Food packaging barrier transfer paper with high damage resistance

Abstract

The invention relates to the field of food packaging, in particular to food packaging barrier transfer paper with high damage resistance. The food packaging barrier transfer paper comprises a base paper layer 1, and an adhesive layer 2, a composite barrier layer and a composite heat sealing layer from bottom to top. Wherein the composite barrier layer comprises a metal dielectric layer 3, a buffer layer 4, a metal dielectric layer 5, a barrier layer 6 and a transfer layer 7 from bottom to top. And the composite heat-sealing layer comprises a double-layer structure including a heat-sealing layer 8 and an isolating layer 9 from bottom to top. The transfer paper provided by the invention has the characteristics of no plastic, high barrier, heat sealability, degradability and direct food contact, meanwhile, the barrier layer of the food packaging barrier transfer paper has higher damage resistance due to the design of the multi-layer barrier structure and the buffer layer, and the temperature resistance and weather resistance of the paper are improved due to the addition of the isolation layer; the factors are superposed, so that the food packaging barrier transfer paper has stable quality performance.

Description

Technical Field

[0001] The present application relates to the field of food packaging, and in particular to a food packaging barrier transfer paper with high damage resistance. Technical Background

[0002] Paper bags, paper cups and paper barrels, which were originally made mainly by laminating technology, urgently need to find a recyclable, degradable and environmentally friendly material to replace them.

[0003] Aluminum-coated transfer paper has gradually begun to be used in food packaging because of its plastic-free, environmentally friendly and biodegradable paper base. The barrier properties of aluminum-coated paper are an important factor affecting the performance of product packaging. However, conventional aluminum-coated transfer paper has insufficient barrier properties and poor damage resistance of the barrier layer, which makes it difficult to meet higher standards of packaging requirements. The heat-sealing performance of the product will affect the production cost and user experience of buyers. There are few existing aluminum-coated transfer paper series products that can be directly heat-sealed.

[0004] Improving the barrier properties of aluminized transfer paper and the damage resistance of the barrier layer can effectively prevent the influence of external factors such as moisture, oxygen, and light on food, ensure the quality and taste of food, and extend the shelf life of food. At the same time, adding a heat-sealing layer to aluminized transfer paper can improve the integration of the paper packaging industry and increase the economic added value of aluminized transfer paper. The use of food-grade raw materials as a whole can expand the market for aluminized transfer paper products in the field of food packaging. Summary of the invention

[0005] In order to achieve the above objectives, the present application provides a food packaging barrier transfer paper with high damage resistance.

[0006] The transfer paper provided in this application can be realized by the following technical solutions:

[0007] A food packaging barrier transfer paper with high damage resistance comprises a base paper layer 1 and, from bottom to top, an adhesive layer 2, a composite barrier layer, and a composite heat sealing layer; wherein the composite barrier layer comprises, from bottom to top, a first metal dielectric layer 3, a buffer layer 4, a second metal dielectric layer 5, a barrier layer 6, and a transfer layer 7; and the composite heat sealing layer comprises, from bottom to top, a double-layer structure of a heat sealing layer 8 and an isolation layer 9.

[0008] Preferably, the base paper layer has a gram weight range of 30-100 g / m2, and the coated side can be directly used for printing food-grade single-side coated glassine paper.

[0009] The glassine paper must be resistant to high temperatures, oxygen, moisture and oil, and 100% of its ingredients must be suitable for food packaging. It must have a dense and uniform texture, good internal strength and damage resistance, and can be used in a variety of different food packaging scenarios.

[0010] Preferably, the glue used in the adhesive layer is FH series food-grade and degradable environmentally friendly glue produced by Shantou Xinyuan Chemical Co., Ltd.

[0011] The glue used in the adhesive layer has a solid content of 45±2% and a viscosity of 35±5s (4 cups at room temperature). It can effectively bond the base paper layer and the metal plated transfer aluminum layer, and maintain the bonding effect under temperature changes. The water-based environmentally friendly adhesive is non-toxic and pollution-free, and meets food safety and hygiene standards.

[0012] Preferably, the composite barrier layer comprises, from bottom to top, a first metal dielectric layer 3 , a buffer layer 4 , a second metal dielectric layer 5 , a barrier layer 6 , and a transfer layer 7 .

