Waterborne polyurethane binder resin as well as preparation method and application thereof

Abstract

The invention discloses waterborne polyurethane binder resin as well as a preparation method and application thereof. The method comprises the following steps: preparing an epoxy pre-emulsion by taking polyether amine, unsaturated carboxylic acid and epoxy resin as main raw materials; the preparation method comprises the following steps: preparing a hydrophilic chain extender by taking small molecular diamine and unsaturated carboxylic acid as main raw materials; the waterborne polyurethane binder resin is prepared by taking oligomer dihydric alcohol as a soft segment, diisocyanate and a hydrophilic chain extender as hard segments and an epoxy pre-emulsion as a dispersion medium. More epoxy resin structures and ureido groups are introduced into a polyurethane structure, the prepared waterborne polyurethane binder resin is high in solid content and good in storage stability, and waterborne printing ink prepared from the waterborne polyurethane binder resin has good resolubility and blocking resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of aqueous polyurethane synthesis, and particularly relates to an aqueous polyurethane binder resin, a preparation method thereof, and an application thereof in printing inks. Background Art

[0002] Aqueous printing inks use water as the main dispersion medium, and have the advantages of low carbon, environmental protection, safety, etc. compared with solvent-based inks. They conform to the "green" development trend of the ink printing industry and are increasingly used in the printing of substrates such as paper, cardboard, plastic films, etc. They are the most promising printing inks.

[0003] Aqueous printing inks mainly consist of binder resin, pigments, water (solvent) and additives. Among them, the performance of the binder resin determines the performance of the aqueous printing ink. Due to its special structure of intercalated soft and hard segments, aqueous polyurethane has excellent flexibility, wear resistance, adhesion and chemical resistance, etc., and is the main binder resin for preparing aqueous printing inks. However, the aqueous polyurethane binder resin prepared by conventional methods has deficiencies such as low solid content, short storage time, poor heat resistance, etc., and the aqueous printing ink formulated from it also has deficiencies in re-solubility and anti-blocking properties, which limits its popularization and application. Summary of the Invention

[0004] The purpose of the present invention is to provide an aqueous polyurethane binder resin, a preparation method and an application thereof, so as to improve the problems of low solid content, short storage time, poor heat resistance of the aqueous polyurethane binder resin, and poor re-solubility and anti-blocking properties of the aqueous polyurethane printing ink.

[0005] To solve the above technical problems, according to one aspect of the present invention, a preparation method of an aqueous polyurethane binder resin is provided, including: Step 1: Mix 100 parts of dehydrated oligomeric diol, 20 - 31.2 parts of diisocyanate, and 0.01 - 0.03 parts of catalyst by mass, and heat up to 65 - 75 °C and react for 1 - 3 hours; Step 2: Cool down to room temperature and add 40 - 55 parts of acetone for dilution; Step 3: Add a hydrophilic chain extender and react for 0.5 - 1 hour; Step 4: Add an epoxy pre-emulsion, stir and emulsify, and then react for 1 - 2 hours; Step 5: Vacuum remove acetone to obtain an aqueous polyurethane binder resin with a solid content of 40 - 45%.

[0006] As a preferred embodiment, in Step 1, the oligomeric diol is one or two of polyneopentyl glycol adipate diol, poly(1,2-propylene adipate) diol, and poly(propylene oxide) diol.

[0007] The diisocyanate is one or two of isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and toluene diisocyanate.

[0008] As a preferred embodiment, in step one, the catalyst is one of dibutyltin dilaurate, stannous octoate, and bismuth neodecanoate.

[0009] As a preferred embodiment, the preparation method of the hydrophilic chain extender in step three is as follows: by mass, mix 2.16 - 7.88 parts of small molecule diamine, 9 - 12 parts of ethanol, and 2.6 - 3.23 parts of unsaturated carboxylic acid, react at room temperature for 0.5 - 1 hour, then heat up to 65 - 75 °C and continue to react for 2 - 3 hours; cool down to 40 - 50 °C, add 3.19 - 5.31 parts of neutralizer and react for 20 - 30 minutes; cool down to room temperature to obtain the hydrophilic chain extender.

