Preparation method of interlayer separation membrane

Abstract

The invention discloses a preparation method of an interlayer separation membrane, which comprises the following steps: compounding a sealing layer and a bottom membrane to form a supporting composite layer, and cutting the supporting composite layer to form a drinking opening in the sealing layer; the tensile strength of the bottom film ranges from 50 MPa to 350 MPa, and the ductility of the bottom film ranges from 90% to 500%. The sealing layer on the supporting composite layer is compounded with the blocking layer through colloid, the colloid is solidified between the blocking layer and the sealing layer to form a stripping layer, and the stripping strength between the bottom film on the supporting composite layer and the sealing layer is smaller than that between the blocking layer and the sealing layer; and the interlayer separation membrane is formed after the bottom membrane is removed. The interlayer separation membrane prepared by the preparation method disclosed by the invention has the advantages of good sealing performance, easy uncovering property and high yield.

Description

Technical Field

[0001] The invention relates to the field of packaging, and in particular to a method for preparing an interlayer separation film. Background Art

[0002] Conventional cover films are usually made of a barrier layer and a heat-sealing layer, and their overall thickness is less than 200μm. When in use, straws are usually inserted, which not only requires straws, but also often causes the straws to be damaged and unable to be inserted into the cup when the cover film is hard or the straws are not set properly, which is very inconvenient to operate; and the use of straws is also extremely environmentally unfriendly.

[0003] In order to overcome the problems that the existing straws are not environmentally friendly and are inconvenient to operate due to damage when the straws are inserted into the cover film, an interlayer separation membrane with at least three layers has been developed, wherein the interlayer separation membrane is a barrier layer, a peeling layer, and a heat-sealing layer from the outside to the inside; wherein a low-strength adhesive is used as a peeling layer and is composited with the barrier layer and the heat-sealing layer, and a drinking port is provided on the heat-sealing layer; when in use, it is only necessary to peel off the barrier layer and keep the heat-sealing layer on the container, and the purpose of drinking without a straw can be achieved through the drinking port reserved on the heat-sealing layer, and there will be no problem of damage to the straw when the straw is inserted into the cover film.

[0004] However, in the preparation process of the interlayer separation membrane, since a drinking port needs to be opened on the heat-sealing layer, it is necessary to cut it to form an opening. However, there are many problems in the actual preparation process, resulting in a low yield rate. Specifically, in the process of cutting and preparing the drinking port on the heat-sealing layer, it is necessary to use a cutter head to process it to form an opening. However, since the heat-sealing layer is made of a soft material, has a low hardness, and a high elongation, if a blade is directly used to cut the heat-sealing layer to form an opening, and then compounded with the barrier layer, this method will cause the heat-sealing layer to deform significantly, and then the position of the drinking port of the prepared interlayer separation membrane cannot be fixed, resulting in a low yield rate of the finally obtained interlayer separation membrane. If the barrier layer and the heat-sealing layer are first compounded and then the cover film is reversely cut to form an opening on the heat-sealing layer to form a drinking opening, the accuracy of the cutter head needs to be precisely controlled; the specific reason is that since the barrier layer is made of Al material with good barrier effect, its toughness is relatively low and stress cracking will occur under a certain pressure; therefore, if the cutter head cuts in too shallowly, although it will not damage the barrier layer, it will not achieve the purpose of forming an opening in the heat-sealing layer; and if the cutter head cuts in too deeply, it will damage the barrier layer, causing stress cracking in the barrier layer, causing the sealing performance of the interlayer separation film to be lost, and the purpose of sealing cannot be achieved. However, the existing equipment cannot accurately control the accuracy of the cutter head, and thus cannot achieve the purpose of effectively forming an opening on the heat-sealing layer without damaging the barrier layer. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is that the interlayer separation membrane disclosed in the prior art has a low pass rate when prepared by conventional methods; thus, a method for preparing an interlayer separation membrane that can more effectively prepare a qualified interlayer separation membrane is provided.

[0006] To this end, the present invention provides the following technical solutions:

[0007] A method for preparing an interlayer separation membrane, comprising:

[0008] The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer; the bottom film is made of a material with a compressive strength between 50MPa and 350MPa and an elongation between 90% and 500%;

[0009] The sealing layer on the supporting composite layer is compounded with the barrier layer through a colloid, and the colloid is solidified between the barrier layer and the sealing layer to form a peeling layer, and the peeling strength between the bottom film on the supporting composite layer and the sealing layer is less than the peeling strength between the barrier layer and the sealing layer; after removing the bottom film, an interlayer separation film is formed.

