Preparation method of a water-based epoxy resin binder and its application in ink

Abstract

The present invention relates to the technical field of ink, and discloses a preparation method of an aqueous epoxy resin binder and its application in ink. Water and nano-titanium dioxide are added to a container, and after ultrasonic treatment, modified silicone oil is added and stirred and dispersed. Then, aqueous epoxy resin, defoamer, leveling agent, and thickener are added and stirred and mixed evenly to obtain the aqueous epoxy resin binder. The catechol structure of the modified silicone oil in the present invention can have a coordination effect with the surface of nano-titanium dioxide, realizing the surface coating modification of nano-titanium dioxide, which is beneficial to reducing the agglomeration of nano-titanium dioxide and improving its dispersibility in the aqueous epoxy resin binder. The emulsion has no precipitation and no stratification, and has very good storage stability. The imino group contained in the modified silicone oil can undergo a curing reaction with the epoxy resin, playing a very good toughening role, and at the same time improving the heat resistance and flame retardancy of the epoxy resin.

Description

Technical Field

[0001] The present invention relates to the technical field of ink, and specifically to a preparation method of an aqueous epoxy resin binder and its application in ink. Background Art

[0002] Epoxy resin is widely used in ink binders, coatings, adhesives and other fields due to its good waterproof, anti-corrosion, insulation and other properties. Toughening and modification of epoxy resin is a research hotspot. Adding carboxyl-terminated nitrile rubber, amino silicone oil, amino-terminated polyurethane, etc. to epoxy resin can improve the toughness and strength of epoxy resin, making it have better practical applications in high-performance ink binders and other aspects.

[0003] Silicone oil is a high molecular polymer containing a polysiloxane structure, with good toughness, high heat resistance and excellent flame retardancy; Patent CN117143479B discloses a solder resist ink for automotive circuit boards and its preparation method. Using epoxy resin, glycidyl methacrylate, hydrogen-containing silicone oil, unsaturated dibasic carboxylic acid, hydrosilylation catalyst and other raw materials, the obtained ink has good thermal shock resistance. However, this patent does not solve the problems of poor toughness, heat resistance and flame retardancy of epoxy resin.

[0004] Nano-titanium dioxide is cheap, easy to obtain, green and pollution-free, with high mechanical strength and high heat resistance, and is widely used in materials such as ink, coating, plastic, etc. Improving the agglomeration problem of nano-titanium dioxide and enhancing its compatibility with polymer resin are research difficulties. Summary of the Invention

[0005] The technical problem solved by the present invention is: to provide an aqueous epoxy resin binder for ink with high mechanical properties and heat resistance.

[0006] The technical solution of the present invention is: a preparation method of an aqueous epoxy resin binder:

[0007] (1) Add toluene, hydrogen-containing silicone oil, allyl intermediate to a reaction vessel, add an isopropanol solution of chloroplatinic acid in a nitrogen atmosphere, heat to 80 - 90 °C, react for 3 - 5 h, rotary evaporate and dry to obtain modified silicone oil.

[0008] (2) Add water and nano-titanium dioxide to a container, after ultrasonic treatment, add modified silicone oil, heat to 40 - 60 °C, stir and disperse for 3 - 6 h, then add aqueous epoxy resin, defoamer, leveling agent, thickener, and stir and mix evenly to obtain an aqueous epoxy resin binder.

[0009] Preferably, in (1), the molar ratio of Si - H bond in hydrogen-containing silicone oil to allyl intermediate is 1:(0.8 - 1); the mass of chloroplatinic acid is 0.015 - 0.022% of the mass of allyl intermediate.

[0010] Preferably, in (2), the masses of nano-titanium dioxide and modified silicone oil are 0.5-4% and 5-20% of the mass of waterborne epoxy resin, respectively.

[0011] Preferably, the preparation method of the allyl intermediate is as follows:

[0012] A1. Add ethanol and water with a volume ratio of 1:(0.6-0.8) and 3,4-dihydroxybenzaldehyde and 3-amino-1,2,4-triazole with a molar ratio of 1:(1-1.1) to a reaction vessel, heat to 60-80°C, react for 1-2 h, remove tetrahydrofuran by rotary evaporation, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain the triazole intermediate.

[0013] A2. Add the triazole intermediate, 3-bromopropene, and the catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with a molar ratio of 1:(1-1.2):(1-1.4) to tetrahydrofuran, react at room temperature for 8-12 h, perform rotary evaporation, wash with petroleum ether, add the product to ethanol, add sodium borohydride, stir and react for 3-5 h, add water, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain the allyl intermediate. The reaction formula is:

[0014]

[0015] Preferably, the application of the waterborne epoxy resin binder in the ink.

