Isocyanate binder

Curing of a diol (HTPB) with isocyanate binder... 

In three-layer flakeboards based on five softwood and hardwood species of 4, 10, and 18% moisture content, with press temperature of 177 °C, 6-min press time, and 3% isocyanate binder, the results showed that moisture content of wood was the most important variable at 18% moisture level, IB and bonding properties were lowest. Species of wood influenced strongly the bonding efficiency. In almost all cases the bending properties were the key characteristic of the panel performance. Southern pine produced the boards with lowest IB (81-116 psi), and red oak gave the highest IB values (98-213 psi) (J95). 

The use of polyurethane as a binder has found two interesting applications foundry cores and woodchip particleboard. The foundry industry has recognized the value of polyurethane adhesive binders to bind sand foundry cores for metal casting. This application is increasing steadily. The use of isocyanate binders for woodchip particleboard is receiving significant attention. The... 

Most investigators agree that the strength and durability of isocyanate-bound wood panels are due to the chemical reaction of the isocyanate group with wood hydroxyls as illustrated by the above equation. Thus, the multifunctional isocyanate molecule forms a chemically bonded bridge between two or more adjacent wood particles. This reaction is only one of several involving isocyanates that can and probably do occur in a hot press during formation of particleboards when isocyanate binder is used. A very important reaction is that of isocyanate with water to produce a very unstable carbamic acid which immediately decomposes to form a primary amine and COg ... 

The West German parent of Mobay Chemical Corporation was very active, along with Deutsche Novopan, in the development of isocyanate as a particleboard binder in Europe. The work of Sachs (12, 13, lL) and of Deppe (L, 5.), along with the aforementioned commercial developments, has provided a background for interest in isocyanate binders in North America. This interest is beginning to be reflected in the literature. For example, Hse (15.) has published papers on the development of both plywood and flakeboard adhesives which combine isocyanate and phenolic resins. In the former case, he claims adequate bonding with wetter veneers than can be used with conventional phenolic adhesive. In the case of... 

Isobind Isocyanate binders, Dow Isonol Polyether polyols, Dow Isoplast Engineering thermoplastic PUR, Dow... 

A paint grade of cerium sulfide has also been developed. The pigment has been evaluated in several coatings formulations such as automotive refinish (acrylic-isocyanate binders), general industrial solvent-based systems (polyester-melamine bin-... 

Cold-Box Process. In the cold-box process which takes place at room temperature, a gas catalyst is passed through the sand to promote curing. The catalysts are triethylamine or meth-ylethylamine for phenolic isocyanate binders, sulfur dioxide for vinyl-unsaturated urethane binders, and methyl formate for an alkali metal salt of a phenolic resole binder. Yii -ortho resins have been developed for the phenolic component by using water-free systems and salts of divalent metals as catalysts. A recent patent describes improvements in the two-package phe-... 

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