Environment-friendly waterproof flame-retardant packaging product and processing technology thereof

Abstract

The invention discloses an environment-friendly waterproof flame-retardant packaging product and a processing technology thereof, and relates to the technical field of packaging products, a preparation method of the packaging product comprises the following steps: mixing recycled corrugated carton fibers and rubber wood fibers in proportion, carrying out alkali treatment, and washing to be neutral to obtain a pretreated paper base; the preparation method comprises the following steps: mixing a sodium silicate solution, a siloxane normal hexane dispersion liquid, a cellulose nanofiber composite dispersion liquid, a polylactic acid blend and a polyelectrolyte compound in proportion, and ultrasonically dispersing uniformly to obtain an environment-friendly composite impregnation liquid; the polyelectrolyte compound is prepared by mixing a polyethylenediamine aqueous solution and a sodium polyphosphate aqueous solution in equal volume; immersing the pretreated paper base into the environment-friendly composite impregnation liquid, adding a hydrochloric acid solution, carrying out impregnation reaction, and carrying out vacuum filtration to obtain a modified wet product; immersing the modified wet-state product into a glutaraldehyde cross-linking agent, carrying out a cross-linking reaction, carrying out vacuum drying, and cutting and finishing to obtain the environment-friendly waterproof flame-retardant packaging product.

Description

Technical Field

[0001] This invention relates to the field of packaging product technology, specifically to an environmentally friendly, waterproof, and flame-retardant packaging product and its processing technology. Background Technology

[0002] Packaging products, as key supporting materials in the storage, transportation, and sales of goods, are widely used in various fields such as food, electronics, logistics, and industrial products. Their performance directly affects the safety and shelf life of goods. With the increasing global awareness of environmental protection and the increasingly stringent regulations, traditional packaging products have gradually exposed many problems that urgently need to be addressed. Traditional packaging materials mostly rely on non-renewable petroleum-based raw materials, which easily generate pollutants during the production process and are difficult to degrade or recycle after disposal. Long-term accumulation can easily cause environmental pollution. Some packaging products that use recycled raw materials often suffer from significant performance degradation due to improper raw material processing or unreasonable formulations, making it difficult to meet actual usage requirements. At the same time, paper-based packaging products easily absorb moisture from the environment due to the hydrophilic properties of cellulose, leading to reduced strength, deformation, or even damage, which in turn affects the quality of the goods inside, especially in humid environments or long-distance transportation. This problem is even more prominent in China. Traditional waterproofing treatments often use halogenated compounds, paraffin wax, and other ingredients, which are not only environmentally unfriendly but may also pose a risk of harmful substance residues. Most packaging products are themselves flammable or combustible materials, which can easily burn rapidly when exposed to a fire source, causing fire hazards. Especially for product packaging in the electronics and chemical industries, the lack of flame retardant properties can cause serious property damage and safety risks. Existing flame-retardant packaging often achieves its flame-retardant effect by adding halogenated flame retardants and other chemical substances. These substances easily release toxic and harmful gases when burning, posing a threat to the environment and human health, and are contrary to environmental protection trends. Packaging products made from bio-based materials or recycled fibers often have problems such as insufficient strength, poor toughness, and weak tear resistance, making it difficult to withstand external forces such as squeezing and collisions during transportation, which limits their application in heavy-duty or precision product packaging.

[0003] Based on the above situation, developing a packaging product that uses environmentally friendly and renewable raw materials, has a simple process, and can simultaneously achieve excellent waterproof, highly effective flame retardancy, and good mechanical properties has become an important development direction in the current packaging field. It is of great significance for promoting the green transformation of the packaging industry and reducing safety risks. Summary of the Invention

