A POLYURETHANE FOAM COMPOSITION SUITABLE FOR BACKING A SUBSTRATE AND A SUBSTRATE CONTAINING THE POLYURETHANE FOAM COMPOSITION

Abstract: This invention is directed to a polyurethane foam composition which is suitable as a backing for a sub­ strate and to a substrate containing the polyurethane foam composition. The foam composition is the reaction product of a frothed polyurethane forming mixture com­ prising a relatively high molecular weight polyether polyol, a relatively low molecular weight polyol, an organic polyisocyanate or polyisothiocyanate, an inorganic filler, a catalyst for urethane formation, and a silicone sur­ factant. The silicone surfactant is a poly(dimethylsiloxa­ ne) polyoxyalkylene branch copolymer having an average molecular weight of less than 30,000 wherein at least 60 percent by weight of the polyoxyalkylene groups ore oxyethylene groups, the dimethylsiloxane content of the copolymer being from 15 to 40 percent by weight, at least 40 percent of the weight of the copolymer is derived from the oxyethylene groups. The silicone sur­ factant is present in the mixture in a quantity from 0.02 to less than 0.5 parts by weight per 100 parts by weight of the combined weights of the relatively high molecular weight polyether polyol and the relatively low molecular weight polyol.

Description: A POLYUREtHANE FOAM COMPOSITION SUITABLE FOR BACKING A SUBSTRATE AND A SUBSTRATE CONTAINING THE POLYURETEANE FOAM COMPOSITION The present invention pertains to a polyurethane foam composition which is the reaction product of a frothed polyurethane forming mixture and to the resultant polyurethane foam backed substrates. Substrates, particulary carpet substrates, have been backed with polyurethane foam as described in U.S. Pat E ts 3,755,212, Dunlap and Parrish; 3,821,130, Barron and Dunlap; and 3,862,879, Barron and Dunlap wherein the frothed polyurethane forming composition does not contain silicone surfactant and in U.S. Patents 3,706,681, Bachura; 3,849,156, Marlin et al.; 3,836,560, 3,947,386, 3,957,842, 4,022,722 and 4,022,941, Prokai et al. wherein the frothed polyurethane forming compositions contain a silicone surfactant. The polyurethane foam compositions of the present invention containing polyoxyalkylene siloxane branch copolymers have fine cells and excellent stability during processing. Furthermore, the compositions of the present invention incorporate low amounts of the silicone surfactant(s) (stabilizer), and have improved esthetics and cost over the same polyurethane foams without the silicone surfactant (non-stabilized) or containing linear siloxane surfactants. It is known that penetration weight (weight of the polyurethane composition absorbed by a substrate) is dependent upon several factors, including type of substrate, component reactivity, temperatllr and nmo- nent viscosity. Penetration weight on the commercially available carpet described in this invention had at least about 25 percent reduction compared to non -stabilized formulations. The reduced penetration and improved stability has resulted, on the average, in a 20 percent improvement in gauge (thickness of foam) over non-stabilized formulations. Cost to the customer has been effectively reduced by the process of this invention because a product (foam backed substrate) is obtained that has the same thickness employing less components by weight. In other terms, the same weight of froth is applied to the back of the substrate and a desirably thicker foam is obtained. It is well known in the art that the frothing or mechanical whipping operation of the polyurethane forming composition is performed in high shear equipment such as a Hobart mixer, Firestone mixer, Oakes mixer and similar known equipment. The air or other inert gas should be introduced into the polyurethane forming mixture and whipped under pressure in order to obtain a workable froth. The mechanical -whipping operation is conducted such that the pressure at the mixer head outlet is in the range from about 85 to about 200 psig (1.48 MPa), preferably from 85 to 