Preparation method of full-alkaline synthetic melamine urea-formaldehyde resin and wood impregnation method thereof

Abstract

The invention provides a preparation method of full-alkaline synthetic melamine urea-formaldehyde resin and a wood impregnation method thereof. The preparation method comprises the following steps: adding 900-1200 parts by weight of a formaldehyde solution, 4-8 parts by weight of a sodium hydroxide solution, 20-120 parts by weight of melamine and 225-500 parts by weight of urea, then adjusting thetemperature to 60-90 DEG C, carrying out a constant-temperature reaction for 0.5-5 hours, and keeping the pH value to be 7-10; keeping the temperature of the constant-temperature reaction to be 60-90DEG C, then adding 150-475 parts by weight of urea and 90-300 parts by weight of maltodextrin or polyvinyl alcohol or starch, and carrying out a reaction for 0.5-5 hours; and adding 10-300 parts by weight of ammonia water and 2-30 parts by weight of triethylene tetramine, carrying out stirring for 5-20 minutes, and carrying out cooling to room temperature for discharging. During use, wood blocksobtained after log sawing are put into a kiln for drying, sodium borate, ammonium borate and quaternary ammonium copper are added into the melamine formaldehyde resin impregnation liquid obtained by the method, adding the dried wood blocks into the mixed solution obtained by the method for impregnation; and drying the impregnated wood block samples to finally obtain a finished product.

Description

technical field [0001] The invention relates to a preparation method of melamine urea-formaldehyde resin and a wood impregnation method thereof. Background technique [0002] With the rapid development of the economy, people's demand for wood is increasing day by day. The shortage of timber has become a common problem in many countries in the world. Fast-growing and high-yielding wood is favored by more and more manufacturers and researchers because of its short growth cycle, high yield, and good economic benefits. The main species of artificial fast-growing forests in my country are poplar, willow, birch, paulownia and eucalyptus. However, fast-growing wood has disadvantages such as poor material, short fibers, easy deformation, and easy to rot and insects. It cannot meet the requirements of high-grade wood processing industry and lacks application value and economic value. In order to improve the performance of fast-growing wood, thereby expanding the range of use of fa...

AI Technical Summary

Problems solved by technology

[0003] Although the utilization rate of the wood-plastic composite method using broken wood is high, it is a waste of the mechanical support and restraint performance of the natural three-dimensional structure of the wood itself. The weather resistance of impregnated solid wood to adverse environmental factors such as water intrusion and sun exposure is lower than that of broken wood composite materials. significantly high, so for cheap fast-growing forest solid wood, it should make full use of the natural structure of solid wood and adopt impregnation modification

However, the initial viscosity and molecular weight of traditional glue are too large, which is not conducive to impregnating solid wood.

In the past, some physical or chemical methods were often used to violently expand wood pores or increase external pressure, such as high-pressure steam drying, high-pressure glue impregnation and other wood treatment methods. However, these treatment processes still have uneven wood treatment and limited performance improvement. , and additional production cost