A water vapor barrier film and preparation method thereof

Abstract

The invention relates to a water vapor barrier film and a preparation method thereof. The water vapor barrier film comprises: a HDPE film layer, a LLDPE film layer, a PA6 film layer, a first adhesive layer, an aluminum foil layer, a second adhesive layer and a mixed film layer; the HDPE film layer, the LLDPE film layer, the PA6 film layer, the first adhesive layer, the aluminum foil layer, the second adhesive layer and the mixed film layer are stacked in sequence; the HDPE film layer, the LLDPE film layer and the PA6 film layer constitute a co-extruded film layer; the first adhesive layer adheres to the co-extruded film layer and the aluminum foil layer; the second adhesive layer adheres to the mixed film layer and the aluminum foil layer; the materials of the mixed film layer comprise: a PP material, a PA6 material, a compatibilizer, a masterbatch and an antioxidant; wherein the weight parts of the PP material are 100-120 parts, the weight parts of the PA6 material are 10-15 parts, the weight parts of the compatibilizer are 20-25 parts, the weight parts of the masterbatch are 1-2 parts, and the weight parts of the antioxidant are 2-5 parts. The beneficial effects of the present invention are: the aluminum foil layer is used as the base layer, the strength is increased by PA6, and good thermal stability and mechanical properties are achieved.

Description

Technical Field

[0001] The invention relates to a water vapor barrier film and a preparation method thereof. Background Art

[0002] As a common product in polymer molding processing, film has a wide range of applications in the fields of packaging and protection. With the progress of society and the development of science and technology, higher and higher requirements are put forward for polymer film materials. The use and development of water vapor barrier films have attracted more and more attention.

[0003] In the field of packaging, the issue of protecting the contents of the package is often involved. To ensure that the contents do not deteriorate or prevent product corruption, water absorption, oxidation, etc., the packaging structure needs to have a very good barrier effect. In the food packaging or pharmaceutical packaging industry, water vapor barrier films are also needed.

[0004] CN204773918U discloses a novel co-extruded packaging film, comprising a packaging surface layer, a packaging inner layer, and five core layers sequentially arranged between the packaging surface layer and the packaging inner layer, wherein the material of the packaging surface layer is polyamide, polyolefin or polyester, the material of the inner layer is polyethylene, the material used for the first core layer and the second core layer is polyamide, the material used for the third core layer is ethylene-vinyl alcohol copolymer, and the material used for the fourth core layer and the fifth core layer is polyethylene. The novel co-extruded packaging film of the utility model is used for packaging products such as food and medicine, and has excellent barrier properties for preventing oxygen, water vapor, etc. from entering, and can also prevent the volatilization of food flavor, ensure the original flavor of food, have good heat sealing performance, meet the requirements of sterilization, avoid the presence of microorganisms to destroy food, and have high barrier protection for food, medicine, etc. The novel co-extruded packaging film can well block the entry of oxygen, water vapor, etc., but its thermal stability and mechanical properties need to be further improved. Summary of the invention

[0005] The object of the present invention is to provide a water vapor barrier film and a preparation method thereof to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A water vapor barrier film comprises: a HDPE film layer, a LLDPE film layer, a PA6 film layer, a first adhesive layer, an aluminum foil layer, a second adhesive layer and a mixed film layer; the HDPE film layer, the LLDPE film layer, the PA6 film layer, the first adhesive layer, the aluminum foil layer, the second adhesive layer and the mixed film layer are stacked in sequence; the HDPE film layer, the LLDPE film layer and the PA6 film layer constitute a co-extruded film layer; the co-extruded film layer is prepared as a whole by co-extrusion molding; the first adhesive layer adheres to the co-extruded film layer and the aluminum foil layer; the second adhesive layer adheres to the mixed film layer and the aluminum foil layer; the materials of the mixed film layer include: a PP material, a PA6 material, a compatibilizer, a masterbatch and an antioxidant; wherein the weight portion of the PP material is 100-120 parts, the weight portion of the PA6 material is 10-15 parts, the weight portion of the compatibilizer is 20-25 parts, the weight portion of the masterbatch is 1-2 parts, and the weight portion of the antioxidant is 2-5 parts.

[0008] As a further solution of the present invention: the first adhesive layer and the second adhesive layer are both epoxy halogen-free flame retardant adhesive layers.

