ester oils according to the invention exhibit a melting point of less than 30 ° c . at a pressure of 1013 bar and have at least one ( optionally substituted ) alkyloxycarbonyl group in the molecule . preferred agents according to the invention contain the ester oils in an amount of 0 . 1 to 3 wt %, particularly 0 . 2 to 1 . 0 wt %, more particularly 0 . 3 to 0 . 5 wt %, based on total weight of the composition . preferred aqueous compositions are those having at least one ester oil chosen from ( c 4 to c 20 ) monocarboxylic acid esters of ( c 3 to c 20 ) alcohols and / or dialkyl carbonates and / or diesters of ( c 3 to c 20 ) alcohols with alpha , omega -( c 4 to c 8 ) carboxylic acids and / or diesters of ( c 2 to c 6 ) diols with ( c 3 to c 10 ) monocarboxylic acids . those agents are inventively preferred and suitable wherein the ester oil is chosen from at least one compound of formula ( i ) and / or formula ( ii ) and / or formula ( iii ) r 1 is a linear ( c 3 to c 20 ) hydrocarbon group , a branched ( c 3 to c 20 ) hydrocarbon group , a ( c 2 to c 6 ) hydroxyalkyl group , a linear ( c 3 to c 18 ) alkoxy group or a branched ( c 3 to c 18 ) alkoxy group , r 2 is a linear ( c 3 to c 20 ) hydrocarbon group or a branched ( c 3 to c 20 ) hydrocarbon group , r 3 and r 4 are , independently of one another , a linear ( c 3 to c 10 ) alkyl group or a branched ( c 3 to c 10 ) alkyl group , r 5 and r 6 are , independently of one another , a linear ( c 2 to c 9 ) alkyl group or a branched ( c 3 to c 10 ) alkyl group , and a 1 and a 2 are , independently of one another , a ( c 2 to c 8 ) alkanediyl group . exemplary linear ( c 3 to c 20 ) hydrocarbon groups are n - propyl , n - butyl , n - pentyl , n - hexyl , n - heptyl , n - octyl , n - nonyl , n - decyl , n - undecyl , n - dodecyl , n - tridecyl , n - tetradecyl , n - pentadecyl , n - hexadecyl , n - heptadecyl , n - octadecyl , n - oleyl . exemplary branched ( c 3 to c 20 ) hydrocarbon groups are isopropyl , 2 - ethylhexyl , heptan - 3 - yl , 2 - octyldodecyl , isostearyl , isocetyl . preferred r 1 groups according to formula ( i ) are 1 - hydroxyethyl , heptyl , heptan - 3 - yl , octan - 2 - yl , nonyl , undecanyl , tridecanyl , pentadecanyl , heptadecanyl . preferred r 2 groups according to formula ( i ) are isopropyl , 2 - ethylhexyl , octyl , decyl , dodecyl , 2 - octyldodecyl , hexadecyl , isohexadecyl ( i . e . isocetyl ), oleyl , octadecyl or isooctadecyl ( i . e . isostearyl ). preferred r 3 and r 4 groups according to formula ( ii ) are independently of one another isopropyl , n - butyl , 2 - ethylhexyl or n - octyl . preferred a 1 groups according to formula ( ii ) are butane - 1 , 4 - diyl , hexane - 1 , 6 - diyl or octane - 1 , 8 - diyl . preferred r 5 and r 6 groups according to formula ( iii ) are independently of one another heptyl , heptan - 3 - yl , octan - 2 - yl , nonyl , undecanyl , tridecanyl , pentadecanyl , heptadecanyl . preferred a 2 groups according to formula ( iii ) are ethane - 1 , 2 - diyl , propane - 1 , 3 - diyl , butane - 1 , 3 - diyl , butane - 1 , 4 - diyl or pentane - 2 , 4 - diyl . the inventive effects are particularly pronounced when the agent comprises as the ester oil at least one compound chosen from 2 , 2 - dimethylpropane - 1 , 3 - diyl di ( 2 - ethylhexanoate ) ( cas no . : 28510 - 23 - 8 , e . g ., schercemol ® ngdo ester from the lubrizol company ) diisopropyl adipate , di - n - butyl adipate , dioctyl maleate , diisopropyl sebacate , tridecyl neopentanoate ( e . g ., ceraphyl ® 55 from the isp company ), decyl oleate ( e . g ., ceraphyl ® 140 from the isp company ), isostearyl neopentanoate ( e . g ., ceraphyl ® 375 from the isp company ), isocetyl stearate ( e . g ., ceraphyl ® 494 from the isp company ), 2 - octyldodecyl stearate ( e . g ., ceraphyl ® ods from the isp company ), isopropyl myristat , isononanoic acid c 16 - 10 alkyl ester , 2 - ethylhexyl palmitate , stearic