation of organic intermediates; preparation of composite flame retardants; preparation of compound anti-aging agents; preparation of anti-aging flame-retardant plastic particles. The plastic particles prepared by the present invention from polypropylene, polytetrafluoroethylene, maleic anhydride grafted polypropylene, encapsulated modified composite flame retardants, compound anti-aging agents, and calcium stearate have good anti-aging and flame-retardant properties.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic preparation, and specifically relates to a preparation process of anti-aging and flame-retardant plastic particles. Background Art

[0002] In modern industry and daily life, plastic products are widely used in many important fields such as construction, electronic appliances, and automobile manufacturing due to their outstanding advantages such as light weight, low cost, and convenient processing. However, in the actual use process of plastic materials, they often face two major problems: aging and fire hazards, which not only seriously affect the service life of plastic products, but also pose a threat to people's lives and property safety.

[0003] In terms of the aging problem, under the long-term action of various factors such as light, heat, oxygen, and mechanical stress, plastic will undergo the degradation and cross-linking of macromolecular chains, resulting in a significant decline in the physical and chemical properties of the material, such as powdering and cracking on the surface, and a substantial reduction in mechanical properties. At the same time, most plastic materials are flammable substances. In the event of a fire, they are extremely likely to fuel the spread of the fire and release a large amount of toxic and harmful gases. Traditional flame-retardant plastics mostly use halogen-based flame retardants. Although they have good flame-retardant effects, they will produce a large amount of toxic smoke and corrosive gases when burning, which does not meet the requirements of environmental protection regulations. In recent years, although the halogen-free flame-retardant system represented by phosphorus-nitrogen flame retardants can reduce environmental hazards, its compatibility with the plastic matrix is poor, which easily leads to a decline in the mechanical properties of the material and insufficient anti-aging performance, and is prone to degradation under long-term ultraviolet irradiation or high-temperature environments.

[0004] Therefore, we propose a preparation process of anti-aging and flame-retardant plastic particles. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a preparation process of anti-aging and flame-retardant plastic particles.

[0006] A preparation process of anti-aging and flame-retardant plastic particles includes the following steps:

[0007] S1: Preparation of organic intermediate

[0008] Use p-formylbenzoic acid, glacial acetic acid, and p-phenylenediamine as raw materials to prepare an organic intermediate;

[0009] S2: Preparation of composite flame retardant

[0010] Prepare a cobalt-zinc solution from cobalt nitrate and zinc nitrate, then react with the organic intermediate to prepare a flame retardant, then modify the flame retardant with a coupling agent, and finally add magnesium chloride and ammonia water to react to prepare a composite flame retardant;

[0011] S3: Preparation of compound anti-aging agent

[0012] A bio-based anti-aging agent is prepared by reacting phytic acid with creatine, and then it is mixed with fluorinated silica powder and nano-lignin in a mass ratio of 2 - 3:2:2 to prepare a compound anti-aging agent;

[0013] S4: Preparation of anti-aging flame-retardant plastic particles

[0014] A compound flame retardant, dimethyl terephthalate, ethylene glycol, zinc acetate and a polycondensation catalyst are used for reaction to prepare a coated modified compound flame retardant. Then, 120 - 130 parts by weight of polypropylene, 38 - 45 parts by weight of polytetrafluoroethylene, 15 - 23 parts by weight of maleic anhydride grafted polypropylene, 12 - 15 parts by weight of the coated modified compound flame retardant, 7 - 12 parts by weight of the compound anti-aging agent, and 2 - 5 parts by weight of calcium stearate are mixed and granulated to obtain anti-aging flame-retardant plastic particles.

[0015] Furthermore, the preparation of the organic intermediate in step S1 specifically includes the following steps:

[0016] S1.1: Add 2 - 3 parts by weight of p-formylbenzoic acid to 50 - 60 parts by weight of absolute ethanol, stir and mix for 20 - 30 min, then add 1 - 2 parts by weight of glacial acetic acid, and a mixed solution is obtained after mixing;

[0017] S1.2: Add 1 - 2 parts by weight of p-phenylenediamine to 50 - 60 parts by weight of absolute ethanol to obtain a p-phenylenediamine ethanol solution;

[0018] S1.3: After mixing the mixed solution and the p-phenylenediamine ethanol solution, react at 68 - 70 °C for 3 - 4 h, then cool to room temperature and filter by suction to obtain a crude product. Wash the crude product 2 - 3 times with a mixed solution of absolute methanol and absolute ethanol in a volume ratio of 1:1, and then vacuum dry at 60 - 65 °C for 12 - 14 h to obtain the organic intermediate.

