Document 68E4d301qyxy12xKkVznw08E

FILE NAME: Flooring (FLR) DATE: 1978 A p r i l DOC#: FLR018 DO CUM ENT DESCRIPTION: Patent - Harris, Armstrong Cork Co. Decorative Non-Vinyl Surface Covering Composition - Updated United States Patent u n Harris ____ (n] 4,083,824 [45) Apr. 11,1978 [54] NON-VINYL SURFACE COVERING COMPOSITION [75] Inventor: Thomas G. Harri, Lancaster, Pa. [73] Assignee: Armstrong Cork Company, Lancaster, Pa. [21] Appl. No.: 789,289 [22] Filed: Apr. 20,1977 [51] Int. Cl.*..........................C08K 3/00; COSK 3/26 [521 U.S. C L .......................... 260/422; 260/17.4 R; 260/42-52; 260/897 B; 260/998.15; 260/DIG. 31 [58] Field of Search....... 260/42.52, 897 B, DIG. 31. 260/998.15, 42.29, 17.4 R [56] References Cited U.S. PATENT DOCUMENTS 3,264,272 8/1966 Rets ............................... 260/78.5 3,833,708 9/1974 Miller et al........................ 260/873 Primary Examiner--James H. Derrington [57] ABSTRACT A non-vinyl flooring composition is described which comprises a mineral filler distributed substantially uni formly throughout a binder comprising a blend of a heteropolymer comprising at least two C, to C, linear or branched alkyl acrylates of Mw from about 100,000 to about 300,000 and further characterized by at least two glass transition temperatures, one being above 25' C., the other being below 25* C., and a random ionic co polymer of an a-olefin end an a,/3-unsaturated carbox ylic acid having 10% to 90% of the carboxylic acid group neutralized with metal ions. 8 Claims, No Drawings a 4,083,824 1 2 formulation. However, the use of such does little to NON-VINYL SURFACE COVERING eliminate the use of vinyl chloride in the compounded COMPOSITION composition. BACKGROUND OF THE INVENTION j areIorneocongicniczoepdoalsymhaevrsin, ggeunneursaulalyl pkrnoopwerntieass. Hioonwomeveersr,, 1. Field of the Invention their use in flooring compositions is severely restricted This invention relates to a non-vinyl composition since they generally have disadvantageous^ low use useful as a surface coveting material. More particularly, temperatures. At normal room temperatures, these co it relates to a floor tile composition comprising a min polymers display extensive creep, such accompanied by eral filler and a binder that is a blend of a heteropolymer 10 a rapid decrease in modulus. Further, processing pioo- and an ionomer resin. lems using these ionic materials arc severe due to their 2. Description of the Prior Art great tenacity for metal surfaces. A widely used resinous binder material having partic ular utility in surface coverings is based on those poly SUMMARY OF THE INVENTION mers of vinyl chloride, such as the thermoplastic poly(- 15 It is, therefore, an object of this invention to provide vinyl cloride). When properly compounded with an an improved flooring composition that is non-vinyl. assortment of plasticizers, heat and light stabilizers, It is a further object of this invention to provide a fillers and pigments, the resultant vinyl composition non-vinyl flooring composition that has good process displays satisfactory physical, traffic abrasion and stain ing properties. resistance properties, such finding particular use as 20 It is an additional object of the present invention to flooring materials. The economics of formulations em provide a non-vinyl flooring composition substantially ploying these vinyl polymers particularly favors high free of asbestos and hav ing good melt strength and ease filler loadings. However, the cavalier addition of Eller of processing. materials to the vinyl resin binder is disadvantageous to It is a further object of the present invention to pro those commercially important physical properties men- 25 vide a non-vinyl, non-fibrous flooring composition pos tioned above. For example, one of the least expensive sessing the desirable physical properties of vinyl floor Tiller materials commonly used in vinyl compositions is ing compositions, but having reduced levels of smoke calcium carbonate. Its sole use in vinyl formulations is generation. generally deterimental to the compounding operation, It is an additional object of the present invention to requiring careful handling at slow speeds on sheet or 30 provide a non-vinyl, non-fibrous flooring composition calendar rolls. Fluidity of the resultant molten mass is possessing the desirable properties of fibrous flooring generally so high 'hat the- ry'i* ftreagth is negligible and compositions, such as good tensile strength, low mois proper calendering is ait but impossible. Lack of dimen ture absorption, enhanced resistance to traffic staining, sional