Approximately equimolar copolymers of maleic anhydride with vinyl methyl ether, vinyl ethyl ether, vinyl methoxy ethyl ether or ethylene having a specified viscosity of 0.4 to 0.7 are modified to form partial esters or mixed partial ester-amides having 40 to 60% by weight of the total carboxyl groups esterified and/or amidated by reacting 0.5 to 25% (of said 40 to 60%) with (1) a C10-22 alcohol or (2) a condensation product of a C10-22 alcohol with ethylene or propylene oxide or (3) a condensation product of a C10-22 fatty acid with ethylene or propylene oxide or (4) a C4-22 primary amine or (5) a condensation product of a C4-22 primary amine with ethylene or propylene oxide or (6) a C2 or C3 alkanolamide of a C10-22 fatty acid, and esterifying the balance of the groups with a C1-3 alkanol. Hair spray compositions.  The modified copolymers are particularly useful in hair-setting compositions, for which purpose the C1-3 alkanol is used in excess, the excess constituting a solvent for the compositions. If a C10-22 alcohol is used in the first step of the modification this also is preferably used in a 10 to 200% excess which is retained to function as a plasticizer.  The composition may be used as a spray by being packed in a pressure-proof container along with a pressure propellant e.g. nitrogen, carbon dioxide, nitrous oxide, propane, isobutane or preferably halogenated saturated hydrocarbons several fluorine or fluorine and chlorine-substituted methanes and ethanes being mentioned.  Other ingredients mentioned are a buffer system such as a mixture of a molar excess of such acids as citric, succinic or oleic with an organic base e.g. triisopropenolamine or a tri-C2- 3 alkylamine; a liquid dimethyl polysiloxane (to render sprayed hair more combable) and perfume.ALSO:Approximately equimolar copolymers of maleic anhydride with vinyl methyl ether, vinyl ethyl ether, vinyl methoxy ethyl ether p  or ethylene having a specific viscosity of 0.4 to 0.7 are modified to form partial esters or mixed partial ester-amides having 40 to 60% by weight of the total carboxyl groups esterified and/or amidated by reacting 0.5 to 25% (of said 40 to 60%) with (1) a C10-22 alcohol or (2) a condensation product of a C10-22 alcohol with ethylene or propylene oxide or (3) a condensation product of a C10-22 fatty acid with ethylene or propylene oxide or (4) a C4-22 primary amine or (5) a condensation product of a C4-22 primary amine with ethylene or propylene oxide or (6) a C2 or C3 alkanolamide or a C10-22 fatty acid, and esterifying the balance of the groups with a C1-3 alkanol. Hair spray compositions.-The modified copolymers are particularly useful in hair-setting compositions, for which purpose the C1-3 alkanol is used in excess, the excess constituting a solvent for the compositions.  If a C10-22 alcohol is used in the first step of the modification this also is preferably used in a 10 to 200% excess which is retained to function as a plasticizer.  The composition may be used as a spray by being packed in a pressure-proof container along with a pressure propellent e.g. nitrogen, carbon dioxide, nitrous oxide, propane, isobutane or preferably halogenated saturated hydrocarbons several fluorine or fluorine and chlorine-substituted methanes and ethanes being mentioned.  Other ingredients mentioned are a buffer system such as a mixture of a molar excess of such acids as citric, succinic or oleic with an organic base e.g. triisopropenolamine or a tri-C2-3 alkylamine; a liquid dimethyl polysiloxane (to render sprayed hair more combable) and perfume.