[0010] As a preferred embodiment, in the preparation method of the hydrophilic chain extender, the small molecule diamine is one of isophorone diamine, ethylenediamine, and 4,4'-dicyclohexylmethane diamine; the unsaturated carboxylic acid is one of acrylic acid and methacrylic acid; the neutralizer is one of triethylamine, triethanolamine, and N,N-dimethylethanolamine.

[0011] As a preferred embodiment, the preparation method of the epoxy pre-emulsion in step four is as follows: by mass, mix 12.1 - 27.86 parts of polyetheramine and 3.79 - 5.58 parts of unsaturated carboxylic acid, react at room temperature for 0.5 - 1 hour, then heat up to 65 - 75 °C and react for 2 - 3 hours; add 10.31 - 15.19 parts of epoxy resin and react for 2 - 3 hours; cool down to 40 - 50 °C, then add 5.26 - 8.5 parts of neutralizer and 6 - 14 parts of acetone and react for 20 - 30 minutes; add 206.4 - 254.74 parts of deionized water and stir to emulsify; cool down to room temperature and add 0.4 - 0.81 parts of aminopropyltriethoxysilane and 0.24 - 0.8 parts of molecular weight regulator to obtain the epoxy pre-emulsion.

[0012] As a preferred embodiment, in the preparation method of the epoxy pre-emulsion, the polyetheramine is one or two of Huntsman's polyoxypropylene diamine D230 and D400; the unsaturated carboxylic acid is one or two of acrylic acid and methacrylic acid; the epoxy resin is one or two of bisphenol A epoxy resin E51 and E44; the neutralizer is one of triethylamine, triethanolamine, and N,N-dimethylethanolamine.

[0013] As a preferred embodiment, in the preparation method of the epoxy pre-emulsion, the molecular weight regulator is one of ethanolamine, diethanolamine, and di-n-butylamine.

[0014] According to another aspect of the present invention, provided is an aqueous polyurethane binder resin obtained by the preparation method described above.

[0015] According to still another aspect of the present invention, provided is the use of the above-mentioned aqueous polyurethane binder resin in the preparation of aqueous printing inks. The aqueous polyurethane binder resin provided by the present invention is formulated with rutile titanium dioxide and a deionized water / ethanol mixed dispersion in proportion to prepare an aqueous printing ink.

[0016] The present invention uses polyetheramine, unsaturated carboxylic acid, and epoxy resin as main raw materials to prepare an epoxy pre-emulsion; uses small molecule diamine and unsaturated carboxylic acid as main raw materials to prepare a hydrophilic chain extender; uses oligomer diol as the soft segment, diisocyanate and hydrophilic chain extender as the hard segment, and epoxy pre-emulsion as the dispersion medium to prepare an aqueous polyurethane binder resin.

[0017] Compared with the conventional preparation method, the preparation method of the aqueous polyurethane binder resin provided by the present invention can introduce more epoxy resin structures and urea groups into the polyurethane structure, thereby effectively improving the heat resistance of the polyurethane and the anti-blocking property of the aqueous printing ink formulated therewith. The special distribution of hydrophilic groups in the aqueous polyurethane binder resin prepared by the method of the present invention makes its water dispersibility better, solid content higher, storage stability better, and the aqueous printing ink formulated therewith has better re-solubility. Specific Embodiments

[0018] The following further illustrates the technical solutions claimed in the present invention through some examples. However, the examples and comparative examples are used to explain the implementation solutions of the present invention and do not exceed the scope of the subject matter of the present invention. The protection scope of the present invention is not limited by the described examples. Unless otherwise specified, the materials and reagents used in the present invention can be obtained from commercial products in the art. Example 1

[0019] Add 14.95 g of polyetheramine D230 to the reactor, slowly add 4.68 g of acrylic acid under stirring, react at room temperature for 0.5 hour, raise the temperature to 65 °C and react for 3 hours, slowly add 12.03 g of epoxy resin E51 and react for 3 hours, cool down to 40 °C, add 6.24 g of triethylamine and 7.5 g of acetone and react for 30 minutes, add 209.79 g of deionized water and stir rapidly for emulsification, after cooling to room temperature, add 0.48 g of aminopropyltriethoxysilane and 0.47 g of ethanolamine to obtain epoxy pre-emulsion 1.

