Color explosion-resistant UV (ultraviolet) gloss oil as well as preparation method and application thereof

Abstract

The invention discloses color bursting-resistant UV (ultraviolet) gloss oil, which is prepared from the following components in parts by weight: 20 to 30 parts of tripropylene glycol diacrylate; 0.5 to 1 part of trimethylolpropane triacrylate; 15 to 25 parts of a diluent; 15 to 20 parts of bifunctional modified polyurethane; 3-6 parts of difunctional modified epoxy acrylate; 12 to 16 parts of four-functional modified polyurethane acrylate; 3 to 6 parts of difunctional modified polyurethane acrylate; 8 to 12 parts of a photoinitiator; 0.05 to 0.15 part of wax powder; 0.005 part of a dispersant; 0.1 to 0.5 part of a leveling agent; and 3-5 parts of an active amine photosensitive accelerator. The invention also provides a preparation method of the color explosion-resistant UV gloss oil. According to the invention, bifunctional modified polyurethane, bifunctional modified epoxy acrylate, bifunctional modified polyurethane acrylate and tetrafunctional modified polyurethane acrylate are compounded with tripropylene glycol diacrylate and trimethylolpropane triacrylate to form a UV gloss oil matrix, so that a cured coating has hardness and toughness; the surface wear resistance is ensured, and meanwhile, the color explosion resistance of the 180-degree folding line at the flip cover of the protective layer of the hard cigarette case is effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of UV varnish and specifically relates to a color explosion-resistant UV varnish for cigarette packets and a preparation method thereof. BACKGROUND

[0002] The UV varnish is a kind of transparent paint composed of UV resin, monomer, initiator and auxiliary agent, which is transferred to the surface of an object through a spraying or printing (offset printing, intaglio printing, silk printing, etc.) process and is cured into a film by UV irradiation, so as to improve the appearance decoration effect of the surface gloss and texture of the object and improve the surface resistance to physical and chemical damage, and is thus widely applied in the fields of automobiles, electrical appliances, furniture and various packaging boxes.

[0003] The cigarette packet is generally coated with a layer of UV varnish by offset printing after printing patterns, and a protective layer is formed after UV curing, so as to improve the gloss and surface hardness of the cigarette packet and thus improve the wear resistance. However, the existing UV varnish applied to the cigarette packet cannot balance the hardness and flexibility, which leads to cracking of the 180° folding line of the hard box cigarette packet cover and thus causes the ink layer at the bottom to burst, seriously affecting the appearance and practicability. SUMMARY

[0004] The present application aims to solve the above technical problems to some extent. To this end, the main purpose of the present application is to provide a color explosion-resistant UV varnish with hardness and flexibility and a preparation method thereof.

[0005] The present application also provides the application of the color explosion-resistant UV varnish, which is suitable for cigarette packets and can improve the color explosion resistance of the 180° folding line in the hard box cigarette packet cover, which has a positive significance for improving the appearance of the cigarette packet.

[0006] The purpose of the present application is achieved by the following technical solutions: A color explosion-resistant UV varnish, comprising the following components in parts by weight: tripropylene glycol diacrylate 20-30 parts; trimethylolpropane triacrylate 0.5-1 part; diluent 15-25 parts; di-functional modified polyurethane 15-20 parts; di-functional modified epoxy acrylate 3-6 parts; tetra-functional modified polyurethane acrylate 12-16 parts; di-functional modified polyurethane acrylate 3-6 parts; photoinitiator 8-12 parts; wax powder 0.05-0.15 parts; dispersant 0.005 parts; leveling agent 0.1-0.5 parts; active amine photosensitive accelerator 3-5 parts.

[0007] In certain embodiments, the composition comprises, by weight parts: tripropylene glycol diacrylate 25 parts; trimethylolpropane triacrylate 0.7 parts; diluent 20 parts; di-functional modified polyurethane 18 parts; di-functional modified epoxy acrylate 4 parts; tetra-functional modified polyurethane acrylate 14 parts; di-functional modified polyurethane acrylate 4 parts; photoinitiator 10 parts; wax powder 0.1 part; dispersant 0.005 parts; leveling agent 0.1 part; active amine photosensitive promoter 4 parts.

