Synthesis of high-imino high-methylated hexamethoxy melamine resin and preparation method of granulation of high-imino high-methylated hexamethoxy melamine resin
By using solid acid large-pore strong acid cationic resin catalyst and twin-screw extrusion technology in the production of high iminomethyl etherified resins, the problem of difficult intermediate generation and growth is solved, and efficient synthesis and granulation are achieved, which improves the Product performance and process efficiency.
Patent Information
- Application Number
- CN202411483036.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-02-07
AI Technical Summary
The existing production processes of high iminomethyl etherified resins are difficult to control the formation and growth of intermediates, resulting in large system viscosity during etherification, affecting process efficiency and product performance.
Using solid acid large pore strong acid cationic resin as catalyst, the reaction between methanol and hexamethylmethyl melamine at a lower temperature is carried out to synthesize hexamethoxy melamine resin, and pelletize using a twin-screw extruder. , separation and screening through an airflow classifier.
It realizes efficient synthesis and granulation of high imino-high methylated hexamethoxy melamine resin, simplifies the process flow, reduces energy consumption, and improves the fluidity and application performance of the product.
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Figure CN119391350A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a method for preparing a high-imino high-methyl etherified hexamethoxy melamine resin and its granulation, and belongs to the technical field of preparation of rubber adhesive materials. Background Art
[0002] Hexamethoxymethylmelamine (HMMM) has a hexafunctional single molecule structure, high reactivity and cross-linking properties, good miscibility with alkyd resins, polyester resins, acrylic resins, epoxy resins, phenolic resins, etc., and good water solubility, making it suitable for use as a cross-linking agent for low-VOC coatings.
[0003] Although there are many preparations and applications of HMMM, the etherification reaction is the dehydration etherification of the active hydroxymethyl terminal hydroxyl group of HMM and the alcohol hydroxyl group under the catalytic action of acid. When the acid is used as a catalyst, methanol is activated to form a carbon cation, which attacks the nucleophilic hydroxymethyl group. Similar to the reaction network of hydroxymethylation of melamine and formaldehyde, HMM also has an etherification condensation reaction with six reaction sites. The precursor of HMMM is HMM, which is obtained by the reaction of melamine and formaldehyde aqueous solution. The product HMM is insoluble in water. In the etherification reaction process of HMM and methanol, water is one of the products of the etherification reaction. The presence of water will affect the equilibrium of the etherification reaction, causing the reaction equilibrium to move in reverse and hindering the formation of etherification products. In order to obtain a high etherification product, a high methyl etherification product can be obtained by reacting dry HMM with methanol.
[0004] In the actual production reaction, methanol reacts with HMM, and methanol is both a solvent and a reactant. However, HMM is not soluble in methanol, and the reaction system is initially a heterogeneous system. The reaction process is carried out on the surface of HMM particles, and the reaction rate is affected by the particle size and aggregation state. As the etherification reaction proceeds, the system gradually becomes homogeneous. Temperature also has a great influence on the etherification reaction, and low temperature is the key to preventing condensation side reactions from occurring during the etherification reaction. Usually, below 50°C, the reaction is mainly manifested as a methyl etherification reaction, and polycondensation rarely occurs. The reaction product is a mononuclear (triazine ring) etherified product with different etherification degrees. When it exceeds 50°C, the polycondensation side reaction increases significantly, and the higher the temperature, the more serious the degree of polycondensation and cross-linking gel. In addition, acid is an etherification reaction catalyst, and too low pH is prone to induce polycondensation and cross-linking between hydroxymethyl groups; if the pH is too high, the reaction rate is too slow and the etherification is incomplete. When the reaction system pH = 3.5, the etherification reaction is complete, and polycondensation side reactions rarely occur.
[0005] Methylated melamine resins are generally divided into polymerized partially methylated melamine resins, polymerized high-imino high-methylated melamine resins and monomeric high-methylated melamine resins. Due to the low degree of etherification of partially methylated products and the low content of hydroxymethyl in monomeric products, high-imino products have the best comprehensive performance in back-end applications, retaining a certain amount of unreacted active hydrogen atoms and a certain amount of residual hydroxymethyl. When it reacts with a matrix resin containing hydroxyl, carboxyl, and amide groups, it has a faster curing property due to the high content of imino in the resin, and the addition of weak acid can accelerate the curing reaction. Therefore, the market prospects are broad.
