Bacteriostatic and antiviral bamboo pulp paper-based hygiene isolation bag and preparation method and application thereof

Abstract

The application discloses a bacteriostatic and antiviral bamboo pulp paper-based health isolation bag and a preparation method and application thereof, and belongs to the field of functional paper-based packaging materials. The isolation bag takes bamboo pulp fiber paper as a base material, and is covered with a water-based polyhydroxy aliphatic ester functional coating on the surface. The application introduces a special polyphenol derivative, chitosan quaternary ammonium salt and nano zinc oxide organic-inorganic hybrid factor, effectively solves the nano particle agglomeration problem by using the special bridging effect of polyphenol, and constructs a high-density cation capture and oxidation inactivation site on the surface of the coating. Compared with the prior art, the application does not need to rely on organic fluorine compounds, and only needs a very low coating amount to achieve excellent waterproof and oil barrier effects and efficient inactivation of viruses. In addition, the isolation bag has a unique environmental chemical responsiveness, can be efficiently dissociated under alkaline conditions to facilitate repulping recycling, and can be completely biodegraded in the natural environment, perfectly meeting the biological safety protection and green environmental protection requirements.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of functional paper-based packaging materials, and particularly relates to a bacteriostatic and antiviral bamboo pulp paper-based health isolation bag and a preparation method and application thereof. BACKGROUND

[0002] With the promotion of "plastic limit order" and green low-carbon development goals, the demand for paper-based packaging materials with cellulose as the matrix, which have barrier properties, reslurry properties and degradability, continues to grow in the hotel, catering and medical industries. Although traditional polyethylene (PE), polypropylene (PP) composite film bags and paper-plastic composite bags can provide certain waterproof and oil-proof performance, they are difficult to separate in the regeneration pulp line and are easy to form adhesives, and their biological safety protection ability is limited. In the prior art, in order to solve the problem of insufficient barrier properties of paper-based materials, various water-based dispersions or emulsion systems with polyhydroxyalkanoate (PHA) as the main film-forming body have appeared. For example, Chinese Patent CN119912795B discloses a pure bio-based water-based dispersion with PHA as the main film-forming material, which can be used for paper-based barrier coatings, adhesives and degradable films by stabilizing the emulsion with solid particles and surfactants. The product has both compostability and reslurry properties, but does not introduce an efficient inhibition or inactivation mechanism for enveloped viruses, nor does it limit bamboo pulp fiber paper-based materials. For another example, Chinese Patent CN120026524B discloses a ternary blended water-based emulsion of PHA, polybutylene adipate / terephthalate (PBAT) and polyvinyl alcohol (PVOH) and its application in paper-based barrier coatings. By forming a PHA, PBAT and PVOH composite film layer on the surface of the paper, the Cobb value and Kit oil-proof grade are improved, and the reslurry efficiency is improved by using the solubility of PVOH in an alkaline pulp tank at room temperature. This technology focuses on solving the balance problem of barrier property, toughness and recyclability, and does not involve bamboo pulp fiber paper as a special substrate and bacteriostatic and antiviral health isolation scenarios. Zhongke Union Chemical and other subjects also disclose a nano-scale paper-based barrier emulsion and a multi-layer controllable degradable coating composition with PHA and PVOH as the main film-forming resins, which further improve the water resistance, oil resistance and degradation properties of paper-based packaging materials, but also do not report a technical solution for synergistically constructing an antiviral active interface with chitosan quaternary ammonium salt (HACC), polyphenol derivatives and nano-zinc oxide (NanoZnO).

[0003] On the other hand, there are many technologies that use bamboo pulp or other plant fibers to improve the environmental friendliness of paper products. For example, there are disclosed graphene oxide antibacterial packaging papers, such as Chinese Patent CN108867189A, which uses wood pulp and bamboo pulp as fiber raw materials, and introduces graphene oxide during the papermaking stage to give the packaging paper the ability to inhibit common bacteria; there is also a utility model CN205443788U which discloses that the bamboo pulp fiber paper or other filter material is treated with antifungal and antibacterial to be used as a humidifying filter screen to improve the hygiene performance of the product. However, the above-mentioned technologies mainly use bamboo pulp fiber and inorganic nano filler to improve the antibacterial or antifungal ability of paper, and do not couple the bamboo pulp paper base with the water-based PHA barrier coating, nor do they systematically consider the synergistic mechanism of pulp separation and end-of-life composting. There are still a large number of antibacterial or antiviral materials based on chitosan, NanoZnO and polyphenols in the prior art. Some composite materials, such as Al-Naamani et al. in Innovative Food Science & Emerging Technologies, use chitosan to coat NanoZnO particles to improve the dispersion stability of NanoZnO and increase the inhibition effect on bacteria; some technologies, such as Bharathi et al. in International Journal of Biological Macromolecules, report that chitosan and NanoZnO hybrid materials can reduce the photocatalytic activity and retain the antibacterial performance by controlling the coating layer on the surface of NanoZnO, which are used for medical or nursing supplies. In addition, many papers, such as Yadav et al. in the journal Food Chemistry, propose a food packaging film based on chitosan as a matrix and modified NanoZnO composite particles loaded with gallic acid (GA), which uses the coordination of GA on the surface of NanoZnO and the film-forming property of chitosan to synergistically improve the antibacterial activity and antioxidant performance; there are also reports that GA or other polyphenols, quaternary ammonium polymers and metal oxides are combined to be applied to active packaging or antibacterial film systems. The above-mentioned technologies show that GA, chitosan and NanoZnO hybrid structures have a certain basis in efficient bacteriostasis, but are mostly based on self-supporting films or fabric coating systems, and chitosan is mostly non-quaternized chitosan or not coupled with water-based PHA paper base barrier system design, and is not integrated with water-based PHA emulsion and paper base repulping process. In addition, for the end-of-life disposal of packaging materials, some studies point out that pure PHA melt-coated paper is difficult to completely separate from the fiber surface under standard paper mill repulping conditions, and plastic particles are easily formed, which affects the stability of the paper machine; paper base coatings based on PVOH or nanocellulose have certain barrier properties, but they are easily lost under high humidity or long-term water vapor contact conditions, and do not take into account the contact inactivation function of enveloped viruses.

[0004] In summary, the prior art has made progress in water-based PHA paper-based barrier coating, bamboo pulp fiber paper antibacterial packaging, and GA, chitosan, NanoZnO hybrid antibacterial materials, but there is no water-based PHA barrier layer without PVOH film-forming resin on the bamboo pulp fiber paper base, and the introduction of GA-HACC-NanoZnO organic-inorganic hybrid factor and environmental chemical response interface structure in the same coating system, so as to realize the system solution of paper-based health isolation bag with high barrier property, high efficient bacteriostatic and antiviral, re-pulping separation and composting degradation ability under the condition of dry coating amount of 3-8g / m². SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, provide a bacteriostatic and antiviral bamboo pulp paper-based health isolation bag and its preparation method and application, which has excellent barrier performance and high efficient bacteriostatic and antiviral ability, and can meet the environmental protection requirements of fluorine-free, re-pulping separation and composting degradation.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A bacteriostatic and antiviral bamboo pulp paper-based health isolation bag, comprising a bag body made of a bamboo pulp fiber paper base and a sealing assembly, at least one side surface of the bamboo pulp fiber paper base is covered with a water-based PHA barrier bacteriostatic and antiviral coating; the coating is formed by curing a coating composition of PHA water-based dispersion and a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor, the coating forms a continuous and dense hydrophobic barrier layer on the surface of the bamboo pulp fiber, and the hybrid factor constructs cation capture and oxidation inactivation active sites on the surface of the coating through the bridging action of the polyphenol derivative, and the TOF content of the coating and the health isolation bag is less than 5mg / kg.

[0008] The basis weight of the bamboo pulp fiber paper base is 35-280g / m², which can be 35g / m², 40g / m², 45g / m², 50g / m², 60g / m², 70g / m², 80g / m², 100g / m², 120g / m², 150g / m², 180g / m², 200g / m², 250g / m² or 280g / m², and the mass fraction of bamboo pulp fiber is ≥70%, which can be 70%, 75%, 80%, 85%, 90%, 95% or 100%, and is treated by calendering or surface sizing.

