A kind of boiling water resistant modified urea-formaldehyde resin adhesive and preparation method thereof

Abstract

The invention discloses a boiling water-resistant modified urea-formaldehyde resin adhesive and a preparation method thereof, which is prepared from formaldehyde, urea, polyvinyl alcohol, melamine and a reinforcing agent, wherein the molar ratio of formaldehyde to urea is 1.15-1.0 : 1, the addition of the melamine accounts for 6-14% of the total weight; the addition of the enhancer accounts for 8-20% of the total weight; the preparation method includes adding the reaction enhancer and then adding the first batch of urea, the molar ratio is 2.0-2.2:1, add the second batch of urea, the molar ratio is 1.4-1.2:1, and finally add the third batch of urea, the molar ratio is 1.15-1.0:1; the advantage of the present invention is: using formaldehyde and urea as raw materials , by adding a reinforcing agent, the flexibility of the resin molecules is increased, an interpenetrating network structure is formed, and the internal stress of the resin curing is reduced, so that the preparation of the modified urea-formaldehyde resin not only has low formaldehyde content, high bonding strength, but also low cost.

Description

technical field [0001] The invention relates to an adhesive, in particular to a boiling water-resistant modified urea-formaldehyde resin adhesive and a preparation method thereof, belonging to the field of adhesives. Background technique [0002] With the improvement of people's living standards and the continuous and stable development of construction, decoration, packaging and other industries, the output of wood-based panels in my country has grown rapidly. The total output of wood-based panels, plywood, furniture, and wood flooring has ranked first in the world for many years in a row. In 2013, the total output of wood-based panels in my country was 272 million m 3 , accounting for about 50% of the world's total production. Average production of 9m per ton of adhesive 3 According to the calculation of wood-based panels, the consumption of wood adhesives in my country in 2013 was about 30 million tons (solid content 50%), among which urea-formaldehyde resin and its mod...

AI Technical Summary

Problems solved by technology

For example: (1) Although the use of low molar ratio modified urea-formaldehyde resin adhesive can effectively reduce the formaldehyde emission of wood-based panel products, the bonding strength of the product is often reduced, which cannot meet the requirements of use; and it can lead to prolonged curing time and reduced production efficiency; ( 2) Adding formaldehyde scavenger to the urea-formaldehyde resin adhesive for wood-based panels can effectively reduce the release of free formaldehyde from wood-based panels, but it often reduces the bonding strength of wood-based panels at the same time; at the same time, the price of general formaldehyde scavenger is often much higher than that of urea-formaldehyde resin adhesives , its addition increases product cost and reduces product competitiveness; (3) Carry out post-treatment to wood-based panels, such as the invention patent application with publication number CN1526528, which discloses a kind of E1 / EO grade environmental protection type prepared by ammonia vacuum method. The manufacturing process of wood-based panels; the utility model patent with the publication number CN2394770 discloses a treatment device for reducing the formaldehyde emission of wood-based panels. The cost has been significantly increased; (4) The use of other environmentally friendly adhesives, such as isocyanate adhesives, has led to a substantial increase in the production cost of wood-based panels and increased difficulty in the production process, which is difficult for enterprises and users to accept; the use of ordinary protein adhesives to prepare wood-based panels has low bonding strength , poor water resistance, easy to mold, poor sizing performance, easy to open glue for wood-based panels

In summary, although the above measures can effectively reduce the release of free formaldehyde from wood-based panels, they cannot completely solve the problem of formaldehyde release, or cannot be popularized due to reasons such as high production costs.

Images