Method for synthesizing methylated melamine formaldehyde resin cross-linking agent with low free formaldehyde content

Abstract

The invention relates to a method for synthesizing a methylated melamine formaldehyde resin cross-linking agent with low free formaldehyde content. The technical scheme comprises the following steps of: putting melamine, formaldehyde and methanol into a reactor kettle, adjusting pH value to between 7 and 10 by using alkali, slowly raising the temperature, controlling the reaction temperature to be between 70 and 90 DEG C and preserving the heat for 1 to 2 hours; cooling reaction liquid, adding acid to adjust the pH value to between 3 and 6, etherifying the reaction liquid, controlling the reaction temperature to be between 50 and 70 DEG C and performing a reaction for 1 to 2 hours; lowering the temperature, adding an alkali terminator to adjust the pH value to between 8 and 10 to obtain mixed liquor A; and adding a formaldehyde catcher into the mixed liquor A, stirring and dissolving the mixture, dewatering in vacuum and removing methanol and formaldehyde to prepare a crude methylated melamine formaldehyde resin cross-linking agent product with low free formaldehyde content. The cross-linking agent has a long shelf life and low free formaldehyde content.

Description

technical field

[0001] The invention relates to a method for synthesizing a textile printing and dyeing crosslinking agent, in particular to a method for synthesizing a methylated melamine formaldehyde resin crosslinking agent. Background technique

[0002] Melamine formaldehyde resin is one of the traditional amino resins, widely used in leather re-kneading agent, wet strengthening agent for papermaking, water-resistant agent, cross-linking agent for coatings, etc. Methylated melamine formaldehyde resin can be used as a base for most matrix resins such as acrylic resins, epoxy resins, and alkyd resins because it is easy to cross-link with polymers with hydroxyl, carboxyl, amino and amide groups in the molecule. Cross-linking agent, compounded with acrylic adhesive, used in fixing agent for embossed fabric of textiles, cross-linking agent of pigment printing, etc., can greatly improve the color fastness and gloss of textiles. However, during use, it exists in the product st...

Examples

Embodiment 1

[0025] The synthetic method of embodiment 1 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0026] (1) Put melamine 1200g (9.5mol), 37% (m / m) formaldehyde 3090g (38mol) and methanol 3030g (95mol) into the reactor, adjust with triethylamine (triethanolamine or diethanolamine can also be used) The pH value is 8, the temperature is raised slowly, the reaction temperature is controlled at 70°C to 80°C, and the solution is kept warm for 1.5 hours after the solution is clarified.

[0027] (2) Cool the reaction liquid to 60°C, add phthalic anhydride to adjust the pH value to 5, control the reaction temperature at 50°C-60°C, react for about 1 hour, and determine the end of the reaction by water tolerance.

[0028] (3) Cool down to 30°C, add triethylamine to adjust pH to 9, and obtain mixed solution A.

[0029] (4) Add formaldehyde scavenger (formaldehyde scavenger is the mixture of urea and borax, its proportioning is by mass and number ratio, m...

Embodiment 2

[0033] The synthetic method of embodiment 2 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0034] (1) Put melamine 1200g (9.5mol), 37% (m / m) formaldehyde 4626g (57mol) and methanol 2432g (76mol) into the reaction kettle, adjust the pH value with sodium hydroxide (potassium hydroxide can also be used) 10. Raise the temperature slowly, control the reaction temperature at 80°C to 90°C, and keep the temperature for 1.5 hours after the solution is clarified.

[0035] (2) Cool the reaction solution to 60°C, add hydrochloric acid (nitric acid or sulfuric acid can also be used) to adjust the pH value to 6, control the reaction temperature at 50°C to 60°C, react for 1 hour, and determine the end of the reaction by water tolerance.

[0036] (3) Cool down to 30° C., add triethanolamine (diethanolamine can also be used) to adjust the pH value to 10, and obtain a mixed solution A.

[0037] (4) Add formaldehyde scavenger (according to the ratio of pa...

Embodiment 3

[0041] The synthetic method of embodiment 3 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0042] (1) Formaldehyde 2313g (28.5mol) and methyl alcohol 2727g (85.5mol) of melamine 1200g (9.5mol), 37% (m / m) are dropped in the reactor, adjust the pH value 7 with basic magnesium carbonate, slowly heat up, Control the reaction temperature at 70°C to 80°C, and keep it warm for 1.5 hours after the solution is clarified;

[0043] (2) Cool the reaction solution to 60°C, add formic acid (or acetic acid) to adjust the pH value to 5, control the reaction temperature at 50°C to 60°C, react for 1 hour, and determine the end of the reaction by water tolerance;

[0044] (3) Lower the temperature to 30°C, adjust the pH to 8 with sodium hydroxide (or potassium hydroxide), and obtain a mixed solution A.

