Copolymer for contact lens, its preparation and contact lens made thereof
AssigneeToyo Contact Lens Co., Ltd.
InventorsKyoichi Tanaka, Kouzou Takahashi, Mitsuhiro Kanada, Yasuyuki Kato, Masuji Ichihara
Life of this patent
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Abstract
A copolymer suitable for use as contact lenses, comprising a polymerization product of (a) at least one monomer selected from methyldi(trimethylsiloxy)sylylpropylglycerol methacrylate and methyldi(trimethylsiloxy)sylylpropylglycerolethyl methacrylate, (b) a hydrophilic monomer, (c) a methacrylic acid alkyl ester and (d) a cross-linking agent having at least two copolymerizable functional groups. Contact lenses made of the above copolymer has excellent oxygen permeability and can be comfortably worn continuously for a long term without a foreign body sensation and pain.
Claims11
A polymerization product of
- (a) 30 to 80% of at least one monomer selected from the group consisting of methyldi(trimethylsiloxy)sylylpropylglycerol methacrylate having the following formula ##STR2## and methyldi(trimethylsiloxy)sylylpropylglycerolethyl methacrylate having the following formula ##STR3## (b) 5 to 30% of at least one hydrophilic monomer selected from the group consisting of ethylene glycol monomethacrylate, diethylene glycol monomethacrylate, triethylene glycol monomethacrylate, N-vinyl pyrrolidone and dimethyl acrylamide,
- (c) 5 to 60% of at least one methacrylic acid alkyl ester monomer selected from the group consisting of methyl methacrylate, ethyl methacrylate and cyclohexyl methacrylate, and
- (d) 0.5 to 15% of at least one cross-linking agent having at least two copolymerizable functional groups selected from the group consisting of ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, allyl methacrylate, divinyl benzene, diallyl phthalate and trimethylolpropane trimethacrylate, said % of (a), (b), (c) and (d) being % by weight based on the total weight of (a), (b), (c) and (d).
A process for preparing a copolymer which comprises bulk-polymerizing
- (a) 30 to 80% of at least one monomer selected from the group consisting of methyldi(trimethylsiloxy)sylylpropylglycerol methacrylate having the following formula ##STR4## and methyldi(trimethylsiloxy)sylylpropylglycerolethyl methacrylate having the following formula ##STR5## (b) 5 to 30% of a hydrophilic monomer, (c) 5 to 60% of a methacrylic acid alkyl ester monomer, and
- (d) 0.5 to 15% of a cross-linking agent having at least two copolymerizable functional groups, in the presence of 0.05 to 1.0 part by weight, per 100 parts by weight of the mixture of (a), (b), (c) and (d), of a free radical polymerization initiator, said % of (a), (b), (c) and (d) being % by weight based on the total weight of (a), (b), (c) and (d).
A contact lens made of a copolymer consisting essentially of
- (a) 30 to 80% by weight of units of at least one monomer selected from the group consisting of methyldi(triethylsiloxy)sylylpropylglycerol methacrylate having the following formula ##STR6## and methyldi(trimethylsiloxy)sylylpropylglycerolethyl methacrylate having the following formula ##STR7## (b) 5 to 30% by weight of hydrophilic monomer units, (c) 5 to 60% by weight of methacrylic acid alkyl ester monomer units, and
- (d) 0.5 to 15% by weight of units of a cross-linking agent having at least two copolymerizable functional groups.
Dependencies are inferred from the claim text.