Anti-blocking liquid packaging film and preparation process

Abstract

The present application relates to the technical field of anti-adhesion packaging material research and development, and discloses an anti-adhesion liquid packaging film and a preparation process, which comprises the following steps: synthesizing octahexyl double-layer cyclic siloxane monomer, preparing an organic-inorganic hybrid type connecting agent through addition reaction of Si-H bonds of the octahexyl double-layer cyclic siloxane monomer and olefinic functional groups of an allyl silane coupling agent, modifying and treating hydroxylated silicon dioxide nanoparticles through the organic-inorganic hybrid type connecting agent, and then dispersing the hydroxylated silicon dioxide nanoparticles in a PE-SILICON-PE block copolymer matrix to prepare an anti-adhesion composite material; a film structure of a nine-layer co-extrusion film is arranged, the anti-adhesion composite material is introduced into the first layer and the ninth layer of the nine-layer co-extrusion film, and a nine-layer co-extrusion blown film process is used to prepare a packaging film with excellent anti-adhesion performance, which can be applied in the field of non-Newtonian liquid product packaging.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of anti-adhesion packaging materials, in particular to an anti-adhesion liquid packaging film and a preparation process. BACKGROUND

[0002] Non-Newtonian liquid food products such as milk, yogurt, honey and fruit juice have high viscosity and complex flowability, and are extremely easy to adhere to the surface of a plastic packaging film, which leads to difficulty in extrusion during use, thereby causing serious food waste and resource waste, so that the development of an easy-to-extrude anti-adhesion packaging material has practical industrial application value.

[0003] The common product structure of plastic packaging films on the market is PET / PA / PE, PET / Al / PA / PE, PA / PE, PET / VMPET / EVAPE, PET / Al / EVAPE, PA-TIE-PE-PE-TIE-PA-TIE-PE-PE, PE / PE-g-MAH / EVOH / PE-g-MAH / PE, and the hydrophobic performance of the plastic packaging film can be significantly improved by modifying the constituent materials of these structures, such as adding hydrophobic substances. For example, a Chinese patent with the authorization number CN118024637B discloses a preparation process of a modified polypropylene packaging sheet and its application, and the anti-adhesion performance of the polypropylene sheet is significantly improved by modifying the polypropylene resin raw material with silicon oil and silicon dioxide nanoparticles.

[0004] Research has found that the surface modifier PE-SILICON-PE block copolymer composed of polyethylene and silicon can be used to improve the anti-adhesion performance of polyethylene film. SUMMARY

[0005] The application develops a new anti-adhesion component, which is composed of a surface modifier PE-SILICON-PE block copolymer and a hydrophobic modifier nano-silicon dioxide. The anti-adhesion performance of the packaging film is improved by using the anti-adhesion component, and the prepared liquid packaging film not only has excellent anti-adhesion performance, but also will not be contaminated at the sealing place during packaging, and is very suitable for packaging liquid products such as sauce (fruit sauce, sesame sauce) and yogurt. After packaging, the effect of not sticking is achieved, which is convenient for consumers to use.

[0006] A preparation process of an anti-adhesion liquid packaging film, comprising the following steps:

[0007] Step one: using cyclohexyltrimethoxysilane as a raw material, an octacyclohexyl double-layer cyclic siloxane monomer containing Si-H bonds is prepared by a hydrolysis-condensation method and a top corner-capping method;

[0008] Step two: an organic-inorganic hybrid type linker is prepared by addition reaction of Si-H bond of octakis(cyclohexyl) bis-cyclosiloxane monomer with alkenyl functional group of allyl silane coupling agent;

[0009] Step three: the Si-OH functional group obtained by hydrolysis reaction of the hydrolysis functional group of the organic-inorganic hybrid type linker is dehydrated and condensed with the -OH functional group on the surface of the hydroxylated silica nanoparticles to modify the organic-inorganic hybrid type linker on the surface of the silica nanoparticles, thereby obtaining modified silica nanoparticles;

[0010] Step four: the modified silica nanoparticles are dispersed in the PE-SILICON-PE block copolymer matrix to prepare an anti-blocking composite material;

[0011] Step five: a nine-layer co-extruded film structure is set, the anti-blocking composite material is introduced into the first layer and the ninth layer of the nine-layer co-extruded film, and a nine-layer co-extrusion blown film process is used to prepare an anti-blocking liquid packaging film.

