Showing papers on "Terephthalic acid published in 2000"

Low melt viscosity amorphous copolyesters with enhanced glass transition temperatures having improved gas barrier properties

Abstract: An amorphous copolyester having a maximum melt viscosity at 1 radian/second and at about 260 to about 290° C. of about 12000 poise, a glass transition temperature ranging from about 88° C. to about 120° C., and an inherent viscosity of at least about 0.6 dl/g. The amorphous copolyesters comprise the reaction product of a diol component and a dicarboxylic acid component. The diol component comprises residues of from about 5.0 to about 50 mole % of 2,2′-(sulfonylbis (4,1-phenyleneoxy))-bis(ethanol) which has the following chemical formula: and from about 50 to about 95 mole % of a mixture of at least two diols selected from the group consisting of ethylene glycol, neopentyl glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and mixture thereof. The dicarboxylic acid component comprises residues of terephthalic acid, isophthalic acid, 1,4-cyclohexandedicarboxylic acid, 2,6-naphthalene dicarboxylic acid and mixtures thereof. The amorphous copolyesters according to the invention have relatively low melt viscosities and relatively high glass transition temperatures. Because of the low melt viscosities and high glass transition temperatures, copolyesters with increased IV or molecular weight can easily be obtained. The copolyesters according to the invention can be used for molded or extruded articles, sheets, and films. Accordingly, the invention also relates to molded and extruded articles, sheets, and films made from a copolyester as described above. Additionally, articles, sheets, and films according to the invention have improved gas barrier properties such that they may be used for packaging perishable goods, such as beverages, foods and cosmetics, as well as other oxygen sensitive products such as inks and adhesives.

Selected cyclohexane-1,3- and 1,4-dicarboxylic acid esters

Abstract: The invention relates to selected cyclohexane-1,3- and 1,4-dicarboxylic acid esters, to their use as plasticizers in synthetic materials and to their production The inventive method of production comprises hydrating the corresponding isophthalic acid and terephthalic acid esters by contacting one or more of such isophthalic acid or terephthalic acid esters with a hydrogen-containing gas in the presence of a catalyst Said catalyst contains as the active metal at least one metal of subgroup VIII of the periodic system alone or together with at least one metal of subgroup I or VII of the periodic system, applied on a substrate The inventive method is further characterized in that the substrate is macroporous

Continuous process for producing poly(trimethylene terephthalate)

Abstract: A continuous process for the production of poly(trimethylene terephthalate) is disclosed. According to the process, a liquid feed mixture comprising bis-3-hydroxypropyl terephthalate and/or low molecular weight polyesters of 1,3-propanediol and terephthalic acid, the liquid feed mixture having a mole ratio of propylene groups to terephthalate groups of 1.1 to 2.2 is fed to a flasher. A first stream of gaseous by-products is continuously vaporized and removed from the flasher, and a liquid flasher reaction product having a mole ratio of propylene groups to terephthalate groups of less than about 1.5 is continuously withdrawn from the flasher. The liquid flasher reaction product is continuously fed to a prepolymerizer where it is continuously polymerized to form a poly(trimethylene terephthalate) prepolymer and a second stream of gaseous by-products. Poly(trimethylene terephthalate) prepolymer having a relative viscosity of at least about 5 is continuously withdrawn from the prepolymerizer and continuously fed to a final polymerizer, where it is continuously polymerized to form a higher molecular weight poly(trimethylene terephthalate) and a third stream of gaseous by-products. Higher molecular weight poly(trimethylene terephthalate) having a relative viscosity of at least about 17 is continuously withdrawn from the final polymerizer.