[0020] Add 6.37 g of isophorone diamine and 9 g of ethanol to the reactor, slowly add 2.7 g of acrylic acid under stirring, react at room temperature for 0.5 hour, raise the temperature to 65 °C and continue to react for 3 hours, then cool down to 40 °C, add 3.6 g of triethylamine and react for 30 minutes, and cool down to room temperature to obtain hydrophilic chain extender 1.

[0021] Add 100 g of dehydrated poly(1,2-propanediol adipate) diol to the reactor. While stirring, add 27.5 g of isophorone diisocyanate and 0.03 g of dibutyltin dilaurate. Raise the temperature to 75 °C and react for 2.5 hours. Cool down to room temperature and then add 50 g of acetone for dilution. Slowly add hydrophilic chain extender 1 and react for 1 hour. Then add epoxy pre-emulsion 1, quickly stir and emulsify, and react for 2 hours. Finally, remove acetone under vacuum to obtain aqueous polyurethane binder resin 1 with a solid content of 45%. Example 2

[0022] Add 27.86 g of polyetheramine D400 to the reactor. While stirring, slowly add 4.67 g of acrylic acid and react at room temperature for 1 hour. Raise the temperature to 70 °C and react for 3 hours. Slowly add 12.7 g of epoxy resin E51 and react for 2.5 hours. Cool down to 50 °C, add 6.22 g of triethylamine and 14 g of acetone, and react for 20 minutes. Add 238.68 g of deionized water, quickly stir and emulsify. After cooling to room temperature, add 0.48 g of aminopropyltriethoxysilane and 0.8 g of diethanolamine to obtain epoxy pre-emulsion 2.

[0023] Add 6.36 g of isophorone diamine and 9 g of ethanol to the reactor. While stirring, slowly add 2.69 g of acrylic acid and react at room temperature for 0.5 hour. Raise the temperature to 70 °C and continue to react for 2.5 hours. Then cool down to 50 °C, add 5.31 g of triethanolamine and react for 20 minutes. Cool down to room temperature to obtain hydrophilic chain extender 2.

[0024] Add 100 g of dehydrated neopentyl glycol adipate diol to the reactor. While stirring, add 27.5 g of isophorone diisocyanate and 0.03 g of stannous octoate. Raise the temperature to 70 °C and react for 3 hours. Cool down to room temperature and then add 50 g of acetone for dilution. Slowly add hydrophilic chain extender 2 and react for 1 hour. Then add epoxy pre-emulsion 2, quickly stir and emulsify, and react for 2 hours. Finally, remove acetone under vacuum to obtain aqueous polyurethane binder resin 2 with a solid content of 44%. Example 3

[0025] Add 15.39 g of polyetheramine D230 to the reactor. While stirring, slowly add 4.82 g of acrylic acid and react at room temperature for 0.5 hour. Raise the temperature to 70 °C and react for 2.5 hours. Slowly add 15.19 g of epoxy resin E44 and react for 2.5 hours. Cool down to 45 °C, add 6.22 g of triethylamine and 8 g of acetone, and react for 25 minutes. Add 243.4 g of deionized water, quickly stir and emulsify. After cooling to room temperature, add 0.8 g of aminopropyltriethoxysilane and 0.24 g of ethanolamine to obtain epoxy pre-emulsion 3.

[0026] Add 7.88 g of 4,4-dicyclohexylmethanediamine and 11 g of ethanol to a reactor. While stirring, slowly add 2.7 g of acrylic acid and react at room temperature for 0.5 hour. Then raise the temperature to 70 °C and continue reacting for 2.5 hours. After that, cool down to 45 °C, add 3.49 g of triethylamine and react for 25 minutes. Then cool down to room temperature to obtain the hydrophilic chain extender 3.

