Abstract: Novel stress-reducing crosslinking oligomers that have application in dental restoratives, thin films, hardcoats, composites, adhesives, and other uses subject to stress reduction are described. The addition-fragmentation process of crosslinking results in a chain-transfer event that provides novel polymers that may be further functionalized. In addition, the addition-fragmentation oligomer comprises pendent functional groups that bond to a substrate by forming an ionic or covalent bond, or etch the substrate by chemically removing some material from the substrate.

Abstract: The disclosure describes a curable composition comprising a first oligomer having a plurality of polymerizable groups; a second component comprising alkylene oxide repeat units and terminal polymerizable groups, a solvent monomer component; and a photoinitiator. The curable composition may be used as an adhesive in optical applications.

Abstract: Acrylic syrup polymer composition are provided by partially polymerizing a (meth)acrylic monomer mixture in the presence of a thiol chain transfer agent to produce a first syrup polymer composition comprising a low molecular weight solute (meth)acrylic copolymer and solvent monomers, quenching the chain transfer agent, further polymerizing the first syrup polymer composition to produce a second syrup polymer composition comprising the low molecular weight solute acrylic copolymer, a high molecular weight solute acrylic copolymer and optionally unreacted solvent monomers, optionally adding a crosslinker and photoinitiator; and further photopolymerizing the syrup polymer composition to produce a pressure-sensitive adhesive.

Abstract: Crosslinkable compositions, crosslinked compositions, articles containing these compositions, and methods of making the articles are provided. The crosslinkable compositions, which include two (meth)acrylate copolymers plus a tackifier, are used to form the crosslinked compositions upon exposure to ultraviolet radiation. The crosslinked compositions can function as pressure-sensitive adhesives. The crosslinkable compositions are well suited for use with hot melt processing methods.

Abstract: Pressure sensitive adhesive compositions are described comprising at least one low Tg ethylenically unsaturated monomer, and at least one silsesquioxane polymer crosslinker comprising a plurality of ethylenically unsaturated groups. The low Tg ethylenically unsaturated monomer typically has a Tg no greater than 10° C. In some embodiments, the composition comprises at least 50, 55, 60, 65, or 70 wt-% of low Tg ethylenically unsaturated monomer. The low Tg ethylenically unsaturated monomer is typically an alkyl (meth)acrylate comprising 4 to 20 carbon atoms. In another embodiment, an adhesive composition is described comprising a syrup. The syrup comprising i) a free-radically polymerizable solvent monomer; ii) a solute (meth)acrylic polymer comprising polymerized units derived from one or more alkyl (meth)acrylate monomers, and iii) at least one silsesquioxane polymer crosslinker comprising a plurality of ethylenically unsaturated groups.

Abstract: A method for preparing an acrylate adhesive is provided by the steps of partially polymerizing a monomer mixture to provide a syrup polymer composition having a high molecular weight solute copolymer. This first syrup composition is again polymerized to provide a second syrup polymer composition having a low molecular weight copolymer. The second syrup polymer composition is provided with a crosslinking agent and further polymerized to provide the adhesive composition.

Abstract: A composition is described comprising a polymer. The polymer comprises polymerized units derived from a cleavable crosslinking monomer. The cleavable crosslinking monomer comprises at least two free-radically polymerizable groups and at least one group having the formula —O—C(R2)(R3)—O—, wherein R2 and R3 are independently hydrogen, alkyl, or aryl. The composition has a Tg no greater than 50° C. In some embodiments, the composition has a storage modulus greater than 3×105 Pa at 25° C. and 1 Hz and may be characterized as a non-tacky polymer. In other embodiments, the composition is a pressure sensitive adhesive. Upon cleavage of at least a portion of the polymerized monomeric units derived from the cleavable crosslinking monomer, the composition exhibits a change in at least one physical property. In another embodiment, the composition comprises a polymer and fragments. The fragments comprise the reaction product of a free-radically polymerizable group bonded to a polymer chain and a pendent hydroxyl group.

Abstract: A composition is described comprising a polymer. The polymer comprises polymerized units derived from a cleavable crosslinking monomer. The cleavable crosslinking monomer comprises at least two free-radically polymerizable groups and at least one group having the formula —O—C(R2)(R3)—O—, wherein R2 and R3 are independently hydrogen, alkyl, or aryl. The composition has a Tg no greater than 50° C. In some embodiments, the composition has a storage modulus greater than 3×105 Pa at 25° C. and 1 Hz and may be characterized as a non-tacky polymer. In other embodiments, the composition is a pressure sensitive adhesive. Upon cleavage of at least a portion of the polymerized monomeric units derived from the cleavable crosslinking monomer, the composition exhibits a change in at least one physical property. In another embodiment, the composition comprises a polymer and fragments. The fragments comprise the reaction product of a free-radically polymerizable group bonded to a polymer chain and a pendent hydroxyl group.

