An alcohol-soluble polyamide resin for ink, its preparation method and application

Abstract

The present invention relates to the technical field of ink resin preparation, and in particular to an alcohol-soluble polyamide resin for ink, its preparation method and application. In the present invention, vegetable oil dimer acid, propionic acid are mixed with ethylenediamine, hexamethylenediamine, and methylpentanediamine in a certain proportion, and polyether diamine, silane monomer, and fluorinated monomer are added under nitrogen protection, and are prepared through preheating at 125 °C, polycondensation at 200 °C, and vacuum pumping at 220 °C to 230 °C. The obtained resin has excellent alcohol solubility (ethanol tolerance 31 - 33 ml / 10g), low freezing point (-4 to -4.5 °C), and high softening point (113 - 115 °C), significantly improving the low-temperature fluidity and high-temperature heat resistance of the ink, and is suitable for the application of high-quality printing inks.

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, carboxylic acid compounds and polyamine compounds 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 field of gravure printing. However, traditional polyamide resins have the following disadvantages:

[0003] 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 composed of alcohol solvents, thus affecting the stability of the ink and the printing quality.

[0004] 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.

[0005] 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, other properties are often sacrificed, such as alcohol solubility or low-temperature anti-gelation properties, making it difficult to achieve an overall performance balance.

[0006] 4. Increasingly strict environmental protection requirements: With the continuous improvement of environmental protection regulations, higher requirements are put forward for the environmental 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 the preparation and use processes, and there is an urgent need to develop new resins that not only meet high-performance requirements but also comply with environmental protection standards.

[0007] 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 key properties such as their alcohol solubility, low-temperature anti-gelation properties, and softening point. For example, a polyamide resin disclosed in a Chinese invention patent application (publication number: CN118930845A, publication date: November 12, 2024) introduces the following structure in the raw materials:

[0008] ;

[0009] 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.

[0010] However, for the alcohol-soluble polyamide resin used in inks, 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 the alcohol-soluble polyamide resin used in inks. At present, there has been no publicly reported alcohol-soluble polyamide resin for inks that meets the above conditions and is particularly excellent. Summary of the Invention

[0011] In order to solve the above technical problems, the object of the present invention is to provide an alcohol-soluble polyamide resin for inks, which, based on carboxylic acid compounds and polyamine compounds, further adds polyether diamine, silane monomer and fluorinated monomer, and has excellent alcohol solubility, low-temperature anti-gelation property and high softening point.

[0012] In order to achieve the above object, the present invention adopts the following technical solutions:

[0013] An alcohol-soluble polyamide resin for inks, the preparation raw materials of which include a) carboxylic acid compounds, b) polyamine compounds; based on a + b being 100 parts by weight, the preparation raw materials further include:

[0014] c) 0.5 - 2.0 parts of polyether diamine;

[0015] d) 0.5 - 1.5 parts of silane monomer;

[0016] e) 0.3 - 1.0 parts of fluorinated monomer.

[0017] The structural formula of the polyether diamine is as follows:

[0018] ;

[0019] y = 5 - 10, (x + z) = 3 - 6.

[0020] 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.

[0021] Preferably, the molar amount of the carboxyl group contained in component a) is in a ratio of 1:(0.8 - 1.2) to the molar amount of the primary amino group contained in component b) and component c).

[0022] Preferably, 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;

[0023] And / or, the polyamine compound is selected from one or more of ethylenediamine, hexamethylenediamine, decamethylenediamine, pentamethylenediamine, methylpentamethylenediamine, isophoronediamine, 1,3-cyclohexanedimethanamine, 4,4'-diaminodicyclohexylmethane, and polyetheramine.

[0024] Preferably, the carboxylic acid compound is 75 - 85 parts of vegetable oil dimer acid and 2 - 8 parts of propionic acid;

[0025] And / or, the polyamine compound is selected from 2 - 6 parts of ethylenediamine, 4 - 10 parts of hexamethylenediamine, and 3 - 10 parts of methylpentamethylenediamine.

[0026] 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).

[0027] Furthermore, the present invention also provides a method for preparing the polyamide resin, and the method includes the following steps:

[0028] 1) Mix the carboxylic acid compound of component a) and the polyamine compound of component b) evenly in a reaction kettle under nitrogen protection;

[0029] 2) Sequentially add component c) polyether diamine, component d) silane monomer, and component e) fluorinated monomer to the mixture;

[0030] 3) Carry out a polycondensation reaction at 125°C - 230°C, and after the reaction is completed, obtain the polyamide resin through steps of cooling, vacuum pumping, and pelletizing.