acid 2 - ethylhexyl ester , cetyl oleate , coco fatty alcohol caprinate / caprylate , n - butyl stearate , oleyl erucate , isopropyl palmitate , oleyl oleate , lauric acid hexyl ester , cetearyl isononanoate , lauryl lactate ( e . g ., ceraphyl ® 31 from the isp company ), ( c12 to c15 ) alkyl lactate ( e . g ., ceraphyl ® 41 from the isp company ), dihexyl carbonate , dioctyl carbonate ( e . g ., cetiol ® cc from the cognis company ), didecyl carbonate . a particularly preferred ester oil according to the present invention is chosen from at least one ester oil of the formula ( i ), wherein the r 1 and r 2 groups are as described above and at least one of the r 1 or r 2 groups is a branched ( c 3 to c 20 ) group . the ester oil is quite particularly preferably chosen from at least one compound of formula ( ia ) r 2 is a linear ( c 3 to c 20 ) hydrocarbon group or a branched ( c 3 to c 20 ) hydrocarbon group , r 7 is a ( c 4 to c 6 ) alkyl group , and r 8 is a methyl group or an ethyl group . the ester oils according to the invention are preferably used in an aqueous composition . in the context of the invention , an aqueous composition comprises at least 50 wt % water , based on total weight of the composition . this aqueous composition can be in various forms , for example , as a lotion , oil - in - water emulsion or water - in - oil emulsion . in this regard it is again preferred to use compounds of formula ( i ) during the reducing step of the permanent hair shaping ( particularly as a component of an aqueous composition comprising at least one keratin - reducing compound ). the keratin - reducing compounds present in the aqueous composition are preferably chosen from compounds having at least one thiol group as well as from their derivatives , from sulfites , hydrogen sulfites and disulfites . exemplary compounds with at least one thiol group as well as their derivatives are thioglycolic acid , thiolactic acid , thiomalic acid , phenylthioglycolic acid , mercaptoethane sulfonic acid as well as their salts and esters ( e . g ., isooctyl thioglycolate and isopropyl thioglycolate ), cystamine , cysteine , s - alkyl and s - aryl thiosulfates and salts of the sulfurous acids . the monoethanolammonium salts or ammonium salts of thioglycolic acid and / or of thiolactic acid as well as the free acids are preferred . they are preferably incorporated in the aqueous composition at a ph of 5 to 12 , especially 7 to 9 . 5 . in order to adjust this ph , the aqueous compositions usually contain alkalizers such as ammonia , alkali metal and ammonium carbonates and hydrogen carbonates or organic amines such as monoethanolamine . exemplary keratin - reducing compounds from the disulfites which can be present in the aqueous composition are alkali metal disulfites such as sodium disulfite ( na 2 s 2 o 5 ) and potassium disulfite ( k 2 s 2 o 5 ), as well as magnesium disulfite and ammonium disulfite (( nh 4 ) 2 s 2 o 5 ). in this regard , ammonium disulfite can be inventively preferred . exemplary keratin - reducing compounds from the hydrogen sulfites which can be present in the aqueous composition are hydrogen sulfites as an alkali metal , magnesium , ammonium or alkanolammonium salt based on a c 2 - c 4 mono , di or trialkanolamine . in this regard , ammonium hydrogen sulfite can be a particularly preferred hydrogen sulfite . exemplary keratin - reducing compounds from the sulfites which can be present in the aqueous composition are sulfites as an alkali metal , magnesium , ammonium or alkanolammonium salt based on a c 2 - c 4 mono , di or trialkanolamine . here , ammonium sulfite is preferred . when using sulfite and / or disulfite and / or hydrogen sulfite , the ph of the aqueous composition is preferably adjusted to a value in the neutral region of ph 5 to 8 , preferably ph 6 to 7 . 