Low peak exotherm curable compositions

Abstract

Compositions having a curable unsaturated compound, an adhesion promoter and curing agent which have a peak exotherm of less than 50° C. are disclosed. The compositions when cured are flexible bioadhesives which are also disclosed. Non-curable diluents can be included in the compositions. Flexible bioadhesives formed on biological structures and having low peak exotherms upon curing of curable compositions to form the flexible bioadhesives are disclosed. Compositions having a curable unsaturated compound and a curing agent and a peak exotherm of less than 50° C. are included in the invention.

Description

The present invention relates to low peak exotherm curable compositions that upon curing are useful as bioadhesives. The compositions of the invention call be placed in contact with one or more skin or mucosal surfaces, or other tissue surfaces, in an initially liquid or malleable form, then subsequently cured or polymerized in place to a final flexible solid or rubbery form. BACKGROUND OF THE INVENTION A broad spectrum of bioadhesives and bioadhesive compositions have been developed, for example, to adhere transdermal patches to the skin and to affix transmucosal patches to mucosal surfaces. In general, the purpose of such bioadhesives is to maintain intimate and prolonged contact with the underlying living tissue surface, in order to allow for the migration of medicinals into the body. In addition, bioadhesive compositions include those that merely adhere a physical barrier, such as a bandage, to living tissue (primarily for the purpose of protecting an underlying wound or compr...

AI Technical Summary

Benefits of technology

These and other objectives are achieved by the present invention, which provides low peak exotherm curable compositions which comprise a curable u

Problems solved by technology

One drawback of existing transdermal and transmucosal patches is their limited ability to conform to biological substrates that are not relatively flat.

However, attachment of such a patch to a more contoured surface, such as on the knuckles of the hand, would be problematical without the ability of the patch to flex and conform in multiple dimensions, especially during movement of the underlying skin.

Transmucosal patches suffer from the same limitations of underlying tissue surface topography, made more difficult by the complexity and difficulty of adhering to a moist substrate, such as the oral mucosa lining the inside of the mouth.

In addition, the cured barrier is rigid, which results in frequent detachment of the cured barrier during lengthy dental procedures (such as power bleaching, which employs a heat or light source to assist in the tooth bleaching process).

Barrier failure (detachment) can result in contact of the underlying soft tissue with potentially harmful dental agents (such as the high-strength hydrogen peroxide used in tooth bleaching procedures or phosphoric acid, used in acid-etching of tooth surfaces prior to bonding procedures).

Yet another disadvantage of OpalDam™ is its high peak exotherm during the curing process.

Another disadvantage of currently available dental “resin dams”, as they are called, comes from the inclusion of low molecular weight monomers, such as triethylene glycol dimethacrylate, urethane dimethacrylate, and hydroxyethyl methacrylate.

Since a typical free radical polymerization of low molecular weight monomers will never proceed to 100 percent completion, there are always residual monomers that do not participate in the polymerization reaction and thus can leach out from the polymerized material to cause unwanted skin reaction and possible health problems.