MXPA96004005A

MXPA96004005A - Copolymers of polyester pirorretardan

Info

Publication number: MXPA96004005A
Application number: MXPA/A/1996/004005A
Authority: MX
Inventors: Asrar Jawed
Original assignee: Monsanto Company
Priority date: 1994-03-11
Filing date: 1995-03-03
Publication date: 1998-07-03

Abstract

The present invention relates to a linear, flame-retardant or slow-burning polyester characterized in that it comprises the product of: a polyester prepolymer, a hydroxyalkyl dicarboxylate compound having the general formula: HO. (CH2) nO-CO-R-CO -O- (CH2) n-OH wherein n is a number from 1 to 8, and a portion having the general formula: -C6H3R2) -R1- (C6H3R2) - and an amount of a flame retardant of a carboxy phosphinic acid which has the generic formula

Description

PIRQRRETARDANTS POLYESTER CQPQLIMERQS BACKGROUND OF THE INVENTION This invention relates to new, non-retardant polyester compositions. In particular, this invention relates to new flame retardant copolyesters and to a method for producing polyester compositions. More particularly, this invention relates to new flame retardant copolyesters produced from terephthalic acid, another portion dicarboxylates and carboxy phosphino acids, a process for producing the copolyesters and shaped articles produced from the copolyesters.

DESCRIPTION OF THE PREVIOUS TECHNIQUE One of the main uses of polyesters is the production of shaped polyester articles and woven and nonwoven textiles such as fabrics, filaments, short fibers or yarn and sheets. In recent years, efforts to make textiles less flammable, to improve the safety features of products such as clothing, bedding, home furniture, aircraft and automotive interior fabrics and industrial fabrics, have increased. It is also recognized that textiles can be blends, particularly mixtures of natural fibers, such as cotton and synthetic fibers, such as polyesters. There are several known methods for flame retardant textiles. United States Patent, 03Lt, 141 teaches the use of brominated phosphoramidates to treat combustible materials such as cotton fibers and synthetic fibers to impart flame retardant or slow burning properties. The flame retardant composition is applied by treating the fabric with a solution of the composition, drying the fabric and curing the composition. United States Patent 3, 969, 437 would teach the use of a specific class of cyclic phosphoric esters to prepare a flame retardant textile finish, durable for cotton-polyester blends. The phosphorus ester used must contain at least one primary alcohol group attached to the carbon and preferably two or more, plus a pentavalent phosphorus ester group. The surface treatment for imparting flame retardant characteristics, and even the mixture of the flame retardant compounds in hardened shaped compositions, has disadvantages. Surface treatments can be removed by cleaning and mixing compounds can be exuded or migrated from the product. Therefore, attempts have been made to overcome these disadvantages by the chemical formation of flame retardant compounds in the polyester.

U.S. Patent 3,922,323 teaches a process for improving the flame resistance of polyesters, especially unsaturated polyesters, by chemical bonding and / or by mixing organic phosphorus compounds 5 and, if desired, halogenated compounds in the polyesters. The halogen that contains, at least bicyclic phosphonic esters, which are free of hydroxy and carboxylic groups are those used. U.S. Patent 3,9M-1,752 describes a synthetic, flame-retardant, linear polyester modified with carboxyphosphonic acids. Linear polyester is the product of the polycondensation of a dicarboxylic acid, a diol and a flame retardant carboxy-phosphino acid monomer, which may contain heteroatoms. However, polyester has a low glass transition temperature. The need for polyester materials remains - flame retardants, which have a high vitreous transition temperature and which will maintain their flame retardant properties, throughout their useful life and for a process to produce such polyester.

BRIEF DESCRIPTION OF THE INVENTION It is an ob} of this invention, provide a flame retardant polyester material, a process for producing the polyester material and shaped articles produced from the polyether. It is another object of this invention to provide a flame retardant copolyester composition in which the flame retardant material is chemically bonded within the polymer structure. These and other objects are fulfilled by this invention, which is related to copolyesters of terephthalic acid, bis-hydroxyalkyl dicapboxylate and a carboxyphosphatic acid monomer, which have flame retardant properties and which have an intrinsic viscosity greater than about 0.6 and preferably within a range from about 0.6, to approximately 1.2, and a glass transition temperature greater than about 65 ° C. The bis-hydroxyalkylene dicarboxylate is preferably bis-β-hydroxyethyl bibenzoate or bis-β-hydroxyethyl naphthate and the carboxy-phosphinic acid opium is preferably 2-carboeti-1 (feni 1) Phosphine, or its cyclic anhydride. Dicarboxylate is copolymerized with carbo-1-phosphinic acid, terephthalic acid and ethylene glycol. The copolyester is preferably a polyethylene dicarboxylate copolyester having from 0 to about 99.9% and preferably from about 10% to about 90% by weight of polyethylene terephthalate.; from 0% to approximately rf lllt-Tl T! - •. ripf mn i ir l T i i-rac i ni-v 99.9% and preferably from approximately 10% to approximately 90% by weight of bis-hydroxyalkyl dicarboxylate; and from about 0.1% to about 10% by weight of the carboxy-phosphinic acid monomer. The copolyester is produced by placing the desired amounts of the terephthalic acid, hydroxyalkyl dicarboxylate, a diol such as ethylene glycol and carboxyphosphonic acid in a reactor filled with nitrogen in the presence of a catalyst, which is preferably based on antimony such as for example, antimony oxide. The reactor is heated to a temperature in the range of about 250 ° C to about 293 ° C, and preferably within the range of about 263 ° C to about 293 ° C for a period of about 3 hours. It is applied to vacuum slowly, to reduce the pressure to a pressure within the range of approximately 0.5 to approximately 1.0 mm of mercury. In addition to the polyethylene terephthalate copolyesters, the invention also includes copolyesters of other polyalkylene dicarboxylates such as polybutylene terephthalate and polyethylene naphthanate.