[0027] Add 100 g of dehydrated polyoxypropylene glycol to a reactor. While stirring, add 27.5 g of isophorone diisocyanate and 0.025 g of dibutyltin dilaurate. Raise the temperature to 70 °C and react for 2.5 hours. Then cool down to room temperature and add 40 g of acetone for dilution. Slowly add the hydrophilic chain extender 3 and react for 1 hour. Then add the epoxy pre-emulsion 3 and rapidly stir for emulsification and react for 2 hours. Finally, remove acetone under vacuum to obtain the aqueous polyurethane binder resin 3 with a solid content of 42%. Example 4

[0028] Add 27 g of polyetheramine D400 to a reactor. While stirring, slowly add 4.52 g of acrylic acid and react at room temperature for 1 hour. Raise the temperature to 75 °C and react for 2.5 hours. Slowly add 13.38 g of epoxy resin E44 and react for 2 hours. Then cool down to 50 °C, add 6.03 g of triethylamine and 13.5 g of acetone and react for 20 minutes. Add 232.41 g of deionized water and rapidly stir for emulsification. After cooling down to room temperature, add 0.48 g of aminopropyltriethoxysilane and 0.6 g of ethanolamine to obtain the epoxy pre-emulsion 4.

[0029] Add 2.25 g of ethylenediamine and 9 g of ethanol to a reactor. While stirring, slowly add 2.7 g of acrylic acid and react at room temperature for 0.5 hour. Raise the temperature to 75 °C and continue reacting for 2 hours. Then cool down to 50 °C, add 3.6 g of triethylamine and react for 20 minutes. Then cool down to room temperature to obtain the hydrophilic chain extender 4.

[0030] Add 50 g of neopentyl glycol adipate diol and 50 g of 1,2-propanediol adipate diol that have been dehydrated to a reactor. While stirring, add 21.55 g of toluene diisocyanate and 0.015 g of bismuth neodecanoate. Raise the temperature to 65 °C and react for 1.5 hours. Then cool down to room temperature and add 55 g of acetone for dilution. Slowly add the hydrophilic chain extender 4 and react for 0.5 hour. Then add the epoxy pre-emulsion 4 and rapidly stir for emulsification and react for 1 hour. Finally, remove acetone under vacuum to obtain the aqueous polyurethane binder resin 4 with a solid content of 43%. Example 5

[0031] Add 26.88 g of polyetheramine D400 to the reactor. Slowly add 5.38 g of methacrylic acid under stirring. React at room temperature for 1 hour, then raise the temperature to 75 °C and react for 3 hours. Slowly add 11.88 g of epoxy resin E51 and react for 2 hours. Cool down to 50 °C, add 6 g of triethylamine and 13.5 g of acetone, and react for 20 minutes. Add 235.97 g of deionized water and stir rapidly for emulsification. After cooling to room temperature, add 0.48 g of aminopropyltriethoxysilane and 0.6 g of ethanolamine to obtain epoxy pre-emulsion 5.

[0032] Add 6.38 g of isophorone diamine and 9 g of ethanol to the reactor. Slowly add 2.7 g of acrylic acid under stirring. React at room temperature for 0.5 hour, then raise the temperature to 70 °C and continue to react for 2.5 hours. After that, cool down to 45 °C, add 3.19 g of N,N-dimethylethanolamine and react for 25 minutes. Cool down to room temperature to obtain hydrophilic chain extender 5.

[0033] Add 100 g of dehydrated neopentyl glycol adipate diol to the reactor. Add 14 g of toluene diisocyanate, 7.3 g of hexamethylene diisocyanate and 0.015 g of bismuth neodecanoate under stirring. Raise the temperature to 65 °C and react for 2 hours. Cool down to room temperature and then add 55 g of acetone for dilution. Slowly add hydrophilic chain extender 5 and react for 0.5 hour. Then add epoxy pre-emulsion 5 and stir rapidly for emulsification, and then react for 1 hour. Finally, remove acetone under vacuum to obtain waterborne polyurethane binder resin 5 with a solid content of 43%. Example 6

[0034] Add 14.93 g of polyetheramine D230 to the reactor. Slowly add 5.58 g of methacrylic acid under stirring. React at room temperature for 1 hour, then raise the temperature to 70 °C and react for 3 hours. Slowly add 14.28 g of epoxy resin E44 and react for 2.5 hours. Cool down to 45 °C, add 5.32 g of N,N-dimethylethanolamine and 7.5 g of acetone, and react for 25 minutes. Add 254.74 g of deionized water and stir rapidly for emulsification. After cooling to room temperature, add 0.81 g of aminopropyltriethoxysilane and 0.8 g of di-n-butylamine to obtain epoxy pre-emulsion 6.

