US2539420A

US2539420A - Hard surface covering

Info

Publication number: US2539420A
Application number: US697560A
Authority: US
Inventors: Jr James E Hazeltine; Catherine S Carr
Original assignee: Armstrong Cork Co
Current assignee: Armstrong World Industries Inc
Priority date: 1946-09-17
Filing date: 1946-09-17
Publication date: 1951-01-30
Anticipated expiration: 1968-01-30

Description

Jan. 30, 1951 J. E. HAZELTINE, JR., ETAL 2,539,420

HARD SURFACE COVERING Filed Sept. 17, 1946 UUUUE [JUDGE UUUUE UUUUE IN! 'E.\' TORS.

Patented Jan. 30, 1951 UNITED STATES PATENT orncs HARD SURFACE COVERING Application September 17, 1946 Serial No. 697,560

9 Claims.

This invention relates to surface coverings such as felt base and also felt backed linoleum for, floor and wall covering use. More particularly, the invention is concerned with a covering of the above type which may be adhesively secured to the desired floor or wall surface and may be removed therefrom without splitting of the felt foundation. According to the present invention, the back of the covering is provided with a discontinuous coating of material to which the adhesive used in bonding the covering to the base will not adhere. By making such coating discontinuous, the adhesive will bond to the covering in those areas which are free of such coating material and a discontinuous bond may be obtained between the covering and the base, permitting ready removal of 'the covering without rupture of the felt foundation. The invention also includes the combination of a covering joined to a base by an interposed adhesive.

Felt base and felt backed linoleum are made with a foundation of felt, generally impregnated with asphalt or other water-proof impregnating agents. In felt base, a wearing layer of paint is provided and in linoleum a wearing layer of oxidized oil, resin, filler, and pigments is provided.

The underside of such coverings is provided with a coating or coatings which usually serve the dual purpose of concealing the unsightly asphalt saturant of the base and at the same time sealing it against bleeding onto the face of the material when it is rolled for storage and shipment.

For a great many years, felt base floor coverings were generally laid loose on the floor and were not cemented because of the impossibility of removing them when so cemented. The felt foundation is weak and when it is cemented to a floor, the felt ruptures when any attempt is made to strip the covering from the floor. This condition is aggravated by the generally laminar character of the felt, due to the felting operation in its formation, for the felt tends to pull apart at different levels between its top and bottom surfaces leaving an irregular layer of saturated felt attached to the floor which cannot, for all practical purposes, be successfully removed.

This problem has been recognized, for the advantages of permanently cementing the floor covering in place are important. Cementing is desirable since it prevents any substantial expansion of the covering which results in buckling and consequent breakage and, at the same time, it eliminates the use of unsightly and hazardous metal binding strips over the seams. Of course, wall coverings must be cemented in place and this has prevented the use of inexpensive saturated felts in the manufacture of wall coverings. In recent years, there has been introduced on the market a felt base material which may be ccmented in place. This covering includes a binder coating, a rupturable coating, and a decorative coating, all applied to the back of the covering. The rupturable coating permits the covering to be stripped from the base by internal rupture of the coating prior to parting of the felt, and the barrier coating is interposed between the felt and the rupturable coating to prevent adherence of the felt saturant to the rupturable coating. The decorative coating is applied over the barrier and rupturable coatings and constitutes the exposed undersurface of the covering which should possess a decorative appearance for display purposes in showrooms and elsewhere.

In the installation of this material, a layer of adhesive is applied to the fioor and the material is pressed into engagement with it. The partible coating is thus disposed between the felt foundation and the adhesive and constitutes a weak link in the structure. When it is desired to remove the covering, it is pried loose in one corner of the room and is stripped from the floor by rupture of the partible coating. This is possible because the partible coating is materially weaker than the felt foundation and the coating ruptures internally before the felt tears.

Instead of providing a partible or rupturable coating between the felt foundation and the base, according to the present invention there is disposed between the adhesive and the covering a discontinuous coating which has substantially no aflinity for the adhesive, and the sole bond between the covering and the base is thus effected in the limited areas of the covering which are free of such coating.

Inasmuch as the adhesive resistant coating is substantially uniformly discontinuous and cover-i; only a portion of the back of the covering, a tain percentage of the total area remains effective for adhesively securing the covering to the floor. However, since this effective area is substantially less than the total area of the back of the covering, the bond between the covering and the base is reduced.

When it is desired to remove coverings embodying our invention, the covering is pried loose in one corner of the room and is stripped from the floor by rupture of the felt or the backing coat in the areas which are not covered by the adhesive resistant coating, thereby leaving small areas of felt or backing paint on the base which are easily removed with soap and water.

