An ultraviolet deoxygenation fresh-keeping packaging material and its application

Abstract

The present invention relates to an ultraviolet deoxygenation fresh-keeping packaging material and its application, belonging to the technical field of packaging materials. In the present invention, trimethylolpropane triacrylate and ethylenediamine are used as raw materials to construct a hyperbranched polymer with terminal double bonds based on Michael addition. Then, a mercapto-containing hindered amine light stabilizer obtained by transesterification of methyl mercaptoacetate and pentamethylpiperidinol and an alkyl mercaptan are added to carry out a thiol-ene click reaction, thereby preparing a light stabilizer. After being melt-blended with plastics and cast into a film as the outer layer, a coating solution prepared from a dispersant, PET, an active substance capable of generating triplet excitons under ultraviolet light irradiation, an antioxidant, an ultraviolet light absorber, and a stabilizer is coated on one side of the outer layer. Finally, after drying, an ultraviolet deoxygenation fresh-keeping packaging material is obtained. When applied to the packaging of articles, it can not only achieve deoxygenation through ultraviolet light irradiation, but also the degradation effect of the outer layer under ultraviolet light is negligible.

Description

Technical Field

[0001] The present invention belongs to the technical field of packaging materials, and particularly relates to an ultraviolet deoxygenation fresh-keeping packaging material and its application. Background Art

[0002] At present, in the packaging of easily oxidized items such as food and medicine, physical or chemical methods are mostly used for deoxygenation. The physical method of deoxygenation is to create a low-oxygen or even oxygen-free environment through vacuum or nitrogen filling treatment, while the chemical method of deoxygenation is to add a chemical deoxidizer to absorb oxygen. Whether it is a physical method or a chemical method, there are problems such as high cost and complex operation. Based on this, a technology for deoxygenation by adding an active substance capable of generating triplet excitons under ultraviolet light irradiation to the packaging material has emerged. However, this technology still has certain drawbacks that limit its actual application effect. This is because in order for the triplet excitons to better interact with the oxygen in the bag, it is necessary to cover an additional layer of polymer film on the surface of the packaging material, such as polypropylene film, polyethylene film, etc., to block the external oxygen. However, since ultraviolet light irradiation is a necessary condition in the actual deoxygenation process, this polymer film will inevitably face degradation, that is, accelerated aging, which ultimately seriously affects various properties, and directly restricts the overall packaging effect, shortens the service life, and is not worth the loss. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide an ultraviolet deoxygenation fresh-keeping packaging material and its application. The present invention uses trimethylolpropane triacrylate and ethylenediamine as raw materials to construct a hyperbranched polymer with terminal double bonds based on Michael addition, and then through the addition of a mercapto-containing hindered amine light stabilizer obtained by transesterification of methyl mercaptoacetate and pentamethyldiethanolamine and alkyl mercaptan to carry out thiol-ene click reaction, thereby preparing a light stabilizer. After melting and blending it with plastic and casting it into a film as the outer layer, a coating solution prepared from a dispersant, PET, an active substance capable of generating triplet excitons under ultraviolet light irradiation, an antioxidant, an ultraviolet light absorber, and a stabilizer is coated on one side of the outer layer, and finally, an ultraviolet deoxygenation fresh-keeping packaging material is obtained after drying. When applied to the packaging of items, it can not only achieve deoxygenation through ultraviolet light irradiation, but also the degradation effect of the outer layer by ultraviolet light is negligible.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A preparation method of an ultraviolet deoxygenation fresh-keeping packaging material, the preparation method comprising the following steps:

[0006] (1) Mix plastic and a light stabilizer at a mass ratio of 98 - 100:1 by stirring at 195 - 200 °C for 5 - 10 min, and then use a casting machine to cast into a film with a thickness of 10 - 15 microns to obtain the outer layer;

[0007] (2) Mix a dispersant, polyethylene terephthalate, an active substance, an antioxidant, an ultraviolet light absorber, and a stabilizer at a mass ratio of 100:20:0.2 - 1.6:0.02 - 0.1:0.02 - 0.1:0.02 - 0.1 by stirring in ultrasonic at 80 - 85 °C for 12 - 14 h to obtain a coating solution;

[0008] (3) Coat the coating solution on one side of the outer layer and dry it to complete the preparation.

