Alcohol-soluble polyamide resin for printing ink as well as preparation method and application of alcohol-soluble polyamide resin

Abstract

The invention relates to the technical field of ink resin preparation, in particular to alcohol-soluble polyamide resin for ink as well as a preparation method and application of the alcohol-soluble polyamide resin. The preparation method comprises the following steps: mixing vegetable oil dimer acid, propionic acid, ethylenediamine, hexamethylenediamine and methyl pentamethylene diamine according to a certain ratio, adding polyether diamine, a silane monomer and a fluorinated monomer under the protection of nitrogen, preheating at 125 DEG C, carrying out condensation polymerization at 200 DEG C, and carrying out vacuum-pumping treatment at 220-230 DEG C, thereby obtaining the product. The obtained resin has excellent alcohol solubility (the ethanol accommodation degree is 31-33 ml / 10 g), a low freezing point (-4 to-4.5 DEG C) and a high softening point (133-115 DEG C), the low-temperature fluidity and high-temperature heat resistance of ink are remarkably improved, and the resin is suitable for being applied to high-quality printing ink.

Description

Technical Field

[0001] The present invention relates to the technical field of ink resin preparation, and particularly relates to an alcohol-soluble polyamide resin for ink, a preparation method thereof, and an application thereof. Background Art

[0002] In the prior art, to prepare a polyamide resin for ink, a carboxylic acid compound and a polyamine compound are usually used to obtain a polyamide resin through a polycondensation reaction. This type of resin is widely used in printing inks due to its good chemical resistance, mechanical properties, and thermal stability, especially in the gravure printing field. However, traditional polyamide resins have the following disadvantages: 1. Insufficient alcohol solubility: Traditional polyamide resins often have poor solubility in alcohol solvents, which can easily lead to uneven dispersion of the resin in printing inks mainly based on alcohol solvents, thus affecting the stability of the ink and the printing quality.

[0003] 2. Limited low-temperature performance: In a low-temperature environment, traditional resins are prone to gelation, and their freezing points are relatively high, which cannot meet the fluidity requirements during the printing process in low-temperature or cold environments, and are likely to cause sticking of printed products or malfunctions of printing machines.

[0004] 3. Difficulty in controlling the softening point: To ensure that the ink has sufficient thermal stability during the printing process, it is required that the resin has a relatively high softening point. However, when traditional resins increase the softening point, they often sacrifice other properties, such as alcohol solubility or low-temperature anti-gelation properties, making it difficult to achieve an overall performance balance.

[0005] 4. Increasingly strict environmental protection requirements: With the continuous improvement of environmental protection regulations, higher requirements are put forward for the environmental protection performance of inks and their raw materials. Traditional polyamide resins for inks may have problems with the emission of harmful volatile organic compounds (VOCs) during preparation and use, and there is an urgent need to develop new resins that not only meet high-performance requirements but also comply with environmental protection standards.

[0006] To overcome the above deficiencies, in recent years, some technical solutions have begun to attempt to introduce functional modified monomers in the molecular design of polyamide resins to improve their key properties such as alcohol solubility, low-temperature anti-gelation properties, and softening point. For example, a polyamide resin disclosed in a Chinese patent application for invention (Publication No.: CN118930845A, Publication Date: November 12, 2024) introduces the following structure in the raw materials: ; The obtained polyamide resin not only has good alcohol solubility and water resistance, but also has relatively high heat resistance and good adhesion ability to substrates.

[0007] However, as an alcohol-soluble polyamide resin for ink, it is required to have excellent alcohol solubility, low freezing point and high softening point, and at the same time meet the environmental requirements for alcohol-soluble polyamide resin for ink. At present, there is no publicly reported alcohol-soluble polyamide resin for ink that meets the above conditions and is particularly excellent. Summary of the Invention

[0008] In order to solve the above technical problems, the object of the present invention is to provide an alcohol-soluble polyamide resin for ink, which has excellent alcohol solubility, low-temperature anti-gelling property and high softening point by further adding polyether diamine, silane monomer and fluorinated monomer on the basis of carboxylic acid compounds and polyamine compounds.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: An alcohol-soluble polyamide resin for ink, the preparation raw materials of which include a) carboxylic acid compounds and b) polyamine compounds; based on a + b being 100 parts by weight, the preparation raw materials further include: c) 0.5 - 2.0 parts of polyether diamine; d) 0.5 - 1.5 parts of silane monomer; e) 0.3 - 1.0 parts of fluorinated monomer.