[0009] The water-based PHA barrier bacteriostatic and antiviral coating is arranged on the inner surface of the bamboo pulp fiber paper base; or arranged on the inner surface and the outer surface at the same time.

[0010] The dry coating amount of the water-based PHA antibacterial and antiviral coating is 3-8 g / m2, and can be 3.0 g / m2, 3.5 g / m2, 4.0 g / m2, 4.5 g / m2, 5.0 g / m2, 5.5 g / m2, 6.0 g / m2, 6.5 g / m2, 7.0 g / m2, 7.5 g / m2 or 8.0 g / m2.

[0011] The PHA aqueous dispersion is prepared from PHA;

[0012] The PHA is selected from short-chain PHA, medium-chain PHA or a copolymer formed between short-chain PHA monomers and medium-chain PHA monomers; the short-chain PHA is selected from one or more of poly-3-hydroxybutyrate (PHB), poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (PHBH), poly-3-hydroxybutyrate-co-4-hydroxybutyrate (P34HB); the medium-chain PHA is selected from one or more of poly-3-hydroxyhexanoate, poly-3-hydroxyheptanoate, poly-3-hydroxyoctanoate, poly-3-hydroxynonanoate, poly-3-hydroxydecanoate, poly-3-hydroxyundecanoate, poly-3-hydroxydodecanoate, poly-3-hydroxylaurate, poly-3-hydroxystearate and copolymers thereof; the solid content of the PHA aqueous dispersion is 30-55 wt%, and can be 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt% or 55 wt%. 50 The particle size is 0.2-2.0 μm, and can be 0.2 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.5 μm, 1.8 μm or 2.0 μm.

[0013] The polyphenol derivative is GA, the hybrid factor is a GA-HACC-NanoZnO hybrid network, and the preparation of the polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor comprises:

[0014] a) preparing an aqueous HACC solution and adjusting the pH to 5.0-7.5 to obtain an HACC solution;

[0015] b) slowly adding a polyphenol derivative solution to the HACC solution and stirring until a uniform and stable pre-complexing system is formed to obtain a pre-complexing system;

[0016] c) adding a NanoZnO aqueous dispersion to the pre-complexing system and performing shearing dispersion until a uniform and stable organic-inorganic hybrid colloid is formed to obtain a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor;

[0017] The mass ratio of the polyphenol derivative to HACC is 0.05-0.30:1, and specifically can be 0.05:1, 0.08:1, 0.10:1, 0.12:1, 0.15:1, 0.18:1, 0.20:1, 0.25:1 or 0.30:1; the mass ratio of NanoZnO to HACC is 0.10-0.60:1, and specifically can be 0.10:1, 0.15:1, 0.20:1, 0.25:1, 0.30:1, 0.35:1, 0.40:1, 0.45:1, 0.50:1, 0.55:1 or 0.60:1.

[0018] The water-based PHA barrier antibacterial and antiviral coating has environmental chemical responsiveness, including the following properties: an alkaline-induced interface dissociation property, which is that, under the conditions of pH≥9 and temperature≥40℃ in a water medium pulping condition, the PHA coating is hydrolyzed, swelled and embrittled, or the interfacial compatibilizer is ionized, swelled and induced to hydrate the interface, so that the coating is detached from the fiber surface in the form of particles or flakes, and the fiber interface dissociation rate measured under the conditions is≥95%; and an enzymatic mineralization property, which is that, in a biologically active soil or compost environment, the ester bond of PHA is broken under the action of PHA depolymerase, the glycosidic bond of bamboo pulp fiber is broken under the action of cellulase, and is further mineralized into carbon dioxide and water after microbial metabolism.

[0019] Under predetermined test conditions, the performance of the hygiene isolation bag simultaneously meets the following indexes: Cobb 60 ≤9g / m²; Kit oil-proof grade≥10; the blocking or inactivation rate for enveloped viruses≥99.9%; the total organic fluorine content measured according to the total organic fluorine test method is less than 5mg / kg.

[0020] The sealing assembly is a self-adhesive sealing strip, a pressure-sensitive adhesive sealing strip, a zipper sealing structure, or a direct heat sealing structure realized by the thermoplasticity of the water-based PHA barrier antibacterial and antiviral coating itself; if an adhesive is used, the pressure-sensitive adhesive or heat sealing adhesive is a water-based system or a biodegradable system.

[0021] The water-based PHA barrier antibacterial and antiviral coating further comprises an organic modified nano-montmorillonite and an interfacial compatibilizer, and the coating comprises, in terms of solid mass parts, PHA 70-85, specifically 70 parts, 72 parts, 75 parts, 78 parts, 80 parts, 82 parts or 85 parts; polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor 10-15 parts, specifically 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts; organic modified nano-montmorillonite 3-6 parts, specifically 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts, 5.0 parts, 5.5 parts or 6.0 parts; interfacial compatibilizer 2-5 parts, specifically 2.0 parts, 2.5 parts, 3.0 parts, 3.5 parts, 4.0 parts, 4.5 parts or 5.0 parts.

[0022] The organic modified nano-montmorillonite has a sheet length-diameter ratio ≥ 50.

[0023] The interfacial compatibilizer contains ionized groups or hydrated groups, and is selected from PVOH and carboxylated derivatives thereof without organic fluorine structure, carboxymethyl cellulose (CMC), cationic starch, carboxylated starch or water-based resin containing carboxylate structure, and the amount of the interfacial compatibilizer in the coating is 2-5 parts by solid mass, specifically 2 parts, 3 parts, 4 parts or 5 parts.

[0024] The film-forming resin phase of the water-based PHA barrier antibacterial and antiviral coating is composed of PHA and a second film-forming polymer, and the PHA accounts for 40-95 wt% of the total mass of the film-forming resin phase, specifically 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt% or 95 wt%, and the second film-forming polymer accounts for 5-60 wt%, specifically 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt% or 60 wt%.

[0025] The second film-forming polymer is selected from one or more of the following types of polymers: acrylic polymers or copolymers obtained by emulsion polymerization of one or more monomers of acrylic acid, methacrylic acid and C1-C8 alkyl esters thereof, hydroxyalkyl acrylate or methacrylate, styrene, acrylonitrile; water-based polyurethane dispersions obtained by polyaddition of aliphatic or cycloaliphatic diisocyanates with polyester diols, polyether diols or polycarbonate diols and dispersed in water; water dispersions of bio-based polyesters or copolymers thereof obtained by polycondensation of one or more diacids of succinic acid, glutaric acid, adipic acid, oxalic acid with one or more diols of ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, isosorbide; water dispersions of polylactic acid (PLA) or copolymers thereof obtained by ring-opening polymerization of lactic acid; polyolefin dispersions obtained by emulsification or dispersion of ethylene, propylene or copolymers thereof; and water dispersions of cellulose derivatives or modified products thereof obtained by carboxymethylation, hydroxypropylation or quaternization modification of cellulose molecules; the second film-forming polymer does not include PVOH and copolymers thereof.

[0026] The second film-forming polymer is a bio-based polyester or an acrylic polymer; the phase state of the second film-forming polymer and the PHA in the coating is a continuous phase-dispersed phase structure or an interpenetrating network structure.

[0027] The application also provides a bacteriostatic and antiviral bamboo pulp paper-based coated paper, which comprises a bamboo pulp fiber paper base and an aqueous PHA barrier bacteriostatic and antiviral coating arranged on at least one side surface of the bamboo pulp fiber paper base; the coating is formed by curing a coating composition formed by a PHA aqueous dispersion and a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor.

