New high-charge density hydrophobically modified cationic HEC
Transcription
New high-charge density hydrophobically modified cationic HEC
j, Cosmet. Sd., 58, 421-434 (July/August2007) New hioh-charoedensityhydrophobically modifiedcationic HECpolymersfor improvedco-deposition of benefitaoents and seriousconditioninofor problemhair T. V. DROVETSKAYA, E. F. DIANTONIO, R. L. KREEGER, J. L. AMOS, and D. P. FRANK, Amercho/Corporation, A Subsidiary of TheDow Chemical Company, 171 RiverRoad, Piscataway, NJ 08854. Synopsis A seriesof newhigh chargedensityPolyquaternium-671 (PQ-67)polymers havebeenprepared and evaluated in shampoo formulations. Thesenewcompositions represent an additionto the familyof highviscosityquaternized hydroxyethylcellulose (HEC) polymerswith cationicsubstitutionof trimethylam- moniumanddimethyldodecyl ammonium 2 (Figure1A)described in (1) and(2). Theevaluation protocol includedobjectivelab methodsand subjectivepanelstudieson differenthair types.Commercialcondi- tioning polymers: PQ-67(Polymers SoftCAT LM3) andcationic guar 4 (Jaguar C-13S ©5)wereusedasperformance benchmarks. It wasfoundthat increasing the cationicchargedensityof the PQ-67 polymersabove1.45 meq/g(equivalent of 2 weight-percent (wt.%) nitrogen)resultedin a several-fold boostof their co-deposition ability. Theseexperimental, high chargedensityPQ-67 polymerswereshownto deliversilicones and otherperformanceingredientsfrom shampoo formulations moreefficientlythan anyotherpolymercurrentlyavailable on the market for rinse-offhair cleansing/conditioning applications.The polymersalso provided improvedwet and/ordry conditioning, volme control,and couldbe instrumentalin achievingsleek lookinghair andimprovedcontrol/manageability of unrulyor frizzyhair.The high chargedensityPQ-67 polymersare alsoideallysuitedfor highly-fragranced surfactant-based formulasthat are usedin aromatherapyandspaproducts dueto their superiorabilityto deliverfragrance. BACKGROUND Hair is a diverse substratethat comes in different shapes,colors and textures. Its properties andappearance varyfor differentracesandagegroups,asdo the benefitsthat consumers are seekingin new hair care products.As more and more consumersare shampooing, grooming,coloring,bleachingor waving/straightening their hair, they are Addressall correspondence to T. V. Drovetskaya. JHydrophobically modified cationic conditioning HEC polymers. 2Supplied byAmerchol Corporation/Dow Chemical Company underthetradenameSoftCAT TMSLandSK. 3 Supplied by Amerchol Corporation/Dow Chemical Company. 4 Guarhydroxypropyltrimonium chloride. 5 Supplied by Rhodia. 421 422 JOURNAL OF COSMETIC SCIENCE A.PQ-67 •+"' C,•I•I-CH,C I' B.PQ-•O •O-(CH2CH20)i(CH2Ct HCH)•H OH CH -'• ( HO C,•}+.H•H,C i- •O-(CH2CHzO)i(CH2(•H CH)•H )7) • n(o•O•)n O Hc,• oOH (CH2C H20 )x'(CH2C H(•.H)œH . CHjI•-CH 3 CI C•H•s Figure 1. Cationic conditioningHEC polymers. also damagingit, and thus the needfor productsthat can mitigate and repair this damageis increasingdramatically.The currentofferingof cationicconditioningpolymersis quite broadand is expanding,with HEC-basedpolymersrepresentinga significant portion of this market. Varying structuralparametersof thesepolymers,suchas molecularweight, cationicand hydrophobicsubstitutionand/or the degreeof ethoxylation significantlyimpactstheir performanceon hair and createsthe much needed diversityof propertiesand benefits.This paper describesthe impact of the charge substitution(CS)in combinationwith the hydrophobic substitution(HS) on the depositionpropertiesand overallconditioningof PQ-67 polymers.New compositional featuresenhancedthe performance of the experimentalhigh chargedensityPQ-67 polymers,whichwerefoundsuperiorwhencomparedto anyof the competitivebenchmarks usedin this studyin