High-adhesion water-based composite ink and preparation method thereof

Abstract

The invention relates to the technical field of ink, and discloses high-adhesion water-based composite ink and a preparation method thereof.A prepared water-based polyurethane connecting material serves as a raw material of the water-based composite ink, the polyurethane connecting material is excellent in hydrophilicity and water solubility, the storage stability of the ink is improved, and the high-adhesion water-based composite ink is obtained. A polyurethane molecular chain contains a heat-resistant structure, so that the heat stability of the polyurethane molecular chain can be improved, and as the polyurethane molecular chain and the surface of a base material have strong coordination interaction, the adhesive property and adhesive force of a polyurethane paint film and the surface of the base material are improved, and the interface bonding strength of the ink and the surface of the base material is improved; meanwhile, a heat-resistant structure introduced by a polyurethane molecular chain is beneficial to improving the thermal decomposition temperature and heat resistance of an ink paint film, the printing effect and retentivity of the ink are ensured, the application scene of the ink is widened, and the ink is suitable for printing in the fields of food packaging bags and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of inks, in particular to a high-adhesion water-based composite ink and a preparation method thereof. Background Art

[0002] Water-based polyurethane inks are non-toxic, environmentally friendly, offer excellent printing quality, superior mechanical properties, and a wide range of applications. Primarily composed of a water-based polyurethane binder, pigments, and additives, they are primarily used in printing, packaging, and on wood, plastic, and metal substrates. Traditional water-based polyurethane inks suffer from poor adhesion and bonding to substrates like aluminum foil, as well as poor heat resistance. The water-based polyurethane binder plays a key role in the ink's performance, and the development of high-performance polyurethane materials is a hot research topic.

[0003] Waterborne polyurethane binders are typically prepared from polyols, isocyanate monomers, and hydrophilic chain extenders. Chinese patent CN115785387B discloses a polyurethane-polyurea aqueous dispersion, its preparation method, and applications. Using polyether polyols, polyester polyols, isocyanates, triazoles, and other chain extenders as raw materials, the resulting polyurethane aqueous dispersion exhibits excellent tensile strength, elongation, and resistance to polar solvents. However, this patent fails to improve the adhesion between the polyurethane and substrates such as aluminum foil, nor does it enhance the polyurethane's heat resistance, hindering its practical application in high-performance inks and other applications. Summary of the Invention

[0004] The invention solves the problem of poor heat resistance of polyurethane ink and simultaneously improves the adhesion between polyurethane ink and metal substrate.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a high-adhesion water-based composite ink and a preparation method thereof, comprising 100 parts by weight of a water-based triazole-based polyurethane binder, 20-30 parts by weight of a pigment, 1.2-2 parts by weight of a thickener, and 0.8-1.5 parts by weight of a defoaming agent.

[0006] The preparation method comprises the following steps: adding a water-based triazole-based polyurethane binder, a pigment, a thickener, and a defoamer into a container, shearing, dispersing, and grinding to obtain a water-based composite ink with high adhesion.

[0007] A further preparation method of a water-based triazole-based polyurethane linker comprises the following steps: adding dried and dehydrated polyether polyol, isocyanate monomer, and dibutyltin dilaurate to a reactor, reacting in a nitrogen atmosphere, then adding acetone, a small molecule chain extender, and a water-based triazole chain extender, continuing the reaction, adding triethylamine for neutralization, and adding water for stirring and dispersion to obtain a water-based triazole-based polyurethane linker.

[0008] Furthermore, the first reaction is stirred at 70-80°C for 3-4 h; and the second reaction is stirred at 40-50°C for 1-1.5 h.

[0009] Furthermore, the molar ratio of the polyether polyol, the isocyanate monomer, the small molecule chain extender, and the water-based triazole chain extender is 1:(2.6-2.8):(0.9-1.1):(0.2-0.5).

[0010] Furthermore, the polyether polyol is polyethylene glycol or polypropylene glycol.

[0011] Furthermore, the isocyanate monomer is isophorone diisocyanate or toluene-2,4-diisocyanate.

[0012] Furthermore, the small molecule chain extender is 1,4-butanediol.