[0009] As a preferred technical solution of the present invention, the light stabilizer in step (1) is prepared by the following steps:

[0010] Step A: Dropwise add an ethylenediamine solution to trimethylolpropane triacrylate while stirring at 40 - 50 °C. After the addition is completed, continue to stir at a constant temperature for 6 - 8 h, and then perform vacuum distillation to obtain component A; the ethylenediamine solution refers to a solution formed by mixing ethylenediamine and methanol at a mass ratio of 1:8 - 10 at room temperature; the molar ratio of trimethylolpropane triacrylate to ethylenediamine is 1:0.25 - 0.26;

[0011] Step B: Add 15 - 20 parts by weight of methyl mercaptoacetate, 3 - 4 parts by weight of pentamethylpiperidinol, and 1 - 2 parts by weight of magnesium methoxide to 100 parts by weight of dimethyl sulfoxide, and then heat and reflux at 70 - 75 °C for 8 - 10 h, and then purify to obtain component B;

[0012] Step C: Add 4 parts by weight of component A, 2 parts by weight of component B, 1 - 1.5 parts by weight of alkyl mercaptan, and 0.5 parts by weight of benzoin dimethyl ether to 100 parts by weight of dimethyl sulfoxide, and then stir and mix under ultraviolet light irradiation at 30 - 35 °C for 1 - 1.5 h, cool to 0 - 5 °C, filter, take the filter residue, wash it with deionized water, and finally vacuum dry at 50 - 70 °C until constant weight to complete the preparation.

[0013] Furthermore, the dropping rate in step A is controlled at 1 - 2 drops / s.

[0014] Furthermore, the vacuum distillation in step A refers to distillation at 30 °C under a vacuum degree of -0.07 MPa until all volatiles are completely removed.

[0015] Further, the purification in step B means first distilling for 30 - 45 min at 60°C to remove volatiles, then distilling for 60 min at 125 - 130°C to collect the distillate and cooling it to room temperature. Subsequently, 25 - 30 parts by weight of deionized water is added, followed by filtration. The filter residue is taken, washed with deionized water, and finally dried under vacuum at 40 - 60°C until constant weight.

[0016] Further, the alkyl mercaptan in step C is at least one of tetradecyl mercaptan, hexadecyl mercaptan, and octadecyl mercaptan.

[0017] Further, the wavelength of the ultraviolet light in step C is 365 nm.

[0018] As a preferred technical solution of the present invention, the operating parameters of the casting machine in step (1) are that the die head temperature is controlled at 190 - 200°C, and the cooling roll temperature is controlled at 30 - 35°C.

[0019] As a preferred technical solution of the present invention, the dispersant in step (2) is at least one of dimethyl isosorbide, tetrahydrofuran, N,N - dimethylformamide, N,N - dimethylacetamide, and dimethyl sulfoxide; the antioxidant is at least one of antioxidant 1076, antioxidant 1010, and antioxidant 264; the ultraviolet light absorber is at least one of phenyl salicylate, resorcinol monobenzoate, and hexamethylphosphoric triamide; the stabilizer is at least one of zinc stearate, cadmium stearate, and lead stearate.

[0020] As a preferred technical solution of the present invention, the active substance in step (2) is at least one of benzophenone, benzophenone derivatives, and β - diketone derivatives.

[0021] As a preferred technical solution of the present invention, the power of the ultrasonic wave in step (2) is 400 W.

[0022] As a preferred technical solution of the present invention, the drying in step (3) means drying at 60 - 70°C for 24 h.

[0023] An ultraviolet deoxygenation fresh - keeping packaging material prepared by the preparation method as described above.

[0024] As a preferred technical solution of the present invention, the thickness of the ultraviolet deoxygenation fresh - keeping packaging material is 18 - 20 microns.

[0025] An application of an ultraviolet deoxygenation fresh - keeping packaging material, wherein the ultraviolet deoxygenation fresh - keeping packaging material is applied to the packaging of articles.

