CA2079799A1 - Terpolymers of maleic anhydride, c1-c5 alkyl vinyl ether and isobutylene or a c12-c14 alfa-olefin, and crosslinked products thereof - Google Patents

Abstract

Terpolymers of maleic anhydride, a C1-C5 alkyl vinyl ether and isobutylene or a C12-C14 alpha-olefin, and crosslinked products thereof, are provided herein for use in thickener, denture adhesive, sunscreen, hair spray, and waterproofing compositions.
The alpha-olefin comonomer is a hydrophobic, straight chain, unsaturated hydrocarbon such as dodecene or tetradecene, which is present in the terpolymer in predetermined amounts relative to the hydrophilic maleic anhydride component, to provide a terpolymer having a suitable HLB for these applications. The isobutylene comonomer provides hydrophilic terpolymer compositions which are particularly useful as denture adhesives.

Description

WO92/017~4 PCT/US9~/04004 - 1 ; 2 ~ 79 7 9 9 TERPOLYMERS OF MALEIC ANHYDRIDE
VINYL ETHER AND ISOBUTYLENE OR A C -C
~ 12 _ 14 ALPHA-OLEFIN, AND CROSShINKED PRODUCTS THEREOF
, This invention relates to terpolymers of maleic anhydride, a Cl-C5 alkyl vinyl ether and isobutylene or a C12-C14 alpha-olefin, and to crosslinked products thereof, which are provided within predetermined compositional ran~es for application in denture adhesive, sunscreen, hair spray and waterproofing compositions; and fox effective compatibility with organic solvents.
: Copo}ymers of maleic anhydride and alkyl vinyl ethers are well known in the art and are conventionally : prepared by free radical precipitation polymerization of : the monomer mixture in an aromatic hydrocarbon solvent such as benzene in the presence of a protective colloid.
Another method involves copolymerization of maleic : -anhydride, an alkyl vinyl ether and/or a C3-C1O alkene in contact!with a~powder bed. ~ In thè-la~ter method,~
disclosed in U.S. Patent 4,370,454, a large excess of-the . . alkyl vinyl .e~her~and/or alkehe, e.g. 3 to''25,`:preferably 5 ,to 15,` moles thereof ï per mole:of maleic anhydride mnnomer, .: is present-during the polymerization,; instead cf the usual l:l ~ole ratio required of`the'copolymer.~'In the powder bed.~method,~ the heat~generated during`;polymerization is ~removQd by:.evaporating:the:excess~alkyl'~vinyl"'èthèr-ànd/nr alkene::whlch boilslrak a lower temperàture than maleic;'~
,i..anhydride n'' ;~The examples'in this patentlwere!directé~.~`to 'copolymers of maleic:anhydride;and alkyl:vinyl~fêthers~ or Jf~:~ copolymers of~ malëiciànhydride`and'alkene. ~ r~

