AU540552B2 - Process for producing spherical and porous vinyl resin particles - Google Patents

Description

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STATIEMENTUNDER REGULATION 15A (a)

R/We, THE B. F. GOODRICH COMPANY, (a corporation organized under the laws Of te- State of New York), of 500 South Main Street, Akron, Ohio 434 C, United States of America, S S S gee S

S OOSS I/SLAS C. 0 55 CS hereby state it is my/our intention that the International ee S C C application identified below proceed as an application under a. 4~.e the Act for a Standard Patent.

C n/Our address for service is care of CLEMEINT HACK Co., ec he CC C *5 Patent Attorneys, 140 Williai,, Street, Melbourne, Victoria, S 6

3000. PTNFFC 6 C C ~0 Be International Application No. PCT/TJS 1/yb4o S.

C. 6 Ce 0 5

C Australian Applicationl No. 73245/81 /A S. a~ P T DATED this 20TH day of NOVEMBER, 'l P O

U THE B. F. GOODRICH COMPANY

Z~~NOV19& j CUIFNT fiAC' C

Forms 7 and 8

AUSTRALJIA

Patents Act 1952 Li's DECARAIO 11fNSUPPORT "OF A CONVENT QN OR NON-CONVENTION APPLIC TION, FOR. A PATENT OR PATENT OF ADDITION

Name(s) of In support qf the appi~a tion/ made by.. App2licant (s) mhp-' F Qn drich Compaiv

Title for a pateni for an invfention entitled PROCESS FOR PRODUCING SIIICA 1D POROUS VTNY4. RESIN PARTICLES. Name(s) and I/We, -Grego, V L. RtmLn address (es) rvivlh Mi!t~ of petson(s) Akro;i, Ohio 4 z'181 U.S.A.

decUhLation do solemnl, and siincerely declare eg. as follows:- 1. '1 am/wql are ttve aVplicant(s) for the patent, or am/are a'*uthor'sed by the abovernentioned apkplicant to maI! this ,aecl~iaration on its behalf.

2. The bai~ic applictcn(s) as defined by Section 141 of the, Act V'as/,vere miade in the following country or cox-'trieis on, the followilg date(s) by the folloWling gpplicant(s) namely.- Co.itj7, f il ing datee ahd name vlnit_-d Sateof Anerica on Mav I1 I1Q Rfl of.%iMlicant (s) for te or oeach bpic iit~loeotion

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3. The iaid 464sic application wa,,s/were the f irst appltcatie~l (,40 made in a Convention country in respect of t~e iVno the. subject of the application.

,o te o 4,c The Vcinventor of the said invention is/are i4I1_ 'sKanti 1 L81h tarrJ-ace 4 f: 'Drijve eadh actual Inventor *SOe reverse 5, The ct 1 upon which the/ ay~plicant(s) is/are entitled saide of this to Olt7je t his application" atre as follows:- !4rn= for tv ir-_ueof /ded /2assianment dated gui dance il,.i avl 1, 80 indeb 'twe en him and completing g. F.i Go h any this part

DiECLAJoD a lr *this 5th day of-Ocober 1981.

Gregory t. tfhan Assistant Secretary 'VC7is fr /'lay /i~et~ and filed after the fil~ing of a patent plti In but the fojmust not be signed until, after it has been om~ 'j ilJle ii a/indicated by te marginal nates. The

~~i!a ii- i; it I:Itq.i AUSTRALIAN PATENT ABRIDGMN .i (19) AU (11) AB93245/81

ij: (54) SUSP'ENSI OLYMER'iZATI' N PROCESS (71) .HE B.P f'00DRIqH/iCOMp'ANY i.. (87) WO 81/0 3 73 2 45/81 i 040552 (22) 7.5.81. 19.5.80 (31) 1510601;~ 2 19.5.j80 (33) US (43) 7.1.82 (44) 22.11.84 C08F 114,/06 08F 4/;s4 CG8F 2/20 ii (72) PIJUS KANTI/B/S U (74) HA (56) US 3620981 US 3s773'0 (57) C1 Airn 1. A suspien4on poiymierizan procqsS for.'pr/- ducing spheriqal particles of pqjymer having high porosity which comprises, polymerizing o!e or more ethy4iLnj.ci Ily unsaturated monoaters having at least one terminal CH C group in, the fo-Itm of discrete droplet,%ir an fcqBous reaction medilam containing, ei Tm-,onomer -soluble free radical yielding catalyst, a disper! ant comphii.ing a water-insolul e, crosslinked interpQlyner of,' Cne or more carboxy'ic monomers qosslinked with a,poly- unsaturated cross.liUnking inonomer havi.ng a r# urality of termially unsaturate6( polymerizable groups, the amount said carboxylic cid mornomer(s) being greater than 25% by weight basad on the weight of the monomers in the interpolymeragd at least ono surfactant employed in the an 'e of 0.005,4 to 1,0% by weight, based on the weight of the monome: to be polymerIzed, said surfaottant containing one or more poly (ethylene oxide) segmnnts, agitating said medium to form drcplets of monomer(s) therein., adding a wator-soluble base to said mediurm to at least partially neiatralize tho dspersant, polnyeriza.ng said monomer(s) iA a f6irst stage at a *0.2

44 3

R11-5 41q i,:r^iii^r O AU7.....5/8 -2- t -aperature in the range of 1.0°C to 100°C with agitation 3": below that at which the dispersion was formed, continuing the polymerization at said temperature and agitation to a conversion of 10% to 30% then increasing the agitation in a second stage to a level not more than that at which the dispersion was formed at the same temperature as in said first stage until the reaction is complete, and recovering the spherical, porous particles of polymer having a diameter in the range of 30 microns to 1000 microns, wherein polymer buildup on the surfaces of the reactor is substantially reduced. 2. A process as defined in claim 1 wherein the monomer is vinyl chloride.

1 5s(41)/31

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PCT PTIrnernational WORLD INTELLECTUAL PROPERTY ORGANIZATION Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCI?)

(51) Iternaltional Patent Classification 3; (11) International Publication Number: WO 81/03333 Al C083L 27/06; CO8J 9/16; C08F 2/00 (43) InternationalPublicatioaDate26 Novemnber 1981 (26.11.81)

(21) Internstional Application Number: PCT/USS 1/00611 (81) Designated States: AU, BR, DE (European patent), FR (European patt GB (European patent), JP, NL (22) International Filing Date: 7 May 1981 (07,05,8 1) (European patent), NG, SE (European patent),

(31) Priority Application Number: 151,060 Published Wfith internationalsearch report q *I (32) Piority Date,, 19 May 1980 (19.05,80) 0*9 I

d~O0 (33) Priority Country; V. 9 WI (71) Applicant; THE B.F GOODRICH COMPANY [US/ p

US]; Dept. 0015 -WHB6, 500 South Mumn Street, Akron, OB 44318 (Ub).

(72) Inveidor: BASU, P~us, Kanti. 6580 Carriage IHill Drive.z Brecksville, OH. 44141 (US). A. J. P. 7T, 1.3 2. (74) Agent: DOXSEY, Albert, Dept, 0015 'WHB6. 500 AUSTR~ALIAN South Main Street, Akron, OH 44318 (US). I'll, V VS 7 DEC 1981J a 0S PATENT OFFICE 9*

(54) Title; PROCESS FOR PRODUCING SPHERICAL AND POROUS VINYL RESIN PARTICLES

(57) Abstract Process for making vinyl polymier narticles that are spherical, highly porous and of uniform size witlvsubstantially nopr(- lymner bUildup on the reactor surfaces. A dispersion or emulsion is first formed with high agitation compris, d of an aqueousgpje- dium containing a water-insotuble suispending or dispersing agent the monomer ofrmoi~ners to be pol~jerized 1amonoiger- soluble free radlical yjiig catalyst,. and a surfact~ent or surfactant system. The dispersion is neutralized/With an alkali and ,hfen poLymerized with.stirring toacnerin abu 0 to about30% and then continuin the reaction toqAonipleti~on with irttrfea- sed.stir-ring, 1W' stirring in both instrim~s being no greater than that used in making ttle dispersion or iftnulsion. The disptrsing agent employed comprises an unneutralized crosslinked interpolymer of one or mor, arboxylic acid, nonomers with a polyun- saturated comno-ond hbving a plarality of terminafly unsaturated polymnierizable yjraups.