[0028] The application also provides an aqueous film-forming coating composition for bamboo pulp paper-based hygiene isolation coating, which at least comprises a film-forming resin phase, a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor and water; the film-forming resin phase is composed of PHA and a second film-forming polymer, wherein the PHA accounts for 40-95wt% of the total mass of the film-forming resin phase, specifically 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, 90wt% or 95wt%, and the second film-forming polymer accounts for 5-60wt% of the total mass of the film-forming resin phase, specifically 5wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt% or 60wt%; the second film-forming polymer is selected from one or more of the above-mentioned second film-forming polymers.

[0029] The application also provides a preparation method of the hygiene isolation bag, which comprises the following steps:

[0030] Step 1. Provide a bamboo pulp fiber paper base raw paper, which is a raw paper treated by calendering and / or surface sizing, or a raw bamboo pulp fiber paper base raw paper is treated by calendering or surface sizing pretreatment to obtain a pretreated bamboo pulp fiber paper base raw paper;

[0031] Step 2. Prepare a water-based PHA barrier antibacterial and antiviral coating, mix a PHA water-based dispersion with a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor, and add a nano-layered barrier filler and an interfacial compatibilizer, and then disperse by shearing to obtain a stable coating, thereby obtaining a water-based PHA barrier antibacterial and antiviral coating; wherein the film-forming resin phase of the stable coating is PHA, or a blend system of PHA and a second film-forming polymer;

[0032] Step 3. The water-based PHA barrier antibacterial and antiviral coating is applied to the surface of the pretreated bamboo pulp fiber paper base raw paper by means of flexographic coating, gravure coating, blade coating or microgravure coating to obtain a wet coating layer;

[0033] Step 4. Dry the wet coating layer under a segmented hot air or infrared drying condition, so that the polyhydroxyalkanoate water-based dispersion particles coalesce into a film and undergo short-range leveling in a setting temperature zone to form a continuous and dense barrier layer and a surface hydrophobic microstructure, thereby obtaining a coated paper material, wherein the drying temperature is higher than the minimum film-forming temperature of the polyhydroxyalkanoate water-based dispersion particles and lower than the crystalline melting temperature thereof;

[0034] Step 5. Fold, edge seal and composite the coated paper material to obtain a sanitary isolation bag.

[0035] The present application also provides the use of the sanitary isolation bag in the packaging of disposable toiletries for hotels and homestays, the sanitary isolation storage of guest rooms and long-term apartment hygiene, the temporary storage of disposable toiletries and disposable personal care products after use, the packaging and temporary storage of toiletry sets for travel vehicles, and the packaging of disposable sanitary products for visitors and caregivers in medical or nursing institutions.

[0036] Compared with the prior art, the use of the present application can obtain the following significant beneficial effects:

[0037] The present application utilizes a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor to construct an active barrier coating with water-based PHA, and the dual bridging effect of the polyphenol derivative (such as GA) effectively solves the agglomeration problem of inorganic nanoparticles in the polymer matrix, and forms a high-density cation capture site (from HACC) and an oxidation inactivation site (from NanoZnO) on the surface of the coating, thereby achieving efficient synergistic blocking and inactivation of bacteria and enveloped viruses, and the inactivation rate for enveloped viruses can be more than 99.9%.

[0038] The application achieves excellent barrier performance of Cobb 60 ≤9g / m² and Kit oil-proof level ≥10 grade, while the TOF content is less than 5mg / kg, meeting the increasingly stringent environmental and fluorine-free requirements.

[0039] The sanitary isolation bag of the application has excellent environmental adaptability and end disposal performance. The interface compatibilizer and PHA structure in the coating endow the material with environmental chemical responsiveness, enabling it to achieve efficient interface dissociation (dissociation rate ≥95%) under alkaline hydro-pulping conditions, facilitating paper-based fiber recycling.

[0040] Compared with the technical solutions of Chinese patents CN119912795B and CN120026524B, the application simultaneously limits the polyhydroxyaliphatic ester without PVOH in the film-forming resin phase and the second film-forming polymer system in the same bamboo pulp fiber paper-based system, and allows the introduction of a small amount of PVOH and its carboxylated derivatives only in the interface compatibilizer. The application combines the synergistic design of gallic acid-chitosan quaternary ammonium salt-nano zinc oxide hybrid antiviral structure and the interface dissociation and compost degradation mechanism caused by alkali, and limits the total organic fluorine content of the coating and the sanitary isolation bag to less than 5mg / kg, achieving high water resistance, high oil resistance and high antiviral performance through non-fluorine materials. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a schematic diagram of the microstructure section of the coated paper material used in the antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag of the application.

[0042] In the figure, 1 is a bamboo pulp fiber paper base; 2 is an interface compatibilizer; 3 is a water-based PHA barrier antibacterial and antiviral coating; 4 is a cation capture and oxidation inactivation active site; 5 is a polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor; 6 is a polyhydroxyaliphatic ester; and 7 is a nano-layered barrier filler. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions and advantages of the application clearer, the application will be further described in detail below in combination with specific examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application shall be included in the protection scope of the application. Unless otherwise specified, the raw materials used in the examples are commercially available industrial products or can be prepared by conventional methods. Unless otherwise specified, the performance test methods are carried out according to the standards described in the summary of the invention.

[0044] Figure 1 The microstructure cross-section of the coated paper material used in the present application is shown in the figure. As shown in the figure, the bottom structure of the material is the interwoven bamboo pulp fiber paper base 1. A thin interfacial compatibilizer 2 is provided on the paper base to enhance the interlayer bonding force. The uppermost is the functional water-based PHA barrier antibacterial and antiviral coating 3. Inside the water-based PHA barrier antibacterial and antiviral coating 3, a continuous polyhydroxyalkanoate 6 is used as the matrix phase, in which there are dispersed sheet-shaped nanolayer barrier fillers 7 that tend to arrange parallel to the surface, which construct a tortuous path to provide excellent barrier effect. At the same time, the coating matrix also embeds a network structure of polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor 5, which effectively constructs cation capture and oxidation inactivation active sites 4 on the exposed surface of the coating (indicated by surface micro-identification in the figure), thereby realizing high-efficiency antibacterial and antiviral functions through the contact mechanism.

[0045] Main reagents and raw materials:

[0046] Table 1 Name, product model and manufacturer of main reagents and raw materials:

[0047]

[0048] Table 2 Main analysis and detection instruments:

[0049]

[0050] Main test standards:

[0051] Cobb 60 Value: determined according to GB / T 1540-2002 “Determination of water absorption of paper and paperboard (Cobb method)”.

[0052] Kit oil resistance grade: determined according to TAPPI T 559 cm-22; for the paper base barrier layer of film-forming or non-fluorine oil-repellent system, the method can still be used as a general comparison index under the condition of the same batch of control samples.

[0053] Virus inactivation rate: when the sample coating surface forms a continuous dense coating film, it can be treated as a non-porous material, and tested according to GB / T 43355-2023 "Determination of antiviral activity on the surface of plastics and other non-porous materials" (equivalent to ISO 21702:2019); when the sample surface still presents obvious porous / fiber structure, it can be tested according to ISO 18184:2025 or GB / T 43823-2024 "Determination of antiviral activity of textiles". H1N1 influenza virus is used as a representative enveloped virus. The test conditions are carried out according to the selected standard; under the example conditions of the specification, the contact time is 2 hours, the host cells are Martin-Dabie canine kidney cells (MDCK), and the virus titer is determined by 50% tissue culture infectious dose (TCID50) method.

[0054] Antibacterial performance: Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 8739 are selected as test bacteria; among them, the test of Staphylococcus aureus is carried out according to GB / T 21866-2025 "Determination of antiviral activity and antibacterial performance of coating film", and the test of Escherichia coli is carried out according to GB / T 21866-2008 "Determination of antibacterial performance and antibacterial effect of antibacterial coating (paint film)"; the antibacterial rate calculated according to the test method in the present application is ≥99% to determine that the antibacterial performance is qualified.

[0055] Barrier performance qualified criteria: Cobb 60 ≤9g / m² and Kit oil-proof grade ≥10 grade to determine that the barrier performance is qualified.

[0056] Antiviral performance qualified criteria: the blocking or inactivation rate of ≥99.9% for enveloped viruses is determined to be qualified for antiviral performance.

