Method for producing 1,4-butanediol derived from renewable resources and polyester obtained therefrom

Abstract

To provide a polyester that is biodegradable, has a low color number, and has excellent mechanical properties. [Solution] A polyester containing 1,4-butylenedicarboxylate repeat units derived from the condensation of a composition of 1,4-butanediol derived from renewable resources with a mixture containing two or more dicarboxylic acids, wherein the composition has a 1,4-butanediol concentration of 99.0% by weight or more, contains 2-pyrrolidone in an amount of 6 ppm or less, and 2-(4'-hydroxybutoxy)-tetrahydrofuran in an amount of 800 ppm or less, and has an APHA color number of 30 or less after degradation.

Description

[Technical Field]

[0001] The present invention relates to a method for producing 1,4-butanediol from renewable resources by a fermentation route, the resulting 1,4-butanediol and polyesters or polyester-polyols of the diacid-diol type obtained from said 1,4-butanediol. [Background technology]

[0002] 1,4-Butanediol is a widely used monomer for the production of various types of products, such as diacid-diol type polyesters or polyester polyols, which contain repeating units derived from at least one dicarboxylic acid and at least one diol. Due to their mechanical and processing properties, polyesters containing repeating units derived from carboxylic acids and diols are currently widely used in all fields of thermoplastic polymeric material applications (e.g., films, molded and blown articles, and fibers). Furthermore, the resulting polyesters are required to be biodegradable, particularly according to standard EN 13432.

[0003] As used herein, the term "renewable resource" refers to a resource that, due to its inherent properties, is naturally regenerated or cannot be depleted on the time scale of a human lifespan (and, in turn, its use does not harm natural resources for future generations). Furthermore, the use of products of renewable origin contributes to the reduction of atmospheric CO2 and the reduction of the use of non-renewable resources. A typical example of a renewable resource is constituted by agricultural crops.

[0004] 1,4-butanediol can be produced by various methods widely known in the prior art, for example it can be obtained from raw materials of petrochemical origin starting from various precursors such as butadiene, acetylene, maleic anhydride or propylene oxide. Alternatively, 1,4-butanediol can be obtained from renewable resources by fermentation processes starting from carbohydrates, such as sugars and lignocellulosic biomass.

[0005] For example, WO 2015 / 158716 describes a method for producing 1,4-butanediol, which comprises fermentation of a culture medium by a microorganism having at least one metabolic pathway for 1,4-butanediol synthesis, the culture medium comprising a mixture of glucose and sucrose. Specifically, 1,4-butanediol derived from renewable resources generally contains various impurities, including by-products derived directly from the fermentation process and by-products derived from the 1,4-butanediol decomposition process. These impurities can have a detrimental effect on diacid-diol type polyesters or polyester-polyols derived from renewable resource-derived 1,4-butanediol.

[0006] For example, a high content of nitrogen-containing impurities, particularly amino acids, proteins, ammonium salts, urea, and microorganisms, typically derived from the raw materials used in the fermentation process during the synthesis of renewable resource-derived 1,4-butanediol and the fermentation process itself, results in a polyester that is less resistant to hydrolysis. Furthermore, the impurity resulting from 2-(4'-hydroxybutoxy)-tetrahydrofuran (which is produced by the dehydration cyclization reaction of 1,4-butanediol) when present in large quantities, causes solid by-products to accumulate in the reactor during the polyester synthesis process, limiting productivity.

[0007] Also, in the case of batch polymerization processes, impurities present in renewable resource derived 1,4-butanediol can require substantial modification of process conditions to adjust the final viscosity of the desired polyester. The processes currently being developed for the purification of 1,4-butanediol from renewable resources generally involve separation systems based on distillation columns. Purification systems known in the prior art may involve the addition of various agents at at least one stage of the distillation to remove impurities present.

[0008] For example, it is known to ensure color stability in the final product by adding a reducing agent at least in one stage of the distillation. The presence of 2-(4'-hydroxybutoxy)-tetrahydrofuran can also have a negative effect on tetrahydrofuran (THF) synthesis. For example, EP 2 730 566 specifically describes a method for producing THF (2-(4'-hydroxybutoxy)-tetrahydrofuran content up to 3500 ppm) starting from 1,4-butanediol. Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, there is a need to develop a method for producing 1,4-butanediol from renewable resources that can increase the purity of the resulting 1,4-butanediol so that it can be advantageously used for the synthesis of biodegradable, diacid-diol type polyesters or polyester-polyols. [Means for solving the problem]

[0010] In the search for new methods for producing 1,4-butanediol derived from renewable resources, the applicant has now surprisingly found that in the purification step of an aqueous composition of 1,4-butanediol derived from renewable resources, a combination of passage through a cation exchange resin and an anion exchange resin at a specific pH range can dramatically reduce the 2-pyrrolidone content of the resulting 1,4-butanediol. DETAILED DESCRIPTION OF THE INVENTION

[0011] Thus, in a first aspect, the present invention relates to a method for producing 1,4-butanediol from renewable resources, the method comprising: (1) providing a fermentation broth comprising renewable resource-derived 1,4-butanediol and water; Then: (2) separating a liquid fraction comprising 1,4-butanediol and water derived from renewable resources from one or more solid fractions, wherein the liquid fraction comprises 2-pyrrolidone in an amount of 80 ppm or greater; (3) passing the resulting liquid fraction through a bed containing one or more cation exchange resins one or more times until the pH of the liquid fraction is between 4 and 2; (4) passing the resulting liquid fraction through a bed containing one or more anion exchange resins one or more times until the pH of the liquid fraction is between 8 and 11; and (5) distilling the liquid fraction to obtain a composition of 1,4-butanediol derived from renewable resources, wherein the concentration of 1,4-butanediol is 99.0% by weight or greater and the amount of 2-pyrrolidone is 6 ppm or less. Purification of 1,4-butanediol from renewable resources, including The compound comprises:

[0012] In the sense of the present invention, the expression "1,4-butanediol derived from renewable resources" means 1,4-butanediol obtained from a fermentation process of at least one sugar in the presence of one or more microorganisms having at least one metabolic pathway for the synthesis of 1,4-butanediol. The method for producing 1,4-butanediol from renewable resources according to the present invention advantageously does not require post-treatment processes commonly used in the prior art for further purification and therefore stabilization of the final product. Indeed, the method according to the present invention is advantageously carried out in the absence of one or more auxiliary agents, such as reducing agents. Non-limiting examples of reducing agents include sodium borohydride and lithium aluminum hydride.

