GB1597612A - Internally plasticized polymer latex - Google Patents

Description

PATENT SPECIFICATION ( 11) 1 597 612

M ( 21) Application No 23561/80 ( 22) Filed 14 Mar 1978 ( 19) = ( 62) Divided Out of No 1597611, > ( 31) Convention Application No's 778819 ( 32) Filed 17 Mar 1977 4, United States of America 876285 9 Feb 1978 in ( 33) United States of America (US) S ( 44) Complete Specification Published 9 Sep 1981 ( 51) INT CL 3 CO 8 F 265/00 II / CO 9 G 1/16 ( 52) Index at Acceptance C 3 P 202 210 216 220 222 316 318 322 368 370 372 378 FC C 3 Y B 230 B 240 B 243 F 550 F 581 ( 54) INTERNALLY PLASTICIZED POLYMER LATEX ( 71) We, ROHM AND HAAS COMPANY a Corporation organized under the laws of the State of Delaware, United States of America, of Independence Mall West, Philadelphia, Pennsylvania 19015, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: 5

This invention is concerned with novel polymer latexes useful in the formation of coatings, adhesives and binders The latexes are particularly useful to replace combinations of polymers and coalescents in polish and other coatings compositions The resulting polishes or coatings may be suitable for application to either hard or soft surfaces and to floor and wall surfaces to form clear coatings having a glossy appearance The invention is 10 also concerned with the coating, adhesive and binder compositions containing the latexes of the invention and in the polishing methods and polished articles associated therewith.

The polymer in a film-forming latex is required to be soft enough to form a film of good integrity yet hard enough that the film has high strength, low dirt pickup and a myriad of other related properties depending on the specific application It is known that if the glass 15 transition temperature (Tg) of the polymer is below the temperature at which the film is being formed, a film of good integrity, that is, not "cheesy", is normally produced on drying a layer of the latex However, the very softness of the latex particles which leads to good film formation means that the produced film tends to be soft or tacky as opposed to being strong, hard, wear resistant and tough The conventional way out of this dilemma is to add, 20 to a relatively hard polymer, coalescents volatile enough to leave the film after film formation has occurred With greater concern about air pollution, it is preferred to eliminate the volatile coalescents Elimination of the coalescents also represents a cost saving.

Another approach toward preparing high Tg polymers with low minimum film formation 25 temperatures (MFT) is the incorporation of a high proportion of hydrophilic monomers (for example those with hydroxyl, amine or carboxyl functions) in the polymer This induces water swelling of the latex particles which softens the particle in the latex However, at normal polymer concentrations, the swelling is accompanied by very high viscosities particularly if the storage or use p H is such that the carboxylic groups or amine groups are 30 neutralized or partially neutralized A further disadvantage is water sensitivity of the final film as well as sensitivity to acidic or basic solutions Polymers of hydrophilic monomers made by solution polymerization procedures and applied in solution are taught in U S.

Patent 3,935,368 and for use in coating vinyl chloride flooring materials.

Still another solution to the problem of getting a hard coating in the form of a well 35 integrated film is that of U S Patent 3,949,107 which teaches applying a polish containing an aqueous dispersion of a resin with a Tg of 30 'C to 80 'C to a floor, either the polish or the floor having been preheated to a temperature above the Tg of the resin.

In the present invention we sequentially form, by polymerization, usually relatively hard (high Tg), relatively hydrophobic polymer on preformed, usually relatively soft (low Tg), 40 1 597 612 hydrophilic functionalized copolymer latex particles, to form latex particles, which for convenience we call internally plasticized polymer latex particles This produces a latex low in viscosity yet film-forming at a temperature low in comparison to the calculated Tg of the polymer in the particles The viscosity and the minimum film forming temperature (MFT) are measured under normal use conditions, i e neutral to high p H for acid-containing 5 polymers and neutral to low p H for base-containing polymers Preferably, the latex of internally plasticized polymer particles is made by preparing a waterswellable addition polymer under normal emulsion polymerization conditions This water swellable polymer may also be water soluble at an appropriate p H and normally is soluble at high p H when containing acidic groups or at low p H when containing basic groups Under the conditions 10 of polymerization, however, it does not dissolve in the aqueous medium but is maintained as a latex A second polymer is then formed by polymerization in the presence of the latex and may interact with and possibly interpenetrate the first This is achieved by the addition to the first latex of monomer which will form polymer less water sensitive, i e less hydrophilic, and usually harder than that of the initial latex, and subsequent polymeriza 15 tion The second monomer system is chosen to have sufficient compatibility with the initial polymer so as to swell the initial polymer The second polymer in its interaction with the first serves to limit the water swellability of the first polymer Thus, the product can be considered to be a hydroplastic first polymer, made more hydrophobic and usually hardened, by the second polymer; or alternatively a, usually hard, hydrophobic second 20 polymer made, more hydroplastic, and usually softer, by the first polymer The internally plasticized polymer formed has properties unlike the properties of either component polymer nor are the properties simply the sum or average of the properties of the components For example, if the first polymer is one which is completely soluble at high p H it is found that after the internally plasticized polymer is formed this first polymer portion is 25 no longer soluble even at very high p H values.

A highly water swellable component polymer would be expected to produce a high viscosity latex, even though the MFT might be low compared to the Tg In this invention, the modification of the properties of the water swellable first stage polymer by the second stage results in the relatively low viscosity of the latex 30 According to this invention there is thus provided a latex of internally plasticized addition polymer particles comprisng (A) early stage polymer and (B) later stage polymer formed by polymerisation in the presence of an emulsion of polymer particles comprising polymer (A), polymers (A) and (B) each making up at least 10 % by weight of the polymer in the particles, polymer (A) containing at least 10 % by weight hydrophilic mers of which at least 35 % by weight hydrophilic mers of which at least 10 % by weight are nonionic and polymer (B) being less hydrophilic than polymer (A) and wherein the polymer particles have a Tg above 150 C and the latex has a viscosity below 5000 centipoises when measured at 20 % by weight solids over the p H range 4 to 10 and has a minimum film temperature more than SC O below the calculated Tg of the polymer particles 40 The preferred polymers of this invention comprise at least one of acrylate, methacrylate, vinyl ester and vinyl aromatic mer units Preferred hydrophilic ionics mers (if any) in the polymers comprise mers with carboxylic acid groups Preferred hydrophilic nonionic mers in the polymer comprise mers of hydroxyalkyl esters of carboxylic acids or vinyl alcohol mers 45 The internally plasticized polymer of this invention may be formed by polymerization of a first ethylenically unsaturated monomer system comprising comparatively hydrophilic monomer, usually by emulsion polymerization and then, in the presence of the resulting latex, emulsion polymerizing a second charge of ethylenically unsaturated monomer which charge, by itself, may form harder and would form more hydrophobic polymer than the first 50 charge polymer The polymer formed by the first charge (or stage) is maintained as an emulsion although it is water swellable or water soluble By "water soluble", in this specification we mean soluble in water when the p H of the water is adjusted, by the addition of acid or base, to completely or partially neutralize the polymer By "water swellable" in this specification we mean that the polymer imbibes water or can be made to 55 imbide water by such a p H adjustment It is preferred that the p H range considered useful be from about 4 to about 10 The swelling ratio of the swellable polymer, i e, the volume of the polymer swollen in a large excess of water divided by the volume of the polymer when dry, is preferably greater than two and more preferably greater than six.

We believe we understand the mode of operation of the hydrophilic monomer, included 60 in amounts ranging from about 10 to about 100 parts per hundred parts of first charge monomer, but this invention is not to be limited by any such theoretical considerations It appears that the hydrophilic monomer may serve, when polymerized, to bind whatever amounts of water are transmitted into the composition, by way of water of hydration for example Any monomer which can be polymerized in the mix and which is hydrophilic 65 3 1 597 612 3 enough to bind water effectively is therefore useful Among suitable the hydrophilic monomers, for example, are: acrylonitrile, methacrylonitrile, hydroxysubstituted alkyl and aryl acrylates and methacrylates, polyether acrylates and methacrylates, alky-phosphatoalkyl acrylates and methacrylates, alkyl-phosphono-alkyl acrylates and methacrylates, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, N-vinyl pyrrolidone, alkyl and 5 substituted alkyl amides of acrylic acid, methacrylic acid, maleic acid (mono and di-amides), fumaric acid (mono and di-amides), itaconic acid (mono and diamides), acrylamide, methacrylamide, also other half acid forms of the above dibasic acids such as half esters, amino monomers such as amino-substituted alkyl acrylates and methacrylates, vinyl pyridines and amino alkyl vinyl ethers, and ureido monomers, including those with 10 cyclic ureido groups The proper scope of the invention should also be interpreted to include variations on the inclusion of the hydrophilic monomer in the monomer mix, such as, for example, when the hydrophilic monomeric units are formed in situ or subsequently formed For example a monomer may be included in the polymerization mix which is not itself hydrophilic but is altered in processing or in a subsequent step, e g by hydrolysis, to 15 provide hydrophilicity; anhydride and epoxide-containing monomers are examples.

Preferred suitable hydrophilic monomers include acrylic compounds, particularly the amides and hydroxy alkyl esters of methacrylic and acrylic acids, amides and hydroxy alkyl esters of other acids are also preferred, but less so than the corresponding methacrylates and acrylates, which are more readily polymerized Monomers containing carboxylic acid 20 groups are also preferred particularly acrylic acid, methacrylic acid and itaconic acid.

Another preferred group of hydrophilic monomers are represented by specific examples of potential hydrophilic monomers which produce the actual hydrophilic mer units in the polymer on hydrolysis These monomers include esters of vinyl alcohol such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl versitate Hydrolysis of 25 these monomers produces hydrophilic vinyl alcohol mer units in the polymer The preferred monomer among these is vinyl acetate.

Polymerized with the hydrophilic monomer in the first charge may be other monomer carefully chosen to give other desirable properties to the final polymer Any polyethylenically unsaturated monomer, if present, is preferably of the type in which the various 30 ethylenic groups, i e the addition polymerizable unsaturated groups, participate in the polymerization at about the same rate Preferably no such crosslinking or graft-linking polyethylenically unsaturated monomer is present in the first stage monomer system The term graft-linking monomer is defined in column 4 line 66 to column 5 line 20 of U S Patent 3,796,771 which definition is hereby incorporated by reference Preferably the first charge 35 comprises monoethylenically unsaturated monomer.