WO 8fh/3301~ PCT/tJS81/0061,I

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kPROCESS FOR P7A' -GSPHERTCAL AND POROU~S VINYL WE.'SIN PARTICLES BACK!R G6U OF LE INVENTION Many poJlymerizab%e monomeric materials, and. parf,#icularly vinyl chlorie.e, are being polymerized t, eay on a larlye scale cqc~mercially e-ither in suspen- ,ijoij media or in aqueous'dispersiorn or emulsion, that latex form, employip g various colloidal suspension #00 a ,igentg, emu f'iers or soaps, and/Xor synthetic deter- gent-type disp-rsing ae jents. In these methods of poly- merization, anci par'ti ,I larly in suspension polymeriza- tion, agil'tation, whic: i is uisually vigorous, is depended on to suspend and/or .disperse the monomer particles or droplets throughout the reaction media and to maintain *4 a a 1L5 suich suspension or dispersion during the, polymerization reaiction and tco assist in heat transfer to the reactor cooling surfaces. However, in most instan'ces,/ polymer particles produced in accordance with these processes are not uniiforma n size and shape. This is due, in most insta nces, to the instability of the monomer dis- porsion which causes agglomeration of- the polymerizing particles. In, subsequent processing of these TDolymers, such as, for examnple, polyvinyl chloride (PVC) it is ,lesirable to have uniform size Q~nd shape in the polymer particles., Various polymerizatioti processes, and mnodifi- cations of existing processes, have been heretofore proposed to' obtain sph ericalt unagglomeratod resin part- icles of 4niform size. For example, one very succ-ess- ful methq/id has been, proposed and described in U.S. Patent No. 3,620,988. In said patented method, a mono- mieric znAterial, such as vinyl chloride, o~f low so"Lub- ility in water, containing a monomer-soluble free radi- cal type catalyst, is, suspen',ed as discrete droplets of a desired size in an aqueous medium thickened with a wate'r-insoluble polymeric gellation agent which inazts

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plastic flow properties to such medium. The polymer- ization reaction is then carried out using a batch or continuous process under substantially quiescent con- ditions, that is, in the absence of turbulence or the absence of shearing forces sufficient to deform the suspended droplets of monomer and/or to damage the poly- mer bead at any stage of conversion. However, when polymerizing vinyl chloride by such a process, the uni- form beads of PVC that are formed are normally clear and. glassy in nature and do not have the desired porosity, which is desirable in subsequent operations involving the finished polymer.... There are many cases where porous polymer particles or beads are desirable, such as where the polymer, such as PVC, is to be employed in making plast- isols and in extrusion operations. Porous beads would also be desirable in the case of PVC where, because of Government regulations, it is necessary to remove sub- stantially all of the unrea.cted vinyl chloride therefrom. Porous polymer beads or particles would Ireatly f,.cili- tate such removal. Another real problem in the manufacture of vinyl resins is polymer buildup on the inner surfaces of the reactor during the polymerizacion reaction. This is particularly prevalent in the commercial production of vinyl chloride polymers when the same are produced in the form of discrete particles by polymerization in an aqueous suspension system. When employing such a sys- tem, the monomer(s) are maintained in the form of small discrete droplets by the use of suspending agents and agitation. When the reaction is complete, the resultant polymer is washed and dried. These aqueous suspension system polymerization reactions are usually conducted under pressure in metal reactors, or glass-lined reac- tors, equipped with baffles and high speed agitators. However, as pointed out above, these suspension systems

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under many circumstances are unstable and during the polymerization reaction, the polymer builds up on the interior surfaces of the polymerization reactor, in- cluding the surfaces of the baffles and agitator. Obviously, this polymer buildup must be removed since it results in further formation of polymer buildup on 6* the reactor surfaces which results in a crust that 6

*6*6 adversely affects heat transfer and contaminates the 66 polymer being produced. Removal of such polymer 6* 66

10 buildup is difficult and costly and the desirable way 6 p of eliminating the polymer buildup is providing a means of polymerization which substantially eliminates its formation in the first place. Thus a process which is capable of pro- ducing vinyl resin particles which are spherical and 4 porous throughout, and which will also substantially *6 9 eliminate polymer buildup in the reactor, is most desir- able. *6 6 6 *66 6 SUMMARY OF THE INVENTION 6

6 20 in the process of the present invention

6@ there is first formed a dispersion or emulsion comprised 6 696 of the monomer or monomers to be polymerized, a surfac- #66 6 tant, or surfactant system, and a monomer-soluble free radical yielding polymerization catalyst, in an aqueous medium containing a water-insoluble suspending or disoer- sing agent comprising an unneutralized cross-linked inter- polymer of one or more carboxylic acid monomers with a polyunsaturated compound having a plurality of termin- ally unsaturated polymerizable groups. Said dispersion is formed using high agitation at a temperaturekbelow the reaction temperature of the catalyst. The disper- sion is/partially neutralized with ana-4a-l' and then polymerized with stizring to a conversion of about 100 to about 30%, said stirring being substantially less than that used in making the cispersion and then continuing the reaction to completion with increased stirring but

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no greater than that used in making the dispersion. The resultant polymer particles are non-agglomerated, spher- ical, highly porous and have the same size distribution as'the original liquid dispersion. Thus, by starting with a dispersion of uniform droplet size, one can ob- tain polymer particles which are also uniform. There is substantially no polymer buildup on the reactor surfaces. Detailed Description While the present invention is described hereinafter with regard to the polymerization of vinyl chloride, it is to be understood that this is merely for purposes of illustration and convenience since the pre- sent process may likewise be employed in the polymer- ization of any polymerizable ethylenically unsaturated monomer or monomers aid particularly where, under normal conditions, undesirable polymer buildup occurs. As examples of such monomers, there may be named other vinyl halides and vinylidene 'alldes, such as vinyl bro- mide, vinyl fluoride, vinylidene chloride, etc., vinyl- idene monomers haying at least one terminal CH2=C<group- ing, such as acrylic acid, methacryvlc acid, acrylo- nitrile, vinyl acetate, and the like; esters of acrylic acid, for example, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, cyanoethyl acrylate, and the like; esters of methacrylic acid, such a. methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like; styrene and styrene derivatives including a-methyl styrene, vinyl toluene, chlorostyrene; vinyl naphthalene; diolefins including butadiene, isoprene, chloroprene, and the like; and mixtures of any of these types of monomers and other unsaturated polymerizable o0lfinic monomers copolynerizable therewith; and other polymerizable olefinic monomers of the types known to those skilled in the art, The present invention, hcwever, is iartic- larly applicable to the polymerization of vinyl chloride

"WO81/03333 PCT/US81/00611

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either alone or in admixture with one or more other vinylidene monomers having at least one terminal CH 2 grouping, copolymerizable therewith in amounts as great as about 80% or more by weight, based on the weight of the monomer mixture. The monomer-soluble or oil-soluble catalysts that may be used in the polymerization process of the present invention ar. the alkanoyl, aroyl, alkaroyl, 1 aralkanoyl diperoxides and monohydroperoxides, azo :10 compounds, peroxy esters, percarbonates, and other free radical type catalysts. As examples of such catalysts, there may be named benzoyl peroxide, lauryl peroxide, diacety! peroxide, cumene hydroperoxides, methyl ethyl ketone peroxide, diisopropylbenzene hydroperoxide, 2,4- dichlorooenzoyl peroxide, naphthoyl peroxide, t-butyl perbenzoate, di-t-butyl perphthalate, isopropyl percar- bonate, acetyl cyclohexane sulfonyl peroxide, di-secon- dary butyl peroxydicarbonate, t-butyl peroxyneodecanoate, di-normal propyl peroxydicarbonate, azo-bis-isobutyroni- 20 trile, am '-azoc-iisobutyrate, 2,2 -azo-bis-(2,4-dimethyl valeronitrile), and many others. The particular free 9 radical catalyst employed will depend upon the monomer(s) being polymerized, the molecular weight and color re- quirements of the polymer, the temperature of polymeri- zation, etc. Insofar as the amount of catalyst employed is concerned, it has been found that an amount in the range of about 0.005% to about 1.0% by weight, based on the weight of the monomer or monomers being polymerized, is satisfactory. However, it is preferred to employ an amount of catalyst in the range of about 0.01% to about 0.20% by weight. An important aspect of the instant invention is the water-insoluble suspending or dispersing agent that is employed in order to stabilize the dispersed monomer droplets against coalescence. The dispersing agent employed is an unneutralized crossllnked inter-