[0026] A deoxygenation method for an ultraviolet deoxygenation fresh - keeping packaging material, the deoxygenation method comprising the following steps:

[0027] Make the ultraviolet deoxygenation fresh-keeping packaging material into a bag, put the items into it, seal it, and then irradiate it with ultraviolet light with a wavelength of 300 - 400 nm for 30 - 60 minutes, and that's it.

[0028] Advantages of the present invention:

[0029] (1) In the present invention, trimethylolpropane triacrylate and ethylenediamine are used as raw materials to construct a hyperbranched polymer with terminal double bonds based on Michael addition. Then, a mercapto-containing hindered amine light stabilizer obtained by transesterification of methyl mercaptoacetate and pentamethylpiperidinol and an alkyl mercaptan are added to carry out a thiol-ene click reaction, thereby preparing a light stabilizer. After melting and blending it with plastic and casting it into a film as the outer layer, a coating solution prepared from a dispersant, PET, an active substance that can generate triplet excitons under ultraviolet light irradiation, an antioxidant, an ultraviolet light absorber, and a stabilizer is coated on one side of the outer layer. Finally, after drying, an ultraviolet deoxygenation fresh-keeping packaging material is obtained. When applied to the packaging of items, it can not only deoxygenate through ultraviolet light irradiation, but also the degradation effect of the outer layer under ultraviolet light is minimal.

[0030] (2) The present invention creatively prepares a light stabilizer, which endows the outer layer of the ultraviolet deoxygenation fresh-keeping packaging material with excellent anti-aging and anti-degradation capabilities when irradiated with ultraviolet light. On the one hand, the light stabilizer is a hindered amine light stabilizer, which itself cannot absorb ultraviolet light, thus effectively ensuring that the actual deoxygenation process can proceed normally and efficiently. On the other hand, since the light stabilizer is prepared based on a hyperbranched polymer, it not only has a high molecular weight, enhancing thermal stability and reducing precipitation in the polymer matrix, but also retains a quasi-spherical structure, and the molecular chains are not easily entangled, thereby greatly improving the mass transfer and diffusion rates and obtaining more excellent light stabilization activity. In addition, after being modified with a certain amount of alkyl mercaptan, it can have better interfacial compatibility with plastic by virtue of the saturated hydrocarbon group of the alkyl mercaptan, promoting the dispersion effect of the light stabilizer, thereby further improving the anti-aging and anti-degradation capabilities of the outer layer.

[0031] (3) When the ultraviolet deoxygenation fresh-keeping packaging material prepared by the present invention is applied to the packaging of items, it can deoxygenate only by being exposed to ultraviolet light. The specific principle is that the active substance absorbs photon energy and enters the excited state. In the excited state, intersystem crossing occurs to form triplet excitons. Triplet excitons have a long lifetime and high energy, which can transfer energy to oxygen molecules, exciting the oxygen molecules from the ground state to the singlet state (singlet oxygen). Then, it promotes the combination of singlet oxygen with other components in the ultraviolet deoxygenation fresh-keeping packaging material, turning into harmless or inactive compounds, and finally achieving the purpose of deoxygenation.

[0032] (4) The ultraviolet deoxidizing and fresh-keeping packaging material prepared by the present invention is particularly suitable for packaging easily oxidized articles such as foods, cosmetics, and drugs. It is convenient for deoxidation and has a remarkable deoxidation effect, effectively extending the shelf life of the articles and having a wide application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0034] Figure 1 It is a physical diagram of the ultraviolet deoxidizing and fresh-keeping packaging material prepared in Example 1 of the present invention during deoxidation.

[0035] Figure 2 It is a comparison diagram of the oxygen content in the bag before and after ultraviolet light irradiation when the ultraviolet deoxidizing and fresh-keeping packaging material prepared in Example 1 of the present invention is deoxidized.

[0036] Figure 3 It is a comparison diagram of the oxygen content in the bag before and after ultraviolet light irradiation when the ultraviolet deoxidizing and fresh-keeping packaging material prepared in Example 2 of the present invention is deoxidized.