Polyester resin and its production process

Abstract: A polyester resin which is excellent in the color tone and the transparency, which has a low acetaldehyde content, and further, which is excellent also in the thermal stability and of which the increase in the acetaldehyde content during e.g. the melt molding is reduced, is provided. A polyester resin produced by polycondensing a dicarboxylic acid component containing terephthalic acid as the main component and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table, (2) a magnesium compound and (3) a phosphorus compound, via an esterification reaction, characterized in that the contents as atoms derived from the respective compounds (1), (2) and (3) satisfy the following formulae (I) to (V), where the total amount of titanium group atoms of the compound (1) is T (mol/ton resin), the total amount of magnesium atoms of the compound (2) is M (mol/ton resin) and the total amount of phosphorus atoms of the compound (3) is P (mol/ton resin): 0.020≦T≦0.200 (I) 0.040≦M≦0.400 (II) 0.020≦P≦0.300 (III) 0.50≦M/P≦3.00 (IV) 0.20≦M/T≦4.00 (V)

Method of preparing modified polyester bottle resins

Abstract: The present invention is a method of preparing a high molecular weight copolyester bottle resin that has excellent melt processing characteristics. The method includes the steps of reacting a diacid or diester component and a diol component to form modified polyethylene terephthalate, wherein diol component is present in excess of stoichiometric proportions. Together, the diacid or diester component and the diol component must include at least 7 percent comonomer. The remainder of the diacid component is terephthalic acid or dimethyl terephthalate and the remainder of the diol component is ethylene glycol. The modified polyethylene terephthalate is copolymerized in the melt phase to an intrinsic viscosity of between about 0.25 dl/g and 0.40 dl/g to thereby form a copolyester prepolymer. Thereafter the copolyester prepolymer is polymerized in the solid phase to form a high molecular weight bottle resin that has an intrinsic viscosity of at least about 0.70 dl/g, and a solid phase density of less than 1.413 g/cc.

Phthalic Acids and Other Benzenepolycarboxylic Acids

Abstract: There are 11 benzenepolycarboxylic acids, some of which are sold as the anhydride or the methyl ester. Two of these substances, terephthalic acid and phthalic anhydride, are principal chemical products. Two others, isophthalic acid and trimellitic anhydride, have substantial commercial sales. The rest have low volume specialized applications or are not available commercially. This is a review of the basic physical properties, manufacturing methods, production volumes and prices, toxicological aspects, and uses of these compounds. Terephthalic acid and its dimethyl ester rank about tenth in tonnage for all organic chemicals, and production is expanding substantially. They are used to make poly(ethylene terephthalate) for fibers, film, and containers. The principle mode of commercial manufacture is direct liquid-phase oxidation of p-xylene using a homogeneous heavy metal–bromine catalyst system. Isophthalic acid and trimellitic anhydride are made from m-xylene and pseudocumene respectively using the same process. Phthalic anhydride is made primarily by gas-phase oxidation of o-xylene over a fixed catalyst containing vanadium and titanium oxides. It is used as a raw material for plasticizers, unsaturated polyesters, and other resins. Keywords: Phthalic acid; Phthalic anhydride; Heat stability; Plasticizers; Terephthalic acid; Dimethyl terephthalate; Saturated polyesters; Poly(ethylene terephthalate); Phthalic acids; Mellophanic acid; Prehnitic acid; Trimesic acid; Trimellitic acid; Anhydrides; Mellitic acids

Preparation of poly(trimethylene terephthalate) with low level of di(1,3-propylene glycol)

Abstract: A process of preparing poly(trimethylene terephthalate) containing less than 2.0 mole % of DPG comprising: (a) providing a molar amount of 1,3-propanediol: C1 to C4 dialkyl ester of terephthalic acid of 1.2:1 to 1.9:1, (b) reacting the 1,3-propanediol with the C1 to C4 dialkyl ester of terephthalic acid to form bis(3-hydroxypropyl)terephthalate monomer in the presence of 10-100ppm (as titanium metal) of an organic titanate catalyst, by weight of the poly(trimethylene terephthalate), and (c) polymerizing the bis(3-hydroxypropyl)terephthalate monomer to obtain the poly(trimethylene terephthalate); and poly(trimethylene terephthalate) produced by the process.

