A resin composition useful for additive manufacturing is provided, which resin composition may exhibit improved shelf life through inhibition of crystallization. Such resin composition may include a crystallization inhibitor as taught herein, and/or a prepolymer produced by reaction of an isocyanate with multiple isomers and comprising a lower percentage of the structurally symmetric isomer. Methods of forming a three-dimensional object using such resin composition are also provided.

The invention provides a polishing pad suitable for polishing at least one of semiconductor, optical, magnetic or electromechanical substrates. It includes a polyurea polishing layer and a polyurea matrix. The polyurea has a soft segment being a copolymer of aliphatic fluorine-free polymer groups and a fluorocarbon having a length of a least six carbons. The polyurea matrix being cured with a curative agent and including gas or liquid-filled polymeric microelements. The polyurea matrix has a bulk region and a transition region adjacent the bulk region that extends to the polishing layer. The polymeric microelements in the transition region decrease in thickness as they approach the polishing layer with thickness of the compressed microelements adjacent the polishing layer being less than fifty percent of a diameter of the polymeric microelements in the bulk region. The polishing layer remains hydrophilic during polishing in shear conditions.

The invention provides a polishing pad suitable for polishing at least one of semiconductor, optical, magnetic or electromechanical substrates. It includes a polyurea polishing layer and a polyurea matrix. The polyurea has a soft segment being a copolymer of aliphatic fluorine-free polymer groups and a fluorocarbon having a length of a least six carbons. The polyurea matrix being cured with a curative agent and including gas or liquid-filled polymeric microelements. The polyurea matrix has a bulk region and a transition region adjacent the bulk region that extends to the polishing layer. The polymeric microelements in the transition region decrease in thickness as they approach the polishing layer with thickness of the compressed microelements adjacent the polishing layer being less than fifty percent of a diameter of the polymeric microelements in the bulk region. The polishing layer remains hydrophilic during polishing in shear conditions.

The present disclosure is to provide a photopolymer composition including a polymer matrix or a precursor thereof including a reaction product of a reactive isocyanate compound having a hydrogen bonding functional group capable of forming multiple hydrogen bonds and at least one isocyanate group, and a polyol having at least two hydroxyl groups; a photoreactive monomer; and a photoinitiator, a hologram recording medium produced from the photopolymer composition, an optical element including the photopolymer composition and a holographic recording method using the photopolymer composition.

The present disclosure is to provide a photopolymer composition including a polymer matrix or a precursor thereof including a reaction product of a reactive isocyanate compound having a hydrogen bonding functional group capable of forming multiple hydrogen bonds and at least one isocyanate group, and a polyol having at least two hydroxyl groups; a photoreactive monomer; and a photoinitiator, a hologram recording medium produced from the photopolymer composition, an optical element including the photopolymer composition and a holographic recording method using the photopolymer composition.

A process for producing an object from a precursor comprises the steps of: I) depositing a free-radically crosslinked resin atop a carrier to obtain a ply of a construction material joined to the carrier which corresponds to a first selected cross section of the precursor; II) depositing a free-radically crosslinked resin atop a previously applied ply of the construction material to obtain a further ply of the construction material which corresponds to a further selected cross section of the precursor and which is joined to the previously applied ply; III) repeating step II) until the precursor is formed; IV) treating the precursor obtained after step III) under conditions sufficient to at least partially trimerize to isocyanurate groups NCO groups present in the free-radically crosslinked resin of the obtained precursor to obtain the object.

A process for producing an object from a precursor comprises the steps of: I) depositing a free-radically crosslinked resin atop a carrier to obtain a ply of a construction material joined to the carrier which corresponds to a first selected cross section of the precursor; II) depositing a free-radically crosslinked resin atop a previously applied ply of the construction material to obtain a further ply of the construction material which corresponds to a further selected cross section of the precursor and which is joined to the previously applied ply; III) repeating step II) until the precursor is formed; IV) treating the precursor obtained after step III) under conditions sufficient to at least partially trimerize to isocyanurate groups NCO groups present in the free-radically crosslinked resin of the obtained precursor to obtain the object.

There are provided a carbodiimide compound excellent in storage stability, and performance as a crosslinking agent, and a method for producing the same, and a resin composition excellent in the film forming properties and solvent resistance of a coating made at low temperature. A polycarbodiimide compound derived from an aliphatic diisocyanate compound having at least one primary isocyanate group, the polycarbodiimide compound having a structure in which all ends are capped with an organic compound having a functional group that reacts with an isocyanate group, carbodiimide group concentration A (%) and weight average molecular weight Mw satisfying the following formula (1), and a resin composition comprising the carbodiimide compound and an aqueous resin having a predetermined acid value at a predetermined ratio.
(A/Mw)×1000≥0.55  (1).

There are provided a carbodiimide compound excellent in storage stability, and performance as a crosslinking agent, and a method for producing the same, and a resin composition excellent in the film forming properties and solvent resistance of a coating made at low temperature. A polycarbodiimide compound derived from an aliphatic diisocyanate compound having at least one primary isocyanate group, the polycarbodiimide compound having a structure in which all ends are capped with an organic compound having a functional group that reacts with an isocyanate group, carbodiimide group concentration A (%) and weight average molecular weight Mw satisfying the following formula (1), and a resin composition comprising the carbodiimide compound and an aqueous resin having a predetermined acid value at a predetermined ratio.
(A/Mw)×1000≥0.55  (1).

An erosion resistant article such as rotor blades for helicopters and wind turbines having the leading edge surface protected from damage from high speed impingement of rain or sand with a protective coating formed from specific polyurethane or polyurea coating having a defined set of minimum physical properties where the protective coating can be applied as a liquid coating and cured in place or as a preformed complementary shaped covering to protect the leading edge against erosion damage in service.