[0013] The buffer layer 4 is an acrylic modified coating produced by Shanghai Weike Optoelectronic New Materials Co., Ltd., with a solid content of 20±2% and a viscosity of 65±5 (apply 4 cups at room temperature). It can improve the flexibility of the vapor-deposited metal dielectric layer, thereby improving the damage resistance of the metal dielectric layer in the composite barrier layer. The food packaging barrier transfer paper can be folded and rubbed multiple times to preserve the complete structure of the metal dielectric layer to the greatest extent.

[0014] The barrier layer 6 is the WB series modified polyvinyl alcohol coating material of Shanghai Weike Optoelectronic New Materials Co., Ltd., with a solid content of 15±2% and a viscosity of 32±2 (coating 4 cups, room temperature), and has a high barrier property against oxygen and water vapor in a high temperature and high humidity environment; the transfer layer 7 is the BL series cellulose transfer coating material of Shanghai Weike Optoelectronic New Materials Co., Ltd., with a solid content of 15±2% and a viscosity of 25±2s (coating 4 cups, room temperature), which meets the national food hygiene and safety standards.

[0015] Preferably, the medium for vapor deposition of the first metal dielectric layer 3 and the second metal dielectric layer 5 is high-purity aluminum, and the vapor deposition thickness is 38 nm.

[0016] Optionally, the medium for vapor deposition of the first metal dielectric layer 3 and the second metal dielectric layer 5 is high-purity zinc sulfide, and the vapor deposition thickness is 38 nm.

[0017] The thickness of the two metal dielectric layers is mainly 38-52nm, which is much lower than the 6000-9000nm thickness of aluminum foil. The metal dielectric layer is uniform, dense and non-porous, which can effectively block the penetration of oxygen and water vapor. At the same time, the nano-thick dielectric layer can be easily degraded by microorganisms in the soil, and the degradation products are easily absorbed by the soil. In addition, the selection of multiple metal dielectrics can be applied to the packaging appearance requirements of different scenarios.

[0018] Preferably, the composite heat-sealing layer comprises a double-layer structure of a heat-sealing layer 8 and an isolation layer 9 from bottom to top.

[0019] The main component of the heat seal layer 8 is acrylic resin, with a solid content of 36±2% and a viscosity of 12±2s (coated 4 cups, room temperature). It has good thermal stability and bonding properties, and can be naturally degraded, which can provide stable heat seal properties for aluminum-plated transfer paper. The main component of the isolation layer 9 is acrylic acid and polyurethane cross-linked polymer, with a solid content of 40±2% and a viscosity of 15±2s (coated 4 cups, room temperature). The isolation layer after the two are cross-linked has excellent heat and weather resistance, which can isolate the heat seal layer from the outside world to ensure that the heat seal layer of the food packaging barrier transfer paper will not adhere to the coating side of the base paper under high temperature and high humidity. In addition, the cross-linking of the two also makes the isolation layer more wear-resistant, scratch-resistant and impact-resistant, providing protection for the barrier layer and the aluminum layer. In terms of mass counting, the heat seal layer 6 accounts for 85 parts and the isolation layer 7 accounts for 15 parts. The test results show that the heat seal fastness of the composite heat seal layer is greater than 2.5N / 15mm under the conditions of 300Kpa1s140℃. After 3 months of simulated shelf testing, the transfer paper composite heat-sealing layer had no adhesion to the base paper coating layer and there was no abnormal change in appearance.

[0020] In summary, this application includes at least one of the following beneficial technical effects:

[0021] High moisture and oxygen barrier properties. Repeated tests have verified that the water vapor transmission rate WVTR < 0.5 (38°C, 90% RH), oxygen transmission rate OTR < 3 (23°C, 50% RH), which can effectively extend the shelf life of the packaged products;

[0022] The structure of the composite barrier layer enables the food packaging barrier transfer paper to have extremely high damage resistance. Even if the food packaging barrier transfer paper is folded and rubbed many times, the barrier layer of the food packaging barrier transfer paper can still maintain the maximum degree of integrity, ensuring that the barrier properties of the food packaging barrier transfer paper always remain within the technical standards.

[0023] The structure of the composite heat-sealing layer improves the heat and weather resistance of the food packaging barrier transfer paper, ensuring that the paper can be used normally and stably in high temperature and high humidity areas. The results of the three-month simulated shelf test show that the transfer paper composite heat-sealing layer has no obvious adhesion to the base paper coating layer.