[0013] In a second aspect, the present invention relates to a 1,4-butanediol composition derived from renewable resources, the composition having a 1,4-butanediol concentration of 99.0 wt% or more, a 2-pyrrolidone content of 6 ppm or less, and an APHA color number of 30 or less, preferably 15 or less, and more preferably 10 or less. The renewable resource derived 1,4-butanediol composition according to the invention is advantageously obtained by the process according to the invention. The composition according to the present invention preferably has a 1,4-butanediol concentration of 99.1% by weight to 99.9% by weight, more preferably 99.5% by weight to 99.9% by weight.

[0014] The compositions according to the invention have surprisingly been found to maintain a stable APHA color number over time, specifically, the APHA color number remains unchanged during storage (e.g., at temperatures above 20°C, typically above 50°C). Compositions according to the present invention typically have an APHA color number of 30 or less, preferably 15 or less, more preferably 10 or less after aging. The APHA color number can be measured using any method known in the prior art, for example, photometrically. Typically, the APHA color number is measured using the standard method DIN EN ISO 6271-1.

[0015] The composition according to the present invention preferably has an amount of 2-pyrrolidone of 5 ppm or less, more preferably 4 ppm or less, more preferably 3 ppm or less, and even more preferably 2.5 ppm or less. When 2-pyrrolidone is present, the composition according to the invention preferably has an amount of 2-pyrrolidone of 0.01 ppm or more, more preferably 0.02 ppm or more. The content of 2-pyrrolidone can be measured by any method known in the prior art, typically by combustion of a sample in an inert atmosphere and analysis of the combustion gases using an analyzer for nitrogen-containing compounds (generally a chemiluminescence analyzer).

[0016] The composition according to the present invention may also have an amount of 2-(4'-hydroxybutoxy)-tetrahydrofuran of 800 ppm, preferably 600 ppm or less, more preferably 550 ppm or less. When 2-(4'-hydroxybutoxy)-tetrahydrofuran is present, the composition according to the present invention preferably has an amount of 2-(4'-hydroxybutoxy)-tetrahydrofuran of 50 to 600 ppm, more preferably 100 to 550 ppm. The content of 2-(4'-hydroxybutoxy)-tetrahydrofuran can be measured using any method known in the prior art. Typically, the content of 2-(4'-hydroxybutoxy)-tetrahydrofuran is measured using gas chromatography.

[0017] Compositions according to the invention may also contain water, typically in an amount of 500 ppm or less, preferably 350 ppm or less. For the purposes of the present invention, the term "ppm" is intended to define parts per million, ie the value of a substance expressed in milligrams (mg) per kilogram (kg) of substance. The compositions according to the invention can also be advantageously used in the process for the preparation of polyester-polyols as intermediates for the synthesis of polyurethanes by reaction with isocyanates.

[0018] The composition according to the invention can be advantageously used in a process for producing polyesters of the diacid-diol type (hereinafter referred to as "polyesters"). Therefore, in a third aspect, the present invention relates to the use of a composition according to the invention in a process for the manufacture of polyesters of the diacid-diol type. The process for producing polyesters according to the invention advantageously requires a residence time that is shorter than that required in processes carried out in the presence of 1,4-butanediol containing 2-pyrrolidone in an amount of 6 ppm or more.

[0019] In a fourth aspect, the present invention provides: (a) (a1) 0 to 80 mol % of units derived from at least one aromatic dicarboxylic acid, based on the total dicarboxylic acid component; and (a2) 20 to 100 mol % of units derived from at least one aliphatic dicarboxylic acid based on the total dicarboxylic acid components a dicarboxylic acid component comprising (b) a diol component containing units derived from a renewable resource-derived 1,4-butanediol composition (a composition having a 1,4-butanediol concentration of 99.0% by weight or more and an amount of 2-pyrrolidone of 6 ppm or less); The present invention relates to a polyester comprising:

[0020] In another embodiment, the present invention provides a method for producing a pharmaceutical composition comprising: (a) (a1) 0 to 80 mol % of units derived from at least one aromatic dicarboxylic acid, based on the total dicarboxylic acid component; and (a2) 20 to 100 mol % of units derived from at least one aliphatic dicarboxylic acid based on the total dicarboxylic acid components a dicarboxylic acid component comprising (b) a diol component obtained by the method for producing renewable resource-derived 1,4-butanediol according to the first aspect of the present invention; The present invention relates to a polyester comprising:

[0021] The renewable resource derived 1,4-butanediol composition used in the process for producing a polyester according to the invention is advantageously a composition according to the invention. The polyesters according to the invention are advantageously biodegradable, preferably biodegradable in accordance with standard EN 13432. The polyesters according to the present invention surprisingly have lower color numbers than similar polyesters in which the diol is substituted with 1,4-butanediol compositions containing 2-pyrrolidone at levels of 6 ppm or greater. In addition, the polyesters according to the invention have excellent mechanical properties.

[0022] In stage (1) of the method according to the invention, a fermentation broth is advantageously obtained by a process for the production of 1,4-butanediol from renewable resources via a fermentation route. The process for producing 1,4-butanediol from renewable resources via a fermentation route is generally carried out according to one of the methods widely known in the prior art, for example according to the method described in WO 2015 / 158716. In stage (1) of the method according to the invention, the fermentation broth comprising renewable resource-derived 1,4-butanediol and water is generally prepared by a method comprising fermenting a culture medium comprising at least one sugar, preferably glucose, and optionally one or more sugars other than glucose, in the presence of one or more microorganisms having at least one metabolic pathway for 1,4-butanediol synthesis.

[0023] The culture medium may also contain other substances necessary for the growth and support of the microorganisms during the fermentation stage by supplying elements such as C, H, O, N, K, S, P, Fe, Ca, Co, Mn, and Mg. Typically, the culture medium may also contain one or more components selected from the group consisting of sugars other than glucose, protein hydrolysates, proteins, amino acids, organic acids, vitamins, mineral salts, yeast extract, and trace elements such as cobalt, calcium, and copper. Cobalt, calcium, and copper may be added to the culture medium, for example, as salts, such as cobalt chloride, calcium chloride, and copper chloride. Generally, the culture medium contains at least one sugar, typically glucose, and optionally one or more sugars other than glucose, at a concentration of 10 to 100 g / L. Because the microorganisms consume one or more sugars during the fermentation stage of the present method, it is generally necessary to replenish the sugars in the fermentation reactor. This replenishment can be carried out continuously or in batch mode, in a manner known to those skilled in the art.