DESCRIPTION OF THE PREFERRED MODALITIES The present invention relates to copolyesters having flame retardant properties. The copolyesters of this invention have an intrinsic viscosity of greater than about 0.6, and preferably within the range of from about 0.6 to about 1.2. The copolyesters are preferably a polyethylene dicarboxylate copolyester having from 0% to about 99.9% and from? preferably from 10% to about 90% by weight of polyethylene terephthalate; from 0% to approximately 99.9% and more preferably from approximately 10% to approximately 90% by weight of another dicarboxylate portion, which is preferably a bis-hydraxalkyl bibenzoate and more preferably bis-bibenzoate. ß-hydro ieti lo; and from about 0.1% to about 10% by weight of a flame retardant carboxy-phosphinic acid monomer having the general formula: 0 0 H0-P-R-C-GH, wherein R is an open chain or cyclic, saturated alkylene radical having from one to about 15 carbon atoms, preferably from 2 to about 10 carbon atoms, or an aryl or aralkylene radical having 1 to about 15 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, 2-ethexylo, iso-octyl, decyl, isodecyl, dodecyl, tetradecyl, and R 1 is an alkyl radical having up to approximately 6 carbon atoms, an aryl radical or an alkaryl radical in which the alkyl substituent has from 1 to about 6 carbon atoms, such as, for example, methyl, ethyl and n-1; -propyl. The carboxy-phosphonic acid is preferably 2-carboxyethyl (phenyl) -fasfic acid, 2-carboxyethyl (meth il) phospholinic acid, cyclic anhydride of 2-carboxyethyl (phenyl) phosphinoic acid or the cyclic anhydride of 2-carboethyl (meth il) phosphinic acid. In the production of polyethylene terephthalate, a polyethylene terephthalate prepolymer is produced as the product of the reaction of 1.1 to 1.2 moles of ethylene glycol and 1.0 moles of terephthalic acid. The polyethylene terephthalate prepolymer generally has a viscosity of 0.2 or less. Similar poly-alkylene terephthalate prepolymers can be produced as the product of the reaction of 1.1 to 1.2 moles of an alkyldiol having from 3 to & carbon atoms and 1.0 mole of terephthalic acid. Similar prepolymers can also be produced with naphthatanes by replacing the terephthalic acid in the reaction with naphthalenedicarboxylic acid. The polyalkylene terephthalate prepolymers and the polyalkylene naphthate prepolymers can be considered as poly-ester prepolymers. The polymerization of 90% by weight of the polyethylene terephthalate prepolymer and 10% by weight of the 2-carboxyethyl (phenyl) fasphinic acid produced a flame-retardant polyester having an intrinsic viscosity of about 0.70. Nevertheless, the resulting polyester had a slight decrease in vitreous transition temperature, melting point and crystallinity when compared to polyethylene terephthalate, but the color of the polyester was better than the color of polyethylene terephthalate without the carboxyphosphinic acid. The glass transition temperature, the melting point and the crystallinity of the polyester can be adjusted to the desired levels by the addition of another dicarboxylate portion according to this invention. The dicarboxylate portion can be produced from any dicarboxylic acid, except unsubstituted terephthalic acid. In this way, the dicarboxylate moiety can be produced from an aliphatic group having 2 to about 12 carbon atoms, substituted or unsubstituted isophthalic acid, dicarboxylic acids, substituted or unsubstituted, of biphenyls, naphthalene , terphenyls and other polyaromatics such as, for example, diphenylether and substituted terephthalic acid. When a dicarboxylic acid other than unsubstituted terephthalic acid is reacted with the terephthalic acid and a diol such as ethylene glycol, the copolyesters of this invention are produced. If, for example, if a polyester having high vitreous transition temperature or other good high temperature properties is desired, then the dicarboxylate portion is preferably produced from an aromatic bis-hydroxyalkyl dicarboxylate. The preferred dicarboxylate moiety is produced from a hydroxyethyl dicarboxylate compound or another hydroxyalkyl dicarboxylate compound having the general formula: HO- (CHas) r, -C) -CO-R-CO-0- <; CHa) r, -OH wherein each n is independently a number between i and A, R is selected from the group consisting of aliphatic groups having from 2 to about 12 carbon atoms; substituted benzene, wherein the substituent is a halogen, an alkyl group having a carbon chain of 1 to about & carbon atoms, phenyl or a substituted phenyl group; naphthyl; substituted naphthyl, wherein the substituent is hydrogen, halogen, an alkyl group having a carbon chain of about 1 to about 2%; carbon atoms, a phenyl group or a substituted phenyl group; and a portion having the general formula: - (CAH3R ??) - R - (C? HaR = l) - wherein A is selected from the group consisting of nothing, oxygen, phenyl, substituted phenyl, an alkyl group which It has a carbon chain of 1 a & carbon atoms and -HC = CH- and wherein each R52 is independently selected from the group consisting of hydrogen, halogen, an alkyl group having a carbon chain having