[0012] Preferably, the allyl silane coupling agent is one of allyl trichlorosilane, allyl trimethoxysilane and allyl triethoxysilane.

[0013] Preferably, the preparation method of the octakis(cyclohexyl) bis-cyclosiloxane monomer is as follows:

[0014] Step S3-1: cyclohexyl trimethoxysilane is used as raw material, and a hydrolysis-condensation method is adopted to generate octakis(cyclohexyl) tetrasilanol sodium salt by catalyzing the hydrolysis condensation reaction of cyclohexyl trimethoxysilane with sodium hydroxide;

[0015] Step S3-2: octakis(cyclohexyl) bis-cyclosiloxane monomer is synthesized by using methyl dichlorosilane as a capping reagent and through corner-capping method under the catalysis of triethylamine, with octakis(cyclohexyl) tetrasilanol sodium salt as raw material.

[0016] Preferably, the formula and amount of each film layer of the anti-blocking liquid packaging film are as follows:

[0017] The first layer: the formula is 40-80wt% low-density polyethylene resin and 20-60wt% anti-blocking composite material, and the amount is 10-30 parts by weight;

[0018] The second layer: the formula is 100wt% high-density polyethylene resin, and the amount is 5-15 parts by weight;

[0019] The third layer: the formula is 100wt% low-density polyethylene resin, and the amount is 5-15 parts by weight;

[0020] The fourth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, and the amount is 3-8 parts by weight;

[0021] The fifth layer: the formula is 100wt% ethylene-vinyl alcohol copolymer resin, and the dosage is 5-15 parts by weight;

[0022] The sixth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, and the dosage is 3-8 parts by weight;

[0023] The seventh layer: the formula is 100wt% low-density polyethylene resin, and the dosage is 5-15 parts by weight;

[0024] The eighth layer: the formula is 100wt% high-density polyethylene resin, and the dosage is 5-15 parts by weight;

[0025] The ninth layer: the formula is 40-80wt% low-density polyethylene resin and 20-60wt% anti-adhesion composite material, and the dosage is 10-30 parts by weight.

[0026] Preferably, the preparation method of the anti-adhesion liquid packaging film is as follows: the raw materials of each layer are respectively put into the hoppers of the nine screw extruders of the nine-layer co-extrusion film blowing machine set, after mixing by stirring, the molten resins are converged at the die head through the flow divider, extruded and blown through the die, the blowing ratio is controlled at 2.5-2.9, and the anti-adhesion liquid packaging film with a thickness of 50-150μm is obtained after cooling and winding.

[0027] Preferably, the formula of the anti-adhesion composite material is that the mass ratio of the hydroxylated silicon dioxide nanoparticles, the organic-inorganic hybrid type connecting agent and the PE-SILICON-PE block copolymer is (0.5-5):1:(3-20).

[0028] Preferably, the particle size of the hydroxylated silicon dioxide nanoparticles is 40-80nm.

[0029] The application of the anti-adhesion liquid packaging film prepared according to the above process in the field of non-Newtonian liquid product packaging.

[0030] Beneficial effects:

[0031] The application first prepares a new type of anti-adhesion component which is composed of a surface modifier PE-SILICON-PE block copolymer and a hydrophobic modifier nano-silicon dioxide, and is compounded by using an organic-inorganic hybrid connecting agent with excellent hydrophobic property; then a nine-layer co-extrusion film structure is set, the anti-adhesion component is introduced into the first layer and the ninth layer of the nine-layer co-extrusion film, and a nine-layer co-extrusion blowing film forming process is adopted to prepare the anti-adhesion liquid packaging film.

[0032] The experimental results show that the anti-adhesion liquid packaging film has excellent anti-adhesion performance and can achieve the effect of not sticking when used for packaging non-Newtonian liquid products such as yogurt. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a chemical structural formula of octa-cyclohexyl sodium silanol salt;

[0034] Figure 2 is a chemical structural formula of octa-cyclohexyl double-layer cyclic siloxane monomer;

[0035] Figure 3 is a chemical structural formula of an organic-inorganic hybrid type linker;

[0036] wherein, Cy is cyclohexyl;

[0037] Figure 4 is a performance experiment result of the anti-adhesion liquid packaging film. DETAILED DESCRIPTION

[0038] The present application uses silica nanoparticles with excellent hydrophobic performance and PE-SILICON-PE block copolymer as an anti-adhesion modification raw material, in order to improve the compatibility of the silica nanoparticles and the PE-SILICON-PE block copolymer, a linker containing octa-cyclohexyl double-layer cyclic siloxane with hydrophobic ability is developed, and the linker is used to modify the hydroxylated silica nanoparticles first, and then the modified silica nanoparticles are compounded with the PE-SILICON-PE block copolymer to obtain an anti-adhesion composite material.

