Adhesives and method for making same

An aqueous dispersion, comprising:

• water;
• microgels of at least one acrylic polymer dispersed in said water;
• and
• at least one interlinking polymer capable of covalently bonding said microgels to each other through said interlinking polymer.

A process for making an adhesive, comprising:

• (i) forming a monomer emulsion comprising water, at least one acrylic monomer, optionally at least one comonomer, optionally a chain transfer agent, an unsaturated carboxylic acid, and an interlinking agent;
• (ii) mixing a polymerization initiator with said monomer emulsion and polymerizing the resulting mixture to form an aqueous dispersion comprising microgels of at least one polymer;
• and
• (iii) heating the dispersion formed in step (ii) at a sufficient temperature and for an effective period of time to covalently bond at least some of said microgels with each other through said interlinking agent.

A process for making an adhesive, comprising:

• (A) forming a first aqueous dispersion comprising microgels of at least one polymer dispersed in water by
• (i) forming a first monomer emulsion comprising water, at least one acrylic monomer, optionally at least one comonomer, optionally a chain transfer agent, and an unsaturated carboxylic acid;
• and
• (ii) mixing a polymerization initiator with said first monomer emulsion and polymerizing the resulting mixture to form said first aqueous dispersion;
• (B) forming a second aqueous dispersion comprising a non-gelled polymer by
• (i) forming a second monomer emulsion comprising water, at least one acrylic monomer, optionally at least one comonomer, optionally a chain transfer agent, an unsaturated carboxylic acid, and an interlinking agent;
• (ii) mixing a polymerization initiator with said second monomer emulsion and polymerizing the resulting mixture to form said second aqueous dispersion;
• (C) combining the first and second aqueous dispersions to form a combined aqueous dispersion;
• and
• (D) heating the combined aqueous dispersion at a sufficient temperature and for an effective period of time to covalently bond at least some of said microgels to at least some of said non-gelled polymer.