Abstract: A method of increasing the efficiency of a multiphoton absorption process and apparatus. The method includes: providing a photoreactive composition; providing a source of sufficient light for simultaneous absorption of at least two photons; exposing the photoreactive composition to at least one transit of light from the light source; and directing at least a portion of the first transit of the light back into the photoreactive composition using at least one optical element, wherein a plurality of photons not absorbed in at least one transit are used to expose the photoreactive composition in a subsequent transit.

Abstract: A process for fabricating of an article by exposing a photoreactive composition to light under multiphoton absorption conditions. The light passes through an optical system having a final optical element having a numeric aperture in a range of from 0.65 to 1.25, inclusive.

Abstract: A method of multiphoton photosensitizing a photoreactive composition comprises irradiating the composition with light sufficient to cause simultaneous absorption of at least two photons, thereby inducing at least one acid- or radical-initiated chemical reaction where the composition is exposed to the light. The composition comprises: (a) at least one reactive species that is capable of undergoing such reaction; and (b) at least one multi-component, multiphoton photoinitiator system.

Abstract: A process for producing microfluidic articles comprises (a) preparing a photoreactive composition comprising (1) at least one reactive species that is a polymer or a polymer precursor and that is capable of undergoing an acid- or radical-initiated chemical reaction and (2) at least one multiphoton photoinitiator system; (b) exposing a portion of the composition to light sufficient to cause simultaneous absorption of at least two photons, thereby forming exposed and unexposed portions of the composition, and thereby inducing at least one acid- or radical-initiated chemical reaction in the exposed portion; and (c) removing either the exposed or the unexposed portion of the composition, so as to form a microfluidic article comprising a seamless polymer matrix that defines at least one inlet, at least one outlet, and a microfluid processing architecture that is capable of fluidic communication with the inlet and the outlet and that is otherwise fully enclosed within the polymer matrix.

Abstract: A multilayer imageable article with at least two layers including a multiphoton imageable composition. The composition includes a multiphoton-sensitive photoactive system and at least one of a dye and a dye precursor. The photoactive system includes a multiphoton sensitizer capable of simultaneously absorbing at least two photons, an electron acceptor capable of transformation to a dye-activating species upon interaction with the multiphoton sensitizer subsequent to absorption of at least two photons, and optionally an electron donor.

Abstract: Methods of fabricating optical elements that are encapsulated in monolithic matrices. The present invention is based, at least in one aspect, upon the concept of using multiphoton, multi-step photocuring to fabricate encapsulated optical element(s) within a body of a photopolymerizable composition. Imagewise, multi-photon polymerization techniques are used to form the optical element. The body surrounding the optical element is also photohardened by blanket irradiation and/or thermal curing to help form an encapsulating structure. In addition, the composition also incorporates one or more other, non-diffusing binder components that may be thermosetting or thermoplastic. The end result is an encapsulated structure with good hardness, durability, dimensional stability, resilience, and toughness.

Abstract: Method of fabricating an optical element. A photodefinable composition is provided that includes (i) a hydrophobic, photodefinable polymer, said photodefinable polymer having a glass transition temperature in the cured state of at least about 80° C.; and (ii) a multiphoton photoinitiator system comprising at least one multiphoton photosensitizer and preferably at least one phtoinitiator that is capable of being photosensitized by the photosensitizer. One or more portions of the composition are imagewise exposed to the electromagnetic energy under conditions effective to photodefinably form at least a portion of a three-dimensional optical element.

Abstract: A method of multiphoton photosensitizing a photoreactive composition comprises irradiating the composition with light sufficient to cause simultaneous absorption of at least two photons, thereby inducing at least one acid- or radical-initiated chemical reaction where the composition is exposed to the light. The composition comprises: (a) at least one reactive species that is capable of undergoing such reaction; and (b) at least one multi-component, multiphoton photoinitiator system.

Abstract: A method of increasing the efficiency of a multiphoton absorption process and apparatus. The method includes: providing a photoreactive composition; providing a source of sufficient light for simultaneous absorption of at least two photons; exposing the photoreactive composition to at least one transit of light from the light source; and directing at least a portion of the first transit of the light back into the photoreactive composition using at least one optical element, wherein a plurality of photons not absorbed in at least one transit are used to expose the photoreactive composition in a subsequent transit.

Abstract: Method of fabricating an optical element. A photodefinable composition is provided that includes (i) a hydrophobic, photodefinable polymer, said photodefinable polymer having a glass transition temperature in the cured state of at least about 80° C.; and (ii) a multiphoton photoinitiator system comprising at least one multiphoton photosensitizer and preferably at least one phtoinitiator that is capable of being photosensitized by the phtosensitizer. One or more portions of the composition are imagewise exposed to the electromagnetic energy under conditions effective to photodefinably form at least a portion of a three-dimensional optical element.