Process for the recovery of crude terephthalic acid (cta)

Abstract: The present invention relates to a process for the preparation of crude terephthalic acid which comprises first introducing a slurry containing crystallized terephthalic acid with impurities in an aliphatic carboxylic acid mother liquor into a rotary filter comprising a case and a rotating drum, wherein the rotating drum is subjected to a uniform pressure differential over the entire drum, and the inside of the drum is at a pressure approximately equal to atmospheric pressure or greater, then filtering said slurry; and finally collecting at least some of the solid portion. Other aspects of the invention include continuously adding the original slurry to the rotary filter and washing the solid portion with additional aliphatic carboxylic acid, water or a combination of the two. The solid portion can then be transferred to a reslurry tank which is at the same pressure as the pressure at the point where the solid portion was collected. The present invention also relates to a process for the preparation of crude terephthalic acid which comprises first introducing a slurry containing crystallized terephthalic acid with impurities in an aliphatic carboxylic acid mother liquor into a rotary filter comprising a case and a rotating drum, wherein the rotating drum is subjected to a uniform pressure differential over the entire drum, then filtering said slurry, washing the solid portion with water; and finally collecting at least some of the solid portion. Other aspects of the invention include continuously adding the original slurry to the rotary filter and additional washing with the aliphatic carboxylic acid mother liquor. The inside of the drum can be less than, greater than or approximately equal to atmospheric pressure. The solid portion can then be transferred to a reslurry tank which is at the same pressure as the pressure at the point where the solid portion was collected.

Thermoplastic resin composition

Abstract: PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition which is excellent in thermal moldability, impact resistance, flame retardance, and heat resistance and does not exhibit discoloration even after thermal molding by mixing a polycarbonate resin with a polyester resin prepared by the polycondensation of a dicarboxylic acid component and a glycol component and adding a phosphonoacetate compound to the resultant resin mixture. SOLUTION: A polyester resin prepared by the polycondensation of a dicarboxylic acid component comprising terephthalic acid or its derivative and a glycol component containing at least 40 mol% 1,4-cyclohexanedimethanol is mixed with a polycarbonate resin having a viscosity average mol.wt. of 20,000-30,000, in a wt. ratio of (90/10)-(10/90). The objective thermoplastic resin composition is prepared by adding 0.01-2 pts.wt. at least one phosphonoacetate compound represented by formula I (wherein R1 and R2 are each H or alkyl; and n is 1 or 2), perferably one represented by formula II, to 100 pts.wt. above- prepared resin mixture.

Method for preparing polyester resin copolymerized with 1,4-cyclohexanedimethanol

Abstract: Disclosed is a method for preparing polyester resins copolymerized with 1,4-cyclohexanedimethanol. In the preparation method, ethylene glycol and 1,4-cyclohexanedimethanol are fed with the molar ratio of the whole glycol component to terephthalic acid ranging from 1.3 to 3.0, and then esterified. Then, the esterified reaction product is polycondensed in the presence of titanium-based compound as a polycondensation catalyst and carboxy phosphonic acid typed compound represented by formula I below as a stabilizer, to give the polyester resins of the present invention having excellent clarity and good color: wherein R1, R2 and R3, which are the same or different, each being selected from the group consisting of hydrogen, alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 1 to 10 carbon atoms and aryl groups having 6 to 10 carbon atoms; and R is selected from the group consisting of alkylene groups having 1 to 10 carbon atoms, cycloalkylene groups having 1 to 10 carbon atoms, and arylene groups having 6 to 10 carbon atoms.

Copolyether composition and processes therefor and therewith

Abstract: A copolyether composition that can be used to produce a dyeable polyester is provided. The composition can comprise repeat units derived from a first diol such as, for example, 1,3-propanediol and a sulfonated dicarboxylic acid such as, for example, 5-sulfo-isophthalic acid. The dyeable polyester composition can comprise repeat units derived from the copolyether composition, an acid such as, for example, terephthalic acid, and a second diol such as, for example, 1,3-propanediol. Also disclosed is a process that can be used for producing the copolyether composition. The process comprises contacting the first diol with the sulfonated dicarboxylic acid. Further disclosed is a process that can be used for producing the dyeable composition in which the process comprises (1) contacting, in the presence of a catalyst, the copolyether composition with a diol such as, for example, 1,3-propanediol, and a dicarboxylic ester such as, for example, dimethylterephthalate or (2) contacting an acid such as for example, terephthalic acid and a diol such as, for example, 1,3-propanediol to produce an intermediate and thereafter contacting the intermediate with the copolyether.