[0010] The tensile strength of the base film is 150MPa-200MPa, and the elongation is 110%-140%; preferably, the base film is made of CPP.

[0011] The peeling strength between the bottom film on the supporting composite layer and the sealing layer is less than 0.1N / 15mm.

[0012] The peel strength between the barrier layer and the sealing layer is greater than 1 N / 15 mm, preferably 1-7 N / 15 mm, and more preferably 2-4 N / 15 mm.

[0013] The thickness of the base film is 30-70 microns, preferably 50-70 microns.

[0014] The peeling layer consists of two layers, namely a base adhesive layer formed by curing an acrylic ester colloid and a surface adhesive layer formed by curing a polyurethane colloid; the base adhesive layer is arranged adjacent to the barrier layer.

[0015] The coating amount of the primer layer is 0.05-0.15 g / m 2 The coating amount of the surface adhesive layer is 0.3-4.5g / m 2 The more the colloid coating amount is, the greater the peel strength is. In order to achieve the purpose of peeling between the barrier layer and the sealing layer without affecting the sealing between the sealing layer and the container, the coating amount of the surface adhesive layer is preferably 0.5-1.5g / m 2 .

[0016] The material of the barrier layer is Al;

[0017] And / or, the sealing layer is made of CPP.

[0018] The thickness of the barrier layer is 30-70 microns;

[0019] And / or, the sealing layer has a thickness of 30-70 microns.

[0020] The curing temperature for forming the peeling layer is 40-75°C, and the curing time is 48-72h; preferably 65±5°C, 48h.

[0021] The technical solution of the present invention has the following advantages:

[0022] 1. The present invention provides a method for preparing an interlayer separation membrane, comprising first forming a supporting composite layer containing a sealing layer, then cutting the supporting composite layer to form a drinking opening on the sealing layer, then using a colloid to composite the sealing layer with a barrier layer, the colloid forming a peeling layer between the sealing layer and the barrier layer, and finally removing a bottom film on the sealing layer to form an interlayer separation membrane having a barrier layer, a peeling layer and a sealing layer; the bottom film is selected to be a material with a compressive strength between 50MPa and 350MPa and an elongation between 90% and 500%, which can ensure that the sealing layer is cut off to form a drinking opening, and the sealing layer will not deform; at the same time, the prepared interlayer separation membrane has good sealing performance and easy peeling performance, effectively ensuring the yield of the prepared interlayer separation membrane.

[0023] 2. In the preparation method of an interlayer separation membrane provided by the present invention, the material of the base film is CPP, which not only has suitable compressive strength and elongation, but also can be compounded with the sealing layer by electrostatic method or adhesive method. It is only necessary to ensure that the peeling strength between the base film and the sealing layer is less than 0.1N / 15mm. This setting can ensure that the base film can be peeled and removed more effectively in the final step, and there are more types of compounding methods. Among them, when compounding by electrostatic method, there is no need to use colloid, and the electrostatic adsorption between the materials can be directly used to effectively ensure the compounding between the base film and the sealing layer, which meets the cutting requirements and effectively saves the preparation cost; when compounding by adhesive method, the stability after compounding is higher and the operation is more stable.

[0024] 3. A method for preparing an interlayer separation membrane of the present invention, wherein the peel strength between the base film and the sealing layer is less than 0.1N / 15mm, and the peel strength between the barrier layer and the sealing layer is set to be greater than 1N / 15mm. The two cooperate with each other to avoid the impact on the peeling layer when the base film is removed during the preparation process. At the same time, the peel strength between the barrier layer and the sealing layer is further limited to 2-4N / 15mm, which can ensure that the sealing layer and the barrier layer can be separated more conveniently during use, thereby effectively ensuring that the prepared interlayer separation membrane has good sealing and easy-to-remove properties.

[0025] 4. The method for preparing an interlayer separation membrane of the present invention does not require a high-precision roller cutter die edge, and does not require frequent replacement of the roller cutter die to maintain its accuracy; at the same time, the hole cutting effect can be judged in advance by peeling off the base film and the sealing film, and there is no need to wait until the cover film is manufactured and sealed with the cup before peeling it off to judge the cutting condition of the incision, thereby shortening the production cycle and improving the yield of the finished product. DETAILED DESCRIPTION

[0026] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0027] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0028] In the following embodiments, the tensile strength test method is: GB / T 28118-2011;

[0029] The testing method for elongation is: GB 1040.3 (thickness < 1mm), GB 1040.2 (thickness > 1mm);

[0030] The test method for peel strength is: GB / T 8808-1988;

[0031] The coating amount detection method is:

