INDUSTRIAL AND ENGINEERING CHEMISTRY
20
denier dry and 0.58 wet at 15 per cent and 21 per cent elongation, respectively. Significant data of a commercial rayon piilp processed and spun at the same time were: hemicellulose content, 5.7 per cent; filtration, excellent; clarity 22 mm.; tensile strength, 1.48 grams per denier dry and 0.60 wet at 16 and 21 per cent elongation, respectively.
Acknowledgment The authors wish to express their appreciation to C. H. Herty, director of the laboratory, for his interest and advice during the execution of the work. They also acknowledge the assistance rendered by the staff of the laboratory. To
VOL. 30, NO. 1
J. S. Fox for the bleaching and the chemical analyses of the pulps and to W. L. Hendrix for the cooking of the pulps special acknowledgment is due.
Literature Cited (1) Carpenter, C . , Tech. Assoc. Papew, 20, 371 (1937). (2) Herty, C . H., Texiile FVmZd, 85. IS40 (Sept., 1935). (3) Herty, C. H., and Res& R. H., Raym and Melliand Tcztilc Monthly. 16, 107-8 (1935). (4) Raseh, R. H., Manufa~turersRecord, Nov.. 1934. ( 5 ) Rasch. R. H., Paperlnd., 17, 948-53 (1936). R E C E ~ VSeytemher E~ 10, 1937. Presented before the Diviaion of Cellulosa Chemistry at the 94th Meeting of the hmeriean Chemioal Society ,Rocheater N . Y . . September B to 10, 1937.
MASTIC FLOOR TILE --CARLETON ELLIS Ellis-FosterCompany , Montdair., N. J.
FIGURE1.
APPEARANC~ OF TILES CONTAINING A SULPURRESINBINDERAFTER A YEAR'SSERYICE
T h e rirela xhows tile in
the making of separate tiles to lay in place was introduced, the binder being hot-mixed with the fillers. Production of individually molded tiles mas first practiced, hut this was superseded later by the present process oi sheeting and cutting to size. As long as asphalt was used as the binder, colors were limited to blacks, although the duller shades of red, green, and brown were possible by heavy pigmentation (8). Candle tar or stearin pitch, mixed with sufficient hard asphalt to give i t the right body and consistency, was the usual hinder. Asphalts such as gilsonite, whose dominant color is brown instead of black, were preferred, since a somewhat wider range of colors W B S then possible. A representative formula is: 25 parts Vegetable itch 25 Asbeatup f i f e 120 Coloring matter to shade GiI8O"ite
vestibule: the other oietuie ii a s l e ~tread exposed out of doois.
B
LL flooring material can be classified under the headings of textile, wood, plastic, or ceramic. Plastic floor compositions include linoleum, rubber, cork, and mastic coverings. Each type of floor has its particular good features. The present outline deals with only one phase of the plastic floor-covering field. The main advantages of mastic flooring are its cheapness and acceptable durability. The material is not as hard and cold as ceramic, and feels more resilient underfoot. Rubber and cork compositions are much more expensive; this is also true of ceramic tile, which comes in a class nith marble. Disadvantages of present mastic products are susceptibility to solvents and grease, more or less eold flow which causes slow indentation when heavy objects are placed on the floor, and liability to scratching. At present, about 12,000,000 pounds of asphalt tile are used yearly in the United States; one company alone is in a position to produce 15,000,000 square feet a year.
The ingredients are mixed a t an elevated temperature and shaped (6).
Light-Colored Tile With the trend in all industries towards lighter and brighter colors, the tile manufacturer in seeking to satisfy this preference turned to materials of lighter color than asphalt. Coumaron resin was a more or less natural choice not only on account of its color but also of its unsaponifiable nature (3). At present the demand for this resin for tiles taxes the supply. Since it is thermoplastic, no change in process was required and the only problem was to find a plasticizcr that would give the right consistency. Fatty acid pitch was selected of necessity since i t imparted a toughness not obtainable with other cheaply available softeners. However, the inherent brown color of fatty acid pitches is a disadvantage, and cheap tiles of very light color are still not possible. The following is an example of such a composition: Vegetable pitoh
