CN106003938A - High-barrier-property polyolefin nano composite thin film and preparation method thereof - Google Patents

Abstract

The invention discloses a high-barrier polyolefin nanocomposite film and a preparation method thereof. Wherein, the high-barrier polyolefin nanocomposite film includes a substrate, a nano-barrier layer arranged on the surface of the substrate, and a surface layer arranged on the surface of the nano-barrier layer; both the substrate and the surface layer are polyolefin films; the The nano-barrier layer is a light-cured coating added with functional nano-materials. The composite film provided by the present invention can be used for the sealed packaging of food, medicine, electrical and electronic products, and chemical products, and can also be used for the sealed storage of gas, liquid and solid. The gas, liquid, and The leakage rate of solids is greatly reduced compared to other sealing membranes.

Description

A kind of high-barrier polyolefin nanocomposite film and preparation method thereof

technical field

The invention relates to the field of composite film materials, in particular to a high-barrier polyolefin nanocomposite film and a preparation method thereof.

Background technique

Plastic packaging materials are the main packaging materials for food and medicine, but their barrier performance is still difficult to meet the actual use requirements. The deterioration or degradation of food and medicine caused by poor packaging reaches 30 to 40%. In addition, oxygen and water will cause food oxidative deterioration microorganisms to multiply and endanger human health. Therefore, improving the gas barrier and water barrier properties of plastic films has attracted extensive attention from the material industry.

There are still many application difficulties in the current barrier film, such as the hygroscopicity of EVOH (ethylene-vinyl alcohol copolymer), which may affect the processing process and the use of end customers, and it does not perform well in high-pressure environments. Polymers have the disadvantage of poor moisture resistance compared to polymers. PVDC (polyvinyl dichloride) also has disadvantages such as poor heat sensitivity, difficult processing, poor transparency, not environmental protection, and high price due to complicated processing process.

Aluminum foil is currently the most widely used high-barrier material, and Tetra Pak and Tetra Pak Pillow are the most widely used packaging forms. The aluminum foil in the composite material cannot be separated in China at present, which makes the packaging material unable to be recycled and reused, which is not conducive to the circular economy. Therefore, there is an urgent need for a high-barrier packaging material that is recyclable and has both gas-barrier and water-barrier properties.

Therefore, the prior art still needs to be improved and developed.

Contents of the invention

In view of the above deficiencies in the prior art, the purpose of the present invention is to provide a polyolefin nanocomposite film with high barrier properties and its preparation method, aiming to solve the problems of poor barrier performance and high cost of barrier materials in the prior art.

Technical scheme of the present invention is as follows:

A polyolefin nanocomposite film with high barrier properties, wherein, it includes a substrate, a nano-barrier layer arranged on the surface of the substrate, and a surface layer arranged on the surface of the nano-barrier layer; both the substrate and the surface layer are polyolefin films; The nano-barrier layer is a light-cured coating added with functional nano-materials.

Said high-barrier polyolefin nanocomposite film, wherein said functional nano-material is a barrier material with a layered structure and/or a nano-material that facilitates the formation of hydrogen bonds by resin molecules.

The high-barrier polyolefin nanocomposite film, wherein the functional nanomaterial is selected from graphene, graphene oxide, rectorite, nano-montmorillonite, organically modified montmorillonite, nano-vermiculite, nano One or more of kaolin, nano-serpentine, nano-potassium titanate, carbon nanotubes, carbon nanoparticles, silicon dioxide, titanium oxide, aluminum oxide, zinc oxide, starch nanocrystals, and nanocellulose.

The high barrier polyolefin nanocomposite film, wherein, the thickness of the substrate is 10um~450μm.

The high barrier polyolefin nanocomposite film, wherein, the thickness of the surface layer is 10um~450μm.

The high barrier polyolefin nanocomposite film, wherein, the surface layer is coated on the surface of the nano barrier layer through an adhesive.

The high barrier polyolefin nanocomposite film, wherein, the nano barrier layer is coated on the surface of the substrate by roll coating.