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What is provided herein are terpolymers o~ maleic anhydride (MA), a Cl-C5 alkyl viny~ ether (AV~) and is~butylene (IB) or a Cl2-Cl4 alpha-olefin (AO), and crosslinked products thereof, for use in thickener, denture adhesive, sunscreen, hair spray and waterproofing compositions.
Suitably, the molar ratio of MA:AVE:AO in the terpolymer is about l:O.90-0.99:0.Ol-O.lO, preferably about l:0.94-0.96:0.04-0.06, respectively.- Representative cl-C5 alkyl viny} ethers include methyl vinyl ether, propyl vinyl ether and butyl vinyl ether. Suitable C12-C14 alpha-olefins are straight chain unsaturated hydrocarbons such as dode¢ene and tetradecene. Crosslinked products of such terpolymers with such crosslinking agents as 1,7-octadiene and 1,9-decadiene also are provided herein.
Suitably the molar ratio of MA:AVE:IB is about 1:0.4-0.9:0.1-0.6, preferably abo-lt 1:0.5-0.8:0.2-0.5. As denture adhesives, the terpolymer provided has a weight.
average molecular weight of,about 30,000 to 40,000, preferably about"50,000"to 350,000,:and in~-the.:form~.of.a mixed, partial salt such as the calcium/sodium ~alts wherein,the~equivalent ratio,,:of,calcium to sodium cations may,.range from 2.1 to lO:l,,preferably between-:3:1,to 7:1, and the degree,of neutralization of.initial carboxyl groups ls,from 0.5 to,0,.9~5,.preferably from 0.7 to 0.9... ~... .
The,!.,terpolymers products of.the invention~are !
~articularly,.characterized by~a;predetermined,ratio~between the~hydropho,bic,,l,,stra1,ght chain unsaturated,C12-.C14~".;i.~
hydrocarbon component.and:the,:hydrophilic, maleic:anhydride -,component, which,~ratio,,affords~alsuitable ;o ,-~ '`?~
hydrophilic-lipophilic,,balance~,~HLB).for.,.the terpolymer:and its crosslinked derivative.
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WO9~/017~ PCT/US91/04nO4 f~
_ 3 _ ~ 2~79799 A preferred process for making the terpolymers of the invention also is characterized in that the monomers are polymerized in a mixed solvent comprising a cycloaliphatic hydrocarbon such as cyclohexane and an aliphatic c~rboxylic ester such as ethyl acetate.
In this process, a suitable reactor is provided with appropriate inlet tubes, agitation means, and heater and temperature control means. The reactor is first purged with nitrogen to remove air from the system. Generally three separate purges are employed, at about 3 bars pressure and about 40C. The reactor is prechar~ed with .
maleic anhydride and the crosslinking agent in a suitable solven~ which may be an aromatic hydrocarbon such as benzene or toluene but is preferably a mixed solvent of a cycloaliphatic hydrocarbon such as cyclohexane and an ester of an aliphatic carboxylic acid such as ethyl acetate. A
solvent system which is a 5Q:S0 mixture of cyclohexane and ethyl acetate.is preferred.
Th~ precharged reactor is purged with nitrogen at about 58C. and a free-radical polymerization initiator is introduced.in three"stages~during the polymerization, ,~
generally.,at the beginning,,after about 1,~-1/2 hours,and~
~inally after about 3 hours, for a poly~erization period of .
,,-about ~ hours. ,Alternately, the initiator,can be ..introduced in.a continuous manner, e~g. as a solution,in the.reaction solvent..,.Any suitable initiator-known~in the t art;,~ay be used including but.not limit,ed to,peroxides.
~er,tiary~butyl~or,,te~rtiary,.~amylperoxy plvalate~,are,~,~..,..J~,~
~preferredl~ The..c,o,ncentration ,o~,initiator,may",,v,ary!w,idely, althou~h suitably the initiator comprises about,O.o5~to ~i%
,.,by.,,weight of ,the maleic~anhydride.reactant. ~