[0024] Furthermore, to limit the content of unused sugars and thus optimize the economic viability of the method, the supply of one or more sugars is advantageously interrupted or gradually reduced before the end of fermentation. Regarding other possible components of the culture medium, the culture medium generally contains salts, essential minerals, and an antifoaming agent. The culture medium can be prepared by any means known to those skilled in the art, such as by mixing all of the components together or by premixing all components except glucose and then adding glucose. The components may be provided individually or as a premix. It is also possible to use a commercially available culture medium as a starting base and then modify its composition, for example, when contacting the culture medium with a microorganism having at least one metabolic pathway for the synthesis of renewable resource-derived 1,4-butanediol. In the method for synthesizing renewable resource-derived 1,4-butanediol, one or more microorganisms can be contacted with any suitable culture medium, optionally containing at least one sugar, to promote microbial growth before the start of fermentation or in a pre-fermentation stage. This stage can be repeated one or more times as necessary to ensure a sufficient initial microbial content. During fermentation, the entire system, including the microorganisms and the culture medium containing one or more sugars, is maintained under conditions suitable for utilizing the metabolic pathway for the synthesis of 1,4-butanediol from renewable resources. Furthermore, one skilled in the art can verify the progress of the process during fermentation, for example, by monitoring one or more parameters and, if necessary, changing the parameters to restore the process to conditions suitable for the production of 1,4-butanediol. The metabolic pathway for 1,4-butanediol synthesis may be naturally occurring in the microorganism, or may be artificially created, for example, by altering, modifying, amplifying, deleting, or restricting an existing metabolic pathway in the microorganism, by introducing genetic material from one or more other microorganisms into the microorganism, by inducing spontaneous genetic mutations, by adding chemicals that inhibit or stimulate the metabolic pathway during the process, or by any genetic engineering technique.Microorganisms having a metabolic pathway for synthesizing 1,4-butanediol are known to those skilled in the art, and are described, for example, in Yim H. et al., Nature Chemical Biology, Vol. 7, July 2011, pp. 445-452 (hereinafter referred to as "Yim et al. 2011") and patent applications WO 2008 / 115840, WO 2009 / 023493, WO 2010 / 030711, WO 2010 / 071697, WO 2010 / 141780, WO 2010 / 141920, WO 2011 / 031897, WO 2011 / 047101, WO 2011 / 066076, WO 2012 / 177943, AU 2013 / 3204409, AU 2013 / 3204038, AU 2013 / 202623, AU 2013 / 203176, AU 2013 / 203177, AU 2013 / 203342, AU 2013 / 203440, AU 2013 / 203480, AU 2013 / 203163. The fermentation broth in stage (1) of the method according to the invention may also contain one or more elements, including one or more microorganisms, cellular debris, optionally unreacted sugars, by-products, metabolic products and any components of the culture medium that have not been assimilated or metabolized by the microorganisms.

[0025] With regard to stage (2) of the method according to the invention, the solid fraction generally contains one or more elements, including one or more microorganisms, cellular debris, optionally unreacted sugars, by-products, mineral salts, metabolic products, and optionally components of the culture medium that have not been assimilated or metabolized by the microorganisms. In the sense of the present invention, solid fraction can also mean suspensions and slurries.

[0026] In stage (2) of the process according to the invention, the reaction medium resulting from the fermentation can be treated by one or more methods selected from sedimentation, centrifugation, filtration, microfiltration, nanofiltration, ultrafiltration, ion exchange, permeation, other suitable solid / liquid separation techniques, and combinations thereof. For example, the reaction medium can first be centrifuged, then filtered, microfiltered, nanofiltered, ultrafiltered, and finally subjected to permeation. In stage (2) of the process according to the invention, one or more operations for evaporation of the reaction medium or various intermediate fractions can also be provided to remove some of the water present. In stage (2) of the process according to the invention, the liquid fraction obtained can be further purified, for example, by treating the liquid fraction comprising renewable resource-derived 1,4-butanediol and water by one or more methods selected from evaporation, distillation, rectification, or combinations thereof. This purification can be carried out, for example, using an apparatus that takes advantage of the different volatilities of the components in the liquid phase comprising renewable resource-derived 1,4-butanediol and water. In one embodiment of the process according to the invention, the liquid phase comprising 1,4-butanediol derived from renewable resources and water is fed to one or more devices that separate at least one vapor phase and at least one condensate by warming and / or condensing at least a portion of the vapor phase to obtain a final composition consisting essentially of 1,4-butanediol derived from renewable resources.

[0027] The liquid fraction obtained in stage (2) of the process according to the invention typically has a 2-pyrrolidone content of more than 100 ppm. The liquid fraction obtained in stage (2) of the process according to the invention typically has an amount of 2-(4'-hydroxybutoxy)-tetrahydrofuran of more than 1500 ppm. The liquid fraction obtained in stage (2) of the process according to the invention generally contains up to 50% by weight, preferably up to 30% by weight, more preferably up to 20% by weight of water relative to the total weight of the liquid fraction. The liquid fraction obtained in stage (2) of the process according to the invention generally comprises from 50 to 95% by weight, preferably from 70 to 90% by weight, more preferably from 75 to 85% by weight, of 1,4-butanediol derived from renewable resources, relative to the total weight of the liquid fraction.

[0028] In stage (3) of the process according to the invention, the cation exchange resin is generally selected from the group consisting of resins derived from strong acids (e.g., sulfonate groups) or weak acids (e.g., carboxylate groups). The cation exchange resin preferably contains a functional group selected from the group consisting of sulfonate groups. Non-limiting examples of cation exchange resins useful in the process according to the invention include, for example, resins commercially available under the trademarks DOWEX® 88 or DOWEX® 88 MB. The pH on leaving stage (3) of the process according to the invention is between 4 and 2, preferably between 4 and 3, and even more preferably between 3.6 and 3.

[0029] In stage (4) of the process according to the invention, the anion exchange resin is generally selected from the group consisting of resins derived from strong bases (e.g., quaternary amine groups) or weak bases (e.g., tertiary amine groups). The anion exchange resin preferably contains a functional group selected from the group consisting of quaternary amine groups. Non-limiting examples of anion exchange resins useful in the process according to the invention include, for example, commercially available resins bearing the trademark DOWEX® 22. The pH on leaving stage (4) of the process according to the invention is between 8 and 11, preferably between 8 and 10, more preferably between 8 and 9.5, even more preferably between 8.6 and 9.5. The order of stages (3) and (4) of the method according to the invention is not particularly limited. Stage (3) may precede or follow stage (4). Preferably, stage (3) precedes stage (4).