[0008] In certain embodiments, the composition comprises, by weight parts: tripropylene glycol diacrylate 25 parts; trimethylolpropane triacrylate 0.7 parts; diluent 15 parts; di-functional modified polyurethane 16 parts; di-functional modified epoxy acrylate 3 parts; tetra-functional modified polyurethane acrylate 12 parts; di-functional modified polyurethane acrylate 3 parts; photoinitiator 8 parts; wax powder 0.1 part; dispersant 0.005 parts; leveling agent 0.1 part; active amine photosensitive promoter 3 parts.

[0009] In certain embodiments, the composition comprises, by weight parts: tripropylene glycol diacrylate 25 parts; trimethylolpropane triacrylate 0.7 parts; diluent 25 parts; di-functional modified polyurethane 20 parts; di-functional modified epoxy acrylate 5 parts; tetra-functional modified polyurethane acrylate 16 parts; di-functional modified polyurethane acrylate 5 parts; photoinitiator 12 parts; wax powder 0.1 part; dispersant 0.005 parts; leveling agent 0.5 parts; active amine photosensitive promoter 5 parts.

[0010] In certain embodiments, the composition comprises, by weight parts: tripropylene glycol diacrylate 30 parts; trimethylolpropane triacrylate 1 part; diluent 20 parts; di-functional modified polyurethane 18 parts; di-functional modified epoxy acrylate 6 parts; tetra-functional modified polyurethane acrylate 16 parts; di-functional modified polyurethane acrylate 6 parts; photoinitiator 12 parts; wax powder 0.1 part; dispersant 0.005 parts; leveling agent 0.3 parts; active amine photosensitive promoter 5 parts.

[0011] In certain embodiments, the diluent is a mixture of ethanol and reactive diluent.

[0012] In certain embodiments, the photoinitiator is a mixture of 3-methyl-4-phenylbenzophenone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0013] In certain embodiments, the active amine photosensitive promoter is a mixture of B-21C and B-27; the leveling agent is a mixture of Dowanol®450 and Dowanol Lencolo 3003.

[0014] As the same inventive concept, the application further provides a preparation method of the explosion-proof color UV varnish, comprising the following steps: 1) mixing the wax powder, tripropyleneglycol diacrylate and dispersant in a formula amount, grinding to obtain a wax paste, and then adding into the tripropyleneglycol diacrylate to disperse uniformly to obtain a wax powder dispersion liquid; 2) mixing the tripropyleneglycol diacrylate, trimethylolpropane triacrylate and diluent, stirring and dispersing, and then sequentially adding the di-functional modified polyurethane, di-functional modified epoxy acrylate, tetra-functional modified polyurethane acrylate and di-functional modified polyurethane acrylate, and stirring uniformly to obtain a UV varnish resin matrix; 3) adding a photoinitiator into the UV varnish resin matrix prepared in the step 2), stirring uniformly, then adding the wax powder dispersion liquid prepared in the step 1), and stirring to add a leveling agent and an active amine photosensitizer, and dispersing uniformly, and then standing for 24 hours to obtain the explosion-proof color UV varnish.

[0015] As the same inventive concept, the application further provides an application of the explosion-proof color UV varnish in a hard box cigarette case.

[0016] Compared with the prior art, the application has at least the following advantages: 1) The explosion-proof color UV varnish provided by the application is compounded into a UV varnish matrix through a specific dispersion process of the di-functional modified polyurethane, di-functional modified epoxy acrylate, tetra-functional modified polyurethane acrylate, di-functional modified polyurethane acrylate, tripropyleneglycol diacrylate and trimethylolpropane triacrylate, so that the cured coating has both hardness and toughness, the surface wear resistance is ensured, the 180° folding line explosion-proof color performance of the hard box cigarette case protective layer at the flap is effectively improved, and the UV varnish curing rate can be greatly improved by reasonably adjusting the composition and amount of the photoinitiator and the active amine photosensitizer to meet the actual production needs.

[0017] 2) The explosion-proof color UV varnish provided by the application is processed twice through a three-roll grinder and a homogenizer to form a wax powder dispersion liquid, and the wax powder dispersion liquid is added into the UV varnish matrix to be dispersed quickly and uniformly, the gloss of the cured coating is not affected, the dynamic and static friction coefficients are reduced, the cigarette case is prevented from being jammed on the cigarette packaging machine, and the water mist is prevented from occurring when the cigarette case is coated.