150 psig (0.69 to 1.14 MPa). In those processes where there is no silicone surfactant present, the substrates absorb an inordinate amount of polyurethane forming components thereby resulting in too much absorption beyond what is necessary for tuftbinding. A loss of gauge and a destabilization line at the substrate/foam interface occurs, wherein the cell structure becomes coarse and unappealing. The loss of gauge and destabilization line are esthetically unappealing to the buyer and results in higher costs to the vendor. The solution to this without a silicone is a high catalyst level or quick reaction time, which severely limits processing latitude. In those processes wherein a silicone surfactant is employed, large quantities of the silicone surfactant are required in order to obtain fine cells or else stability of the polyurethane forming froth is not sufficient to give a fine celled foam or prevent an inordinate amount of penetration (absorption). In the present invention, a large quantity of surfactant ( > 0.5 part) limits the processing of the froth because froth viscosity is too high to be adequately processed onto the back of a substrate such as a carpet and the pressure in the mixer head may exceed the working limit of 200 psig (1.48 MPa). Also, in the present invention, the improvement in penetration and gauge is no longer measurable from greater than 0.3 parts surfactant. There is no real advantage, therefore, to using surfactant levels above 0.5 parts from a processing or cost standpoint. The present invention is directed to a polyurethane foam composition which is the reaction product of a frothed polyurethane forming mixture comprising: (A) a polyethylene polyol having an average of from 2 to 8 hydroxyl groups per molecule and an average hydroxyl equivalent weight of from 100 to 3000; ; (B) a polyol having an vra of from 2 to 8 hydroxyl groups per molecule and an average hydroxyl equivalent weight of from 31 to 230, component (B) being optional when component (A) contains an end cap of at least two moles of ethylene oxide per active hydrogen atom or an internal block of at least three moles of ethylene oxide residues per active hydrogen atom, when components (A) and (B) are employed together, they are employed in proportions providing from 50 to 95 parts by weight of component (A) and from 50 to 5 parts by weight of component (B) based upon 100 parts by weight of the total quantity of components (A) and (B), the hydroxyl equivalent weight of component (A) is at least 1.5 times greater than the hydroxyl equivalent weight of component (B), the mixture of components (A) and (B) or component (A) when employed alone has a Brookfield viscosity employing a number 2 spindle at 12 rpm of at least 100 centipoise (0.1 Pascal-second)- at 250C; (C) an organic polyisocyanate or polyisothio cyanate having an average of from 2 to 4 NCX groups per molecule, each X being indepen dently oxygen or sulfur, components (A), (B) and (C) being employed in quantities so as to provide an NCXjo4 ratio of from 0.85:1 to 2: :1; (D) at least one inorganic filler; (E), at least one catalyst for reacting components (A) and (B) with component (C), component (E) being employed in a quantity such that an unfrothed .m.iYtu- of mponents to), (B), (C), (E) and (F) obtains a Brookfield vis cosity employing a number 4 spindle at 30 rpm greater than 10,000 centipoise (10 Pascal seconds) at 250C in less than 40 minutes; and (F) a silicone surfactant, characterized in that component (F) is a poly(dimethylsiloxane) polyoxyalkylene branch copolymer having an average molecular weight ofless than 30,000, preferably less than 10,000, wherein at least 60 percent by weight, preferably 100 percent by weight, of the polyoxyalkylene groups are oxyethylene groups, the dimethylsiloxane content of the copolymer being from 15 to 40 percent by weight, and at least 40 percent of the weight of the copolymer is derived from the oxyethylene groups, component (F) being present in a quantity from 0.02 to less than 0.5 parts by weight per 100 parts by