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W092~017~4 PCT/U~91/0400 1~2 ~7 97 99 - 4 -Then, simultaneously with feeding of initiator, the alkyl vinyl ether and isobutylene or alpha-olefin monomers are introduced separately or together into the precharged reactor, and at a controlled rate, during the course of the polymerization.
Overall, the molar ratio of maleic anhydride to th~ combined alkyl vinyl ether and isobutylene or alpha-olefin mcnomers in the process is sat at about less than-l:l. In practice ahout a 10% excess of the alkyl `
~inyl ether over the l:l ratio is used to ensure complete conversion of the maleic anhydride to the terpolymer. The molar amounts of alkyl vinyl ether present in the ~erpolymer is about 0.4-0.9, preferably 0.6-0.8, and the molar amounts of isobutylene present in the terpolymer is about O.l-0.6~ preferably about 0.2-0.5.
The molar amount of Cl2-Cl4 alpha-ole~in present in the resultant terpolymer is about 0.0l-0.lO, preferably 0.04-0.06. The crosslinker, when present, corresponds to about 5 wt. ~ of total monomers in the terpolymer. The predetermined amount of hydrophobic -C12-Cl:4 ~alpha-ole~in~in~thé;t~rpolymer~will provide terpolymers with a suitable HLB for various commercial -applications. ~ - f -' Of course, during the polymerization, the reaction mixture is-agitàted effectively, and, at the conclusion of the`polymerization, the~-reaction product'is ~éld at`-thè~
polymerization temperaturé for àbout l l/2~hours. -Thén excess3alkyl vinyl'ethér;-is~entèd and the product'isf ~
discharged,~ filtered~and~the'~inelpowders~of thé'terpolymer r ~ r~ ,c; ~ ~; rlY ~ ." ~ t 5 dried. ~
For usé;as a denture~aa~esive~ the terpolymèr: i5 converted to its mixed, partial salt, which preferably is employed as a dry powder having a particle size of less than 250 ~, and, more desirably, a par.ticle size of from about 5 to about 200 U.
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Denture adhesive compositions are provided herein by incorporating dry powders of the above adhesi~e copolymer as mixed salts into a liquid base carrier by mixing until a homogeneous cream paste suspension or collodial dispersion is obtained, usually within a period of from about 20 minutes to about 5 hours. The resulting composition contains an effective adhesive amount of the adhesive copolymer mixed salt, generally between about 5 and about 50 wt. %, and preferably between about 10 and about 35 wt. %, of the final composition.
Suitable mixed partial salts herein include the calcium/sodium mixed partial salts which are prepared by reacting the copolymer with suitable bases. Preferably the equivalent ratio of calcium cations to sodium cations in the mixed partial salts may range from 2:1 to 10:1 and most preferably is between.3:1 and 7:1 ~on a mole ratio basis, ~
the range of calcium to sodium cations is-~rom 1:1 to 5:1, most preferably from 1.5:1 to 3.5:1~. The sum total of cations in the mixed partial salt should be suff icient to give.a degree of neutralization of from 0.5 to 0.95 and pre~erably 0..7-.to 0.9 of the total initial carboxyl groups ~-in the~copolymer.~ Inithe determination o~ the'total ; -: initial carboxyl groups in the copolymer, the anhydride ... .-radical is considered as containing 2 initial carboxyl groups.
.: . The bass,carrier portion of the composition .g~nerally includes~a~.water soluble or;partially:^water soluble hydrophilic;carrier which~is capable of swelling upon exposure to moisture to form a mucilaginous mass.
Such carrier materials include natural and synthetic gums, viscous liquids, gels and powders. Among those suitably employed as base carriers in the composition~are karaya gum, gelatine, gum tragacanth, gum acacia, gum shiraz, algin, sodium alginate, tragacanth, methyl cellulose, a mixture of petrolatum and mineral oil, glycerine, .

