the present invention is concerned with a polymer having an amino acid residue or an amino acid ester residue as a pendant group in at least a part of a monomer unit which can be obtained by reacting polysuccinimide with an amino acid ester in the presence or absence of a basic catalyst and which is free from irritation to organisms ( e . g ., eyes and skin ). a &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention is characterized by dissolving the polysuccinimide in an organic solvent , and then adding an amino acid ester to the solution in the presence or absence of a basic catalyst to carry out the reaction . next , the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention will be described . no particular restriction is put on the preparation process of the polysuccinimide which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention . the polysuccinimide which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention can usually be obtained by heating aspartic acid at 170 to 180 ° c . under reduced pressure in the presence of phosphoric acid to carry out dehydration condensation . if the polysuccinimide having a higher molecular weight is required , for example , the polysuccinimide obtained by the abovementioned procedure can be treated with a condensation agent such as dicyclohexylcarbodiimide . no particular restriction is put on the organic solvent which can be used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , and any organic solvent can be used , so long as it can substantially dissolve the polysuccinimide and the amino acid ester and / or does not substantially impede the progress of the reaction . typical examples of the organic solvent include organic aprotic polar solvents such as dimethylformamide ( dmf ), dimethylacetamide ( dmac ), n - methylpyrrolidone ( nmp ), dimethylimidazolidinone ( dmi ), dimethyl sulfoxide ( dmso ) and sulfolane . they can be used singly or in combination . no particular restriction is put on the amino acid ester which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , and any amino acid ester can be used , so long as it is substantially soluble in the organic solvent and / or does not substantially impede the progress of the reaction . the formula of the amino acid ester can be represented by the following formula ( vii &# 39 ;): ## str5 ## ( 4 ) amino acid residue moiety of amino acid ester : no particular restriction is put on the amino acid residue of the amino acid ester ( vii &# 39 ;). typical examples of the amino acid ester include esters having , in their molecules , as the amino acid residues , the residues of the amino acids which will be hereinafter exemplified . these esters can be used singly or in combination . typical examples of the amino acids include aliphatic amino acids such as glycine , alanine , valine , leucine and isoleucine ; oxyamino acids such as serine and threonine ; sulfur - containing amino acids such as methionine , cysteine and cystine ; acidic amino acids such as aspartic acid and glutamic acid ; basic amino acids such as lysine , ornithine and arginine ; aromatic amino acids such as phenylalanine and tyrosine ; heterocyclic amino acids such as tryptophan , histidine , proline and oxyproline ; and amide group - containing amino acids such as asparagine and glutamine . these amino acids can be used irrespective of l - form , d - form and dl - form . in particular , the amino acid residue is preferably a glycine residue and / or a lysine residue . no particular restriction is put on x in the formula ( vii &# 39 ;) of the amino acid ester , so long as x is any one of alkyl groups , cycloalkyl groups and a benzyl group . typical examples of the amino acid esters include aliphatic esters such as methyl esters , ethyl esters , butyl esters and hexyl esters ; alicyclic esters such as cyclohexyl esters ; and benzyl esters . they can be used singly or in combination . of the amino acid esters , lower aliphatic esters such as methyl esters and ethyl esters are preferable , and methyl esters are more preferable . the amino acid esters may be in the forms of free esters and mineral acid salts such as hydrochlorides and sulfates . no particular restriction is put on the amount of the amino acid ester which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it is substantially soluble in the organic solvent and / or does not substantially impede the progress of the reaction . the amount of the amino acid ester is usually in the range of 0 . 1 to 10 equivalents , preferably 0 . 1 to 1 . 