It is desired that the first charge polymer be softer than the second charge polymer The hardness of the first charge can be controlled by the choice of the hydrophilic monomer and of any comonomer used therewith Suitable comonomers which form soft polymers in the presence of free radical catalysts include primary and secondary alkyl acrylates, with alkyl 40 substituents having up to eighteen, or even more, carbon atoms, primary or secondary alkyl methacrylates with alkyl substituents of at least five, for example to eighteen or more carbon atoms, or other ethylenically-unsaturated compounds which are polymerizable with free radical catalysts to form soft solid polymers, including vinyl esters of saturated monocarboxylic acids of more than two carbon atoms The preferred ethylenically 45 unsaturated compounds are the stated acrylates and methacrylates and of these the most practical esters are those with alkyl groups of at most 8 carbon atoms.

The preferred monomers which by themselves yield soft polymers may be summarized by the formula 50 CH, = C-COO Rx R' 55 wherein R' is hydrogen or the methyl group and Rx represents, when R' is methyl, a primary or secondary alkyl group of 5 to 18 carbon atoms, or, when R' is hydrogen, an alkyl group of not over 18 carbon atoms, preferably of 1 to 8 carbon atoms and more preferably 1 to 4 carbon atoms 60 Typical compounds coming within the above definition are methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, sec-butyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, 3,5,5-trimethylhexylacrylate, decyl acrylate, dodecyl acrylate, cetyl acrylate, octadecyl acrylate, octadecenyl acrylate, n-amyl methacrylate, sec-amyl methacrylate, 65 1 597 612 4 1 597 612 4 hexyl methacrylate, 2-ethylbutyl methacrylate, octyl methacrylate, 3,5,5trimethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, and those with substituted alkyl groups such as butoxylethyl acrylate or methacrylate.

As polymerizable ethylenically unsaturated monomers, which by themselves form hard polymers, there may be used alkyl methacrylates having alkyl groups of at most four carbon 5 atoms, also tert-amyl methacrylate, tert-butyl or tert-amyl acrylate, cyclohexyl, benzyl or isobornyl acrylate or methacrylate, acrylonitrile, or methacrylonitrile, these constituting a preferred group of the monomers which by themselves compounds from hard polymers.

Styrene, vinyl chloride, chlorostyrene, vinyl acetate and p-methylstyrene, which also form hard polymers, may be used 10 Preferred monomers, which by themselves form hard polymers, may be summarized by the formula CH 2 = C-X 15 R' wherein R' is hydrogen or the methyl group and wherein X represents one of the groups 20 CN, phenyl, methylphenyl, and ester-forming groups, -COOR", wherein R" is cyclohexyl or, when R' is hydrogen, a tert-alkyl group of four to five carbon atoms, or, when R' is methyl, an alkyl group of one to four carbon atoms Some typical examples of these have already been named Other specific compounds are methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, n-butyl methacry 25 late, sec-butyl methacrylate, and tert-butyl methacrylate Acrylamide and methacrylamide may also be used as monomers to contribute hardness to the copolymer.

These monomers may contain other functional groups for other purposes such as to produce crosslinking in the polymer on curing or enhanced adhesion to a substrate.

Examples of such functional groups are carboxyl, in the form of the free acid or salt, amido 30 including substituted amido, such as alkoxy alkyl amido and alkylol amido, epoxy, hydroxy, amino including oxazolidinyl and oxazinyl, and ureido In most instances these functional groups are also hydrophilic groups, and many of the monomers are hydrophilic.

Another group of monomers useful in this invention and which if polymerized by themselves yield soft polymers are butadiene, chloroprene, isobutene, and isoprene These 35 are monomers commonly used in rubber latices along with monomers which produce hard polymers and also useful in this invention, such as acrylonitrile, styrene, and other "hard monomers" as given above The olefin monomers, particularly ethylene and propylene, are suitable "soft monomers" Particularly useful first stage copolymers are ethylene/ethyl acrylate copolymers and ethylene/vinyl acetate copolymers containing added hydrophilic 40 monomer.

A further class of polymers useful in this invention are polymers of esters of vinyl alcohol such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate and vinyl versatate.

Preferred is poly(vinyl acetate) and copolymers of vinyl acetate with one or more of the following monomers: vinyl chloride, vinylidene chloride styrene, vinyl toluene, acrylonit 45 rile, methacrylonitrile, acrylate or methacrylate esters, and the functional group containing monomers given above In the largely vinyl ester polymers it is preferred that the first stage polymers contain at least 10 % and preferably at least 30 % by weight vinyl acetate units with at least 80 % being most preferred Before polymerization of vinyl alcohol esters is complete some hydrolysis to vinyl alcohol mer units normally occurs or is deliberately accomplished 50 The vinyl alcohol mer units so produced are hydrophilic and considered here as though derived from vinyl alcohol monomer The amount of hydrolysis can be controlled by means of control of the time, temperature and p H of the reaction to produce the desired amount of vinyl alcohol in the product Longer times, higher temperatures, very acidic or very alkaline conditions all serve to increase the amount of hydrolysis and thus the amount of vinyl 55 alcohol in the final product The amount of hydrolysis can be determined by acid-base titration procedures in water or in suitable solvent systems.

A preferred composition of this invention is one in which the mers of the first stage comprise by weight 65 to 85 % (C 1-C 4)-alkyl acrylate, (C 1-C 4)-alkyl methacrylate and/or styrene, 5 to 10 % acrylic acid, methacrylic acid, and/or itaconic acid, and 10 to 25 % 60 hydroxy (C 1-C 4)-alkyl acrylate and/or hydroxy (C 1-C 4)-alkyl methacrylate, and the mers of the later stage polymer comprise methyl methacrylate, and/or styrene Another preferred composition is one in which the mer units of the first stage comprise, by weight, 50 to 85 % vinyl acetate (for subsequent hydrolysis), 1 to 10 % acrylic acid, methacrylic acid, itaconic acid and/or maleic acid (derivable from maleic anhydride), and 8 to 25 % vinyl alcohol, and 65 S 1 597 612 5 the mer units of the later stage comprise 70 to 100 % methyl methacrylate and/or styrene and 0 to 30 %, preferably 10 to 20 %, by weight acid containing mers, such as acrylic, methacrylic and/or itaconic acid mers It is desirable that the acid mers in the first stage comprise up to 5 %, based on the first stage polymer weight, of maleic anhydride or maleic acid with 0 2 to 2 per cent being preferred In this usage, the term "mer" means the unit, in 5 the addition polymer, derived from the named monomer by addition to the double bond.

In general the preferred hydrophilic monomers used in this invention are monomers with a solubility of at least six grams per 100 grams of water, those with a solubility of at least 20 grams per 100 grams of water are more preferred and most preferred are those in which at least 50 grams of the monomer is soluble in 100 grams of water The first stage polymer 10 contains at least 10 % hydrophilic mers, 10 % to 70 % being preferred, at least 25 % is more preferable with the range 25 % to 35 % being most preferable Of the hydrophilic monomer content it is preferable to have at least 0 5 % ionic hydrophilic mers such acidic mers, such as mers containing carboxyl or basic groups such as amino groups, in either the unneutralized or neutralized form It is also necessary that at least 10 % of the hydrophilic 15 mers be nonionic, i e not ionizable, such as hydroxyethyl acrylate or methacrylate, which may be produced in situ such as nonionic mer units from hydroxyethyl ester and vinyl alcohol mer units.

The last stage polymer is more hydrophobic and preferably harder than the first stage By more hydrophobic is meant that the later stage polymer alone is less water-swellable than is 20 the first stage polymer alone By harder is meant that the modulus of the later stage polymer is greater than that of the first stage polymer, measurements being conducted on polymer samples immersed in water It is preferred that the last stage monomer be monoethylenically unsaturated.

The internally plasticized polymers of the present invention are conveniently prepared by 25 known emulsion polymerization procedures utilizing a multi-stage, sequential technique.

However, they may also be prepared by a continuous polymerization in which the composition of monomer being fed continuously is changed, either stepwise or continuously, during the polymerization In such a polymerization any abrupt or discontinuous change in the composition of the monomer feed may be regarded as a stage 30 terminal If there are no such changes in the feed composition to indicate a change from one stage to another, the first half of the polymer feed may be regarded as representing one stage and the second half as representing a second stage In the simplest form of the latexes of the invention, the hydrophilic polymer is formed in a first stage and the more hydrophobic polymer is formed in a second stage Either of the component polymers can 35 themselves also be sequentially polymerized, i e consist of multiple stages The monomers of the first stage, together with initiators, soap or emulsifier, polymerization modifiers or chain transfer agents, are formed into the initial polymerization mix and polymerized, e g, by heating, mixing, cooling as required, in well known and wholly conventional fashion until the monomers are substantially depleted Monomers of the second and, in turn, of any 40 subsequent stage are then added with appropriate other materials so that the desired polymerization of each stage occurs in sequence to substantial exhaustion of the monomers.

It is preferred that in each stage after the first, the amounts of initiator and soap, if any, are maintained at such a level that polymerization occurs on existing particles, and no substantial number of new particles, or "seeds" forms in the emulsion 45 When polymerizations are conducted in multi-stage, sequential processes, there can additionally be stages which are, in composition and proportion, the combination of the two distinct stages, and which produce polymers having properties which are intermediate therebetween The hydrophilic first stage is at least 10 %, preferably 20 % to 80 %, more preferably 30 % to 70 % and most preferably 40 % to 60 % of the total polymer There may 50 of course, be other stages before, between or after the two of principal interest These other stages are always smaller weight proportions of the whole polymer than either of the principal component polymers when they cannot be considered a portion of one or the other of the principal component polymers by virtue of their composition It is preferred that the polymer of the invention be a two stage polymer Those skilled in a given art field 55 will usually prepare a few internally plasticized polymer latex samples differing in first to second stage weight ratio and select the one with the best properties for the given application The equal weight ratio is the usual starting point for these trials which usually consist of one higher and one lower ratio with the spread of the ratio being chosen by consideration of the final properties desired, for example hardness, MFT, latex viscosity, 60 tack-free time.