[0024] The product contains no plastic components, and all raw materials are naturally degradable. After verification by degradation tests, the degradation rate reaches over 90%, which significantly reduces the long-term burden of waste packaging materials on the environment and promotes sustainable development of the environment.

[0025] Food grade standard, all raw materials and production processes used comply with food safety regulations and standards, ensuring the safety of packaging materials when in contact with food. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. The accompanying drawing is a schematic diagram of the cross-sectional structure of an embodiment of the present application.

[0027] 1. Base paper layer; 2. Adhesive layer; 3. Metal dielectric layer; 4. Buffer layer; 5. Metal dielectric layer; 6. Barrier layer; 7. Transfer layer; 8. Heat seal layer; 9. Isolation layer. DETAILED DESCRIPTION

[0028] The present application is described in detail below in conjunction with the accompanying drawings and specific implementation examples. This implementation example is implemented based on the technical solution of the present application, and provides a detailed implementation method and specific operation process, but the protection scope of the present application is not limited to the following implementation examples. In the following examples, unless otherwise specified, the raw materials or processing techniques used are conventional commercially available raw materials or conventional processing techniques in the art. Example

[0029] A food packaging barrier transfer paper with high damage resistance, as shown in the attached figure, comprises a base paper layer 1 and an adhesive layer 2, a composite barrier layer, and a composite heat seal layer composited on the non-coated surface of the base paper layer 1 from bottom to top. The composite barrier layer comprises a first metal dielectric layer 3, a buffer layer 4, a second metal dielectric layer 5, a barrier layer 6, and a transfer layer 7 from bottom to top, and the composite heat seal layer comprises a heat seal layer 8 and an isolation layer 9 from bottom to top.

[0030] The optional grammage range of the base paper layer 1 is 30-100g / m 2 In this embodiment, the base paper layer 1 is 62g / m 2 Single side coated food grade glassine paper.

[0031] The adhesive layer 2 is used to connect the substrate layer 1 and the first metal dielectric layer 3, and uses water-based acrylic glue. In this embodiment, the adhesive layer 2 uses FH-331C food glue produced by Shantou Xinyuan Chemical Co., Ltd., with a solid content of 45±2% and a viscosity of 35±5s (apply 4 cups, room temperature). The composite glue application amount in this embodiment is 5.5-6g / m 2 .

[0032] The first metal dielectric layer 3 and the second metal dielectric layer 5 are formed by vapor deposition technology, so that they have excellent air tightness and can effectively block the penetration of oxygen and moisture. The thickness of the metal dielectric layer is 48-52nm. In this embodiment, the first metal dielectric layer 3 and the second metal dielectric layer 5 select high-purity aluminum metal as the metal dielectric, and the deposition thickness is 38nm.

[0033] The buffer layer 4 can improve the flexibility of the vapor-deposited metal dielectric layer, thereby improving the damage resistance of the metal dielectric layer in the composite barrier layer. After the food packaging barrier transfer paper is folded and rubbed multiple times, the complete structure of the metal dielectric layer can be preserved to the greatest extent. The main component is modified acrylic resin. In this embodiment, the buffer layer 4 uses WB-2000A coating material from Shanghai Weikai Optoelectronic New Materials Co., Ltd. with a solid content of 20±2% and a viscosity of 65±5s (apply 4 cups, room temperature).

[0034] The main component of the barrier layer 6 is modified polyvinyl alcohol, which mainly provides oxygen and moisture barrier properties to the food packaging barrier transfer paper; the function of the transfer layer 7 is to separate the barrier layer and the metal dielectric layer from the BOPET film to achieve a plastic-free effect. In this embodiment, the barrier layer 6 uses the barrier coating material WB-2012A of Shanghai Weikai Optoelectronic New Materials Co., Ltd., with a solid content of 15±2%, a viscosity of 32±2s (coating 4 cups, room temperature), and the dry coating weight in this embodiment is 1.2g / m 2 , thermal efficiency 74. The transfer layer 5 uses BL-0306A food-grade transfer coating material from Shanghai Weikai Optoelectronic New Materials Co., Ltd., with a solid content of 15±2% and a viscosity of 25±2s (coating 4 cups at room temperature). The dry coating weight in this embodiment is 1.15g / m 2 , thermal efficiency 74.