[0009] As a further solution of the present invention: the compatibilizer is maleic anhydride grafted polypropylene and maleic anhydride grafted ethylene octane copolymer.

[0010] As a further solution of the present invention: the weight ratio of maleic anhydride grafted polypropylene to maleic anhydride grafted ethylene octane copolymer is 1:1.

[0011] As a further solution of the present invention: the raw materials are mixed, melted, extruded and granulated to obtain mixed particles, and then the mixed particles are prepared into a mixed film layer by extrusion.

[0012] The above-mentioned method for preparing a water vapor barrier film comprises the following steps:

[0013] Step 1, preparing a co-extrusion film layer by co-extrusion molding, so that the HDPE film layer, the LLDPE film layer and the PA6 film layer form a whole;

[0014] Step 2: preheating the aluminum foil layer using a heating roller;

[0015] Step 3, coating the first adhesive layer and the second adhesive layer on both sides of the aluminum foil layer using a double-sided coating machine;

[0016] Step 4: preheating the co-extruded film layer and the mixed film layer using a heating roller;

[0017] Step 5: Adhere the co-extruded film layer through the first adhesive layer, adhere the mixed film layer through the second adhesive layer, and use a hot pressing roller to simultaneously hot-press the co-extruded film layer, the first adhesive layer, the aluminum foil layer, the second adhesive layer and the mixed film layer into a multi-layer film structure as a whole, wherein one side of the PA6 film layer of the co-extruded film layer faces the aluminum foil layer.

[0018] Step 6: The multi-layer film structure is cooled to room temperature by natural cooling and then rolled up to obtain a water vapor barrier film.

[0019] As a further solution of the present invention: a method for preparing a mixed film layer comprises the following steps:

[0020] Step 1, weigh the PP material, PA6 material, compatibilizer, masterbatch and antioxidant in the above parts by weight;

[0021] Step 2, mixing the PP material, the PA6 material and the compatibilizer and stirring, and adding the masterbatch and the antioxidant during the stirring process to obtain a mixed raw material for standby use;

[0022] Step 3, melting, extruding and granulating the mixed raw materials to obtain mixed particles;

[0023] Step 4, preparing a mixed film layer from the mixed particles by extrusion;

[0024] As a further solution of the present invention: when the aluminum foil layer is preheated by using a heating roller, the temperature of the aluminum foil layer is controlled to be between 120 degrees Celsius and 150 degrees Celsius.

[0025] As a further solution of the present invention: when the co-extruded film layer is preheated, the temperature of the co-extruded film layer is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

[0026] As a further solution of the present invention: when the mixed film layer is preheated, the temperature of the mixed film layer is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

[0027] The invention is beneficial in that an aluminum foil layer is used as a base layer, the strength is increased by PA6, and the invention has good thermal stability and mechanical properties.

[0028] Compared with the method of directly adding the mixture to the co-extrusion molding equipment, the method of mixing and stirring before melt granulation has a higher degree of material fusion and stable performance of the finished product.

[0029] Masterbatches can be selected in different colors as needed to prepare films of different colors.

[0030] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a water vapor barrier film of the present invention;

[0032] Figure 2 The present invention is a flow chart of a method for preparing a water vapor barrier film.

[0033] List of Figure Numbers:

[0034] Water vapor barrier film 100 , HDPE film layer 10 , LLDPE film layer 20 , PA6 film layer 30 , first adhesive layer 40 , aluminum foil layer 50 , second adhesive layer 60 , mixed film layer 70 . DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, a water vapor barrier film 100 includes: an HDPE film layer 10, an LLDPE film layer 20, a PA6 film layer 30, a first adhesive layer 40, an aluminum foil layer 50, a second adhesive layer 60 and a mixed film layer 70. The HDPE film layer 10, the LLDPE film layer 20, the PA6 film layer 30, the first adhesive layer 40, the aluminum foil layer 50, the second adhesive layer 60 and the mixed film layer 70 are stacked in sequence. The HDPE film layer 10, the LLDPE film layer 20 and the PA6 film layer 30 constitute a co-extruded film layer. The co-extruded film layer is prepared as a whole by co-extrusion molding. The first adhesive layer 40 adheres to the co-extruded film layer and the aluminum foil layer 50. The second adhesive layer 60 adheres to the mixed film layer 70 and the aluminum foil layer 50.