[0035] Add 6.38 g of isophorone diamine and 9 g of ethanol to the reactor. Slowly add 2.7 g of acrylic acid under stirring. React at room temperature for 0.5 hour, then raise the temperature to 65 °C and continue to react for 3 hours. After that, cool down to 45 °C, add 3.49 g of triethylamine and react for 25 minutes. Cool down to room temperature to obtain hydrophilic chain extender 6.

[0036] 100 g of dehydrated polypropylene glycol was added to a reactor. While stirring, 21.55 g of toluene diisocyanate and 0.01 g of dibutyltin dilaurate were added. The temperature was raised to 65 °C and reacted for 1 hour. After cooling to room temperature, 45 g of acetone was added for dilution. Hydrophilic chain extender 6 was slowly added and reacted for 0.5 hour. Then epoxy pre-emulsion 6 was added and rapidly stirred for emulsification and reacted for 1 hour. Finally, acetone was removed under vacuum to obtain an aqueous polyurethane binder resin 6 with a solid content of 40%. Example 7

[0037] 12.1 g of polyetheramine D230 was added to a reactor. While stirring, 3.79 g of acrylic acid was slowly added and reacted at room temperature for 0.5 hour. The temperature was raised to 75 °C and reacted for 2 hours. 10.31 g of epoxy resin E51 was slowly added and reacted for 2 hours. After cooling to 50 °C, 5.26 g of triethylamine and 6 g of acetone were added and reacted for 20 minutes. 206.4 g of deionized water was added and rapidly stirred for emulsification. After cooling to room temperature, 0.4 g of aminopropyltriethoxysilane and 0.44 g of ethanolamine were added to obtain epoxy pre-emulsion 7.

[0038] 5.95 g of isophorone diamine and 12 g of ethanol were added to a reactor. While stirring, 3.01 g of methacrylic acid was slowly added and reacted at room temperature for 1 hour. The temperature was raised to 75 °C and continued to react for 2 hours. After cooling to 50 °C, 3.5 g of triethylamine was added and reacted for 20 minutes. After cooling to room temperature, hydrophilic chain extender 7 was obtained.

[0039] 100 g of dehydrated poly(1,2-propylene adipate)diol was added to a reactor. While stirring, 20 g of toluene diisocyanate and 0.02 g of bismuth neodecanoate were added. The temperature was raised to 65 °C and reacted for 1.5 hours. After cooling to room temperature, 55 g of acetone was added for dilution. Hydrophilic chain extender 7 was slowly added and reacted for 0.5 hour. Then epoxy pre-emulsion 7 was added and rapidly stirred for emulsification and reacted for 1 hour. Finally, acetone was removed under vacuum to obtain an aqueous polyurethane binder resin 7 with a solid content of 43%. Example 8

[0040] 6.74 g of polyetheramine D230 and 12.6 g of polyetheramine D400 were added to a reactor. While stirring, 4.22 g of acrylic acid was slowly added and reacted at room temperature for 1 hour. The temperature was raised to 70 °C and reacted for 3 hours. 11.49 g of epoxy resin E51 was slowly added and reacted for 3 hours. After cooling to 50 °C, 8.5 g of triethanolamine and 10 g of acetone were added and reacted for 20 minutes. 232.76 g of deionized water was added and rapidly stirred for emulsification. After cooling to room temperature, 0.44 g of aminopropyltriethoxysilane and 0.42 g of ethanolamine were added to obtain epoxy pre-emulsion 8.

[0041] Add 2.16 g of ethylenediamine and 11 g of ethanol to the reactor. Slowly add 2.6 g of acrylic acid under stirring. React at room temperature for 0.5 hour, then raise the temperature to 65 °C and continue to react for 3 hours. Cool down to 40 °C, add 3.53 g of triethylamine and react for 30 minutes. Then cool down to room temperature to obtain the hydrophilic chain extender 8.

