UV transfer printing mold for cigarette packet printing as well as preparation method and application of UV transfer printing mold

Abstract

Based on the combination of dynamic cross-linked network design and a nano topology enhancement technology, the UV transfer printing mold comprises a base layer and a release layer, the base layer is a PET film with the thickness of 100-200 microns, the release layer is formed by printing composite resin on a base material through a printing plate and then conducting dual-wavelength UV curing, and the release layer is formed by conducting UV curing on the base material through a UV curing technology. The release force of the release layer is reduced along with temperature rise, the thickness of the release layer is 2-3 microns, and the surface energy is less than or equal to 18 mN / m. The invention further discloses a preparation method of the UV transfer printing mold for cigarette packet printing and application of the UV transfer printing mold in cigarette packet printing. According to the UV transfer printing mold for cigarette packet printing and the preparation method and application of the UV transfer printing mold, heavy metal materials are not involved, metal pollution cannot be caused, the VOCs discharge amount is smaller than 5 g / m, and the UV transfer printing mold is more environmentally friendly, short in preparation time, low in cost, convenient to modify and prepare and more suitable for a UV transfer printing process for cigarette packet printing.

Description

Technical Field

[0001] The present invention belongs to the technical field of UV transfer printing of cigarette packages, and in particular relates to a UV transfer mold for cigarette package printing, a preparation method thereof, and an application thereof. Background Art

[0002] UV Transfer Printing uses the non-stick properties of ultraviolet (UV) light-curing glue and metal materials to transfer the texture or pattern on the mold to the surface of substrates such as PET, PC, and PMMA. In the traditional nickel plate transfer process, the manufacturing cost of the nickel plate is high, and the preparation process is time-consuming. Generally, more than 10 hours of electroplating processing are required. The cost of a single nickel plate exceeds 5,000 yuan. In addition, the electroplating solution contains cyanide and heavy metal ions, making wastewater treatment difficult and seriously damaging the environment. In addition, the nickel plate has a high hardness (HV ≥ 300) and insufficient flexibility, making it unable to adapt well to curved substrates. When the curvature radius of the nickel plate is <5mm during preparation, the risk of cracking of the nickel plate is >40%, and the surface roughness Ra of the nickel plate is generally >0.8μm after 2,000 transfers, which has increased significantly and requires re-electroplating to reduce the surface roughness.

[0003] Unlike traditional nickel plate transfer processes, UV release agent technology has begun to attract the attention of packaging companies due to its fast curing speed and environmental friendliness. However, the release force of existing UV release agent technology is unstable, with fluctuations often exceeding 30%, resulting in obvious incomplete patterns after transfer. It also has poor heat resistance. When the temperature is above 80°C, the release layer will soften and deform, resulting in the inability to perform normal transfer. In addition, its accuracy is low and it is unable to replicate micron-level precision textures. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a UV transfer mold for cigarette packaging printing, which has printing accuracy comparable to that of nickel plates, is environmentally friendly and safe, and has controllable release force, as well as a preparation method and application thereof.

[0005] The technical solution of the present invention to solve the above technical problems is: A UV transfer mold for cigarette pack printing, based on a combination of dynamic cross-linking network design and nanotopological enhancement technology, includes a base layer and a release layer. The base layer is a PET film with a thickness of 100-200 μm. The release layer is formed by printing a composite resin onto a substrate using a printing plate and then curing it with dual-wavelength UV. The release force of the release layer decreases with increasing temperature. The release layer is 2-3 μm thick and has a surface energy of ≤18 mN / m.

[0006] Specifically, the composite resin is prepared from 40-55wt% of fluoroacrylate, 20-30wt% of silicone-modified polyurethane, 5-8wt% of nano-silicon dioxide, 10-15wt% of diluent and 5-10wt% of temperature-sensitive photoinitiator.

[0007] Specifically, the diluent is dicyclopentadiene acrylate, and the temperature-sensitive photoinitiator is an ITX derivative.