[0039] Experimental Example 1:

[0040] The octa-cyclohexyl double-layer cyclic siloxane monomer is prepared, and the preparation process is as follows:

[0041] (1) Synthesis of octa-cyclohexyl sodium silanol salt, the synthesis method is as follows: cyclohexyl trimethoxysilane is used as a raw material, a hydrolysis-condensation method is adopted, and the hydrolysis condensation reaction of cyclohexyl trimethoxysilane is catalyzed by sodium hydroxide to generate octa-cyclohexyl sodium silanol salt, and the chemical structural formula is as shown in Figure 1 , and the specific experimental steps are as follows: under the action of nitrogen protection, 20.4g of cyclohexyl trimethoxysilane, 2.7g of sodium hydroxide, 100ml of isopropyl alcohol and 5ml of deionized water are added into a three-necked flask, the temperature is raised to 40℃, and the stirring is continued until it is completely dissolved, the temperature is continuously raised to 90℃, and the stirring is continued to reflux for 4h, and then the temperature is cooled to room temperature, and the stirring is continued for 15h, and then the filtration is carried out, and the isopropyl alcohol is repeatedly washed, and then the vacuum drying is carried out to obtain the octa-cyclohexyl sodium silanol salt;

[0042] (2) Synthesis of octa-cyclohexyl double-layer cyclic siloxane monomer, the synthesis method is as follows: octa-cyclohexyl sodium silanol salt is used as a raw material, methyl dichlorosilane is used as a capping reagent, and the octa-cyclohexyl double-layer cyclic siloxane monomer is synthesized by the vertex-capping method under the catalysis of triethylamine, and the chemical structural formula is as shown in Figure 2The specific experimental steps are as follows: under the protection of nitrogen, 6.0 g of octahexylsilicane sodium salt, 1.5 mL of triethylamine and 50 mL of tetrahydrofuran are added into a three-necked flask, and stirred and dissolved in an ice bath for 2 h, then 10 mL of tetrahydrofuran solution containing 1.5 g of methyldichlorosilane is slowly added into the three-necked flask, the ice bath is removed, and the reaction is stirred at room temperature for 24 h, the solvent is removed by rotary evaporation, repeatedly washed with methanol, and vacuum dried to obtain octahexyl double-layer cyclic siloxane monomer;

[0043] The nuclear magnetic resonance hydrogen spectrum of the octahexyl double-layer cyclic siloxane monomer is characterized as follows: 1 H NMR (CDCl3, 400 MHz) δ: 0.09 (s, 6H), 1.48-1.69 (m, 88H), 3.53 (s, 2H).

[0044] Experimental Example 2:

[0045] An organic-inorganic hybrid type linker is prepared by addition reaction of Si-H bonds of the octahexyl double-layer cyclic siloxane monomer and alkenyl functional groups of an allyl silane coupling agent to generate an organic-inorganic hybrid type linker, and the chemical structural formula is as shown in Figure 3 ;

[0046] The allyl silane coupling agent is one of allyl trichlorosilane, allyl trimethoxysilane and allyl triethoxysilane; in this experimental example, allyl trichlorosilane is selected;

[0047] The specific experimental steps of the organic-inorganic hybrid type linker are as follows: under the protection of nitrogen, 3.0 g of octahexyl double-layer cyclic siloxane monomer and 30 mL of anhydrous toluene are added into a three-necked flask, and stirred at room temperature until completely dissolved, then 10 mL of allyl trichlorosilane solution (prepared by 1.0 g of allyl trichlorosilane and 10 mL of anhydrous toluene) and 4 drops of Karstedt catalyst are sequentially added into the three-necked flask, the temperature is increased to 80°C, and the reaction is stirred for 24 h, then the temperature is cooled to room temperature, the solvent is removed by rotary evaporation, and vacuum dried to obtain the organic-inorganic hybrid type linker;

[0048] The nuclear magnetic resonance hydrogen spectrum of the organic-inorganic hybrid type linker is characterized as follows: 1 H NMR (CDCl3, 400 MHz) δ: 0.55 (s, 6H), 0.97-1.13 (m, 4H), 1.48-1.69 (m, 88H), 1.78-1.82 (t, 4H), 2.08-2.15 (m, 4H).

