Patent ID: 11945895
Assignee: ALCON INC.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  G | IPC C  G

Claim 3:
4. The photochromic polydiorganosiloxane vinylic crosslinker of claim 3, wherein the photochromic polydiorganosiloxane vinylic crosslinker is defined by formula (1), in which:
ν1 is an integer of from 3 to 500 and ω1 is an integer of from 1 to 80,
E1 is a monovalent radical of, R0 is hydrogen or methyl;
a1 is zero or 1;
X0 is O or NRN1;
RN1 is hydrogen or a C1-C15 alkyl;
L0 is a C2-C8 alkylene divalent radical or a divalent radical of, L0′ is a C2-C8 alkylene divalent radical which has zero or one hydroxyl group;

L0″ is C3-C8 alkylene divalent radical which has zero or one hydroxyl group;
X1 is —O—, —NRN1—, —NHCOO—, —OCONH—, —CONRN1—, or —NRN1CO—;
X1′ is O or NRN1;
q1 is an integer of 1 to 20;
q2 is an integer of 0 to 20;
RPC is a monovalent radical of, Le is a divalent radical of —C3H6—O—R2—, a2 is zero or 1;
a3 is zero or an integer of from 1 to 3;
R1 is a linear or branched C1-C10 alkylene divalent radical;
R2 is a linear or branched C3-C10 alkylene divalent radical;
R3 is a direct bond or a linear or branched C1-C4 alkylene divalent radical;
XPC and each X2 independently of others are a covalent linkage of, RN2 is hydrogen, a linear or branched C1-C15 alkyl, cyclohexyl, cyclopentyl, a substituted or unsubstituted phenyl, or a substituted- or unsubstituted-phenyl-C1-C6 alkyl;
each Lx independently is a linear or branched C1-C24 alkylene divalent radical which optionally has one or more hydroxyl or C1-C4-alkoxy groups or C1-C4-acylamino groups,, or a divalent radical which optionally has one or more hydroxyl or C1-C4-alkoxy groups and is obtained by removal of two hydrogen atoms from two different atoms of a hydrocarbon that has up to 20 carbon atoms and comprises at least one divalent radical selected from the group consisting of cycloalkylene radical, substituted cycloalkylene radical, phenylene radical, substituted phenylene radical, cycloheteroalkylene radical, and substituted cycloheteroalkylene radical;
each R4, R5 and R6 independent of one another are a linear or branched C1-C15 alkylene divalent radical which has zero or one hydroxyl group; and PC is a photochromic group.