[0006] At present, the production process of high-iminomethyl etherified resin is roughly divided into two types: one is a one-step method, that is, the raw materials are put in at one time, and the reaction is controlled by adjusting the pH value of the system; the other is a two-step method, that is, the intermediate of tetramethylol melamine is first synthesized (very difficult to industrialize), and then etherification is carried out. However, in actual synthesis, no matter which process is used, it is difficult to control the generation and growth of the intermediate, resulting in a very high viscosity of the system during the back-end etherification. Summary of the invention
[0007] The purpose of the present invention is to provide a method for synthesizing a high-imino high-methyl etherified hexamethoxy melamine resin and preparing the same by granulation.
[0008] The specific contents are as follows: a high-imino high-methylated hexamethoxymelamine resin is synthesized by a methylation reaction at a relatively low temperature using a solid acid macroporous strongly acidic cationic resin as a catalyst and a reaction amount of methanol to hexahydroxymethylmelamine (HMM) of 7 to 9:1; and then raw materials such as high-methylated hexamethoxymelamine resin (HMMM), white carbon black, mineral oil for dispersant, and urotropine as a promoter are put into a high-speed mixer in a certain proportion and mixed until the mixture is uniform; and then the mixed raw materials are put into a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws; and finally, the particles are separated and sieved through an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 5.5 mm;
[0009] The structure of high imino high methyl etherified hexamethoxy melamine resin is as follows:
[0010]
[0011] A method for synthesizing a high-imino high-methyl etherified hexamethoxy melamine resin and preparing the same by granulation, the method comprising the following steps:
[0012] a) The preparation route diagram of high imino high methyl etherified hexamethoxy melamine resin is as follows:
[0013]
[0014] b) Methanol and hexahydroxymethylmelamine (HMM) are added to a reactor equipped with a reflux condenser and an exhaust gas collection device in a certain molar ratio, and the catalyst is a macroporous strongly acidic cationic resin, and mechanical stirring is turned on to react at a lower temperature for 30 to 45 minutes, and then react at a higher temperature for 50 to 60 minutes;
[0015] c) heating to remove methanol and water, and the recovered methanol can be reused after distillation. When the temperature reaches 90°C, start the vacuum system and continue to heat up. When the temperature reaches 110°C, continue stirring and keeping warm for 30 minutes;
[0016] d) Cooling to 90° C. and filtering while hot. The macroporous strongly acidic cationic resin obtained by filtration can be reused after drying to obtain the product highly methylated hexamethoxy melamine resin (HMMM);
[0017] e) Highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil for dispersant, urotropine as accelerator and other raw materials are put into a high-speed mixer according to a certain proportion and mixed until they are uniformly mixed. Then the mixed raw materials are put into a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and sieved by an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 5.0 mm.
[0018] The molar ratio of methanol to hexahydroxymethylmelamine (HMM) in step b) is 7 to 9:1; the lower reaction temperature in step b) is 40° C. to 50° C. for 30 to 45 minutes; the higher reaction temperature in step b) is 50° C. to 55° C. for 50 to 60 minutes.
[0019] The amount of the macroporous strongly acidic cationic resin used in step b) is 3% to 5% of the mass of the reactant hexahydroxymethylmelamine (HMM).
[0020] In step d), the ratio of the highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil and hexamethylenetetramine is 67:30-32:0.5-2:0.5-1.
[0021] The white carbon black in step d) is fumed silica, with an oil absorption value greater than 3.0 and an addition or subtraction amount less than 3%.
[0022] The mineral oil in step d) is a C10-C14 alkane.