Abstract: Addition-fragmentation agents of the formula are disclosed: wherein R1, R2 and R3 are each independently Z-Q-, a (hetero)alkyl group or a (hetero)aryl group with the proviso that at least one of R1, R2 and R3 is Zm-Q-, Q is a linking group have a valence of m+1; Z is an ethylenically unsaturated polymerizable group, m is 1 to 6; each X1 is independently —O— or —NR4—, where R4 is H or C1-C4 alkyl, and n is 0 or 1.

Abstract: A polymerizable composition comprising a (meth)acrylate copolymer having pendent photoinitiator groups and a high Tg monomer or macromer is described. The resulting copolymer is physically crosslinking and is of the formula I: (I).

Abstract: Adhesive (co)polymers of this disclosure comprise: a) an isobutylene copolymer having pendent succinate groups and optionally a tackifier. The pendent succinic acid groups ionically crosslinks the isobutylene copolymer by hydrogen bonding with adjacent pendent succinic acid groups.

Abstract: A pre-adhesive composition is described comprising an acid- and epoxy-functional (meth)acryloyl copolymer, which when crosslinked with or without using an ionic photoacid generator (PAG) provides a pressure-sensitive adhesive and pressure-sensitive adhesive articles having desirable properties.

Abstract: A pressure sensitive adhesive composition is described comprising at least one low Tg (meth)acrylic polymer, and at least one silsesquioxane polymer crosslinker comprising a plurality of ethylenically unsaturated groups. The low Tg (meth)acrylic polymer typically has a Tg no greater than 10° C. In some embodiments, the low Tg (meth)acrylic polymer comprises at least 50, 55, 60, 65, or 70 wt-% of polymerized units derived from low Tg ethylenically unsaturated monomer(s). The low Tg ethylenically unsaturated monomer(s) is typically an alkyl (meth)acrylate comprising 4 to 20 carbon atoms. Also described are pressure sensitive adhesive articles and methods of preparing such articles.

Abstract: A pressure-sensitive adhesive obtained from crosslinking a pre-adhesive composition comprising poly(meth)acrylate macromolecules that comprise a number-average molecular weight of from about 25000 to about 200000.

Abstract: A method for preparing an acrylate adhesive is provided by the steps of partially polymerizing a monomer mixture to provide a syrup polymer composition having a high molecular weight solute copolymer. This first syrup composition is again polymerized to provide a second syrup polymer composition having a low molecular weight copolymer. The second syrup polymer composition is provided with a crosslinking agent and further polymerized to provide the adhesive composition.

Abstract: A composition is described comprising a polymer. The polymer comprises polymerized units derived from a cleavable crosslinking monomer. The cleavable crosslinking monomer comprises at least two free-radically polymerizable groups and at least one group having the formula —O—C(R2)(R3)—O—, wherein R2 and R3 are independently hydrogen, alkyl, or aryl. The composition has a Tg no greater than 50° C. In some embodiments, the composition has a storage modulus greater than 3×105 Pa at 25° C. and 1 Hz and may be characterized as a non-tacky polymer. In other embodiments, the composition is a pressure sensitive adhesive. Upon cleavage of at least a portion of the polymerized monomeric units derived from the cleavable crosslinking monomer, the composition exhibits a change in at least one physical property. In another embodiment, the composition comprises a polymer and fragments. The fragments comprise the reaction product of a free-radically polymerizable group bonded to a polymer chain and a pendent hydroxyl group.

Abstract: An adhesive composition is described comprising a tackifier and at least one grafted isobutylene copolymer. The grafted isobutylene copolymer has the formula: R1—(R2—Z) wherein R1 represents an isobutylene copolymer, R2 is a covalent bond or multivalent alkylene or arylene, and Z is a grafted polymer. Z is typically a homopolymer of copolymer comprising alkene repeat units, aralkylene repeat units, or a combination thereof. Also described are adhesive coated articles, methods of making adhesive coated articles, and grafted isobutylene polymers.

Abstract: A polymerizable composition comprising a (meth)acrylate copolymer having pendent photoinitiator groups and a high Tg monomer or macromer is described. The resulting copolymer is physically crosslinking and is of the formula I: (I).

Abstract: Adhesive compositions comprising a copolymer of isobutylene repeat units and alkene repeat units are described. At least a portion of the alkene repeat units are bonded to a pendent nitrogen atom of a quaternary ammonium salt comprising a free-radically polymerizable substituent. The adhesive optionally comprises other components such as tackifier, unfunctionalized polyisobutylene polymer, plasticizer, and combinations thereof.

Abstract: A curable silsesquioxane polymer, a composition including such polymer, an article having a layer disposed thereon that includes the curable polymer and/or the cured polymer, and a method of forming a cured coating, wherein the curable silsesquioxane polymer includes a three-dimensional branched network having the formula: wherein the oxygen atom at the * is bonded to another Si atom within the three-dimensional branched network; R is an organic group comprising an ethylenically unsaturated group; and R2 is an organic group that is not an ethylenically unsaturated group; R3 is a non-hydrolyzable group; and n or n+m is an integer of greater than 3.