[0004] The purpose of this invention is to provide an environmentally friendly, waterproof, and flame-retardant packaging product and its processing technology to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A processing technology for an environmentally friendly, waterproof, and flame-retardant packaging product includes the following steps: S1: Paper base pretreatment: Recycled corrugated cardboard fiber and rubberwood fiber are mixed in a certain proportion, subjected to alkali treatment, washed until neutral, and dried at 50-60℃ for 8-12 hours to obtain pretreated paper base; S2: Preparation of environmentally friendly composite impregnation solution: Sodium silicate solution, siloxane-hexane dispersion, cellulose nanofiber composite dispersion, polylactic acid blend and polyelectrolyte complex are mixed in proportion and ultrasonically dispersed evenly to obtain environmentally friendly composite impregnation solution. The components in the preparation of the environmentally friendly composite impregnation solution are as follows (by mass percentage): sodium silicate solution 40-60 wt%, siloxane-hexane dispersion 15-25 wt%, cellulose nanofiber composite dispersion 10-20 wt%, polylactic acid blend 5-15 wt%, and polyelectrolyte complex 3-8 wt%. The ultrasonic dispersion is carried out at a temperature of 25-35℃ for 40-80 min. S3: Impregnation modification: The pretreated paper base is immersed in an environmentally friendly composite impregnation solution, hydrochloric acid solution is added, impregnation reaction is carried out, and vacuum filtration is performed to obtain the modified wet product; In the preparation process of the modified wet product, the mass ratio of pretreated paper base to environmentally friendly composite impregnation solution is 1:(5-10); the hydrochloric acid solution is prepared by diluting 37wt% hydrochloric acid to 0.5-1.5mol / L; the impregnation reaction temperature is 25-35℃, and the reaction time is 30-60min; the vacuum filtration vacuum degree is 70-90kPa, and the time is 10-30min; the water content of the modified wet product is 40-60wt%. S4: Crosslinking and curing: The modified wet product is immersed in glutaraldehyde crosslinking agent, crosslinking reaction occurs, vacuum drying is performed, and cutting and finishing are carried out to obtain environmentally friendly waterproof and flame-retardant packaging products. In the preparation process of environmentally friendly waterproof and flame-retardant packaging products, the mass ratio of modified wet product to glutaraldehyde crosslinking agent is 1:(8-15); the crosslinking reaction temperature is 30-40℃, and the crosslinking time is 20-40 min; the glutaraldehyde crosslinking agent is prepared by diluting 50wt% glutaraldehyde solution to 0.3-0.8wt%; the vacuum drying temperature is 40-60℃, and the drying time is 12-24 h; the moisture content of the environmentally friendly waterproof and flame-retardant packaging products is 8-12wt%. The recycled corrugated cardboard fiber is prepared by crushing and separating waste corrugated cardboard; the rubberwood fiber is prepared by mechanically crushing and separating rubberwood processing waste. In the preparation of the pretreated paper base, the mass ratio of recovered corrugated cardboard fiber to rubberwood fiber is (30-70):(70-30); the alkaline treatment process uses 2-5wt% sodium hydroxide solution, the treatment temperature is 60-80℃, and the treatment time is 1-2h; the mass ratio of the total mass of recovered corrugated cardboard fiber and rubberwood fiber to the mass of sodium hydroxide solution is 1:(10-20). The concentration of the sodium silicate solution is 5-10 wt%; The concentration of the siloxane-n-hexane dispersion is 1.64-2.44 wt%. The viscosity of the siloxane in the siloxane-hexane dispersion is 100±80 mPa·s; The preparation method of the cellulose nanofiber composite dispersion includes the following steps: adding dried bleached cork pulp to a mixed aqueous solution of ammonium dihydrogen phosphate and urea, heating to 80-85℃ and soaking for 30-40 min, drying to constant weight at 105-110℃, curing at 140-160℃ for 15-25 min, washing the product until the conductivity is ≤20μS / cm, adjusting the pH to 9-10 with sodium hydroxide solution, preparing a 0.3-0.8wt% suspension, ultrasonically dispersing for 1.5-2.5 h, centrifuging to obtain a phosphorylated cellulose nanofiber dispersion; In the preparation of phosphorylated cellulose nanofiber dispersion, the mass ratio of dried bleached cork pulp: ammonium dihydrogen phosphate: urea is 1:(0.3-0.5):(1.5-2.0). Chitosan powder was added to a 30-35 wt% sodium hydroxide solution, heated to 85-95℃ and reacted for 2.5-3.5 h. After washing until neutral, a 0.3-0.8 wt% suspension was prepared. The pH was adjusted to 3-4 with acetic acid and ultrasonically dispersed for 1.5-2.5 h to obtain an acetylated chitosan nanocrystal dispersion. In the preparation of acetylated chitin nanocrystal dispersion, the mass ratio of chitin to 30-35 wt% sodium hydroxide solution is 1:(20-30). Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed in a certain proportion and ultrasonically dispersed for 20-30 min to obtain cellulose nanofiber composite dispersion. In the preparation of cellulose nanofiber composite dispersion, the mass ratio of phosphorylated cellulose nanofiber dispersion to acetylated chitin nanocrystal dispersion is (50-70):(50-30). The preparation method of the polylactic acid blend includes the following steps: adding polylactic acid, 1,4-butanediol, octadecenylsuccinic anhydride and zinc acetate into a reaction vessel, heating to 200-205℃ and reacting for 3-3.5h, cooling to 160-165℃ and continuing to react for 45-50min to obtain a polylactic acid-based compound; In the preparation of polylactic acid-based compounds, the mass ratio of polylactic acid:1,4-butanediol:octadecenylsuccinic anhydride is 1:(0.03-0.07):(0.12-0.25); the amount of zinc acetate added is 1% of the mass of polylactic acid. Add polybutylene succinate, maleic anhydride, and dicumyl peroxide to a mixer, heat to 180-185℃ and mix for 3-5 minutes to obtain modified polybutylene succinate. In the preparation of modified polybutylene succinate, the mass ratio of polybutylene succinate: maleic anhydride: dicumyl peroxide is 100:(5-10):2. Polylactic acid-based compounds and modified polybutylene succinate were melt-blended in a certain proportion to obtain polylactic acid blends; In the preparation of polylactic acid blends, the mass ratio of polylactic acid-based compound to modified polybutylene succinate is (70-85):(30-15). The preparation method of the polyelectrolyte complex includes the following steps: mixing equal volumes of polyethylene glycol aqueous solution and sodium polyphosphate aqueous solution, heating to 70-72℃ and annealing for 2-2.5 hours to obtain the polyelectrolyte complex; In the preparation of the polyelectrolyte complex, the concentration of the polyethylene glycol aqueous solution is 15 wt%, and the concentration of the sodium polyphosphate aqueous solution of the same volume is 45 wt%.