[0008] Preferably, the release force varies from 0.15 N / cm at 30°C to 0.08 N / cm at 60°C.

[0009] Specifically, after dual-wavelength UV curing, the release layer forms a bionic honeycomb structure with an open porosity of 30~40% and a pore size of 0.5-2μm. The dual-wavelength UV is composed of ultraviolet light with a main wavelength of 365nm and an auxiliary wavelength of 405nm. The curing energy of the main wavelength is 600mJ / cm², and the curing energy of the auxiliary wavelength is 200mJ / cm².

[0010] The present invention also discloses a method for preparing the UV transfer mold for cigarette pack printing, comprising the following steps: Preparation of composite resin: 40-55wt% fluoroacrylate, 20-30wt% silicone-modified polyurethane and 5-8wt% nano-silica are placed in 10-15wt% diluent, stirred to mix thoroughly, and then 5-10wt% temperature-sensitive photoinitiator is added. After further stirring, the composite resin is obtained. Prepare the printing plate by modifying the pattern directly online according to the micro-plate printing process and obtain the printing plate after CTP plate making; Substrate treatment: corona treatment of the substrate to ensure that the surface tension of the substrate is ≥50mN / m; Release layer printing, using a printing plate to coat the composite resin and printing the composite resin on the substrate; The release layer is cured by using dual-wavelength UV to cure the printed release layer, and the UV transfer mold is obtained after the curing is completed.

[0011] Specifically, the diluent is dicyclopentadiene acrylate, and the temperature-sensitive photoinitiator is an ITX derivative.

[0012] Specifically, the dual-wavelength UV light is composed of ultraviolet light with a main wavelength of 365 nm and an auxiliary wavelength of 405 nm.

[0013] Another technical solution of the present invention to solve the above technical problems is: An application of the UV transfer mold for cigarette pack printing as described above in cigarette pack printing, wherein the UV transfer mold is used to perform UV transfer operation on the cigarette pack. Before starting printing, the UV transfer mold is activated by heat treatment at 30~60℃ for 10 minutes to adjust the release force of the release layer of the UV transfer mold.

[0014] The present invention has the following beneficial effects: (1) The UV transfer mold prepared by the present invention does not involve heavy metal materials and will not cause metal pollution. Its VOCs emission is less than 5g / m³, which is more environmentally friendly.

[0015] (2) The preparation method of the present invention reduces the time required to prepare the UV transfer mold to 2 to 3 hours, effectively reducing the mold preparation cycle and having a higher fault tolerance rate. The pattern can be modified online at any time according to the actual situation and then directly modified by laser ablation, achieving the effect of high precision and low production cost.

[0016] (3) The UV transfer mold prepared by the present invention has high wear resistance and heat resistance, and its release force is more stable, with low fluctuation, and has a lower curvature radius, which is more conducive to the UV transfer operation of cigarette packaging products. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the UV transfer mold of the present invention.

[0018] The meanings of the serial numbers in the accompanying drawings are as follows: 1 base material, 2 release layer. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the embodiments.

[0020] The present invention discloses a UV transfer mold for cigarette pack printing, which is based on a combination of dynamic cross-linking network design and nanotopological enhancement technology, and includes a base layer 1 and a release layer 2. The base layer is a PET film with a thickness of 100-200 μm. The release layer is formed by printing a composite resin onto a substrate using a printing plate and then subjecting it to dual-wavelength UV curing. The release force of the release layer decreases with increasing temperature, and the variation range of the release force is from 0.15 N / cm at 30°C to 0.08 N / cm at 60°C. The thickness of the release layer is 2-3 μm, and the surface energy is ≤18 mN / m. After dual-wavelength UV curing, the release layer forms a bionic honeycomb structure with an open porosity of 30-40% and a pore size of 0.5-2 μm. The dual-wavelength UV is composed of ultraviolet light with a main wavelength of 365 nm and an auxiliary wavelength of 405 nm. The curing energy of the main wavelength is 600 mJ / cm², and the curing energy of the auxiliary wavelength is 200 mJ / cm². Example

[0021] A UV transfer mold for cigarette pack printing according to Example 1 of the present invention is prepared by the following steps.

