WATER-DISPERSABLE POLYURETHANE/ACRYLIC POLYMER COMPOSITIONS

Abstract: The present invention provides for aqueous polymer dispersions characterized by a water-dispersible polyurethane/acrylic support resin/acrylic polymer, with the acrylic polymer being polymerized from monomers in the presence of the water-dispersible polyurethane and acrylic support resin. The dispersions can be prepared having balanced properties such as toughness, durability, hardness, abrasion and detergent resistance, and depth and retention of gloss. The compositions are particularly suitable in floor coatings.

Description: ATER-DISPERSABLE POLYURETHANE/ACRYLIC POLYMER COMPOSITIONS This invention relates to polyurethane/ acrylic polymer aqueous dispersions which, when applied as a coating, will air dry to a hard, abrasion-resistant film having excellent toughness, durability, and gloss. More particularly, the invention relates to aqueous polymer dispersions characterized by an acrylic polymer formed by polymerizing acrylic and styrene type monomers in the presence of a water-dispersible polyurethane and a vinyl support resin. "Acrylic" as used herein to define a monomer or polymer embraces acrylic acid and methacrylic acid, and derivatives thereof such as the esters. Polyurethanes are well known in, inter alia, the protective coating industry to be materials having exceptional hardness, abrasion resistance, toughness, flexibility, and, when aliphatic in nature, UV stability. These materials have been extensively developed in order to build into the polyurethane specific properties so that the polyurethane can be used in specialized areas. One area of development has been the modification of the polyurethanes with components having ethylenic unsaturation. Thus, -Guagliardo et al, U.S. Patent No. 4,317,895; and Guagliardo, U.S. Patent No. 4,318,833 disclose coating compositions based on a thermoplastic copolymer prepared by polymerizing one or more ethylenically unsaturated monomers in the presence of a fully reacted polyurethane. The resulting copolymers are stated to be particularly useful in auto otive finishes. - Tideswell et al, U.S. Patent No. 4,107,229 discloses vinyl terminated, fully reacted urethane compositions com¬ prising the reaction product of a polyisocyanate, an hy- droxyalkylated novolac, and an ethylenically unsaturated alcohol. The vinyl terminated compositions are then copoly- merized with ethylenically unsaturated monomers to produce thermoset polymers useful in the manufacture of molded arti¬ cles, laminates, and in the formulation of marine coatings. - Suling et ai, U.S. Patent No. 4,233,424; and Suling et al, U.S. Patent No. 4,300,886 disclose polymers useful in making dental appliances obtained by bead polymerization of from about 88 to 99.5% by weight of a polymer of methacrylic acid esters, with from 0.5 to 12% by weight of a polyurethane. - Niederhauser et al, U.S. Patent No. 3,641,199 dis¬ closes urethane elastomer impact modifiers wherein ethylen¬ ically unsaturated monomers are polymerized in the presence of a polyurethane. The modified polymers are stated to offer an improved balance of physical properties, including impact strength, clarity, and weather resistance. - Other patents disclosing polyurethanes modified with acrylic resins include Suzuki et al, U.S. Patent No. 4,038,257; Kondo et al, U.S. Patent No. 3,773,857; Olstow- ski, U.S. Patent No. 4,125,487; Gould et al, U.S. Patent No. 4,490,423; Stevenson, U.S. Patent No. 4,035,439; and Gould et al, U.S. Patent No. 4,454,309. Although the prior art establishes that the poly¬ urethanes have been extensively modified with the acrylics, in most all instances the modifications have been for the pur_po.se of providing polyurethane compositions having speci¬ fic; properties for a particular application. There is still a need for modified polyurethanes dispersed in or dispersi- ble in water which, while retaining the advantageous proper¬ ties of the polyurethanes, will also have the beneficial characteristics of resin systems such as the acrylics. Moreover, it is particularly desirable to have the ability to modify the polyurethanes in a manner which will permit the obtaining of a variation in the physical characteristics of the polymeric compositions, such as the ability to pre¬ pare the compositions to have either low, high, or inter¬ mediate glass transition temperatures (Tg), and a balancing of flexibility, durability, hardness, toughness, and gloss in coatings prepared from the polymer compositions without need for the addition of large amounts of modifying compo¬ nents. Accordingly, it is a primary object of the present invention to provide for polyurethane/acrylic polymer aqueous dispersions which can be tailored in - composition to provide coatings based on the dispersions with varying physical characteristics, which may vary widely to satisfy widely varying applications. In addition, the polyurethane/acrylic polymer aqueous dispersions are tailored to have balanced progert±es in coatings prepared from the dispersions with respect to abrasion and detergent resistance, depth and retention of gloss, and recoatability which causes the aqueous dispersions to be particularly suitable for use in floor care compositions. Specifically, the present invention provides for a water-dispersible polymer composition characterized