A method for preparing a barrier polyolefin nanocomposite film as described above, comprising the steps of:

A. Disperse the functional nanomaterial in a solvent, and mix it with a photocurable resin and a photoinitiator to prepare a slurry;

B. Coating the slurry on the surface of the substrate to form a nano-barrier layer;

C. Coating a surface layer on the surface of the nano-barrier layer to finally obtain a high-barrier polyolefin nanocomposite film.

The preparation method, wherein, in the step C, the surface layer is coated on the surface of the nano-barrier layer through an adhesive.

The preparation method, wherein, in the step B, the nano-barrier layer is coated on the surface of the substrate by rolling coating.

Beneficial effects: the composite film provided by the present invention includes a multilayer structure of a substrate, a nano-barrier layer and a surface layer, wherein the substrate and the surface layer are both polyolefin films, and the nano-barrier layer adds functions The photocurable coating of permanent nanomaterials can improve the barrier performance of the composite film through the above-mentioned multi-layer structure to meet different packaging requirements. The composite film provided by the present invention can be used for the sealed packaging of food, medicine, electrical and electronic products, and chemical products, and can also be used for the sealed storage of gas, liquid and solid. The gas, liquid, and The leakage rate of solids is greatly reduced compared to other sealing membranes.

Description of drawings

Fig. 1 is a schematic structural view of a polyolefin nanocomposite film with high barrier properties in the present invention.

detailed description

The present invention provides a high-barrier polyolefin nanocomposite film and a preparation method thereof. In order to make the purpose, technical solution and effect of the present invention clearer and clearer, the present invention will be further described in detail below. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

A kind of high barrier polyolefin nanocomposite film provided by the present invention, as shown in Figure 1, it comprises substrate 10, the nano-barrier layer 20 that is arranged on the surface of substrate 10, the surface layer that is arranged on the surface of nano-barrier layer 20 30; the substrate 10 and the surface layer 30 are polyolefin films;

Wherein, the substrate 10 is a polyolefin film; for example, polypropylene PP (copolymerized, homopolymerized, or random, etc.), or polyethylene PE (linear low density LLDPE, low density LDPE, high density HDPE). The thickness of the substrate is preferably 10 um-450 μm, for example, the thickness is 80 μm.

Wherein, the surface layer 30 is a polyolefin film; for example, polypropylene PP (copolymerization, homopolymerization, random, etc.), or polyethylene PE (linear low density LLDPE, low density LDPE, high density HDPE). The thickness of the surface layer is preferably 10 um-450 μm, for example, 120 μm.

Wherein, the nano-barrier layer 20 is a light-cured coating added with functional nano-materials. The functional nanomaterial is a barrier material with a layered structure and/or a nanomaterial that facilitates hydrogen bond formation of resin molecules, so that the barrier layer has an ultra-high barrier effect of both high gas barrier and high water barrier properties. .

The functional nanomaterial is selected from graphene, graphene oxide, rectorite, nano-montmorillonite, organically modified montmorillonite, nano-vermiculite, nano-kaolin, nano-serpentine, nano-potassium titanate, carbon nano One or more of tubes, carbon nanoparticles, silicon dioxide, titanium oxide, aluminum oxide, zinc oxide, starch nanocrystals, nanocellulose, etc.

In the present invention, the surface layer 30 is coated on the surface of the nano-barrier layer 20 through an adhesive.

The nano-barrier layer 20 is coated on the surface of the substrate by rolling coating. During the preparation process, the slurry of the nano-barrier layer 20 may be coated on the surface of the substrate 10 by rolling coating, and then cured.

The present invention also provides a method for preparing the barrier polyolefin nanocomposite film as described above, which comprises the steps of:

S1. Disperse the functional nanomaterial in a solvent, and mix it with a photocurable resin and a photoinitiator to prepare a slurry;

S2, coating the slurry on the surface of the substrate to form a nano-barrier layer;

S3. Coating a surface layer on the surface of the nano-barrier layer to finally obtain a high-barrier polyolefin nanocomposite film.

Specifically, in the preparation method of the present invention, the slurry of the nano-barrier layer is prepared first: the nano-barrier material is dispersed in a solvent, and then mixed with a photocurable resin and a photoinitiator to prepare the slurry.