0 equivalent per one equivalent of the monomer unit of the polysuccinimide . ( 7 ) opening of imide rings by reaction with amino acid ester : by the reaction of the polysuccinimide with the amino acid ester , the imide rings of the polysuccinimide can be opened . when the ring opening reaction is carried out by using less than one equivalent of the amino acid ester per one equivalent of the monomer unit of the polysuccinimide , some unreacted imide rings usually remain . if desired , the unreacted imide rings may remain as it is , or they may be opened by further ring opening reaction with the other amino acid ester . furthermore , if desired , the unreacted imide rings may be opened by ring opening reaction with a substituted amine such as ethanolamine , cysteamine and dibutylamine . by adding a base to polysuccinimide to effect an alkali hydrolysis reaction , the imide rings of the polysuccinimide can be opened . accordingly , the unopened imide rings of the polysuccinimide that remained in the ring opening reaction of the polysuccinimide with the amino acid ester , if desired , can be opened by subjecting them to the alkali hydrolysis reaction with an aqueous basic solution . no particular restriction is put on the kind of alkali compound which is used in the alkali hydrolysis reaction , so long as it does not substantially lower the molecular weight of the polysuccinimide and can open the imide rings in the polysuccinimide molecules to a desired level . typical examples of the base , which is used to open the imide rings of the polysuccinimide by alkali hydrolysis reaction with an aqueous basic solution , include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide ; metal carbonates such as sodium carbonate and potassium carbonate ; organic bases such as triethylamine , triethanolamine , n - methylmorpholine and diisopropylethylamine ; and ammonia . they can be used singly or in combination . in general , a hydroxide such as sodium hydroxide can be used . the above - mentioned basic compounds are usually added as an aqueous basic solution . no particular restriction is put on the process for preparing the amino acid ester which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention . in general , the amino acid ester which is used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , can be prepared by heating amino acid in an excess alcohol in the presence of a mineral acid catalyst such as sulfuric acid or hydrochloric acid . no particular restriction is put on a basic catalyst which can be optionally used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it can substantially accelerate the reaction rate . typical examples of the basic catalyst include aliphatic tertiary amines such as trimethylamine , triethylamine , tripropylamine , tributylamine , diisopropylethylamine ( diea ), triethanolamine and triethylenediamine ( dabco ); an alicyclic tertiary amines such as n - methylmorpholine ; aromatic tertiary amines such as dimethylaniline and diethylaniline ; and tetramethylguanidine . they can be used singly or in combination . no particular restriction is put on the amount of the basic catalyst which can be used in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it can substantially accelerate the reaction rate . the amount of the basic catalyst to be used is usually in the range of 0 to 2 equivalents per one equivalent of the amino acid ester . when the amino acid ester is the mineral acid salt , a neutralization equivalent of a base is added . no particular restriction is put on the reaction temperature which is employed in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it can substantially maintain the progress of the reaction . in general , the reaction temperature is selected from a temperature range of 5 to 150 ° c . room temperature is usually selected . as the reaction temperature , the most suitable temperature for the amino acid ester used can be selected from the temperature range of 5 ° to 150 ° c . no particular restriction is put on the concentration of the reaction system which is employed in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it can substantially maintain the progress of the reaction . the concentration of the reaction system is selected in terms of the concentration of the polysuccinimide . in general , the concentration of the polysuccinimide is selected from a concentration range of 1 to 30 % by weight . as the concentration of the reaction system , the most suitable concentration for the amino acid ester used can be selected from a concentration range of 1 to 30 % by weight . no particular restriction is put on the ratio of an α - amide type monomer unit to a β - amide type monomer unit which are contained in the polymer obtained by the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention . in the polymer obtained by the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , the α - amide type monomer unit and the β - amide type monomer unit randomly exist in general . no particular restriction is put on the isolation process of the polymer from a reaction solution after the completion of the reaction which can be employed in the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention , so long as it permits the isolation of a reaction product in a desired purity . the isolation may be carried out by any of known and already used methods . in general , a known and used isolation operation such as concentration , recrystallization or reprecipitation can be employed . one typical example of the isolation methods is the following method . after the completion of the reaction , an excess in a poor solvent ( e . g ., methyl alcohol , ethyl alcohol , isopropyl alcohol or the like ) is added to a reaction solution in which a reaction product is dissolved at a proper temperature . the deposited crystals of the reaction product are then isolated by decantation , filtration , suction filtration or the like . afterward , the crystals are sufficiently washed with a poor solvent which does not dissolve the crystals , and then dried . another typical example of the isolation methods is the following method . after the completion of the reaction , a reaction solution in which a reaction product is dissolved is added to the same excess poor solvent as previously described at a proper temperature . the deposited crystals of the reaction product are then isolated , and the crystals are washed and then dried in the same manner as previously described . as described above , when a base is added to the polysuccinimide to carry out the reaction , the imide rings of the polysuccinimide can be opened . similar to the operation of this ring opening reaction , a basic compound is added to the polymer having an amino acid residue or an amino acid ester residue as a pendant group in at least a part of a monomer unit which can be obtained by the &# 34 ; process for preparing the polymer &# 34 ; regarding the present invention to carry out the alkali hydrolysis reaction , whereby a polymer can be obtained in which the carboxyl group of the pendant group is free or in the state of a salt . the above - mentioned ring opening reaction and the reaction the of converting the carboxyl group of the pendant group can be simultaneously carried out by suitably setting the reaction conditions such as the kind of polymer having the amino acid residue or the amino acid ester residue as the pendant group in at least a part of the monomer unit , the kind and concentration of basic compound , the reaction temperature , the reaction time and the like . no particular restriction is put on the kind of alkali compound which can be used in the above - mentioned alkali hydrolysis reaction , so long as it does not substantially lower the molecular weight of the polysuccinimide and can convert the carboxyl group of the pendant group to a desired level . typical examples of the base which can be used in the conversion of the carboxyl group of the pendant group by the alkali hydrolysis reaction include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide ; metal carbonates such as sodium carbonate and potassium carbonate ; organic bases such as triethylamine , triethanolamine , n - methylmorpholine and diisopropylethylamine ; and ammonia . they can be used singly or in combination . in general , alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferable . the above - mentioned basic compounds are usually added as an aqueous basic solution . as stated above , the above - mentioned alkali compound is usually added as an aqueous basic solution . regarding the above - mentioned alkali hydrolysis reaction , in case that the alkali compound is added as an aqueous basic solution , no particular restriction is put on the concentration of the alkali compound , so long as it does not substantially lower the molecular weight of the polysuccinimide and can convert the carboxyl group of the pendant group to a desired level . in general , the concentration of the alkali compound is preferably in the range of 0 . 01 to 5n , more preferably 0 . 1 to 3n . if the concentration of the alkali compound is too low , the efficiency of the hydrolysis decreases . conversely , if the concentration of the alkali compound is too high , hydrolysis of the main chaing and side chains , and a decrease of the molecular weight might occur inconveniently . the present invention is concerned with a polymer having an amino acid residue or an amino acid ester residue as a pendant group in at least a part of a monomer unit which is free from irritation to organisms ( e . g ., eyes and skin ). no particular restriction is put on the preparation process of the &# 34 ; polymer &# 34 ; regarding the present invention . the preferable embodiment of the preparation process of the &# 34 ; polymer &# 34 ; regarding the present invention is the aforesaid &# 34 ; preparation process of the polymer &# 34 ; regarding the present invention . no particular restriction is put on the ratio of an α - amide type monomer unit ( i &# 39 ;) to a β - amide type monomer unit ( ii &# 39 ;) which are contained in the molecule of &# 34 ; polymer &# 34 ; regarding the present invention . ## str6 ## in the &# 34 ; polymer &# 34 ; regarding the present invention , the α - amide type monomer unit and the β - amide type monomer unit randomly exist . the weight - average molecular weight ( mw ) of the polymer is usually in the range of 2 , 000 to 300 , 000 , preferably 3 , 000 to 200 , 000 , more preferably 5 , 000 to 100 , 000 . no