Composite adhesive for easy-to-tear opening cover, sealed container and capping method

Abstract

The invention relates to the technical field of adhesives, in particular to a composite adhesive for an easy-to-tear opening cover, a sealed container and a capping method. The composite adhesive comprises acrylic resin, a methacrylate polymer and an acrylate copolymer, wherein the mass ratio of the acrylic resin to the methacrylate polymer to the acrylate copolymer is (3-5): 1: (0.5-2). The composite adhesive has proper adhesive force, so that bonding and sealing between the easy-to-tear opening cover and the container body can be realized, and meanwhile, the easy-to-tear opening cover and the container body can be separated when proper opening force is applied, so that the easy-to-tear opening cover has two properties of firm sealing and easy opening at the same time; and meanwhile, the composite adhesive also has relatively strong high-temperature resistance, so that a sealed container prepared from the composite adhesive can be stored in a high-temperature environment for a long time without cracking, air leakage and the like, and more stringent storage requirements and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and in particular to a composite adhesive having strong initial sealing properties and controllable peeling properties, a container obtained by processing the composite adhesive, and a method for capping the container. Background Art

[0002] Easy-tear lids are a widely used technology in the packaging industry, achieving a balance between a secure seal and easy opening. When attached to a sealed container, they effectively seal the interior, protecting the contents. Furthermore, they can detach from the container upon application of appropriate force, allowing for easy opening. Consequently, these lids have found widespread application in the food, pharmaceutical, and chemical industries.

[0003] The ability of the easy-tear open lid to achieve the above-mentioned effects is based on the combined influence of multiple factors, including the materials of the open lid, the sealed container body, the glue, and the processing technology during sealing. Among them, glue is one of the core factors that determine the sealing performance and easy-opening performance of the easy-tear open lid.

[0004] Common commercially available glues, when used to bond the easy-tear lid to the sealed container body, typically allow the sealed container to be stored for long periods at temperatures between 30 and 40°C without cracking or leaking. Furthermore, the easy-tear lid can be detached from the sealed container with an application of a force of 35 to 40 N. However, in recent years, the frequent occurrence of accidental cracking of easy-tear lids in food and other applications due to high temperatures has necessitated the development of a glue for easy-tear lids that can maintain sealing performance while also ensuring easy opening in high-temperature environments. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a composite adhesive for an easy-to-tear open lid that has both strong adhesion and easy-to-open performance.

[0006] A second object of the present invention is to provide a sealed container that has both sealing properties and easy-to-open properties after using the composite adhesive for the easy-to-open lid.

[0007] The third object of the present invention is to provide a method for adding a cap to the sealed container by using the composite adhesive suitable for the easy-tear open cap.

[0008] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a composite adhesive for an easy-tear open cover, comprising: acrylic resin, methacrylate polymer and acrylate copolymer, wherein the mass ratio of the acrylic resin, methacrylate polymer and acrylate copolymer is (3~5):1:(0.5~2).

[0009] As a further improvement of the present invention, the acrylic resin is selected from at least any one of acrylic acid-acrylate copolymer, methyl methacrylate, polymer of 2-(dimethylamino)ethyl methacrylate, and polymer of 2-methyl-2-ethyl acrylate and 2-methyl acrylate.

[0010] As a further improvement of the present invention, the methacrylate polymer is selected from at least any one of methyl methacrylate, butyl methacrylate, and ethyl methacrylate.

[0011] As a further improvement of the present invention, the acrylate copolymer is selected from at least any one of a polymer of 2-butyl acrylate and vinyl acetate, and a polymer of 2-octyl acrylate, 2-ethyl acrylate and 2-ethylhexyl acrylate.

[0012] As a further improvement of the present invention, the solid content of the composite adhesive for the easy-tear open cover is 40-50%.

[0013] In a second aspect, the present invention provides a sealed container comprising a container body and an easy-tear open cover covering an opening at the top of the container body, wherein the easy-tear open cover and the container body are bonded together using any one of the above-mentioned easy-tear open cover composite adhesives.

[0014] As a further improvement of the present invention, a supporting ring block is provided on the top of the container body, and the supporting ring block and the easy-tear open cover are adhered to each other through a composite adhesive of the easy-tear open cover.

[0015] As a further improvement of the present invention, an epoxy coating is formed on the outer surface of the supporting ring block.

[0016] As a further improvement of the present invention, the easy-tear opening cover is made of any one of aluminum foil composite paper, tin-plated tinplate, epoxy tinplate, and polyester tinplate.