by water-dispersible polyurethane, an acrylic support resin, and an acrylic polymer; said acrylic polymer being formed from acrylic monomers polymerized in the presence of a mixture of said water-dispersible polyurethane and acrylic support resin to provide the water-dispersible polymer composition. The components of the final aqueous dispersion will comprise from 3 to 85% by weight water-dispersible polyurethane, 5 to 40% by weight acrylic support resin, and 15 to 85% by weight of the acrylic polymer formed in situ by polymerizing the acrylic monomers. Preferably, tire components of the final aqueous dispersion will comprise from 3 to 65% by weight polyurethane, 5 to 30% by weight acrylic support resin, and 25 to 92% by weight of the acrylic polymer formed in situ. More preferably, the final aqueous dispersion will comprise from 5 to 40% by weight polyurethane, 5 to 25% by weight acrylic support resin, and 35 to 90% by weight of the acrylic polymer formed .in situ. Most preferably, the final aqueous dispersion will comprise from 10 to 25% by weight polyurethane, 8 to .15% by weight acrylic support resin, and 60 to 82% by weight acrylic polymer formed .in situ. By polymerizing the acrylic monomers in the presence of the polyurethane and support resin, it is possible to control the properties of the aqueous dispersion to obtain the favorable properties of the polyurethane such as UV stability (if aliphatic in nature), hardness, abrasion resistance, toughness, and resistance to salt and organic chemicals; and also in general the favorable properties of acrylic systems which can show excellent UV stability, good depth and retention of gloss, and recoatability. Moreover, it is possible by the judicious selection of the three com¬ ponents of the system to obtain a variety of properties in¬ cluding a-glass transition temperature which varies from a high glass transition temperature to a low glass transition temperature to provide a hard resin or a soft resin; and to vary the properties of the dispersions to provide coatings based on the dispersions having a balancing of properties such as hardness, abrasion resistance, toughness, resistance to chemicals such as detergents, .and depth and retention of gloss so as to permit the formation of compositions which can be used in such diverse applications as floor coatings, graphic arts inks, paint binders, plastics additives, pigment-dispersant, resins, adhesives, and the like without need for the addition of large amounts of modifying compo¬ nents such as surfactants. The Water-Dispersible Polyurethanes Used According To The Invention The water-dispersible polyurethanes which can be used in the compositions of the present invention are pref- erably the low molecular weight linear polyurethanes. These materials will generally have a number average molecular weight between about 5,000 and 50,000, and preferably from about 15,000 to 40,000. These polyurethanes generally com¬ prise low molecular weight polyols reacted with polyisocyan- ates. A typical scheme for preparing aqueous urethane dispersions comprises the preparation of an isocyanate ter¬ minated prepolymer containing free acid groups. This is achieved by combining a polyether or polyester polyol with a diol acid such as dimethanol propionic acid (DMPA) with an excess of a diisocyanate. The acid groups of the ioscyanate prepolymer are then neutralized with a tertiary amine, dis¬ persed in water and chain extended with a diamine. The polyisocyanates used herein preferably are the linear diisocyanates such as 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,4-cyclohexylene diisocy¬ anate, l-methyl-2,4-diisocyanatocyclohexane, 1-isocyanato- 3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (isophorone diisocyanate, or IPDI), 2,4'-diisocyanato-dicyclohexyl- methane, 4,4'-diisocyanato-dicyclohexyl ethane, and meta- and pa a-tetramethylxylenediisocyanate. In addition to the above diisocyanates, the urethane oligomers obtained by iso- cyanurate or diurethane formation can be employed. It is preferable to use isocyanates and polyisocyanates containi / ig aliphatic and/or cycloaliphatic bound isocyanate groups in order to obtain good light stability. The polyol employed is generally a linear polyol of the type derived from poly- alkylene ether glycols, polyester polyols including dihy- droxy. polyesters, dihydroxy polyester amides, polyester polycarbonate polyols, polyhydroxy polyacetals, polycarbon¬ ate polyols, and the like. More preferably the water-dispersible polyurethanes will have anionic characteristics obtained, for example, by including acid groups which can be neutralized by base ma¬ terials. However, any of the water-dispersible polyure¬ thanes have application according to the present invention, including, those prepared from the aromatic .isocyanates such as 2,4'*-tol_ylene diisocyanate, m-phenylene diisocyanate, 4-chl.oro—1,3-phenylene diisocyanate, 4,4'-biphenylene diiso- cyanarfcs-,. 11,.5-naphthylene diisocyanate, and the like, with !