Method for producing polyester (co)polymer

Abstract

The present invention relates to a chemical process for the preparation of polyester (co)polymers starting from monomers and / or oligomers, comprising a step of reacting a mixture of at least (a) one or more diol monomers and (b) one or more dicarboxylic acid monomers and / or their esters and / or one or more oligomers comprising monomer units of (a) and (b), in which at least one diol monomer (a) is a secondary diol monomer and (c) a monohydric alcohol having a boiling point at ambient pressure equal to or higher than 175° C. and an acid dissociation constant equal to or lower than 12.0 and equal to or higher than 7.0, measured in water at 25° C., is further added in an amount of 2.5 to 100% by weight relative to the total weight of the monomers and / or oligomers.

Description

[Technical field]

[0001] The present invention relates to a process for the chemical preparation of polyester (co)polymers, comprising the step of reacting a mixture of at least one or more secondary diols with one or more dicarboxylic acids and / or their esters, to novel polyester (co)polymers obtainable by said process, to compositions comprising said novel polyester (co)polymers, and to molded articles comprising said polyester (co)polymers. [Background technology]

[0002] Polyethylene terephthalate (PET) is an important polyester material and is currently the second largest "big 5" plastic by volume, with a global annual production of approximately 80 million tonnes [www.textileworld.com / textile-world / features / 2019 / 07 / challenges-facing-recycled-polyester / ]. The most common uses of PET are in fibers (textiles; 56 million tonnes / year) and disposable packaging such as bottles (20 million tonnes / year), engineering plastics and films. Although PET has many favorable properties, a significant drawback of the material is that it is not biodegradable, yet recycling of PET still accounts for only about 3% of all PET used worldwide. Research has therefore begun to develop new classes of polyesters, which has already led to the discovery of alternative monomers that can be used to produce new (co)polymers.

[0003] For example, it has been discovered that many monomers useful in today's fossil-based plastics can likely be synthesized from bio-based feedstocks. One example of this is 2,5-furandicarboxylic acid (FDCA), which has been found to be a bio-based alternative to terephthalic acid (TPA) and is used in the manufacture of PET. Poly(ethylene-2,5-furanoate) (PEF), a completely bio-based polyester when prepared from bio-based FDCA and bio-based ethylene glycol, exhibits superior thermal, barrier and mechanical properties compared to fossil-based PET.

[0004] Other interesting monomers are, for example, 1,4:3,6-dianhydrohexitols, a class of rigid diol monomers derived from diol monomers such as D-glucose, D-mannose or D-idose. Said monomers can be obtained by reduction of the respective sugar to the corresponding sugar alcohol followed by two subsequent dehydration reactions. Isosorbide is the most widely available 1,4:3,6-dianhydrohexitol, since it is derived from the sugar alcohol sorbitol.

[0005] For example, International Patent Application No. 2018 / 211133 describes a method for the preparation of an isosorbide (or related) polyester copolymer comprising the following monomers: (i) one or more bicyclic diols selected from the group consisting of isosorbide, isoidide, isomannide, 2,3:4,5-di-O-methylene-galactitol and 2,4:3,5-di-O-methylene-D-mannitol, in the range of from ≧25 mol % to ≦49.9 mol %, relative to the total molar amount of monomers; The method includes the steps of: (ii) polymerizing one or more oxalic acid diesters having a chemical structure according to formula (VI): R2-OC(O)-C(O)-OR3(VI), in a range of ≧45 mol % to ≦50 mol %, based on the total molar amount of monomers, where R2 and R3 are each independently a C3-C20 alkyl group, a C2-C20 alkenyl group, a C4-C20 cycloalkyl group, a C4-C20 aryl group, or a C5-C20 alkylaryl group; (iii) one or more linear C2-C12 diols, in a range of ≧0.1 mol % to ≦25 mol %, based on the total molar amount of monomers; and (iv) optionally one or more additional monomers, in a range of ≧0 mol % to ≦5 mol %, based on the total molar amount of monomers.