[0016] Beneficial effects: The present invention utilizes the addition reaction of the vinyl group of the allyl intermediate with the Si-H bond of the hydrogen-containing silicone oil. The obtained modified silicone oil contains hydrophilic imino, catechol structure and triazole structure, significantly improving the hydrophilicity of the modified silicone oil, making the modified silicone oil compatible well in the waterborne epoxy resin binder and the emulsion not easy to delaminate. And the catechol structure of the modified silicone oil can coordinate with the surface of nano-titanium dioxide, realizing the surface coating modification of nano-titanium dioxide, which is beneficial to reducing the agglomeration of nano-titanium dioxide and improving its dispersibility in the waterborne epoxy resin binder. The emulsion has no precipitation and no delamination, and the storage stability is very good.

[0017] The imino group contained in the modified silicone oil of the present invention can react with the epoxy resin to bond the flexible polysiloxane of the silicone oil to the epoxy resin molecular chain, enhancing the bonding strength between the silicone oil and the epoxy resin, playing a good toughening role. At the same time, the uniformly dispersed nano-titanium dioxide plays a good reinforcing role, which is beneficial to improving the tensile strength and elongation at break of the epoxy resin.

[0018] The modified silicone oil of the present invention forms a stable curing cross-linked network in the epoxy resin, which is beneficial to improving the heat resistance of the epoxy resin, increasing the thermal decomposition temperature. Moreover, the polysiloxane structure and triazole structure in the modified silicone oil form a nitrogen-silicon flame retardant, which generates incombustible gases such as inorganic silicon substances and nitrogen during combustion. Combining with nano-titanium dioxide, it exhibits good flame retardant performance and increases the limiting oxygen index. Detailed Embodiments

[0019] To further understand the present invention, the preferred embodiments of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve. The raw materials, reactions, and post-treatment means described in the examples are all common raw materials on the market and technical means well-known to those skilled in the art, unless otherwise specified.

[0020] The defoamer of the present invention has the model number YL-218, produced by Nantong Yongle Chemical Industry. The leveling agent has the model number BYK-345, produced by GreenLink (Jining) Chemical Technology Co., Ltd. The waterborne epoxy resin has the model number MR1487W, produced by Guangdong Ked ding Functional Materials Co., Ltd. The hydrogen-containing silicone oil has a hydrogen content of 1.58%, produced by Zhejiang Woxingman New Material Technology Co., Ltd.

[0021] Example 1

[0022] (1) Add 100 mL of ethanol, 60 mL of water, 40 mmol of 3,4-dihydroxybenzaldehyde, and 44 mmol of 3-amino-1,2,4-triazole to a reaction vessel, heat to 80 °C, react for 1 h, rotary evaporate to remove tetrahydrofuran, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain the triazole intermediate.

[0023] (2) Add 30 mmol of the triazole intermediate, 36 mmol of 3-bromopropene, and 42 mmol of 1,8-diazabicyclo[5.4.0]undec-7-ene to 80 mL of tetrahydrofuran, react at room temperature for 8 h, rotary evaporate, wash with petroleum ether. Add the product to 100 mL of ethanol, add 36 mmol of sodium borohydride, stir and react for 5 h, add water, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain the allyl intermediate.

[0024] (3) Add 50 mL of toluene, 50 g of hydrogen-containing silicone oil, and the allyl intermediate to a reaction vessel, and control the molar ratio of the Si-H bond in the hydrogen-containing silicone oil to the allyl intermediate to be 1:1; in a nitrogen atmosphere, add 2 mL of an isopropanol solution of chloroplatinic acid, where the mass of chloroplatinic acid is 0.018% of the mass of the allyl intermediate; heat to 85 °C, react for 5 h, rotary evaporate, and dry to obtain the modified silicone oil.

[0025] (4) Add 240 mL of water and 1 g of nano-titanium dioxide (average particle size 40 nm) to a container. After ultrasonic treatment for 10 min, add 10 g of modified silicone oil, heat to 40 °C, stir and disperse for 4 h, then add 200 g of waterborne epoxy resin, 1.4 g of defoamer, 1.6 g of leveling agent, and 1.5 g of thickener sodium carboxymethylcellulose, stir and mix evenly to obtain a waterborne epoxy resin binder.

