A high-performance anti-caking UV varnish for soft packaging of cigarettes and its preparation method

Abstract

The invention relates to a high-performance anti-caking UV varnish for soft packaging of cigarettes and a preparation method thereof. The UV varnish comprises the following components calculated by weight: 25-35% of a modified aliphatic polyurethane acrylate resin, 10-15% of a fatty acid-modified epoxy acrylate, 30-35% of propoxylated neopentyl glycol diacrylate, 10-20% of ethoxylated 1,6-hexanediol diacrylate, 5-12% of a reactive tertiary amine co-initiator, 6-10% of a photoinitiator combination, and 2.48-4.82% of an auxiliary agent combination. The combination of the main resin, monomer, photoinitiator, etc. adopted in the present invention can obtain a UV varnish having excellent adhesion, ethanol resistance, friction resistance, environmental protection and other properties. In addition, the matching of appropriate specific auxiliary agents, wax powder, a polysiloxane surface-modified nano-alumina particle dispersion, and p-hydroxyanisole can further enable the soft packaging paper for cigarettes to have appropriate surface hardness and a suitable friction coefficient, thereby significantly reducing the caking phenomenon.

Description

Technical Field

[0001] The invention relates to the technical field of inks, and in particular to a high-performance anti-caking UV varnish for soft packaging of cigarettes and a preparation method thereof. Background Art

[0002] The high efficiency of gravure printing places many demands on UV varnish, ultra-low VOC emissions during the printing process, and higher requirements on the flexibility of ink for soft packaging. In addition, the surface hardness and friction resistance of the varnish must be guaranteed, and the protective layer of varnish must not mist under various temperature and humidity conditions. Even if the printed sheet passes the data inspection after the printing process, the printed product may occasionally become hardened after die-cutting, especially in seasons with large temperature and humidity differences. Manual elimination of the hardening phenomenon is necessary, which is time-consuming and labor-intensive. Therefore, it is urgent and important to develop a high-performance anti-hardening UV varnish technology for soft cigarette packaging. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-performance UV varnish technology for preventing hardening of soft packaging of cigarettes, so as to solve the problem that printed materials of soft packaging of cigarettes are prone to hardening, thereby improving production efficiency and reducing unnecessary labor costs, and obtaining a UV varnish with excellent performance and not easy to harden.

[0004] Specifically, the present invention provides a high-performance UV varnish for preventing hardening of soft cigarette packaging, comprising the following components calculated by weight percentage:

[0005] Modified aliphatic polyurethane acrylate resin 25-35%

[0006] Fatty acid modified epoxy acrylate 10-15%

[0007] Neopentyl glycol propoxylate 30-35%

[0008] Ethoxylated 1,6-hexanediol diacrylate 10-20%

[0009] Reactive tertiary amine co-initiator 5-12%

[0010] Photoinitiator combination 6-10%

[0011] Additive combination 2.48-4.82%

[0012] The auxiliary agent combination includes wax powder, polysiloxane surface-modified nano-alumina particle dispersion and p-hydroxyanisole;

[0013] Calculated by weight percentage, the wax powder is 1-2%, the polysiloxane surface-modified nano-alumina particles are 0.8-1.2%, and the p-hydroxyanisole is 0.08-0.12%. The p-hydroxyanisole is used as a polymerization inhibitor.

[0014] Furthermore, the modified aliphatic polyurethane acrylate resin is a hexafunctional polyurethane acrylate. Preferably, the hexafunctional polyurethane acrylate is 236 from Zhaoqing Baojun Chemical.

[0015] Furthermore, the fatty acid modified epoxy acrylate is a difunctional modified epoxy acrylate. Preferably, the difunctional modified epoxy acrylate is B-151 from Guangdong Boxing.

[0016] Furthermore, the reactive tertiary amine co-initiator has a functionality of 2. Preferably, the reactive tertiary amine co-initiator is 8000 from Zhaoqing Baojun Chemical.

[0017] Furthermore, the photoinitiator combination is a mixture of (2,4,6-trimethylbenzoyl)di(p-tolyl)phosphine oxide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone and a polymerized benzophenone derivative type 2 photoinitiator.

[0018] Furthermore, calculated by weight percentage, the TMO (2,4,6-trimethylbenzoyl) di(p-tolyl) phosphine oxide is 0.5-1.5%, the 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone is 0.5-1.5%, and the polymeric benzophenone derivative type 2 photoinitiator is 5-7%.

[0019] Furthermore, the auxiliary agent combination also includes a leveling agent and a defoaming agent.

[0020] Furthermore, calculated by weight percentage, the leveling agent is 0.5-1%, and the defoaming agent is 0.1-0.5%.