[0013] Furthermore, the preparation method of the water-based triazole chain extender is as follows: add a solvent, 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, 5-carboxyl-3-amino-1,2,4-triazole, and a sodium hydroxide aqueous solution to a reaction flask equipped with a condenser, first stir and react at 45-55°C for 3-4 hours, then stir and react at 85-95°C for 6-7 hours, remove the solvent by rotary evaporation, add water to dilute, add hydrochloric acid solution dropwise to adjust the pH to 3-4, precipitate the precipitate, filter the product, and recrystallize and purify it in water to obtain a water-based triazole chain extender. The reaction formula is:

[0014]

[0015] Furthermore, the solvent is acetone or 1,4-dioxane.

[0016] Furthermore, the molar ratio of 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, 5-carboxy-3-amino-1,2,4-triazole, and sodium hydroxide is 1:(2-2.2):(4.8-6.2).

[0017] Beneficial technical effects: The present invention reacts 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine and 5-carboxyl-3-amino-1,2,4-triazole to obtain a water-based triazole chain extender, which is then reacted with a polyether polyol, an isocyanate monomer, a small molecule chain extender, etc. to obtain a water-based polyurethane linker. The water-based triazole chain extender contains multiple hydrophilic groups such as carboxyl groups and triazoles, which gives the polyurethane excellent hydrophilicity and water solubility, has good dispersibility in water, does not stratify, and has no sediment, which is beneficial to improving the storage stability of the ink.

[0018] The present invention compounds a water-based triazole-based polyurethane binder, a pigment, a thickener, and the like to obtain a water-based composite ink with high adhesion. The polyurethane molecular chain contains a triazole group and a heat-resistant triazine structure. The triazole group has a strong coordination interaction with the surface of a metal substrate such as an aluminum veneer, thereby improving the bonding performance and adhesion of the polyurethane paint film to the metal substrate surface. At the same time, the introduction of the heat-resistant triazine structure into the polyurethane molecular chain is beneficial to increasing the thermal decomposition temperature and heat resistance of the ink paint film. DETAILED DESCRIPTION

[0019] The following further describes the hydroxy acrylate resin and its preparation method according to the present invention in conjunction with specific implementation examples. It should be understood that the embodiments given in the present invention are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0020] Example 1:

[0021] (1) Add 300 mL of acetone solvent, 60 mmol of 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine (CAS registration number 13436-79-8), 120 mmol of 5-carboxyl-3-amino-1,2,4-triazole (CAS registration number 3641-13-2), and 40 mL of an aqueous solution containing 288 mmol of sodium hydroxide to a reaction flask equipped with a condenser. Stir the reaction at 45°C for 4 hours, then stir the reaction at 95°C for 6 hours. Rotary evaporation is performed to remove the solvent, 40 mL of water is added to dilute the mixture, and a 20% by mass hydrochloric acid solution is added dropwise to adjust the pH to 4. The precipitate is precipitated, filtered, and the product is recrystallized and purified in water to obtain a water-based triazole chain extender. The structural formula is:

[0022] (2) 100 mmol of dried and dehydrated polyethylene glycol, 260 mmol of isophorone diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, stirred and reacted at 70°C for 4 h in a nitrogen atmosphere, and then 110 mL of acetone, 110 mmol of 1,4-butanediol, and 20 mmol of a water-based triazole chain extender were added, stirred and reacted at 45°C for 1.5 h, 80 mmol of triethylamine was added for neutralization, and 350 mL of water was added for stirring and dispersion to obtain a water-based triazole-based polyurethane linker.

[0023] (3) 1 kg of water-based triazole-based polyurethane binder, 200 g of titanium dioxide pigment slurry BASF Dispers White 0022, 15 g of thickener hydroxyethyl cellulose, and 12 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink with high adhesion.

[0024] Example 2:

[0025] (1) To a reaction flask equipped with a condenser, 250 mL of 1,4-dioxane solvent, 60 mmol of 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, 132 mmol of 5-carboxy-3-amino-1,2,4-triazole, and 50 mL of an aqueous solution containing 372 mmol of sodium hydroxide were added, and the mixture was stirred at 55°C for 3 h, and then stirred at 85°C for 7 h. The solvent was removed by rotary evaporation, and 40 mL of water was added for dilution. A 20% by mass hydrochloric acid solution was added dropwise to adjust the pH to 3, and the precipitate was precipitated. The product was filtered and recrystallized in water to obtain a water-based triazole chain extender.