[0057] Fiber interface dissociation rate: take the cut coated paper sample, weigh 10.0g by dry mass, add deionized water to a total mass of 500g (pulp concentration 2.0wt%), and adjust the pH of the system to 9.0±0.2 with 1mol / L sodium hydroxide solution; the system is placed in a constant temperature condition of 45℃, and a high-speed shearing disperser is used for pulping for 20min, the type of high-speed shearing disperser is IKAT25 digital, the specification of matching dispersing head is S25N-25G, and the rotation speed is set to 10000±500rpm; the system temperature is maintained at 45℃±2℃ by constant temperature water bath or temperature control jacketed container during pulping. After pulping, 0.20mm screen is used for screening, the residual material on the screen is washed with deionized water and collected and dried at 105℃ to constant weight, the percentage of residual material on the screen to the sample dry mass is calculated, and the fiber interface dissociation rate is calculated as (1-residual material mass / sample mass)×100%; the fiber interface dissociation rate ≥95% is determined to be qualified for reslurry separation performance.

[0058] Final aerobic biodegradation rate: The final aerobic biodegradation rate of 90 days was determined under controlled composting conditions according to GB / T 19277.1-2025 "Determination of the ultimate aerobic biodegradability of a material under controlled composting conditions - Method by determination of released carbon dioxide - Part 1: General method", and the obtained "90-day final aerobic biodegradation rate" was used as an index to characterize the degradation performance under composting conditions in the application. A 90-day final aerobic biodegradation rate ≥ 90% was determined to be qualified for biological degradation performance under composting conditions.

[0059] TOF content: The test was performed according to T / CNFIA 190-2024 "Determination of total organic fluorine content in paper, paperboard and paper products for food contact - Ion chromatography method" or equivalent standards. The sample was pretreated and determined according to the standard provisions. The ion chromatography method was used to determine the content of fluoride ions in the solution and converted to TOF content. The limit of quantification of the TOF test method in the application was set to 5 mg / kg. When the measured value was less than 5 mg / kg, it was determined to be not detected. A TOF content less than 5 mg / kg was determined to meet the requirement of no organic fluorine.

[0060] Sample humidification: The sample conditioning was performed according to GB / T 10739-2023 "Standard atmospheric conditions for sample handling and testing of paper, paperboard and pulp".

[0061] General preparation method of PHA aqueous dispersion:

[0062] Unless otherwise specified, the PHA aqueous dispersion used in the examples of the application was prepared as follows:

[0063] Step 1. Add SDS to deionized water as an emulsifying dispersant. The amount of SDS is 0.3 wt% based on the mass of the water phase. Stir until completely dissolved to obtain a water phase;

[0064] Step 2. Add PHA powder to the water phase in batches under stirring to avoid clumping caused by one-time input. Disperse at 70-85℃ using a high-speed shearing disperser at 10000 rpm for 45 min to obtain a coarse dispersion system;

[0065] Step 3. Subject the coarse dispersion system to two homogenization treatments using a high-pressure homogenizer at a working pressure of 60 MPa. Control the temperature of the material liquid to 45℃ during the homogenization process. After homogenization, cool to room temperature. Adjust the solid content of the dispersion to 45 wt% by adding deionized water and / or adjusting the ratio of PHA resin to water phase. Obtain a PHA aqueous dispersion. The solid content of the PHA aqueous dispersion is determined by the constant weight method at 105℃. 50The emulsion particle size distribution was determined at 25°C by dynamic light scattering particle size analyzer and calculated according to the cumulative distribution. Before testing, the emulsion sample was diluted to 0.07wt% with deionized water and stirred uniformly, and then tested. D 50 Control at 0.6 μm.

[0066] General preparation method of interfacial compatibilizer solution:

[0067] Step 1. PVOH-COOH and CMC were weighed according to the solid mass ratio of 2:1, respectively. PVOH-COOH was first added to deionized water, heated and stirred at 90°C until PVOH-COOH was completely dissolved, then cooled to 40°C to obtain a PVOH-COOH solution;

[0068] Step 2. Under stirring conditions, CMC was added to the PVOH-COOH solution in batches and continued to stir for 60 min until the system was uniform. Finally, deionized water was added to make the total solid content of PVOH-COOH and CMC 3.5wt%, and deaerated at room temperature. An interfacial compatibilizer solution was obtained.

[0069] Preparation process of self-made PE-coated paper:

[0070] Step 1. Bamboo pulp base paper with a basis weight of 45g / m² was selected as the paper base, and low-density polyethylene (LDPE) resin was selected as the coating resin. The extruded polyethylene melt was uniformly coated on one side or both sides of the paper base on a laboratory extrusion coating machine. The polyethylene extrusion coating layer was controlled at a basis weight of 15g / m² to obtain a composite material.

[0071] Step 2. The composite material was cooled and shaped to obtain a PE-coated paper.

[0072] Except for Comparative Example 3 which used the PE-coated paper listed in Table 1 as the base material, Examples 1-6 and Comparative Examples 1, 2 and 4 all used bamboo pulp base paper listed in Table 1 as the paper base.

[0073] Hygienic isolation bag sealing assembly and process description:

[0074] Step 1. Regarding the water-based pressure-sensitive adhesive: Since the sealing assembly is not the key innovative part of the coating system of the present application, if an adhesive is used, the water-based pressure-sensitive adhesive is selected from commercially available water-based acrylic pressure-sensitive adhesive dispersion with a solid content of 45wt% and a pH of 7.5, or a water-based pressure-sensitive adhesive prepared by the emulsion polymerization method disclosed in the prior art is used as a substitute;

[0075] Step 2. Regarding direct heat-seal structure: when direct heat-seal structure is achieved by using the thermoplasticity of the waterborne PHA barrier antibacterial antiviral coating itself, the bag opening or edge area is heat-sealed at 135°C, 0.3MPa, 1.0s, forming a heat-sealed edge with a width of 10mm, thereby obtaining a direct heat-seal structure.

[0076] Examples:

[0077] Example 1:

[0078] Preparation of GA-HACC-NanoZnO hybrid factor: HACC powder was weighed and added to deionized water, and stirred magnetically or mechanically at room temperature until completely dissolved, to prepare a 1.0wt% HACC aqueous solution; 0.1mol / L dilute hydrochloric acid and / or 0.1mol / L sodium hydroxide aqueous solution were used to adjust the pH to 6.0. Under mechanical stirring at 500rpm, a 0.3wt% GA solution was first prepared with deionized water (stirring until completely dissolved), and then the GA solution was slowly added to the HACC solution at a dropwise addition rate of 1.0mL / min, until the mass ratio of GA (dry basis) to HACC (dry basis) reached 0.15:1; during the dropwise addition process, the system pH was maintained at 6.0 by supplementing the above-mentioned dilute acid / dilute base solution, and after the dropwise addition was completed, the stirring was continued for 30min to form a uniform and stable pre-complexation system. Subsequently, NanoZnO aqueous dispersion (as listed in the main reagent and raw material table) was added. The solid content of the NanoZnO aqueous dispersion was determined by the constant weight method at 105°C, and the dry mass of NanoZnO was converted accordingly; the required amount of NanoZnO aqueous dispersion was calculated according to the mass ratio of NanoZnO (dry basis) to HACC (dry basis) of 0.35:1. When the NanoZnO aqueous dispersion is a high-solid system, it is first diluted with deionized water to 5.0wt% to reduce the system viscosity and improve the shear dispersion efficiency. A high-speed shear disperser was used to shear disperse at 10000rpm for 20min to obtain a GA-HACC-NanoZnO hybrid factor aqueous dispersion.