[0006] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention first treats recycled corrugated cardboard fiber and rubberwood fiber with alkali to remove lignin, hemicellulose and impurities from the fiber surface, expose cellulose hydroxyl groups, and roughen the fiber surface. On the one hand, it enhances the reactivity of the fiber with the functional groups in the subsequent impregnation solution, and on the other hand, it improves the bonding force between fibers, laying the foundation for the subsequent improvement of mechanical properties. Secondly, using sodium silicate solution as an inorganic silicon source, a dense siloxane network is formed during subsequent curing, enhancing thermal stability; in conjunction with the migration of hydrophobic segments in the siloxane-hexane dispersion to the material surface, the surface energy is reduced, imparting preliminary waterproofing. Furthermore, the phosphorus groups of phosphorylated cellulose nanofibers in the cellulose nanofiber composite dispersion serve as the flame-retardant core, while the nitrogen groups of acetylated chitosan nanocrystals synergize with the phosphorus. Simultaneously, the two combine through electrostatic interaction, enhancing the stability of the dispersion. The nanofibers fill the voids in the paper base, increasing the structural density. The negative charge introduced during the phosphorylation process interacts with the positive charge of the subsequent polyelectrolyte complex, promoting the uniform adhesion of the impregnation solution to the paper base. Next, polylactic acid (PLA) compounds provide rigidity, while modified polybutylene succinate (PBS) provides flexibility. The compatibility of the two is improved after melt blending, forming a continuous polymer film on the paper base surface to block moisture and oxygen. At the same time, the biodegradability of PLA ensures environmental friendliness, and modified PBS improves the crack resistance of the material. Finally, the complex formed by polyethylene glycol and sodium polyphosphate in the polyelectrolyte complex enhances the adhesion of the impregnation solution through ionic bonding. At the same time, phosphate ions further supplement flame retardant elements and work synergistically with phosphorus in cellulose nanofibers to improve flame retardant efficiency.

[0007] 2. This invention removes excess liquid through vacuum filtration, allowing functional components to be uniformly adsorbed on the fiber surface and internal pores, forming a composite structure of fiber-layered functional layers, laying the foundation for waterproof and flame-retardant properties. Furthermore, the aldehyde groups of glutaraldehyde react with the hydroxyl groups of the fibers, the amino / hydroxyl groups in the polylactic acid blend, and the amino groups in the polyelectrolyte complex to form a three-dimensional network structure. This structure locks in the functional components in the impregnation liquid, reducing loss during use; it also reduces the material's hygroscopicity while enhancing the bonding force between fibers and between fibers and the impregnation layer, improving mechanical properties and structural stability, and ensuring the long-lasting waterproof and flame-retardant properties of the prepared environmentally friendly waterproof and flame-retardant packaging products. Detailed Implementation

