Aminosiloxanes of high purity

A composition having a Hazen number of from 0 to 100 and a H2N-functionality of from 1.96 to less than 2.00 comprising:

• (A) at least one aminoalkyl-functional polysiloxane of general formula (I):
• wherein
• R1 is independently selected from the group consisting of a monovalent linear alkyl, branched alkyl, arylalkyl, alkylaryl, and aryl groups containing up to 20 carbon atoms,
• each R2 is independently a linear or branched divalent C3 or C4 alkyl group, and
• n is an integer of from 0 to 7;
• and
• (B) at least one compound comprising at least one iminoalkyl functional group obtained from the hydrosilylation of at least one olefinic amine and at least one hydridosiloxane in the presence of a platinum catalyst,
• wherein the H2N-functionality is determined by 1H NMR using the equation:
• [H2N−functionity=2.0*(1−[mol % impurity−CH]/100,
• wherein the mole percent impurity-CH functionality is calculated from the corresponding area integral of the impurity (N═CH)-signals of the iminoalkyl groups, observed in the range of from 7.4 to 7.7 ppm versus the integrals of the SiCHn′, where n′ is 1 or 2 observed in the range of from 0.4 to 0.7 ppm, and wherein the composition is made by a process comprising the steps of:
• (i) reacting a composition having an H2N-functionality of greater than 0 and less than 1.96 and/or color according to Hazen number of greater than 100 comprising at least one an aminoalkyl-functional polysiloxane and at least one compound comprising at least one iminoalkyl functional group with a stoichiometric excess, related to the content of H2N-groups, of an acid with a pKa less than or equal to 5.5 and a stoichiometric excess of water, related to the acid, to provide for a reaction product composition,
• (ii) removing the volatile compounds present in the reaction product composition of step (i) by distillation, optionally with the use of an inert carrier gas, at a temperature of from 40° C. to 250° C. and at a pressure of from 0.1 mbar to 1030 mbar to provide for a devolatilized higher boiling composition,
• (iii) neutralizing the resulting devolatilized higher boiling composition of step (ii) with at least one base to provide for a neutralized and devolatilized higher boiling composition, and
• (iv) depolymerizing the neutralized and devolatilized higher boiling composition of step (iii) in the presence of at least one base to produce a composition containing at least one amino-functional polysiloxane of formula (I), and
• (v) distilling the composition containing at least one amino-functional polysiloxane of step (iv) at a temperature of from 60° C. to 250° C. and at a pressure of from 0.1 mbar to 1030 mbar to provide for the composition comprising components (A) and (B) and having a Hazen number of from 0 to 100 and a H2N-functionality of from 1.96 to less than 2.00.