Branched copolymers as additives for viscosity reduction of mineral binder compositions

An additive for mineral binder compositions, comprising at least one copolymer prepared in a multistage process wherein the copolymer is selected from the group consisting of

• a) copolymer of the general structure (I):
• where
• R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl,
• X is O or NH,
• A is in each case independently C1-C10 alkylene,
• R2 is a C1-C16 alkyl,
• B is in each case independently C1-C10 alkylene,
• R3 is H, C1-C16 alkyl, or C(O)R1 with R1 as defined above,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 0-100,
• p is 0 or 1,
• q is an integer in the range of 1-10, and
• if q is 1, o is an integer in the range of 1-10, and, if q>1, each o is independently an integer in the range of 1-50,
• (b) copolymer of the general structure (II):
• where
• R1 is selected from C1-C18 alkyl,
• A is in each case independently ethylene, propylene and/or butylene,
• B is in each case independently ethylene, propylene and/or butylene,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 1-100,
• o is an integer in the range of 1-50, and
• (c) copolymer of the general structure (III):
• where
• R1 is selected from C1-C18 alkyl,
• A is in each case independently ethylene, propylene and/or butylene,
• B is in each case independently ethylene, propylene and/or butylene,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 1-100,
• o is an integer in the range of 1-50, and
• x is an integer in the range of 1-9, with the proviso that x<o, and wherein, the multistage process comprising the steps of
• 1) optionally reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R1-XH, with an alkoxylating agent and/or a halogenated alcohol or halogenated amine Hal-R2-XH, where R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, Hal is Cl, Br or I, and R2 is a C1-C16 alkyl,
• 2) reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R1-XH, where R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, or the reaction product from step 1) with glycidol or epichlorohydrin or a mixture of glycidol and an alkoxylating agent or a mixture of epichlorohydrin and an alkoxylating agent, and
• 3) reacting the reaction product from step 2) with an alkoxylating agent.

A mineral binder composition comprising at least one mineral binder and at least one copolymer prepared in a multistage process wherein the copolymer is selected from the group consisting of

• (a) copolymer of the general structure (I):
• where
• R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl,
• X is O or NH,
• A is in each case independently C1-C10 alkylene,
• R2 is a C1-C16 alkyl,
• B is in each case independently C1-C10 alkylene,
• R3 is H, C1-C16 alkyl, or C(O)R1 with R1 as defined above,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 0-100,
• p is 0 or 1,
• q is an integer in the range of 1-10, and
• if q is 1, o is an integer in the range of 1-10, and, if q>1, each o is independently an integer in the range of 1-50,
• (b) copolymer of the general structure (II):
• where
• R1 is selected from C1-C18 alkyl,
• A is in each case independently ethylene, propylene and/or butylene,
• B is in each case independently ethylene, propylene and/or butylene,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 1-100,
• o is an integer in the range of 1-50, and
• (c) copolymer of the general structure (III):
• where
• R1 is selected from C1-C18 alkyl,
• A is in each case independently ethylene, propylene and/or butylene,
• B is in each case independently ethylene, propylene and/or butylene,
• m is in each case independently an integer in the range of 2-350,
• n is an integer in the range of 1-100,
• o is an integer in the range of 1-50, and
• x is an integer in the range of 1-9, with the proviso that x<o, and wherein, the multistage process comprising the steps of
• 1) optionally reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R1-XH, with an alkoxylating agent and/or a halogenated alcohol or halogenated amine Hal-R2-XH, where R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, Hal is Cl, Br or I, and R2 is a C1-C16 alkyl,
• 2) reacting a starter S, selected from the group consisting of alcohols, amines, carboxylic acids and amides of the general formula R1-XH, where R1 is a C1-C18 alkyl, C2-C18 alkylene, C3-C10 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl or C1-C18 carbonyl, X is O or NH, or the reaction product from step 1) with glycidol or epichlorohydrin or a mixture of glycidol and an alkoxylating agent or a mixture of epichlorohydrin and an alkoxylating agent, and
• 3) optionally reacting the reaction product from step 2) with an alkoxylating agent.