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W~92/017~4 PCT/US91/Q~004 2~7~799 - 6 ~
polyvinylpyrrolidone, K-30 and K-90, carboxymethyl cell~lose, ethylene oxide polymers, of which the preferred is a mixture of petrolatum and mineral oil in a ratio of 40:60-60:40.
The adheslve terpolymer of the invention can be employed as the sole adhesive component in the denture adhesive composition or it can be used as a coadhesive with another adhesive material. Such adhesive additive, if present, will generally comprise about 5-20~ by weight of the composition. Suitable adhesive additives include natural or synthetic polymers such as cellulose, karaya gum, gum tragacanth, gum acacia, carboxymethyl cellulose or salt thereof, polymethaorylate, polyvinylpyrrolidone, polyvinyl acetate, or any mixture of the above.
The compositions of the invention are particularly useful for affixin~ dentures and can also be used in surgical procedures which require temporary displacement of tissue. As-a denture adhesive, the thermal stability of the present composition, over a temperature range which is ~ at least sufficient to embrace all conditions encountered ; by living tissue, e.gs. 5~-50C., is particularly desirable. ~Because of their~increased adhesive stren~th ~and thermal stability, the composition retains its adhesive properties over a long period of time, i.e. up to 24~hours.

The following illustrates~a~few represe~tative ~ormulations into which the~adhesive;terpolymser-~can be r~added in effective amounts up to about 50~ ;s~;~

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., Crea~ Denture Adhesive Com~osit'on Wt. %

Mineral Oil 30 Petrolatum 25 Sodium carboxymethyl cellulose 20 (aZdhesive additive) Colorant Flavoring Agent . ~ 0~5 Material of Invention 23~5 . .
Paste Ostomy Adhesive Composition Wt. %

Mineral oil ~heavy) 35 Glycerine . ~ . 5 Polyvinylpyrro lidone 20 Carboxymethyl cellulose 5 TOSY1ate Of -qUat. aminO-N-PrOPY1PYrrO1idOne 0.5 Natrial.of Xnvention . 34.5 .. ,. ~ .. ~ .. ~ .. ... .. . . . . . . .. ... . .. .. . . .
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Denture Adhesive Powder Composition Wt %

Gum tragacanth 40 Gum~acacia.i, :: .3 :: '. ...... : . 20 Spearmint oil ~ Ø05 .
Material~of~Inventioni.~ 39. 05 :~

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W~92/017~4 PCT/US91/~004 - 8 - ~i!
2~79rdt(~

98 g. (l.oo mole) of maleic anhydride (MA) and 21.04 g. (0.125 mole) of dodecene (DD) in 534 g. of toluene was.precharged in a reactor eguipped with suitable inlet tubes, agitation means, and heater and temperature control means, and the reactor was purged three times with nitrogen at 50 psi nitrogen pressure at 58~C. Then 3.92 g. (4 wt. %
on MA) of Lupersol 11 in 15 g. of toluene was added at a rate of 9.9 ml/min. Simutaneously, 55.12 g. (72.13 ml) (O.~5 mole) of methyl vinyl ether (MV~) was fed into the reactor over a period of 4 hours while agitating the reaction mixture at about 280 rpm. The reactant monomers corresponds to 23% solids in this solvent system. The reactor was held at 58C. for 1 hour, cooled, excess methyl vinyl ether was vented, the product was discharged from the reactor, filtered, washed, and dried.
A solid product was obtained which had a molar ratio of maleic anhydride to methyl vinyl ether to dodecene tMA:MVE:DD) o~ about 1.0:0.95:0.0S. The yield was 147.3 g.
(91.2%). The specific viscosity was 0.15 as measured in 1%
methyl ethyl ketone, viscometer I 616, size loo.
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; 60.0 g. (0.612 mole~ of maleic an~ydride.was -precharged into a reactor with 4.78 g. (0.343 mole)`~of:
tatradecene, 4.7~ g. (0.0434 mole) of 1,7-octadiene and 420 g. of a 50:50 mixture of cyclohexane and ethyl acetate. The reac~or was purged with nitrogen and heated to 58C. Then a mixture of 39.09 g. (50.88 ml., 0.365 ~.
mole) of methyl vinyl ether was admitted into the raactor slowly over a period of 3 hours. Simultaneously, three ,. `:
portions of 0~1 g. each (O.5% based on MA) of Lupersol 11 wer~ admitted during the polymerization. After 3 hours, , .

WO92J01724 PCT/~S91/OqO04 2~3797 ,.,....

the reaction product was held at 58C. for 1-1/2 hours, cooled to room temperature, excess methyl vinyl ether vented and the product was discharged, filtered and dried to provide a fine, dry crosslinked terpolymer product.
The crosslinked terpolymer comprised a molar ratio of maleic anhydride to methyl vinyl ether to tetradecene (MA:MVE:TD) of about 1.0:0.96:0.04 and was crosslinked with 5.0% by weight of l,7-octadiene based on the total weight of.the terpolymer.