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polymer of one or more carboxylic acid monomers~with a polyunsatura~ted compound having a plurality of ter,,i- nally unsaturated polymerizable groups, for examrple, a cro ss.l'inked polyacrylic acid polymer. The Crosslink- ing is necessary since an uncrosslinked polyacrylic acid polymer will produce a highly agglomerated charge, 'that is, due to an unstable environment, the polymer particlers" coalesce producing thie agqlomerat-s. Due~ to the cross- linking the interpolvrnera~te incapable of forming a true soltion in water an-d tliis are classified as water- Ansoluble. Hiowevor, the structure of the interpoly-mer must be such that it has enough affinity for water to swell appreciably in an aqueous medium, thus thickening the water phase but not to the extent that it cannot be agitated, as hereinafter described. Interpolyxers that have little or no aflfinity for water and do not swell to any measurable degree, are not suitable for the purposes of the present invention.: After forming the dispersion or emulsion of the polymerization reaction ingredients and prior to polymerization therEcf it is necessary, and most impor- tant to/1,partially neutralize the reaction medium, and mainly the dispersing agent therein, in order to insure the rstabilization of the monomer droplets thi-rein during the subsegbent stirred reaction period. This neutraliz- ation is accomplished by adding to the reaction medium, prior to the start of the polymerization reactioin, a ,water-soluble base, such as sodiumn hydroxide, in order to adjust the pH of said medium~in a range of about .S to about 7.0. This adjustment in pH is made in order t-o, obtaira sufficient "yield value"~ in the mediumn, as des- cribed hereinafter. The Viscosity of -the polymeriza- tion medium can be regulated by adjus 4 -ing the amouint of suspending or dispersing agent added3 thereto and its degree of neutralization. The amount of suspending or dispersing

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agent that is required for proper yield value is easily determined. The minimunm yield value required in aqueous polymerization medium for suspension stability with any given monomeric material depends on several factors, namely, the density difference between the mono- meric and aqueous phases, labeled D-D and expressed as grams/cm 3 the desired or actual radius of the suspended monomer droplet, expressed in cm.; and the acceleration of gravity expressed in cm,/ 2 2 sec. usually 980 cm./sec. The minimum Brookfield Yield Value (BYV) for permanent susrension can be cal- S. culated by the formula: 2 BYV=[2.6RB(D-Do)g} /3 wherein the terms are as identified above. In practice, it is desirable to employ aqu- eous media having a BYV in excess of the calculated rin- imum in order to make certain that suspension stability is easily achieved and is fully maintained throughout the reaction. It is satisfactory to employ aqueous 20 polymerization media having a measured or actual 3BY, at least 50% end preferably from about 20.0% to about 600% or more, higher than the calculated minimum. Actually, BYV values are measured or calcu- Jatd from rheolgical data obtained by the use cf the Brookfield RVT Viscometer, operated at the temperature to be utilized in the polymerization, whereby one measures the Brookfield apparent viscosity BAV in centipoises at 0.5 rpm. and at 1.0 rpm. If these data are plotted against shear rate and the curve extrapola- ted to zero shear rate, the BYV is obtained directly. However, the minimum BYV for permanent stability can ibe approximated from the formula: .OrDmr BAVt0.Srow-BAV1.0 (11) Approx. 3YV= 100-- In many cases, a useful and easily measured iind calculated viscometric parameter is the ratio "P'

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dirooel theth aBprcn licld *iseee4ity me sured at 20 rpm. This ratio will vary somewhat de- ngo h0antd fBV h oml no crtsagiorclcrecinfco hc bv o pnsaer rthserr

man n o the magnirte practicalh foermuain1)rage *4*

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o rtesanemcaroic aorcionofacers which aceus- fulint prrn therros ney~ri iprigo

sudinrsg agents oreths whichn innin tls oe cabn ataiivem t rang of aboutd i0 the abou -poiio Vsuln t~~C t

ofesct Lomes cabxyruhavag ran h oprtheg fruang 1 be frmIu 5 o bu 10.Th rokil

w~~thiV R' a ir h range~ Isberoe rof adu wh taouih i isahdenor s1500 linke LSooaet~siun ru uc to oIo h o b y b na Carboxyhi acids witi thi dmnomes which aidse- b n ao s as paricndri the kdouleri d~~isperinalo

susthendingagentsl aeidhs whuch s ai aid laston

Woth e pc tnyr oe acrbxl ro theag ormula Frl

whend Ri a dro reno monovalentu titezt crunt group espciallne thos neeofr the ubl rre carbostnao Carboxylic haciswti th-e~i deiltix jn eais

thusly4V hrisuhatedulIoc'stria cyicad ~t of the BYV divided by the aplfarent Brookfield viscosity measured at 20rpm. This ratio will vary somewhat de- pending on the magnitude o, BYV. The formula above incorporates an empirical correction factor which comn- pensat.es.for this error. In general, BYV values with the suspending or dispersing agents of the present invention will be, at a minimum, in the range of about 20 to about 50 for the usual monomers and particle sizes. Most often, with many of these monomers, the practical operating range will be frorr about 50 to about 120. .The Brookfield apparent viscosity at 20rpm. of the polymerization media of such BYV will be in the ran1qe of about 760 C: to about 1500 centipoises. The amount of dispersant employed is in the range of about 0,02"i to about by weight, based on the weight of the monomer(s) The carboxylic acid monomers, which are use- ful in preparing the crosslinked polymeric dispersing or suspending agents, are preferably those which contain at least one active carbon to carbon double bone in the s-position with respect to a cearboxyl group, having the forrmula 0@S*ITII

R I-C=&-C0OH within R' is hydrogen or a -COO11 group, and3 each of R" e~..*and R" I is a hydrog en or a monovalont substituon, 4rouj which is linked to one of the doub,'Y )Ixndud carbont atoms. Carboxyl~ic acids within tis definition include aciis, such as acr~li'c and, wherein the doule bond is ter.minal thusl.1y CH 2 =C-COII or the dicarbuxylic acids, such inaiceo acid, cuvi other anhydridos having the eerlfoml

R-C-C 4) -wherein R and R' art-, monovalent subotituont. qrro an~d especially those selectod fr.omi tho gIrout, coni hydrogen, halogen, alkyl, ary' alkaryl aro1lv;1, aind

WO :8/03333 PCT/US81/00611

cycloaliphatic radicals. Included within the class of carboxylic acids, shown by generic formula above, are widely divergent materials, such as acrylic acid itself, meth- acrylic acid, ethacrylic acid, a-and a-chloro- and bromo- acrylic acids, crotonic acid, maleic acid, itaconic acid, and many others. Polymerizable carboxylic anhydrides include any of the anhydrides of the above acids, including 10 mixed anhydrides, and those shown by generic formula above, including maleic anhydride, and others. In many cases it is perferred to copolymerize an anhy- dride monomer with a comonomer, such as methyl vinyl ether, styrene, and the like. In the present invention, it is preferred to employ polymeric suspending agents which are derived from polymers produced by the polymerization of the c 3- monoolefinically unsaturated carboxylic acids. The pre- ferred carboxylic acids are those derived from the acry- 20 lic acids and a-substituted acrylic acids having the general formula a,. aR R

9

(d)CH2 =C-COCH

wherein R is a monovalent substituent selected from the group consisting of hydrogen, halogen, hydzoxyl, carbox- yl, amide, ester, lactone, and lactam groups. The most preferred polymeric suspending agents are those prepared from the lightly crosslinked interpolymers of acrylic acid since these are the most efficient. The crosslinking agents which may be employed with any of the carboxylic monomers, or mixtures thereof, may be any compound, not necessarily monomeric in nature, containing two or more terminal polymerizable CH2=C< groups per molecule. Examples of this class of

