Preparation process of anti-aging flame-retardant plastic particles

Abstract

The invention provides a preparation process of anti-aging flame-retardant plastic particles, and belongs to the technical field of plastic preparation. The preparation process comprises the following steps: preparing an organic intermediate; preparing a composite flame retardant; preparing a compound anti-aging agent; and preparing the anti-aging flame-retardant plastic particles. Plastic particles prepared from polypropylene, polytetrafluoroethylene, maleic anhydride grafted polypropylene, the wrapping modified composite flame retardant, the compound anti-aging agent and calcium stearate have good anti-aging and flame-retardant properties.

Description

Technical Field

[0001] The invention relates to the technical field of plastic preparation, and in particular 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 actual use, plastic materials 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] Regarding the aging problem, under the long-term effects of light, heat, oxygen, mechanical stress and other factors, plastics will undergo 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 significant reduction in mechanical properties. At the same time, most plastic materials are flammable substances. When a fire occurs, it is very easy to promote the spread of fire and release a large amount of toxic and harmful gases. Traditional flame-retardant plastics mostly use halogen flame retardants. Although they have good flame retardant effects, they will produce a large amount of toxic smoke and corrosive gases when burned, which does not meet the requirements of environmental protection regulations. In recent years, halogen-free flame retardant systems represented by phosphorus-nitrogen flame retardants can reduce environmental hazards, but they have poor compatibility with plastic matrices, which can easily lead to a decline in the mechanical properties of the material, and their anti-aging properties are insufficient. They are prone to degradation under long-term ultraviolet irradiation or high temperature environments.

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

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a preparation process of anti-aging flame-retardant plastic particles.

[0006] A preparation process of anti-aging flame-retardant plastic particles comprises the following steps: S1: Preparation of organic intermediates The organic intermediate is prepared by using p-formylbenzoic acid, glacial acetic acid and p-phenylenediamine as raw materials; S2: Preparation of composite flame retardant A cobalt-zinc solution is prepared by cobalt nitrate and zinc nitrate, and then reacted with an organic intermediate to prepare a flame retardant, and then the flame retardant is modified by a coupling agent, and finally magnesium chloride and ammonia water are added to react to prepare a composite flame retardant; S3: Preparation of compound anti-aging agent A bio-based antioxidant is prepared by reacting phytic acid with creatine, and then mixed with fluorinated silicon dioxide powder and nano-lignin in a mass ratio of 2-3:2:2 to prepare a compound antioxidant; S4: Preparation of anti-aging flame retardant plastic particles A composite flame retardant, dimethyl terephthalate, ethylene glycol, zinc acetate and a polycondensation catalyst are reacted to prepare a wrapped modified composite flame retardant, and 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.

[0007] Furthermore, the preparation of the organic intermediate in step S1 specifically comprises the following steps: S1.1: Add 2-3 parts by weight of p-formylbenzoic acid to 50-60 parts by weight of anhydrous ethanol, and then stir and mix for 20-30 minutes, and then add 1-2 parts by weight of glacial acetic acid, and mix to obtain a mixed solution; S1.2: adding 1-2 parts by weight of p-phenylenediamine to 50-60 parts by weight of anhydrous ethanol to obtain a p-phenylenediamine ethanol solution; S1.3: After mixing the mixed liquid and the ethanol solution of p-phenylenediamine, react at 68-70°C for 3-4 hours, then cool to room temperature and filter to obtain a crude product. Wash the crude product 2-3 times with a mixed solution of anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1, and then vacuum dry at 60-65°C for 12-14 hours to obtain an organic intermediate.