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:The terpolymer was crosslinked with other crosslinking agents selected from dienes, divinyl ethers and allyl carbohydrates with similar results.
: . . . . .
~ . EXAMPLE 4 .
. The 1,7-octadiene crosslinker was introduced with the externally fed monomers. The reaction product slurry . I
was.~thick~but filterable, and it was dried at 65C. in .~vacuum oven..-~
The crosslinked ~erpolymars prepared~above found particular application in thickener, adhesive, sunscreen, hair ~pray and waterproofing compositions.

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2~7~7~9 lo- ~
EXAMPLE lA

65 g. (0.67 mole) of maleic anhydride in 194 g. of a 50:50 mixture of cyclohexane and ethyl acetate was precharged in a reactor equipped with suitable inlet tubes, agitation means, and.heater and temperature control means, and the reactox was purged three times with nitrogen at 3 bars pressure and at 58C. Then 0.217.g. of Lupersol 11 in ,.
2 g. of a 50:50 mixture of cyclohexane and ethyl acetate was added. Simutaneously, a mixture of 28.9 g. (37.6 ml., 0.5 mole) of methyl vinyl ether and 9.3 g. (15.8 ml., 0.17 mole) of isobutylene was fed into the reactor over a period of 3 hours while agitating the reaotion mixture at about 180 rpm. Two additional portions of initiator of 0.217 g.
each were introduced after 1-1/2 and 3 hours. T~e reactant monomers constitute a 20% solids mixture in this solvent system. The reactor then was held at 58C. for 1-l/2 hours, cooled, excess methyl vinyl ether was vented and the product-was.discharged:from.the reactor. The desired powder terpolymer,was obtained by filtration;.it had a molar.,ratio:of maleic.anhydride..to methyl:vinyl ether to isobutylene of 1:0.75:0.25, which was substantially.the ,same ratio as the;reactants,used in the~process.

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W~92/01724 PCT/US91/0~004 --~. ,, - 11- 2~97~9 EX~MPLES 2A - 12A

The process of Example lA was followed to provide the terpolymers of desired compositions using monomers of different feeding composition and in various solvent systems.

. -- TABLE 1 : -Molar Com~osition of Reactant Monomers in Examples 2A - 12A
Methyl.
Maleic Vinyl Ex. No. Anhydride . EtherIsobutylene Solvent 2A 1 0.85 0.25CH/EA
3A l 0.80 0.25CH/EA
4A . 1 0.55 0.55CH/EA
5A . 1 0.60 0.60CH/EA
6A 1 0.50 0.50toluene `7A 1 0.82 0.28toluene 8A 1 . .. ......... 0.750.25~ ~ benzene 9A 1 0.~3 0.28benzene lOA , . .~ 0.88 0.28 benzene llA . r ~ 0 ~ 50 z 1 ~ O ~ 50 - benzene 12A 1 ! 0.25 0 ~ 75 !benzene `
The molar, composition of the terpolymer obtained ~was subskantially the same as that of charged reactant ,!J,. ~ m,o,nom~,ers.~n~,he pr,o,cess.:..~ . ~ :~, A',;;' ' . , ,~ .
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65.0 g. (0.663 mole) of maleic anhydride was precharged into a reactor with 5.33 g. (0.048 mole) of 1,7-octadiene and 535 g. of toluene. The reactor was purged with nitrogen and heated to 58C. Then a mixture of 21.17 g. (27.67 ml., 0.365 mole) of methyl vinyl ether and 20.46 g. (34.81 ml., 0.365 mole) of isobutylene was admitted into the reactor slowly over a period of 4 hours.
Simultaneously, three portions of 0.65 g. each of Lupersol 11 was admitted during the polymerization of 4 hours. Then the reaction product was held at 58C. for 1 hour, cooled to room temperature, excess methyl vinyl ether was ven~d and the product was ~iltered. 100.5 g. of dry terpolymer powder was collected.
The crosslinked terpolymer obtained in this manner had a molar ratio of maleic anhydride to methyl vinyl ether to isobutylene of 1:0.50 0.50 and was crosslinked with 5.0%
by weight of 1,7-octadiene based'on the total weight of the terpolymer.