stability, as exhibited by sheet shrinkage upon and good dimensional stability. These and other objects removal from the calendar (nerve), is a further problem 35 will become apparent to one skilled in the art from the in these formulations. Of course, many difficulties with consideration of the specification. the calcium carbonate-only filled compositions can readily he resolved by the use of fibrous fillers, espe cially asbestos. Compositions containing such filler ma DESCRIPTION OF THE PREFERRED EMBODIMENTS terial display good melt strength, exhibiting the proper 40 In accordance with the present invention, a decora degree of viscous flow and melt elasticity, so that they tive non-vinyl surface covering is formed by the admix can be readily sheeted, calendered and/or transported ture of a mineral filler, such beirg substantially uni without excessive tearing or elongation in the manufac formly distributed throughout a binder that is a blend of turing process. However, the use of asbestos has re a copoly block acrylate and an ionic copolymer. cently found a great deal of disfavor since various medi- 45 The mineral fillers of preference herein are those of a cal researchers and govci ament officials have suggested non-fibrous nature such as limestone, whiting, clay, talc, that exposure to asbestos fiber-containing products may silica, pumice, wood floor, and mixtures thereof. As pose a serious health peril to the general public. At the disclosed earlier, while fibrous fillers are within the preset time, many states and municipalities arc contem scope of the present invention, such do not represent plating or have preliminarily passed legislation to end 50 highly desirable fillers. In the preparation of the compo the use of asbestos in the confines of their jurisdiction. sitions of the various embodiments herein, filler mix The manufacturing of asbestos-free compositions has, tures of reduced fiber content are preferred. Non- therefore, become a prime goal in the flooring industry. fibrous type filler compositions are particularly useful Additionally, vinyl chloride resins themselves have and limestone represents the most preferred filler, espe become subject to health hazard study. The monomer, cially limestone comprising very coarse to very fine vinyl chloride, is a noted carcinogen. This, in concert particle sizes, such having average particle sizes ranging with the recent scarcity of the monomer-forming start from about 40 to about 340 mesh (Tyler). The amount ing materials, suggests the importance of discovering of filler to be blended with the surface treating composi non-vinyl resin binders. tion described below can vary widely and will normally In U.S. Letters Pat. No. 3,904,579, a novel flooring 1 be in the range of from about 60 to about 85 weight composition is disclosed that comprises a plasticized percent. vinyl chloride polymer compounded with a terpolymer The mineral filler as disclosed above is distributed comprising vinyl chloride/vinyl C2-C<alkanoate/C- substantially uniformly throughout a binder system 2-C4 alkene and filler. While the composition contains comprising as one ingredient a clear heteropolymer that no asbestos, the terpolymer comprises at least 75% to i comprises at least two C, to C, linear or branched alkyl 80% of the com position, such containing vinyl chloride. acrylates. These heteropolymeric acrylates, sometimes Chlorinated polyethylene is disclosed to be of use in referred to herein as copoly block acrylates, are of mo place of, or along with, poly(vinyl chloride) in this lecular weight (Mw) from about 100,000 to about WOIB! 4,0S3,824 3iX),uOO and display at least two secondary transition the like, are useful herein. Other types of plasticizers temperatures (Tg), one above room temperature, e.g. such as esters of inorganic acids, including tricresyl 25* C. to 50' C., and one below room temperature phosphate, octyl diphenyl phosphate, and the like, Para- ( --30 to, but not including, 25* C.). The pieparation of plex G-2S linear polyester or epoxidized soybean oil can these heteropolymers is disclosed in U.S. Pat, No. also be used. These plasticizers should preferably have 3,251,904, filed Nov. 3, 1961, and incorporated herein low vapor pressure at compounding temperatures, i.e. by reference. Illustrative of the heteropolymers is heter 400* F. They are employed in plasticizing amounts opoly (60% methyl methacryIate/30% ethyl sufficient to provide mechanical properties which are acrylate/10% butylacrylate) of Tg +7*. +72* C.. and desirable in the end use applications. Normally, a satis Mw 131,000 by GPC, as well as hetcropoly(50% iO