The copolymer is preferably made by the emulsion copolymerization of the several monomers in the proper proportions Conventional emulsion polymerization techniques are described in United States patents 2,754,280 and 2,795,564 Thus the monomers may be emulsified with anionic, cationic, or nonionic dispersing agent, about 0 5 % to 10 % thereof 65 1597 612 1 597 612 usually being used, based on the weight of total monomer When watersoluble monomer is used, the dispersing agent serves to emulsify any other monomer A polymerization initiator of the free radical type, such as ammonium or potassium persulfate, may be used alone or in conjunction with an accelerator, such as potassium metabisulfite, or sodium thiosulfate The initiator and accelerator, commonly referred to as catalyst, may be used in 5 proportions of 1/2 to 2 % each based on the weight of monomer to be copolymerized The polymerization temperature may be from room temperature to 90 WC or more as is conventional.

Examples of emulsifiers or soaps suited to the polymerization process of the present invention include alkali metal and ammonium salts of alkyl, aryl, alkaryl, and aralkyl 10 sulfonates, sulfates, and polyether sulfates; the corresponding phosphates and phosphonates; and ethoxylated fatty acids, esters, alcohols, amines, amides and alkyl phenols.

Chain transfer agents, including mercaptans, polymercaptans, and polyhalogen compounds, are often desirable in the polymerization mix "Polymer Handbook", 2nd Edition, J Brandrup and E H Immergut, editors (John Wiley and Sons, New York 1975) Section 15 IV Part 15 entitled "Solubility Parameter Values" by H Burrell, on pages IV-337 to IV-359, herein incorporated by reference, defines solubility parameter, describes how it is determined or calculated, contains tables of solubility parameters and gives further references to the scientific literature on solubility parameters The solubility parameter is the square root of the cohesive energy density which in turn is the numerical value of the 20 potential energy of 1 cc of material, the potential resulting from the van der Waals attraction forces between the molecules in a liquid or solid Burrell describes a number of ways of calculating solubility parameters from experimentally determined physical constants and two ways of calculating them from the structural formula of a molecule The structural formula methods are normally used when the data for the calculation from 25 physical constants are not available or are considered particularly unreliable Calculation from the structural formula utilizes tables of group molar attraction constants such as those given on page IV-339 in the "Polymer Handbook" The table of Small is preferred.

The solubility parameter concept may be considered an extension of the old rule "like dissolves like" recognized from the early days of chemistry A noncrosslinked polymer will 30 normally dissolve in a solvent of similar solubility parameter and a cross-linked polymer will normally be swollen by a solvent of similar solubility parameter Conversely, solvents with solubility parameters far from those of the polymers will neither dissolve nor swell the polymer As given by Burrell the solubility parameter of polymers may be determined, among other ways, by measuring the swelling of the polymer in a series of solvents 35 Solubility parameter for polymers may also be estimated by calculation from the group molar attraction constants as mentioned above In the usual situation, it is found that solvents with a range of solubility parameters around that of the polymer will dissolve the uncrosslinked polymer Those skilled in the art have added the further refinement of classifying solvents as poorly, moderately and strongly hydrogen bonded It is found that 40the range of solubility parameter for dissolving a given uncrosslinked polymer differs from one class to the next although usually considerable overlap is observed Burrell's Table 4 starting on page IV-349 gives ranges of solubility parameters for poorly, moderately and strongly hydrogen bonded solvents used to dissolve a large number of polymers In Table 5 starting on page IV-354, there is given solubility parameters of a number of polymers 45 determined by calculation and by other methods.

To form the internally plasticized polymer system of this invention the first stage polymer and monomers of the later stage may be chosen so as to interact to an appropriate degree.

There are both upper and lower limits to the degree of compatibility preferred between the first stage polymer and the monomer charges of subsequent (second later or last as 50 hereinabove described) stages It is found that the appropriate degree of compatibility may be expressed in numerical terms by a property based on solubility parameter and herein named the interpenetration parameter, Ip The interpenetration parameter may be regarded as a solubility parameter adjusted so as to put strongly, moderately and weakly hydrogen bonding solvents on the same scale For a given molecule, the interpenetration 55 parameter is defined as the solubility parameter plus the hydrogen bonding increment value given below Solubility parameters of various molecules, including a number of monomers, are given in Tables 1 and 2 of Burrell starting on page IV-341 These tables also give the hydrogen bonding group appropriate for the given molecule The increment values, a new teaching in this invention, are 17 2 for strongly hydrogen bonding molecules, 7 2 for 60 moderate hydrogen bonding molecules and 2 8 for poorly hydrogen bonding molecules.

The following table contains a list of monomers along with values of their solubility parameter, interpenetration parameter and water solubility Also given is the hydrogen bonding class appropriate for the monomer The solubility parameter values and hydrogen bonding class of most of these monomers are those given in Table 1 of Burrell Vinyl 65 7 1 597 612 7 alcohol is a special case because, as is well known, this monomer does not have a stable existence Polymers containing mer units corresponding to vinyl alcohol may be prepared by hydrolysis of a polymer containing the corresponding vinyl ester, such as vinyl acetate, mer unit The solubility parameter of this hypothetical monomer is computed by the method of Small as indicated above Values for other monomers not in Burrell's table are 5 determined or computed following the teachings in Burrell's writings v s Dimensions for the solubility parameters given in the table are the usual ones, square root of (calories per cubic centimeter) The interpenetration parameter has the same dimensions Water solubility is given in grams of monomer per 100 grams of water at 25 C The hydrogen bonding class strong, moderate or poor is ascertained by using the method of C M Hansen, 10 Journal of Paint Technology, Vol 39, p 104-117 and 505-514 ( 1967).

1 597 612 Solubi Interpene Water lity Hydrogen tration Sol AbbreMonomer Parameter Bonding Parameter ubility viation Acrolein 9 8 S 27 0 40 Acr.

Acrylic Acid 12 0 S 29 2 CM AA Acrylonitrile 10 5 P 13 3 25-30 AN o-bromostyrene 9 8 P 12 6 Br St 1.3-butadiene 7 1 P 9 9 Bd i-butyl acrylate 8 5 M 15 2 0 2 i BA n-butyl acrylate 8 8 M 16 0 0 2 BA Butyl methacrylate 8 2 M 15 4 0 01 BMA Chlorostyrene 9 5 P 12 3 Cl St i-decyl acrylate 8 2 M 15 4 0 01 i DA Dichloroethylene 9 1 P 11 9 0 01 DCE Ethyl acrylate 8 6 M 15 8 1 51 EA Ethylene oxide 11 1 M 18 3 CM EO Ethylene epichlorohydrin 12 2 S 29 4 EEPC Dimethylamino ethyl methacrylate 7 0 S 24 2 CM DMAEMA Dihydroxypropyl methacrylate 9 0 S 26 2 CM DHPMA Ethylhexyl acrylate 7 8 M 15 0 EHA Ethyl methacrylate 8 3 M 15 5 0 1 EMA 1-hexene 7 4 P 10 2 hex Hydroxyethyl methacrylate 8 0 S 25 2 HEMA Isoprene 7 4 P 10 2 Ipn 16.3 ( 79)l M An 13.6 S 30 8 Maleic anhydride 9 1597 619 Q Solubi Interpene Water lity Hydrogen tration Sol Abbre Monomer Parameter Bonding Parameter ubility viation 5 Methacrylic acid 11 2 S 28 4 CM MAA Methyl acrylate 8 9 M 16 1 5 2 MA Methyl methacrylate 8 8 M 16 0 1 6 MMA 2-methylstyrene 8 5 P 11 3 Me St Styrene 9 3 P 12 1 ST 15 Vinyl acetate 9 0 M 16 2 2 3 V Ac Vinyl chloride 7 8 M 15 0 V Cl 20 Vinyl toluene 9 1 P 11 9 Vtol (Vinyl alcohol) 8 4 S 25 6 (CM) VOH S = Strong 25 P = Poor M = Moderate CM= Completely Miscible 30 As maleic acid In preferred latex polymers of this invention, the inter-penetration parameter of the first stage will be greater than that of the second stage, preferably at least one unit (calorie per 35 cubic centimeter) greater; however, in these preferred polymers the interpenetration parameter of the first stage is not too much greater than that of the second stage The difference is preferably not more than 8 and is more preferably not more than 6, most preferably 1 to 6 units When the first stage polymer contains 65 % or more, by weight, of Cl-C 4 alkyl acrylate, Cl-C 4 alkyl methacrylate, styrene or a mixture thereof, it is desirable 40 that the first stage Ip be not more than 6 units greater than that of the later stage with a difference of 1 to 4 units being preferred and 2 to 3 units most preferred When the first stage polymer contains 50 % or more by weight, of vinyl acetate it is desirable that the first stage Ip be 1 to 8 units greater than that of the later stage with a difference of 2 to 6 units being preferred and 4 to 5 units most preferred It should be appreciated in this context that 45 the second stage or the later stage may contain some hydrophilic monomers and still conform to these guidelines for the difference between the interpenetration parameter of the first stage and that of the second stage.

As stated above, in a preferred embodiment, the first stage contains acidic, preferably carboxylic, mer units as well as the other hydrophilic mer units The carboxylic mer units 50 are preferably obtained from the monomers acrylic acid, methacrylic acid or itaconic acid.

The other hydrophilic mer units are preferably hydroxy C 1-C 4 alkyl methacrylate, hydroxy Cl-C 4 alkyl acrylate or vinyl alcohol units.

The viscosity of the polymer emulsion produced may be measured by any of the known procedures, preferably by Brookfield Synchro-Letric Viscometer model LV 1 with 55 preference in choice of spindle and speed being given to the combinations which will result in a mid-range reading Measurements, at 20 C, are made at p H values in the range of 3 to on emulsions adjusted, with water, to 20 % solids content The p H of acidcontaining copolymer emulsions is generally adjusted by the use of a mineral base, an organic base, such as an amine, or ammonia with the latter being preferred Internally plasticized 60 polymer latices containing basic groups, such as amine groups or quaternary ammonium groups, may have their p H adjusted by the use of mineral acids, such as hydrochloric acid, or organic acids such as acetic acid The latex viscosity, over the p H range 3 to 10, is generally below 5,000 centipoises, better still below 500 centipoises, better still below 150 centipoises, better still below 40 centipoises, and most preferably below 10 centipoises; the 65 1 597 6 iq 1 597 612 lower values being particularly desirable for certain applications, such as floor polishes.