[0018] 3) The explosion-proof color UV varnish provided by the application is reasonably combined with the leveling agent and the diluent, on the one hand, the viscosity of the UV varnish is effectively reduced and the flowability is improved, so that the UV varnish matches the offset printing process, and on the other hand, the curing rate is further improved. DETAILED DESCRIPTION

[0019] The application will be further described in conjunction with specific examples, which are only descriptive and not limiting, and cannot limit the protection scope of the application.

[0020] When a range, preferably a range, or a preferred upper and lower limit of a numerical value is expressed in the form of a certain amount, concentration or other value or parameter, it should be understood that any range is specifically disclosed by combining any pair of range upper limit or preferred numerical value with any range lower limit or preferred numerical value, regardless of whether the range is specifically disclosed. Unless otherwise indicated, the numerical value range listed herein includes the endpoints of the range, and all integers and fractions within the range.

[0021] Unless otherwise specified, all percentages, parts, ratios, etc. herein are by weight.

[0022] Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to that described can also be applied in the present application. The experimental methods in the examples are not specified, which are usually carried out according to the conventional conditions or according to the conditions recommended by the manufacturer.

[0023] A kind of explosion-proof color UV light oil, by weight parts, it includes the following components: tripropylene glycol diacrylate 20-30 parts;Trimethylolpropane triacrylate 0.5-1 part;Diluent 15-25 parts;Di-functional modified polyurethane 15-20 parts;Di-functional modified epoxy acrylate 3-6 parts;Four functional modified polyurethane acrylate 12-16 parts;Di-functional modified polyurethane acrylate 3-6 parts;Photoinitiator 8-12 parts;Wax powder 0.1 part;Dispersant 0.005 part;Leveling agent 0.1-0.5 part;Active amine photosensitive accelerator 3-5 parts.

[0024] The tripropylene glycol diacrylate and trimethylolpropane triacrylate are purchased from Changxing Chemical Industry Co., Ltd. in Taiwan; The diluent is a mixture of ethanol and active diluent (model number SU-750) with a mass ratio of 1:20, and the ethanol and active diluent are purchased from Guangzhou Chemical Reagent Factory and Guangzhou Shanghe New Material Technology Co., Ltd., respectively; The di-functional modified polyurethane and di-functional modified epoxy acrylate are purchased from Guangdong Boxing New Material Technology Co., Ltd., with product model numbers TR-Z035 and B-153, respectively; The four functional modified polyurethane acrylate and di-functional modified polyurethane acrylate are purchased from Guangdong Lankelu New Material Co., Ltd., with product model numbers L-6390 and L-6298, respectively; The initiator is a mixture of 3-methyl-4-phenylbenzophenone (model 1212) and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (model TPO) in a mass ratio of 15:1, purchased from Guangzhou Yuer New Material Technology Co., Ltd. The wax powder was purchased from Nanjing Tianshi New Material Technology Co., Ltd., and is polyethylene wax micro powder (model PEW-0211). The dispersant was purchased from Foshan Qianyou Chemical Co., Ltd., and is a special polyurethane polymer (model AKN-2009). The leveling agent is a compound of two polyether siloxane copolymers, with a mass ratio of DIG450 and DIG Lencolo3003 of 6:0.5. DIG450 was purchased from Dongguan Haoyouduo New Materials Co., Ltd., and DIG Lencolo3003 was purchased from Guangdong Lankelu New Materials Co., Ltd. The active amine photosensitizer is active amine photosensitizer B-21C and active amine photosensitizer B-27 in a mass ratio of 4:1, purchased from Guangdong Boxin New Material Technology Co., Ltd.