weight of the combined weights of components (A) and (B). Preferably, the foam has a cell count of greater than 16 per 0.0025 square inches (1.6 mm2) at a position approximately midway between the carpet-foam interface and the outer edge of the foam. Preferably, the resultant cured foam has a density of less than 13 lb/ft3 (208 Kg/m3). Suitable relatively high molecular weight polyether polyols which can be employed in the present invention include adducts of one or more compounds containing 2 to 8 hydroxyl groups per molecule and one or more hydrocarbylene or halogen substituted hydrocarbylene oxides. Suitable hsa vs,rl fling compounds include those having from 2 to 20, preferably from 2 to 6 carbon atoms such as, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,2-butane diol, 1,3-butane diol, 1,4-butane diol, glycerine, trimethylol propane, p,p'-isopropylidine diphenol, and mixtures thereof. Suitable hydrocarbylene or halogen substituted hydrocarbylene oxides which can be employed to prepare polyether polyols include those having from 2 to 12, preferably from 2 to 4 carbon atoms such as, for example, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, epichlorohydrin, epibromohydrin, 3-methyl-l, 2-butylene oxide, 3,3,-dimethyl-1,2-butylene oxide, and mixtures thereof. Other relatively high molecular weight polyols which can be employed herein include polymercontaining polyols such as, for example, those disclosed in U.S. Patents RE 29,118 (Stamberger), RE 28,715 (Stamberger), RE 29,014 (Pizzini et al) and 3,869,413 (Blankenship et al). Suitable low molecular weight polyols include, for example, ethylene glycol, propylene glycol, 1,3-propane diol, 1,4-butane diol, dipropylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, tetrapropylene glycol, heptapropylene glycol, and mixtures thereof. Also suitable as low molecular weight polyols are adducts of initiator compounds having from 2 to 8 active hydrogen atoms per molecule and a hydrocarbylene oxide as hore.-seforo descriç2d so long as the resultant adduct has the desired equivalent weight for the low equivalent weight polyol. Particularly suitable initiator compounds include, for example, water, ethylene glycol, propylene glycol, glycerine, trimethylol propane, aniline, ammonia, ethylene diamine, diethylenetriamine, aminoethylethanolamine, pentaerythritol, glucose, fructose, sucrose, sorbitol, and mixtures thereof. When adducts of initiator compounds having more than 8 active hydrogen atoms per molecule are employed, they must be employed in admixture with polyols having less than 8 hydroxyl groups per molecule in quantities so as to result in an average of from 2 to 8 hydroxyl groups per molecule. When the viscosity of a mixture of polyol components (A) and (B) or the viscosity of polyol (A) when employed alone is below 100 centipoise (0.1 Pascal -second) at 250C, the resultant filled, foam-forming system is too fluid to froth adequately and does not result in a fine celled, low density foam. Suitable organic polyisocyanates include, for example, 2,4-toluenediisocyanate, 2,6-toluenediisocyanate, xylylenediisocyanate, p,p"-diphenylmethane- diisocyanate, p-phenylenediisocyanate, naphthalenediisocyanate, dianisodine diisocyanate, polymethylene polyphenylisocyanate, hexamethylene diisocyanate, and mixtures thereof. Also suitable are the isocyanate terminated prepolymers prepared from one or more of the above mentioned polyisocyanates and one or more of the above mentioned polyols. Suitable also are the trimerized diisocyanates and crude diisocyanates. Also suitable are the corresponding polyisothiocyanates, including isothiocyanate terminated prepolymers. Suitable catalysts which can be employed include, for example, tertiary amines, organometallic compounds, particularly metal carboxylates, and mixtures thereof. Particularly suitable catalysts include, for example, di-n-butyl tin-bis(mercaptoacetic acid isooctyl ester), dimethyl tin dilaurate, dibutyl tin dilaurate, stannous octoate, lead octoate, triethylene diamine, N-methyl morpholine, and