[0010] The structural formula of the polyether diamine is as follows: ; y = 5 - 10, (x + z) = 3 - 6.

[0011] Preferably, the polyether diamine adopts Jeffamine ED-600 resin; and / or, the silane monomer is selected from 3-aminopropyltriethoxysilane (APTES) or 3-aminopropyltrimethoxysilane (APTMS); and / or, the fluorinated monomer is selected from 2-(perfluorooctyl) vinyl ether, fluorinated acrylate monomer or fluorinated methacrylate monomer.

[0012] Preferably, the molar amount of carboxyl groups contained in component a) is in a ratio of 1:(0.8 - 1.2) to the molar amount of primary amino groups contained in component b) and component c).

[0013] Preferably, the carboxylic acid compounds are selected from one or more of dimer acid, trimer acid, oleic acid, methyl oleate, adipic acid, sebacic acid, succinic acid and propionic acid; and / or, the polyamine compounds are selected from one or more of ethylenediamine, hexamethylenediamine, decamethylenediamine, pentamethylenediamine, methylpentamethylenediamine, isophoronediamine, 1,3-cyclohexanedimethanamine, 4,4'-diaminodicyclohexylmethane and polyetheramine.

[0014] Preferably, the carboxylic acid compounds are 75 - 85 parts of vegetable oil dimer acid and 2 - 8 parts of propionic acid; And / or, the polyamine compound is selected from 2 - 6 parts of ethylenediamine, 4 - 10 parts of hexamethylenediamine, and 3 - 10 parts of methylpentanediamine.

[0015] Preferably, the vegetable oil dimer acid is selected from cottonseed oil dimer acid, soybean oil dimer acid, palm oil dimer acid or a mixture thereof, and the mixing ratio is cottonseed oil dimer acid:soybean oil dimer acid:palm oil dimer acid = (4 - 6):(2 - 3):(2 - 3).

[0016] Furthermore, the present invention also provides a method for preparing the polyamide resin, and the method includes the following steps: 1) Mix the carboxylic acid compound in component a) and the polyamine compound in component b) evenly in a reaction kettle under nitrogen protection; 2) Sequentially add component c) polyether diamine, component d) silane monomer and component e) fluorinated monomer to the mixture; 3) Carry out a polycondensation reaction at 125°C - 230°C, and after the reaction is completed, obtain the polyamide resin by steps of cooling, vacuum pumping and pelletizing.

[0017] Preferably, in step 2), the addition of polyether diamine, silane monomer and fluorinated monomer is carried out by a continuous or intermittent dropping method under the condition that the temperature is 120°C - 130°C.

[0018] Preferably, the polycondensation reaction is carried out at 200°C for 0.5 - 1.5 hours, and then the temperature is raised to 220°C - 230°C and a vacuum pumping treatment is carried out for 1 - 1.5 hours.

[0019] Furthermore, the present invention also provides an ink, which contains the polyamide resin as an ink binder, as well as pigments, solvents and necessary ink additives.

[0020] Due to the adoption of the above technical solution, the present invention introduces polyether diamine, silane monomer and fluorinated monomer into the traditional polyamide resin system for inks, significantly improving the overall performance of the resin. The specific technical effects are as follows: 1. Excellent alcohol solubility: By introducing polyether diamine, a flexible polyether segment is embedded in the resin molecular chain of the present invention, thereby greatly improving the solubility in alcohol solvents, enabling the resin to be quickly and evenly dispersed in the ink formulation, and ensuring the uniformity and stability of the printing ink.

[0021] 2. Low freezing point and anti-gel performance: The added fluorinated monomer utilizes the low-polarity characteristics of the perfluoroalkyl side chain to effectively reduce the freezing point of the resin (which can be as low as below -4°C), and still maintain good fluidity in a low-temperature environment, preventing the gelation from affecting the printing quality and meeting the printing requirements in a cold environment.

[0022] 3. High softening point and thermal stability: By introducing silane monomers, moderate cross-linking is formed in the resin molecular structure, which improves the softening point of the resin (can reach or exceed 110 °C) and thermal stability. Thus, it ensures that the ink is not easily softened or deformed during high-temperature printing or storage, improving the heat resistance and service life of the product.

[0023] 4. Environmental friendliness: The present invention uses an alcohol solvent system, avoiding the use of traditional highly toxic benzene or ester solvents. At the same time, attention is paid to environmental protection and sustainable development in raw material selection, reducing the emission of harmful volatile organic compounds (VOCs), which is in line with current environmental protection regulations and the development trend of green printing.

