Abstract: Nail polish is disclosed, based upon a film-former, a resin component and a solvent system, containing as film-former and/or resin component an O-benzyl-N-hydroxyalkyl chitosan fo the formula (I)HO[C.sub.6 H.sub.11-m-q NO.sub.4 (R.sup.1).sub.m (R.sup.2).sub.n (R.sup.3).sub.q ].sub.p H (I)(with m=0 to 0.6; n=0.1 to 10; q=0.1 to 4; p=an integer from 50 to 5,000; R.sup.1 =acetyl; R.sup.2 =hydroxyethyl, 2-hydroxypropyl or 2-hydroxybutyl and R.sup.3 =benzyl).The polish film obtained with the nail polish possesses a high luster, outstanding adhesion, as well as an increased hardness compared to nail polishes based upon nitro-cellulose, with even more sufficient elasticity. Also included in the present invention are the new O-benzyl-N-hydroxyalkyl-chitosans of formula (I).

Abstract: The invention is directed to cosmetic compositions for the treatment of hair or skin characterized in that they contain new N-hydroxybutyl-chitosans, or their salts, consisting of(a) 4 to 40 mole percent monomer units of the formula (I) ##STR1## and (b) 60 to 96 mole percent monomer units of the formula (II) ##STR2## wherein R.sup.1 and R.sup.2 are identical or different and designate hydrogen or the group ##STR3## with n being equal to an integer from 1 to 5, provided that R.sup.1 and R.sup.2 are not simultaneously hydrogen in at least 50 percent of the units of formula (II). In addition, it is directed to new N-hydroxybutyl-chitosans and their salts and a process for producing these new compounds from butylene oxide and chitosan.

Abstract: The present invention relates to a cosmetic for the treatment of hair and skin which is characterized by a content of novel N-hydroxy-propyl-isopropyl ether chitosans consisting of (a) 4 to 40 mole percent of monomer units having the formula (I) ##STR1## and (b) 60 to 96 mole percent of monomer units having the formula (II) ##STR2## wherein R.sup.1 and R.sup.2 are identical or different and represent hydrogen or the group ##STR3## wherein n equals 1 or 2, with the condition that in at least half the units having the formula (II) R.sup.1 and R.sup.2 do not simultaneously represent hydrogen. The present invention also relates to novel N-hydroxy-propyl-isopropyl ether chitosans.

Abstract: New alkyl-hydroxypropyl-chitosans of the formula IHO[C.sub.6 H.sub.11-m-q NO.sub.4 (R.sup.1).sub.m (R.sup.2).sub.n (R.sup.3).sub.q ].sub.p H (I)(m=0-0.6; n=0.5-10; q=0.5-4; p=50-5000; R.sup.1 =acetyl; ##STR1## R.sup.3 =C.sub.1 -C.sub.6 -alkyl) and their salts with organic or inorganic acids. The invention is directed, in addition, to a process for producing the chitosan derivatives of the formula I, as well as cosmetic compositions for the treatment of hair or skin, particularly compositions for strengthening hair, comprising a content of these chitosan derivatives. The described alkyl-hydroxypropyl-chitosans are distinguished by their favorable solubility in organic solvents. Therefore, they can also be used, for example, in anhydrous hairsprays.

Abstract: Cosmetic compositions are disclosed, for the treatment of skin or hair, with a content of new N-hydroxypropyl-chitosan derivatives, composed of (a) 4 to 40 Mol-% units of Formula (I) ##STR1## and (b) 60 to 96 Mol-% units of Formula (II) ##STR2## wherein R.sup.1 and R.sup.2 are the same or different and are each hydrogen or the group ##STR3## with n being equal to an integer from 1 to 5, with the proviso that in at least 50% of the units (II), R.sup.1 and R.sup.2 are not simultaneously hydrogen, or the salts thereof; along with new N-hydroxypropyl-chitosan derivatives and their salts as well a a process for the production of these new compounds from propylene oxide and chitosan.

Abstract: Cosmetic compositions are disclosed, for the treatment of skin or hair, with a content of new N-hydroxypropyl-chitosan derivatives, composed of (a) 4 to 40 Mol-% units of Formula (I) ##STR1## and (b) 60 to 96 Mol-% units of Formula (II) ##STR2## wherein R.sup.1 and R.sup.2 are the same or different and are each hydrogen or the group ##STR3## with n being equal to an integer from 1 to 5, with the proviso that in at least 50% of the units of (II), R.sup.1 and R.sup.2 are not simultaneously hydrogen, or the salts thereof; along with new N-hydroxypropyl-chitosan derivatives and their salts as well as a process for the production of these new compounds from propylene oxide and chitosan.