[0079] Coating preparation: the PHBV resin listed in the main reagent and raw material table was prepared to obtain a coating with a solid content of 45wt%, a D 50A PHBV aqueous dispersion with a solid content of about 0.6 μm was used as the film-forming resin, and the film-forming resin phase was composed of the PHBV aqueous dispersion alone. The PHBV was 80 parts, the hybrid factor was 12 parts, the organically modified nano-montmorillonite was 5 parts, and the PVOH-COOH / CMC (solid mass ratio 2:1) interfacial compatibilizer was 3 parts, all by solid mass. The interfacial compatibilizer solution was prepared according to the "General Preparation Method for Interfacial Compatibilizer Solution" (total solid content of the solution was 5.0 wt%). The amounts of the components were all converted to the corresponding solid mass before being weighed, and the solid content was measured by the constant weight method at 105°C. During the preparation of the coating, the interfacial compatibilizer solution and the hybrid factor aqueous dispersion were first mixed for 10 min under mechanical stirring at 500 rpm; then the organically modified nano-montmorillonite was added under high-speed shearing dispersion and sheared and dispersed for 10 min at 10,000 rpm (if necessary, the nano-montmorillonite can be pre-wetted with a small amount of deionized water before being added to reduce agglomeration); finally, the PHBV aqueous dispersion was added and sheared and dispersed for 20 min at 10,000 rpm to obtain a uniform coating; and the pH was adjusted to 7.5 with 0.1 mol / L dilute hydrochloric acid or 0.1 mol / L sodium hydroxide aqueous solution. The viscosity of the coating was measured at 25°C using a rotary viscometer (spindle 3, 60 rpm), and the viscosity was 800 mPa·s.

[0080] Coating and film formation: The coating was applied to the surface of the bamboo pulp base paper using a laboratory doctor blade coating method at a coating speed of 10 m / min; the solid content of the coating was measured by the constant weight method at 105°C, and the required wet coating amount was calculated according to the formula "target dry coating amount = target wet coating amount × coating solid content" to control the dry coating amount to be 5 g / m². The wet coating amount was checked by weighing the difference in mass before and after coating and dividing by the coating area. After coating, the coating was dried in stages at 95°C, 115°C, and 125°C to form a film, with a residence time of 2 min in each temperature zone, and the coating was then left to stand at 23°C and 50% relative humidity for 24 h before subsequent testing.

[0081] Example 2: The difference from Example 1 was only in the composition of the film-forming resin phase. The film-forming resin was composed of a blend of a PHBV aqueous dispersion and an acrylic copolymer emulsion, and the PHBV accounted for 70 wt% and the acrylic copolymer accounted for 30 wt% by solid mass of the film-forming resin phase. The PHBV was 56 parts, the acrylic copolymer was 24 parts, the GA-HACC-NanoZnO hybrid factor was 12 parts, the organically modified nano-montmorillonite was 5 parts, and the PVOH-COOH / CMC (solid mass ratio 2:1) interfacial compatibilizer was 3 parts, all by solid mass. The remaining process conditions were the same as in Example 1.

[0082] Example 3: The difference from Example 1 is the composition of the film-forming resin phase. PHBV accounts for 95wt%, and acrylic copolymer accounts for 5wt% according to the solid mass of the film-forming resin phase. According to the solid mass parts: PHBV is 76 parts, acrylic copolymer is 4 parts, GA-HACC-NanoZnO hybrid factor is 12 parts, organic modified nano montmorillonite is 5 parts, PVOH-COOH / CMC (solid mass ratio 2:1) interfacial agent is 3 parts. Other conditions remain unchanged.

[0083] Example 4: The difference from Example 1 is the composition of the film-forming resin phase. PHBV accounts for 40wt%, and acrylic copolymer accounts for 60wt% according to the solid mass of the film-forming resin phase. According to the solid mass parts: PHBV is 32 parts, acrylic copolymer is 48 parts, GA-HACC-NanoZnO hybrid factor is 12 parts, organic modified nano montmorillonite is 5 parts, PVOH-COOH / CMC (solid mass ratio 2:1) interfacial agent is 3 parts. Other conditions remain unchanged.

[0084] Example 5: The difference from Example 1 is that PHBH aqueous dispersion is used instead of PHBV aqueous dispersion in the film-forming resin phase, and the film-forming resin phase is composed of PHA aqueous dispersion alone; in the preparation of the hybrid factor, the mass ratio of GA:HACC is 0.30:1, and the mass ratio of NanoZnO:HACC is 0.60:1. Other conditions remain unchanged. This example verifies the high load end point of the hybrid factor.

[0085] Example 6: The difference from Example 1 is that in the preparation of the hybrid factor, the mass ratio of GA:HACC is 0.05:1, and the mass ratio of NanoZnO:HACC is 0.10:1. Other conditions remain unchanged. This example verifies the low load end point of the hybrid factor.

[0086] Comparative Example:

[0087] Comparative Example 1: The difference from Example 1 is that no GA-HACC-NanoZnO hybrid factor is added in the coating. According to the solid mass parts: PHBV is 92 parts, organic modified nano montmorillonite is 5 parts, PVOH-COOH / CMC (solid mass ratio 2:1) interfacial agent is 3 parts, and the remaining process conditions are the same as Example 1.

[0088] Comparative Example 2: The difference from Example 1 is that physical blending is used instead of pre-complexation hybridization. The total amount of active components is still kept at 12 parts by solid mass, and the proportions are configured according to Example 1: HACC is 8.0 parts, GA is 1.2 parts, and NanoZnO is 2.8 parts (corresponding to GA:HACC = 0.15:1, NanoZnO:HACC = 0.35:1). In Comparative Example 2, the pre-complexation steps of GA and HACC, and the pre-complexation steps of the GA-HACC system and NanoZnO are not performed; instead, the active components are directly added during the preparation of the coating: first, the interfacial compatibilizer solution and the GA aqueous solution are mixed at 500 rpm mechanical stirring for 10 min; then, the HACC aqueous solution is added and stirring is continued for 20 min; subsequently, the NanoZnO aqueous dispersion is added and is sheared and dispersed at 10,000 rpm for 20 min using a high-speed shearing disperser to obtain a uniformly dispersed system; then, the nano-layered barrier filler is dispersed according to the shearing and dispersing conditions of Example 1, and finally, the PHA aqueous dispersion is sheared and dispersed for 20 min according to the shearing and dispersing conditions of Example 1; the pH is adjusted to 7.5 using 0.1 mol / L dilute hydrochloric acid or 0.1 mol / L sodium hydroxide aqueous solution. The remaining components and the coating and drying conditions for film formation are the same as in Example 1.

[0089] Comparative Example 3: Self-made PE-coated paper. The substrate of Comparative Example 3 is bamboo pulp base paper with a basis weight of 45 g / m². A low-density polyethylene (LDPE) resin is used to form a polyethylene extrusion coating layer with a basis weight of 15 g / m² on one side of the bamboo pulp base paper by extrusion coating, to simulate the structure and performance of common PE-coated bamboo pulp paper.

[0090] Comparative Example 4: Uncoated bamboo pulp base paper.

[0091] Application Example:

[0092] Application Example 1: Performance test of hotel toiletry packaging bag.

[0093] The coated paper materials prepared in Examples 1 to 6 and Comparative Examples 1 to 4 are used to prepare toothbrush hygiene isolation packaging bags as follows: the coated paper material is cut into 120 mm x 180 mm, and the inner coating layer is folded inward to form a bag shape; the two sides and the bottom edge area (10 mm wide) are coated with an aqueous acrylic pressure-sensitive adhesive dispersion in a strip pattern, and the wet coating amount is 30 g / m² based on the area of the actual adhesive coating area; it is dried to tack dry in a 60°C air-drying oven for 2 min, and then pressed with a rubber roller, and left to stand at room temperature for 1 h to obtain a bag body; the bag opening is sealed with a self-adhesive water-based pressure-sensitive adhesive sealing strip. Then, the comprehensive performance of the obtained packaging bag is tested under simulated hotel actual use environment. Except for the fiber interfacial disintegration rate and the controlled composting test, which directly use the coated paper sample according to the corresponding method, the Cobb 60, Kit oil resistance rating, virus inactivation rate and antibacterial performance tests were all cut from the non-sealed edge area of the bag body (avoiding the adhesive and heat-sealed edge); all samples were conditioned at 23°C, 50% relative humidity for 24 hours according to GB / T 10739-2023 before Cobb 60 testing, and virus / antibacterial testing was carried out after conditioning (if the conditioning conditions are specified in the relevant standards, then the specified conditions are followed). Test conditions include: Cobb 60 testing at 23°C, 50% relative humidity, oil resistance testing, H1N1 influenza virus resistance testing, fiber interface separation testing under alkaline hydro-pulping conditions at pH 9, 45°C, 20 min, and controlled composting test according to GB / T 19277.1-2025.