Then coating: the prepared slurry is coated on the surface of the substrate to form a film using a suitable coating method, and this step (ie, the coating step) is repeated until the required number of nano-barrier layers is obtained. For example, in the present invention, the nano-barrier layer is coated on the surface of the substrate by rolling coating.

Finally, the compounding of the surface layer: the surface layer is coated on the surface of the nano-barrier layer with an adhesive, so the nano-barrier layer is first coated with an adhesive, and then compounded with the surface layer, and finally a high-barrier polyolefin nanocomposite is obtained film.

The oxygen permeability coefficient of the high-barrier polyolefin nanocomposite film prepared by the invention is reduced by about 57%, and the carbon dioxide permeability coefficient is reduced by about 48%, which can meet the packaging requirements of various foods, medicines, cosmetics, electrical and electronic products, and chemical products. At the same time, the preparation process is environmentally friendly, has high efficiency, can be produced on a large scale, and has broad application prospects.

Example 1

A preparation method of high barrier polyolefin nanocomposite film, comprising the following steps:

Step 1: Prepare the substrate: graphene oxide, carbon nanoparticles, UV photocurable resin, photoinitiator, surface layer and adhesive; the substrate is biaxially stretched polypropylene PP (thickness is 40 μm); the The surface layer is biaxially stretched polypropylene PP with a thickness of 15 μm; the adhesive is polyurethane acrylic resin. In terms of parts by mass, 0.3 parts of graphene oxide (prepared by improved Hummer'S method) and 0.2 parts of carbon nanoparticles (prepared by hydrothermal method) were weighed and dissolved in 15 parts of water, and ultrasonically treated for 60 min to obtain a uniform dispersion of GO, and then Add 20 parts of (water-soluble) polyurethane acrylate (that is, UV light-curable resin), stir ultrasonically for a period of time (for example, 30 minutes, the same below), and then add 0.2 parts of TEGO Glide 100 leveling agent, TEGO Foamex 810 water-based defoamer 1.0 parts, 0.2 parts of TEGO Dispers 760W wetting and dispersing agent, 0.2 parts of TEGO Wet 270 substrate wetting agent, 1.3 parts of E-808 water-based adhesion promoter (n-butyraldehyde aniline condensate) and 1 part of polyurethane associative Thickener, slowly add 0.6 parts of 819DW (photoinitiator) and 0.4 parts of aryl alkyl ketones dropwise under stirring, then add 58.6 parts of (water-soluble) polyurethane acrylate, and then add 1 part of polyurethane associative The thickener adjusts the viscosity of the system, enters the emulsifier, and at room temperature, adjusts the rotational speed of the emulsifier to 8000 rpm, emulsifies for 30 minutes, and prepares the slurry.

Step 2: Coat the slurry in Step 1 on the substrate by roll coating, and irradiate it under the ultraviolet light of a high-pressure mercury lamp for one minute to cure to obtain a nano-barrier layer;

Step 3: Then apply an adhesive on the nano-barrier layer, and attach the surface layer to the nano-barrier layer.

Example 2

A preparation method of high barrier polyolefin nanocomposite film, comprising the following steps:

Step 1: Prepare the substrate: nano rectorite, nano silica, UV photocurable resin, photoinitiator, surface layer and adhesive; the substrate is polyethylene PE with a thickness of 58 μm; the surface layer It is polyethylene PE 20μm; the adhesive is silicone rubber. In terms of parts by mass, weigh 0.3 parts of nano-rectorite and 0.2 parts of nano-silicon dioxide and ultrasonically disperse them in 18 parts of water to obtain a uniform dispersion, then add 18 parts of (water-soluble) polyurethane acrylate, stir ultrasonically for a period of time, and then Add 0.2 parts of TEGOGlide 100 leveling agent, 1.0 parts of TEGO Foamex 810 water-based defoamer, 0.2 parts of TEGO Dispers 760W wetting and dispersing agent, 0.2 parts of TEGO Wet 270 substrate wetting agent, and 1.3 parts of E-808 water-based adhesion promoter 1 part and 1 part of polyurethane associative thickener, slowly add 0.6 part of 819DW and 0.4 part of aryl alkyl ketone compound dropwise under stirring, then add 57.6 parts of (water-soluble) polyurethane acrylate, and then add 1 part of polyurethane The associative thickener adjusts the viscosity of the system, enters the emulsifier, and at room temperature, adjusts the rotation speed of the emulsifier to 8000 rpm, emulsifies for 30 minutes, and prepares a slurry.