ι any- pD-yoU component which can^ be a polyester having reac¬ tive hydroxyl groups such as the alkyd resin polyesters of the type formed by the reaction between glycols, such as ethylene glycol, diethylene glycol, triethylene glycol, tri- me hylene. glycol, neopentyl glycol, pentamethylene glycol, hexaπtethylene glycol, deca ethylene glycol and the like, with dibasic acids such as maleic, succinic, glutaric, adi- pic, phthalic, terephthalic, hexahydroterephthalic and para- phenylenediacetic acids. Other alkyd resins formed using glycerine or other polyhydroxy compounds with dibasic acids, as well as to esters of polyhydric alcohols and hydroxy fatty acids, such as glyceryl ricinoleate and castor oil can be used. The polyurethanes useful herein can also include modifiers such as amines and the like. As will be more fully apparent hereinafter, it is essential to select the components for the polyurethane in order that the polyurethane will have water-dispersible characteristics and which provides the specific characteris¬ tics for a tailored end application. Water-dispersible polyurethanes particularly useful herein are commercially available, for example the Spensol Series such as Spensol L-50, L-51, L-52, L-53, L-54, L-55, and L-56 marketed by N. L. Industries, Buffalo, New York. Other suitable, com¬ mercially available water-dispersible polyurethanes are marketed by Witco Chemical Corporation, New York, New York, under the tradename Witcobond W-232, W-234, W-240, and W-290H. Still other water-dispersible polyurethanes are commercially available from Mobay Chemical Corporation, Pittsburgh, Pennsylvania, under the tradename Baybond XW 121, Impranil DLH, and .Impranil DLN; from Sanncor, Leominister, Massachusetts, under the tradename Sancure 895, 896, 899, 1815, 1817, and 815; from Hauthaway S Sons Company, Linn, Massachusetts, under-the tradename Hauthane HD-2007; and from Polyvinyl Chemical, Inc., Wilmington, Massachusetts, under the tradename Neorez R-960, R-966, and R-940. The- Acrylic Support Resin The acrylic support resin is a fully formed acrylic addition polymer such as is disclosed in commonly assigned U.S. Patent Nos. 4,414,370; 4,529,787, and 4,546,160, the disclosures thereof being incorporated herein by reference. More particularly, - the '370 patent discloses styrene and acrylic acid co- polymers made by bulk thermal initiation . which have a low weight average molecular weight and having a relatively high number average molecular weight. The process produces re¬ sins having relatively high aromatic content, making the resins particularly suitable for use in high solids coat¬ ings. - the '787 patent discloses aromatic/acrylate polymers manufactured in a bulk initiated process wherein the process utilizes a polymerization initiator in the presence of low solvent levels to produce polymers having a narrow molecular weight distribution and a low chromophore content. These polymers have a number average molecular weight of from about 500 to 6000, a polydispersity of less than about 2.5, and a dispersion index of less than about 4.5. The poly¬ mers, because of their low chromophore content, are particu¬ larly useful in protective coatings of the type herein con¬ templated, including floor polishes. - the *160 patent discloses a continuous bulk polymeriz¬ ation process for producing polymers having a number average molecular weight of about 1000 to about 2500, a polydisper¬ sity of less than about 3, a dispersion index of up to about 5, and a low chromophore content. Whereas the aforesaid commonly assigned patents disclose polymers having particularly desirable characteris¬ tics for use as the support resin according to the present invention, other acrylic polymers can be used as the support resin according to this invention. For example, resins made by a solution process are suitable for use herein. Vasanth R. Kamath and James D. Sargent, Sr., Pennwalt Corporation, in a paper entitled "High Solids Acrylic Coatings: Resin Synthesis With T-Amyl Peroxides," presented at the Water- Borne and High-Solids Coatings Symposium on February 5-7, 1986, in New Orleans, Louisiana, disclose low solution vis- cosity and narrow MWS resins made by polymerizing monomers in a solvent using t-amyl peroxide. Examples of solution prepared resins are also disclosed in patents such as U.S. Patent Nos. 2,556,488; 3,673,168; 3,753,958; 3,879,357, and 3,968,059 noted in the above-referenced U.S. Patent No. 4,414,370. The polymers useful as the support resin herein, made by bulk or solution processes, include homo- and co- polymers of monomers having only one reactive site of ethy- lenic unsaturation per molecule including 2-hydroxyethyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 2-hydroxymethyl methacry¬ late, 2-hydroxypropyl methacr late, 6-hydroxyhexyl methacry- late, 5,6-dihydroxyhexyl methacrylate, methyl methacrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)- acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, isoamyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, N,N-dimethyl-aminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, t- butylaminoethyl (meth)acrylate, 2-sulfoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, benzyl (meth)acrylate, 2-n- butoxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, cinnamyl (meth)acrylate, cyclo- hexyl (meth)acrylate, cyclopentyl (meth)acrylate, 2-ethoxy- ethyl (meth)acrylate, furfuryl (meth)acrylate, hexafluoro- isopropyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 2-nitro-2-methylpropyl ('meth).acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-phenylethyl (meth)acrylate, phenyl (meth)acrylate, propargyl (meth)acry¬ late, tetrahydrofurfuryl (meth)acrylate, tetrahydropyranyl (meth)acrylate, and (meth)acrylic acid. As used herein, "meth" in parentheses before acrylic or acrylate is used to designate either the methacrylic or acrylic compound. Other monomers which can be used in forming the support resin in¬ clude ethylenic monomers such as vinyl acetate, vinyl pyri- dine, vinyl pyrollidone, methyl crotonate, maleic anhydride, styrene, alpha-methylstyrene and the like, preferably in combination with an acrylic monomer. Preferred support resins for use herein are those prepared from a mixture of monomers. It has been found that the support resin preferably will have a glass transition temperature (Tg) within the range of from about -40 to 135°C, and an acid value within a range of 50 to 260. Within these ranges it is possible to provide water-dispersible polyure¬ thane/acrylic polymer compositions which are hard resins having a high glass transition temperature or water-disper¬ sible polyurethane/acrylic polymer compositions which are soft resins with a low glass transition temperature, with modification between the extreme ranges. The Acryriic Monomers The acrylic monomers which can be polymerized in the presence of the water-dispersible polyurethane and sup¬ port resin are largely the same monomers which can be used in the formation of the acrylic support resin and as such include the monomers acrylic acid and methacrylic acid and monomers derived from acrylic acid and methacrylic acid such as^ the esters of acrylic acid and methacrylic acid including methyl (me hTac " ry_ate, ~ ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)- acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, ir—hexyl (meth)acrylate, isoamyl (meth)acrylate, trifluoro- e-thyl (meth)acrylate, benzyl (meth)acrylate, 2-n-butoxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, sec-butyl- (meth)-acrylate, tert-butyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, cinnamyl (meth)acrylate, cyclohexyl (meth)- acrylate, cyclopentyl (meth)acrylate, 2-ethoxyethyl (meth)- acrylate, furfuryl (meth)acrylate, hexafluoroisopropyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-methoxy- butyl (meth)acrylate, 2-nitro-2-methylpropyl (meth)aerylate, n-octyl-(meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-phenylethyl (meth)acrylate, phenyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and tetrahydropyranyl (meth)acrylate; monomers containing hydroxyl functionality such as 2-hydroxyethyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxy-butyl acrylate, 6-hydroxy-hexyl acrylate, 2-hydroxymethyl methacrylate, 2-hydroxypropyl methacrylate, 6-hydroxyhexyl methacrylate, 5,6-dihydroxyhexyl methacrylate and the like; and monomers which include aromatic content derived from -C=C- containing aromatic compounds such as styrene, alpha-methylstyrene, vinyl toluene, p-methylstyrene, tertiary-butylstyrene, and the like. Other modifiers which can be used include ethy¬ lenically unsaturated monomers such as vinyl acetate, methyl crotona'te, and the like. It has been found that particular¬ ly advantageous water-dispersible polyurethane/acrylic poly- Ϊer compositions are obtained when the acrylic monomers elected for polymerizing in the presence of the support resin and water-dispersible urethane, when polymerized in ■the absence of the support resin and water-dispersible poly¬ urethane according to the solution polymer method described in Kamath and Sargent, supra, will provide a Tg value of be¬ tween -40 to 135°C. Polymerization Reaction Of Monomers In Presence Of Water-Dispersible Polyurethane And Support Resin The reaction of the monomer component in the pre¬ sence-of. the. water-dispersible polyurethane and support resin is carried out in bulk at temperatures of from about 50 to 120°C, and preferably at temperatures of from about 75 to 90°C. Alternatively, the polymerization can be con¬ ducted using a continuous monomer feed process at tempera¬ tures of from about 50 to 120°C, and preferably at tempera¬ tures of from about 75 to 90°C. The bulk polymerization process can be conducted substantially similar to the bulk polymerization process defined in the aforementioned 'commonly assigned U.S. Patent Nos. 4,414,370; 4,529,787, and- 4,546,160. In the bulk poly¬ merization process, the water-dispersible polyurethane dis¬ persed in deionized water, and the support resin are mixed and transferred into a suitable reaction vessel such as a three-neck flask equipped with overhead stirrer, condenser, thermometer, addition funnel, and purged with nitrogen. The acrylic;monomers are mixed and added to the reaction vessel. An initiator, such as ammonium persulfate (APS) which can be dissolved in deionized water is conventionally added, and the reaction mixture heated to effect polymerization. The reaction is normally completed within from about one to four hours. It may be desirable to add a second charge of ini¬ tiator prior to the reaction completion. In the continuous monomer feed process, the water- dispersible polyurethane, deionized water, and the support resin are mixed and transferred into a suitable reaction vessel such as a three-neck or four-neck flask again equipped with overhead stirrer, condenser, thermometer, addition funnel, and purged with nitrogen. The monomers and initiator are added to the reaction flask, and the reaction