[0037] Figure 4 It is a comparison diagram of the oxygen content in the bag before and after ultraviolet light irradiation when the ultraviolet deoxidizing and fresh-keeping packaging material prepared in Example 3 of the present invention is deoxidized.

[0038] Figure 5 It is a comparison diagram of the oxygen content in the bag before and after ultraviolet light irradiation when the ultraviolet deoxidizing and fresh-keeping packaging material prepared in Example 4 of the present invention is deoxidized. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific embodiments, structures, features, and their effects according to the present invention.

[0040] The plastics in all examples and comparative examples of the present invention are polypropylene, purchased from PetroChina Company Limited, with the model of EPC30R-H; polyethylene terephthalate is purchased from Shanghai Xingxiang Plastic Co., Ltd., with the brand of PET powder.

[0041] Example 1

[0042] A preparation method of an ultraviolet deoxidizing and fresh-keeping packaging material, the preparation method comprising the following steps:

[0043] (1) Mix plastic and a light stabilizer at a mass ratio of 98:1 and stir at 195 °C for 5 minutes, and then use a casting machine to cast into a film with a thickness of 10 microns to obtain the outer layer;

[0044] (2) Mix a dispersant, polyethylene terephthalate, an active substance, an antioxidant, an ultraviolet light absorber, and a stabilizer in a mass ratio of 100:20:0.2:0.02:0.02:0.02 in an ultrasonic bath at 80 °C with stirring for 12 h to obtain a coating solution;

[0045] (3) Coat the obtained coating solution on one side of the outer layer and dry it to complete the preparation.

[0046] The light stabilizer described in step (1) is prepared through the following steps:

[0047] Step A: Dropwise add an ethylenediamine solution to trimethylolpropane triacrylate with stirring at 40 °C. After the addition is completed, continue stirring at a constant temperature for 6 h, and then perform vacuum distillation to obtain component A; the ethylenediamine solution refers to a solution prepared by mixing ethylenediamine and methanol at a mass ratio of 1:8 at room temperature; the molar ratio of trimethylolpropane triacrylate to ethylenediamine is 1:0.25;

[0048] Step B: Add 15 parts by weight of methyl mercaptoacetate, 3 parts by weight of pentamethyldipiperidinol, and 1 part by weight of magnesium methoxide to 100 parts by weight of dimethyl sulfoxide, then heat under reflux at 70 °C for 8 h, and purify to obtain component B;

[0049] Step C: Add 4 parts by weight of component A, 2 parts by weight of component B, 1 part by weight of alkyl mercaptan, and 0.5 part by weight of benzoin dimethyl ether to 100 parts by weight of dimethyl sulfoxide, then stir and mix under ultraviolet light irradiation at 30 °C for 1 h, cool to 0 °C, filter, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 50 °C until constant weight to complete the preparation.

[0050] The dropping rate described in step A is controlled at 1 drop / s.

[0051] The vacuum distillation described in step A means distilling at 30 °C under a vacuum degree of -0.07 MPa until all volatiles are completely removed.

[0052] The purification described in step B means first distilling at 60 °C for 30 min to remove volatiles, then distilling at 125 °C for 60 min to collect the distillate and cooling it to room temperature, then adding 25 parts by weight of deionized water, filtering, taking the filter residue, washing it with deionized water, and finally drying it under vacuum at 40 °C until constant weight.

[0053] The alkyl mercaptan described in step C is tetradecyl mercaptan.

[0054] The wavelength of the ultraviolet light described in step C is 365 nm.

[0055] The working parameters of the casting machine described in step (1) are that the die head temperature is controlled at 190 °C and the cooling roll temperature is controlled at 30 °C.

[0056] The dispersant described in step (2) is N,N-dimethylformamide; the antioxidant is antioxidant 1076; the ultraviolet light absorber is phenyl salicylate; the stabilizer is zinc stearate.

[0057] The active substance described in step (2) is 4-methylbenzophenone.

[0058] The power of the ultrasonic wave described in step (2) is 400 W.

[0059] The drying described in step (3) means drying at 60 °C for 24 h.