[0025] In the following examples, the viscosity of the varnish was tested using a #2 Zein cup, and the viscosity was assessed by the outflow time of the varnish in the cup; the longer the outflow time, the higher the viscosity. Surface drying involved coating cigarette paper with varnish on an offset printing machine and then UV curing (UV lamp power 21kW*75%, 3 lamps, printing and curing speed 8000 sheets / hour). The varnish layers were observed to be sticky when the paper was folded in half. The explosion resistance test involved folding the cigarette paper 180° and then applying pressure to the folded end with an ink bursting device to deepen the crease. The ink layer was then observed under a microscope to see if it cracked. Abrasion resistance was tested according to GB / T 7705-2008 6.8. The coefficient of friction was tested according to GB / T 22895-2008. Lamination involved cutting cigarette paper into 6*8cm pieces, wrapping a layer of BOPP film on its surface, hot pressing it at 120℃ for 1 minute, and then observing whether water vapor appeared on the surface after cooling.

[0026] Example 1 This embodiment provides a method for preparing a blast-resistant UV varnish, comprising the following steps: 1) Grind 0.1 parts of wax powder, 0.1 parts of tripropylene glycol diacrylate and 0.005 parts of dispersant in a three-roll mill (slow roller speed 30 rpm, medium roller speed 80 rpm, fast roller speed 250 rpm) for 30 min to obtain a wax paste with a solid content of 50%. Add 1.8 parts of tripropylene glycol diacrylate and disperse in a homogenizer at 3000 rpm for 60 min to obtain a wax powder dispersion with a solid content of 5%. 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane, 4 parts of difunctional modified epoxy acrylate, 14 parts of tetrafunctional modified polyurethane acrylate and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 30 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; 3) Add 10 parts of photoinitiator to the UV varnish resin matrix prepared in step 2) under stirring, and stir at 500 rpm for 120 min; then add the wax powder dispersion prepared in step 1) under stirring at 400 rpm, and stir for 30 min; finally add 0.1 parts of leveling agent and 4 parts of active amine photosensitizer, stir at 150 rpm for 10 min, and let stand for 24 h to obtain explosion-proof UV varnish.

[0027] Example 2 This embodiment provides a method for preparing a blast-resistant UV varnish, comprising the following steps: 1) Grind 0.1 parts of wax powder, 0.1 parts of tripropylene glycol diacrylate and 0.005 parts of dispersant in a three-roll mill (slow roller speed 30 rpm, medium roller speed 80 rpm, fast roller speed 250 rpm) for 30 min to obtain a wax paste with a solid content of 50%. Add 1.8 parts of tripropylene glycol diacrylate and disperse in a homogenizer at 3000 rpm for 60 min to obtain a wax powder dispersion with a solid content of 5%. 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 15 parts of diluent, stir at 250 rpm for 60 min, then add 16 parts of difunctional modified polyurethane, 3 parts of difunctional modified epoxy acrylate, 12 parts of tetrafunctional modified polyurethane acrylate and 3 parts of difunctional modified polyurethane acrylate in sequence, and stir at 600 rpm for 60 min, 30 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; 3) Add 8 parts of photoinitiator to the UV varnish resin matrix prepared in step 2) while stirring at 500 rpm and stir for 120 min; then add the wax powder dispersion prepared in step 1) while stirring at 400 rpm and stir for 30 min; finally add 0.1 parts of leveling agent and 3 parts of active amine photosensitizer, stir at 150 rpm for 10 min, and let stand for 24 h to obtain explosion-proof UV varnish.

[0028] Example 3 This embodiment provides a method for preparing a blast-resistant UV varnish, comprising the following steps: 1) Grind 0.1 parts of wax powder, 0.1 parts of tripropylene glycol diacrylate and 0.005 parts of dispersant in a three-roll mill (slow roller speed 30 rpm, medium roller speed 80 rpm, fast roller speed 250 rpm) for 30 min to obtain a wax paste with a solid content of 50%. Add 1.8 parts of tripropylene glycol diacrylate and disperse in a homogenizer at 3000 rpm for 60 min to obtain a wax powder dispersion with a solid content of 5%. 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 25 parts of diluent, stir at 200 rpm for 60 min, then add 20 parts of difunctional modified polyurethane, 5 parts of difunctional modified epoxy acrylate, 16 parts of tetrafunctional modified polyurethane acrylate and 5 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 30 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; 3) In the UV varnish resin matrix prepared in step 2), add 12 parts of photoinitiator under stirring at 600 rpm and stir for 120 min; then add the wax powder dispersion prepared in step 1) under stirring at 400 rpm and stir for 30 min; finally add 0.5 parts of leveling agent and 5 parts of active amine photosensitizer, stir at 200 rpm for 10 min, and let stand for 24 h to obtain explosion-proof UV varnish.