[0021] The present invention also provides a method for preparing the high-performance anti-caking UV varnish for soft cigarette packaging, comprising the following steps:

[0022] S1, pretreatment, adding propoxylated neopentyl glycol diacrylate, ethoxylated 1,6-hexanediol diacrylate, a photoinitiator combination, and p-hydroxyanisole into a stirred tank under normal temperature and pressure and stirring;

[0023] S2, reprocessing, stirring the mixture in the stirred tank under heating until it is transparent and free of particles;

[0024] S3, primary processing, adding modified aliphatic polyurethane acrylate resin, fatty acid modified epoxy acrylate, reactive tertiary amine co-initiator, and stirring;

[0025] S4, further processing, adding leveling agent, defoaming agent, wax powder, polysiloxane surface modified nano-alumina particle dispersion, and stirring evenly;

[0026] S5. After the finished product is fully stirred, filter it with a strainer.

[0027] Furthermore, in step S2, stirring is performed at 1400-1600 rpm; in step S3, stirring is performed at 500-700 rpm; and in step S4, stirring is performed at 500-800 rpm.

[0028] Furthermore, in step S5, the filter screen is 200 mesh.

[0029] Beneficial effects:

[0030] 1) The present invention uses a modified aliphatic polyurethane acrylate resin as the main resin, which can give the high-performance anti-caking UV varnish for cigarette flexible packaging of the present invention better flexibility and increase the UV curing drying speed, thereby achieving better high-speed printability;

[0031] 2) The present invention uses fatty acid-modified epoxy acrylate, which has a fast curing speed, high crosslinking degree, and good flexibility. The use of benzene-free monomers reduces odor and the harmfulness of benzene solvents, improving environmental standards and meeting the latest VOC standards in the cigarette packaging industry, EU EN71 Part 3, RoHS and other standards;

[0032] 3) The photoinitiator uses TMO (2,4,6-trimethylbenzoyl) di(p-tolyl) phosphine oxide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, and a polymeric benzophenone derivative type 2 photoinitiator. This initiator system is odorless, environmentally friendly, and has zero VOC emissions. It can achieve a high printing speed of 120-150 meters per minute.

[0033] 4) The addition of multiple additives can impart excellent surface effects to the varnish. In particular, based on the selection of the aforementioned components, the present invention has found that the addition of specific additives, wax powder, a dispersion of polysiloxane-surface-modified nano-alumina particles, and p-hydroxyanisole in specific proportions can impart an appropriate hardness (not too soft or too hard) and a suitable coefficient of friction to the UV varnish layer of soft cigarette packaging paper, thereby significantly reducing the phenomenon of caking.

[0034] 5) The present invention does not require the addition of organic solvents. Since there are no organic solvents such as ketones, benzenes, esters, alcohols, etc. in the entire formula, there is no emission of organic solvents during the construction process, thus meeting environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A physical picture showing a compacted soft cigarette packaging;

[0036] Figure 2A physical picture showing the manual elimination of the compaction phenomenon of soft cigarette packaging. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below in conjunction with the examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0038] In the following examples, the modified aliphatic polyurethane acrylate resin is 236 from Zhaoqing Baojun Chemical, the fatty acid modified epoxy acrylate is B-151 from Guangdong Boxing, the propoxylated neopentyl glycol diacrylate is EM2251 from Changxing Chemical Industry (Guangdong) Co., Ltd. in Taiwan, China, the ethoxylated 1,6-hexanediol diacrylate is Photomer4362 from Aijianmeng, the reactive tertiary amine co-initiator is 8000 from Zhaoqing Baojun Chemical, and TMO It is KX2013 from Shenzhen Kexin, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone is KX2012 from Shenzhen Kexin, the polymerized benzophenone derivative type 2 photoinitiator is 236 from Huizhou Huahong, the leveling agent is 432 from Digao, the defoaming agent is 900 from Digao, the wax powder is 731MG from Sanye, USA, and the polysiloxane surface-modified nano-alumina particle dispersion is BYK3601. Example 1

[0039] S1. Pretreatment: 30 kg of propoxylated neopentyl glycol diacrylate, 15 kg of ethoxylated 1,6-hexanediol diacrylate, 1 kg of photoinitiator TMO (2,4,6-trimethylbenzoyl) di(p-tolyl) phosphine oxide, 1 kg of photoinitiator 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, 7 kg of polymerized benzophenone derivative type 2 photoinitiator, and 0.1 kg of p-hydroxyanisole were weighed according to the ratio and added into a stirred tank under normal temperature and pressure and stirred;

[0040] S2, further processing, using a high-speed disperser with a rotation speed of 1400-1600 rpm to stir the mixture in the stirring tank under a state of heating to 80 degrees until it is transparent and free of particles;

[0041] S3, primary processing, add 30 kg of modified aliphatic polyurethane acrylate resin, 15 kg of fatty acid modified epoxy acrylate, and 10 kg of reactive tertiary amine co-initiator below 70 degrees, and then stir at a speed of 500-700 rpm for 20-30 minutes;

[0042] S4. Further processing: If the temperature is below 70°C, add 1 kg of leveling agent, 0.5 kg of defoamer, 1.5 kg of wax powder, and 1 kg of polysiloxane-surface-modified nano-alumina particle dispersion. Continue stirring at 500-800 rpm for 20-30 minutes until thoroughly mixed.

