Offset printing ink containing waterborne polyurethane-acrylic resin and preparation method of offset printing ink

Abstract

The invention discloses offset printing ink containing waterborne polyurethane-acrylic resin and a preparation method of the offset printing ink. The ink is prepared from the following components in parts by weight: 30-60 parts of pigment, 15-25 parts of waterborne polyurethane-acrylic resin, 2-5 parts of a dispersing agent, 1-3 parts of a flatting agent, 1-3 parts of an emulsifying agent, 1-2 parts of a drying agent and 60-180 parts of a solvent. The prepared offset printing ink contains the waterborne polyurethane-acrylic resin, the water resistance, the wear resistance and the flexibility of the ink are improved, the performance of the ink is further improved by adding the dispersing agent, the flatting agent and the emulsifying agent, the adhesive force of the ink is improved through combined use of Solsperse 20000 and diacetylene glycol, and the adhesive force of the ink is improved through combined use of BYK-333 and EFKA 3650. Due to the combined use of lecithin and Boltorn H20, the emulsifying property of the ink is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of printing inks, and particularly relates to an offset printing ink containing aqueous polyurethane-acrylic resin and a preparation method thereof. Background Art

[0002] Offset printing ink is a type of ink specifically used in offset printing presses, playing a key role in the offset printing process. It primarily consists of pigments, binders, and additives. Pigments are the main component of the ink, giving it its color. Offset printing inks can use a variety of pigments, including organic and inorganic pigments. For example, phthalocyanine blue, an organic pigment, produces a vibrant blue with high color saturation and good light and heat resistance. Inorganic pigments, such as red iron oxide, are red pigments with strong hiding power, good chemical stability, and a relatively low price. The binder is the ink's carrier, ensuring uniform dispersion of the pigment particles and determining the ink's rheological properties (such as viscosity and flowability). The binder for offset printing inks is typically composed of various resins and solvents. Resins can be natural, such as rosin resin, or synthetic, such as polyamide and acrylic resins. Different types of resins have different properties. For example, polyamide resins offer excellent flexibility and water resistance, while acrylic resins offer excellent light and chemical resistance. Solvents regulate the viscosity and drying speed of inks. Common solvents include mineral oil, alcohols, and esters. Appropriate binders ensure smooth transfer of ink from the printing plate to the paper during the printing process. Additives play a supporting role in offset printing inks, improving their properties. Common additives include desiccants, which accelerate the drying process. Water repellents improve the ink's water resistance and prevent emulsification due to contact with water during the printing process. Furthermore, anti-smear agents reduce friction between printed sheets and prevent smearing, which is crucial for improving the quality of printed products.

[0003] Waterborne Polyurethane-Acrylic Hybrid Resin (WPUA) is an environmentally friendly polymer material that combines the advantages of polyurethane (PU) and acrylic. Its polyurethane (PU) segments provide flexibility, abrasion resistance, chemical resistance, and adhesion, while the acrylic segments enhance hardness, weather resistance, UV resistance, and cost-effectiveness. Using water as the dispersion medium, WPUA is low in VOCs (volatile organic compounds), making it environmentally safe. The molecular chain of waterborne polyurethane (WPU) contains hydrophilic groups such as carboxyl and sulfonic acid groups. Although it improves water dispersibility, it also leads to high water absorption and poor water resistance after the ink is formed into a film. When WPUA ink comes into contact with organic solvents such as alcohols and esters, it may swell or dissolve, affecting the stability of the printed matter and the tinting strength is also deteriorated; the stability of WPUA emulsion is greatly affected by pH value, and long-term storage may cause thickening, flocculation or even demulsification; the viscosity of some WPUA inks changes greatly under high shear, affecting printing uniformity; some water-based acrylic resins have poor solubility and are easy to dry out the screen during printing, affecting continuous printing. Therefore, it is necessary to add some additives to the ink components to improve the above-mentioned deficiencies. Summary of the Invention

[0004] The object of the present invention is to provide an offset printing ink containing an aqueous polyurethane-acrylic resin and a preparation method thereof.