mixtures thereof. Suitable inorganic filler materials which can be employed herein include, for example, calcium carbonate, alumina trihydrate, talc, bentonite, antimony trioxide, kaolin, barytes either as obtained or treated with fatty acids or organotitanates, and mixtures thereof. The inorganic filler is usually employed in quantities of from 25 to 300, preferably from 50 to 200 parts per 100 parts by weight based on the total polyol composition. Suitable silicone surfactants which can be employed herein include the branched organosilicon polyglycol block copolymers having an average molecular weight below 30,000. Such surfactants are described in U.S. Patent 3,518,288 (Haluska). Particularly suitable are DC193 and DC197 commercially available from Ddw Corning Corporation; and L5430 commercially available from Union Carbide Corporation. Particularly suitable silicone surfactants are those represented by the formula (CH3 )3Si [oSi(cH3 m [OSiCH3] nOSi(CH3)s -D(OCXH2x)pA wherein m has a value of from 6 to 180, preferably from 6 to 60, most preferably from 11 to 2C;n has a value of from 3 to 30, preferably from 3 to 10, most preferably from 3 to 5; each x is independently 2, 3 or 4 with the proviso that in at least 60, preferably 100 percent, of the (OCXH2x) groups, x has a value of 2; p has a value of from 9 to 30, preferably from 9 to 20, most preferably from 9 to 12; and A is selected from EMI10.1 especially where R is methyl, EMI10.2 (carbonate ester), EMI10.3 (urethane), -OH (hydroxyl), or -R (alkyl), especially methyl; and D is an alkylene radical containing from 3 to 18 carbon atoms, where D is most preferably a propylene radical. These are disclosed by Haluska in U.S. Patent 3,518,288 and Bachura in U.S. Patent 3,706,681. If desired, the formulations can contain flame suppressing agents such as, for example, dibromoneopentyl glycol, tris (dichloropropyl) phosphate, polyammonium phosphate, beta-chloroethyl phosphonate ester, chlorophosphate ester, polyvinylidene chloride, and mixtures thereof. Suitable substrates to which the frothed compositions of the present invention are applied include carpet, particularly tufted carpet, paper, synthetic and natural textile fabrics such as, for example, nylon, polyester, acrylic, cotton, and wool. Suitable primary backing materials which can be employed in the present invention when the substrate is a tufted carpet include those prepared from, for example, jute, polypropylene, nylon, polyesters, and polyacrylates. Suitable yarns which can be tufted or woven into the primary backing include those prepared from, for example, wool, nylon, polyester, acrylic, cotton, polypropylene, polyethylene, and blends thereof. The following examples are illustrative of the present invention but are not to be construed as to limiting the scope thereof in any manner. GENERAL PROCEDURE In the examples and comparative runs, a master batch containing a polyol mixture, filler(s) and silicon surfactant was well blended to form a homogeneous creamy dispersion and placed in a run tank maintained at a temperature not less than 450F (70C) under a pad of nitrogen. Another run tank containing the polyisocyanate was maintained at a temperature not less than 600F (160C). The contents of the run tanks, and catalyst were metered into an Oakes frother where the contents were frothed employing air as the inert gas. The resultant froth was then placed onto the back of the carpet via a hose and doctored to the desired thickness. The froth exit temperature was maintained at a temperature of at least 860F.