[0037] The materials of the mixed film layer 70 include: PP material, PA6 material, compatibilizer, masterbatch, antioxidant. The raw materials are mixed, melted, extruded and granulated to obtain mixed particles, and then the mixed particles are prepared into the mixed film layer 70 by extrusion.

[0038] The weight portion of the PP material is 100-120 parts, the weight portion of the PA6 material is 10-15 parts, the weight portion of the compatibilizer is 20-25 parts, the weight portion of the masterbatch is 1-2 parts, and the weight portion of the antioxidant is 2-5 parts.

[0039] As a first specific implementation manner, the weight portion of PP material is 100 parts, the weight portion of PA6 material is 10 parts, the weight portion of compatibilizer is 20 parts, the weight portion of masterbatch is 1 part, and the weight portion of antioxidant is 2 parts.

[0040] As a second specific implementation manner, the weight portion of PP material is 110 parts, the weight portion of PA6 material is 12 parts, the weight portion of compatibilizer is 22 parts, the weight portion of masterbatch is 2 parts, and the weight portion of antioxidant is 4 parts.

[0041] As a third specific implementation manner, the weight portion of PP material is 120 parts, the weight portion of PA6 material is 15 parts, the weight portion of compatibilizer is 25 parts, the weight portion of masterbatch is 2 parts, and the weight portion of antioxidant is 5 parts.

[0042] As a fourth specific implementation manner, the weight portion of PP material is 120 parts, the weight portion of PA6 material is 10 parts, the weight portion of compatibilizer is 20 parts, the weight portion of masterbatch is 2 parts, and the weight portion of antioxidant is 5 parts.

[0043] As a fifth specific implementation manner, the weight portion of PP material is 120 parts, the weight portion of PA6 material is 12 parts, the weight portion of compatibilizer is 21 parts, the weight portion of masterbatch is 2 parts, and the weight portion of antioxidant is 5 parts.

[0044] As a specific implementation manner, the first adhesive layer 40 and the second adhesive layer 60 are both epoxy halogen-free flame-retardant adhesive layers.

[0045] As a specific implementation, the compatibilizer is maleic anhydride grafted polypropylene and maleic anhydride grafted ethylene octyl copolymer. Specifically, the weight ratio of maleic anhydride grafted polypropylene and maleic anhydride grafted ethylene octyl copolymer is 1:1.

[0046] The raw materials are mixed, melted, extruded and granulated to obtain mixed particles, and then the mixed particles are prepared into a mixed film layer 70 by an extrusion method.

[0047] The method for preparing the water vapor barrier film 100 comprises the following steps:

[0048] Step 1, preparing a co-extruded film layer by co-extrusion molding, so that the HDPE film layer 10, the LLDPE film layer 20 and the PA6 film layer 30 form a whole;

[0049] Step 2: preheating the aluminum foil layer 50 using a heating roller;

[0050] Step 3: coating the first adhesive layer 40 and the second adhesive layer 60 on both sides of the aluminum foil layer 50 using a double-sided coating machine;

[0051] Step 4: preheating the co-extruded film layer and the mixed film layer 70 using a heating roller;

[0052] Step 5: Adhere the co-extruded film layer through the first adhesive layer 40, adhere the mixed film layer 70 through the second adhesive layer 60, and use a hot pressing roller to simultaneously hot-press the co-extruded film layer, the first adhesive layer 40, the aluminum foil layer 50, the second adhesive layer 60 and the mixed film layer 70 into a multi-layer film structure as a whole, wherein one side of the PA6 film layer 30 of the co-extruded film layer faces the aluminum foil layer 50.

[0053] Step 6: The multi-layer film structure is cooled to room temperature by natural cooling and then rolled up to obtain a water vapor barrier film 100.

[0054] As a specific implementation, the method for preparing the mixed film layer 70 includes the following steps:

[0055] Step 1, weigh the PP material, PA6 material, compatibilizer, masterbatch and antioxidant in the above parts by weight;

[0056] Step 2, mixing the PP material, the PA6 material and the compatibilizer and stirring, and adding the masterbatch and the antioxidant during the stirring process to obtain a mixed raw material for standby use;

[0057] Step 3, melting, extruding and granulating the mixed raw materials to obtain mixed particles;

[0058] Step 4, preparing the mixed particles into a mixed film layer 70 by extrusion;

[0059] As a specific implementation manner, when the aluminum foil layer 50 is preheated by using a heating roller, the temperature of the aluminum foil layer 50 is controlled to be between 120 degrees Celsius and 150 degrees Celsius.