" - - ` ' EXAMPLE 1 4A
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The terpolymer wa~ crosslinked with other crosslinking agents seiected from dienes, divinyl ethers and allyl carbohydrates with similar results. ~- "

-EXAMPLE`15A ' The 1,7-octadiene crosslinker was introducéd with the externally fed monomers. The reaction product slurry was thick bu~ filterable, and it was dried at 65C. in vacuum oven. 98.9 g. of a dry product comprising the crosslinked terpolymer was 'obtained. ' ' .
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WO9~/017~ Pff~T/US91/f~O

- 13 - f~7 97 EXAMPLE lB

A 1-liter resin kettle was equipped with a stirrer, re~lux condenser, a N2 inlet tube and an inlet closed with a rubber septum for introduction of a polymerization initiator. The kettle was charged with 60.0 g. (0.61 mole) of malelc anhydride (MA), ~7.9 g. (50 wt. %) of ethyl acf-ttate f~EA) and 97.9 g. (50 w~- %) off cyf,,lohexane (CH). Agitation of the mixture at 130 rpm was begun, and the sys~em was purged by bubbling in N2 for 30 minutes, during which time the maleic anhydride dissolved complfEf~ely. The reaction mixture was then warmed to 58C.
and 0. 2 g. of Lupersol 11 (Pennwalt) was injected through the septum to initiate polymerization. Simultaneou~ly, ff~ropwise addition o.19.6 g. (0.33 mole) of methyl vinyl ether (~VE) and 18 . 88 g. (0. 33 mole) of isobukylene (IB) was begun and continued over a period of 3 hours.
Lupersol 11 was added in an amount of O . 4 g. after 1-l/2 hours. After completion' of all additions, which required 58 C ., the resulting mixture was maintained at 58oc. ~or l-1/2 hours. Therea,,f,ter', ~ the reaction mixture was cooled to room temperaturfef, excess MVE ve~ted and the slurry was pumpfed out of the kfe~tle intfD a filtration ùnit. : There the slurry was ~iltered and the polymer product was dried for about-12 hour's at'~'65C. " in~a forfsed'air-oven. fThe pol ~ er product was la ~uniform, 'i~ine~white powder, having a molar atio -of ~ ~ E IB-Iof~fl 0.55 0 55. f ,~,r~ ..f~.;-?f~ J ~i ';' ~- ;`EX~PLE ~B ^l ~

'3 ` -:;~The':procedure''of Example'~ lB ~'was followff~d to~;
provide copolymers ~o~ varying'~compOsitions`Jwithin' thle/molar range of 1: O . 4-0 . 9: O .1-0 . 6, including one at 1. O: O . 75: O . 25.

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W~92/0~724 PCT/US9l/~004 ~' 2~7 97 ~ - 14 - ~

EX~MPLE 3B

PREPARATION OF DENTURE_ADHESIVE COMPOSITIONS OF INVENTION

The terpolymers of Examp}es lB - 2B were converted to their mixed, partial salts illustrate~ as follows:
58~6 g. of the terpolymer was charged into a 250 ml raund bottom, 3-necked flask together with 260 g. of isopropyl alcohol. The contents were agitated to make a slurry and 18O1 g. of calcium hydroxide was added slowly with agitation during 15 minutes. Then 2.85 g. of sodium hydroxide dissolved in 112.5 g. of water was added wlth agitation. The mixture was heated at~45C. with agitation for 4-1/2 hours. The pH of ~he liquid phase was 6.1. The mixture was filtered and the precipitate was dried in a vacuum oven overnight at 65~c. to provide 93.4 g. of a dried product. Similar copolymer conversions to the mixed partial salts were effected for the terpolymers of Example 2B.
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. PREPARATION OF ADHESIVE COMPOS~TIONS FOR INSTRON TESTING
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'. .,~, ,-~ The dry,,mixed salt,of,the MA/MVE/IH terpolymer of ' i Example,,lB,.was-milled,,to pass through:a,number 60:.mesh - sieve (250 u) and the,~resulting,,powder~was then~dispersed at a temperature o~ 55-~5C., followed by cooling to Z0-25C., into a petrolatum:,base using mechanical stirring. The ratlo o~ copolymer to base by weight was 1:2! ~;.The,resulting cream dispersion,was collected as the 3si~ed~ ~,adhes,iv, e i,composition ~ 37~