particular restriction is put on the amino acid residue in the α - amide type monomer unit ( i &# 39 ;) and the β - amide type monomer unit ( ii &# 39 ;) contained in the &# 34 ; polymer &# 34 ; regarding the present invention . typical examples of the amino acid residue include the residues of the following amino acids . they can be used singly or in combination . typical examples of the amino acids include aliphatic amino acids such as glycine , alanine , valine , leucine and isoleucine ; oxyamino acids such as serine and threonine ; sulfur - containing amino acids such as methionine , cysteine and cystine ; acidic amino acids such as aspartic acid and glutamic acid ; basic amino acids such as lysine , ornithine and arginine ; aromatic amino acids such as phenylalanine and tyrosine ; heterocyclic amino acids such as tryptophan , histidine , proline and oxyproline ; and amide group - containing amino acids such as asparagine and glutamine . these amino acids can be used irrespective of l - form , d - form and dl - form . no particular restriction is put on an ester moiety x in the α - amide type monomer unit ( i &# 39 ;) and the β - amide type monomer unit ( ii &# 39 ;) contained in the &# 34 ; polymer &# 34 ; regarding the present invention , so long as x is any one of alkyl groups , cycloalkyl groups , a benzyl group , a hydrogen atom and alkali metals . typical examples of the ester moiety include aliphatic esters such as methyl esters , ethyl esters , butyl esters and hexyl esters ; alicyclic esters such as cyclohexyl esters ; and benzyl esters . they can be used singly or in combination . as the ester moiety , lower aliphatic esters having 1 to 5 carbon atoms such as methyl esters and ethyl esters are preferable , and methyl esters are especially preferable . next , the present invention will be described in more detail with reference to experimental examples and a comparative example . the description of synthetic examples , embodiments , examples and the like in this specification is intended to aid the grasp of the present invention , and it is not intended to limit the technical scope of the present invention . the procedures of evaluation employed in the examples and the comparative example will be described in the following ( 1 ) to ( 6 ). ( 1 ) evaluation of weight - average molecular weight of polysuccinimide used as a raw material : the weight - average molecular weight ( hereinafter referred to as &# 34 ; mw &# 34 ;) of the polysuccinimide used as a raw material was evaluated in terms of polystyrene by gel permeation chromatography ( hereinafter referred to as &# 34 ; gpc &# 34 ;). ______________________________________device : jasco corp . 880 - pudetector : shodex rid - 300column : shodex kd - 804 + kd - 80msolvent : 0 . 01m libr / dmfconc . : 0 . 5 wt % amount : 20 μlflow rate : 1 . 0 ml / min______________________________________ the mw of the polymer was evaluated in terms of polyethylene oxide under the following conditions by gpc . ______________________________________device : jasco corp . 880 - pudetector : jasco corp . 830 - ricolumn : shodex ohpak b - 804solvent : mixed solvent of 0 . 1m kcl / water : methanol = 8 : 2conc . : 0 . 5 wt % amount : 20 μlflow rate : 0 . 4 ml / min______________________________________ straight hairs having a length of 32 cm were washed with a 0 . 25 wt % aqueous sodium lauryl sulfate solution , dried , and then bundled every 3 g . the hairs were immersed in a 3 wt % aqueous polymer solution for one minute to uniformly apply the solution thereon , scraped with fingers five times to remove the excess polymer solution , wound onto a rod having a diameter of 1 . 4 cm , fixed with a rubber band , and then dried at 50 ° c . for 2 hours . the dried hairs were gently detached from the rod , and then hung in a constant temperature and constant humidity tank at 30 ° c . and at a relative humidity of 90 %. afterward , the length of the curl was measured with time , and a curl retention ratio (%) was then calculated in accordance with the following formula : wherein l is the length ( cm ) of the original straight hairs , l 0 is the length ( cm ) of the curl after 0 hour , and l n is the length ( cm ) of the curl after n hours . a rabbit eye mucosa irritation test was carried out as follows . ( a ) preparation of sample : a sample was ground into fine powder in a mortar , and the used in the test . ( b ) number of used animals : three male animals ( unwashed eye group only ) were used per analyte . within 24 hours before the start of administration , it was confirmed by a fluorescein sodium solution treatment that the eyes of these animals were normal . ( c ) measurement of weight : the weight of each animal was measured immediately before the administration once on the administration day . ( d ) administration way : the lower eyelid of a right eye was gently separated from an eyeball , and 0 . 