[0060] An ultraviolet oxygen-removing and freshness-preserving packaging material prepared by the preparation method as described above.

[0061] The thickness of the ultraviolet oxygen-removing and freshness-preserving packaging material is 18 microns.

[0062] An application of an ultraviolet oxygen-removing and freshness-preserving packaging material, wherein the ultraviolet oxygen-removing and freshness-preserving packaging material is applied to the packaging of articles.

[0063] A method for removing oxygen from an ultraviolet oxygen-removing and freshness-preserving packaging material, the oxygen-removing method comprising the following steps:

[0064] Make the ultraviolet oxygen-removing and freshness-preserving packaging material into a bag, load the articles, seal it, and then irradiate it with ultraviolet light with a wavelength of 365 nm for 30 min.

[0065] Example 2

[0066] On the basis of Example 1, 4-methylbenzophenone is changed to an equal weight of p-bromobenzophenone, and the rest remain unchanged.

[0067] Example 3

[0068] On the basis of Example 1, 4-methylbenzophenone is changed to an equal weight of dibenzoylmethane, and the rest remain unchanged.

[0069] Example 4

[0070] On the basis of Example 1, 4-methylbenzophenone is changed to an equal weight of 1-(4-hydroxyphenyl)-3-phenyl-1,3-propanedione, and the rest remain unchanged.

[0071] Example 5

[0072] A preparation method of an ultraviolet oxygen-removing and freshness-preserving packaging material, the preparation method comprising the following steps:

[0073] (1) Stir and mix plastic and a light stabilizer at a mass ratio of 100:1 at 200 °C for 10 min, and use a casting machine to cast a film with a thickness of 15 microns to obtain an outer layer;

[0074] (2) Mix the dispersant, polyethylene terephthalate, active substance, antioxidant, ultraviolet absorber and stabilizer in a mass ratio of 100:20:1.6:0.1:0.1:0.1 in ultrasonic at 85 °C and stir for 14 h to obtain a coating solution;

[0075] (3) Coat the obtained coating solution on one side of the outer layer and dry it to complete the preparation.

[0076] The light stabilizer described in step (1) is prepared by the following steps:

[0077] Step A: Dropwise add an ethylenediamine solution to trimethylolpropane triacrylate while stirring at 50 °C. After the addition is completed, continue stirring at a constant temperature for 8 h, and then perform vacuum distillation to obtain component A; the ethylenediamine solution refers to a solution prepared by mixing ethylenediamine and methanol at a mass ratio of 1:10 at room temperature; the molar ratio of trimethylolpropane triacrylate to ethylenediamine is 1:0.26;

[0078] Step B: Add 20 parts by weight of methyl mercaptoacetate, 4 parts by weight of pentamethylpiperidinol and 2 parts by weight of magnesium methoxide to 100 parts by weight of dimethyl sulfoxide, then heat and reflux at 75 °C for 10 h, and purify to obtain component B;

[0079] Step C: Add 4 parts by weight of component A, 2 parts by weight of component B, 1.5 parts by weight of alkyl mercaptan and 0.5 parts by weight of benzoin dimethyl ether to 100 parts by weight of dimethyl sulfoxide, then stir and mix under the irradiation of ultraviolet light at 35 °C for 1.5 h, cool to 5 °C, filter, take the filter residue, wash it with deionized water, and finally vacuum dry at 70 °C until constant weight to complete the preparation.

[0080] The dropping rate described in step A is controlled at 2 drops / s.

[0081] The vacuum distillation described in step A refers to distillation at 30 °C under a vacuum degree of -0.07 MPa until all volatiles are completely removed.

[0082] The purification described in step B refers to first distilling at 60 °C for 45 min to remove volatiles, then distilling at 130 °C for 60 min to collect the distillate and cooling it to room temperature, then adding 30 parts by weight of deionized water, filtering, taking the filter residue, washing it with deionized water, and finally vacuum drying at 60 °C until constant weight.

[0083] The alkyl mercaptan described in step C is hexadecyl mercaptan.

[0084] The wavelength of the ultraviolet light described in step C is 365 nm.