from 1 to about 6 carbon atoms, phenylene and phenyl replaced. More specifically, the dicarboxylate moiety is preferably produced from bis-β-hydroxyethyl bibenzoate. Although the dicarboxylate moiety is preferably a hydroxyethyl dicarboxylate compound, it is recognized that other hydroxyalkylene groups can be used and it is preferred that each of the alkyl groups be independently selected from the group consisting of alkyl radicals having from 1 to &; carbon atoms, such as, for example, the methyl, propyl, isopropyl, butyl, hexyl, 2-ethylbutyl, octyl and 2-ethylhexyl groups. The preferred dicarboxylate monomer is bis-β-hydroxyethyl bibenzoate; however, the bi-phenol portion is not required. As shown in the above, the copolyesters of this invention can be produced equally well from a naphthanate or other dicarboxylate such as, for example, bis-hydroxyethyl naphthana, bis-hydroxyethyl isophthalate and bis-hydroxyethyldifeni. léter. Although these examples are of dicarboxylates having the b is-hydraxyl groups, other hydroalkylaryl groups may be used such as, for example, bie-hydroxybutyl, bis-hydroxyhexyl and bis-hydroxyoctyl. The dicarboxylate portions used in the process have structures which will reinforce the polymer and impart rigidity to the polymer backbone. How 13 As a result the copoiiester will have a higher glass transition temperature and the tensile and flex properties of the polyester will be improved. When polyethylene naphthate or other dicarboxylates are used to produce copolyesters according to this invention, the resulting copolyesters have improved characteristics or performance properties, such as, for example, higher vitreous transition temperature. The flame retardant carboxy phospholinic acid monomer has the general formula: 0 0 HO - P - R - C - OH 15 wherein R is an open chain or cyclic, saturated radical having from one to about 15 carbon atoms, preferably from 2 to about 10 carbon atoms, '? < - * carbon, or an arylene or aralkylene radical having from about 15 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, 2-ylhexyl, iso- octyl, decyl, isodecyl, dodecyl, tetradecyl, -C ^ H., -, -C ^ H ^ -CHa. and CsH ^ -CHa.-CHa.-, and R is an alkyl radical having up to about 6 carbon atoms, an aryl radical or an alkaplo radical in which the alkyl substituent has from 1 to about 6 carbon atoms, such as, for example, methyl, ethyl and n- and i-propyl. The carboxy-phosphonic acid and preferably 2-carboxy i 1 (phenyl-1) phospholinic acid, 2-carboxyethyl-yl (meth yl) -phosphinoic acid, cyclic anhydride, 2-carboxylic acid (phenyl) phosphinoic acid or the cyclic anhydride of 2-carboxyethyl (me i 1) phospholinic acid. The preferred acid 2-carboxyethyl acid < phenyl) phosphonic, can be prepared in accordance with the teaching in U.S. Patent 4,061,462. The 2-carboxyethyl (phenyl) phosphinoic acid is prepared in two stages, i1, by first reacting the dichloro (phenyl) phosphine with acrylic acid employed at a molar excess of 25% to 4-5% to form a mixture of 3 intermediates, 3- (chlorophenylphosphinyl) propionyl chloride, 2-carboxyethyl (phenyl) phosphinoic acid cyclic anhydride and mixed anhydride of acrylic acid with 3-chlorocarbonylethyl 1- (phenyl-1) phospholinic acid. The second stage of the process is the hydrolysis of the mixture of the three intermediates, to obtain the desired product, 2-carboxy-yl (phenyl) -phosphinoic acid. The flame retardant copolyesters are preferably copolyethers of polyethylene dicarboxylate, having from about 99.9% to 0%, and preferably from about 90% to about 10% by weight of polyethylene terephthalate; from 0% to approximately 99.9%, from preferably from about 10% to about 90% by weight of another dicarbaxy lato portion; and from about 0.1% to about 10% of the flame retardant 2-carboxyethyl (fen i 1) phosphonic acid or its cyclic anhydride. The desired properties in the copolyester products will determine the amount of the other dicarboxylate portion included in the copolyester. Although the desired polyester of this invention can be produced by the polymerization from about 99.9% to about 90% by weight of the polyethylene terephthalate prepolymer and from about 0.1% to about t '. , 10% by weight of 2-carboxyethyl and 1 (phenyl) phosphinoic acid, the properties of the polyester can be improved by the addition of a hydroxyethylenisoate, preferably a bis-β-hydroxyethyl benzoate, to the polymerization to produce a copolyester. As the content of the bibenzoate increases In the case of bis-ß-hydroxylation, the flame-retardant properties of the carboxy-phosphonic acid increased surprisingly and the glass transition temperature of the copolyester increased. The expected decrease in reactivity during the polymerization reaction, which results from the addition of phosphinic acid instead carbonyl group was not observed. The high molecular weight of the polyester product indicated that the phosphinic acid group was highly reactive and the analysis of the final group does not show terminal phosphinic acid groups in a high proportion. In addition, the addition of phosphorus compounds usually create an observable, additional