A method of forming a polymer includes polymerizing a first pre-polymer, produced by the reaction of a dicarboxylic acid, or ester thereof with a first alkylene diol; with a second pre-polymer produced by the reaction of an aromatic sulfonate or a salt thereof, or ester thereof, with a second alkylene diol; to form a metal sulfonate co-polymer; reacting the metal sulfonate co-polymer with a fast crystallizing polyester block having a degree of polymerization of at least about 20 to provide an amorphous sulfonated co-polyester; and crystallizing the amorphous sulfonated co-polyester to form a crystallized sulfonated co-polyester.

The present invention relates to a process for preparing transparent polybutylene naphthalate polyester, for improving barrier performance of polyesters used in making of monolayer or multilayer containers, comprising steps of: a) mixing butane diol with polymerization catalysts, monoethylene glycol, color toner, and at least one crystallization suppressing agent, wherein said crystallization suppressing agent controls the rate of crystallization so as to control size and shape of crystals to ensure transparency; b) reacting said mixture with naphthalene dicarboxylic acid or ester thereof to obtain oligomerized product via esterification or ester interchange; c) polymerizing said oligomer using at least one polymerization catalyst to obtain amorphous polybutylene naphthalate polyester chips; d) crystallizing said polybutylene naphthalate polyester chips; and e) subjecting said polyester chips to solid state polymerization to upgrade the intrinsic viscosity (I.V.) up to more than 0.40 dl/gm.

The present invention relates to a process for preparing transparent polybutylene naphthalate polyester, for improving barrier performance of polyesters used in making of monolayer or multilayer containers, comprising steps of: a) mixing butane diol with polymerization catalysts, monoethylene glycol, color toner, and at least one crystallization suppressing agent, wherein said crystallization suppressing agent controls the rate of crystallization so as to control size and shape of crystals to ensure transparency; b) reacting said mixture with naphthalene dicarboxylic acid or ester thereof to obtain oligomerized product via esterification or ester interchange; c) polymerizing said oligomer using at least one polymerization catalyst to obtain amorphous polybutylene naphthalate polyester chips; d) crystallizing said polybutylene naphthalate polyester chips; and e) subjecting said polyester chips to solid state polymerization to upgrade the intrinsic viscosity (I.V.) up to more than 0.40 dl/gm.

Copolyesters such as polyethylene terephthalate (PET) or polyethylene furanoate (PEF) modified with bifuran polyacids such as dimethyl-2,2′-bifuran-5,5′-dicarboxylate (BFE), 2,2′-bifuran-5,5′-dicarboxylic acid (BDA), or bis(2-hydroxyethyl)-2,2′-bifuran-5,5′-dicarboxylate (BHEB), and/or bifuran polyhydroxyls, may have improved properties such as glass transition temperature (T.sub.g), tensile modulus, barrier properties, crystallinity, and/or impact strength. Polyethylene terephthalate-co-bifuranoate (PETBF) has an improved T.sub.g. Also described are polyethylene furanoate-co-bifuranoates (PEFBF).

Copolyesters such as polyethylene terephthalate (PET) or polyethylene furanoate (PEF) modified with bifuran polyacids such as dimethyl-2,2′-bifuran-5,5′-dicarboxylate (BFE), 2,2′-bifuran-5,5′-dicarboxylic acid (BDA), or bis(2-hydroxyethyl)-2,2′-bifuran-5,5′-dicarboxylate (BHEB), and/or bifuran polyhydroxyls, may have improved properties such as glass transition temperature (T.sub.g), tensile modulus, barrier properties, crystallinity, and/or impact strength. Polyethylene terephthalate-co-bifuranoate (PETBF) has an improved T.sub.g. Also described are polyethylene furanoate-co-bifuranoates (PEFBF).

The invention relates to the field of polymers and concerns a method for the crystallization of polyester. More particularly, it relates to a crystallization method that comprises a step of providing a polyester comprising at least one 1,4:3,6-dianhydrohexitol unit, and a step of crystallizing said semi-crystalline polyester, said method being characterized in that the crystallization step is performed at a pressure of at least 600 mbar absolute. The method according to the invention makes it possible to strongly limit, or even eliminate, the phenomenon of polyester expansion during crystallization. Advantageously, the elimination of the expansion phenomenon through pressure conditions implemented according to the invention thus makes it possible to dispense with obtaining very fragile empty spheres that break when agitated and thus cause the formation of undesirable fine particles.

The invention relates to the field of polymers and concerns a method for the crystallization of polyester. More particularly, it relates to a crystallization method that comprises a step of providing a polyester comprising at least one 1,4:3,6-dianhydrohexitol unit, and a step of crystallizing said semi-crystalline polyester, said method being characterized in that the crystallization step is performed at a pressure of at least 600 mbar absolute. The method according to the invention makes it possible to strongly limit, or even eliminate, the phenomenon of polyester expansion during crystallization. Advantageously, the elimination of the expansion phenomenon through pressure conditions implemented according to the invention thus makes it possible to dispense with obtaining very fragile empty spheres that break when agitated and thus cause the formation of undesirable fine particles.

The invention provides a laminated polyester film that is highly transparent, is resistant to blocking, and has excellent adhesion to a hardcoat layer and UV ink. The laminated polyester film contains a polyester film substrate and a coating layer on at least one surface of the polyester film substrate, wherein the coating layer is formed by curing a composition containing a urethane resin with a polycarbonate structure and a branched structure, a crosslinking agent, and a polyester resin.

The present invention provides laminated iron having excellent printability and a preparation method therefor. The laminated iron is prepared by using a mode of performing thermal-compounding on a polyester thin film having a durable and high surface tension force and a steel plate, wherein the polyester thin film is prepared by copolymerizing terephthalic acid, isophthalic acid, ethylene glycol and a fourth component and then bidirectionally stretching a co-polymer; a feeding mole ratio is that terephthalic acid:isophthalic acid:ethylene glycol:a fourth component=(135-165):(148-194):(11-15):(0.01-12); the fourth component is selected from one or more of isophthalic-5-sulfonate, 1,4-cyclohexane dimethanol, neo-pentanediol and trimellitic acid; and 800-2000 ppm of SiO.sub.2 in parts by mass is added to a copolymerized polyester by using a mode of in-situ polymerization. The laminated iron has excellent printability and satisfies usage requirements of packaging containers for food, beverage and the like.

The present invention provides laminated iron having excellent printability and a preparation method therefor. The laminated iron is prepared by using a mode of performing thermal-compounding on a polyester thin film having a durable and high surface tension force and a steel plate, wherein the polyester thin film is prepared by copolymerizing terephthalic acid, isophthalic acid, ethylene glycol and a fourth component and then bidirectionally stretching a co-polymer; a feeding mole ratio is that terephthalic acid:isophthalic acid:ethylene glycol:a fourth component=(135-165):(148-194):(11-15):(0.01-12); the fourth component is selected from one or more of isophthalic-5-sulfonate, 1,4-cyclohexane dimethanol, neo-pentanediol and trimellitic acid; and 800-2000 ppm of SiO.sub.2 in parts by mass is added to a copolymerized polyester by using a mode of in-situ polymerization. The laminated iron has excellent printability and satisfies usage requirements of packaging containers for food, beverage and the like.