[0008] Furthermore, the preparation of the composite flame retardant in step S2 specifically includes the following steps: 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, and ultrasonically disperse for 20-30 minutes to obtain a cobalt-zinc solution, add 7-8 parts by weight of an organic intermediate to 10-12 parts by weight of methanol, and ultrasonically treat for 10-20 minutes 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 reactor, react at 160-180° C. for 12-14 hours, after the reaction is completed, wash with methanol for 2-3 hours, and then vacuum dry at 60-80° C. for 12-14 hours to obtain a flame retardant; S2.3: Disperse 2-3 parts by weight of the flame retardant in 20-30 parts by weight of anhydrous ethanol, and ultrasonically disperse for 20-30 minutes, then add 0.8-1% of the mass of the flame retardant silane coupling agent KH-550, adjust the pH to 4-5 with glacial acetic acid, stir and mix at 70-72°C for 4-6 hours, and then centrifuge, wash, and dry to obtain a coupling agent modified flame retardant; S2.4: Add 10-12 parts by weight of coupling agent modified flame retardant to 100-120 parts by weight of anhydrous ethanol, and then ultrasonically disperse for 10-12 minutes. Then, under magnetic stirring at 150-180r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, and add a 0.5 mol / L magnesium chloride solution at a rate of 3mL / min at 40-42°C. When the pH is 10, stop adding and continue the reaction for 60-70 minutes. Then filter, wash and dry to obtain a composite flame retardant.

[0009] Furthermore, step S3 of preparing the compound anti-aging agent specifically comprises the following steps: S3.1: 8-10 parts by weight of 70-80wt% phytic acid solution and 4-5 parts by weight of creatine powder are mixed and added into 50-60 parts by weight of deionized water, and then stirred at 60-65°C for 4-5h, and then rotary evaporated in a rotary evaporator until completely dry powder is obtained, which is a bio-based antioxidant; S3.2: Mix 1-2 parts by weight of silicon dioxide powder and 2-3 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter and add them into a quartz reactor. Place the quartz reactor between two circular metal electrodes and introduce CF 4 and Ar mixture, fluorination treatment to obtain fluorinated powder, placing the fluorinated powder in a tube furnace, calcining at 230-240° C. for 4-5 hours, and then grinding to obtain fluorinated silicon dioxide powder; S3.3: The bio-based antioxidant, fluorinated silica powder and nano-lignin are mixed in a mass ratio of 2-3:2:2, and then stirred and mixed at 300-400 r / min for 20-30 minutes to obtain a compound antioxidant.

[0010] Furthermore, step S4 of preparing anti-aging flame-retardant plastic particles specifically comprises 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, and perform ultrasonic dispersion for 5-10 minutes. 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. The reaction is completed when the amount of methanol evaporated reaches the theoretical amount. Then, add 0.1-0.2 parts by weight of a polycondensation catalyst, and react at 200-210°C for 1-2 hours. Then, vacuum to 13-15 Pa, and then heat to 285-290°C. React for 1-2 hours. Cool the reactant, wash and dry it to obtain a coated 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 encapsulated modified composite flame retardant, 7-12 parts by weight of compound anti-aging agent, and 2-5 parts by weight of calcium stearate into a mixer, mix for 30-50 minutes to obtain a mixture, add the mixture into a twin-screw extruder, extrude and granulate to obtain anti-aging flame retardant plastic particles.

[0011] Furthermore, the fluorination treatment in step S3.2 is specifically performed at 7-8 kV, 50-60 kHz for 15-20 min.

[0012] Furthermore, in step S3.2, CF 4 The flow ratio of the mixture with Ar is 1:10.

[0013] Furthermore, the extrusion granulation parameters in step S4.2 are 300-320 r / min, 180-200°C.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The flame retardant prepared by the present invention is prepared by coordinating with cobalt and zinc after synthesizing an organic intermediate, wherein the metal ions of cobalt and zinc can catalytically decompose the free radicals generated by the combustion of plastics at high temperature, interrupting 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, and the metal ions enhance the stability of the carbon layer by catalyzing cross-linking reactions, and the carbon layer can isolate heat and oxygen, delay combustion, and improve flame retardant properties; the aromatic structure of the organic intermediate can absorb ultraviolet light, reduce the molecular chain breakage and color change of the plastic caused by UV irradiation, and the metal-organic framework structure has high thermal stability, which can delay the thermal aging of the plastic in a high temperature environment. The flame retardant is added to the preparation of plastic particles, through the organic-inorganic synergistic effect, while improving the flame retardant grade of the plastic and imparting anti-aging properties.

[0015] 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.

[0016] 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

[0017] 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.

[0018] Figure 1 This is a process flow chart for preparing anti-aging and flame-retardant plastic particles used in an embodiment of the present invention.