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materials include polyuns aturated -hydrocarbons, -polyethers, -polyesters, -nitriles, -acids, -acid an- hydrides, -ketones, -alcohols and polyunsatvrated comn- po2-.-ds of this class incorporating one or more of these s and other functicual groutms. Specifically, there may be used divinyl benzene, -int ,iaphthalene, low molecula.,r weight and soluble ,arized dienes, such as, polybutadiene and other soluL'- hornopolyiners of open chain aliphatic conjugated dienes, which soluble %W 60

polymers dd. not contain any appreciable number of con- a. d&

jugated double bonds, and other polyunsaturated hydro- :)oiis; polyursaturated esters, ester-arnides and, other 00s ester derivatives, such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, allyl acrylate, methy- lene bis-aarylanide, methylene bismethacrylamide, tri- acrylyl triazine, hexallyl trimethylene trisulfone and many others; polyunsaturated ethers, such as diviflyl ether, diallyl ether, dimethy. ally! ether, dially. ethylene glycol ether, diallyl, triallyl and other poly- :04 a2llyl ethers of glycerol, butene-l,2-diol, l-phenyl-1,2, 3-propanetriol the polyalyl, -vinyl, and -croty. poly others containing from 2 to 7 or more of these or other alkenyl ether groupings per molecule and made from polyhydric alcohols, st'ch as the carbohydrate sugars, and the so-called "sugar alcohols", including erythri- tol, pentaerythritol, arabitol, iditol, mnannitol, sor- bitol, inositol, raffinose, glucose, sucrose, and many others.; and other poly1hydroxy carbohydrate derivatives; the corresponding polyulkenyl silanes, such as the vinyl and a3.lyl silanes; and others. Of this larrge class of.. cross linldnq agents, the polyalkenyl polypethers of the oarbohydrate sugars, sug4ar alcohols, and other poly- hydroxy oarbohydrate type derivatives conta:Ln~.ia fromn 2 to 7 alkenyl ether group.- per moeueare pacticularly Useful. .Such matertale., are eaiyprepared 1-y a Williamson-type synthesis invc~vina the reaction of an

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alkenyl halide, such as allyl chloride, allyl bromide, methally! chloride, crotyl chloride, and the like, with a strongly alkaline solution of one or more of the polyhydroxy carbohydrate derivatives. In the monomeric mixture for making the crosslinked polymers employed as suspending agents in the polymerization process of the present invention, the 9*9* 9. 4 a two essential monomeric materials should be present in Certain proportions, although the exact proportions will 9. 9 *o 10 vary considerably depending on the characteristics de- 9*

9. *a sired in the polymer. Small amounts of the polyalkenyl polyether copolymerize quite readily with carboxylic monomers and the crosslinking effect of the polyalkenyl polyether on the carboxylic monomer is so strong that as little as by weight thereof, based on the weight of 4 9 the total mixture, produces a great reduction .in the water-and solvent-solubility of the resulting crosslink- ed polymer. When 0.1% to more preferably 0.2% to by weight of the polyether is utilized, water- 98 9 20 insoluble polymers are obtained, especially with acrylic acids, which are extremely water-sensitive. Useful dis- persing agents are also obtained when 0.1% to and preferably 0.2% to by weight of the polyether is copolymerized with maleic anhydride. In the dual co- polymer, or two-componenet interpolymer, this means that the remainder of the monomeric mixture will be the car- boxylic monomer, The monomeric proportion employed in the production of multi-component in terpolymers may vary in a somewhat similar manner. However, it is generally de- sirable to utilize as much of the carboxylic monomer or monomers and as little of the other monomeric constlt- uents as is consistent with the desired water-insolu- bility and other properties. In these interpolymers, therefore, the carboxylic monomer or monomers should never be less than 25%, and preferably not le!ss than

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by weight of the total. Aonom~eric mixture. 14ulti-com- ponent interpolymers may A~e from monomeri6 mixtures comprising from 25% to 95% (j:6 a carboxylic monomer, such as acrylic acid, 0.1% to 30%, of a polyaJlkenyl polyether, such as polyallyl polyether of sucrose, and 5.0% to 74.9% of an additional monomer- or monomers'. Preterred 0* 4 multi-ccmponenet interpolymers are the tripolymers re- suiting from the polymerization of monomeric mixtures containing, respectively? from 40% to 95% by weight of J0 acrylic acid, 0.20% 2.5% by weight of polyallyl poly-.: ether, such as that of sucrose, anid 4% to 59% of an additional ni6nomer or monomers, su~ch as maleic anhydride, N-methyl acrylamide, methyl vinyl 1,ther, etliryl vinyl ether, n-butyl vi:nyl ether, and th~i like, and mixtures of maleic anhydride, a vinyl alk~yl ether, such as vinyl methyl ether, and a, polyallyl pv.lyether, in which the suma of the moles of vinyl ether and polyallyJ. polyether is substantiallyv equivalent to the molar quantity of maJleic anhydride present. It should be borne in mind 0 L that in the above proportions, if a maximum amount of two i

of the monomers are utilized, that somewhat less than maximum amounts of the other monomers must be utilized. Suitable for use as &:dditional monomers in the production of~ multi -component interpcolymers are mono- olefinic vinylidene monomers containing one terminal CH2 C< group, such as styrene, the chloro- dnd ethoxy- styrenes, etc acrylamide, N-methyl-acrylamide, N,N1- dimethyl acrylamide, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, 2-ethy-lhexylacryleate, methyl mtethacrylate, vinyl acetate, vinyl benzoate, vinylt pyridine, vinyl chloride, vinylidene chloride, vinylidene chlorobromide, vinyl carbazole, vinyl Pyrr- olidone, methyl ',in l ether, ethyl vinyl ether, n-butyl vinyl ether, methyl vinyl ketone, ethylene, isobutylene, d3.methyl xaleate, diethy. 'naleate, and many others. In addition, to the above monoolofinic monomers, many )f the

OMP~ I K wipo

1-1. -li.

WO 8103S33 PCT/US81/00611 ~;R~v

13

divinyl dialkenyl'or other polyfunctional esters, amides, ethers, ketones, and the like, may be used in the pro- duction of multi-compdnent interpolymers, especially those polyfunctional monomers which nominally function as crosslinking or insolubilizing monomers. Of the above additional monomers, N-methyl acrylamide, methyl C. vinyl ether, ethyl vinyl ether and divinyl ether have been found particularly useful in the production of the unneutralized crosslinked interpolymers for use as water- .e 10 insoluble suspending agents in the polymerization pro- C C. cess of the instant invention. One important aspect of the present inven- tion is the choice of surfactant or surfactant system. I C

C. C It is necessary that the surfactant or surfactants cho- sen for use in the invention be such that at least one of the surfactants contain one or more poly(ethylene oxide) (PEO) 5s,m 4nents. It has been found that the 4 water-insoluble crosslinked suspending agent in the reaction medium is an indispensable part of the surfac- C 20 tant system. The ability of the surfactant to prevent "dro sti.cking", that is, to prevent the monomer droplets C UC* _rom coalescing, is due to the complexing, or association, 4

of the same with the suqpending agent. This, of course, prevents agglomeration in the finished product or poly- mer, It is believed that the key to the mechanism for preventing agglomeration lies in the hydrogen bonding interaction between the PEO segments of the surfactant and the unneutralized -COOH groups on the suspending agent chains. It has been found that the satisfactory amount of surfactant or surfactants, usefuil in the pre- sent invention, in the range of about 0.005% t> about 1.0% by wei( d on the weight of the monomer or monomers to be p A'ized. Preferably, an amount of such surfactant(s) in the range of about 0.02% to about 0.5% is employed. With respect to the surfactants, it has