Generally, floor coverings are cemented to the Pounds Carnauba wax 112.5 Candelilla wax 37.5 Borax 7.5 Ammonia, 26 9.0 Potassium oleate solution 110.0 Shellac solution 82.0

Sufficient water to form an emulsion containing 20% solids.

We have found that the best results are obtained with emulsions containing 20% solids; however, the invention may be carried out satisfactorily with solids content ranging from to 30%.

' In certain specific installations of fioor and wall coverings, it may be found desirable to use an adhesive other than a water soluble adhesive. In such installations, our invention can be satisfactorily employed so long as the coating used has substantially no affinity for the particular adhesive used.

We have found that best results are obtained when the adhesive resistant coating covers a portion of the back of the felt ranging within the limits of 30% to 60% of the total surface area. Preferably a coverage of 50% is found to be very satisfactory. If a coverage of less than 30% is obtained, the bond between the covering and the base is too strong and the felt back will rupture in attempted removal, permitting some of the felt to adhere to the floor. If the coating covers more than 60% of the area of the back of the material, the bond will not be sufficient to properly secure the covering to the base and heavy trafiice may cause the floor covering to break loose from the base and buckle or break.

We have found that the particular configuration in which the coating is applied to the backing is not important; but best results are obtained when the coating is applied in such manner as to form continuous strips of the adhesive resistant coating both lengthwise and crosswise of the material with uncoated areas disposed within the grid-work. These strips may be in straight lines or they may be arranged in any desired configuration so long as the elements of the design are substantially interconnected or continuous. If it be found desirable to break the continuity of the lines, the break should preferably not exceed .05 inch. If a break of more than .05 inch be present, the adhesive bond between the floor covering and the base may not sever satisfactorily.

In order that the invention may be more readily understood, the same will be specifically described in conjunction with the attached drawing, in which:

Figure l is a perspective view of a surface covering embodying our invention;

Figure 2 is a plan view of the bottom surface of the material showing the preferred configuration for the coating which has no aflinity for adhesives;

Figure 3 is a perspective view of a modification showing a different configuration of coating;

Figure 4 is a perspective view of a building structure embodying our invention, showing the covering of Figure 1 secured in place by an adhesive; and

Figure 5 is a perspective view of a modification of our invention showing the adhesive resistant coating applied directly to the felt foundation.

The covering shown in Figure 1 consists of a linoleum composition layer 2, an asphalt saturated base 3, backing coats I, and an adhesive resistant coating 5.

Referring to Figure 4, there is shown a floor covering, similar to that shown in Figures 1 and 2, secured to a base 6 by means of a layer of adhesive I. From this view, it will be observed that while the adhesive covers the entire area of the base, it adheres to the floor covering only in the areas in which the outer backing paint layer 4 is exposed. I

It will be understood that the coatings l are shown to an exaggerated degree in order that they may be more easily illustrated.

While our invention has been described in connection with-a covering material having one or more coats of backing paint applied to the undersurface of the felt foundation, it will be understood that the invention may be carried out successfully using covering materials having no backing paint. In carrying out the invention on coverings of this type, the adhesive resistant coating is applied directly to the undersurface of the impregnated felt foundation. Such structure is illustrated in Figure 5 and consists of a wear layer 8, a felt foundation 9, and an adhesive resistant coating l0.

It has heretofore been determined that there are certain limits of adhesion, within which the required severance for the adhesive and the back of the material is obtained. Limits of 3 to 30 pounds resistance are satisfactory, but limits of 6 to 30 pounds are preferred. If the tensile resistance be substantially greater than 30 pounds, the bond between the adhesive and the covering is sufficiently strong to prevent ready removability, but if the tensile resistance is substantially less than 3 pounds, there is danger of the covering becoming loose during use due to heavy traffic. For that reason, a minimum of 6 pounds is preferred. Felt base products having tensile strength above 30 pounds do not rupture when attempts are made to remove them from blocks of wood to which they are secured by an adhesive bond which ruptures at 30 pounds or less.

The limits of adhesion may be determined by the Scott test in the following manner:

To one side of a strip of wood 6 inches long and 2 inches wide, a thin layer of linoleum cement or paste is applied, using a notched doctor blade to distribute the paste or cement evenly over the entire area. To the strip of cement is immediately applied a strip of covering to be tested, 8 inches by 2 inches wide, one end of which is placed flush with the one end of the strip of wood, the other end extending free beyond the wood strip. After rolling to obtain a satisfactory bond between the wood and the covering, the sample is maintained at normal room temperature for approximately 4 days to dry the paste or cement. The resistance of the bond to tensile force is determined by placing the sample in a Scott tensile strength machine at right angles to the direction of the force thus exerted. The strength of the force recorded as the covering is removed from the wood strip measures the resistance of the bond to tensile force.

