Prepolymers with dangling polysiloxane-containing polymer chains

1. An actinically crosslinkable prepolymer, comprising:

(1) dangling polysiloxane units derived from one or more monoethylenically functionalized polysiloxane-containing monomers and/or one or more monoethylenically-functionalized polysiloxane-containing macromers, wherein the dangling polysiloxane units is free of ethylenically unsaturated group;

(2) hydrophilic units derived from one or more hydrophilic vinylic monomers;

(3) polysiloxane-containing crosslinking units derived from at least one polysiloxane-containing crosslinker, wherein said at least one polysiloxane-containing crosslinker comprises two or more ethylenically unsaturated groups and a moiety of

in which R 1 and R 2 are independently a monovalent C 1 -C 10 alkyl, C 1 -C 10 ether, C 1 -C 10 fluoroalkyl, C 1 -C 10 fluoroether, or C 6 -C 18 aryl radical, which mah comprise hydroxy group, primary, secondary, or tertiary amine group, carboxy group, or carboxylic acid; n is an integer of 4 or higher; and

(4) optionally hydrophobic units derived from at least one hydrophobic vinylic monomer, wherein the prepolymer comprises multiple ethylenically unsaturated groups and is capable of being actinically crosslinked, in the absence of one or more monomers, to form a silicone hydrogel contact lens.

2. The prepolymer of claim 1 , wherein the dangling polysiloxane units is present in the prepolymer in an amount sufficient to provide the silicone hydrogel contact lens with a reduction in modulus of at least about 10% or more and/or with an increase in ion permeability of at least about 20% or more.

3. The prepolymer of claim 1 , wherein the dangling polysiloxane units is present in the prepolymer in an amount sufficient to provide the silicone hydrogel contact lens with a reduction in modulus of at least about 30% or more and/or with an increase in ion permeability of at least about 60% or more.

4. The prepolymer of claim 2 , wherein the prepolymer is obtained from an intermediary copolymer with pendant or terminal functional groups and the dangling polysiloxane units by covalently attaching actinically crosslinkable groups to the intermediary copolymer through the pendant or terminal functional groups, wherein the pendant or terminal functional groups are selected from the group consisting of hydroxy groups, amino groups (—NH 2 ), carboxyl groups (—COOH), epoxy groups, aldehyde groups (—CHO), amide groups (—CONH 2 ), acid halide groups (—COX, X═Cl, Br, or I), isothiocyanate groups, isocyanate groups, halide groups (—X, X═Cl, Br, or I), acid anhydride groups, and combinations thereof.

5. The prepolymer of claim 4 , wherein the intermediary copolymer is obtained by copolymerization of an actinically polymerizable composition A or B, wherein the composition A comprises the components of:

(1) at least one monoethylenically functionalized polysiloxane-containing monomer and/or at least one monoethylenically unsaturated polysiloxane-containing macromer,

(2) at least one hydrophilic vinylic monomer,

(3) at least one polysiloxane-containing crosslinker, and

(4) optionally at least one hydrophobic vinylic monomer, provided that at least one of components (2)-(4) further comprises at least one functional group through which an ethylenically unsaturated group can be covalently linked to the obtained intermediary copolymer,

wherein the composition B comprises the components of:

(1) at least one monoethylenically functionalized polysiloxane-containing monomer and/or at least one monoethylenically unsaturated polysiloxane-containing macromer,

(2) at least one hydrophilic vinylic monomer,

(3) at least one polysiloxane-containing crosslinker,

(4) optionally at least one hydrophobic vinylic monomer, and

(5) at least one chain transfer agent having a functional group through which an ethylenically unsaturated group can be covalently linked to the obtained intermediary copolymer.

6. The prepolymer of claim 5 , wherein the at least one monoethylenically functionalized polysiloxane-containing monomer and the at least one monoethylenically unsaturated polysiloxane-containing macromer independently of each other are defined by