[0023] Beneficial Effects
[0024] It can be seen from the above technical scheme and implementation method that the present invention synthesizes high methylated hexamethoxy melamine resin (HMMM) by methylation reaction at a relatively low temperature by using solid acid macroporous strong acidic cationic resin as catalyst, according to the reaction amount of methanol and hexahydroxymethyl melamine (HMM) of 7 to 9:1, the method has the advantages of simple synthesis process, low reaction temperature, less amount of methanol used, recycling of solid acid as catalyst, reducing alkali neutralization step, suitable for large-scale production, etc., and the synthesis process is a one-step method, which is carried out continuously without the need to process intermediate products, saving energy consumption. Utilizing the characteristics of mineral oil, efficient granulation can be achieved by twin-screw co-extrusion technology, which is suitable for preparing high methylated hexamethoxy melamine resin (HMMM) adhesive particles, facilitating the packaging, transportation and use of hexamethoxy melamine resin (HMMM) adhesive, and the addition of mineral oil is conducive to improving the fluidity of hexamethoxy melamine resin (HMMM) adhesive. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The high imino high methyl etherified hexamethoxy melamine resin of the present invention 1 HNMR
[0026] Figure 2 The GC-MS of the high imino high methyl etherified hexamethoxy melamine resin of the present invention is
[0027] Figure 3 FT-IR of the high imino high methyl etherified hexamethoxy melamine resin of the present invention
[0028] Figure 4 This is a physical picture of the highly methylated hexamethoxy melamine resin (HMMM) of the present invention. Figure 5 This is a physical picture of the high methylated hexamethoxy melamine resin (HMMM) adhesive particles of the present invention DETAILED DESCRIPTION
[0029] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.
[0030] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.
[0031] The high-imino high-methylated hexamethoxy melamine resin of the invention is synthesized by using a solid acid macroporous strongly acidic cationic resin as a catalyst, and the reaction amount of methanol and hexahydroxymethyl melamine (HMM) is subjected to a methylation reaction at a relatively low temperature to synthesize a high-methylated hexamethoxy melamine resin (HMMM). The preparation process is as follows: methanol and hexahydroxymethyl melamine (HMM) are added to a reactor equipped with a reflux condenser and a tail gas collecting device in a molar ratio of 7-9:1, and the catalyst macroporous strongly acidic cationic resin is used in an amount of 3-5% of the mass of HMM, and mechanical stirring is turned on to react at 40-50°C for 30-45 minutes, and then react at 50-55°C for 50-60 minutes, and the temperature is increased to evaporate methanol and water, and the recovered methanol can be reused after rectification. When the temperature reaches 90°C, start the vacuum system and continue to heat up. When it reaches 110°C, continue stirring and keeping warm for 30 minutes, then cool to 90°C and filter while hot. The macroporous strongly acidic cationic resin obtained by filtration can be dried and reused to obtain the product highly methylated hexamethoxymelamine resin (HMMM).
[0032] Then, high methyl etherified hexamethoxy melamine resin (HMMM), white carbon black, mineral oil for dispersion, accelerator hexamethylenetetramine and other raw materials are placed in a high-speed mixer in a certain proportion and mixed until they are evenly mixed. Then the mixed raw materials are placed in a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and screened by an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 5.5 mm. The particle size distribution is relatively uniform. The twin-screw co-extrusion technology can achieve efficient granulation and is suitable for preparing particles.
[0033] Example 1
[0034] 1.0 mol hexahydroxymethyl melamine (HMM), actual weight 306.27 g, 8.0 mol methanol, actual weight 256.34 g, 15 g macroporous strong acidic cationic resin, add into a 2000 ml three-necked flask, install reflux condenser, tail gas collection device, etc., start mechanical stirring, slowly heat up to 40°C and keep stirring for 30 minutes, continue to slowly heat up to 50°C, and keep stirring for 40 minutes after the material in the kettle is transparent. Heat up to evaporate methanol and water, and the recovered methanol can be reused after distillation. When the temperature reaches 90°C, the vacuum system is started and the temperature is continued to rise. When the temperature reaches 110°C, stirring and heat preservation are continued for 30 minutes, and then the mixture is cooled to 90°C and filtered while hot. The macroporous strongly acidic cationic resin obtained by filtration can be reused after drying to obtain 386.9 g of the product highly methylated hexamethoxymelamine resin (HMMM), of which the non-volatile matter is 99.09%, the viscosity is 2680 cps / 25°C, the degree of etherification is 5.89, and the free formaldehyde content is less than 0.1%.
