CA1127338A - Internally plasticized polymer latex - Google Patents

Abstract

INTERNALLY PLASTICIZED POLYMER LATEX
Abstract This invention relates to a latex of internally ? 75-119A plasticized polymer particles, low in viscosity although high HLG/sjg in hydrophilic components and film forming at temperatures below the calculated Tg of the polymer. The polymer may be prepared by a multistage emulsion polymerization process.
The first stage is highly water-swellab1e or water-soluble.
The principal second or later stage is less hydrophilic and of higher Tg than the first stage and is polymerized in the emulsion in the presence of the first stage.

Description

~.1;;~733!3 ~CKGROUN~ OF THE INVE~TIO~1 This invention relates to a polymer latex in which the arran~ement of the polymer molecules in t~e latex particle is novel. The latexes are useful in the formation of coatings, adhesives and binders. They are ~articularly use-ful to supplant combinations of polymers and coale~centsin polish and coatings compositions. The polishes or coatings may be a~plied to either hard or soft surface~ and are especially useful for application to flooring and ~all surfaces to form clear coatings having a glossy appearance.
,lO The polymer in a film-for~ing latex is required to be soft enough to form a film of good integrity yet hard enough so the film has high strength, low dirt pick-up and a myriad of other related prooerties depen~ing on the specific application. It s known that if t'ne glass trans-ition tem~erature (Tg) of the polymer is below the temperature at which the film is being formed, a film of good integrity, that i5 , not "cheesy", is normally produced on drying a latex. ~ow~verl ~he ver~ softness of the latex articles which leads to good film formation means that the ?roduced film i3 ~oft ~r tacky as o~posed ~o being s~rong, hard, wear resistant and tough. The ar~ recognized way out of the dile~ma of having a polymer which is soft enough to form a we~l integrated film yet hard enough to form a use~ul film is to ad~ coalescents volatile enoug~ to leave the ~ilm af~er film formation has occurred. Wîth the advent of greater concern about air pollu~ion, there has arisen the need to eliminat~ the volatile coalescents if Possi~le.

Elimination of the coalescentsis also economical, the ccst of the coalescent being saved.
Another approach toward preparing high Tg polymers with low minimum film formation temperatures (MFT) is the i~corporation of a high proportion of hydrophilic monomers (e.g. those with hydroxyl, amine or carboxyl functions) in the polymer. This induces water swelling of the latex par~icles which simultaneously softens the particle in the latex. At normal polymer concentrations the swelling accompanied by very high viscosities particularly if the storage or use p~ is such that the carboxylic groups or amine groups are neutralized or partially neutrali~ed.
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 by J. Wéiss in U.S. Patent 3,935,368 for use in coating vinyl chloride flooring materials.
Still another solu~ion to ~he ~roblem of getting hard coating in the form of a well integrated film is that-of D. Schoenholz et al. in ~.S. Patent 3,949,107. Sch~enholz tezcnes applying a polish containing an aqueous disper~ion - o o of a resin with a Tg of 30 C. to 80 C~ to a ~loor, having either the polish or ~he floor preheated to a temperature aboYe the Tg of the resi~.
This disclosure teaches a latex low enough in o ~i~cosity to make suitable formulations for application and which, without coalescents, is ~ilm forming and produces tough, hard films.

~7338 ~

BRIEF SUMMARY OF THE INVENTION
.
Thls invention relates to a process for producing a latex of lnkernally plastlclzed polymer partlcles, the polymers produced by the process and polishes and other prOducts made from the latex.
In the present invention lt is taught that the sequential polymerization of a hard (high Tg) relatively hydrophobic monomer system onto soft (low Tg) hydroph~lic ~unctlonalized copolymer latex particles, to form latex partlcles whlch for con~enience are called lnternally plas-- ticized polymer latex particles, produces a latex low ln vlscosity yet film forming at a temperature low in comparison to the calculated Tg of the polymer ln the particles. The vlscosity and the MFT are measured under normal use condi-tions, l.e. neutral to high pH for acid-containlng polymers and neutral to low pH for base-containing polymers~ Pref-erably, the latex of internally plastlclzed polymer particles ls made as fallows:
Under normal emulsion polymeriza~ion conditions a water-swellable addition polymer is prepared.
Thls water swellable polymer may also be water soluble at an appropriate PH and normally ls soluble at high pH when containlng acid groups or ak low pH when containing basic groups. Under the conditions of polymerization, however, lt does not dissolve in the aqueou~ medium but is ma~ntalned as a latex. A second polymer, poly-merized ln the presence of, interacting with and possibly lnterpenetrating the first, ls formed by the addition of certain monomers less water ~en itive, i.e. le~ hydrophlllc, and normally harder than the inltial monomer system.

1~27338 The second ~onomer system i3 chosen to have sufficient com-patibility with the initial polymer so as to swell the initial polymer. .The second polymer in its interaction wit'n the fi~st ~erves to sharply limit the water swellability of S the first polymer. Thus, the product ~an be considered to be a hydroplastic first polymer hardened and made more hydrophobic by the second polymer or al~ernatively a hard hydr~phobic second polymer made softer and more hydroplastic by the first polymer. The internally plasticized polymer formed has pr~perties unlike the properties of either paren~ type of polymer nor are ~he properties simply the sum or average of the properties of the parents. For exam~le~ if the first polymer is one which is completely - . soluble at high pH it is found that after thé internally plasticized polYmer is formed this first Polymer ~ortion is no lonqer soluble even at verY high P~ valu~s.
. A highly water swellable component polymer would be expected to produce a high viscosity latex, even ~hough the MFT might be low compared to the Tg. In this invention, the modification of the properties of the water swellable Eirst stage polymer ~y the second stage results in the rela-tively low viscosity of the latex.
The present invention then in one aspect, resides in a latex of internally plasticized addition polymer part,icies, ha-vlng a calculated Tg above about 20C, Gomprlsing: A) a ~irst stage polymer comprising at l~ast 10% hydrophllic mer unlts co~prislng nonionlc hydrophlllc unlts and B) a later stage J less hydrophilic, polymer polymerlzed ln the presence of an emulslon of the rirst ~t~ge polymer, wherein the ~lrst and later stage polymers are each at least about 20~ Or the addition polymer, by l~Z7338 welght; the latex havlng (1~ a Ylscosi~y below about 5,00 centipGise~, at 20~ ~ollds over the pH range 4 to '0, and

(2) a minimum ~llm temperature more ~han 5C below ~he calculated Tg of ~ a ~ tion polymer. mis aspect of the mvention is also disclo~d, and is cla~E~, Ln our Canadian Patent Application No.
298,684, filed M~h 10, 1978, of which the present application is a divisional.
In another aspect, the pre~ent inven~ion resides in a latex of internally plasticized addition polymer partlcles comprlsing:
A) a ~lrst stage polymer, polymerlzed from a monomer nix consistlng essentially of monoethylenically unsaturated monomers~
comprlsing, by weight, at least 10%
hydrophilic mers, the hydrophlllc mers comprising at least 10% nonionic and at least 0.5% lonic mers, and B~ a less hydrophilic, hlgher Tg, later stage polymer polymerized in the presence o~ an emulsion of the first stage polymer;
A) belng ~rom 20% to 80% of the combined weight of A~ and B);
the interpenetration parameter of A) being greater ~han that Or B) by up to e~gh$. units.
The invention also provides a process for producing a latex of internally pla~ticized addition polymer particles, comprlsing:
(a) polymerizing a first stage polymer comprising at least 10~ hydrophillc mer units comprislng nonlonic hydrophillc units an~
(b~ in the presence o~ an emulsion of the rlrst ~tage polymer polymerlzing a later stage less hydrophllic polymer wherein the ~lrst and later stage polymers are each at lea3t about 20% of the addltion polymer, by welght, to produce a latex havlng (1) a ~l~c081ty below about 5,000 centlpol~es 5 Q - .

7~
~t 20% ~olias and over the pH r~nge 4 ~o 10, and (2) a mintmum rllm temperature more than 5~C below $he calrulated Tg of the . addltion polymer;
the addltion polymer havlng a calculated Tg above about 20C. This aspect of the present Lnvention is also disclosed, and is cla~E~, in Canadian Application Nb. 298,694, of which this application is a divisional.
The present invention, in a further aspect~
resides in a process, for producing a latex ~f internally plastlclzed addltlon polymer parttcles 9 comprlslng (a~ produclng a ~lrst stage polymer, poly-merize~ ~rom a monomer mix conslstlng essentially of monoethylenically unsat-urated `monomers, compris~ng at least lO~ by weight hydrophilic mers, the hydrophilic mers comprislng at least 10% by weight nonionlc mers and at least 0.5% by weight ionic mers and (b) polymerizing, in the presence of an emulsion of the ~lrst stage pol-~mer, a later ~tage polymer less hydrophilic, having an lnterpenetration parameter higher by up to elgh~ units~ and a higher Tg than khe ~irst stage polyrner, the ~irst stage polymer being ~rom 20 to 80% by weight o~
the total ~irst and later stage polymers.
The preferred polymer~ o~ this invention comprise at least sne of acrylate, methacrylate, vinyl ester and vinyl aromatic mer units. The preferred hydrophilic ionic mers in tfie polymers comprise a carboxylic acid group. The preferred hydrophilic nonionic mers in the polymer comprise hydroxyalkyl esters of carboxylic acids cr vinyl alcohol mers.