P OMPI ~t~ ~I ~tr~f_4" been demonstrated that there is a minimum length that the PEO segments must have in order that they can be effective in complexing with the water-insoluble cross- linked suspending agents in the reaction medium and thus prevent drop sticking. This minimum length has been found to bejetween 11 and 15 PEO (poly(ethylene oxide)) units. Surfactants having shorter PEO segment lengths are only partially effective in most cases and the resin particles produced from a stirred reaction are larger and have a broader size distribution. This S Sr is. believed to be due to partial drop agglomeration in the early stages of the reaction. Among the surfactants useful for the pur- pose of preventing the monomer droplets from coalescing are those falling within the following generic classes: polyoxyethylene alkylphenols; 12) polyox ethylene S.

alcohols; polyoxyethylene esters of fatty acids; polyoxyethylene alkylamines; polyoxyethylene alkylamides; and polyalkylene oxide block copolymers. As examples of surfactants in the above-named classes there may be named the following: polyoxyethylene sorbitan monooleate, polyoxyethylene (20) sorbitan mono-" 1lurate, polyoxyethylene (20) sorhitan monopalmnitate, polyoxyethylene (20) 5orbitan monostearate, polyoxyethy- lene (40) stearate, polyoxyethylene (50) stearate, polyoxyethylene esters of mixed fattt and resin acids, polyoxyethylene (20) palmitate, polyethylene glycol monolaurate, polyethylene glycol monooleate, polyethy- lene glycol ricinoleate, polyethylene glycol monostear- ate, polyethylene glycol distearate, polyoxyethylene(2 stearate, polyoxyethylene (40) stearate, polyoxyethylene (251 castor oil, polyoxyethylene (52) castor oiJ, poly- oxyethylene laurate, polyoxyethylene (15) tallate. polyoxyethylene lauryl: ether, polyoxyethylene (12) lauryl ether, polyoxyethylene (23) lauryl ether, poly- oxyethylene tridecyl ether, polyoxyethylene *j~

REA OMPI WIPO ~Haul~J~i

WO 8110333S3 PCT/US81/0061 I

tridecyl ether, polyoxyethylene (10) oleyl ether, poly- oxyethylene (20) oleyl ether, polyoxyethylene oleyl ether, polyoxyethylene (15) cetL-yl stearyl ether, polyoxyethylene (20) stearyl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecyl ether, poly- oxyethylene (9)1 nonyl phenyl ether, polyoxyethylene (21) *coconut ester, and the like, etc. As examples of the block copolymer surfactaints is the family of surfactants :manufactured by BASF,'Wyandotte and sold under the trade- mark "Plixrr,-nic". These surfactants are polyethylene oxide polypropylene oxide block copolymners and have the following general formula:

CH wherein the sum of x and z is3 an integer from 1 to 212 C 15 and y is an integer from 16 to 69. These compouds have a mnultip- iJ tyofn ctional groups and accordingly, a very large number of *~.modifications is possibie. As pointed. out above, mix- tures said compounds can also be used. Any amounts of the polyethylene oxide surfactants 4.n combination may be mployed 'so long as the combined weight thereof is within the ranges of surfactant(s) given above. 4 Surfactants, other than the essential poly- ethylene oxide-containing materials referred to above, may also be ac7ded to the reaction mixture for the pur- pose of improving the porosity of the vinyl resin par- ticles or for otherwise modifyin~g or controlling the inter'nal structure, or skin structure, of the vinyl resin particles. Surf actants employed for this purpose are chosen on the basis of their Hydrophile-Li4pophile Balance (ULP) values and inc~nde all the general classes of compounds listed above, even though the polyethylene oxide segmtent length is of no importance with respect to these additional surfactants. A'lso, uaseful surf ac- tants are tho~se compounds from the sorbitan ester family or the polyol families, as well as the polyvinyl

OMPI_ ,,WIPf'

'WO-R1103333 WO 81~3331 CUMS81/0061 1

6

alcohols, which do not contain pDolye/thylene oxide ment8. As examples of such surfactants there may be named sorbitan triojeate, sorbitan tristearate, sorbitan ronooleate, sorbitan monopalmitate, Alcotexe, which is 72.5% hydrolyzed polyvinyl acetate, and the like. The satisfactory surfgactants for irrproving the vinyl resin porosity' and internal structlare of the Polymer particleg". will have an HI1B in the rangei of about 2 to about 19 and pr-eferablyj an 1iLB in tho rs nge of about 2 to about 6, These surfactants, whioh are added to enhance rnon- olmer droplet stabilizatiori and polymer particle por- osity, can be employed iri any relative amounts so long as the pol.yethylene oxi~te containina surfactant is ad~ded within the rangef4 specified hereinabove. When esmploying the polyethylene oxide containiing surfactaats alone, a skin is formed around the polMer particle. 'However, this skin is so thi.n that pliasticizers -Nan penetrate it when making polymer comptounds. On the ot-her hand, wheni a surfactant, which does not contain a polyethylene oxide segment, is added to the system, the skin on the polyvmer particle has holes in it which improves the plasticizer uptake rate. It must be emphasized, however, t±hat the -polyethylene oxide segmert containing surf actait must he present in order to o~,tain the required stability of the reaction medium, or mixture. As has beeii pointed out previously, i.t i.s most important to neutralize the reaction med-Jum, and mainly the dispersing agent tberein, in order tc in- sure the stabilization of monomer droplets during the subsequent stirred reaction period. That is to soy, the manneir of forming the monomer emulsion or dispers.or. is most important and the point at which the alkali solution is added to the emulsion, in order to get the desired yield value in the polymerization medium, is critical. It has been found that if this p~rocedure is

UREA7. OMPI

SWO 1/0333 PCT/US81/00611

17

reversed in order, that is, by adding the alkali solu- tion first and then forming the emulsion, the resultant monomer droplets do not have the resistance to droplet sticking that is characteristic of these systems even though the appropriate polyethylene oxide surfactants are present. This was demonstrated by two test runs that were made using the following recipe in both runs wherein the parts are by weight:

Water (demineralized) 200 parts S* 1 Vinyl chloride 100 parts

Dispersing agent 0.12 part Nonylpheroxypoly (30) ethyleneoxy ethano. 0.08 part Nonylphenoxypoly 4) ethyleneoxy S" 15 ethanol 0.10 part Di- (secondary butyl) peroxydi- carbonate 0.03 part Sodium hydroxide 0.011 part S(Carboxylic fornt of copolymer of anhydrous 20 acrylic acid and mixture of polvallyl ethers *of sucrose containing an average of 3 to 6 allyl ether groups per molecule. In the first run the alkali was added at the beginning to bring the pH up to 5.0 followed by minutes of emulsification. In the second run, emuls- ificatica was done in unneutralized dispersing agent, before adding the NaOH, followed by a short period of blending in the NaOH. The total emulsification time was the same in both runs. The result was that the second run, wherein the NaOH was added later, was a perfectly normal run when stirred at 50 rpm during the reaction. On the other hand, in the first rur wherein the NaOH was added at the -ginning, stirring at 50 rpm. quickly resulted in the t. ion breaking due to droplet sticking and the run had a be aborted within an hour.

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.081/0333 PCT/US81/00611

18

It should be noted that the emulsification procedure affects only the resistance to droplet sticking and this difference in emulsification procedure is not important unless the reaction is a stirred one, such as in the process of the present invention. In a quies- cent reaction, such as described in U.S. Patent No. 3,620;988, the monomer droplets are suspended by the mucilage and do not collide with each other so that a..

