MXPA00010292A - Polyester film and methods for making same - Google Patents

Abstract

A polyester film made from a polymer having ethylene glycol moieties, isosorbide moieties and terephthalnoyl moieties, and the method of making the film is described. The polyester film is used to form articles such as films, lacquers, labels, capacitors, insulators, and the like, and has an inherent viscosity of at least 0.35 dL/g when measured as a 1%(weight/volume) solution of the polyester in o-chlorophenol at a temperature of 25°C.

Description

POLYESTER FILM AND METHODS FOR THE ELABORATION FIELD OF THE INVENTION This invention relates to a film formed from a polyester, methods for making polyester and film, and articles made from the film. More specifically, this description relates to films made of a polyester having a portion of isosorbide, a portion of terephthaloyl and a portion of ethylene glycol, and methods for making the same, as well as articles made therefrom.

BACKGROUND OF THE INVENTION Polymeric films have various uses, such as in packaging, especially of food products, adhesive tapes, insulators, capacitors, photographic development, x-ray development and as laminates, for example. For many of these uses, the heat resistance of the film is an important factor. Therefore, a melting point and a glass transition temperature (Tg) are desirable to provide better heat resistance and more stable electrical characteristics. Also, you want these movies Ref: 123439 have a good tensile strength and a high elongation at break. Various polymeric compositions have been used in an attempt to satisfy all the above criteria. In particular, poly (ethylene terephthalate) (PET) is preferred for its vitreous transition temperature, tensile strength and low cost. However, there are still problems in obtaining a product having the desired crystallinity and strength, as well as other desirable characteristics such as high optical clarity, resistance to decomposition by the environment, for example. Various polymer compositions have been proposed but none is completely satisfactory. Therefore, there is a need for new materials suitable for the production of polymeric films that provide desirable glass transition temperatures, tensile strength, and crystallinity, high optical density, and resistance to decomposition by the environment and low cost. The 1, 4: 3, 6-dianhydro-D-sorbitol diol, referred to in the following as isosorbide, the structure of which is illustrated below, is easily manufactured from renewable resources, such as sugars and starches. For example, isosorbide can be made from D-glucose by hydrogenation followed by acid-catalyzed dehydration.

Isosorbide has been incorporated as a monomer in polyesters that also include terephthaloyl moieties. See, for example, R. Storbeck et al, Makromol. Chem., Vol. 194, pp. 53-64 (1993); R. Storbeck et al, Polymer, Vol. 34, p. 5003 (1993). However, it is generally considered that secondary alcohols such as isosorbide have little reactivity and are sensitive to acid catalyzed reactions.

See, for example D. Braun et al., J. Prakt. Chem., Vol. 334, pp. 298-310 (1992). As a result of the poor reactivity, polyesters made with an isosorbide monomer and the terephthalic acid esters are expected to have a relatively low molecular weight. Ballauff et al, Polyesters (Derived from Renewable Sources), Polymeric Materials Encyclopedia, Vol. 8, p. 5892 (1996). Copolymers containing portions of isosorbide, portions of ethylene glycol and portions of terephthaloyl have been reported only rarely. A copolymer containing these three portions, in which the ratio and moles of ethylene glycol to isosorbide is about 90:10, are reported in published German patent application No. 1,263,981 (1968). The polymer is used as a minor component (approximately 10%) of a combination with polypropylene to improve the dyeability of the polypropylene fiber. It is prepared by melt polymerization of dimethyl terephthalate, ethylene glycol and isosorbide, but the conditions which are described are only mentioned in general terms in the publication, and a polymer having a high molecular weight is not provided. Copolymers of these same three monomers are newly described again, where it has been observed that the vitreous transition temperature (Tg) of the copolymer is increased with an isosorbide monomer content of up to about 200 ° C for the terephthalate homopolymer of isosorbide. The polymer samples are made by reacting terephthaloyl dichloride in solution with the diol monomers. This method provides a copolymer with a molecular weight that is apparently higher than that obtained in the German patent application described above but still relatively low in comparison to other polyester polymers and copolymers. In addition, these polymers are manufactured by solution polymerization and are therefore free of diethylene glycol portions as a polymerization product. See R. Storbeck, Dissertation, Universitát Karlsruhe (1994); R. Storbeck, et al., J. Appl. Polymer Science, Vol. 59, pp. 1199-1202 (1996). U.S. Patent 4,418,174 describes a process for the preparation of polyesters useful as raw materials in the production of aqueous baked lacquers. The polyesters are prepared with an alcohol and an acid. One of the many preferred alcohols is dianhydrosorbitol. However, the average molecular weight of the polyesters is from 1,000 to 10,000, and a polyester containing a portion of dianhydro sorbitol is not actually produced. U.S. Patent 5,179,143 describes a process for the preparation of compression molded materials. In addition, polyesters containing hydroxyl are disclosed therein. These hydroxyl-containing polyesters are listed to include polyhydric alcohols including 1, 4: 3, 6-dianhydrosorbitol. However, again, the highest molecular weights reported are relatively low, that is, from 400 to 10,000 and in fact a polyester containing the 1, 4: 3, 6-dianhydrosorbitol portion is not made. Published PCT applications WO 97/14739 and WO 96/25449 disclose cholesteric and nematic liquid crystalline polyesters that include portions of isosorbide as monomeric units. Such polyesters have relatively low molecular weights and are not isotropic.

