A method for making silicone hydrogel contact lenses, comprising the steps of:
- introducing a lens-forming formulation into a mold for making contact lenses, wherein the lens-forming formulation comprises
- (a) a solvent selected from the group consisting of water, 1,2-propylene glycol, dipropylene glycol, tripropylene glycol, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, a polyethyleneglycol having a molecular weight of about 400 Daltons or less, and mixtures thereof,
- (b) at least one amphiphilic siloxane-containing vinylic monomer of formula (I)
- Q-X1-hL-X2—BSi (I)
- In which:
- Q is an ethylenically unsaturated group of formula (II)
- in which
- R12 is hydrogen or C1-C4 alkyl,
- Z1 is a linear or branched C1-C12 alkylene radical, —O—, or —NH—,
- Z2 is a direct bond or a linear or branched C1-C12 alkylene radical,
- A is —O— or —NH—,
- q1 and q2 independent of each other are an integer of 0 or 1;
- X1 and X2 independent of each other are a direct bond or a cross linkage of formula (III)
- —X3—R′1—X4-E-X5—R′2—X6 (III)
- in which
- X3, X4, X5, and X5 independent of one other are a linkage selected from the group consisting of a direct bond, —O—, —NR′—, —CO—NR′—, —NR′—CO—, —NR′—CO—NH—, —NH—CO—NR′—, —O—CO—NH—, —NH—CO—O—, —S—CO—NH—, —O—CO—, —CO—O—, —S—, and —NH—CO—S— in which R′ is H or C1-C4 alkyl,
- E is a linear or branched alkylene, cycloalkane diradical or arene diradical with up to 40 carbon atoms,
- R′1 and R′2 independent of each other is a direct bond, a linear or branched C1-C10 alkylene divalent radical, or a divalent radical of —R′3—X4-E-X5—R′4— in which E, X4 and X5 are as defined above and R′3 and R′4 independent of each other are a direct bond or a linear or branched C1-C10 alkylene radical;
- hL is a hydrophilic oligomeric segment selected from the group consisting of (1) polyoxazoline (—[(N(COR″)C2H4— in which R″ is H, methyl or ethyl) which is obtained in a ring-opening polymerization of oxazoline, (2) a polypeptide segment composed of at least one amino acid selected from the group consisting of asparagine, glutamine, alanine, glycine, and combinations thereof, and (3) a hydrophilic polymer segment composed of hydrophilic monomeric units derived from at least one hydrophilic vinylic monomer selected from the group consisting of (meth)acrylamide, N,N-dimethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, N-vinyl-2-pyrrolidone, N-vinyl-N-methyl isopropylamide, N-vinyl-N-methyl acetamide, N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, N-vinyl-N-methyl acetamide, N-methyl-3-methylene-2-pyrrolidone, 1-ethyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone, 1-ethyl-5-methylene-2-pyrrolidone, 5-methyl-3-methylene-2-pyrrolidone, 5-ethyl-3-methylene-2-pyrrolidone, 1-n-propyl-3-methylene-2-pyrrolidone, 1-n-propyl-5-methylene-2-pyrrolidone, 1-isopropyl-3-methylene-2-pyrrolidone, 1-isopropyl-5-methylene-2-pyrrolidone, 1-n-butyl-3-methylene-2-pyrrolidone, 1-tert-butyl-3-methylene-2-pyrrolidone, and mixtures thereof;
- BSi is a monovalent radical of formula (1A) or (1B)
- in which
- Y is a C1-C6 alkylene radical or a C1-C6 substituted alkylene radical containing one or more hydroxyl groups,
- B1 and B2 independent of each other are C1-C6 alkyl, phenyl, or benzyl,
- T is a C1-C12 alkyl or an alkoxyalkyl radical having 3 to 8 carbon atoms,
- m is an integer of 0 to 3,
- p is an integer of 1 to 6,
- r is an integer of 2 to 20,
- A1, A2 and A3 independent of each other are C1-C6 alkyl, phenyl, benzyl, or a radical of formula (2)
- in which B3, B4 and B5 independent of each other are C1-C6 alkyl, phenyl, or benzyl, provided that at least two of A1, A2 and A3 are radicals of formula (2),
- (c) at least one hydrophilic vinylic monomer, and
- (d) at least one component selected from the group consisting of a hydrophilized polysiloxane-containing crosslinker, a hydrophilic crosslinker, a photoinitiator, a thermal initiator, a UV-absorbing vinylic monomer, a visibility tinting agent, an antimicrobial agent, a bioactive agent, a leachable lubricant, a leachable tear-stabilizing agent, and mixtures thereof;
- polymerizing the lens-forming formulation in the mold to form a silicone hydrogel contact lens, wherein the formed silicone hydrogel contact lens has a water content of from about 20% to about 75% by weight when fully hydrated, an oxygen permeability (Dk) of at least 40 barrers, and an elastic modulus of from about 0.1 MPa to about 2.0 MPa.