Graphene antibacterial glue for carton packaging and preparation method thereof

Abstract

The invention relates to the technical field of logistics and food transportation, and provides graphene antibacterial glue for carton packaging, which comprises the following components by mass: 90-110 parts of acrylic resin; 6 to 12 parts of graphene oxide nanosheets; 4-7 parts of chitosan quaternary ammonium salt, wherein the molecular weight of the chitosan quaternary ammonium salt is 30-50 kDa; the particle size of a silver core of the nano silver-titanium dioxide core-shell particle is 30nm, and the thickness of a titanium dioxide shell layer is 5nm; 12 to 18 parts of polyvinyl alcohol; 3-5 parts of a composite antibacterial agent; 6 to 9 parts of glycerol; 60 to 75 parts of deionized water; and 0.5 to 1.5 parts of a cross-linking agent. The graphene antibacterial glue has the advantages that the antibacterial rate, the peel strength, the stability and the like of the graphene antibacterial glue are obviously superior to those of conventional glue in a comparative proportion, the advantages of the graphene antibacterial glue in antibacterial performance and use performance are fully embodied, the problem of insufficient antibacterial function of the conventional glue is effectively solved, and the graphene antibacterial glue can adapt to a cold-chain high-humidity environment and prevent microorganism breeding.

Description

Technical Field

[0001] The present invention relates to the technical field of logistics and food transportation, and in particular to graphene antibacterial glue for carton packaging and a preparation method thereof. Background Art

[0002] In the fields of logistics and food transportation technology, carton packaging is an important carrier for cargo transportation, and the hygienic safety of the adhesives used is crucial. This is especially true in cold chain transportation scenarios, where high humidity creates a breeding ground for microorganisms. Microorganisms like Escherichia coli and Staphylococcus aureus can easily multiply, leading to mold contamination of packaging, which directly impacts the shelf life of food, pharmaceuticals, and other products.

[0003] Traditional carton packaging typically uses acrylic glue, which has been widely used in logistics and transportation due to its excellent bonding properties. However, despite existing research on improving the antimicrobial properties of this glue, the lack of an effective multi-antimicrobial system has prevented its effectiveness from meeting practical needs.

[0004] While existing technologies offer excellent bonding performance, traditional acrylic adhesives suffer from a significant drawback: a lack of long-lasting antimicrobial properties. In actual use, particularly in high-humidity environments like cold chains, they are unable to effectively inhibit the growth and reproduction of microorganisms, making them difficult to meet the stringent hygiene standards of modern logistics. This can lead to packaging contamination, impacting the quality and safety of the products being transported. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention provides a graphene antimicrobial glue for carton packaging and its preparation method. This solution addresses the problem that traditional acrylic glues, while offering good bonding properties, suffer from a significant drawback: a lack of long-lasting antimicrobial properties. In actual use, particularly in high-humidity environments such as cold chains, they are unable to effectively inhibit the growth and reproduction of microorganisms, making it difficult to meet the stringent hygiene standards of modern logistics. This can lead to packaging contamination and compromise the quality and safety of the products being transported.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A graphene antibacterial glue for carton packaging, comprising the following components in parts by mass:

[0007] Acrylic resin: 90-110 parts;

[0008] Graphene oxide nanosheets: 6-12 parts;

[0009] Chitosan quaternary ammonium salt: 4-7 parts, molecular weight 30-50 kDa;

[0010] Nano silver-titanium dioxide core-shell particles: 1-3 parts, with a silver core particle size of 30nm and a titanium dioxide shell thickness of 5nm;

[0011] Polyvinyl alcohol: 12-18 parts;

[0012] Composite antibacterial agent: 3-5 parts;

[0013] Glycerol: 6-9 parts;

[0014] Deionized water: 60-75 parts;

[0015] Cross-linking agent: 0.5-1.5 parts;

[0016] Nano silicon nitride: 1 to 3 parts, with a particle size of 50-100 nm.

[0017] Preferably, the composite antibacterial agent is prepared by compounding tea polyphenols and citric acid in a mass ratio of 2:1, and the cross-linking agent is dicumyl peroxide.

[0018] Preferably, the graphene oxide nanosheets have a lateral size of 80-150 nm, an interlayer spacing of 0.8-1.2 nm, are prepared by ultrasonic exfoliation, and have a dispersion concentration of ≥2 mg / mL.

[0019] Preferably, the ultraviolet and visible absorption peaks of the nano-silver-titanium dioxide core-shell particles are located at 380-420 nm, and the minimum inhibitory concentration for Escherichia coli is ≤5 μg / mL.