color in the product. Surprisingly, the addition of the carboxyphosphinoic acid in this invention allows the use of larger amounts of catalyst and still had less color in the product than the polyesters produced without the inlidic acid. Copolyesters of polyethylene terephthalate and carboxyphosphonic acid having from about 0.1% to about 20% of another dicarboxylate moiety, such as a bibenzaate or naphthanate, produce a polyester having low melting point (Tm), poor crystallinity and low crystallization speed. However, these copolyesters have a high vitreous transition temperature and better stability against ultraviolet light than polyethylene terephthalate. These polyesters would be particularly suitable for use in the production of biaxially oriented films or other similar products. The copolyesters of polyethylene terephthalate and carboxyphosphonic acid having from about 20% to about 45% of another dicarba-ilata portion, such as a bibenzoate or naphthanate, produce an amorphous polyester which does not have a melting point. These polyesters would be particularly suitable for use as a high-temperature amorphous polyethylene terephthalate substitute. The copolyesters of polyethylene terephthalate and the carboxylic acid acid having more than about 45%, and preferably about 45% to about 90% of another dicarboxylate portion, such as a bibenzoate, produce a polyester having a high melting point (Tm) and higher crystallinity, when compared to polyethylene terephthalate prepared under the same conditions. These polyesters would be particularly suitable for use as high efficiency engineering plastics. The addition of a little percent of another portion of dicarboxylate in the form, for example, bis-β-hydroxyethyl bibenzoate during the polymerization of the polyethylene terephthalate, increases the glass transition temperature of the resulting polyethylene terephthalate copolyester. It is possible to produce copolymers of polyethylene terephthalate and another dicarboxylate, in which the copolyesters have about 99.9% by weight of polyethylene terephthalate and in which the copolymers have about 99.9% by weight of the other dicarboxylate moiety. The properties of the copolyesters of polyethylene terephthalate are dependent on the amount of the other dicarboxylate portion included in the copolyester. Copolyesters having from about 99.9% to about 60% by weight of polyethylene terephthalate and from about 0.1% to about 20% by weight of another dicarboxylate portion have low melting point, poor crystallinity and a glass transition temperature highest. Copolyesters having from about 60% to about 55% by weight of polyethylene terephthalate and from about 20% to about 45% by weight of another dicarboxylate portion are amorphous. Copolyesters having from about 55% to about 10% by weight of polyethylene terephthalate and from about 45% to about 90% by weight of another dicarboxylate portion have a high melting point, high crystallinity and higher vitreous transition temperature. The copolyesters are produced by placing the desired amounts of the polyethylene terephthalate prepolymer, bis-β-hydroxyethyl bibenzoate, and 2-carboethyl (feni 1) phospholinic acid in a reactor filled with nitrogen, in the presence of a catalyst. which is preferably antimony. The reactor is heated to a temperature in the range of about 250 ° C to about 293 ° C, and preferably in the range of about 263 ° C to about 293 ° C, for about 3 hours. Vacuum is applied slowly to reduce the pressure to a pressure of about 0.5 to about 1.0 mm of mercury. The reaction is continued to these conditions for an additional 0.5 to 1.5 hours and then the heat and vacuum are removed. The copolyesters and processes have been described in the above using polyethylene terephthalate prepolymer and the preferred hydroxyethyl dicarboxylate moiety. Nevertheless, the copolyesters can also be produced using ethylene glycol and the appropriate diacid in the process with the polyethylene terephthalate prepolymer. In this way, ethylene glycol and bi-phenyl-dicarboxylic acid can be used in the process to replace the bis-β-hydroxyethyl bibenzoate. Similarly, ethylene glycol and naphthalenedicarboxylic acid can be used. Ethylene glycol is used in the above description of the process and is the preferred diol. However, other aliphatic diols may also be used such as, for example, aliphatic diols having from 3 to about 7 carbon atoms. The carboxyphosphonic acid and its cyclic anhydride are not volatile under the process conditions for the production of the polyesters, since they can be incorporated into the polyester for inclusion in the condensation reaction. When incorporated into the molecule during the condensation reaction, the phosphorus-containing structural unit is randomly distributed in the linear polyester product. The polyesters of this invention can be made into shaped articles. They can be spun into filaments and fibers using well-known procedures and standard additional treatments. The polyesters can also be extruded into sheets or formed into shaped articles, which can be solid or hollow by the molds.