continued until the monomers are completely reacted. Again the reaction is normally completed within from about one to four hours. Again it may be desirable to add a second charge of initiator prior to the end of the reaction. In this process it can be advantageous to first charge a small portion of the monomers, i.e., 10% of the total, and then after an initial heating add the remaining monomer content over time. It is also possible in preparing the urethane- acrylic emulsions of this invention to add the support resin and/or water-dispersible urethane at different stages of the polymerization process. For example, in a first step an acidic emulsion can be made, followed by neutralization to a pH above 7. In a second step the support resin and water- dispersible urethane can be added. In a third step the reactive monomers can be added. In the alternative processes, an aqueous dispersion of * the polymer composition is recovered comprising the poly¬ urethane, the support resin, and acrylic polymer polymerized in situ. As set forth hereinbefore, the physical charac¬ teristics of the aqueous dispersion can be modified by judi¬ cious selection of the water-dispersible polyurethane, the support resin, and the polymer composition within the ranges set forth above. Uses Of The Aqueous Dispersion Of Polyure-thane/Support Resin/Polymerized Monomers The compositions of the present invention are aqueous, dispersions having physical characteristics includ¬ ing, molecular weight, hardness, and curing characteristics which are controlled based on the selection of the starting polyurethane, support resin and monomer content, as well as on the ratios of components to each other to provide com¬ positions having varying characteristics. If the disper¬ sions are prepared in bulk, they can be used as such without adjustment. If the materials are prepared by a continuous monomer feed process, it may be desirable to adjust the solids content and the like as is conventional in the art. The products can be used in various applications, including as floor polish ingredients, graphic arts inks, plastics, additives, paint binders, adhesives, coatings, and the like. The products can be tailored to a particular need, particu¬ larly with respect to protective coatings on floors, to obtain the desired hardness, toughness, durability, abrasion and detergent resistance, and gloss characteristics essen¬ tial to such compositions. Possible Additives In the formulation of the compositions containing the water-dispersible polymer compositions, it is possible to include either during preparation of the water-dispersi¬ ble composition or as a post-additive a surfactant to pro¬ vide improved wettability and the like, or a film fortifier such as a natural or synthetic wax, levelling agents, plas- ticizers and coalescing agents, depending on the ultimate use of the dispersions. A unique characteristic of the water- dispersible polymer compositions of the present invention, however, is that excellent film-forming characteristics of the dispersions can be maximized with minimum amount of additives such as surfactants, levelling agents, plastici- zers, or coalescing agents. DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS Having described the invention in general terms, the:- following detailed examples are set forth to further illustrate the invention. Parts and percentages are by weight unless otherwise indicated. EXAMPLE 1 In this example the water-dispersible polyurethane at 30% by weight solids is a commercially available material marketed by N. L. Industries under the designation Spensol L-51. Spensol L-51 is an anionic aqueous dispersion of the reactioir product of isophorone diisocyanate, a low molecular weight polyester polyol, based on polyalkylene glycol, and d ethanol propionic acid. The acrylic support resin which is: an acid functional styrene/acrylic resin is manufactured and " sold, by S. C. Johnson & Son, Inc. under the tradename Joncryl 678. The support resin is made using the bulk poly¬ merization process as described in U.S. Patent No. 4,546,160. The monomers reacted in the presence of the water-dispersible polyurethane and support resin comprised a mixture of methyl methacrylate and 2-hydroxyethyl methacrylate. The weight percentages are as follows: 47.73% by weight Spensol L-51 as an aqueous dispersion (14.32 non-volatile); 29.68% by weight deionized water; 14.80% by weight of a 20% aqueous dispersion of the support resin (2.96 non-volatile); 6.56% by weight methyl methacrylate monomer (6.56 non-volatile); 1-16% by weight 2-hydroxyethyl methacrylate monomer (1.16 non-volatile); 0.05% by weight ammonium persulfate ini¬ tiator, and 0.02% by weight t-butyl peroctoate initiator. Procedure (A) All of the components were charged to a four-neck round bottom flask, except for 90% of the monomers and the t-butyl peroctoate. The center neck of the flask is fitted with an agitator, one side neck is fitted with a nitrogen gas inlet, and one side neck is fitted with a thermometer. The final side neck is fitted with an addition funnel. The mixture was heated to 80°C. Thereafter, the remaining 90% of the monomers was added over a period of one to one and . one-half hours. After all of the monomer was added, the t-butyl peroctoate was added and the reaction charge held at 80°C for an additional hour. After