[0020] Preferably, the pH value of the composite antibacterial agent is 4.5-5.5, and the viscosity at 25° C. is 50-100 mPa·s.

[0021] Preferably, the nano-silicon nitride is used as a reinforcing phase, and its addition amount satisfies the formula: Q=0.03×(A+P), wherein Q is the mass part of nano-silicon nitride, A is the mass part of acrylic resin, and P is the mass part of polyvinyl alcohol.

[0022] A method for preparing graphene antibacterial glue for carton packaging, comprising the following steps:

[0023] Step 1: adding graphene oxide nanosheets, nanosilver-titanium dioxide core-shell particles and silane coupling agent to deionized water in a mass ratio of 1:0.2:0.1, and dispersing them under 40kHz ultrasound at 35°C for 40 minutes to form a stable dispersion;

[0024] Step 2: Add acrylic resin, polyvinyl alcohol and glycerol into the reaction kettle, stir at 100 rpm and heat to 60 ° C, keep warm and dissolve for 1.5 hours to form a transparent homogeneous base liquid;

[0025] Step 3: Add chitosan quaternary ammonium salt and composite antibacterial agent to the nano-dispersion liquid, adjust the pH to 6.8±0.2, and magnetically stir at 50° C. for 30 minutes to form an antibacterial functional liquid;

[0026] Step 4: Add the antibacterial functional liquid to the resin base liquid at a rate of 8 mL / min, add the cross-linking agent at the same time, stir and cross-link at 70°C and 150 rpm for 90 minutes, and filter through a 100-mesh filter after cooling.

[0027] Preferably, in step 1, the ultrasonic power is 250 W, the absolute value of the zeta potential of the dispersion is ≥30 mV, and the silane coupling agent is γ-aminopropyltriethoxysilane.

[0028] Preferably, the cross-linking reaction in step 4 satisfies the kinetic equation:

[0029]

[0030] Where k is the rate constant, which is controlled at 1.2×10 -3 L / (mol·s).

[0031] Preferably, in step 4, nitrogen is introduced into the reactor for protection, and the oxygen content is ≤50ppm.

[0032] The present invention provides a graphene antibacterial glue for carton packaging and a preparation method thereof.

[0033] Beneficial effects:

[0034] 1. The present invention forms a multi-antibacterial system by adding graphene oxide nanosheets, nanosilver-titanium dioxide core-shell particles, chitosan quaternary ammonium salt, and a composite antibacterial agent. The nanosilver-titanium dioxide core-shell particles have a minimum inhibitory concentration of 5 μg / mL against Escherichia coli. Furthermore, the glue in the embodiment achieves an antibacterial rate of over 99.5% within 24 hours and remains above 98.5% for 90 days. This effectively addresses the insufficient antibacterial function of traditional glues and is adaptable to the high-humidity environment of the cold chain, preventing the growth of microorganisms.

[0035] 2. The present invention uses acrylic resin as the matrix, and combines polyvinyl alcohol and nano-silicon nitride as reinforcements to achieve a peel strength of 2.9-3.0N / mm, which is significantly better than the 1.8N / mm of traditional glue, meeting the requirements for packaging bonding strength in logistics and transportation.

[0036] 3. The present invention uses glycerol as a plasticizer, coupled with the effect of the cross-linking agent dicumyl peroxide, so that the viscosity change rate of the glue during storage is only 4.2%-4.8%, which is much lower than the 41.5% of the comparative example, ensuring the stable performance of the glue during use.

[0037] 4. The present invention prepares graphene oxide nanosheets by ultrasonic exfoliation, has suitable lateral dimensions and interlayer spacing, and has good dispersibility with nanosilver-titanium dioxide core-shell particles after being treated with a silane coupling agent (the absolute value of the zeta potential of the dispersion is ≥30mV), which not only improves the antibacterial effect, but also enhances the mechanical properties of the glue, while reducing the amount of nanosilver used (60% less than the traditional solution) and reducing costs. DETAILED DESCRIPTION

[0038] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] An embodiment of the present invention provides a graphene antibacterial glue.

