US 3908059 A
Ceiling tile, and their manufacture, which tile have a decorative face produced by applying a binder and a vast plurality of minute expandable plastic particles to patterned areas of the tile face and then applying heat to expand the particles and cure and/or dry the binder.
Claims available in
Description (OCR text may contain errors)
United States Patent Prince Sept. 23, 1975 DECORATIVE CEILING TILE 3,239,365 3/1966 Petry 117/45 X 3,359,352 12/1967 Powell et a1. 264/54 X  Inventor- Dav! f 3,565,836 2/1971 Fuller 117/123 x 73 Assigneez National Gypsum Company 3,778,364 12/1973 Mani et al 204/159.l5 Buffalo N Y 3,779,800 12/1973 Heiser 117/155 UA 3,798,098 3/.1974 Ogawa et a1. 117/8 X  Filed: Mar. 1, 1974 3,804,657 4/1974 Eyman et al 117/15 X 21 A l. N 447,077 1 pp 0 Primary ExaminerM1chael R. Lus1gnan Attorney, Agent, or FirmRobert F. Hause  US. Cl. 428/206; 427/198; 427/278;
428/327 511 Im. c1. D2111 1/10  ABSTRACT  Fi ld f S h 117/g 35 9 38 45 Ceiling tile, and their manufacture, which tile have a 117/62 1195 123 D 12 13 15; 2 4/45 decorative face produced by applying a binder and a 264/47 52 54 126; 427/198 278; 423/206 327 vast plurality of minute expandable plastic particles to patterned areas of the tile face and then applying heat  References i d to expand the particles and cure and/or dry the UNITED STATES PATENTS bmde 3,224,894 12/1965 Palmer 117/45 10 Claims, 6 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,908,059
US Patent Sept. 23,1975 Sheet 2 of2 DECORATIVE CEILING TILE .on its front face.
There is a constant search in the field of ceiling tiles for new and improved, lower cost means for providing desirable and unique designs on the tile face. It is also advantageous if such means are adaptable to the simultaneous presence of means of absorbing sound, such as perforations or holes extending through the tile face into the porous interior body of the tile.
Design means which are three-dimensional are particularly desired over two-dimensional printed designs. The majority of available three-dimensional designs require expensive equipment to produce them or are costly processes in other respects, and only a few such processes have proven commercially successful.
It is an object of the present invention to provide a novel and economical method of forming threedimensional tile face designs.
It is a further object to provide a novel ceiling tile having a unique three-dimensional face design produced by this method.
The above and other objects of the invention will be more readily apparent when considered in relation to the preferred embodiments as set forth in the specification and shown in the drawings in which:
FIG. 1 is an isometric view of a ceiling tile having a coating composition made in accordance with the invention applied to designed areas on the tile face.
FIG. 2 is a sectional view of the tile of FIG. 1 taken along line 2-2.
FIG. 3 is an isometric view of a ceiling tile on which the expandable microspheres in the coating composition have been expanded to prooduce a threedimensional tile face design.
FIG. 4 is a sectional view of the tile of FIG. 3 taken along line 44.
FIG. 5 is a sectional view of a modified form of the tile of FIG. 4.
FIG. 6 is a sectional view of a further modified form of the tile of FIG. 4.
Referring to FIGS. 1 and 2, there is shown a ceiling tile 10 having a main body portion 12 which may be formed of any of the common materials used, such as cellulose fibers, mineral fibers or low density cementi- I tious materials. The tile may have any of the common edge formations such as the butt and bevel edge 14 which is shown, or a tongue and groove edge, or a kerfed edge for the insertion of thin metal edge alignment strips. The main body portion 12 has a front face 16 on which the novel three-dimensional design structure is formed, as will be described herebelow. Needle perforations 18 are shown extending into tile 10, to improve sound absorption of the tile.
A coating 20 is applied to preselected design areas, for example as shown in FIG.l. The coating 20 is a thoroughly mixed composition consisting essentially of expandable plastic microspheres and a binder such as paint.
The expandable plastic microspheres are preferably vinylidine chloride acrylonitrile fine particles which are produced and sold as Dow Saran Microspheres by Dow Chemical Company in a particle size of about 5 to 8 microns, containing in each particle a blowing agent which will expand manyfold as the vinylidine chloride acrylonitrile softens at temperatures of about 225F. A mass of the 5 to 8 micron expandable microspheres has the appearance of a very fine dust, and is readily dispersible in substantially any paint to form the composition of coating 20, without materially changing the appearance of characteristics of the original paint.
EXAMPLE I In the preferred embodiment, a coating composition is formed by admixing the following ingredients After thorough mixing of the above ingredients, the coating composition has all of the characteristics of a white latex paint. This composition is then applied as coating 20 to preselected designed areas of the front face 16, as by a designed printing roller, or a designed silk screen, or a designed template, or any other suitable design-forming means.
The coated tile is then subjected to heat sufficient to raise the temperature of the tile face 16 to about 225F for about 25 seconds or an equivalent amount of heating. A two-square foot gas-fired infrared heater, with a 30,000 BTU/hour output disposed 15 inches from the tile face for 25 seconds will be suitable to expand and cure the coating 20 to form three-dimensional raised embossments 30, as seen in FIGS. 3 and 4. This same heater can provide a suitable expansion and cure by placement at about 12 inches from the tile face for 18 seconds, or 7 inches from the tile face for about 10 seconds or less, etc.