Method for hydrogenating terephthalic acid

Abstract: PROBLEM TO BE SOLVED: To circulate a solvent for use when 1,4-cyclohexanedimethanol is produced from terephthalic acid. SOLUTION: The concentration of a 6-10C aliphatic alcohol in a 1,4- cyclohexanedicarboxylic acid solution produced by hydrogenating the terephthalic acid is adjusted to <=0.2 wt.% in the method for hydrogenating the terephthalic acid comprising reacting the terephthalic acid with hydrogen in the presence of the solvent and a palladium catalyst, producing the 1,4- cyclohexanedicarboxylic acid, further reacting the resultant reactional product liquid with hydrogen, producing the 1,4-cyclohexanedimethanol, extracting the 1,4-cyclohexanedimethanol from the reactional product liquid with the 6-10C aliphatic alcohol and circulating the solvent discharged from the extraction step as the solvent for hydrogenating the terephthalic acid for use.

Process for profile extrusion of a polyester

Abstract: In a process for producing a profile by profile extrusion, a melt of a polyester composition is extruded through a die to form a profile. The processability of the polyester composition is improved by the addition of a branching agent, which provides increased melt strength and increased high shear thinning. The polyester composition has an inherent viscosity of at least 0.65 dl/g. The diacid component of the polyester composition has from 100 to 98.0 mole percent of residues of a primary acid selected from terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid and mixtures thereof. The glycol component of the polyester composition has from 100 to 98.0 mole percent of residues of a primary glycol selected from ethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, and mixtures thereof. The polyester composition has from 0.05 to 2.0 mole percent of residues of the branching agent selected from an acidic branching agent with a tri-functional or greater monomer, an alcoholic branching agent with a tri-functional or greater monomer, and mixtures thereof. The branching agent is present as part of either the diacid component or glycol component depending on whether the functionality is acidic or alcoholic, respectively.

Aqueous biphasic hydroformylation

Abstract: What has to be achieved to combine the major important advantages of homogeneous and heterogeneous catalysis? It seems to be a non-complex problem with a simple solution: find a way of separating the catalyst and the reaction products under mild conditions that is ecologically as well as economically efficient However, to get there is not that simple Normally the organometallic catalysts applied in solution are not very stable against high temperatures, water or oxygen Usually, reaction products, especially bulk chemicals, are separated in two ways Firstly, by gas phase separation technologies like distillation as applied for eg the synthesis of acetic acid by the carbonylation of methanol or the hydroformy lation of alkenes to aldehydes Secondly, by reaction conditions that keep the reaction partners, starting materials, and the products in the gas phase as eg for the gas phase process for the production of phthalic anhydride In the case of the production of terephthalic acid the product is insoluble in the reaction medium acetic acid, in which the Co and Mn based oxidation catalyst are dissolved This way it is possible to separate the product from the catalyst solution by simple filtration However, such beneficial circumstances occur rather seldom, as mixtures of liquid reaction media and liquid products are the rule Thus it is a major step forward if catalytic reactions can be performed in liquid multi-phase systems with clean and fast separation of

Method for producing high-purity terephthalic acid

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing high-purity terephthalic acid without deteriorating its quality in which the amount of virgin water used in the process is reduced. SOLUTION: This method for producing high-purity terephthalic acid comprises the following process: p-xylene is oxidized by molecular oxygen in a liquid phase to obtain a reaction product containing crude terephthalic acid, which is then further oxidized by molecular oxygen at a temperature higher than that of the first oxidation without feeding any additional p-xylene to produce a slurry containing higher-purity terephthalic acid. Terephthalic acid is then separated as solid from the slurry and dissolved in a water- containing liquid to produce a solution, which is hydrogenated in the presence of a catalyst. The reaction product yielded is subjected to solid/liquid separation, thus obtaining high-purity terephthalic acid. Furthermore, at least part of the liquid component of the solid/liquid separation is returned to the hydrogenation process.