[0022] To prepare the composite resin, 40wt% fluoroacrylate, 30wt% silicone-modified polyurethane, and 5wt% nanosilica were added to 15wt% diluent dicyclopentadiene acrylate. After stirring to thoroughly mix, 10wt% of a temperature-sensitive photoinitiator, a TX derivative, was added and stirred again to obtain the composite resin. The addition of silica effectively improves the mechanical properties of the cured release layer, enhancing its wear resistance and heat resistance. Furthermore, the addition of a temperature-sensitive photoinitiator enables the release force to self-regulate with temperature, improving the adaptability and stability of the release force of the release film in various environments.

[0023] Preparation of printing plates, based on the micro-printing process. Micro-printing is an online content printing and personalized customization platform that focuses on converting social platform content (such as Weibo, WeChat, QQ Space, etc.) into physical books or e-books, providing online editing, online modification, and then customized printing plate services through laser engraving. This embodiment adopts this method, by directly modifying the pattern online and obtaining the printing plate after CTP plate making, effectively reducing the plate making cost.

[0024] Substrate treatment: corona treatment of the substrate is performed to ensure that the surface tension of the substrate is ≥50mN / m. In this embodiment, the substrate is a 100μm PET film. Corona treatment is performed by using high-frequency high-voltage electricity to form tiny holes on the surface of the PET film, thereby increasing the surface tension and improving its adhesion to ink, glue, etc., ensuring good bonding between the release layer and the substrate layer in subsequent processes.

[0025] For release layer printing, a printing plate is coated with a composite resin, and the composite resin is printed on the substrate. Because the printing plate is made using CTP, its minimum line width can be 15μm, so the final UV transfer mold can also have a high precision, comparable to traditional nickel plates.

[0026] The release layer is cured using dual-wavelength UV to obtain the UV transfer mold. Dual-wavelength UV curing, with a primary wavelength of 365nm at 600mJ / cm² and an auxiliary wavelength of 405nm at 200mJ / cm², forms a bionic honeycomb structure with a 40% open porosity and a pore size of 1.2±0.3μm on the surface of the release layer, improving the stability and precision of the release layer.

[0027] In actual printing applications, pre-activation treatment of the UV transfer mold and heat treatment at 60°C for 10 minutes can effectively clear the honeycomb structure on the surface of the release layer and improve the stability and durability of the release layer. Example

[0028] A UV transfer mold for cigarette pack printing in this embodiment 2 is prepared by the following steps.

[0029] To prepare the composite resin, 55wt% fluoroacrylate, 20wt% silicone-modified polyurethane, and 8wt% nanosilica were added to 10wt% dicyclopentadiene acrylate (diluent). After stirring to thoroughly mix, 7wt% of a temperature-sensitive photoinitiator, a TX derivative, was added and stirred again to obtain the composite resin. The addition of silica effectively improves the mechanical properties of the cured release layer, enhancing its wear resistance and heat resistance. Furthermore, the addition of a temperature-sensitive photoinitiator enables the release force to self-regulate with temperature, improving the adaptability and stability of the release force of the release film in various environments.

[0030] Preparation of printing plates, based on the micro-printing process. Micro-printing is an online content printing and personalized customization platform that focuses on converting social platform content (such as Weibo, WeChat, QQ Space, etc.) into physical books or e-books, providing online editing, online modification, and then customized printing plate services through laser engraving. This embodiment adopts this method, by directly modifying the pattern online and obtaining the printing plate after CTP plate making, effectively reducing the plate making cost.