[0019] Figure 2For organic intermediates １ HNMR spectrum.

[0020] Figure 3 This is the SEM image of the encapsulated modified composite flame retardant.

[0021] Figure 4 This is the TEM image of the encapsulated modified composite flame retardant. DETAILED DESCRIPTION

[0022] The following is a detailed description of the preparation process of an anti-aging flame-retardant plastic particle provided by the present invention in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternative methods to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0023] Organic intermediate structure:

[0024] Example 1 A preparation process of anti-aging flame retardant plastic particles, such as Figure 1 As shown, the following steps are included: S1: Preparation of organic intermediates S1.1: 2 parts by weight of p-formylbenzoic acid are added to 50 parts by weight of anhydrous ethanol, and then stirred for 20 minutes, and then 1 part by weight of glacial acetic acid is added, and mixed to obtain a mixed solution; S1.2: adding 1 part by weight of p-phenylenediamine to 50 parts by weight of anhydrous ethanol to obtain a p-phenylenediamine ethanol solution; S1.3: After mixing the mixed solution with the p-phenylenediamine ethanol solution, react at 68°C for 3 hours, then cool to room temperature and filter to obtain a crude product, wash the crude product twice with a mixed solution of anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1, and then vacuum dry at 60°C for 12 hours to obtain an organic intermediate; S2: Preparation of composite flame retardant S2.1: 2 parts by weight of cobalt nitrate and 1 part by weight of zinc nitrate are added to 10 parts by weight of methanol, and ultrasonically dispersed for 20 minutes to obtain a cobalt-zinc solution; 7 parts by weight of an organic intermediate are added to 10 parts by weight of methanol, and ultrasonically treated for 10 minutes to obtain an organic intermediate mixed solution; S2.2: After mixing the cobalt zinc solution and the organic intermediate mixed solution, 2 parts by weight of glacial acetic acid were added, and then the mixture was transferred to a hydrothermal reactor and reacted at 160° C. for 12 hours. After the reaction was completed, the mixture was washed with methanol for 2 hours, and then vacuum dried at 60° C. for 12 hours to obtain a flame retardant; S2.3: Disperse 2 parts by weight of the flame retardant in 20 parts by weight of anhydrous ethanol, and ultrasonically disperse for 20 minutes, then add 0.8% by weight of the flame retardant silane coupling agent KH-550, adjust the pH to 4 with glacial acetic acid, stir and mix at 70°C for 4 hours, and then centrifuge, wash, and dry to obtain a coupling agent modified flame retardant; S2.4: 10 parts by weight of coupling agent modified flame retardant are added to 100 parts by weight of anhydrous ethanol, and then ultrasonically dispersed for 10 minutes. Then, under magnetic stirring at 150 r / min, ammonia water is added to adjust the pH to 12, and the stirring speed is maintained. At 40°C, a magnesium chloride solution with a concentration of 0.5 mol / L is added dropwise at a rate of 3 mL / min. When the pH reaches 10, the addition is stopped, and the reaction is continued for 60 minutes. Then, suction filtration, washing, and drying are performed to obtain a composite flame retardant; S3: Preparation of compound anti-aging agent S3.1: 8 parts by weight of 70 wt% phytic acid solution and 4 parts by weight of creatine powder are mixed and added into 50 parts by weight of deionized water, followed by stirring and reacting at 60° C. for 4 h, and then rotary evaporating in a rotary evaporator until a completely dry powder is obtained, which is a bio-based antioxidant; S3.2: 1 part by weight of silica powder and 2 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter were mixed and added into a quartz reactor, the quartz reactor was placed between two circular metal electrodes, and CF 4 and Ar mixture, fluorination treatment was performed at 7 kV, 50 kHz for 15 min to obtain fluorinated powder, the fluorinated powder was placed in a tube furnace, calcined at 230 ° C for 4 h, and then ground to obtain fluorinated silicon dioxide powder; S3.3: The bio-based antioxidant, fluorinated silica powder and nano-lignin are mixed in a mass ratio of 1:1:1, and then stirred at 300 r / min for 20 minutes to obtain a composite antioxidant; S4: Preparation of anti-aging flame retardant plastic particles S4.1: Add 9 parts by weight of the composite flame retardant to 300 parts by weight of ethylene glycol, and disperse by ultrasonication for 5 minutes. Then, add 9 parts by weight of dimethyl terephthalate and 0.1 parts by weight of zinc acetate. Then, stir at 150 r / min and heat to 180°C. The reaction is terminated when the amount of methanol evaporated reaches the theoretical amount. Then, add 0.1 parts by weight of antimony trioxide, a polycondensation catalyst, and react at 200°C for 1 hour. Then, vacuum to 13 Pa, and then heat to 285°C and react for 1 hour. After the reactant is cooled, washed and dried, a coated modified composite flame retardant is obtained. 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 encapsulated modified composite flame retardant, 7 parts by weight of compound anti-aging agent, and 2 parts by weight of calcium stearate into a mixer, mix for 30 minutes to obtain a mixture, add the mixture into a twin-screw extruder, extrude and granulate at 300 r / min and 180°C to obtain anti-aging flame-retardant plastic particles.

