Multi-functional acrylate, methacrylate pressure sensitive adhesive

Polyfunctional acrylates, methacrylate, and other unsaturated monomers are widely used in coatings, adhesives, sealants, elastomers, crosslinked films, cast sand binders, and composite structures. These monomers can be cross-linked by a free radical chain reaction, which requires a substance (e.g., peroxide, peroxide, or nitrogen compounds) capable of producing free radicals that break down to form free radicals when heated or at ambient temperatures in the presence of a class or transition metal accelerator.

Another way to initiate a reaction is to use UV light to break down photosensitive initiators to form free radicals. This method is not yet widely used but is improving. This method provides a very rapid processing process that allows a large number of applications to be carried out because the transition from a liquid reactive composition to a cross-linked solid substance is done essentially at the same time as UV exposure.

The disadvantage of both methods of initiating free radical reactions is that the decomposition of the initiator or photosensitive initiator produces low-molecular weight components that may volatilize during or after the production process, resulting in safety problems for workers, consumers and the environment. For example, these low molecular weight parts are easy to be absorbed by the skin, which has adverse effects on health. Another disadvantage is that acrylic’s free radical reactions are usually inhibited by oxygen, such as the presence of oxygen, which prevents the reaction from progressing completely.

These limitations exist in several major approaches. This problem with the escape of the photoinitiator component during production or subsequent leakage has been solved by the preparation of acrylic monomers/oligomers containing the “indigenous” photoinitiator. This can be achieved by taking a compound (or suitable derivative) known as a photosensitive initiator as the starting material and functionalizing it with an appropriate unsaturated group (e.g., acrylic or methacrylic acid) to produce a new compound with the dual function of a monomer/oligomer and a photosensitive initiator. Or it can be grafted onto a formed oligomer/polymer to produce a higher molecular weight photoinitiator. Regardless of the effectiveness of these methods, they always add additional production processes and costs.