[0019] Furthermore, the preparation of the compound flame retardant in step S2 specifically includes the following steps:

[0020] S2.1: Add 2 - 3 parts by weight of cobalt nitrate and 1 - 2 parts by weight of zinc nitrate to 10 - 12 parts by weight of methanol, ultrasonically disperse for 20 - 30 min to obtain a cobalt-zinc solution, and add 7 - 8 parts by weight of the organic intermediate to 10 - 12 parts by weight of methanol, ultrasonically treat for 10 - 20 min to obtain an organic intermediate mixed solution;

[0021] S2.2: After mixing the cobalt-zinc solution and the organic intermediate mixed solution, add 2 - 3 parts by weight of glacial acetic acid, then transfer to a hydrothermal reaction kettle, react at 160 - 180 °C for 12 - 14 h. After the reaction is completed, wash with methanol for 2 - 3 h, and then vacuum dry at 60 - 80 °C for 12 - 14 h to obtain the flame retardant;

[0022] S2.3: Disperse 2 - 3 parts by weight of the flame retardant in 20 - 30 parts by weight of absolute ethanol, ultrasonically disperse for 20 - 30 min, then add 0.8 - 1% of silane coupling agent KH - 550 based on the mass of the flame retardant, adjust the pH to 4 - 5 with glacial acetic acid, stir and mix at 70 - 72 °C for 4 - 6 h, then centrifuge, wash, and dry to obtain the coupling agent - modified flame retardant;

[0023] S2.4: Add 10 - 12 parts by weight of the coupling agent - modified flame retardant to 100 - 120 parts by weight of absolute ethanol, then ultrasonically disperse for 10 - 12 min, then under magnetic stirring at 150 - 180 r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, at 40 - 42 °C, dropwise add a magnesium chloride solution with a concentration of 0.5 mol / L at a rate of 3 mL / min. When the pH is 10, stop dropping and continue to react for 60 - 70 min, then perform suction filtration, wash, and dry to obtain the composite flame retardant.

[0024] Further, the preparation of the compound anti - aging agent in step S3 specifically includes the following steps:

[0025] S3.1: Mix 8 - 10 parts by weight of a 70 - 80 wt% phytic acid solution and 4 - 5 parts by weight of creatine powder, then add them to 50 - 60 parts by weight of deionized water, then stir and react at 60 - 65 °C for 4 - 5 h, then perform rotary evaporation in a rotary evaporator until completely dry powder is obtained, which is the bio - based anti - aging agent;

[0026] S3.2: Mix 1 - 2 parts by weight of silicon dioxide powder and 2 - 3 parts by weight of 2H - perfluorodecyltrimethoxysilane organic matter, then add them to a quartz reaction kettle. Place the quartz reaction kettle between two circular metal electrodes, introduce a CF4 and Ar mixture, and perform fluorination treatment to obtain the fluorinated - treated powder. Place the fluorinated - treated powder in a tubular furnace and calcine at 230 - 240 °C for 4 - 5 h, then grind and crush to obtain the fluorinated silicon dioxide powder;

[0027] S3.3: Mix the bio - based anti - aging agent, fluorinated silicon dioxide powder, and nano - lignin in a mass ratio of 2 - 3:2:2, then stir and mix at 300 - 400 r / min for 20 - 30 min to obtain the compound anti - aging agent.

[0028] Further, the preparation of the anti - aging flame - retardant plastic particles in step S4 specifically includes the following steps:

[0029] S4.1: Add 9 - 12 parts by weight of the composite flame retardant to 300 - 400 parts by weight of ethylene glycol, disperse ultrasonically for 5 - 10 min, then add 9 - 10 parts by weight of dimethyl terephthalate and 0.1 - 0.2 parts by weight of zinc acetate. Then stir at 150 - 180 r / min and heat to 180 - 185 °C. React until the amount of methanol distilled out reaches the theoretical amount, then add 0.1 - 0.2 parts by weight of the polycondensation catalyst and react at 200 - 210 °C for 1 - 2 h. Then evacuate to 13 - 15 Pa, then raise the temperature to 285 - 290 °C and react for 1 - 2 h. Cool the reactant, wash and dry to obtain the encapsulated modified composite flame retardant;

[0030] S4.2: Add 120 - 130 parts by weight of polypropylene, 38 - 45 parts by weight of polytetrafluoroethylene, 15 - 23 parts by weight of maleic anhydride grafted polypropylene, 12 - 15 parts by weight of the encapsulated modified composite flame retardant, 7 - 12 parts by weight of the compound anti - aging agent, and 2 - 5 parts by weight of calcium stearate into a mixer, mix for 30 - 50 min to obtain a mixed material. Add the mixed material into a twin - screw extruder, extrude and pelletize to obtain the anti - aging flame - retardant plastic particles.

[0031] Further, the fluorination treatment in step S3.2 is specifically carried out at 7 - 8 kV and 50 - 60 kHz for 15 - 20 min.

[0032] Further, the flow rate ratio of the CF4 and Ar mixture in step S3.2 is 1:10.

[0033] Further, the extrusion and pelletizing parameters in step S4.2 are 300 - 320 r / min and 180 - 200 °C.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] 1. The flame retardant prepared by the present invention through synthesizing an organic intermediate and then coordinating with cobalt and zinc. Among them, the metal ions of cobalt and zinc can catalyze the decomposition of free radicals generated by plastic combustion at high temperature, interrupt the combustion chain reaction. And the organic intermediate containing aromatic rings and imine structures can promote the formation of a dense carbon layer during combustion, while the metal ions enhance the stability of the carbon layer through catalytic cross - linking reactions. This carbon layer can isolate heat and oxygen, delay combustion, and improve the flame - retardant performance; the aromatic structure of the organic intermediate can absorb ultraviolet light, reduce the molecular chain breakage and color change of plastics caused by UV irradiation, and the metal - organic framework structure has high thermal stability, which can delay the thermal aging of plastics in high - temperature environments. Adding this flame retardant to the preparation of plastic particles through the organic - inorganic synergistic effect can endow anti - aging performance while improving the flame - retardant grade of plastics.