[0025] Example 2 A preparation process of anti-aging flame retardant plastic particles, such as Figure 1 As shown, the following steps are included: S1: Preparation of organic intermediates S1.1: 2 parts by weight of p-formylbenzoic acid are added to 50 parts by weight of anhydrous ethanol, and then stirred for 30 minutes, and then 1 part by weight of glacial acetic acid is added, and mixed to obtain a mixed solution; S1.2: adding 1 part by weight of p-phenylenediamine to 50 parts by weight of anhydrous ethanol to obtain a p-phenylenediamine ethanol solution; S1.3: After mixing the mixed solution with the p-phenylenediamine ethanol solution, react at 70°C for 4 hours, then cool to room temperature and filter to obtain a crude product, wash the crude product three times with a mixed solution of anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1, and then vacuum dry at 65°C for 14 hours to obtain an organic intermediate; S2: Preparation of composite flame retardant S2.1: 2 parts by weight of cobalt nitrate and 1 part by weight of zinc nitrate are added to 10 parts by weight of methanol, and ultrasonically dispersed for 30 minutes to obtain a cobalt-zinc solution; 7 parts by weight of an organic intermediate are added to 10 parts by weight of methanol, and ultrasonically treated for 20 minutes to obtain an organic intermediate mixed solution; S2.2: After mixing the cobalt zinc solution and the organic intermediate mixed solution, 2 parts by weight of glacial acetic acid were added, and then the mixture was transferred to a hydrothermal reactor and reacted at 180° C. for 14 hours. After the reaction was completed, the mixture was washed with methanol for 3 hours, and then vacuum dried at 80° C. for 14 hours to obtain a flame retardant; S2.3: Disperse 2 parts by weight of the flame retardant in 20 parts by weight of anhydrous ethanol, and ultrasonically disperse for 30 minutes, then add 0.8% by weight of the flame retardant silane coupling agent KH-550, adjust the pH to 4 with glacial acetic acid, stir and mix at 72°C for 6 hours, and then centrifuge, wash, and dry to obtain a coupling agent modified flame retardant; S2.4: 10 parts by weight of coupling agent modified flame retardant are added to 100 parts by weight of anhydrous ethanol, followed by ultrasonic dispersion for 12 minutes, and then under magnetic stirring at 180 r / min, ammonia water is added to adjust the pH to 12, and the stirring speed is maintained. At 42°C, a magnesium chloride solution with a concentration of 0.5 mol / L is added dropwise at a rate of 3 mL / min. When the pH reaches 10, the addition is stopped, and the reaction is continued for 70 minutes, followed by suction filtration, washing, and drying to obtain a composite flame retardant; S3: Preparation of compound anti-aging agent S3.1: 8 parts by weight of 70 wt% phytic acid solution and 4 parts by weight of creatine powder are mixed and added into 50 parts by weight of deionized water, followed by stirring and reacting at 65° C. for 5 h, and then rotary evaporating in a rotary evaporator until completely dry powder is obtained, which is a bio-based antioxidant; S3.2: 1 part by weight of silica powder and 2 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter were mixed and added into a quartz reactor, the quartz reactor was placed between two circular metal electrodes, and CF 4 and Ar mixture, fluorination treatment was performed at 8 kV, 60 kHz for 20 min to obtain fluorinated powder, the fluorinated powder was placed in a tube furnace, calcined at 240 ° C for 5 h, and then ground to obtain fluorinated silicon dioxide powder; S3.3: The bio-based antioxidant, fluorinated silica powder and nano-lignin are mixed in a mass ratio of 1:1:1, and then stirred at 400 r / min for 30 min to obtain a composite antioxidant; S4: Preparation of anti-aging flame retardant plastic particles S4.1: Add 9 parts by weight of the composite flame retardant to 300 parts by weight of ethylene glycol, and ultrasonically disperse for 10 minutes. Then, add 9 parts by weight of dimethyl terephthalate and 0.1 parts by weight of zinc acetate. Then, stir at 180 r / min and heat to 185°C. The reaction is completed when the amount of methanol evaporated reaches the theoretical amount. Then, add 0.1 parts by weight of polycondensation catalyst germanium dioxide, react at 210°C for 2 hours, and then vacuum to 15 Pa, and then heat to 290°C and react for 2 hours. After the reactant is cooled, washed and dried, a coated modified composite flame retardant is obtained. 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 encapsulated modified composite flame retardant, 7 parts by weight of compound anti-aging agent, and 2 parts by weight of calcium stearate into a mixer, mix for 50 minutes to obtain a mixture, add the mixture into a twin-screw extruder, extrude and granulate at 320r / min and 200°C to obtain anti-aging flame-retardant plastic particles.