BRIEF DESCRIPTION OF THE INVENTION Contrary to the teachings and hopes that have been published in the prior art, the copolyes are isotropic, ie semicrystalline and amorphous or non-liquid crystalline, containing portions of terephthaloyl, portions of ethylene glycol, portions of isosorbide and, optionally, portions of diethylene glycol, are easily synthesized in molecular weights which are suitable for manufacturing manufactured products such as films, on an industrial scale. The process conditions for producing a polyester film, particularly the amounts of monomers used in the polyester, are desirably chosen so that the final polymer product used for the manufacture of films has the desired amounts of the various monomer units, preferably with equimolar amounts of monomer units derived from a diol and a diacid. Due to the volatility of some of the monomers, including isosorbide, and depending on the method of making the polyester, some of the monomers are desirably excessively included at the start of the polymerization reaction and are removed as the reaction proceeds. This is particularly true for ethylene glycol isosorbide. The polyester can be formed by any method known in the art. However, preferably, the polyester is formed by solvent or melt polymerization. The choice of method can be determined by the desired amount of diethylene glycol in the final product. In a preferred embodiment, the number of terephthaloyl moieties in the polymer is in the range of about 25% to about 50 mole% (moles% of the total polymer). The polymer may also include amounts of one or more aromatic diacid portions such as, for example, those derived from isophthalic acid, 2,5-furanodicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2, 7 acid. -naphthalenedicarboxylic acid and 4,4'-dibenzoic acid at combined concentrations of up to about 25 mol% (moles% of the total polymer). In a preferred embodiment, units of ethylene glycol monomers are present in amounts of about 5 mol% to about 49.75 mol%. The polymer may also contain portions of diethylene glycol. Based on the manufacturing method, the amount of diethylene glycol portions is in the range of about 0.0 mole% to about 25 mole%. In a preferred embodiment, the isosorbide is present in the polymer in amounts in the range of about 0.25 mol% to about 40 mol%. One or more different diol monomer units may also be included, in amounts up to a total of about 45 mole%. The polyester has an inherent viscosity, which is an indicator of molecular weight, of at least about 0.35 dL / g, measured in a 1% (w / v) solution in o-chlorophenol at a temperature of 25 ° C. A higher inherent viscosity, such as for example about 0.40 dl / g, preferably at least about 0.50 dl / g, is desired for optimum film formation. Further processing of the polyester can generate inherent viscosities of up to about 1.0 dl / g. The polyester films of the present invention are manufactured by any method known in the art and are suitable for use in a variety of applications, such as food packaging, labels, photo or X-ray development, insulators, capacitors, various tapes. and similar. These films provide high temperature resistance and increased strength with respect to other commonly used film-forming materials, such as polyethylene terephthalate PET.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES OF THE INVENTION The isotropic polyester films and the method for their preparation are described in detail in the following. In particular, a method for making the polyester comprising portions of terephthaloyl, portions of ethylene glycol and portions of isosorbide is the process described, as well as processes for forming films from such a polymer. In a preferred embodiment, the ethylene glycol monomer units are present in the polymer in amounts of about 33 mole% to about 49.9 mole%, preferably from about 37 mole% to about 45 mole%, although larger amounts can be included as is necessary to obtain the desired results. The polymer composition may also contain diethylene glycol monomer units. Depending on the manufacturing method, the amount of diethylene glycol monomer units is in the range of from about 0.0 mole% to about 5.0 mole%, preferably from 0.25 mole% to about 5.0 mole%, although higher amounts can be included as needed to obtain the desired results. Diethylene glycol can be made as a byproduct of the polymerization process, or it can be added directly to the composition to help accurately regulate the amount of diethylene glycol monomer units that are in the polymer. In the preferred embodiments, portions of isosorbide are present in the polymer in amounts in the range of about 0.25 mole% to about 30 mole%, preferably from about 0.25 mole% to about 20 mole%, preferably 0.25 mole%, so preferable 12.0 mole%, more preferably from about 1.0 mole% to about 6.0 mole% although larger amounts may be included as necessary to obtain the desired results. One or more monomer units of another diol may optionally be included in amounts up to a total of about 2.0 mole%, preferably less than 1.0 mole%. The amount of other diols included, however, may be greater than necessary to obtain the desired results. Examples of the optional units or other diol units include aliphatic alkylene glycols having 3-12 carbon atoms and having the empirical formula HO-CnH2n-OH, where n is an integer of 3-12, including branched diols such as 2, 2-dimime thi 1 -1,3-propanediol; cis or trans-1,4-cyclohexanedimethanol and mixtures of cis and trans isomers; triethylene glycol; 2, 2-bis [4- (2-hydroxyethoxy) phenyl] propane; 1,1-bis [4- (2-hydroxyethoxy) phenyl] cydohexane; 9, 9 -bis [4 - (2-hydroxyethoxy) phenyl] fluorene; 1, 4: 3, 6-dianhydromanitol; 1,4: 3,6-dianhydroiditol; and 1,4-anhydroerythritol. The terephthaloyl moieties in the polyester can vary from 25-50 mole%, preferably from about 40-50 mole% although larger amounts may be included as necessary to obtain the desired results. If desired, other aromatic diacid portions in the polymer can include, for example, those derived from isophthalic acid, 2,5-furanedicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2-7- naphthalenedicarboxylic acid and 4'-dibenzoic acid, at combined levels of up to about 10 mol%, preferably between 0..01 and 5 mol% of the total polymer, although larger amounts may be included as necessary to obtain the desired results . It is preferable that equimolar amounts of the diacid monomer units and the diol monomer units are present in the polymer in order to obtain a high molecular weight and a high inherent viscosity, which provides a lower shrinkage rate and a lower temperature. glass transition greater (Tg) than, for example, poly (ethylene terephthalate). The polyester formed has an inherent viscosity, which is an indicator of molecular weight, of at least about 0.35 dl / g, measured in a 1% (w / v) solution of the polymer in o-chlorophenol at a temperature of 25 °. C. Preferably, the inherent viscosity is at least about 0.40 dl / g and preferably at least about 0.45 dl / g, and can be as high as 2.0 gl / g or even higher. More preferably, an inherent viscosity of about 0.5-0.7 dl / g is desired. The molecular weight is not usually measured directly. Instead, the inherent viscosity of the polymer in solution or the molten viscosity is used as an indicator of molecular weight. For the present polymers, the inherent viscosity is measured by the method previously described, with a molecular weight corresponding to an inherent viscosity of about 0.35 dl / g or greater. Higher molecular weights corresponding to inherent viscosity of at least about 0.45 dl / g are preferred, and molecular weights corresponding to inherent viscosities as high as about 1.0 dl / g at 2.0 dl / g or even higher, can be obtained if desired. Generally, the ratio of inherent viscosity / molecular weight can be adjusted to the linear equation: log (IV) = 0.586 x log (Mw) -2.9672 the inherent viscosities are a better indicator of molecular weight for sample comparisons and are used as the molecular weight indicator here. The polyesters used to make the films of the invention can be manufactured in any of several methods. The product compositions vary to some extent depending on the method used, particularly on the amount of diethylene glycol residues that is present in the polymer. These methods include the reaction of the diol monomers with the acid chlorides of terephthalic acid and any other acid that may be present. The reaction of terephthaloyl dichloride with isosorbide and ethylene glycol is easily carried out by combining the monomers in a solvent (for example toluene) in the presence of a base, such as pyridine, which neutralizes the HCl as it is produced. This procedure is described in R. Storbeck et al., J. Appl. Polvmer Science, Vol. 59, pp. 1199-1202 (1996). Other well known variations can also be used using terephthaloyl dichloride (for example interfacial polymerization) or simply by stirring the monomers together while heating. When the polymer is made using acid chlorides, the ratio of monomer units in the polymer of the product is approximately the same as the ratio of monomers that react. Therefore, the ratio of monomers charged to the reactor is approximately the same as the desired ratio in the product. A stoichiometric equivalent of the diols and diacids will generally be used to obtain a high molecular weight polymer, for example one with an inherent viscosity of at least about 0.35 dl / g, suitable for making films. The polymers can also be manufactured by a melt polymerization process, in which the acid component is terephthalic acid or dimethyl terephthalate, and which can also include the free acid or the dimethyl ester of any other aromatic diacid that may be desired in the composition of the polyester polymer. The diacids or dimethyl esters are heated with the diols (ethylene glycol, isosorbide, optional diols) in the presence of a catalyst at a high enough temperature so that the monomers combine to form esters and diesters, then oligomers and finally polymers. The polymer product at the end of the polymerization process is a molten polymer. The diol monomers (for example ethylene glycol and isosorbide) are volatile and are distilled from the reactor as the polymerization proceeds. Therefore, an excess of these diols is desirably loaded into the reaction to obtain a polymer, and the amounts must be adjusted according to the characteristics of the polymerization vessel, such as the efficiency of the distillation column and the efficiency of the recovery of monomers and recycling. Such modifications in the amounts of monomers and the like according to the characteristics of a reactor can be easily carried out by persons skilled in the art. In addition, a person skilled in the art can easily determine the amount of each component desirably charged to any particular reactor to form the polymer of the invention. The melt polymerization process described above is the preferred method for making the polymer and is described in detail in commonly assigned, co-pending US application No. 09 / 064,844.