5 . inventively preferred c 2 - c 4 alkanolamines are 2 - aminoethanol ( monoethanolamine ) and n , n , n - tris ( 2 - hydroxyethyl ) amine ( triethanolamine ). monoethanolamine is a particularly preferred c 2 - c 4 alkanolamine that is added , particularly in an amount of 0 . 2 to 6 wt %, based on total aqueous composition . the keratin - reducing compound is preferably added in an amount of 5 to 20 wt %, based on total aqueous composition . moreover , the aqueous composition can additionally comprise further components that promote the action of the keratin - reducing compound on the keratin . such components include swelling agents for keratin - containing fibers such as c 1 - c 6 alcohols and water - soluble glycols or polyols such as glycerin , 1 , 2 - propylene glycol or sorbitol and urea or urea derivatives such as allantoin and guanidine , as well as imidazole and its derivatives . a preferred additional component is 1 , 2 - propylene glycol , particularly in an amount of 0 . 1 to 5 wt %. the quantities refer to the total aqueous composition . in a preferred embodiment , the aqueous composition comprises 0 to 5 wt % 1 , 2 - propylene glycol and / or 0 to 5 wt % urea . in a preferred embodiment the inventive aqueous composition additionally comprises at least one surfactant . preferred surfactants are independently chosen from anionic surfactants , zwitterionic surfactants , amphoteric surfactants , non - ionic surfactants , cationic surfactants . it is particularly preferable when agents according to the invention additionally comprise at least one non - ionic surfactant . non - ionic surfactants contain , for example , a polyol group , a polyalkylene glycol ether group or a combination of polyol ether groups and polyglycol ether groups as the hydrophilic group . exemplary compounds of this type are addition products of 2 to 100 moles ethylene oxide and / or 1 to 5 moles propylene oxide to linear and branched fatty alcohols containing 8 to 30 carbon atoms , to fatty acids containing 8 to 30 carbon atoms and to alkyl phenols containing 8 to 15 carbon atoms in the alkyl group , methyl or c 2 - c 6 alkyl group end blocked addition products of 2 to 50 moles ethylene oxide and / or 1 to 5 moles propylene oxide to linear and branched fatty alcohols with 8 to 30 carbon atoms , to fatty acids with 8 to 30 carbon atoms and to alkyl phenols with 8 to 15 carbon atoms in the alkyl group , such as , for example , the commercially available types dehydrol ® ls , dehydrol ® lt ( cognis ), c 12 - c 30 fatty acid mono and diesters of addition products of 1 to 30 moles ethylene oxide to glycerin , addition products of 5 to 60 moles ethylene oxide to castor oil and hydrogenated castor oil , polyol esters of fatty acids , such as , for example , the commercial product hydagen ® hsp ( cognis ) or sovermol types ( cognis ), alkoxylated triglycerides , alkoxylated fatty acid alkyl esters of the formula ( e4 - i ) wherein r 1 co is a linear or branched , saturated and / or unsaturated acyl group containing 6 to 22 carbon atoms , r 2 is hydrogen or methyl , r 3 is linear or branched alkyl groups containing 1 to 4 carbon atoms , and w is a number from 1 to 20 , amine oxides , sorbitol esters of fatty acids and addition products of ethylene oxide to sorbitol esters of fatty acids such as the polysorbates , sugar esters of fatty acids and addition products of ethylene oxide to sugar esters of fatty acids , addition products of ethylene oxide to fatty acid alkanolamides and fatty amines , sugar surfactants of the type alkyl and alkenyl oligoglycosides according to formula ( e4 - ii ), wherein r 4 is an alkyl or alkenyl group containing 4 to 22 carbon atoms , g is a sugar group containing 5 or 6 carbon atoms , and p is a number from 1 to 10 . amine oxides as well as addition products of 2 to 100 moles ethylene oxide and / or 1 to 5 moles propylene oxide to linear and branched fatty alcohols containing 8 to 30 carbon atoms , to fatty acids containing 8 to 30 carbon atoms and to alkyl phenols containing 8 to 15 carbon atoms in the alkyl group have proven to be quite particularly preferred non - ionic surfactants . similarly , preparations with excellent properties are obtained when they comprise c 12 - c 30 fatty acid mono and diesters of addition products of 1 to 30 moles ethylene oxide to glycerin and / or addition products of 5 to 60 moles ethylene oxide to castor oil and hydrogenated castor oil as the non - ionic surfactants . suitable anionic surfactants are in principle all anionic surface - active materials that are suitable for use on the human body . they are characterized by a water solubilizing anionic group such as a carboxylate , sulfate , sulfonate or phosphate group and a lipophilic alkyl group containing about 8 to 30 carbon atoms . in addition , the molecule may comprise glycol or polyglycol ether groups , ester , ether and amide groups as well as hydroxyl groups . exemplary suitable anionic surfactants are , each in the form of the sodium , potassium and ammonium , as well as the mono , di and trialkanolammonium salts containing 2 to 4 carbon atoms in the alkanol group , linear and branched fatty acids with 8 to 30 carbon atoms ( soaps ), ether carboxylic acids of the formula r — o —( ch 2 ch 2 o ) x — ch 2 — cooh , wherein r is a linear alkyl group with 8 to 30 carbon atoms and x = 0 or 1 to 16 , acyl sarcosides with 8 to 24 carbon atoms in the acyl group , acyl taurides with 8 to 24 carbon atoms in the acyl group , acyl isethionates with 8 to 24 carbon atoms in the acyl group , mono - and dialkyl esters of sulfosuccinic acid with 8 to 24 carbon atoms in the alkyl group and mono - alkyl polyoxyethyl esters of sulfosuccinic acid with 8 to 24 carbon atoms in the alkyl group and 1 to 6 oxyethylene groups , linear alkane sulfonates containing 8 to 24 carbon atoms , linear alpha - olefin sulfonates containing 8 to 24 carbon atoms , alpha - sulfo fatty acid methyl esters of fatty acids containing 8 to 30 carbon atoms , alkyl sulfates and alkyl polyglycol ether sulfates of the formula r — o ( ch 2 ch 2 o ) x — oso 3 h , wherein r is preferably a linear alkyl group containing 8 to 30 carbon atoms and x = 0 or 1 to 12 , mixtures of surface - active hydroxysulfonates , sulfated hydroxyalkyl polyethylene glycol ethers and / or hydroxyalkylene propylene glycol ethers , sulfonates of unsaturated fatty acids with 8 to 24 carbon atoms and 1 to 6 double bonds , esters of tartaric acid and citric acid with alcohols , which represent the addition products of about 2 - 15 molecules of ethylene oxide and / or propylene oxide on fatty alcohols containing 8 to 22 carbon atoms , sulfated fatty acid alkylene glycol esters of the formula ( e1 - ii ) wherein r 7 co — is a linear or branched , aliphatic , saturated and / or unsaturated acyl group containing 6 to 22 carbon atoms , alk is ch 2 ch 2 , chch 3 ch 2 and / or ch 2 chch 3 , n is a number from 0 . 5 to 5 , and m is a cation , as are described in de - os 197 36 906 , amido ether carboxylic acids , condensation products of c 8 - c 30 fatty alcohols with protein hydrolysates and / or amino acids and their derivatives , known to one skilled in the art as albumin fatty acid condensates , such as the lamepon ® types , gluadin ® types , hostapon ® kcg or the amisoft ® types . preferred anionic surfactants are alkyl sulfates and ether carboxylic acids with 10 to 18 carbon atoms in the alkyl group and up to 12 glycol ether groups in the molecule , sulfosuccinic acid mono and dialkyl esters with 8 to 18 carbon atoms in the alkyl group and sulfosuccinic acid mono - alkyl polyoxyethyl esters with 8 to 18 carbon atoms in the alkyl group and 1 to 6 oxyethylene groups , monoglycerin disulfates , alkyl and alkenyl ether phosphates as well as albumin fatty acid condensates . amphoteric surfactants are understood by one skilled in the art to include the zwitterionic surfactants and ampholytic surfactants . zwitterionic surfactants are those surface - active compounds that carry at least one quaternary ammonium group and at least one — coo (−) or — so 3 (−) group in the molecule . particularly suitable zwitterionic surfactants are betaines such as the n - alkyl - n , n - dimethylammonium glycinates , for example , the cocoalkyl dimethylammonium glycinate , n - acylaminopropyl - n , n - dimethylammonium glycinates , for example , the cocoacylaminopropyl - dimethylammonium glycinate , and 2 - alkyl - 3 - carboxymethyl - 3 - hydroxyethyl imidazolines with 8 to 18 carbon atoms in each of the alkyl or acyl groups , as well as cocoacylaminoethyl hydroxyethylcarboxymethyl glycinate . a preferred zwitterionic surfactant is the fatty acid amide derivative known under the incl name cocamidopropyl betaine . ampholytic surfactants include such surface - active compounds that , apart from a c 8 - 24 alkyl or acyl group , comprise at least one free amino group and at least one — cooh or — so 3 h group in the molecule and are able to form internal salts . examples of suitable ampholytic surfactants are n - alkylglycines , n - alkylamino propionic acids , n - alkylamino butyric acids , n - alkylimino dipropionic acids , n - hydroxyethyl - n - alkylamidopropylglycine , n - alkyltaurines , n - alkylsarcosines , 2 - alkylamino propionic acids and alkylamino acetic acids , each with about 8 to 24 carbon atoms in the alkyl group . particularly preferred suitable ampholytic surfactants are chosen from n - cocoalkylamino propionate , cocoacylaminoethylamino propionate and the c 12 - c 18 acyl sarcosine . it is inventively particularly preferred if at least one surfactant of the aqueous composition is chosen from anionic surfactants , amphoteric surfactants , non - ionic surfactants . furthermore , it is again preferred if the aqueous composition comprises at least one non - ionic surfactant and at least one amphoteric surfactant . the aqueous composition according to the invention preferably comprises the surfactants in an amount of 0 . 5 to 5 . 0 wt %, particularly 0 . 8 to 3 . 0 wt %, based on total weight of the aqueous composition . the aqueous compositions can additionally comprise silicones . inventively useable silicones are preferably linear , cyclic or branched silicones , selected from the cyclomethicones , dimethiconols , dimethicone copolyols , amodimethicones , trimethylsilylamodimethicones and phenyl trimethicones . these silicone types are known to the person skilled in the art following the nomenclature of the cosmetic , toiletry and fragrance association ( ctfa ) and disclosed in : m . d . berthiaume , society of the cosmetic chemists monograph series , “ silicones in hair care ”, ed . : l . d . rhein , ed . : society of the cosmetic chemists , 1997 , chapter 2 , to which reference is expressly made . polysiloxanes , such as dialkyl and alkylarylsiloxanes , for example dimethylpolysiloxane and methylphenylpolysiloxane , as well as their alkoxylated analogs , analogs terminated with hydroxyl groups and quaternized analoga , as well as cyclic siloxanes . in this regard , the silicones with the incl names dimethicone , peg - 12 dimethicone , peg / ppg - 18 / 18 dimethicone , cyclomethicone , dimethiconol , quaternium - 80 and amodimethicone as well as their mixtures are particularly preferred . examples of such silicones are those products from dow corning commercialized with the names dc 190 ( incl name : peg / ppg - 18 / 18 dimethicone ), dc 193 ( incl name : peg - 12 dimethicone ), dc 200 , dc1401 ( incl name : cyclomethicone , dimethiconol ) and dc 1403 ( incl name : dimethicone , dimethiconol ) as well as the commercial products dc 244 ( incl name : cyclomethicone ), dc 344 ( incl name : cyclomethicone ) and dc 345 ( incl name : cyclomethicone ) from dow corning , q2 - 7224 ( manufacturer : dow corning ; a stabilized trimethylsilylamodimethicon , dow corning 929 emulsion ( comprising a hydroxyl - amino - modified silicone , also called amodimethicone ), sm - 2059 ( manufacturer : general electric ), slm - 55067 ( manufacturer : wacker ) as well as abil quat 3270 and 3272 ( manufacturer : th . goldschmidt ; diquaternary polydimethylsiloxane , incl name : quaternium - 80 ). the silicones are preferably present in amounts of 0 . 1 to 10 wt %, more preferably 0 . 3 to 5 wt %, based on total weight of the composition . the aqueous composition can additionally comprise protein hydrolysates . protein hydrolysates are product mixtures obtained by acid -, base - or enzyme - catalyzed degradation of proteins ( albumins ). according to the invention , the added protein hydrolysates can be of vegetal as well as animal origin . animal protein hydrolysates include protein hydrolysates of elastin , collagen , keratin , silk and milk albumin , which can also be present in the form of their salts . such products are marketed , for example , under the trade names dehylan ® ( cognis ), promois ® ( rita corp . ), collapuron ® ( cognis ), nutrilan ® ( cognis ), gelita - sol ® ( deutsche gelatine fabriken stoess & amp ; co ), lexein ® ( inolex ) and kerasol ® ( croda ). a preferred protein hydrolysate is the silk protein hydrolysate ( promois ® silk 720 , promois ® silk 1000 ). according to the invention , it is also possible to use protein hydrolysates of vegetal origin ( e . g ., protein hydrolysates of soya , almond , rice , pea , potato and wheat ). such products are available , for example , under the trade names gluadin ® ( cognis ), diamin ® ( diamalt ), lexein ® ( inolex ) and crotein ® ( croda ). likewise , it is possible to add derivatives of protein hydrolysates ( e . g ., in the form of their fatty acid condensation products ). such products are marketed , for example , under the trade names lamepon ® ( cognis ), gluadin ® ( cognis ), lexein ® ( inolex ), crolastin ® ( croda ) or crotein ® ( croda ). although it is preferred to add the protein hydrolysates as such , optionally , other mixtures containing amino acid or individual amino acids and amino acid derivatives can also be added in their place , such as arginine , asparagine , aspartic acid , citrulline , histidine , ornithine , lysine and pyroglutamic acid . the amino acids can be added both as the free amino acid as well as the salts ( e . g ., as the hydrochloride or the alkali metal , alkaline earth metal or ammonium salts ). additionally , oligopeptides of on average 2 - 3 amino acids which have a high content (& gt ; 50 %, especially & gt ; 70 %) of the cited amino acids have also proved to be inventively useable . arginine , asparagine , aspartic acid as well as their salts and oligopeptides or hydrolysates , which are rich in the cited preferred amino acids , are inventively particularly preferred . asparagine and aspartic acid as well as their salts or hydrolysates are quite particularly preferred . furthermore , the above cited use of ester oils or the inventive aqueous composition is suitable in particular for use during the heat - supported , permanent hair shaping — particularly at 80 ° c . to 250 ° c ., more particularly at 120 ° c . to 200 ° c . in this regard it is again preferred if a heated solid — particularly heated to 80 ° c . to 250 ° c ., more particularly to 120 ° c . to 200 ° c .— as the heat source is brought in direct contact with the hair . this is particularly the case when using curling irons or smoothing irons . use of at least one ester oil in a heat - supported hair smoothing method is advantageous . the preferred embodiments of the first subject matter of the invention also apply mutatis mutandis for this subject matter of the invention . a third subject matter of the invention is a method for perming hair , wherein ( i ) the hair is shaped with the aid of shaping auxiliaries after , before or during step ( ii ), ( ii ) an aqueous composition of the second subject matter of the invention is applied onto the hair , ( iii ) after a contact time z1 the hair is rinsed and optionally dried , and ( iv ) finally , an aqueous preparation comprising at least one oxidizing agent is applied on the fibers and rinsed out again after a contact time z2 . shaping auxiliaries include winding aids such as curlers or papillotes in the case of a perm , or auxiliaries for a mechanical smoothing such as a comb or a brush , a smoothing board or a heatable smoothing iron in the case of straightening hair . in the context of a perm method , if the shaping auxiliaries , for example , winding aids , are fixed on the fibers for a longer period of time , then these shaping auxiliaries are advisably removed after step ( iv ). in this connection , it can be advantageous to leave the shaping auxiliaries in the hair during step ( iv ), then to remove them and afterwards to repeat step ( iv ) as a so - called setting step ( v ). the contact time z1 is preferably 5 to 60 minutes , more preferably 10 to 30 minutes . the contact time z2 is preferably 1 to 30 minutes , more preferably 5 to 20 minutes . in a preferred embodiment , the keratin - containing fibers are moistened prior to step ( i ). this can be accomplished by spraying the fibers with a liquid , preferably with water . preferably , prior to step ( i ) the fibers are shampooed with a conventional shampoo , rinsed and then rubbed with a towel . at the conclusion of the rubbing step the hair remains noticeably damp . the preferred suitable embodiments of the aqueous composition according to step ( ii ) are those cited in the second subject matter of the invention ( see above ). in the context of another embodiment of the inventive method , the hair in step ( iii ) after rinsing or after drying , is subjected to a heat treatment — particularly at temperatures of 80 ° c . to 250 ° c ., more particularly at temperatures of 120 ° c . to 200 ° c . in this regard , it is preferred if a heated solid — particularly heated to 80 ° c . to 250 ° c ., more particularly to 120 ° c . to 200 ° c .— acting as the heat source is brought in direct contact with the hair . this is particularly the case when using curling irons or smoothing irons . when using curling irons a strand of hair is wound round a suitably warmed round body ( e . g ., a bar - shaped or tubular body ) and after a retention period — particularly 10 to 30 seconds — unwound again . a dry keratin - containing fiber according to step ( iii ) of the inventive method is then present if enough of the residual water adhering to the hair is removed so that the hairs are individually separated . in a dry keratin - containing fiber , the moisture content of the fiber is preferably essentially in equilibrium with the moisture in the air or the fiber takes up moisture from the surrounding air . the drying in step ( iii ) is then preferably carried out if a heat treatment is effected during an additional smoothing step ( e . g ., with suitably warmed plates ) between step ( iii ) and step ( iv ) in the context of a smoothing method . in another development of this embodiment in the context of a hair smoothing method , the fibers in step ( iii ) are subjected to a heat treatment with mechanical smoothing of the fiber at a temperature of 120 - 220 ° c . according to the invention , mechanical smoothing refers to a stretching of frizzy hair along the longest spatial dimension of the hair fiber . heat treatment with mechanical smoothing of the hair preferably occurs at a temperature of 140 - 200 ° c . the heat treatment can occur with hot air . in this case , during combing the hair is heated exactly at the spot where the mechanical smoothing is effected . moreover , the heat treatment is particularly preferably carried out in the course of smoothing with the help of suitably warmed plates , especially metallic or ceramic plates , by pressing the plate onto the hair being smoothed and moving the pressed down plate along the hair fiber . the plates can be optionally coated with heat - resistant materials . the hair fiber to be smoothed is particularly preferably pressed between two suitably warmed plates , and both plates are simultaneously moved along the longest spatial dimension of the fiber . in this regard , both plates are again preferably connected to one another , such that both plates can be evenly moved along the hair fiber . if the heat treatment is carried out on living hair , then the hair fiber is fixed at one end ( hair root ). in this case the plates are preferably evenly moved from the hair root along the whole of the hair fiber . this movement mechanically smoothes the fiber . a suitable instrument for the heat treatment is , for example , the “ ceramic flat master ” instrument ( commercialized by efalock , germany ). furthermore , the fibers can be treated with a conventional conditioner between step ( iii ) and ( iv ) and / or in the context of a subsequent treatment at the end of the inventive method . for carrying out the second step , the oxidative fixing , the aqueous preparation can preferably comprise , for example , hydrogen peroxide as the oxidizing agent and the usual stabilizers for stabilizing aqueous hydrogen peroxide preparations . the ph of such aqueous h 2 o 2 preparations containing 0 . 5 to 3 . 0 wt % h 2 o 2 is preferably in the range 2 to 4 . it can be adjusted with inorganic acids , preferably phosphoric acid . other possible oxidizing agents are sodium bromate and / or potassium bromate . bromates of this type are added in concentrations of 1 to 10 wt % and the ph of the solution is adjusted to 4 to 7 . apart from the oxidizing agent , additional known auxiliaries and additives can be present in the aqueous preparation for carrying out the second step of the inventive hair shaping method : they include surface - active substances , quaternary ammonium salts , cationic polymers , fragrances and opacifiers . both of the aqueous compositions of the inventive method can be formulated as a cream , gel or liquid . it can be preferred to make up the preparations in the form of aerosol foams with a liquefied gas such as propane - butane mixtures , n 2 o , dimethyl ether , fluorohydrocarbon propellants or mixtures thereof that are filled into aerosol containers with foam valves . the following examples are intended to describe the subject matter of the invention in more detail : the following compositions e1 and v1 of the table 1 were obtained by mixing the raw materials : plantapon ® acg lc n - cocoyl - l - glutamic acid disodium salt ( 31 wt % active substance in water with ca . 2 . 7 wt % isopropanol , inci name : disodium cocoyl glutamate ) ( cognis ) merquat ® 100 poly ( dimethyldiallylammonium chloride ) ( ca . 40 % solids ; inci name : polyquaternium - 6 ) ( ondeo nalco ) the following composition of the table 2 was obtained by mixing the raw materials : onto each hair strand alkinco 6634 , natural dark european hair ( alkinco company ) was applied per g of hair 1 ml of a composition of table 1 and left for 20 minutes . each strand was then rinsed for 5 minutes with water . the aqueous oxidizing agent - containing composition of table 2 was then applied ( 1 ml per 1 g hair ). after a contact time of 10 minutes each strand was rinsed for 5 minutes with water . the strands were then dried in air and stored for conditioning at 25 ° c . and 40 % relative humidity for 24 hours . in comparison to the hair treated with composition v1 , the hair treated with composition e1 exhibited a softer feel and a better combability . there was less damage to the hair . in both cases the perm result was very good .
the invention describes the use of ester oil for haircare , particularly during the reduction stage , when perming hair , to corresponding perming agents and to a method for perming hair .