the necessity of preventing monomer droplet sticking does not arise. Thus, it can be seen that the choice of the neutralization procedure in the present inven- tion is critical in order to attain the desired objec- tives. In addition to the use of sodium hydrcxide, other alkali metal hydroxides may be employed, such as potassium hydroxide, lithium hydroxide, and the like, and also ammonium hydroxide. It is preferable to add the hydroxides to the emulsion or polymerization med- o.. ium, after emulsification is complete, by means of an aqueous solution thereof. Satisfactory solutions are those containing trom about 1.0% to about 50.0% by weight of the alkali metal hydroxide or ammonium hydro- xide. Preferably, an ac0oeous solution containinq from about 10.0% to about 25.0% of the hydroxide is employed... Another very important aspect of the pre- sen' invention is the type and amount of agitation, or stirring employed, both in forming the polymerization recipe emulsion and during the reaction thereof Prior to the start of the polymerization reaction, all of the ingredients of the polymerization recipe are agitated or stirred to form an emulsion or dispersion wherein sufficient shear action is used tv disoerse or suspend the monomer(s) in the reaction medivum in the form of tiny droplets. This is referted to as the first stage of agitaticn. The droplets of monomer s should be of such size that when transformed into polymer particles, which are spherical and porous, the same will be of the desired size. The polymer particles produced in accord- ance with the present invention should have a diameter in the range of about 30 microns to about 1000 microns. Preferably, for most end uses, the polymer particles will have a diameter in the range of about 80 microns to about 300 microns. .It is most important to choose and maintain the proper and sufficient agitation throughout the 13.0 polymerization reaction and the various stages of con- version thereof in order to produce the spherical and S" porous particles of polymer having the proper or des- ired size. Various means can be employed to get and maintain the proper agitation and shearing action. The reaction vessel or polymerizer is made of stainless steel u. glass lined and fitted 4,ith a heating and cool- ing jacket and having a rotatable shaft mounted ntrally thereof. On said shaft are mounted one or more three- Spronged agitator blades, the prcngs of which are prefer- ably curved and pitched, a20 that is, are contoured. Of course, blades with more or less than three prongs may be used. Further, baffles are mounted internally of the reaction vessel which gives an up and down, or pumping, action to the reaction medium in addition to the circular motion thereof. One or more baffles are employed mounted on the inner wall of the reactor or adjacent thereto. iA The amount and manner .f acrtation desired or necessary to obtain the des:red results will vary depending upon the particular monomer or monomers being polymerized. Also, the particular polymer particle size desired in the end product. This means that the rpm. of the rotatable shaft carrying tne agitator blades m:ust re regulated within certain prescribed limits. There are many variables involved in obtaining the optimum on- ditions for any particular polymerization recipe, such gl EA OMPQ.

^Sa^

WO 81/03333 PCT/US81/0061 I

as, for example, the size of the reactor, the number of blades and prongs thereon, as well as the shape thereof, which will dictate the rpm. to be employed in obtaininig the desirable piarticle size, as well as the desired porosity of the polymer particles. In the usual. ase, using~ a polymerization reactor having a capacity of about 30 gal:,ons, an rpm. with a plur ality of agi- tator blades, zuch =ts one of the Pi audler type, in the range of about 50 rpm,. to about 150 ri-In. is satisfac- tory. It must be horne in mind, however, that as the reactor capacity is incroased or decreased, adjustment in the diameter width and pitch of the blades must be made in order to achieve thi desiLred agitation and shear action. This adjustmert can readily be made by those skilled in the atrt without undue diffI.Culty. It should also be noted that the agitation and shear action will also be influenced by the monomerls) being poly- merized and the temperature of the pciy -riaion re- action. In the present invention, It i~s not only important to choose the proper agitation, or proper rpm., W:& but the agitation is done in stages wherein the rpm. varies in each s-_age. This can be ref4erred to as eaqiT_- tation ramping of a sort. As pointed out above, the first stage of agitation is that of forxnitq the disper- sion or emulsion of the ingredients prior to the start of polymerization. In the next stage, or second stage, agitation r stirring is employed but at a rate lower than the first stage. The second stage commences w~ith the start of the polymerization reaction and continueo until a conversion of monoierj to polymer o:)f ab(,.ut. 0. to about 30.0%. The~ein the third staae, the stirring is increased but the rate is not above t rate of stirr:ing in the first stage. The thirdi stac,- 33 continues to completion of the reaiction which a

total conversion of about G0.0% to about,

WO 81/033,33 PCT/US81/00611

21

Th range of rpm. of the agitator in t first stage, wherein the polymerizatior dispersion or emulsion is formed, using a Pfaudler or like agitator, has been set out above. In the second stage, in the first part of the polymerization reaction, the rpm. of the agitator will be in the range of 0 rpm, to about 1/4 of the rpm employed in the first stage. In the Sthird or final stage the rpm. will be in the range of

0 rpm. to a maximum which is equal to the rpm. employed o in the first stage. To give an example, keeping in o mind that the size of 1-he reactor has a great influence -on the rpms., when polymerizing vinyl chloride, in

accordance with the present invention and using a three liter reactor, an rpm. of 600 will be used in the first stage, an rpm. of 70 is u ed in the second stage from 0% to 30% conversion, and an rpm. of 400 is used in the third stage from 30% to 70% conversion, or completion off of the reaction. It is to be noteO that in the second and/or 20 third stages one can condv.ct the reaction with no stir- ring or agitation. However, due to the exothermic nature of the reaction, it is generally advan-.ageous to agitate the reaction mixture in order to facilitaLe heat removal. In fact, this is one of the main problems with a totally quiescent polymerization reaction wherein the heat removal is difficult and very expensive. The ad- vantage of the present invention is that, by virtue of the surfactant system employed, the polymerization medium can be agitated to varying degrees throughout the entire reaction period. When using stirring, .as in the present process, the polymer particles produced have an average particle size and size distribution substantially the same as corresponding polymers made quiescently. How- ever, the polymer particles of the instant invention have a substantially higher porosity than the quies-

WO,*81,/03333 8103333PCT/US81/Q061 1 ~WG

cently produced polymers. For example, using the same recipe and the same final conversion conditions, a quiesc.-ntly produced polymer had a porosity, measured with a mercury porosimeter of 0.1052cc./gm. at 86% con- version while a polymer, produced using stirring at 1 rpm. up to 30% conversion and then at 50 rpm. to 86"o convers4,on, had a porosity of 0.2213 cc./gm. Similar results have always been obtained regardless of the surfactant system employed. The polymerization process of the present inavention may be carried cut at any temperature which is normal for the monomeric material to be polymerized. UsuaUly, a temperature in the range of about 300C. to about l0OC. will be emploved with most known poly- 151 merizable monomeric materials, as set nut nereinabove. Preferably, a temperature i.n the range of about to about 700 C. is employed. The temperature is con- trolled during the polymerization process by keerinq the reaction medium in contact with cooliig surfaces. This is accomplished by passing a coolinq medium, such as water, brine, and the like, through th.e jaclket surround- ing the reaction vessel or polymeriztdr. The cooling is necessary since most all the polymerization zeactions are exothermic in nature. It is understood, ot course, taat, where necessary, a heati.ng Medium can be f* ,.rctl- ated through the jacket. One of the problems encountered in t.hL poly- merization of unsaturated mcnoolefinla monomers iF the undesirable polymer buildup that occurs on the 4 nterior surfaces of the reactor. This buildup o4 poyrsit- feit- with heat transfer, ,eoress(iouctivity, and adversely affects polymier qa.y rouienshav? been propQsed to allevi-atQ polymer builduip, suach as coating of the internal surfaces Qf the reactor prior to conduct2,nq the polymeriz,..tio.n :,tcess therein, However, in the- use of the poo~~ h

REA& OMPI W I

W 81/03333 PCT/US81/00611

23

invention, unexpectedly, polymer buildup is substantially eliminated without the need of coating the reactor sur- faces or adding a polymer buildup inhibitor to the polymerization recipe. It is not known why the present invention reduces polymer buildup, but the advantage thereof will be readily apparent to those skilled in the art, th In order to rate the buildup in the various polymerizations of the present invention, as particul- 10 arly set forth in the specific examples which follow o hereinafter, a rating scale has been devised with res- *pect to paper and sandy buildup. In a regular suspen- sion polymerization process, where normal amounts of both types of buildup occur, the reactor is given a rating of 1.5. Any rating below 1.0 is good or a def- inite improvement. .n other words, a rating of 0,0 is perfect, and so on. To further illustrate the present inven- tion, the following specific examples tre given, it 20 being understood that this is merely intended in an illustrative and not a limitative sense. In the examples, V* all parts and percents are by weight unless otherwise indicated. Example I In this example, a stainless steel three liter reactor equipped with a 2 blade helix agitator was employed. Xn addition to the dispersant, 2 surfactants were used. The following recipe was employed: Ingredient Parts Vinyl Chloride 1J Water (Demineral i ed) 400 Dispers ant 1 0.24 Pluronic P-123 (Water- Soluble} 0.30 Fluronic AL 61 0iI- L ,Soluble) 0.50