- 5b -~lZ733~ ' ?ET~IL5~ ~SCRI~TIO~
The internally plasticized polymer of this invention is formed by emulsion polymeriza`tion of a first ethylenically unsaturated monomer system comorising comparatively hydro~hilic monomers and then polymerizing a second charge o~ ethylenically unsaturated monomers which are by themselves; the ~recursors of a harder and more hydrophobic polymer than the ~irst charge polymer. The polymer formed by the first charge or stage is maintained as an emulsion although it is water swellable or water soluble. ~ater soluble, in this usage, ~eans soluble in water when the pR of the water is adjusted by the addition of acid or base to completely or partially neutralize the polymer. Water swellable means t~at the ~olymer imbibes water or can be made to imbibe water by p~ adjus~ment as above. It is ~referred that the ~ ran~e considered useful be from about 4 to about 10. The swellin~ ratio of the swellable polymer, i.e., the volume of the polymer swollen $n a large excess o~ water divided by the volume of the polymer when dry, is ~referably grea~er than two and more preferably greater than ~iXD
~ he mode of operation of ~he hydro~hilic monomer, included in amounts rangin~ from about 10 to about 1~0 parts per hundred parts of first charge monomer is believed to be understood but the evidence is not so conclu ive that it should be considered binding. It ao~ears that the hydro-philic monomer serves, when polymerize~, to bind whatever a~ounts of water are ~ransmitted into the composition, in the manner of water of hydration, for examDle. Any monomer which can be polymerized in the ~ix and which is hydrophilic 11;~7338 enough to effectively bind water is contemplated within the scope of the invention. .~ong the hydrophilic monomers which can be mentioned, by way of example only, are acrylonitrile, methacrylonitrile, hydroxy-substituted alkyl and aryl acrylates and methacrylates, polyether acrylates and methacrylates, ~ phosphato-alkyl acryla~es and methacrylates, alkyl-phosphono~alkyl acrylates and methacrylates, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, N-vinyl pyrrolidone, alkyl and substituted alkyl amides o~ acrylic acid, methacrylic acid, maleic acid (mono- and di-a.~ides), fumaric acid ~mono- and di-amides~, itaconic acid (mono- and di-amides), 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 meth-1~ acrylates, vinyl pyridines and amino al'.cyl vinyl ethers,and ureido monomers, including tnose with cyclic ureido groups, and the like. Many others will occur to those skilled in the art, and the scope of the present invention should ~e interpreted to include such hydrophilic monomers generally.
The proper scope of the invention should also be interpreted to include variations on the inclusion of the hydcopbilic mono,ner, such as, for example, when a monomer is included in the polymerization mix wbich is not itself hydrophilic, but is altered in processing or in a subsequent ste~, e.g.
by hydrolysis or the like, ~o provide hydro~hilicity;
anhydride- and epoxide-containing monomers are exam~les.
Among the e~fective hydrophilic monomers, it is pre~rred to utilize acrylic com~ounds, particularly ~he a~ides and hydroxy al~yl est~rs of methacrylic and acrylic acids, amides ~nd hydroxy alkyl esters of other acids

3.~ 7338 ) are also preferred, but less so than the corresoon~ing methacrylates and acrylates, which are more readily poly-merized. Mono~ers-containing carboxylic acid are also ~re-ferred,particularly acrylic acid, methacrylic acid and S itaconic acid. Another preferred group o~ hydrophilic monomers are those representing speciEic exa~ples of potential ~ydroo~ilic monomers which ~roduce the actual hydrophilic mer units in ~he ooly~er by a hydrolysis process.
Thèse monomer~ are the esters of vinyl alcohol such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl versitate. ~ydrolysis of these ,nonomers Produces vinyl alcohol mer units in the ~olymer w`nich mer units are hydrophilic. The preferred monomer of these is vinyl acetate.
Polymerized with the hydrophilic monomers in the first charge ar~ ot~er ~onomers carefully cnosen to give other desirable properties to the final ~ol~mer. ~ny poly-ethylenicallv unsaturated mono~ers, if present, are preferably of the type in which the various ethylenic groups, i.e. the addition polymerizable unsaturated groups, oarticioate in ~he polymerization at about the same rate. Preferably no such crosslinking or graft-linking ~olyethylenically unsaturated monomers are ~resent in the first stage ~ono!ner syste~. The t2rm graft-linking mono~er i5 defined in U.S. patent 3,79S,77l colum~ 4, line 66 to column 5, line 20.
Preferably the first charge monomers are mono-. .
ethylenically unsaturated.
It is desired that ~he first charge polymer be softer than the second charge ~olymer. The hardness of the first charge i~ controlled by t~e choice of the hydrophilic ~27338, monomers and of the comonomers used therewlth. The poly-merlzable comonomers whlch ~orm so~t polymers in the presence Or rree radical catalysts desirably lnclude any primary and secondary alkyl acrylate, wlth alkyl substituents up to eighteen or more carbon atoms, primary or secondary alkyl methacrylates with alkyl substltuents of flve to elghteen or more carbon atoms, or other ethylenically-unsaturated compounds which are polymerlzable with ree radical catalysts to form soft solld polymers, lncluding vinyl esters o~ sat-urated monocarboxylic acids of more than two carbon atoms.The pre~erred ethylenically unsaturated compounds are the stated acrylates and methacrylates and of these the most practlcal esters are those with alkyl groups of not over 8 - carbon atoms.
The preferred monomers whlch by themselves yield soft polymers may be summarized by the formula ,~ CH2 - C-COORX
R' wherein R' is hydrogen or the me~hyl group and Rx represents, when R' ls methyl, a primary or secondary alkyl group-o~ 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 pre~erably 1 to 4 carbon atoms.
Typical compounds coming withln the above de~inition 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-trlmethylhexylacrylate, decyl acrylate, dodecyl acrylate, cetyl acrylate9 octadecyl acrylate, ~L~Z~ 3~

octadecenyl acrylate, n-amyl ~ethacrylate, sec-amyl meth-acrylate, hexyl methacrylate, 2-et~ylbutyl methacrylatP, octyl methacrylate, 3,5,5-trimethylhexyl ~ethacrylate, decyl me~hacrylate, dodecyl methacrylate, octadecyl methacrylate, S ~nd those with substituted alkyl groups such as butoxylethyl acrylate or methacrylate.
~ s polymerizable ethylenically unsaturated mono~ers, which by themselves form hard polymers, there may be used alkyl methacrylates having alkyl groups of n~t over four carbon atoms, also tert-amyl methacrylate, ter-butyl or tert-amyl acrylate, cyclohexyl, benzyl or isobornyi acrylate or methacrylate, acrylonitrile, or methacrylonitrile, these constituting a preferred group of the compounds forming hard polymers. Styrene, vinyl chloride, chlorostyr~ne, vinyl acetate and a;methylstyrene, which also for~ hard polymers, may be used.
Preferred monomers, which by themselYes form hard polymers, may be summarized by the formula C~ ~-X

wherein R' is hydrDgen or the methyl grouP and wher~in X
represen~s one of the groups -~N, ~henyl, methylphenyl, and e~ter-forming groups, -C~ORn, wherein R" is cyclohexyl or, when ~' is hydrogen, a tert-alkyl group of four to ~ive carbon atom.s, or, when R' is methy1, an alkyl group of one to four carbon ato~s. 50me ~ypical examples of these have already been named. Other specific compounds are me~hyl methacrylate, ethyl ~ethacrylate, propyl ,nethacrylate, isopro~yl ~ethacrylate, isobutyl methacrylate, n-butyl ~ethacrylate, sec-butyl ~ethacrylate, and tert-but~l methacrylate. Acrylamide and methacrylamide may also be used as hardening components of the co~olymer.
These monomers may contain other ~unctional grou~s ~or other pur~oses such as to ~roduce crosslinking in the ~olym2r on curing or enhanced adhesion to a substrate. ~xam~les of such functional groups are carboxyl, ~n the form of the free acid or salt, amido including sub-stituted amido, such as alkoxy alkyl amido and alkylol amido, lU e~oxy, hydroxy, amino including o~azolidinyl and oxazinyl, and ureido. In most instances these functional grouPs are also hydrophilic grouPs, and many of the monomers ~re - hydro~hilic.
~nother grou~ o~ monomers of this invention which by themselves yi~ld soft polymer are butadiene, chloro~rene, isobutene, and isoprene. These are monomers commonly used in rubber latices along with a hard monomer also useful in ~his invention, such as acrvlonitrile, styrene, and other hard ~onomers as given above. The ole~in monomers, 2articularly ethylene and propylene~ are suitable for ~oft ~onomers. Par ic~larly useful ~irst stage co~olymers are et~ylene/ethyl acrylate copolymer~ and et~ylene/vinyl acetate copolymers containing added hy~ro~hilic mono~er.
A further class of pol~ers o~ this invention are polymers of the esters of vinyl alcohol such as vinyl formate, vinyl acetate, vinyl ~ropionatet vinyl butyratë
and vinyl versita~e~ Preerred is ~oly(vinyl acet~te) and coPolymer~ of vinyl ace~ate with one or more o~ the ollowing monomers: vinyl chloride, vinylidene chloride ~3;38 ' styrene, vinyl toluene, acryionitrile, methacrylonitrile, ~crylate or methacrylate esters, and the functional grou~
conta1nlng 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 3~ by weight vinyl acetate units with at least 80% being most preferred. ~efore polymerization of vinyl alcohol es~ers is complete some hydrolysis to vinyl alcohol mer units normally occurs or is accomplished~ The vinyl alcohol mer units so produced are hydro~hilic and considered here as though derived from vinyl alcobol monomer. The amount of hydrolysis can be contro~led by means of control of the time, temperature and p~ of the reaction to produce ~he desired a~ount of vinyl alcohol in the pr,oduct. Longer ti~es, higher temperatures, very acidic or very al'caline conditions all serve to increase the amount of hydrolysis and thus the amount of vinyl alcohol in the final 2roduct. The amount of hydrolysis can be determined by aci~-base titra~ion procedures in water or in suitable ~olvent systems.
A preferred composition of this invention is one in which the mono~ers of the first stage comprise ~; to ~5%
C -C alkyl acrylate, C -C alkyl methacrylate, styrene, or a mixture thereof~ 5 to 10~ acrylic acid, methacrylic acid, itaconic acid, or a mixture thereof and 1~ to 25~ hydroxy C -C
2~ alkyl acrylate, hydroxy C ~C alkyl methacrylate or a mix~ure there~f, by weight, and the mono~ers of the later ~tage pol~mer consist essentially of methyl me~hacrylater styrene, or a-mixture thereof. ~nother preferred composition is one in which the mer units of the first stage com-prise 5O ~o 85% vinyl acetate, 1 to 10~ acrylic acid, (~ .27338 ~

methacrylic acid, ltaconic acld, malelc acld (derivable from maleic anhydride) or a mlxture thereof~ and 8 to 25% vinyl alcohol, by weight, and the mer units of the last stage con~lst essentlally of methyl methacrylate, or styrene mers or a mixture thereof and 0 to 30%, preferably 10 to 20%, by weight acid, such as acryllc, methacrylic or itaconic, mers. It ls desirable that the acid component of the ~irst stage comprise up to 5%, based on the polymer weight, of maleic anhydrlde or maleic acid with 0.2 to 2 percent being pre~erred. In this usage, the term ~Imer~ means the unit, in the addition polymer, derived from the named monomer by ad-dition to the double bond.
In general the pre~erred hydrophilic monomers of this lnvention are monomers with a solubility of at least six grams per 100 grams o~ water, those with a solubility of at least 20 grams per 100 grams of water are more preferred and mosk preferred are those in which at least 50 grams o~ the mon-omer is soluble in 100 grams of water~ The first stage polymer contains at least 10% hydrophilic monomers, 10% to 70% being preferred, at least ~5% is more pref`erable wlth the range 25% to 35% being most pre~erable. Of the hydrophillc monomer content lt is desirable to have at least 0.5% be acidic groups7 such as carboxyl group, or basic groups~ such as amino groups, in either the unneutralized or neutralized ~orm. It ls also desirable that at least 10% of the hydrophllic mon-omer be nonionic, l.e. not loni~able,such as hydroxyethyl acrylate or methacrylate, or produce nonionic mer units such as these hydroxyethyl ester and vinyl alcohol mer units.
The last stage polymer is more hydrophobic and preferably harder than the ~irst stage. By more hydrophobic (~ 33~ ~