[0049] Example 1:

[0050] (1) The preparation method of the modified silica nanoparticles is as follows: the Si-OH functional groups obtained by the hydrolysis reaction of the silicon chloride groups of the organic-inorganic hybrid type linker are subjected to dehydration condensation reaction with the -OH functional groups on the surface of the hydroxylated silica nanoparticles, the organic-inorganic hybrid type linker is modified on the surface of the silica nanoparticles, and the modified silica nanoparticles are obtained. The specific experimental steps are as follows: 3 g of hydroxylated nano-silica powder, 40 mL of ethanol and 10 mL of deionized water are added to a four-necked flask, and stirring is carried out under the condition of a 40°C water bath for 1 h, then 2 g of the organic-inorganic hybrid type linker is added to the four-necked flask, and stirring is carried out at 60°C for 3 h, and then the temperature is cooled to room temperature and the mixture is left to stand for 10 h, and then filtration is carried out, washing is carried out with deionized water, centrifugation is carried out, and vacuum drying is carried out, to obtain the modified silica nanoparticles.

[0051] The preparation method of the anti-adhesion composite material is as follows: the modified silica nanoparticles are dispersed in a PE-SILICON-PE block copolymer matrix to obtain the anti-adhesion composite material. The specific experimental steps are as follows: 30 g of PE-SILICON-PE block copolymer and 5 g of modified silica nanoparticles are added to a double-screw extruder, and then blending, melting, extrusion and pelletization are carried out by the double-screw extruder to obtain the anti-adhesion composite material.

[0052] The process parameters of the double-screw extruder are set as follows: the temperatures of zones 1-3 are 130°C, 150°C and 175°C respectively, and the rotation speed is 40 r / min.

[0053] (2) The preparation method of the anti-adhesion composite material is as follows: the modified silica nanoparticles are dispersed in a PE-SILICON-PE block copolymer matrix to obtain the anti-adhesion composite material. The specific experimental steps are as follows: 30 g of PE-SILICON-PE block copolymer and 5 g of modified silica nanoparticles are added to a double-screw extruder, and then blending, melting, extrusion and pelletization are carried out by the double-screw extruder to obtain the anti-adhesion composite material. The difference between the preparation of the anti-adhesion composite material and the preparation of the anti-adhesion composite material is that the hydroxylated nano-silica powder is used instead of the modified silica nanoparticles.

[0054] The PE-SILICON-PE block copolymer is purchased from Shanghai Yiqing Trade Co., Ltd., and the model number is EXFOLA-PE3027. The hydroxylated nano-silica powder is purchased from Beijing Zhongke Keyou Technology Co., Ltd., and the particle size is 40-80 nm.

[0055] Example 2:

[0056] (1) The preparation method of the anti-adhesion liquid packaging film is as follows:

[0057] Step one: The anti-adhesion liquid packaging film is set to a nine-layer symmetrical film structure, and the formula and amount of each film layer are as follows:

[0058] The first layer: the formula is 60wt% low density polyethylene resin and 40wt% anti-blocking composite, the amount is 20 parts by weight;

[0059] The second layer: the formula is 100wt% high density polyethylene resin, the amount is 10 parts by weight;

[0060] The third layer: the formula is 100wt% low density polyethylene resin, the amount is 10 parts by weight;

[0061] The fourth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, the amount is 5 parts by weight;

[0062] The fifth layer: the formula is 100wt% ethylene-vinyl alcohol copolymer resin, the amount is 10 parts by weight;

[0063] The sixth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, the amount is 5 parts by weight;

[0064] The seventh layer: the formula is 100wt% low density polyethylene resin, the amount is 10 parts by weight;

[0065] The eighth layer: the formula is 100wt% high density polyethylene resin, the amount is 10 parts by weight;

[0066] The ninth layer: the formula is 60wt% low density polyethylene resin and 40wt% anti-blocking composite, the amount is 20 parts by weight;