[0006] Isosorbide is utilized in polyesters, for example, to increase the glass transition temperature and lower the melting temperature compared to the parent polymer, since the bent structure of isosorbide weakens the interactions between the polymer chains. One example of a polymer in which isosorbide can be incorporated is the polyester poly(1,4-cyclohexanedimethylene terephthalate) (PCT), which has excellent mechanical properties due to its rigid structure. However, the main drawback of this polyester is that it has a high melting temperature of 278 to 318°C, which is close to the decomposition temperature of the polymer. This makes the polyester difficult to process, since thermal degradation can cause embrittlement of the final material. The incorporation of isosorbide into PCT polyesters was investigated. The problem with isosorbide is that it has two secondary alcohol functionalities, present in ethylene glycol or the abovementioned cyclohexanedimethanol, which usually react only very slowly, especially when compared to the highly reactive primary alcohol functionalities. As a result, it has been confirmed that it has been very difficult to produce high molecular weight copolymers with high isosorbide content to date. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Patent Application No. 2018 / 211133 [Patent Document 2] U.S. Patent Application Publication No. 2011282020 [Patent Document 3] International Patent Application No. 2013 / 062408 [Patent Document 4] International Patent Application No. 2010 / 010282 Summary of the Invention [Problem to be solved by the invention]

[0008] It would be advantageous to provide an efficient method for chemically producing copolymers containing a high content of monomers derived from secondary diols, especially (bi)cyclic secondary diols, especially isosorbide, so that (new) high molecular weight copolyesters are produced, preferably sustainable. In particular, new copolyesters having improved properties over currently known polyesters, such as improved mechanical properties, thermal properties, gas barrier properties, and / or alkali resistance and / or biodegradability, would be of interest. Furthermore, it would be an advancement to be able to produce a variety of polyester copolymers with tunable properties that may be suitable for a particular target application. [Means for solving the problem]

[0009] The present invention therefore relates to a chemical process for the preparation of polyester (co)polymers starting from monomers and / or oligomers, comprising at least (a) one or more diol monomers; and (b) one or more dicarboxylic acid monomers and / or esters thereof; and / or One or more oligomers containing monomer units (a) and (b) reacting a mixture of At least one diol monomer (a), in particular at least 5 mol % of the diol monomer (a), more preferably at least 10 mol % of the diol monomer (a) is a secondary diol monomer, further (c) A monohydric alcohol having a boiling point of 175°C or more at ambient pressure and an acid dissociation constant measured in water at 25°C of 12.0 or less and 7.0 or more. is added in an amount of 2.5 to 100% by weight based on the total weight of the monomers and / or oligomers.

[0010] Advantageously, the process allows a more complete conversion of the secondary diol, so that a smaller excess of secondary diol is required in the feed. By using limited amounts of monohydric alcohol (c), it is possible to produce high molecular weight polyester (co)polymers containing significant amounts of monomer units derived from said secondary diol, especially when said diol is a (bi)cyclic secondary diol. The process of the invention opens the possibility of the facile production of copolymers with an increased amount of monomer units derived from rigid, sterically hindered (bi)cyclic secondary diols. In particular, when said secondary diol is isosorbide, a high content of isosorbide-derived monomers in the polyester (co)polymer product can be found, surprisingly.

[0011] The process of the present invention therefore makes it possible to prepare polyester (co)polymers with tunable properties comprising monomer units derived from renewable materials whilst obtaining high number average molecular weights of the polyester end product.

[0012] The present invention provides an advantageous method for the preparation of both existing and, in particular, new polyester (co)polymers, which can be advantageously used in a wide range of (industrial) applications, such as films, fibers, injection (blow) molded parts, as well as bottles and packaging materials.

[0013] Additionally, the present invention provides compositions containing any one of the novel polyester (co)polymers described above, and additionally, one or more additives and / or one or more additional polymers.