1 g of the sample was put in a conjuctival sac . afterward , both the eyeballs were gently closed and then maintained for about one second . the left eye was not treated , and so it was regarded as a control . ( e ) mark : after 24 , 48 and 72 hours and after 5 , 7 , 14 and 21 days from the administration of the sample , the irritation states of the eyes were observed in accordance with the following table ( the oecd method ) to decide the mark of the irritation states . cornea , iris and conjunctivae were observed , and other damages were also observed . furthermore , on the basis of the obtained results , the strength of the irritation was judged in accordance with the classification of eye irritation evaluation ( federal register , 1972 ). ______________________________________rabbit eye mucosa irritation test mark table ( the oecd method ) state of eye bypart to be evaluated mark positive irritation______________________________________1 cornea ( the 0 negative no ulceration or opacity mark of the opacity . cornea is evaluated 1 positive cornea : scattered in a portion in or diffuse areas of which the opacity is opacity ( which is densest .) different from a usual light opacity state ). details of iris : clearly visible . 2 positive cornea : easily dis - cernible translucent areas of opacity . details of iris : slightly obscured . 3 positive cornea : nacreous areas of opacity . details of iris : they are not visible , and size of pupil is barely dis - cernible . 4 positive the iris is not dis - cernible . 2 iris 0 negative normal 1 positive any of markedly deepened folds , con - gestion , swilling , moderate circum - corneal injection is discernible . the iris reacts to light . 2 positive any of no reaction to light , hemorrhage and marked tissue destruction is dis - cernible . 3 conjunctivae 0 negative vessels are normal ( which is evaluated 1 positive some vessels are by the redness of definitely injected . palpebral and 2 positive diffuse crimson red bulbar conjunctivae is shown , and in - excluding the dividual vessels are cornea and the iris ) not easily discern - ible . 3 positive diffuse beefy red is shown . 4 chemasis 0 negative no swelling 1 positive slight swelling ( which includes nictitating mem - brane ) 2 positive obvious swelling with partial ever - sion of lids . 3 positive swelling with lids about half closed . 4 positive swelling with lids more than half closed . ______________________________________ as a reactor , there was used a separable flask equipped with a stirrer , a heater , a thermometer and a nitrogen line . from reaction to isolation , the temperature of a system was maintained at 20 ° to 25 ° c . during the reaction , the reaction system was sufficiently stirred . as a raw material , polysuccinimide having a weight - average molecular weight of 62 , 000 was used . 29 . 1 g ( 0 . 3 mol ) of the polysuccinimide was dissolved in 174 . 7 g of dmf , and the mixture was then poured into the reactor together with 37 . 7 g ( 0 . 3 mol ) of glycine methyl ester hydrochloride . afterward , 60 . 7 g ( 0 . 6 mol ) of triethylamine was continuously added dropwise to the reactor over 2 hours to carry out reaction , and after the addition , the reaction was further continued for 29 hours . after the completion of the reaction , the resultant reaction solution was filtered with suction to remove a by - product , i . e ., triethylamine hydrochloride , as a filter residue ( hereinafter referred to as &# 34 ; filter mass &# 34 ;), and the filtrate containing a produced polymer was fed to a next isolation step . the filtrate was poured with stirring into 2 , 500 ml of ethanol which was a poor solvent for the produced polymer , thereby precipitating the produced polymer . the suspension of the produced polymer was filtered with suction to isolate the produced polymer in the form of a mass . furthermore , this mass was dispersed in the poor solvent , stirred and then filtered with suction , and this serial operation was then repeated several times to sufficiently wash the produced polymer . afterward , the produced polymer was dried by hot air at 60 ° c . to obtain the produced polymer isolated . the produced polymer thus isolated was subjected to evaluation described hereinafter , the curl retention test and the rabbit eye mucosa irritation test . the yield of the produced polymer was 48 . 4 g ( yield : 86 . 8 %). the unit molecular formula and the elemental analysis values of the produced polymer were as follows : ______________________________________unit molecular formula : c . sub . 7 h . sub . 10 n . sub . 2 o . sub . 4elemental analysis values : calc . found______________________________________c 45 . 16 45 . 97h 5 . 40 5 . 49n 15 . 05 14 . 48______________________________________ for the produced polymer , 1 h - nmr was measured , and as a result , the following peaks were detected . neither of a peak at 5 . 1 ppm inherent in a methylene group ([ ch2 - psi ]) of a succinimide monomer unit and a peak at 3 . 