[0030] In stage (5) of the process according to the invention, the distillation is generally carried out using one or more distillation columns. The distillation preferably comprises at least one water removal stage, at least one heavy fraction removal stage, and at least one light fraction removal stage. The distillation can be carried out using any method known in the prior art, for example, the method described in WO 2014 / 152665. According to one embodiment of the invention, the distillation is carried out using at least three distillation columns. According to one preferred embodiment of the invention, the distillation is carried out using three distillation columns, the first of which is for the purpose of separating water, the second for the purpose of separating heavy fractions, and the third for the purpose of separating light fractions.

[0031] The method for producing a polyester according to the present invention is typically (i) (a) (a1) 0 to 80 mol % of units derived from at least one aromatic dicarboxylic acid and / or its ester, salt, or derivative, based on the total dicarboxylic acid component; and (a2) 20 to 100 mol % of units derived from at least one aliphatic dicarboxylic acid and / or its ester, salt or derivative, based on the total dicarboxylic acid components a dicarboxylic acid component comprising (b) a diol component comprising units derived from the renewable resource-derived 1,4-butanediol composition described above; Preparation of oligomeric products by esterification and / or transesterification of a mixture comprising (ii) polycondensation of the oligomeric products obtained in stage (i), and (iii) Granulation of the polyester obtained in stage (ii) Includes:

[0032] The dicarboxylic acids may advantageously be obtained from renewable resources. The carboxylic acids may be aliphatic or aromatic and are preferably selected from the group consisting of aromatic dicarboxylic acids of the phthalic acid type, heterocyclic aromatic dicarboxylic compounds, saturated aliphatic dicarboxylic acids, unsaturated aliphatic dicarboxylic acids, esters, salts and mixtures thereof. The phthalic acid type aromatic dicarboxylic acid is preferably phthalic acid or isophthalic acid, more preferably terephthalic acid, their esters, salts and mixtures. The heterocyclic aromatic dicarboxylic acid compound is preferably 2,5-furandicarboxylic acid, 2,4-furandicarboxylic acid, 2,3-furandicarboxylic acid, 3,4-furandicarboxylic acid, more preferably 2,5-furandicarboxylic acid, their esters, salts and mixtures.

[0033] The saturated aliphatic dicarboxylic acid is preferably a C2-C 24 , preferably C4 to C 13 , more preferably C4 to C 11 saturated dicarboxylic acids, their C1-C 24 Preferably, the saturated aliphatic dicarboxylic acid is selected from succinic acid, 2-ethylsuccinic acid, glutaric acid, 2-methylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, brassylic acid, and C1-C4 alkyl esters thereof, salts and mixtures thereof. 24 is selected from alkyl esters of The unsaturated aliphatic dicarboxylic acid is preferably itaconic acid, fumaric acid, 4-methylene-pimelic acid, 3,4-bis(methylene)nonanedioic acid, 5-methylene-nonanedioic acid, or any of their C1-C 24 Preferably, the alkyl esters are selected from C1 to C4 alkyl esters, salts thereof and mixtures thereof.

[0034] The diol component may also include one or more diols other than 1,4-butanediol. Preferably, the diol component consists essentially of the renewable resource derived 1,4-butanediol composition according to the present invention. When present, the additional diols may be obtained from fossil or renewable sources. When present, the additional diol is typically selected from the group consisting of saturated aliphatic diols, unsaturated aliphatic diols, aromatic diols, and mixtures thereof.

[0035] More preferably, the saturated aliphatic diol is selected from the group consisting of 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, 2-methyl-1,3-propanediol, sorbitol dianhydride, mannitol dianhydride, iditol dianhydride, cyclohexanediol, cyclohexanemethanediol, dialkylene glycols and polyalkylene glycols (e.g., polyethylene glycol, polypropylene glycol) having a molecular weight of 100 to 4000, and mixtures thereof.

[0036] The unsaturated aliphatic diol is more preferably selected from the group consisting of cis 2-butene-1,4-diol, trans 2-butene-1,4-diol, 2-butyne-1,4-diol, cis 2-pentene-1,5-diol, trans 2-pentene-1,5-diol, 2-pentyne-1,5-diol, cis 2-hexene-1,6-diol, trans 2-hexene-1,6-diol, 2-hexyne-1,6-diol, cis 3-hexene-1,6-diol, trans 3-hexene-1,6-diol, 3-hexyne-1,6-diol, and mixtures thereof. Instead, the aromatic diol is more preferably selected from the group consisting of 2,5-furan dimethanol, 2,4-furan dimethanol, 2,3-furan dimethanol, 3,4-furan dimethanol, more preferably 2,5-furan dimethanol, and mixtures thereof.

[0037] In one embodiment of the invention, the polyester repeat units are 1,4-butylenedicarboxylate repeat units derived from the condensation of a composition of 1,4-butanediol derived from renewable resources in accordance with the present invention with a mixture comprising two or more dicarboxylic acids, preferably dicarboxylic acids of the types described above. In one preferred embodiment, the repeating units, in terms of total dicarboxylic acid content, are: - 35 to 100 mol %, preferably 40 to 95 mol % of one or more aromatic dicarboxylic or heteroaromatic dicarboxylic acid compounds, esters or salts thereof; 0 to 65 mol %, preferably 5 to 60 mol %, of one or more aliphatic dicarboxylic acids, their esters and salts The dicarboxylic acids are derived from a mixture of aromatic and aliphatic dicarboxylic acids, including

[0038] In another preferred embodiment, the repeat units are derived from a mixture comprising at least two aromatic dicarboxylic acids, the mixture having, in terms of total aromatic dicarboxylic acid content: 1 to 99 mol %, preferably 5 to 95 mol %, more preferably 10 to 80 mol % of terephthalic acid, its esters or salts; 99 to 1 mol %, preferably 95 to 5 mol %, more preferably 90 to 20 mol % of 2,5-furandicarboxylic acid, its ester or salt Includes: In another preferred embodiment of the present invention, the repeating units are derived from a mixture containing at least two saturated aliphatic dicarboxylic acids, the mixture containing at least 50 mol %, preferably 60 mol % or more, more preferably 65 mol % or more of one or more saturated aliphatic dicarboxylic acids relative to the total aliphatic dicarboxylic acid content, and the saturated aliphatic dicarboxylic acids are succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, and their C1-C 24 Preferably, the ester is selected from the group consisting of C1 to C4 esters and mixtures thereof.