[0031] Preferably, in step 2), the addition of polyether diamine, silane monomer, and fluorinated monomer is carried out by continuous or intermittent dropping under the condition of a temperature of 120°C - 130°C.

[0032] 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.

[0033] 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.

[0034] Since the present invention adopts the above technical solution, polyether diamine, silane monomer, and fluorinated monomer are introduced into the traditional polyamide resin system for inks, significantly improving the overall performance of the resin. The specific technical effects are as follows:

[0035] 1. Excellent alcohol solubility: By introducing polyether diamine, flexible polyether segments are embedded in the molecular chain of the resin 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.

[0036] 2. Low freezing point and anti-gel performance: The added fluorinated monomer utilizes the low-polarity characteristics of the perfluoroalkyl side chain to effectively lower 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.

[0037] 3. High softening point and thermal stability: By introducing silane monomers, moderate crosslinking is formed in the molecular structure of the resin, enhancing the softening point of the resin (which can reach or exceed 110°C) and thermal stability, thus ensuring that the ink is not easily softened or deformed during high-temperature printing or storage, and improving the heat resistance and service life of the product.

[0038] 4. Environmental friendliness: The present invention adopts 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), and conforming to the current environmental protection regulations and the development trend of green printing.

[0039] 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-gel performance, 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 the printed matter.

[0040] 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 the structure and process, and have broad application prospects and high commercial promotion value. Specific Embodiments

[0041] The following combines the embodiments of the present invention, and clearly and completely describes the technical solutions in the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0042] Example 1

[0043] Composition:

[0044] Component a) Carboxylic acid compound:

[0045] - 80 parts of vegetable oil dimer acid (cottonseed oil dimer acid: soybean oil dimer acid: palm oil dimer acid = 5:2:3, the same below)

[0046] - 4 parts of propionic acid

[0047] Component b) Polyamine compounds:

[0048] - 3.5 parts of ethylenediamine

[0049] - 6.5 parts of hexamethylenediamine

[0050] - 7 parts of methylpentanediamine

[0051] Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts

[0052] Component d) Silane monomer (3-aminopropyltriethoxysilane, APTES): 1.0 part

[0053] Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 part

[0054] Defoamer: 12 ml / ton

[0055] Preparation method:

[0056] 1) Mixing and preheating

[0057] Add vegetable oil dimer acid, propionic acid and defoamer into the reaction kettle. Under the condition of nitrogen protection, stir evenly and heat to about 125 °C to form a uniform acidic reaction solution;

[0058] 2) Addition of amine mixture

[0059] At 125 °C, add the pre-mixed amine mixture (including ethylenediamine, hexamethylenediamine, methylpentanediamine, polyether diamine, silane monomer and fluorinated monomer) slowly into the reaction kettle by continuous or intermittent dropping method to ensure that the temperature of the reaction solution remains stable;

[0060] 3) Polycondensation reaction

[0061] 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;

[0062] 4) Post-treatment and granulation

[0063] Subsequently, continue to raise the temperature to 220 °C - 230 °C, turn off 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;

[0064] Finally, cool down the reaction system to 160 °C to 180 °C, and use granulation equipment to granulate and package the product to obtain the target polyamide resin.

[0065] Example 2

[0066] Composition:

[0067] Component a)

[0068] - Vegetable oil dimer acid: 79 parts

[0069] - Propionic acid: 3.5 parts

[0070] Component b)

[0071] - Ethylenediamine: 4 parts

[0072] - Hexamethylenediamine: 6 parts

[0073] - Methylpentanediamine: 6.5 parts

[0074] Component c) Polyether diamine (Jeffamine ED-600): 1.0 part

[0075] Component d) Silane monomer (3-aminopropyltrimethoxysilane, APTMS): 1.0 part

[0076] Component e) Fluorinated monomer (fluorinated acrylate monomer): 0.5 part

[0077] Defoamer: 12 ml / ton.

[0078] Preparation method:

[0079] 1) Mixing and preheating

[0080] Add vegetable oil dimer acid, propionic acid and defoamer into the reaction kettle, stir evenly under nitrogen protection and heat to 125 °C.

[0081] 2) Addition of amine mixture

[0082] Under the condition of 125 °C, slowly add dropwise the amine mixture composed of ethylenediamine, hexamethylenediamine, methylpentanediamine, polyether diamine, silane monomer and fluorinated monomer in an intermittent manner to ensure the temperature stability during the reaction.

[0083] 3) Polycondensation reaction After the addition is completed, raise the temperature to 200 °C and keep it warm for 1 hour to fully polycondense each component in the system.

[0084] 4) Post-treatment and granulation Then raise the temperature to 225 °C and treat it under vacuum for 1.5 hours. Finally, cool down to 170 °C for granulation and packaging to obtain the required polyamide resin.