[0017] In a third aspect, the present invention provides a method for capping a sealed container, which is used to process and prepare any of the above-mentioned sealed containers, comprising the following steps: S1. transporting the container body to a coating point, coating the top of the container body with a composite adhesive for an easy-to-tear open lid, and coating the composite adhesive in an amount of 9 to 10 g / m 2; S2. Transfer the container body to the hot pressing point, cover the top opening of the container body with an easy-to-tear open cover and carry out hot pressing sealing, wherein the hot pressing temperature is 210~230 ℃, the hot pressing pressure is 0.5~0.7MPa, and the hot pressing duration is 0.3~0.5s to complete the sealing of the container.

[0018] The beneficial effect of the present invention is that it ensures good bonding strength between the easy-tear open lid and the container body, especially in a high-temperature environment, the two can still maintain close bonding without cracking or leakage, so that the sealed container can meet the sealing requirements in more stringent and complex usage environments; at the same time, after being subjected to an appropriate opening force, the easy-tear open lid and the container body can be separated, which also enables the sealed container to have the function of being easily opened.

[0019] Achieving these effects relies primarily on improvements to the composite adhesive, one of the core requirements. By controlling the ratio of the three components of the composite adhesive—acrylic resin, methacrylate polymer, and acrylate copolymer—the present invention ensures the composite adhesive possesses suitable adhesion, enabling a seal between the easy-tear lid and the container body. Furthermore, the two can be separated by applying an appropriate opening force (e.g., 20-25 N), ensuring the easy-tear lid achieves both a secure seal and easy opening. Furthermore, the composite adhesive exhibits strong high-temperature resistance, ensuring that sealed containers made with it can be stored in high-temperature environments (e.g., 50-60°C) for long periods without cracking or leaking, thus meeting more stringent storage requirements.

[0020] Secondly, further optimization to achieve the above-mentioned effects relies on the optimized selection of materials and structures for the easy-tear open lid and the container body. For example, by providing a support ring or other structures on the container body, a structural foundation can be provided for the easy-tear open lid to adhere to the container body. Alternatively, by forming an epoxy coating or other materials on the outer surface of the support ring or using tin-plated tinplate or other materials for the easy-tear open lid, effective adhesion between the easy-tear open lid and the composite adhesive, and between the support ring and the composite adhesive, can be achieved by selecting appropriate materials, thereby ensuring that the composite adhesive can achieve its desired bonding effect.

[0021] Finally, further optimization to achieve the aforementioned effects relies on adjustments to the capping method. By adjusting multiple processing parameters, such as the amount of composite adhesive applied, hot pressing temperature, pressure, and duration, we ensured that a composite adhesive layer of appropriate thickness, uniform distribution, and fully activated activity was formed on the support ring, ensuring a sufficient heat seal for the easy-tear lid and a pleasant opening experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following drawings are provided for use in conjunction with preferred embodiments of the present invention to help understand the objects and advantages of the present invention, wherein: Figure 1 This is a schematic diagram of the structure of the various parts of the sealed container before the easy-tear open lid is glued. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and implementation examples.

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention, rather than to represent all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention. Example 1:

[0025] This embodiment provides a sealed container, such as Figure 1 As shown, it includes a container body 1 and an easy-tear open lid 2. The easy-tear open lid 2 can cover the opening at the top of the container body 1. When the two are combined with a composite adhesive, the easy-tear open lid 2 can form a seal with the inner cavity of the container body 1, so that the two together form a sealed container. For example, the composite adhesive used in this embodiment includes acrylic acid-acrylate copolymer and butyl methacrylate as the main agent, and a polymer of 2-butyl acrylate and vinyl acetate as an additive. The mass ratio of the three components is 4:1:0.5, and the solid content of the composite adhesive is 40%.

[0026] Preferably, a supporting ring block 101 is provided at the top of the container body 1. For example, in this embodiment, the side wall of the supporting ring block 101 is fixedly connected to the inner wall of the container body 1, so that the supporting ring block 101 is fixed to the top of the inner cavity of the container body 1. The upper wall 101-1 of the supporting ring block 101 can support the composite glue and the easy-tear open cover 2, that is, the easy-tear open cover 2 is encapsulated on the top of the container body 1 through the supporting ring block 101.