depositionof performance ingredientsand for overallconditioning. This performance makesthe new structures a valuableadditionto the family of cationic conditioningpolymers.Thesepolymerswere found to be especiallyusefulto manage hair types that benefit from volume control and extra-conditioning,suchas unruly, 6 difficult-to-managehair or for Asianhair types. RESULTS POLYMER AND DISCUSSION COMPOSITION New experimentalhigh chargedensityPQ-67 polymersbelongto the family of high viscosityquaternizedhydroxyethylcellulose(HEC) derivativeswith cationic substitution of trimethyl ammoniumand dimethyldodecylammonium(Figure 1A) describedin (1) and (2) and recently commercializedfor personalcare applicationsby Amerchol Corporationand the Dow ChemicalCompanyunderthe trade nameof PolymersSoftCAT TMSL and SK. Similar to the commerciallyavailablegrades,experimentalPQ-67 samples described in thispaperwereproducedby reactingHEC polymerswith 3-chloro2-hydroxypropyldodecyldimethyl ammonium chloride and 2,3-epoxypropyltrimethyl ammoniumchloridein aqueousisopropanol (2). In this work we usedpolymersmadeof a high viscosityHEC with the degreeof ethoxylationsimilar to one of commercially c,Wearecurrently inprogress evaluating performance ofexperimental highcharge density PQ-67polymers on Asian hair. 2006 TRI/PRINCETON CONFERENCE 423 availablePQ-67 gradessuchasPolymers SoftCATSLandSK. Lowlevelsof hydrophobic dimethyldodecyl ammoniumsubstitution(HS •< 0.01) wereusedto impart hydrophobic characterto thesepolymers. Severalstructuralparametersof cationiccellulosicether derivatives,suchas PQ-67 (Figure 1A) and their non-hydrophobic structuralanalogs,PQ-10 (Fig. lB) polymers havea profoundimpacton theirperformance on hairandskin.Theseparameters include molecularweight (Mw), cationiccharge(CS), as well as the degreeof the side chain substitutionwith ethyleneoxide (EO MS). Examplesof such structure-performance relationships for PQ-10 polymersin surfactantsystemswere previouslydescribedin industrysources (3-6). On the otherhand,the structuralpotentialof PQ-67 compositionsis muchlessexploredandunderstood. In additionto the structuralfeaturesalready presentin PQ-10, the structureof PQ-67 polymersoffersonemorevariable-thedegree of hydrophobic substitution(HS), whichis anotherusefultool for modifying,controlling, and improvingcertainperformance aspectsof thesepolymerson hair (1) and skin (7). The newresultspresented belowdemonstrate that increasing the cationicchargeto above2 wt.% N in the hydrophobically modifiedquaternizedHEC polymers,suchas PQ-67, resultedin a severalfold boostof their depositionand deliveryproperties, and significantlyimprovedthe overallperformance of thesepolymerson hair, especially non-chemically treated,coarse,difficult to manageand unruly hair types. The highchargedensityPQ-67 polymerswereevaluated in shampoo formulations using objectivequantitativelab methodsand subjectivepanel evaluationon hair tresses. Commercialconditioningpolymers:PQ-67 with chargedensitylessthen 1.45 meq/g (SoftCATTMSL and SK) and cationicguar (Jaguar © C-13S)wereusedasperformance benchmarks. PERFORMANCE IN SHAMPOOS WITH SILICONES The principalintent of shampooing is to cleanthe hair. However,productsthat are designedsolelyfor cleansingcanleavehair tangledand unmanageable whenwet, and raspydry and dull-lookingupon drying ((1) and references therein). As previouslydescribed in (1), manyconditioningpolymersandvariousotherperformanceingredients,e.g. insolublesilicones, canimprovethe hair conditionby reducing the combingfriction of hair and providinga soft, smoothfeel and healthy, shiny appearance. Cationicpolymers,suchasPQ-10, PQ-67, and cationicguar, areknownto workin theseways,in thesesystems, aloneor in combination with otheractives.They