A method for preparing a biobased degradable water-based ink

Abstract

The application relates to the technical field of inks, and discloses a preparation method of a biobased degradable water-based ink. Vanillin-based spiroacetal diglycidyl ether and diacid are subjected to esterification polymerization to obtain a biobased polyester resin, and then the biobased resin is mixed and dispersed with a petroleum-based resin, pigments, additives and the like to obtain the biobased degradable water-based ink. The biobased resin contains multiple hydrophilic hydroxyl groups, has good solubility and dispersibility in the water-based ink, and has more intensive cross-linking effects such as hydrogen bond with the acrylic resin, so that the hardness of the ink is improved. Meanwhile, the polar hydroxyl groups greatly enhance the hydrogen bond combination and anchoring effect between the paint film and the base material, so that the adhesion is improved. In addition, the easily hydrolyzable spiroacetal bond and the degradable chemical bonds such as the polyester structural unit in the molecular chain of the biobased resin provide more attack sites for water and microorganisms, improve the degradability, and realize the degradable function.

Description

Technical Field

[0001] This invention relates to the field of ink technology, specifically to a method for preparing a bio-based biodegradable water-based ink. Background Technology

[0002] The traditional ink industry has long relied on petroleum-based resins as binders. While these resins offer excellent performance, they suffer from drawbacks such as non-renewability, high emissions of volatile organic compounds (VOCs) during production, and environmental pollution due to their difficulty in degradation after disposal. With increasingly stringent environmental regulations and the growing emphasis on sustainable development, developing environmentally friendly alternatives has become an urgent need in this field. The emergence of water-based acrylic resin inks, using water as a diluent, has significantly reduced VOC emissions, representing a major step forward in safety and environmental friendliness. However, their core resins are still largely derived from non-renewable petroleum resources, and the cured paint film remains difficult for microorganisms to decompose in the natural environment. The ultimate degradation problem has not been fundamentally solved, limiting their overall green attributes throughout their lifecycle.

[0003] To address the environmental concerns associated with petroleum-based inks, bio-based inks have emerged. Bio-based inks are those whose main components are derived from renewable biomass resources, such as vegetable oils (soybean oil, tung oil), rosin, cellulose, and starch. Using bio-based raw materials reduces dependence on fossil resources and lowers the product's carbon footprint. However, "bio-based" does not equate to "biodegradable." Whether an ink is biodegradable depends on its molecular chemical structure. Many bio-based resins (such as some highly cross-linked modified resins) remain very stable in the natural environment and are difficult for microorganisms to decompose. Therefore, developing truly biodegradable inks requires not only raw materials derived from biomass but also the introduction of easily broken chemical bonds in the molecular design to create a breakthrough for hydrolysis and microbial degradation.

[0004] Spirocyclic acetals are a special type of cyclic acetal structure with two rings sharing a single carbon atom. This structure is highly unstable under acidic conditions or in the presence of certain enzymes, readily undergoing hydrolytic ring-opening reactions. By chemically embedding these easily degradable spirocyclic acetal structural units into the polymer backbone, when discarded ink enters the natural environment (such as soil or oceans, which are typically weakly acidic), these spirocyclic acetal bonds preferentially break, causing the polymer chain to disintegrate into smaller molecular fragments, thereby greatly promoting subsequent microbial degradation. Summary of the Invention

[0005] (a) Technical problems to be solved:

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing bio-based biodegradable water-based inks, solving the problem of non-degradability of water-based inks.

[0007] (II) Technical Solution:

[0008] A method for preparing a bio-based biodegradable water-based ink, comprising 100 parts of petroleum-based resin, 20-40 parts of bio-based resin, 90-150 parts of deionized water, 7-15 parts of ethanol, 1-6 parts of pigment, 1-3 parts of defoamer, 0.1-0.5 parts of dispersant, 0.5-2 parts of thickener, and 2-5 parts of wetting agent.

[0009] The preparation method of bio-based biodegradable water-based ink is as follows:

[0010] Step (1): Add spirocyclic acetal diglycidyl ether, dicarboxylic acid, and catalyst to a flask, heat and stir to react, and obtain a bio-based resin. The preparation reaction formula is:

[0011]

[0012] Step (2): Add petroleum-based resin, bio-based resin, deionized water, ethanol, pigment, defoamer, dispersant, thickener, wetting agent, and neutralizer to a beaker, and disperse using a high-speed homogenizer to obtain bio-based biodegradable water-based ink.

[0013] Furthermore, the ratio of spirocyclic acetal diglycidyl ether, dicarboxylic acid, and catalyst is 100g:(68-114)g:(0.08-0.18)g.