(300C), The carpet containing the polyurethane-forming froth composition was then cured in an'oven at a temperature of 2500F (1210C). The carpet onto which the frothed polyurethaneforming compositions were doctored was a flat level loop carpet containing 100 percent continuous filament nylon pile weighing 14 oz/yd2 (0.47 Kg/m2) tufted at a gauge of 0.1 inch (3 mm) through an FLW (woven polypropylene needlepunched with nylon or polypropylene fiber) primary backing weighing 4.25 oz/yd2 (0.144 Kg/m2) at a stitch rate of 8 per inch and a pile height of 0.125 inch (3.18 mm). In the following examples and comparative runs, the properties were determined by the following tests. The viscosity of the unfilled urethane forming components is obtained by mixing the components for 3 minute(s) and placing 10 ml. of the resultant mixture in a Brookfield LVF Viscometer, maintaining the temperature of the mixture at 250C f 0.50C and determining the viscosity over the desired period of time. The Brookfield LVF Viscometer was employed using a number 4 spindle rotating at 30 rpm. The viscosity of a mixture of polyols (A) and (B) or the viscosity of polyol (A) when employed alone is obtained by placing 200 ml of the mixture of polyols (A) and (B) or polyol (A) alone in a Brookfield LVF Viscometer, maintaining the temperature of the material being measured at 250C, i 0.50C, and determining the viscosity employing a number 2 spindle rotating at 12 rpm. Penetration weight was calculated by subtracting the greige weight (the weight of the carpet sample to which the polyurethane-forming froth composition was applied so as to provide a secondary backing), from the greige weight plus polyurethane-forming materials which had soaked into the tufts and primary backing which was the weight of the sample after "skiving" the foam from the back of the carpet sample and brushing with a wire brush to remove as much of the remaining foam as possible. The cell count was determined employing a microscope equipped with a Polaroid camera to take photomicrographs of foam and visually count the number of cells along the surface plane in a given area. Each area was ten units by ten units, each unit being 0.005 inches (0.1 mm) (0.0025 inch2)(l.6 mm2). The pictures were taken of the foam surface at or near the center of the foam after splitting the foam for this purpose. The surface plane after splitting was dyed so that individual cells were clearly visible. The foam density was determined by the following formula: 0.08333 x coating weight-penetration wt. (oz/yd2) = Gauge, (inches) density, lb/ft3 [1000 x coating weight-penetration wt. (Kg/m2) = Gauge, (mm) density, (Kg/ma The coating weight was obtained by subtracting the greige weight from the total sample weight of the carpet (greige) and foam. Gauge is the thickness of the foam on the back of the carpet and was measured after the carpet with the foam had been cured. The following components were employed in the examples and comparative runs. The composition of the polyurethane-forming mixtures and the resulting foam properties for Examples 1 to 13 and Comparative Runs A to H are shown in Table I. Polyol A is a glycerine initiated polyoxypropylene glycol end capped with 15 weight percent ethylene oxide. The resultant primary hydroxyl-containing polyether polyol had an average OH equivalent weight of 1650 and an endcap of an average of 3.75 moles of ethylene per active hydrogen of the polyol. Polyol B is diethylene glycol having- an average OH equivalent weight of 53. Polyol C is a polyoxyethylene glycol having an average OH equivalent weight of 100. Polyol D is a glycerine initiated polyoxypropylene glycol having an average OH equivalent weight of 87. Polyol E is a glycerine initiated heteropolyol prepared from a mixture of propylene oxide and ethylene oxide in a ratio of 88/12 weight percent respec tively. The resultant secondary hydroxyl -containing polyether polyol has an average OH equivalent weight of 1270 and an internal block of an average of 2.2 moles of ethylene oxide residues per active hydrogen atom of the polyol. Polyol F is dipropylene glycol having an average OH equivalent weight of 67. Polyol G is a polyoxypropylene glycol having an average OH equivalent weight of 1000. Polyol H is a polyoxypropylene triol containing 20 weight percent of a 50/50 styrene/acry].onitrie copolymer and having an average OH equivalent weight of 2000. Polyol I is an adduct of a mixture of sucrose and glycerine with propylene oxide having an average functionality of 4.6 and an OH equivalent weight