The invention relates to the field of powder coatings, and specifically discloses a heat-curable powder coating composition and a preparation method thereof. The powder coating composition comprises: i) component A comprising at least one amorphous solid polyester resin compound having a Michael donor reactive group; ii) component B comprising at least one amorphous ethylenically unsaturated solid polyester resin with a Michael acceptor reactive group; iii) component C comprising at least one (semi) crystalline solid reactive diluent; iv) component D comprising at least one epoxy group-containing solid substance; v) component E comprising at least one basic catalyst. The present invention also discloses a preparation method of the above heat-curable powder coating composition. By adopting the invention, ultra-low temperature curing can be realized. The curing temperature is as low as 90-110° C., and the curing time is short.

Urethane/urea-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing urethane/urea-containing bis(alkenyl) ether-containing polythioether prepolymers and/or urethane/urea-containing bis(alkenyl) ether curing agents exhibit improved physical properties suitable for use in aerospace sealant applications.

The present invention relates to a multi-aziridine crosslinker composition, characterized in that the multi-aziridine crosslinker composition is an aqueous dispersion having a pH ranging from 8 to 14 and comprises a multi-aziridine compound in dispersed form, wherein said multi-aziridine compound has: a. from 2 to 6 of the following structural units A: whereby R.sub.1 is H, R.sub.2 and R.sub.4 are independently chosen from H or an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms, R a is an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms, m is 1, b. one or more linking chains wherein each one of these linking chains links two of the structural units A; and c. a molecular weight in the range from 500 to 10000 Daltons wherein the molecular weight is determined using MALDI-TOF mass spectrometry according to the description.

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A resin composition for the secondary coating of an optical fiber is a resin composition containing a non-reactive urethane compound having a number average molecular weight of 10000 or more and 50000 or less, a photopolymerizable compound, and a photopolymerization initiator, the content of the non-reactive urethane compound is 0.05 parts by mass or more and 5 parts by mass or less based on the total amount of the resin composition, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 8000 or more and 20000 or less, a diisocyanate, and a compound having active hydrogen.

A resin composition for the secondary coating of an optical fiber is a resin composition containing a non-reactive urethane compound having a number average molecular weight of 10000 or more and 50000 or less, a photopolymerizable compound, and a photopolymerization initiator, the content of the non-reactive urethane compound is 0.05 parts by mass or more and 5 parts by mass or less based on the total amount of the resin composition, and the non-reactive urethane compound is a reaction product of a polyol having a number average molecular weight of 8000 or more and 20000 or less, a diisocyanate, and a compound having active hydrogen.

A crosslinkable composition is useful for preparing a skin contact adhesive or a coating on a substrate. The crosslinkable composition includes (A) a polyurethane-polyorganosiloxane copolymer and (B) a curing catalyst. The skin contact adhesive prepared by crosslinking the crosslinkable composition is useful in applications such as adhesives for medical tapes, adhesives for wound dressings, adhesives for prosthetics, ostomy appliance adhesives, adhesives for medical monitoring appliances, adhesives for scar therapy treatments, adhesives for cosmetic patches, and transdermal drug delivery systems.

A urethane oligomer according to a) or b) has: a) at least two backbone residues R issued from a polyisocyanate without the NCO groups, linked between them with a diol residue R.sub.B (diol without the two OH groups) by two urethane bonds and each backbone residues R carrying (or linked to) at least two urethane segments each containing at least one terminal allyl group, b) at least one backbone residue R issued from a polyisocyanate without the NCO groups, the backbone residue R carrying (or linked to) at least two urethane segments each linked to R by one urethane bond with at least one urethane segment (arm) containing at least one terminal allyl group, and at least one urethane segment (arm) containing at least one terminal (meth)acrylate group. A curable composition containing the urethane oligomer reduces oxygen inhibition in coatings, adhesives, sealants or in resin matrix with good surface properties.

The invention relates to a method for producing radiation-curable alkenyl ether polyols, to radiation-curable alkenyl ether polyols produced using the method according to the invention, and to the use thereof for the synthesis of radiation-interlinkable oligomers or polymers by means of polyaddition reactions or polycondensation reactions, in particular for the synthesis of radiation-curable polyesters, polyethers, polyurethanes and polyureas, particularly preferably UV-curable polyurethanes. The invention also relates to radiation-curable polyurethane polymers that are obtained by reacting at least one alkenyl ether polyol according to the invention with a polyisocyanate.

The invention relates to a method for producing radiation-curable alkenyl ether polyols, to radiation-curable alkenyl ether polyols produced using the method according to the invention, and to the use thereof for the synthesis of radiation-interlinkable oligomers or polymers by means of polyaddition reactions or polycondensation reactions, in particular for the synthesis of radiation-curable polyesters, polyethers, polyurethanes and polyureas, particularly preferably UV-curable polyurethanes. The invention also relates to radiation-curable polyurethane polymers that are obtained by reacting at least one alkenyl ether polyol according to the invention with a polyisocyanate.

A roll excellent in abrasion resistance, which contains: a resin layer containing a first atom group having a plurality of sulfur atoms, a plurality of second atom groups having a carbon chain that has a plurality of carbon atoms arranged in a line and has an end bonded to any one of the plurality of sulfur atoms, and a plurality of third atom groups each of which has a urethane bond and is bonded to any one of the plurality of second atom groups; and a cylindrical foamed resin having an outer surface covered with the resin layer.