are assumedto form a polymersurfactant complex(coacervate phase)that separates and precipitatesontothe hair during the rinse-offcycle(1,8-10). Coacervates canoptionally incorporateperformanceingredientssuchas silicones,fragrance,sunscreens, and other benefitagentsthusassisting in their deposition on hair (1,3,4). Experimental polymers describedin this paperare conjecturedto performalongthis line. Depositionof silicones onhair hasbeenevaluatedin two shampoo systems that included differentsurfactantbasesand differenttypesof silicones:Shampoo Formulation A containingsodiumlaurethsulfate(SLES)/disodiumcocamphodiacetate (DSCADA), 1 wt.% 424 JOURNAL OF COSMETIC SCIENCE dimethicone with an average particlesize-0.3 microns, 7 andconditioning polymers incorporated at 0.25% levelandShampoo Formulation B containingsodiumlaurethsulfate (SLES)/disodium laurethsulfosuccinate (DSLSS)/cocamidopropyl betaine(CAPB),1 wt. % dimethiconol with average particlesize-0.5 micron s andconditioning polymers incorporated at 0.2% level.Depositionof siliconesfrom shampooformulationsdepends upon many factors;type of silicone,its averageparticle size,the surfactantbase,the presence andtypeof cationicpolymersareamongstthe mostimportant(6,11). Hair type canalsoplay a significantrolein the deposition of silicones and, therefore,impactthe choiceof cationicpolymersto assistin and/orcontrolthisdeposition. Forexample,aswe previouslydescribedin (1) and the SoftCAT product literature, the low to medium chargedensity(-1.0 to 1.45 wt.% N) PQ-67 polymersideallysuitthe needsof bleached damagedhair. They do not overloadthis susceptible-to-cationic-deposition hair type while maximizingthe depositionof muchneededsiliconeascomparedto cationicguar and PQ-10 polymers.Depositionof siliconeon virgin hair aswell ason any "intermediate" hair type variessignificantlydependingon a specificshampooformulation.Examplesof systemswherehigh-viscosityhigh-chargePQ-10 gradesoutperformedtheir cationicguar counterpartshave beenpreviouslydescribedin (11). As we showlater, Shampoo Formulation B alsofalls into this category.At the sametime, the Shampoo Formulation A yieldedsignificantlybettersiliconedepositionon Europeanvirgin brown hairwhenformulated withcationic guar. 9 Oneofthegoalsofthepresent studywasto furtherexploreandtune structuralparameters of PQ-67 polymersin orderto closethis gap. We, therefore,beganour investigationwith the Formulation A, wherethe shortcomingwasfirst identified,and then expendedour evaluationscopeto includeother systems. Conditioningperformance of two prototypeshampoo systems described belowis largely dueto the presence of silicones and their ability to reachhair and staybehind(in small amounts)after the rinse-offcycleis complete.Ability to depositsiliconeis therefore crucialin thesesystemsandgreatlycontributesto the overallconditioningeffect.On the otherhand,the contributionof the cationicconditioningpolymersandotheringredients foundin shampoos canalsoplay an importantrole in the overallperformance. In order to accountfor theseeffectsandmakesurethat the performance differences arelikely to be noticedand appreciated by the end consumer, we includedsubjectivepanelstudies on hair tresses in our evaluation. Performance in Shampoo Formulation A Siliconedeposition.The total amount of siliconedepositedon hair treated with the ShampooFormulationA was measuredusing atomic absorptionspectrophotometry. Commercial European virginhair•øwaswashed twotimes TM witheachformulation. The 7 DowCorning © Emulsion 1664(supplied by DowCorning)is a non-ionic emulsion of highmolecular weight polydimethylsiloxane with 50% siliconecontent. sDowCorning © Emulsion 1785(supplied by DowCorning) is an anionic emulsion of highmolecular weight polydimethylsiloxane with 60% siliconecontent. 