[0026] (2) 100 mmol of dried and dehydrated polypropylene glycol 2000, 280 mmol of isophorone diisocyanate, and 1.3 mmol of dibutyltin dilaurate were added to a reactor, stirred and reacted at 80°C for 3 h in a nitrogen atmosphere, then 110 mL of acetone, 100 mmol of 1,4-butanediol, and 40 mmol of a water-based triazole chain extender were added, stirred and reacted at 45°C for 1.5 h, 120 mmol of triethylamine was added for neutralization, and 400 mL of water was added for stirring and dispersion to obtain a water-based triazole-based polyurethane linker.

[0027] (3) 1 kg of water-based triazole-based polyurethane binder, 300 g of titanium dioxide pigment slurry BASF Dispers White 0022, 12 g of thickener hydroxyethyl cellulose, and 15 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink with high adhesion.

[0028] Example 3:

[0029] (1) 100 mmol of dried and dehydrated polyethylene glycol 2000, 270 mmol of toluene-2,4-diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, and stirred at 75°C for 4 h in a nitrogen atmosphere. Then, 110 mL of acetone, 90 mmol of 1,4-butanediol, and 35 mmol of an aqueous triazole chain extender (prepared in Example 1) were added, and stirred at 50°C for 1 h. 110 mmol of triethylamine was added for neutralization, and 400 mL of water was added for dispersion and stirring to obtain an aqueous triazole-based polyurethane linker.

[0030] (2) 1 kg of water-based triazole-based polyurethane binder, 260 g of titanium dioxide pigment slurry BASF Dispers White 0022, 14 g of thickener hydroxyethyl cellulose, and 15 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink with high adhesion.

[0031] Example 4:

[0032] (1) 100 mmol of dried and dehydrated polyethylene glycol 2000, 280 mmol of toluene-2,4-diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, and stirred at 80°C for 3 h in a nitrogen atmosphere. Then, 100 mL of acetone, 90 mmol of 1,4-butanediol, and 50 mmol of an aqueous triazole chain extender (prepared in Example 1) were added, and stirred at 40°C for 1.5 h. 140 mmol of triethylamine was added for neutralization, and 400 mL of water was added for dispersion and stirring to obtain an aqueous triazole-based polyurethane linker.

[0033] (2) 1 kg of water-based triazole-based polyurethane binder, 200 g of titanium dioxide pigment slurry BASF Dispers White 0022, 20 g of thickener hydroxyethyl cellulose, and 10 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink with high adhesion.

[0034] Example 5:

[0035] (1) 100 mmol of dried and dehydrated polypropylene glycol 2000, 260 mmol of toluene-2,4-diisocyanate, and 1.3 mmol of dibutyltin dilaurate were added to a reactor, and stirred at 75°C for 4 h in a nitrogen atmosphere. Then, 100 mL of acetone, 90 mmol of 1,4-butanediol, and 40 mmol of an aqueous triazole chain extender (prepared in Example 1) were added, and stirred at 40°C for 1.5 h. 120 mmol of triethylamine was added for neutralization, and 400 mL of water was added for dispersion and stirring to obtain an aqueous triazole-based polyurethane linker.

[0036] (2) 1 kg of water-based triazole-based polyurethane binder, 300 g of titanium dioxide pigment slurry BASF Dispers White 0022, 12 g of thickener hydroxyethyl cellulose, and 8 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink with high adhesion.

[0037] Comparative Example 1: The main difference between this comparative example and Example 1 is that 1,4-butanediol is used instead of the aqueous triazole chain extender.

[0038] (1) 100 mmol of dried and dehydrated polyethylene glycol, 260 mmol of isophorone diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, stirred and reacted at 70°C in a nitrogen atmosphere for 4 h, then 110 mL of acetone and 130 mmol of 1,4-butanediol were added, stirred and reacted at 45°C for 1.5 h, and 350 mL of water was added and stirred to obtain a polyurethane binder.