[0008] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0009] Example 1: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 300g of recycled corrugated cardboard fiber and 700g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 60:40 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate were added to a reaction vessel, heated to 200℃ and reacted for 3h, then cooled to 160℃ and reacted for 45min. After cooling, polylactic acid-based compounds were obtained. Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 80:20. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 55 wt% sodium silicate solution, 20 wt% siloxane-hexane dispersion, 15 wt% cellulose nanofiber composite dispersion, 7 wt% polylactic acid blend, and 3 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0010] Example 2: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 500g of recycled corrugated cardboard fiber and 500g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 55:45 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate were added to a reaction vessel, heated to 200℃ and reacted for 3h, then cooled to 160℃ and reacted for 45min. After cooling, polylactic acid-based compounds were obtained. Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 75:25. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 50 wt% sodium silicate solution, 22 wt% siloxane-hexane dispersion, 18 wt% cellulose nanofiber composite dispersion, 6 wt% polylactic acid blend, and 4 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0011] Example 3: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 700g of recycled corrugated cardboard fiber and 300g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 65:35 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate were added to a reaction vessel, heated to 200℃ and reacted for 3h, then cooled to 160℃ and reacted for 45min. After cooling, polylactic acid-based compounds were obtained. Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 70:30. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh the following components by mass percentage: 45wt% sodium silicate solution, 25wt% siloxane-hexane dispersion, 12wt% cellulose nanofiber composite dispersion, 10wt% polylactic acid blend, and 8wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30℃ for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0012] Comparative Example 1: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 300g of recycled corrugated cardboard fiber and 700g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate to a reaction vessel, heat to 200℃ and react for 3h, cool to 160℃ and continue to react for 45min, cool to obtain polylactic acid-based compound; Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 80:20. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 58 wt% sodium silicate solution, 25 wt% siloxane-hexane dispersion, 10 wt% polylactic acid blend, and 7 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0013] Comparative Example 2: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 300g of recycled corrugated cardboard fiber and 700g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 60:40 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 55 wt% sodium silicate solution, 25 wt% siloxane-hexane dispersion, 20 wt% cellulose nanofiber composite dispersion, and 5 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0014] Comparative Example 3: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: Mix 300g of recycled corrugated cardboard fiber and 700g of rubberwood fiber evenly, add the mixed fiber to 15kg of 3wt% sodium hydroxide solution, place it in a 70℃ water bath, stir for 1.5h, wash the alkali-treated fiber with deionized water until the filtrate is neutral, place it in a 55℃ environment for vacuum drying for 10h, crush and sieve to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 60:40 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate were added to a reaction vessel, heated to 200℃ and reacted for 3h, then cooled to 160℃ and reacted for 45min. After cooling, polylactic acid-based compounds were obtained. Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 80:20. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 55 wt% sodium silicate solution, 20 wt% siloxane-hexane dispersion, 15 wt% cellulose nanofiber composite dispersion, 7 wt% polylactic acid blend, and 3 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, vacuum filter, and vacuum dry at 50℃ to obtain environmentally friendly waterproof and flame-retardant packaging products.