[0035] Highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil, hexamethylenetetramine and other raw materials are placed in a high-speed mixer according to a certain ratio of 67:32:0.5:0.5 (mass ratio) and mixed until they are evenly mixed. Then the mixed raw materials are placed in a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and sieved by an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 3.5 mm, and the particle size distribution is relatively uniform. The twin-screw co-mixing extrusion technology can achieve efficient granulation and is suitable for preparing particles.
[0036] Example 2
[0037] 1.0 mol hexahydroxymethyl melamine (HMM), actual weight 306.27 g, 7.0 mol methanol, actual weight 224.29 g, 12 g macroporous strong acidic cationic resin, add into a 2000 ml three-necked flask, install reflux condenser, tail gas collection device, etc., start mechanical stirring, slowly heat up to 45°C and keep stirring for 45 minutes, continue to slowly heat up to 55°C, and keep stirring for 50 minutes after the material in the kettle is transparent. Heat up to evaporate methanol and water, and the recovered methanol can be reused after distillation. When the temperature reaches 90°C, the vacuum system is started and the temperature is continued to rise. When the temperature reaches 110°C, stirring and heat preservation are continued for 30 minutes, and then the mixture is cooled to 90°C and filtered while hot. The macroporous strongly acidic cationic resin obtained by filtration can be reused after drying to obtain 385.10 g of the product highly methylated hexamethoxymelamine resin (HMMM), of which the non-volatile matter is 98.63%, the viscosity is 2910 cps / 25°C, the degree of etherification is 5.90, and the free formaldehyde content is less than 0.1%.
[0038] Highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil, hexamethylenetetramine and other raw materials are placed in a high-speed mixer according to a certain ratio of 67:31:1.5:0.5 (mass ratio) and mixed until they are evenly mixed. Then the mixed raw materials are placed in a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and sieved by an airflow classifier to obtain particles with a particle size distribution between 3.5 mm and 4.5 mm, and the particle size distribution is relatively uniform. The twin-screw co-mixing extrusion technology can achieve efficient granulation and is suitable for preparing particles.
[0039] Example 3
[0040] 1.0 mol hexahydroxymethyl melamine (HMM), actual weight 306.27 g, 9.0 mol methanol, actual weight 288.38 g, 13.5 g macroporous strong acidic cationic resin, add into a 2000 ml three-necked flask, install reflux condenser, tail gas collection device, etc., start mechanical stirring, slowly heat up to 40°C and keep stirring for 30 minutes, continue to slowly heat up to 50°C, and keep stirring for 40 minutes after the material in the kettle is transparent. Heat up to evaporate methanol and water, and the recovered methanol can be reused after distillation. When the temperature reaches 90°C, the vacuum system is started and the temperature is continued to rise. When the temperature reaches 110°C, stirring and heat preservation are continued for 30 minutes, and then the mixture is cooled to 90°C and filtered while hot. The macroporous strongly acidic cationic resin obtained by filtration can be reused after drying to obtain 387.32 g of the product highly methylated hexamethoxymelamine resin (HMMM), of which the non-volatile matter is 99.20%, the viscosity is 2985 cps / 25°C, the degree of etherification is 5.92, and the free formaldehyde content is less than 0.1%.
[0041] Highly methylated hexamethoxy melamine resin (HMMM), white carbon black, hexamethylenetetramine and other raw materials are placed in a high-speed mixer according to a certain ratio of 67:30:2:1 (mass ratio) and mixed until they are evenly mixed. Then the mixed raw materials are placed in a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and sieved by an airflow classifier to obtain particles with a particle size distribution between 4.0 mm and 5.5 mm. The particle size distribution is relatively uniform. The twin-screw co-mixing extrusion technology can achieve efficient granulation and is suitable for preparing particles.
