Silane-modified polyurea compounds based on polyisocyanates having isocyanurate and allophanate groups

A polyurea compound obtained via reaction

• of a polyisocyanate based on isophorone diisocyanate and having isocyanurate and allophanate groups
• with an amino silane of general formula (I)
• R1a(R1O)(3-a)Si(CH2)nNHCHR2CH2COOR3 (I)
• where the radicals R1 independently of one another are selected from C1-C20-alkyl or C6-C20-aryl,
• a is an integer between 0 and 2,
• n is an integer between 1 and 4,
• R2 is selected from H, C1-C20-alkyl, C6-C12-aryl and —COOR3, and
• R3 in each case is C1-C20-alkyl.

A process for preparing a polyurea compound by

• a) providing a polyisocyanate based on isophorone diisocyanate and having isocyanurate and allophanate groups,
• b) reacting at least a portion of the NCO groups of the polyisocyanate with an aminosilane of general formula (I)
• R1a(R1O)(3-a)Si(CH2)nNHCHR2CH2COOR3 (I)
• where the radicals R1 independently of one another are selected from C1-C20-alkyl or C6-C20-aryl,
• a is an integer between 0 and 2,
• n is an integer between 1 and 4,
• R2 is selected from H, C1-C20-alkyl, C6-C12-aryl and —COOR3, and
• R3 in each case is C1-C20-alkyl,
• c) optionally reacting a portion of the NCO groups of the polyisocyanate with a dialkylamine or an alcohol,
• wherein steps b) and c) can be performed simultaneously or in succession in any desired sequence.