[0039] In the case of copolyesters, they preferably contain 70 mole %, more preferably 80 mole %, of 1,4-butylenedicarboxylate units. In addition to the 1,4-butylenedicarboxylate units, the copolyesters preferably contain alkylene dicarboxylate units derived from the condensation of one or more diols whose alkylene groups are not 1,4-butanediol, preferably diols selected from the group consisting of saturated aliphatic diols, unsaturated aliphatic diols, aromatic diols, and mixtures thereof.

[0040] Representative examples of polyesters are: poly(l,4-butylene succinate), poly(l,4-butylene adipate), poly(1,4-butylene azelate), poly(l,4-butylene sebacate), poly(l,4-butylene adipate-co-l,4-butylene succinate), poly(1,4-butylene azelate-co-1,4-butylene succinate), poly(l,4-butylene sebacate-co-1,4-butylene succinate), poly(1,4-butylene succinate-co-1,4-butylene adipate-co-1,4-butylene azelate). late), poly(1,4-butylene adipate-co-1,4-butylene azelate), poly(1,4-butylene sebacate-co-1,4-butylene adipate), poly(1,4-butylene hexadecanedioate), poly(1,4-butylene octadecanedioate), poly(1,4-butylene hexadecanedioate-co-1,4-butylene terephthalate), poly(1,4-butylene octadecanedioate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene terephthalate), Poly(1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene azelate-co-1,4-butylene terephthalate), poly(1,4-butylene brassylate-co-1,4-butylene terephthalate), poly(1,4-butylene succinate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene azelate-co-1,4-butylene sebacate-co-1,4-butylene terephthalate) late), poly(1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate), poly(1,4-butylene succinate-co-1,4-butylene sebacate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene succinate-co-1,4-butylene terephthalate), poly(1,4-butylene azelate-co-1,4-butylene succinate-co-1,4-butylene terephthalate), poly(1,4-butylene adipate-co-1,4-butylene 2,5-furandicarboxylate), poly(1,4-butylene sebacate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene azelate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene brassylate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene succinate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene adipate-co-1,4-butylene sebacate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene azelate-co-1,4-butylene sebacate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene adipate Poly(1,4-butylene succinate-co-1,4-butylene sebacate-co-1,4-butylene-2,5-furandicarboxylate), Poly(1,4-butylene adipate-co-1,4-butylene succinate-co-1,4-butylene-2,5-furandicarboxylate) ), poly(1,4-butyleneazelate-co-1,4-butylenesuccinate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene-hexadecanedioate-co-1,4-butylene-2,5-furandicarboxylate), poly(1,4-butylene-octadecanedioate-co-1,4-butylene-2,5-furandicarboxylate).

[0041] The polyester according to the present invention preferably comprises, in addition to 1,4-butylenedicarboxylate units and optionally different alkylenedicarboxylate units, repeat units derived from at least one hydroxy acid in an amount of 0 to 49 mol %, preferably 0 to 30 mol %, relative to the total moles of the dicarboxylic acid component. Examples of convenient hydroxy acids are glycolic acid, hydroxybutyric acid, hydroxycaproic acid, hydroxyvaleric acid, 7-hydroxyheptanoic acid, 8-hydroxycaproic acid, 9-hydroxynonanoic acid, lactic acid or lactide. The hydroxy acids may be inserted into the chain itself or may first be subjected to reaction with a dicarboxylic acid or diol. The diacid-diol type polyesters according to the present invention have an MFR (measured at 190°C and 2.16 kg according to standard ISO 1133-1) in the range of 1 to 50 g / 10 min, preferably 1.5 to 30 g / 10 min, more preferably 2 to 20 g / 10 min, and even more preferably 3 to 10 g / 10 min.

[0042] In a fifth aspect, the present invention provides a method for manufacturing a semiconductor device comprising: at least one polyester according to the invention, -One or more polyesters other than the above polyesters The present invention relates to a mixture comprising: The mixture according to the invention preferably comprises at least one polyester according to the invention, 1 to 70% by weight, relative to the weight of the polyester, of one or more polymers other than the aforementioned polyesters The compound comprises:

[0043] Typically, the blends according to the invention are produced by mixing with one or more polymers, typically in an amount of 1 to 70% by weight relative to the weight of the polyester, preferably in an extruder at temperatures of 150° C. to 250° C. The polymers are generally selected from the group consisting of hydroxy acid polyesters, polyolefins, aromatic polyesters free of 1,4-butylenedicarboxylate units, polyester- and polyether-urethanes, polyurethanes, polyamides, polyamino acids, polyethers, polyureas, polycarbonates and / or one or more additives selected from fillers, plasticizers, UV stabilizers, lubricants, nucleating agents, surfactants, antistatic agents, pigments, flame retardants, compatibilizers, polyphenols, reinforcing agents, coupling agents, antioxidants, mildew inhibitors, waxes and process coadjuvants.

[0044] Among the hydroxy acid polyesters, the following are preferred: lactic acid polyesters, poly-ε-caprolactone, polyhydroxybutyrate, polyhydroxybutyrate-valerate, polyhydroxybutyrate-propanoate, polyhydroxybutyrate-hexanoate, polyhydroxybutyrate-decanoate, polyhydroxybutyrate-hexadecanoate, polyhydroxybutyrate-octadecanoate, poly3-hydroxybutyrate-4-hydroxybutyrate.

[0045] Preferably, the hydroxy acid polyester comprises one or more lactic acid polyesters in an amount of at least 80% by weight relative to the total weight of the hydroxy acid polyesters. The lactic acid polyesters are preferably selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, poly-D,L-lactic acid stereocomplex, copolymers containing 50 mol % or more of said lactic acid polyesters, or mixtures thereof. Particularly preferred are lactic acid polyesters containing at least 95% by weight of repeating units derived from L-lactic acid or D-lactic acid or a combination thereof, typically having an average molecular weight (Mw) of 50,000 or more and a kinematic viscosity (at 1000 s at 190°C according to standard ASTM D3835) of 50 to 700 Pas, preferably 80 to 500 Pas. -1 velocity gradient, 1 mm diameter and L / D of 10), TM Products are trademarked Biopolymer 4043D, 3251D and 6202D. Preferably, a mixture comprising at least one polyester according to the invention and at least one hydroxy acid polyester comprises from 1% to 80% by weight, preferably from 2% to 70% by weight, of said hydroxy acid polyester relative to the total weight of both polyesters.