[0036] 2. The present invention first modifies the flame retardant by a coupling agent to increase active sites, so as to facilitate the subsequent wrapping of magnesium hydroxide on the surface of the modified flame retardant. Secondly, the microcapsule technology is used to encapsulate the flame retardant to prepare a flame retardant with a double shell structure. The encapsulation treatment effectively improves the agglomeration of the flame retardant and promotes its dispersion in the plastic matrix. At the same time, the silane coupling agent pretreatment promotes the chemical bonding between the polyester layer and the flame retardant. At the same time, the non-polar chain segment of the coupling agent is compatible with the plastic matrix, which improves the compatibility of the flame retardant with the plastic, thereby improving the mechanical properties of the plastic. After the outer capsule is broken, the inner layer of magnesium hydroxide first decomposes and absorbs heat to delay the fire; the inner layer of modified flame retardant then releases active ingredients to catalyze carbonization to form a multi-level flame retardant response. The introduction of the magnesium hydroxide wrapping layer can further improve the flame retardant properties of the material, and the compactness, continuity and thermal stability of the carbon layer generated by the combustion of the double-shell structure flame retardant are greatly improved, thereby effectively improving the flame retardant properties of the plastic particles, and also improving the compatibility of the flame retardant with the plastic matrix and improving its mechanical properties.

[0037] 3. The phytic acid molecule in the present invention contains 6 phosphate groups, which can effectively remove hydroxyl radicals and peroxy radicals generated during the oxidation process of plastics, inhibit chain oxidation reactions, and 2H-perfluorodecyltrimethoxysilane forms a perfluoroalkyl chain layer on the surface of silica through chemical bonding, thereby improving hydrophobicity, effectively blocking water penetration, and inhibiting plastic hydrolysis caused by wet heat aging. The CF bond energy formed by plasma fluorination is high, which can resist acid, alkali and organic solvent erosion, and prolong the life of plastics in harsh environments. The surface polarity of fluorinated silica is reduced, and the compatibility with the plastic matrix is ​​improved, reducing agglomeration, and the polyphenol structure and Conjugated double bonds can absorb ultraviolet rays and reduce chain breakage and yellowing of plastics caused by light aging. The phenolic hydroxyl groups of lignin form a hydrogen bond network with the phytic acid-creatine system to synergistically capture free radicals and improve the antioxidant efficiency. The compound antioxidant effectively improves the anti-aging properties of plastic particles through the triple protection mechanism of "bio-based antioxidant-fluorinated hydrophobic shielding-lignin ultraviolet absorption". The carbonization tendency of nano-lignin is combined with the carbonization layer of the previous flame retardant to enhance the density of the carbon layer during combustion. The phosphate decomposition products of phytic acid can catalyze the carbonization of the flame retardant system to form a "flame retardant-antioxidant" dual-functional carbon layer, further improving the flame retardant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, further serve to explain the principles of the invention and to enable those skilled in the relevant art to make and use the invention.

[0039] Figure 1 The present invention is a flow chart of a process for preparing anti-aging flame-retardant plastic particles used in an embodiment of the present invention.

[0040] Figure 2For the organic intermediate １ 1H NMR spectrum.

[0041] Figure 3 SEM image of the encapsulated modified composite flame retardant.

[0042] Figure 4 TEM image of the encapsulated modified composite flame retardant. Detailed implementation manners

[0043] The preparation process of an anti-aging flame-retardant plastic particle provided by the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted here that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0044] Structural formula of the organic intermediate:

[0045]

[0046] Example 1

[0047] A preparation process of an anti-aging flame-retardant plastic particle, as Figure 1 shown, includes the following steps:

[0048] S1: Preparation of the organic intermediate

[0049] S1.1: Add 2 parts by weight of p-formylbenzoic acid to 50 parts by weight of absolute ethanol, stir and mix for 20 min, then add 1 part by weight of glacial acetic acid, and obtain a mixed solution after mixing;

[0050] S1.2: Add 1 part by weight of p-phenylenediamine to 50 parts by weight of absolute ethanol to obtain a p-phenylenediamine ethanol solution;

[0051] S1.3: After mixing the mixed solution and the p-phenylenediamine ethanol solution, react at 68 °C for 3 h, then cool to room temperature and filter by suction to obtain a crude product. Wash the crude product 2 times with a mixed solution of absolute methanol and absolute ethanol with a volume ratio of 1:1, and then vacuum dry at 60 °C for 12 h to obtain the organic intermediate;

[0052] S2: Preparation of the composite flame retardant

[0053] S2.1: Add 2 parts by weight of cobalt nitrate and 1 part by weight of zinc nitrate to 10 parts by weight of methanol, ultrasonically disperse for 20 min to obtain a cobalt-zinc solution, and add 7 parts by weight of the organic intermediate to 10 parts by weight of methanol, ultrasonically treat for 10 min to obtain an organic intermediate mixed solution;

