Anti-counterfeit printing process for cigarette packaging paper and cigarette packaging paper

Abstract

The invention relates to the technical field of anti-counterfeit packaging, in particular to an anti-counterfeit printing process for cigarette packaging paper and the cigarette packaging paper.The anti-counterfeit printing process comprises the following steps that S1, according to a preset pattern, multi-color ink is offset-printed on a printing stock, and drying and curing are conducted to form a basic ink layer; s2, blending microcapsule color-changing ink as gloss oil, and coating the gloss oil on a specified area on the surface of the basic ink layer by a glazing unit of the offset press to form a gloss oil layer; the glazing unit comprises an anilox roller used for transferring glazing oil to the surface of the basic ink layer, the range of the line number of the anilox roller is 80-120 lpi, and the range of the ink loading amount is 11-13 cm < 3 > / m < 2 >; and S3, drying and curing the gloss oil layer. According to the anti-counterfeit printing technology, the technological process can be shortened, the technology cost is saved, and the cigarette packaging paper obtained through the anti-counterfeit printing technology has the good color changing effect.

Description

Technical Field

[0001] This invention relates to the technical field of anti-counterfeiting packaging, specifically to an anti-counterfeiting printing process for cigarette packaging paper. Background Technology

[0002] In the tobacco product packaging industry, innovation in anti-counterfeiting technology has always been a crucial means of ensuring brand security and combating counterfeiting. Currently, anti-counterfeiting printing on cigarette packaging paper primarily relies on the special optical properties of color-changing inks. Among these, microcapsule color-changing inks have attracted considerable attention due to their dynamically reversible color-changing effect. The color-changing mechanism of this ink is based on its microcapsule structure: when the ink capsules in the microcapsule color-changing ink are subjected to pressure (such as friction) or heat, the color developer liquefies and reacts with the pigment, displaying a color change; when the pressure decreases or the temperature drops, the color developer and pigment gradually separate and solidify, and this reversible change allows the ink color to return to its original state.

[0003] The printing of microcapsule color-changing inks is often achieved through gravure printing and screen printing. For example, invention patent CN118219659A discloses a microcapsule thermochromic ink printing process suitable for eggplant labels. This process includes: after the offset print is dry, using a screen printing stencil to print the microcapsule thermochromic ink onto the designated areas, followed by curing. The core reason why gravure and screen printing have become mainstream in the industry is that they can relatively well meet the requirements of microcapsule color-changing ink printing: to ensure the color-changing effect, microcapsule color-changing inks tend to use gravure and screen printing, which can form a relatively thick ink layer, on the substrate, rather than ordinary offset or flexographic printing, which forms a thinner ink layer.

[0004] However, while gravure and screen printing technologies can technically meet the printing requirements of microcapsule inks, the additional use of gravure and screen printing machines leads to high equipment costs. Gravure plate making is complex, time-consuming, and extremely expensive per-plate set. Similarly, the production of high-mesh-count screen printing plates is time-consuming and costly. Therefore, there is an urgent need for a lower-cost and more efficient printing process to meet the needs of widespread industrial applications. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an anti-counterfeiting printing process for cigarette packaging paper and the cigarette packaging paper itself. The anti-counterfeiting printing process can save on process costs and shorten the process flow, and the cigarette packaging paper obtained through the anti-counterfeiting printing process has a good color-changing effect.

[0006] To achieve the above-mentioned objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides an anti-counterfeiting printing process for cigarette packaging paper, comprising the following steps: S1. According to the preset pattern, offset print multicolor inks on the substrate, dry and cure to form a base ink layer; S2. Microcapsule color-changing ink is prepared as a varnish. The varnishing unit of the offset printing machine applies the varnish to a designated area on the surface of the base ink layer to form a varnish layer. The varnishing unit includes an anilox roller for transferring the varnish to the surface of the base ink layer. The anilox roller has a line count ranging from 80 to 120 lpi and an ink loading range of 11 to 13 cm. 3 / m 2 ; S3. Dry and cure the varnish layer.