[0029] Example 4 This embodiment provides a method for preparing a blast-resistant UV varnish, comprising the following steps: 1) Grind 0.1 parts of wax powder, 0.1 parts of tripropylene glycol diacrylate and 0.005 parts of dispersant in a three-roll mill (slow roller speed 30 rpm, medium roller speed 80 rpm, fast roller speed 250 rpm) for 30 min to obtain a wax paste with a solid content of 50%. Add 1.8 parts of tripropylene glycol diacrylate and disperse in a homogenizer at 3000 rpm for 60 min to obtain a wax powder dispersion with a solid content of 5%. 2) Mix 28.1 parts of tripropylene glycol diacrylate, 1 part of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane, 6 parts of difunctional modified epoxy acrylate, 16 parts of tetrafunctional modified polyurethane acrylate and 6 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 30 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; 3) Add 12 parts of photoinitiator to the UV varnish resin matrix prepared in step 2) under stirring, and stir at 600 rpm for 120 min; then add the wax powder dispersion prepared in step 1) under stirring at 400 rpm, and stir for 30 min; finally add 0.3 parts of leveling agent and 5 parts of active amine photosensitizer, stir at 200 rpm for 10 min, and let stand for 24 h to obtain explosion-proof UV varnish.

[0030] Comparative Example 1 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that only 18 parts of difunctional modified polyurethane and 4 parts of difunctional modified epoxy acrylate are added in step 2). Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane and 4 parts of difunctional modified epoxy acrylate in sequence, and stir at 400 rpm for 60 min and 30 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0031] Comparative Example 2 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that in step 2), only 18 parts of difunctional modified polyurethane and 4 parts of difunctional modified polyurethane acrylate are added. Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min and 15 min respectively to obtain the UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0032] Comparative Example 3 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that only 4 parts of difunctional modified epoxy acrylate and 4 parts of difunctional modified polyurethane acrylate are added in step 2). Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 4 parts of difunctional modified epoxy acrylate and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min and 15 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0033] Comparative Example 4 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that only 18 parts of difunctional modified polyurethane and 14 parts of tetrafunctional modified polyurethane acrylate are added in step 2). Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane and 14 parts of tetrafunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min and 60 min respectively to obtain the UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0034] Comparative Example 5 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that in step 2), only 18 parts of difunctional modified polyurethane, 4 parts of difunctional modified epoxy acrylate, and 14 parts of tetrafunctional modified polyurethane acrylate are added. Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane, 4 parts of difunctional modified epoxy acrylate and 14 parts of tetrafunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 30 min and 60 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0035] Comparative Example 6 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that in step 2), only 18 parts of difunctional modified polyurethane, 14 parts of tetrafunctional modified polyurethane acrylate, and 4 parts of difunctional modified polyurethane acrylate are added. Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane, 14 parts of tetrafunctional modified polyurethane acrylate and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0036] Comparative Example 7 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that in step 2), only 18 parts of difunctional modified polyurethane, 4 parts of difunctional modified epoxy acrylic acid, and 4 parts of difunctional modified polyurethane acrylate are added. Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 18 parts of difunctional modified polyurethane, 4 parts of difunctional modified epoxy acrylic acid and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 60 min, 30 min and 15 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0037] Comparative Example 8 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that in step 2), only 4 parts of difunctional modified epoxy acrylate, 14 parts of tetrafunctional modified polyurethane acrylate, and 4 parts of difunctional modified polyurethane acrylate are added. Specifically: 2) Mix 23.1 parts of tripropylene glycol diacrylate, 0.7 parts of trimethylolpropane triacrylate and 20 parts of diluent, stir at 200 rpm for 60 min, then add 4 parts of difunctional modified epoxy acrylate, 14 parts of tetrafunctional modified polyurethane acrylate and 4 parts of difunctional modified polyurethane acrylate in sequence, and stir at 400 rpm for 30 min, 60 min and 15 min respectively to obtain UV varnish resin matrix; the process steps and parameters are the same as in Example 1.