[0054] S2.2: Mix the cobalt-zinc solution and the organic intermediate mixture, add 2 parts by weight of glacial acetic acid, then transfer to a hydrothermal reaction kettle, react at 160 °C for 12 h. After the reaction is completed, wash with methanol for 2 h, then dry in vacuum at 60 °C for 12 h to obtain the flame retardant;

[0055] S2.3: Disperse 2 parts by weight of the flame retardant in 20 parts by weight of absolute ethanol, ultrasonically disperse for 20 min, then add 0.8% by mass of the silane coupling agent KH-550 based on the mass of the flame retardant, adjust the pH to 4 with glacial acetic acid, stir and mix at 70 °C for 4 h, then centrifuge, wash, and dry to obtain the coupling agent-modified flame retardant;

[0056] S2.4: Add 10 parts by weight of the coupling agent-modified flame retardant to 100 parts by weight of absolute ethanol, then ultrasonically disperse for 10 min, then under magnetic stirring at 150 r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, at 40 °C, dropwise add a magnesium chloride solution with a concentration of 0.5 mol / L at a rate of 3 mL / min. When the pH is 10, stop dropping and continue to react for 60 min, then carry out suction filtration, washing, and drying to obtain the composite flame retardant;

[0057] S3: Preparation of the compound anti-aging agent

[0058] S3.1: Mix 8 parts by weight of a 70 wt% phytic acid solution and 4 parts by weight of creatine powder, add 50 parts by weight of deionized water, then stir and react at 60 °C for 4 h, then carry out rotary evaporation in a rotary evaporator until completely dry powder is obtained, which is the bio-based anti-aging agent;

[0059] S3.2: Mix 1 part by weight of silicon dioxide powder and 2 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter, add to a quartz reaction kettle, place the quartz reaction kettle between two circular metal electrodes, and introduce a CF4 and Ar mixture with a flow ratio of 1:10, carry out fluorination treatment at 7 kV and 50 kHz for 15 min to obtain the fluorinated powder. Place the fluorinated powder in a tubular furnace, calcine at 230 °C for 4 h, then grind and pulverize to obtain the fluorinated silicon dioxide powder;

[0060] S3.3: Mix the bio-based anti-aging agent, the fluorinated silicon dioxide powder, and nano-lignin in a mass ratio of 1:1:1, then stir and mix at 300 r / min for 20 min to obtain the compound anti-aging agent;

[0061] S4: Preparation of the anti-aging flame retardant plastic particles

[0062] S4.1: Add 9 parts by weight of the composite flame retardant to 300 parts by weight of ethylene glycol, ultrasonically disperse for 5 min, then add 9 parts by weight of dimethyl terephthalate and 0.1 part by weight of zinc acetate. Then stir at 150 r / min and heat to 180 °C. When the amount of methanol distilled out reaches the theoretical amount, the reaction ends. Then add 0.1 part by weight of the polycondensation catalyst antimony trioxide, react at 200 °C for 1 h, then evacuate to 13 Pa, then raise the temperature to 285 °C and react for 1 h. Cool the reactant, wash and dry to obtain the encapsulated modified composite flame retardant;

[0063] S4.2: Add 120 parts by weight of polypropylene, 38 parts by weight of polytetrafluoroethylene, 15 parts by weight of maleic anhydride grafted polypropylene, 12 parts by weight of the encapsulated modified composite flame retardant, 7 parts by weight of the compound anti-aging agent, and 2 parts by weight of calcium stearate into a mixer, mix for 30 min to obtain a mixed material. Add the mixed material into a twin-screw extruder and extrude and pelletize at 300 r / min and 180 °C to obtain the anti-aging flame retardant plastic particles.

[0064] Example 2

[0065] A preparation process of anti-aging flame retardant plastic particles, as Figure 1 shown, includes the following steps:

[0066] S1: Preparation of organic intermediate

[0067] S1.1: Add 2 parts by weight of p-formylbenzoic acid to 50 parts by weight of absolute ethanol, then stir and mix for 30 min, then add 1 part by weight of glacial acetic acid, and obtain a mixed solution after mixing;

[0068] S1.2: Add 1 part by weight of p-phenylenediamine to 50 parts by weight of absolute ethanol to obtain a p-phenylenediamine ethanol solution;

[0069] S1.3: After mixing the mixed solution and the p-phenylenediamine ethanol solution, react at 70 °C for 4 h, then cool to room temperature and filter to obtain a crude product. Wash the crude product 3 times with a mixed solution of absolute methanol and absolute ethanol with a volume ratio of 1:1, and then vacuum dry at 65 °C for 14 h to obtain the organic intermediate;

[0070] S2: Preparation of composite flame retardant

[0071] S2.1: Add 2 parts by weight of cobalt nitrate and 1 part by weight of zinc nitrate to 10 parts by weight of methanol, ultrasonically disperse for 30 min to obtain a cobalt-zinc solution, and add 7 parts by weight of the organic intermediate to 10 parts by weight of methanol, ultrasonically treat for 20 min to obtain an organic intermediate mixed solution;