2 ppm inherent in a methine group ([ ch - psi ]) of the another succinimide monomer unit were detected . consequently , it can be considered that a polysuccinimide monomer unit is not substantially present in the molecule of the produced polymer . therefore , the monomer unit of the polymer obtained in example 1 can be considered to be substantially constituted only of the following α - amide type monomer unit ( ia ) and β - amide type monomer unit ( iia ). ## str7 ## the same reactor as in example 1 was used . from reaction to isolation , the temperature of a system was maintained at 20 to 25 ° c ., and the reaction system was sufficiently stirred during the reaction as in example 1 . oxygen was removed from the reaction system by dry nitrogen bubbling which operation is different from example 1 . as a raw material , polysuccinimide having a weight - average molecular weight of 62 , 000 was used . beforehand , a cysteamine / dmf suspension and a polysuccinimide / dmf solution were prepared . that is to say , there were beforehand prepared the cysteamine / dmf suspension in which 8 . 2 g ( 0 . 106 mol ) of cysteamine was suspended in 32 . 0 g of dmf , and the polysuccinimide / dmf solution in which 10 . 0 g ( 0 . 103 mol ) of the polysuccinimide was dissolved in 40 . 0 g of dmf . oxygen in the dmf used herein had been sufficiently removed by dry nitrogen bubbling . the above - mentioned cysteamine / dmf suspension was poured into the reactor . the above - mentioned polysuccinimide / dmf solution was continuously added dropwise to the reactor over 0 . 5 hour to carry out reaction , and after the addition , the reaction was further continued for 24 hours . the reaction solution was poured with stirring into 400 ml of methanol which was a poor solvent for a produced polymer , thereby precipitating the produced polymer . the suspension of the produced polymer was filtered with suction to isolate the produced polymer in the form of a mass . furthermore , this mass was dispersed in the poor solvent , stirred and then filtered with suction , and this serial operation was then repeated several times to sufficiently wash the produced polymer . afterward , the produced polymer was dried by hot air at 60 ° c . to isolate the produced polymer . the produced polymer thus isolated was subjected to evaluation described hereinafter , the curl retention test and the rabbit eye mucosa irritation test . the yield of the produced polymer was 14 . 7 g ( yield : 82 . 3 %). the unit molecular formula and the elemental analysis values of the produced polymer were as follows : ______________________________________unit molecular formula : c . sub . 6 h . sub . 10 n . sub . 2 o . sub . 2 selemental analysis values : calc . found______________________________________c 41 . 37 41 . 22h 5 . 74 5 . 65n 16 . 09 16 . 00______________________________________ ( 5 ) monomer unit of the produced polymer : the monomer unit of the polymer obtained in comparative example 1 can be considered to be substantially constituted only of the following α - amide type monomer unit ( viii ) and β - amide type monomer unit ( ix ). ## str8 ## for the polymers obtained in example 1 and comparative example 1 , a curl retention test was carried out . the results are shown in table 1 . table 1______________________________________curl retention ratio (%) time ( hr ) 0 . 5 1 . 0 2 . 0 3 . 0 4 . 0 5 . 0______________________________________example 1 60 52 48 42 38 30comp . ex . 1 24 18 10 5 2 2blank 5 0 0 0 0 0______________________________________ for the polymers obtained in example 1 and comparative example 1 , a rabbit eye mucosa irritation test was carried out . the results are shown in table 2 . table 2______________________________________rabbit eye mucosa irritation test . hours after administration 24 48 72 5 7 14 21 hrs hrs hrs days days days days______________________________________ex . 1cornea opacity 0 0 0 0 0 0 0iris abonormal 0 0 0 0 0 0 0conjuctivae redness 0 . 3 0 0 0 0 0 0chemasis 0 0 0 0 0 0 0cx . 1cornea opacity 1 . 3 1 . 3 1 . 3 0 . 7 0 . 7 1 . 0 1 . 3iris abonormal 0 0 . 7 0 . 7 0 0 0 0conjuctivae redness 2 . 0 2 . 3 1 . 7 1 . 3 1 . 3 1 . 3 0chemasis 3 . 7 1 . 7 1 . 7 1 . 3 1 . 3 1 . 3 1 . 3______________________________________ as is apparent from comparison between example 1 and comparative example 1 shown in table 1 , the polymer regarding the present invention has excellent hair setting properties . as is apparent from comparison between example 1 and comparative example 1 shown in table 2 , the polymer regarding the present invention has no irritation to the eye mucosa . the same procedure as in example 1 was carried out except that 29 . 1 g ( 0 . 3 mol ) of polysuccinimide , 18 . 8 g ( 0 . 15 mol ) of glycine hydrochloride methyl ester and 30 . 4 g ( 0 . 3 mol ) of triethylamine were used , to carry out reaction , thereby obtaining a polymer . the same procedure as in example 1 was carried out except that 2 , 750 ml of ethanol was used , to isolate the polymer . the yield of the produced polymer was 39 . 5 g ( yield : 93 . 0 %). the unit molecular formula and the elemental analysis values of the produced polymer were as follows : ______________________________________unit molecular formula : ( c . sub . 7 h . sub . 10 n . sub . 2 o . sub . 4 ). sub . 0 . 5 -( c . sub . 4 h . sub . 3 no . sub . 2 ). sub . 0 . 5elemental analysis values : calc . found______________________________________c 47 . 30 47 . 13h 4 . 25 4 . 51n 14 . 74 14 . 66______________________________________ for the produced polymer , 1 h - nmr was measured , and as a result , the following peaks were detected . a peak at 5 . 1 ppm inherent in [ ch2 - psi ] and a peak at 3 . 2 ppm inherent in [ ch - psi ] were detected . consequently , it can be considered that a polysuccinimide monomer unit is also substantially present in the molecule of the produced polymer . the same operations as in &# 34 ;( 1 ) reaction &# 34 ; and &# 34 ;( 2 ) isolation &# 34 ; of example 1 were conducted to obtain a polymer . 9 . 3 g ( 0 . 05 mol ) of the polymer obtained in the above - mentioned step ( 1 ) was dissolved in 55 . 8 g of pure water , and 12 . 92 g ( 0 . 052 mol ) of a 4n aqueous naoh solution was then continuously added dropwise at 45 ° to 50 ° c . over 2 hours to carry out an alkali treatment . this alkali treated solution was concentrated to 22 g , and then fed to the following isolation operation . the reaction solution was poured with stirring into 400 ml of methanol which was a poor solvent for the alkali treated polymer , thereby precipitating the alkali treated polymer . the suspension of the alkali treated polymer was filtered with suction to isolate the alkali treated polymer in the form of a mass . furthermore , this mass was dispersed in the poor solvent , stirred and then filtered with suction , and this serial operation was then repeated several times to sufficiently wash the alkali treated polymer . afterward , the alkali treated polymer was dried by hot air at 60 ° c . to isolate the produced polymer . the weight - average molecular weight of the alkali treated polymer was 56 , 000 . the unit molecular formula and the elemental analysis values of the produced polymer were as follows : ______________________________________unit molecular formula : c . sub . 6 h . sub . 7 n . sub . 2 o . sub . 4 naelemental analysis values : calc . found______________________________________c 37 . 12 37 . 24h 3 . 63 4 . 01n 14 . 43 14 . 14______________________________________ the monomer unit of the polymer obtained in example 3 can be considered to be substantially constituted only of the following units ( ib ) and ( iib ). ## str9 ## the same reactor as in example 1 was used . from reaction to isolation , the temperature of a system was maintained at 20 ° to 25 ° c ., and the reaction system was sufficiently stirred during the reaction as in example 1 . as a raw material , polysuccinimide having a weight - average molecular weight of 62 , 000 was used . 29 . 1 g ( 0 . 3 mol ) of the polysuccinimide was dissolved in 174 . 7 g of dmf , and the mixture was then poured into the reactor together with 69 . 9 g ( 0 . 3 mol ) of lysine methyl ester dihydrochloride . afterward , 91 . 1 g ( 0 . 9 mol ) of triethylamine was continuously added dropwise to the reactor over 2 hours to carry out reaction , and after the addition , the reaction was further continued for 7 hours . after the completion of the reaction , the resultant reaction solution was filtered with suction to remove a by - product , i . e ., triethylamine hydrochloride , as a filter residue ( hereinafter referred to as &# 34 ; filter mass &# 34 ;), and the filtrate containing a produced polymer was fed to a next isolation step . the same operation as in &# 34 ;( 2 ) isolation &# 34 ; of example 1 was carried out to isolate the polymer . the weight - average molecular weight of the produced polymer was 48 , 000 . the yield of the produced polymer was 29 . 7 g . the unit molecular formula and the elemental analysis values of the produced polymer were as follows : ______________________________________unit molecular formula : c . sub . 11 h . sub . 19 n . sub . 3 o . sub . 4elemental analysis values : calc . found______________________________________c 51 . 36 50 . 79h 7 . 39 7 . 36n 16 . 34 15 . 92______________________________________ the monomer unit of the polymer obtained in example 4 can be considered to be substantially constituted only of the same α - amide type monomer unit and β - amide type monomer unit as in example 1 except that it has the residue of the lysine methyl ester dihydrochloride .
a polymer containing the following monomer unit and / or : ## str1 ## and a process for preparing the polymer which comprises , in ring opening reaction of the polysuccinimide , opening the ring of polysuccinimide by using an amino acid ester having an extremely high reactivity in place of an α - amino acid having an extremely low reactivity . the polymer is characterized by having no irritation to organisms , and for example , the polymer is useful in the industrial fields of fields of medical supplies , health , beauty and sanitary aids , quasi - pharmaceuticals , and the like .