[0094] Table 3 Test results of application example 1:

[0095]

[0096] Analysis: This application example comprehensively investigates the barrier properties, biological safety and environmental friendliness of each sample. Among them, the final aerobic biodegradation rate of 90 days ≥ 90% is judged as the biodegradation performance under composting conditions is qualified, and the fiber interface separation rate ≥ 95% is judged as the interface separation performance under repulping conditions is qualified. From the data, it can be seen that the Cobb 60 values of examples 1 to 6 are all controlled below 9 g / m², and the Kit oil resistance rating is all 10 levels, meeting the requirements of high water resistance and high oil resistance performance for hotel toiletry disposable packaging and related scenarios. Among them, the Cobb 60 of example 4 with 60% acrylic acid copolymer content is 6.5 g / m², and the Kit oil resistance rating is 10 levels; compared with examples 1-3 (Cobb 60 is 7.8-8.2 g / m², and the Kit oil resistance rating is all 10 levels), the Cobb 60 of example 4 is reduced by 1.3-1.7 g / m². The fiber interface separation rate of example 4 is 95.0%, and the 90-day final aerobic biodegradation rate is 90.2%, both of which are near the lower limit of the repulping separation qualified criterion (≥ 95%) and the composting biodegradation qualified criterion (≥ 90%). The PE-coated paper of comparative example 3 performs excellently in Cobb 60 and Kit indicators, but basically has no repulping separation and composting degradation ability, making it difficult to meet the green replacement needs of disposable supplies. In terms of virus resistance, all examples containing hybrid factors show very high inactivation rates, with an inactivation rate of not less than 99.9% against enveloped viruses.

[0097] Application Example 2: Surface hydrophobicity and bathroom high humidity environment adaptability test.

[0098] The toothbrush packaging bags prepared in Application Example 1, Examples 1 to 6, and Comparative Examples 1 to 4 were cut into 40 mm x 60 mm flat pieces, and then conditioned at 23°C and 50% relative humidity for 24 hours according to GB / T 10739-2023 "Standard Atmosphere Conditions for Sample Preparation and Testing of Paper, Paperboard and Pulp". Subsequently, the static water contact angle θ0 of the front surface of the sample was measured at room temperature using a contact angle measuring instrument: deionized water was used as the test droplet, the droplet volume was 3.0 ± 0.2 μL, and the contact angle was read within 5 seconds after the droplet contacted the sample surface; the average value of 5 points selected at different positions of each sample was taken, and then the water contact angle θ24h was measured after the sample was treated in a constant temperature and humidity chamber at 40°C and 90% relative humidity for 24 hours, according to the same droplet volume and reading time.

[0099] Table 4: Test results of Application Example 2:

[0100]

[0101] Analysis: This application example aims to simulate the surface performance stability of packaging materials in high-humidity environments such as bathrooms. The initial water contact angles of Examples 1 to 6 are all greater than 100°, and remain above 98° after 24 hours of high-humidity treatment at 40°C and 90% relative humidity, indicating that the water-based PHA coating can still maintain a stable hydrophobic surface in a bathroom high-humidity environment, which is beneficial to inhibit the formation of water film and the adhesion of pollutants. Example 4 has a higher content of acrylic copolymer, with an initial contact angle of 112° and a contact angle of 108° after high-humidity treatment, which is consistent with its excellent Cobb 60 and Kit data. Comparative Example 4, which is not coated with bamboo pulp raw paper, has an initial contact angle of only 47°, which decreases to 30° after high humidity, showing obvious hydrophilicity and moisture sensitivity, which is not conducive to hygiene isolation in actual bathroom scenarios. Although Comparative Example 3 is a PE film-coated paper with a contact angle of about 92° and no change after high humidity, its non-pulping and non-compostable shortcomings limit environmental friendliness.

[0102] Application Example 3: Antimicrobial performance test.

[0103] The toothbrush hygiene isolation packaging bags prepared in application example 1 of examples 1 to 6 and comparative examples 1 to 4 are cut into 50 mm x 50 mm flat pieces, wherein the test of Staphylococcus aureus is carried out according to GB / T 21866-2025, and the test of Escherichia coli is carried out according to GB / T 21866-2008; the antibacterial performance of the sample on Staphylococcus aureus ATCC6538 and Escherichia coli ATCC8739 is tested by the film sticking method. The brief process is as follows: the bacterial suspension of a specified concentration is added dropwise on the surface of the control sample and the test sample, and after 24 h of action at 35±1℃ and relative humidity ≥90%, the surviving bacteria are eluted and counted, and the antibacterial rate is calculated according to the standard formula. In the present application, the antibacterial rate ≥99% is determined as the antibacterial performance qualified. The test results are shown in Table 5.

[0104] Table 5: Test results of antibacterial performance of application example 3:

[0105]

[0106] Experimental explanation and analysis: As shown in Table 5, the antibacterial rates of examples 1 to 6 on Staphylococcus aureus are 99.95% to 99.99%, and the antibacterial rates on Escherichia coli are 99.92% to 99.99%, which all meet the “antibacterial performance qualified criterion (antibacterial rate ≥99%)” of the present specification. It is shown that under the condition of dry coating amount of 5 g / m², the coating of the present application can achieve high-efficiency inhibition on the two representative bacteria tested. Comparative example 1 does not add GA-HACC-NanoZnO organic-inorganic hybrid factor, and the antibacterial rates are all less than 10%, and almost no antibacterial property is shown; comparative example 2 contains GA, HACC and NanoZnO, but is only a simple physical blending structure, the nanoparticles are easy to agglomerate and part of them are completely embedded by the film-forming resin, and the antibacterial rate is about 70%, which is obviously lower than the hybrid network structure of the present application; the antibacterial rates of comparative examples 3 and 4 are both less than 10%, which are PE-coated paper and uncoated bamboo pulp base paper respectively. The above results further verify the decisive contribution of the GA-HACC-NanoZnO organic-inorganic hybrid factor to the antibacterial performance in the system of the present application.

[0107] Application example 4: Test of organic fluorine content.

[0108] The toothbrush hygiene isolation packaging bag samples prepared by examples 1 to 6 and comparative examples 1 to 4 are subjected to TOF determination of the coated paper according to the TOF content test method described in the “main test standard” at 23℃, and each sample is determined for 3 times to take the average value. The test results are shown in Table 6.

[0109] Table 6: Test results of organic fluorine content:

[0110]

[0111] Analysis: This application example verifies whether the coating system and the comparative sample of the present application contain organic fluorine compounds. According to the TOF test method, when the measured value is less than the detection limit of 5 mg / kg, it is determined to be not detected. In this application example, the TOF content of all example and comparative sample is less than 5 mg / kg, which is determined to be not detected, indicating that the PHA, water-based second film-forming polymer, HACC, GA, NanoZnO, nanolayer barrier filler, interfacial compatibilizer and sealing component used do not introduce organic fluorine structure, which can meet the requirements of paper-based disposable sanitary isolation packaging without organic fluorine, and verify the significant advantage of the present application in environmental protection and fluorine-free.