[0042] Add 100 g of dehydrated poly(1,2-propylene adipate) diol to the reactor. Add 31.2 g of 4,4'-dicyclohexylmethane diisocyanate and 0.03 g of bismuth neodecanoate under stirring. Raise the temperature to 75 °C and react for 3 hours. Cool down to room temperature and then add 50 g of acetone for dilution. Slowly add the hydrophilic chain extender 8 and react for 1 hour. Then add the epoxy pre-emulsion 8 and rapidly stir for emulsification and react for 2 hours. Finally, remove acetone under vacuum to obtain the aqueous polyurethane binder resin 8 with a solid content of 43%. Example 9

[0043] Add 15.2 g of polyetheramine D230 to the reactor. Slowly add 2.38 g of acrylic acid and 2.84 g of methacrylic acid under stirring. React at room temperature for 1 hour, then raise the temperature to 70 °C and react for 3 hours. Slowly add 15.01 g of epoxy resin E44 and react for 3 hours. Cool down to 45 °C, add 6.25 g of triethylamine and 8 g of acetone and react for 25 minutes. Add 233.31 g of deionized water and rapidly stir for emulsification. After cooling down to room temperature, add 0.65 g of aminopropyltriethoxysilane and 0.36 g of ethanolamine to obtain the epoxy pre-emulsion 9.

[0044] Add 6.37 g of isophorone diamine and 9 g of ethanol to the reactor. Slowly add 2.7 g of acrylic acid under stirring. React at room temperature for 0.5 hour, then raise the temperature to 70 °C and continue to react for 2.5 hours. Cool down to 45 °C, add 3.54 g of triethylamine and react for 25 minutes. Then cool down to room temperature to obtain the hydrophilic chain extender 9.

[0045] Add 50 g of dehydrated poly(1,2-propylene adipate) diol and 50 g of poly(propylene oxide) diol to the reactor. Add 27.5 g of isophorone diisocyanate and 0.03 g of dibutyltin dilaurate under stirring. Raise the temperature to 70 °C and react for 2.5 hours. Cool down to room temperature and then add 45 g of acetone for dilution. Slowly add the hydrophilic chain extender 9 and react for 1 hour. Then add the epoxy pre-emulsion 9 and rapidly stir for emulsification and react for 2 hours. Finally, remove acetone under vacuum to obtain the aqueous polyurethane binder resin 9 with a solid content of 43%. Example 10

[0046] Add 15.2 g of polyetheramine D230 to the reactor, slowly add 4.76 g of acrylic acid under stirring, react at room temperature for 0.5 h, raise the temperature to 70 °C and react for 2.5 h, slowly add 6.48 g of epoxy resin E51 and 7.5 g of epoxy resin E44 and react for 2.5 h, cool down to 45 °C, add 6.25 g of triethylamine and 8 g of acetone and react for 25 min, add 231.04 g of deionized water and stir rapidly for emulsification, after cooling to room temperature, add 0.65 g of aminopropyltriethoxysilane and 0.36 g of ethanolamine to obtain epoxy pre-emulsion 10.

[0047] Add 6.38 g of isophorone diamine and 10 g of ethanol to the reactor, slowly add 3.23 g of methacrylic acid under stirring, react at room temperature for 1 h, raise the temperature to 70 °C and continue to react for 2.5 h, then cool down to 45 °C, add 3.54 g of triethylamine and react for 25 min, and cool down to room temperature to obtain hydrophilic chain extender 10.

[0048] Add 50 g of neopentyl glycol adipate diol and 50 g of polypropylene glycol which have been dehydrated to the reactor, add 27.5 g of isophorone diisocyanate and 0.03 g of stannous octoate under stirring, raise the temperature to 75 °C and react for 2 h, cool down to room temperature and then add 45 g of acetone for dilution, slowly add hydrophilic chain extender 10 and react for 1 h, then add epoxy pre-emulsion 10 and stir rapidly for emulsification and react for 2 h, finally remove acetone under vacuum to obtain waterborne polyurethane binder resin 10 with a solid content of 43%.

