Production process of high-barrier hologram paper

Abstract

The invention provides a high-barrier hologram paper production process, and relates to the technical field of hologram paper processing. The high-barrier hologram paper is composed of a base material layer, a glue layer, a laser layer, an inner barrier layer and an outer barrier layer, the base material layer is coated with glue and then covered with the laser layer, low-temperature drying is conducted, then heating and pressurizing treatment is conducted, and the inner barrier layer is composed of ethylene-vinyl alcohol copolymer, polymethyl methacrylate, sodium polyacrylate, styrene and alkylphenol polyoxyethylene ether. The outer barrier layer is further added with spherical silicon dioxide and nano zinc sulfide compared with the inner barrier layer, and the outer barrier layer and the inner barrier layer are dried and then subjected to cold roller pressurization treatment after being coated. The defects in the prior art are overcome, the blocking effect is effectively improved by adjusting the drying and compounding process temperature and arranging the blocking layer, meanwhile, the basic performance of the hologram paper is guaranteed, and the quality of the hologram paper is comprehensively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser paper processing, and particularly relates to a production process of high-barrier laser paper. Background Art

[0002] As a kind of paper with unique optical effects, laser paper is widely used in the fields of anti-counterfeiting, packaging, printing, etc. The special treatment on its surface makes it have an effect similar to the flowing of luster, giving products a strong visual impact and recognition. At the same time, laser paper also has good processing performance and can be repeatedly pasted with other materials such as tapes and plastics, enhancing the anti-counterfeiting effect of products. With the continuous improvement of the market's requirements for product quality, higher requirements are also put forward for the barrier performance of laser paper.

[0003] The existing methods for improving the barrier property of laser paper mainly include introducing new barrier materials, such as inorganic barrier materials like zinc sulfide and aluminum nitride, and organic barrier materials like polyvinyl alcohol resin and polyvinylidene chloride, to comprehensively improve the barrier property. However, when these materials are introduced, they are usually compounded by methods such as coating and drying and hot pressing. And the more barrier layers, the better the barrier effect. But as the number of layers increases, the process operations also increase, which will ultimately cause quality differences in laser paper. In particular, multiple drying or hot pressing treatments will, to a certain extent, increase the warping degree of laser paper and also reduce the folding endurance to varying degrees, thus leading to a reduction in the quality of laser paper. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a production process of high-barrier laser paper. By adjusting the process temperatures of drying and compounding, and setting barrier layers, while effectively improving the barrier effect, the basic properties of laser paper are ensured, and the quality of laser paper is comprehensively improved.

[0005] To achieve the above object, the technical solution of the present invention is realized through the following technical solutions: A production process of high-barrier laser paper, the preparation method of the high-barrier laser paper includes the following steps: S1. After the surface of the substrate layer is treated, a glue layer is coated, and then a laser layer is laminated on the outside of the glue layer; S2. After the laser layer is laminated, it is cooled to -2°C to -6°C for drying, and then returned to room temperature and then heated and pressurized; S3. Set ethylene-vinyl alcohol copolymer, polymethyl methacrylate, sodium polyacrylate, styrene, and alkylphenol polyoxyethylene ether as the functional components of the inner barrier material; add spherical silica and nano zinc sulfide as the outer barrier material to the inner barrier material; S4. After coating the outer part of the laser layer with an inner barrier material, heat it up and dry it to form an inner barrier layer, then perform cold roll pressure lamination treatment. After that, coat an outer barrier material above the inner barrier layer, continue to heat it up and dry it to form an outer barrier layer, then perform cold roll pressure lamination treatment, and finally cut it to obtain a high-barrier laser paper.

[0006] Preferably, in step S1, the material of the base material layer is kraft paper or white cardboard, and the surface treatment method is hot air blowing to keep the surface of the base material layer clean and dry.

[0007] Preferably, in step S1, the coated glue layer selects waterborne polyurethane glue as the raw material.

[0008] Preferably, in step S1, the laser layer is a PET film with an aluminum foil film vapor-deposited on the surface, and the laser layer is printed or engraved according to requirements.

[0009] Preferably, in step S2, the preliminary drying time is 12 - 24 h, and the temperature of the heating and pressure treatment is 40 - 50 °C, the pressure is 4 - 6 N / cm 2 , and the treatment time is 2 - 3 h.