[0026] Example 3 A preparation process of anti-aging flame retardant plastic particles, such as Figure 1 As shown, the following steps are included: S1: Preparation of organic intermediates S1.1: 3 parts by weight of p-formylbenzoic acid are added to 60 parts by weight of anhydrous ethanol, and then stirred for 20 minutes, and then 2 parts by weight of glacial acetic acid are added, and mixed to obtain a mixed solution; S1.2: adding 2 parts by weight of p-phenylenediamine to 60 parts by weight of anhydrous ethanol to obtain a p-phenylenediamine ethanol solution; S1.3: After mixing the mixed solution with the p-phenylenediamine ethanol solution, react at 68°C for 3 hours, then cool to room temperature and filter to obtain a crude product, wash the crude product twice with a mixed solution of anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1, and then vacuum dry at 60°C for 12 hours to obtain an organic intermediate; S2: Preparation of composite flame retardant S2.1: 3 parts by weight of cobalt nitrate and 2 parts by weight of zinc nitrate are added to 12 parts by weight of methanol, and ultrasonically dispersed for 20 minutes to obtain a cobalt-zinc solution; 8 parts by weight of an organic intermediate are added to 12 parts by weight of methanol, and ultrasonically treated for 10 minutes to obtain an organic intermediate mixed solution; S2.2: After mixing the cobalt zinc solution and the organic intermediate mixed solution, 3 parts by weight of glacial acetic acid were added, and then the mixture was transferred to a hydrothermal reactor and reacted at 160° C. for 12 hours. After the reaction was completed, the mixture was washed with methanol for 2 hours, and then vacuum dried at 60° C. for 12 hours to obtain a flame retardant; S2.3: Disperse 3 parts by weight of the flame retardant in 30 parts by weight of anhydrous ethanol, and ultrasonically disperse for 20 minutes, then add 1% by weight of the flame retardant silane coupling agent KH-550, adjust the pH to 5 with glacial acetic acid, stir and mix at 70°C for 4 hours, and then centrifuge, wash, and dry to obtain a coupling agent modified flame retardant; S2.4: 12 parts by weight of coupling agent modified flame retardant are added to 120 parts by weight of anhydrous ethanol, and then ultrasonically dispersed for 10 minutes. Then, under magnetic stirring at 150 r / min, ammonia water is added to adjust the pH to 12, and the stirring speed is maintained. At 40°C, a magnesium chloride solution with a concentration of 0.5 mol / L is added dropwise at a rate of 3 mL / min. When the pH reaches 10, the addition is stopped, and the reaction is continued for 60 minutes. Then, suction filtration, washing, and drying are performed to obtain a composite flame retardant; S3: Preparation of compound anti-aging agent S3.1: 10 parts by weight of 80 wt% phytic acid solution and 5 parts by weight of creatine powder are mixed and added into 60 parts by weight of deionized water, and then stirred at 60° C. for 4 h, and then rotary evaporated in a rotary evaporator until completely dry powder is obtained, which is a bio-based antioxidant; S3.2: 2 parts by weight of silica powder and 3 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter were mixed and added into a quartz reactor, the quartz reactor was placed between two circular metal electrodes, and CF 4 and Ar mixture, fluorination treatment was performed at 7 kV, 50 kHz for 15 min to obtain fluorinated powder, the fluorinated powder was placed in a tube furnace, calcined at 230 ° C for 4 h, and then ground to obtain fluorinated silicon dioxide powder; S3.3: The bio-based antioxidant, fluorinated silicon dioxide powder and nano-lignin are mixed in a mass ratio of 3:2:2, and then stirred at 300 r / min for 20 min to obtain a composite antioxidant; S4: Preparation of anti-aging flame retardant plastic particles S4.1: Add 12 parts by weight of the composite flame retardant to 400 parts by weight of ethylene glycol, and disperse by ultrasonication for 5 minutes. 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 is completed when the amount of methanol evaporated reaches the theoretical amount. Then, add 0.2 parts by weight of titanium dioxide, a polycondensation catalyst, and react at 200°C for 1 hour. Then, vacuum to 13 Pa, and then heat to 285°C and react for 1 hour. After the reactant is cooled, washed and dried, a coated modified composite flame retardant is obtained. 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 encapsulated modified composite flame retardant, 12 parts by weight of compound anti-aging agent, and 5 parts by weight of calcium stearate into a mixer, mix for 30 minutes to obtain a mixture, add the mixture into a twin-screw extruder, extrude and granulate at 300 r / min and 180°C to obtain anti-aging flame-retardant plastic particles.