The minimum film temperature (MFT) should be measured on a film cast from the latex at 20 % solids and a p H of 7-1/2 to 9 for ammonia-neutralized, acidcontaining polymers and of 3 to 4 for acetic acid neutralized base containing polymers The procedure of The American Society for Testing Materials method D 2354-68 is followed The MFT is more 5 than 5 C O below the calculated glass transition temperature (Tg) of the polymer when the Tg is above 50 C Preferred are MF Ts below 18 WC with polymers having a Tg calculated for the entire polymer composition of greater than 250 C The term MFT, as used herein to define certain polymers, refers to the value determined on a latex at the p H and solids just given.

In some of the examples given later, MFT values determined under other conditions are 10 given only for comparison purposes and do not apply or refer to the MF Ts used in defining the polymers of this invention.

Hardness is expressed as Knoop Hardness Number (KHN) and is determined by means of the Tukon Microhardness Tester on a film formed by casting the latex on a solid substrate such as a glass panel It is preferred that the polymers have a KHN greater than 3 15 with greater than 5 being more preferred and greater than 8 most preferred.

The calculated Tg of each stage and that of the overall polymer is determined by calculation based upon the Tg of homopolymers of individual monomers as described by Fox, Bull Am Physics Soc 1,3, page 123 ( 1956) Tables of the Tg of homopolymers are given in "Polymer Handbook" Section III, Part 2 by W A Lee and R A Rutherford The 20 preferred calculated Tg of the first stage is less than 40 WC with less than 5 YC being more preferred and less than -100 C being most preferred The preferred calculated Tg of the second stage is greater than 350 C with greater than 750 C being more preferred and greater than 100 C being most preferred The calculated Tg of the polymer based on the overall polymer composition is greater than 15 'C, preferably greater than 20 WC with greater than 25 C being preferred for floor polish and similar uses For some other uses, such as adhesives, binders and paints, polymers with calculated Tg values below about 40 C, including subzero values, are suitable.

Internally plasticized polymer emulsions of this invention may have a noteworthy combination of properties especially ( 1) low minimum film temperature coupled with high 30 hardness and high Tg; and ( 2) low polymer emulsion viscosity even when neutralized Thus, comparatively hard latex polymer systems can be used with much less coalescent than usual, or no coalescent at all This is particularly valuable in situations in which the coalescent gives rise to secondary disadvantages Because of the absence or minimization of added coalescent in the formulation, coatings which develop hardness at a very high rate can be 35 made from the polymers of this invention Further advantages implied by the elimination of added plasticizer, coalescent or organic solvent are cost reduction, reduced flammability during processing and decreased emission of toxic and polluting vapors during and following application These properties are of particular importance in the formulation and use of water based industrial coatings, both clear and pigmented In ink technology, the 40 extremely fast drying and non-flammability advantages of internally plasticized polymers are of great importance In trade sales coatings, the combination of high hardness and low minimum film temperature makes for a block resistant air drying coating A further advantage of the latex of this invention is that formulation is very easy, which results in a considerable cost saving, because of the fewer ingredients and the ease of mixing in the 45 plant operation The ease of mixing probably results from the latex made by this invention being resistant to the so-called "shocking" phenomenon; that is, the latex is not easily flocculated or gelled when mixed with another component of the formulation Thus, ingredients usually may be mixed in any order in the usual plant equipment and, in addition, the equipment itself it left in a much cleaner condition than with ordinary latexes 50 As described above, the polymer latexes of this invention are particularly useful to replace the latex plus plasticizer or latex plus coalescent systems which comprise a number of formulations used in a wide variety of applications for polymer latexes These latexes are useful in forming free films as well as in forming coatings such as in paints, lacquers, varnishes, powdered coatings, and the like The latexes of this invention are also useful as 55 impregnants and adhesives for both natural and synthetic materials such as paper, textiles, wood, plastics, metal and leather and as binders for nonwoven fabrics They may be used to lower the minimum film forming temperature or to aid in film formation of other latex systems when used in combination therewith Pigments, dyes, fillers, antioxidants, antiozonants, stabilizers, flow control agents, surfactants or other optional ingredients may 60 be included in the polymer compositions of the invention.

The polymer compositions of this invention can be applied with or without a solvent by casting permanently or removably onto a suitable substrate, particularly for use as coatings, fillers or adhesives Application by brushing, flowing, dipping, spraying and other known means may be used to apply the latex of this invention One of the particular advantages of 65 11 1 597 612 11 the present invention is that reactive polymers can be prepared for use as air cured or thermally cured coatings, fillers or adhesives without requiring organic solvents, coalescents or plasticizers although small amounts of these materials may be desired This is particularly valuable because elimination of volatile solvents or other volatiles, such as coalescents, decreases a potential ecological hazard 5 It is of especial importance that the acid groups, hydroxyl groups, or other functional groups incorporated in the first stage of the polymerization remain available for further reaction such as neutralization or crosslinking This availability distinguishes the internally plasticized polymer latex from a latex in which a second or later stage so coats or interacts with the first stage as to decrease or eliminate the availability of first stage functional groups 10 for subsequent reactions The crosslinking referred to may be by any of the usual means, such as coordination crosslinking, ionic crosslinking or the formation of covalent bonds; In general, the reactions of these latices may be ionic or covalent reactions Ionic reactions are illustrated by the ionic crosslinking in the application of these latices to floor polishes as taught below The formation of covalent bonds by reaction with aminoplasts, epoxies, 15 isocyanates and beta hydroxyethyl esters are well known in the art.

The polymer latexes of the present invention are particularly useful in formulating floor polish and are advantagously used in the floor polishes taught by U S 3, 328,325 Fiarman, U.S 3,467,610 and U S 3,573,239.

In general polishing compositions using the polymers of the present invention can be 20 defined in terms of the following proportions of the main constituents:

Constituent: Proportion (A) Water-insoluble internally plasticized 25 addition polymer, parts by weight 10-100 (B) Wax do 0 90 30 (C) Alkali-soluble resin do 0 90 (D) Wetting, emulsifying and dispersing agents percent 05-20 35 (E) Polyvalent metal compound do 0 50 (F) Water to make total solids 0 5 % to 45 % preferably to 30 %.

40 {D) is in weight percent on weight of A+B+C E) is in weight percent on weight of A.

The total of A B and C should be 100 The amount of C, when present, may be up to 90 % of the weight of the copolymer of A, and preferably from about 5 % to 25 % of the 45 weight of the copolymer of A.

For a non-buffable, self-polishing composition, the wax should not be over 35 parts by weight, preferably 0 to 25 parts by weight in 100 parts total of polymer plus wax according to the above table Satisfactory non-buffable floor polish formulations have been prepared without the inclusion of a wax Thus wax is not an essential component of a self-polishing 50 composition For a dry buffable polish composition, the wax should be at least 35 parts by weight on such total Examples of wetting and dispersing agents include alkali metal and amine salts of higher fatty acids having 12 to 18 carbon atoms, such as sodium, potassium, ammonium, or morpholine oleate or ricinoleate as well as the common nonionic surface active agents Additional wetting agent improves the spreading action of the polish 55 For polishing floors, the coating obtained from the composition preferably has a Knoop hardness number of 0 5 to 20 when measured on a film thereof 05-2 mils thick on glass.

This range of hardness provides good resistance to abrasion and wear and can be obtained by the appropriate selection of monomers to be polymerized.

Preferred embodiments of the invention will now be described, for illustration only in the 60 following examples, in which the parts and percentages are by weight unless otherwise indicated.

The words "Triton", "Nopco", "Zopaque", Abex" and "Carbitol" used in the Examples are Registered Trademarks and the word "Versitate" used in this specification is a derivative of the Registered Trademark "Versatic" 65 1 597 612 EXAMPLE 1

Preparation of internally plasticized polymer emulsion A latex with first stage, second stage and average Tg values of -140 C, 105 'C, and 340 C.

respectively, is prepared as follows:

5 A Equipment A five liter, four-necked flask is equipped with a condenser, stirrer, thermometer and monomer addition pumps Heating, cooling and nitrogen sparging facilities are provided.

B Material charges 10 Kettle Monomer Charges Raw Material Charge Stage 1 Stage 2 Water 2008 g 400 g 400 g 15 Sodium lauryl sulfate (surfactant) 16 2 2 Butyl acrylate (BA) 600 20 Methyl methacrylate (MMA) 140 1000 Methacrylic acid (MAA) 60 25 Hydroxyethyl methacrylate (HEMA) 212 Sodium persulfate in 100 g Water (catalyst) 12 30 C Procedure 1 Add kettle charge water and surfactant to the kettle and start agitation and nitrogen sparge 35 2 Combine the materials of each of the monomer charges and thoroughly mix to create stable monomer emulsions.

3 Heat the kettle to 82-840 C with continued agitation and nitrogen sparging.

4 Add the catalyst solution to the kettle and start the addition of monomer charge stage 1 at such a rate that the addition is completed in about 50 minutes Maintain the 40 temperature at 82-840 C throughout the polymerization.

When monomer charge stage 1 addition is completed hold for 15 minutes at 82-840 C.

6 After the hold period start the addition of monomer charge stage 2 at such a rate that the addition is completed in about 60 minutes Maintain the temperature at 82-840 C.

throughout the polymerization 45 7 When monomer charge stage 2 addition is completed, hold for 30 minutes at 82-840 C, then cool and filter.

A sample of the latex is neutralized to a p H of 9 with ammonia; the MFT is below 15 'C and the viscosity is 15 centipoise (Brookfield Viscosity; 20 % solids) A film cast from the neutralized latex has a hardness of 12 1 KHN 50 EXAMPLE 2

Sequential charge ratio Following the general procedure of Example 1 three internally plasticized polymer latices are prepared having the same first and second stage compositions but differing in the first to 55 second stage weight ratio Details are given in Table I.