[0024] 5. Balanced comprehensive performance: By reasonably matching carboxylic acid compounds and polyamine compounds and precisely controlling the addition ratio of each functional monomer, the polyamide resin obtained in the present invention achieves a good balance among alcohol solubility, low-temperature anti-gelling property, high-temperature heat resistance, and environmental friendliness. It not only meets the application requirements of the ink in various extreme environments but also can significantly improve the adhesion, gloss, and overall printing quality of printed products.

[0025] In summary, the alcohol-soluble polyamide resin for ink and its preparation method provided by the present invention significantly improve the application performance of the resin in the ink formulation through the optimization of structure and process, and have broad application prospects and high commercial promotion value. Detailed implementation manners

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0027] Example 1 Composition: Component a) Carboxylic acid compound: - Vegetable oil dimer acid (cottonseed oil dimer acid: soybean oil dimer acid: palm oil dimer acid is 5:2:3, the same below) 80 parts - Propionic acid 4 parts Component b) Polyamine compound: - Ethylenediamine 3.5 parts - Hexamethylenediamine 6.5 parts - Methylpentanediamine 7 parts Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts Component d) Silane monomer (3-aminopropyltriethoxysilane, APTES): 1.0 part Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 parts Defoamer: 12 ml / ton

[0028] Preparation method: 1) Mixing and preheating Add vegetable oil dimer acid, propionic acid and defoamer into the reaction kettle. Under the protection of nitrogen, stir evenly and heat to about 125 °C to form a homogeneous acidic reaction solution; 2) Addition of amine mixture At 125 °C, add the pre-mixed amine mixture (including ethylenediamine, hexamethylenediamine, methylpentanediamine, polyether diamine, silane monomer and fluorinated monomer) into the reaction kettle in a continuous or intermittent dropping manner, ensuring that the temperature of the reaction solution remains stable; 3) Polycondensation reaction After all the amine mixture is added, raise the reaction temperature to 200 °C and keep it warm for about 1 hour to fully condense the carboxyl group and amino group to generate polyamide chains; 4) Post-treatment and granulation Subsequently, continue to raise the temperature to 220 °C - 230 °C, close the nitrogen, and carry out vacuum treatment for 1 - 1.5 hours to remove the water and other volatile by-products generated during the reaction; Finally, cool the reaction system to 160 °C - 180 °C, and use granulation equipment to granulate and package the product to obtain the target polyamide resin.

[0029] Example 2 Composition: Component a) - Vegetable oil dimer acid 79 parts - Propionic acid 3.5 parts Component b) - Ethylenediamine 4 parts - Hexamethylenediamine 6 parts - Methylpentanediamine 6.5 parts Component c) Polyether diamine (Jeffamine ED-600): 1.0 part Component d) Silane monomer (3-aminopropyltrimethoxysilane, APTMS): 1.0 part Component e) Fluorinated monomer (fluorinated acrylate monomer): 0.5 part Defoamer: 12 ml / ton

[0030] Preparation method: 1) Mixing and preheating Add vegetable oil dimer acid, propionic acid and defoamer into the reaction kettle. Stir evenly under nitrogen protection and heat to 125 °C.

[0031] 2) Addition of amine mixture Under the condition of 125 °C, the amine mixture solution composed of ethylenediamine, hexamethylenediamine, methylpentamethylenediamine, polyether diamine, silane monomer and fluorinated monomer was slowly added dropwise intermittently to ensure the temperature stability during the reaction process.

[0032] 3) Polycondensation reaction After the addition was completed, the temperature was raised to 200 °C and kept warm for 1 hour to allow the components in the system to fully polycondense.

[0033] 4) Post-treatment and granulation Subsequently, the temperature was raised to 225 °C, and it was treated under vacuum for 1.5 hours. Finally, the temperature was lowered to 170 °C for granulation and packaging to obtain the required polyamide resin.

[0034] Example 3 Composition: Component a) - Vegetable oil dimer acid: 81 parts - Propionic acid: 3 parts Component b) - Ethylenediamine: 3 parts - Hexamethylenediamine: 6 parts - Methylpentamethylenediamine: 5.5 parts Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts Component d) Silane monomer (APTES): 1.0 part Component e) Fluorinated monomer (fluorinated methacrylate monomer): 0.5 part Defoaming agent: 12 ml / ton.