[0045] (4) Add formaldehyde scavenger to mixed solution A (according to the ratio of mass and number, mixed solution A: urea: borax = 1000: 45: 10), stir...

technical field

[0001] The invention relates to a method for synthesizing a textile printing and dyeing crosslinking agent, in particular to a method for synthesizing a methylated melamine formaldehyde resin crosslinking agent. Background technique

[0002] Melamine formaldehyde resin is one of the traditional amino resins, widely used in leather re-kneading agent, wet strengthening agent for papermaking, water-resistant agent, cross-linking agent for coatings, etc. Methylated melamine formaldehyde resin can be used as a base for most matrix resins such as acrylic resins, epoxy resins, and alkyd resins because it is easy to cross-link with polymers with hydroxyl, carboxyl, amino and amide groups in the molecule. Cross-linking agent, compounded with acrylic adhesive, used in fixing agent for embossed fabric of textiles, cross-linking agent of pigment printing, etc., can greatly improve the color fastness and gloss of textiles. However, during use, it exists in the product st...

Examples

Embodiment 1

[0025] The synthetic method of embodiment 1 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0026] (1) Put melamine 1200g (9.5mol), 37% (m / m) formaldehyde 3090g (38mol) and methanol 3030g (95mol) into the reactor, adjust with triethylamine (triethanolamine or diethanolamine can also be used) The pH value is 8, the temperature is raised slowly, the reaction temperature is controlled at 70°C to 80°C, and the solution is kept warm for 1.5 hours after the solution is clarified.

[0027] (2) Cool the reaction liquid to 60°C, add phthalic anhydride to adjust the pH value to 5, control the reaction temperature at 50°C-60°C, react for about 1 hour, and determine the end of the reaction by water tolerance.

[0028] (3) Cool down to 30°C, add triethylamine to adjust pH to 9, and obtain mixed solution A.

[0029] (4) Add formaldehyde scavenger (formaldehyde scavenger is the mixture of urea and borax, its proportioning is by mass and number ratio, m...

Embodiment 2

[0033] The synthetic method of embodiment 2 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0034] (1) Put melamine 1200g (9.5mol), 37% (m / m) formaldehyde 4626g (57mol) and methanol 2432g (76mol) into the reaction kettle, adjust the pH value with sodium hydroxide (potassium hydroxide can also be used) 10. Raise the temperature slowly, control the reaction temperature at 80°C to 90°C, and keep the temperature for 1.5 hours after the solution is clarified.

[0035] (2) Cool the reaction solution to 60°C, add hydrochloric acid (nitric acid or sulfuric acid can also be used) to adjust the pH value to 6, control the reaction temperature at 50°C to 60°C, react for 1 hour, and determine the end of the reaction by water tolerance.

[0036] (3) Cool down to 30° C., add triethanolamine (diethanolamine can also be used) to adjust the pH value to 10, and obtain a mixed solution A.

[0037] (4) Add formaldehyde scavenger (according to the ratio of pa...

Embodiment 3

[0041] The synthetic method of embodiment 3 low free formaldehyde etherification melamine formaldehyde resin cross-linking agent

[0042] (1) Formaldehyde 2313g (28.5mol) and methyl alcohol 2727g (85.5mol) of melamine 1200g (9.5mol), 37% (m / m) are dropped in the reactor, adjust the pH value 7 with basic magnesium carbonate, slowly heat up, Control the reaction temperature at 70°C to 80°C, and keep it warm for 1.5 hours after the solution is clarified;

[0043] (2) Cool the reaction solution to 60°C, add formic acid (or acetic acid) to adjust the pH value to 5, control the reaction temperature at 50°C to 60°C, react for 1 hour, and determine the end of the reaction by water tolerance;

[0044] (3) Lower the temperature to 30°C, adjust the pH to 8 with sodium hydroxide (or potassium hydroxide), and obtain a mixed solution A.

[0045] (4) Add formaldehyde scavenger to mixed solution A (according to the ratio of mass and number, mixed solution A: urea: borax = 1000: 45: 10), stir...

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