[0014] Furthermore, in step (1), the dicarboxylic acid is malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, or octanoic acid.

[0015] Furthermore, the catalyst in step (1) is 2,4,6-tris(dimethylaminomethyl)phenol or N,N-dimethylbenzylamine.

[0016] Furthermore, in step (1), the heating temperature is 100-130℃ and the reaction time is 4-8h.

[0017] Furthermore, in step (2), the petroleum-based resin is a water-based acrylic resin.

[0018] Further, in step (2), a neutralizing agent is added to adjust the pH of the ink to 7-8.5.

[0019] Furthermore, the neutralizing agent in step (2) is triethylamine, triethanolamine, or ammonia water with a mass fraction of 20-30%.

[0020] Furthermore, in step (2), the dispersion speed is 600-800 r / min, and the dispersion time is 15-25 min.

[0021] (III) Beneficial Technical Effects:

[0022] This invention involves esterifying and polymerizing vanillin-based spirocyclic acetal diglycidyl ether and diacid to obtain a bio-based resin, vanillin-based spirocyclic acetal polyester. The vanillin-based spirocyclic acetal polyester is then mixed and dispersed with petroleum-based resin, pigments, additives, etc., to prepare a bio-based biodegradable water-based ink.

[0023] The bio-based biodegradable water-based ink of this invention utilizes a vanillin-based spirocyclic acetal polyester resin containing multiple hydrophilic hydroxyl groups. This results in excellent solubility and dispersibility in water-based inks, and the resin undergoes more concentrated hydrogen bonding and other cross-linking interactions with acrylic resins, significantly improving the rigidity of the paint film and thus increasing the ink's hardness. Simultaneously, these polar hydroxyl groups greatly enhance the hydrogen bonding and anchoring effect between the paint film and the substrate, thereby reducing the adhesion grade and improving adhesion. Furthermore, the easily hydrolyzable spirocyclic acetal bonds and biodegradable chemical bonds such as polyester structural units in the vanillin-based spirocyclic acetal polyester molecular chain provide more attack sites for water and microorganisms, increasing the degradation rate and achieving biodegradability. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Spirocyclic acetal diglycidyl ether was prepared according to the method described in the journal *Polymers for Advanced Technologies*, 2022; 33: 1665–1676, in the paper "Design of controllable degradable epoxy resin: High performance and feasible upcycling." The structural formula is as follows:

[0026] Spirocycloaldiphenol was prepared according to the method described in the journal *Polymers for Advanced Technologies*, 2022; 33: 1665–1676, in the paper "Design of controllable degradable epoxy resin: High performance and feasible upcycling." The structural formula is as follows:

[0027] The following water-based acrylic resin was purchased from Shengwanjia New Materials (Shandong) Co., Ltd. The following defoamer, model X-2111, was purchased from Shanghai Liqi Chemical Additives Co., Ltd. The following dispersant, model DISPERBYK-2013, was purchased from Wanqing Chemical Technology Co., Ltd. The following thickener, model UV1080, was purchased from Shanghai Yuanfeng Plastics Technology Co., Ltd. The following wetting agent, model Dow X405, was purchased from Nanjing Baiju Technology Co., Ltd.

[0028] Example 1:

[0029] Step (1): Add 60g (116.23mmol) spirocyclic acetal diglycidyl ether, 69g (472.15mmol) adipic acid, and 0.08g 2,4,6-tris(dimethylaminomethyl)phenol to a flask, heat to 120℃, and stir for 6h to obtain bio-based resin.

[0030] Step (2): Add 100g of water-based acrylic resin, 20g of bio-based resin, 120g of deionized water, 8g of ethanol, 5g of pigment carbon black, 1g of defoamer, 0.2g of dispersant, 1.6g of thickener, and 2g of wetting agent to a beaker, and add 30% ammonia water to adjust the pH of the ink to 8. Disperse the ink for 20 minutes at 800r / min using a high-speed homogenizer to obtain bio-based biodegradable water-based ink.

[0031] Example 2:

[0032] Step (1): Add 60g of spirocyclic acetal diglycidyl ether, 40g of succinic acid and 0.11g of N,N-dimethylbenzylamine to a flask, heat to 130℃, stir and react for 4h to obtain bio-based resin.

[0033] Step (2): Add 100g of water-based acrylic resin, 25g of bio-based resin, 90g of deionized water, 15g of ethanol, 1g of pigment carbon black, 2g of defoamer, 0.1g of dispersant, 2g of thickener, and 3g of wetting agent to a beaker, and add triethylamine to adjust the pH of the ink to 7. Disperse the ink using a high-speed homogenizer at a speed of 600r / min for 25min to obtain bio-based biodegradable water-based ink.

