Preparation of isocyanato silanes

A process for the preparation of an alkoxysilyl group-containing isocyanate compound having the general Formula (I):

• (R1O)3-aR2aSi—R3—NCO (I)
• wherein
• each R1 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;
• each R2 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;
• R3 is a branched or straight chain alkylene or cycloalkylene group of from 1 to 12 carbon atoms, an arylene group of from 6 to 10 carbon atoms, or an aralkylene group of from 7 to 10 carbon atoms;
• and
• a is 0, 1 or 2 comprising:
• (i) reacting ClC(═O)Cl with a corresponding alkoxysilyl group-containing amine having the general Formula (II):
• (R1O)3-aR2aSi—R3—NH2 (II)
• wherein
• each R1 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;
• each R2 is independently a branched or straight chain alkyl or cycloalkyl group of from 1 to 6 carbon atoms;
• R3 is a branched or straight chain alkylene or cycloalkylene group of from 1 to 12 carbon atoms, an arylene group of from 6 to 10 carbon atoms, or an aralkylene group of from 7 to 10 carbon atoms;
• and
• a is 0, 1 or 2,
• in the presence of a tertiary amino-containing compound having the general Formula (II):
• R4R5NR6O—[CH2CH2O—]x[CH2CH(CH3)O—]y[C4H8O—]zR7—X (III)
• wherein
• each R4 is independently a straight or branched chain alkyl, cycloalkyl, alkenyl, aryl, aralkyl or arenyl group up to 18 carbon atoms, a heterocarbon group containing from 2 to 18 carbon atoms and at least one oxygen or (—)2NR8 group, wherein R8 is a straight or branched chain alkyl, cycloalkyl, akenyl, aryl, aralkyl or arenyl group from 1 to 10 carbon atoms, or a group in which R4 has a chemical bond with R5 to form a cyclic structure containing the nitrogen atom;
• each R5 is independently a straight or branched chain alkyl, cycloalkyl, alkenyl, aryl, aralkyl or arenyl group up to 18 carbon atoms, a heterocarhon group containing from 2 to 18 carbon atoms and at least one oxygen or (—)2NR8 group, wherein R8 is a straight or branched chain alkyl, cycloarkyl, akenyl, aryl, aralkyl or arenyl group from 1 to 10 carbon atoms, or a group in which R5 has a chemical bond with R4 to form a cyclic structure containing the nitrogen atom;
• R6 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene or arylene group of from 5 to 10 carbon atoms, or a —R9C(═O)— group wherein R9 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene group of from 5 to 10 carbon atoms or an arylene group of from 1 to 10 carbon atoms;
• R7 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene or arylene group of from 5 to 10 carbon atoms, or a —(O═C—)R9— group wherein R9 is a straight or branched alkylene group of from 1 to 10 carbon atoms, a cycloalkylene group of from 5 to 10 carbon atoms or an arylene group of from 1 to 10 carbon atoms;
• X is hydrogen or a —NR4R5 group, wherein R4 and R5 have the same meanings as above;
• x is 0 to 50;
• y is 0 to 50;
• and
• z is 0 to 50, with the proviso that the sum of x+y+z is from 2 to 100,
• to provide for an alkoxysilyl group-containing isocyanate compound;
• (ii) separating the hydrochloride salt tertiary amino-containing compound from the alkoxysilyl group-containing isocyanate compound of step (i);
• and optionally,
• (iii) purifying the alkoxysilyl group-containing isocyanate of step (ii).