[0085] The working parameters of the casting machine in step (1) are that the die head temperature is controlled at 200 °C and the cooling roll temperature is controlled at 35 °C.

[0086] The dispersant in step (2) is N,N-dimethylformamide; the antioxidant is antioxidant 1010; the ultraviolet light absorber is resorcinol monobenzoate; the stabilizer is zinc stearate.

[0087] The active substance in step (2) is 4-methyldibenzoyl methane.

[0088] The power of the ultrasound in step (2) is 400 W.

[0089] The drying in step (3) means drying at 70 °C for 24 h.

[0090] An ultraviolet deoxygenation fresh-keeping packaging material prepared by the preparation method as described above.

[0091] The thickness of the ultraviolet deoxygenation fresh-keeping packaging material is 20 microns.

[0092] An application of an ultraviolet deoxygenation fresh-keeping packaging material, wherein the ultraviolet deoxygenation fresh-keeping packaging material is applied to the packaging of articles.

[0093] A deoxygenation method for an ultraviolet deoxygenation fresh-keeping packaging material, the deoxygenation method comprising the following steps:

[0094] Make the ultraviolet deoxygenation fresh-keeping packaging material into a bag, put the articles in, seal it, and then irradiate it with ultraviolet light with a wavelength of 365 nm for 60 min.

[0095] Example 6

[0096] A preparation method for an ultraviolet deoxygenation fresh-keeping packaging material, the preparation method comprising the following steps:

[0097] (1) Stir and mix plastic and a light stabilizer at a mass ratio of 99:1 at 198 °C for 8 min, and cast it into a film with a thickness of 12 microns by a casting machine to obtain an outer layer;

[0098] (2) Stir and mix a dispersant, polyethylene terephthalate, an active substance, an antioxidant, an ultraviolet light absorber and a stabilizer at a mass ratio of 100:20:1:0.05:0.05:0.05 in ultrasonic waves at 83 °C for 13 h to obtain a coating solution;

[0099] (3) Coat the coating solution on one side of the outer layer and dry it to complete the preparation.

[0100] The light stabilizer in step (1) is prepared by the following steps:

[0101] Step A: While stirring, add an ethylenediamine solution dropwise to trimethylolpropane triacrylate at 45°C. After the addition is complete, continue stirring at a constant temperature for 7 h, and then perform vacuum distillation to obtain Component A; the ethylenediamine solution refers to a solution formed by mixing ethylenediamine and methanol at a mass ratio of 1:9 at room temperature; the molar ratio of trimethylolpropane triacrylate to ethylenediamine is 1:0.255.

[0102] Step B: Add 18 parts by weight of methyl thioglycolate, 3.5 parts by weight of pentamethylpiperidinol, and 1.5 parts by weight of magnesium methoxide to 100 parts by weight of dimethyl sulfoxide, and then heat under reflux at 73°C for 9 h, followed by purification to obtain Component B.

[0103] Step C: Add 4 parts by weight of Component A, 2 parts by weight of Component B, 1.3 parts by weight of alkyl mercaptan, and 0.5 parts by weight of benzoin dimethyl ether to 100 parts by weight of dimethyl sulfoxide, and then stir and mix under ultraviolet light irradiation at 33°C for 1.3 h. Cool to 3°C, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 60°C until a constant weight is achieved, thus completing the preparation.

[0104] The dropping rate in Step A is controlled at 1.5 drops / s.

[0105] The vacuum distillation in Step A refers to distillation at 30°C under a vacuum degree of -0.07 MPa until all volatile substances are completely removed.

[0106] The purification in Step B refers to first distilling at 60°C for 40 min to remove volatile substances, then distilling at 128°C for 60 min to collect the distillate and cooling it to room temperature. Then, add 28 parts by weight of deionized water, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 50°C until a constant weight is achieved.

[0107] The alkyl mercaptan in Step C is octadecanethiol.

[0108] The wavelength of the ultraviolet light in Step C is 365 nm.

[0109] The working parameters of the casting machine in Step (1) are that the die head temperature is controlled at 195°C and the cooling roll temperature is controlled at 33°C.