[0005] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin. The printing ink comprises the following components in parts by weight: 30-60 parts of a pigment, 15-25 parts of an aqueous polyurethane-acrylic resin, 2-5 parts of a dispersant, 1-3 parts of a leveling agent, 1-3 parts of an emulsifier, 1-2 parts of a drying agent, and 60-180 parts of a solvent.

[0006] The pigment is one or more of carbon black, titanium dioxide, black iron oxide, red iron oxide, yellow iron oxide, phthalocyanine blue, benzidine yellow, permanent red, pigment red 48, phthalocyanine green, and quinacridone.

[0007] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0008] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate are used as monomers, azobisisobutyronitrile is used as an initiator, and the reaction is carried out at 60-80° C. for 8-10 hours to prepare polyacrylate;

[0009] (2) preparing a polyurethane resin prepolymer by mixing polyether polyol and isophorone diisocyanate, wherein the molar ratio of the functional groups -NCO:-OH of the two is (1-3):1, and the molecular weight of the polyether polyol is 1000-2500;

[0010] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 60-80° C. for 4-6 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:(1-5).

[0011] In step (1), the molar ratio of methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate is (2-4): (3-8): (1-3): 1, and the amount of azobisisobutyronitrile is 0.5-2% of the total weight of the monomers.

[0012] The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of (1-5):1.

[0013] The leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of (1-3):1.

[0014] The emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of (2-6):1.

[0015] The desiccant is one or more of cobalt isooctanoate, zirconium isooctanoate, manganese naphthenate, calcium naphthenate, and iron naphthenate.

[0016] The solvent is one or more of n-heptane, n-hexane, white oil, linseed oil, soybean oil, and C9 petroleum resin solution.

[0017] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0018] (1) Add waterborne polyurethane-acrylic resin and solvent into a blender, stir at 30-100 rpm for 20-30 min, then heat to 70-90° C., add pigment, and continue stirring for 10-20 min;

[0019] (2) Cooling to 35-45°C, adding a dispersant, a leveling agent, an emulsifier, and a desiccant, and stirring at a speed of 200-400 rpm for 20-30 minutes to obtain a slurry;

[0020] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 35-45°C and the grinding pressure was controlled to be 8-12 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 4-8 μm to obtain printing ink.

[0021] The present invention has the beneficial effects that the offset printing ink prepared by the present invention contains a water-based polyurethane-acrylic resin, which improves the water resistance, abrasion resistance and flexibility of the ink. The performance of the ink is further improved by adding a dispersant, a leveling agent and an emulsifier. The combination of Solsperse 20000 and diacetylene glycol improves the adhesion of the ink, the combination of BYK-333 and EFKA 3650 improves the fluidity of the ink, and the combination of lecithin and Boltorn H20 improves the emulsification of the ink. DETAILED DESCRIPTION

[0022] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0023] Example 1

[0024] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin. The printing ink comprises the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of a dispersant, 2 parts of a leveling agent, 2 parts of an emulsifier, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane. The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 3:1; the leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of 2:1; and the emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of 4:1.

[0025] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0026] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0027] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0028] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0029] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0030] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0031] (2) cooling to 40°C, adding a dispersant, a leveling agent, an emulsifier, and manganese naphthenate, and stirring at 300 rpm for 25 minutes to obtain a slurry;

[0032] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0033] Example 2

[0034] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin. The printing ink comprises the following components in parts by weight: 35 parts of black iron oxide, 18 parts of an aqueous polyurethane-acrylic resin, 3 parts of a dispersant, 1 part of a leveling agent, 1 part of an emulsifier, 1 part of cobalt isooctanoate, and 80 parts of white oil. The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 1:1; the leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of 1:1; and the emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of 2:1.