[0014] The present invention further provides a molded article comprising a polyester (co)polymer according to the invention or a composition containing said polyester (co)polymer and one or more additives, and / or additional (co)polymers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention relates to a polymerization process for producing polyester copolymers. A "polyester" is herein understood to be a polymer having multiple monomer units linked through ester functional groups in its backbone. The ester functional groups can be formed by reacting a hydroxyl group (-OH) with a carboxyl / carboxylic acid group (-C(=O)OH). Typically, polyesters are synthetic polymers produced by the reaction of one or more difunctional carboxylic acids with one or more difunctional hydroxyl compounds. A "polyester copolymer" is herein understood to be a polyester in which three or more monomer units are joined to the same polymer backbone.

[0016] A "monomer unit" is understood herein to be a unit that can be obtained after polymerization of a monomer contained in a polyester copolymer or polyester oligomer, i.e. a "monomer unit" is a building block provided by a monomer or compound to the structure of a polymer or oligomer, and in this specification is in particular the smallest diol or diacid repeat unit.

[0017] "Monomer" or "monomer compound" is understood herein to be the smallest diol or diacid compound used as the starting compound to be polymerized.

[0018] An "oligomer" or "oligomeric compound" is understood herein to be a molecular structure having a total average number of monomer units in the range of 2 to 9 monomer units, preferably in the range of 3 to 5 monomer units. Apart from monomer units derived from diols and diacids, other monomer units may also be part of the oligomer, for example derived from hydroxycarboxylic acids, in particular α-hydroxycarboxylic acids such as glycolic acid, lactic acid, and mandelic acid. The average molecular weight (Mn) of the oligomer may be from 300 grams / mol or more up to 1750 grams / mol.

[0019] In the process of the present invention, at least a secondary diol is used. Said secondary diol may be selected from cyclic or acyclic, preferably aliphatic, diols. A preferred example of an acyclic aliphatic diol is a vicinal substituted diol, such as 2,3-butanediol. Preferably, at least one secondary diol (a) is selected from cyclic or bicyclic secondary diols, in particular from 1,4:3,6-dianhydrohexitol, cis- and / or trans-2,2,4,4-tetramethyl-1,3-cyclobutanediol, in particular from 1,4:3,6-dianhydrohexitol, preferably from isosorbide and / or isoidide, in particular one secondary diol is isosorbide. In a preferred embodiment, isosorbide is the only secondary diol used in said process. The group of 1,4:3,6-dianhydrohexitols consists of isosorbide (1,4:3,6-dianhydro-D-sorbitol), isoidide (1,4:3,6-dianhydro-L-iditol) and isomannide (1,4:3,6-dianhydro-D-mannitol).

[0020] The most important difference between the classes of 1,4:3,6-dianhydrohexitol isomers may be the orientation of the two hydroxyl groups. This difference in orientation may result in different orientations of the ester groups of the polymer, leading to some diversity in the spatial arrangement and physical and chemical properties of the polymer. According to the method of the present invention, it is possible for the polyester (co)polymer to have only one isomer of the monomer units derived from 1,4:3,6-dianhydrohexitol, or to have a mixture of two or more isomers of the monomer units derived from 1,4:3,6-dianhydrohexitol, for example a mixture of monomer units derived from isosorbide and / or isomannide and / or isoidide.

[0021] According to the method of the present invention, at least one of the one or more secondary diols (a) is selected from cyclic or bicyclic secondary diols, and other diols can also be used. Depending on the desired properties of the polyester copolymer to be produced, a wide range of diols can be selected. The type and amount of other monomer units in the copolymer can affect, for example, the thermal properties and crystallinity, as well as the barrier properties, mechanical properties and other properties. For example, the glass transition temperature Tg of the polyester copolymer to be produced can be targeted to a desired value by adjusting the amount of the other monomer units.