We have found that covering material having approximately 50% of the underside covered with an adhesive resistant coatingmaterial, applied in accordance with the configuration shown in Figure 2, requires approximately pounds tensile force to remove the covering from the block. As the area covered by the coating is decreased,

the force required to remove the sample is in-- creased.

In the embodiment shown in Figure 3, the adhesive resistant coating covers approximately 60% of the back of the covering. This sample required approximately 11 pounds tensile force to sever the bond between the covering material and the base. It will be seen that the force required to remove these samples falls well within the rangerecited above and, therefore, covering material cemented to the floor in this manner would not tend to rupture upon being removed nor would the bond between the floor covering and the base be severed due to heavy traffic on the floor.

While we have described and illustrated certain preferred embodiments of our invention, it will be understood it is not limited to such form, since it may be otherwise embodied within the scope of the following claims.

We claim:

1. A hard surfaced flexible covering for floors, walls and the like including an asphalt-impregnated felt base adapted to be removabiy cemented to an underlying supporting surface with a bond strong enough for normal use and to be subsequently removed therefrom without being destroyed by tearing, the said base having a continuous lower face coated with a discontinuous layer of a wax-including material presenting open spaces through which areas of said lower face are exposed, the said exposed areas extending generally parallel with the lower surface of the waxincluding layer and at a depth uniformly approximating the thickness of said layer, such that the floor covering is more flrmly attachable by adhesive contacting the said exposed areas of the said lower face than the adhesive contacting the exposed surface of the wax-including layer.

2. A hard surface flexible covering for floors, walls and the like including an asphalt-impregnated felt base adapted to be removabiy cemented to an underlying supporting surface with a bond strong enough for normal use and to be subsequently removed therefrom without being destroyed by tearing, the under surface of the cov-. ering comprising a set of spaced exposed areas and a set of intervening areas permanently coated with awax-including material having a poor bond with floor covering cement, the set of intervening areas being formed of a discontinuous.

surface by cement in said spaced areas than in said intervening areas.

3. A hard surface flexible covering for floors, walls, and the like including a moisture-resistant felt base adapted to be removabiy cemented to an underlying supporting surface with a bond strong enough for normal use and to be subsequently 6 removed therefrom without being destroyed by tearing, the said base having a continuous lower face coated with a discontinuous layer of a waxincluding material presenting open spaces through which areas of said lower face are exposed, the said exposed areas extending generally parallel with the lower surface of the waxincluding layer and at a depth uniformly approximating the thickness of said layer, such that the floor covering is more firmly attachable by adhesive contacting the said exposed areas of the said lower face than the adhesive contacting the exposed surface of the wax-including layer.

4. A building structure comprising a flexible hard surface covering and an underlying supporting surface, an adhesive securing said hard surface covering to said underlying supporting surface, said hard surface covering including a moisture-resistant felt base adapted to be removabiy cemented to the underlying supporting surface with a bond strong enough for normal use and to be subsequently removed therefrom without being destroyed by tearing, the said base having a continuous lower face coated with a discontinuous layer of a wax-including material presenting open spaces through which areas of said lower face are exposed, the said exposed areas extending generally parallel with the lower surface of the wax-including layer and at a depth-uniformly approximating the thickness of said layer, such that the floor covering is more firmly attachable by adhesive contacting the exposed areas of the said lower face than the adhesive contacting the exposed surface of the wax-including layer.

5. The covering as claimed in claim 3 wherein the exposed areas are separated from one another by the discontinuous layer of wax-including material.

6. The covering as claimed in claim 3 wherein the discontinuous layer of wax-including material covers from 30% to of the area of the back of the covering.

7. The building structure claimed in claim 4 wherein the bond between the flexible hard surface covering and the underlying supporting 'surface is less resistant to tensile force than is the moisture-resistant felt base.

8. The building structure claimed in claim 4 wherein the bond between the flexible hard surface covering and the underlying supportingsurface is capable of rupture by tensile forces rang-- ing between 6and 30 pounds.

9. The covering as claimed in claim 3 wherein the discontinuous layer of wax-including material comprises a solids content ranging between 10% and 30%.

JAMES E. HAZELTINE, JR. CATHERINE S. CARR.

REFERENCES crrr-zn The following references are of record in the file of this patent:

UNITED STATES PATENTS