[0035] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0036] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the mixture was reacted at 60° C. for 10 h to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 2:3:1:1, and the amount of azobisisobutyronitrile was 0.6% of the total weight of the monomers;

[0037] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 1:1, and the molecular weight of the polyether polyol is 1200;

[0038] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 60° C. for 6 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:2.

[0039] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0040] (1) Add waterborne polyurethane-acrylic resin and white oil into a blender and stir at 40 rpm for 30 min. Then, heat to 70°C, add black iron oxide, and continue stirring for 20 min.

[0041] (2) cooling to 35° C., adding a dispersant, a leveling agent, an emulsifier, and cobalt isooctanoate, and stirring at a speed of 200 rpm for 30 min to obtain a slurry;

[0042] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 35°C and the grinding pressure was controlled to be 8 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 8 μm to obtain printing ink.

[0043] Example 3

[0044] An offset printing ink containing an aqueous polyurethane-acrylic resin, the printing ink comprising the following components in parts by weight: 60 parts of phthalocyanine green, 25 parts of an aqueous polyurethane-acrylic resin, 5 parts of a dispersant, 3 parts of a leveling agent, 3 parts of an emulsifier, 2 parts of zirconium isooctanoate, and 180 parts of a C9 petroleum resin solution; the dispersant being a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 5:1; the leveling agent being a mixture of BYK-333 and EFKA 3650 in a mass ratio of 3:1; and the emulsifier being a mixture of lecithin and Boltorn H20 in a mass ratio of 6:1.

[0045] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0046] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the mixture was reacted at 80° C. for 8 h to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 4:8:3:1, and the amount of azobisisobutyronitrile was 2% of the total weight of the monomers;

[0047] (2) polyurethane resin prepolymer is prepared by mixing polyether polyol and isophorone diisocyanate, wherein the molar ratio of the functional groups -NCO:-OH of the two is 3:1, and the molecular weight of the polyether polyol is 2200;

[0048] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 80° C. for 4 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0049] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0050] (1) Add waterborne polyurethane-acrylic resin and C9 petroleum resin solution into a blender and stir at 80 rpm for 20 min. Then, heat to 90°C, add phthalocyanine green, and continue stirring for 10 min.

[0051] (2) cooling to 45° C., adding a dispersant, a leveling agent, an emulsifier, and zirconium isooctanoate, and stirring at 400 rpm for 20 min to obtain a slurry;

[0052] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 45°C and the grinding pressure was controlled to be 12 Pa / cm 2 The mixture was ground and dispersed by a three-roll mill until the slurry particle size was 4 μm to obtain printing ink.

[0053] Comparative Example 1

[0054] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin, the printing ink comprising the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of Solsperse 20000, 2 parts of a leveling agent, 2 parts of an emulsifier, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane; the leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of 2:1; and the emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of 4:1.

[0055] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0056] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0057] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0058] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0059] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0060] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0061] (2) Cooling to 40°C, adding Solsperse 20000, leveling agent, emulsifier, and manganese naphthenate, and stirring at 300 rpm for 25 minutes to obtain a slurry;

[0062] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0063] Comparative Example 2

[0064] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin, the printing ink comprising the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of diacetylene glycol, 2 parts of a leveling agent, 2 parts of an emulsifier, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane; the leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of 2:1; and the emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of 4:1.

[0065] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0066] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0067] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0068] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0069] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0070] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0071] (2) cooling to 40° C., adding diacetylene glycol, a leveling agent, an emulsifier, and manganese naphthenate, and stirring at 300 rpm for 25 min to obtain a slurry;

[0072] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0073] Comparative Example 3

[0074] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin. The printing ink comprises the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of a dispersant, 2 parts of BYK-333, 2 parts of an emulsifier, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane. The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 3:1. The emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of 4:1.