Step 2: Coating the slurry in Step 1 on the substrate, and irradiating it under the ultraviolet light of a high-pressure mercury lamp for one minute, and curing to obtain a nano-barrier layer;

Step 3: Then apply an adhesive on the nano-barrier layer, and attach the surface layer to the nano-barrier layer.

Example 3

A preparation method of high barrier polyolefin nanocomposite film, comprising the following steps:

Step 1: Prepare the substrate: organically modified montmorillonite, carbon nanoparticles, solvent-based photocurable resin, surface layer and adhesive; the substrate is polypropylene PP with a thickness of 100 μm; the surface layer is polypropylene Acrylic PP with a thickness of 15 μm; the adhesive is acrylic resin. In terms of parts by mass, weigh 0.3 parts of organically modified montmorillonite and 0.2 parts of carbon nanoparticles and ultrasonically disperse them in 25 parts of DMF (dimethylformamide) to obtain a uniform dispersion, and then add 8 parts of SR238 reactive diluent (1,6-hexanediol diacrylate), then add 35 parts of hexafunctional urethane acrylate, 30 parts of difunctional hexaurethane acrylate and ultrasonically stir for a period of time, add 0.5 part of EFKA3299 leveling agent, and slowly drop it under stirring 0.6 parts of 1173 photoinitiator and 0.4 part of Irgacure184 photoinitiator were put into the disperser, and at room temperature, the speed of the disperser was adjusted to 8000 rpm, and the dispersion was carried out for 30 minutes to prepare a slurry.

Step 2: Coat the slurry in Step 1 on the substrate by roll coating, and irradiate it under the ultraviolet light of a high-pressure mercury lamp for one minute to cure to obtain a nano-barrier layer;

Step 3: Then apply an adhesive on the nano-barrier layer, and attach the surface layer to the nano-barrier layer.

Table 1 shows the influence of different examples on the oxygen permeability coefficient of the high barrier polyolefin nanocomposite film. The multilayer composite film includes a base material, a barrier layer, and a surface layer, but the barrier layer does not contain nanomaterials. The single-layer polyolefin film refers to only the substrate.

Table I

Oxygen permeability coefficient (cm ³ cm/(cm ² •s•Pa)) Single layer polyolefin film 2.80×10 ^-14 Multilayer composite film (without adding nanomaterials) 3.80×10 ^-15 Example 1 1.65×10 ^-15 Example 2 2.31×10 ^-15 Example 3 1.92×10 ^-15

It can be seen from Table 1 that when the polyolefin is made into a multilayer composite film, the oxygen permeability coefficient decreases by about 10 times, and when the multilayer composite film is added with nanomaterials, the oxygen permeability coefficient of the material to be tested decreases significantly. The oxygen permeability coefficient of the multilayer composite film without adding nanomaterials is 3.80×10 ^-15 cm ³ cm/(cm ² ·s·Pa), when the multilayer composite film is added with graphene oxide and carbon nanoparticles, the oxygen permeability coefficient decreases ^{The oxygen permeability coefficient dropped to 2.31×10 -15 cm 3 cm /} ( cm ² •s•Pa), when organically modified montmorillonite and carbon nanoparticles are added to the multilayer composite film, the oxygen permeability coefficient drops to 1.92×10 ^-15 cm ³ cm/(cm ² •s•Pa), due to The large sheet structure of sheet nanomaterials causes the oxygen permeation path to change, forming a curved permeation path. Therefore, after adding nanomaterials, the oxygen permeability has been greatly reduced. When the composite film is added with graphene oxide and carbon nanoparticles , the oxygen permeability coefficient drops to 1.65×10 ^-15 cm ³ cm/(cm ² •s•Pa), which is 57% lower than the oxygen permeability coefficient of the multilayer composite membrane without adding nanomaterials.

Table 2 shows the influence of different examples on the CO ₂ permeability of high barrier polyolefin nanocomposite films.