[0027] Comparative Example 1 Compared with Example 1, the difference of 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 the other steps remain unchanged to prepare anti-aging flame retardant plastic particles, which is recorded as Comparative Example 1.

[0028] Comparative Example 2 Compared with Example 1, the difference of Comparative Example 2 is that Comparative Example 2 removes steps S2.3-S2.4, replaces the composite flame retardant in step S4.1 with the flame retardant, and prepares anti-aging flame-retardant plastic particles without changing the other steps, which is recorded as Comparative Example 2.

[0029] Comparative Example 3 Compared with Example 1, the difference of 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 the flame retardant, and the other steps remain unchanged to prepare anti-aging flame retardant plastic particles, which is recorded as Comparative Example 3.

[0030] Comparative Example 4 Compared with Example 1, the difference of 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 the other steps remain unchanged to prepare the anti-aging flame retardant plastic particles, which is recorded as Comparative Example 4.

[0031] Comparative Example 5 Compared with Example 1, the difference of 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 other steps remain unchanged to prepare anti-aging flame-retardant plastic particles, which is recorded as Comparative Example 5.

[0032] Comparative Example 6 Compared with Example 1, the difference of Comparative Example 6 is that, in Comparative Example 6, the fluorinated silicon dioxide powder in steps S3.2 and S3.3 is removed, and the other steps remain unchanged to prepare the anti-aging flame-retardant plastic particles, which is recorded as Comparative Example 6.

[0033] Comparative Example 7 Compared with Example 1, the difference of Comparative Example 7 is that, in Comparative Example 7, the medium-nano lignin in step S3.3 is removed, and the other steps remain unchanged to prepare the anti-aging flame-retardant plastic particles, which is recorded as Comparative Example 7.

[0034] Comparative Example 8 Compared with Example 1, the difference of Comparative Example 8 is that, in Comparative Example 8, the compound anti-aging agent in steps S3 and S4.2 is removed, and the other steps remain unchanged to prepare the anti-aging flame-retardant plastic particles, which is recorded as Comparative Example 7.