forced cooling, the re- sultant dispersion was filtered. (B) A floor coating composition was prepared based on the polymer dispersion of (A) above comprising 74.12% by weight of the aqueous dispersion; 19.66% by weight water; 1.0% by weight Carbitol; 3.10% by weight Ninate 411 which is a liquid amine aryl sulfonate anionic emulsifier at 92% non¬ volatile, marketed by Stepan Chemical Company; 0.66% by we gh±. KP—140 which is a tributoxyethyl phosphate plasti- cizear marketed by the FMC Corporation; and 0.16% by weight BΥK-3 " 44, a silicone surfactant and levelling agent marketed by BYK Chemie. (C) The floor composition (B) above when applied to a floor as an air-dry coating had durability, toughness, abra¬ sion and detergent resistance, and hardness superior to a commercial air-dry acrylic floor coating, and had equivalent depth and retention of gloss. EXAMPLE 2 A procedure as set forth in Example 1 is repeated except that a soft support resin comprising styrene, methyl methacrylate, butylacrylate and acrylic acid, and having the following characteristics is used: Tg Calc -23 Acid Number 110 Number Average Molecular Weight (Mn)........ 3030 Weight Average Molecular Weight (Mw) 9090 Sedimentation Average Molecular Weight (Mz). 21570 Mz/Mw 2.37 Mw/Mn 3.00 The weight percentages of the components are as follows: 30.23% by weight polyurethane, Spensol L-51 as an aqueous dispersion (9.07 non-volatile); 41.62% by weight deionized water; 14.83% by weight of a 20% aqueous dispersion of the soft support resin (2.97 non-volatile) as above described; 11.22% by weight methyl methacrylate monomer (11.22 non¬ volatile); 1.98% by weight 2-hydroxyethyl methacrylate monomer (1.98 non-volatile); and 0.12% by weight ammonium persulfate initiator. To the emulsion obtained was added 5% of Jonwax 26 which is an emulsified polyethylene wax and a solvent. When used in a non-skid overprint application, the results ob¬ tained are as follows: 60 Degree Gloss Black Leneta 64 White Leneta 44 White Clay Coat 45 Slide Angle Degree Static. 25 Kinetic 14 Rub Resistance Sutherland w/4 lb. wt. 200 Cycles... Excellent 400 Cycles Excellent 600 Cycles Excellent 800 Cycles Very Good 1000 Cycles Very Good Water Resistance Excellent Block Resistance 140°F/40 psi/16 hours Dry Excellent Wet Back Good Wet Face Fair EXAMPLE 3 A similar procedure as outlined in Example 1 is used. The weight percentages of components are as follow: 15.77% by weight Spensol L-52 as an aqueous dispersion (4.73 non-volatile); 35.30% by weight deionized water; 17.50% by weight of a 20% aqueous dispersion of the support resin used iή-_Example 1 (3.50 non-volatile); 0.22% by weight of a 30% aqueous solution of the ammonium salt of tridecyl ether sulfate; 0.74% by weight Triton X-100 sold by Rohm & Haas; 10.71% by weight styrene monomer (10.71 non-volatile); 13.39% by weight 2-ethylhexyl acrylate monomer (13.39 non¬ volatile); 2.68% by weight butyl acrylate monomer (2.68 non—volatile) ; 0.13% by weight ammonium persulfate initia¬ tory- 0.06% by weight t-butyl peroctoate initiator, and 3.50% by weight diethylene glycol ethyl ether. The above composition as a blisterpack adhesive is drawn down with a #8 RDS rod onto a styrene-butadiene satur¬ ated.: (SBS) stock board. The film had properties as follows: Gloss 60/Degree SBS Stock 30 Surface Tack None Block Resistance 120°F/4 psi/24 hours Face/Back 2 Face/Face 0 Seal Conditions 250°F/Hot 9 250 o F/Cold 7 275°F/Hot 10 275°F/Cold 8 300°F/Hot 10 300 o F/Cold 10 Rated from 1-10 (10 = best) EXAMPLE 4 A similar procedure as outlined in Example 1 is used. The weight percentages for the emulsion are as fol¬ lows: 17.52% by weight of Spensol L-51 as an aqueous dis¬ persion (5.26 non-volatile); 23.69% by weight of a 20% aqueous solution of a support resin as used in Example 2 (4.74 non-volatile); 28.68% by weight deionized water; 12.72% by weight styrene monomer (12.72 non-volatile); 12.72% by weight butyl acrylate monomer (12.72 non-volatile); 4.49% by weight 2-hydroxyethyl methacrylate monomer (4.49 non-volatile); and 0.18% by weight of ammonium persulfate initiator. Exxate 600 which is an acetate ester of hexanol and butyl, cellosolve were added to the finished emulsion. Samples were drawn down as a non-pigmented overprint for packaging on black/white and clay coated stock with a #6 RDS rod and dried for ten minutes at 140°F. The film properties obtained are as follows: G3_αss - Black..... 65 - White 55 - Clay Coat 55 Water Resistance (30 min).... Excellent Static Slide Angle 30° Kinetic Slide Angle 27r « o The sample as above prepared was mixed with Jonwax 26 which is an emulsified polyethylene wax and Joncryl 52 which i-s an aqueous ammonia solution of Joncryl 678 in the proportions listed below. Each sample was drawn down on * blax ~ k/white and clay coated stock with a #6 RDS rod, dried at room temperature overnight, and evaluated as listed be¬ low. B Example #4 Emulsion 85 75 65 Jonwax 26 5 5 5 Joncryl 52 10 20 30 Gloss - 60 Degree Black 66 69 80 White 43 52 65 Clay Coat White 44 54 65 Slide Angle Degree Static 30 30 37 Kinetic 17 17 18 Rub (1000 cycles) Excellent Excellent Excellent Water Resistance <30 Min.. Excellent Excellent Good EXAMPLE 5 Using a similar procedure as in Example 1, an emul¬ sion was prepared using Spensol DV-4854 and a soft support resin based on styrene, butylacrylate, and acrylic acid. The resin had the following characteristics: Tg Calc -37 Acid Number 177 Number Average Molecular Weight (Mn) 3100 Weight Average Molecular Weight (Mw) 12700 Sedimentation Average Molecular Weight (Mz). 