A fiber sizing agent includes: a vinyl ester resin (A) having an alkoxy polyoxyalkylene structure and a urethane bond; and an aqueous medium. The fiber sizing agent has excellent fiber sizing properties for various fibers such as glass fibers and carbon fibers. A molded article obtained from a molding material including the fiber sizing agent is excellent in various physical properties such as bending strength, compressive strength, and interlaminar shear strength, and thus can be used, for example, for an automobile member, an aircraft member, a windmill member, and an industrial member.

The present invention is directed to a two-component (2K) curable composition comprising: a first component comprising, based on the weight of the component: from 80 to 100 wt. % of a) i) at least one partially (meth)acrylated epoxy resin; and, from 0 to 20 wt. % of a) ii) at least one epoxy resin distinct from said resin a) i); and, a second component comprising b) at least one polyamine having at least two amine hydrogens reactive toward epoxide groups, wherein said curable composition is characterized by a ratio of the amine hydrogen equivalent of said at least one polyamine (b) to the total equivalents of epoxy groups and acrylate groups of said first component (a) of from 0.5:1 to 1.05:1.

A method for improving corrosion resistance of vinyl ester resin is provided, which belongs to the technical field of polymer materials. The method includes adding vinyl ester resin into a MXene nanosheet solution and evaporating the solvent; then adding cobalt isooctoate promoter and butanone peroxide initiator in sequence, standing for curing after defoaming, and then heating.

This invention outlines a method for synthesizing a blended resin system in a one pot reaction that may utilize, for example, bio-based anhydrosugars such as isosorbide as a principle component to produce isosorbide dimethacrylate and other monomeric materials for thermosetting applications. This invention establishes a one-pot procedure for reacting a hydroxy group containing compound with methacrylic anhydride in the first step and using the by-product methacrylic acid to react with glycidyl ethers to form additional methacrylate compounds in the second step. This methodology can be formulated to produce a wide array of resin systems that have controlled ratios of hydroxy group containing compound/cross-linker/reactive diluent. Additionally, the novel resin systems may be partially to fully bio-based, promoting global sustainability and reducing costs, and when free radically polymerized have properties that meet or exceed their petroleum derived counterparts.

Compositions and methods for forming epoxy resin systems are provided. In one embodiment, a composition is provided for an epoxy resin system including a liquid epoxy resin component including a liquid epoxy resin and an acrylate monomer, a curing agent component including a compound having an imidazole group and, optionally, a co-curing agent for the compound having an imidazole group comprising a phenolic monomer compound, a branched chain carboxylic acid, and combinations thereof, and a non-aromatic polyol compound. The composition may be used to form composites, such as used in commercial wind turbine blade manufacturing.

A resin composition is based on a resin chosen from the group consisting of unsaturated polyester resins and vinyl ester resins, a crosslinking initiator and a crosslinking agent of general formula R.sub.1—X—R.sub.2, in which X is an optionally substituted alkylene group and R.sub.1 and R.sub.2 are, independently of one another, an acrylate, methacrylate or vinyl group, an alkenyl group bearing an unsaturated carbon at the chain end, or an alkynyl group bearing an unsaturated carbon at the chain end.

A resin composition is based on a resin selected from the group consisting of vinyl ester resins and unsaturated polyester resins, a crosslinking initiator and a crosslinking agent of general formula (I)

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in which i is an integer between 2 and 4, X is an i-valent group comprising at least one ring of 6 atoms selected from carbon and nitrogen and comprising at least 2 heteroatoms selected from nitrogen and oxygen, and R is an acrylate group, methacrylate group, vinyl group, alkenyl group bearing an unsaturated carbon at the chain end, or alkynyl group bearing an unsaturated carbon at the chain end.

The present invention provides a solvent-free varnish composition, including: a thermosetting resin (A) having two or more (meth)acryloyl groups in a molecule thereof; a thermosetting resin (B) having one or more epoxy groups in a molecule thereof; a monofunctional vinyl-based monomer having an ether bond or an ester bond; an organic peroxide having a 10-hour half-life temperature of 40° C. or more; and a curing catalyst for an epoxy resin, in which a mixed resin of the thermosetting resin (A) and the thermosetting resin (B) has an epoxy equivalent of from 500 to 5,000. The solvent-free varnish composition can be used as an insulating varnish that shows a small energy loss and requires a short curing time in its curing treatment step, and that provides a cured product that barely causes the precipitation of an oligomer or the like even when exposed to a refrigerant-based environment containing a refrigerant and a refrigerating machine oil under high temperature and high pressure.

The thermosetting resin composition according to an embodiment of the present invention contains a component (A) which is a novolac vinyl ester resin having a hydroxyl group and an ethylenically unsaturated group in the molecule, a component (B) which is an ethylenically unsaturated monomer, and a component (D) which is a polyisocyanate compound, wherein the component (A) has a hydroxyl value of 30-150 mgKOH/g, and the mole number of the hydroxyl group with respect to the mole number of the ethylenically unsaturated group per gram of the component (A) ((the amount of the hydroxyl group [mol/g])/(the amount of the ethylenically unsaturated group [mol/g])) is 0.1-0.8.

The invention provides highly functional epoxy resins that may be used themselves in coating formulations and applications but which may be further functionalized via ring-opening reactions of the epoxy groups yielding derivative resins with other useful functionalities. The highly functional epoxy resins are synthesized from the epoxidation of vegetable or seed oil esters of polyols having 4 or more hydroxyl groups/molecule. In one embodiment, the polyol is sucrose and the vegetable or seed oil is selected from corn oil, castor oil, soybean oil, safflower oil, sunflower oil, linseed oil, tall oil fatty acid, tung oil, vernonia oil, and mixtures thereof. Methods of making of the epoxy resin and each of its derivative resins are disclosed as are coating compositions and coated objects using each of the resins.