[0034] Example 3:

[0035] Step (1): Add 60g of spirocyclic acetal diglycidyl ether, 55g of glutaric acid, and 0.05g of 2,4,6-tris(dimethylaminomethyl)phenol to a flask, heat to 100℃, and stir for 8h to obtain bio-based resin.

[0036] Step (2): Add 100g of water-based acrylic resin, 30g of bio-based resin, 130g of deionized water, 7g of ethanol, 6g of pigment carbon black, 3g of defoamer, 0.5g of dispersant, 0.5g of thickener, and 5g of wetting agent to a beaker, and add triethanolamine to adjust the pH of the ink to 8.5. Disperse the ink for 15 minutes at 800r / min using a high-speed homogenizer to obtain bio-based biodegradable water-based ink.

[0037] Example 4:

[0038] Step (1): Add 100g of waterborne acrylic resin, 35g of bio-based resin (obtained by the preparation method in Example 1), 150g of deionized water, 10g of ethanol, 4g of pigment carbon black, 2g of defoamer, 0.3g of dispersant, 1.2g of thickener, and 2g of wetting agent to a beaker, and add 20-30% ammonia water to adjust the pH of the ink to 8. Disperse the ink for 15 minutes at 600r / min using a high-speed homogenizer to obtain bio-based biodegradable waterborne ink.

[0039] Example 5:

[0040] Step (1): Add 100g of waterborne acrylic resin, 40g of bio-based resin (obtained by the preparation method in Example 1), 120g of deionized water, 8g of ethanol, 2g of pigment carbon black, 1g of defoamer, 0.3g of dispersant, 1.5g of thickener, and 3g of wetting agent to a beaker, and add triethylamine to adjust the pH of the ink to 7. Disperse the ink using a high-speed homogenizer at a speed of 600r / min for 20min to obtain bio-based biodegradable waterborne ink.

[0041] Comparative Example 1: Compared with Example 1, this comparative example does not contain bio-based resin.

[0042] Step (1): Add 100g of water-based acrylic resin, 120g of deionized water, 8g of ethanol, 5g of pigment carbon black, 1g of defoamer, 0.2g of dispersant, 1.6g of thickener, and 2g of wetting agent to a beaker, and add 30% ammonia water to adjust the pH of the ink to 8. Disperse the ink for 20 minutes at 800r / min using a high-speed homogenizer to obtain water-based ink.

[0043] Comparative Example 2: Compared with Example 1, this comparative example uses bisphenol A diglycidyl ether (CAS No. 1675-54-3) instead of spirocyclic acetal diglycidyl ether.

[0044] Step (1): Add 39.5g (116.23mmol) of bisphenol A diglycidyl ether, 69g of adipic acid, and 0.08g of 2,4,6-tris(dimethylaminomethyl)phenol to a flask, heat to 120℃, and stir for 6h to obtain bisphenol A resin.

[0045] Step (2): Add 100g of water-based acrylic resin, 20g of bisphenol A resin, 120g of deionized water, 8g of ethanol, 5g of pigment carbon black, 1g of defoamer, 0.2g of dispersant, 1.6g of thickener, and 2g of wetting agent to a beaker, and add 30% ammonia water to adjust the pH of the ink to 8. Disperse the ink using a high-speed homogenizer at 800r / min for 20min to obtain water-based ink.

[0046] Comparative Example 3: Compared with Example 1, this comparative example uses spirocyclic acetal diphenol instead of spirocyclic acetal diglycidyl ether.

[0047] Step (1): Add 160 mL benzenesulfonyl chloride, 70 mL N,N-dimethylformamide, and 500 mL pyridine to a flask, stir well, seal and let stand for 30 min, add 69 g (472.15 mmol) adipic acid, stir at 25 °C for 10 min, add 191 g (472.15 mmol) spirocyclic acetal diphenol dissolved in 500 mL pyridine dropwise, heat to 120 °C, stir and react for 2 h, add 950 mL N,N-dimethylformamide to dilute, filter, wash with anhydrous ethanol, dry, and obtain polyester.

[0048] Step (2): Add 100g of water-based acrylic resin, 20g of polyester, 120g of deionized water, 8g of ethanol, 5g of pigment carbon black, 1g of defoamer, 0.2g of dispersant, 1.6g of thickener, and 2g of wetting agent to a beaker, and add 30% ammonia water to adjust the pH of the ink to 8. Disperse the ink using a high-speed homogenizer at 800r / min for 20min to obtain water-based ink.

[0049] The hardness of the ink was tested according to the method of GB / T 6739-2022.

[0050] The adhesion of the ink was tested according to the method of GB / T 13217.7-2023.