Press molding, injection molding and extrusion. All of these shaped articles (fibers, sheets and other shapes) are also an object of this invention. The fibers and filaments have very good properties and permanent fire retardant, and self-extension. Since they have a good degree of whiteness they have good dyeing properties for the disperse dye and their receptivity includes acid dyes in color shades of medium to intense intensity. The tensile strength of the filaments and fibers, second order transition temperature and melting point approximately corresponds to the values for the polyesters, which do not contain the flame retardant carboxy phosphino acid. Fibers and filaments are generally useful for applications where easily ignitable textiles can not be tolerated and it is possible to use these fibers in combination with natural fibers, such as cotton and other synthetic fibers. Sheets and shaped articles produced from fire retardant polyester are generally used in locations where it is desired to reduce possible serious risks if ignition and fire occur. If the transparency of the shaped articles is not of interest, their solidity and the flame retardant properties can be increased by the inclusion of inorganic fiber materials, such as, for example, glass and quartz fibers and carbon in the usual amounts in the polyester. before molding. --- go TT 39 This invention will be explained in detail in accordance with the following examples, which are for illustrative purposes only and can not limit the present invention. The ratio of the reactants and the properties of the resulting copolymers are shown in the following table.

EXAMPLE I A round-bottomed flask is filled with 16 grams of the esterification product of ethylene glycol and terephthalic acid, where the molar ratio was 1.2 to 1, respectively, 2 grams of the esteri fi cation product of ethylene glycol and 4,4'-biphenyldicarboxylic acid. (Bis-ß-hydroxyethyl bibenzoate) where the molar ratio was 2 to 1, respectively, 2 grams of 2-carboxyethyl-il (phenyl) -phosphinoic acid and 0.02 grams of antimony oxide, Sb., - ,. 0; a. The flask is adapted to a vacuum system, filled with nitrogen, and evacuated three times to remove all oxygen. Then the flask is placed in a salt bath, preheated to 250 ° C. The temperature is increased to 250 ° C to 265 ° C for a period of 1 hour and the ethylene glycol is removed by distillation. After 90 minutes at 265 ° C, the pressure was reduced to 1.42 mmHg in 15 minutes. The pressure is further reduced for a period of 45 minutes at 0.20 mmHg. The reaction is continued at these conditions for an additional 30 minutes to complete the polymerization and the heat and vacuum are removed. The resulting polymer has an inherent viscosity of 0.90 at a concentration of 0.5 grams / deciliter in a solution of 60% phenol / 40% tetrachloroethane at 25 ° C. The polymer had an ileoglycol diet content of 1.45% by weight and the glass transition temperature and the melting point determined by a differential scanning calorimeter were 77 ° C and 216 ° C, respectively. The results of Example 1 are shown in Table 1.