[0010] Preferably, the inner barrier material in step S3 includes the following raw materials by weight: 4 - 10 parts of water, 15 - 20 parts of ethanol, 10 - 15 parts of ethylene-vinyl alcohol copolymer, 4 - 6 parts of polymethyl methacrylate, 2 - 4 parts of sodium polyacrylate, 0.1 - 0.4 parts of styrene, and 0.2 - 0.4 parts of alkylphenol polyoxyethylene ether.

[0011] Preferably, in step S3, the addition amount of spherical silica in the outer barrier material is 2% - 4% of the total mass of the inner barrier material, the addition amount of nano zinc sulfide is 1.2% - 1.6% of the total mass of the inner barrier material, and the particle size of the spherical silica is 10 - 20 nm, and the particle size of the nano zinc sulfide is 80 - 120 nm.

[0012] Preferably, in step S4, the heating and drying method is to first heat up to 50 - 80 °C and preheat for 15 - 20 min, then heat up to 150 - 160 °C for drying, and then naturally cool down to room temperature.

[0013] Preferably, in step S4, the cold roll pressure lamination method is to use a pressure roll with a temperature of 2 - 6 °C to apply a pressure of 10 - 15 N / cm 2 to the inner barrier layer or the outer barrier layer for 20 - 30 min.

[0014] The present invention provides a production process for high-barrier laser paper. Compared with the prior art, the advantages are as follows: 1. The present invention uses ethylene-vinyl alcohol copolymer, polymethyl methacrylate, sodium polyacrylate, styrene, and alkylphenol polyoxyethylene ether coating as the inner barrier layer, and ethylene-vinyl alcohol copolymer, polymethyl methacrylate, sodium polyacrylate, styrene, alkylphenol polyoxyethylene ether, spherical silica, and nano zinc sulfide coating as the outer barrier layer, effectively improving the overall barrier effect of the laser paper, reducing the water vapor transmission rate and oxygen transmission rate, and at the same time enhancing the overall tear resistance strength.

[0015] 2. During the preparation process of the present invention, the laser layer is compounded with glue, and after controlling low-temperature drying, heating and pressurization treatment is carried out. Subsequently, the coating and drying method for the inner barrier layer and the outer barrier layer is to first heat and dry, then return to room temperature, and then cold roll press and compound, ensuring the compound strength between the layer films, reducing the warping degree of the laser paper, and further enhancing the barrier effect of the barrier paper. Brief Description of the Drawings

[0016] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation to the present application.

[0017] Figure 1 It is a schematic diagram of the layered structure of the high-barrier laser paper in Embodiment 1 of the present invention.

[0018] In the figure: 1. Substrate layer; 2. Glue layer; 3. Laser layer; 4. Inner barrier layer; 5. Outer barrier layer. Detailed Embodiments

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] In the following examples and comparative examples, the kraft paper used has a thickness of 0.07 mm, and the laser layer is prepared by evaporating a layer with a thickness of 0.008 mm on the surface of a PET film with a thickness of 0.012 mm; the particle size of the spherical silica is 10 - 20 nm, and the particle size of the nano zinc sulfide is 80 - 120 nm; the water-based polyurethane glue selected is Baowei water-based polyurethane transfer direct coating glue BW-812.

[0021] Example 1, production process of high-barrier laser paper: (1)Blow-dry the kraft paper surface with hot air at 45 °C. After ensuring the surface is clean and dry, apply a layer of waterborne polyurethane glue with a thickness of 0.01 mm. Then, laminate a laser layer on the outside. Control the temperature at -4 °C for drying treatment for 18 h. After that, restore it to room temperature, then raise the temperature to 45 °C, and treat it under a pressure of 5 N / cm 2 for 2.5 h; (2)Prepare the inner barrier material according to the following raw materials by weight: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, and 0.3 parts of alkylphenol polyoxyethylene ether; Add 0.3% of spherical silica and 1.4% of nano zinc sulfide by total mass to the above inner barrier material to obtain the outer barrier material.