[0031] Substrate treatment: corona treatment of the substrate is performed to ensure that the surface tension of the substrate is ≥50mN / m. In this embodiment, the substrate is a 100μm PET film. Corona treatment is performed by using high-frequency high-voltage electricity to form tiny holes on the surface of the PET film, thereby increasing the surface tension and improving its adhesion to ink, glue, etc., ensuring good bonding between the release layer and the substrate layer in subsequent processes.

[0032] For release layer printing, a composite resin is coated on a printing plate, and the composite resin is printed on a substrate. Since the printing plate is made using CTP, its minimum line width can be 15 μm, so the final UV transfer mold can also have a higher precision. The minimum line width of the traditional nickel plate mold is 20 μm, which is more precise in comparison.

[0033] The release layer is cured using dual-wavelength UV to obtain the UV transfer mold. Dual-wavelength UV curing, with a primary wavelength of 365nm at 600mJ / cm² and an auxiliary wavelength of 405nm at 200mJ / cm², forms a bionic honeycomb structure with a porosity of 35% and a pore size of 0.8±0.3μm on the surface of the release layer, improving the stability and precision of the release layer. Example

[0034] A UV transfer mold for cigarette pack printing in this embodiment 3 is prepared by the following steps.

[0035] To prepare the composite resin, 50wt% fluoroacrylate, 24wt% silicone-modified polyurethane, and 6wt% nanosilica were added to 12wt% diluent dicyclopentadiene acrylate. After stirring to thoroughly mix, 8wt% of a temperature-sensitive photoinitiator, a TX derivative, was added and stirred again to obtain the composite resin. The addition of silica effectively improves the mechanical properties of the cured release layer, enhancing its wear resistance and heat resistance. Furthermore, the addition of a temperature-sensitive photoinitiator enables the release force to self-regulate with temperature, improving the adaptability and stability of the release force of the release film in various environments.

[0036] Preparation of printing plates, based on the micro-printing process. Micro-printing is an online content printing and personalized customization platform that focuses on converting social platform content (such as Weibo, WeChat, QQ Space, etc.) into physical books or e-books, providing online editing, online modification, and then customized printing plate services through laser engraving. This embodiment adopts this method, by directly modifying the pattern online and obtaining the printing plate after CTP plate making, effectively reducing the plate making cost.

[0037] Substrate treatment: corona treatment of the substrate is performed to ensure that the surface tension of the substrate is ≥50mN / m. In this embodiment, the substrate is a 100μm PET film. Corona treatment is performed by using high-frequency high-voltage electricity to form tiny holes on the surface of the PET film, thereby increasing the surface tension and improving its adhesion to ink, glue, etc., ensuring good bonding between the release layer and the substrate layer in subsequent processes.

[0038] For release layer printing, a printing plate is coated with a composite resin, and the composite resin is printed on the substrate. Because the printing plate is made using CTP, its minimum line width can be 15μm, so the final UV transfer mold can also have a high precision, comparable to traditional nickel plates.

[0039] The release layer is cured using dual-wavelength UV to obtain the UV transfer mold. Dual-wavelength UV curing, with a primary wavelength of 365nm at 600mJ / cm² and an auxiliary wavelength of 405nm at 200mJ / cm², forms a bionic honeycomb structure with a porosity of 30% and a pore size of 1.7±0.3μm on the surface of the release layer, improving the stability and precision of the release layer.

[0040] The UV transfer mold prepared in Example 2 of the present invention is compared with the traditional nickel plate mold, as shown in the following table.