[0067] Step two: the raw materials in step one are respectively put into the hoppers of the nine screw extruders of the nine-layer co-extrusion film blowing machine group, after mixing by stirring, the molten resins are converged at the die head through the flow divider, extruded and blown through the die, the blowing ratio is controlled at 2.7, cooled and wound, to obtain an anti-blocking liquid packaging film with a thickness of 60μm;

[0068] The process parameters of the screw extruders corresponding to the first, second, third, seventh, eighth and ninth layers are set as follows: the temperatures of the first to third zones are 130℃, 150℃ and 175℃ respectively, the flow channel temperature is 170℃, and the rotating speed is 30r / min;

[0069] The process parameters of the screw extruders corresponding to the fourth and sixth layers are set as follows: the temperatures of the first to third zones are 120℃, 140℃ and 165℃ respectively, the flow channel temperature is 160℃, and the rotating speed is 15r / min;

[0070] The process parameters of the screw extruder corresponding to the fifth layer are set as follows: the temperatures of the first to third zones are 180℃, 200℃ and 210℃ respectively, the flow channel temperature is 205℃, and the rotating speed is 40r / min.

[0071] (2) Preparation of packaging film a: only use anti-adhesion blending material to replace anti-adhesion composite material in anti-adhesion liquid packaging film, the rest is the same as anti-adhesion liquid packaging film, and packaging film a is prepared as Comparative Example 1.

[0072] (3) Preparation of packaging film b: refer to the preparation experiment of anti-adhesion liquid packaging film, the difference is only that anti-adhesion composite material is not used, and packaging film b is prepared as Comparative Example 2.

[0073] The low-density polyethylene resin (LDPE) was purchased from Jiangsu Rantai Plastic Co., Ltd., and its brand was LD 150DW; the high-density polyethylene resin (HDPE) was purchased from Dongguan Longhang Plastic Raw Material Co., Ltd., and its brand was FB5600; the maleic anhydride grafted polyethylene resin (PE-g-MAH) was purchased from Dongguan TaoTao Plastic Raw Material Co., Ltd., and its brand was 4288; the ethylene-vinyl alcohol copolymer resin (EVOH) was purchased from Guangzhou Best New Material Technology Co., Ltd., and its brand was ET3803RB.

[0074] Performance test:

[0075] (1) Anti-adhesion performance: the anti-adhesion performance was analyzed by testing the residual amount of yogurt on the sample, and the specific test steps were as follows: a sample with a size of 3 cm x 2 cm was fixed on a clamp with a size of 5 cm x 4 cm, a drop of yogurt (Ili original fermented milk) was injected to the top end of the film sample using a 20 mL syringe filled with yogurt, the initial yogurt mass was weighed, in order to simulate the situation when a person drinks yogurt, the test sample was placed at an angle of 45° with the horizontal plane, after the yogurt flowed down, it was placed for 20 s, the residual yogurt mass after tilting was recorded, and the yogurt residual amount was calculated, and the specific method was as follows:

[0076] Yogurt residual amount (%) = residual yogurt mass on the sample after tilting / initial yogurt mass on the sample;

[0077] (2) Barrier performance: Y110 oxygen transmission tester and TC-03 water vapor transmission tester were used to test the barrier performance of the sample according to GB / T 1038-2000 and GB / T 1037-2021 respectively;

[0078] (3) Mechanical properties: the sample with a size of 30 mm x 5 mm was fixed on an Instron 5565 universal tensile testing machine, and the tensile test was carried out at a tensile rate of 5 mm / min, and the tensile strength in the longitudinal and transverse directions was recorded respectively;

[0079] The experimental results are shown in Table 1 and Figure 4 .

[0080] Table 1 Performance test results of packaging film

[0081]

[0082] Through comprehensive analysis of the above experimental results, the following conclusions can be drawn:

[0083] The anti-sticking composite material obtained by modifying the hydroxylated silica nanoparticles with an organic-inorganic hybrid type linker and then compounding with PE-SILICON-PE block copolymer can significantly reduce the yogurt residue of the packaging film, and has a very significant effect on improving the anti-sticking performance of the packaging film.