~s meant ~hat-the later stage polymer if polymerized alone is less water-swellable than is the first stage polymer.
By harder is meant that the ~odulus of the later stage polymer is greater than that of the first stage ~olymer S the measurements being conducted on polymer samples immersed in water. It is ~referred that the last stage monomers 7 _ 14 -~12~3~8 J

be monoethylenically unsaturated.
The internally ~lasticized poly~ers of the present invention are usually prepared by emulsion polymerization procedures utilizing a multi-stage or sequential technique.
~owever, they may also be prepared by a continuous poly-merization in which the composition of the monomers being fed continuously is changed, either ste~-wise or continuously, during the polymerization. In such a poly~erization any discontinuous change in the composition of the monomer feed may be regarded as a stage terminal. If there are no abrupt, or appreciably steeper than average, changes in the feed com~osition to indicate a change from one stage to another, one may regard the first half of the polymer feed as rep-resenting one stage and the second half as representing lS a second stage. In simplest form, the hydropbilic polymer is formed in a first st~ge and the hydrophobic harder polymer is formed in a second stage. Either of the polymers can themselves also be sequentially polymerized, i.eO
consist of multi~le stages. The monomers of the first 2a stage, together with initiators, soa~ or emulsifier~
~olymerization modifiers or chain transfer agentsr and the like are formed into the initial ~oly~erization mix and poly~erized, e.g., by heating, mixing, cooling as r~quired, in well ~nown and wholly conventional fashion until the monomers are subs~antially depleted. .~onomers of the second~ana~in turn of any additional stage are then added with ap~ropriate other ma~erials so that the desired polymeriza~ion of each s~age occurs in sequence to substantial exhaustion o~ the monomers. It is pre-3n ferred that in each stage subsequent to the first, ~he .~ , ,:

~;27;~38;

amounts of initiator and soa~, if any, are maintained at a level such that polymerization occurs in existing pàrticles, and no substantial number of new Particles, or ~seeds" form in the em~lsion.
When polymerizations are conducted in multi-stage, sequential ~rocesses, there can additionall~ be stages whi~
are, in composition and proportion, the co~bination o~ the two distinct s~ages, and which ~roduce ~olymers having ~roperties whiG~ are intermediate therebetween. The hydroPhilic first stage is preferably between 20% and 80%, more ~referably between 30~ and 70~ and most preferabl~ between 40% and 60%
of the tot~l polymer. There may of course, be lesser stages present before, between or after these two of princi?al interest. These other stages are always either smaller than the princi~al stage$ or can be considered a ~ortion of one or the other of the princi~al stages as indicated by their co~Posltion. It is preferred that the ~olymerizatlon be in two stages. Those skilled in a given art field will usually prepare a few internally plasticized poly~er latex sam~les differing in first to second ~tage weight ratio and s~lec~
the one with the best pro~erties for the given aPolication.
The equal weight rati~ is the starting point for t~ese trials whic~ usually consist of one higber and one lower ra~io with the s~read of the ratio being chosen by consideration of tbe final properties desired, ~.9., hardness, MFT, latex viscosity, tack-free time, etc.
The co~oly~er is preferably made by the emulsion copolymerization of t~e several monomers in t~e pro~er ~ro-portions. Conven~ional emulsion ~oly~eri~ation techniques are described in United S~ates patents 2,754,2S0 and 2,795,554.

~2733~ - ' Thus t~e mono~ers may be emulsified wit~ an anionic, a c~tionic, or a nonionic dispersing agent, about O.S% to 10~ thereof being used on the weight o~ total ~onomers. ~hen water-soluble monomers are used, the dispersing agent serves to emulsiy the other monomers. A Pol~merization initiator of the free radical type, such as a~monium or potassiu~
persulfate, may be used alone or in conjunction with an ac-~elerator, such as potassium ~etabisulfite, or sodium thio-sulfate. The initiator and accelerator, co~moniy referred to as catalyst, may be used in pro~ortions of 1/2 to 2~ eac~
based on the weigh of monomers to be copolymerized. ~he polymerization temperature ~ay be from room tem~erature to 90 C. or more as is conventional.
~xamples o~ emulsifiers or soaps suited to the polymerization process of the present invention include alkali metal and a.~monium salts of alkyl, aryl, alkaryl, and aralkyl sulfonates, sulfates, and polyether sulfates;
the corresponding phosphates and phosphonates, and ethoxy-lated fatt~ aclds, esters~ alcohols, amines, amides and alkyl phenol~. --Ch~in transfer agents, including mercaptans,~olymercaptans, and polyhalogen compoun~s,are often desirable in the ~olymerization mix.
~ no~her way of describing and defining the first and second stage monomers of this invention is by use oE
tbe solubility ~arameter conce~t. ~Polymer aandbook"~
2nd Edition, 3. 3randrup and E. ~. Immergut, editors ~John '~iley an~ Sons, ~ew York 1975) Section IV Part 15 entitled "~olubili~y Parameter Values" by ~. Burrell, on l~Z7338 pages IV-337 to IV-359, defines solubili~y parameter, describes how it is determined or calculated, contains tables of solubility parameters and gives further references to the scientific literature on solubility ~arameters. ~he solubility parameter is the square root of the cohesive eneregy density w'~ich in turn is the numerical value of the potential energy of 1 cc. of material, the potential resulting from the van der ~aals attraction forces between t~e molecules in a liquid or solid. Burrell describes a number of ways of cal~ulating solubility parametees from experimentally determined physical constants and two ways of calculatin~
the.~ from the structur~l formula of a molecule. T~e structural formula methods are.normally used whe~ the data for the calculation from physical constants are not available or are considered ~articularly unreliable.
Calculation Erom t~e structural formula utilizes tables of group molar attraction constants such as those given on ~age IV-339 in the ~andbook. The table of Small is preferred.
The ~olubility parameter conceot may be con-sidered an extension of the ol~ rule "like dissolves like~
recognized from the earl~ days of chemistrY0 A non-crosslinked oolymer will normally dissolve in a solvent of 3imilar solubili~y parameter an~ a crosslinked ~olymer will nor~ally-be-swollen by a solvent of similar solubility oarameter. Conversely, solvents with solubility parameters far fro~ those of ~he polymers will neither dissolve nor swell the ~oly~er. As ~iven by ~u~rell the _ 18 ~

-solubility parameter of polymers may be determined, among other ways, by measuring the swelling of the polymer in a series of solvents. Solubility parameter for polymers may also be estimated by calculation from the group molar a~traction 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. ~hose skilied in the - art have added the further refinement of classifying ~olvents as poorly, moderately and strongly hydrogen bonded.
It is found that the range of solubility parameter for dissolving a given uncrosslinked polymer differs fro~ one class to the next al~hough usually considerable overlap is observed. 8urrell's Table 4 starting on page IV-349 gives ranges of so~ubility parameters ~or poorly, moderately and strongly hydrogen bonded solvents used to dissolve a large num~er of polymers. In Table S starting on page IV-354, there is given solubility parameters of a number of polymers deter~ined by calculation and by other ~ethods.
To for.~ ths internally plasticized ~olymer system of this invention the first stage polymer and monomer~
of the later stage must be carefully chos~n so as to interact to an appropriate degree. There are both upper and lower limits to the degree of compatibility desired between the first stage polymer and the monomer charges of later 5second or last a~ hereinabove described) s~ages. It is found that the appropriate degree of compatibility may be expressed in numerical terms by a property b~sed on solubility parameter ænd herein named the interpenetration parameter, Ip. The 7338 t interpenetration p~rameter may be regarded as a solubility parameter adjusted so as to ~ut strongly, moderately and weakly hydrogen bonding solvents on the same scale. For a given molecule, the interpenetration parameter is defined S as the solubility parameter Plus the hvdrogen bondinq increment value given below. Solubility parameters of various molecules, lncluding a number of mono~ers, are given in Tables 1 and 2 of ~urrell starting on ~age IV-341. These tables also give the ~ydrogen bonding grou~ appropriate for the given molecule~ The increment values, a new teaching in this invention, are 17.2 for strongly hydrogen bonding mole~ules, 7.2 for moderate hydrogen bonding molecules and 2.8 for poorly hydrogen bonding moleculesO
The following table contains a list of monomers along with values of their solubility parameter, inter-penetration parameter and water splubility. ~lso ~iven is tbe hydro~en ~onding class appropriate or th monomer.
T~e solubilit~ parameter v~lues and hydrogen bonding class of most of these monomers are those given in ~able 1 of Burrell. ~inyl al~ohol is a s~ecial case because, as is w~ll known, this mono,mer does not have a stable existence. Polymers containing mer units corresponding to vinyl ~lcohol may be prepare~ by hydrolysis of a ~oly~er containing t'ne corresponding vinyl es~er, such as vinyl acetate, mer uni~. The solubili~y parameter o~ this hy~o-thetisal msnomer is computed by the method of ~mall as indicated above. Yalues for other monomers not in Burrell's table are determined or computed following the teachings ~ 20 -( ~Z73~8 ~n Burrell's writings v.s. Di~ensions for the solubility parameters given in the table are the usual ones, square root of ~calories per cubic centimeter). The inter~enetration parameter has the same dimensions. Water solubility is given in grams of monomer per 100 grams of water at 25 C.
~he hydrogen bonding class ~trong, moderate or poor is ascertained by using the ~ethod of C. M. Hansen, Journal of Paint Tecilnology, Vol. 39g p. 104-117 and 505-514 (1967).

Interpene- Water Solu~ility ~ydrogen tration Sol- Abbre-Monomer Parameter Bonding Parameter ubilitY viation Acrolein 9.8 S, 27.0 40 Acr.
Acrylic ~cid 12.0 S 29.2 CM AA
Acrylonitrile10.5 P`13.3 25-3~ A~
o-bromostyrene 9.8 P 12.6 BrSt 1,3-butadiene 7.1 P 9.9 Bd ~-bu~yl acrylate8.5 M 15.2 0.2 iBA
n-butyl acrylate8.8 M 16.0 0.~ BA
Butyl methacrylate 8.2 M 1~.4 0.01 BMA
Chlorostyrene 9.5 P 12.3 ClSt i-decyl acrylate8.2 M 15.4 0~01 iD~
Dichloroethylene9~1 P 11~9 0.01 DCE
~thyl acrylate8.6 M 15~8 1.51 Ethylene oxide11.1 ~ 18.3 CM E0 Ethylene epi- 12.2 S 29.4 EEPC
chlorohydrin Di.~ethylamino7.0 S 24.2 CM D~E~
~thyl methacrylate Dihydroxypropyl9~0 5 26.2 CM D~P.
methacrylate ~thylhexyl acrylate 7.8 ~ 15.0 E~A

Interpene- ~ater Solubility ~ydro~en tration Sol-Monomer Parameter Bondinq Parameter ubility Abbre.
Ethyl methacrylate B.3 M 15~50.1 E~A
l-hexene 7.4 P 10.2 . hex ~ydroxyethyl 8.0 S 25.2 qEM~
~ethacrylate Isoprene 7.4 P 1~.2 Ipn ~aleic anhydride13.6 S 300816.3(79) ~.~n Methacrylic acid 11.2 S 28.4CM ~AA
Methyl acrylate 8.9 M 16.15.2 ~A
~ethyl ~ethacrylate 8.8 M 16Ø 1.6 M~
C~ - methylstyrene 8~5 P 11.3 MeSt Styrene 9.3 P 12.1 ST
Vinyl acetate 9.0 M 16.22.3 ~c Vinyl chloride. 708 M 15.0 VCl.
Vanyl toluene 9.1 P 1$.~ Vtol (Vinyl alcohol) 8.4 S 25.6 (CM1 VOH
S - ~trong P - Poor M = ~oderate CM- ComplQtely Misci~le As maleic a~id ~L273~8 For a latex polymer of this ~nvention, the inter-penetration parameter o~ the first stage is greater than that of the second stage, pre~erably at least one unlt (calorle per cubic centlmeter) ~reater. However, the lnter-penetration parameter of the ~irst stage must not be toomuch greater than that of the second stage. The dlfference iR not more than 8 and is deslrably between 1 and 6 unlts.
When the first stage polymer contains 65~ or more, by welght, of Cl-C4 alkyl acrylate, Cl-C4 alkyl methacrylate, styrene or a mixture thereof, ik is desirable that the rlrst stage Ip be not more than 6 units greater than that of the later stage wlth a difference of 1 ~o 4 units being preferred and 2 to 3 units most preferred. When ~he first stage polymer contains 50% or more, by weight, of vinyl acetate it is desirable that the first st~ge Ip be 1 ~o 8 units greater than that of the later stage with a dlf~erence or 2 to 6 unlts being preferred and 4 to 5 units most preferred. It should be appreciated in this context that the second stage or the later stage may con-kain some hydrophillc monomers and still conform to these rules for the difference between the interpenetra~ion para-meter of the first stage and that o~ the second stage.
~; In a preferred embodiment of this lnvention, the flrst stage contains acldic, preferably carboxylic, mer unit3 2S well as other hydrophilic mer units. The carboxyllc mer units are preferably obtained from the monomers acrylic acid, methacrylic acid or itaconic acld. The other hydrophilic mer unlts are prererably hydroxy Cl~C4 alkyl methacrylate, hydroxy Cl-C4 alkyl acrylate or vinyl alcohol unlts.
The viscosity of the polymer emulsion produced ls mea~ured by any o~ the procedureR known to those skilled ~ 23 -3~L;2733~ t in the art. Preferably there is em~loyed a arookfield ~ynchro-Letric viscometer mod~l L~ 1 with ~reference in choice o~ s~indle and s~eed being given to the combinations wbich will result in a mid-range reading. Measurements, at~

.,~ / .

~lZ7338 20 C, are made at pa values in the range of 3 to 10 on emul-QiOnS adjusted, with water, to 20~ solids content. The pH
of acid-containing copolymer emulsions is generally adjusted by the use of a ~ineral base, an organic base, ~uch as an amine, or ammonia with the latter being pre-ferred. Internally ~lasticized polymer latices containing bas~c groups, such as amine groups or quaternary am.nonium groups, have their pa adjusted by the use of mineral acids, such as hydroGhloric acid, or organic acids such as a~e~ic a~id. The latex viscosity, over the pa range 3 to 1~, is generally below 5,000 centipoises, better still below `~ 500 centipoises, better still below 1~0 centipoises, better ~till below 40 centipoises, and most preferably below i3 ; centipoises; the lowèr values being particularly desira~le for certain ap~lications, such as floor polishes.
The minimum filln temperature (;~F~) is determined on a film cast from the latex at 20% solids and a pH
normally in the range between 7-1~2 and 9 for a~monia-neutralized, acid-containing polymers and in the neighborhood of 3-4 for acetic acid neutralized base containing poly~ers. The procedure of T~e ~merican ~ociety-for Testing ~aterials method ~2354-68 i5 followed. The o ; ~FT is more than 5 C~ below the calrulated glass transition ~ . o ~ temperature ~Tg) of the`~olymer when the Tg is above 5 C.
o Preferred are MF~s below 18 CO with polymers having a Tg calculated for the entire polymer composition of greater o than 25 C. The term MFT, as used herein to defin~ certain polymers, refers to the value determined on a latex at the ~ 7338 i pH and solids given above in this paragra~h. In some of the exam~les hereinbelow, MFT values determined under other conditions are given only for comparison purposes and ~re not the MFTs used in deEining the oolylners o~ this invention.
S Hardness is expressed as ~noop Hardness Number ~XHN~ deter~ine~ by means of the Tukon Micro-hardness Tester on a film for,~ed by casting the latex on a ~olid substrate such as a glass panel. It i5 preferre~
that the polymers have a KHN greater than 3 with grea~er than 5 being ~ore preferred and ~reater tnan 8 most preferred.
The calculated Tg of each stage and that of the overall polymer is determined by calculation based upon the Tg of hoinopolymer~ of individual mono~ers as described by Fox, Bull. Am. Physics Soc. 1, 3, page 123 ~1956).
lS Tables of the ~g of hompolymers are ~iven in ~Polymer Handbook" 8eotion III, Part 2 by W. ~. Lee and ~
Rutherford. The desired calculated Tg of the firs~ stage o o ~S 12ss than 40 C wi~h less ~han 5 C. being preferred and less than -1~ C. being most preferred. The desired calculated Tg of the second stage is greater than 35 C, with greater than 75 C. being preferred and greater than 1~0 C. being most preferred. The calculated Tg o~ ~he polymer based on the overall poly~er co,npositio~ is preferably o o grsa~er than 20 C. with greater than 30 C. being preferred for-~loor polish and similar uses. For so~e other uses, such as adhesives, binders and paints, polymers with calculated Tg values below about 40 C, including 8ubzero values, are suitable.

~127~
.

The internally olasticized oolymer e~ulsions of this invention have a noteworthy co~bination of oroo-erties esoecially (1) low minimum fil~ temperature couolëd with high hardness and high Tg; and (2) low polymer emulsion viscosity even when neutralized. Thus, comoaratively hard latex polymer systems can be used ~it~ much less coalescent than usual, or no ~oalescent ~t all. This utility is oarticularly v~luable in situations ~ in which the coalescent gives rise to secondary disadvantages. 10 ~ecause of the absence or minimization of added coalescent in the formulation, coatings whicb develo~ hardness at very high rate can be ~ade ~rom the Polymers o~ this invention. Furt~er advantages i~lied by the elimination of added ?lasticizer, coalescent or organic solvent are lowering of the cost, reduced fla~mability auring the ~rocessing and decreased emission of toxic and ~olluting vapors during and following ap~lication. These proPerties are o~ ~artic~lar i~oortance in the ~ormulation and use o~ ~ater based in~ustrial c~atings, both clear and ~i~mentedO
In ink technology, the extremely ~ast drying and non-flammabillty advantages of internally plasticized oolymers are of great im~ortance. In trade sales coatings, the co~bination o~ high hardness and low ~inimum fil~ te~oerature ~akes for a block resistant air ~rying ~oating. ~ Eurther advantage of the latex of this invention is ~hat formulation i~ very easy, wh~ch results in a considera~le cost saving, because of the fewer ingredients and the ease o~ mixing in the olant ooeration. T~e ease of ~ixing ~robably results from the latex made by ~his invention being resistant .

}
l~Z73~

to the so-called "shocking~ ~eno~enon; that is, t~e latex is not easily flocculated or gelled when mixed with another component o~ the for~ulation. Thus, ingredients usually may be mixed in any order in the usual plant equi~ent S and, in addition, the equi~ment itself is left in a much cleaner condition than with ordinary latexes.
As described above, the poly~er latexes of this in-ention are particularly useful to r~lace the latex plus ~lasticizer or latex lus coalescent systems which ~omprise a number of formulations used in a wide variety of apelications for Polymer latexes. These latexes are useful in for~ing free fil~s as well as in fotming coatings ~uch as in paints, lacguers, varnishes, powdered coatings, - and the like. The late~es o~ this invention are also useful as im~re~nants and adhesives for both natural and synthetic materials such as paDer, textiles, woo~, plastics, ~etal and leather and as binders or nonwoven fabrics. They may be used to lower the ~ini~u~ ilminq te~perature or to aid in film formation Oe other latex systems when used in combination therewit~. ~ig~ents, dyest fillers, antioxidants, antiozonants, stabilizer~, flow control agents, suractants or other or,tional in-gredients may be included in the ~oly~er comoositions of th~ invention.
The polymer co~?ositions of this invention can be ap~lied with or wit~out a solvent by casting ~ermanentiy o~ removably onto a sui~able ~ubstrate, par~iculasly for use as coatings, fillers or adhesives. ~p~lication by b~u hing, elowing, di~ing, s~raying and other mPans L;Z733~ ~

known in the various art fields may be used to aD~l~ t~e latex of this-~nvention. One of the Particular advantages of the present invention is that reactive polymers can be prepared ~or use as air cured or thermally cured coatings, S fillers or adhesives without requiring organic solvents, ; coalescents or olasticizers although s~all amounts Oe these materials may be desired. T~is is ~articularly valuable for eli~ination oE volatile solvents or other volatiles, such as coalescents, decreases a ~otential e~ological ~azard.
It is of especial i~oortance t~at the acid grol~s, hydroxyl grou~s, or other functional groups incorPorated in the first stage of the ~oly~erization are available for fur~er reaction suc~ as neutralization or crosslinkin~.
lS This availability distin~uishes the internally ~lasticized ~oly~er latex from a latex in w'nich a second or later stage so coats or interacts with t~e first st ge as to decrease or eli~inate the availability of first stage unctional grou~s for su~se~uent reactions. ~he crosslin~ing referred to may be by any of the usual ~eans, suc~ as coordination crosslinking, ionic crosslinking or the for-mation of covalent bondsO In genetal, the reactions of these latices may be ionic or covalent reactions. Ionic reactions ~re illustrated by the ionic crosslinking in the a~pli-cation o~ t~ese latices to ~loor ~olishes as taught below.The fsrmation-of covalent bonds by reactisn with a~inoolasts, e~oxies, isocyanate~, beta ~droxyeth~l esters and t~e like are well known in the art.
T~e polymer latexes of t~e oresent invention are par~icularly useful in ormulating floor polish and 2g -~ ( i ~27338 are advantaqQusly used in the floor oolishes ta~ by Zdanowski, U.S. Patent 3,328,325 issued June 27, 1967; by Fiarman, U.S. Patent 3,467,610 issued September 16, 1969;
and a second invention of Zdanowski disclosed in U.S. Patent 3,573,239 issued Narch 30, 1971.
In general polishing compositions using the polymers of the present invention can be defined ln ; terms of the following proportions of the main constituent-,:
Constituent: Pro~ortion (~) Water-insoluble internally plasticized addition polymer, parts by weight........... 10-100 (B) 'flax................................ do..... .0- 90 (C) ~lkali-soluble resin................. do..... .0- 90 (I)) ^~etting, emulsif-ying and disper.sing agents............................ percent. 0.5-20 (~) Polyvalent ~etal com~ound......... ~.. do..... .0- 50 5F) Water to ~ake total solids 0.5~ to 45%, preferably 5 ~o 30%.
(~3 ~s in weight ~ercent on weight of ~+a~c (~) is in weight ~ercent on weight o~ A.
The total of A, ~ and C should be 100. The amount of C, when present, ~ay be u~ to 90~ of the weight of the cooolymer of A, and preferably from about 5% to 2~% of the weight of the co~olymer of ~.
For a nonbuffable, self-polishing com~osition7 the ~ax should not be over 35 parts by weight, preferabl~
0 to 25 parts by weight in 100 parts ~otal of polymer plus wax according to the above table. Satis~actory non-buffable floor polish formulations have been Prepared wit~-out t~e inclusion of a wax. Thus wax is not an essential ( 33~3 component of a seif-oolishing com?osition. For a dry buffa~le polish composition, the wax should be at least 35 ~arts by weight on such total. ~xamples of wetting and disPersing agents include alkali metal and a~ine salts of higher fatty 5 acids having 12 to 18 carbon atoms~ such as sodium;
potassiu~, am~onium, or morpholine oleate or ri~inoleate, as well as the com,~on nonionic surface active agents.
~dditional wettin~ agent improves the spreading ~ction of the polish.
For polishing floors, the coating obtained from the com~osition ~referably has a '~noo~ hardness nu~ber of 0.5 to 20 when measured on a film thereo~ 0.5-2.5 mils thi~k on glass. This range o~ hardness Drovides good resistance to abrasion and wear and can be obtained by the 1~ approPriate selection of ~onomers to be polymerized.
The follo~ing exam?les, in which ~he parts and percentages are by weight unless other-~ise indicated, a~e i~lustrative of tne inventionO

Example 1 ~ Preoaration of Internally Plasticized Poly~er ~mulsion A latex ~ith f irst stage, second ~tage and avera~e 1q o o o values of -14 C., 105 C., ar.d 34 C resoectivelv, is Pre-~ared as follows~
uipment ~ five liter, four-necked flask is e~ui~ped with a condenser, stirrer, thermometer and monomer addition pumps. ~eating, cooling and nitrogen sPargin~ facilities are provide~.

.

~273~

. ~at~rial Charges Xettle onomer Char~es Raw Material Char~e ~1 ~2 Water 2008 9 4Q0 9 400 . Sodiu~ lauryl ~ulfate ~sur~actant) 16 2 2 Butyl acrylate (BA) - 600 ~et~yl methacrvlate (~MA) - 140 1~00 Methacr~lic acid (M~A) - ~0 ~ydroxyethyl methacrylate (HE~A) - 212 So~ium Persulfate in 1~0 9 ~ater (catalvst) 12 -C. Proce~ure :15 1. ~dd kettle char~e water and surfactant to the kettle and st~rt agitation and nitroaen soarge.
2. Combine the ~aterials Oe each o~ the mono~er charges and thoroughly mix to create stable monomer e~ulsions.
- 20 3. ~eat tbe kettle to 8~-~4 C~ witb continued agitation and nitrogen sparging.

4. ~dd the catalyst solution to the kettle an.1 start the addition of monomer char~e #l at such a rate that the addition is co.n~leted in about 50 minu~es. ~ain~ain t'ne temper~ture at 82-34 C.
throughout ~he polymerization.

5. When .n~nomer charge #l addition is co~?leted hold for 15 m~nutes at 82-~4 C.

6. ~fter the hold ~eriod sta~t the addi~ion of ~ono~er charge ~2 at such a ra~e t~at the addition is _ 32 -~73~8 co~leted in about 50 minutes. ~aintain the o temperature at 82-84 C. througho~t the ?olymerization.

7. When monomer charge #2 addition is co~leted, hold for 30 minutes at 82-84 C., t~en cool and filter.
A sample of the latex is neutralized to a vH of 9 with O
ammonia; the MFT is below 15 C. and the viscosity is 15 centipoise t~rookfield Viscosity; 20% solids). A film cast from the neutralized latex has a hardness of 12~ gN.
; Exam~le 2 - Sequential Charqe Ratio ld Following the general procedure of Example 1 three internally plasticized polymer latices are prepared having the same first and second stage compositions but differin~
in t~e Eirst to second stage weight ratio.
It is found t~at the property balance, low MFT
lS and simultaneously ~ow viscosity emulsion, is sensitive to th2 weight ratio of the hard hy~rophobic second stage charge to the soft hydro~hilic first stage chargeO T'nus, in a given monomer com~osition field, a few experiments ~ay be needed to determine the charge ratio required for the product of this invention. Table l shows the effects of c~anging th~ c~rge ratio, Exa~le 23 having a low ~FT, low viscosity w~en neutralized and a high Tg.
It i~ seen that Exam~le 2B is a latex polymer of this invention whereas the Example 2A is much too high in viscosity 25 at pH 9 and 2C is too high in klFT.

_ ~3 _ `\ .

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I
. c b Cb O

b~¦ ~ 1~ 0 0 0 U O
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V ~ ~ .
~ ~ ~q Z i~ ~ a I

~ ~ . , r ~ Cb S: L
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~.~ z733~

ExainDle 3 - Polyme{ization Process The difference ~etween a single emulsion co~oly~er, an internally plasticized polymer and a physical blend of two polymers is seen in the data in ~able II. ~11 of S the polymers were ~repared by emulsion polymerization following essen~ially the procedure of ~xa~ple 1 except for t'aere being no second charge in the pre~arations oF
Exa~nples 3A and~3~. The overall com?osition of each of the three examples is the same; the calculated Tg is 47 C.
- T~3LE II

Polymer Composition BA/MM~/~A~ T/Viscosity lS Exam~le ~MA//M~A Description p~ 3 ~H 9 3~ 23/S6/~ //0 single charge, 52/3 46/55 simple copolymer 3B 23/~/~/15//50 internally plas- 40/~ 10/140 ticized polymer a 3C 23/~/6/15//50 physical blend 10/10 10/
gellation a Physical blend 50:50 of (BA/MMA/M~ E~A: 46/12/12/30) and (~MA: 100).
The polymer of Exa~ple 3B i5 the same as that o~ ~xa~ple 2B.

It is seen, in Table II, that the single charge polyner Example 3~ has an MFT in the neighborhood of the calculated Tg. The physical blend, i.e. Xxa~?le 3C: a blend of an e~ulsion having the co~position of the first stage of tne ~a~ple 3B polymer with one naving the second stage 3~ co.nposition, is so viscous a~ high P~ that the emulsion gels even when diluted to 20% solids before p~ adjustment.

,2733~' Note that neutralized to a p~ of 9 the internally plastici~ed polymer has a much lower ~FT and only a moderat21y nigher viscosity than the single charge copolymer.
Exam~le 4 - Balance of ~ydrophile/~Ydrophobe Character of Stages Using the polymer emulsion of Example 2B as a control, the co~positional relationship between the ; water-s~elled first stage polymer and that of the second stage is varied. Interaction of the first stage polymer with the second stage is sho~n by achievement of internal plasticization, with controlled viscosity, by sequentially charged (1) soft, hydrophilic and functionalized and (2) ; hard and hydrophobic copolymers. This internal plasticization is demonstrated to depend on the balance of hydrophobe/
1~ hydrophile character of the two monomer char7es by the data in Table III.
T~3LE III
Tg MFT/Viscosity Exam~le Composition (1) (2) Avq. ~ 3 pH 9 4A* ~A/.~IMA/MAA/~E~A//MMA 4 10047 40/ 1~/
~3/~/~/15//50 ~ 140 43 BA/~MA/t~lAA/~EMA//~MA -13 1053~ 30/ 10/
2g/0/~ //S0 1~ 70 4C EA/~AA/H~ A//MMA 14 105 S3 55/1~/
2~ ~9/~/15//50 1~140~
4~ BA/MMA/MAA/HE~A//~T 4 100 4620/ 10/
22.5/6.5/6/15//53 1030,00-3 *The polymer emulsion of Emulsion 4A is the same as that of Example 2B.
The results, in Table III, show that vs. ~xample 4A a more hydrophobic, i.e. less hydrophilic, first stage -oolymer is good, 4~; a more hydrophilic first stage, 4C, leads to nigh viscosity; a ~oo hydropho~ic second stage, 4D, leads to X

1~;Z73;3~3 very high viscosity at high pH, too 'nigh for most uses.
~xample 5 - Interpenetration Parameter Emulsion polymers of a num~er of compositions, differing in interpenetration parameter (Ip) of the two stages, are prepared by the procedure of Example 1 or Example 8 (Examples 5E, 5I and 5~ eterminations of the ~mulsion vi~cosity and MFT, done on the emulsion neutralized to a pH in the range 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 for~ed internally plasticized polymers. Tables IV.A and 8 present these data.
TABL~ IV.A
Example Composition Ratio 5A BA/MMA/MAA/H~MA//MMA 23/6/6/15//50 5B BA/MMA/MAA/~EMA//MMA 30/7/3/10//50 5C BA/MMA/MAA/HEMA//MMA 30.5/9/3/7.5//50 SD BA/MMA/MAA/~EMA//MMA 34.8/3.4/4.3/8.5//43 5E EA/VAc/VO~/MAn/AA//ST 5~5/37.8/5.6/0.4/0.7//50 5F BA/M~A/MAA/DHPMA//MMA 25/11.5/6/7//50 BA/MMA/MA~/VAc/VOH//M~A 23/6/6/13.5/1.5//50 5'~ BA!~MA/DMAEMA//MMA 18/17/15//50 5I EA/VAc/VO~ T 24/23.3/2.1//50 5J BA/MMA/MAA//ST/AN 25/21.5/3.5//30/20 5K BA/MMA/MAA/HE.~A//ST 22.5/6.5/6/15//50 5L MMA//BA/MMA/MAA/~EMA 50//2.3/6/6/15 5M BA~VOH/VAc//M~A 24/2.1/23.9//5U
5N BA/MMA/MAA/~HPMA//M~A 25/11.5/6/7.5//50 BA/MMA/MAA/~EMA//MMA 30/7/3/10//50 5P BA/MMA/MAA/~EMA//MMA 30.5/8.25/3.75/7.$//50 5~ B~/M~A/MAA//ST/AN 25/19/6//30/20 ~'~ 5R EA/ST/MAA//ST 21/24/5//50 " : ~

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l~Z733~

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~38-1~2733~3 ~

~otes for Table ~V.B
l. Viscosity is measured on the latex, 2~
solids brought to a p-d of 9 with ammonia . except for Example SH whic~ is at pH of ~ . 3 with acetic acid.
2. MFT, in degrees Celsius, latex supplied . at 20% sol ds and pH 9 with ammonia exce~t Example 5,1 (PH3 as above).
3. Hardness is expressed as ~noop dardness Number (-~H~1 determined by the procedure given in Resin Review, Vol. XVI, No. 2, p. 9 ff (l966), a publi.cation of the.Rohm and ~aas Company.
4. Tg i~ calculated for a high poly~er by the l~ . procedure of Fox, v.s. ~(l) n and ~(2) n re~-resent first and second or later stage and ~vg. n the value calculated for the co~-position as a whole.
S. Ip is calculated for the first stage ~l) and the second stage (2). The difference between these I~ values is tabulated under 2)~.
The data in Table IV.~ show that an internally . plasticized poly~er is obtained, as indicated by the glass 2~ transition temperature, minimum film temperature, emulsion viscosity and h~rdness values, when the interpenetration parameter value of ~he firs~ stage polymer is greater than that of the second but no~ too much greater. Example 5J, a polymer latex of the prior art, is not one of internally ; 39 -:`

plasticized particles as e~idenced by the proximity oE the Tg and the MFT. ~s indicated in Table IV, A this ~olymer ha~ only seven percent hydrophilic met units in t~e first stage polymer. Example 5K is not of internally plasticized particles of this invention as evidenced by its high viscosity;
as indicated in Table IV, B its composition is such that an undesirably high difference in the Xp exists between the polymers of the two stages. Example 5~ is not of this invention, its viscosity is so high a gel forms; note that the Ip difference between the polymers of the two stages is too low, it is below zero. Exa~ples 3~2 and 5R, ~olymer latexes of the prior art, hav~ MFT values above their Tg values; neither contains nonionic hydrophilic monomers in the Eirst s~age.
li Exam~le 5 - Floor Polish A floor polish is prepared by mixing ingredients in the following recipe (except Exam~les ~A and 6E as noted below):
~ole Material Char~e Vehicle ~olymer emulsi~n -- 15% solids 190.0 par~s Wax Poly ~M-40 - 15~ solids 15.0 parts ITrademark, Cosden Oil & Chemical Co.) Wetting aid Fluorad FC128 - 1~ solids 0.5 parts (Tradelnark, 3M Co.) Leveling Tributoxyethyl ~hospha~e - 0.5 parts aid 100~ active gefoamer SWS-211 ~ 504 solids (Trademark 0.~1 parts Stauffer Wacker Silicone Corp.) ~ase ~mmonia - 10% aqueous to pH ~
The floor polish is a~plied and tested by the procedure described in detail In Resin Review, Volume XVI, iTo. 2, 196O pub~ished by Rohm and Haas Company, Philadelphia, 73~B

Pennsylvania 19105 except when another procedure ls specified. eolyrrler emulsions used an~ the test results obtalned are in Table V.A and V..B.
TABLE V.~
S Exam~le 6A 6~ 6C 6D 6E
Polymer emulsion (note 1) Ex. 2B Ex. 50 Ex. 5P Ex. 5E
tnote 3) (note 4) Test(note 2) Visual gloss One coat g-vg vg vg vg g-vg Two coats vg vg-exc. vg-exc. vg-exc. vg Leveling One coat exc. excO exc. exc. exc.
Two coats exc. exc. exc. exc. exc.
- 15 60 gloss(~M 3~ 71 82 79 80 77 ~eel mark ~esistance(~rM i) vg-exc. g-vg vg vg-exc. fair Water resistance(TM 4) One hour good exc. exc. exc. exc.
?0 One day g-~g exc. exc. exc. exc.
Oeter~ent resistance(T~ 6) One day . vg good good vg --Three days vg-exc. -~ - fair Seven days vg-exc. vg -vg~exc. vg-exc. --Removability(~ 71 vg exc. exc. exc~ fair Static coeff.
of friction(Tff 1) 0.5 0.6 0.6 0.6 --- Powd~ring~TM 2) slight nil nil nil --Notes for T~BL~ Y.A
30 1. Example 6~ is illustrative of the state of the art.
It employs a floor polish polymer emulsion havin~ 1.65%
zinc ion crosslinkerl This polish is prepared by mixing ingredien~s in the follo~ing recipe:

7~8 ~ ~ `

Role Materaal Char~e Vehicle BA/MMA/MAA co~olymer e~ulsion 80 parts - 15% solids Wax Poiy EM-~0 - 15% solids 1; ~arts (Trademark t Cosden Oil and Che~ical Co.) Alkali Solu- low molecular weight all acrylic resin bl~ Resin - 15~ 601 ids 5 parts Coalescent diethyleneglycol monomethylether 4 parts Plasticizer dibutyl phthalate 1.0 part Wetting aid Fluor~d FC-12~ 1% solids 0.4 parts . ~Trademark, 3M Co.) Leveling aid tributoxyethyl phosphate - 10~% active loO part Defoamer SW~ 50% solids 0.01 parts 1~ (Trademar~, StaufEer Wacker Silicone Co.
2. ~pplication of the floor polishes is described in AST~ ~ethod D1435-64, Metbod B. (ASTM - ~merican Society for Testing ~aterials, Philadel~hi~, Pennsylvania).
Test methods, identified in brackets, are listed below.
3. Example ~D is for~ulated with 1.25~ zinc ion on emulsion poly~mer solids.
4. The recipe for the poli~h of Example ~E differ from that for 6B, C and ~ in the omission of wax and defoamer and ~he addition of 2 p~rts of coalescent, diethylene-glycol monomethylether.
~est :~ethods for TA~LE V.A - given in brackets in the table.
1. Sli~: ~ST'l~ method ~2047-72; panels conditioned at 2~ C.
- and 55% rela~ive humidity.
2. Powderingi -ASTM me~hod D2043-69~
3~ 60 9105s: ASTM methood ~1455-54 - Vinyl ~ile (~entile No. R-44, Rentile Fl~ors, Inc.) substituted for OT~A
tile in this test.
-~2-~ ~.;Z73~8 4. Water resistance: ASTM method ~1793-~5, dyna~ic test peocedure.
i. ~ubber heel mark resistance: CSM~ method 9-73 (Chemical Specialties Manufacturers ~ssociation, Washington, ~.C.), test modified by rotating 1~ minutes in each direction.
6. Detergent resistancD is run on black vinyl asbestos tilD
using 10 ml. of 5% aqueous Forward (trademark S. C.
Johnson) detergent, running 50 cyclPs in the one day, 7; in the three day and 100 cycles in the seven day tests.
7. Removabili~y is run for 75 cycles using 10 ml~ of 3%
Spic and Span (trademark Procter & Gamble) and l~
aqueous am~onia9 on black vinyl asbe~tos tile.
- Wear tests are carried ou~ in a corridoc having a vinyl as~estos tile floor whic~ i3 subjected to a daily trafic load of 3,500 to 4,000 ped2strian passes. ~ section of the cocrido~ (10 feet wide by 24 feet long) is cordoned o~f and stripped of residual ~olish and repolished in the typical janitorial procedure, a follows:
The floor dust .~o?ped to remove loose dirt, a 1:1 aqueous solution o~ com~ercial stripper solution, Step-Off (3. C. Johnson & Sons, ~nc., Racine, Wisconsin 53404) is applied by string ~op at a rate of ca. 1,000 square feet/gallon; after a 5 m;nute soak period~ the floor is scrubbed with a 16 inch black stripping floor pad (3M Co~pany, St. eaul, Minnesota 5~101;"Scotch Brite"*
Slim Line Floor Pad #51-~520-0105-0) on a 300 rp~ floor ~achine ~Mercury Floor Machines Inc., Engl2wood, ~ew Jersey, model H 15-c); the stripped flooe i.s thoroughly cinsed twice by damp moppi.ng ~ith clear ~atec, and allowed * Trademark 33~3 to dry. The strippe~ floor is divided into 6 foot sections perpendicular to the nor~al direction oE corridor traffic ~low. To each of these sections a coat of the polish to be tested is ap~lie~, with a string mop, at a rate o~
ca. 2,000 square feet/gallon. After allowing-one hour or the initial polish to dry a second coat i5 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 1~ the procedures used in obtaining the Table VoA~ data, are in Table V.B~
T~aLE V.B
Exam~le ~ 6B 6C 6D
Initial:
1~ Gloss (visual) vg vg vg+ vg+
heveling exc exc exc exc Recoatability exc vg-exc vg-exc exc One week traffic:
Gloss (visual) g-vg vg ~g vg~
~irt Qicl~-u?
resistance exc exc exc exc alack heel mark resistance vg-exc vg vg-exc vg Scuff resistancevg-exc vg+ vg-exc vg 2~ Two week traffic:
~105s ( visual) good good good+ good~
Dirt pic'~-up --zesistance vg vg vg vg-Black heel mark 34 resistance vg vg- vg vg Sc~E~ ~esi3tanc2 g-vg g-vg- g-vg g~vg ~z~