(Attorney's File Number 032358-001), incorporated herein by reference. The melt polymerization process uses dimethyl terephthalate and terephthalic acid, also summarized in the following.

Process of dimethyl terephthalate In this process, which is carried out in two stages, terephthalic acid and optional diacid monomers are used, if present, as its dimethyl ester derivatives. The diols (for example ethylene glycol and isosorbide) are mixed with the dimethyl ester of the aromatic diacid (for example dimethyl terephthalate) in the presence of an ester exchange catalyst, which causes an exchange of ethylene glycol of the methyl group of the esters of dimethyl through a transesterification reaction. This results in the formation of methanol, which is removed by distillation from the reaction flask, and bis (2-hydroxyethyl terephthalate) due to the stoichiometry of the reaction, a little more than two moles of ethylene glycol are desirably added as reactants for the ester exchange reaction. Catalysts that carry out ester exchange include salts (usually acetates) of the following metals: Li, Ca, Mg, Mn, Zn, Pb and combinations thereof, Ti (OR) 4, wherein R is a group alkyl having 2-12 carbon atoms, and PbO. The catalyst components are generally included in an amount of about 10 ppm to about 100 ppm. Preferred catalysts for ester exchange include Mn (OAc) 2, Co (0Ac) 2, and Zn (? A) 2, where OAc is the abbreviation for acetate and combinations thereof. The polycondensation catalyst which is necessary for the second stage of the reaction, preferably Sb (III) oxide, can now be added or at the beginning of the polycondensation step. A catalyst that has been used particularly successfully for ester exchange is based on salts of Mn (II) and Co (II) at levels of about 50 ppm to about 100 ppm each. These are used in the form of Mn (II) acetate tetrahydrate and Co (II) acetate tetrahydrate, although other salts of the same metals can also be used. The ester exchange is carried out approximately by heating and stirring the reagent mixture under an inert atmosphere (eg nitrogen) at atmospheric pressure from room temperature to a temperature high enough to introduce ester exchange (approximately 150 °). C). The methanol is formed as a by-product and is distilled off from the reactor. The reaction is gradually heated to about 250 ° C until the methanol production is stopped. The completion of methanol production can be recognized by a decrease in the upper temperature of the reaction vessel. A small amount of an additive having a boiling point of 170-240 ° C can be added to the ester exchange to aid in heat transfer within the reaction medium and to help retain volatile components in the container that can Sublimate in the fill column. The additive must be inert and must not react with alcohols or dimethyl terephthalate at temperatures below 300 ° C. Preferably, the additive has a boiling point greater than 170 ° C, more preferably within the range of 170 ° C to 240 ° C, and is used in an amount between about 0.05 and 10% by weight, more preferably between about 0.25 and 1% by weight of the reaction mixture. A preferred additive is tetrahydronaphthalene. Other examples include diphenylether, diphenylsulfone and benzophenone. Other such solvents are described in U.S. Patent 4,294,956, the content of which is incorporated herein by reference. The second stage of the reaction is initiated by adding a polycondensation catalyst, if not added at the beginning of the process and a sequestering agent for the transesterification catalyst. Polyphosphoric acid is an example of a sequestering agent and is preferred. It is usually added in an amount of about 10 to about 100 ppm phosphorus per g of dimethyl terephthalate. Examples of preferred polycondensation catalysts are antimony (III) oxide, which can be used at levels of about 100 to about 400 ppm.