[0049] Comparative Example 1 Add 100 g of 1,2-propanediol adipate diol which has been dehydrated to the reactor, add 27.5 g of isophorone diisocyanate and 0.03 g of dibutyltin dilaurate under stirring, raise the temperature to 75 °C and react for 2.5 h, then add 5.03 g of dimethylolpropionic acid and 5 g of N,N-dimethylformamide and continue to react for 2.5 h, cool down to 45 °C, add 3.6 g of triethylamine and 50 g of acetone and react for 25 min, after cooling down to room temperature, add 221.15 g of deionized water for emulsification and dispersion under high-speed stirring, then add 5.51 g of isophorone diamine, 0.48 g of aminopropyltriethoxysilane, 0.47 g of ethanolamine and 6.5 g of deionized water composition, react for 2 h, and remove acetone under vacuum to obtain waterborne polyurethane binder resin with a solid content of 38%.

[0050] Comparative Example 2 Add 100 g of dehydrated poly(1,2-propanediol adipate) diol to a reactor. While stirring, add 27.5 g of isophorone diisocyanate and 0.03 g of dibutyltin dilaurate. Heat up to 75 °C and react for 2.5 hours. Then add 4.01 g of epoxy resin E51, 5.03 g of dimethylolpropionic acid, and 5 g of N,N-dimethylformamide and continue to react for 3 hours. Cool down to 45 °C, add 3.6 g of triethylamine and 55 g of acetone and react for 25 min. After cooling down to room temperature, add 247.37 g of deionized water under high-speed stirring for emulsification and dispersion. Then add 3.68 g of isophorone diamine, 0.48 g of aminopropyltriethoxysilane, 0.47 g of ethanolamine, and 5 g of deionized water composition and react for 2 hours. Remove acetone under vacuum to obtain an aqueous polyurethane binder resin with a solid content of 36%.

[0051] Performance Test (1) Storage Stability Test of Aqueous Polyurethane Binder Resin Place the aqueous polyurethane binder resin in a sealed container and let it stand at room temperature. Observe and record the storage time when obvious stratification, flocculation, and precipitation occur in the resin.

[0052] (2) Redissolution and Anti-blocking Property Tests of Aqueous Printing Ink Prepare an aqueous printing ink by mixing the aqueous polyurethane binder resin, rutile titanium dioxide, and deionized water / ethanol mixed dispersion liquid in a mass ratio of 1∶1∶1. Use a wire rod to coat the prepared aqueous printing ink on a surface-treated polyester (PET) plastic film. After the ink layer dries, obtain the test sample.

[0053] Redissolution Test: Drop a water / ethanol mixed dispersion liquid on the sample ink layer. After standing for 5 seconds, stand the sample up. If more of the ink layer is dissolved and flows down, it indicates stronger redissolution; if less of the ink layer is dissolved and flows down, it indicates weaker redissolution.

[0054] Anti-blocking Property Test: Test the sample according to the national standard GB / T 13217.8-2009.

[0055] Table 1 Properties of Aqueous Polyurethane Binder Resin and the Prepared Aqueous Printing Ink Specimen Storage stability of aqueous polyurethane (days) Redissolvability of aqueous printing ink Anti-blocking property of aqueous printing ink Example 1 276 Stronger Non-blocking Example 2 274 Stronger Non-blocking Example 3 253 Stronger Non-blocking Example 4 245 Stronger Non-blocking Example 5 248 Stronger Non-blocking Example 6 237 Stronger Non-blocking Example 7 239 Stronger Non-blocking Example 8 250 Stronger Non-blocking Example 9 268 Stronger Non-blocking Example 10 262 Stronger Non-blocking Comparative Example 1 193 Weaker Blocking Comparative Example 2 167 Weaker Blocking Comparative Document 1 and Comparative Document 2 are the conventional preparation methods of aqueous polyurethane binder resin. As can be seen from Table 1, compared with the conventional preparation methods, the aqueous polyurethane binder resin prepared by the present invention has a high solid content and good storage stability, and the aqueous printing ink prepared from it has good redissolution and anti-blocking properties.