[0046] Among the polyolefins, the following are preferred: polyethylene, polypropylene, their copolymers, polyvinyl alcohol, polyvinyl acetate, polyethyl-vinyl acetate and polyethylene vinyl alcohol. Among the aromatic polyesters, the following are preferred: PET, PBT, PTT, especially those with a renewable content of 30% or more, and polyalkylene furan dicarboxylates, among which poly(1,2-ethylene-2,5-furan dicarboxylate), poly(1,3-propylene-2,5-furan dicarboxylate), poly(1,4-butylene-2,5-furan dicarboxylate), and mixtures thereof are particularly preferred.

[0047] Examples of polyamides are: polyamides 6 and 6.6, polyamides 9 and 9.9, polyamides 10 and 10.10, polyamides 11 and 11.11, polyamides 12 and 12.12 and combinations thereof, in particular combinations of the 6 / 9, 6 / 10, 6 / 11 or 6 / 12 type. The polycarbonate may be selected from the group consisting of polyethylene carbonate, polypropylene carbonate, polybutylene carbonate, mixtures and copolymers thereof. The polyester may be selected from the group consisting of polyethylene glycol, polypropylene glycol, polybutylene glycol, copolymers thereof and mixtures thereof, having a molecular weight of 70,000 to 500,000.

[0048] Preferably, the mixture comprising at least one polyester according to the invention and at least one polymer selected from the group consisting of polyolefins, aromatic polyesters, polyester- and polyether-urethanes, polyurethanes, polyamides, polyamino acids, polyethers, polyureas, polycarbonates and mixtures thereof comprises from 5% to 80% by weight of said polymer, more preferably from 10% to 60% by weight, relative to the total weight of the polyester obtained by the process according to the invention and said polymer.

[0049] The fillers are preferably selected from the group consisting of kaolin, barytes, clay, talc, carbonates or calcium and magnesium, iron and lead, aluminium hydroxide, diatomaceous earth, aluminium sulphate, barium sulphate, silica, mica, titanium dioxide, wollastonite, starch, cellulose, chitin, chitosan, alginate, proteins such as gluten, zein, casein, collagen, gelatin, natural gum, rosin acid and derivatives and mixtures thereof.

[0050] The term "starch" refers to all types of starch, in particular wheat flour, native starch, hydrolyzed starch, destructed starch, gelatinized starch, plasticized starch, thermoplastic starch, complexed starch, and biofillers, including mixtures thereof. Starches, such as those derived from potato, corn, tapioca, and pea, are particularly suitable according to the invention. Starches that are easily destructed and have a high initial molecular weight, such as potato starch and corn starch, have proven particularly advantageous. Starch and cellulose may be present as such or in a chemically modified form, such as starch with a degree of substitution of 0.2 to 2.5, cellulose esters, hydroxypropyl starch, starches modified with fatty chains, or as cellophane.

[0051] In the case of destructed starches, mention may be made of the teachings contained in patents EP 0 118 240 and EP 0 327 505. Destructed starch here means starch that has been modified so as to show essentially no so-called "Maltese crosses" under an optical microscope in polarized light and no so-called "ghosts" under an optical microscope in phase contrast. Advantageously, the disruption of the starch is carried out by an extrusion process at a temperature between 110° C. and 250° C., preferably between 130° C. and 180° C., preferably at a pressure between 0.1 MPa and 7 MPa, preferably between 0.3 MPa and 6 MPa, preferably applying a specific energy of at least 0.1 kWh / kg during the extrusion. This disruption can be carried out in stage (2) of the process according to the invention or can be carried out in a separate phase after which the starch is fed to stage (2) in already disrupted form.

[0052] The starch is preferably disrupted in the presence of 1 to 40% by weight of one or more plasticizers selected from water and polyols having 2 to 22 carbon atoms, based on the weight of the starch. The water may be naturally present in the starch. Among the polyols, polyols having 1 to 20 hydroxyl groups and 2 to 6 carbon atoms, their ethers, thioethers, and organic and inorganic esters are preferred. Examples of polyols include glycerin, diglycerol, polyglycerol, pentaerythritol, polyglycerol ethoxylate, ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, sorbitol monoacetate, sorbitol diacetate, sorbitol monoethoxylate, sorbitol diethoxylate, and mixtures thereof. In a preferred embodiment, the starch is disrupted in the presence of glycerol or a mixture of plasticizers comprising glycerol, more preferably 2 to 90% by weight of glycerol. Preferably, the disrupted starch comprises 1 to 40% by weight of a plasticizer selected from the above, relative to the weight of the starch. Compositions comprising disrupted starch are particularly preferred. Preferably, the starch in the mixture is present in the form of particles having a circular or elliptical cross section, or in any case a cross section resembling an ellipse, and an arithmetic mean diameter of 1 μm or less, more preferably a median diameter measured along the major axis of the particle of 0.5 μm or less. As for cellulose, it may be present, for example, in the form of cellulose fibers or as wood flour.

[0053] Advantageously, two or more fillers may be used in the mixture according to the invention. Mixtures containing starch and at least one other filler are particularly preferred. As for the plasticizers, phthalates, such as diisononyl phthalate, trimellitates, such as C4-C 20 Monoalcohols, preferably C4-C selected from the group consisting of n-octanol and n-decanol 20One or more plasticizers selected from the group consisting of esters of trimellitic acid with monoalcohols and aliphatic esters having the following structure may be present in addition to any plasticizers, preferably those used in preparing the disrupted starch described above: R1-OC(O)-R4-C(O)-[-O-R2-OC(O)-R5-C(O)-] m -O-R3 (In the formula, R1 is H, C1~C 24 Saturated and unsaturated straight and branched chain alcohol residues of the type C1-C 24 selected from one or more groups comprising a polyol residue esterified with a monocarboxylic acid; R2 comprises a —CH2—C(CH3)2—CH2— group and a C2-C8 alkylene, and contains at least 50 mol% of the —CH2—C(CH3)2—CH2— group; R3 is H, C1~C 24 Saturated and unsaturated straight and branched chain alkyl groups of the type C1-C 24 selected from one or more groups comprising a polyol residue esterified with a monocarboxylic acid; R4 and R5 may be the same or different and each represent one or more of C2 to C 22 , preferably C2 to C 11 , more preferably C4 to C9 alkylene, and at least 50 mol% C7 alkylene; and m is an integer from 1 to 20, preferably from 2 to 10, more preferably from 3 to 7. Preferably, in this ester, at least one R1 and / or R3 group is selected from the group consisting of at least one C1-C stearic acid, palmitic acid, 9-ketostearic acid, 10-ketostearic acid, and mixtures thereof, preferably in an amount of 10 mol % or more, more preferably 20 mol % or more, and even more preferably 25 mol % or more, based on the total amount of R1 and / or R3 groups. 24 It contains a polyol residue esterified with a monocarboxylic acid.