[0022] In this way, some properties of the polyester copolymer produced, such as Tg, can be easily targeted to the desired value by adjusting the selection of the type and amount of diol during the above-mentioned process, as well as the selection of the type and amount of one or more dicarboxylic acids or any esters thereof (b). According to the process of the present disclosure, polyester copolymers having number average molecular weights of industrial interest can be obtained within an industrially advantageous reaction time.

[0023] As mentioned above, the choice of the type and amount of diol in the process, among others, influences the final Tg. If a high Tg (especially above 80° C., more preferably 100° C. or higher, in particular up to 160° C. (including 160° C.), but even up to 210° C. for selected applications) is the objective, in addition to the secondary diol monomer (a), a diol selected from C2-C18 aliphatic diols, in particular from linear, cyclic or branched, saturated C2-C12 aliphatic diol compounds, preferably ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, ethylene ... At least one further diol is added, selected from the group consisting of choline, 1,4-cyclohexanedimethanol, and acetals of polyols, in particular acetals of C6 polyols, in particular 2,3:4,5-di-O-methylene-galactitol, 2,4:3,5-di-O-methylene-D-mannitol, 2,4:3,5-di-O-methylene-D-glucitol, 2,3:4,5-di-O-isopropylidene-galactitol, 2,4:3,5-di-O-isopropylidene-D-mannitol and 2,4:3,5-di-O-isopropylidene-D-glucitol. In particular, 1,4-cyclohexanedimethanol and 1,3-propanediol are preferred further diols, respectively, which improve the impact strength of the polyester copolymer.

[0024] According to the method as claimed in the present application, at least one (bi)cyclic secondary diol is used to prepare a polyester copolymer having a sufficient amount of monomer units derived from said (bi)cyclic secondary diol to impart some of the properties concerned. In particular, when a high Tg is aimed at, the polyester copolymer produced by said method preferably has at least 10 mol %, preferably 20 to 30 mol %, better still 30 to 40 mol %, up to 60 mol %, and even up to 100 mol % for selected applications, of monomer units derived from said (bi)cyclic secondary diol, as a percentage of the total amount of monomer units derived from diols in the polyester copolymer. Preferably, said monomer units derived from diols are monomer units derived from 1,4:3,6-dianhydrohexitol.

[0025] As mentioned above, the type and amount of (b) one or more dicarboxylic acids and / or any esters thereof may also have the effect of modulating the properties of the polyester (co)polymer produced. In the current process, the one or more dicarboxylic acid monomers and / or their esters (b) are selected from (hetero)aromatic dicarboxylic acids (i.e. heteroaromatic dicarboxylic acids and aromatic dicarboxylic acids) and from C2 to C18 aliphatic dicarboxylic acids, which may be linear, cyclic or branched, and / or their mono- and / or diesters.

[0026] When higher stiffness is desired, the one or more dicarboxylic acid monomers and / or their esters (b) are selected from terephthalic acid, terephthalic acid monoesters, terephthalic acid diesters, furandicarboxylic acid, furandicarboxylic acid monoesters, and furandicarboxylic acid diesters (especially 2,5-furandicarboxylic acid and / or its mono / diesters).

[0027] If a more flexible (co)polymer is desired, the dicarboxylic acid monomer or monomers and / or their esters (b) are selected from aliphatic dicarboxylic acids, preferably 1,4-cyclohexanedicarboxylic acid, diglycolic acid, and carboxylic acids of the formula HOOC(CH2) n COOH, where n is an integer from 0 to 20, and / or their esters. Preferred linear dicarboxylic acids and / or their esters are oxalic acid, succinic acid, adipic acid, and / or their esters, with succinic acid being particularly preferred.