of 130. Polyol J is a glycerine initiated polyoxypropylene triol having an OH equivalent weight of 240. Polyisocyanate A is an 80/20 mixture of 2,4-/2,6 -toluene diisocyanate having an average NCO equivalent weight of 87. Polyisocyanate B is prepolymer prepared by reacting an excess of polyisocyanate A with a polyol mixture consisting of 64 weight percent of polyol C and 36 weight percent polyol D. The resultant isocyanate containing prepolymer had an NCO content of 26.7 percent and an average NCO equivalent weight of 157. Polyisocyanate C is a carbodiimide modified methylene diphenyldiisocyanate having an NCO equivalent weight of 143 commercially available from Upjohn Company as ISOLATES 143L. Catalyst A is di-n-butyl tin bis(isooctylmercapto acetate), commercially available from Witco Chemical Co. as FomrezdUL-6. Catalyst B is dimethyl tin dilaurate commercially avail able from Witco Chemical Co. as FomreUL-28. Filler A is alumina trihydrate commercially avail from Kaiser Aluminum Company as H36U. Filler B is calcium carbonate commercailly available from Georgia Marble Company as D-70. Silicone A is a nonhydrolyzable poly(dimethyl siloxane) polyoxyethylene copolymer having a weight average molecular weight of 4000 commercially available from Dow Corning Corporation as'DC-197. Silicone B is a 40 percent by weight solution of a linear siloxane-polyoxyalkylene block copolymer having a weight average molecular weight of 100,000 in a hydrocarbon solvent commercially available from Union Carbide Corporation as L 5614. Silicone C is a siloxane-polyoxyalkylene block copolymer having a weight average molecular weight of 40,000, commercially available from Thw Gold schmidt as B 1651. It is a 55 percent weight solution in an aromatic hydrocarbon solvent. Silicone D is a hydrolyzable polysiloxane surfactant having a weight average molecular weight of 4,000, commercially available from. Th. Goldschmidt as B 1048. Silicone E is a nonhydrolyzable methyl capped siloxane polyoxyalkylene block copolymer having a weight average molecular weight of 3,000, commercially available from Union Carbide Corporation as L 5340. Silicone F is a non hydrolyzable silicone surfactant having a weight average molecular weight of. 15,000 commercailly available from from. Dow Corning Corporation as DC 190. Silicone G is a silicone surfactant believed to be diluted in a polyoxyalkylene glycol and is commer- cially available from Union Carbide C'orporation as L 5303. TABLE I Polyurethane Compara- Exam- Exam- Exam Forming mixture, tive Run ple ple ple parts by weight A 1 2 3 Comp.(A) polyether polyol A/90 A/90 A/90 A/90 Comp.(B) polyol B/10 B/10 B/10 B/10 Comp.(C) polyisocyanate B/46.1 B/46.1 B/46.1 B/46.1 Comp.(D), A/40 A/40 A/40 A/40 filler B/40 B/40 B/40 B/40 Comp.(E), catalyst A/0.06 A/0.06 A/0.06 A/0.06 Comp. (F), silicone 0 A/0.05 A/0.11 A/0.25 HEW(A)/ HEW(B) 31/1 31/1 31/1 31/1 Viscosity(A)+(B)) or (A) alone, cps 680 680 680 680 (p.a) (0.68) (0.68) (0.68) (0.68) Viscosity (A), (B), (C), (E) +(F) cps 10,600 11,000 10,600 10,000 (p.a) (10.6) (11) (10.6) (10) at 16 min. 15 min. 16 min. 2 min. TABLE I (cont'd) Comparai Exam- Exam- Exam tive Run ple ple ple A 1 2 3 Foam properties coating weight, oz/yd2 45 46 48 54 (Kg/m2) (1.5) (1.6) (1.6) (1.8) Penetration weight, oz/yd2 16 10 8 6 (kg/m2) (0.5) (0.3) (0.3) (0.2) Gauge, in. 0.235 0.271 0.294 0.333 (mm) (5.97) (6.88) (7.47) (8.46) Cell count, cells per area 26 17 17 35 Foam density, lb/ft3 10.3 11.1 11.2 11.9 (Kg/m3) (165) (178) (179) (191) TABLE I (cont'd) Polyurethane Exam- Exam- Exam Forming mixture, ple ple ple parts by weight 4 5 6 Comp.(A) polyether polyol A/90 H/90 A/100 Comp.(B) polyol B/10 B/10 - Comp.(C) polyisocyanate C/45.1 B/44 B/11.4 Comp.(D), A/55 A/55 A/55 filler Comp.