Method for preparing urea-formaldehyde resin adhesive

A technology for urea-formaldehyde resins and adhesives, applied in adhesives, aldehyde/ketone condensation polymer adhesives, adhesive types, etc., can solve the problem that the release of free formaldehyde is very low, and the limit of free formaldehyde release has not been reached to protect human health and other issues to achieve the effect of reducing production costs

Inactive Publication Date: 2008-06-04
LANZHOU UNIVERSITY
View PDF0 Cites 17 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The new standard has a very low limit on the release of free formaldehyde, but the wood-based panels currently produced in my country are still difficult to meet the requirements of the new national standard. This is mainly due to the use of urea-formaldehyde resin adhesives with high free formaldehyde content, which is also a major technology that is currently difficult to solve problem
Moreover, the new standard still does not meet the basic requirements for the protection of human health on the release of free formaldehyde, and there is a possibility or requirement to continue to reduce

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for preparing urea-formaldehyde resin adhesive

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] 1. Add 190g of 36% formaldehyde into a 500ml container, add 1g of 30% sodium hydroxide solution under stirring, then heat up to 40°C, add 56g of urea, the molar ratio of urea to formaldehyde is 1:2.45, and then Raise the temperature to 80°C and stir for 60 minutes. When the pH of the solution is 6.5, add 19g of urea. The molar ratio of urea to formaldehyde is 1:1.84. Keep the temperature of the solution at 80°C for 30 minutes. After 30 minutes, add 20 % ammonium chloride solution 1g, continue to keep the temperature of the solution at 80°C for 60 minutes, and when the pH value of the solution was 5, add 30% sodium hydroxide solution 1g , keeping the temperature of the solution at 80°C for 30 minutes to make the pH of the solution 7 to obtain the raw gum;

[0024] 2. Add 17g of urea to the original gum prepared in step 1 under stirring. The molar ratio of urea to formaldehyde is 1:1.5-1.40. The solution is heated to 90°C and kept at this temperature for 30 minutes. After...

Embodiment 2

[0027] 1. Add 190g of 36% formaldehyde into a 500ml container, add 1g of 30% sodium hydroxide solution under stirring, then heat up to 60°C, add 56g of urea, the molar ratio of urea to formaldehyde is 1:2.45, and then Raise the temperature to 90°C and stir for 60 minutes. When the pH of the solution is 7.5, add 19g of urea. The molar ratio of urea to formaldehyde is 1:1.84. Keep the temperature of the solution at 85°C for 30 minutes. After 30 minutes, add 20 % ammonium chloride solution 1g, continue to keep the temperature of the solution at 85°C for 60 minutes, when the pH value of the solution is 6, add 1g of 30% sodium hydroxide solution, keep the temperature of the solution at 85°C React for 30 minutes, make the pH value of the solution 7 to make the original gum;

[0028] 2. Add 23g of urea to the original gum prepared in step 1 under stirring. The molar ratio of urea to formaldehyde is 1:1.5-1.40. The solution is heated to 96°C and kept at this temperature for 30 minutes...

Embodiment 3

[0031] 1. Add 190g of 36% formaldehyde into a 500ml container, add 1g of 30% sodium hydroxide solution under stirring, then heat up to 40°C, add 56g of urea, the molar ratio of urea to formaldehyde is 1:2.45, and then Raise the temperature to 80°C and stir for 60 minutes. When the pH of the solution is 6.5, add 19g of urea. The molar ratio of urea to formaldehyde is 1:1.84. Keep the temperature of the solution at 80°C for 30 minutes. After 30 minutes, add 20 % ammonium chloride solution 1g, continue to keep the temperature of the solution at 80°C for 60 minutes, when the pH value of the solution is 5, add 1g of 30% sodium hydroxide solution, keep the temperature of the solution at 80°C React for 30 minutes, make the pH value of the solution 7 to make the original gum;

[0032] 2. Add 23g of urea to the raw gum prepared in step 1 under stirring, the molar ratio of urea to formaldehyde is 1:1.5-1.40, heat up the solution to 90°C, keep the temperature for 30 minutes, then cool th...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a preparation method for urea-formaldehyde resin adhesive. Ethyleneurea and melamine, or polyvinyl alcohol is taken as formaldehyde catching agent, and then added with carbamide, flour and lauxite to react to obtain the urea-formaldehyde resin adhesive. The invention with low formaldehyde content is low cost composite board adhesive that meets the requirements of environmental protection, ensures that all good performances of the urea-formaldehyde resin adhesive are kept and lowers the production cost, thus obtaining a pragmatic adhesive that can be afforded entirely by composite board processing enterprises.

Description

technical field [0001] The invention relates to a preparation method of an environment-friendly urea-formaldehyde resin adhesive, in particular to a method for preparing a urea-formaldehyde resin adhesive with a composite formaldehyde scavenger. Background technique [0002] my country is a country of Shaolin, and there is a big contradiction between the supply and demand of timber. An important way to solve this contradiction is to vigorously develop the production and utilization of composite panels centered on wood-based panels. Using urea-formaldehyde resin adhesive to produce 1 cubic meter of particleboard can replace 3.1 cubic meters of log boards; and using urea-formaldehyde resin adhesive to produce 1 ton of fiberboard can replace 5.6 cubic meters of log boards. That is to say, adhesives are of great significance to improving the utilization rate of wood; at the same time, the consumption of adhesives in the wood industry is also huge. A large amount of adhesive mus...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C09J161/24
Inventor 石辉文武小莉刘涛
Owner LANZHOU UNIVERSITY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap