Silsesquioxane resin and silyl-anhydride composition

A silsesquioxane-containing composition comprising (A) a silsesquioxane resin and (B) a silyl-anhydride, wherein:

• the (A) silsesquioxane resin is of formula (I):
• [HSiO3/2]t1[Z-L-SiO3/2]t2[H(R1O)SiO2/2]d[(R1O)xSiO(4-x)/2]y[R2SiO3/2]t3 (I),
• wherein:
• subscript t1 is a mole fraction of from 0.4 to 0.9;
• subscript t2 is a mole fraction of from 0.1 to 0.6;
• subscript d is a mole fraction from 0 to 0.45;
• subscript x is an integer of 1, 2, or 3;
• subscript y is a mole fraction from 0 to 0.25;
• subscript t3 is a mole fraction from 0 to 0.15;
• the sum of t1+t2=from ≥0.9 to ≤1 and the sum of t1+t2+d+y+t3=1;
• each R1 is independently H or (C1-C6)alkyl;
• each R2 is independently HO-L- or HOOC-L-;
• each L is independently a divalent (C1-C20)hydrocarbon group that is unsubstituted or substituted with at least 1 substituent independently selected from (C1-C3)alkyl, —OH, and a fluorine atom up to and including perfluoro-substitution;
• and
• each Z is —OH, —COOH, —O-THP, —OCH(R3a)2, —OC(R3b)3, —COOCH(R3a)2, —COOC(R3b)3, —OCOOCH(R3a)2, or —OCOOC(R3b)3,
• wherein THP is tetrahydropyran-2-yl;
• wherein each R3a is independently a (C1-C6)alkyl, (C3-C12)cycloalkyl, (C6-C10)aralkyl, ((C1-C6)alkyl)3SiCH2CH2-, or 2 R3a together with the carbon atom to which they are both bonded are a (C3-C12)cycloalkyl or a (C6-C12)bicycloalkyl;
• and
• wherein each R3b is independently a (C1-C6)alkyl, (C3-C12)cycloalkyl, (C6-C10)aralkyl, ((C1-C6)alkyl)3SiCH2CH2-;
• or 2 R3b together with the carbon atom to which they are both bonded are a (C3-C12)cycloalkyl or a (C6-C12)bicycloalkyl and the remaining R3b is independently a (C1-C6)alkyl, (C3-C12)cycloalkyl, (C6-C10)aralkyl, or ((C1-C6)alkyl)3SiCH2CH2-;
• or all 3 R3b together with the carbon atom to which they are all bonded are a (C7-C12)bicycloalkyl;
• and
• the (B) silyl-anhydride is of formula (II):
• (R4O)3Si-(L1)m-C(R5)2—C(═O)—O—C(═O)—R6 (II), wherein:
• each R5 is independently H, a (C1-C6)alkyl, or a monovalent group of formula -(L2)n-Si(OR4)3;
• or both R5 are taken together to form a (C2-C5)alkane-diyl;
• or one R5 is taken together with R6 to form a bond or (C1-C4)alkane-diyl, and the remaining R5 is independently H, a (C1-C6)alkyl, or a monovalent group of formula -(L2)n-Si(OR4)3;
• or both R5 are taken together with R6 to form ═CH—;
• R6 is taken together with R5 as described above or R6 is a (C1-C8)hydrocarbyl or a monovalent group of formula —C(R7)2-(L2)n-Si(OR4)3;
• subscript m is an integer of 0 or 1;
• each subscript n is independently an integer of 0 or 1;
• each R4 is independently an unsubstituted (C1-C6)alkyl;
• each L1 and L2 is independently a (C1-C8)hydrocarbon-diyl;
• and
• each R7 is independently H or a (C1-C6)alkyl;
• or both R7 are taken together to form a (C2-C5)alkane-diyl.