[0038] Comparative Example 9 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as in Example 1, except that no diluent is added; the process steps and parameters are the same as in Example 1.

[0039] Comparative Example 10 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as in Example 1, except that no active amine photosensitizer is added; the process steps and parameters are the same as in Example 1.

[0040] Comparative Example 11 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1, except that it contains 23.8 parts of tripropylene glycol diacrylate and does not contain trimethylolpropane triacrylate; the process steps and parameters are the same as those in Example 1.

[0041] Comparative Example 12 The preparation method of the explosion-resistant UV varnish provided in this comparative example has the same component ratio as that in Example 1. The difference is that the wax powder is not prepared into a wax powder dispersion in advance but is added directly, and it contains 25 parts of tripropylene glycol diacrylate. The process steps and parameters are the same as those in Example 1.

[0042] The performance of the explosion-resistant UV varnishes prepared in Examples 1-4 and Comparative Examples 1-12 was tested, and the results are shown in Table 1: Table 1 Performance indicators of explosion-resistant UV varnishes for each embodiment and comparative example Note: The varnish with a flow time exceeding 100s as tested by the #2 Zein cup was deemed too viscous for offset printing and therefore Comparative Example 5 was not coated with offset varnish. The varnish layers stuck together after the cigarette paper was folded in half, indicating that they could not be completely dried. Therefore, Comparative Examples 6 and 7 were not subjected to other performance tests. Static and dynamic friction coefficients <0.3 were considered acceptable. The appearance of water mist after lamination was considered unacceptable.

[0043] As can be seen from Table 1, the explosion-resistant UV varnish prepared by this invention has a moderate viscosity, which can be matched with offset printing process. After UV curing, it can be quickly dried. The varnish layer formed has both excellent toughness and hardness. When used on cigarette paper, it can prevent the ink layer below from cracking after the cigarette paper is folded 180°. At the same time, it can make the surface have good wear resistance and low coefficient of friction, and will not cause water mist phenomenon that affects the appearance during heat lamination.

[0044] Comparing Comparative Examples 1-8 with Example 1, it can be seen that the difunctional modified polyurethane used in this application has excellent flexibility but slightly poor wear resistance. The difunctional modified epoxy acrylate and difunctional modified polyurethane acrylate have good flexibility but poor wear resistance, while the tetrafunctional modified polyurethane acrylate has a good balance between hardness and flexibility. Therefore, the difunctional modified polyurethane and tetrafunctional modified polyurethane acrylate are used as the main components, supplemented with two flexible difunctional resins. At the same time, by adding two UV monomers, a synergistic effect is produced after compounding. The cured coating has both excellent toughness and hardness. Comparing Comparative Example 9 with Example 1, it can be seen that adding a specific diluent can effectively reduce the viscosity of the varnish in the application, while adding only a low-viscosity UV monomer cannot effectively reduce the viscosity of the varnish. A comparison of Comparative Example 10 and Example 1 shows that the addition of an active amine photosensitizer in this application can significantly improve the curing rate of UV varnish; As can be seen from the comparison between Comparative Example 11 and Example 1, the curing rate of UV varnish can be significantly improved by using trifunctional UV monomers in this application; A comparison of Comparative Example 12 and Example 1 shows that in this application, the wax powder is dispersed into a wax powder dispersion in two steps before being added to the varnish, which facilitates rapid and uniform dispersion. After curing, it is evenly distributed in the coating, effectively reducing the static and dynamic friction coefficients of the coating and preventing water mist during heat lamination. The explosion-resistant UV varnish provided in this application meets the requirements for tobacco packaging varnishes in all its basic properties, effectively improving the appearance defect of color explosion when folded at 180°, and has the advantages of low cost and good practicality.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A type of explosion-resistant UV varnish, characterized in that, The product comprises the following components by weight: 20-30 parts of tripropylene glycol diacrylate; 0.5-1 parts of trimethylolpropane triacrylate; 15-25 parts of difluid; 15-20 parts of difunctional modified polyurethane; 3-6 parts of difunctional modified epoxy acrylate; 12-16 parts of tetrafunctional modified polyurethane acrylate; 3-6 parts of difunctional modified polyurethane acrylate; 8-12 parts of photoinitiator; 0.05-0.15 parts of wax powder; 0.005 parts of dispersant; 0.1-0.5 parts of leveling agent; and 3-5 parts of active amine photosensitizer.