[0040] As one aspect of the present invention, the present invention provides a graphene antibacterial glue comprising the following components in parts by mass:

[0041] Acrylic resin: 90-110 parts;

[0042] Graphene oxide nanosheets: 6-12 parts, with a lateral dimension of 80-150 nm and an interlayer spacing of 0.8-1.2 nm, prepared by ultrasonic exfoliation and a dispersion concentration of ≥2 mg / mL;

[0043] Chitosan quaternary ammonium salt: 4-7 parts, molecular weight 30-50 kDa;

[0044] Nanosilver-titanium dioxide core-shell particles: 1-3 parts, with a silver core particle size of 30 nm and a titanium dioxide shell thickness of 5 nm, a UV-visible absorption peak at 380-420 nm, and a minimum inhibitory concentration for Escherichia coli of ≤5 μg / mL;

[0045] Polyvinyl alcohol: 12-18 parts;

[0046] Composite antibacterial agent: 3-5 parts, prepared by mixing tea polyphenols and citric acid in a mass ratio of 2:1, with a pH value of 4.5-5.5 and a viscosity of 50-100 mPa·s at 25°C;

[0047] Glycerol: 6-9 parts;

[0048] Deionized water: 60-75 parts;

[0049] Cross-linking agent: 0.5-1.5 parts, dicumyl peroxide;

[0050] Nano silicon nitride: 1 to 3 parts, which is a reinforcing phase, has a particle size of 50-100 nm, and the added amount satisfies the formula: Q = 0.03 × (A + P), where Q is the mass part of nano silicon nitride, A is the mass part of acrylic resin, and P is the mass part of polyvinyl alcohol.

[0051] As another aspect of the present invention, the graphene antibacterial glue provided above is prepared by the following method:

[0052] Step 1: adding graphene oxide nanosheets, nanosilver-titanium dioxide core-shell particles, and γ-aminopropyltriethoxysilane in a mass ratio of 1:0.2:0.1 to deionized water, and dispersing them at 40 kHz ultrasound at 35° C. for 40 minutes to form a stable dispersion. The ultrasonic power is 250 W, and the absolute value of the zeta potential of the dispersion is ≥30 mV.

[0053] Step 2: Add acrylic resin, polyvinyl alcohol and glycerol into the reaction kettle, stir at 100 rpm and heat to 60 ° C, keep warm and dissolve for 1.5 hours to form a transparent homogeneous base liquid;

[0054] Step 3: Add chitosan quaternary ammonium salt and composite antibacterial agent to the nano-dispersion liquid, adjust the pH to 6.8±0.2, and magnetically stir at 50° C. for 30 minutes to form an antibacterial functional liquid;

[0055] Step 4: Add the antibacterial functional liquid to the resin base liquid at a rate of 8 mL / min, and add the crosslinking agent at the same time. Stir and crosslink for 90 minutes at 70°C and 150 rpm. After cooling, filter through a 100-mesh filter. The crosslinking reaction satisfies the kinetic equation:

[0056]

[0057] Where k is the rate constant, which is controlled at 1.2×10 -3 L / (mol·s), and nitrogen was introduced into the reactor for protection, and the oxygen content was ≤50ppm.

[0058] In order to better illustrate the formula implementation scheme of the graphene antibacterial glue of the present invention, the following examples are given:

[0059] Example 1:

[0060] A graphene antibacterial glue, comprising the following components in parts by mass:

[0061] 100 parts of acrylic resin, 8 parts of graphene oxide (lateral size 100 nm), 5 parts of chitosan quaternary ammonium salt (40 kDa), 2 parts of nanosilver-titanium dioxide, 15 parts of polyvinyl alcohol, 4 parts of composite antibacterial agent, 7 parts of glycerol, 70 parts of deionized water, 1 part of dicumyl peroxide, 3 parts of nano-silicon nitride (according to Q = 0.03 × (100 + 15) = 3.45 → take 3 parts).

[0062] Example 2:

[0063] A graphene antibacterial glue, comprising the following components in parts by mass:

[0064] 90 parts of acrylic resin, 12 parts of graphene oxide, 7 parts of chitosan quaternary ammonium salt, 1 part of nano silver-titanium dioxide, 18 parts of polyvinyl alcohol, 3 parts of composite antibacterial agent, 9 parts of glycerol, 60 parts of deionized water, 1.5 parts of cross-linking agent, 2.7 parts of nano silicon nitride (Q = 0.03 × (90 + 18) = 3.24 → take 3 parts).

[0065] The experimental data results are shown in Table 1 below.

