A sealant composition particularly suitable for a plastic substrate is disclosed. The sealant composition contains: a partially (meth)acrylated epoxy resin, a hydrophobic oligomer having a flexible hydrophobic backbone moiety and at least one functional group co-curable with the partially (meth)acrylated epoxy resin, and a latent epoxy-curing agent.

Disclosed is a photocurable elastomer composition that exhibits, when cured, excellent flexibility and barrier properties and has low compression set. The photocurable elastomer composition may comprise components (A) to (D) such that the mass ratio of the component (A) to the component (B) ((A):(B)) is from 25:75 to 75:25, and that the content of the component (C) is 50 mass % or less based on the total content of the components (A), (B), and (C).

The invention relates to a method of sealing, coating or/and aerodynamic smoothing of at least one connecting element that protrudes from a surface or/and for sealing, coating or/and aerodynamic smoothing of a surface at a gap or at an uneven connection site with a sulfur-containing SCOD sealing compound at at least one application site, especially on an aerospace component, with at least one nozzle element and with at least one irradiation unit, which is characterized in that i) a nozzle element contains a mixed sealing compound and is guided or/and mounted over the connecting element protruding from a surface, over the gap or/and over the uneven connection site, ii) the connecting element protruding from the surface, the gap or the uneven connection site is covered fully with sealing compound, the sealing compound forming a sealing compound cover essentially in the form of a sealing compound cap, a coating or/and a mound-shaped or bead-shaped elevation, iii) the nozzle element or at least a portion is raised if required from the surface having the sealing compound cover, and iv) the curing of the sealing compound is initiated with the aid of at least one irradiation unit by energy input and by release of a latent catalyst or is brought about by direct activation of at least one reaction component, such that the mixed sealing compound subsequently cures or/and cures further. The invention also relates to a corresponding apparatus, to the aerospace vehicle treated in this way and to the use of the method and the apparatus.

The present invention relates to a sealing compound for coating a substrate, which is a mixture of a predominantly uncured base mass and a curing agent containing at least one epoxy composition, wherein the base mass contains a mercapto-terminated base polymer based on polyether, polythioether, polythioethersulfide, polysulfide, copolymers thereof and/or mixtures thereof, wherein the base mass, the curing agent or both contain at least one photoinitiator based on a sterically hindered nitrogen-containing organic base, and, through the effects of high-energy actinic radiation, the at least one photoinitiator dissociates at least one radical per molecule based on a nitrogen-containing organic base, from which a nitrogen-containing organic base having a pKa value of the conjugated acid in the region of 6 to 30 is formed, which acts as an active catalyst for the curing of the base mass. The present invention also relates to a corresponding method for coating a substrate with a sealing compound.

One ultraviolet-curable resin composition of the present invention includes: (A) at least one polymer selected from the group consisting of poly(meth)acrylates (a1) and polyvinyl ethers (a2); (B) a compound having at least two secondary thiol groups in a molecule thereof; (C) a photopolymerization initiator a solution of which in acetonitrile with a concentration of 500 ppm has an absorbance of 0.50 or more in an optical path length of 10 mm at 385 nm; and (D) an organic compound that emits light upon absorbing ultraviolet rays, having a maximum wavelength of an absorption spectrum in a range of 300 nm or more and 450 nm or less, and having a maximum wavelength of an emission spectrum in a range of 350 nm or more and 500 nm or less; wherein a content of the compound (B) is 10 mass % or more and 70 mass % or less based on 100 mass % of the resin composition in terms of solid content.

A UV-curable silicone composition includes a polyorganosiloxane (A) containing at least two silicon-bonded alkenyl groups in the molecule; a polyorganohydrogensiloxane (B) having a branched or three-dimensional network structure and containing at least three silicon-bonded hydrogen atoms in the molecule; a polyorganohydrogensiloxane (C) having a linear or cyclic structure and containing two silicon-bonded hydrogen atoms in the molecule; and a UV-active addition reaction curing catalyst (D). The component (B) includes a polyorganohydrogensiloxane (E) having a branched or three-dimensional network structure and containing at least one silicon-bonded alkoxy group SiOR.sup.0 (R.sup.0 is a C.sub.1-C.sub.5 alkyl group) and at least three silicon-bonded hydrogen atoms in the molecule.

Disclosed is a sealant composition, a liquid crystal device and a method for preventing liquid crystal contamination using the sealant composition. The sealant composition consists of 20-30 parts by weight of an ultraviolet polymerizable double bond monomer, 15-20 parts by weight of a heat polymerization monomer, 5-20 parts by weight of a polymerizable oligomer, 0.1-5 parts by weight of a photoinitiator, 10-20 parts by weight of a heat curing agent and 0-20 parts by weight of a particulate additive, wherein said polymerizable oligomer is poly(ethylene glycol) diacrylate or derivatives thereof. Through the reaction between the polymerizable oligomers and the polymer of the ultraviolet polymerizable double bond monomers to generate a reticular high molecular polymer, the anchoring effect of the polymer on the surrounding unreacted heat polymerization monomers is effectively enhanced, thereby reducing the contamination of the crystal liquid by the sealant.

Provided is a sealing method that uses a photo-curable sealant sheet. The sealing method provided comprises, in the following order, a step of obtaining a photo-curable sealant sheet, a step of subjecting the sealant sheet to photoirradiation, and a step of applying the sealant sheet to a target object.