Polymerizable carbamic ester resins useful for preparing cast optical articles

Claim 2

Optical articles of cured polymerizable resin, said"polymerizable resin comprising (a) one or more polymerizable carbamic ester resins having 4 or more ethylenically-unsaturated carbamic ester groups per molecule; (b) one or more diluent monomers having one or more ethylenically-unsaturated groups copolymerizable with ethylenically-unsaturated compounds; and (c) an energy-activatable source of free radicals; characterized in that said polymerizable resin, when uncured, has a backbone derived from a polyol having (1) at least 4 hydroxyalkyl or hydroxycycloalkyl groups per molecule, (2) a hydroxyl equivalent weight of 75 to 1000, and (3) a molecular weight of 300 to 5000 and is a liquid at a temperature above 40°C, said optical articles have a thickness greater than 2 millimeters, an index of refraction greater than 1.45 and less than 1.75, light transmission greater than 85%, yellow coloration less than 4 Gardner b units, and a Barcol hardness greater than 15.

Claim 3

Optical articles according to Claim 1, further characterized in that said polymerizable resin comprises 60 to 80 percent by weight of said polymerizable carbamic ester resin and 40 to 20 percent by weight of said diluent monomer.

Claim 4

Optical articles according to any preceding claim, further characterized in that said backbone is derived from a polyol having a hydroxyl equivalent weight of 175 to 300 and a molecular weight of 700 to 2100.

Claim 5

Optical articles according to any preceding claim, further characterized in that said polymerizable carbamic ester resins have the formula: wherein: R 1 is a hydrogen atom or a methyl radical; A is a divalent aliphatic radical selected from - R 2- and in which R 2 is an alkylene radical having 1 to 6 carbon atoms or a 5- or 6-membered cycloalkylene radical having 5 to 10 carbon atoms, said aliphatic radical optionally containing 1 or 2 catenary oxygen atoms or groups; B is said backbone and is a polyvalent radical obtained by removal of the hydroxyl groups from a polyester polyol, polyether polyol, or polyacrylate polyol; and n is 4 to 15.

Claim 6

Optical articles according to any preceding claim, further characterized in that said backbone is derived from a polyester polyol.

Claim 7

Optical articles according to any preceding claim, further characterized in that said polyester polyol is an ester of cyclic and acyclic compounds, said cyclic compounds being selected from the group consisting of alicyclic dicarboxylic acids having 5 to 8 carbon atoms per molecule, aromatic dicarboxylic acids having 5 to 15 carbon atoms per molecule, anhydrides of said alicyclic and said aromatic dicarboxylic acids, and cycloalkylene diols having 4 to 15 carbon atoms per molecule, said acyclic compounds being aliphatic acyclic polyols having 2 to 15 carbon atoms per molecule, and said cyclic and acyclic compounds being combined in a ratio between 0.02:1 and 0.5:1.

Claim 8

Optical articles according to any preceding claim, further characterized in that said article is an opthalmic lens or a video disk.

Claim 9

A process for preparing cast optical articles according to any of Claims 1 to 4 or 7, characterized in that: a) bubbles are removed from a polymerizable carbamic, ester resin prepared by (i) reacting together at least one monoisocyanato-substituted addition-polymerizable ethylenically-unsaturated organic compound and at least one polyol having four to 15 hydroxyalkyl or hydroxycycloalkyl groups per molecule, a hydroxyl equivalent weight of 75 to 1000, and a molecular weight of 300 to 5,000, the resulting reaction product being essentially free of unreacted isocyanate; and (ii) 50 to 80 parts by weight of said reaction product are mixed with 50 to 20 parts by weight of at least one diluent monomer having one or more ethylenically-unsaturated groups copolymerizable with ethylenically-unsaturated compounds, and 0 to 5 parts by weight of an energy-activatable source of free radicals; b) the resulting optical casting resin is introduced into a suitable mold; and c) said optical casting resin is polymerized.

Claim 10

Polymerizable carbamic ester resins for use in any preceding claim, characterized in that said resins comprise a polyester resin.

Claim 11

Polymerizable carbamic ester resins for use in any of Claims 1 to 4, 7, or 8, characterized in that said resins comprise a polyacrylate resin.