9Notethattheexactsame shampoo formulation withlowercharge density PQ-67polymers (SoftCAT SL grade)yieldedsuperiordeposition of silicones on single-bleached hair compared to cationicguar(1). mAll hairusedin thisworkanddescribed in thispaperwassupplied byInternational HairImporters Co. •J Consecutive washings, nodryingin-between. 2006 TRI/PRINCETON CONFERENCE 425 siliconewas extractedfrom the hair by a 50/50 (v/v) methyl isobutyl ketone/toluene solution.The siliconecontent was measured,and then the microgramsof siliconeper gram of hair wascalculated. Depositionof siliconeon Europeanvirgin brown hair from the prototypeShampooA formulatedwith PQ-10 polymers,PQ-67 polymers,and cationicguar is shownon Figure2A. Accordingto this data,increasingthe chargesubstitutionin PQ-10 polymers (HS = 0) resultedin moresiliconedepositedon hair. A moderateincreasefrom N45 to 95 microgramsof siliconeper gram of hair was observed.This trend becamemore pronouncedin the PQ-67 group comparedto PQ-10. The sameincreaseof cationic chargefrom -1.0 to 1.8 wt.% N resultedin a severalfold boostof siliconedeposition from PQ-67 formulas:from -45 to 215 microgramsof silicone. 700 / Ai 600 500 400 3OO 200 100 0 HS= 0 (PQ.10) LowHS(PQ-67) Cat.guar []%N~1.8 I I D%N ~1.0 []%N~1.25 3600- 30002400- 1800- • . 001 I Low HS Medium HS HighHS Cat.guar B%N-1.25 B%N-1.45 B%N~1.8 []%N~2.1 !a%N-2.5 I Figure 2. Siliconedepositionfrom ShampooFormulationA on Europeanvirgin brown hair. A. Polymers PQ-10 and PQ-67 with CS of 1.0-1.8 wt.% N. B. PQ-67 with CS 1.25-2.5 wt.% N and cationicguar. 426 JOURNAL OF COSMETIC SCIENCE a. '- 500 0 O.07wt.% 0.15wt.% 0.25wt.% I[3Cat. guar []PQ-67, Medium HS[]PQ-67, High HS1 Cationic guar PQ-67, PQ-67, %N-2.1, %N-2.5, Medium HS Medium HS ¸ 1wt.% silicone []0.3wt.% silicone] Figure 3. Siliconedepositionon Europeanvirgin brown hair: formulationswith fractionalamountsof PQ-67 polymeror silicone.A. Formulationswith 0.007 to 0.25 wt.% Polymerand I wt. % Silicone.B. Formulationswith 0.25 wt.% Polymer and 0.3 to 1 wt.% Silicone. Furtherstudiesrevealedthat evenminimal amountof hydrophobe,suchas,for example, the low level hydrophobicsubstitutionpresentin the commercialproductsSoftCAT SL-5, SK-M, and SK-H, was sufficientto observethe significantboost in silicone depositionbetweenPQ-10 and PQ-67 polymers.At the sametime, varying HS in polymerswith the CS corresponding to 1.0-1.8 wt.% N did not resultin significant changesin siliconedeposition.As discussed earlierand accordingto the data presented on Figure 2A, the prototypebenchmarkFormulationA preparedwith cationicguar depositedsignificantlymore silicone(-675 microgramsiliconeper gram of hair) on virgin brownhair comparedto eithergroupof cationiccellulosicpolymers.In orderto closethis gap, we focusedon the PQ-67 structureswith the idea of combiningthe impactsof CS and HS on depositionperformance.The chargesubstitutionwasfurther increased and high chargedensitypolymerswerepreparedat threelevelsof hydrophobic substitution: low,medium, andhigh•2 (Fig.2B).According to thedatapresented in Figure 2B, a step-change in siliconedepositionon hair from PQ-67 shampoos occurred when the chargesubstitutionin polymersexceeded2 wt.% cationicnitrogen. Experi- mentalhigh chargedensityPQ-67 polymersdeposited up to -3,500 microgramsilicone per gramEuropeanvirgin brownhair, dependingon their CSandHS. They significantly outperformedotherPQ-67 andcationicguarbenchmarks usedin the study.In a second studya series ofhighcharge density PQ-67•3shampoos wereformulated withfractional amountsof polymer (0.07-0.25 wt.%) or silicone(0.3 wt.%). These shampooswere evaluatedfor siliconedepositionin comparisonto completeformulations(Shampoo FormulationA) containing0.25 wt.