Copolyesters of 1,3-propanediol having improved gas barrier properties

Abstract: The invention relates to a copolyester having an inherent viscosity ranging from about 0.4 to about 1.4 dl/g and a cold crystallization temperature ranging from about 120 to about 160 °C. Such copolyesters comprise the reaction product of a glycol component comprising from about 85 to about 100 mole % of 1,3-propanediol, a dibasic acid component comprising from about 85 to about 100 mole % of a dibasic acid selected from terephthalic acid, napthalenedicarboxylic acid, anhydrides, acid chlorides, and lower alkyl esters thereof, and mixtures thereof, and from about 5 to about 15 mole % of a comonomer. The presence of the comonomer lowers the crystallization temperature of the copolyesters according to the invention such that amorphous preforms can be easily molded from the copolyesters. Such amorphous preforms are readily stretch blow molded into bottles or other container shapes or may be injection molded into various shapes or objects or extruded into film or sheeting. Accordingly, in another embodiment the invention relates to film and containers prepared from the copolyester composition described above. The films and containers according to the invention have improved gas barrier properties such that they may be used for packaging perishable goods, such as beverages, foods, and cosmetics.

Polyester-based resin composition and method for producing sheet

Abstract: PROBLEM TO BE SOLVED: To provide a polyester resin composition wherein peelability from a calender roll, resistance to embossing heat and solvent resistance are imparted by blending a specific resin and compound in a polyester resin composition having a specific amorphous or low-crystallinity polyester resin as main ingredients. SOLUTION: The polyester resin composition is characterized in that an organic phosphotriester compound of 0.1-3 pts.wt. as a lubricant is blended with respect to a polyester resin component of 100 pts.wt. The component comprises an amorphous or low-crystallinity polyester resin of 60-95 wt.%, which is composed of a dicarboxylic acid component having terephthalic acid as a main ingredient and a diol component comprising 1,4-cyclohexane dimethanol of 15-80 mol% and ethylene glycol of 20-85 mol%, and at least one high-crystallinity polyester resin of 5-40 wt.% selected from polybutylene terephthalate resin and polyethylene terephthalate resin. COPYRIGHT: (C)2002,JPO

Process for producing pure terephthalic acid with improved recovery of precursors, solvent and methyl acetate

Abstract: Process for producing pure terephthalic acid having improved means for recovering and/or recycling terephthalic acid precursors, residual acetic acid and other reaction by-products, such as methyl acetate.

Process for producing alkyd resin

Abstract: A process in which a polyester resin which is derived from starting materials containing terephthalic acid as a main component and is a regenerated resin recovered from wastes is depolymerized and esterified using a mixture of a polyhydric alcohol ingredient comprising a tetrahydric or higher alcohol, a fat and/or fatty acid, and a polybasic acid ingredient to thereby produce an alkyd resin in a short time.

Fused-ring and linking group effects of proton donors and acceptors on simple H-bonded liquid crystals

Abstract: Two fused-ring structures, 6-decyloxy-2-naphthoic acid C10ONA (3) and 6-dodecyloxyisoquinoline IS (8), were synthesized and utilized as proton donor and acceptor moieties to construct a series of simple mesogenic supramolecules. The other complementary hydrogen-bonded (H-bonded) moieties are benzoic acids, thiophenecarboxylic acid and pyridines containing different alkyl chain lengths connected by ether and ester linkages, i.e. 4-alkoxybenzoic acid C n OBA (1), terephthalic acid monoalkyl ester C n COOBA (2), 2,5-thiophenedicarboxylic acid monodecyl ester C10COOTHA (4), 4-alkoxypyridine C n OP (6) and isonicotinic acid alkyl ester C n COOP (7). Several series of simple mesogenic supramolecular dimers were constructed from 1:1 molar ratios of proton donors (C n OBA, C n COOBA, C10ONA and C10COOTHA) and proton acceptors (IS, C n OP and C n COOP), though the proton acceptor C n COOP induced phase separation in all complexes. In order to investigate their fused-ring and linking group effects on the mesogenic ...

Synthesis and characterization of new bivalent tin chelate of 3-hydroxy-2-methyl-4-pyrone and its use as catalyst for polyesterification

Abstract: We describe here the synthesis of a new tin chelate Sn(C6H5O3)2.2H2O. The catalytic performance of this chelate is shown for polyesterification reactions involving terephthalic acid and poliols, such as neopentylglygol and trimetilolpropane. The complex is highly active for low molecular weight (Mn= 1700 and Mw= 4500) polymer formation. IR spectra also show free OH in the polymer chain.