[0043] S5. The finished product is fully stirred and then filtered using a 200-mesh filter to obtain the UV varnish of Example 1.

[0044] Comparative Example 1

[0045] The only difference between Example 1 and Example 1 is that the amount of p-hydroxyanisole is 0.2 kg.

[0046] The UV varnish of Comparative Example 1 was obtained.

[0047] Comparative Example 2

[0048] The only difference from Example 1 is that the wax powder is 1 kg.

[0049] The UV varnish of Comparative Example 2 was obtained.

[0050] Comparative Example 3

[0051] The only difference from Example 1 is that the amount of wax powder is 2.5 kg.

[0052] The UV varnish of Comparative Example 3 was obtained.

[0053] Comparative Example 4

[0054] The only difference from Example 1 is that the dispersion of the polysiloxane surface-modified nano-alumina particles is 0.5 kg.

[0055] The UV varnish of Comparative Example 4 was obtained.

[0056] Comparative Example 5

[0057] The only difference from Example 1 is that the dispersion of the polysiloxane surface-modified nano-alumina particles is 1.5 kg.

[0058] The UV varnish of Comparative Example 5 was obtained.

[0059] Performance testing:

[0060] The UV varnishes obtained in Example 1 and Comparative Examples 1-5 were respectively coated on silver cardboard materials. After UV curing, relevant properties were tested. The test results are shown in Table 1.

[0061] Viscosity: Test with a 3# cup;

[0062] Solid content: tested according to the national standard "GB / T 1725-2007";

[0063] Gloss / 60°: tested according to GB / T 7706-2008;

[0064] Dynamic friction coefficient: tested according to GB / T 22895-2008;

[0065] Adhesion: According to the national standard "GB9286-1988", the coating surface is tested by the 100-grid method;

[0066] Flexibility: Tested according to the test method for paint film flexibility in GB T 1731-1993;

[0067] Water resistance: Tested according to Method A of GB T 1733-1993 Determination of water resistance of paint film;

[0068] Ethanol resistance: According to the force of 500 g / cm2, 99.6% alcohol is rubbed back and forth. One round trip is counted as one time, and the stroke is 2~3 cm.

[0069] Abrasion resistance: Use a paper tape tester to test the friction force of RCA175;

[0070] Surface hardness test: Tested according to the coating hardness pencil test method "GB6379-86"

[0071] Hardening rate: 100 sheets of silver cardboard coated with UV varnish were stacked and placed in a temperature and humidity test chamber with a humidity range of 20%-50% and a temperature range of -10-40 degrees Celsius for 3 days. After removal, the hardening rate was calculated using the following formula:

[0072] Hardening rate = .

[0073] Table 1 Test results

[0074] Test items Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Viscosity (s / 25℃) 35 36 33 42 32 40 Solid content (%) 99 99 99 99 99 99 Glossiness ≥85 ≥85 ≥85 ≥85 ≥85 ≥85 Dynamic friction coefficient 0.12 0.3 0.38 0.13 0.35 0.42 Surface hardness B B 2B HB 2B 2H Hardening rate 3% 20% 15% 20% 25% 15% Adhesion / Grade 5 5 5 4 5 4 color light yellow light yellow light yellow light yellow light yellow light yellow Smell (nose) Low Low Low Low Low Low Flexibility (mm) 4 5 5 2 3 2 Water resistance (hours) ≥48 ≥48 ≥48 ≥48 ≥48 ≥48 Ethanol resistance (times) ≥100 ≥100 ≥100 ≥100 ≥100 ≥100 Wear-resistant (ring) ≥100 ≥100 ≥100 ≥100 ≥100 ≥100

[0075] According to the test results in Table 1, the combination of the main resin, monomer, photoinitiator, etc. adopted in the present invention can obtain a UV varnish with excellent adhesion, ethanol resistance, friction resistance, and environmental protection properties. The adaptation of the appropriate specific auxiliary wax powder, polysiloxane surface-modified nano-alumina particle dispersion, and p-hydroxyanisole can further make the soft cigarette packaging paper have a suitable surface hardness (not too soft or too hard) and a suitable friction coefficient, thereby significantly reducing the phenomenon of caking.