[0039] (2) 1 kg of water-based triazole-based polyurethane binder, 200 g of titanium dioxide pigment slurry BASF Dispers White 0022, 15 g of thickener hydroxyethyl cellulose, and 12 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a composite ink.

[0040] Comparative Example 2: The main difference between this comparative example and Example 1 is that 2,2-dihydroxypropionic acid is used instead of the aqueous triazole chain extender.

[0041] (1) 100 mmol of dried and dehydrated polyethylene glycol, 260 mmol of isophorone diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, stirred and reacted at 70°C for 4 h in a nitrogen atmosphere, then 110 mL of acetone, 110 mmol of 1,4-butanediol, and 20 mmol of 2,2-dihydroxypropionic acid were added, stirred and reacted at 45°C for 1.5 h, 40 mmol of triethylamine was added for neutralization, and 350 mL of water was added for stirring and dispersion to obtain a waterborne polyurethane binder.

[0042] (2) 1 kg of water-based polyurethane binder, 200 g of titanium dioxide pigment slurry BASF DispersWhite 0022, 15 g of thickener hydroxyethyl cellulose, and 12 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a water-based composite ink.

[0043] Comparative Example 3: The main difference between this comparative example and Example 1 is that a triazole chain extender is used instead of an aqueous triazole chain extender.

[0044] (1) Add 300 mL of acetone solvent, 60 mmol of 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, and 120 mmol of 3-amino-1,2,4-triazole (CAS registration number 61-82-5, structural formula ), 20mL of 144mmol of sodium hydroxide aqueous solution was stirred at 45℃ for 4h, then stirred at 95℃ for 6h, the solvent was removed by rotary evaporation, water and ethyl acetate were added, and the organic phase was rotary evaporated. The product was recrystallized and purified in ethanol to obtain a triazole chain extender. The structural formula is

[0045] (2) 100 mmol of dried and dehydrated polyethylene glycol, 260 mmol of isophorone diisocyanate, and 1.2 mmol of dibutyltin dilaurate were added to a reactor, stirred and reacted at 70°C for 4 h in a nitrogen atmosphere, then 110 mL of acetone, 110 mmol of 1,4-butanediol, and 20 mmol of a triazole chain extender were added, stirred and reacted at 45°C for 1.5 h, and 350 mL of water was added and stirred to obtain a triazole-based polyurethane linker.

[0046] (3) 1 kg of triazole-based polyurethane binder, 200 g of titanium dioxide pigment slurry BASF DispersWhite 0022, 15 g of thickener hydroxyethyl cellulose, and 12 g of defoamer TEGO FOAMEX 1488 were added to a container, sheared, dispersed, and ground to obtain a composite ink.

[0047] Place the polyurethane binder at room temperature for 4-12 months and observe its dispersion.

[0048] Table 1 Dispersion of binder

[0049]

[0050]

[0051] After testing, the polyurethane connecting materials of Examples 1-5 have good dispersibility and high storage stability. This is mainly because the water-based triazole chain extender contains multiple hydrophilic groups such as carboxyl groups and triazole, which gives the polyurethane excellent hydrophilicity and water solubility. It has good dispersibility in water, no stratification, and no sediment.

[0052] In Comparative Example 1, no hydrophilic chain extender was added, and the polyurethane linker had obvious sediment after storage, and had good dispersibility but poor storage stability.

[0053] In Comparative Example 2, conventional 2,2-dihydroxypropionic acid was used as the aqueous chain extender. The obtained polyurethane linker also had good hydrophilicity and water solubility. However, after the storage time reached 12 months, a small amount of sediment was found in the solution.

[0054] The triazole chain extender of Comparative Example 3 does not contain a hydrophilic carboxyl group, and has poor dispersibility and storage stability.

[0055] The ink was sprayed onto the aluminum veneer substrate and cured at 80°C for 8 hours. The film adhesion grade was tested according to the method in GB / T 9286-2021.

[0056] The paint film was placed in a thermogravimetric analyzer and the thermal properties were tested in a nitrogen atmosphere with a heating rate of 10°C / min and a temperature range of 25-700°C.