The polycondensation reaction is typically carried out at a temperature from about 250 ° C to 285 ° C. During this time, ethylene glycol is distilled off from the reaction due to the condensation of bis (2-hydroxyethyl) terephthalate to form a polymer and a by-product of ethylene glycol, which is collected as a distillate. The polycondensation reaction described above is preferably carried out under vacuum, which can be applied while the reactor is heated to the polycondensation reaction temperature after the polyphosphoric acid and the Sb (III) oxide have been added. Alternatively, vacuum may be applied after the polycondensation reaction temperature reaches 280 ° C-285 ° C. In any case, the reaction is accelerated by the application of vacuum. Heating under vacuum continues until the molten polymer reaches the desired molecular weight, usually recognized by an increase in the viscosity of function at a predetermined level. This is observed as an increase in the torque required for the agitation motor to maintain agitation at constant rpm. An inherent viscosity of at least 0.5 dl / g and generally up to about 0.65 dl / g or greater, can be obtained by this melt polymerization process without additional efforts being made to increase the molecular weight. For a certain composition, the molecular weight ranges can be further increased by solid state polymerization, described below.

Process of terephthalic acid The process of terephthalic acid is similar to the process of dimethyl terephthalate, except that the initial esterification reaction leading to bis (2-hydroxyethyl) terephthalate and to the other low molecular weight esters is carried out at a slightly elevated pressure ( autogenous pressure of approximately 172 to 345 kPa (25 to 50 psig)). Instead of a two-fold excess of the diols, a smaller excess (from about 10% to about 60%) of the diols is used (ethylene glycol, isosorbide and other diols, if any). The intermediate esterification product is a mixture of oligomers, since sufficient diol is not present to generate a diester of terephthalic acid. The catalysts are also different. It is not necessary to add catalysts in the esterification reaction. A polycondensation catalyst is still necessary (for example salts of Sb (III), or Ti (IV)) to obtain a high molecular weight polymer. The catalyst that is needed to obtain a high molecular weight can be added after the esterification reaction, or it can be conveniently loaded with the reactants at the start of the reaction. Catalysts that are useful for making a high molecular weight polymer directly from terephthalic acid and the diols include acetate or other salts of Co (II) alkanoate and Sb (III), Sb (III) oxides and Ge (IV), and Ti (OR) 4 (wherein R is an alkyl group having 2 to 12 carbon atoms) as well as metal oxides solubilized in glycol. The use of these and other catalysts in the preparation of the polyesters is well known in the art. The reaction can be carried out in discrete stages, but this is not necessary. In large-scale practice, it can be carried out in stages as the reactants and intermediates are pumped from the reactor to the reactor at increasing temperatures. In a batch process, the reactants and catalyst can be charged to the reactor at room temperature and then gradually heated to about 285 ° C as the polymer is processed. The pressure is vented in the range of about 200 ° C to about 250 ° C, and then vacuum is desirably applied. The esterification to form the esters of bis (2-hydroxyethyl) terephthalate and the oligomers is carried out at elevated temperatures (between room temperature and about 220 ° C to 265 ° C under autogenous pressure), and the polymer is processed at temperatures in the range of about 275 ° C to about 285 ° C under high vacuum (less than 10 Torr, preferably less than 1 Torr). The vacuum is necessary to remove residual ethylene glycol and water vapor from the reaction to increase molecular weight. A polymer having an inherent viscosity of at least 0.5 dl / g and generally up to about 0.65 dl / g can be obtained by a direct polymerization process, without subsequent polymerization in the solid state. The development of the polymerization can be followed by melt viscosity, which is easily observed by the torque required to maintain the stirring of the molten polymer.

Solid state polymerization The polymers can be made by melt condensation processes described above having an inherent viscosity of at least about 0.50 dl / g, and often as high as about 0.65 dl / g or greater, without further treatment. The compositions of ethylene glycol, isosorbide and terephthalic acid having isosorbide in an amount of about 0. 25% to about 10% on a mole basis can have their molecular weight further increased by solid state polymerization. The product made by melt polymerization, after extrusion, cooling and granulation, is essentially non-crystalline. The material can be made of semicrystalline material by heating at a temperature in the range of about 115 ° C to about 140 ° C for an extended period of time (about 2 to about 12 hours). This induces crystallization so that the product can be heated to a much higher temperature to increase the molecular weight. The freshly extruded product becomes sticky if it is heated to a temperature higher than about 140 ° C before it has crystallized, rendering polymerization in the solid state impossible without the pre-crystallization heating cap. The process works best for low levels of isosorbide, from about 0.25 mol% to about 3 mol%, because the polyester crystallizes more easily with low levels of isosorbide. The polymer can also be crystallized prior to polymerization in the solid state by treatment with a relatively poor solvent for polyesters, such as acetone, which induces crystallization. Such solvents reduce the glass transition temperature T) g) which allows crystallization. Solvent-induced crystallization followed by solid state polymerization is known for polyesters and is described in U.S. Patent Nos. 5,164,478 and 3,684,766, which are incorporated herein by reference.

The crystallized polymer is subjected to polymerization in the solid state by placing the granulated or powdered polymer in a stream of inert gas, usually nitrogen, or under a vacuum of 1 Torr, at an elevated temperature, above about 140 ° C, but below of the melting temperature of the polymer, for a period of about 2 to about 16 hours. The solid state polymerization is preferably carried out at temperatures from about 190 ° C to about 210 ° C for a period from about 2 to about 16 hours. Good results are obtained by heating the polymer from about 195 ° to about 198 ° C for about 10 hours. This polymerization in the solid state can increase the inherent viscosity to about 0.8 dL / g or higher.

