An object of the present disclosure is to provide a photocurable composition from which a molded product having excellent mechanical properties is obtained. The present disclosure provides a photocurable composition containing a urethane (meth)acrylate oligomer and a vinyl monomer, wherein the vinyl monomer includes a first monomer having a glass transition temperature (Tg) of −100° C. or more and 20° C. or less, and a second monomer having a glass transition temperature (Tg) of more than 20° C. and 150° C. or less, an amount of the urethane (meth)acrylate oligomer ranges from 20 mass % to 80 mass %, an amount of the first monomer ranges from 15 mass % to 75 mass %, an amount of the second monomer ranges from 5 mass % to 65 mass %, and a total amount of the urethane (meth)acrylate oligomer and the vinyl monomer is 100 mass %.

The present invention refers to a photo-curable composition comprising at least one polythiol having at least two thiol groups, at least one polyisocyanate having at least two isocyanate groups, at least one (poly-)ene compound having at least one —C═C group, and at least one photolatent base catalyst. Furthermore, the present invention pertains to a method of photo-curing the photo-curable composition according to the present invention as well as to a method of three dimensional printing an object with the photo-curable composition according to the present invention. Moreover, the present invention refers to a cross-linked polymer or a three-dimensional object obtained by the methods according to the present invention, and use of the polymer or the object as an antireflective coating, encapsulant for LEDs, microlense for CMOS image sensors, as optical material, as biomedical functional coating, packaging and textile, stents, scaffolds, dental applications, and as reversible adhesive for debond on demand applications.

[Problem] To provide a radiation curable resin composition that is suitable as a primary material of an optical fiber and has a fast curing rate by irradiation with radiation.

[Solution] A radiation polymerizable composition for forming a primary coating layer of an optical fiber, the radiation polymerizable composition comprising: (A) a urethane oligomer comprising a structure represented by formula (I) below:

##STR00001## wherein R is a vinyl group and * is a bond; (B) one or more compounds of: (i) maleic anhydride, (ii) a compound represented by formula (II):

##STR00002## wherein R.sup.1 is a single bond or an alkanediyl group comprising 1 to 6 carbon atoms, and R.sup.2 is a hydrogen atom, a hydroxy group, or a group represented by predetermined formula (II-1) or formula (II-2), or (iii) a compound represented by formula (III):

##STR00003## wherein R.sup.5 is an alkanediyl group comprising 1 to 6 carbon atoms; and (C) a radiation polymerization initiator.

[Problem] To provide a radiation curable resin composition that is suitable as a primary material of an optical fiber and has a fast curing rate by irradiation with radiation.

[Solution] A radiation polymerizable composition for forming a primary coating layer of an optical fiber, the radiation polymerizable composition comprising: (A) a urethane oligomer comprising a structure represented by formula (I) below:

##STR00001## wherein R is a vinyl group and * is a bond; (B) one or more compounds of: (i) maleic anhydride, (ii) a compound represented by formula (II):

##STR00002## wherein R.sup.1 is a single bond or an alkanediyl group comprising 1 to 6 carbon atoms, and R.sup.2 is a hydrogen atom, a hydroxy group, or a group represented by predetermined formula (II-1) or formula (II-2), or (iii) a compound represented by formula (III):

##STR00003## wherein R.sup.5 is an alkanediyl group comprising 1 to 6 carbon atoms; and (C) a radiation polymerization initiator.

Processes for preparing a polymer polyol (PMPO) in which a base polyol is continuously produced in a continuous base polyol reactor, the base polyol is continuously discharged from the continuous base polyol reactor; the base polyol is continuously introduced to a continuous PMPO reactor, which is different from the continuous base polyol reactor, and PMPO is continuously removed from the PMPO reactor. Production plant configured to carry out such processes are also described.

Processes for preparing a polymer polyol (PMPO) in which a base polyol is continuously produced in a continuous base polyol reactor, the base polyol is continuously discharged from the continuous base polyol reactor; the base polyol is continuously introduced to a continuous PMPO reactor, which is different from the continuous base polyol reactor, and PMPO is continuously removed from the PMPO reactor. Production plant configured to carry out such processes are also described.

Compositions that are curable to polythioether polymers are provided, comprising: a) a dithiol monomer; b) a diene monomer; c) a radical cleaved photoinitiator; d) a peroxide; and e) an amine; where the peroxide and amine together are a peroxide-amine redox initiator. In some embodiments, the amine is a tertiary amine. In some embodiments, the amine is selected from the group consisting of dihydroxyethyl-p-toluidine, N,N-diisopropylethylamine, and N, N, N′, N″, N″-pentamethyl-diethylenetriamine. In some embodiments, the peroxide is selected from the group consisting of di-tert-butyl peroxide, methyl ethyl ketone peroxide, and benzoyl peroxide. In some embodiments, the composition may additionally comprise a polythiol monomer having three or more thiol groups.

Compositions that are curable to polythioether polymers are provided, comprising: a) a dithiol monomer; b) a diene monomer; c) a radical cleaved photoinitiator; d) a peroxide; and e) an amine; where the peroxide and amine together are a peroxide-amine redox initiator. In some embodiments, the amine is a tertiary amine. In some embodiments, the amine is selected from the group consisting of dihydroxyethyl-p-toluidine, N,N-diisopropylethylamine, and N, N, N′, N″, N″-pentamethyl-diethylenetriamine. In some embodiments, the peroxide is selected from the group consisting of di-tert-butyl peroxide, methyl ethyl ketone peroxide, and benzoyl peroxide. In some embodiments, the composition may additionally comprise a polythiol monomer having three or more thiol groups.

A curable composition for making polyisocyanurate comprising products obtained by combining and mixing at an isocyanate index of at least 100 at least a polyisocyanate composition, an isocyanate reactive composition comprising at least 50 mol % diols and a toughening agent comprising acrylic block copolymers.

Fiber coatings with low Young's modulus and high tear strength are realized with coating compositions that include an oligomeric material formed from an isocyanate, a hydroxy acrylate compound and a polyol. The oligomeric material includes a polyether urethane acrylate and a di-adduct compound, where the di-adduct compound is present in an amount of at least 2.35 wt %. The reaction mixture used to form the oligomeric material may include a molar ratio of isocyanate:hydroxy acrylate:polyol of n:m:p, where n may be greater than 3.0, m may be between n−1 and 2n−4, and p may be 2. Young's modulus and tear strength of coatings made from the compositions increase with increasing n. Coatings formed from the present oligomers feature high tear strength for a given Young's modulus.