[0026] Example 2

[0027] (1) Add 100 mL of ethanol, 60 mL of water, 40 mmol of 3,4-dihydroxybenzaldehyde, and 40 mmol of 3-amino-1,2,4-triazole to a reaction vessel, heat to 60 °C, react for 2 h, rotary evaporate to remove tetrahydrofuran, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain a triazole intermediate.

[0028] (2) Add 30 mmol of triazole intermediate, 30 mmol of 3-bromopropene, and 30 mmol of 1,8-diazabicyclo[5.4.0]undec-7-ene to 60 mL of tetrahydrofuran, react at room temperature for 12 h, rotary evaporate, wash with petroleum ether, add the product to 120 mL of ethanol, add 39 mmol of sodium borohydride, stir and react for 3 h, add water, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain an allyl intermediate.

[0029] (3) Add 60 mL of toluene, 50 g of hydrogen-containing silicone oil, and the allyl intermediate to a reaction vessel, control the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to the allyl intermediate to be 1:1; in a nitrogen atmosphere, add 2 mL of an isopropanol solution of chloroplatinic acid, where the mass of chloroplatinic acid is 0.022% of the mass of the allyl intermediate; heat to 80 °C, react for 5 h, rotary evaporate, and dry to obtain a modified silicone oil.

[0030] (4) Add 260 mL of water and 4 g of nano-titanium dioxide (average particle size 40 nm) to a container. After ultrasonic treatment for 10 min, add 10 g of modified silicone oil, heat to 60 °C, stir and disperse for 3 h, then add 200 g of waterborne epoxy resin, 2 g of defoamer, 1.6 g of leveling agent, and 1 g of thickener sodium carboxymethylcellulose, stir and mix evenly to obtain a waterborne epoxy resin binder.

[0031] Example 3

[0032] (1). Add 50 mL of toluene, 50 g of hydrogen-containing silicone oil, and allyl intermediate (prepared in Example 1) to the reaction vessel, and control the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to the allyl intermediate to be 1:0.8; in a nitrogen atmosphere, add 2 mL of an isopropanol solution of chloroplatinic acid, where the mass of chloroplatinic acid is 0.015% of the mass of the allyl intermediate; heat to 90 °C and react for 3 h, then perform rotary evaporation and drying to obtain modified silicone oil.

[0033] (2). Add 260 mL of water and 8 g of nano-titanium dioxide (average particle size 40 nm) to the vessel, ultrasonicate for 10 min, then add 10 g of modified silicone oil, heat to 50 °C, stir and disperse for 6 h, then add 200 g of waterborne epoxy resin, 1.5 g of defoamer, 1.2 g of leveling agent, and 1.8 g of thickener sodium carboxymethylcellulose, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0034] Example 4

[0035] (1). Add 60 mL of toluene, 50 g of hydrogen-containing silicone oil, and allyl intermediate (prepared in Example 1) to the reaction vessel, and control the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to the allyl intermediate to be 1:1; in a nitrogen atmosphere, add 2 mL of an isopropanol solution of chloroplatinic acid, where the mass of chloroplatinic acid is 0.02% of the mass of the allyl intermediate; heat to 90 °C and react for 4 h, then perform rotary evaporation and drying to obtain modified silicone oil.

[0036] (2). Add 260 mL of water and 4 g of nano-titanium dioxide (average particle size 40 nm) to the vessel, ultrasonicate for 10 min, then add 25 g of modified silicone oil, heat to 50 °C, stir and disperse for 3 h, then add 200 g of waterborne epoxy resin, 2 g of defoamer, 1.6 g of leveling agent, and 1 g of thickener sodium carboxymethylcellulose, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0037] Example 5

[0038] (1). Add 50 mL of toluene, 50 g of hydrogen-containing silicone oil, and allyl intermediate (prepared in Example 1) to the reaction vessel, and control the molar ratio of Si-H bonds in the hydrogen-containing silicone oil to the allyl intermediate to be 1:0.8; in a nitrogen atmosphere, add 2 mL of an isopropanol solution of chloroplatinic acid, where the mass of chloroplatinic acid is 0.02% of the mass of the allyl intermediate; heat to 80 °C and react for 5 h, then perform rotary evaporation and drying to obtain modified silicone oil.

