Urea formaldehyde resin adhesive for moisture-proof environment-friendly medium density fiberboard and production method as well as composite additives thereof

Abstract

The invention discloses a urea formaldehyde resin adhesive for a moisture-proof environment-friendly medium density fiberboard and composite additives thereof. The adhesive is mainly prepared from the following raw materials in parts by weight: 50-60 parts of formaldehyde of which the mass concentration is 37%, 35-40 parts of urea of which the purity is 98%, and 4.5-7.5 parts of composite additives, wherein the composite additives comprise the following components in parts by weight: 40-90 parts of melamine, 1-30 parts of modified starch, 1-30 parts of anti-swelling agent and 1-5 parts of accelerant. By utilizing the renewable low-cost modified starch, the water resistance and bonding strength of the urea formaldehyde resin adhesive can be improved, the release amount of formaldehyde is reduced, the consumption of melamine is reduced, the product quality is stable, and the cost is lower. The invention also discloses a production method of the adhesive, which is characterized in that: the formaldehyde is fed for two times, the composite additives are fed for three times and are in end point control for three times, and the urea is fed for four times. Thus, few additives are used for playing a greater role, and the problems of higher reaction speed, longer adhesive curing time and the like caused by the melamine are avoided.

Description

technical field [0001] The invention belongs to the field of modified urea-formaldehyde resin adhesives, and in particular relates to a urea-formaldehyde resin adhesive for moisture-proof and environment-friendly medium-fiber boards, a production method and a composite auxiliary. Background technique [0002] In recent years, my country has become a major producer of wood-based panels. However, although the output is large, there are not many varieties, especially the functional varieties are too few. As far as fiberboard is concerned, most factories only produce furniture-type or common-type medium-density fiberboard used in dry conditions, which cannot meet the requirements of the development of the situation. The new national standard GB / T 11718-2009 for medium density fiberboard (referred to as medium fiberboard), which was implemented on April 1, 2010, has been classified according to the conditions of use. There are three major types of MDF: ordinary type, furniture ...

AI Technical Summary

Problems solved by technology

Although the above-mentioned methods can produce moisture-proof and environmentally friendly fiberboards, phenolic resins, melamine resins or isocyanates are too expensive, and melamine-modified urea-formaldehyde resins, regardless of blending and copolymerization, use more melamine (generally accounting for 8 to 20% of the total resin amount). %), leading to high cost and poor market acceptance

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