[0072] S2.2: Mix the cobalt-zinc solution and the organic intermediate mixture, add 2 parts by weight of glacial acetic acid, then transfer to a hydrothermal reaction kettle and react at 180 °C for 14 h. After the reaction is completed, wash with methanol for 3 h, and then dry in vacuum at 80 °C for 14 h to obtain a flame retardant;

[0073] S2.3: Disperse 2 parts by weight of the flame retardant in 20 parts by weight of absolute ethanol, ultrasonically disperse for 30 min, then add 0.8% by mass of the silane coupling agent KH-550 based on the mass of the flame retardant, adjust the pH to 4 with glacial acetic acid, stir and mix at 72 °C for 6 h, then centrifuge, wash, and dry to obtain a coupling agent-modified flame retardant;

[0074] S2.4: Add 10 parts by weight of the coupling agent-modified flame retardant to 100 parts by weight of absolute ethanol, then ultrasonically disperse for 12 min, then under magnetic stirring at 180 r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, and at 42 °C, dropwise add a magnesium chloride solution with a concentration of 0.5 mol / L at a rate of 3 mL / min. When the pH is 10, stop dropping and continue to react for 70 min, then perform suction filtration, wash, and dry to obtain a composite flame retardant;

[0075] S3: Preparation of compound anti-aging agent

[0076] S3.1: Mix 8 parts by weight of a 70 wt% phytic acid solution and 4 parts by weight of creatine powder, add 50 parts by weight of deionized water, then stir and react at 65 °C for 5 h, and then perform rotary evaporation in a rotary evaporator until completely dry powder is obtained, which is a bio-based anti-aging agent;

[0077] S3.2: Mix 1 part by weight of silicon dioxide powder and 2 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter, add to a quartz reaction kettle, place the quartz reaction kettle between two circular metal electrodes, and introduce a mixture of CF4 and Ar with a flow ratio of 1:10, perform fluorination treatment at 8 kV and 60 kHz for 20 min to obtain a fluorinated powder. Place the fluorinated powder in a tubular furnace and calcine at 240 °C for 5 h, then grind and crush to obtain fluorinated silicon dioxide powder;

[0078] S3.3: Mix the bio-based anti-aging agent, fluorinated silicon dioxide powder, and nano-lignin in a mass ratio of 1:1:1, then stir and mix at 400 r / min for 30 min to obtain a compound anti-aging agent;

[0079] S4: Preparation of anti-aging flame retardant plastic particles

[0080] S4.1: Add 9 parts by weight of the composite flame retardant to 300 parts by weight of ethylene glycol, ultrasonically disperse for 10 min, then add 9 parts by weight of dimethyl terephthalate and 0.1 part by weight of zinc acetate. Then stir at 180 r / min and heat to 185 °C. When the amount of methanol distilled out reaches the theoretical amount, the reaction ends. Then add 0.1 part by weight of the polycondensation catalyst germanium dioxide and react at 210 °C for 2 h. Then evacuate to 15 Pa, then raise the temperature to 290 °C and react for 2 h. Cool the reactant, wash and dry to obtain the encapsulated modified composite flame retardant;

[0081] S4.2: Add 120 parts by weight of polypropylene, 38 parts by weight of polytetrafluoroethylene, 15 parts by weight of maleic anhydride grafted polypropylene, 12 parts by weight of the encapsulated modified composite flame retardant, 7 parts by weight of the compound anti-aging agent, and 2 parts by weight of calcium stearate to a mixer and mix for 50 min to obtain a mixed material. Add the mixed material to a twin-screw extruder and extrude and pelletize at 320 r / min and 200 °C to obtain the anti-aging flame retardant plastic particles.

[0082] Example 3

[0083] A preparation process of anti-aging flame retardant plastic particles, as Figure 1 shown, includes the following steps:

[0084] S1: Preparation of organic intermediate

[0085] S1.1: Add 3 parts by weight of p-formylbenzoic acid to 60 parts by weight of absolute ethanol, then stir and mix for 20 min, then add 2 parts by weight of glacial acetic acid, and obtain a mixed solution after mixing;

[0086] S1.2: Add 2 parts by weight of p-phenylenediamine to 60 parts by weight of absolute ethanol to obtain a p-phenylenediamine ethanol solution;

[0087] S1.3: After mixing the mixed solution and the p-phenylenediamine ethanol solution, react at 68 °C for 3 h, then cool to room temperature and filter to obtain a crude product. Wash the crude product 2 times with a mixed solution of absolute methanol and absolute ethanol with a volume ratio of 1:1, and then vacuum dry at 60 °C for 12 h to obtain the organic intermediate;

[0088] S2: Preparation of composite flame retardant

[0089] S2.1: Add 3 parts by weight of cobalt nitrate and 2 parts by weight of zinc nitrate to 12 parts by weight of methanol, ultrasonically disperse for 20 min to obtain a cobalt-zinc solution, add 8 parts by weight of the organic intermediate to 12 parts by weight of methanol, and ultrasonically treat for 10 min to obtain an organic intermediate mixed solution;

[0090] S2.2: Mix the cobalt-zinc solution and the organic intermediate mixture, add 3 parts by weight of glacial acetic acid, then transfer to a hydrothermal reaction kettle and react at 160 °C for 12 h. After the reaction is completed, wash with methanol for 2 h, and then vacuum dry at 60 °C for 12 h to obtain the flame retardant;