[0039] (2) Add 260 mL of water and 4 g of nano-titanium dioxide (average particle size 40 nm) into a container. After ultrasonic treatment for 10 min, add 40 g of modified silicone oil, heat to 50 °C, stir and disperse for 6 h, then add 200 g of waterborne epoxy resin, 2 g of defoamer, 1.6 g of leveling agent, and 1 g of thickener carboxymethyl cellulose sodium, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0040] Comparative Example 1

[0041] (1) Add 240 mL of water and 1 g of nano-titanium dioxide (average particle size 40 nm) into a container. After ultrasonic treatment for 10 min, add 200 g of waterborne epoxy resin, 1.4 g of defoamer, 1.6 g of leveling agent, and 1.5 g of thickener carboxymethyl cellulose sodium, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0042] Comparative Example 2

[0043] (1) Add 240 mL of water and 1 g of nano-titanium dioxide (average particle size 40 nm) into a container. After ultrasonic treatment for 10 min, add 10 g of hydrogen-containing silicone oil, heat to 40 °C, stir and disperse for 4 h, then add 200 g of waterborne epoxy resin, 1.4 g of defoamer, 1.6 g of leveling agent, and 1.5 g of thickener carboxymethyl cellulose sodium, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0044] Comparative Example 3

[0045] (1) Add 10 g of modified silicone oil (prepared in Example 1), 200 g of waterborne epoxy resin, 1.4 g of defoamer, 1.6 g of leveling agent, and 1.5 g of thickener carboxymethyl cellulose sodium into a container, and stir and mix evenly to obtain a waterborne epoxy resin binder.

[0046] Store the waterborne epoxy resin binder at 25 °C for 1 - 6 months, and observe the stability of the emulsion.

[0047] Table 1

[0048]

[0049] Add 11.3 g of diethylenetriamine curing agent into the waterborne epoxy resin binder, stir and mix evenly, coat it on the surface of tinplate, and bake at 120 °C for 1 h and 150 °C for 20 min respectively; test the adhesion according to the method of GB / T 13217.7 - 2023.

[0050] Add 11.8 g of diethylenetriamine curing agent into the waterborne epoxy resin binder, stir and mix evenly, pour it into a mold, cure at 100 °C for 2 h and 120 °C for 4 h to make a cast specimen. Test the tensile properties according to the method of GB / T 2567 - 2021.

[0051] Weigh 5 mg of the cast specimen and conduct thermogravimetric analysis in a thermogravimetric analyzer under a nitrogen atmosphere with a heating rate of 10 °C / min and a maximum test temperature of 800 °C.

[0052] Test the limiting oxygen index of the cast specimen according to the method of GB / T 2406.1-2008.

[0053] Table 2

[0054]

[0055] Table 3

[0056]

[0057] As can be seen from Tables 1-3, nano-titanium dioxide was added to the epoxy resin binder in Comparative Example 1. Due to the easy agglomeration of nano-titanium dioxide and its poor compatibility and dispersibility with epoxy resin, the storage stability of the epoxy resin binder emulsion was poor. When stored for a long time, titanium dioxide precipitation was likely to occur, and the adhesion grade, tensile strength, and elongation at break of the cured product were low, resulting in poor mechanical properties. At the same time, the initial thermal decomposition temperature, mass residue rate, and limiting oxygen index were low, and the heat resistance and flame retardancy were poor.

[0058] In Comparative Example 2, nano-titanium dioxide and hydrogen-containing silicone oil were added. Since hydrogen-containing silicone oil is hydrophobic and incompatible in the aqueous epoxy resin binder emulsion, the emulsion was prone to stratification and titanium dioxide precipitation after storage, resulting in poor storage stability. Moreover, hydrogen-containing silicone oil could not undergo a curing reaction with epoxy resin, and its compatibility with epoxy resin was poor. After curing, the adhesion grade, tensile strength, and elongation at break of the epoxy resin were low, resulting in poor mechanical properties. At the same time, the initial thermal decomposition temperature, mass residue rate, and limiting oxygen index were low, and the heat resistance and flame retardancy were poor.