Film Training Process The polyester polymer formed by one of the above methods, or by any other method known in the art, can be formed into a film for use in any of many different applications, such as food packaging, labels, dielectric insulation, a barrier of water vapor or similar. The monomer composition of the polyester polymer is preferably chosen to result in a partially crystalline polymer desirable for film formation, wherein the crystallinity provides strength and elasticity. A polyester produced for the first time generally has a semicrystalline structure. The crystallinity is increased by reheating or stretching or both of the polymer, as in the production of film. In the process of the invention, a film is made from the polymer by any process known in the art. The difference between a film and a sheet is the thickness, but there is no established standard in the industry regarding the time when a film becomes a sheet. For purposes of this invention, a film is of a thickness of = 0.25 mm (10 mils), preferably between about 0.025 mm and 0.15 mm (1 mil and 6 mils). However, thicker films up to a thickness of about 0.50 mm (20 mils) can be formed. The film of the invention is preferably formed either by solution emptying or by extrusion. Extrusion is particularly preferred for the formation of "endless" products such as films and sheets, which arise as a continuous length. In extrusion, the polymeric material, whenever provided as a molten polymer or with plastic granules or granules, is fluidized and homogenized. This mixture is then driven through a die with the proper shape to produce the desired cross-sectional and cross-sectional film shape. The extrusion force can be exerted by a piston or ram (water hammer extrusion) or by a rotating screw (screw extrusion) which works inside a cylinder in which the material is heated and plasticized from which it is then extruded through the die in a continuous flow. Single screw, double screw and multiple screw extruders can be used, as is known in the art. Different kinds of die are used to produce different products, such as blowing film, formed by a blowing head for blow extrusions, (sheets and strips) and solid hollow sections (circular dies). In this way, films of different widths and thicknesses can be made and, in some cases, for example when the film is used as a coating, they can be extruded directly onto the object to be coated. For example, wires and cables can be lined directly with polymer films extruded from oblique heads. After extrusion, the polymeric film is captured by rollers, cooled and extracted by means of suitable devices which are designed to avoid any subsequent deformation of the film.

The use of extruders as is known in the art allows films to be produced by extrusion of a thin layer of polymer onto cooled rolls and then further downward stretching of the film to the proper size (= 0.25 mm) by tension rolls. Preferably, the finished film has a thickness of = 0.25 mm. Blown film, which is generally stronger, more resistant and manufactured faster than a cast film, is manufactured by extrusion of a tube. By producing a blown film, the molten flow is diverted upwardly from the extruder and fed through an annular die. As this tube leaves the die, internal pressure is introduced through the die mandrel with air, which expands the tube from about 1.5 to about 2.5 times the diameter of the die and simultaneously removes the film, causing a reduction in thickness. The resulting sleeve subsequently slides along one side, producing a film width greater than that which can be conveniently made via the cast film method. In the extrusion coating, the substrate (paper, sheet, cloth and the like) is compressed together with the extruded polymer melt by means of pressure rollers so that the polymer impregnates the substrate for maximum adhesion. For the production of large amounts of film, a rolling calender is used. The rough film is fed into the separation of the calender, a machine comprising several heatable parallel cylindrical rollers which rotate in opposite directions and disperse the polymer and stretch them to the required thickness. The last rollers smooth the film produced in this way. If the film is required to have a textured surface, the final roller is provided with an appropriate patterning pattern. Alternatively, the film can be reheated and then passed through a printing calender. The calandria is followed by one or more cooling drums. Finally, the finished movie is rolled up. Alternatively, as mentioned above, a support material can be coated directly with a film. For example, textile materials, paper, cardboard, metals, various materials, construction and the like can be coated directly with the polyester polymer for the purpose of electrical insulation, protection against corrosion, protection against the action of moisture or chemicals, impermeability to gases and liquids or increase in mechanical resistance. The coatings are applied to sheet materials or other sheet materials by continuously operating dispersion coating machines. A coating blade, known as a doctor's blade, ensures a uniform dispersion of the coating materials (in the form of solutions, emulsions or dispersions in water or in an organic medium) on the support material, which is moved together with the rollers. The coating is then dried. Alternatively, when the coating is applied to the support material in the form of a polymeric film, the process is called laminate. It is also possible to coat metal articles of complex shapes with the polymer film by means of a rotary sintering process. The articles, heated above the melting point of the polymer, are introduced into a fluidized bed of powdered polymer wherein the powder particles are held in suspension by an updraft of air and, therefore, deposit a coating on the metal by Sintering The extruded films can also be used as the starting material for other products, for example, the film can be cut into small segments for use as a feedstock for other processing methods, such as injection molding. The extrusion process can be combined with various post-extrusion operations for greater versatility. Such post-formation operations include altering round or oval shapes, blowing the film to different dimensions, machining and perforating, biaxially stretching and the like, as are known to those skilled in the art.

The polymeric film of the invention can be combined with other polymeric materials during extrusion and / or finishing to form laminates or multilayer films with improved characteristics, such as water vapor resistance. In particular, the polymeric film of the invention can be combined with one or more of the following: poly (ethylene terephthalate) (PET), aramid, polyethylene sulfide (PES), polyphenylene sulfide (PPS), polyimide (Pl) , polyethyleneimine (PEI), polyethylene naphthalate (PEN), polysulfone (PS), polyetheretherketone (PEEK), olefins, polyethylene, cyclic poly (olefins) and cyclohexylene terephthalate and dimethylene, for example. Other polymers which can be used in combination with the polyester polymer of the invention are those which are included in the copending applications serial numbers 09/064, 826 (Attorney's File Number 0323580Q5) and 09 / 064,720 (Attorney's File Number 032358-008). A multi-layered or laminated film can be made by a method known in the art, and can have up to five or more separate layers which are bonded by heat, adhesive or a tie layer, as is known in the art. A film can also be formed by emptying the solution, which produces a film of consistently more uniform caliber compared to that made by melt extrusion. Solution casting comprises dissolving polymeric, powdered granules or the like in a suitable solvent with any desired formulant, such as a plasticizer or colorant. The solution is filtered to remove dirt or large particles and emptied from a slot die to a moving band, preferably stainless steel, where the film cools. The film is then removed from the band to a rolling roller. The extruded thickness is five to ten times in the finished film. The film can then be finished in a similar way to the extruded film. A person ordinarily skilled in the art will be able to identify the appropriate process parameters based on the polymer composition and the processes used for film formation. Regardless of the manner in which the film is formed, it is desirable to subject it to biaxial orientation by stretching in both machine and transverse directions after training. Stretching in the machine direction starts by forming the film simply by rolling it up and holding the film. This inherently stretches the film in the pickup direction, orienting some of the fibers. Although this becomes more resistant to the film in the direction of. The machine allows the film to easily tear in the direction at right angles, because all fibers are oriented in one direction. Therefore, biaxially stretched films are preferred. The biaxial stretching directs the fibers parallel to the plane of the film, but leaves the fibers oriented randomly within the plane of the film. This provides superior tensile strength, flexibility, robustness and shrinkage capacity, for example compared to unoriented films. It is desirable to stretch the film along two axes at right angles to each other. This increases the tensile strength and the elastic modulus in the stretching directions. It is more desirable for the amount of stretching in each direction to be generally equivalent, so properties or similar behavior are provided within the film when tested from any direction. However, in certain applications, for example those in which a certain amount of shrinkage or greater strength is desired in one direction than in another, such as labels or adhesive and magnetic tapes, this will require an irregular or axial orientation of the fibers. in the film. The biaxial orientation can be obtained by any process known in the art. However, tensioning is preferred, wherein the material is stretched while heating in the transverse direction simultaneously with, or subsequent to, stretching in the machine direction.

