Binding of fibrous material utilizing a crosslinked polyamic acid

Abstract

Improved binder technology for use with fibrous materials is provided whereby the adjoining fibers of a fibrous material are bound in the absence of a phenol-formaldehyde reaction product. A curable binder composition is provided which comprises a water-soluble polyamic acid and an organic crosslinking agent capable of undergoing a covalent crosslinking reaction with the polyamic acid. The polyamic acid is formed by the reaction of a polycarboxylic acid and / or polyanhydride having a molecular weight of at least 150 with ammonia and / or amine compound. The binding composition is coated on a fibrous material and is heated to achieve crosslinking of the polyamic acid to form a cured water-resistant binder in association with the fibrous material wherein adjoining fibers are bound at cross-over points.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The subject invention pertains to an improved aqueous binding composition for use with fibrous materials. More specifically, the subject invention pertains to the use of a curable binding composition comprising a water-soluble polyamic acid and an organic crosslinking capable of reaction with the polyamic acid. Such polyamic acid is formed by the reaction of a polycarboxylic acid and / or polyanhydride having a molecular weight of at least 150 and ammonia and / or an amine compound. The aqueous binding composition is coated on a fibrous material and is heated to achieve crosslinking to form a water-resistant cured binder in association with the fibrous material wherein adjoining fibers are bound at cross-over points.[0003]2. Description of the Related Art[0004]Binders for fibrous materials, such as fiberglass, have a variety of uses ranging from stiffening applications where the binder is applied to woven or non-woven fiber...

AI Technical Summary

Problems solved by technology

Fiberglass binders also cannot be equated with paper or wood product “binders” where the adhesive properties are tailored to the chemical nature of the cellulosic substrates.

Many such resins are not suitable for use as fiberglass binders.

Also, viscous binders tend to be tacky or sticky and hence they lead to the unwanted accumulation of fiber on the forming chamber walls.

This accumulated fiber may later fall onto the mat causing dense areas and product problems.

However, binder-coated fiberglass products are often of the commodity type, and thus cost becomes a driving factor, generally ruling out in some instances such resins as thermosetting polyurethanes, epoxies, and others.

This hydrophilicity can result in fiberglass insulation that is more prone to absorb water, thereby possibly compromising the integrity of the product.

Also, the thermosetting acrylic resins now being used as binding agents for fiberglass have been found to not react as effectively with silane coupling agents of the type traditionally used by the industry.

The addition of silicone as a hydrophobing agent results in problems when abatement devices are used that are based on incineration.

Also, the presence of silicone in the manufacturing process can interfere with the adhesion of certain facing substrates to the finished fiberglass material.