[0007] This invention first uses the offset printing unit of an offset printing press to print a base ink layer, and then uses the varnishing unit of the same offset printing press to coat microcapsule color-changing ink. This eliminates the need for additional printing equipment such as screen printing machines, shortening the process and saving costs. The printed mark obtained through this anti-counterfeiting printing process still has a good color-changing effect. Furthermore, since the ink layer thickness of offset printing is thinner than that of gravure and screen printing, to avoid weakening the color-changing effect of the microcapsule color-changing ink due to the thin ink layer, this invention controls the line count setting of the anilox roller to match the particle size range of the fine-particle microcapsule ink. This ensures that the anilox roller can screen out ink particles with smaller particle sizes, thereby improving the color-changing effect by increasing the contact probability between the developer and the pigment per unit area. Furthermore, an upper limit on the line count is set to avoid insufficient ink transfer and poor color saturation due to excessively high line counts. The ink load setting of the anilox roller is used to precisely control the thickness of the varnish layer; a suitable ink load setting effectively ensures ink leveling.

[0008] Preferably, by weight, the microcapsule color-changing ink comprises 25-31 parts scratch-changing pigment, 60-70 parts water-emulsion acrylic resin, 0.5-1.5 parts water-based additives, and 2-6 parts ethylene glycol.

[0009] Preferably, the aqueous additives include sodium dioctyl succinate iodate, triethanolamine, and water.

[0010] Gravure printing quantitatively transfers ink through engraved cells, while screen printing requires inks with thixotropic properties that can rapidly change viscosity. Both rely heavily on highly volatile ester systems as solvents for microcapsule materials. However, ester solvents generate VOC emissions during production, posing a significant pollution risk. The offset printing process employed in this invention, with its low printing pressure, thin ink layer, and short thermal stress application time, provides a milder physicochemical environment, making it an ideal carrier for low-pollution, water-based microcapsule color-changing inks.

[0011] Preferably, the particle size of the microcapsule color-changing ink is 3~7μm.

[0012] Preferably, the viscosity of the microcapsule color-changing ink is 40-50 seconds when tested with a Zahn No. 3 cup at 25°C.

[0013] Set an appropriate viscosity range to avoid excessively high viscosity affecting ink leveling or too low viscosity affecting ink transferability.

[0014] Preferably, the pH value of the microcapsule color-changing ink is 7.5-8.5. By controlling the pH value of the ink within this range, the drying performance of the ink is ensured. More preferably, the microcapsule color-changing ink further includes 0.3-0.7 parts of a neutralizing agent, preferably ethanolamine, which adjusts the pH without affecting the ink viscosity.

[0015] Preferably, the varnishing unit further includes a scraper for controlling the thickness of the varnish layer, wherein the thickness of the varnish layer is 8~9μm.

[0016] Preferably, the varnishing unit further includes a plate for positioning the designated area, the plate including a rubber blanket for overall varnishing or a flexible plate for local varnishing.

[0017] Preferably, the varnish layer is dried and cured by infrared hot air drying, which has a highly efficient drying effect.

[0018] Preferably, the conditions for infrared hot air drying include: infrared temperature of 35~45℃ and hot air power of 40~60%.

[0019] Secondly, the present invention provides a cigarette packaging paper, which is printed using the anti-counterfeiting printing process for cigarette packaging paper as described above.

[0020] The beneficial effects of this invention are as follows: This invention provides a printing process for microcapsule color-changing ink based on offset printing technology. It not only has the advantages of high popularity and short plate-making cycle of existing offset printing equipment, but also breaks through the limitations of traditional processes by introducing water-based offset printing ink system and adjusting microcapsule particle size distribution. The cigarette packaging paper printed by the above printing process has the advantages of economy, environmental protection and high color-changing performance. Attached Figure Description

[0021] Figure 1 Test images of color saturation and leveling properties of varnish layers obtained by anilox roller printing with different parameters. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Example 1

[0023] S1. Using coated paper for cigarettes as the printing substrate, multi-color inks are offset printed on the substrate using a multi-color offset printing machine according to the preset pattern. After being dried and cured by infrared hot air at an infrared temperature of 40°C and a hot air power of 50%, a basic ink layer is formed. S2. Microcapsule color-changing ink is prepared as a varnish. The varnishing unit of the multi-color offset printing press applies the varnish to a designated area on the surface of the base ink layer to form a varnish layer. The varnishing unit includes a flexible plate for positioning the designated area, an anilox roller for transferring the varnish to the surface of the base ink layer, and a doctor blade for controlling the thickness of the varnish layer. The anilox roller has a line count of 80 lpi and an ink loading of 13 cm. 3 / m 2 A varnish layer with a thickness of 8.5 μm was obtained by sieving solid capsule pigments with a thickness of 3~7 μm. The microcapsule color-changing ink, by mass, comprises 28 parts scratch-sensitive color-changing pigment, 65 parts water-emulsion acrylic resin, 1 part water-based additive, 4 parts ethylene glycol, and 0.5 parts ethanolamine. The water-based additive comprises 0.4 parts sodium dioctyl succinate iodate, 0.4 parts triethanolamine, and 0.2 parts deionized water. Its pH is 8.5, and its viscosity is measured in 45 seconds using a Zahn No. 3 cup at 25°C. S3. The varnish layer is dried and cured by infrared hot air at an infrared temperature of 40°C and a hot air power of 50%. Example 2

[0024] The embodiments are basically the same, except that the anilox roller has a line count of 120 lpi and an ink load of 11 cm. 3 / m 2 .