[0032] Step 1 (sampling): take a flat sample of about 100cm long on the machine; Step 2 (cutting samples): use a sampling knife to cut 4 samples of 100 square centimeters; Step 3 (weighing gross weight): use an electronic balance to weigh the gross weight of the adhesive and record it; Step 4 (wiping the glue): use a cloth dipped in ethyl acetate to wipe it repeatedly for more than three times, and then carefully observe whether the glue is wiped clean; Step 5 (weighing net weight): use an electronic balance to weigh the net weight of the aluminum foil and record it. Step 6 (calculation): use an electronic calculator according to the formula: (gross weight - net weight) / number of samples = gram weight of glue per sample; calculate the coating amount according to the area of ​​each sample.

[0033] Embodiment 1:

[0034] A method for preparing an interlayer separation membrane, comprising:

[0035] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a base film with a thickness of 55 μm and a material of CPP, the base film has a tensile strength of 170-200 MPa and an elongation of 130-150% (the average tensile strength is 173.44 MPa, and the average elongation is 138.80%); obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0036] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0037] Stripping layer forming: firstly, an acrylic colloid solution for forming a base adhesive layer is coated on the barrier layer, and then a polyurethane colloid solution is coated on the acrylic colloid solution for forming a base adhesive layer. After drying, the acrylic colloid and the polyurethane colloid form a base adhesive layer and a surface adhesive layer respectively. The coating amount of the base adhesive layer on the barrier layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0038] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.71N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0039] Embodiment 2:

[0040] A method for preparing an interlayer separation membrane, comprising:

[0041] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a base film with a thickness of 70 μm and a material of CPP, the base film has a strength of 300-350 MPa and an elongation of 90-130%; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0042] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0043] Stripping layer forming: firstly, an acrylic colloid solution for forming a base adhesive layer is coated on the barrier layer, and then a polyurethane colloid solution is coated on the acrylic colloid solution for forming a base adhesive layer. After drying, the acrylic colloid and the polyurethane colloid form a base adhesive layer and a surface adhesive layer respectively. The coating amount of the base adhesive layer on the barrier layer is 0.05-0.15g / m 2 The coating amount of the surface adhesive layer is 1.5-2.5g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0044] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 3.35N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0045] Embodiment 3:

[0046] A method for preparing an interlayer separation membrane, comprising:

[0047] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a base film with a thickness of 45 μm and a material of CPP, wherein the base film has a tensile strength of 130-160 MPa and an elongation of 150-180%; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0048] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0049] Stripping layer forming: firstly, an acrylic colloid solution for forming a base adhesive layer is coated on the barrier layer, and then a polyurethane colloid solution is coated on the acrylic colloid solution for forming a base adhesive layer. After drying, the acrylic colloid and the polyurethane colloid form a base adhesive layer and a surface adhesive layer respectively. The coating amount of the base adhesive layer on the barrier layer is 0.05-0.15g / m 2 The coating amount of the surface adhesive layer is 2-3g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 45±5℃ for 72h;

[0050] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 5.42N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to be peeled off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0051] Embodiment 4:

[0052] A method for preparing an interlayer separation membrane, comprising:

[0053] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a base film with a thickness of 30 μm and a material of CPP, the base film has a strength of 90-130 MPa and an elongation of 180%-200%; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0054] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0055] Stripping layer forming: first apply acrylate colloid solution on the Al layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the Al layer is 0.05-0.15g / m 2 The coating amount of the surface adhesive layer is 3.5-4.5g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0056] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 6.83N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0057] Embodiment 5:

[0058] A method for preparing an interlayer separation membrane, comprising:

[0059] Material preparation: obtain a sealing layer with a thickness of 30 μm and a material of CPP; obtain a base film with a thickness of 55 μm and a material of CPP, the strength of the base film is 160-180 MPa, and the elongation is 130%-150%; obtain a barrier layer with a thickness of 35 μm and a material of Al; obtain an acrylic colloid solution, and obtain a polyurethane colloid solution;

[0060] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0061] Stripping layer forming: first apply acrylate colloid solution on the Al layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the Al layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The sealing layer on the supporting composite layer and the adhesive layer on the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0062] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.75N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0063] Embodiment 6:

[0064] A method for preparing an interlayer separation membrane, comprising:

[0065] Material preparation: obtain a sealing layer with a thickness of 30 μm and a material of CPP; obtain a base film with a thickness of 30 μm and a material of CPP, the base film has a strength of 90-120 MPa and an elongation of 180%-200%; obtain a barrier layer with a thickness of 35 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0066] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0067] Stripping layer forming: first apply acrylate colloid solution on the Al layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the Al layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The sealing layer on the supporting composite layer and the adhesive layer on the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0068] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.83N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0069] Comparative Example 1:

