A resin composition that has good heat resistance and handleability and that can produce a prepreg which has a good balance between tackyness and drapability and which causes little resin flow during prepreg molding, a prepreg that is manufactured using the resin composition, and a fiber-reinforced composite are provided. A resin composition that contains a maleimide compound, diallyl bisphenol A, and a diallyl isophthalate polymer, a prepreg in which reinforcing fibers are impregnated with the resin composition, and a fiber-reinforced composite material that is obtained by molding the prepreg are provided.

A functionalized carbon fiber having covalently bound on its surface a sizing agent containing epoxy groups, at least some of which are engaged in covalent bonds with crosslinking molecules, wherein each of said crosslinking molecules possesses at least two epoxy-reactive groups and at least one free functional group reactive with functional groups of a polymer matrix in which the carbon fiber is to be incorporated, wherein at least a portion of said cros slinking molecules are engaged, via at least two of their epoxy-reactive groups, in crosslinking bonds between at least two epoxy groups of the sizing agent. Composites comprised of these functionalized carbon fibers embedded in a polymeric matrix are also described. Methods for producing the functionalized carbon fibers and composites thereof are also described.

A method, according to one embodiment, depolymerizes waste polyester by means of a multi-step reaction, wherein a latter reaction is carried out at a low temperature, and ion exchange, etc., is further carried out, thereby enabling the provision of high-purity and high-quality recycled bis(2-hydroxyethyl) terephthalate having reduced generation of diethylene glycol-derived impurities and oligomers.

Through a transesterification reaction in which a predetermined amount of bis(2-hydroxyethyl)terephthalate relative to glycol is fed in a divided or continuous manner, bis(glycol)terephthalate with a low residual amount of an ethylene glycol derivative is prepared, and polyester engineering products or biodegradable polyester products with high crystallinity can be produced therefrom.

A composition with improved adhesive and sealant properties comprises a) a pre-polymer comprising a polymeric unit of the general formula (-A-B-).sub.n, wherein A represents a substituted or un-substituted ester, B represents a substituted or un-substituted acid ester comprising at least two acid ester functionalities, and n represents an integer greater than 1; wherein the content of grafted anhydride in the composition is less than 0.05 mol/mol of polyacid.

In an aspect, a method for reducing the molecular weight of a polyester comprises extruding a composition comprising a chain scission agent and a polyester in a molten state to form a modified polyester. The chain scission agent can comprise a C.sub.2-12 diol and can be present in an amount of 0.1 to 5 weight percent based on the total weight of the composition. The polyester can comprise a C.sub.2-12 alkyl phthalate polyester having a weight average molecular weight, Mwi, of 15,000 to 100,000 g/mol based on polystyrene standards. The modified polyester can have a weight average molecular weight, Mw.sub.f, of at least 5% less than the weight average molecular weight of the polyester.

An object of the present invention is to provide an aqueous dispersion composition containing polyester resin having high storage stability, film-forming properties, tackiness, adhesiveness, and water resistance. An aqueous dispersion composition containing polyester resin, comprises, a polyester resin (A), a coalescing aid (B), and an aqueous medium (C), wherein the coalescing aid (B) has a Hansen solubility parameter with a dispersion term (d) of 15.4 MPa.sup.0.5 or more and less than 18.0 MPa.sup.0.5, a polarization term (p) of 4.1 MPa.sup.0.5 or more and less than 9.1 MPa.sup.0.5, and a hydrogen bond term (h) of 7.0 MPa.sup.0.5 or more and less than 12.3 MPa.sup.0.5.

A thermosetting composition having: I) an unsaturated curable polyester comprising the residues of an ,-unsaturated polycarboxylic acid compound, said ,-unsaturated polycarboxylic acid compound having at least two carboxylic acid groups or at least one anhydride group, and having at least one unsaturation in a position that is , relative to a carbonyl group and not located on an aromatic ring; and II) a phenolic resin having at least one methylol group. The unsaturated curable polyester resin can be dispersed in water or dissolved in a solvent and is suitable for waterborne or solventborne coating compositions. Phenolic based crosslinking coating compositions that contain these unsaturated curable polyester resins are curable at elevated temperatures.

The invention relates to the use of at least one mixed mineral organoclay rheology additive, which comprises or consists of a quaternary alkyl-ammonium salt treated mineral clay mixture prepared by forming an aqueous hormite clay slurry (a), forming an aqueous smectite clay slurry (b), combining the aqueous hormite clay slurry (a) with the aqueous smectite clay slurry (b) to form a combined clay slurry (c), treating the combined clay slurry (c) with one or more quaternary alkyl-ammonium salts, and separating the thus produced quaternary alkyl-ammonium salt treated mineral clay mixture from the aqueous medium. The invention also relates to a process for producing a mixed mineral organoclay rheology additive and the use of the thus produced additive as a thickening agent in liquid compositions.

A functionalized carbon fiber having covalently bound on its surface a sizing agent containing epoxy groups, at least some of which are engaged in covalent bonds with crosslinking molecules, wherein each of said crosslinking molecules possesses at least two epoxy-reactive groups and at least one free functional group reactive with functional groups of a polymer matrix in which the carbon fiber is to be incorporated, wherein at least a portion of said crosslinking molecules are engaged, via at least two of their epoxy-reactive groups, in crosslinking bonds between at least two epoxy groups of the sizing agent. Composites comprised of these functionalized carbon fibers embedded in a polymeric matrix are also described. Methods for producing the functionalized carbon fibers and composites thereof are also described.