The shrinkage can be controlled by keeping the film in a stretched position and heating it for a few seconds before cooling. This heat stabilizes the oriented film, which can be forced to shrink only at temperatures above the heat stabilization temperature. The above conditions and process parameters for making the film by any method known in the art is readily determined by those skilled in the art for any given polymer composition and application as desired. The properties shown by a film will depend on several factors indicated above, and include the polymer composition, the method of making the polymer, the method of making the film and whether the film is treated for stretching or is biaxially oriented. These factors affect many properties of the film, such as shrinkage, tensile strength, elongation at break, impact resistance, dielectric strength and constant, tensile modulus, chemical resistance, point of fusion and similar. In particular, the amount of isosorbide incorporated in the polymer composition directly affects the vitreous transition temperature (Tg) and the inactive fold properties of the film. When the isosorbide is present in an amount of up to about 6.0%, preferably from about 1.0% to 3.0%, the film will retain cracks and wrinkles after bending, which is particularly desirable for applications such as food wraps. Films with approximately 6.0% isosorbide or greater do not show these properties of inactive folds, and therefore may be more suitable for use as flexible coatings, labels and films. The properties of the film can be further adjusted by adding certain additives to the polymeric composition such as colorants, dyes, fillers, stabilizers for UV and heat, antioxidants, plasticizers, lubricants, optically active additives and the like. The fillers may include, for example, kaolin clay, calcium carbonate, silicon oxide, calcium terephthalate, aluminum oxide, titanium oxide, calcium phosphate, lithium fluoride and the like, which can be used for improve the slippage of the polymeric material, as may be desired for use on labels. Alternatively, the isotropic polyester polymers of the invention may be combined with one or more additional polymers, which may be formed into a film as described herein. The combination can be formed to improve certain characteristics of the polymer of the invention. For example, a polyester polymer of the invention can be combined with polyethylene to improve its use as a barrier to water vapor. Other polymers can be added to change characteristics such as air permeability, optical transparency, strength and / or elasticity. Polymers suitable for combination with the polyester polymer of the invention will be known to those ordinarily skilled in the art. In particular, films of the present invention can be made with the polyesters described in co-pending application 09/064, 720 [Attorney's File Number 032358-008] and the polyester combinations described in co-pending application 09 / 064,826 [Attorney's File Number 032358-005], the content of which is incorporated herein by reference. The film of the invention, its manufacture and properties are further illustrated by the following limiting examples.

EXAMPLES The molecular weights of the polymer can be estimated based on the inherent viscosity (I.V.) which is measured for a solution of 1% (weight / volume) of polymer in o-chlorophenol at a temperature of 25 ° C. The concentrations or levels of catalyst component are expressed as ppm, based on a comparison of the weight of the metal with the weight of dimethyl terephthalate or terephthalic acid, depending on the monomer used.

A) Polymerization The following polymerization reagents are added to a Hastalloy B polymerization reactor with a maximum capacity of 189 1 (50 gallons) to which a water cooled reflux column, Hastalloy B with a radius of 15 cm, is placed. (6") packed with stainless steel rings, a stainless steel impeller stirrer, a water cooled condenser and a bypass: 78.02 kg of dimethyl terephthalate, 15.42 kg of isosorbide and 49.90 kg of ethylene glycol, corresponding to a molar ratio of 1: 0.26: 2.00 The catalyst is also charged and consists of 29.57 g of Mn (II) acetate tetrahydrate, 21.43 g of Co (II) acetate tetrahydrate and 35.02 g of Sb (III) oxide. corresponds to 85 ppm manganese (weight of metal as a fraction of the weight of dimethyl terephthalate), 90 ppm of cobalt, and 375 ppm of antimony.The stirred reactor (50 rpm) is purged with a stream of nitrogen while increasing the temperature at 250 ° C. over a period of four hours The reactor is coated and a temperature-controlled hot oil cycle system is used as a heating medium Methanol is continuously collected as the reaction is heated above about 1 hour. 50 ° C. By noting the moment when the temperature decreases in the upper part of the packed reflux column, it is possible to determine the completion of methanol production, which indicates the completion of the first reaction stage, the transesterification of the diols and dimethyl terephthalate. At this point, 77 ppm of phosphorus is added in the form of a solution of polyphosphoric acid in ethylene glycol. In this case, 153 ml of the solution is used, which has a concentration of 10.91 g per 100 g of polyphosphoric acid solution. Also at this time, the nitrogen purge is stopped. Heating is continued. The reaction is heated to 285 ° C for a period of about 2 hours. Then vacuum is gradually applied using a vacuum pump with a multiple vacuum with a 20 horsepower fan. Obtaining full vacuum, preferably less than 1 Torr, requires approximately 1 hour. During this time, ethylene glycol is removed by distillation and a low molecular weight polymer is formed. The molten polymer is heated under vacuum at 285 ° C for about 2 hours, until the polymer obtains a sufficient melt viscosity, determined by an increase in the torque of the agitator. When a sufficient viscosity is obtained, the polymerization is stopped, and the reactor is emptied through a heated die in the lower part. The molten polymer emerges as a filament that, when cooled by immersion in a cold water channel, can be chopped or cut into granules. The polymer granules are dried overnight in a rotating drum which is heated to 120 ° C. The cooled polymer is removed from the flask and crushed. The inherent viscosity of the solution (I.V.) of the material is 0.64 dl / g. The monomeric unit composition of the polymer, determined by NMR of the proton is about 6% isosorbide, 42% ethylene glycol, 2% diethylene glycol and 50% terephthalic acid, all expressed as moles% of the polymer. It is notable that the amount of isosorbide in the polymer is about half the amount that is charged, when compared to the amount of terephthalic acid. The unreacted isosorbide is found in the distillates, especially in ethylene glycol. The amount of isosorbide in the polymer by this process, in this way depends a lot on the efficiency of the distillation or other distillation methods that are used in the process. A person skilled in the art can easily establish the specific details of the process, according to the characteristics of the reactor, distillation columns and the like.