[0110] The dispersant in Step (2) is N,N-dimethylformamide; the antioxidant is antioxidant 264; the ultraviolet light absorber is hexamethylphosphoric triamide; the stabilizer is zinc stearate.

[0111] The active substance in Step (2) is 4-methyldibenzoyl ketone.

[0112] The power of the ultrasonic wave in Step (2) is 400 W.

[0113] The drying in step (3) means drying at 65°C for 24 h.

[0114] An ultraviolet deoxygenation fresh-keeping packaging material prepared by the preparation method as described above.

[0115] The thickness of the ultraviolet deoxygenation fresh-keeping packaging material is 19 microns.

[0116] An application of an ultraviolet deoxygenation fresh-keeping packaging material, wherein the ultraviolet deoxygenation fresh-keeping packaging material is applied to the packaging of articles.

[0117] A deoxygenation method for an ultraviolet deoxygenation fresh-keeping packaging material, the deoxygenation method comprising the following steps:

[0118] Make the ultraviolet deoxygenation fresh-keeping packaging material into a bag, load the article, seal it, and then irradiate it with ultraviolet light with a wavelength of 365 nm for 45 min.

[0119] Comparative Example 1

[0120] On the basis of Example 6, the alkyl mercaptan in step C is changed to an equal weight of dimethyl sulfoxide, and the rest remains unchanged.

[0121] Comparative Example 2

[0122] On the basis of Example 6, the alkyl mercaptan in step C is changed to an equal weight of component B, and the rest remains unchanged.

[0123] Comparative Example 3

[0124] On the basis of Example 6, steps A and C are not carried out, and the rest remains unchanged.

[0125] Comparative Example 4

[0126] On the basis of Example 6, the light stabilizer in step (1) is changed to an equal weight of plastic, and the rest remains unchanged.

[0127] Test Example 1

[0128] Anti-ultraviolet aging test:

[0129] Extrude and mold the mixed materials in step (1) of Example 6 and Comparative Examples 1-4 respectively, and naturally cool them to room temperature to obtain sheets with specifications of 120 mm * 25 mm * 4 mm. Then, test the tensile strength according to Standard GB / T 1040.2-2022 (the tensile speed is 5 mm / min), denoted as A1. At the same time, irradiate the above sheets with ultraviolet light with a wavelength of 365 nm for 2000 h. After the irradiation ends, test the tensile strength again by the same method, denoted as A2. Then, the decrease rate of the tensile strength can be calculated.

[0130] Table 1. Anti-ultraviolet aging test results

[0131] Rate of decrease in tensile strength / % Example 6 3.3 Comparative Example 1 7.1 Comparative Example 2 5.7 Comparative Example 3 18.6 Comparative Example 4 19.3

[0132] From Test Example 1, by comparing Example 6 with Comparative Examples 1-4, it can be seen that the outer layer of the ultraviolet deoxygenation and freshness preservation packaging material prepared by the present invention can have more excellent anti-ultraviolet aging and degradation capabilities.

[0133] Regarding Figure 1 the analysis, there is delayed photoluminescence under ultraviolet light irradiation, proving the generation of triplet excitons.

[0134] Regarding Figure 2 the analysis, after ultraviolet light irradiation, the oxygen content in the bag decreased from 18% to 4%, proving that deoxygenation can be effectively carried out.

[0135] Regarding Figure 3 the analysis, after ultraviolet light irradiation, the oxygen content in the bag decreased from 18% to 3.2%, proving that deoxygenation can be effectively carried out.

[0136] Regarding Figure 4 the analysis, after ultraviolet light irradiation, the oxygen content in the bag decreased from 18% to 2.9%, proving that deoxygenation can be effectively carried out.

[0137] Regarding Figure 5 the analysis, after ultraviolet light irradiation, the oxygen content in the bag decreased from 18% to 5.3%, proving that deoxygenation can be effectively carried out.