in which X denotes —COO—, —CONR 14 , —OCOO—, or —OCONR 14 —, where each R 14 is independently H or C 1 -C 7 alkyl; R 11 denotes a divalent C 1 -C 25 alkyl or C 6 -C 30 aryl radical, which may interrupted by —O—, —COO—, —CONR 14 —, —OCOO— or —OCONR 14 — and may comprise hydroxy group, primary, secondary, or tertiary amine group, carboxy group, or carboxylic acid; R 12 is a monovalent C 1 -C 25 alkyl or C 6 -C 30 aryl radical, which may interrupted by —O—, —COO—, —CONR 14 —, —OCOO— or —OCONR 14 — and may comprise hydroxy group, primary, secondary, or tertiary amine group, carboxy group, or carboxylic acid; R 3 , R 4 , R 5 ′, R 6 , R 7 , R 8 , R 9 and R 10 , independently of one another, are C 1 -C 8 -alkyl, C 1 -C 4 alkyl- or C 1 -C 4 — alkoxy-substituted phenyl, fluoro(C 1 -C 18 )alkyl), cyano(C 1 -C 12 -alkyl), hydroxy-C 1 -C 6 -alkyl or amino-C 1 -C 6 -alkyl; m and p independently of each other are an integer of from 5 to 700 and (m+p) is from 5 to 700.

7. The prepolymer of claim 6 , wherein the at least one hydrophilic vinylic monomer is selected from the group consisting of N,N-dimethylacrylamide (DMA), 2-hydroxyethylmethacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl acrylate, hydroxypropyl methacrylate (HPMA), trimethylammonium 2-hydroxy propylmethacrylate hydrochloride, aminopropyl methacrylate hydrochloride, dimethylaminoethyl methacrylate (DMAEMA), glycerol methacrylate (GMA), N-vinyl-2-pyrrolidone (NVP), dimethylaminoethylmethacrylamide, acrylamide, methacrylamide, allyl alcohol, vinylpyridine, N-(1,1-dimethyl-3-oxobutyl)acrylamide, acrylic acid, a C 1 -C 4 -alkoxy polyethylene glycol (meth)acrylate having a weight average molecular weight of from 200 to 1500, methacrylic acid, N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, N-vinyl-N-methyl acetamide, allyl alcohol, N-vinyl caprolactam, and combinations thereof.

8. The prepolymer of claim 7 , wherein the polymerizable composition A or B further comprises at least one silicone-containing vinylic monomer which is different from the monoethylenically functionalized polysiloxane-containing monomer and/or the monoethylenically unsaturated polysiloxane-containing macromer.

9. The prepolymer of claim 8 , wherein the at least one silicone-containing vinylic monomer is selected from the group consisting of 3-methacryloxy propylpentamethyldisiloxane, bis(methacryloxypropyl)tetramethyl-disiloxane, N-[tris(trimethylsiloxy)silylpropyl]-acrylamide, N-[tris(trimethylsiloxy)silylpropyl]methacrylamide, and tris(trimethyl-silyloxy)silylpropylmethacrylate, N-[tris(trimethylsiloxy)silylpropyl]methacrylamide, N-[tris(trimethylsiloxy)silylpropyl]acrylamide, (3-methacryloxy-2-hydroxypropyloxy)-propylbis(trimethylsiloxy)methylsilane, (3-methacryloxy-2-hydroxypropyloxy)propyl-tris(trimethylsiloxy)silane, (3-methacryloxy-2-(2-hydroxyethoxy)propyloxy)propyl-bis(trimethylsiloxy)methylsilane, N-2-methacryloxyethyl-O-(methyl-bis-trimethylsiloxy-3-propyl)silylcarbamate, 1,3-bis[4-vinyloxycarbonyloxy)but-1-yl]tetramethyl-disiloxane, 3-(trimethylsilyl)propyl vinyl carbonate, 3-(vinyloxycarbonylthio)propyl-[tris(trimethyl-siloxy)silane], 3-[tris(trimethylsiloxy)silyl]propylvinyl carbamate, 3-[tris(trimethylsiloxy)silyl]propyl allyl carbamate, 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate, t-butyldimethylsiloxyethyl vinyl carbonate, trimethylsilylethyl vinyl carbonate, trimethylsilylmethyl vinyl carbonate, and combinations thereof.

10. The prepolymer of claim 8 , wherein intermediary copolymer comprises: (1) from about 5% to about 40% by weight of dangling polysiloxane units derived from one or more monoethylenically functionalized polysiloxane-containing monomers and/or macromers; (2) from about 20% to about 60% by weight of hydrophilic units derived from one or more hydrophilic monomers; (3) from 1% to about 60% by weight of crosslinking polysiloxane units derived from a polysiloxane-containing crosslinker; (4) from 0 to about 2% by weight of silicone-free crosslinker; and (5) from about 1 to about 30% by weight of silicone-containing units derived from one or more silicone-containing vinylic monomers.