[0091] S2.3: Disperse 3 parts by weight of the flame retardant in 30 parts by weight of absolute ethanol, ultrasonically disperse for 20 min, then add 1% by mass of the silane coupling agent KH-550 based on the mass of the flame retardant, adjust the pH to 5 with glacial acetic acid, stir and mix at 70 °C for 4 h, then centrifuge, wash, and dry to obtain the coupling agent-modified flame retardant;

[0092] S2.4: Add 12 parts by weight of the coupling agent-modified flame retardant to 120 parts by weight of absolute ethanol, then ultrasonically disperse for 10 min, then under magnetic stirring at 150 r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, and at 40 °C, add a magnesium chloride solution with a concentration of 0.5 mol / L at a rate of 3 mL / min. When the pH reaches 10, stop adding and continue to react for 60 min, then perform suction filtration, washing, and drying to obtain the composite flame retardant;

[0093] S3: Preparation of the compound anti-aging agent

[0094] S3.1: Mix 10 parts by weight of an 80 wt% phytic acid solution and 5 parts by weight of creatine powder, add 60 parts by weight of deionized water, then stir and react at 60 °C for 4 h, and then perform rotary evaporation in a rotary evaporator until completely dry powder is obtained, which is the bio-based anti-aging agent;

[0095] S3.2: Mix 2 parts by weight of silicon dioxide powder and 3 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter, add to a quartz reaction kettle, place the quartz reaction kettle between two circular metal electrodes, and introduce a mixture of CF4 and Ar with a flow ratio of 1:10, perform fluorination treatment at 7 kV and 50 kHz for 15 min to obtain the fluorinated powder. Place the fluorinated powder in a tubular furnace and calcine at 230 °C for 4 h, then grind and crush to obtain the fluorinated silicon dioxide powder;

[0096] S3.3: Mix the bio-based anti-aging agent, the fluorinated silicon dioxide powder, and nano-lignin in a mass ratio of 3:2:2, and then stir and mix at 300 r / min for 20 min to obtain the compound anti-aging agent;

[0097] S4: Preparation of the anti-aging flame retardant plastic particles

[0098] S4.1: Add 12 parts by weight of the composite flame retardant to 400 parts by weight of ethylene glycol, disperse ultrasonically for 5 min, then add 10 parts by weight of dimethyl terephthalate and 0.2 parts by weight of zinc acetate, then stir at 150 r / min and heat to 180 °C. The reaction ends when the methanol distillation amount reaches the theoretical amount. Then add 0.2 parts by weight of the polycondensation catalyst titanium dioxide, react at 200 °C for 1 h, then evacuate to 13 Pa, then raise the temperature to 285 °C and react for 1 h. Cool the reaction product, wash and dry it to obtain the encapsulated modified composite flame retardant;

[0099] S4.2: Add 130 parts by weight of polypropylene, 45 parts by weight of polytetrafluoroethylene, 23 parts by weight of maleic anhydride grafted polypropylene, 15 parts by weight of the encapsulated modified composite flame retardant, 12 parts by weight of the compound anti-aging agent, and 5 parts by weight of calcium stearate into a mixer, mix for 30 min to obtain a mixed material. Add the mixed material into a twin-screw extruder and extrude and pelletize at 300 r / min and 180 °C to obtain the anti-aging flame retardant plastic particles.

[0100] Comparative Example 1

[0101] Compared with Example 1, the difference in Comparative Example 1 is that Comparative Example 1 removes step S4.1, replaces the encapsulated modified composite flame retardant in step S4.2 with the composite flame retardant in step S2.4, and prepares the anti-aging flame retardant plastic particles with the remaining steps unchanged, denoted as Comparative Example 1.

[0102] Comparative Example 2

[0103] Compared with Example 1, the difference in Comparative Example 2 is that Comparative Example 2 removes steps S2.3 - S2.4, replaces the composite flame retardant in step S4.1 with a flame retardant, and prepares the anti-aging flame retardant plastic particles with the remaining steps unchanged, denoted as Comparative Example 2.

[0104] Comparative Example 3

[0105] Compared with Example 1, the difference in Comparative Example 3 is that Comparative Example 3 removes steps S2.3 - S2.4 and S4.1, replaces the encapsulated modified composite flame retardant in step S4.2 with a flame retardant, and prepares the anti-aging flame retardant plastic particles with the remaining steps unchanged, denoted as Comparative Example 3.

[0106] Comparative Example 4

[0107] Compared with Example 1, the difference in Comparative Example 4 is that Comparative Example 4 removes the encapsulated modified composite flame retardant in steps S1 - S2, S4.1 and S4.2, and prepares the anti-aging flame retardant plastic particles with the remaining steps unchanged, denoted as Comparative Example 4.

[0108] Comparative Example 5

[0109] Compared with Example 1, the difference in Comparative Example 5 is that in Comparative Example 5, the bio-based anti-aging agent in Steps S3.1 and S3.3 is removed, and the remaining steps remain unchanged to prepare anti-aging flame-retardant plastic particles, denoted as Comparative Example 5.

