Adhesives for paper 1879-1920: recipes and proprietary products

© 2009 Alice CannonThis research examines historical recipes recommended for use on paper-based collection from 1870-1920. The historical development of the adhesives industry is presented, including the use of advertising amongst commercial adhesive manufacturers. A review of binders used during the timeframe of interest was performed, to determine whether synthetic polymers may have been in use. Recipes were collected from various contemporary sources, including trade books, patents, journals and newspapers. Ingredient lists were analysed statistically in order to determine common ingredients and formulations. Water-resistant formulations were also identified. These included mixtures of binders, plant resins, linseed oil and/or the use of chemical hardeners such as potassium dichromate, tannic acid and alum. Binders such as casein, egg albumen and even starch and flour are less soluble in water and therefore more difficult to remove. Theories of adhesion and their application to paper substrates are discussed. Physical adsorption and mechanical interlocking are the two most significant adhesion theories that apply to paper. Mechanisms affecting the degree of adhesion on ageing of both adhesive and paper include chain scission, crosslinking, oxidation and interactions with polyvalent metal ions. Results of analysis for known and unknown adhesive samples are presented. Analysis methods investigated include microscopy, solubility testing, chemical spot tests, X-ray fluorescence and Fourier Transform Infrared spectroscopy. Binder mixtures, small sample sizes and a lack of reference data were the main barriers to obtaining positive identification of samples. Solubility issues and possible treatment methodologies for insoluble adhesives are discussed. These focus on the use of enzymes, chelating agents, heat and pH adjustment. Regardless of the treatment path chosen, removal of adhesives from paper substrates can be difficult if the adhesive only swells, rather than solubilises, and is inaccessible for mechanical removal