Abstract: A photocurable composition includes at least one N-oxyazinium salt photoinitiator, a photosensitizer for the N-oxyazinium salt photoinitiator, an N-oxyazinium salt efficiency amplifier, and one or more photocurable acrylates. This composition can be cured using irradiation under high efficiency. Curing can be carried out in oxygen-containing environment.

Abstract: Provided is a photocurable ink jet recording ink composition having a low viscosity and excellent curing property and photopolymerization initiator solubility. The photocurable ink jet recording ink composition includes a polymerizable compound and a photopolymerization initiator. The polymerizable compound includes vinyl ether group-containing (meth)acrylic esters represented by Formula (I) in an amount of 20% by mass or more based on the total mass of the ink composition. The photopolymerization initiator includes a bisacylphosphine oxide photopolymerization initiator in an amount of 5% by mass or more based on the total mass of the ink composition and a thioxanthone photopolymerization initiator. The content ratio of the bisacylphosphine oxide photopolymerization initiator to the thioxanthone photopolymerization initiator is from 3:1 to 5:4.

Abstract: A photosensitive resin composition which is effective in avoiding troubles in the step of plating with various metals in printed wiring board production, such as under-film metal deposition and film peeling, and which forms a wiring-protecting film excellent in adhesion, flexibility, insulation reliability, and heat resistance. The photosensitive resin composition comprises (A) a carboxylated polymer, (B) a compound having at least two photopolymerizable unsaturated double bonds, (C) a photopolymerization initiator, and (D) a nitrogen compound represented by a specific feature.

Abstract: Compounds of the formula (I), wherein A1 is formula (II); A2 is formula (III); A3 is formula (IV); A4 is formula (V); w, x, y and z independently of each other are an integer from 0-4, provided that the sum of x+y+z is an integer from 2-4, corresponding to the valency of Q; M1, M2, M3 and M4 for example are a direct bond, CO or O; Y for example is a direct bond or S; Q is a (x+y)-valent linking group; R1 is for example hydrogen, C1-C20alkyl or phenyl or naphthyl; R2 and R?2 for example are is hydrogen or C1-C20alkyl; R3, R4, R?3, R?4, R?3 and R?4 for example are hydrogen, halogen, phenyl, or C1-C20alkyl; and R24 is for example a direct bond; exhibit an unexpectedly good performance in photopolymerization reactions.

Abstract: The invention relates to combined radiation- and moisture-curing compounds, which are characterized in particular by rapid curing by means of moisture. The compounds can be used as adhesives, coatings or potting materials. The use of the compounds according to the invention is particularly preferred for filling electro-optical components.

Abstract: A radiation curable composition comprising a curable compound, a photo-initiator and a co-initiator characterized in that said co-initiator is represented by Formula I, wherein MA is the residue of a mono- or oligofunctional Michael acceptor; L is a divalent linking group positioning the two tertiary amines in a 1-3 to 1-10 position, with the proviso that both amines are aliphatic; R1, R2 and R3 independently represent an optionally substituted alkyl group, an optionally substituted alkenyl group , an optionally substituted alkynyl group or an optionally substituted (hetero) alkaryl group; any two of R1, R2 and R3 may represent the necessary atoms to form a ring; any two of R1, R2 and R3 may represent the necessary atoms to form a ring with any of the atoms of the linking group L; n is an integer ranging from 1 to 6.

Abstract: The present invention provides a low viscosity photocurable composition including (i) a cationically curable component (ii) a free radically active component (iii) an antimony-free cationic photoinitiator (v) a free radical photoinitiator, and (vi) a toughening agent. The photocurable composition can be cured using rapid prototyping techniques to form three-dimensional articles which can be used in various aerospace and investment casting applications.

Abstract: A specific type of carbazole photoinitiator is capable of providing radiation curable compositions that are curable by UV LEDs and do not exhibit an unstable yellowing behaviour in an image upon storage like ITX.

Abstract: The photocuring efficiency of an N-oxyazinium salt photoinitiator is increased by mixing it with an organic phosphine as a photoinitiator efficiency amplifier. This mixture or photoinitiator composition can be used to cure acrylates or other photocurable compounds, particularly in an oxygen-containing environment.