[0035] The heat seal layer 8 can provide the product with stable heat seal performance, and its main component is acrylic resin. The main components of the isolation layer 9 are acrylic acid and polyurethane. The isolation layer after cross-linking has excellent heat and weather resistance, which can ensure that the product has excellent anti-sticking properties under high temperature and high humidity. In addition, the cross-linking of the two also makes the isolation layer more wear-resistant, scratch-resistant and impact-resistant, providing protection for the barrier layer and the aluminum layer. In this embodiment, the heat seal 8 uses the BH-888E heat seal coating of Zhongshan Bohai Fine Chemical Co., Ltd., with a solid content of 36±2% and a viscosity of 12±3s (apply 4 cups, room temperature). The amount of glue applied to the topcoat in this embodiment is 5.5-6g / m2. The isolation layer 9 adopts BH-888 heat-sealing coating produced by Zhongshan Bohai Fine Chemical Co., Ltd., with a solid content of 40±2% and a viscosity of 15±3s (apply 4 cups at room temperature). In this embodiment, the amount of glue applied on the top coating is 0.9-1.1g / m 2 The composite heat-sealing layer is counted by weight, with the heat-sealing layer 8 accounting for 85 parts and the isolation layer 9 accounting for 15 parts.

[0036] The method for manufacturing the above-mentioned high-barrier, high-damage-resistance, heat-sealable food packaging transfer paper specifically comprises the following steps:

[0037] Step 1: BL-0306A is coated on the surface of biaxially oriented polyester film (BOPET), and after being fully dried, WB-2012A is coated on the surface of BL-0306A and fully dried to prepare a coating pre-coating film. The coating pre-coating film is placed in a vacuum aluminum coating machine for vacuum aluminum coating on the coating side, with an aluminum layer thickness of 38nm, to prepare a single barrier layer transfer film, and the single-layer silver transfer film is corona-treated (dyne value greater than 48), and WB-2000A is coated on the metal side and fully dried, and then placed in a vacuum aluminum coating machine for vacuum aluminum coating on the coating side, with an aluminum layer thickness of 38nm to prepare a composite barrier layer transfer film.

[0038] Step 2: Use FH-331C glue on a wet laminating machine to laminate the metal aluminum layer side of the aluminum-plated composite barrier layer transfer film with the non-coated side of the 62g glassine paper. After drying and curing in an oven, use a paper film stripping machine to separate the BOPET film from the paper base to make barrier composite paper. The BOPET film can be recycled.

[0039] Step 3: Apply heat-sealing coating BH-888E on the transfer coating side BL-0306A of the barrier composite paper, and after sufficient drying, apply isolation layer BH-888 on the surface of the heat-sealing layer and after sufficient drying, a high-barrier, high-damage-resistant, heat-sealable food packaging transfer paper is prepared.

[0040] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A food packaging barrier transfer paper with high damage resistance, characterized in that: It comprises a base paper layer (1) and, from bottom to top, an adhesive layer (2), a composite barrier layer, and a composite heat-sealing layer; The composite barrier layer comprises, from bottom to top, a first metal dielectric layer (3), a buffer layer (4), a second metal dielectric layer (5), a barrier layer (6), and a transfer layer (7); and the composite heat sealing layer comprises, from bottom to top, a double-layer structure of a heat sealing layer (8) and an isolation layer (9).

2. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The base paper layer (1) has a grammage range of 30-100 g / m2 and can be directly used for printing food-grade single-side coated glassine paper.

3. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The glue used in the adhesive layer (2) is water-based acrylic glue.

4. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The first metal dielectric layer (3) and the second metal dielectric layer (5) are formed in a vacuum environment using physical vapor deposition technology, the dielectrics selected are metal aluminum and zinc sulfide, and the thickness of the two metal dielectric layers is 38-52 nm.

5. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The buffer layer (4) is a modified acrylic paint.

6. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The barrier layer (6) is a modified polyvinyl alcohol coating, and the transfer layer (7) is a cellulose transfer coating.

7. The food packaging barrier transfer paper with high damage resistance according to claim 1, characterized in that: The main material of the heat-sealing layer (8) is acrylic resin, and the main material of the isolation layer (9) is a polymer generated by cross-linking acrylic acid and polyurethane.

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