factory range of plasticizer, including mixtures thereof, methyl methacrylate/50% ethyl acrylate) of Tg +3*, is from about 0 weight percent to about 5 weight per + 35* C., and Mw 280,000 by GPC. cent based on the total binder composition. As a second ingredient to be used herein, it has been Small amounts of stabilizers may be incorporated to ascertained that when 20 weight percent to 80 weight reduce the effects of degradation of heat and light. percent of a certain ionic copolymer resin is blended 15 Suitable light stabilizers include epoxidized soya bean with the above heteropolymeric acrylates, surprising oil, epoxidized tallates, wood rosin, phosphites, resorci processing, physical and end use properties are imbued nol disalicylatc, resorcinol dibenzoate, phenyl phthal- to surface covering compositions using these compo ate, phenyl benzoate, ortho-tolyl benzoate, cugenol, and nents as binders. The term ionic copolymer resin as used organic phosphates and other complexes of such metals herein is defined as a polymeric substance containing 20 as barium, cadmium, strontium, lead, tin and the like. ionized carboxyl groups, such forming ionic cross-links Suitable heat stabilizers include barium-cadmium through metal ions in the intermolecular structure of soaps, barium-cadmium-zinc soaps, epoxides, sulfides these materials. The ionic copolymers of use in accor and sulfites of the metals silver, calcium, cadmium, dance with the present invention are exemplified by magnesium, cerium, sodium, strontium and the like. those disclosed in U.S. Pat. No. 3,264,272, Hied Apr. 8, 25 Normally, the novel compositions in accordance with 1963, incorporated by reference. the present invention contain from about 2.5 to about The ionic copolymers contemplated of particular use 7.5 weight percent of the above heat and light stabilizers in the compositions herein are those of random charac based on total amount of binder. If desired, small ter and formed from ethylene and 2.5% to 25% by amounts of antioxidants such as the hindered phenols, weight carboxylated monomer (acrylic acid or meth- 30 e.g. di-t-butyl-p-cresol, and lubricants such as stearic acrylic acid), preferably 5% to 20% by weight. In the add, waxes, and so forth, may be incy^jes/rri i s obtain case of copolymers formed from monocarboxylic acid further improved calendering and compounding char monomers, the ionic cross-linking agents, e.g. the metals acteristics. (in the form of metal hydroxides) used to form the ion For most purposes, the compositions of this invention ized carboxyl groups are of valence 1 to 3 such as, for 35 are prepared with a pigment. Examples of suitable pig- example, sodium, zinc and aluminum, preferably zinc. rnents are titanium dioxide, phthalocyanine blue, phtha- When copolymers containing the dicarboxylic acid locyanine green, chrome yellow, chrome orange, red `moiety are present, the ionic cross-linking agent is pref- iron oxide, carbon black, lamp black, chrome oxide erabiy in the form of zinc. While these ionic copolymers green, and the like. The proportion of pigment in the can be of any commercially available secondary transi- 40 composition varies depending on the type of pigment tion temperature (Tg), the Tg of preference is from and may be as low as 0.5% by weight and up to about --10* to about +10* C. These copolymers are further 5.0% by weight total composition, inert and extender characterized by a melt index of 0.1 to 1000 grams per pigments, such as silica aerogels, talcs, and diatoma- minute, preferably 0.5 to 20 grams per minute (ASTM- ceous silica, commonly used in organic coatings are 45 suitable for controlling the gloss of the composition, if The above-disclosed copoty block acrylate and ionic desired. copolymer arc mixed with the mineral filler in the ratios The compositions in accordance with the present of 8-32:32--8:60 to 3-12:12-3:85, preferably from 8-32:- invention have tensile strength of from 1800 psi to 3000 20--20:60 to 3-12:7.5-7.5:85, most preferably 10:10:80. psi, displaying greater product durability than, vinyl Mixing can be any conventiona! technique utilized for 50 counterparts. They also show enhanced resistance to blending filler with resinous materials. These techniques traffic staining. include the fusing of the composition in the Baker Per- The surface covering compositions of this invention kins mixer and sheeting through hot rolls. are of particular use in the calendering and molding of In addition to the copoly block acrylate and ionic floor tiles. Such molding can produce tiles of various copolymer binder blend in accordance with the present 