Abstract: Photocuring methods are made more efficient by using an N-oxyazinium salt photoinitiator with an organic phosphine as a photoinitiator efficiency amplifier. This photoinitiator composition can be used to cure acrylates or other photocurable compounds, particularly in an oxygen-containing environment. The method can be used to prepare various articles, fibers, or devices with photocured compositions.

Abstract: A radiation curable composition for UV LED curing includes at least one co-initiator selected from the group consisting of an aliphatic tertiary amine and a dialkyl aniline derivative; and at least one specific carbazole photoinitiator. The radiation curable composition can be advantageously used to prevent unstable yellowing behaviour in an image upon storage.

Abstract: This invention relates to polymerizable compositions comprising a salt of a barbituric acid derivative. The compositions are typically shelf-life stable and may be polymerized through mixing of an acidic component with the salt of a barbituric acid derivative.

Abstract: A photocationically polymerizable adhesive composition and an optical member, the photocationically polymerizable adhesive composition including about 75 to about 99.8 parts by weight of a compound including one of aliphatic epoxy, alicyclic epoxy, oxetane, and vinyl ether compounds, about 0.1 to about 5 parts by weight of a titanate coupling agent, and about 0.1 to about 20 parts by weight of a photopolymerization initiator, wherein a sum of weights of the compound, the titanate coupling agent, and the photopolymerization initiator is 100 parts by weight.

Abstract: This invention relates to polymerizable compositions comprising a salt of a barbituric acid derivative. The compositions are typically shelf-life stable and may be polymerized through mixing of an acidic component with the salt of a barbituric acid derivative.

Abstract: The present invention provides a photocurable pressure-sensitive adhesive composition which has sufficient adhesion before being irradiated with light, and after being irradiated with light, keeps a sufficient pot life and has a short cure-completion time at a room temperature. A cured product produced from the composition has high adhesion force to adherends difficult to be attached, and excellent durability. The photocurable pressure-sensitive adhesive composition comprises a crosslinking compound (A) that is crosslinkable by the action of a base, a photobase generator (B) which becomes active upon light irradiation to generate a base, and a tackifying component (C).

Abstract: The object of the present invention is to provide an active energy ray-curable ink-jet printing ink, including: a coloring agent; a compound having an ethylenic double bond; and a photo-polymerization initiator, wherein the photo-polymerization initiator includes a compound represented by general formula (1): (wherein A represents any one of —O—, —CH2—, —CH(CH3)—, and —C(CH3)2—; and each of R1 and R2 independently represents a hydrogen atom, a methyl group, or a trimethylsilyl group), and an ?-aminoketone-based compound and/or an acyl phosphine oxide-based compound, and 40% by mass or more of the compound represented by general formula (1) is included with respect to the total photo-polymerization initiator.

Abstract: A photoinitiator composition comprising a combination of aminoalkyl phenone, thioxanthone and multifunctional amino benzoate synergist for use in printing inks and coatings that are curable using UV radiation, particularly from LED lamps.

Abstract: An ink composition is provided that includes (Component A) at least one compound selected from the group consisting of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide, (Component B) at least one compound selected from the group consisting of 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, (Component C) a thioxanthone compound, (Component D) a polymerization inhibitor, and (Component E) a polymerizable compound, Component C having a content of 0.01 to 5 wt % relative to the total weight of the ink composition, Component D having a content of 0.01 to 5 wt % relative to the total weight of the ink composition, the sum of the content of Component A and the content of Component B being 6.0 to 9.

Abstract: An ink composition for ultraviolet curable ink jets including monomer A represented by a general formula (I): CH2?CR1—COOR2—O—CH?CH—R3??(I) (in the formula, ‘R1’ represents a hydrogen atom or methyl group, ‘R2’ represents a divalent organic residue having a carbon number of 2 to 20, and ‘R3’ represents a hydrogen atom or a monovalent organic residue having a carbon number of 1 to 11), and a photopolymerization initiator containing an acylphosphine oxide-based photopolymerization initiator and a thioxanthone-based photopolymerization initiator, in which the total content of the acylphosphine oxide-based photopolymerization initiator and the thioxanthone-based photopolymerization initiator is 8% by mass to 16% by mass with respect to the total mass of the ink composition.

Abstract: The invention pertains to an oligomer or polymer substituted by one or more bisacylphosphine oxide moieties, characterized in that said bisacylphosphine oxide moiety is linked via the phosphorous atom, optionally via a spacer group, to the oligomer or polymer backbone; as well as to specifically functionalized bisacylphosphine oxides, suitable to prepare said polymers or oligomers.

Abstract: Provided is a recording method using a light-curable-type ink set including a light-curable-type color-ink composition containing a polymerizable compound, a photopolymerization initiator, and a coloring material and a light-curable-type clear-ink composition containing a polymerizable compound and a photopolymerization initiator, wherein the light-curable-type color-ink composition contains (1) an acylphosphine oxide-based photopolymerization initiator and (2) at least one of a thioxanthone-based photopolymerization initiator and/or an ? aminoalkylphenone-based photopolymerization initiator which is in a range of 0.

Abstract: The invention relates to light-curable dental materials comprising at least one polymerizable compound having at least one ethylenically unsaturated bond and a hexaarylbisimidazole, e.g. as a photopolymerization initiator. The invention also relates to the use of a hexaarylbisimidazole polymerization initiator in light curable dental materials and also to cured dental materials obtainable by light-curing the light-curable dental materials of the invention.

Abstract: Provided is a UV curable type ink-jet ink composition containing a monomer A which is expressed by the following general formula (I): CH2?CR1—COOR2—O—CH?CH—R3??(I) (in the formula, R1 is a hydrogen atom or methyl radical, R2 is a bivalent organic residue radical having a carbon number in a range of 2 to 20, and R3 is a hydrogen atom or a univalent organic residue radical having a carbon number in a range of 1 to 11), a compound B containing five or more (meth)acryloyl radicals per molecule, and a monofunctional (meth)acrylate C having an aromatic ring skeleton, wherein the monofunctional (meth)acrylate C which is in a range of 5 to 35 wt % with respect to the total weight of the ink composition is contained.

Abstract: The present invention relates to an aminimide compound having a structure represented by the following general formula (I) in the molecule thereof, relates to a curable composition using the aminimide compound and relates to a method for curing the composition; in which R0 represents a hydrogen atom, an alkyl group which may have an optional substituent, an aryl group which may have an optional substituent, or a heterocyclic residue which may have an optional substituent. R1, R2 and R3 each independently represent a hydrogen atom, or an optional substituent. However, at least two of R1, R2 and R3 may bond to each other to form a cyclic structure.

Abstract: An ink composition is provided that includes (A) an N-vinyllactam, (B) another polymerizable compound, (C) a polymerization initiator, and (D) a basic compound, the content of the N-vinyllactam (A) being less than 15 wt % of the total weight of the ink composition. There is also provided an inkjet recording method that includes (a1) a step of discharging the ink composition onto a recording medium and (b1) a step of curing the ink composition by irradiating the discharged ink composition with actinic radiation. There is also provided a printed material recorded by the inkjet recording method.

Abstract: Provided is an ultraviolet-curable ink jet ink composition with excellent curability and storage stability, the composition containing a monomer A represented by Formula (I): CH2?CR1—COOR2—O—CH?CH—R3 (wherein R1 represents a hydrogen atom or a methyl group, R2 represents a C2-C20 divalent organic residue, and R3 represents a hydrogen atom or a C1-C11 monovalent organic residue); a (meth)acrylated amine compound; a hindered amine compound other than the (meth)acrylated amine compound; and a photopolymerization initiator.

Abstract: An ink set for inkjet recording is provided that includes at least a colored liquid comprising at least a radically polymerizable compound, a photopolymerization initiator, and a colorant and an undercoat liquid comprising at least a radically polymerizable compound and a photopolymerization initiator, the undercoat liquid comprising a sensitizer represented by Formula (I) below. In Formula (I) above, X denotes O, S, or NR, n denotes 0 or 1, R denotes a hydrogen atom, an alkyl group, or an acyl group, and R1, R2, R3, R4, R5, R6, R7, and R8 independently denote a hydrogen atom or a monovalent substituent. There is also provided an inkjet recording method employing the ink set for inkjet recording, the method including a step of applying the undercoat liquid on top of a recording medium, a step of semi-curing the undercoat liquid, and a step of carrying out image formation by discharging the colored liquid on top of the semi-cured undercoat liquid.