% cationicguar and 1 wt.% silicone.Accordingto Figure 3A, the amountof depositedsiliconewasproportionalto the amountof the high chargedensityPQ-67 polymeraddedto the formulation.Lessthen one third of the PQ-67 amount(0.07 wt.% versus0.25 wt.%) wasenoughto matchthe siliconedeposition from the cationicguar formula. In addition, data presentedon Figure 3B shows that the formulationcontainingonethird of the amountof silicone(0.3 wt.% versus1.0 wt.% siliconein a "complete"ShampooFormulationA) and high chargedensityPQ-67 polymersyieldedsiliconedepositionon hair that was similar to the depositionfrom a "complete"formulationcontainingcationicguar. •2 All polymers described in thispaperhadHS < 0.01. •3 PQ-67polymers containing 2.5 wt.% N. 2006 TRI/PRINCETON A. Baseline (untreated) CONFERENCE B. Before combing 427 C. After combing .-= . ... . . : PQ-67 Cationic guar PQ-67 Cationic guar Figure 4. Volume and frizz control. Subjectivepanelevaluationon tresses.To confirmthat the effectsdescribedabovewere perceivableto humansubjects,pairsof commercialfrizzy hair tresses wereshampooed, dried overnightand distributedto five expertpanelistsskilledin evaluatingconditioning and other propertiesof hair. Each pair had one tresstreated with Shampoo A formulated witha highcharge density PQ-67polymer TMandonetresstreated witha control shampoocontainingcationicguar. Panelistswere askedto evaluatethree attributes:they wereaskedto chooseonehair swatchin eachpair that had lessvolume/ frizz, waseasierto combandfelt smoother/softer. Eachpanelistperformedevaluations twice on differentpairsof hair tresses.Photosof the swatcheswere taken beforetreatment (Figure4A), after treatmentbeforecombing(Figure4B), and after repeated combing(Figure4C). As shownin Figure4, the high chargedensityPQ-67 formulationprovidedexcellent volumecontrolfor frizzy hair. Its superiorperformance comparedto the cationicguar controlwas clearlynoticeablebeforeand after the hair was combed(Figure 4). The resultsof the subjectivepanel evaluationare presentedin Figure 5A. The study confirmed that the PQ-67 formulationwas perceivedby panelistsas providing better volumecontrol (10/10)andalsosignificantly improving dryfeel(8/10)15anddrycomb (9/10)•6offrizzyhairagainst thecationic guar.Aspreviously discussed, thehighcharge densityPQ-67 polymersweresignificantlymoreefficientin depositingsilicones on hair comparedto the cationicguarcontrol(Figure3B). Therefore,a secondpanelevaluation studywasconductedto comparea completeformulationwith cationicguar to a sample formulation containing a PQ-67polymer 17andonlyaboutonethirdof theamount of silicone (0.3 wt.% versus 1.0 wt.%). Hair tresses treated with the formulations were evaluatedwet anddry in pairsin the samewayasdescribed above.The resultsof wet/dry comband feel propertyevaluations are presentedin Figure 5B. It wasfound that the high chargedensityexperimentalPQ-67 polymerusedin this studysignificantlyim- PQ-67polymer with%N -2.5 andmedium HS wasusedin thisstudy. Exactsignificance level= 89% (binomial distribution). Exactsignificance level= 98%(binomial distribution). PQ-67polymer with 2.5 wt.%,mediumHS. 428 JOURNAL OF COSMETIC SCIENCE Dry Comb Dry Feel Less Volume IraCationic guar[]PQ-67, %N~2.5,Medium HSI Next day: 10- El Wet Wet Feel Comb Dry Comb Dry Feel Less PQ-67 Cationic guar Volume I1:1 Cationic guar! PQ-67, %N2.5,Medium HSI Figure 5. Subjectivepanelevaluationon œrizzy hair. A. ShampooFormulationA: 0.25 wt.% polymer,1 wt.% silicone.B. Shampoo FormulationA: 0.25 wt.% PQ-67, 0.07 wt.% siliconeversus0.25 wt.% cationic guar, 1.0 wt.