Claims

1. A process for the preparation of an anti-blocking liquid packaging film, characterized in that, The method comprises the following steps: Step 1: an octacyclohexyl double-layered cyclic siloxane monomer containing Si-H bonds is prepared by using cyclohexyltrimethoxysilane as a raw material and adopting a hydrolysis-condensation method and a vertex-capping method; Step 2: an organic-inorganic hybrid type linker is prepared by addition reaction of Si-H bonds of the octacyclohexyl double-layered cyclic siloxane monomer and alkenyl functional groups of an allyl silane coupling agent; Step 3: the organic-inorganic hybrid type linker is modified on the surface of the silica nanoparticles by dehydration condensation reaction of Si-OH functional groups obtained by hydrolysis reaction of hydrolysis functional groups of the organic-inorganic hybrid type linker and -OH functional groups on the surface of the hydroxylated silica nanoparticles, to obtain modified silica nanoparticles; Step 4: the modified silica nanoparticles are dispersed in a PE-SILICON-PE block copolymer matrix to prepare an anti-blocking composite material; Step 5: a nine-layer co-extruded film structure is set, the anti-blocking composite material is introduced into the first layer and the ninth layer of the nine-layer co-extruded film, and a nine-layer co-extrusion blown film process is adopted to prepare an anti-blocking liquid packaging film.

2. The process for preparing an anti-blocking liquid packaging film according to claim 1, characterized in that, The allyl silane coupling agent is one of allyl trichlorosilane, allyl trimethoxysilane and allyl triethoxysilane.

3. The process for preparing an anti-blocking liquid packaging film according to claim 1, characterized in that, The preparation method of the octacyclohexyl double-layered cyclic siloxane monomer is as follows: Step S3-1: cyclohexyltrimethoxysilane is used as a raw material, a hydrolysis-condensation method is adopted, and sodium hydroxide is used to catalyze the hydrolysis condensation reaction of cyclohexyltrimethoxysilane to generate octacyclohexyl tetrasilanol sodium salt; Step S3-2: octacyclohexyl tetrasilanol sodium salt is used as a raw material, methyl dichlorosilane is used as a capping reagent, and triethylamine is used as a catalyst to synthesize the octacyclohexyl double-layered cyclic siloxane monomer by a vertex-capping method.

4. The process for preparing an anti-blocking liquid packaging film according to claim 1, characterized in that, The formula and amount of each film layer of the anti-blocking liquid packaging film are as follows: The first layer: the formula is 40-80wt% low-density polyethylene resin and 20-60wt% anti-blocking composite material, and the amount is 10-30 parts by weight; The second layer: the formula is 100wt% high-density polyethylene resin, and the amount is 5-15 parts by weight; The third layer: the formula is 100wt% low-density polyethylene resin, and the amount is 5-15 parts by weight; The fourth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, and the amount is 3-8 parts by weight; The fifth layer: the formula is 100wt% ethylene-vinyl alcohol copolymer resin, and the amount is 5-15 parts by weight; The sixth layer: the formula is 100wt% maleic anhydride grafted polyethylene resin, and the amount is 3-8 parts by weight; The seventh layer: the formula is 100wt% low-density polyethylene resin, and the amount is 5-15 parts by weight; The eighth layer: the formula is 100wt% high-density polyethylene resin, and the amount is 5-15 parts by weight; The ninth layer: the formula is 40-80wt% low-density polyethylene resin and 20-60wt% anti-blocking composite material, and the amount is 10-30 parts by weight.

5. The process for preparing an anti-blocking liquid packaging film according to claim 4, characterized in that, The preparation method of the anti-sticking liquid packaging film is as follows: the raw materials of each layer are respectively put into the hoppers of nine screw extruders of a nine-layer co-extrusion film blowing machine set, after mixing by stirring, the molten resins are converged at the machine head through a flow divider, extruded and blown through a die, the blowing ratio is controlled at 2.5-2.9, and then cooled and rolled to obtain the anti-sticking liquid packaging film with a thickness of 50-150 μm.

6. The process for preparing an anti-blocking liquid packaging film according to claim 1, characterized in that, The formula of the anti-sticking composite material is that the mass ratio of hydroxylated silicon dioxide nanoparticles, organic-inorganic hybrid type connecting agent and PE-SILICON-PE block copolymer is (0.5-5):1:(3-20).

7. The process for preparing an anti-blocking liquid packaging film according to claim 1, characterized in that, The particle size of the hydroxylated silicon dioxide nanoparticles is 40-80 nm.

8. A liquid packaging film against blocking prepared by the process according to any one of claims 1-7, characterised in that, The application of the packaging film in the field of non-Newtonian liquid product packaging.

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