[0056] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention can have various deformations and modifications. Any modification, improvement, and equivalent substitution made within the concept and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A preparation method of an aqueous polyurethane binder resin, characterized in that, Comprising: Step 1: Mix 100 parts of dehydrated oligomeric diol, 20 - 31.2 parts of diisocyanate, and 0.01 - 0.03 parts of catalyst by mass fraction, and heat up to 65 - 75 °C for reaction for 1 - 3 hours; Step 2: Cool down to room temperature and add 40 - 55 parts of acetone for dilution; Step 3: Add a hydrophilic chain extender and react for 0.5 - 1 hour; Step 4: Add an epoxy pre-emulsion, stir and emulsify, and then react for 1 - 2 hours; Step 5: Remove acetone under vacuum to obtain an aqueous polyurethane binder resin with a solid content of 40 - 45%.

2. The preparation method of the aqueous polyurethane binder resin according to claim 1, characterized in that, In Step 1, the oligomeric diol is one or two of polyneopentyl glycol adipate diol, poly(1,2 - propylene adipate) diol, and poly(propylene oxide) diol; the diisocyanate is one or two of isophorone diisocyanate, hexamethylene diisocyanate, 4,4 - dicyclohexylmethane diisocyanate, and toluene diisocyanate.

3. The preparation method of the aqueous polyurethane binder resin according to claim 1 or 2, characterized in that, In Step 1, the catalyst is one of dibutyltin dilaurate, stannous octoate, and bismuth neodecanoate.

4. The preparation method of the aqueous polyurethane binder resin according to claim 3, characterized in that, The preparation method of the hydrophilic chain extender in Step 3 is as follows: Mix 2.16 - 7.88 parts of small molecule diamine, 9 - 12 parts of ethanol, and 2.6 - 3.23 parts of unsaturated carboxylic acid by mass fraction, react at room temperature for 0.5 - 1 hour, heat up to 65 - 75 °C and continue to react for 2 - 3 hours; cool down to 40 - 50 °C, add 3.19 - 5.31 parts of neutralizer and react for 20 - 30 minutes; cool down to room temperature to obtain the hydrophilic chain extender.

5. The preparation method of the aqueous polyurethane binder resin according to claim 4, characterized in that, In the preparation method of the hydrophilic chain extender, the small molecule diamine is one of isophorone diamine, ethylenediamine, and 4,4 - dicyclohexylmethane diamine; the unsaturated carboxylic acid is one of acrylic acid and methacrylic acid; the neutralizer is one of triethylamine, triethanolamine, and N,N - dimethylethanolamine.

6. The preparation method of the aqueous polyurethane binder resin according to claim 1 or 5, characterized in that, The preparation method of the epoxy pre-emulsion in Step 4 is as follows: Mix 12.1 - 27.86 parts of polyetheramine and 3.79 - 5.58 parts of unsaturated carboxylic acid by mass fraction, react at room temperature for 0.5 - 1 hour, heat up to 65 - 75 °C and react for 2 - 3 hours; add 10.31 - 15.19 parts of epoxy resin and react for 2 - 3 hours; cool down to 40 - 50 °C, then add 5.26 - 8.5 parts of neutralizer and 6 - 14 parts of acetone and react for 20 - 30 minutes; add 206.4 - 254.74 parts of deionized water and stir for emulsification; cool down to room temperature and add 0.4 - 0.81 parts of aminopropyltriethoxysilane and 0.24 - 0.8 parts of molecular weight regulator to obtain the epoxy pre-emulsion.

7. The preparation method of the aqueous polyurethane binder resin according to claim 6, characterized in that, In the preparation method of the epoxy pre-emulsion, the polyetheramine is one or two of Huntsman's poly(propylene oxide) diamine D230 and D400; the unsaturated carboxylic acid is one or two of acrylic acid and methacrylic acid; the epoxy resin is one or two of bisphenol A epoxy resin E51 and E44; the neutralizer is one of triethylamine, triethanolamine, and N,N - dimethylethanolamine.

8. The preparation method of the aqueous polyurethane binder resin according to claim 7, characterized in that, In the preparation method of the epoxy pre-emulsion, the molecular weight regulator is one of ethanolamine, diethanolamine, and di-n-butylamine.

9. An aqueous polyurethane binder resin, characterized in that, Obtained by the preparation method according to any one of claims 1-8.

10. Use of the aqueous polyurethane binder resin according to claim 9 in the preparation of aqueous printing inks.