EXAMPLES II-VII The process of Example 1 was repeated six times with the ratio of the esterification product of ethylene glycol and terephthalic acid to the esterification product of ethylene glycol and 4,4 '-bi-phenyldicarboxylic acid (bis-β-hydroxyethyl bibenzoate) which it is varied while the amount of the 2-carboxyethyl-1 (phenyl-1) -phosphonic acid and the catalyst in the process are kept constant. The polymerization is carried out in the same manner as described in Example I. The polymers produced in Examples II-VII, the inherent viscosity of the polymers at a concentration of 0. 5 grams / deciliter in a solution of 60% phenol / 40% tetrachloroethane at 25 ° C, and its content of polyethylene glycol and the glass transition temperature and melting point 23 determined by differential scanning calorimeter, are shown in Table 1.

EXAMPLE VIII The procedure of Example I was repeated with 16 grams of ethylene glycol esterification product and terephthalic acid, where the molar ratio was 1.2 to 1 respectively, 2 grams of 2-carboxy et? L (phenyl) -phosphinic acid and 0.02 grams of the antimony oxide catalyst. The polymerization is carried out in the manner described in Example I. The resulting polymer had an inherent viscosity of 0.92 at a concentration of 0.5 grams / deciliter in a solution of 60% phenol / 40% tetrachloroethane at 25 ° C. C. The polymer had a diethylene glycol content of 2.10% by weight and the glass transition temperature and the melting point determined by differential scanning calorimeter were 66.1 ° C and 239 ° C, respectively. The results of Example VIII are shown in Table 1.

EXAMPLE IX The procedure of Example 1 is repeated with 16 grams of this product of ethylene glycol and 4,4'-bipheni-d-carboxylic acid (bis-β-hydroxyethyl bibenzoate) where the molar ratio was 2 to 1 respectively, 2 grams of the 2-carboxiet i 1 (pheny1) -phosphinic acid and 0.02 grams of antimony oxide catalyst. The polymerization is carried out in the same manner as described in Example I. The resulting polymer has an ileoglycol diet content of 1.7% by weight and the vitreous transition temperature determined by differential scanning calorimeter was 90.1C, C. The results of Example IX are shown in Table 1. The following table shows the results of the reactions described in the previous Examples. The table includes the ratio of the reactants present in the reactor and the properties of the resulting copolymers. The properties included in the table are the intrinsic viscosity (I.V.), the dietary content and the glass transition temperature and the melting point in degrees centigrade < Tg). In Table 1, the term "PET" means the esterification product of ethylene glycol and terephthalic acid (polyethylene terephthalate prepolymer), the term "HEß" means the esterification product of ethylene glycol and 4,4 '-di acid. f-boxyl enylcarbonate (b is-ß-hydroxyethyl bibenzoate), the term "CPA" means 2-carboxyethyl (pheny1) phosphonic acid and the term "DEG" means dietary and glycol. ?3 TABLE 1 EXAMPLE PCT / HRB / f? PA DBGÍ%). I. Y. "Paf» P. Mlsf 1 2 20 - 0 - 0 1.45 0.90 77.0 - 218.6 II 14 - 4 - 2 1.0 0.63 78.1 - III 12 - 6 - 2 1.27 1.05 81.1 - IV 10 - 8 - 2 2.34 0.88 80.1 - V 6 - 12 - 2 4.26 0.83 82.7 - 205-1 VI 4 - 14 - 2 3.47 0.77 88.1 - 226.4 VII 2 - 16 - 2 3.7S 0.6 90.8 - 245 VIII 18 - 0 - 2 2.10 0.92 68.1 - 239.9 IX 0 - 18 - 2 1.7 90.1 - Although certain embodiments of the invention have been illustrated and described herein, it is to be understood that the invention is not limited thereto and that the invention may be practiced in a variety of ways within the scope of the following claims.