% silicone. proved bothdrycombandfeel(8/10)t8 and,possibly, wetfeeloffrizzyhairdespite the fact that it wasusedin a systemwith threetimeslesssiliconecomparedto the cationic guar formulation.On the day of the evaluation,after all the manipulationson hair were completedthe panelistswerenot ableto seedifferences in volume.Nevertheless, oneday later hair tresses treatedwith the cationicguarformulashowedsignificantlymorefrizz andunwanted volume •9Figure5B,whilethePQ-67formulation continued toprovide much needed volume and frizz control. Performance in Shampoo Formulation B Siliconedeposition.The total amount of siliconedepositedon Europeanvirgin hair Exactsignificance level= 89% (binomialdistribution). Frizzandvolumeincrease aretypicalto thishairtypeandcanbecaused byatmospheric moisture. 2006 TRI/PRINCETON CONFERENCE 429 looo 400 , 0 UCARE JR-30M ........ -•' ........ :•:• '"SoftCAT SK-MH SoftCAT SK-H i PQ-67 PQ-•7 %N- 2.1%N-2.5 Cat. guar Com m e rcial 2-in-1 sham poo Figure 6. Siliconedepositionfrom ShampooFormulationB on Europeanvirgin brownhair. treatedwith ShampooFormulationB wasmeasured followingthe proceduredescribed above.PolymersPQ-10 (UCARETMJR-30M), PQ-67 (SoftCATTMSK-MH and H), and cationicguar(JaguarC-13S©) wereusedasbenchmarks. A marketleadingcommercial shampooproduct that had an SLES/DSLSS/CAPBsurfactantbase,dimethiconol,and guar hydroxypropyltrimethylammoniumchloridelistedon the ingredientlabel wasalso includedin the studyasan additionalbenchmark.The resultsobtainedfor the silicone depositionfrom eachformulationare presentedin Figure 6. It hasbeenfoundthat the PQ-10 polymerwith medium-highcationiccharge(UCARETMJR-30M, %N -1.8) and PQ-67 polymerwith medium cationiccharge(SoftCATrM SK-H, 1.45 wt.% N) outperformedcationicguarn the prototypeformulationB. Theyyieldedsiliconedeposition in the rangeof-430 and 490 micrograms of siliconeper gram of hair, respectively, whichwascloseto the amountdeliveredby the commercialshampooproductthat listed an SLES/DSLSS/CAPB surfactant systemandcationicguar:-460 micrograms of silicone. Experimentalhigh chargedensityPQ-67 polymersdescribedin this paperdelivered significantlymoresilicone(-850 and 1,100 micrograms, respectively, dependingon the CS) showingagaina significantincreasein siliconedepositionover the benchmarks. Subjectivepanel evaluationon tresses.In order to further validate the outstanding conditioningperformance of the high chargedensityPQ-67 polymersin the prototype ShampooFormulationB, a sampleshampoocontainingone of thesepolymers(-2.1 wt.% N, mediumHS) wascomparedto the market-leadingcommercialshampooused in the siliconedepositionstudy(Figure7A). Pairsof Europeanvirgin brownhair tresses werepreparedasdescribedaboveanddistributedto panelists.The hair wasevaluatedfor wet/dry comband feel properties.Accordingto the resultspresentedin Figure 7A, the panelistspreferredtheprototypeFormulationB containinga high chargedensityPQ-67 polymer overthecommercial shampoo forbothwetcomb(9/10)20andfeel(8/10).TM 20Exactsignificance level= 98% (binomialdistribution). 21Exactsignificance level= 89% (binomial distribution). 430 JOURNAL OF COSMETIC SCIENCE 10• ß- 108- 8 6- •.6 ,,- 4 . z .. '•,t.•' o Wet Comb Wet Feel . .... -3 •. Dry Comb Dry Feel 0 Wet Comb Wet Feel Dry Comb Dry Feel [E]Commercial shampoo BPQ-67, 2.5wt.%N,Medium HS]I[]Cationic guar []PQ-67, 2.1wt.%N,Medium HS} Figure 7. Subjectivepanelevaluationon Europeanvirgin hair. A. ShampooFormulationB: PQ-67 versus commercialshampoo.B. ShampooFormulationB: PQ-67 versuscationicguar. After the hair dried,panelists'choicesindicatedno statisticaldifferencein dry comband feel betweenswatches (Figure7A). A secondpanelstudywasconductedto comparethe Shampoo Formulation B madewith a highcharge densityPQ-67polymer 22to an identical formulation containing cationic guar. 23Asexpected fromthesilicone depositiondata,the PQ-67 formulationoutperformed the guarcontrolin bothcombandfeel in the