[0042] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for synthesizing a high-imino high-methyl etherified hexamethoxy melamine resin and preparing the same by granulation, characterized in that: The invention discloses a high-imino high-methylated hexamethoxymelamine resin. The high-methylated hexamethoxymelamine resin (HMMM) is synthesized by a methylation reaction at a relatively low temperature with a reaction amount of methanol to hexahydroxymethylmelamine (HMM) of 7 to 9:1 using a solid acid macroporous strongly acidic cationic resin as a catalyst. The high-methylated hexamethoxymelamine resin (HMMM), white carbon black, mineral oil for a dispersant, urotropine as a promoter and other raw materials are put into a high-speed mixer in a certain proportion and mixed until the mixture is uniform. The mixed raw materials are then put into a twin-screw extruder. The raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and screened by an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 5.5 mm.
2. The method for preparing a high-imino high-methyl etherified hexamethoxy melamine resin and granulating the same according to claim 1, characterized in that: The structure of high imino high methyl etherified hexamethoxy melamine resin is as follows:
3. A method for preparing a high-imino high-methyl etherified hexamethoxy melamine resin and granulating the same as claimed in claim 1, characterized in that The method comprises the following steps: a) The preparation route diagram of high imino high methyl etherified hexamethoxy melamine resin is as follows: b) Methanol and hexahydroxymethyl melamine (HMM) are added to a reactor equipped with a reflux condenser and an exhaust gas collection device in a certain molar ratio, and the catalyst is a macroporous strongly acidic cationic resin, and mechanical stirring is turned on to react at a lower temperature for 30 to 45 minutes, and then at a higher temperature for 50 to 60 minutes; c) heating to remove methanol and water, and the recovered methanol can be reused after distillation. When the temperature reaches 90°C, start the vacuum system and continue to heat up. When the temperature reaches 110°C, continue stirring and keeping warm for 30 minutes; d) Cooling to 90° C. and filtering while hot. The macroporous strongly acidic cationic resin obtained by filtration can be reused after drying to obtain the product highly methylated hexamethoxy melamine resin (HMMM); e) Highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil for dispersant, urotropine as accelerator and other raw materials are put into a high-speed mixer according to a certain proportion and mixed until they are uniformly mixed. Then the mixed raw materials are put into a twin-screw extruder, and the raw materials are extruded into particles through efficient mixing, stirring and extrusion of the twin screws. Finally, the particles are separated and sieved by an airflow classifier to obtain particles with a particle size distribution between 3.0 mm and 5.0 mm.
4. The method for preparing the synthesis of a high-imino high-methyl etherified hexamethoxy melamine resin and granulation thereof according to claim 3, characterized in that: The molar ratio of methanol to hexahydroxymethylmelamine (HMM) in step b) is 7 to 9:1; the lower reaction temperature in step b) is 40° C. to 50° C. for 30 to 45 minutes; the higher reaction temperature in step b) is 50° C. to 55° C. for 50 to 60 minutes.
5. The method for preparing the synthesis of a high-imino high-methyl etherified hexamethoxy melamine resin and granulation thereof according to claim 3, characterized in that: The amount of the macroporous strongly acidic cationic resin used in step b) is 3% to 5% of the mass of the reactant hexahydroxymethylmelamine (HMM).
6. The method for preparing the synthesis of a high-imino high-methyl etherified hexamethoxy melamine resin and granulation thereof according to claim 3, characterized in that: In step d), the ratio of the highly methylated hexamethoxy melamine resin (HMMM), white carbon black, mineral oil and hexamethylenetetramine is 67:30-32:0.5-2:0.5-1.
7. The method for preparing the synthesis of a high-imino high-methyl etherified hexamethoxy melamine resin and granulation thereof according to claim 3, characterized in that: The white carbon black in step d) is fumed silica, with an oil absorption value greater than 3.0 and an addition or subtraction amount less than 3%.
8. The method for preparing the synthesis of a high-imino high-methyl etherified hexamethoxy melamine resin and granulation thereof according to claim 3, characterized in that: The mineral oil in step d) is a C10-C14 alkane.