Disclosed are polyurea compositions comprising the reaction products of a polyformal-isocyanate prepolymer and a curing agent comprising an amine. The compositions are useful as sealants in aerospace applications.

Disclosed are polyurea compositions comprising the reaction products of a polyformal-isocyanate prepolymer and a curing agent comprising an amine. The compositions are useful as sealants in aerospace applications.

The present invention relates to a composition comprising a) at least one polyoxymethylene (A) having terminal OH-groups of more than 15 mmol/kg, b) at least one coupling agent (B), c) one or more hindered amine light stabilizer (C) having a molecular weight ranging from 500 to 1000 g/mol, and d) optionally at least one reinforcing fiber (D).

The present invention relates to a composition comprising a) at least one polyoxymethylene (A) having terminal OH-groups of more than 15 mmol/kg, b) at least one coupling agent (B), c) one or more hindered amine light stabilizer (C) having a molecular weight ranging from 500 to 1000 g/mol, and d) optionally at least one reinforcing fiber (D).

The invention relates to a method for producing NCO-modified polyoxymethylene block copolymers comprising the step of polymerizing formaldehyde in a reaction vessel in the presence of a catalyst, the polymerization of formaldehyde in addition taking place in the presence of a starter compound comprising at least 2 Zerewitinoff active H atoms to obtain an intermediate product. The intermediate product obtained is reacted further with an isocyanate to obtain an NCO-modified polyoxymethylene block copolymer. The invention also relates to NCO-modified polyoxymethylene block copolymers obtained by a method of this type and to the use of said copolymers for producing polyurethane polymers.

The invention relates to a method for producing NCO-modified polyoxymethylene block copolymers comprising the step of polymerizing formaldehyde in a reaction vessel in the presence of a catalyst, the polymerization of formaldehyde in addition taking place in the presence of a starter compound comprising at least 2 Zerewitinoff active H atoms to obtain an intermediate product. The intermediate product obtained is reacted further with an isocyanate to obtain an NCO-modified polyoxymethylene block copolymer. The invention also relates to NCO-modified polyoxymethylene block copolymers obtained by a method of this type and to the use of said copolymers for producing polyurethane polymers.

Thermoplastic films are disclosed that are suitable for use as auto wraps. The films include a thermoplastic polymer layer comprising a thermoplastic polyurethane polymer and a polyvinyl acetal polymer. The films further comprise a patterned adhesive layer. The thermoplastic films, when tested by a 25% Heat Relaxation Test at a thickness of about 0.006 inches, exhibit a final load from about 0.02 to about 0.3 pounds force; and when tested by a 25% Elastic Recovery test, exhibit a residual strain at one minute of 2% or greater.

Fiber reinforced polyoxymethylene polymer compositions are disclosed. A coupling agent is included in the composition for compatibilizing or forming bonds between the reinforcing fibers or a size composition on the reinforcing fibers and the polyoxymethylene polymer. In one embodiment, a latent coupling agent is contained in the sizing composition on the reinforcing fibers. In an alternative embodiment, a coupling agent-enriched polymer is added to the composition. Physical properties are dramatically improved without having to add any free isocyanate compounds.

Fiber reinforced polyoxymethylene polymer compositions are disclosed. A coupling agent is included in the composition for compatibilizing or forming bonds between the reinforcing fibers or a size composition on the reinforcing fibers and the polyoxymethylene polymer. In one embodiment, a latent coupling agent is contained in the sizing composition on the reinforcing fibers. In an alternative embodiment, a coupling agent-enriched polymer is added to the composition. Physical properties are dramatically improved without having to add any free isocyanate compounds.