[0112] Experimental results and analysis:

[0113] According to the test data and phenomena of application examples 1 to 4, the performance of the antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag prepared by the present application is comprehensively analyzed as follows:

[0114] Analysis of the key role of hybrid factors on antibacterial and antiviral performance: The data of examples 1 to 6 show that the coating layer introducing the polyphenol derivative-HACC-NanoZnO organic-inorganic hybrid factor has an inactivation rate of more than 99.90% for enveloped viruses (such as H1N1), and an antibacterial rate of more than 99.92% for Staphylococcus aureus and Escherichia coli. In contrast, comparative example 1 does not add the hybrid factor and has almost no antiviral ability; and comparative example 2 contains the same total amount of GA, HACC and NanoZnO, but uses a simple physical blending method, and its antiviral inactivation rate is only 65.40% and the antibacterial rate is about 70%. This significant difference confirms the core advantage of the "organic-inorganic hybrid network structure" of the present application: the polyphenol derivative (GA) acts as a molecular bridge, on the one hand, it coordinates with NanoZnO through the polyphenol hydroxyl group, and on the other hand, it forms hydrogen bonds or grafts with HACC, effectively inhibiting the agglomeration of NanoZnO, so that it remains in a highly dispersed state on the surface of the coating layer. This structure not only maximizes the exposure area of active sites, but also constructs a synergistic killing mechanism of "cation capture (HACC)" and "oxidative inactivation (NanoZnO)", thereby achieving high efficiency at a lower addition amount.

[0115] Barrier mechanism and performance advantage of fluorine-free system: all examples achieve Cobb 60The high barrier properties, ≤8.5 g / m² and Kit oil-resistant rating 10, are primarily due to the high crystallinity and strong hydrophobicity of PHA itself, as well as the "maze effect" created by nano-layered barrier fillers (such as nano-montmorillonite) in the coating, which prolongs the penetration path of water and oil molecules. Compared to Comparative Example 3 (PE coated paper), although the Cobb value of the PE coated paper is lower (2.1 g / m²), the barrier properties of this invention fully meet the single-use requirements of sanitary isolation bags and completely solve the problems of non-degradability, difficulty in re-sizing, and potential fluorinated additives in PE materials.

[0116] Environmental chemical responsiveness and repulping degradation performance: Data from the examples confirm the excellent "life-cycle environmental friendliness" of the coating of this invention. Under alkaline hydraulic pulping conditions (pH 9, 45°C), the fiber interface dissociation rate of the examples was above 95.0%. This is because the interfacial compatibilizer (such as carboxyl-containing components) and PHA resin in the coating swell or hydrolyze under alkaline and warm conditions, destroying the bonding force between the coating and bamboo pulp fibers, causing the coating to detach in the form of tiny fragments, thus achieving paper-plastic separation. Under composting conditions, the final aerobic biodegradation rate after 90 days exceeded 90%, confirming the complete biodegradability of the PHA substrate and natural bamboo pulp fibers. This contrasts sharply with the "double failure" of Comparative Example 3 (PE coated paper) in both repulping and degradation tests.

[0117] Trend analysis of the impact of changes in the content of key components on performance: Based on the above embodiments and further verification experiments on the numerical ranges in the invention, the trend analysis of the impact of changes in the content of each component on performance is as follows:

[0118] 1) Effect of coating amount: Within the range of 3–8 g / m², as the dry coating amount increases, Cobb… 60 The value shows a downward trend, and the oil resistance level tends to stabilize. When the coating amount is less than 3 g / m², the coating is difficult to completely cover the fiber pores on the surface of bamboo pulp paper, and pinholes are prone to occur, resulting in a significant decrease in barrier properties. When the coating amount exceeds 8 g / m², the improvement in barrier performance slows down, and it also increases costs and may affect the flexibility of the coating. The preferred coating amount of around 5 g / m² in this invention achieves the best balance between performance and cost.

[0119] 2) Effect of hybrid factor addition: Within the range of 10-15 parts, the antiviral and antibacterial efficiencies increase with the increase of hybrid factor content. When the content is less than 10 parts, the density of active sites on the surface is insufficient, and the inactivation time is prolonged; when the content is more than 15 parts, it may slightly interfere with the film-forming continuity of PHA, resulting in a slight increase in Cobb value (decreased barrier properties), and the increased viscosity of the coating affects the coating leveling properties.

[0120] 3) The effect of the ratio of PHA to the second film-forming polymer: As the ratio of the second film-forming polymer (such as an acrylic copolymer) increases (as in Example 4), the flexibility and initial film-forming property of the coating improves (Cobb value decreases), but the biodegradation rate is slightly delayed (from >90% to 90.2%). This shows that within the PHA content range of 40-95wt%, the barrier property, mechanical property and degradation property can be balanced by adjusting the ratio to adapt to different application scenarios.

[0121] 4) The effect of the internal ratio of the hybrid factor: As the mass ratio of GA to HACC increases from 0.05 to 0.30:1, increasing the GA content helps to improve the stability of the hybrid system and prevent NanoZnO from precipitating. As the mass ratio of NanoZnO to HACC increases from 0.10 to 0.60:1, increasing the NanoZnO ratio directly enhances the oxidative inactivation ability, but it is necessary to match sufficient HACC for coating and dispersion, otherwise, excessive NanoZnO will agglomerate and cause a decrease in efficiency.

[0122] In summary, the present application successfully solves the technical problem that traditional paper-based packaging is difficult to balance between fluorine-free barrier, high-efficiency antiviral and re-pulp biodegradability by constructing a water-based PHA coating containing a specific organic-inorganic hybrid factor on the surface of bamboo pulp fiber paper, and provides a safe, efficient and green sanitary isolation solution.

[0123] Those skilled in the art should understand that the above examples are only exemplary and are not intended to limit the scope of the present application. Any modification, equivalent replacement, improvement, etc. of the technical solutions of the present application within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A sanitary isolation bag based on bamboo pulp and paper, comprising a bag body and a sealing assembly made of bamboo pulp fiber paper base, characterized in that: At least one side of the bamboo pulp fiber paper base is coated with a water-based polyhydroxy fatty acid ester barrier antibacterial and antiviral coating. The coating is formed by curing a coating composition consisting of an aqueous dispersion of polyhydroxy fatty acid esters and a coating composition of polyphenol derivatives, chitosan quaternary ammonium salt, and nano zinc oxide organic-inorganic hybrid factors. The coating forms a continuous and dense hydrophobic barrier layer on the surface of bamboo pulp fiber, and the hybrid factor constructs cation capture and oxidative inactivation active sites on the coating surface through the bridging effect of polyphenol derivatives, and the total organic fluorine content of the coating and the sanitary isolation bag is less than 5 mg / kg. The polyphenol derivative is gallic acid, and the hybridization factor is a gallic acid-chitosan quaternary ammonium salt-nano zinc oxide hybrid network. The preparation of the polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybridization factor includes: a) Prepare an aqueous solution of chitosan quaternary ammonium salt and adjust the pH to 5.0–7.5 to obtain the chitosan quaternary ammonium salt solution; b) Slowly add the polyphenol derivative solution to the chitosan quaternary ammonium salt solution and stir until a uniform and stable pre-complexed system is formed to obtain the pre-complexed system; c) Add the nano zinc oxide aqueous dispersion to the pre-complexed system and perform shear dispersion until a uniform and stable organic-inorganic hybrid colloid is formed to obtain the polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor. The mass ratio of polyphenol derivatives to chitosan quaternary ammonium salt is 0.05–0.30:1, and the mass ratio of nano zinc oxide to chitosan quaternary ammonium salt is 0.10–0.60:

1.

2. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The basis weight of the bamboo pulp fiber paper base is 35-280 g / m², the mass ratio of bamboo pulp fiber is ≥70%, and it is subjected to calendering or surface sizing treatment.

3. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The water-based polyhydroxy fatty acid ester barrier antibacterial and antiviral coating is disposed on the inner surface of the bamboo pulp fiber paper base; or simultaneously disposed on the inner and outer surfaces.

4. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The dry coating amount of the waterborne polyhydroxy fatty acid ester barrier antibacterial and antiviral coating is 3-8 g / m².

5. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The polyhydroxy fatty acid ester aqueous dispersion is prepared from polyhydroxy fatty acid ester; The polyhydroxy fatty acid ester is selected from short-chain polyhydroxy fatty acid esters, medium- and long-chain polyhydroxy fatty acid esters, or copolymers that form short-chain polyhydroxy fatty acid ester monomers and medium- and long-chain polyhydroxy fatty acid ester monomers. The short-chain polyhydroxy fatty acid ester is selected from one or more of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate). The medium- and long-chain polyhydroxy fatty acid esters are selected from one or more of poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxynonanoate), poly(3-hydroxydecanoate), poly(3-hydroxyundecanoate), poly(3-hydroxydodecanoate), poly(3-hydroxydodecanate), poly(3-hydroxypalmitate), poly(3-hydroxystearate), and copolymers thereof. The solid content of the polyhydroxy fatty acid ester aqueous dispersion is 30-55 wt%, D 50 The range is 0.2–2.0 μm.

6. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The waterborne polyhydroxyalkanoate barrier antibacterial and antiviral coating possesses environmental chemical responsiveness, including the following properties: alkali-induced interfacial dissociation performance, wherein under aqueous media pulping conditions of pH ≥ 9 and temperature ≥ 40℃, the polyhydroxyalkanoate coating undergoes hydrolysis, swelling, and embrittlement, or the interfacial compatibilizer undergoes ionization, swelling, and induces interfacial hydration, causing the coating to desorb from the fiber surface in the form of particles or flakes, with a fiber interfacial dissociation rate ≥ 95% measured under the aforementioned conditions; It also exhibits enzymatic mineralization properties, which involve the breaking of ester bonds in polyhydroxy fatty acid esters under the action of polyhydroxy fatty acid ester depolymerization enzymes in bioactive soil or compost environments, and the breaking of glycosidic bonds in bamboo pulp fibers under the action of cellulases. After microbial metabolism, these are further mineralized into carbon dioxide and water.

7. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: Under predetermined test conditions, its performance simultaneously meets the following specifications: Cobb 60 ≤9g / m²; Kit oil resistance rating ≥10; blocking or inactivation rate against enveloped viruses ≥99.9%; total organic fluoride content measured by the total organic fluoride test method is less than 5mg / kg.

8. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The sealing component is a self-adhesive sealing strip, a pressure-sensitive adhesive sealing strip, a zipper-type sealing structure, or a direct heat-sealing structure achieved by utilizing the thermoplasticity of the water-based polyhydroxyalkanoate barrier antibacterial and antiviral coating itself; wherein, if an adhesive is used, the pressure-sensitive adhesive or heat-sealing adhesive is a water-based system or a biodegradable system.

9. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The waterborne polyhydroxy fatty acid ester barrier antibacterial and antiviral coating also includes organically modified nano-montmorillonite and an interface compatibilizer. Based on solid mass, the coating comprises: 70-85 parts polyhydroxy fatty acid ester; 10-15 parts polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor; 3-6 parts organically modified nano-montmorillonite; and 2-5 parts interface compatibilizer. The organically modified nano-montmorillonite has a lamellar aspect ratio ≥ 50; The interface compatibilizer contains ionization groups or hydration groups, selected from polyvinyl alcohol and its carboxylated derivatives without organofluorine structures, carboxymethyl cellulose, cationic starch, carboxylated starch, or aqueous resins containing carboxylates.

10. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1, characterized in that: The film-forming resin phase of the aqueous polyhydroxyalkanoate barrier antibacterial and antiviral coating is composed of polyhydroxyalkanoate and a second film-forming polymer. Relative to the total mass of the film-forming resin phase, the polyhydroxyalkanoate accounts for 40-95 wt%, and the second film-forming polymer accounts for 5-60 wt%. The second film-forming polymer is selected from one or more of the following polymers: acrylic polymers or copolymers thereof obtained by emulsion polymerization of one or more monomers selected from acrylic acid, methacrylic acid and their C1-C8 alkyl esters, hydroxyalkyl acrylates or methacrylates, styrene, and acrylonitrile; Aqueous polyurethane dispersions obtained by addition polymerization of aliphatic or alicyclic diisocyanates with polyester diols, polyether diols, or polycarbonate diols and then dispersion in water; An aqueous dispersion of a bio-based polyester or its copolymer obtained by polycondensation of one or more dicarboxylic acids selected from succinic acid, glutaric acid, adipic acid, and oxalic acid with one or more diols selected from ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, and isosorbide; An aqueous dispersion of polylactic acid or its copolymers obtained by ring-opening polymerization of lactic acid; A polyolefin dispersion obtained by emulsification or dispersion of ethylene, propylene or their copolymers; And aqueous dispersions of cellulose derivatives or their modified forms obtained by carboxylation, hydroxypropylation or quaternization of cellulose molecules; The second film-forming polymer is a bio-based polyester or an acrylic polymer, and its phase state with the polyhydroxyalkanoate in the coating is a continuous phase-dispersed phase structure or an interpenetrating network structure.

11. A type of antibacterial and antiviral bamboo pulp paper-based coated paper, characterized in that: The invention includes a bamboo pulp fiber paper base and a water-based polyhydroxy fatty acid ester barrier antibacterial and antiviral coating as described in any one of claims 1 to 10, disposed on at least one side of the bamboo pulp fiber paper base. The coating is formed by curing a coating composition consisting of an aqueous dispersion of polyhydroxy fatty acid esters and a polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor.

12. An aqueous film-forming coating composition for coating sanitary barriers on bamboo pulp paper base, characterized in that: It includes at least the film-forming resin phase, polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor and water; The film-forming resin phase is composed of polyhydroxyalkanoate and a second film-forming polymer, wherein, relative to the total mass of the film-forming resin phase, the polyhydroxyalkanoate accounts for 40-95 wt% and the second film-forming polymer accounts for 5-60 wt%; The second film-forming polymer is selected from one or more of the second film-forming polymers of claim 10.

13. A method for preparing an antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to any one of claims 1 to 10, characterized in that... Includes the following steps: Step 1. Provide bamboo pulp fiber paper base paper, wherein the bamboo pulp fiber paper base paper is base paper that has been calendered and / or surface sizing treated, or untreated bamboo pulp fiber paper base paper is pretreated by calendering or surface sizing to obtain pretreated bamboo pulp fiber paper base paper; Step 2. Prepare a waterborne polyhydroxy fatty acid ester barrier antibacterial and antiviral coating. Mix the waterborne polyhydroxy fatty acid ester dispersion with a polyphenol derivative-chitosan quaternary ammonium salt-nano zinc oxide organic-inorganic hybrid factor, and add organic modified nano montmorillonite and an interface compatibilizer. After shear dispersion, a stable coating is obtained, and the waterborne polyhydroxy fatty acid ester barrier antibacterial and antiviral coating is obtained. The film-forming resin phase of the stabilized coating is a polyhydroxy fatty acid ester, or a blend of a polyhydroxy fatty acid ester and a second film-forming polymer. Step 3. Apply the water-based polyhydroxyalkanoate barrier antibacterial and antiviral coating to the surface of the pretreated bamboo pulp fiber paper base paper using flexographic coating, gravure coating, doctor blade coating or microgravure coating to obtain a wet coating. Step 4. The wet coating is dried under segmented hot air or infrared drying conditions to cause the polyhydroxy fatty acid ester aqueous dispersion particles to aggregate into a film and undergo short-path leveling in the shaping temperature zone, forming a continuous dense barrier layer and a hydrophobic microstructure on the surface, thereby obtaining coated paper. The drying temperature is higher than the minimum film-forming temperature of the polyhydroxy fatty acid ester aqueous dispersion particles and lower than their crystallization melting temperature. Step 5. Fold and seal the coated paper material, and then attach a sealing assembly to obtain a sanitary isolation bag.

14. The antibacterial and antiviral bamboo pulp paper-based sanitary isolation bag according to claim 1 is used in the disposable packaging of toiletries in hotels and homestays, the sanitary isolation and storage of guest rooms and long-term rental apartments, the recycling and temporary storage of disposable toiletries and disposable personal care products after use, the packaging and temporary storage of toiletries kits distributed on tourist transportation vehicles, and the packaging of disposable sanitary products used by visitors and caregivers in medical or nursing institutions.

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