Claims

NOVELTY OF THE INVENTION CLAIMS 1. A linear, fire retardant or slow burning polyester characterized in that it comprises the product of: a polyester prepolymer; a hydroxyalkyl dicarboxylate compound having the general formula: HO- (CHa) r-0-CO-R-CO-0- < CHaf) "- OH wherein n is a number from 1 to 6, and R is selected from the group consisting of aliphatic groups having from 2 to about 12 carbon atoms; benzene; substituted benzene in which the substituent is a halogen, an alkyl group having a carbon chain of 1 to about or carbon atoms, or a phenyl or a substituted phenyl group; naphthyl; substituted naphthyl in which the substituent is hydrogen, halogen, an alkyl group having a carbon chain of 1 to about 6 carbon atoms, phenyl or substituted phenyl; and a portion having the general formula: -Ci, HaRa) -Rx- < C? HßRa) - wherein R1 is selected from the group consisting of nothing, oxygen, phenyl, substituted phenyl, an alkyl group having a carbon chain of 1 to about 6 carbon atoms, and -HC = CH- and wherein each Ra independently selects from the group consisting of hydrogen, halogen, an alkyl group having a carbon chain of 1 to about 6 carbon atoms, phenyl and substituted phenyl; and an amount of flame retardant of a carboxy phosphinic acid having the general formula: 0 HO-P-R-C-0H 10 wherein R is selected from the group consisting of saturated or cyclic open-chain alkylene radicals, having from 1 to about 15 carbon atoms, and radicals .15 arylene and aralkylene having from about 15 carbon atoms and RA is selected from the group consisting of alkyl radicals having up to about 6 carbon atoms, aryl radicals and alkaryl radicals, in which the alkyl substituent has from 1 to approximately 6. The linear flame-retardant polyester according to claim 1, characterized in that the polyester prepolymer is selected from the group consisting of polyethylene terephthalate prepolymer, prepolymer 25 polybutylene terephthalate and poly naphthalate prepolymer. 3. The flame-retardant linear polyester according to claim 2, characterized in that the polystyrene prepolymer is poly terephthalate prepolymer. 4. The linear polyester, flame retardant according to claim 2, characterized in that the polyester prepolymer is the prepolymer of polystyrene naphthanate. 5. A linear, flame-retardant polyester characterized in that it comprises the product of a polyester prepolymer, bis-hydroxyalkyl bibenzoate and a flame retardant carboxy-phospholinic acid monomer, the monomer of carba-i-phospholinic acid is present in an amount of Approximately 0.1% to about 10% by weight based on the total weight of the polyester. 6. The linear polyester, flame retardant according to claim 5, characterized in that the alkyl substituent of the bis-hydroxyalkyl bibenzoate is selected from the group consisting of alkyl radicals having from 1 to 6 carbon atoms. 7. The linear polyester, flame retardant according to claim 6, characterized in that the bibepzoata of b is-h idrox is a bis-β-hydroxyethyl bibenzoate. 6. The linear polyester, flame retardant according to claim 5, characterized in that the carbonic acid and phosphonic acid monomer is selected from the group consisting of 2-carboxy et i 1 (pheny1) phospholinic acid, 2- carboxyethyl (methy1) phospholinic acid, the cyclic anhydride of 2-carboxy and 11 (feml) phosphine and the cyclic anhydride of 2-carboxy and l (methyl) phospholinic acid. 9. The linear polyester, retarder of 5 according to claim 6, characterized in that the monomer of the carboxyphosphine acid is the 2-carboxyethyl (phenyl) phophinic acid. 10. The linear polyester, retardant according to claim 6, characterized in that the 1, carboxy-acid monomer is phospholinic acid (methyl). 11. A linear, flame-retardant polyester characterized in that it comprises the product of a polyester prepolymer, bis-hydroxyalkyl naphthana and a monomer Ib of the flame retardant carboxy-phosphonic acid, the monocarboxylic acid monomer which is present in an amount of about 0.1% to about 1% by weight based on the total weight of the polyester. 12. The linear, flame-retardant polyester according to claim 11, characterized in that the alkyl substituent of bis-hydroxyalkyl naphthanate is selected from the group consisting of alkyl radicals having from 1 to 6 carbon atoms. 13. The linear polyester, flame retardant of 5 with torpudad with claim 12, characterized in that the bis-hydroxyalkyl naphthana is bis-β-hydroxyl εyl naphthana. 14"The flame-retardant linear polyester according to claim 11, characterized in that the carboxy-1-phosphonic acid monomer is selected from the group consisting of 2-carboxyethyl-1 (phenyl) -phosphonic acid, 2-carboxyethyl acid (methyl) phosphinoic acid, the cyclic anhydride of 2-carboxyethyl-l (phenyl-1) phospholinic acid and the cyclic anhydride of 2-carboxyethyl (meth i) phospholinic acid. 15. The linear polyester, flame retardant of i., .. according to claim 14, characterized in that the mon? of the carboxy-phosphinoic acid in the 2-carboxyethyl acid (fe il) phosphine. 16. The flame retardant linear polyester, according to claim 14, characterized in that the The carboxy-phosphonic acid monomer is 2- carbaxyethyl (meth i 1) phospholinic acid. 17. A process for the production of a linear, flame-retardant polyester, characterized in that it comprises condensing a mixture of a prepolymer of 20 polyester, bis-hydroxyalkyl bibenzoate and a flame retardant amount of a carboxyphosphonic acid monomer in the presence of a catalyst at a temperature between about 250 ° C and about 293 ° C. 16. The procedure for the production of a The flame retardant linear polyester according to claim 17, characterized in that the polyester prepolymer is selected from the group consisting of polyethylene terephthalate prepolymer, polybutylene terephthalate prepolymer and polyethylene naphthalene prepolymer. 19. The process for the production of a flame retardant linear polyester according to claim 16, characterized in that the polyester prepolymer is the polyethylene terephthalate prepolymer. 