[0085] Example 3

[0086] Composition:

[0087] Component a)

[0088] - 81 parts of vegetable oil dimer acid

[0089] - 3 parts of propionic acid

[0090] Component b)

[0091] - 3 parts of ethylenediamine

[0092] - 6 parts of hexamethylenediamine

[0093] - 5.5 parts of methylpentanediamine

[0094] Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts

[0095] Component d) Silane monomer (APTES): 1.0 part

[0096] Component e) Fluorinated monomer (fluorinated methacrylate monomer): 0.5 part

[0097] Defoamer: 12 ml / ton

[0098] Preparation method:

[0099] 1) Mixing and preheating Add vegetable oil dimer acid, propionic acid and defoamer into the reaction kettle, heat to 125 °C after introducing nitrogen for protection

[0100] 2) Addition of amine mixture Under the condition of 125 °C, add the amine solution mixed by ethylenediamine, hexamethylenediamine, methylpentanediamine, polyether diamine, silane monomer and fluorinated monomer into the reaction kettle by continuous dropping

[0101] 3) Polycondensation reaction Raise the reaction temperature to 200 °C and keep it for 1 hour to promote the full reaction of carboxylic acid and amine to form polyamide

[0102] 4) Post-treatment and granulation Further raise the temperature to 220 °C - 230 °C, turn off nitrogen and carry out vacuum treatment for 1 - 1.5 hours, and finally cool the system to 160 °C - 180 °C for granulation and packaging

[0103] Comparative example 1 (without adding polyether diamine)

[0104] Composition:

[0105] Component a)

[0106] - 80 parts of vegetable oil dimer acid

[0107] - 4 parts of propionic acid

[0108] Component b)

[0109] - Ethylenediamine: 3.5 parts

[0110] - Hexamethylenediamine: 6.5 parts

[0111] - Methylpentanediamine: 7 parts

[0112] Component c) None

[0113] Component d) Silane monomer (APTES): 1.0 part

[0114] Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 part

[0115] Defoamer: 12 ml / ton

[0116] Preparation method:

[0117] Operate according to the steps in Example 1, but do not add polyether diamine in step 2. Other operating conditions remain the same.

[0118] Comparative Example 2 (without adding silane monomer)

[0119] Composition:

[0120] Component a)

[0121] - Vegetable oil dimer acid: 80 parts

[0122] - Propionic acid: 4 parts

[0123] Component b)

[0124] - Ethylenediamine: 3.5 parts

[0125] - Hexamethylenediamine: 6.5 parts

[0126] - Methylpentanediamine: 7 parts

[0127] Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts

[0128] Component d) None

[0129] Component e) Fluorinated monomer (2-(perfluorooctyl) vinyl ether): 0.5 part

[0130] Defoamer: 12 ml / ton

[0131] Preparation method:

[0132] Prepare with reference to Example 1, but do not add silane monomer in step 2, and keep the remaining operating steps and conditions the same.

[0133] Comparative Example 3 (without adding fluorinated monomer)

[0134] Composition:

[0135] Component a)

[0136] - 80 parts of vegetable oil dimer acid

[0137] - 4 parts of propionic acid

[0138] Component b)

[0139] - 3.5 parts of ethylenediamine

[0140] - 6.5 parts of hexamethylenediamine

[0141] - 7 parts of methylpentanediamine

[0142] Component c) Polyether diamine (Jeffamine ED-600): 1.5 parts

[0143] Component d) Silane monomer (APTES): 1.0 part

[0144] Component e) None

[0145] Defoamer: 12 ml / ton

[0146] Preparation method:

[0147] The same as Example 1, but without adding fluorinated monomer in Step 2. Other steps remain unchanged.

[0148] Comparative Example 4 (without adding polyether diamine and fluorinated monomer at the same time)

[0149] Composition:

[0150] Component a)

[0151] - 80 parts of vegetable oil dimer acid

[0152] - 4 parts of propionic acid

[0153] Component b)

[0154] - 3.5 parts of ethylenediamine

[0155] - 6.5 parts of hexamethylenediamine

[0156] - 7 parts of methylpentanediamine

[0157] Component c) None

[0158] Component d) Silane monomer (APTES): 1.0 part

[0159] Component e) None

[0160] Defoamer: 12 ml / ton.

[0161] Preparation method:

[0162] Refer to the preparation method of Example 1, but do not add polyether diamine and fluorinated monomer in Step 2, and keep other operations the same.