Abstract: A dual-cure curable material kit comprising: (A) a radical-polymerizable monomer component; (B) a photopolymerization initiator component comprising (b1) an ?-diketone compound, (b2) an aliphatic tertiary amine compound having a tertiary amino group in which three saturated aliphatic groups are bonded to a nitrogen atom and one of the saturated aliphatic groups has an electron-withdrawing group as a substituent, and (b3) an s-triazine compound having a trihalomethyl group as a substituent, or a diaryliodonium salt compound; and a chemical polymerization initiator component (C) comprising (c1) an organic peroxide, and (c2) an N,N-di(hydroxyalkyl)-p-toluidine compound; which is packed separately at least in two packages so that the component (b2) and the component (b3) of the photopolymerization initiator component (B) are not packed together in a single package and the component (c1) and the component (c2) of the chemical polymerization initiator component (C) are not packed together in a single package.

Abstract: An object of the present invention is to provide an energy ray-curable ink composition which is excellent in curability and adhesion, and is also excellent in storage stability. The present invention relates to an energy ray-curable ink composition comprising a coloring material; a polyfunctional monomer having three or more ethylenical double bonds in one molecule as a polymerizable compound; an ?-aminoalkylphenone-based compound and a thioxanthone-based compound as photopolymerization initiators; and a hindered amine-based compound having a 2,2,6,6-tetramethylpiperidinyl group as an antigelling agent.

Abstract: An ink composition is provided that includes compound A represented by Formula (I) below, compound B represented by Formula (II) below, and a polymerizable compound, wherein, in Formula (I), X denotes O, S, or NRa, n1 denotes 0 or 1, Ra, R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 independently denote a hydrogen atom or a monovalent substituent, and two of R1, R2, R3, R4, R5, R6, R7, and R8 that are adjacent may be linked to each other to form a ring, and in Formula (II), X denotes O, S, or NRb, n2 denotes 0 or 1, Rb, R11, R12, R13, R14, R15, R16, R17, and R18 independently denote a hydrogen atom or a monovalent substituent, and two of R11, R12, R13, and R14 that are adjacent may be linked to each other to form a ring. There is also provided an inkjet recording method comprising (a) a step of discharging the ink composition onto a recording medium, and (b) a step of curing the ink composition by irradiating the discharged ink composition with actinic radiation.

Abstract: A UV-curable ink jet ink composition contains a polymerizable compound, a photopolymerization initiator containing an acylphosphine-based photopolymerization initiator having a phenyl group in the molecule thereof, and a fluorescent brightening agent. The fluorescent brightening agent in a predetermined concentration has a higher maximum absorbance than the photopolymerization initiator in the same concentration, in a wavelength region of 360 to 420 nm.

Abstract: To provide a temporary bonding adhesive for a semiconductor wafer that reduces damage to a semiconductor wafer, makes it readily detachable, and can shorten the time required for thermal decomposition, and a manufacturing method for a semiconductor device using this. A temporary bonding adhesive for a semiconductor wafer, being a temporary bonding adhesive used for temporarily bonding a semiconductor wafer onto a supporting substrate in order to process a semiconductor wafer, and for detaching a semiconductor wafer from a supporting substrate by heating after processing, containing a resin composition composition whereof the 50% weight loss temperature decreases after irradiation by active energy rays.

Abstract: An alkali development-type solder resist includes (A) a carboxyl group-containing photosensitive resin obtained by reacting (a) a compound having two or more cyclic ether or thioether groups in the molecule with (b) an unsaturated monocarboxylic acid, reacting the product with (c) a polybasic acid anhydride, reacting the resulting resin with (d) a compound having a cyclic ether group and an ethylenic unsaturated group in the molecule, and reacting the product additionally with (c) a polybasic acid anhydride, (B) an oxime ester-based photopolymerization initiator containing a specific oxime ester group, (C) a compound having two or more ethylenic unsaturated groups in the molecule, and (D) a thermosetting component, wherein the dry film obtained by applying the composition has an absorbance of 0.3 to 1.2 per 25 ?m of the film thickness at a wavelength of 350 to 375 nm.

Abstract: A radiation-curable ink composition contains (A) aminoacrylate at 1 mass % to 10 mass %, inclusive, (B) phenoxyethyl acrylate at 20 mass % to 50 mass %, inclusive, and (C) tetraethylene glycol diacrylate at 1 mass % to 20 mass %, inclusive, in its reaction component, as well as (E) bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide at 3 parts by mass to 8 parts by mass, inclusive, (F) 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide at 3 parts by mass to 5 parts by mass, inclusive, in 100 parts by mass of the reaction component, and (G) diethylthioxanthone at 1 part by mass to 3 parts by mass, inclusive, in 100 parts by mass of the reaction component.

