Rubber cement

Bottle of rubber cement, showing a brush built into the cap, and a photo about to be cemented to graph paper.

Rubber cement is an adhesive made from elastic polymers (typically latex) mixed in a solvent such as acetone, hexane, heptane or toluene to keep them fluid enough to be used. Water-based formulas, often stabilised by ammonia, are also available. This makes it part of the class of drying adhesives: as the solvents quickly evaporate, the "rubber" portion remains behind, forming a strong, yet flexible bond. Often a small percentage of alcohol is added to the mix.

Composition

General

Rubber cement is simply a mixture of solid rubber in a volatile solvent that will dissolve it. When the cement is applied, the solvent evaporates, leaving the rubber as the adhesive. Almost any rubber (pre-vulcanized or not) can be used.[1] The rubbers used might be natural rubber, gum mastic or gum arabic. Early solvents used included chloroform and benzene.[2] In the United States of America, current formulations include n-heptane. In the UK, a product called Marabu-Fixogum uses acetone.

Special compositions

Many compositions have included hardeners and/or vulcanizing agents designed to improve the cohesion of the rubber.[3]

Usage

Rubber cement is favored in art applications where easy and damage-free removal of adhesive is desired. For example, rubber cement is used as the marking fluid in erasable pens.

Because rubber cements are designed to peel easily or rub off without damaging the paper or leaving any trace of adhesive behind, they are ideal for use in paste-up work where excess cement might need to be removed. It also does not become brittle as paste does. Older formula rubber cements are not considered an archivally sound adhesive because of their low pH value (acidic) and will cause deterioration of photographs and papers over time. Newer formulas of rubber cement such as Elmer's 'No-Wrinkle' are acid-free and considered "photo safe".[4]

Hazards

The solvents used in rubber cement present some hazards, including flammability and potential for abuse as inhalants. Therefore, as with any adhesive, rubber cement should be used in an open area. Also, care needs be taken to avoid heat sources, as n-heptane and n-hexane are highly flammable. Rubber cement and rubber cement thinner (which is used to replace the solvent that evaporates from the container and to remove stains of glue) that contain acetone will damage polished surfaces and many plastics.[5]

References

  1. ↑ The Great Soviet Encyclopedia (in Russian). 3. Moscow: USSR. 1977.
  2. ↑ Dawidowsky, f; Brannt, William T (1905). Glue, Gelatine, Animal Charcoal, Phosphorus, Cements, Pastes, and Micilages (in German and English) (2nd ed.). 810 Walnut St;Philadelphia, USA: Henry Carey Baird & Co. p. 282.
  3. ↑ A USA 4007233 A, Yuji Kako; Toyoji Kikuga & Akira Toko, "Rubber cement compositions", published Feb 8, 1977
  4. ↑ "acid-free VS archival". Wetcanvas. Retrieved September 25, 2016.
  5. ↑ Actio Software Corporation (2007). Devcon - Rubber Cement. Retrieved from http://www.devcon.com/techinfo/14900.PDF.
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