[0041] index Example 2 Traditional nickel plate mold Minimum line width 15μm 20μm Centrifugal force fluctuations ±3.5% ±8% Transfer life 12,000 times 2000 times Surface adaptability Curvature radius ≥ 2mm When the curvature radius is less than 5mm, the risk of cracking is greater than 40%. As can be seen from the above table, the performance of the UV transfer mold provided by the present invention is significantly better than that of the traditional nickel plate mold. At the same time, combined with the cost of the traditional nickel plate mold, the manufacturing cost of the conventional nickel plate is 5,800 yuan / piece, so its actual single transfer cost is 0.18 yuan, while the manufacturing cost of the UV transfer mold provided by the present invention is 320 yuan / piece, which is equivalent to a single transfer cost of 0.03 yuan. The actual cost is much lower than that of the traditional nickel plate mold, and the preparation cycle of the nickel plate mold is as long as dozens of hours, while the preparation time of the UV transfer mold prepared by the present invention is only 2 to 3 hours, which reduces the preparation cost. In actual testing, the release layer brain model was detected to be H grade. Under a load of 750g, it was transferred 5,000 times without any damage, which further confirmed the excellent performance of the UV transfer mold provided by the present invention.

[0042] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. A UV transfer mold for cigarette pack printing, characterized in that: Based on the combination of dynamic cross-linking network design and nanotopological enhancement technology, it includes a base layer and a release layer. The base layer is a PET film with a thickness of 100-200μm. The release layer is formed by printing a composite resin onto a substrate through a printing plate and then curing it with dual-wavelength UV. The release force of the release layer decreases with increasing temperature. The thickness of the release layer is 2-3μm, and the surface energy is ≤18mN / m.

2. The UV transfer mold for cigarette pack printing according to claim 1, characterized in that: The composite resin is prepared from 40-55wt% of fluoroacrylate, 20-30wt% of organosilicon-modified polyurethane, 5-8wt% of nano-silicon dioxide, 10-15wt% of diluent and 5-10wt% of temperature-sensitive photoinitiator.

3. The UV transfer mold for cigarette pack printing according to claim 2, characterized in that: The diluent is dicyclopentadiene acrylate, and the temperature-sensitive photoinitiator is an ITX derivative.

4. The UV transfer mold for cigarette pack printing according to claim 3, characterized in that: The release force varies from 0.15 N / cm at 30°C to 0.08 N / cm at 60°C.

5. The UV transfer mold for cigarette pack printing according to any one of claims 1 to 4, characterized in that: After dual-wavelength UV curing, the release layer forms a bionic honeycomb structure with an open porosity of 30-40% and a pore size of 0.5-2 μm. The dual-wavelength UV is composed of ultraviolet light with a main wavelength of 365 nm and an auxiliary wavelength of 405 nm. The curing energy of the main wavelength is 600 mJ / cm², and the curing energy of the auxiliary wavelength is 200 mJ / cm².

6. A method for preparing a UV transfer mold for cigarette pack printing according to any one of claims 1 to 5, characterized in that: The steps include: Preparation of composite resin: 40-55wt% fluoroacrylate, 20-30wt% silicone-modified polyurethane and 5-8wt% nano-silica are placed in 10-15wt% diluent, stirred to mix thoroughly, and then 5-10wt% temperature-sensitive photoinitiator is added. After further stirring, the composite resin is obtained. Prepare the printing plate by modifying the pattern directly online according to the micro-plate printing process and obtain the printing plate after CTP plate making; Substrate treatment: corona treatment of the substrate to ensure that the surface tension of the substrate is ≥50mN / m; Release layer printing, using a printing plate to coat the composite resin and printing the composite resin on the substrate; The release layer is cured by using dual-wavelength UV to cure the printed release layer, and the UV transfer mold is obtained after the curing is completed.

7. The preparation method according to claim 6, characterized in that: The diluent is dicyclopentadiene acrylate, and the temperature-sensitive photoinitiator is an ITX derivative.

8. The method according to claim 6, wherein: The dual-wavelength UV light is composed of ultraviolet light with a main wavelength of 365 nm and an auxiliary wavelength of 405 nm.

9. Use of the UV transfer mold for cigarette pack printing according to any one of claims 1 to 5, characterized in that: The UV transfer mold is used to perform UV transfer operation on the cigarette pack. Before starting printing, the UV transfer mold is activated by heat treatment at 30-60°C for 10 minutes to adjust the release force of the release layer of the UV transfer mold.

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