20. The process for the production of a linear polyester, flame retardant according to claim 1, characterized in that the alkyl substituent of the bis-hydroxyalkyl bibenzoate is selected from the group consisting of alkyl radicals having from 1 to 6. carbon atoms. 21. The process for the production of a linear, flame retardant .15 polyester according to claim 20, characterized in that the bis-hydroxyalkyl bibenzoate is the bis-hydroxyethyl bibenzoate. 22. The process for the production of a flame-retardant linear polyester in accordance with 20 claim 17, characterized in that the carboxy-phosphinic acid monomer is selected from the group consisting of 2-carboxyethyl &< phenyl) phosphinoic acid, 2-carboxyethyl-1 (ethyl) phosphinoic acid, the 2-carboxyethyl (phenyl-1) phosphinoic acid cyclic anhydride and the cyclic anhydride 2-carboxylic acid i 1 (met i 1) phosphonic acid. 23. The procedure for the production of a -o linear polyester, flame retardant according to claim 17, characterized in that the monomer of the carboxy-fssf acid is 2-carboxyethyl (phenyl) phospholinic acid. 24. A process for the production of a flame retardant linear polyester, characterized in that it comprises condensing a mixture of a polyester prepolymer., bis-hydroxyalkyl bibenzoate and a monomer of the flame-retardant carbo-i-phosphonic acid, the carboxy-phosphonic acid monomer is present in an amount from about 0.1% to about 10% by weight based on the total weight of the polyester , in the presence of a catalyst at a temperature between about 250 ° C and about 293 ° C. 25. The process according to claim 24, characterized in that the alkyl substituent of the bis-hydroxyalkyl bibenzoate is selected from the group consisting of alkyl radicals having from 1 to 6 carbon atoms. 26. The process according to claim 25, characterized in that the bis-hydroxyalkyl bibenzoate is the bibenzoate of b is-ß-h idroxiet i lo. 27. The process according to claim 24, characterized in that the carboxy osphinic acid monomer is selected from the group consisting of 2-carboxyethyl acid.; feni 1) phospholinic acid, 2-carboxyethyl-1 (ethi-1) phospholinic acid, the cyclic anhydride of 2-carbaxyl and l (phenyl) phospholinic acid and the cyclic anhydride of 2-carboxy and 11 (f in 11) Phosph 26. The process according to claim 27, characterized in that the carboxy-phosphonic acid monomer is 2-carboxy et i1 (phenyl1) phospholinic acid. 29. The process according to claim 27, characterized in that the carboxy-phosphonic acid monomer is 2-carboxy et? L (meth i) phospholinic acid. 30. A process for the production of a lr, flame-retardant polyester characterized in that it comprises condensing a mixture of a polyester polymer, a dicarboxylic acid, a diol and a flame retardant amount of a carboxy-phosphinic acid monomer in the presence of a catalyst, at a temperature between about 250 ° C, and about 293 ° C. 31. The process for the production of a flame retardant lr polyester according to claim 30, characterized in that the dicarboxylic acid is selected from the group consisting of aliphatic dicarboxylic acids having from 2 to about 12 carbon atoms. , isophthalic acid, substituted terephthalic acid and the dicarboxylic acids of biphenyls, naphthalene, terphenyls and diphenyl ether. 32. The process for the production of a flame-retardant lr polyester according to claim 31, characterized in that the dicarboxylic acid is b-phenyl icarboxylic acid. 33. The process for the production of a flame-retardant lr polyester according to claim 31, characterized in that the dicarboxylic acid is naphthalenedicarboxylic acid. 34. The process for the production of a flame retardant lr polyester according to claim 31, characterized in that the diol is selected from the group consisting of aliphatic diols having from 3 to 7 carbon atoms. 35. The process for the production of a flame-retardant lr polyester according to claim 34, characterized in that the diol is et i-glycol. 36. The flame retardant lr polyester according to claim 1, characterized in that it is in the form of a shaped article. 37. The lr polyester, flame retardant according to claim 1, characterized in that it is in the form of a fiber. 36. A lr, flame-retardant paloster formed in an article characterized in that it comprises the product of a polyester prepolymer, dicarboxylic acid, and a flame-retardant amount of 2-carboxyethyl-1-acid (phenyl-1 > fos-phrinic. of flame-retardant lr polyester, according to claim 36, characterized in that the 2-carboxyethyl- (phenyl) -phospholinic acid is present in an amount of from about 0.1% to about 10% by weight based on the total weight of the E >pol.i ester 40. The shaped article of lr polyester, flame retardant according to claim 36, characterized in that the polyester prepolymer is selected from the group consisting of prepolymer of polyethylene terephthalate, prepolymer. of polybutylene terephthalate and polyethylene naphthalene prepolymer 41. The article formed of lr polyester, flame retardant in accordance with the reiv indication 40, characterized in that the polyester prepolymer is 15 polyethylene terephthalate. 42. The shaped article of the linear polyester, flame retardant according to claim 36, characterized in that the dicarboxylic acid is selected from the group consisting of aliphatic dicarboxylic acids which 20 have from 2 to about 12 carbon atoms, isophthalic acid, substituted terephthalic acid and the dicarboxylic acids of biphenyls, naphthalenes, terphenyls and diphenyl ether. 43. The shaped article of linear polyester, flame retardant, according to claim 42, characterized in that the dicarboxylic acid is biphenyldicarboxylic acid. 44. The shaped article of linear polyester, flame retardant according to claim 42, characterized in that the dicarboxylic acid is naphthalenedicarboxylic acid. 45. The shaped article of linear polyester, flame retardant according to claim 42, characterized in that the shaped article is a fiber.