[0025] Comparative Example 1 The embodiment is essentially the same as the previous one, except that the anilox roller has a line count of 196 lpi and an ink load of 6.5 cm. 3 / m 2 .

[0026] Comparative Example 2 The embodiments are basically the same, except that the anilox roller has a line count of 157 lpi and an ink load of 8 cm.3 / m 2 .

[0027] Comparative Example 3 The embodiments are basically the same, except that the anilox roller has a line count of 120 lpi and an ink load of 8 cm. 3 / m 2 .

[0028] Comparative Example 4 The embodiments are basically the same, except that the anilox roller has a line count of 80 lpi and an ink load of 17 cm. 3 / m 2 .

[0029] Comparative Example 5 The embodiments are basically the same, except that the anilox roller has a line count of 60 lpi and an ink load of 23 cm. 3 / m 2 .

[0030] The results of color protection and leveling tests on the varnish layers printed in the examples and comparative examples are as follows: Figure 1 As shown, the numbers in the first row of the leveling test chart correspond to the line count values ​​of the anilox roller in the examples / comparative examples, and the numbers in the second row of the leveling test chart correspond to the ink load values ​​of the anilox roller in the examples / comparative examples.

[0031] It is evident that both Example 1 and Example 2 exhibit good color protection and leveling properties. Specifically, when the anilox roller has a line count of 80 lpi and an ink loading of 13 cm⁻¹, the results are particularly satisfactory. 3 / m 2 The printing effect is optimal when the anilox roller has the highest line count. Furthermore, excessively high anilox roller line count or insufficient ink load will result in insufficient ink transfer, leading to poor color protection. Additionally, referring to the illustrations in Comparative Examples 4 and 5, the orange peel effect (i.e., the uneven, rough texture of the varnish layer resembling orange peel) is due to the differences in the printing and spreading properties between water-based and ester-based inks. Excessive ink load on the anilox roller will cause the water-based ink to shrink and fail to spread properly on the flexographic plate, resulting in poor ink leveling.

Claims

1. An anti-counterfeiting printing process for cigarette packaging paper, characterized in that, Includes the following steps: S1. According to the preset pattern, offset print multicolor inks on the substrate, dry and cure to form a base ink layer; S2. Microcapsule color-changing ink is prepared as a varnish. The varnishing unit of the offset printing machine applies the varnish to a designated area on the surface of the base ink layer to form a varnish layer. The varnishing unit includes an anilox roller for transferring the varnish to the surface of the base ink layer. The anilox roller has a line count ranging from 80 to 120 lpi and an ink loading range of 11 to 13 cm. 3 / m 2 ; S3. Dry and cure the varnish layer.

2. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, By weight, the microcapsule color-changing ink comprises 25-31 parts scratch-changing pigment, 60-70 parts water-emulsion acrylic resin, 0.5-1.5 parts water-based additives, and 2-6 parts ethylene glycol.

3. The anti-counterfeiting printing process for cigarette packaging paper according to claim 2, characterized in that, The aqueous additives include sodium dioctyl succinate iodate, triethanolamine, and water.

4. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The microcapsule color-changing ink has a particle size of 3~7μm.

5. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The viscosity of the microcapsule color-changing ink was measured to be 40-50 seconds using a Zahn No. 3 cup at 25°C.

6. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The pH value of the microcapsule color-changing ink is 7.5~8.

5.

7. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The thickness of the varnish layer is 8~9μm.

8. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The varnishing unit also includes a plate for positioning the designated area, the plate including a rubber blanket for overall varnishing or a flexible plate for local varnishing.

9. The anti-counterfeiting printing process for cigarette packaging paper according to claim 1, characterized in that, The method for drying and curing the varnish layer is infrared hot air drying.

10. A type of cigarette packaging paper, characterized in that, It is printed using the anti-counterfeiting printing process for cigarette packaging paper as described in any one of claims 1-9.

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