Preparation method of low-formaldehyde stiffening agent

A stiffener and low-formaldehyde technology, which is applied in the field of preparation of low-formaldehyde stiffeners, can solve the problems of shortened storage time of stiffener products, unscientific and effective preparation of low-formaldehyde stiffeners, and large energy loss.

Active Publication Date: 2020-10-23
HANGZHOU TRANSFAR FINE CHEM CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, increasing the alcohol-water ratio reduces the free formaldehyde in the stiffening agent. The main principle is to remove methanol through the concentration process. The removal of methanol will take away the residual formaldehyde, thereby reducing the content of free formaldehyde in the stiffening agent. These methods not only reduce aldehyde The effect is not good, and a large amount of methanol is consumed, and the energy loss is relatively large, so it is not an economical and practical method for preparing low-formaldehyde stiffeners
Adding aldehyde scavengers is the most common met

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] First, put 721kg of methanol and 2kg of hydrochloric acid into reactor A, adjust the pH value to 4.0-6.0; raise the temperature to 60-62°C, keep the acidified methanol in reactor A in a boiling reflux state, and put it into reactor B; Drop into 1200kg methyl alcohol, turn on stirring, drop into urea 300kg, melamine 630kg, triethanolamine 38kg, formaldehyde (44%) 2045kg, liquid caustic soda 6kg is heated up to 78-82 ℃, methylolation insulation 60 minutes; Pump the material into the reaction kettle A. After the feeding is completed, mix and react the materials in the kettle for 20 minutes, and adjust the pH value to 7.0-9.0 with liquid caustic; when the material in the reaction kettle A is below 60°C, use the pump to transfer to distillation kettle, vacuum distillation to remove excess water, formaldehyde and methanol in the system, distill the solid content of the product to 75%, detect free formaldehyde 0.8%, and then transfer to the stripping tower to remove the formald...

Embodiment 2

[0025] First, put 1442kg of methanol and 3kg of formic acid into reactor A, adjust the pH value to 4.0-6.0; raise the temperature to 60-62°C, keep the acidified methanol in reactor A in a boiling reflux state, and put it into reactor B; Put in 2400kg methanol, turn on the stirring, put in 120kg of urea, 756kg of melamine, 38kg of dicyandiamide, 2045kg of formaldehyde (44%), 8kg of potassium hydroxide and heat up to 78-82°C, keep the methylolation for 60 minutes; Pump the materials in the reactor A into the reaction kettle A. After the feeding is completed, mix and react the materials in the kettle for 60 minutes, and adjust the pH value to 7.0-9.0 with liquid caustic; To the distillation pot, decompression distillation removes excess water, formaldehyde and methanol in the system, distills the solid content of the product to 75%, detects 0.9% of free formaldehyde, and then transfers to the stripping tower, keeping the feed amount of the stiffening agent at 600kg / hour, the ga...

Embodiment 3

[0028] First, put 942kg of methanol and 3kg of nitric acid into reactor A, adjust the pH value to 4.0-6.0; raise the temperature to 60-62°C, keep the acidified methanol in reactor A in a boiling reflux state, and put it into reactor B; Put in 1500kg of methanol, turn on the stirring, put in 200kg of urea, 698kg of melamine, 20kg of dicyandiamide, 2045kg of formaldehyde (44%), 8kg of liquid caustic soda and heat up to 78-82°C, keep the methylolation for 60 minutes; The materials in the reactor A are pumped into the reaction kettle A. After the feeding is completed, the materials in the kettle are mixed and reacted for 45 minutes, and the pH value is adjusted to 7.0-9.0 with liquid alkali; Distillation kettle, vacuum distillation to remove excess water, formaldehyde and methanol in the system, distill the solid content of the product to 75%, then transfer to the stripping tower, detect 0.7% of free formaldehyde, and then transfer to the stripping tower to keep it stiff The feedi...

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PUM

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Abstract

The invention discloses a preparation method of a low-formaldehyde stiffening agent. An existing stiffening agent is mainly formed by polycondensation of melamine, formaldehyde and urea, and excessiveformaldehyde is used in raw materials, so that the content of free formaldehyde in a stiffening agent product is high, and the stiffening agent product has great influence on human bodies and the environment. According to the invention, urea, formaldehyde, melamine, organic amine and methanol are used as raw materials; the high-etherification-degree melamine-urea-formaldehyde resin is prepared through a double-kettle process, the conversion rate of formaldehyde participating in a reaction is increased, most of free formaldehyde in a finished product is removed through a gas stripping process,the content of the prepared stiffening agent free formaldehyde is smaller than or equal to 0.2%, and the requirement of a user for environmental protection is better met.

Description

technical field [0001] The invention relates to the field of printing and dyeing auxiliaries, in particular to a preparation method of a low-formaldehyde stiffening agent. Background technique [0002] Formaldehyde is an irritating gas, toxic and carcinogenic, so all countries have imposed strict restrictions on formaldehyde on textiles. Melamine-urea-formaldehyde resin is a common cost-effective stiffening agent. Due to the excessive use of formaldehyde in the preparation of the stiffening agent, there is a relatively high free formaldehyde in the stiffening agent product, and the free formaldehyde of the general product is ≥1%. Especially in summer, the methanol in the product is mixed with free formaldehyde and volatilizes into the air, seriously endangering the physical and mental health of producers and users, and also reducing the quality of the product. [0003] The reaction process for the preparation of the stiffening agent includes two processes: the methylolation...

Claims

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Application Information

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IPC IPC(8): C08G12/38D06M15/423D06M101/32
CPCC08G12/38D06M15/423D06M2101/32Y02P20/10
Inventor 何文栋杨小波缪宇龙张德明司马聪陈萍萍
Owner HANGZHOU TRANSFAR FINE CHEM CO LTD
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