The abbreviations used in Tables V.A and Y.~ are:
exc = excellent; vg = very good, g = good ~ = plu3;
- = minus except when used between abbreviations, where it means nto".
Exam~le 7 - Lacquer and Paint The polymer latex of Example 1 is formulated ~s follows:
~xamPle 7~: Adjust the 40% solids latex to p~ 9 with 14% aqueous ammonia.
E~ample 7B: To 100 parts by weig~t of the latex, adjusted to pH 8.5 with 14% aqueous ammonia, is added a mixture o~ 9.7 parts of water and 15.3 parts of butoxyethanol.
~xample 7C: The ingredientc are mixed as follows:
Parts by Weight Water ; . 4.7 Ta~ol 165 (22% aqueous) 1~3 Triton CF-l~ (100~) 0.16 Nopcv NXZ 0.05 Zopaque RCL-9 (TiO 2igment~ 18.8 Grlnd on high speed di~perser (4,000 ft/min.) for i~ min. and letdo~n under agitation ~ith:
Polymer latex 70.4 Water 1.~
8utoxyethanol 2. a TOTAL 100.0 Trade~ark, ~ohm and daas Company, Philadelonia, Pa.
Trademark, Diamond Shamrock Chemical Company Trad~mark, Glidden-Durkee ~ivision, SCM Corooration I' ' 'i llZ7~

~ey lacquer and paint ~roperties are determined by followin~ the-usual paint industry procedures. Results of the determinations, on films made from the formul~tions by coatin9 ,netal sheet3, ace in Table VI.
T~LE VI
(1) Pro~ert~ Ex. 7A Ex. 7B Ex. 7C
~ry to touch/tack free time (min. at 25 C and 40~ R.~.) 19/21 Air dry hardness Krl~ 1 hr.
at 2~ C and 40% R.H. 6.5 ca. 1 Ultimate 'nardness KHN 6.5 6.5 (baked 3~ min.) ~ot print (oO C/lo hr./4 psi) ~baked 2~0 F/~0') none nonev.sl.trace i~and~el fle~ibility (1.5 ~il/
10~0/1 hr. at 250 F) ~ , 1/4, 1/8 inch blends)0/1/1 //1 //7-8 Itmpact In-LD (~/R) ~lodinei~ (2) 1200S* 5~/16 T-Bend ~ _ ~

20 Water Soak (1~ hr. at 100 F) moderate moderate moderate rust, no rust, mod rust, mod blisters blisters blisters Cleveland ~ondensing Cabinet sl. rust, tlo hours at 40 C) no blister~
Che,~ical aQd stain resistance:
~lcohol (lo hours) modera~e ~oderate ~oderate at~ack at~Ack at~ack Ink (30 minutes) no a~tack Mustard (30 minutes) no attack 3~ Lipstick (3~ minutes) no attask Gasoline (30 min.3 slight sl. ~osl. to attack Imoderate moder~te attack attack ~esults det2r~ined on 1.5 mil thick films baked 1 hour 3~ at 250 F. for ~iln te-ts unless other condition3 are noted.

~ir dried films have values of 2/1.
f. trademark ~6-~L1273~8 The data in Table VI.A indic~te ~hat the ~xaln?le 7A latex d~ies'very rapidly to full hardness,' to for~ a ` film which is both hard and flexible, without the aid ' of a coalescent. Coalescent slows hardness developnent S and has a deleterious effect on some resistance properties.
Baking is required to maximize certain properties. T~e resistance prooer~ies are good in general although water soak and alcohol'resistance results are not as good as the other results.
Example 7C shows that the latex of Exa~ple 1 can be e~nployed to for~ pig~ented Eilms wit'n comparati~ely little coalescent. The p~ysical properties of the film or~ed parallels that of the unpigmented film. Other tests on the film formed from Example 7C indicate:
' 15 moderate rustin~ of-a sa~ple exposed five days in a humidity cabinet, signs of failure aftee three days in a salt s~ray oabinet and a c'nange in gloss after 32 hours at 38 C. in a Cleveland Condensing Cabinet a5 ~ollo~s: -o o o Initial (20 /60 ~80 ) gloss S4/77/8~
o o o 2~ Final (20 /6~ /80 ) gloss 21/60f72 Example 8 - An ~nternallv Plasticized Polymer Emulsion ased on Vinvl Acetate ~ latex, wit'n ~irst stage, second stage and average Tg values of 25, 100 and $~ degrees CelSius re~pectively and Ip values of 17.5 and 12,1 for the first and second ~t~ges respectively, is prepared as follows:
A. ~g~
A five liter, five-n2cked flask is equip~ed wit~
a condensor, an efEicient agicatDr, a thermometer, addîtion 3~ unnels and heating, cooling and nitrogen spar~ing facilities.

1~273~

3. Material Charges Mono~er Charge ~ettle Raw ~aterial 1 1~ 2 Charqe deionized water16~.3g 154 9 883.7g S octylphenoxy Poly (39)ethoxyethanol3.4 5.1 1.7 ~bex 18S (33~) (T~ ~lcolac Inc)8.5 12.8 4.3 sodium dodecylbenzene ~ulfonate (23~) 6.8 lQ.2 3.4 ethyl acrylate 37.B - 19.1 vinyl acetate 298.5 .- 150.8 s~yren~ - ~17.5 maleic anhydride4.1 1~- acrylic acid - 7.2 ++
Initiator: ~e (0.15~ FeSO .6~ O) 5.4 ml 0.26g ammonium persul~ate (hP~) in 8g WatQr.
0.26g sodium sul~oxylate for-maldehyde in 8g water.

Catalyst: 1.929 ~PS and 0.32g t-butyl hvdro-oeroxide (tB~P) in llOg ~ater.

~ctivator: 1.92~ NaHSO in llOg water.
.. _ 3 Chaser: 0.52g tBHP in 5g water.
0.39g sodium sulfoxylate for.~aldeht~de ~n 5g water.

C, Procedure Th~ .~ono~er charges and ke~tle char~es are weigbed separately and each is ~ixed to form an emul3ion. The initiator mix is ore~ared and charge~ to t~e kettle. Efficient kettle stirring is maint~ined throughout the entire reaction ~ 48 -3;~8;

sequence. The hea~ of reacti~n drives the kettle o o temoerature from 22 C to a maxi~um ~ca 50 C in ca. 7 ~in.).
A~ the temperature-maximum, monomer c~arge 1 addition 15 begun at a rate of 13 ~l/~in and addition o.f the catalyst solution and activator solution is ~egun as ~eparate ~eed streams at a rate of 1 ml/min. The reaction te~perature is maintained at ca. 62 C throu~houtO
When one half of the mono~er charge 1 addition is co~?leted (ca. 22 min) charge 1~ is ~ixed with ~he re~aining monomers of charge 1 and the addition continued. ~fter about 45 .~inutes this monomer charge ~1 + 1~) ~ddition i3 com~leted and the kettle contents o are maintained at 52 C for 15 ~inutes. ~ono~er charge 2 addition is then begun at a rate of l3 ml/min. This 1~ second addition is ~completed in about one hour and the kettle contents are maint~ined at 52 C ~or 10 minutes while t~e catal~st and activator char~es are o .
com?leted. The reaction ~ixture is bald at ~2 for an additional 15 minutes and then allowed to cool to 55 C. The chaser is now char3ed ra~idly, and the reaction mixture ~aintained at 50-60 C for 15 minute,.
The ~roduct is allowed to cool to room temperature and is packaged.
~ sample of the product latex is neutralized to a ~ of 8.5 with a~.~onia and is found to have a viscosity of 40 centi~oi3e (20~ solids 3rookfield Synchro-Lectric Viscome~er Mod~l L-~l spindle 1 at 60 rpm) and a MF~ below 15 C. ~ il~ cast from this sample has a hardness of 17 ~N.

~Z7338 Example 9 - An Internally Plasticized Pol~er Emulsion H~ing an Acid-Contain~ng Last Stage . . .
A latex, with ~irst ~tage, second stage and average Tg values of 28, 112 and 65 degrees Celsius respectlvely and Ip values o~ 17.5 and 14.5 ror the rirst and second stages re~pectlvely, is prepared using the same equipment as Example

8 and a similar procedure as follo~s:
Material Charges Monomer Charge Kettle 10 Ra~ Material 1 lA 2 Charge deionized water154.0 g. 64 g. 154.0 g. 832 g.
octylphenoxy poly (39~ethoxyethanol 5.1 5.1 '`Abex 26S"(33%) (TM Alcolac Inc) 12.B 12.8 sodium dodecylbenzene sulfonate (23%) 10.3 10.3 ethyl acrylate 56.9 - -vlnyl acetate 449.3 - -styrene - 440.0 methacrylic acid 7 . 2 77 . 6 maleic anhydride - 4.1 - -Initiator: Fe++ (0.15% FeS04 6H 0~ 6.4 ml 0.26g ammonium persu~fate (APS) in 8g water.
0.26g sodium sul~oxylate for-maldehyde in 8g water.
Catalyst: 1.92g APS and 0.32g t-butyl hydro-perox~de (tBHP) in llOg water.
Actlvator: 1.92g NaHS03 in 110 g water.
Chaser: 0.52g tBHP in 5g water.
0.39g sodlum sul~oxylate formaldehyde ln ~g water.
r r 7331~

Procedure 1. Charge kettle and ad~ust temperature to 20-22C; sparge with N2.
2. Prepare charge 1 and add 231 g. to kettle.
3~ Add maleic anhydride in water and methacrylic acld ~charge lA) to remalnder of monomer charge 1 and emulslfy.
4. Add initiator; turn off N2 sparge.
5. Wlthln several minu~es of inltiator additlon, an exo-thermic reactlon occurs, with the temperature peaking at 55-60C.
6. At the peak, start addition of monomer charge 1 and hal~ of the catalyst and activator. Allow temperature to rise to 62C and hold at 62C throughou~ addition.
7. Charge 1 addition takes 40-45 minutes; when charge 1 and half of the catalys~ and activator have been added, hold system at 62 for 20 minutes.
8. After 20 minutes, start additlon of charge 2 and o~
catalyst and activator.