[0035] Preparation method: 1) Mixing and preheating Vegetable oil dimer acid, propionic acid and defoaming agent were added into the reaction kettle. After purging with nitrogen, it was heated to 125 °C.

[0036] 2) Addition of amine mixture Under the condition of 125 °C, the amine solution composed of ethylenediamine, hexamethylenediamine, methylpentamethylenediamine, polyether diamine, silane monomer and fluorinated monomer was added to the reaction kettle by continuous dropping.

[0037] 3) Polycondensation reaction The reaction temperature was raised to 200 °C and kept warm for 1 hour to promote the full reaction of carboxylic acid and amine to form polyamide.

[0038] 4) Post-treatment and granulation Further, the temperature was raised to 220 °C - 230 °C, nitrogen was turned off and vacuum treatment was carried out for 1 - 1.5 hours. Finally, the system temperature was lowered to 160 °C - 180 °C for granulation and packaging.

[0039] Comparative Example 1 (without adding polyether diamine) Composition: Component a) - 80 parts of vegetable oil dimer acid - 4 parts of propionic acid Component b) - 3.5 parts of ethylenediamine - 6.5 parts of hexamethylenediamine - 7 parts of methylpentanediamine Component c) None Component d) Silane monomer (APTES): 1.0 part Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 part Defoamer: 12 ml / ton

[0040] Preparation method: Operate according to the steps in Example 1, but do not add polyether diamine in step 2. Other operating conditions remain the same.

[0041] Comparative Example 2 (without adding silane monomer) Composition: Component a) - 80 parts of vegetable oil dimer acid - 4 parts of propionic acid Component b) - 3.5 parts of ethylenediamine - 6.5 parts of hexamethylenediamine - 7 parts of methylpentanediamine Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts Component d) None Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 part Defoamer: 12 ml / ton Preparation method: Refer to the preparation of Example 1, but do not add silane monomer in step 2, and the remaining operation steps and conditions remain the same.

[0042] Comparative Example 3 (without adding fluorinated monomer) Composition: Component a) - 80 parts of vegetable oil dimer acid - 4 parts of propionic acid Component b) - 3.5 parts of ethylenediamine - 6.5 parts of hexamethylenediamine - 7 parts of methylpentanediamine Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts Component d) Silane monomer (APTES): 1.0 part Component e) None Defoamer: 12 ml / ton Preparation method: Same as Example 1, but do not add fluorinated monomer in Step 2. Other steps remain unchanged.

[0043] Comparative Example 4 (Neither polyether diamine nor fluorinated monomer is added) Composition: Component a) - Vegetable oil dimer acid: 80 parts - Propionic acid: 4 parts Component b) - Ethylenediamine: 3.5 parts - Hexamethylenediamine: 6.5 parts - Methylpentanediamine: 7 parts Component c) None Component d) Silane monomer (APTES): 1.0 part Component e) None Defoamer: 12 ml / ton.

[0044] Preparation method: Refer to the preparation method of Example 1, but do not add polyether diamine and fluorinated monomer in Step 2, and other operations remain the same.

[0045] Comparative Example 5 (All functional monomers are not added) Composition: Component a) - Vegetable oil dimer acid: 80 parts - Propionic acid: 4 parts Component b) - Ethylenediamine: 3.5 parts - Hexamethylenediamine: 6.5 parts - Methylpentanediamine: 7 parts Component c) None Component d) None Component e) None Defoamer: 12 ml / ton.

[0046] Preparation method: Carry out according to the preparation method of Example 1, but do not add any functional monomers (i.e., neither polyether diamine, silane monomer nor fluorinated monomer) in Step 2, and the remaining operating conditions remain unchanged.

[0047] Perform performance tests on the alcohol-soluble polyamide resins provided in the examples and comparative examples. The test methods are as follows, and the test results are shown in Table 1.

[0048] Freezing point test: The test is carried out according to the method specified in QB / T 4752-2014 "Alcohol-soluble polyamide resin for ink". The smaller the freezing point value, the stronger the anti-freezing and anti-gel properties of the polyamide resin.

[0049] 2. Ethanol tolerance test: The test is carried out according to the method specified in 5.8 of QB / T 4752-2014 "Alcohol-soluble polyamide resin for ink". The larger the ethanol tolerance, the stronger the alcohol solubility of the polyamide resin.

[0050] 3. Initial drying test: The test is carried out according to the method for testing the initial drying of liquid ink in 5.2 of GB / T 13217.5-2023 "Test methods for ink drying". The appropriate initial drying property of the polyamide resin endows the ink with reasonable solvent release property, printing suitability, gloss and rheology.

[0051] 4. Softening point test: The softening point test is carried out according to the method specified in GB / T 12007.6-1989 "Epoxy resin - Determination of softening point - Ring and ball method". The larger the softening point value, the better the thermal stability of the polyamide resin.

[0052] The experimental data table given below shows that the examples are superior to the comparative examples in all performance indicators, proving that the improved alcohol-soluble polyamide resin for ink of the present invention has significant technical advantages. The specific data are shown in Table 1.

[0053] Table 1 Performance test comparison table

[0054] Data description: After introducing polyether diamine, silane monomer and fluorinated monomer in the examples, the freezing point is reduced to -4 to -4.5 °C, much lower than that of the comparative examples (the freezing point is between +1 and +3 °C); The ethanol tolerance is increased to 31 - 33 ml / 10g, while the comparative examples are only in the range of 12 - 26 ml / 10g, showing excellent alcohol solubility; The initial drying data is maintained at 21 - 22 seconds, meeting the requirements of printing applications; The softening point is maintained at 113 - 115 °C, ensuring thermal stability at high temperatures.

[0055] The above is the description of the embodiments of the present invention. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. An alcohol-soluble polyamide resin for ink, wherein the raw materials for its preparation include a) a carboxylic acid compound and b) a polyamine compound; characterized in that: The raw materials for preparation include, with a+b as 100 parts by weight: c) 0.5-2.0 parts of polyether diamine; d) 0.5-1.5 parts of silane monomer; e) 0.3-1.0 parts of fluorinated monomer; The structural formula of the polyether diamine is as follows: ； y =5-10, (x+z)=3-6.

2. The polyamide resin according to claim 1, characterized in that The polyether diamine is Jeffamine ED-600 resin; and / or the silane monomer is 3-aminopropyltriethoxysilane (APTES) or 3-aminopropyltrimethoxysilane (APTMS); and / or the fluorinated monomer is 2-(perfluorooctyl) vinyl ether, fluorinated acrylate monomer or fluorinated methacrylate monomer.

3. The polyamide resin according to claim 1, characterized in that The ratio of the molar amount of carboxyl groups contained in component a) to the molar amount of primary amino groups contained in components b) and c) is 1:(0.8-1.2).

4. The polyamide resin according to claim 1, characterized in that The carboxylic acid compound is selected from one or more of dimer acid, trimer acid, oleic acid, methyl oleate, adipic acid, sebacic acid, succinic acid and propionic acid; And / or, the polyamine compound is selected from one or more of ethylenediamine, hexamethylenediamine, decanediamine, pentamethylenediamine, methylpentamethylenediamine, isophoronediamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane and polyetheramine.

5. The polyamide resin according to claim 1, characterized in that The carboxylic acid compound is selected from 75-85 parts of vegetable oil dimer acid and 2-8 parts of propionic acid; And / or, the polyamine compound is selected from 2 to 6 parts of ethylenediamine, 4 to 10 parts of hexamethylenediamine, and 3 to 10 parts of methylpentamethylenediamine.

6. The polyamide resin according to claim 5, characterized in that The vegetable oil dimer acid is selected from cottonseed oil dimer acid, soybean oil dimer acid, palm oil dimer acid or a mixture thereof, and the mixing ratio is cottonseed oil dimer acid: soybean oil dimer acid: palm oil dimer acid (4-6): (2-3): (2-3).

7. A method for preparing the polyamide resin according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: 1) uniformly mixing the carboxylic acid compound of component a) and the polyamine compound of component b) in a reaction kettle under nitrogen protection; 2) adding component c) polyether diamine, component d) silane monomer and component e) fluorinated monomer to the mixture in sequence; 3) carrying out polycondensation reaction at 125° C. to 230° C., and after the reaction is completed, cooling, vacuuming and granulating are performed to obtain the polyamide resin.

8. The method according to claim 7, characterized in that In step 2), the polyether diamine, silane monomer and fluorinated monomer are added at a temperature of 120° C. to 130° C. by continuous or intermittent dropwise addition.

9. The method according to claim 7 or 8, characterized in that: The polycondensation reaction is kept at 200° C. for 0.5 to 1.5 hours, then the temperature is raised to 220° C. to 230° C. and a vacuum treatment is performed for 1 to 1.5 hours.

10. An ink comprising the polyamide resin according to any one of claims 1 to 6 as an ink vehicle, a pigment, a solvent and necessary ink additives.

Images