Abstract: The present invention provides switchable adhesives comprising a mixture, in proportions by weight, of 20% to 98% of an adhesive, 2% to 80% of curable molecules and 0.05% to 10% of photoinitiator. Preferably, the adhesive and curable molecules are mutually soluble when dry, or the curable molecules and adhesive may be uniformly dispersed in each other. Preferably the amount of adhesive in the mixture is in the range 40% to 98% by weight, more preferably 60% to 95% by weight, even more preferably 70% to 85% by weight. Preferably the proportion of curable molecules in the mixture ranges from 2% to 60% by weight, more preferably 5% to 40% by weight, even more preferably 15% to 30% by weight. Preferably, the photoinitiator is present in the mixture in the proportions 0.5% to 5% by weight, more preferably 1% to 3% by weight.

Abstract: The present invention provides a pigment dispersion liquid including a pigment, a compound having a cyclic urea structure and having an acid group or a basic group, a dispersant, and a solvent. The pigment may be a pigment having a urea structure or an imide structure. The pigment may also be a pigment having a barbituric skeleton.

Abstract: Improvedly storage stable dental compositions useful for the preparation of dental prostheses and for dental restoration containing a uniquely pretreated dental filler material.

Abstract: Disclosed are photopolymerizable compositions suitable for uses such as dental composite resins, and that comprise (A) a radical-polymerizable monomer, (B) a photopolymerization initiator that comprises (B1) an ?-diketone compound, (B2) a photoacid generating agent, (B3) an aromatic amine compound, and (C) an organic filler containing a phthalate ester fluorescent agent.

Abstract: A radiation curable solid overcoat composition that is capable of being ink jetted comprising at least one curable wax that is curable by free radical polymerization; at least one monomer, oligomer, or prepolymer; at least one non-curable wax; at least one free-radical photoinitiator or photoinitiating moiety; and a colorant; wherein the components form a curable solid overcoat composition that is a solid at a first temperature, wherein the first temperature is from about 20 to about 25° C.; and wherein the components form a liquid composition at a second temperature, wherein the second temperature is greater than about 40° C.

Abstract: The invention relates to a coating formulation for preparing a hydrophilic coating, wherein the hydrophilic coating formulation comprises a hydrophilic polymer, a supporting polymer comprising a backbone and at least 2 reactive moieties capable of undergoing polymerization reactions, a Norrish Type I photoinitiator and a Norrish Type II photoinitiator.

Abstract: Stable, highly filled cationic dental compositions useful for the production of dental prostheses and dental restoration materials contain: (1) at least one compound which is reactive cationically when activated, advantageously at least one UV- and cationically reactive oxirane-functionalized silicone; (2) at least one dental filler, advantageously SiO2; (3) at least one organic polymer or copolymer dispersant having an amine index less than or equal to 100 mg of potassium hydroxide per gram of dispersant, advantageously a polyurethane/acrylate copolymer or alkylammonium salt thereof; (4) at least one cationic photoinitiator, advantageously iodonium borate; and (5) optionally, at least one photosensitizer.

Abstract: Dental compositions are described which are photocurable by radiation with a wavelength greater than 390 nm. The compositions include a cationically active compound, a dental filler, optionally a dispersant, a cationic photoinitiator and a photosensitizer which is a thioxanthone salt substituted by at least one group containing an ammonium function. The composition has the advantage of remedying the color stability problems of finished dental products after crosslinking.

Abstract: The present invention provides an energy ray-curable ink composition excellent in the continuous discharge property, and excellent in curability and adherability. The present invention relates to an energy ray-curable ink composition which contains a coloring agent, contains only a monofunctional monomer having an acrylic equivalent of 300 or less, and having one ethylenic double bond in one molecule, and a polyfunctional monomer having an acrylic equivalent of 150 or less, and having two or more ethylenic double bonds in one molecule as a polymerizable compound, contains an ?-aminoalkylphenone compound and a thioxanthone compound as a photopolymerization initiator, and contains a silicone compound having a polydimethylsiloxane structure as a surface conditioner.