41810 Mz/Mw 3.29 Mw/Mn 4.10 The weight percentages of the components are as follows: 26.47% by weight of an aqueous dispersion of Spensol DV-4854 (8.58 non-volatile); 27.65% by weight deionized water; 17.24% by weight of a 20% aqueous solution of the resin described above (4.74 non-volatile); 2.00% by weight diethy- lene glycol monoethyl ether; 11.24% by weight of styrene monomer (11.24 non-volatile); 11.24% by weight butyl acry¬ late monomer (11.24 non-volatile); 3.97% by vreight 2-hydroxy- ethyl methacrylate monomer (3.97 non-volatile), and 0.19% by we±ght ammonium persulfate initiator. The above aqueous dispersion is then ground with a white pigment concentrate composed of iθ2 pigment, resin solution, and water. The mixture is printed onto polypropy¬ lene with a flexohand printer and dried for 10 seconds at 150°F. Grind Film Properties Adhesion Poor Wetting Good Dry Crinkle Good Other procedures can be used for preparing the urethane/acrylic emulsions whereby the support resin and/or :l water-dispersible urethane is added at different stages of the polymerization process. This modification can include making an acidic emulsion in the first stage, followed by neutralization to a pH above 7.0. In a second stage, sup¬ port resin and/or water-dispersible urethane are added. The third stage is the addition of reactive monomers. EXAMPLE 6 The following emulsion was prepared: A: Deionized Water 253.1 g Ethoxylated Octylphenol (10 moles ethylene oxide) (Triton X-100) 2.2 g Ammonium Salt of Tridecylether Sulfate (30% aqueous solution) 7.4 g B_: Deionized Water 15.0 g Ammonium Persulfate 1.58 g Cs Methyl Methacrylate 98.0 g Styrene 9.7 g Butyl Acrylate 20.8 g Methacrylic Acid 10.0 g D_: Spensol L-51 197.8 g Pri acor 4983 (ethylene/acrylic acid) (25% solids cut in D.I. water and NH3) 237.3 g Resin described in Example 5 (27.5% aqueous solution) 70.5 g E_: Methyl Methacrylate 102.5 g Styrene 9.7 g Butyl Acrylate 20.8 g 2-Hydroxyethy1 Methacr late 5.5 g Component A ^ is added to the reaction and heated to 80°C under a nitrogen atmosphere. 10% of weight of compo¬ nent C_ is added to the reactor and stirred for three min¬ utes. Component B_ is added and the reaction is held for five minutes. The rest of component C_ is added over a 35-40 minute period. After holding for ten minutes, ammonium hydroxide (10 g) is added. Component O is added dropwise over 40 minutes. Once half of component D has been charged (20 minutes), component E_ is added simultaneously over 40 minutes. Once component E_ is added, the reaction is held at 80°C for 45 minutes, cooled, and filtered. The emulsion is evaluated in a floor polish formu¬ lation similar to Example 1. The formulation has good water and detergent resistance, and a three-coat 60 degree gloss of €i/7 on vinyl asbestos tiles. In the above examples the polyurethane can be replaced with other water-dispersible polyurethanes to pro¬ vide compositions with modified characteristics. The criti¬ cal feature is that the polyurethane be water-dispersible and be compatible with the support resin and the acrylic polymer which is formed jri situ. The support resin utilized i the examples .can also be replaced with other support- re¬ sins so as to provide varying characteristics in the final composition. _ For example, if a hard, high glass transition temperature resin is desired, the monomers used in forming the support resin can include aromatic content. The hard¬ ness or softness of the final composition can be varied by varying the monomers employed in the support resin and/or by varying the amount of support resin utilized. The monomers selected for polymerization in the presence of the water- dispersible and support resin can be changed to provide con¬ trolled characteristics to the final polymer dispersions. Additionally, in the preparation of a floor coating composition based on the aqueous polymer dispersions of this invention, the components of the floor coating composition can be varied whereby the aqueous polymer dispersion will comprise from about 40 to 85 weight percent of the composi¬ tion, based on the aqueous dispersion as prepared, Carbitol will comprise from about 0 to 10 weight percent of the com¬ position, a wax will comprise from about 0 to 10 weight per¬ cent of the composition, an emulsifier will comprise from about 0 to 6 weight percent of the composition, and plasti- cizers and levelling agents will comprise from about 0 to 2.5 weight percent of the composition, with the balance of the composition being water. An important advantage in using the aqueous polymer dispersions of the present inven¬ tion in a floor coating composition is in the ability to formulate the compositions utilizing only low levels of additives. Compositions falling within the aforesaid ranges will provide air-dried films having excellent gloss, dur¬ ability, and resistance to spotting. As will be apparent to one skilled in the art, various modifications can be made within the scope of the aforesaid description. Such modifications being within the ability of one skilled in the art form a part of the present invention and are embraced by the appended claims.