[0138] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an ultraviolet deoxygenation fresh-keeping packaging material, characterized in that: The preparation method comprises the following steps: (1) mixing the plastic and the light stabilizer at a mass ratio of 98-100:1 at 195-200° C. for 5-10 minutes, and casting the film into a film with a thickness of 10-15 μm using a casting machine to obtain an outer layer; (2) mixing the dispersant, polyethylene terephthalate, active substance, antioxidant, ultraviolet light absorber and stabilizer in a mass ratio of 100:20:0.2-1.6:0.02-0.1:0.02-0.1:0.02-0.1 under ultrasound at 80-85° C. for 12-14 hours to obtain a coating solution; (3) coating the coating liquid on one side of the outer layer and drying it, thereby completing the preparation; The light stabilizer in step (1) is prepared by the following steps: Step A: adding ethylenediamine solution dropwise to trimethylolpropane triacrylate while stirring at 40-50° C., stirring at a constant temperature for 6-8 hours after the addition is completed, and distilling under reduced pressure to obtain component A; the ethylenediamine solution refers to a solution of ethylenediamine and methanol mixed at a mass ratio of 1:8-10 at room temperature; the molar ratio of the trimethylolpropane triacrylate to the ethylenediamine is 1:0.25-0.26; Step B: adding 15-20 parts by weight of methyl thioglycolate, 3-4 parts by weight of pentamethylpiperidinol and 1-2 parts by weight of magnesium methoxide to 100 parts by weight of dimethyl sulfoxide, and then heating under reflux at 70-75° C. for 8-10 hours, purifying, and obtaining component B; Step C: Add 4 parts by weight of component A, 2 parts by weight of component B, 1-1.5 parts by weight of alkyl mercaptan and 0.5 parts by weight of benzoin dimethyl ether to 100 parts by weight of dimethyl sulfoxide, then stir and mix for 1-1.5 hours under ultraviolet light irradiation at 30-35° C., cool to 0-5° C., filter, take the filter residue, wash with deionized water, and finally vacuum dry at 50-70° C. until constant weight, and the preparation is completed.

2. The method for preparing a UV deoxygenation fresh-keeping packaging material according to claim 1, characterized in that: The reduced pressure distillation in step A refers to distillation at 30° C. under a vacuum degree of −0.07 MPa until the volatiles are completely removed.

3. The method for preparing a UV deoxygenation fresh-keeping packaging material according to claim 1, characterized in that: The purification in step B refers to first distilling at 60°C for 30-45min to remove volatiles, then distilling at 125-130°C for 60min to collect the fraction and cool it to room temperature, then adding 25-30 parts by weight of deionized water, filtering, taking the filter residue, washing it with deionized water, and finally vacuum drying it at 40-60°C until constant weight.

4. The method for preparing a UV deoxygenation fresh-keeping packaging material according to claim 1, characterized in that: The alkyl mercaptan in step C is at least one of tetradecanethiol, hexadecanethiol and octadecanethiol.

5. The method for preparing a UV deoxygenation fresh-keeping packaging material according to claim 1, characterized in that: The working parameters of the casting machine in step (1) are as follows: the die head temperature is controlled at 190-200°C, and the cooling roller temperature is controlled at 30-35°C.

6. The method for preparing a UV deoxygenation fresh-keeping packaging material according to claim 1, characterized in that: The dispersant in step (2) is at least one of dimethyl isosorbide, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide; the antioxidant is at least one of antioxidant 1076, antioxidant 1010 and antioxidant 264; the ultraviolet light absorber is at least one of phenyl o-hydroxybenzoate, resorcinol monobenzoate and hexamethylphosphoric acid triamide; the stabilizer is at least one of zinc stearate, cadmium stearate and lead stearate; the active substance is at least one of benzophenone, benzophenone derivatives and β-diketone derivatives.

7. An ultraviolet deoxygenation fresh-keeping packaging material prepared by the preparation method according to any one of claims 1 to 6.

8. The ultraviolet deoxygenation fresh-keeping packaging material according to claim 7, characterized in that: The thickness of the ultraviolet deoxygenation fresh-keeping packaging material is 18-20 microns.

9. An application of the ultraviolet deoxygenation fresh-keeping packaging material prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The ultraviolet deoxygenation fresh-keeping packaging material is used in the packaging of articles.

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