wet and dry state, Figure 7B. DEPOSITION OF FRAGRANCE Fragranceis anotherimportant performanceingredientbesidessiliconesthat greatly contributesto the overallaesthetics of shampooproductsand their acceptance by consumers.Delivery of long-lastingfragranceto the hair from rinse-offformulationssuch as shampoosand conditionersrepresentsa seriouschallenge.The high chargedensity PQ-67 polymersthat demonstrated remarkableperformance in assistingthe deposition of siliconeson hair werealsotestedfor depositionof fragrancefrom a shampooformu- lation.WhiteTeaFragrance 24wasformulated at 1 wt.%in anSLES/DSCADA 25prototypeshampoo formulationalongwith 0.4 wt.% cationicconditioningpolymer.The fragrance deposition fromashampoo containing ahighcharge density PQ-67polymer 26 wasevaluated against similarshampoos containing nopolymer, SoftCAT SK-MH,27and cationicguar in a seriesof subjectivepanel evaluationstudieson Europeanvirgin hair tresses conducted in the same manner as described above. The results of these studies are summarizedin Figure8. It wasshownthat the high chargedensityPQ-67 polymerused in this studyimproveddepositionof the white tea fragranceon virgin brownhair and thatthedifference wasperceivable to thepanelists in all threecases (9/1()2• or 8/1029). _,2PQ-67polymer with 2.1 wt. %N andmediumIIS wasusedin thisstudy. 23JaguarC-I 3S. 24Provided by Fragrance Resources, Inc. 25Thesamesurfactant system asusedin theShampoo Formulation A. 26PQ-67polymer with 2.5 wt.%N andmediumIlS. 27SoIkCAT SK-MHwasfoundto delivermorefragrance onskinfromrinse-off formulations compared to other PQ-67 and PQ-10 polymersand cationicguar (SoftCATSK Conditioning Polymers, productbrochure issuedby AmercholCorporation/DowChemicalCompany(2005)). 2• ExactSignificance level= 98% (binomialdistribution). 29ExactSignificance level= 89% (binomial distribution). 2006 TRI/PRINCETON CONFERENCE 431 9 ! ! ß::L•x,.,,. ßßß 0 PQ-67 vs. blank PQ-67 vs. SoftCAT SK-MH PQ-67 vs. Cat. guar Figure 8. Fragrancedepositionon Europeanvirgin brown hair, wet subjectives. Coacervate studies. In orderto understandthe origin of the step-changeboostin assisted depositionof performanceingredientsobservedfor the high chargedensity PQ-67 polymers,their coacervate formationwas studiedin clearshampoosystemsformulated withnosilicone and0.3 wt.% polymer in a SLES/DSCADA surfactant 3øbaseand0.3 wt.% polymer.Haze measurements wereperformedusingthe Nippon Denshoku300A hazemeterin a 50 mm path lengthcell.As discussed above,cationicpolymersareknown to form coacervateswith anionic surfactants.Clear in a concentrated form, surfactant solutionswith PQ-10 and PQ-67 cationicpolymersbecomehazyupon dilution. This haziness,which is an indicator of coacervateformation, was measured over a dilution rangeof 0-10 and haze (coacervate) curveswere studies.As shownin Figure 9, the coacervate curvesof PQ-67 polymerswith wt.% N rangingfrom 1.25 to 2.5% changed their shapeandpositiondependingon charge.In the rangeof 1.25 up to 1.8 wt.% N, their shapeprogressively evolvedfrom lowerand broadercurves(low CS) to higherand "sharper"(narrower)curves(higherCS). In addition, thesecurvesprogressively shifted toward the lower dilution ratio. This trend was earlier noticedand describedfor the PQ-10 polymers,such as, for example UCARE'rM LR-30M(%N -1.0) andJR-30M(%N -1.8).• On thecontrary, the hazecurvesfor the high chargedensityPQ-67 polymerswith % N above2.0 did not follow the sametrend. They becamehigher and broaderat the sametime (Figure 9) extendingovera broaderrangeof dilution comparedto their 1.8% N predecessor. This is a knownindicatorof morecoacervate beingformedthat raisesexpectations of superior deposition/co-deposition and conditioningperformance.Therefore,theseobservations arein agreementwith earlierfindingsfrom the siliconeandfragrancedepositionstudies 30Thesamesurfactant system asusedin theShampoo Formulation A. 31UCARET M productliterature, Amerchol Corporation. 