It is found that the property balance, low MFT and simultaneously low viscosity emulsion, is sensitive to the weight ratio of the hard hydrophobic second stage charge to the soft hydrophilic first stage charge This makes it apparent that, for a given monomer composition, a few simple trial and error experiments may be needed to determine the 60 charge ratio required to achieve a product according to this invention Table 1 shows the effects of changing the charge ratio, Run 2 B having a low MFT, low viscosity when neutralized and a high Tg It is seen that Run 2 B is a latex polymer of this invention whereas the Run 2 A much too high in viscosity at p H 9 and 2 C too high in MFT Runs 2 A and 2 C are therefore for comparative purposes only 65 Run 2 A (Comparative) 2 B 2 C (Comparative) TABLE I

Polymer Composition BA/MMA/MAA/HEMA//MMA 27.617 217 2/18//40 23/6/6/15/50 18.4/4 814 8/12//60 Tg MFT/Viscosity ( 20 % Solids) ( 1) ( 2) Avg p H 3 p H 9 4 105 38 29/2 10/18,000 4 105 47 40/6 10/140 4 105 58 76/2 62/34 tli A double slash (//) is used to indicate the separation between the first and second stage.

MFT is in degrees Celcius/viscosity in centipoise at 20 C.

Tg is calculated, in degrees Celcius, for the first stage ( 1), second stage ( 2) and overall polymer-Avg.

J.) 14 1 597 612 14 EXAMPLE 3

Polymerization process The difference between a single emulsion copolymer, an internally plasticized polymer and a physical blend of two polymers is seen in the data in Table II All of the polymers were prepared by emulsion polymerization following essentially the procedure of Example 5 1 except for there being no second charge in the preparations of Runs 3 A and 3 C which were therefore for comparative purposes only The overall composition of each of the three examples is the same; the calculated Tg is 47 C.

TABLE II 10

Polymer Composition BAIMMA/MAA/ MFT/Viscosity Run HEMA//MMA Description p H 3 p H 9 15

3 A (Comparative) 23/56/6/1511//0 single charge, 52/3 46/55 simple copolymer 20 3 Bb 23/6/6/15//50 internally plas 40/6 10/140 ticized polymer 3 C 25 (Comparative) 23/6/6/15//50 physical blenda 10/10 10/ gellation a Physical blend 50:50 of (BA/MMA/MAA/HEMA: 46/12/12/30) and (MMA: 100).

b The polymer of Run 3 B is the same as that of Run 2 B 30 It is seen, in Table II, that the single charge polymer of Run 3 A has an MFT in the neighborhood of the calculated Tg The physical blend, i e Run 3 C: a blend of an emulsion having the composition of the first stage of the Run 3 B polymer with one having the second stage Run 3 B composition, is so viscous at high p H that the emulsion gels even when diluted 35 to 20 % solids before p H adjustment Note that neutralized to a p H of 9 the internally plasticized polymer has a much lower MFT and only a moderately higher viscosity than the single charge copolymer.

EXAMPLE 4 40

Balance of hydrophile/hydrophobe character of stages Using the polymer emulsion of Run 23 as a control, the compositional relationship between the water-swelled first stage polymer and that of the second stage is varied.

Interaction of the first stage polymer with the second stage is shown by achievement of internal plasticization, with controlled viscosity, by sequentially charged ( 1) soft, 45 hydrophilic and functionalized and ( 2) hard and hydrophobic copolymers This internal plasticization is demonstrated to depend on the balance of hydrophobe/hydrophile character of the two monomer charges by the data in Table III.

1 597 612 1 597 612 15 TABLE III

Tg ( 1) ( 2) Run Composition Avg.

MFT/Viscosity p H 3 p H 9 4 A BA/MMA/MAA/HEMA//MMA 23/6/6/15//50 4 B BA/MMA/MAA/HEMA//MMA 29/0/6/15//50 4 100 47 -13 105 35 4 C EA/MAA/HEMA//MMA 29/6/15//50 4 D BA/MMA/MAA/HEMA//ST (Comparative)22 5/6 5/6/15//150 14 105 53 4 100 46 55/ 10/ 1400 20/ 10/ 30,000 The polymer emulsion of Emulsion 4 A is the same as that of Run 2 B. The results, in Table III, show that vs Run 4 A a more hydrophobic, i e less hydrophilic, first stage polymer is good, 4 B; a more hydrophilic first stage, 4 C, leads to high viscosity; a too hydrophobic second stage, 4 D, leads to very high viscosity at high p H, too high for most uses.

EXAMPLE 5

Interpenetration parameter Emulsion polymers of a number of compositions, differing in interpenetration parameter (Ip) of the two stages, are prepared by the procedure of Example 1 (Runs 5 A to 5 D, SF to 5 H, 5 J to SL and SN to 5 R) or Example 8 (Runs SE, SI and SM) given hereinafter.

Determinations of the emulsion viscosity and MFT, done on the emulsion neutralized to a p H of 7 5 to 8 5 with ammonia and diluted to 20 % polymer solids, and of the film hardness show which of the preparations have formed internally plasticized polymers Tables IV A and B present these data.

40/ 30/ 10/ 10/ 1 597 612 1 597 612 TABLE IV A

Run Composition Ratio A BAMMAIMAA/HEMA/IMMA B B Al MMAIMAA/HEMAYMMA C BAIMMAIMAA/HEMAUMMA D BAWMAIMAA/HEMA/IMMA E EA/V Ac/V O HIM An/AM/ST F BAIMMAIMAA/DHPMAYMMA G BAIMMA/MAA/V Ac IVOHI/MMA H B Al MMAIDMAEMA/IN 1 MA I EA/V Ac IVOW/ST BA/MMA/MAA//ST/AN (Comp) K BAIMMANAA/HEMM/ST (Comp) L MMA/1 BAIMMAIMAA/HEMA (Comp) M BANOHN Ac/IMMA N BAMMAIMAA/DHPMA/IMMA BA/MMANAA/HEMA/IMMA P BAMMAIMAA/HEMA/IMMA Q BAIMMAIMAM/ST/AN (Comp) R EA/STIMAM/ST (COMP) 23/6/6/15/30 30/7/3/101150 30.5/9/3/7 51150 34.8/9414 3/851/43 5.5137815 6/04107//50 25/11 516171/50 23/6/6/13 5/15/50 18117/151/50 23/23 9/2 1//50 25/21 5/35/30/20 22.516 5/6115//50 50//23/616115 24/2 1/23 91/50 25/11 5/617 5/150 3 on 13 lloilso 30.5/82513 75 n 5//50 25119/61130/20 21/24/5/150 -Ij TABLE IV B

Tg 4 MFT 2 KHN 3 ( 1) ( 2) < 10 18 4 105 < 15 12 -14 105 18 13 -14 105 18 12 -14 105 < 10 15 4 105 14 1 105 < 15 < 15 < 15 6 105 100 3 100 pAvg ( 1) ( 2 J 47 20 2 16 0 34 18 6 16 0 34 18 1 16 0 28 18 3 16 0 47 19 0 16 0 43 17 8 16 0 48 18 5 16 0 58 17 5 12 1 44 16 4 12 1 SJ (Comp) 20 K (Comp) 30,000 SM 4,250 SN SL (Comp) P SQ (Comp) SR (Comp) Gel 42 < 10 < 15 < 10 < 10 < 15 < 15 9 9 6 99 7 100 3 105 4 105 5 -14 105 -14 105 8 99 42 100 46 16 9 12 6 47 20 3 12 1 46 16 4 16 0 4.3 9.2 0.4 47 19 0 16 0 3 0 47 16 0 20 3 -4 3 34 18 6 16 0 2 6 34 18 3 16 0 49 17 5 12 6 69 17 2 12 1 2.3 4.9 5.1 Run A SB SC Viscosity' cps.

SD SF SG SH SE SI 720 ( 1-2) 4.2 2.6 2.1 2.3 3.0 1.8 2.5 5.4 4.3 S" -4 a.,, -4 j 18 1 597 612 18 Notes for Table IV B 1 Viscosity is measured on the latex at 20 % solids brought to a p H of 9 with ammonia except for Example 5 H which is at p H of 3 with acetic acid.

2 MFT, in degrees Celcius, latex at 20 % solids and adjusted to p H 9 with ammonia except Example 5 H (p H 3 as above) 5 3 Hardness is Knoop Hardness Number (KHN) determined by the procedure given in Resin Review, Vol XVI, No 2, p 9 ff ( 1966), a publication of the Rohm and Haas Company.

4 Tg is calculated for a high polymer by the procedure of Fox, v s "( 1)" and "( 2)" represent first and second or later stage and "Avg " the value calculated for the 10 composition as a whole.

5.Ip is calculated for the first stage ( 1) and the second stage ( 2) The difference between these Ip values is tabulated under "( 1-2)".

The data in Table IV B show that an internally plasticized polymer is obtained, as 15 indicated by the glass transition temperature, minimum film temperature, emulsion viscosity and hardness values, when the interpenetration parameter value of the first stage polymer is greater than that of the second but not too much greater Run 5 J,' a polymer latex of the prior art, is not one of internally plasticized particles as evidenced by the proximity of the Tg and the MFT As indicated in Table IV, A this polymer has only seven 20 percent hydrophilic mer units in the first stage polymer Run 5 K is not of internally plasticized particles of this invention as evidenced by its high viscosity.

Runs 5 Q and SR, polymer latexes of the prior art, have MFT values above their Tg values; neither contains nonionic hydrophilic monomers in the first stage.

25 EXAMPLE 6

Floor polish A floor polish is prepared by mixing ingredients in the following recipe (except Runs 6 A and 6 E as noted below):

30 Role Material Charge Vehicle Polymer emulsion 15 % solids 100 0 parts Wax Poly EM-40 15 % solids 15 0 parts 35 (Trademark, Cosden Oil & Chemical Co) Wetting aid Fluorad FC 128 1 % solids 0 5 parts (Trademark, 3 M Co) 40 Leveling Tributoxyethyl phosphate 0 5 parts aid 100 % active Defoamer SWS-211 50 % solids (Trademark 0 01 parts 45 Stauffer Wacker Silicone Corp) Base Ammonia 10 % aqueous to p H 8 50 The floor polish is applied and tested by the procedure described in detail in Resin Review, Volume XVI, No 2, 1966 published by Rohm and Haas Company, Philadelphia, Pennsylvania 19105 except when another procedure is specified Polymer emulsions used and the test results obtained are in Table V A and V B. 1 597 612 1 597 612 TABLE V A.