[0022] (3)Coat the outer layer of the laser layer with an inner barrier material with a thickness of 0.01 mm. Raise the temperature to 65 °C for preheating for 15 min, then raise the temperature to 155 °C and dry until the inner barrier material is completely cured to form an inner barrier layer. Then, naturally cool it to room temperature. Then, use a pressure roller at a temperature of 4 °C to apply a pressure of 15 N / cm 2 to the inner barrier layer for 20 min; (4)Coat the outer layer of the inner barrier layer with an outer barrier material with a thickness of 0.01 mm. Raise the temperature to 65 °C for preheating for 15 min, then raise the temperature to 155 °C and dry until the outer barrier material is completely cured to form an outer barrier layer. Then, naturally cool it to room temperature. Then, use a pressure roller at a temperature of 6 °C to apply a pressure of 10 N / cm 2 to the inner barrier layer for 30 min, and then cut to obtain the high-barrier laser paper.

[0023] Comparative Example 1, production process of high-barrier laser paper: (1)Blow-dry the kraft paper surface with hot air at 45 °C. After ensuring the surface is clean and dry, apply a layer of waterborne polyurethane glue with a thickness of 0.01 mm. Then, laminate a laser layer on the outside. Control the temperature at -4 °C for drying treatment for 18 h. After that, restore it to room temperature, then raise the temperature to 45 °C, and treat it under a pressure of 5 N / cm 2 for 2.5 h; (2)Prepare the barrier material according to the following raw materials by weight: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, and 0.3 parts of alkylphenol polyoxyethylene ether; (3)Coat the outer layer of the laser layer with a barrier material with a thickness of 0.01 mm. Raise the temperature to 65 °C for preheating for 15 min, then raise the temperature to 155 °C and dry until the inner barrier material is completely cured to form an inner barrier layer. Then, naturally cool it to room temperature. Then, use a pressure roller at a temperature of 4 °C to apply a pressure of 15 N / cm 2 to the inner barrier layer for 20 min; (4) Coat a barrier material with a thickness of 0.01 mm outside the inner barrier layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the outer barrier material is completely cured to form an outer barrier layer, then naturally cool down to room temperature, and then use a pressure roller at a temperature of 6 °C to apply a pressure of 10 N / cm 2 to the inner barrier layer for 30 min, and then cut to obtain high-barrier laser paper.

[0024] Comparative Example 2, production process of high-barrier laser paper: (1) Blow the surface of kraft paper with hot air at 45 °C, ensure the surface is clean and dry, then coat a layer of water-based polyurethane glue with a thickness of 0.01 mm, and then laminate a laser layer on the outside, control the temperature at -4 °C and dry for 18 h, then restore to room temperature, and then heat up to 45 °C, and apply a pressure of 5 N / cm 2 for 2.5 h; (2) Prepare a composite material according to the following parts by weight of raw materials: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, 0.3 parts of alkylphenol polyoxyethylene ether; Add 0.3% of spherical silica and 1.4% of nano zinc sulfide by total mass to the above composite material to obtain a barrier material; (3) Coat a barrier material with a thickness of 0.01 mm outside the laser layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the inner barrier material is completely cured to form an inner barrier layer, then naturally cool down to room temperature, and then use a pressure roller at a temperature of 4 °C to apply a pressure of 15 N / cm 2 to the inner barrier layer for 20 min; (4) Coat a barrier material with a thickness of 0.01 mm outside the inner barrier layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the outer barrier material is completely cured to form an outer barrier layer, then naturally cool down to room temperature, and then use a pressure roller at a temperature of 6 °C to apply a pressure of 10 N / cm 2 to the inner barrier layer for 30 min, and then cut to obtain high-barrier laser paper.

[0025] Comparative Example 3, production process of high-barrier laser paper: (1) Blow the surface of kraft paper with hot air at 45 °C, ensure the surface is clean and dry, then coat a layer of water-based polyurethane glue with a thickness of 0.01 mm, and then laminate a laser layer on the outside, control the temperature at 45 °C and dry for 3 h, and then apply a pressure of 5 N / cm 2 for 2.5 h; (2)Prepare the inner barrier material according to the following raw materials by weight: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, and 0.3 parts of alkylphenol polyoxyethylene ether; Add 0.3% of spherical silica and 1.4% of nano zinc sulfide by total mass to the above inner barrier material to obtain the outer barrier material.