[0075] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0076] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0077] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0078] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0079] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0080] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0081] (2) Cooling to 40°C, adding dispersant, BYK-333, emulsifier, and manganese naphthenate, and stirring at 300 rpm for 25 minutes to obtain a slurry;

[0082] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0083] Comparative Example 4

[0084] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin, the printing ink comprising the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of a dispersant, 2 parts of EFKA 3650, 2 parts of an emulsifier, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane; the dispersant being a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 3:1; and the emulsifier being a mixture of lecithin and Boltorn H20 in a mass ratio of 4:1.

[0085] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0086] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0087] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0088] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0089] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0090] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0091] (2) cooling to 40°C, adding dispersant, EFKA 3650, emulsifier, and manganese naphthenate, and stirring at 300 rpm for 25 min to obtain a slurry;

[0092] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0093] Comparative Example 5

[0094] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin. The printing ink comprises the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of a dispersant, 2 parts of a leveling agent, 2 parts of lecithin, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane. The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 3:1. The leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of 2:1.

[0095] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0096] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0097] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0098] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0099] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0100] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0101] (2) cooling to 40°C, adding dispersant, leveling agent, lecithin, and manganese naphthenate, and stirring at 300 rpm for 25 min to obtain a slurry;

[0102] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0103] Comparative Example 6

[0104] Disclosed is an offset printing ink containing an aqueous polyurethane-acrylic resin, the printing ink comprising the following components in parts by weight: 45 parts of carbon black, 20 parts of an aqueous polyurethane-acrylic resin, 4 parts of a dispersant, 2 parts of a leveling agent, 2 parts of Boltorn H20, 1.5 parts of manganese naphthenate, and 120 parts of n-hexane; the dispersant being a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of 3:1; and the leveling agent being a mixture of BYK-333 and EFKA 3650 in a mass ratio of 2:1.

[0105] The preparation method of the aqueous polyurethane-acrylic resin is as follows:

[0106] (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate were used as monomers, and azobisisobutyronitrile was used as an initiator, and the reaction was carried out at 70° C. for 9 hours to prepare polyacrylate; the molar ratio of the methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate was 3:6:2:1, and the amount of the azobisisobutyronitrile was 1% of the total weight of the monomers;

[0107] (2) polyether polyol and isophorone diisocyanate are mixed to prepare a polyurethane resin prepolymer, wherein the molar ratio of the functional groups -NCO:-OH of the two is 2:1, and the molecular weight of the polyether polyol is 1500;

[0108] (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 70° C. for 5 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:4.

[0109] The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin is characterized by following the steps:

[0110] (1) Add waterborne polyurethane-acrylic resin and n-hexane into a blender and stir at 50 rpm for 25 min. Then, heat to 80°C, add carbon black, and continue stirring for 15 min.

[0111] (2) Cooling to 40°C, adding dispersant, leveling agent, Boltorn H20, and manganese naphthenate, and stirring at 300 rpm for 25 minutes to obtain a slurry;

[0112] (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 40°C and the grinding pressure was controlled to be 10 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 6 μm to obtain printing ink.

[0113] Experimental example:

[0114] The tinting strength of the offset printing inks prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to the national standard GB / T 14624.2-2008. The experimental results were statistically analyzed using statistical software. The measurement data were used to The data were expressed as mean ± standard deviation. The Kolmogorov-Smirnov test was used for data normality test. For data that met the normal distribution, the t-test was used to compare the mean differences between the two groups. The difference was considered statistically significant when P < 0.05. The results are shown in Table 1:

[0115] Table 1

[0116]

[0117] Note: * represents P < 0.05 compared with the group in Example 1.

[0118] The fluidity of the offset inks prepared in Examples 1-3 and Comparative Examples 3-4 was tested according to the national standard GB / T 13217.4-2020. The test results are shown in Table 2:

[0119] Table 2

[0120]

[0121] Note: * represents P < 0.05 compared with the group in Example 1.