(Comparative) Run 6 A 6 B 6 C 6 D 6 E Polymer emulsion (note 1) Run 2 B Run 50 Run 5 P Run 5 E (note 3) (note 4) Test(note 2) Visual gloss One coat Two coats Leveling One coat Two coats gloss (TM 3) Heel mark resistance (TM 5) Water resistance (TM 4) One hour One day Detergent resistance (TM 6) One day Three days Seven days Removability (TM 7) Static coeff.

of friction ( TM 1)Powdering (TM 2) vgexc.

g-vg vg vgexc.

good g-vg vg vg-exc.

vg-exc.

vg exc.

exc.

good vg exc.

0.5 exc.

exc.

good vgexc.

exc.

exc.

exc.

vg vgexc.

exc.

0.6 0 6 0 6 nil nil nil slight g-vg vg vg vgexc.

exc.

exc.

vg vgexc.

exc.

exc.

vg vgexc.

exc.

exc.

exc.

exc.

g-vg vg exc.

exc.

fair exc.

exc.

fair fair fair 1 597 612 2 Notes for TABLE V A.

1 Run 6 A is illustrative of the state of the art It employs a floor polish polymer emulsion having 1 65 % zinc ion crosslinker This polish is prepared by mixing ingredients in the following recipe:

5 Role Material Charge Vehicle BA/MMA/MAA copolymer emulsion 80 parts 15 % solids 10 Wax Poly EM-40 15 % solids 15 parts (Trademark, Cosden Oil and Chemical Co) 15 Alkali Solu low molecular weight all acrylic ble Resin resin 15 % solids 5 parts Coalescent diethyleneglycol monomethylether 4 parts 20 Plasticizer dibutyl phthalate 1 0 part Wetting aid Fluorad FC-128 1 % solids 0 4 parts (Trademark, 3 M Co) 25 Leveling aid tributoxyethyl phosphate % active 1 0 part Defoamer SW-211 50 % solids 0 01 parts (Trademark, Stauffer Wacker 30 Silicone Co) 2 Application of the floor polishes is described in ASTM method D 1436-64, Method B. (ASTM American Society for Testing Materials, Philadelphia, Pennsylvania) Test methods, identified in brackets, are listed below 35 3 Run 6 D is formulated with 1 25 % zinc ion on emulsion polymer solids.

4 The recipe for the polish of Run 6 E differs from that for 6 B, C and D in the omission of wax and defoamer and the addition of 2 parts of coalescent, diethyleneglycol monomethylether.

Test Methods for Table V A given in brackets in the table 40 1 Slip: ASTM method 02047-72; panels conditioned at 25 C and 55 % relative humidity.

2 Powdering: ASTM method D 2048-69.

3 60 gloss: ASTM method D 1455-64 Vinyl tile (Kentile No R-44, Kentile Floors, Inc) substituted for OTVA tile in this test.

4 Water resistance: ASTM method D 1793-66, dynamic test procedure 45 Rubber heel mark resistance: CSMA method 9-73 (Chemical Specialties Manufacturers Association, Washington, D C), test modified by rotating 15 minutes in each direction.

6 Detergent resistance is run on black vinyl asbestos tile using 10 ml of 5 % aqueous Forward (trademark S C Johnson) detergent, running 50 cycles in the one day 75 in 50 the three day and 100 cycles in the seven day tests.

7 Removability is run for 75 cycles using 10 ml of 3 % Spic and Span (trademark Procter & Gamble) and 1 % aqueous ammonia, on black vinyl asbestos tile.

Wear tests are carried out in a corridor having a vinyl asbestos tile floor which is subjected to a daily traffic load of 3,500 to 4,000 pedestrian passes A section of the corridor ( 10 feet 55 wide by 24 feet long) is cordoned off and stripped of residual polish and repolished in the typical janitorial procedure, as follows:

The floor dust mopped to remove loose dirt, a 1:1 aqueous solution of commercial stripper solution, Step-Off (S C Johnson & Sons, Inc, Racine, Wisconsin 53404) is applied by string mop at a rate of ca 1,000 square feet/gallon; after a 5 minute soak period, 60 the floor is scrubbed with a 16 inch black stripping floor pad ( 3 M Company, St Paul, Minnesota 55101; Scotch Brite Slim Line Floor Pad No 61-6520-0105-0) on a 300 rpm floor machine (Mercury Floor Machines Inc, Englewood, New Jersey, model H-15-c); the stripped floor is thoroughly rinsed twice by damp mopping with clear water, and allowed to dry The stripped floor is divided into 6 foot sections perpendicular to the normal direction 65 I 597 612 21 1 597 612 '1 of corridor traffic flow To each of these sections a coat of polish to be tested is applied, with a string mop, at a rate of ca 2,000 square feet/gallon After allowing one hour for the initial polish to dry a second coat is applied in the same manner The appearance of the polishes is rated initially and after one and two weeks of heavy traffic The results of these observations and other tests, following the procedures used in obtaining the Table V A.

data, are in Table V B. TABLE V B.

Run 6 A 6 B 6 C 6 D Initial:

Gloss (visual) Leveling Recoatability vg vg vg+ exc exc exc exc vg-exc vg-exc exc One week traffic:

Gloss (visual) g-vg vg vg vg+ Dirt pick-up resistance exc Black heel mark resistance Scuff resistance exc vg-exc vg-exc vg+ exc exc vg vg-exc vg vg-exc vg Two week traffic:

Gloss (visual) Dirt pick-up resistance Black heel mark resistance Scuff resistance good good good+ good+ vg vg vg vgvg vgg-vg vg vg g-vg g-vg g-vg The abbreviations used in Tables V A and V B are:

exc = excellent; vg = very good; g = good; + = plus; = minus except when used between abbreviations, where it means "to".

vg+ exc 1 597 612 9.1 22 1 597 612 22 EXAMPLE 7

Lacquer and paint The polymer latex of Example 1 is formulated as follows:

Run 7 A: Adjust the 40 % solids latex to p H 9 with 14 % aqueous ammonia 5 Run 7 B: To 100 parts by weight of the latex, adjusted to p H 8 5 with 14 % aqueous ammonia, is added a mixture of 9 7 parts of water and 15 3 parts of butoxyethanol.

Run 7 C: The Ingredients are mixed as follows:

Parts by weight 10 Water 4 7 Tamol 165 ( 22 % aqueous) 1 3 15 (Rohm and Haas Co) Triton CF-10 ( 100 %) 0 16 (Rohm and Haas Co) 20 Nopco NXZ (Diamond Shamrock) 0 05 20 Zopaque RCL-9 (Ti O pigment) 18 8 (SCM Corp; Glidden-Durkee Division 25 Grind on high speed disperser ( 4,000 ft/min) 25 for 15 min and letdown under agitation with:

Polymer latex 70 4 30 Water 1 8 Butoxyethanol 2 8 35 Total 100 0 35 Key lacquer and paint properties are determined by following the usual paint industry procedures Results of the determinations, on films made from the formulations by coating metal sheets, are in Table VI 40 1 597 612 TABLE VI

Property( 1) Run 7 A Run 7 B Run 7 C Dry to touch/tack free time 5 (min at 25 C and 40 % R H) 19/21 Air dry hardness KHN, 1 hr.

at 25 C and 40 % R H 6 5 ca 1 10 Ultimate hardness KHN 6 5 6 5 (baked 30 min) is Hot print ( 600 C/16 hr / 15 4 psi) (baked 250 F/60 ') none none v sl trace Mandrel flexibility ( 1 5 mil/B-100011 hr at 250 F) 20 ( 1/2, 1/4, 1/8 inch blends) 0/1/1 ll/ /-8 Impact In-Lb (D/R) Alodine 1200 S 50/16 ( 2) 25 T-Bend T T 1 Water Soak ( 16 hr at 100 'F) moderate moderate moderate rust, no rust, mod rust, mod blisters blisters blisters 30 Cleveland condensing cabinet si rust, ( 16 hours at 40 C) no blisters Chemical and stain 35 resistance:

Alcohol ( 16 hours) moderate moderate moderate attack attack attack 40 Ink ( 30 minutes) no attack Mustard ( 30 minutes) no attack Lipstick ( 30 minutes) no attack 45 Gasoline ( 30 min) slight si to s Ito attack moderate moderate attack attack s O 1 Results determined on 1 5 mil thick films baked 1 hour at 250 F for film tests unless other conditions are noted.

2 Air dried films have values of 2/1.

The data in Table VI A indicate that the Run 7 A latex dries very rapidly to full hardness, 55 to form a film which is both hard and flexible, without the aid of a coalescent Coalescent slows hardness development and has a deleterious effect on some resistance properties.

Baking is required to maximize certain properties The resistance properties are good in general although water soak and alcohol resistance results are not as good as the other results 60 Run 7 C shows that the latex of Example 1 can be employed to form pigmented films with comparatively little coalescent The physical properties of the film formed parallels that of the unpigmented film Other tests on the film formed from Run 7 C indicate: moderate rusting of a sample exposed five days in a humidity cabinet, signs of failure after three days in a salt spray cabinet and a change in gloss after 32 hours at 380 C in a Cleveland 65 24 1 597 612 24 Condensing Cabinet as follows:

Initial ( 20 /60 /80 ) gloss 54/77/88 Final ( 20 /600/80 ) gloss 21/60/72 EXAMPLE 8

An internally plasticized polymer emulsion based on vinyl acetate A latex, with first stage, second stage and Tg values of 25, 100 and 58 degrees Celcius respectively and Ip values of 17 5 and 12 1 for the first and second stages respectively, is prepared as follows: 10 A Equipment A five liter, five-necked flask is equipped with a condensor, an efficient agitator, a thermometer, addition funnels and heating, cooling and nitrogen sparging facilities.

15 B Material Charges Monomer charge Kettle Raw material 1 1 A 2 charge 20 deionized water 166 3 g 154 g 883 7 g octylphenoxy poly ( 39) ethoxyethanol 3 4 5 1 1 7 25 Abex 185 ( 33 %) (Alcolac Inc) 8 5 12 8 4 3 sodium dodecylbenzene 30 sulfonate ( 23 %) 6 8 10 2 3 4 ethyl acrylate 37 8 19 1 vinyl acetate 298 5 150 8 35 styrene 517 5 maleic anhydride 4 1 40 acrylic acid 7 2 Initiator: Fe++ ( 0 15 % Fe SO 4 6 H 20) 6 4 ml 0.26 g ammonium persulfate (APS) in 8 g water 45 0.26 g sodium sulfoxylate formaldehyde in 8 g water.