[0110] Comparative Example 6

[0111] Compared with Example 1, the difference in Comparative Example 6 is that in Comparative Example 6, the fluorinated silica powder in Steps S3.2 and S3.3 is removed, and the remaining steps remain unchanged to prepare anti-aging flame-retardant plastic particles, denoted as Comparative Example 6.

[0112] Comparative Example 7

[0113] Compared with Example 1, the difference in Comparative Example 7 is that in Comparative Example 7, the meso-nano lignin in Step S3.3 is removed, and the remaining steps remain unchanged to prepare anti-aging flame-retardant plastic particles, denoted as Comparative Example 7.

[0114] Comparative Example 8

[0115] Compared with Example 1, the difference in Comparative Example 8 is that in Comparative Example 8, the compound anti-aging agent in Steps S3 and S4.2 is removed, and the remaining steps remain unchanged to prepare anti-aging flame-retardant plastic particles, denoted as Comparative Example 7.

[0116] The limiting oxygen index of the anti-aging flame-retardant plastic particles prepared in Examples 1-3 and Comparative Examples 1-4 and Comparative Example 8 was measured according to GB / T2406-2008, and the measurement results are shown in Table 1 for reference.

[0117] Table 1. Limiting oxygen index of Examples 1-3 and Comparative Examples 1-4 and Comparative Example 8

[0118]

[0119] From the data of Comparative Examples 1-4 in Table 1, it can be seen that the prepared flame retardant with a double-shell structure effectively improves the flame retardant performance of the plastic particles. From the data of Comparative Example 8, it can be seen that the addition of the compound anti-aging agent can synergistically improve the flame retardant performance of the plastic particles.

[0120] The tensile strength of Examples 1-3 and Comparative Example 1 was measured according to GB / T1040.2-2022, and the impact performance was tested according to GB / T1843-2008. The measurement results are shown in Table 2 for reference.

[0121] Table 2. Measurement results of tensile strength and elongation at break of Examples 1-3 and Comparative Example 1

[0122]

[0123] As can be seen from the data in Table 2, the use of microencapsulation technology to encapsulate it resulted in a flame retardant with a double-shell structure. The encapsulation treatment effectively improved the dispersion of the flame retardant between the plastic matrices, thereby effectively enhancing the mechanical properties of the plastic.

[0124] The tensile strength was measured for Examples 1-3 and Comparative Examples 4-8, and then irradiated with ultraviolet light having an irradiance of 600 W / m 2 , and the cumulative irradiation dose was 400 kWh / m 2 . The tensile strength after photoaging was detected, and thermal air aging was carried out under the conditions of 200°C × 30 days, and the tensile strength after thermal air aging was detected. The measurement results are shown in Table 3 for reference.

[0125] Table 3. Anti-aging measurement results of Examples 1-3 and Comparative Examples 4-8

[0126]

[0127] As can be seen from the data of Comparative Example 4 in Table 3, the encapsulated modified composite flame retardant can improve the anti-aging performance of the plastic. As can be seen from the data of Comparative Examples 6-8, the compound anti-aging agent effectively improves the anti-aging performance of the plastic particles through the triple protection mechanism of "bio-based antioxidant-fluorinated hydrophobic shielding-lignin ultraviolet absorption". From multiple perspectives, a synergistic anti-aging effect can be generated among the three, thereby effectively enhancing the anti-aging performance of the plastic particles.