[0060] As a specific implementation manner, when the co-extruded film layer is preheated, the temperature of the co-extruded film layer is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

[0061] As a specific implementation manner, when the mixed film layer 70 is preheated, the temperature of the mixed film layer 70 is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

[0062] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0063] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A water vapor barrier film, characterized in that: include: HDPE film layer, LLDPE film layer, PA6 film layer, first adhesive layer, aluminum foil layer, second adhesive layer and mixed film layer; the HDPE film layer, the LLDPE film layer, the PA6 film layer, the first adhesive layer, the aluminum foil layer, the second adhesive layer and the mixed film layer are stacked in sequence; the HDPE film layer, the LLDPE film layer and the PA6 film layer constitute a co-extruded film layer; the co-extruded film layer is prepared as a whole by co-extrusion molding; The first adhesive layer adheres the co-extruded film layer and the aluminum foil layer; The second adhesive layer adheres to the mixed film layer and the aluminum foil layer; the material of the mixed film layer includes: PP material, PA6 material, compatibilizer, masterbatch, and antioxidant; The weight portion of the PP material is 100-120 parts, the weight portion of the PA6 material is 10-15 parts, the weight portion of the compatibilizer is 20-25 parts, the weight portion of the masterbatch is 1-2 parts, and the weight portion of the antioxidant is 2-5 parts; The compatibilizer is maleic anhydride grafted polypropylene and maleic anhydride grafted ethylene octane copolymer; The weight ratio of the maleic anhydride grafted polypropylene to the maleic anhydride grafted ethylene octane copolymer is 1:

1.

2. A water vapor barrier film according to claim 1, characterized in that: The first adhesive layer and the second adhesive layer are both epoxy halogen-free flame-retardant adhesive layers.

3. The water vapor barrier film according to claim 1, characterized in that: The raw materials are mixed, melted, extruded and granulated to obtain mixed particles, and then the mixed particles are prepared into the mixed film layer by an extrusion method.

4. The method for preparing a water vapor barrier film according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, preparing a co-extruded film layer by co-extrusion molding, so that the HDPE film layer, the LLDPE film layer and the PA6 film layer form a whole; Step 2: preheating the aluminum foil layer using a heating roller; Step 3, coating the first adhesive layer and the second adhesive layer on both sides of the aluminum foil layer using a double-sided coating machine; Step 4, preheating the co-extruded film layer and the mixed film layer using a heating roller; Step 5, gluing the co-extruded film layer through the first adhesive layer, gluing the mixed film layer through the second adhesive layer, and simultaneously hot-pressing the co-extruded film layer, the first adhesive layer, the aluminum foil layer, the second adhesive layer and the mixed film layer into a whole consisting of a multi-layer film structure by using a hot pressing roller, wherein one side of the PA6 film layer of the co-extruded film layer faces the aluminum foil layer; Step 6: The multi-layer film structure is cooled to room temperature by natural cooling and then rolled up to obtain a water vapor barrier film.

5. The method for preparing a water vapor barrier film according to claim 4, characterized in that: The method for preparing the mixed film layer comprises the following steps: Step 1, weigh the PP material, PA6 material, compatibilizer, masterbatch and antioxidant in the above parts by weight; Step 2, mixing the PP material, the PA6 material and the compatibilizer and stirring, and adding the masterbatch and the antioxidant during the stirring process to obtain a mixed raw material for standby use; Step 3, melting, extruding and granulating the mixed raw materials to obtain mixed particles; Step 4: preparing a mixed film layer from the mixed particles by extrusion.

6. The method for preparing a water vapor barrier film according to claim 4, characterized in that: When the aluminum foil layer is preheated by using a heating roller, the temperature of the aluminum foil layer is controlled to be between 120 degrees Celsius and 150 degrees Celsius.

7. The method for preparing a water vapor barrier film according to claim 4, characterized in that: When the co-extruded film layer is preheated, the temperature of the co-extruded film layer is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

8. The method for preparing a water vapor barrier film according to claim 4, characterized in that: When the mixed film layer is preheated, the temperature of the mixed film layer is controlled to be between 80 degrees Celsius and 100 degrees Celsius.

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