Single-Component Bonding Adhesives

Full bond strength achieved immediately upon cure single-component systems Adhesive remains unchanged until cured No viscosity adjustments Shelf-life of at least six months... 

A particular adhesive group used for high heat-resistant bonding is the single-component reactive adhesive, as a combination of phenolic resin and nitrile rubber, in the form of heat activated films (HAF). These contain latent hardeners for the phenolic resins, which are activated at a temperature of approximately more than 120°C. The advantages include clean and precise handling. 

The polymers of the 2-cyanoacryhc esters, more commonly known as the alkyl 2-cyaiioacrylates, are hard glassy resins that exhibit excellent adhesion to a wide variety of materials. The polymers are spontaneously formed when their Hquid precursors or monomers are placed between two closely fitting surfaces. The spontaneous polymerisation of these very reactive Hquids and the excellent adhesion properties of the cured resins combine to make these compounds a unique class of single-component, ambient-temperature-curing adhesives of great versatiUty. The materials that can be bonded mn the gamut from metals, plastics, most elastomers, fabrics, and woods to many ceramics. 

With single-component adhesives, the adhesive components are premixed in their final proportions. They are however chemically blocked. As long as they are not subjected to the specific conditions which activate the hardener, they will not bond. They require either high temperature or substances or media (light and humidity) from their surroundings to initiate the curing mechanism. The containers in which this type of adhesive is stored are carefully chosen to prevent any undesirable reaction. 

Single-component solventless reactive liquid adhesives where the diisocyanate group is the key bonding element in a prepolymer base. 

Thermoplastic adhesives soften and melt when heated (provided that they do not decompose). In other words, they do not cross-link during cure. These adhesives are single-component and harden upon cooling by evaporation of a solvent or water vehicle. They have poor creep resistance, fair peel strength, and are used mostly in unstressed joints and designs with caps, overlaps, and stiffeners. The most common application is to bond nonmetallic materials such as wood, leather, cork, and paper.In general, thermoplastic adhesives are not used for structural applications or at temperatures above 66°C (150°F). Thermoplastic adhesives includeit t ... 

Smith has described in detail the practical advantages of carboxyl functional Neoprenes AF and AJ for making improved contact adhesives. The early room temperature bond strength of conventional neoprene contact adhesive is dependent on the crystallization rate of the polymer. Single component adhesive systems based on carboxyl functionality undergo crosslinking reactions with divalent... 

Polyurethane adhesives for plastics are available primarily in both single-component and two-component forms. They are very tough, flexible products with excellent peel strength and are also extremely versatile for the bonding of larger plastic components. 

Toughened acrylic. This rapidly developing group of materials is based on several acrylic monomers three basic forms are available. Some are truly single-component adhesives, the anaerobic versions, while others require some form of hardener. One version of the latter has a catalytic surface primer which is applied to one of the surfaces to be bonded. Alternatively, the hardener may be a resin which is mixed directly into the adhesive. 

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