Method for producing hydrophilic organopolysiloxane gels

Method for producing a hydrophilic organopolysiloxane gel preparation, comprising:

• combining a mixture (X) and at least one diluent (4) for viscosity adjustment, wherein the mixture (X) comprises
• (a) 80 to 99.9 wt % of at least one hydrophobic organopolysiloxane gel prepared from the reaction either of an unsaturated organopolysiloxane resin (1a) or of an unsaturated organopolysiloxane (1b) or of a diene (1c) with an Si—H-containing organopolysiloxane (2a) optionally in the mixture with an Si—H-containing organopolysiloxane (2b) in the presence of a catalyst (K) which promotes the addition of Si-bonded hydrogen onto aliphatic multiple bond (i.e. hydrosilylation catalyst) in the presence of a diluent (4), the reaction being stopped by addition of a stopper compound (5) which is used as a catalyst poison and which remains in the hydrophobic organopolysiloxane gel,
• (b) 0.1 to 20 wt % of at least one compound (3), wherein the at least one compound (3) is (3a) organopolysiloxanes containing glycoside radicals and of the general formula (V), (3c) organopolysiloxanes containing cyclodextrin radicals and of the formula (VII), or a combination thereof,
• wherein the general formula (V) is
• RhR3iSiO(4-h-i)/2 (V),
• wherein R may be identical or different and is a monovalent, optionally substituted hydrocarbon radical having 1 to 18 carbon atoms per radical, with exclusion of heteroatoms and hetero groups which would hinder a hydrosilylation reaction by adversely affecting the catalyst,
• wherein R3 may be identical or different and is a radical of the formula
• Z—(R4O)j—R5— (Va),
• wherein Z is a glycoside radical composed of 1 to 10 monosaccharide units,
• wherein R4 may be identical or different and is a divalent hydrocarbon radical having 2 to 4 carbon atoms,
• wherein j is 0 or an integer from 1 to 20,
• wherein R5 may be identical or different and is a divalent hydrocarbon radical having 2 to 12 carbon atoms,
• wherein h and i are each 0, 1, 2 or 3, with the proviso that h+i≤3 and in at least one repeating unit i has a value of at least 1;
• wherein the formula (VII) is
• RhR9iSiO(4-h-i)/2 (VII);
• wherein R may have the definitions indicated above,
• wherein R9 may be identical or different and is a radical of the formula
• C—R10— (VIIa);
• wherein C is a cyclodextrin radical of the form
• wherein R11 is a hydrogen radical or a methyl radical,
• wherein q is the integers 6 (alpha cyclodextrin), 7 (beta cyclodextrin) or 8 (gamma cyclodextrin),
• wherein R10 is a divalent hydrocarbon radical having 2 to 18 carbon atoms which is optionally interrupted with heteroatoms,
• wherein h and i each have the definition indicated earlier on above;
• where the sum of the mixture (X) always makes 100 wt %, and
• wherein the at least one diluent (4) is different from (3a) and (3c), wherein the hydrophilic organopolysiloxane gel preparation exhibits an increase in the water absorption capacity by at least a factor of 10 compared with the hydrophobic organopolysiloxane gel used.

Hydrophilic organopolysiloxane gel preparation, comprising:

• wherein the hydrophilic organopolysiloxane gel preparation comprises a mixture (X) and at least one diluent (4) for viscosity adjustment, wherein the mixture (X) comprises
• (a) 80 to 99.9 wt % of at least one hydrophobic organopolysiloxane gel prepared from the reaction either of an unsaturated organopolysiloxane resin (1a) or of an unsaturated organopolysiloxane (1b) or of a diene (1c) with an Si—H-containing organopolysiloxane (2a) optionally in the mixture with an Si—H-containing organopolysiloxane (2b) in the presence of a catalyst (K) which promotes the addition of Si-bonded hydrogen onto aliphatic multiple bond (i.e. hydrosilylation catalyst) in the presence of a diluent (4), the reaction being stopped by addition of a stopper compound (5) which is used as a catalyst poison and which remains in the hydrophobic organopolysiloxane gel;
• (b) 0.1 to 20 wt % of at least one compound (3), wherein the at least one compound (3) is (3c) organopolysiloxanes containing cyclodextrin radicals and of the formula (VII);
• wherein the formula (VII) is
• RhR9iSiO(4-h-i)/2 (VII);
• wherein R may have the definitions indicated above;
• wherein R9 may be identical or different and is a radical of the formula
• C—R10— (VIIa);
• wherein C is a cyclodextrin radical of the form
• wherein R11 is a hydrogen radical or a methyl radical;
• wherein q is the integers 6 (alpha cyclodextrin), 7 (beta cyclodextrin) or 8 (gamma cyclodextrin);
• wherein R10 is a divalent hydrocarbon radical having 2 to 18 carbon atoms which is optionally interrupted with heteroatoms;
• wherein h and i each have the definition indicated earlier on above;
• where the sum of the mixture (X) always makes 100 wt %;
• wherein the at least one diluent (4) is different from (3c);
• and
• wherein the hydrophilic organopolysiloxane gel preparation exhibits an increase in the water absorption capacity by at least a factor of 10, compared with the hydrophobic organopolysiloxane gel used.