W IP OMt_ mMI wI raffittiiteftlfiiff^^^^^ 'AT-C)

WO 81/03333 PCT/US81/0061i

24-

Example I (Continued) Xredient Parts Sodium Hydroxide 0.0212 DU-secondary butyl per- oxydicarbonate (SE3P) 00 1 )Polyacrylic acid crosslinked with 0.2- 0.3 part/10O monomer of ally. pentaery- thritol First, the catalyst (SBP) and the oi].-solu- 1o ble surfactant (Pluronic L-61) were dissol~ved in the vinyl chloride and stored at Ot The reactor was then charged with the water and dispersant and the wat~ar- soluble surfactant (Pluronic P-123) was ad~ded thereto. The reactor was evacuated and the ag:Ltator ro+.ated at 6"0 rpm. With the agitator running, the vinyl chloride mixture. was added and the St-irr ing continued until the vinyl chlor 4 le was emulsified into -the proper size drop- lets. The reactor then filled wit.i. water containing the dispersant in the same proportion as in the original Mixture. The temperature was raised to the reactioni temperatiare and the sodium hydroxide was Jinject- ed into the reactor. Thereafter the agitator speed was reduced to 70 rpm. and held there until 20-30% conver- sion was reached. Tfhen the agitator speed was increased to 400 rpm. and held there untL. completion of the reac- tion or 70% conversi.on. The aUispersant in water mixture was continuously a~dded to the reactor as the volume de- creased due to formation of polymer in order to keep the reactor full. The t3nie of reaction was 4 .5 houris at which timne the reactor was coolad rapidly -ncl the-_ pf'41y- mer slurry remo~ved. The pH of the slurry was The reactor was exam~ined for polymer ouildorp witirh thie foiloiv- ing rat' t-aper buildup 0.9 and Sandy,,, buildup 0.9. Tests were run on tho recovered and di polrmar withi the following resul. Average particle size L2I nrs

0MPI R AjT9O

WO 81/O~33 PCT/US8I/0061 1

25

Particle size Distribution 33.7% Poros i.ty 0.242 cc./gralmi I- Powder Mix Time 638 seconds (1)Powder mix time is the time in seconds it takes "he dry polymer to absorb plasticizer. The porosity was measured with a mercury porosimeter. i The polymer groduced was spherical a'Dd Lnagglomerated. Examvle TI b In this example two runs were made using the SO S 10 same recipe in orde2: to compare the porosity of the .5 SO S polymer particles when produced by the present inven- 5S5 tion an,' -,hcn produced quiescently, without stirring. The recipe used was as follows: Ingredient Parts Vinyl chloride 100

k S S

S S *5 S w1ater (demineral.l-ed) Dispersant(1 800

Igepal CO-880 2 (Water-Soluble) 0.03 *5 S I S Igepal CO-430 (Oil-Soluble1W-AVrV. ,k 0,10 sodium hydroxida 0.58 m". Di-secandary b~utyl peroxydi- 55.5 carbonate (8BP) 0.06

I 1P ~olyacrylic acid crosslirnked with 0.2-0.3 part/ 2.00 monomer of allyl pentaerythritol. 2 Nnlhnx oy(0 tyeex tao 2 S 'Nonylphenco<y poly ethylneoxy ethanol

(Note: Th: IGEPALs surfactants are made and sold by GAiF Corp., Chemical Products.) The procedure of Example I was followeO except for the agitation. In both runs the agitator was operated at 600 rpm. to eiu;ify:' the vinyl chloride into the proper droplet size. In one ru.% qute scent) the agitation was stopped at the beginning of the reaction and no furthe-. stirring was onmployed. In the other run, the agitator was run a I rpm. up to 30% conversion and then

6 7 OMPI 1,3RE-A

'WO 81/m33 ~WO 8/0333 ~>'PCT/US81/0061 1

26

at 50 rpm. until completion of the reaction (86% conver- sion) .The reactor was examined, in each case, upon completiton to determine the polymer buildup. The poro- sity of the polymers was measured with marcury poro- erimeter. The results were as follows: Run Quiescent Stirred Buildup Paper o.5 0.3 Sandy 0.0 0.0 Porosity 0.1032 cc/gran '0.2213~c As can be seen, the porosity was substantially higher 0* (over 100% higher) when using the present invention. Example III** Tn this example, two runs were made to show the effect of using one surfactant in the system which does not contain a polyethylene oxide (PEO) segment. When using PEC containing surf actants, a skin is formed around the polymer particle. Two runs were made to dem-*o. onstrate the difference, particul~arly with respect to '0. Powder Mix Time. The recipes employed were as follows*. Run No. 12 Ingredient Parts Parts Vinyl Chloride 100 100 Water (demineralized) 130 150 Di spersant ()0.12 0.12 Igepal CO-730 2 (Water-soluble) 0.57 0108 Igepal CO-210 3 (oil-sol~uble) 0.12

Sodium hydroxide (2556) 0.22 nil, 0.23m1. Di-secondary butyl peroxydicarbonate 0.02 0.02 1 'Polyacrylic acid crosslinked wi.th 0 3 mon',tner of ally! pentaerythritc:" 2 )Nonylphenoxy poly (15) ethyleneoxy ethanol. 3 Nonylphenoxy poly ethylerneoxy athanQl(. 33 47.% hydrolyzed polyvinyl acetate.

A% o 81/03333 PCT/US81/00611 -K

3"

27

K The procedure of Example I was followed except for the agitation. In Run No. 1, the agitator A was operated at 600 rpm. to emulsify the vinyl chloride. After addition of the NaOH, the agitator speed was ad- justed to 50 rpm. until 20% conversion was reached. Then the agitator speed was raised to 400 rpm. and held there until completion of the reaction (70% conversion). a a. The only difference in Run No. 2 was that the agitator was operated at 400 rpm. during emulsification and at 10 65 rpm. in the second stage. The reactor was examined, 4.

.4 in each case, upon completion of the reaction to deter- a mine the polymer buildup. The powder mix time of the a. a polymerS was measured and the results were as follows: Run No. 1 2 Buildup S Paper 0.5 0.0 S Sandy 0.0 a' Powder Mix Time (Seconds) 544 382 a It can readily be seen from these results that the poly- a a a 20 mer buildup was still relatively low but the Powder Mix a.. a Time was vastly improved when part of the recipe was ~6 replaced with a non PFO segment containing surfactant a

0 (Alcotex). This is attributed to the fact that the S.. a skin structure of the polymer particles .s substantially modified. Th. skin, instead of being cont iuous, now has holes in it leading to the porous interior of the polymer particle. This greatly improves the plastic- izer uptake rate. The holes in the skin were observed with a scanning electron microscope (SEM). The present invention has many advantages, chief among which is the production of highly porous and spherical particles of polymer. This in turn enhances the plasticizer uptake of the polymer. In addition, polymez buildup in the reactor is substantially reduced thus afforaing more efficient heat transfer. Numerous other advantages of the present invention will be app-

OMPI W]P

WO 8 1/103333 PCT/US8 1/006 11"

28

arent to those skilled in the art, While the present invention has been des- cribed in terms of its specific ernbQdiments, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be inc- luided within the scope of the present invention, which' s to be limited only by scope of the appended claims.- S S S 9*.

S@ S S S* S

5* Se S S S

S S

~.0 a 00*

0

0

S.0

U R3EA C OMPI

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Claims (3)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A suspension polymerization process for pro- ducing spherical particles of polymer having high porosity which comprises, polymerizing one or more ethylenically unsaturated monomers having at least one terminal CH 2 =C group in the form of discrete droplets in an aqueous reaction medium containing, a monomer-soluble free radical yielding catalyst, a dispersant comprising a water-insoluble, crosslinked interpolymer of one or more carboxylic monomers crosslinked with a poly- unsaturated crosslinking monomer having a plurality of terminally unsaturated polymerizable groups, the amount said carboxylic acid monomer(s) being greater than 25% by weight based on the weight of the monomers 9 in the interpolymer,and at least one surfactant employed in the range of 0.005% to 1.0% by weight, based on the 9 weight of the monomer(s) to be polymerized, said S

surfactant containing one or more poly (ethylene oxide) segments, agitating said medium to form droplets of monomer(s) therein, adding a water-soluble base to said .9 medium to at least partially neutralize the dispersant, polymerizing said monomer(s) in a first stage at a temperature in the range of 1.01C to 10 0 C with agitation 9 9 94 4 below that at which the dispersion was formed, continuing the polymerization at said temperature and agitation to a conversion of 10% to 30% then increasing the agitation in a second stage to a level not more than that at which the dispersion was formed at the same temperature as in said first stage until the reaction is complete, and recovering the spherical, porous particles of polymer having a diameter in the range of 30 microns to 1000 microns, wherein polymer buildup on the surfaces of the reactor is substantially reduced.