[0051] The biodegradability of the ink was tested according to the method of GB / T 19277.1-2011, and the biodegradation time was 30 days.

[0052] Table 1 Performance Tests of Inks

[0053] hardness Adhesion (Grade) Biodegradation rate (%) Example 1 2H 1 12.28 Example 2 2H 0 15.43 Example 3 3H 0 17.05 Example 4 3H 1 19.94 Example 5 3H 1 22.11 Comparative Example 1 5B 2 1.32 Comparative Example 2 2H 1 7.26 Comparative Example 3 1H 2 12.17

[0054] Compared to Comparative Example 1, the bio-based biodegradable water-based inks of Examples 1-5 contain a number of hydrophilic hydroxyl groups in their vanillin-based spirocyclic acetal polyester resin. This results in good solubility and dispersibility in water-based inks, and the resin undergoes more concentrated hydrogen bonding and other cross-linking interactions with acrylic resins, significantly improving the rigidity of the paint film and thus increasing the ink's hardness. Simultaneously, these polar hydroxyl groups also greatly enhance the hydrogen bonding and anchoring effect between the paint film and the substrate, thereby reducing the adhesion grade and improving adhesion. Furthermore, the easily hydrolyzable spirocyclic acetal bonds and degradable chemical bonds such as polyester structural units in the vanillin-based spirocyclic acetal polyester molecular chain provide more attack sites for water and microorganisms, increasing the degradation rate and achieving degradable functionality.

[0055] Comparative Example 1 is an ink without added bio-based resin. Acrylic resin does not contain a rigid structure, so the ink has a low hardness. Furthermore, petroleum-based resin is derived from non-renewable petroleum resources and is difficult to biodegrade after disposal, resulting in a low biodegradation rate.

[0056] Comparative Example 2 shows that bisphenol A resin was synthesized by replacing spirocyclic acetal diglycidyl ether with bisphenol A diglycidyl ether. The resin molecule is derived from non-renewable petroleum resources and does not contain a biodegradable spirocyclic acetal structure. It is difficult to biodegrade after disposal and has a low biodegradation rate.

[0057] Comparative Example 3 uses spirocyclic acetal diphenol to replace spirocyclic acetal diglycidyl ether to synthesize bio-based resin. Polyester is synthesized by esterification reaction of the hydroxyl group of spirocyclic acetal diphenol with adipate. However, the resulting polyester does not contain hydroxyl groups, has poor hydrophilicity, and has poor solubility and dispersibility in water-based inks, which is not conducive to improving the performance of inks. The resulting ink has poor hardness and adhesion properties.

[0058] The present invention has been described in detail above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing a bio-based biodegradable water-based ink, characterized in that, The bio-based biodegradable water-based ink comprises 100 parts petroleum-based resin, 20-40 parts bio-based resin, 90-150 parts deionized water, 7-15 parts ethanol, 1-6 parts pigment, 1-3 parts defoamer, 0.1-0.5 parts dispersant, 0.5-2 parts thickener, and 2-5 parts wetting agent. The preparation method of the bio-based biodegradable water-based ink is as follows: add petroleum-based resin, bio-based resin, deionized water, ethanol, pigment, defoamer, dispersant, thickener, wetting agent and neutralizer to a beaker, and disperse using a high-speed homogenizer to obtain bio-based biodegradable water-based ink. The petroleum-based resin is a water-based acrylic resin; The preparation method of the bio-based resin is as follows: spirocyclic acetal diglycidyl ether, dicarboxylic acid, and catalyst are added to a flask, and the mixture is heated and stirred to react, thereby obtaining the bio-based resin. The ratio of the spirocyclic acetal diglycidyl ether, the dicarboxylic acid, and the catalyst is 100g:(68-114)g:(0.08-0.18)g; The dicarboxylic acid is malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, or octanoic acid.

2. The method for preparing bio-based biodegradable water-based ink according to claim 1, wherein the addition of a neutralizing agent adjusts the pH of the ink to 7-8.

5.

3. The method for preparing bio-based biodegradable water-based ink according to claim 1, wherein the neutralizing agent is triethylamine, triethanolamine, or ammonia water with a mass fraction of 20-30%.

4. The method for preparing bio-based biodegradable water-based ink according to claim 1, characterized in that, The dispersion speed is 600-800 r / min, and the dispersion time is 15-25 min.

5. The method for preparing bio-based biodegradable water-based ink according to claim 1, characterized in that, The catalyst is 2,4,6-tris(dimethylaminomethyl)phenol or N,N-dimethylbenzylamine.

6. The method for preparing bio-based biodegradable water-based ink according to claim 1, characterized in that, The heating temperature is 100-130℃, and the reaction time is 4-8h.

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