[0059] In the aqueous epoxy resin binder of Examples 1-5, nano-titanium dioxide and modified silicone oil were added. The modified silicone oil contains hydrophilic imino, catechol structure and triazole structure, which significantly improves the hydrophilicity of the modified silicone oil, making the modified silicone oil compatible well in the aqueous epoxy resin binder and the emulsion not easy to stratify. Moreover, during the stirring and dispersion process, the catechol structure of the modified silicone oil can coordinate with the surface of nano-titanium dioxide, realizing the surface coating modification of nano-titanium dioxide, which is beneficial to reducing the agglomeration of nano-titanium dioxide and improving its dispersibility in the aqueous epoxy resin binder. The emulsion has no precipitation and no stratification, and the storage stability is very good. In addition, the imino contained in the modified silicone oil can react with the epoxy resin to bond the flexible polysiloxane of the silicone oil to the epoxy resin molecular chain, enhancing the bonding strength between the silicone oil and the epoxy resin and playing a good toughening role. At the same time, the uniformly dispersed nano-titanium dioxide plays a good reinforcing role, which is beneficial to improving the tensile strength and elongation at break of the epoxy resin. The modified silicone oil forms a stable curing cross-linking network in the epoxy resin, which is beneficial to improving the thermal performance of the epoxy resin and increasing the thermal decomposition temperature. Moreover, the polysiloxane structure and triazole structure in the modified silicone oil form a nitrogen-silicon flame retardant, which generates incombustible gases such as inorganic silicon substances and nitrogen during combustion, combines with nano-titanium dioxide, and plays a good flame retardant performance, with the limiting oxygen index increasing.

[0060] Compared with Example 1, in Comparative Example 3, modified silicone oil was added, and the epoxy resin binder emulsion did not stratify, had no precipitation, and had good storage stability. However, nano-titanium dioxide was not added, and the tensile strength and elongation at break of the epoxy resin were relatively low. Moreover, the initial thermal decomposition temperature, mass loss rate and limiting oxygen index were slightly lower than those of Example 1.

Claims

1. A method for preparing a waterborne epoxy resin binder, characterized in that: The preparation method of the waterborne epoxy resin binder is: (1) Add toluene, hydrogenated silicone oil and the structural formula The allyl intermediate is added with an isopropanol solution of chloroplatinic acid in a nitrogen atmosphere, heated to 80-90°C, reacted for 3-5h, rotary evaporated, and dried to obtain a modified silicone oil; (2) Add water and nano-titanium dioxide into a container, add modified silicone oil after ultrasonic treatment, stir and disperse, then add water-based epoxy resin, defoamer, leveling agent, thickener, stir and mix to obtain a water-based epoxy resin binder.

2. The method for preparing the waterborne epoxy resin binder according to claim 1, characterized in that: The molar ratio of Si-H bonds in the hydrogenated silicone oil to the allyl intermediate in (1) is 1:(0.8-1); the mass of chloroplatinic acid is 0.015-0.022% of the mass of the allyl intermediate.

3. The method for preparing a waterborne epoxy resin binder according to claim 1, characterized in that: The mass of the nano titanium dioxide and the modified silicone oil in (2) is 0.5-4% and 5-20% of the mass of the waterborne epoxy resin respectively.

4. The method for preparing the waterborne epoxy resin binder according to claim 1, characterized in that: The temperature during the stirring and dispersing in (2) is 40-60° C. and the time is 3-6 hours.

5. The method for preparing the waterborne epoxy resin binder according to claim 1, characterized in that: The preparation method of the allyl intermediate is: A1. Add ethanol, water, 3,4-dihydroxybenzaldehyde and 3-amino-1,2,4-triazole to a reaction vessel, heat to 60-80°C, react for 1-2h, rotary evaporate, extract with ethyl acetate, dry the organic phase to remove water, and purify by recrystallization to obtain a triazole intermediate; A2. Add triazole intermediate, 3-bromopropylene and 1,8-diazabicyclo[5.4.0]undec-7-ene to tetrahydrofuran, react at room temperature for 8-12 hours, rotary evaporate, wash, add the product to ethanol, add sodium borohydride, stir and react for 3-5 hours, add water, extract with ethyl acetate, dry the organic phase to remove water, purify by recrystallization, and obtain the allyl intermediate.

6. The method for preparing the waterborne epoxy resin binder according to claim 5, characterized in that: The molar ratio of 3,4-dihydroxybenzaldehyde to 3-amino-1,2,4-triazole in A1 is 1:(1-1.1).

7. The method for preparing the waterborne epoxy resin binder according to claim 5, characterized in that: The volume ratio of ethanol to water in A1 is 1:(0.6-0.8).

8. The method for preparing the waterborne epoxy resin binder according to claim 5, characterized in that: The molar ratio of the triazole intermediate, 3-bromopropylene and 1,8-diazabicyclo[5.4.0]undec-7-ene in A2 is 1:(1-1.2):(1-1.4).

9. Use of a water-based epoxy resin binder obtained by the preparation method according to any one of claims 1 to 8 in ink.

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