[0054] Examples of aliphatic esters of this type are described in Italian patent application MI2014A000030 and applications PCT / EP2015 / 050336, PCT / EP2015 / 050338. If present, the selected plasticizer is preferably present in an amount of 0.2% to 20% by weight, more preferably 0.5% to 10% by weight, relative to the total weight of the mixture. The lubricant is preferably selected from esters and metal salts of fatty acids, such as zinc stearate, calcium stearate, aluminum stearate and acetyl stearate. When used, lubricants are preferably used in an amount of up to 1% by weight, more preferably up to 0.5% by weight, based on the total weight of the mixture. Examples of nucleating agents include sodium saccharin, calcium silicate, sodium benzoate, calcium titanate, boron nitride, talc, zinc stearate, and low molecular weight PLA. These additives are preferably added in an amount of up to 10% by weight, more preferably 2% to 6% by weight, based on the total weight of the polyester. Pigments may also be added if necessary, such as clay, copper phthalocyanine, titanium dioxide, silicates, iron oxide and hydroxide, carbon black, and magnesium oxide. These additives are preferably added in an amount of up to 10% by weight.

[0055] As regards the polyphenols, they are preferably selected from the group consisting of lignin, silybin, silydianin, isosilybin and silychristin, and mixtures thereof, and are preferably present in an amount of 0.5% to 7% by weight relative to the total weight of the mixture. In one preferred embodiment, the polyphenols of plant origin advantageously comprise a mixture containing silybin, silydianin, isosilybin, and silychristin. This mixture can advantageously be obtained by alcohol extraction from de-oiled cake of Silybum marianum seeds and is commercially available and commonly known as silymarin. The polyesters obtained by the process according to the invention are highly suitable for use alone or in mixtures with other polymers in many practical applications for the manufacture of products such as films, fibers, nonwovens, sheets, folded, thermoformed, blown, and unfolded articles, and articles laminated using extrusion coating techniques.

[0056] In a sixth aspect, the present invention relates to an article comprising at least one polyester according to the invention. In one embodiment of the invention, the product according to the invention comprises a mixture according to the invention. Products according to the present invention are particularly suitable for use in a variety of applications, including food applications.

[0057] Examples of products comprising at least one polyester according to the invention are: -film; -Bags for collecting organic matter (e.g. food waste or grass clippings); - Thermoformed or single- or multi-layer food packaging, for example containers for milk, yogurt, meat or beverages; -coatings obtained using the extrusion coating method; - multilayer laminates having layers of paper, plastic materials, aluminum, metallized film; -Foam or foam beads for the production of parts formed by heating; -Foamed and semi-foamed products, including foam blocks formed from pre-foamed products; -Foam sheets, thermoformed foam sheets and food packaging containers obtained therefrom; -fruit and vegetable containers in general; - as fillers, gelling, broken and / or complexed starches, native starches, wheat flour, compositions with other natural fillers of vegetable or mineral origin; and Fibres, microfibres, composite fibres with a core comprising a hard polymer (e.g. PLA, PET, PTT, etc.) and an outer shell of the material according to the invention, dablens composite fibres, fibres with various cross sections from round to multilobal, flock fibres, woven and non-woven or spunbonded or thermobonded fabrics for the sanitation sector, hygiene practices, agriculture and clothing, which can be used in applications as a replacement for plasticised PVC.

[0058] The product according to the invention is preferably a film. Films according to the invention can be uniaxially or biaxially stretched films. In one embodiment of the invention, the film according to the invention is a multilayer film with other polymeric materials. The films according to the invention are particularly suitable for use as mulching films in the agricultural sector. In addition, the films according to the invention are particularly suitable as stretch films for food, agricultural bales and waste packaging. [Example]

[0059] The following examples illustrate the invention in a non-limiting manner. Measurement method The content of 2-pyrrolidone (hereinafter referred to as "2-P") was determined by combustion of the samples under an inert atmosphere and analysis of the combustion gases using a chemiluminescence analyzer (Analytik Jena Multi EA5000 analyzer). The content of 2-(4'-hydroxybutoxy)-tetrahydrofuran (hereinafter referred to as "HB-THF") was determined by gas chromatography on the product obtained after the distillation stage. The water content was determined by conventional methods on the product obtained after the distillation stage. The APHA color number (measured in Pt-Co units) was measured spectrophotometrically according to the standard method DIN EN ISO 6271-1 before and after the accelerated ageing test. The accelerated aging test was carried out by heating a sample of 1,4-butanediol to 200°C in a stirred system maintained under these conditions for 2 hours. The system was then cooled to room temperature. At the end of the test, the thermal stability of the 1,4-butanediol was evaluated by APHA color spectrophotometry according to the standard method DIN EN ISO 6271-1. The results are reported in Table 1.

[0060] Example 1 The renewable resource derived 1,4-butanediol composition according to the present invention was obtained from the fermentation broth described in patent application WO 2015 / 158716. The resulting fermentation broth was processed to separate a liquid fraction containing renewable resource-derived 1,4-butanediol and water from one or more solid fractions, and the resulting liquid fraction was then subjected to a purification process using sequential microfiltration, nanofiltration, ion exchange, and evaporation treatments to obtain a liquid fraction containing 20 wt. % water based on the total weight of the liquid fraction. The remaining liquid fraction is then (a) a purification process in which the liquid fraction is passed through a bed comprising a cation exchange resin containing sulfonate groups until a pH of 4 or less is obtained for the liquid fraction upon leaving the cation exchange resin, followed by passage through an ion exchange resin containing quaternary amine groups until a pH of 8 or more is obtained for the liquid fraction upon leaving the ion exchange resin; (b) Distillation were added sequentially. The contents of 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran in the resulting composition were measured after distillation. The results are shown in Table 1.