[0076] Compared with the prior art, the above embodiment has the following beneficial effects:

[0077] 1) The present invention uses a modified aliphatic polyurethane acrylate resin as the main resin, which can give the high-performance anti-caking UV varnish for cigarette flexible packaging of the present invention better flexibility and increase the UV curing drying speed, thereby achieving better high-speed printability;

[0078] 2) The present invention uses fatty acid-modified epoxy acrylate, which has a fast curing speed, high crosslinking degree, and good flexibility. The use of benzene-free monomers reduces odor and the harmfulness of benzene solvents, improving environmental standards and meeting the latest VOC standards in the cigarette packaging industry, EU EN71 Part 3, RoHS and other standards;

[0079] 3) The photoinitiator uses TMO (2,4,6-trimethylbenzoyl) di(p-tolyl) phosphine oxide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone, and a polymeric benzophenone derivative type 2 photoinitiator. This initiator system is odorless, environmentally friendly, and has zero VOC emissions. It can achieve a high printing speed of 120-150 meters per minute.

[0080] 4) The addition of multiple additives can impart excellent surface effects to the varnish. In particular, based on the selection of the aforementioned components, the present invention has found that the addition of specific additives, wax powder, a dispersion of polysiloxane-surface-modified nano-alumina particles, and p-hydroxyanisole in specific proportions can impart an appropriate hardness (not too soft or too hard) and a suitable coefficient of friction to the UV varnish layer of soft cigarette packaging paper, thereby significantly reducing the phenomenon of caking.

[0081] 5) The present invention does not require the addition of organic solvents. Since there are no organic solvents such as ketones, benzenes, esters, alcohols, etc. in the entire formula, there is no emission of organic solvents during the construction process, thus meeting environmental protection requirements.

[0082] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A high-performance UV varnish for preventing hardening of soft packaging of cigarettes, characterized in that: It includes the following components calculated in percentage by weight: Modified aliphatic polyurethane acrylate resin 25-35% Fatty acid modified epoxy acrylate 10-15% Neopentyl glycol propoxylate 30-35% Ethoxylated 1,6-hexanediol diacrylate 10-20% Reactive tertiary amine co-initiator 5-12% Photoinitiator combination 6-10% Additive combination 2.48-4.82% The auxiliary agent combination includes wax powder, polysiloxane surface-modified nano-alumina particle dispersion and p-hydroxyanisole; Calculated by weight percentage, the wax powder accounts for 1-2%, the polysiloxane surface-modified nano-alumina particles account for 0.8-1.2%, and the p-hydroxyanisole accounts for 0.08-0.12%.

2. The high-performance anti-caking UV varnish for soft packaging of cigarettes according to claim 1, characterized in that: The modified aliphatic polyurethane acrylate resin is hexafunctional polyurethane acrylate.

3. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 1, characterized in that: The fatty acid modified epoxy acrylate is a difunctional modified epoxy acrylate.

4. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 1, characterized in that: The reactive tertiary amine co-initiator has a functionality of 2.

5. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 1, characterized in that: The photoinitiator combination is a mixture of (2,4,6-trimethylbenzoyl)di(p-tolyl)phosphine oxide, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinylphenyl)-1-butanone and a polymeric benzophenone derivative type 2 photoinitiator.

6. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 5, characterized in that: Calculated by weight percentage, the (2,4,6-trimethylbenzoyl)di(p-tolyl)phosphine oxide is 0.5-1.5%, the 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinylphenyl)-1-butanone is 0.5-1.5%, and the polymeric benzophenone derivative type 2 photoinitiator is 5-7%.

7. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 1, characterized in that: The auxiliary agent combination also includes a leveling agent and a defoaming agent.

8. The high-performance anti-caking UV varnish for soft cigarette packaging according to claim 7, characterized in that: Calculated by weight percentage, the leveling agent is 0.5-1%, and the defoaming agent is 0.1-0.5%.

9. The method for preparing the high-performance anti-caking UV varnish for soft cigarette packaging according to any one of claims 7-8, characterized in that: The steps include: S1, pretreatment, adding propoxylated neopentyl glycol diacrylate, ethoxylated 1,6-hexanediol diacrylate, a photoinitiator combination, and p-hydroxyanisole into a stirred tank under normal temperature and pressure and stirring; S2, reprocessing, stirring the mixture in the stirred tank under heating until it is transparent and free of particles; S3, primary processing, adding modified aliphatic polyurethane acrylate resin, fatty acid modified epoxy acrylate, reactive tertiary amine co-initiator, and stirring; S4, further processing, adding leveling agent, defoaming agent, wax powder, polysiloxane surface modified nano-alumina particle dispersion, and stirring evenly; S5. After the finished product is fully stirred, filter it with a strainer.

10. The preparation method according to claim 9, characterized in that In step S2, stirring is performed at 1400-1600 rpm; in step S3, stirring is performed at 500-700 rpm; and in step S4, stirring is performed at 500-800 rpm.

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