LEATHER, ARTIFICIAL, or leather substitute, has been made in various ways for over seventy-five years, the earliest patents having been granted in England about 185o. The most popular material used at present consists essentially of a suitable cotton base fabric to which has been applied a waterproof coating composition. The material so prepared is smooth and in order to simulate genuine leather must be given a suitable pat tern or design. The design may be either a reproduction of genu ine leather or merely a conventional pattern. The material may be made in either solid colours or in multitone effects by applying additional coatings of contrasting colours after embossing. In this way Spanish or Morocco leather finishes as well as many other pleasing effects can be produced. The fabrics used as a base for the material may be either sheetings which are of the plain weave type, or drills, sateens, moleskins and broken twills which are of the twill weave type. The weight per square yard of the fabrics varies from 2 ounces to 20 ounces depending on th type of material to be manufactured. Bef ore coating the fabrics are usually dyed a colour similar to that of the coating composition to be applied. The heavier fabrics are often napped on the un coated side to make the finished product softer and more pliable. The coating compositions applied to the fabric are of two gen eral types,—Cellulose Nitrate compositions or drying oil com positions, the former being the most commonly used. The Cellu lose Nitrate compositions consist of dry Cellulose Nitrate dis persed in a mixture of suitable organic solvents, such as de natured Ethyl Alcohol or Methyl Alcohol, Methyl, Ethyl or Butyl Acetate, Acetone and hydrocarbons of the Methane or Benzene series, to which is added pigment previously dispersed in a suitable softener or plasticizer. The finished composition thus consists of Cellulose Nitrate dispersed in an organic medium, pig ment and softener or plasticizer. The most common softener
used is pure castor oil ; Oxidized castor, rapeseed, cottonseed, fish or linseed oil are also used. Among common plasticizers used are Dibutyl Phthalate, Dibutyl Tartrate, Triphenyl and Tricresyl Phosphate. The pigments used are usually of mineral origin, although many lakes are used to produce the more brilliant colors. The drying oil compositions consist essentially of suitably bodied drying or semi-drying oils, pigment and fillers, such as clay, talc or barytes. The coating composition is applied by passing the fabric under a "doctor" knife attached to a suitable framework. The coated fabric is then passed through a drying chamber where the solvent is volatilized, to be recovered by some manufacturers. The drying oil compositions must be "baked" or dried for a period of several hours. Rubber compound coated fabrics are sometimes embossed in leather grains and the material sold as Artificial Leather. This material, however, cannot be produced in the variety of colours and grains that is possible with the Cellu lose Nitrate type.
Artificial leather finds a variety of uses, in many places taking the place of leather and in some instances being preferred to genuine leather. Among innumerable uses are upholstery of furni ture and automobile seats, automobile tops, both of open and closed type, bookbinding, notebook covers, luggage of various kinds, various parts of shoes, protective coverings where water proofness is essential, decorative purposes as wall coverings, table covers, etc. The manufacture of Artificial Leather in the United States occupies an important position in the industries of the country. The material is also manufactured in Europe and finds extensive uses there. In the United States between 45 and 5o million yards are manufactured yearly and the industry is steadily growing. (E. H. N.)