[0057] Table 2 Paint film performance test

[0058]

[0059]

[0060] After testing, compared with Comparative Example 1, the adhesion level of Examples 1-5 and the ink of Comparative Example 3 on the surface of the aluminum veneer substrate reached Level 0, and the thermal decomposition temperature was higher and the heat resistance was good. This is mainly because the water-based triazole chain extender and the triazole chain extender contain triazole groups and heat-resistant triazine structures, and are introduced into the polyurethane molecular chain. The triazole groups have a strong coordination interaction with the surface of metal substrates such as aluminum veneers, thereby improving the bonding performance and adhesion between the polyurethane paint film and the surface of the metal substrate. At the same time, the introduction of heat-resistant triazine structures into the polyurethane molecular chain is beneficial to improving the heat resistance of the paint film and having a higher thermal decomposition temperature.

[0061] Comparative Example 2 uses conventional 2,2-dihydroxymethylpropionic acid as a chain extender, which does not contain triazole groups and triazine groups. The coordination interaction between polyurethane and the surface of metal substrates such as aluminum veneers is low, resulting in poor bonding performance and adhesion. At the same time, the thermal decomposition temperature is low and the heat resistance is poor.

[0062] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A high-adhesion water-based composite ink, characterized in that: The water-based composite ink comprises 100 parts by weight of a water-based triazole-based polyurethane binder, 20-30 parts by weight of a pigment, 1.2-2 parts by weight of a thickener, and 0.8-1.5 parts by weight of a defoamer; The preparation method of the water-based triazole polyurethane connecting material is as follows: adding dried and dehydrated polyether polyol, isocyanate monomer, and dibutyltin dilaurate into a reaction kettle, reacting in a nitrogen atmosphere, and then adding acetone, a small molecule chain extender, and a structural formula of The water-based triazole chain extender is further reacted, triethylamine is added for neutralization, and water is added for stirring and dispersion to obtain a water-based triazole-based polyurethane linker.

2. The high-adhesion water-based composite ink according to claim 1, characterized in that: The first reaction was stirred at 70-80°C for 3-4 h; the second reaction was stirred at 40-50°C for 1-1.5 h.

3. The high-adhesion water-based composite ink according to claim 1, characterized in that: The molar ratio of the polyether polyol, the isocyanate monomer, the small molecule chain extender, and the water-based triazole chain extender is 1:(2.6-2.8):(0.9-1.1):(0.2-0.5).

4. The high-adhesion water-based composite ink according to claim 3, characterized in that: The polyether polyol is polyethylene glycol or polypropylene glycol; the isocyanate monomer is isophorone diisocyanate or toluene-2,4-diisocyanate; and the small molecule chain extender is 1,4-butanediol.

5. The high-adhesion water-based composite ink according to claim 3, characterized in that: The preparation method of the water-based triazole chain extender comprises the following steps: adding a solvent, 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, 5-carboxyl-3-amino-1,2,4-triazole, and a sodium hydroxide aqueous solution into a reaction flask; after the reaction, removing the solvent by rotary evaporation; adding water for dilution; dropping a hydrochloric acid solution to adjust the pH to 3-4; precipitating a precipitate; filtering the product, and then recrystallizing and purifying it in water to obtain the water-based triazole chain extender.

6. The high-adhesion water-based composite ink according to claim 5, characterized in that: The solvent is acetone or 1,4-dioxane.

7. The high-adhesion water-based composite ink according to claim 5, characterized in that: The molar ratio of the 6-(N,N-dihydroxyethyl)amino-2,4-dichloro-1,3,5-triazine, 5-carboxyl-3-amino-1,2,4-triazole and sodium hydroxide is 1:(2-2.2):(4.8-6.2).

8. The high-adhesion water-based composite ink according to claim 5, characterized in that: In the preparation method of the water-based triazole chain extender, the reaction is first stirred at 45-55° C. for 3-4 hours, and then stirred at 85-95° C. for 6-7 hours.

9. A method for preparing a high-adhesion water-based composite ink according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: adding a water-based triazole-based polyurethane connecting material, a pigment, a thickener, and a defoaming agent into a container, and performing shearing, dispersion, and grinding to obtain a water-based composite ink with high adhesion.

Images