US 2828219 A
Description (OCR text may contain errors)
March 25,1958 w, HEIGES ETAL' 2,828,219
FLOOR AND WALL COVERING 'Filed July 29. 1955 LOW MOLECULAR WEIGHT HYDROCARBON wAx PLUS POLYETHYLENE POLYMER HIGH MOLECULAR WEIGHT POLYE THYLENE POLYMER COMPRESSED CORK PARTICLE INVENTQR RUSSELL, w HEIGES WILLJAM BER-EEO.
Unite A 2,828,219 Patented Mar. 25;, 1
FLOGR AND WALL COVERING Russell W. Heiges, and William R. Reed, Pittsburgh, Pa., assignors to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania Application July 29, 1955, Serial No. 525,400
2 Claims. (Cl. 117-72) This invention relates to a floor and wall tile having applied thereto a soil-resistant, wear-resistant coating. More particularly, this invention relates to an irregular floor and wall tile such as cork tile having applied thereto a polyethylene type protective coating to render the surface resistant to dirt and wear.
In coating floor and wall tile, such as cork tile, with a wear-resistant coating composition, it has been necessary to select a composition which will fill all of the small imperfections in the surface of the tile which are common to products formed from natural ,cork. In order to satisfactorily fill all of these imperfections, it has been necessary that the coating composition have a low viscosity. As a general rule, compositions having low viscosity, even though they satisfactorily fill the imperfections in the surface of the tile, do not have the wear resistance and soil resistance necessary to serve as a satisfactory coating composition. In order to overcome this difficulty, finishes have been prepared from blends of well-known waxes and polyethylene to form a coating composition with low melt viscosity and good wear and soil resistance. However,
the polyethylene is not completely compatible with the wax'constituents, resulting in a composition which has the disadvantage of showing white scratches on the surface under normal tralfic. These scratches are diflicult to remove. Crystallization of the wax also contributes to the white scratching condition.
In order to overcome the disadvantages of the prior art compositions, the present invention has been developed in which the coating is applied in a plurality of layers. The first layer is a coating composition having a low viscosity which will satisfactorily fill all of the imperfections appearing on the surface of the cork tile, and the other layer or layers are a low viscosity polyethylene type which renders the surface wear-resistant and soil-resistant. Inasmuch as the top layer or film is all of the same composition, the problem of incompatibility is not present and the white scratch marks do not occur. Polyethylene is of such nature that the problem of crystallizationdoes not occur.
In preparing the low viscosity coating composition for the first coating, the following formulation has been found satisfactory and is presented here by way of example.
Parts by weight Low molecular weight polyethylene (molecular weight ranging between 1,000 and 3,000) 1 /2 a first or cover coat; however, any of the low melt vis-' cosity products can be used satisfactorily for this purpose.
The above coating composition is applied as a hot melt application at a regular two-roll coating device. The coating composition forms a pool between the applicator roll and a second roll. The sheet of material to which the hot melt is to be applied is passed between the applicator roll and a back-up roll in such manner that the film of wax adhering to the applicator roll is transferred therefrom onto the surface of the sheet of material passing through the device. The sheet then passes through an ironing roll heated to a temperature of approximately 380 R, which irons the coating composition firmly onto the surface of the tile and smooths out any ridges or grape Vining appearing on the surface. This forms a tile having a relatively smooth coating applied thereto, filling all of the small imperfections in the surface of the cork tile.
The drawing illustrates a piece of cork tile 2 comprised of compressed cork particles 3. To this cork tile sheet there is applied a dual coating of wax in which the first layer 4 applied directly to the surface of the cork particles 3 is a blend containing a major portion of hydrocarbon wax and a minor portion of a polyethylene polymer having a relatively high molecular weight, and the surface coating 5 is a polyethylene polymer having a relatively low molecular weight.
The top or wear coating comprises a film of polyethylene of a relatively low molecular weight ranging between 1,000 to 3,000. This coating of polyethylene is applied from a hot melt of the polyethylene placed in the two-roll applicator in the same manner as expressed for the first coating. The polyethylene coating is also ironed onto the surface. The system outlined above results in a cork tile having a relatively'low viscosity first coat which fills all the imperfections and which has applied thereover a coat of a relatively hard polyethylene wax, forming a smooth wearand soil-resistant surface on the product.
The invention may be carried out by substituting a polyethylene coating for the first coating to be applied to the cork tile. When using this modification, it is recommended that a polyethylene material of a relatively low molecular weight, such as that falling Within the range of 1,000 to 3,000, be used to cover the imperfections in the tile. This first coating of polyethylene should be rather thin so as to fiow into the imperfections. This coating is ironed onto the surface of the cork tile in the same manner as described earlier. The additional second coat of polyethylene is then applied thereover in the manner expressed above. Either of the systems outlined herein produces a finish which is relatively hard, wear-- resistant, and soil-resistant, and has the high gloss desirable in a product of this type.
It will be obvious from the foregoing that we have developed a floor and wall covering having applied thereto a finish which adequately fills all the imperfections in the surface of the tile and presents a smooth hard glossy wearand soil-resistant surface which is easy to maintain.
1. A-cork composition floor and wall covering having a wear-resistant finish comprising a film of a blend containing a majorportion of hydrocarbon wax and a minor portion of a polyethylene polymer having a molecular weight in excess of 10,000 and a surface coating of a References Cited in the file of this patent polyethylene polymer having a relatively low molecular UNITED STATES PATENTS weight falling Within the range of 1,000 to 3,000. 1
2. A cork composition floor and wall covering hav- 1'824885 Hammond Septing a Wear-resistant finish comprising a film of a blend 5 2290794 Alvarado July 21, 1942 containing about 70% of hydrocarbon wax and about 2698309 Clark et 1954 7% of a polyethylene polymer having a molecular weight FOREIGN PATENTS in excess of 10,000 and a surface coating of a polyethylene 566,745 Great Britain Jam 11, 1945 polymer having a relativelylow molecular weight falling within the range of 1,000 to 3,000. 10