[0015] Comparative Example 4: Processing technology of an environmentally friendly waterproof and flame-retardant packaging product: S1: 1000g of recycled corrugated cardboard fiber is added to 15kg of 3wt% sodium hydroxide solution, placed in a 70℃ water bath, and stirred for 1.5h. The alkali-treated fiber is washed with deionized water until the filtrate is neutral, placed in a 55℃ environment for vacuum drying for 10h, crushed and sieved to obtain pretreated paper base; S2: Add 30g of ammonium dihydrogen phosphate and 150g of urea to 5L of deionized water to prepare a mixed aqueous solution. Add 100g of dried bleached cork pulp to the mixed aqueous solution, heat to 80℃ and soak for 35min, place at 108℃ to dry to constant weight, and further heat to 150℃ to solidify for 20min. Wash the product until the conductivity is ≤20μS / cm, adjust the pH to 9.5, prepare a 0.5wt% suspension, disperse by ultrasonication, and take the supernatant to obtain a phosphorylated cellulose nanofiber dispersion. Add 50g of chitin powder to 1000g of 32wt% sodium hydroxide solution, heat to 90℃ and react for 3h, wash until neutral, prepare a 0.5wt% suspension, adjust the pH to 3.5, and ultrasonically disperse for 2h to obtain acetylated chitin nanocrystal dispersion; Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed at a mass ratio of 60:40 and ultrasonically dispersed to obtain cellulose nanofiber composite dispersion. 100g polylactic acid, 5g 1,4-butanediol, 18g octadecenylsuccinic anhydride and 1g zinc acetate were added to a reaction vessel, heated to 200℃ and reacted for 3h, then cooled to 160℃ and reacted for 45min. After cooling, polylactic acid-based compounds were obtained. Add 100g of polybutylene succinate, 8g of maleic anhydride, and 2g of dicumyl peroxide to a mixer, heat to 180℃ and mix for 4 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were heated to 170°C and melt-blended for 10 minutes at a mass ratio of 80:20. After cooling, the mixture was pulverized to obtain polylactic acid blend powder. An equal volume of 15wt% polyethylene glycol diamine aqueous solution and 45wt% sodium polyphosphate aqueous solution were mixed, annealed at 70°C for 2 hours, and then cooled to obtain a polyelectrolyte composite. Weigh out the following components by mass percentage: 55 wt% sodium silicate solution, 20 wt% siloxane-hexane dispersion, 15 wt% cellulose nanofiber composite dispersion, 7 wt% polylactic acid blend, and 3 wt% polyelectrolyte complex. Add them to an ultrasonic dispersion instrument and ultrasonically disperse at 30°C for 60 min to obtain an environmentally friendly composite impregnation solution. S3: Immerse 100g of pretreated paper base in 800g of environmentally friendly composite impregnation solution, add 1mol / L hydrochloric acid solution to adjust the pH of the system to 4.0, heat to 30℃ and impregnate at a constant temperature for 45min, stir at 10min intervals, and vacuum filter to obtain modified wet product. S4: Immerse the modified wet product in 1200g of 0.5wt% glutaraldehyde crosslinking agent, heat to 35℃ and crosslink at a constant temperature for 30min, and then vacuum dry at 50℃ to obtain an environmentally friendly waterproof and flame-retardant packaging product.

[0016] Test: Environmental performance: According to GB / T 19277.1-2011, the environmentally friendly waterproof and flame-retardant packaging products were buried in soil for 28 days, and the biodegradation rate was calculated; Waterproof performance: Water contact angle test was conducted according to GB / T 38141-2019, with a 5μL deionized water droplet, and the reading was taken after 30 seconds; Flame retardant performance: Limiting oxygen index was tested according to GB / T 2406.2-2009, and the sample size was 80×10×4mm; Mechanical properties: Tensile strength and elongation at break were tested according to GB / T 1040.3-2006. The sample size was 50×10×4mm and the tensile rate was 2mm / min. The test results are shown in Table 1 below.

[0017] Table 1 Performance Test Data of Environmentally Friendly Waterproof and Flame-Retardant Packaging Products

[0018] Conclusion: The environmentally friendly waterproof and flame-retardant packaging products prepared by this invention have excellent flame-retardant and waterproof properties.

[0019] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A processing technology for an environmentally friendly, waterproof, and flame-retardant packaging product, characterized in that: Includes the following steps: S1: Paper base pretreatment: Recycled corrugated cardboard fiber and rubberwood fiber are mixed in a certain proportion, subjected to alkali treatment, and washed until neutral to obtain pretreated paper base; S2: Preparation of environmentally friendly composite impregnation solution: Sodium silicate solution, siloxane-hexane dispersion, cellulose nanofiber composite dispersion, polylactic acid blend and polyelectrolyte complex are mixed in proportion and ultrasonically dispersed evenly to obtain environmentally friendly composite impregnation solution. The polyelectrolyte complex was prepared by mixing equal volumes of an aqueous solution of polyethylene glycol and an aqueous solution of sodium polyphosphate. S3: Impregnation modification: The pretreated paper base is immersed in an environmentally friendly composite impregnation solution, hydrochloric acid solution is added, impregnation reaction is carried out, and vacuum filtration is performed to obtain the modified wet product; S4: Crosslinking and curing: The modified wet product is immersed in glutaraldehyde crosslinking agent, crosslinking reaction occurs, vacuum drying is performed, and the product is cut and finished to obtain environmentally friendly waterproof and flame-retardant packaging products.

2. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: In the preparation of the pretreated paper base, the mass ratio of recovered corrugated cardboard fiber to rubberwood fiber is (30-70):(70-30); the alkali treatment process uses 2-5wt% sodium hydroxide solution, the treatment temperature is 60-80℃, and the treatment time is 1-2h; the mass ratio of the total mass of recovered corrugated cardboard fiber and rubberwood fiber to the mass of sodium hydroxide solution is 1:(10-20).

3. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: The components in the preparation of the environmentally friendly composite impregnation solution are as follows (by mass percentage): sodium silicate solution 40-60 wt%, siloxane-hexane dispersion 15-25 wt%, cellulose nanofiber composite dispersion 10-20 wt%, polylactic acid blend 5-15 wt%, and polyelectrolyte complex 3-8 wt%.

4. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: In the preparation of modified wet products, the mass ratio of pretreated paper base to environmentally friendly composite impregnation liquid is 1:(5-10).

5. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: In the preparation of environmentally friendly waterproof and flame-retardant packaging products, the mass ratio of modified wet product to glutaraldehyde crosslinking agent is 1:(8-15); the crosslinking reaction temperature is 30-40℃, and the crosslinking time is 20-40min.

6. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: The preparation method of the cellulose nanofiber composite dispersion includes the following steps: adding dried bleached cork pulp to a mixed aqueous solution of ammonium dihydrogen phosphate and urea, heating to 80-85℃ and soaking for 30-40 min, drying to constant weight at 105-110℃, curing at 140-160℃ for 15-25 min, washing the product until the conductivity is ≤20μS / cm, preparing a 0.3-0.8wt% suspension, adjusting the pH to 9-10, ultrasonically dispersing for 1.5-2.5 h, centrifuging to obtain a phosphorylated cellulose nanofiber dispersion; Chitosan powder was added to a 30-35 wt% sodium hydroxide solution, heated to 85-95℃ and reacted for 2.5-3.5 h. After washing until neutral, a 0.3-0.8 wt% suspension was prepared, the pH was adjusted to 3-4, and the suspension was ultrasonically dispersed for 1.5-2.5 h to obtain an acetylated chitosan nanocrystal dispersion. Phosphorylated cellulose nanofiber dispersion and acetylated chitin nanocrystal dispersion were mixed in a certain proportion and ultrasonically dispersed for 20-30 minutes to obtain cellulose nanofiber composite dispersion.

7. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 6, characterized in that: In the preparation of phosphorylated cellulose nanofiber dispersion, the mass ratio of dried bleached cork pulp: ammonium dihydrogen phosphate: urea is 1:(0.3-0.5):(1.5-2.0). In the preparation of acetylated chitin nanocrystal dispersion, the mass ratio of chitin to 30-35 wt% sodium hydroxide solution is 1:(20-30). In the preparation of cellulose nanofiber composite dispersion, the mass ratio of phosphorylated cellulose nanofiber dispersion to acetylated chitin nanocrystal dispersion is (50-70):(50-30).

8. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 1, characterized in that: The preparation method of the polylactic acid blend includes the following steps: adding polylactic acid, 1,4-butanediol, octadecenylsuccinic anhydride and zinc acetate into a reaction vessel, heating to 200-205℃ and reacting for 3-3.5h, cooling to 160-165℃ and continuing to react for 45-50min to obtain a polylactic acid-based compound; Add polybutylene succinate, maleic anhydride, and dicumyl peroxide to a mixer, heat to 180-185℃ and mix for 3-5 minutes to obtain modified polybutylene succinate. Polylactic acid-based compounds and modified polybutylene succinate were melt-blended in a certain proportion to obtain polylactic acid blends.

9. The processing technology for an environmentally friendly waterproof and flame-retardant packaging product according to claim 8, characterized in that: In the preparation of polylactic acid-based compounds, the mass ratio of polylactic acid: 1,4-butanediol: octadecenylsuccinic anhydride is 1:(0.03-0.07):(0.12-0.25). In the preparation of modified polybutylene succinate, the mass ratio of polybutylene succinate: maleic anhydride: dicumyl peroxide is 100:(5-10):

2. In the preparation of polylactic acid blends, the mass ratio of polylactic acid-based compound to modified polybutylene succinate is (70-85):(30-15).

10. An environmentally friendly waterproof and flame-retardant packaging product prepared by the processing technology of an environmentally friendly waterproof and flame-retardant packaging product according to any one of claims 1-9.

Images