[0128] The above embodiments merely illustrate the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation process of anti-aging flame-retardant plastic particles, characterized in that, It includes the following steps: S1: Preparation of organic intermediate S1.1: Add 2 - 3 parts by weight of p - formylbenzoic acid to 50 - 60 parts by weight of absolute ethanol, stir and mix for 20 - 30 min, then add 1 - 2 parts by weight of glacial acetic acid to obtain a mixed solution; S1.2: Add 1 - 2 parts by weight of p - phenylenediamine to 50 - 60 parts by weight of absolute ethanol to obtain a p - phenylenediamine ethanol solution; S1.3: After mixing the mixed solution and the p - phenylenediamine ethanol solution, react at 68 - 70 °C for 3 - 4 h, then cool to room temperature and filter by suction to obtain a crude product. Wash the crude product 2 - 3 times with a mixed solution of absolute methanol and absolute ethanol with a volume ratio of 1:1, and then vacuum - dry at 60 - 65 °C for 12 - 14 h to obtain the organic intermediate; S2: Preparation of composite flame retardant S2.1: Add 2 - 3 parts by weight of cobalt nitrate and 1 - 2 parts by weight of zinc nitrate to 10 - 12 parts by weight of methanol, ultrasonically disperse for 20 - 30 min to obtain a cobalt - zinc solution. Add 7 - 8 parts by weight of the organic intermediate to 10 - 12 parts by weight of methanol and ultrasonically treat for 10 - 20 min to obtain an organic intermediate mixed solution; S2.2: After mixing the cobalt - zinc solution and the organic intermediate mixed solution, add 2 - 3 parts by weight of glacial acetic acid, then transfer to a hydrothermal reaction kettle and react at 160 - 180 °C for 12 - 14 h. After the reaction is completed, wash with methanol for 2 - 3 h, and then vacuum - dry at 60 - 80 °C for 12 - 14 h to obtain the flame retardant; S2.3: Disperse 2 - 3 parts by weight of the flame retardant in 20 - 30 parts by weight of absolute ethanol, ultrasonically disperse for 20 - 30 min, then add 0.8 - 1% of the silane coupling agent KH - 550 based on the mass of the flame retardant, adjust the pH to 4 - 5 with glacial acetic acid, stir and mix at 70 - 72 °C for 4 - 6 h, then centrifuge, wash, and dry to obtain the coupling - agent - modified flame retardant; S2.4: Add 10 - 12 parts by weight of the coupling - agent - modified flame retardant to 100 - 120 parts by weight of absolute ethanol, ultrasonically disperse for 10 - 12 min, then under magnetic stirring at 150 - 180 r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, at 40 - 42 °C, dropwise add a magnesium chloride solution with a concentration of 0.5 mol / L at a rate of 3 mL / min. When the pH is 10, stop dropping and continue to react for 60 - 70 min, then perform suction filtration, washing, and drying to obtain the composite flame retardant; S3: Preparation of compound anti - aging agent Prepare a bio - based anti - aging agent by reacting phytic acid with creatine, and then mix it with silicon dioxide fluoride powder and nano - lignin in a mass ratio of 2 - 3:2:2 to prepare the compound anti - aging agent; S4: Preparation of anti - aging flame - retardant plastic particles A wrapped modified composite flame retardant is prepared by reacting a composite flame retardant, dimethyl terephthalate, ethylene glycol, zinc acetate and a polycondensation catalyst. Then, 120-130 parts by weight of polypropylene, 38-45 parts by weight of polytetrafluoroethylene, 15-23 parts by weight of maleic anhydride grafted polypropylene, 12-15 parts by weight of the wrapped modified composite flame retardant, 7-12 parts by weight of a compound anti-aging agent, and 2-5 parts by weight of calcium stearate are mixed and granulated to obtain anti-aging flame retardant plastic particles.

2. The preparation process of an anti-aging and flame-retardant plastic particle according to claim 1, wherein, The preparation of the compound anti-aging agent in step S3 specifically includes the following steps: S3.1: Mix 8-10 parts by weight of a 70-80 wt% phytic acid solution and 4-5 parts by weight of creatine powder, add them to 50-60 parts by weight of deionized water, then stir and react at 60-65 °C for 4-5 h, and then perform rotary evaporation in a rotary evaporator until completely dry powder is obtained, which is the bio-based anti-aging agent; S3.2: Mix 1-2 parts by weight of silica powder and 2-3 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter, add them to a quartz reaction kettle, place the quartz reaction kettle between two circular metal electrodes, introduce a mixture of CF4 and Ar, and perform fluorination treatment to obtain the fluorinated powder. Place the fluorinated powder in a tubular furnace and calcine it at 230-240 °C for 4-5 h, and then grind and crush it to obtain fluorinated silica powder; S3.3: Mix the bio-based anti-aging agent, fluorinated silica powder and nano-lignin in a mass ratio of 2-3:2:2, and then stir and mix at 300-400 r / min for 20-30 min to obtain the compound anti-aging agent.

3. The preparation process of an anti-aging and flame-retardant plastic particle according to claim 2, wherein, The preparation of the anti-aging flame retardant plastic particles in step S4 specifically includes the following steps: S4.1: Add 9-12 parts by weight of the composite flame retardant to 300-400 parts by weight of ethylene glycol, ultrasonically disperse for 5-10 min, then add 9-10 parts by weight of dimethyl terephthalate and 0.1-0.2 parts by weight of zinc acetate, then stir and heat to 180-185 °C at 150-180 r / min. When the amount of methanol distilled out reaches the theoretical amount, the reaction ends. Then add 0.1-0.2 parts by weight of the polycondensation catalyst and react at 200-210 °C for 1-2 h. Then evacuate to 13-15 Pa, then raise the temperature to 285-290 °C and react for 1-2 h. Cool the reactant and wash and dry it to obtain the wrapped modified composite flame retardant; S4.2: Add 120-130 parts by weight of polypropylene, 38-45 parts by weight of polytetrafluoroethylene, 15-23 parts by weight of maleic anhydride grafted polypropylene, 12-15 parts by weight of the wrapped modified composite flame retardant, 7-12 parts by weight of the compound anti-aging agent, and 2-5 parts by weight of calcium stearate to a mixer, mix for 30-50 min to obtain a mixed material, and add the mixed material to a twin-screw extruder for extrusion granulation to obtain anti-aging flame retardant plastic particles.

4. The preparation process of an anti-aging and flame-retardant plastic particle according to claim 2, characterized in that, The fluorination treatment in step S3.2 is specifically carried out at 7-8 kV and 50-60 kHz for 15-20 min.

5. The preparation process of an anti-aging and flame-retardant plastic particle according to claim 2, characterized in that, The flow ratio of the CF4 and Ar mixture in step S3.2 is 1:

10.

6. The preparation process of an anti-aging and flame-retardant plastic particle according to claim 3, characterized in that, The extrusion granulation parameters in step S4.2 are 300 - 320 r / min and 180 - 200 °C.

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