[0061] Comparative Example 1 A renewable resource-derived 1,4-butanediol composition was obtained according to the procedure described in Example 1, except that in stage (a) of Example 1, the cation exchange resin was used for a longer time until the pH of the liquid fraction was 4.5, and the anion exchange resin was run for a longer time until the pH reached 7. The contents of 2-pyrrolidone and 2-(4'-hydroxybutoxy)-tetrahydrofuran in the resulting composition were measured after distillation. The results are shown in Table 1.

[0062] Comparative Example 2 Commercial grade fossil-derived 1,4-butanediol (manufactured by Markor Chemical Industry Co., Ltd.) was used. As shown by the data provided in Table 1, compositions of 1,4-butanediol derived from renewable resources obtained by a method according to the present invention, such as the composition described in Example 1 according to the present invention, unexpectedly have lower 2-pyrrolidone values than the 2-pyrrolidone values of the compositions obtained according to each of Comparative Examples 1 and 2. Furthermore, as shown by the data provided in Table 2, compositions of renewable resource-derived 1,4-butanediol obtained by the method according to the present invention, such as the composition described in Example 1 according to the present invention, advantageously have APHA color numbers that are stable over time without requiring post-treatment procedures for further purification and therefore stabilization of the final product, as is typically required for fossil-source-derived 1,4-butanediol. Specifically, as shown by the data provided in Table 1, compositions of renewable resource-derived 1,4-butanediol obtained by the method according to the present invention surprisingly maintain an APHA color number of less than 10 before and after accelerated aging testing.

[0063] [Table 1]

[0064] Preparation of Polyesters of Examples 2 and 3 The reagents terephthalic acid, adipic acid and / or azelaic acid, 1,4-butanediol (from Example 1) and esterification catalyst (Tyzor TE®) were fed into a 25 liter steel reactor equipped with an oil heater, a distillation column, a vacuum line with a distillate removal system and a mechanical stirrer. The reactor was sealed under nitrogen, the agitator was turned on, and the temperature was gradually increased to 220°C over 1 hour, during which time water from the esterification process began to distill off. The temperature was then increased to 240°C over an additional 1 hour. Distillation proceeded for 1 hour at 240°C, at the end of which the apparent conversion was greater than 100%. At the end of the esterification stage, a polymerization catalyst (1000 ppm tetrabutyl orthotitanate, TnBt) was added, the temperature of the melt was maintained at 240° C., and the pressure was gradually reduced to below 2 mbar over a period of about 30 minutes. The temperature of the melt was maintained at 240° C. and the reaction was continued for 4 hours until the desired intrinsic viscosity was obtained. The material was then discharged as filaments through a spinner, cooled in a water bath, and pelletized.

[0065] Example 2 A polyester poly(1,4-butylene adipate-co-1,4-butylene azelate-co-1,4-butylene terephthalate) was obtained, having 48 mol % of 1,4-butylene terephthalate units, 16 mol % of azelaic acid units, and 36 mol % of adipic acid units, based on the total dicarboxylic acid content. The 1,4-butylene units of this polyester were obtained from 1,4-butanediol according to Example 1.

[0066] Example 3 A polyester poly(1,4-butylene adipate-co-1,4-butylene terephthalate) was obtained having 47 mol % of 1,4-butylene terephthalate units and 53 mol % of adipic acid units, based on the total dicarboxylic acid content. The 1,4-butylene units of this polyester were obtained from 1,4-butanediol according to Example 1. The MFR values of the polyesters according to Examples 2 and 3 are reported in Table 2.

[0067] [Table 2]

Claims

1. A polyester comprising 1,4-butylenedicarboxylate repeating units derived from the condensation of a composition of 1,4-butanediol obtained from a fermentation process of at least one sugar in the presence of one or more microorganisms having at least one metabolic pathway for the synthesis of 1,4-butanediol with a mixture comprising two or more dicarboxylic acids, the composition has a concentration of 1,4-butanediol of 99.0% by weight or more, an amount of 2-pyrrolidone of 0.01 ppm to 6 ppm or less, and an amount of 2-(4'-hydroxybutoxy)-tetrahydrofuran between 50 ppm and 550 ppm, and an APHA color number after aging of 30 or less, wherein the aging is carried out by heating a sample of 1,4-butanediol to 200°C in a stirred system maintained under these conditions for 2 hours, followed by cooling to room temperature, and the APHA color is measured at the end of the aging according to the standard method DIN EN ISO 6271-1, polyester.

2. the repeating unit is a mixture of aromatic dicarboxylic acids or a mixture of aromatic dicarboxylic acids and aliphatic dicarboxylic acids, - 35 to 100 mol % relative to the total dicarboxylic acid content of one or more aromatic or heteroaromatic dicarboxylic acid compounds or their esters or salts, 2. A polyester according to claim 1, derived from a mixture containing from 0 to 65 mole % of one or more aliphatic dicarboxylic acids or esters or salts thereof, relative to the total dicarboxylic acid content.

3. The repeating unit is a mixture of an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid, - 40 to 95 mole % of one or more aromatic dicarboxylic or heteroaromatic dicarboxylic acid compounds or their esters or salts, relative to the total dicarboxylic acid content - 5 to 60 mole % of one or more aliphatic dicarboxylic acids or their esters or salts relative to the total dicarboxylic acid content 3. The polyester of claim 1, which is derived from a mixture comprising:

4. The repeating unit is a mixture comprising at least two aromatic dicarboxylic acids, - 1 to 99 mole % terephthalic acid or its esters or salts, with respect to the total aromatic dicarboxylic acid content, - 99 to 1 mole % of 2,5-furandicarboxylic acid or its esters or salts, relative to the total aromatic dicarboxylic acid content The polyester according to any one of claims 1 to 3, which is derived from a mixture comprising:

5. The repeating units are a mixture containing at least two saturated aliphatic dicarboxylic acids, and at least 50 mol % of the total aliphatic dicarboxylic acid content is succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, or their C 1 ~C 24 4. The polyester according to claim 1, which is derived from a mixture comprising one or more saturated aliphatic dicarboxylic acids selected from the group consisting of alkyl esters of the following compounds:

6. The saturated aliphatic dicarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, brassylic acid, and their C 1 ~C 4 6. The polyester of claim 5, wherein the alkyl ester is selected from the group consisting of alkyl esters of the formula:

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