B) Film Making The above polymer is extruded as a film using a Killion PL 100 film extrusion line. The process conditions are as follows: Temperature of the extruder barrel: Zone 1 180 ° C Zone 2 220 ° C Zone 3 240 ° C Zone 4 240 ° C Holding ring temperature 240 ° C Adapter temperature (inlet) 230 ° C Melting pump temperature 230 ° C melting pump rmp 10 Performance 1361 g (3 lb / h) Adapter temperature (outlet) 220 ° C Extruder melt pressure 10,342 kPa (-1500 psi) Die adapter temperature 220 ° C Die temperature 220 ° C Die lip temperature 220 ° C Die separation 0.25 mm (10 mils) Die size 10 cm (4 inches) Drain temperature 50 ° C Speed of die Drain 2 and 3 m / min Filter size 25 micrometers The film that comes out of the die has a width of 10 cm (4 inches) and a thickness of 0. 10 mm (4 mils) The physical properties of the film are given in Table 1.

Table 1 1 Film 00.10 mm} Test ASTM t, rc) 95 differential scanning calorimetry voltage modulus (kPa (Mpsi)) 1.97 x 10"(0.286) D882 elongation at tensile stress (%) 3.9 D882 tensile strength (Kpsi)) 5.58 x 104 (8.1) D882 dielectric strength (Volts / thousandth of an inch) 2872 D 149 dielectric constant 3.7 D 150T barrier to 0¡, cc.mm/m2-dia-atm 8.4 Mocon OX-Trap 2/20 (Minn.MN) refractive index @ 633 nm Abbe refractometer machine direction (mm) 40.00 (1.575) 90 ° relative to MD in a plane 39.97 (1.5737) out of plane 39.93 (1.5723) I C) Stretching of the Film The extruded film is stretched uniaxially and biaxially using a modified Bruckner drawing frame (Bruckner, Siegsdorf, Germany). The sample is inserted csn the address of the machine (MD) on the Y axis of the machine. The drawing speed is 38 mm (1.50 inches) / second. Table 2 describes the drawing ratios, machine temperatures and drawing conditions, as well as the mechanical properties measured according to ASTM 882. It should be understood that the embodiments described in the foregoing are only illustrative and that modifications may occur to an expert. in the technique. Accordingly, this invention is not limited to the embodiments described herein.

Table 2 It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (41)

REGVINDICATIONS Having described the invention as above, the content of the following claims is claimed as property:

1. A film, characterized in that it comprises a polyester, wherein the polyester comprises portions of terephthaloyl; optionally, one or more additional aromatic diacid portions; portions of ethylene glycol; portions of isosorbide and, optionally, one or more additional diol portions, wherein the polyester has an inherent viscosity of at least about 0.35 dl / g, when measured as a 1%, weight / volume, solution of the polyester in o- chlorophenol, at a temperature of 25 ° C

2. The film according to claim 1, characterized in that the terephthaloyl moieties are derived from terephthalic acid or dimethyl terephthalate.

3. The film according to claim 1, characterized in that the polyester further comprises portions of diethylene glycol.

4. The content film according to claim 1, characterized in that one or more additional diol portions are derived from aliphatic alkylene glycols or branched aliphatic glycols having 3-12 carbon atoms and having the empirical formula H0-C-H2p-0H , wherein n is an integer of 3-12, cis or trans-1,4-cyclohexanedimethanol or mixtures thereof; triethylene glycol; 2, 2-bis [4- (2-hydroxyethoxy) phenyl] propane; 1, 1-bis [4- (2-hydroxyethoxy) phenyl] -cydohexane; 9, 9-bis [4- (2-hydroxyethoxy) phenyl] -fluorene; 1.4: 3, 6-dianhydromanitol; 1,4: 3,6-dianhydroiditol; and 1,4-anhydroerythritol.

5. The conformance film with claim 4, characterized in that one or more additional diol portions are derived from cis-1,4-cyclohexanedimethanol, trans-1, -cyclohexanedimethanol or mixtures thereof.

6. The film according to claim 1, characterized in that one or more additional aromatic diacid portions are derived from isophthalic acid, 2,5-furanodicarboxylic acid, 2, 5-thiofenodicarboxylic acid, 2,6-naphthandicarboxylic acid, acid 2, 7-talenodicarboxylic acid or 4,4'-benzoic acid.

7. The film according to claim 6, characterized in that one or more additional aromatic diacid portions are derived from isophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-bibenzoic acid or mixtures thereof.

8. The film according to claim 1, characterized in that the inherent viscosity is about 0.45 to 1.0 dl / g.

9. The film according to claim 8, characterized in that the inherent viscosity is from about 0.50 dl / g to 0.70 dl / g.

10. The film according to claim 1, characterized in that the terephthaloyl moieties are present in an amount of about 40 to 50 mole% of the polyester, one or more additional aromatic diacid portions are present in an amount of about 0.1 to 10.0 mole% of the polyester, the ethylene glycol moieties are present in an amount of about 33 to 49.9 mole% polyester, the isosorbide moieties are present in an amount of about 0.25 to 20.0 mole% of the polyester, and one or more additional diol moieties are present in an amount of up to about 2.0 mole% of the polyester.