2. The explosion-resistant UV varnish according to claim 1, characterized in that, The product comprises the following components by weight: 25 parts tripropylene glycol diacrylate; 0.7 parts trimethylolpropane triacrylate; 20 parts diluent; 18 parts difunctional modified polyurethane; 4 parts difunctional modified epoxy acrylate; 14 parts tetrafunctional modified polyurethane acrylate; 4 parts difunctional modified polyurethane acrylate; 10 parts photoinitiator; 0.1 parts wax powder; 0.005 parts dispersant; 0.1 parts leveling agent; and 4 parts active amine photosensitizer.

3. The explosion-resistant UV varnish according to claim 1, characterized in that, The product comprises the following components by weight: 25 parts tripropylene glycol diacrylate; 0.7 parts trimethylolpropane triacrylate; 15 parts diluent; 16 parts difunctional modified polyurethane; 3 parts difunctional modified epoxy acrylate; 12 parts tetrafunctional modified polyurethane acrylate; 3 parts difunctional modified polyurethane acrylate; 8 parts photoinitiator; 0.1 parts wax powder; 0.005 parts dispersant; 0.1 parts leveling agent; and 3 parts active amine photosensitizer.

4. The explosion-resistant UV varnish according to claim 1, characterized in that, The product comprises the following components by weight: 25 parts tripropylene glycol diacrylate; 0.7 parts trimethylolpropane triacrylate; 25 parts diluent; 20 parts difunctional modified polyurethane; 5 parts difunctional modified epoxy acrylate; 16 parts tetrafunctional modified polyurethane acrylate; 5 parts difunctional modified polyurethane acrylate; 12 parts photoinitiator; 0.1 parts wax powder; 0.005 parts dispersant; 0.5 parts leveling agent; and 5 parts active amine photosensitizer.

5. The explosion-resistant UV varnish according to claim 1, characterized in that, The product comprises the following components by weight: 30 parts of tripropylene glycol diacrylate; 1 part of trimethylolpropane triacrylate; 20 parts of diluent; 18 parts of difunctional modified polyurethane; 6 parts of difunctional modified epoxy acrylate; 16 parts of tetrafunctional modified polyurethane acrylate; 6 parts of difunctional modified polyurethane acrylate; 12 parts of photoinitiator; 0.1 parts of wax powder; 0.005 parts of dispersant; 0.3 parts of leveling agent; and 5 parts of active amine photosensitizer.

6. The explosion-resistant UV varnish according to claim 1, characterized in that, The diluent is a mixture of ethanol and an active diluent.

7. The explosion-resistant UV varnish according to claim 6, characterized in that, The photoinitiator is a mixture of 3-methyl-4-phenylbenzophenone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

8. The explosion-resistant UV varnish according to claim 7, characterized in that, The active amine photosensitizer is a mixture of B-21C and B-27; the leveling agent is a mixture of DIGIC 450 and DIGIC Lencolo 3003.

9. A method for preparing a blast-resistant UV varnish according to any one of claims 1-8, characterized in that, Includes the following steps: 1) Mix the wax powder, tripropylene glycol diacrylate and dispersant according to the formula, grind to obtain wax paste, and then add it to tripropylene glycol diacrylate and disperse evenly to obtain wax powder dispersion. 2) Mix tripropylene glycol diacrylate, trimethylolpropane triacrylate and diluent, stir and disperse, then add difunctional modified polyurethane, difunctional modified epoxy acrylate, tetrafunctional modified polyurethane acrylate and difunctional modified polyurethane acrylate in sequence, stir evenly to obtain UV varnish resin matrix. 3) Add a photoinitiator to the UV varnish resin matrix prepared in step 2), stir evenly, then add the wax powder dispersion prepared in step 1), add a leveling agent and an active amine photosensitizer while stirring, disperse evenly, and let stand for 24 hours to obtain the explosion-proof UV varnish.

10. The application of a blast-resistant UV varnish according to any one of claims 1-8 in a hard-pack cigarette box.

Images