55 shapes and sizes including the usual 9 inch X 9 inch tile. invention, a wide range of plasticizers can also be incor The compositions can be molded into sheets and such porated in these compositions. Illustrative plasticizers used to cover large areas of floor surfaces. It is also include esters of aliphatic glycols and aliphatic dicar within the contemplation of the present invention to use boxylic acids such as dibutyl sebacate, dioctyl sebacate, the molded sheets for other applications where non- dioctyl adipate, didecyl adipate, dioctyl azelate, trieth 60 vinyl compositions of superior tensile strength are de ylene glycol di(2-ethylhexanoate), diethylene glycol sired, for example, as covering tables, counters and the diperlargonate, triethylene glycol dicaprylate, and the like. like; esters of aliphatic alcohols and aromatic acids, or In the examples that follow, smoke generated by the aromatic glycols and aliphatic acids, or aromatic alco- illustrative compositions is measured by the method hois and aromatic acids, including dibutyl phthalate, 65 described in "Method for Measuring Smoke From dicapryl phthalate, dioctyl phthalate, dipropylene gly- Burning Materials" by D. Gross et al, ASTM Special col dibenzoate, butyl benzyl sebacate, butyl benzyl Technical Bulletin No. 422 (1967). The actual measure- phthalate, dibenzyl sebacate, dibenzyl phthalate, and rnents were made on an instrument designated Model 5 4,083, 4-5800, Aminco-NBS Smoke Density Chamber, Ameri can Instrument Company. stabilizer, barium zinc phosphite 0.89% by weight; as bestos, 711 fiber; titanium dioxide 1.0% by weight. Test samples were made by sheeting the components of the compositions at roll temperatures of about 270V230* F. The sheets were removed from the mill, 5 allowed to cool, and test samples were then cut from the sheet. Sheets obtained in this manner were approxi mately 14 inches wide by about 0.060 inches in thick ness. Test samples for smoke determinations were cut from the sheets produced in this manner. 10 Coaiptrative-l lonomer (melt index 5.0) Random (eihylene/elhyl ccrylate 8020) copolymer Asbestos Limestone (4QM) Titanium Dioside % by wt. 3.74 14.96 5.00 75.30 1.00 In accordance with the test procedure mentioned 100.00 above, each sample was exposed to an energy flux of 2.5 w /cm 3from a radiant heater under flaming conditions. The above was blended on a Baker Petkins mixer to Flames from a multi-directional propane burner im 290* F. and discharged. It was then sheeted on the mill pinged upon the sample and then into the trough at the IS with the rolls set at 270V230* F. The mix was slightly bottom of the sample. dry and the roll tack was poor. Tiles were cut from the The sample was exposed until a minimum transmit sheet and press polished (59.0 mils). Physical properties tance value was obtained. After the smoke had been were determined (Table I). EXAMPLE 1 flushed from the cabinet, the residual attenuation of the light beam, caused by deposits on the windows in the 20 test chamber, was recorded and a correction applied to Example I the maximum absorbence value. % by w t Specific optical densities were then normalized with respect to unit surface area of the sample (D,,). The specific optical densities are defined by the following 25 expression: D,,(corr) = V /A 'L X A max. (corr) wear. V equals test chamber volume; L equals optical path lonomer (melt index 5,0) Copoly block acrylate Coumaicne indene resin Asbestos Limestone (40M) Titanium Dioxide 8.00 8.00 2.00 5.04 75.95 1.01 100.00 length; A' equals surface area of the sample; A max. (corr) equals A max. minus A ,, A max. (corr) minus maximum corrected absorbence during tht test, A max. minus maximum measured absorbence during the test, A,, minus absorbence caused by deposits on the win dow. The above was blended in a Baker Perkins mixer to 290* F. (20 minutes) and discharged. It was then sheeted on the mill with the rolls set at 270V230* F. The mix displayed the desired wetness and roll tack. Tiles were cut from the sheet and press polished (66 mils). Physical Examples 35 properties were determined (Table I). Traffic stainir.g in the following illustrative examples is evaluated by exposure to heavy foot traffic for six Comparative-! weeks and examining thereafter both before and after % by w t cleaning. Ratings were visual with 1 best, 9 worst be Random (ethylene/ethyl acrylate 80:20) fore cleaning and after cleaning. 