[0026] (3)Coat the inner barrier material with a thickness of 0.01 mm on the outside of the laser layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the inner barrier material is completely cured to form an inner barrier layer, then naturally cool down to room temperature, and then apply a pressure of 15 N / cm2 to the inner barrier layer with a pressure roller at a temperature of 4 °C for 20 min; (4)Coat the outer barrier material with a thickness of 0.01 mm on the outside of the inner barrier layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the outer barrier material is completely cured to form an outer barrier layer, then naturally cool down to room temperature, and then apply a pressure of 10 N / cm 2 to the inner barrier layer with a pressure roller at a temperature of 6 °C for 30 min, and then cut to obtain the high-barrier laser paper.

[0027] Comparative Example 4, production process of high-barrier laser paper: (1)Blow the surface of the kraft paper with hot air at 45 °C to ensure that the surface is clean and dry, then coat a layer of waterborne polyurethane glue with a thickness of 0.01 mm, and then laminate a laser layer on the outside, control the temperature at -4 °C and dry for 18 h, then return to room temperature, and then heat up to 45 °C, with a pressure of 5 N / cm 2 for 2.5 h; (2)Prepare the inner barrier material according to the following raw materials by weight: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, and 0.3 parts of alkylphenol polyoxyethylene ether; Add 0.3% of spherical silica and 1.4% of nano zinc sulfide by total mass to the above inner barrier material to obtain the outer barrier material.

[0028] (3)Coat the inner barrier material with a thickness of 0.01 mm on the outside of the laser layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the inner barrier material is completely cured to form an inner barrier layer; (4)Coat the outer barrier material with a thickness of 0.01 mm on the outside of the inner barrier layer, heat up to 65 °C and preheat for 15 min, then heat up to 155 °C and dry until the outer barrier material is completely cured to form an outer barrier layer, and cut to obtain the high-barrier laser paper.

[0029] Comparative Example 5, production process of high-barrier laser paper: (1)Blow-dry the kraft paper surface with hot air at 45°C. After ensuring the surface is clean and dry, apply a layer of waterborne polyurethane glue with a thickness of 0.01 mm. Then, laminate a laser layer on the outside, control the temperature at -4°C for drying treatment for 18 h, then return to room temperature, and then raise the temperature to 45°C, and apply pressure at 5 N / cm 2 for 2.5 h; (2)Prepare the inner barrier material according to the following raw materials by weight: 6 parts of water, 18 parts of ethanol, 12 parts of ethylene-vinyl alcohol copolymer, 5 parts of polymethyl methacrylate, 3 parts of sodium polyacrylate, 0.2 parts of styrene, and 0.3 parts of alkylphenol polyoxyethylene ether; Add 0.3% of spherical silica and 1.4% of nano zinc sulfide by total mass to the above inner barrier material to obtain the outer barrier material.

[0030] (3)Coat the inner barrier material with a thickness of 0.01 mm on the outside of the laser layer, raise the temperature to 155°C and dry until the inner barrier material is completely cured to form an inner barrier layer. Then, naturally cool to room temperature. Then, use a pressure roller at 4°C to apply a pressure of 15 N / cm 2 for 20 min; (4)Coat the outer barrier material with a thickness of 0.01 mm on the outside of the inner barrier layer, raise the temperature to 155°C and dry until the outer barrier material is completely cured to form an outer barrier layer. Then, naturally cool to room temperature. Then, use a pressure roller at 6°C to apply a pressure of 10 N / cm 2 for 30 min, and then cut to obtain the high-barrier laser paper.

[0031] Refer to Figure 1 , and use the methods of Example 1 and Comparative Examples 1-5 to prepare laser papers respectively for the following tests: 1. Detect the warping height, folding endurance, oxygen permeability, and water vapor permeability of each group of laser papers; Among them, the detection method for the warping height is: Cut each group of laser papers into samples with a horizontal size of 4 cm × vertical size of 5 cm, flatten them on a horizontal plane, control the distance between the sample edge and the horizontal plane ≤ 1.5 mm, and then place them for 8 h. Record the distance between the sample edge and the horizontal plane after 8 h as the warping height; The detection method for folding endurance: Fold each group of samples by hand, using the method of folding 180° forward and 180° backward, and observe and record the number of folds when the surface of the laser paper bursts.