Abstract: The present invention involves the use of powder coating methods to form coated abrasives. In one embodiment, the powder is in the form of a multiplicity of binder precursor particles comprising a radiation curable component. In other embodiments, the powder comprises at least one metal salt of a fatty acid and optionally an organic component that may be a thermoplastic macromolecule, a radiation curable component, and/or a thermally curable macromolecule. In either embodiment, the powder exists as a solid under the desired dry coating conditions, but is easily melted at relatively low temperatures and then solidified also at reasonably low processing temperatures. The principles of the present invention can be applied to form make coats, size coats, and/or supersize coats, as desired.

Abstract: A multiphoton-activatable, photoreactive composition comprises: (a) at least one reactive species that is capable of undergoing an acid- or radical-initiated chemical reaction; (b) a photochemically-effective amount of a multiphoton photosensitizer comprising at least one multiphoton up-converting inorganic phosphor; and (c) a photochemically-effective amount of a one-photon photoinitiator system that is capable of being photosensitized by the multiphoton photosensitizer.

Abstract: A process for fabricating of an article by exposing a photoreactive composition to light under multiphoton absorption conditions. The light passes through an optical system having a final optical element having a numeric aperture in a range of from 0.65 to 1.25, inclusive.

Abstract: Provided is a treated substrate comprising a backing material coated with a resin derived from a curable precursor resin, which comprises an energy-curable component comprising a cyanate ester resin and a curing agent. Also provided is an abrasive article comprising a plurality of abrasive particles incorporated into a bond system, wherein the bond system comprises a make resin derived from a first curable precursor resin, which comprises a first curable component comprising a cyanate ester resin and a first curing agent, and wherein the bond system additionally comprises a size resin derived from a second curable precursor resin, which comprises a second curable component comprising a cyanate ester resin and a second curing agent. Also provided are methods of making a treated substrate and an abrasive article.

Abstract: A process for producing microfluidic articles comprises (a) preparing a photoreactive composition comprising (1) at least one reactive species that is a polymer or a polymer precursor and that is capable of undergoing an acid- or radical-initiated chemical reaction and (2) at least one multiphoton photoinitiator system; (b) exposing a portion of the composition to light sufficient to cause simultaneous absorption of at least two photons, thereby forming exposed and unexposed portions of the composition, and thereby inducing at least one acid- or radical-initiated chemical reaction in the exposed portion; and (c) removing either the exposed or the unexposed portion of the composition, so as to form a microfluidic article comprising a seamless polymer matrix that defines at least one inlet, at least one outlet, and a microfluid processing architecture that is capable of fluidic communication with the inlet and the outlet and that is otherwise fully enclosed within the polymer matrix.

Abstract: Methods for producing a region of at least partially reacted material in a photoreactive composition and apparatus. The methods include: providing a photoreactive composition; providing a source of sufficient light for simultaneous absorption of at least two photons by the photoreactive composition; providing an exposure system capable of inducing image-wise multiphoton absorption; generating a non-random three-dimensional pattern of light by means of the exposure system; and exposing the photoreactive composition to the three-dimensional pattern of light generated by the exposure system to at least partially react a portion of the material in correspondence with the non-random three-dimensional pattern of light incident thereon.

Abstract: The present invention provides a composition for use in coated abrasives. The curable composition comprises a mixture of: i) from about 30 to about 60 weight percent of an oligomeric aminoplast resin having on average at least one pendant &agr;,&bgr;-unsaturated carbonyl group per oligomeric unit; ii) from about 70 to about 40 weight percent of a thermoplastic polyamide miscible in said aminoplast resin, the weight percents being based on the total resin content; and iii) a sufficient amount of a catalyst for the curable oligomeric aminoplast resin having on average at least one pendant &agr;,&bgr;-unsaturated carbonyl group per oligomeric unit, said catalyst being stable at a temperature of mixing of the components. The curable composition can either be in the form of a melt-processable solid or a molten mixture. The present invention also provides single and multilayered treated backing substrates used in coated abrasives.

Abstract: A method for making a structure including applying a multiphoton-curable composition to a molded article, wherein the composition comprises a curable species and a multiphoton photoinitiator system, and at least partially curing the multiphoton-curable composition to form a structure on the article.

Abstract: Provided is a treated substrate comprising a backing material coated with a resin derived from a curable precursor resin, which comprises an energy-curable component comprising a cyanate ester resin and a curing agent. Also provided is an abrasive article comprising a plurality of abrasive particles incorporated into a bond system, wherein the bond system comprises a make resin derived from a first curable precursor resin, which comprises a first curable component comprising a cyanate ester resin and a first curing agent, and wherein the bond system additionally comprises a size resin derived from a second curable precursor resin, which comprises a second curable component comprising a cyanate ester resin and a second curing agent. Also provided are methods of making a treated substrate and an abrasive article.

Abstract: A multiphoton-activatable, photoreactive composition comprises: (a) at least one reactive species that is capable of undergoing an acid- or radical-initiated chemical reaction; (b) a photochemically-effective amount of a multiphoton photosensitizer comprising at least one multiphoton up-converting inorganic phosphor; and (c) a photochemically-effective amount of a one-photon photoinitiator system that is capable of being photosensitized by the multiphoton photosensitizer.