(E), catalyst A/0.01 A/0.07 A/0.06 Comp. (F), silicone A/0.15 A/0.15 A/0.15 HEW(A)/ HEW(B) 31/1 38/1 - Viscosity(A)+(B)) ) or (A) alone, cps 680 1455 810 (p.a) (0.68) (1.455) (0.81) Viscosity (A),(B),(C),(E) +(F) cps 10,000 10,000 10,000 (p.a) (10) (10) (10) at 2 min. 8 min. 20 min. TABLE I (cont'd) Exam- Exam- Exam ple ple ple 4 5 6 Foam properties coating weight, oz/yd2 47 44 45 (Kg/mê) tl.6j (1.5) (1.5) Penetration weight, oz/yd2 6 5 11 (kg/m2) (0.2) (0.2) (0.4) Gauge, in. 0.264 0.311 0.231 (mm) (6.71) (7.90) (5.87) Cell count, cells per area 35 30 19 Foam density, lb/fts 12.8 10 12.5 (Kg/m3) (205) (160) (200) TABLE I (cont'd) Polyurethane Exam- Exam- Exam- Exam Forming mixture, ple ple ple ple parts by weight 7 8 9 10 Comp.(A) polyether polyol E/88 G/85 1/85 J/85 Comp.(B) polyol F/12 F/15 F/15 F/15 Comp.(C) polyisocyanate B/46.1 B/60 B/166 B/108 Comp. (D), filler A/55 A/55 A/55 A/55 Comp. (E), catalyst B/0.25 B/0.07 A/0.09 B/0.06 Comp. (F), silicone A/0.10 A/0.25 A/0.15 A/0.45 HEW(A)/ HEW(B) 19/1 15/1 1.9/1 3.6/1 Viscosity(A)+(B)) or (A) alone, cps 500 245 2260 180 (p.a) (0.5) (0.245) (2.26) (0.18) Viscosity (A),(B)t(C),(E) +(F) cps 10,400 10,000 10,000 10,000 (p.a) (10.4) (10) (10) (10) at 13 min. 8 min. 12 min. 9 min. TABLE I (cont'd) Exam- Exam- Exam- Exam ple ple ple ple 7 8 9 10 Foam properties coating weight, oz/yd2 43 46 47 47 (KgXma) (1.5) (1.6) (1.6) (1.6) Penetration weight, oz/yd2 6 10 8 12 (kg/m2) (0.2) (0.3) (0.3) (0.4) Gauge, in. 0.291 0.264 0.353 0.292 (mm) (7.39) (6.71) (8.97) (7.44) Cell count, cells per area 27 17 18 20 Foam density, lbjft3 10.4 11.2 9.3 . 9.8 (Kg/m3) (167) (179) (149) (157) TABLE I (cont'd) Polyurethane Exam- Exam- Exam Forming mixture, ple ple ple parts by weight 11 12 13 Comp.(A) polyether polyol A/90 A/90 A/90 Comp.(B) polyol B/10 B/10 B/10 Comp.(C) polyisocyanate B/46.1 B/46.1 B/46.1 Comp.(D), filler A/55 A/55 A/55 Comp (E), catalyst A/0.07 A/0.07 A/0.07 Comp.(F), silicone F/0.15 D/0.15 E/0.15 HEW(A)/ HEW(B) 31/1 31/1 31/1 Viscosity(A)+(B)) or (A) alone, cps 680 680 680 (p.a) (0.68) (0.68) (0.68) Viscosity (A),(B),(C),(E) +(F) cps 10,500 11,000 10,500 (p.a) (10.5) (11) (10.5) at 15 min. 16 min. 15 min. TABLE I (cont'd) Exam- Exam- Exam ple ple ple 11 12 13 Foam properties coating weight, oz/yd2 48 51 47 (Kg/mê) (1.6) (1.7) (1.6) Penetration weight, oz/yd2 8 9 6 (kg/m2) (0.31) (0.3) (0.2) Gauge, in. 0.303 0.303 0.312 (mm) (7.70) (7.70) (7.92) Cell count, cells per area 19 18 29 Foam density, lb/fta 11 11.6 11 (Kg/m3) (176) (186) (176) TABLE I (cont'd) Polyurethane Compar- Compar- Compar- Compar Forming mixture, ative ative ative ative parts by weight Run B Run C Run D Run E Comp.(A) polyether polyol A/90 A/90 A/90 A/90 Comp.(B) polyol B/10 B/10 B/10 B/10 Comp.(C) polyisocyanate B/46.1 B/46.1 B/46.1 B/46.1 Comp. (D), filler A/55 A/55 A/55 A/40 B/40 Comp.(E), catalyst A/0.07 A/0.07 A/0.07 A/0.06 Comp.(F), silicone B/0.05 B/0.l1 B/0.25 B/0.56 HEW(A)/ HEW(B) 31/1 31/1 31/1 31/1 Viscosity(A)+(B)) or (A) alone, cps 680 680 680 680 (pea) (0.68) (0.68) (0.68) (0.68) Viscosity (A),(B),(C), (E) +(F) cps 11,500 12,000 11,500 12,800 (p.a) (11.5) (12) (11.5) (12.8) at 16 min. 16 min. 15 min. 16 min. TABLE I (cont'd) Compar- Compar- Compar- Compar ative ative ative ative Run B Run C Run D Run E Foam properties coating weight, oz/yd2 47 48 51 50 (Kg/m2) (1.6) (1.6) (1.7) (1.7) Penetration weight, oz/yd2 14 14 8 5 (kg/m2) (0,5) (0.5) (0.3) (0.2) Gauge, in. 0.245 0.224 0.290 0.306 (mm) (6.22) (5.69) (7.37) (7.77) Cell count, cells per area 8 2 6 16 Foam density, lb/ft3 11.1 12.9 12.3 12.1 (Kg/m3) (178) (207) (197) (194) TABLE I (cont'd) Polyurethane Compar- Compar- Compar Forming mixture, ative ative ative parts by weight Run F Run G Run H Comp.(A) polyether polyol A/90 A/90 A/90 Comp.(B) polyol B/10 B/10 B/10 Comp.(C) polyisocyanate B/46.1 B/46.1 B/46.1 Comp. (D), filler A/55 A/55 A/55 Comp.(E), catalyst A/0.07 A/0.07 A/0.07 Comp.(F), silicone C/0.05 C/0.15 C/0.56 HEW(A)/ HEW(B) 31/1 31/1 31/1 Viscosity(A)+(B)) or (A) alone, cps 680 680 680 (p.a) (0.68) (0.68) (0.68) Viscosity (A), (B), (C), (E) +(F) cps 11,500 11,000 13,000 (p.a) (11.5) (11) (13) at 16 min. 16 min. 19 min. TABLE I (cont'd) Compar- Compar- Compar ative ative ative Run F Run G Run H Foam properties coating weight, oz/yd2 46 43 47 (Kg/m2) (1.6) (1.5j (1.6) Penetration weight, oz/yd2 15 11 9 (kg/m2) (0.5) (0.4) (0v.3) Gauge, in. 0.248 0.277 0.306 (mm) (6.30 (7.04) (7.77) Cell count, cells per area 7 13 10 Foam density, lb/ft3 10.4 9.6 10.3 (Kg/m3) (167) (154) (165)