[0035] The limiting oxygen index of the anti-aging flame-retardant plastic particles prepared in Examples 1-3, Comparative Examples 1-4 and Comparative Example 8 was measured according to GB / T2406-2008. The measurement results are shown in Table 1.

[0036] Table 1. Limiting oxygen index of Examples 1-3, Comparative Examples 1-4, and Comparative Example 8

[0037] From the data of Table 1 and Comparative Examples 1-4, it can be seen that the prepared double-shell flame retardant effectively improves the flame retardant properties 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 properties of the plastic particles.

[0038] 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.

[0039] Table 2. Determination results of tensile strength and elongation at break of Examples 1-3 and Comparative Example 1

[0040] From the data in Table 2, it can be seen that the microencapsulation technology is used to encapsulate it to produce a double-shell flame retardant. The encapsulation process effectively improves the dispersion of the flame retardant between the plastic matrix, thereby effectively improving the mechanical properties of the plastic.

[0041] The tensile strength of Examples 1-3 and Comparative Examples 4-8 was measured, and then the irradiation intensity was 600W / m 2 The cumulative irradiation is 400kWh / m 2 , detect the tensile strength after light aging, carry out hot air aging under the conditions of 200℃×30 days, detect the tensile strength after hot air aging, and refer to Table 3 for the measurement results.

[0042] Table 3. Anti-aging test results of Examples 1-3 and Comparative Examples 4-8

[0043] From the data in Table 3 and Comparative Example 4, it can be seen that the encapsulated modified composite flame retardant can improve the anti-aging properties of the plastic. From the data in Comparative Examples 6-8, it can be seen that the compound anti-aging agent effectively improves the anti-aging properties of the plastic particles through the triple protection mechanism of "bio-based antioxidant-fluorinated hydrophobic shielding-lignin ultraviolet absorption". The three can produce a synergistic anti-aging effect from multiple angles, thereby effectively improving the anti-aging properties of the plastic particles.

[0044] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A process for preparing anti-aging flame-retardant plastic particles, characterized in that: The steps include: S1: Preparation of organic intermediates The organic intermediate is prepared by using p-formylbenzoic acid, glacial acetic acid and p-phenylenediamine as raw materials; S2: Preparation of composite flame retardant A cobalt-zinc solution is prepared by cobalt nitrate and zinc nitrate, and then reacted with an organic intermediate to prepare a flame retardant, and then the flame retardant is modified by a coupling agent, and finally magnesium chloride and ammonia water are added to react to prepare a composite flame retardant; S3: Preparation of compound anti-aging agent A bio-based antioxidant is prepared by reacting phytic acid with creatine, and then mixed with fluorinated silicon dioxide powder and nano-lignin in a mass ratio of 2-3:2:2 to prepare a compound antioxidant; S4: Preparation of anti-aging flame retardant plastic particles A composite flame retardant, dimethyl terephthalate, ethylene glycol, zinc acetate and a polycondensation catalyst are reacted to prepare a wrapped modified composite flame retardant, and 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 process for preparing anti-aging flame-retardant plastic particles according to claim 1, characterized in that: Step S1: Preparation of organic intermediates, specifically comprising the following steps: S1.1: Add 2-3 parts by weight of p-formylbenzoic acid to 50-60 parts by weight of anhydrous ethanol, and then stir and mix for 20-30 minutes, and then add 1-2 parts by weight of glacial acetic acid, and mix to obtain a mixed solution; S1.2: adding 1-2 parts by weight of p-phenylenediamine to 50-60 parts by weight of anhydrous ethanol to obtain a p-phenylenediamine ethanol solution; S1.3: After mixing the mixed liquid and the ethanol solution of p-phenylenediamine, react at 68-70°C for 3-4 hours, then cool to room temperature and filter to obtain a crude product. Wash the crude product 2-3 times with a mixed solution of anhydrous methanol and anhydrous ethanol in a volume ratio of 1:1, and then vacuum dry at 60-65°C for 12-14 hours to obtain an organic intermediate.