432 JOURNAL OF COSMETIC SCIENCE lOO -O- 8o %N ~ 1.25 --O-- %N ~ 1.45 ß 60 N • 40 --e-- %N ~ 1.8 --Z• %N ~ 2.1 • %N ~ 2.5 2o i 1.0 3.3 Dilution 5.0 Ratio 7.5 10.0 Figure 9. Coacervate formationin shampoos containingPQ-67 polymers. describedin this paper.This providessomeinsightson the mechanisticaspectsof the high chargedensityPQ-67 polymers'outstandingperformance. OTHER PROPERTIES IN SHAMPOOS As shownabove,novel high chargedensityPQ-67 polymersdemonstratedimproved overallperformanceand, in particular,showedoutstandingability to depositbenefit agentson hair from shampooformulations.At the sametime, thesepolymerswerefound to retain the goodqualitiesof the PQ-10 and their lower chargedensityPQ-67 coun- terparts, suchasenabling crystal clearformulations, 32showing noexcessive build-up on hair33(asshown onFigure10),andhaving nonegative impact onfoam '•4(asshown on Figure 11). CONCLUSIONS A seriesof new experimentalhigh chargedensityPQ-67 polymerswere preparedand evaluatedin shampooformulations.Thesenewcompositions demonstrated outstanding performancein assistingdepositionof performanceingredientssuch as siliconeand fragranceon humanhair. They were foundsuperiorcomparedto PQ-10, lowercharge densityPQ-67 polymers,and cationicguar benchmarks.In severalstudiesexperimental polymersoutperformedthe cationicguar benchmarkevenwhenlesspolymeror silicone 32Measuring lessthan4% hazeonNipponDenshoku 300Ahazemeter, 50 mmpathlength, 0.3• polymer. 33Theamountofdeposited polymer wasassessed bydetecting theamountof anionicRed80 dyeboundto the cationicpolymerdepositedto the hair as describedin (1). The depositionvalueswere normalizedper amount of polymer depositedafter one wash. The prototype formulation included 0.3 wt.• polymer (experimental high chargedensityPQ-67 polymerwith 2.1 wt.% N andmediumhydrophobic substitution, UCAREr• JR-30M (PQ-10), or Jaguar © C-13S) in a SLES/DSCADA surfiictant base. 34Quantitative foammeasurements wereperformed asdescribed in (12):all foamgenerated whileshampooing a hair tresswas collectedand weighed and then its volume and density were calculated.).The prototypeformulationincluded0.3 wt.% polymer(experimental high chargedensityPQ-67 polymerwith 2.1 wt.% N and mediumhydrophobic substitution, UCARETMJR-30M (PQ-10), or Jaguar © C-13S)in a SLES/DSCADA surfactant base. 2006 TRI/PRINCETON CONFERENCE 433 1.75 1.5 1.25 1 1 wash 3 washes 5 washes I .•bCationic guar • PQ-10 -•- PQ-67 I Figure 10. Polymerdepositionon Europeanvirgin brownhair. Red 80 ArtionicDye Test. o 35 x 30 E m 25 ß• 20 • 15 E 10 E 5 o > •..: • .' 0 No Polymer Cat. guar PQ-10 PQ-67 Figure 11. Foamvolumeand densitymeasurement. wasusedin the formulationcontainingPQ-67. Along with excellentoverallconditioning, shampoos formulatedwith newPQ-67 polymersprovidedimprovedvolumecontrol and manageabilityto problemhair--a much neededbenefitfor anti-frizz/smoothing formulasand productsthat target sleekhair look. Perceivableimprovementin delivery of fragranceto the hair was also substantiated.This could also make the polymers 434 JOURNAL OF COSMETIC SCIENCE describedherewell suitedfor aromatherapyand spaformulas.Accordingto the performancedatapresentedin thispaper,the newhigh chargedensityPQ-67 polymersshould be recommended for a rangeof hair typesthat would benefitfrom enhanceddeposition, premium conditioningand volume control: from normal, not chemicallytreated to problemhair (frizzy, unruly, coarseetc.) as well as Asian hair types. REFERENCES (1) T.V. Drovetskaya,R.L. Kreeger,J. L. Amos, and C.B. 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