Formaldehyde-free light shaving board and preparation method thereof

Abstract

The invention discloses a formaldehyde-free light shaving board and a preparation method thereof. The density of the formaldehyde-free light shaving board ranges from 0.4 g / cm<3> to 0.6 g / cm<3>. The formaldehyde-free light shaving board is mainly prepared from raw materials including wood shavings, isocyanate, dicarboxylic acid modified polyether polyol containing benzene rings, a tackifier, a catalyst and water. The prepared light shaving board is low in density, excellent in performance, capable of meeting various performance index requirements of the national standard GB / T 4897-2015 for theshaving board, excellent in size stability and water resistance, capable of being widely applied to various indoor decorations, light in board material, convenient to move indoors and high in practicability.

Description

Technical field[0001]The invention belongs to the field of aldehyde-free lightweight man-made boards, in particular the field of lightweight particleboard and fiberboard, and relates to an aldehyde-free lightweight particleboard and a preparation method thereof.Background technique[0002]With the continuous reduction of forest resources, the crisis of wood shortage and rising raw material prices is becoming more and more obvious, which forces people to find more raw material-saving processes to prepare boards and reduce the consumption of wood raw materials. The density of traditional particleboard is about 600-750kg / m3, Each cubic board needs to consume 1.1-1.3 tons of wood raw materials, which consumes more wood.[0003]The existing technology prepares the particleboard, the adhesive is mostly urea glue system, mainly including urea-formaldehyde, phenolic, melamine modified formaldehyde resin glue, this kind of adhesive uses formaldehyde as the main synthetic raw material, the free f...

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Problems solved by technology

Liu Yanlong and others reacted the isocyanate group (-NCO) in the water-foaming polyurethane prepolymer with water to form a foam, filled the gap between the shavings, and obtained a density of less than 500kg / m 3 The lightweight particleboard needs 4-10 minutes of hot pressing time, and the opening time of raw materials is short and requires a long hot pressing time, which affects the production efficiency and production cost of the product

BASF patent US8187709B2 mentions the use of EPS particles to prepare formaldehyde-free lightweight particleboard, which can be obtained with a density of 300-600kg / m 3 The lightweight particleboard, but the EPS particles contain some blowing agents, especially the recommended EPS, which contains small molecular substances such as pentane, which releases flammable gases during the hot pressing process. In the high-temperature construction environment of wood-based panels, there Safety risk, and the distribution of EPS particles in the wood-based panel is uneven, and defects are formed on the surface, which affects the board-making effect on the surface of the board

[0004] Most of the polyols mentioned in the market are polyether polyols or polyester polyols, and the end groups are hydroxyl end groups. After contacting with isocyanate adhesives, they can react quickly, and the reaction releases heat, which promotes the formation of isocyanate and water. Side reactions such as polyurea, for some fields that require a slow reaction of isocyanate glue, the performance is easily affected

The conventional method is to add inorganic acid to polyol to inhibit the activity of isocyanate. The added inorganic acid has certain corrosion on equipment, etc. and the mixing uniformity and storage stability are poor.

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