9. Addition of charge 2 takes about ~5 minutes; addition of catalyst and activator takes an additlonal 10 minutes.

10. Hold for 30 mlnutes at 62C.

11. After hold period, cool to 55 then add chaser and hold ~or 10 minu~es be~ore coGling to room temperature.

12. At room temperature, adJust PH to 4.5-5.0 with 10%
NH4HC03 aqueous æolution.
A sample of the product latex has a v~scosity of 19 centlpoise (20% solids Brookfleld Synchro-Lectric Vlscometer Model LVl splndle 1 at 60 rpm) and a MFT of 37C.
A fllm cast from this sample has a hardness of 14 KHN~ when 1~ Zn++ (as ZN(NH~)4~HC03~2) on polymer sollds is admlxed, as taught in US Patent 3~328,325, the hardness of a film is 15.5 KHN.

`' l~ ! . , , ~Z733~ ~

Example 10 - ffect of Hydrophllic Monomer Level Followlng the procedure of Example 9, a group of polymer emuislons are prepared havlng ~he composltlons and propèrtles glven ln Table VII. From these emulsions ~loor 5 pollshes are prepared by mixing ingredients ln the followlng recipe:
Role Materlal Charge .
Vehlcle Polymer emulsion--15% solids 90.0 parts Wax AC 392--15~ sollds 10.0 parts (Trademark, Allled Chem. Corp.~
Wetting aid Fluora~ FC128--1% sollds 0.5 parts (Trademark, 3M Co.) Leveling Tributoxyethyl phosphate-- 0.5 parts aid 100~ active Coalescent Methyl"Carbitol"* 4.0 Base Ammonia--10% aqueous to pH 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 o~ lOD and lOE are noted.
The AC-3~2 is prepared at 35~ sol~ds, as follows, and ls diluted to 15% solids wl~h water.
Formulation Parts '2y Weight A-C Polyethylene 392 40 Octylphenoxy poly(9)ethoxyethanol 10 KOH (90~ Flake) 1.2 Sodlum Meta Bisulfite 0.4 Water ~1 to 50~ Solids 50 Water #2 to 35~ Solids 43 Charge the ~lrst five lngredlents to produce the 50% con-centrate into a stirred pressure reactor. Begin agitation and heat to 95C (203F) with the vent open. Close the vent and continue heating to 150C ~302~F) ~or 1/2 hour.
5~ -Trademark,Methyl "Carbitol" is diethylene glycol monomethyl ether.

C ~L~Z733~3 -Add water #2 (43 parts) at 95C (203F) to the reactor whlle the.temperature is at 150C (302) and then cool to room temperature with agitation as qulckly as possible. Add 500 ppm formaldehyde preservative. -- /
.
, - 52a ~

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.

~ 733~ ) Example 11 - Effect o~ Acid Variatlons Following t~.e procedure of Example 9, a group of polymer emulsions are prepared having the composltlons and properties given in Table VIII. Floor polishes are prepared fr~m these emulsions and are tested as described ln Example 10. Results of these tests are in Table VIII wherein lt ls seen that Example llA does not have pronounced weaknesses and that the copolymers utilizing maleic anhydride are not hazy.

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Example 12 - Flrst Stage/Last Stage Ratio Variations . Polymer emulsions are prepared, by the procedure o~ Example 99 havir.g a range o~ flrst stage to last stage weight ratios as shown in ~able IX. The composltion of the ~lrst atage of each 1~ EA/VAc/VOH/MAn/MAA = 11/75.6/11.2/0.8/
1.4 and has a Tg(l) of 27.7C and an Ip(l) of 17.5. The last ~tage of each ls polystyrene having a Tg(2) o~ 100C
and an Ip(2) of 12.1. Thus the Ip(l) - Ip(2) value of each latex polyrner is 5.4. Floor polishes are prepared from these -iO emulsions and tested as described in Examples 6 and 10;
test results are ln Table IX.
Table IX
Example 12A 12B 12C 12D 12E
Polymer emulsion - 15 First//last stage 70//3060//40 50//50 40//60 30//70 (by weight) Yi~coslty*(cps) 22 21 24 20 17 Tg-average C ~603 53-0 60.0 67.3 75-Poli~h properties Visual haze nil nil nil sllght moderate Vlsual gloss good good+ good good fair-gd Levellng vg vg~ vg vg v~
Detergent resistance ~alr fair fair good vg Removabillty fair ~air ~alr poor poor Heel mark reslstance good good good good good Overall wear resi~tance good good good~ good good *At 40% sollds and a pH Or 5.

- 57 ~

~Z733~
Example 13 - Malelc Anhydrlde/Methacrylic Acld Levels Polymer emulsions are prepared, by the procedure of Example 9, with a range of malelc anhydride and methacrylls acld levels in the first stage as shown ln Table X. Each last stage is polystyrene and represents 50 weight percent of the polymer. The polymer of Example 13A is the same as that of Example llA. The compositlonal differences being comparatlvely small the Tg values and the IP values for the other three polymers are but little different from those for Example 13A. Polishes prepared from these emulsions are tested as ln Examples 6 and 10 to give the performance results recorded in Table X. A wide range of removability and of detergent resistance is achieved; remarkable in vlew of the vinyl acetate content of the polymer.

.
.

~ 58 -~Z~33~

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~ ~Z7338 ~xample 14 - Acid in the Last Stage The pollsh of ~xample 14A is prepared frcm the same polymer latex as that o~ Example llA. A fllm of this polymer ls found to have a Knoop Hardness Number of 10.
The pollsh of Example 14B is prepared from the polymer latex of Example 9 and is crosslinked with 1% Zn++, on polymer solids, added as Zn(NH3)4(HC03)2. The polish of Example 14C is prepared from a sample of the polymer latex of Example 6A, Table V. A, Note l; a film of this polymer has a KHN ol 13. These polishes are tested as in Examples 6 and 10; the results are in Table XI. Note the balance of removablllty and detergent resistance obtained while main-taining a high level of performance in other properties.
Table XI
Example 14A 14B 14C
Pollsh properties Leveling vg-exc. vg vg-exc.
Visual gloss*
one coat g-vg/g g-vg/g-vg.vg/~-vg two coats vg-exc/vg~ exc/vg-exc. vg-exc/exc.
Vtsual haze nil nil nll Detergent resistance ~alr vg vg exc.
Removability good vg-exc. exc.

*Recorded as r~sults on viny rtile/on OTVA ~ile see Test Method 3 o~ Table V. A. Example 6.

Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A latex of internally plasticized addition polymer particles comprising:
A) a first stage polymer, polymerized from a monomer mix consisting essentially of monoethylenically unsaturated monomers, comprising, by weight, at least 10%
hydrophilic mers, the hydrophilic mers comprising at least 10% nonionic and at least 0.5% ionic mers, and B) a less hydrophilic, higher Tg, later stage polymer polymerized in the presence of an emulsion Or the first stage polymer;
A) being from 20% to 80% of the combined weight Or A) and B);
the interpenetration parameter of A) being greater than that of B) by up to eight. units.

2. The addition polymer of claim 1 polymerized from monomers comprising at least one of acrylate esters, methacrylate esters, esters of vinyl alcohol and mono-ethylenically unsaturated aromatic hydrocarbons.

3. The addition polymer Or claim 2 being an aqueous emulsion polymerized d polymer with A) being from 30 to 70% of the combined weight of A) and B) and the interpenetration parameter of A) being greater than that of B) by 1 to 6 units.

4. The addition polymer of claim 3 in which the hydrophilic ionic mers comprise hydroxyalkyl esters of carboxylic acids.

5. The addition polymer of claim 4 in which the hydrophilic ionic mers comprise a carboxylic acid group.

6. The addition polymer of claim 3 in which the hydrophilic nonionic mers comprise vinyl alcohol mer units.

7. A process, for producing a latex of internally placticized addition polymer particles, comprising (a) producing a first stage polymer, poly-merized from a monomer mix consisting essentially of monoethylenically unsat-urated monomers, comprising at least 10% by weight hydrophilic mers, the hydrophilic mers comprising at least 10% by weight nonionic mers and at least 0.5% by weight ionic mers and (b) polymerizing, in the presence of an emulsion of the first stage polymer, a later stage polymer less hydrophilic, having an interpenetration parameter higher by up to eight units, and a higher Tg than the first stage polymer, the first stage polymer being from 20 to 80% by weight of the total first and later stage polymers.

8. The process of claim 7 in which the latex has a viscosity below 40 centipoises at 20% solids over the pH range 4 to 10 and a minimum film temperature more than 5°C below the Tg calculated for the addition polymer; and in which the monomers of the first stage consist essentially of 65 to 85 Cl-C4 alkyl acrylate, Cl-C4 alkyl methacrylate, styrene or a mixture thereof; 5 to 10% acrylic acid, methacrylic acid, itaconic acid or a misture thereof;
and 10 to 25% hydroxy Cl-C4 alkyl methacrylate, hydroxy Cl-C4 alkyl acrylate or a mixture thereof, by weight, and the monomers of the last stage consist essentially of methyl methacrylate, styrene or a mixture thereof; the interpenetration parameter of the first stage being 1 to 4 units higher than that of the later stage.

9. The process of claim 7 in which the latex has a viscosity below 40 centipoises at 20% solids over the pH range 4 to 10 and a minimum film temperature more than 5°C below the Tg calculated for the addition polymer; and in which the mer units of the first stage polymer comprise by weight 65 to 85% vinyl acetate, 5 to 10% acrylic acid, methacrylic acid, itaconic acid or a mixture thereof, 8 to 25% vinyl alcohol and the mer units of the last stage polymer consist essentially of methyl methacrylate or styrene mers,or a mixture thereof,and 0 to 30%, by weight, acrylic, methacrylic or itaconic acid mers,or a mixture thereof; the interpenetration parameter of the first stage being 2 to 6 units higher than that of the later stage.