Claims: CLAIMS 1. A water-dispersible polymer composition characterized by a water-dispersible polyurethane, an acrylic support resin, and an acrylic polymer; said acrylic polymer being formed from acrylic monomers polymerized in the presence of a mixture of said water-dispersible polyurethane and acrylic support resin to provide the water-dispersible polymer composition. 2. The composition of claim 1 characterized in that said acrylic support resin has a Tg between about -40 and 135°C and an acid value between about 50 to 260, and the monomers polymerized in the presence of the water-dispersible polyurethane and acrylic support resin are selected whereby when copolymerized in the absence of the support resin and water-dispersible polyurethane will provide a polymer having a Tg value of between -40 and 135°C. 3. The composition of claim 1 or 2 characterized in that said water-dispersible polyurethane is a reaction product of an aliphatic diisocyanate, or an aromatic diisocyanate, and a low molecular weight linear polyol. 4. The composition of claim 3 characterized in that said water-dispersible polyurethane is anionic. 5. The composition of claims 1, 2, 3 or 4 characterized in that the monomers forming the acrylic polymer include unsaturated aromatic monomers, preferably styrene or alpha-methylstyrene. 6. The composition of any of claims 1-5 characterized in that said water-dispersible polyurethane is present at from about 10 to 65% by weight, said acrylic support resin is present at from about 5 to 25% by weight, and said acrylic polymer which is formed from said acrylic monomers in the presence of said water-dispersible polyurethane and acrylic support resin is present at from about 25 to 75% by weight. 7. The composition of any of claims 1-5 characterized in that said water-dispersible polyurethane is present at from about 5 to 65% by weight, said acrylic support resin is present at from about 5 to 35% by weight, and said acrylic polymer which is formed from said acrylic monomers in the presence of said water-dispersible polyurethane and acrylic support resin is present at from about 25 to 85% by weight. 8. The composition of any of claims 1-7 characterized in that said support resin comprises the bulk polymerization reaction product of styrene, alpha-methylstyrene, butylacrylate, methylmethacrylate, and (meth)acrylic acid. 9. The composition of any of claims 1-8 characterized in that the acrylic monomers making up said acrylic polymer comprises a mixture of (meth)acrylic acid esters, preferably including a hydroxy(meth)acrylic acid ester. 10. Method of forming an aqueous polymer dispersion characterized by the steps of (1) providing a mixture of water-dispersible polyurethane and acrylic support resin, and (2) polymerizing in the presence of said mixture of step (1) at least one acrylic monomer to form a water-dispersible polymer composition of said polyurethane, said support resin, and said formed acrylic polymer. 11. The method of claim 10 characterized in that said acrylic support resin has a Tg between about -40 and 135°C and an acid value between about 50 to 260, and the monomers polymerized in the presence of the water-dispersible polyurethane and acrylic support resin are selected whereby when copoly erized in the absence of the support resin and water-dispersible polyurethane will provide a polymer having a Tg value of between -40 to 135-C. 12. The method of claims 10 or 11 characterized in that said water-dispersible polyurethane is a reaction product of an aliphatic diisocyanate, or an aromatic diisocyanate, and a low molecular weight linear polyol. 13. The method of claim 12 characterized in that said water-dispersible polyurethane is anionic. 14. The method of claims 11, 12 or 13 characterized in that the monomers forming the acrylic polymer including unsaturated aromatic monomers, preferably styrene or alphamethystyrene. 15. The method of claims 11, 12, 13 or 14 characterized in that said water-dispersible polyurethane is present, at from about 10 to 65% by weight, said acrylic support resin is present at from about 5 to 25% by weight, and said acrylic polymer which is formed from said acrylic monomers in the presence of said water-dispersible polyurethane and acrylic support resin is present at from about 25 to 75% by weight. 16. The method of any of claims 11, 12, 13 or 14 characterized in that said water-dispersible polyurethane is present at from about 5 to 65% by weight, said acrylic support, resin is present at from about 5 to 35% by weight, and said acrylic polymer which Ls ^ formed from said acrylic monomers in the presence of said water-dispersible polyurethane and acrylic support resin is present at from about 25 to 85% by weight. 17. The method of any of claims 11-16 characterized in that said support resin comprises the bulk polymerization reaction product of styrene, alpha-methylstyrene, butylacrylate, methylmethacyrlate, and (meth)acrylic acid. 18. The method of any of claims 11-17 characterized in that the acrylic monomers making up said acrylic polymer comprises a mixture of (meth)acrylic acid esters and styrene-type monomers. IS.. An aqueous floor polish characterized by (-a) from 40-85 weight percent of an aqueous dispersion of the water-dispersible polymer composition of claims 1-9; (b) from 0-10 weight percent wax; (c) from 0-10 weight percent Carbitol; (d) from 0-6 weight percent surfactant; (e) from 0-2.5 weight percent plasticizer; (f) from 0-2.5 weight percent levelling agent; and (g) the balance of the composition water.

Inventors: CARLSEN RUSSELL O, KAWA JOHN, KRAWCZAK DAWN T, LEE HUNG-HEE, PIETTE STEPHEN C, CARLSEN, RUSSELL, O., KAWA, JOHN, KRAWCZAK, DAWN, T., LEE, HUNG-HEE, PIETTE, STEPHEN, C.
Applicants: JOHNSON & SON INC S C, S.C. JOHNSON & SON, INC.
Application year: 1989
Main classification: C08K5
IPC codes: C08F2, C08F283, C08F291, C08L33, C08L75, C09D175, C09G1