Certain phosphonate compounds useful as photoinitiators are provided herein.

An acylphosphine oxide compound represented by Formula 1-1 or Formula 2-1 which can be used as a photopolymerization initiator. In Formula 1-1 and Formula 2-1, A represents an m-valent group, L's each independently represent a single bond or a divalent linking group, R.sup.1's each independently represent an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R.sup.2 and R.sup.3 each independently represent an alkyl group, an aryl group, or an alkoxy group, m represents an integer of 3 or more, n1's each independently represent an integer of 0 to 4, and n2's each independently represent an integer of 0 to 5. ##STR00001##

An acyl phosphine oxide initiator including an acyl group selected from the group consisting of a benzoyl group substituted by an urea group or an oxalylamide group; a 2,6-dimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group; a 2,6-dimethoxy benzoyl group substituted in position 3 by an urea group or an oxalylamide group; a 2,4,6-trimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group; and a 2,4,6-trimethoxybenzoyl group substituted in position 3 by an urea group or an oxalylamide group, wherein the urea group and the oxalylamide group include a tertiary amine group positioning a phosphorus atom of the acylphosphine oxide initiator in a 1 to Z position, where position 1 is defined as that of the phosphorus atom and position Z is defined as the nitrogen atom of the tertiary amine group with Z representing an integer of at least 11; and that the acyl phosphine oxide initiator contains no more than two photoinitiating moieties having a phosphine oxide group.

The present disclosure is drawn to an amine synergist including a tertiary benzylamine with a substituted benzene ring attached to a tertiary amine. The tertiary amine can be modified with multiple water soluble groups.

The present disclosure is drawn to a reactive polyurethane dispersion including a polymer strand having a polymer backbone that has two ends terminating at a first capping unit and a second capping unit. The polymer backbone can include polymerized monomers including a reactive diol and a blend of two or more diisocyanates. The reactive diol can be an acrylate-containing diol, a methacrylate-containing diol, or combination thereof. The first capping unit can be an acrylate-containing monoalcohol or methacrylate-containing monoalcohol reacted with an isocyanate group of the diisocyanates. The second capping unit can be an ionic stabilizing group. The polymer backbone can be devoid of ionic stabilizing groups.

A photopolymerization initiator which is a compound having a structure in which one or more carbonyl groups that link to a carbon atom are further directly bonded to an aromatic ring of an aromatic acyl group that bonds to a phosphorus atom in an acylphosphine oxide structure. A producing method of a photopolymerization initiator produces the photopolymerization initiator. In a polymerizable composition and an ink jet recording method, the photopolymerization initiator is used. Furthermore, an acylphosphine oxide compound has a partial structure represented by Formula 1 or Formula 2. ##STR00001##

The present disclosure is drawn to a photo active agent which includes a diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide modified with a tertiary amine having a water solubilizing group attached to the tertiary amine.

An inkjet ink composition comprising: one or more UV curable monomers; oligomers having one or more acrylic groups; one or more photoinitiators; one or more surfactants; and paraffin wax.

A photopolymerization initiator is an acylphosphine oxide compound represented by Formula 1-1 or Formula 2-1. A polymerizable composition or an ink jet recording method is a polymerizable composition or an ink jet recording method in which the photopolymerization initiator is used. In addition, an acylphosphine oxide compound represented by Formula 1-1 or Formula 2-1 which can be preferably used as the photopolymerization initiator. In Formula 1-1 and Formula 2-1, A represents an m-valent group, L's each independently represent a single bond or a divalent linking group, R.sup.1's each independently represent an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R.sup.2 and R.sup.3 each independently represent an alkyl group, an aryl group, or an alkoxy group, m represents an integer of 3 or more, n1's each independently represent an integer of 0 to 4, and n2's each independently represent an integer of 0 to 5.

##STR00001##

Provided are a curable composition for imprinting and a cured product, a pattern forming method, and a lithography method in which the curable composition for imprinting is used, the curable composition having excellent resolution ability, filling properties into a mold, and releasability from a mold in a case where a fine pattern having a size of 20 nm or less is prepared. The curable composition for imprinting includes: a monofunctional polymerizable compound; a bifunctional polymerizable compound; and a photopolymerization initiator, in which a content of the monofunctional polymerizable compound is 5 to 30 mass % with respect to a content of all the polymerizable compounds, a content of the bifunctional polymerizable compound is 70 mass % or higher with respect to a content of all the polymerizable compounds, at least one bifunctional polymerizable compound is a bifunctional polymerizable compound in which the number of atoms linking two polymerizable groups to each other is 2 or less, and a content of a bifunctional polymerizable compound that does not include an alicyclic structure and an aromatic ring structure and in which the number of atoms linking two polymerizable groups to each other is 3 or more is 30 mass % or lower with respect to the content of all the polymerizable compounds.