Environment-friendly urea resin for laminating plywoods from high water-content veneers and preparation and application thereof

An environmentally friendly urea-formaldehyde resin and formaldehyde technology, used in adhesives, adhesive types, aldehyde/ketone condensation polymer adhesives, etc. The effect of increased crosslink density, high bond strength and low formaldehyde emission

Active Publication Date: 2011-06-08
广西鑫恒晶木业股份有限公司
View PDF1 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this urea-formaldehyde resin is only suitable for veneer pressing plywood in the normal moisture content range. When veneer with high moisture content is used to press plywood, the pre-pressing effect and bonding strength will decrease significantly, and the formaldehyde emission will also increase.

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
  • Environment-friendly urea resin for laminating plywoods from high water-content veneers and preparation and application thereof
  • Environment-friendly urea resin for laminating plywoods from high water-content veneers and preparation and application thereof
  • Environment-friendly urea resin for laminating plywoods from high water-content veneers and preparation and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] The raw material formula of table 1 embodiment one

[0033]

[0034] Note: F and U represent the weights of formaldehyde solution and urea added respectively, U 1 -U 3 respectively represent the weight of urea added in the first to third batches, f and u represent the moles of formaldehyde and urea respectively, u 1 -u 3 respectively represent the moles of urea added in the first to the third batch, and f / u represents the ratio of the moles of formaldehyde to the moles of urea.

[0035] Concrete reaction steps are as follows:

[0036] 1) Add 37% formaldehyde solution and PVA solution to the reaction kettle in sequence, turn on the steam to heat to 40-50°C, and turn off the steam;

[0037] 2) Use formic acid to adjust pH=4.0, and slowly add U 1 ,

[0038] 3) Then open the steam valve and turn off the steam when the temperature rises to 60-80°C, and raise the temperature to 90°C by the self-exothermic reaction. At 85°C, add M 1 and ammonia water, adjust the pH t...

Embodiment 2

[0052] The raw material formula of table 2 embodiment two:

[0053]

[0054]

[0055] Note: F and U represent the weights of formaldehyde solution and urea added respectively, U 1 -U 3 respectively represent the weight of urea added in the first to third batches, f and u represent the moles of formaldehyde and urea respectively, u 1 -u 3 respectively represent the moles of urea added in the first to the third batch, and f / u represents the ratio of the moles of formaldehyde to the moles of urea.

[0056] Concrete reaction steps are as follows:

[0057] 1) Add 37% formaldehyde solution and PVA solution to the reaction kettle in sequence, turn on the steam to heat to 40-50°C, and turn off the steam;

[0058] 2) Use formic acid to adjust pH=4.2, and slowly add U 1 ,

[0059] 3) Then open the steam valve and turn off the steam when the temperature rises to 60-80°C, let it heat up to 90°C, and add M at 85°C 1 and ammonia water, adjust the pH to 8.5, and keep warm for 40...

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

PropertyMeasurementUnit
viscosityaaaaaaaaaa
viscosityaaaaaaaaaa
viscosityaaaaaaaaaa
Login to view more

Abstract

The invention relates to a preparation method and application of environment-friendly urea resin for laminating plywoods from high water-content veneers. The method for synthesizing the resin is simple, and low in cost; the laminated plywoods can meet the national E1 grade and even E0 grade environmental protection requirements; and the problems of low prepressing performance and water resistance when the high water-content veneers are laminated into the plywoods are mainly solved. In the synthesis of the urea resin, an acid-base-acid-base process is adopted, formaldehyde and polyvinyl alcohol are added at one time, urea is added by three batches, melamine is added by two times, and after ammonia water is added, the ammonia water, the urea, the formaldehyde and urea-form condensate are reacted to generate a series of triazine ring compounds, and the microstructure of the resin is improved. When the resin is cured, the crosslinking density is improved, wet shear strength of the plywoods is obviously improved and the formaldehyde emission is obviously reduced.

Description

technical field [0001] The invention relates to a low-toxic environment-friendly urea-formaldehyde resin and a preparation method thereof, in particular to an environment-friendly urea-formaldehyde resin for plywood production and a preparation method thereof, belonging to the field of wood-based panel adhesives. Background technique [0002] Plywood has always been favored by people because of its excellent performance, easy processing, moderate price and retaining the natural texture and texture of wood. It is the earliest and most prosperous traditional product in wood-based panels. In recent years, the output of plywood in my country has been increasing continuously, accounting for about 40% of the total output of wood-based panels. With the advancement of science and technology, the continuous emergence and improvement of derivative products and deep-processing varieties of plywood, various types of plywood will be more and more widely used in various fields of the nati...

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): C08G12/12C09J161/24
Inventor 雷得定纪良刘波
Owner 广西鑫恒晶木业股份有限公司
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