[0163] Comparative Example 5 (all functional monomers are not added)

[0164] Composition:

[0165] Component a)

[0166] - 80 parts of vegetable oil dimer acid

[0167] - 4 parts of propionic acid

[0168] Component b)

[0169] - 3.5 parts of ethylenediamine

[0170] - 6.5 parts of hexamethylenediamine

[0171] - 7 parts of methylpentanediamine

[0172] Component c) None

[0173] Component d) None

[0174] Component e) None

[0175] Defoamer: 12 ml / ton.

[0176] Preparation method:

[0177] Carry out according to the preparation method of Example 1, but do not add any functional monomers in Step 2 (that is, do not add polyether diamine, silane monomer and fluorinated monomer), and keep the remaining operating conditions unchanged.

[0178] 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.

[0179] Freezing point test: Conduct the test according to the method specified in QB / T4752-2014 "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.

[0180] 2. Ethanol tolerance test: Conduct the test according to the method specified in 5.8 of QB / T4752-2014 "Alcohol-soluble Polyamide Resin for Ink". The larger the ethanol tolerance, the stronger the alcohol solubility of the polyamide resin.

[0181] 3. Initial drying property test: The test is carried out according to the initial drying property test method for liquid inks in 5.2 of GB / T 13217.5-2023 "Test Methods for Ink Drying Inspection". The initial drying property of the suitable polyamide resin endows the ink with reasonable solvent release property, printing suitability, gloss and rheology.

[0182] 4. Softening point test: The softening point test is carried out according to the method specified in GB / T 12007.6-1989 "Determination of Softening Point of Epoxy Resins - Ring and Ball Method". The larger the softening point value, the better the thermal stability of the polyamide resin.

[0183] 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.

[0184] Table 1 Comparison Table of Performance Tests

[0185]

[0186] Data description:

[0187] After introducing polyether diamine, silane monomer and fluorinated monomer in the examples, the freezing point is reduced to -4 to -4.5 °C, which is much lower than that of the comparative examples (the freezing point is between +1 and +3 °C);

[0188] 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;

[0189] The initial drying property data is maintained at 21 - 22 seconds, meeting the requirements of printing applications;

[0190] The softening point is maintained at 113 - 115 °C, ensuring thermal stability at high temperatures.

[0191] 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 should be accorded the widest scope consistent with the principles and novel points disclosed herein.

Claims

1. An alcohol-soluble polyamide resin for ink, the raw materials for its preparation comprising a) carboxylic acid compounds, b) polyamine compounds; characterized in that, The preparation raw materials with a + b being 100 parts by weight 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; The structural formula of the polyether diamine is as follows: ； y = 5 - 10, (x + z) = 3 - 6; The carboxylic acid compound is selected from 75 - 85 parts of vegetable oil dimer acid and 2 - 8 parts of propionic acid; the polyamine compound is selected from 2 - 6 parts of ethylenediamine, 4 - 10 parts of hexamethylenediamine, and 3 - 10 parts of methylpentamethylenediamine.

2. The polyamide resin according to claim 1, wherein The polyether diamine uses Jeffamine ED - 600 resin.

3. The polyamide resin according to claim 1, wherein The silane monomer is selected from 3 - aminopropyltriethoxysilane or 3 - aminopropyltrimethoxysilane.

4. The polyamide resin according to claim 1, wherein, The fluorinated monomer is selected from 2 - (perfluorooctyl) vinyl ether, fluorinated acrylate monomer or fluorinated methacrylate monomer.

5. The polyamide resin according to claim 1, wherein, The molar amount of the carboxyl group contained in component a) is in a ratio of 1:(0.8 - 1.2) to the molar amount of the primary amino group contained in component b) and component c).

6. The polyamide resin according to claim 1, 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 being (4 - 6):(2 - 3):(2 - 3).

7. A method for preparing the polyamide resin according to any one of claims 1-6, characterized in that, The method includes the following steps: 1) Mix the carboxylic acid compound of component a) and the polyamine compound of 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) Conduct polycondensation reaction at 125°C - 230°C, and after the reaction is completed, obtain the polyamide resin through steps of cooling, vacuum pumping and granulation.

8. The method according to claim 7, characterized in that, In step 2), the addition of polyether diamine, silane monomer and fluorinated monomer is carried out by continuous or intermittent dropping under the condition of a temperature of 120°C - 130°C.

9. The method according to claim 7 or 8, characterized in that, The polycondensation reaction is kept at 200°C for 0.5 - 1.5 hours, and then heated to 220°C - 230°C and subjected to vacuum pumping treatment for 1 - 1.5 hours.

10. An ink, comprising the polyamide resin described in any one of claims 1 - 6 as an ink binder, as well as pigments, solvents and ink additives.

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