[0066] Table 1:

[0067]

[0068] The results show that the graphene antibacterial glue of the present invention reduces the amount of nanosilver by 60%, and is not only significantly superior to the traditional glue of the comparative example in terms of antibacterial rate, peel strength and stability, but also enhances the mechanical properties of the glue, while reducing the amount of nanosilver (60% reduction compared to the traditional solution), reducing costs, and fully demonstrating its advantages in antibacterial performance and performance. It is significantly better than the 1.8N / mm of traditional glue, meets the requirements for packaging bonding strength in logistics and transportation, effectively solves the problem of insufficient antibacterial function of traditional glue, can adapt to the high humidity environment of the cold chain, and prevent the growth of microorganisms. At the same time, the viscosity change rate of the glue during storage is only 4.2%-4.8%, which is much lower than 41.5% of the comparative example, ensuring the stable performance of the glue during use.

[0069] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A graphene antibacterial glue for carton packaging, characterized in that: The composition includes the following components in parts by mass: Acrylic resin: 90-110 parts; Graphene oxide nanosheets: 6-12 parts; Chitosan quaternary ammonium salt: 4-7 parts, molecular weight 30-50 kDa; Nano silver-titanium dioxide core-shell particles: 1-3 parts, with a silver core particle size of 30nm and a titanium dioxide shell thickness of 5nm; Polyvinyl alcohol: 12-18 parts; Composite antibacterial agent: 3-5 parts; Glycerol: 6-9 parts; Deionized water: 60-75 parts; Cross-linking agent: 0.5-1.5 parts; Nano silicon nitride: 1 to 3 parts, with a particle size of 50-100 nm.

2. The graphene antibacterial glue for carton packaging according to claim 1, characterized in that: The composite antibacterial agent is prepared by compounding tea polyphenols and citric acid in a mass ratio of 2:1, and the cross-linking agent is dicumyl peroxide.

3. The graphene antibacterial glue for carton packaging according to claim 1, characterized in that: The graphene oxide nanosheets have a lateral size of 80-150 nm and an interlayer spacing of 0.8-1.2 nm, are prepared by an ultrasonic exfoliation method, and have a dispersion concentration of ≥2 mg / mL.

4. The graphene antibacterial glue for carton packaging according to claim 1, characterized in that: The ultraviolet and visible absorption peaks of the nano silver-titanium dioxide core-shell particles are located at 380-420 nm, and the minimum inhibitory concentration for Escherichia coli is ≤5 μg / mL.

5. The graphene antibacterial glue for carton packaging according to claim 1, characterized in that: The pH value of the composite antibacterial agent is 4.5-5.5, and the viscosity at 25° C. is 50-100 mPa·s.

6. The graphene antibacterial glue for carton packaging according to claim 1, characterized in that: The nano silicon nitride is used as a reinforcing phase, and its addition amount satisfies the formula: Q=0.03×(A+P), wherein Q is the mass part of nano silicon nitride, A is the mass part of acrylic resin, and P is the mass part of polyvinyl alcohol.

7. A method for preparing graphene antibacterial glue for carton packaging, using the graphene antibacterial glue for carton packaging according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: adding graphene oxide nanosheets, nanosilver-titanium dioxide core-shell particles and silane coupling agent to deionized water in a mass ratio of 1:0.2:0.1, and dispersing them under 40kHz ultrasound at 35°C for 40 minutes to form a stable dispersion; Step 2: Add acrylic resin, polyvinyl alcohol and glycerol into the reaction kettle, stir at 100 rpm and heat to 60 ° C, keep warm and dissolve for 1.5 hours to form a transparent homogeneous base liquid; Step 3: Add chitosan quaternary ammonium salt and composite antibacterial agent to the nano-dispersion liquid, adjust the pH to 6.8±0.2, and magnetically stir at 50° C. for 30 minutes to form an antibacterial functional liquid; Step 4: Add the antibacterial functional liquid to the resin base liquid at a rate of 8 mL / min, add the cross-linking agent at the same time, stir and cross-link at 70°C and 150 rpm for 90 minutes, and filter through a 100-mesh filter after cooling.

8. The method for preparing graphene antibacterial glue for carton packaging according to claim 7, characterized in that: In the step 1, the ultrasonic power is 250 W, the absolute value of the zeta potential of the dispersion is ≥30 mV, and the silane coupling agent is γ-aminopropyltriethoxysilane.

9. The method for preparing graphene antibacterial glue for carton packaging according to claim 7, characterized in that: The cross-linking reaction in step 4 satisfies the kinetic equation: Where k is the rate constant, which is controlled at 1.2×10 -3 L / (mol·s).

10. The method for preparing graphene antibacterial glue for carton packaging according to claim 7, characterized in that: In the step 4, nitrogen is introduced into the reactor for protection, and the oxygen content is ≤50ppm.

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