3. The preparation process of the anti-aging flame-retardant plastic particles according to claim 2, characterized in that: Step S2: Preparation of the composite flame retardant, specifically comprising the following steps: 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, and ultrasonically disperse for 20-30 minutes to obtain a cobalt-zinc solution, add 7-8 parts by weight of an organic intermediate to 10-12 parts by weight of methanol, and ultrasonically treat for 10-20 minutes 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 reactor, react at 160-180° C. for 12-14 hours, after the reaction is completed, wash with methanol for 2-3 hours, and then vacuum dry at 60-80° C. for 12-14 hours to obtain a flame retardant; S2.3: Disperse 2-3 parts by weight of the flame retardant in 20-30 parts by weight of anhydrous ethanol, and ultrasonically disperse for 20-30 minutes, then add 0.8-1% of the mass of the flame retardant silane coupling agent KH-550, adjust the pH to 4-5 with glacial acetic acid, stir and mix at 70-72°C for 4-6 hours, and then centrifuge, wash, and dry to obtain a coupling agent modified flame retardant; S2.4: Add 10-12 parts by weight of coupling agent modified flame retardant to 100-120 parts by weight of anhydrous ethanol, and then ultrasonically disperse for 10-12 minutes. Then, under magnetic stirring at 150-180r / min, add ammonia water to adjust the pH to 12, maintain the stirring speed, and add a 0.5 mol / L magnesium chloride solution at a rate of 3mL / min at 40-42°C. When the pH is 10, stop adding and continue the reaction for 60-70 minutes. Then filter, wash and dry to obtain a composite flame retardant.

4. The process for preparing anti-aging flame-retardant plastic particles according to claim 3, characterized in that: Step S3 is the preparation of a composite anti-aging agent, which specifically comprises the following steps: S3.1: 8-10 parts by weight of 70-80wt% phytic acid solution and 4-5 parts by weight of creatine powder are mixed and added into 50-60 parts by weight of deionized water, and then stirred at 60-65°C for 4-5h, and then rotary evaporated in a rotary evaporator until completely dry powder is obtained, which is a bio-based antioxidant; S3.2: 1-2 parts by weight of silica powder and 2-3 parts by weight of 2H-perfluorodecyltrimethoxysilane organic matter are mixed and added into a quartz reactor, the quartz reactor is placed between two circular metal electrodes, and a mixture of CF4 and Ar is introduced to perform fluorination treatment to obtain a fluorinated powder, the fluorinated powder is placed in a tube furnace, calcined at 230-240° C. for 4-5 hours, and then ground to obtain fluorinated silica powder; S3.3: The bio-based antioxidant, fluorinated silica powder and nano-lignin are mixed in a mass ratio of 2-3:2:2, and then stirred and mixed at 300-400 r / min for 20-30 minutes to obtain a compound antioxidant.

5. The process for preparing anti-aging flame-retardant plastic particles according to claim 4, characterized in that: Step S4 is the preparation of anti-aging flame-retardant plastic particles, which 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, and perform ultrasonic dispersion for 5-10 minutes. 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. The reaction is completed when the amount of methanol evaporated reaches the theoretical amount. Then, add 0.1-0.2 parts by weight of a polycondensation catalyst, and react at 200-210°C for 1-2 hours. Then, vacuum to 13-15 Pa, and then heat to 285-290°C. React for 1-2 hours. Cool the reactant, wash and dry it to obtain a coated 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 encapsulated modified composite flame retardant, 7-12 parts by weight of compound anti-aging agent, and 2-5 parts by weight of calcium stearate into a mixer, mix for 30-50 minutes to obtain a mixture, add the mixture into a twin-screw extruder, extrude and granulate to obtain anti-aging flame retardant plastic particles.

6. The process for preparing anti-aging flame-retardant plastic particles according to claim 4, characterized in that: The fluorination treatment in step S3.2 is specifically performed at 7-8 kV, 50-60 kHz for 15-20 min.

7. The process for preparing anti-aging flame-retardant plastic particles according to claim 4, characterized in that: The flow ratio of the CF4 and Ar mixture in step S3.2 is 1:

10.

8. The process for preparing anti-aging flame-retardant plastic particles according to claim 5, characterized in that: The extrusion granulation parameters in step S4.2 are 300-320 r / min, 180-200°C.

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