11. The conformance film with claim 11, characterized in that one or more additional diol portions comprise portions of diethylene glycol in an amount of up to about 5.0 mole% of the polyester.

12. The conformance film with claim 10, characterized in that the isosorbide portions are present in an amount of about 6.0-12.0%.

13. The conformance film with claim 12, characterized in that the isosorbide portions are present in an amount of about 1.0-3.0%.

14. The conformance film with claim 13, characterized in that the film has inactive fold properties.

15. The film of con fi dence with claim 1, characterized in that it has a thickness less than or equal to 0.25 mm.

16. The film according to claim 1, characterized in that it has been biaxially stretched.

17. A method for making a film, characterized in that the film comprises a polyester, the method is characterized in that it comprises: a) forming the polyester; and b) making the polyester in a film; wherein the polyester comprises portions of terephthaloyl; optionally, one or more additional diacid portions; portions of ethylene glycol; portions of isosorbide; and, optionally, one or more additional diol portions, wherein the polyester has an inherent viscosity of at least about 0.35 dl / g when measured as a 1%, weight / volume solution of the polyester in o-chlorophenol a a temperature of 25 ° C.

18. The method according to claim 17, characterized in that the formation of the polyester comprises: (a) combining in a reactor a monomer comprising a terephthaloyl moiety; optionally one or more additional monomers comprising a portion of aromatic diacid; a monomer comprising a portion of ethylene glycol; a monomer comprising a portion of isosorbide and optionally, one or more additional monomers comprising a portion of diol with a condensation catalyst suitable for condensing diacids and glycols; and (b) heating the monomers and the catalyst at a temperature sufficient to polymerize the monomers in a polyester polymer having at least terephthaloyl portions, ethylene glycol portions and isosorbide portions, wherein the heating is continued for a time sufficient to provide a polyester having an inherent viscosity of at least about 0.35 dl / g when measured as a 1%, weight / volume solution of the polyester in o-chlorophenol at a temperature of 25 ° C.

19. The method according to claim 18, characterized in that the heating of the monomers also includes agitation of the monomers with the concurrent removal of the by-products by distillation or evaporation, or both.

20. The m e d o d o f o f a m e d d a n c e n d l a n c e r 18, characterized in that the monomer comprising a terephthaloyl moiety is terephthalic acid.

21. The method of confinement with claim 20, characterized in that the water and unreacted monomer are removed while the monomers polymerize.

22. The method of con? Neity with claim 18, characterized in that the monomer comprising a terephthaloyl moiety is dimethyl terephthalate.

23. The method according to claim 22, characterized in that the methanol and monomer that has not reacted are removed while the monomers polymerize.

24. The method of conferring with claim 17, characterized in that one or more additional monomers comprising a diol portion are selected from the group consisting of aliphatic alkylene glycols and branched aliphatic glycols having 3-12 carbon atoms and having the form empirical H0-CnIí2n-0H, where n is an integer of 3-12; cis and trans-1, 4-cyclohexanedimethanol and mixtures thereof, triethylene glycol; 2, 2 -bis [4 - (2-hydroxyethoxy) phenyl] propane; 1,1-bis [4- (2-hydroxyethoxy) phenyl] -cydohexane; and 9, 9-bis [4- (2-hydroxyethoxy) phenyl] -fluorene.

25. The method according to claim 17, characterized in that one or more additional monomers comprise other aromatic or alicyclic diacid portions and are selected from the group consisting of isophthalic acid, 2,5-furanodicarboxylic acid, 2,5-thiophenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid and 4,4'-benzoic acid.

26. The method according to claim 18, characterized in that the terephthaloyl moieties are present in an amount of about 40 to about 50 mole% of the polyester, one or more additional diacid portions are present in an amount of up to about 10 mole% of the polyester, the ethylene glycol moieties are present in an amount of about 33 to about 49.9 mole% of the polyester, the isosorbide moieties are present in a amount of about 0.25 to about 20.0 mole% of the polyester, and one or more additional diol portions are present in an amount of up to about 2.0 mole% of the polyester.

27. The method according to claim 17, characterized in that one or more additional diol portions are diethylene glycol portions in an amount of up to about 5.0 mole% of the polyester.

28. The method according to claim 27, characterized in that the isosorbide portions are present in an amount of about 6.0 to 12.0% of the polyester.

29. The method of con? Rmity with claim 28, characterized in that the isosorbide portions are present in an amount from about 1.0 to 3.0% of the polyester.

30. The conformance method with claim 17, characterized in that the film has a thickness less than or equal to 0.25 mm.

31. The conformance method with claim 17, characterized in that the film is stretched biaxially.

32. The method of confidentiality with claim 17, characterized in that it further comprises increasing the molecular weight of the polyester by polymerization in the solid state.

33. The method according to claim 32, characterized in that the solid state polymerization comprises: (a) crystallizing the polyester by heating the polyester at a temperature in the range of about 115 ° C to about 140 ° C; and (b) heating the polyester under vacuum or in a stream of inert gas at an elevated temperature above 140 ° C but below the melting temperature of the polyester to provide a polyester having an increased inherent viscosity.

34. The method of con? Rmity with claim 33, characterized in that the heating step (b) is carried out at a temperature of about 195 ° to 198 ° C for about 10 hours.

35. The method according to claim 33, characterized in that the increased inherent viscosity is at least about 0.65 dl / g.

36. The method of confinement in claim 17, characterized in that the production of the polyester in a film comprises: (a) melting the polyester; (b) extruding the molten polyester; and c) cooling the extruded polyester, whereby a film is formed.

37. An article, characterized in that it is manufactured from the film according to claim 1.

38. The article according to claim 37, characterized in that the article is selected from the group consisting of a label, an insulator, a coating, a capacitor, a laminate, a photographic film, an x-ray film and a tape.

39. The article according to claim 37, characterized in that the film is approximately 0.025-0.15 mm.

40. The article according to claim 37, characterized in that the film is stretched biaxially.

41. The article according to claim 37, characterized in that the film has inactive fold properties.