Plasticized acrylics for pressure sensitive adhesive applications

A plasticized polymer based pressure sensitive adhesive comprising a mixture of:

• a. about 100 parts by weight of a base copolymer having a Tg greater than about 0° C., wherein the base copolymer is in a particulate and formed from and comprises:
• (1) about 50 to 70% by weight of a high Tg comonomer component, wherein the homopolymer formed from the high Tg comonomer component has a Tg of at least about 20° C.;
• (2) optionally, up to about 20% by weight based on the total weight of the base copolymer of an acidic comonomer;
• and
• (3) about 30 to 50% by weight of one or more low Tg (meth)acrylate comonomer, wherein the Tg of the homopolymer of the low Tg comonomer is less than about 20° C., and
• b. about 1 to about 100 parts based on the base copolymer of a non-reactive, non-volatile, non-acrylic-based plasticizing agent.

A method of coating a plasticized polymer based pressure sensitive adhesive comprising the steps of:

• a. admixing about 100 parts by weight of a base copolymer having a Tg greater than about 0° C. and about 1 to about 100 parts of a non-reactive, non-volatile, non-acrylic-based plasticizing agent, wherein the base copolymer is formed from:
• (1) about 50 to 70% by weight of a high Tg comonomer component, wherein the homopolymer formed from the high Tg comonomer component has a Tg of at least about 20° C.;
• (2) optionally, up to about 20% by weight based on the total weight of the base copolymer of an acidic comonomer;
• and
• (3) about 30 to 50% by weight of one or more low Tg (meth)acrylate comonomer, wherein the Tg of the homopolymer of the low Tg comonomer is less than about 20° C., and
• b. coating the admixture prepared according to part (a) onto a substrate from a solvent or aqueous solution.

A method of coating a plasticized polymer based pressure sensitive adhesive comprising the steps of:

• a. powder coating a layer of a powdered base copolymer having a Tg greater than about 0° C. onto a substrate, wherein the base copolymer is formed from:
• (1) about 50 to 70% by weight of a high Tg comonomer component, wherein the homopolymer formed from the high Tg comonomer component has a Tg of at least about 20° C.;
• (2) optionally, up to about 20% by weight based on the total weight of the base copolymer of an acidic comonomer;
• and
• (3) about 30 to 50% by weight of one or more low Tg (meth)acrylate comonomer, wherein the Tg of the homopolymer of the low Tg comonomer is less than about 20° C., and
• c. coating a liquid, non-reactive, non-acrylic-based plasticizing agent over all or a portion of the powdered base copolymer layer such that about 100 parts of the coated base copolymer are plasticized with about 1 to 100 parts of the non-reactive, non-acrylic-based plasticizing agent.

A method of coating a plasticized polymer based pressure sensitive adhesive comprising the steps of:

• a. coating a layer of a base copolymer having a Tg greater than about 0° C. onto a substrate, wherein the base copolymer is formed from:
• (1) about 50 to 70% by weight of a high Tg comonomer component, wherein the homopolymer formed from the high Tg comonomer component has a Tg of at least about 20° C.;
• (2) optionally, up to about 20% by weight based on the total weight of the base copolymer of an acidic comonomer;
• and
• (3) about 30 to 50% by weight of one or more low Tg (meth)acrylate comonomer, wherein the Tg of the homopolymer of the low Tg comonomer is less than about 20° C., and
• b. coating a liquid or solid, non-reactive, non-acrylic-based plasticizing agent over all or a portion of the powdered base copolymer layer such that about 100 parts of the coated base copolymer are plasticized with about 1 to 100 parts of the non-reactive, non-acrylic-based plasticizing agent.

A method of coating a plasticized polymer based pressure sensitive adhesive using radiation polymerization methods comprising the steps of:

• a. preparing a prepolymeric syrup comprising:
• (1) about 50 to 70% by weight of a high Tg comonomer component, wherein the homopolymer formed from the high Tg comonomer component has a Tg of at least about 20° C.;
• (2) optionally, up to about 20% by weight based on the total weight of the base copolymer of an acidic comonomer;
• and
• (3) about 30 to 50% by weight of one or more low Tg (meth)acrylate comonomer, wherein the Tg of the homopolymer of the low Tg comonomer is less than about 20° C., and
• b. combining the prepolymeric syrup with about 1 to 100 parts based on 100 parts of the sum of components a(1) to a(3) of a non-reactive, non-volatile, non-acrylic-based plasticizing agent to form a polymerizable mixture;
• and
• c. exposing the polymerizable mixture to radiation sufficient to polymerize the polymerizable mixture and to form the plasticized polymer based pressure sensitive adhesive.