[0070] The difference between this comparative example and the embodiment is that the base film is made of PE material whose tensile strength and elongation are both outside the range values, and the specific process is as follows:

[0071] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a base film with a thickness of 70 μm and a material of PE with static electricity, the base film has a tensile strength of 10-20 MPa and an elongation of 530%-570%; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0072] Drinking opening forming: the sealing layer and the base film are compounded to form a supporting composite layer, and the supporting composite layer is cut to form a drinking opening on the sealing layer;

[0073] Stripping layer forming: first apply acrylate colloid solution on the Al layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the barrier layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The peeling layer is compounded with the barrier layer, and after heat curing at 65±5℃ for 48h, a peeling layer is formed between the barrier layer and the sealing layer;

[0074] Obtaining the interlayer separation film: After the peeling layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.77N / 15mm, while the peel strength between the base film and the sealing layer is less than 0.1N / 15mm. Therefore, the base film is very easy to peel off from the sealing layer. After removing the base film, the interlayer separation film is obtained, and then the interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting to form a sealing cover film.

[0075] Comparative Example 2:

[0076] The difference between this comparative example and the embodiment is that the barrier layer and the sealing layer are directly compounded and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0077] Material preparation: obtain a sealing layer with a thickness of 80 μm and a material of CPP; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0078] Stripping layer forming: first apply acrylate colloid solution on the barrier layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the barrier layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0079] Drinking port forming: adjust the cutting depth of the roller die blade, cut the positioning line where the drinking port and the edge of the cover film are disconnected, so that the drinking port is formed on the sealing layer to prepare the interlayer separation film;

[0080] Obtaining the sealing cover film: the interlayer separation film is embossed and die-cut, and the die-cutting knife locates the outer contour positioning line of the sealing layer film to complete the die-cutting to form the sealing cover film.

[0081] Comparative Example 3:

[0082] The difference between this comparative example and the embodiment is that the barrier layer and the sealing layer are directly compounded and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0083] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a barrier layer with a thickness of 80 μm and a material of Al; obtain an acrylic colloid solution and a polyurethane colloid solution;

[0084] Stripping layer forming: first apply acrylate colloid solution on the barrier layer, then apply polyurethane colloid solution on the acrylate colloid solution used to form the base glue layer. After drying, the acrylate colloid and polyurethane colloid form the base glue layer and the surface glue layer respectively. The coating amount of the base glue layer on the barrier layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2 The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0085] Drinking port forming: adjust the cutting depth of the roller die blade, cut the positioning line where the drinking port and the edge of the cover film are disconnected, so that the drinking port is formed on the sealing layer to prepare the interlayer separation film;

[0086] Obtaining the sealing cover film: the interlayer separation film is embossed and die-cut, and the die-cutting knife locates the outer contour positioning line of the sealing layer film to complete the die-cutting to form the sealing cover film.

[0087] Comparative Example 4:

[0088] The difference between this comparative example and the embodiment is that the barrier layer and the sealing layer are directly compounded and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0089] Material preparation: obtain a sealing layer with a thickness of 50 μm and a material of CPP; obtain a barrier layer with a thickness of 50 μm and a material of Al; obtain an acrylic colloid solution and obtain a polyurethane colloid solution;

[0090] Stripping layer forming: firstly, an acrylic colloid solution for forming a base adhesive layer is coated on the barrier layer, and then a polyurethane colloid solution is coated on the acrylic colloid solution for forming a base adhesive layer. After drying, the acrylic colloid and the polyurethane colloid form a base adhesive layer and a surface adhesive layer respectively. The coating amount of the base adhesive layer on the barrier layer is 0.1-0.15g / m 2 The coating amount of the surface adhesive layer is 0.5-1.5g / m 2The sealing layer side of the supporting composite layer and the surface adhesive layer side of the barrier layer are contacted and laminated with each other, and a peeling layer is formed between the barrier layer and the sealing layer after heat curing at 65±5℃ for 48h;

[0091] Drinking port forming: adjust the cutting depth of the roller die blade, cut the positioning line where the drinking port and the edge of the cover film are disconnected, so that the drinking port is formed on the sealing layer to prepare the interlayer separation film;

[0092] Obtaining the sealing cover film: the interlayer separation film is embossed and die-cut, and the die-cutting knife locates the outer contour positioning line of the sealing layer film to complete the die-cutting to form the sealing cover film.