2. A process 7a defined in claim 1 wherein the monomer is vinyl chloride.

3. A process as defined in claim 1 wherein the dispersant is employed in the range of 0.02% to by weight, based on the weight of the monomer(s).

5 S

WO 81/033333 PCT\US81/9,0611

a .bot l .0 d on t -we-t.hJ C .4-n zoL

I ts A process as defined in claim 1 wherei.n *J N

the dispersant is a crosslinked interpolyner of aclylic S acid. A process as defined in claim 1 where n the dispersant is polyacrylic acid crosslinked with ).2 to 0.3 part/00 parts of monomer.,of kt y pep.-erythri, ol. IA 0 A process as defined in claim 1 wherein: the surfactant is a combination of an oiL-soluba and water-soluble surfactant. .0 3

1 A process as defined in ctliLui wherein the pH of the reaction medium is in' the range of to -etek*4 7. 0. A process as defined in claim 1 wheein the surfactants are nonylphenoxy poly ethylneoxy ethanol and nonyiphenoxy poly (30) ethylenecxy ethanol. q~e A process as defined in claim 1 wherein the surfactants are nonviphenoxy poly (15) ethyleneoxy ethanol and nonylphenoxy poly etbyleneoxy ethanol. V i

0 *3*

3 0**

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WO 81/03333 PCT/U,$81/006] 1

29

1. A process for producing spherical par- i tic es of polymer having high porosity which comprises, polym rizing one or more ethylenically unsaturated mon- omers h ving at least one terminal CH 2 =C group in the form of dscrete droplets in an aqueous reaction medium containing, a monomer-soluble free radical yielding o- catalyst, a ispersant comprising a water-insoluble, crosslinked poymer of one or more carboxylic monomers with a polyunsa rated crosslinking monomer having a plurality of termrally unsaturated polymerizable groups, and at least one su factant containing one or more poly (ethylene oxide) segm nts, agitating said medium to form droplets of monomer(s) herein, adding a water-soluble base to said medium to n tralize the dispersant, polymerizing said monomer() in a first stage at a Stemperature in the range of bout to about 100 0 C. 1.0 0 C. with agitation below that at wich the dispersion was formed, continuing the polymeri tion at said temperature and agitation to a conversion of out 10% to about then increasing the agitation in a econd stage to a level not more than that at whic the dispersion was formed at the same temperature as in sad first stage until the reaction is complete, and recovering the spherical, porous particles of polymer hav\ng a diameter in the range of about 30 microns to about 16 0 microns, wherein polymer buildup on the surfaces of th\ reactor is substantially reduced. 2. A process as defined in claim 1 Wherein the monomer is vinyl chloride.

3. A process as defined in claim 1 wherin the dispersant is employed in the range of about 0.02%\ to about 2.0% by weight, based on the weight of the mon- orer(s) 4. A process as defined in claim 1 wherein ^the-s rfactas-4n-t mpI yed -OthReq-4ang-.oeQ-^5

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INTERNATIONAL SEARCH REPORT International Application No PCT.'US 81/00611 1. CLASSIFICATION OF SUBJEC.T MATTER Ofi several classiflcatton symbols apply. indicate all)

According to I'ternaticnal Patent Classification (IPC) or to both National Casification and IPC TNT. CI-- C08L 27/06; C08J 9/16; C08F 2/00 U.S. CL. 260/29.6R, 29.GXA, 29.6T-; 521/56, 65, 145; 526/201, 203, 207, 208, 209, 210 FIELDS SEARCHED Minimum Documentation SearchedA Classification Sy-tem IClassiication Symbola

I260/29..6R, 29.6XA, Z9.6RB, 29. T; 521/56, 65,-145; U.S. 526/201, 202, 203, 207, 208, 209, 210, 213, 214, 215, 217, 344.2, 910, 911 Documnentation Searched other than Minimum Documentation to tho Extzint that such Documents are Included in the Fields Searched S0 S S 000 S

SASS S

S. S fit. DOCUMENTS COIISI09HED TO BE RELEVANT"1 S S 55 Category Citation of Document, Ie with indication, where appropriate, of the relevant passages Relevant to Claim No, 14 OW 0 5 S X ~TUS,A3,228,919 PUBELISHED 11 JAilUAPX 1966, 1-10 0 GATTA ET AL S..

X tJS,A3,340,243 ?UBL2.SHED 05 SEPTEMBER 1967,11 BEER ET AL.

X LS,A3,423,352 PUBLISHED 21. JANUAR 196 7 9,10 S *55503 ThPINE ET AL OS

OS 5 x US,A3,620,988 PIM-ISH20 3.6 N-OVE MB ZZ p1,-1 COHIEN. *0 5 0 f~ x US,-3,7v06,722 .1 P ::S--TED 79[ E: 19 Z2 1 1 0 N1S0N ET A,'r. S

US A3,907,730 PUB ISHED 22 S El"TE.%E R 5 IJTON E S 06* 0

0

Special categories of citetl documents: so document defining the general state of the art I~P" locjment published prior to the internetionat Mling date but earlier document but published on or after the international oir or after the priority date claimed filing date IT" iater document pubished on or after #Pe nrterrntionat ilna document cited (Or special reason other than thosft referred date of priority dale and not in conflict with the ap;iation. to in the other catories b~ut cited to understand the priiicirle or theory undotving document referring to an oral disclosure, use. exhibition ar the invention othter means 1.X. document of particular reievance IV. CERTIFICATtON Date of the Actual Compietion ofthe Internationat Search D~ate of maing of ii'i ainternational Soarev, R~eport

08 JULY- 1981 0 International searching Authorityr Iueti A 1f0p6* ISA/US Form PCTIISA/2io (.second shelf) (October 19M lnternaflonaw Application No, PCT/US 81/006111 ]FURTrHERt INFORMATION. CONTINUED FROMtTHE SECOND SHEET 1. CLASSI ICAT1)4 OF S UBJECT MATTER (it several classification ;symbols apply, Indicate all) 3 According to Wwntereonal Palent-Clasalication (IPC) ,3r to both National ClaslIlcatlon and [PC U.S. CL 3-26/215,217,344.2,910,911.

V.Lj OBERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHfABLE I10

This Inteonastial search repor* hai not been established In reapect of certain claims unider Artlclei 17(2) for the following reasons: aiclaim numbers because they relato to subject matter 13 not required to be searchecd by this Authority, namely: 0

2.Ct Claim numbers- because they rmlate to parts of the inte-atIcrnat applicatlon that do not comply with the preacied requirL. mania tQsuch an externt that no meanlnl~ful Internatio~nal search can be carried out %3specicilly: 0

1.

VIJJ 08SERVATIONS WHERE UNITY OF INVENTION IS LACKING

This- International Searching Authority found multiple Inventions In this Internationalf application as follows.,

As all required aditltlonal search lees wets timely paid by the applicant, thia international search repot covers ail searchable claims of the International application. A* only some of the required adiional search fees were timely paid by the applicant, this international search report 0overa orf thoat* claims of the International application tor which fees were pid, speclicallyclaims-

3MNo required addfitional search fees wete timely pif~ by the applicant Consequen!!y, this international esatch report is retticteit to the Invention first mentioned in the cilims. It Is covered by claim numnhers:

Rermark an Protest ~J1-be additional search fees were accompanied by applicant's protest. N o protest accompenled the payment of additional search fees.

Form P CTI[SA210 (supplemental' sheat (October 19M