Catalyst: 1 92 g APS and 0 32 g t-butyl hydro 50 peroxide (t BHP) in 110 g water.

Activator: 1 92 g Na HSO 3 in 110 g water.

Chaser: 0 52 g t BHP in 5 g water 55 0.39 g sodium sulfoxylate formaldehyde in Sg water.

C Procedure 60 The monomer charges and kettle charges are weighed separately and each is mixed to form an emulsion The initiator mix is prepared and charged to the kettle Efficient kettle stirring is maintained throughout the entire reaction sequence The heat of reaction drives the kettle temperature from 22 C to a maximum (ca 60 C in ca 7 min) At the temperature maximum, monomer charge 1 addition is begun at a rate of 13 ml/min and addition of the 65 1 597 612 catalyst solution and activator solution is begun as separate feed streams at a rate of 1 ml/min The reaction temperature is maintained at ca 62 C throughout When one half of the monomer charge 1 addition is completed (ca 22 rain) charge 1 A is mixed with the remaining monomers of charge 1 and the addition continued After about 45 minutes this monomer charge ( 1 + 1 A) addition is completed and the kettle contents are maintained at 5 62 C for 15 minutes Monomer charge 2 addition is then begun at a rate of 13 ml/min This second addition is completed in about one hour and the kettle contents are maintainedat 62 C for 10 minutes while the catalyst and activator charges are completed The reaction mixture is held at 62 for an additional 15 minutes and then allowed to cool to 55 C The chaser is now charged rapidly, and the reaction mixture maintained at 5060 C for 15 10 minutes The product is allowed to cool to room temperature and is packaged.

A sample of the product latex is neutralized to a p H of 8 5 with ammonia and is found to have a viscosity of 40 centipoise ( 20 % solids Brookfield SynchroLectric Viscometer Model

LV 1 spindle 1 at 60 rpm) and a MFT below 15 C A film cast from this sample has a hardness of 17 KHN 15 EXAMPLE 9

An internally plasticized polymer emulsion having an acid-containing last stage A latex, with first stage, second stage and average Tg values of 28, 112 and 65 degrees Celcius respectively and Ip values of 17 5 and 14 5 for the first and second stages 20 respectively, is prepared using the same equipment as Example 8 and a similar procedure as follows:

Material Charges Monomer charge Kettle Raw material 1 1 A 2 charge deionized water 154 0 g 64 g 154 0 g 832 g.

octylphenoxy poly ( 39) ethoxyethanol 5 1 5 1 Abex 265)33 %) (TM Alcolac Inc) 12 8 12 8 sodium dodecylbenzene sulfonate ( 23 %) 10 3 10 3 ethyl acrylate 56 9 vinyl acetate 449 3 styrene 440 0 methacrylic acid 7 2 77 6 maleic anhydride 4 1 Initiator: Fe++ ( 0 15 % Fe SO 4 6 H 20) 6 4 ml 0.26 g ammonium persulfate (APS) in 8 g water.

0.26 g sodium sulfoxylate formaldehyde in 8 g water.

Catalyst: 1 92 g APS and 0 32 g t-butyl hydroperoxide (t BHP) in 110 g water.

Activator: 1 92 g Na HSO 3 in 110 g water.

Chaser: 0 52 g t BHP in 5 g water.

0.39 g sodium sulfoxylate formaldehyde in 5 g water.

1 597 612 Procedure 1 Charge kettle and adjust temperature to 20-22 C; sparge with N 2.

2 Prepare charge 1 and add 231 g to kettle.

3 Add maleic anhydride in water and methacrylic acid (charge 1 A) to remainder of monomer charge 1 and emulsify 4 Add initiator; turn off N 2 sparge.

Within several minutes of initiator addition, an exothermic reaction occurs, with the temperature peaking at 55-60 C.

6 At the peak, start addition of monomer charge 1 and half of the catalyst and activator.

Allow temperature to rise to 62 C and hold at 62 C throughout addition 10 7 Charge 1 addition takes 40-45 minutes; when charge 1 and half of the catalyst and activator have been added, hold system at 62 for 20 minutes.

8 After 20 minutes, start addition of charge 2 and of catalyst and activator.

9 Addition of charge 2 takes about 55 minutes; addition of catalyst and activator takes an additional 10 minutes 15 Hold for 30 minutes at 62 C.

11 After hold period, cool to 55 then add chaser and hold for 10 minutes before cooling to room temperature.

12 At room temperature, adjust p H to 4 5-5 0 with 10 % NH 4 HCO 3 aqueous solution.

A sample of the product latex has a viscosity of 19 centipoise ( 20 % solids Brookfield 20

Synchro-Lectric Viscometer Model LV 1 spindle 1 at 60 rpm) and a MFT of 37 C A film cast from this sample has a hardness of 14 KHN; when 1 % Zn + (as ZN(NH 3) 4 (HCO 3)2) on polymer solids is admixed, as taught in US 3,328,325, the hardness of a film is 15 5 KHN.

EXAMPLE 10 25

Effect of hydrophilic monomer level Following the procedure of Example 9, a group of polymer emulsions are prepared having the compositions and properties given in Table VII From these emulsions floor polishes are prepared by mixing ingredients in the following recipe:

30 Role Material Charge Vehicle Polymer emulsion 15 % solids 90 O parts Wax AC 392 15 % solids 10 0 parts 35 (Trademark, Allied Chem Corp) Wetting aid Fluorad FC 128-1 % solids O 5 parts (Trademark, 3 M Co) 40 Leveling Tributoxyethyl phosphate O 5 parts aid 100 % active Coalescent Methyl carbitol 4 0 45 Base Ammonia 10 % aqueous to p H 7 5 Each floor polish is applied and tested by the procedure described in Example 6 The results are in Table VII where the superior polish properties of 10 D and 10 E are noted.

The AC-392 is prepared at 35 % solids, as follows, and is diluted to 15 % solids with water 50 Formulation Parts by weight A-C Polyethylene 392 40 Octylphenoxy poly( 9)ethoxyethanol 10 KOH ( 90 % Flake) 1 2 Sodium Meta Bisulfite O 4 Water ( 1) to 50 % solids 50 Water ( 2) to 35 % solids 27 1 597 612 27 Charge the first five ingredients to produce the 50 % concentrade into a stirred pressure reactor Begin agitation and heat to 95 C ( 203 F) with the vent open Close the vent and continue heating to 150 C ( 302 F) for 1/2 hour Add water ( 43 parts) at 95 C ( 203 F) to the reactor while the temperature is at 150 C ( 302 ) and then cool to room temperature with agitation as quickly as possible Add 500 ppm formaldehyde preservative 5 Run Polymer emulsion Composition Weight ratio Tg ( 1), 'C Tg ( 2), C Tg average, C MFT, C Ip ( 1) Ip ( 2) Ip( 1) Ip( 2) Polish properties Viscosity(cps)/p H A V Ac/VOHI/ST 49.5/0 5//50 below 15 16.2 12.1 4.1 2.0/8 2 TABLE VII

B C V Ac/VOH/MAA//IST V Ac/VOH/MAAI/ST 46.75/2 0/1 25//50 45 5/2 5/2 0//150 33 34 100 59 60 below 15 below 15 16.5 16 7 12.1 12 1 4.4 3.6/8 0 4.6 4.5/8 3 D E EA/V Ac/VOH/MAA//IST EA//IV Ac/VOH/MAA//ST 5/39 1/3 4/2 5//50 10/32 2/2 8/5//50 31 30 100 57 56 below 15 below 15 17.4 17 9 12.1 12 1 5.3 5 8 3.5/7 2 3.7/7 O fair very good moderate-severe good excellent slight-moderate Visual gloss Leveling Visual haze poor fair severe k c.

poor very good severe good excellent slight 00 29 1 597 612 29 EXAMPLE 11

Effect of acid variations Following the procedure of Example 9, a group of polymer emulsions is prepared as given in Table VIII Floor polishes are prepared from these emulsions and are tested as described in Example 10 Results of these tests are in Table VIII wherein it is seen that 5 Example 11 A does not have pronounced weaknesses and that the copolymers utilizing maleic anhydride are not hazy.

W TABLE VIII

Run Polymer emulsion Composition Weight ration Tg( 1), 'C Tg( 2), C Tg average, C MFT, C Ip ( 1) Ip ( 2) Ip( 1) Ip( 2) viscosity(cps) 11 A 11 B 11 C all expressed as EA/V Ac/VOH/M An/MAA//ST 5.5/37 8/5 6/0 4/0 7//50 5 5/40 3/3 5/0/0 7//50 5 5/39 7/4 4/0 4/0//1150 27.7 26 4 26 2 100 100 59 2 59 1 23 24 24 17.5 17 0 17 1 12.1 12 1 12 1 5.5 4 9 5 0 24 18 20 11 D 5.5/42 7/1 8//0/10/50 58.3 16.5 12.1 4.4 Polish properties Viscosity(cps)/p H 3 0/7 5 Visual haze nil Leveling very good(vg) Visual gloss good Detergent resistance fair-good Removability fair At 40 % solids and a p H of 5.

L/ -4 2.8/7 2 slight(sl) vg-excellent good-vg vg-excellent poor 3.4/7 5 nil vg good vg-excellent poor 3.0/7 2 sl-mod good fair excellent poor 11 R t c AO 1 597 612 EXAMPLE 12

First stage/last stage ratio variations Polymer emulsions are prepared, by the procedure of Example 9, having a range of first stage to last stage weight ratios as shown in Table IX The composition of the first stage of each is EA/V Ac/VOH/M An/MAA = 11/75 6/11 210 8/1 4 and has a Tg( 1) of 27 7 C and an Ip( 1) of 17 5 The last stage of each is polystyrene having a Tg( 2) of 100 C and an Ip( 2) of 12.1 Thus the Ip( 1) Ip( 2) value of each latex polymer is 5 4 Floor polishes are prepared from these emulsions and tested as described in Examples 6 and 10; test results are in Table IX.