Claims: WHAT IS CLAIMED IS: 1. A polyurethane foam composition which is the reaction product of a frothed polyurethane forming mixture comprising: (A) a polyethylene polyol having an average of from 2 to 8 hydroxyl groups per molecule and an average hydroxyl equivalent weight of from 100 to 3000; (B) a polyol having an average of from 2 to 8 hydroxyl groups per molecule and an average hydroxyl equivalent weight of from 31 to 230, component (B) being optional when component (A) contains an end cap of at least two moles of ethylene oxide per active hydrogen atom or an internal block of at least three moles of ethylene oxide residues per active hydrogen atom, when components (A) and (B) are employed together, they are employed in proportions providing from 50 to 95 parts by weight of component (A) and from 50 to 5 parts by weight of component (B) based upon 100 parts by weight of the total quantity of components (A) and (B), the hydroxyl equivalent weight of component (A) is at least 1.5 times greater than the hydroxyl equivalent weight of compo- nent (B), the mixture of components (A) and (B) or component (A) when employed alone has a Brookfield viscosity employing a number 2 spindle at 12 rpm of at least 100 centipoise (0.1 Pascal-second) at, a 20: : (C) an organic polyisocyanate or polyisothio cyanate having an average of from 2 to 4 NCX groups per molecule, each X being indepen dently oxygen or sulfur, components (A), (B) and (C) being employed in quantities so as to provide an NCXtO+ratic of from 0.85:1 to 2:1; (D) at least one inorganic filler; (E) at least one catalyst for reacting components (A) and (B) with component (C), component (E) being employed in a quantity such that an unfrothed mixture, of components (A), (B); (C), (E) and (F) obtains a Brookfield vis cosity employing a number 4 spindle at 30 rpm greater than 10,000 centipoise (10 Pascal seconds) at 250C in less than 40 minutes; and (F) a silicone surfactant, characterized in that component component (F) is a poly(dimethyl siloxane) polyoxyalkylene branch copolymer having an average weight of less than 30,000, wherein at least 60 percent by weight of the polyoxyalkylene groups are oxyethylene groups, the dimethylsiloxane content of the copolymer being from 15 to 40 percent by weight, and at least 40 percent of the weight of the copoly mer is derived from the oxyethylene groups, component (F) being present in a quantity from 0.02 to less than 0.5 parts by weight per 100 parts by weight of the combined weights of components (A) and (B). 2. The foam composition of Claim 1 characterized in that component (F) is represented by the formula (CH3)3Si[OSi(CH3)2] m [OSiCH3 ]nOSi(CH3 )3 -D(OCxH2 PA wherein m has a value of from 6 to 180, n has a value of from 3 to 30, each x is independently 2, 3 or 4 with the proviso that in at least 60 percent of the (OCXH2x) groups, x has a value of 2; p has a value of from 9 to 30; A is selected from 0 " -OCR (acyloxy) especially where R is methyl, EMI32.1 (carbonate ester), EMI32.2 (urethane) -OH (hydroxyl), or -R (alkyl); and D is an alkylene radical containing from 3 to 18 carbon atoms. 3. The foam composition of Claim 2 characterized in that m has a value of from 6 to 60; n has a value of from 3 to 10; each x has a value of 2; p has a value of from 9 to 20; A is acetate, urethane, hydroxyl or methyl. 4. The foam composition of Claim 3 characterized in that'm has a value of from 11 to 20; n has a value of from 3 to 5; p has a value of from 9 to 12 and D is the propylene radical. 5. A substrate having a polyurethane foam backing containing an inorganic filler or mixture of such filler characterized in that the polyurethane foam is the composition of any of Claims 1, 2 or 3.

Inventors: JENKINES, RANDALL CRAIG, PORTER, JAMES RICHARD
Applicants: THE DOW CHEMICAL COMPANY
Application year: 1981
Main classification: C08L75
IPC codes: C08J9, C08G18, D06N7, D06N3