[0027] Preferably, an epoxy coating is formed on the outer surface of the supporting ring block 101; preferably, the easy-tear open cover 2 is made of tin-plated tinplate. First of all, after the supporting ring block 101 is provided with an epoxy coating, its own chemical resistance, low friction coefficient and temperature resistance and other properties can be improved; and the tin-plated tinplate material used for the easy-tear open cover 2 has good barrier properties, weather resistance, sealing reliability and strong mechanical strength, etc. In summary, the above material selection ensures that the supporting ring block 101 and the easy-tear open cover 2 themselves have good heat resistance and other properties. Secondly, the epoxy coating and the tin-plated tinplate will be in direct contact with the composite glue. The selection of the above materials is adapted to the bonding ability of the composite glue, that is, after the above materials are selected, it can be ensured that the composite glue is properly bonded to the two respectively, so as to not only seal the container to ensure the sealing, but also make the easy-tear open cover 2 have easy-tear properties.

[0028] Preferably, if Figure 1 As shown, the easy-tear open cover 2 includes an open cover body 201 and a pull handle 202. The pull handle 202 is the main force point for the user to tear the open cover when opening the sealed container. The setting of this part is conducive to the smooth development of the tearing work.

[0029] The method for adding a cover to the sealed container, i.e., the method for bonding the easily tearable cover 2 to the container body 1, is as follows: S1. The container body 1 is transferred to the coating point. In this embodiment, the upper wall 101-1 of the supporting ring block 101 at the top of the container body 1 is coated with a composite adhesive for an easy-to-tear open cover. The coating amount is 10 g / m 2 ; S2. Transfer the container body 1 to the hot pressing point, cover the easy-tear open cover 2 on the supporting ring block 101 on the top of the container body 1 and carry out hot pressing sealing, wherein the hot pressing temperature is 220°C, the hot pressing pressure is 0.5 MPa, and the hot pressing duration is 0.4s to complete the capping work of the sealed container. Example 2:

[0030] This embodiment provides a sealed container, which differs from the embodiment 1 in that the composite adhesive used in this embodiment includes a polymer of 2-methyl-2-ethyl acrylate and 2-methyl acrylate and methyl methacrylate as a main agent, and a polymer of 2-octyl acrylate, 2-ethyl acrylate and 2-ethylhexyl acrylate as additives, the mass ratio of the three being 4.5:1:1, and the solid content of the composite adhesive is 44%.

[0031] The easy-to-tear open cover 2 is made of polyester tinplate. Example 3:

[0032] This embodiment provides a sealed container, which differs from the embodiment 1 in that the composite adhesive used in this embodiment contains methyl methacrylate and methyl methacrylate as main agents, and a polymer of 2-butyl acrylate and vinyl acetate as additives, the mass ratio of the three being 5:1:0.5, and the solid content of the composite adhesive is 47%.

[0033] The easy-to-tear open cover 2 is made of epoxy tinplate. Example 4:

[0034] This embodiment provides a sealed container, which differs from the embodiment 1 in that the method for covering the sealed container is as follows: S1. The container body 1 is transferred to the coating point. In this embodiment, the upper wall surface 101-1 of the supporting ring block 101 at the top of the container body 1 is coated with a composite adhesive for an easy-to-tear open cover. The coating amount is 9.8 g / m 2 ; S2. Transfer the container body 1 to the hot pressing point, cover the easy-tear open cover 2 on the supporting ring block 101 on the top of the container body 1 and carry out hot pressing and sealing, wherein the hot pressing temperature is 215°C, the hot pressing pressure is 0.7 MPa, and the hot pressing duration is 0.3s to complete the covering work of the sealed container. Example 5:

[0035] This embodiment provides a sealed container, which differs from the embodiment 1 in that the method for covering the sealed container is as follows: S1. The container body 1 is transferred to the coating point. In this embodiment, the upper wall surface 101-1 of the supporting ring block 101 at the top of the container body 1 is coated with a composite adhesive for an easy-to-tear open cover. The coating amount is 10 g / m 2 ; S2. Transfer the container body 1 to the hot pressing point, cover the easy-tear open cover 2 on the supporting ring block 101 on the top of the container body 1 and carry out hot pressing sealing, wherein the hot pressing temperature is 230°C, the hot pressing pressure is 0.6 MPa, and the hot pressing duration is 0.5s to complete the capping work of the sealed container.