[0093] Experimental Example: The performance of the supporting composite layer prepared in the embodiment and the comparative example was tested, and the performance test items included hole cutting effect, curling effect, sealing effect and easy-to-remove effect.

[0094] The method for testing the hole cutting effect is: randomly cut a section, peel it open to see whether the hole is completely cut through; if it is completely cut through, the effect is good; if the cut is not completely disconnected and there is a connection, the effect is poor.

[0095] The curling effect is detected by rolling up the prepared interlayer separation membrane and checking the tightness of the roll; if the roll is tight and not loose, the effect is good, and if the roll is loose, the effect is poor.

[0096] The specific results of the above-mentioned hole cutting effect and curling effect are shown in Table 1 below.

[0097] Table 1

[0098] Hole cutting effect Curl effect Example 1 good good Example 2 good good Example 3 good good Example 4 good good Example 5 good good Example 6 good good Comparative Example 1 Difference good

[0099] The sealing cover film prepared in the embodiment and the comparative example and the PP cup were hot pressed at 240°C and 0.5MPa for 1s; after hot pressing, the cup was tested for sealing and easy peeling, wherein the sealing test conditions are: negative pressure 50Kpa, 30s / 60s for leakage. The easy peeling test method is: prepare a 15mm sample film, perform a 180° peeling test, and test the force used during peeling, i.e., the peeling strength in Table 2 below.

[0100] The test results of the above-mentioned sealing performance and ease of opening are shown in Table 2 below.

[0101] Table 2

[0102]

[0103] Among them, the sealing cover film without leakage and drawing is a qualified finished product.

[0104] From the above results, it can be seen that only when a material with a compressive strength between 50MPa-350MPa and an elongation between 90%-500% is used as the base film and composited with the sealing layer to form a supporting composite layer, the drinking mouth is formed on the supporting composite layer, and finally the interlayer separation membrane formed by the composite barrier layer is formed, can both sealing performance and easy removal be guaranteed.

[0105] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing an interlayer separation membrane, characterized in that: include: Compounding the sealing layer and the base film to form a supporting composite layer, and cutting the supporting composite layer to form a drinking opening on the sealing layer; The base film is made of a material with a tensile strength between 50MPa and 350MPa and an elongation between 90% and 500%; Compounding the sealing layer on the supporting composite layer with the barrier layer through a colloid, wherein the colloid is solidified between the barrier layer and the sealing layer to form a peeling layer, wherein the peeling strength between the bottom film on the supporting composite layer and the sealing layer is smaller than the peeling strength between the barrier layer and the sealing layer; After removing the base film, an interlayer separation film is formed.

2. The method for preparing an interlayer separation membrane according to claim 1, characterized in that: The tensile strength of the base film is 150MPa-200MPa, and the elongation is 110%-140%; preferably, the base film is made of CPP.

3. The method for preparing an interlayer separation membrane according to claim 1 or 2, characterized in that: The peeling strength between the bottom film on the supporting composite layer and the sealing layer is less than 0.1N / 15mm.

4. The method for preparing an interlayer separation membrane according to any one of claims 1 to 3, characterized in that: The peel strength between the barrier layer and the sealing layer is greater than 1 N / 15 mm, preferably 1-7 N / 15 mm, and more preferably 2-4 N / 15 mm.

5. The method for preparing an interlayer separation membrane according to any one of claims 1 to 4, characterized in that: The thickness of the base film is 30-70 microns.

6. The method for preparing an interlayer separation membrane according to any one of claims 1 to 5, characterized in that: The peeling layer consists of two layers, namely a base adhesive layer formed by acrylic ester colloid and a surface adhesive layer formed by polyurethane colloid; the base adhesive layer is arranged adjacent to the barrier layer.

7. The method for preparing an interlayer separation membrane according to claim 6, characterized in that: The coating amount of the primer layer is 0.05-0.15 g / m 2 The coating amount of the surface adhesive layer is 0.3-4.5g / m 2 .

8. The method for preparing an interlayer separation membrane according to any one of claims 1 to 7, characterized in that: The material of the barrier layer is Al; And / or, the sealing layer is made of CPP.

9. The method for preparing an interlayer separation membrane according to claim 8, characterized in that: The thickness of the barrier layer is 35-70 microns; And / or, the sealing layer has a thickness of 30-70 microns.

10. The method for preparing an interlayer separation membrane according to any one of claims 1 to 9, characterized in that: The curing temperature for forming the peeling layer is 40-75°C, and the curing time is 48-72h; preferably 65±5°C, 48h.

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