Syrup polymer compositions and adhesives therefrom

A method for preparing acrylate adhesives comprising the steps of

• a) partially polymerizing an acrylic monomer mixture to a conversion rate of 5 to 40% in the presence of a thiol chain transfer agent to produce a first syrup polymer composition comprising a low Mw solute copolymer having a Mw from 3000 to 300,000 and unreacted solvent monomers;
• b) quenching the thiol chain transfer agent
• c) adding a branching agent and optional photoinitiator,
• d) further polymerizing to produce a polymer composition comprising a low Mw copolymer, and a high Mw crosslinked copolymer having a Mw of 300,000 to 3,000,000.

A method for preparing acrylate adhesives comprising the steps of:

• a) partially polymerizing an acrylic monomer mixture to a conversion rate of 5 to 40% in the presence of a thiol chain transfer agent to produce a first syrup polymer composition comprising a low Mw solute copolymer having a Mw from 3000 to 300,000 and unreacted solvent monomers;
• b) quench the thiol chain transfer agent;
• c) add a polymerizable photoinitiator to the syrup polymer of step b);
• d) further photopolymerize the syrup polymer composition of step c) to produce a second syrup polymer composition comprising the low Mw solute copolymer, a high Mw solute copolymer having a Mw of 300,000 to 3,000,000 having pendent photoinitiator groups, and unreacted solvent monomers;
• and
• e) optionally add a crosslinker to the syrup polymer composition of step d);
• and further photopolymerizing.