[0036] Performance testing In this example, the sealed containers from Examples 1-5 were tested for four performance characteristics: rupture force, full opening force, opening reliability, and sealing. The testing procedures followed the "Test Methods" section of the standard document, "Aluminum Foil Easy-Tear Covers for Packaging Containers" (BBT 0069-2014). During the sealing test, the sealed containers were placed at 80°C. The test results are shown in Table 1.

[0037] Table 1 Performance test results of sealed containers in Examples 1 to 5

[0038] As can be seen from the test results in Table 1, the tearing force and full opening force of the easy-tear open lid 2 of the sealed containers in Examples 1 to 5 can be maintained between 20 and 25 N. This force is of appropriate magnitude, and the user can open the sealed container relatively easily. At the same time, during the opening process, the easy-tear open lid 2 does not break and the pull handle 202 provided thereon is intact, which proves that the tearing process of opening the lid is relatively smooth and no part of the easy-tear open lid 2 will remain on the container body 1 after tearing. Finally, as shown in the results in Table 1, the sealed container still does not leak under high temperature environment, which proves that the connection between the easy-tear open lid 2 and the supporting ring block 101 is firm and has excellent heat resistance.

[0039] To sum up, in the present invention, the sealed container obtained by adjusting the composition of the composite glue, coordinating the components such as the material and structure of the easy-tear open cover 2 and the container body 1, and adjusting various processing parameters in the capping process can achieve an excellent balance between firm sealing and easy opening, so that while sealing and protecting the substances in the container, it is also convenient for users to open and take them out more easily, which meets market demand and is conducive to its promotion and use.

[0040] Finally, it should be noted that the above implementation cases are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above implementation cases, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above implementation cases, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the implementation cases of the present invention.

Claims

1. A composite adhesive for an easy-tear open cover, characterized in that: Includes: Acrylic resin, methacrylate polymer and acrylate copolymer, wherein the mass ratio of the acrylic resin, the methacrylate polymer and the acrylate copolymer is (3-5):1:(0.5-2).

2. The composite adhesive for an easy-tear open cover according to claim 1, characterized in that: The acrylic resin is selected from at least any one of acrylic acid-acrylate copolymer, methyl methacrylate, polymer of 2-(dimethylamino)ethyl methacrylate, and polymer of ethyl 2-methyl-2-acrylate and methyl 2-acrylate.

3. The composite adhesive for an easy-tear open cover according to claim 1, characterized in that: The methacrylate polymer is selected from at least any one of methyl methacrylate, butyl methacrylate, and ethyl methacrylate.

4. The composite adhesive for an easy-tear open cover according to claim 1, characterized in that: The acrylic acid ester copolymer is selected from at least any one of a polymer of 2-butyl acrylate and vinyl acetate, and a polymer of 2-octyl acrylate, 2-ethyl acrylate and 2-ethylhexyl acrylate.

5. The composite adhesive for an easily tearable open cover according to claim 1, characterized in that: The solid content of the composite adhesive for the easy-tear open cover is 40~50%.

6. A sealed container, characterized in that: The invention comprises a container body (1) and an easy-tear open cover (2) covering the top opening of the container body (1), wherein the easy-tear open cover (2) and the container body (1) are bonded by using a composite adhesive for an easy-tear open cover according to any one of claims 1 to 4.

7. A sealed container according to claim 6, characterized in that: A supporting ring block (101) is provided on the top of the container body (1), and the supporting ring block (101) and the easy-tear opening cover (2) are adhered to each other by composite glue of the easy-tear opening cover.

8. A sealed container according to claim 7, characterized in that: An epoxy coating is formed on the outer surface of the supporting ring block (101).

9. A sealed container according to claim 6, characterized in that: The easy-to-tear opening cover (2) is made of any one of aluminum foil composite paper, tin-plated tinplate, epoxy tinplate, and polyester tinplate.

10. A method for covering a sealed container, characterized in that: The method for preparing a sealed container according to any one of claims 6 to 9 comprises the following steps: S1. The container body (1) is transferred to the coating point, and the composite adhesive for the easy-to-tear open cover is coated on the top of the container body (1) with a coating amount of 9-10 g / m 2 ; S2. The container body (1) is transferred to a hot pressing point, the easy-to-tear open cover (2) is covered on the top opening of the container body (1) and hot pressing is performed, wherein the hot pressing temperature is 210-230°C, the hot pressing pressure is 0.5-0.7 MPa, and the hot pressing duration is 0.3-0.5 s, so as to complete the capping work of the sealed container.

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