Table II

Carbon dioxide permeability coefficient cm ³ cm/(cm ² •s•Pa) Single layer polyolefin film 2.60×10 ^-13 Multilayer composite film (without adding nanomaterials) 3.49×10 ^-14 Example 1 1.83×10 ^-14 Example 2 1.98×10 ^-14 Example 3 1.92×10 ^-14

It can be seen from Table 2 that when the polyolefin is made into a multilayer composite film, the oxygen permeability coefficient drops by about 10 times, and the carbon dioxide permeability coefficient of the multilayer composite film without adding nanomaterials is 3.49×10 ^-14 cm ³ cm/(cm ² •s•Pa); when graphene oxide and carbon nanoparticles were added to the multilayer composite film, the carbon dioxide permeability dropped to 1.83×10 ^-14 cm ³ cm/(cm ² •s•Pa); when the multilayer composite film was added When adding nano-rectorite and nano-silica, the carbon dioxide permeability coefficient drops to 1.98×10 ^-14 cm ³ cm/(cm ² •s•Pa); when organically modified montmorillonite and carbon nanoparticles are added to the multilayer composite film , the carbon dioxide permeability coefficient dropped to 1.92×10 ^-14 cm ³ cm/(cm ² •s•Pa) , which was 48% lower than the CO ₂ permeability of the multilayer composite film without adding nanomaterials. When nanomaterials are added, gas molecules must bypass these nanomaterials along the "tortuous path" to penetrate. At this time, the "tortuous path" effect becomes more and more obvious, so the barrier performance of the coating shows a significant improvement .

In summary, the composite film provided by the present invention can be used for sealed packaging of food, medicine, electrical and electronic products, and chemical products, and can also be used for sealed storage of gases, liquids and solids. This high-barrier polyolefin nanocomposite film Compared with other sealing membranes, the leakage rate of gas, liquid and solid is greatly reduced.

It should be understood that the application of the present invention is not limited to the above examples, and those skilled in the art can make improvements or transformations according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. A polyolefin nanocomposite film with high barrier property, is characterized in that, comprises base material, the nano barrier layer that is arranged on the base material surface, the surface layer that is arranged on the nano barrier layer surface; Described base material and surface layer are Polyolefin film; the nano-barrier layer is a light-cured coating added with functional nano-materials. 2. The high-barrier polyolefin nanocomposite film according to claim 1, characterized in that, the functional nanomaterial is a layered structure barrier material and/or a nanomaterial that is conducive to the formation of hydrogen bonds by resin molecules. 3. The high-barrier polyolefin nanocomposite film according to claim 1, wherein the functional nanomaterial is selected from graphene, graphene oxide, rectorite, nano-montmorillonite, organically modified montmorillonite Desoil, nano-vermiculite, nano-kaolin, nano-serpentine, nano-potassium titanate, carbon nanotubes, carbon nanoparticles, silicon dioxide, titanium oxide, aluminum oxide, zinc oxide, starch nanocrystals, nanocellulose, etc. one or more. 4. The high-barrier polyolefin nanocomposite film according to claim 1, characterized in that, the thickness of the substrate is 10um~450μm. 5. The high barrier polyolefin nanocomposite film according to claim 1, characterized in that the thickness of the surface layer is 10um~450μm. 6. The high-barrier polyolefin nanocomposite film according to claim 1, wherein the surface layer is coated on the surface of the nano-barrier layer by an adhesive. 7. The high-barrier polyolefin nanocomposite film according to claim 1, wherein the nano-barrier layer is coated on the surface of the substrate by roll coating. 8. a preparation method of barrier polyolefin nanocomposite film as claimed in claim 1, is characterized in that, comprises the steps: A. Disperse the functional nanomaterial in a solvent, and mix it with a photocurable resin and a photoinitiator to prepare a slurry; B. Coating the slurry on the surface of the substrate to form a nano-barrier layer; C. Coating a surface layer on the surface of the nano-barrier layer to finally obtain a high-barrier polyolefin nanocomposite film. 9. The preparation method according to claim 8, characterized in that, in the step C, the surface layer is coated on the surface of the nano-barrier layer by an adhesive. 10. The preparation method according to claim 8, characterized in that, in the step B, the nano-barrier layer is coated on the surface of the substrate by roll coating.