40 copolymer 14.40 In the illustrative examples, the following compo Copoly block acrylate Coumarone indene resin 3.60 2.00 nents were admixed in the ratios noted, lonomer resin: Mole % carboxylic acid monomer, 2.8 mole % as methacrylic acid; % neutralization, 20%; Asbestos Limestone TtUnium Dioxide 4.92 74.10 0.98 100.00 type cationic crosslinker, zinc; melt ride*., j.Og/10 45 minutes. Copoly block acrylate: (ethyl methacrylate/ethyl The above was blended in a Baker Perkins mixer to 290* F. (20 minutes) and discharged. It was then sheeted acrylate/butyl acrylate) in 60/30/10; Tg +7, +72; H w 131,000. on the mill with the rolls set at 220V280* F. The roll tack was poor and the sheet weak. Tiles were cut from T t" typical vinyl tile composition of Table II com- 50 the sheet and press polished (63 mils). Physical proper prise tne Jollowing: vinyl chloride/vinyl acetate co ties were determined (Table I). polymer, Mw 41,600, and vinyl chloride homopolymer, Mvv 60,000, 11% by weight; coumarone indene resin 2.0% by weight; phthalate plasticizer 4.8% by weight; Table 1________________________ Physical Properties__ Comparative-1 I Comparative-2 Thickness (mils) Specific Gravity Indentation - one minute * ten minutes - thirty seconds (II5` F.) Tensile Strength (psi) Elongation (%) Olsen Stifines* (in lbs.) Bend Break Angle (degrees) Moisture Growth (% L) .Moisture Absorption (% W) Traffic Rating1 59 2.06 8.4 9.1 13.0 1563 7.3 3.3 40 + 0.09 +0.53 4.(8) 66 2.08 4.2 5.0 7.0 2197 14 5.6 1! +0.06 + 0.50 i.(d 63 1.95 8.6 10.0 17.0 1080 2.8 2.2 29 +0.19 +0.79 .() 'Rating t* : j . cleaning I b a t 9 w orn, .ftc r clca>-g (I) b a t (9) worst L~ j auw L 4,083,824 8 The effect on stiffness of increasing the ratio of kno* (2):minerel filler is from 8-32:32-8:60 to 3-12:- mer to acrylic heterocopolymer (at same binder con 12-3:85. tent) is shown in Table II. All components arc as shown 2. The composition of claim 1 wherein said compo is Example 1. Table II nent (2) is methacrylic acid and said metal ion is zinc. 3. The composition of claim I wherein said mineral filler is calcium carbonate of from about 40 to about 340 Typi cal mesh (Tyler). Ex. Ex. Ex. Vbyl 4. A non-vinyl, low-smoke surface covering composi 1 2 3 Tile tion comprising toooiacrcopoly block acrylate Ttuckaeu (nit) Specific Gravity Indentation oac nuntiU - 30 tee*., IIS* F. Tenale Strength (psi) Elongation {%)' Obca SiifTnca (in-lbi) Bend Break Angle (degree) Moisture Growth {% L) MoiBure Abaotption (96 W) Dimension*! Subiiity (% L) Dm(corr) Filming Mode so. so (6 2M 4.2 7.0 2197 1.4 3.6 12 +0.06 +0.50 -0.12 48 20.10 66 2.13 1.2 7.0 1130 at 4.6 7 + 0.0 + 0.72 - 0 01 34 1020 67 2.02 4.7 7.0 2422 1.1 6.1 13 -004 + 0.30 -0.17 69 --_ to 61 Z15 5.7 22.0 199 2.1 1.9 is 27 U16 +2.31 -a n 164 (a) 60% to 85% by weight of a non-fibrous filler, (b) 40% to 15% by weight of a binder comprising the components (1) 20% to 80% by weight based on total binder of a copoly block acrylate comprising at least two C| to C , linear or branched alkyl acrylates of Mw from about 100,000 to about 300,000 and further characterized by at least two glass transition temperatures, one being above 25* C., the other being below 25* C , and 20 (2) 80% to 20% by weight based on total binder of What is claimed is: a random ionic copolymer comprising ethylene 1. A non-vinyl surface covering compositions com and 2.5% to 25% by weight acrylic acid or prising methacrylic acid crosslinked by a monovalent or polyvalent metal ion, said ionic copolymer hav (a) a mineral filler distributed substantially uniformly 25 ing a melt index of 0.1 to 1000 grams per minute. throughout 5. The surface covering composition of claim 4 (b) a binder comprising the components wherein said non-fibrous filler is calcium carbonate, and ( 1) a copoly block acrylate comprising at least two said ionic copolymer has a melt index ofG.5 to 20 grams O, to C, linear or branched alkyl acrylates of Mw per minute. from about 100,000 to about 300 000 and further 30 (. The surface covering composition defined in claim characterized by at least two glass transition 5 wherein the particle size of said calcium carbonate is temperatures, one being above 2i* C., the other about 40 mesh to about 340 mesh (Tyler). being below 23* C.; and 7. Molded floor tiles from the composition defined in (2) a random ionic copolymer comprising ethylene claim 4 having a tensile strength greater than 1800 psi to and 2.5% to 23% by weight acrylic acid or me- 35 3000 psi. thyacrylic acid crosslinked by a monovalent or 8. The molded floor tiles of claim 4 additionally con polyvalent metal ion, said ionic copolymer hav taining asbestos and said component (2) is 30 to 70 ing a melt index of 0.1 to 1000 grams per minute, weight percent of said binder. wherein the ratio of component (l):component 40 45 50 55 60 65