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WO92/017~PCT/US91/04004 ~s- 2~7~7~
~ 15 --EXA.MPI,E 5B
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Adhesive compositions of GANTREZ MS-955, which is a commercial mixed salt copolymer of maleic anhydride and methyl vinyl ether, also were prepared for testing in the same manner as described above for Examples lB - 2~.

~ --, -EVALUATION OF DENTURE ADHESIVE COMPOSITIONS
.
2 g. samples of each of th2 above prepared compositlons were evaluated for adhesion characteristics by Instron ~esting according to the following procedure:
In the first step, the upper and lower plates of the Ins~ron apparatus were brought together to obtain a zero position. The upper plate was then raised 0.06 inch and the upper cycle limit on the Instron indicator is set at this point. The upper plate was then lowered and the lower cycle limit was set. In its lowest position, the upper plate was distanced 0OO3 inch above the lower plate.
With these Instron se~tings determined, the upper plate was then raised and 2 g. of the test sample was uniformly spread over he surface of the lower plate in a 1/16 to 1/8 inch thickness; thereafter si~ulated salivary fluid was applied over the sample ! so that it was barely covered.
The Instron crosshead was cycled between the previously set limits at a crosshead speed of 0.2 in./min.
The Instron chart was set in the continuous mode at a speed of 2 in./min. to record the compression and adhesion force for each cycle, 5 to 100 cycles.
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W092/0l724 PCI'/US9l/04004 2~799 - 16 - ` ' At the end of 100 cycles, the motion of the upper plate was halted and raised high enough to clean the surface before the next adhesive test.
Each recording was analyzed and the adhesional forces (lbs.) for the 1st, 5th, 10th, 20th, 40th .... 100th cycles were recorded and then plotted graphically.

The results of this study are shown in the FIGURE
which data show that significantly better initial stick :
strength and long term adhesion is obtained for adhesive :
.
formulations containing the t~rpolymer compositions of the ~ ~
invention as compared to a related copolymer composition ~ .
(MS-955), which is considered useful as a denture adhesive.
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Claims (6)

WHAT IS CLAIMED IS:

1. A terpolymer characterized by comprising maleic anhydride, a C1-C5 alkyl vinyl ether and isobutylene or a C12-C14 alpha-olefin, optionally crosslinked with a crosslinking agent.

2. A terpolymer according to claim 1 which is further characterized by comprising maleic anhydride, a C1-C5 alkyl vinyl ether and a C12-C14 alpha olefin in the molar ratio of about 1.0:0.90-0.99:0.01-0.10.

3. A terpolymer according to claim 1 which is further characterized by comprising maleic anhydride, a C1-C5 alkyl vinyl ether and isobutylene in the molar ratio of 1:0.4-0.9:0.1-0.6.

4. A terpolymer according to claim 3 still further characterized in having a weight average molecular weight of about 30,000 to 400,000.

5. A terpolymer according to claim 4 further characterized by being in the form of a mixed, partial salt which is particularly useful as a denture adhesive composition when mixed with a base carrier.

6. A terpolymer according to claim 5 still further characterized in being in the form of a mixed, partial calcium/sodium salt wherein the calcium to sodium cation equivalent ratio is 2:1 to 10:1 and has a degree of neutralization of from 0.5 to 0.95 of the total initial carboxyl groups.