Urea formaldehyde condensate additive agent, production method and urea formaldehyde condensate adhesive agent

Abstract

The invention relates to a urea resin additive used in hard boards and a urea resin binder which comprises the additive and a preparation method thereof; the additive comprises substances which are dipped in and extracted from tea scraps and can eliminate formaldehyde; the extracting steps comprise steps of dipping and extracting the tea scraps by utilizing alkaline solution, filtering the tea scraps to obtain a filtrate and adjusting the ph value of the filtrate. By mixedly using the extracts of the tea scraps and the urea resin gel, the tea scrap extracts is led to be chemically reacted with the formaldehyde in the heat pressing process of the hard board, thus reducing the releasing amount of the formaldehyde of the hard board and having remarkable and durable effect without rebound; furthermore, the mechanical property of the prepared hard board is improved instead of being reduced.

Description

Technical field [0001] The invention relates to an additive for an adhesive, an adhesive containing the additive and a preparation method thereof, in particular to an additive for a urea-formaldehyde resin adhesive for wood-based panels and a urea-formaldehyde resin adhesive containing the additive and a preparation method thereof method. Background technique [0002] In the past 30 years of reform and opening up, my country's timber industry has developed rapidly. In 2006, the output value of my country's wood-based panels was 127 billion yuan, and the total output of wood-based panels was 74,285,600 cubic meters, of which plywood was 27,287,800 cubic meters, fiberboard was 24,666,000 cubic meters, particleboard was 8,432,600 cubic meters, and blockboard was 11.55 million cubic meters. The total output of wood-based panels, the output of plywood and the increased production capacity of medium-density fiberboard in the past four years rank first in the world. Wood floor productio...

AI Technical Summary

Problems solved by technology

For example, 1) Although the use of a 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; the curing time is prolonged and the production efficiency is reduced; 2) the use of other Environmentally friendly adhesives, such as isocyanate adhesives, often lead to a substantial increase in the production cost of wood-based panels, which is difficult for enterprises and users to accept; 3) Adding formaldehyde scavenger to the urea-formaldehyde resin adhesive for wood-based panels can effectively reduce free formaldehyde in wood-based panels. release amount, but it often reduces the bonding strength of wood-based panels at the same time; at the same time, the price of general formaldehyde capture agents is often much higher than that of urea-formaldehyde resin adhesives, and its addition increases product costs and reduces product competitiveness. FC-5 formaldehyde scavenger sold at 50,000 yuan / ton. If 1%-2% is added to the glue, the cost of urea-formaldehyde resin per ton will increase by 500-1,000 yuan; 4) Post-treatment of wood-based panels, For example, the invention patent application with the publication number CN1526528 discloses a manufacturing process of E1 / E0 grade environment-friendly wood-based panels, using the ammonia vacuum method, and the utility model patent with the publication number CN2394770 discloses a method for reducing formaldehyde release from wood-based panels. A large amount of processing equipment, but the investment in post-processing equipment is often large