[0122] The offset inks prepared in Examples 1-3 and Comparative Examples 3-4 were tested using an emulsification rate meter. 50 g of the offset ink sample was added to the test cup of the emulsification rate meter, and 50 g of the prepared fountain solution was added. After stirring at 200 r / min for 10 minutes, excess free water was removed and the percentage of water absorbed by the ink as a percentage of the ink mass was calculated. The test results are shown in Table 3:

[0123] Table 3

[0124]

[0125] Note: * represents P < 0.05 compared with the group in Example 1.

[0126] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An offset printing ink containing an aqueous polyurethane-acrylic resin, characterized in that The printing ink is composed of the following components in parts by weight: 30-60 parts of pigment, 15-25 parts of waterborne polyurethane-acrylic resin, 2-5 parts of dispersant, 1-3 parts of leveling agent, 1-3 parts of emulsifier, 1-2 parts of desiccant and 60-180 parts of solvent.

2. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The pigment is one or more of carbon black, titanium dioxide, black iron oxide, red iron oxide, yellow iron oxide, phthalocyanine blue, benzidine yellow, permanent red, pigment red 48, phthalocyanine green, and quinacridone.

3. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The preparation method of the aqueous polyurethane-acrylic resin is as follows: (1) Methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate are used as monomers, azobisisobutyronitrile is used as an initiator, and the reaction is carried out at 60-80° C. for 8-10 hours to prepare polyacrylate; (2) preparing a polyurethane resin prepolymer by mixing polyether polyol and isophorone diisocyanate, wherein the molar ratio of the functional groups -NCO:-OH of the two is (1-3):1, and the molecular weight of the polyether polyol is 1000-2500; (3) Adding polyacrylate to polyurethane resin prepolymer, and continuing the reaction at 60-80° C. for 4-6 hours to obtain waterborne polyurethane-acrylic resin; the mass ratio of the polyacrylate to the polyurethane resin prepolymer is 1:(1-5).

4. The aqueous polyurethane-acrylic resin offset printing ink according to claim 3, characterized in that: In step (1), the molar ratio of methyl methacrylate, acrylic acid, butyl acrylate and pentaerythritol tetraacrylate is (2-4): (3-8): (1-3): 1, and the amount of azobisisobutyronitrile is 0.5-2% of the total weight of the monomers.

5. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The dispersant is a mixture of Solsperse 20000 and diacetylene glycol in a mass ratio of (1-5):

1.

6. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The leveling agent is a mixture of BYK-333 and EFKA 3650 in a mass ratio of (1-3):

1.

7. The offset printing ink containing aqueous polyurethane-acrylic resin according to claim 1, characterized in that: The emulsifier is a mixture of lecithin and Boltorn H20 in a mass ratio of (2-6):

1.

8. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The desiccant is one or more of cobalt isooctanoate, zirconium isooctanoate, manganese naphthenate, calcium naphthenate, and iron naphthenate.

9. The aqueous polyurethane-acrylic resin offset printing ink according to claim 1, characterized in that: The solvent is one or more of n-heptane, n-hexane, white oil, linseed oil, soybean oil, and C9 petroleum resin solution.

10. The method for preparing the offset printing ink containing aqueous polyurethane-acrylic resin according to claim 1, characterized in that: Follow these steps: (1) Add waterborne polyurethane-acrylic resin and solvent into a blender, stir at 30-100 rpm for 20-30 min, then heat to 70-90° C., add pigment, and continue stirring for 10-20 min; (2) Cooling to 35-45°C, adding a dispersant, a leveling agent, an emulsifier, and a desiccant, and stirring at a speed of 200-400 rpm for 20-30 minutes to obtain a slurry; (3) The slurry obtained in step (2) was transferred to a three-roll mill, and the grinding temperature was controlled to be 35-45°C and the grinding pressure was controlled to be 8-12 Pa / cm 2 , and then dispersed by three-roll mill until the slurry particle size is 4-8 μm to obtain printing ink.

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