EXAMPLE II The coating composition may be varied widely. The microspheres may be combined with substantially any binder composition, at many varying ratios. A suitable coating composition can be formed using only the following, based on total dry weight:
Vinyl acetate ethylene 43.5% Vinylidine chloride acrylonitrile microspheres 56.5%
Plus sufficient water for applica tion consistency EXAMPLE I In place of the above-mentioned microspheres, expandable polystyrene microspheres may be used.
A wetting agent such as propylene glycol may be added at proportions of 0 to about 15 percent of the total coating composition. dry weight. A dispersing agent may be used at from 0 to about 3 percent of total dry weight. A UV absorber may be present at from to about 1 percent of dry weight. Pigments may be included at proportions of from 0 to about 60 percent of total dry weight.
The binder and the microspheres may be present at weight ratios of one to the other of from about 80:20 to about 35:65.
EXAMPLE IV Following is another example of a composition for forming coating 20:
Other binders include styrene, styrene butadiene and vinyl acetate ethylene chloride. Standard commercial latex paints have been combined with microspheres to form a composition for forming coating 20.
The coating 20, as applied, will preferably have a viscosity of about 2,000 to 20,000 centipoises, and will be applied to a total area of from about to about 90 percent of the total area of face 16. In a design covering about 50 of face 16, using a composition for the coating which is 50 percent solids, about 6 wet grams of compositions will be applied per square foot of tile face 16, or from about 4 to about 10 grams wet.
The expandable microspheres in coating 20 are capable of expanding, when unrestrained from a particle size of about 5 to 8 microns to a soft but relatively strong hollow sphere of about to 28 microns. In forming embossments 30, it has been found preferable to expand the microspheres in coating 20 to only about 50 to about 75 percent of their total expansion capability.
In a coating that is being heated, the microspheres are restrained to some degree from expanding in any direction except perpendicular to the tile face, and accordingly, with the expansion of three dimensions being caused to substantially all occur in one direction, the expanded microspheres have been found to increase the thickness of coating 20, in converting to embossments 30, from a starting thickness of about 2 to 5 mils up to an embossment thickness ranging from about 50 to 70 mils.
One highly desirable and unexpected characteristic of the embossments 30 is the form in which they develop. The embossments 30 are made up of numerous globules 32, each globule being a vast collection of expanded microspheres. These globules 32 take many varied shapes and are of many varied sizes, all of which contributes to a highly desirable appearance of the em bossments 30.
A completely unexpected characteristic is provided in modified embossments 40 and occurs when the designed areas of coating 20 are printed onto the face l6 using a printing roller with extra pressure. A relatively greater amount ofcoating is caused to form around the periphery of the design area and relatively greater expansion of microspheres occurs in the edge portions of each embossment 40, as shown in FIG. 5. A plurality of expanded globules 42 are disposed along the periphery of am embossment 40 which have been expanded to an average height of about mils, whereas the expanded globules 44 located in the central portion of embossment 40 have an average height of about 50 mils.
FIG. 6 shows a further modified form of the invention in which a ceiling tile 50 has a main body portion 62 which has a front face 64 containing preformed patterned depressions 66. In this embodiment. the coating 20 is applied to all of the undepressed areas of the front face 64, and is then expanded and cured, forming expanded microsphere embossments 68 on all of the areas which were already relatively raised areas. This provides a combination of greater depth of design with the very desirable variability of the forms of the microsphere globules 32.
The design means of the present invention is considered adaptable to endless modifications of sizes and shapes of designs. The finished product has a very soft and rich appearance which is highly acceptable in the trade. The expanded and cured embossments, made up of the numerous globules, have a firm bond to the tile and are highly resistant to being scuffed off.
Having completed a detailed description of the preferred embodiments of my invention, so that those skilled in the art may practice the same, I contemplate that variations may be made without departing from the essence of the invention or the scope of the appended claims.
I. The method of forming three-dimensional designs on portions of the face of a ceiling tile, comprising the steps of mixing together a liquid binder and a large plurality of heat-expandable plastic particles of about 5 to 8 microns, applying said mixture as a thin, paint-like coating to design areas of the face of a ceiling tile, arranging said design area in relatively uniformly distributed areas throughout said tile face and leaving from about 10 to about 90 percent of the tile face uncoated between said distributed coated design areas, heating said tile face sufficiently to expand said plastic particles, and drying said binder, whereby a pleasing, relatively thick plurality of random plastic globules are formed in the said design areas.
2. The method of claim 1 wherein said expandable particles are formed of vinylidine chloride acrylonitrile and a blowing agent.
3. The method of claim 1 wherein the ratio of said binder to said expandable particles is from about :20 to about 35:65.
4. The method of claim 1 wherein said binder is a paint composition.
5. The method of claim 3 wherein said coating is ap plied at a rate of about 4 to about 10 grams per square foot of tile.
'6. The method of claim 1 wherein said heating consists of raising the temperature of the tile face for a period of time equivalent to about 225F. for about 25 seconds.
7. The method of claim 1 wherein said coating is applied by a printing roller, applying said roller with suffiareas of said tile which are not depressed, whereby said expanded coating combines with said depressed formation of said tile face to provide a greater threedimensional effect.
9. A ceiling tile having a three-dimensional design on v the tile face made by the method of claim 1.
10. A ceiling tile as defined in claim 9 wherein said three-dimensional design consists of an expanded coating of about 50 to mils;
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 90 ()59 DATED 3 September 23, 1975 'NVENTOR(5) 1 David S. Prince It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Signed and Scaled this seventeenth D ay Of February 1 976 [SEAL] A ttes t.
RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner uj'Patents and Trademarks