Abstract: A radiation curable inkjet fluid includes a radiation curable composition including at least 25 wt % of a vinylether acrylate and at least 15 wt % of a polymerizable compound including at least three acrylate groups, each wt % being based upon the total weight of the radiation curable composition; and a photoinitiator including a tertiary amine group and 0 to 3 wt % of isopropylthioxanthone based upon the total weight of the radiation curable inkjet fluid. Also, an inkjet printing method using the radiation curable inkjet fluid.

Abstract: A curable composition containing a lake dye having an absorption maximum in the wavelength region of from 700 nm to 1100 nm and a thermosetting compound and/or a photo-setting compound; a solid imaging device installing therein a filter prepared using the curable composition; and a lake dye represented by the following formula (V): wherein L1 represents a methine chain composed of odd number(s) of methine group(s); A1 and A2 are each independently represents an alkyl group having a sulfo group; Y represents a cation necessary to balance a charge and selected from the group consisting of alkali earth metal ions (Mg2+, Ca2+, Ba2+, Sr2+), transition metal ions (Ag+, Fe+, Co2+, Ni2+, Cu2+, Zn2+) and (Al3+).

Abstract: Stable and substantially filled cationic dental compositions are described which include: (1) at least one cationically reactive compound (A); (2) at least one dental filler (B); (3) optionally, at least one dispersant (C) composed of at least one organic polymer or copolymer; (4) at least one cationic photoinitiator (D); and (5) optionally, at least one photosensitizer (E). The dental filler (B) is treated with at least one organosilicon coupling agent (F), and at least one compound (G). The organosilicon coupling agent (F) has at least one reactive function (rfA) directly linked to a silicon atom forming after activation of a chemical bond with the dental filler, and at least one reactive function (rfB) not directly linked to a silicon atom, forming after activation, a chemical bond with a reactive function (rfC) of the compound (G).

Abstract: The invention concerns dental compositions. Said composition comprises (1) a silicone crosslinkable and/or polymerizable by cation process; (2) an efficient amount of at least an initiator such as onium borate; (3) at least a photosensitizer; and (4) a dental filler present in the composition in a proportion of at least 10 wt. % relative to the composition total weight. Said dental compositions are useful for making dental prostheses or for dental restoration.

Abstract: An oxime ester compound represented below is useful as a photopolymerization initiator. A photopolymerization initiator including this as an active constituent has high sensitivity and causes no concern about coloration or contamination. (X represents a halogen atom or alkyl group. R1, R2, and R3 each independently represent R, OR, COR, SR, CONRR?, or CN, wherein R and R? each represent an alkyl group, an aryl group, an aralkyl group, or a heterocyclic group; these groups may be substituted with (a) halogen atom(s) and/or (a) heterocyclic group(s); the alkylene moiety in the alkyl or aralkyl group may be interrupted by (an) unsaturated bond(s), (an) ether bond(s), (a) thioether bond(s), or (an) ester bond(s); and R and R? may form a ring. Y1 represents an oxygen, sulfur, or selenium atom; A represents a heterocyclic group; m represents an integer 0-4; p represents an integer 0-5; and q represents 0 or 1.

Abstract: Compounds of the formula (I), wherein A1 is formula (II); A2 is formula (III); A3 is formula (IV); A4 is formula (V); w, x, y and z independently of each other are an integer from 0-4, provided that the sum of x+y+z is an integer from 2-4, corresponding to the valency of Q; M1, M2, M3 and M4 for example are a direct bond, CO or O; Y for example is a direct bond or S; Q is a (x+y)-valent linking group; R1 is for example hydrogen, C1-C20alkyl or phenyl or naphthyl; R2 and R?2 for example are is hydrogen or C1-C20alkyl; R3, R4, R?3, R?4, R?3 and R?4 for example are hydrogen, halogen, phenyl, or C1-C20alkyl; and R24 is for example a direct bond; exhibit an unexpectedly good performance in photopolymerization reactions.

Abstract: An actinic-radiation curable ink composition includes a colorant, a dendritic polymer serving as a polymerizable compound, and a thioxanthone photoinitiator having a plurality of functional groups. The proportion of the thioxanthone photoinitiator is in the range of 3% to 27% by mass with respect to the total mass of the dendritic polymer.