TABLE IX

Run 12 A 12 B 12 C 12 D 12 E Polymer emulsion First//last stage (by weight) MFT C 701/30 60//40 50//50 40//60 30//70 19 21 23 24 80 viscosity(cps) Tg-average C Polish properties Visual haze 22 21 24 20 17 46.3 53.0 60.0 67.3 75.0 nil nil nil slight moderate good good+ good good fair-gd vg vg+ vg vg vg Detergent resistance Removability Heel mark resistance Overall wear resistance fair fair good fair fair fair fair good vg poor poor good good good good good good good+ good good At 40 % solids and a p H of 5.

EXAMPLE 13

Maleic anhydride/methacrylic acid levels Polymer emulsions are prepared, by the procedure of Example 9, with a range of maleic anhydride and methacrylic acid levels in the first stage as shown in Table X Each last stage is polystyrene and represents 50 weight percent of the polymer The polymer of Run 13 A is the same as that of Run 11 A The compositional differences being comparatively small the Tg values and the Ip values for the other three polymers are but little different from those for Run 13 A Polishes prepared from these emulsions are tested as in Examples 6 and 10 to give the performance results recorded in Table A wide range of removability and of detergent resistance is achieved; remarkable in view of the vinyl acetate content of the polymer.

Visual gloss Leveling TABLE X

Run Polymer emulsion Composition Weight ratio 5 5/ MFT, C viscosity(cps) Polish properties Visual haze Visual gloss Leveling V Detergent resistance Removability At 40 % solids and a p H of 5.

13 A 13 B 13 C first stage is EA/V Ac/VOH/M An/MAA 37.8/5 6/0 4/0 7 5 5137 2/6 0/0 4/0 3 5 3137 0/6 210 210 7 23 23 26 24 22 18 nil good ery good)vg) fair-good fair nil good vg vg-excellent poor nil good vg fair-good fair-good 3 D 5.5/36 9/6 5/0 8/0 7 nil fair-good good-vg poor excellent (A t O L/i ( 7 \ t Oi ci 331593123 EXAMPLE 14

Acid in the last stage The polish of Run 14 A is prepared from the same polymer latex as that of Run 11 A A film of this polymer is found to have a Knoop Hardness Number of 10 The polish of Run 14 B is prepared from the polymer latex of Example 9 and is crosslinked with 1 % Zn', on 5 polymer solids, added as Zn(NH 3)4 (HCO 3)2 The polish of Run 14 C is prepared from a sample of the polymer latex of Run 6 A, Table V A, Note 1; a film of this polymer has a KHN of 13 These polishes are tested as in Examples 6 and 10; and results are in Table XI.

Note the balance of removability and detergent resistance obtained while maintaining a high level of performance in other properties 10 TABLE XI

Run 14 A 14 B 14 C 15 Polish properties Leveling vg-exc vg vg-exc.

Visual gloss' 20 one coat g-vglg g-vglg-vg vg/g-vg two coats vg-exc/vg+ exc/vg-exc vg-exc/exc.

*25 Visual haze nil nil nil Detergent resistance fair vg vg-exc.

Removability good vg-exc exc 30 Recorded as results on vinyl tile/on OTVA tile see Test Method 3 of Table V A.

Example 6.

Our co-pending application Number 10033/78 (Serial No 1597611) from which the 35 present application is divided claims a latex of internally plasticized addition polymer particles comprising (A) early stage polymer and (B) later stage polymer formed by polymerisation in the presence of an emulsion of polymer particles comprising polymer (A), polymers (A) and (B) each making up at least 10 % by weight of the polymer in the particles, polymer (A) containing at least 10 % by weight hydrophilic mers of which at least 40 % weight are nonionic and polymer (B) being less hydrophilic than polymer (A) wherein polymer B is of higher Tg than polymer (A) and, of the hydrophilic units in polymer (A), at least 0 5 % are ionic and the interpenetration parameter of polymer (A) is greater than that of polymer B by at most eight units, polymer (A) comprising units of monoethylenically unsaturated monomer, and attention is directed to the claims thereof under Section 9 of the 45 Patents Act 1949.

Claims (1)

1 A latex of internally plasticized addition polymer particles comprising (A) early stage 50 polymer and (B) later stage polymer formed by polymerisation in the presence of an emulsion of polymer particles comprising polymer (A), polymers (A) and (B) each making up at least 10 % by weight of the polymer in the particles, polymer (A) containing at least % by weight hydrophilic mers of which at least 10 % by weight are nonionic and polymer (B) being less hydrophilic than polymer (A) and wherein the polymer particles have a Tg 55 above 150 and the latex has a viscosity below 5000 centipoises when measured at 20 % by weight solids over the p H range 4 to 10 and has a minimum film temperature more than 5 C below the calculated Tg of the polymer particles.

2 A latex as claimed in Claim 1 wherein the polymers (A) and (B) each make up at least 20 % by weight of the latex polymer 60 3 A latex as claimed in Claim 2 containing no stages other than polymers (A) and (B).

4 A latex as claimed in any preceding Claim wherein the calculated Tg of the polymer particles is above 20 C.

A latex as claimed in any preceding Claim having a viscosity below 500 centipoises, the polymer particles having a Tg above 30 C and the latex polymer being such that a film 65 1 597 612 1 597 612 formed therefrom has a Knoop Hardness Number of at last 5.

6 A latex as claimed in any preceding Claim having a viscosity below 150 centipoises.

7 A latex as claimed in any preceding Claim wherein the viscosity is below 40 centipoises and the latex polymer is such that a film formed therefrom has a Knoop Hardness Number of at least 8 5 8 A latex as claimed in Claim 7 in which the viscosity is below 10 centipoises, and 50 to % of the hydrophilic mers are mers of hydroxyalkyl ester of a, Punsaturated acid.

9 A latex as claimed in Claim 8 in which the mers in the addition polymer comprise mers of acrylate, methacrylate, vinyl esters, and/or vinyl aromatic monomer.

10 A latex as claimed in Claim 5 in which polymer (A) comprises 10 % to 70 % by 10 weight hydrophilic mers; polymers (A) and (B) each being at least 30 % by weight of the latex polymer, and the viscosity of the latex being below 150 centipoises.

11 A latex as claimed in Claim 10 in which the minimum film temperature is at most 18 C and a film formed from the latex polymer has a Knoop Hardness Number of at least 5.

12 A latex as claimed in Claim 11 wherein the viscosity is below 40 centipoises and the 15 Knoop Hardness Number of a film formed from the latex polymer is at least 8.

13 A latex as claimed in Claim 12 in which the viscosity is below 10 centipoises and polymers (A) and (B) each make up at least 40 % by weight of the latex polymer.

14 A latex as claimed in Claim 13 in which the latex polymer comprises units of one or more of the following monomers: acrylate esters, methacrylate esters, vinyl esters and vinyl 20 aromatic monomers.

A latex as claimed in Claim 14 in which the units of polymer (A) comprise by weight, 65 to 85 % (C 1-C 4)-alkyl acrylate, (C 1-C 4)-alkyl methacrylate and/or styrene units; 5 to 10 % acrylic acid, methacrylic acid and/or itaconic acid units; and 10 to 25 % hydroxy-(C 1-C 4)-alkyl methacrylate and/or hydroxy (C 1-C 4) alkyl acrylate units, and the 25 units of polymer (B) comprise methyl methacrylate and/or styrene units.

16 A latex as claimed in Claim 14 in which the units of polymer (A) comprise, by weight, 50 to 85 % vinyl acetate units; 1 to 10 % acrylic, methacrylic, itaconic and/or maleic acid units; and 8 to 25 % vinyl alcohol units; and the units of polymer (B) comprise 100 to 70 % methyl methacrylate and/or styrene units and 0 to 30 % acidic units, by weight 30 17 A latex as claimed in Claim 16 in which the units of polymer (A) contain, by weight, 1 to 4 % acid units, of which 0 2 to 2 % by weight of polymer (A), are units of maleic acid, 0 to 20 % (C 1-C 4) alkyl acrylate, 65-80 % vinyl acetate and 10 to 20 % vinyl alcohol units; and the units of polymer (B) comprise 10 to 20 % acid units, by weight.

18 A latex as claimed in any of Claims 1 to 9 wherein the polymers (A) and (B) each 35 make up at least 30 % by weight of the latex polymer.

19 A latex as claimed in Claim 1 substantially as described in any of the foregoing Examples 1,2 B,3 B,4 A to C, 5 A to I, 5 M to P 6 B to E, 7 to 14.

The internally plasticised polymer of the latex as defined in any one of the preceding claims, in finely divided or other physical form 40 21 An aqueous polish composition capable of forming a coating having a Knoop Hardness Number of at least 0 5 and containing:

a) 10 to 100 parts by weight of polymer as claimed in Claim 20.

b) O to 90 parts by weight of alkali-soluble resin in an amount of at most 90 % by weight of the weight of (a), 45 c) 0 to 90 parts by weight of wax, d) wetting, emulsifying and dispersing agents in an amount of 0 5 to 20 % by weight of the total of (a), (b) and (c), (e) polyvalent metal compound in an amount of O to 50 % by weight of (a), (f) water to make total solids of 0 5 to 45 % 50 22 A process of polishing a hard surface comprising coating the surface with a composition as claimed in Claim 21 and drying the coating or allowing the coating to dry.

23 A polished hard surface prepared by a process as claimed in Claim 22.

1 597 612 35 24 A process for producing a latex of internally plasticized addition polymer particles comrparising:

a forming by polymerisation an emulsion of polymer particles comprising polymer (A) as defined in any one of Claims 1 to 19 and (b) forming by polymerisation, in the presence of that emulsion, polymer (B) as defined 5 in any one of Claims 1 to 19 as a later stage polymer on the particles comprising polymer (A); the amount of monomer for each of polymers (A) and (B) being so chosen that each makes up at least 10 % by weight of the polymer in the particles.

For the Applicants, 10 D W ANGELL, Chartered Patent Agent, Rohm and Haas Company, European Operations, Chesterfield House, 15 Bartar Street, London, WC 1 2 TP.

Printed for Her Majestys Stationery Office by Croydon Printing Company Limited Croydon, Surrey, 1981.

Published by The Patent Office, 25 Southampton Buildings, London, WC 2 A IAY, from which copies may be obtained.