[0032] Oxygen permeability: Refer to ASTM D3985, use a differential pressure method tester, and control the detection conditions at 0.1 MPa and the detection time at 24 h; The water vapor permeability refers to ASTM E96 and uses a gravimetric method tester to detect the passing rate for 24 h.

[0033] The specific results are shown in Table 1 as follows:

[0034] As can be seen from the above table, the laser paper prepared in Example 1 has good oxygen and water vapor barrier effects, and the overall warping height is low and the folding endurance is good.

[0035] 2. Detect the mechanical properties of the laser paper prepared in each group, where: The detection method for tensile strength is to refer to ISO 1924-2 and use a universal material testing machine for detection; The detection method for tear strength is to refer to ISO 1974 and use an Elmendorf tear strength tester for detection; The specific results are shown in Table 2 as follows:

[0036] As can be seen from the above table, Example 1 and Comparative Examples 2-5 have better comprehensive mechanical properties.

[0037] In actual use, laser papers with different thicknesses and different layers can be set according to requirements, and a UV layer can be provided on the outermost layer of the laser paper according to requirements, and the changes in the number of layers and thickness are within the scope of this application.

[0038] In addition, the above embodiments 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A production process for high-barrier laser paper, characterized in that, The preparation method of the high-barrier laser paper comprises the following steps: S1. After surface treatment of the substrate layer, a glue layer is coated, and then a laser layer is laminated on the outer side of the glue layer; S2. After the laser layer is laminated, the temperature is lowered to -2°C to -6°C for drying, and then the temperature is restored to normal temperature and then heated and pressurized; S3. Ethylene-vinyl alcohol copolymer, polymethyl methacrylate, sodium polyacrylate, styrene, and alkylphenol polyoxyethylene ether are set as the functional components of the inner barrier material; spherical silica and nano zinc sulfide are added to the inner barrier material as the outer barrier material; S4. After coating with the inner barrier material on the outside of the laser layer, it is heated and dried to form an inner barrier layer, and then cold-rolled and laminated. Then, the outer barrier material is coated above the inner barrier layer, and it is continuously heated and dried to form an outer barrier layer, and then cold-rolled and laminated. Then, it is cut to obtain the high-barrier laser paper.

2. The production process according to claim 1, characterized in that: In the step S1, the material of the substrate layer is kraft paper or white cardboard, and the surface treatment method is hot air blowing to keep the surface of the substrate layer clean and dry.

3. The production process according to claim 1, characterized in that: In the step S1, the coated glue layer selects waterborne polyurethane glue as the raw material.

4. The production process according to claim 1, characterized in that: In the step S1, the laser layer is a PET film with an aluminum foil film vapor-deposited on the surface, and the laser layer is printed or engraved according to requirements.

5. The production process according to claim 1, characterized in that: In the step S2, the time for preliminary drying is 12 - 24 h, and the temperature for temperature and pressure increase treatment is 40 - 50 °C, and the pressure is 4 - 6 N / cm 2 , and the treatment time is 2 - 3 h.

6. The production process according to claim 1, characterized in that: The inner barrier material in the step S3 comprises the following raw materials in parts by weight: 4-10 parts of water, 15-20 parts of ethanol, 10-15 parts of ethylene-vinyl alcohol copolymer, 4-6 parts of polymethyl methacrylate, 2-4 parts of sodium polyacrylate, 0.1-0.4 parts of styrene, and 0.2-0.4 parts of alkylphenol polyoxyethylene ether.

7. The production process according to claim 6, characterized in that: In the step S3, the addition amount of spherical silica in the outer barrier material is 2%-4% of the total mass of the inner barrier material, and the addition amount of nano zinc sulfide is 1.2%-1.6% of the total mass of the inner barrier material. The particle size of the spherical silica is 10-20nm, and the particle size of the nano zinc sulfide is 80-120nm.

8. The production process according to claim 1, characterized in that: In the step S4, the heating and drying method is to first heat to 50-80°C and preheat for 15-20 min, then heat to 150-160°C for drying, and then naturally cool to normal temperature.

9. The production process according to claim 1, wherein: In the step S4, the cold roll pressing and compounding method is to use a pressure roll with a temperature of 2-6°C to apply a pressure of 10-15 N / cm 2 to the inner barrier layer or the outer barrier layer for 20-30 minutes.

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