[0028] In a preferred embodiment of the process of the present invention, the total amount of diol(s) of secondary diol monomer (a) and any optional further diol(s) and the total amount of one or more dicarboxylic acid monomers and / or any esters thereof (b) are used in said process in a molar ratio of the total amount of diols to the total amount of dicarboxylic acids or any esters thereof of from 1.5:1.0 to 1.0:1.0, and when rigid polymers are intended, preferably the only secondary diol (a) is isosorbide, the only further diol is selected from ethylene glycol, 1,4-cyclohexanedimethanol and 1,3-propanediol and the one or more dicarboxylic acids or any esters thereof (b) is terephthalic acid and / or furandicarboxylic acid. For flexible polymers, preferably, the only secondary diol (a) is isosorbide, a further diol must be present and is selected from ethylene glycol, 1,4-cyclohexanedimethanol, 1,3-propanediol and 1,6-hexanediol, and the dicarboxylic acid or dicarboxylic acids or any esters thereof (b) is succinic acid.

[0029] If the polyester copolymer is intended to have a (relatively) high glass transition temperature in the range of 80° C. or more to less than 160° C., preferably 140° C. or less, then the polyester (co)polymer may be very suitable for use in applications where products such as films, fibers, injection molded parts or packaging materials need to be heat resistant, for example, for coffee cups, microwave applications and certain medical applications. Also (co)polymers for ABS replacement may be intended. On the other hand, if the polyester copolymer is intended to have a moderate glass transition temperature in the range of 60° C. or more to 100° C., then said polyester copolymer may be very suitable for use in applications where products need to remain elastic at low temperatures and / or be able to withstand the cold without breaking or becoming too embrittled, for example, in the case of outdoor furniture. When the polyester copolymer is targeted for a glass transition temperature in the range of 60° C. or more to 120° C. or less, or 100° C. or less, it can be very suitable as a replacement for poly(ethylene terephthalate) (PET) in applications such as bottles and / or containers.

[0030] The process of the invention advantageously includes a step of adding a monohydric alcohol in the process, which has the effect of facilitating the production of high molecular weight polyester (co)polymers in the process. This is an unexpected effect, for example, monoalcohols are known to be "terminators" in certain polymerization reactions, capping the ends of growing polymer chains. The monohydric alcohol may already be added at the beginning of the esterification reaction, which, surprisingly, does not have a detrimental effect on the molecular weight. The exact opposite is observed, where much higher molecular weights can be obtained than when the polymerization is carried out in the absence of a monohydric alcohol. Preferably, the process may be carried out starting from a step of reacting diol monomer (a) with dicarboxylic acid monomer (b) in the presence of a monohydric alcohol, without necessarily first converting these dicarboxylic acid monomers to the corresponding diesters. Even in the presence of a monohydric alcohol and when water is produced during the esterification reaction, the polymerization process of the invention leads to high molecular weight polyester (co)polymers.

[0031] Advantageously, the addition of monohydric alcohol in the present process reduces the number of process steps by two by eliminating the need for the initial dicarboxylic acid diaryl ester generation step and subsequent purification step typically applied in esterification reactions, thereby significantly reducing the complexity and cost of the process.

[0032] In the monohydric alcohol, the hydroxy group is the only reactive functional group, and furthermore the boiling point of said alcohol is from 175° C. or more to 300° C. or less at ambient pressure and the acid dissociation constant (pKa) is less than 12.0 and more than 7.0 (measured in water at 25° C. as known from the literature). The amount of alcohol used is from 2.5 to 100% by weight, preferably from 5 to 95% by weight, more preferably from 10 to 90% by weight, in particular from 20 to 80% by weight, in particular from 30 to 70% by weight, based on the total weight of the monomers and / or oligomers. In particular, said alcohol (c) is an optionally substituted phenol, in particular selected from phenol, 4-methylphenol, 4-ethylphenol, 2-methoxyphenol, 4-methoxyphenol, 4-ethyl-2-methoxyphenol, 4-chlorophenol, and any combination thereof. The monohydric alcohol may be added in several stages of the process. Advantageously, the total amount of monohydric alcohol (c) is added at the beginning of the reaction. The addition of the monohydric alcohol may take place before the reaction starts, for example it is preferred to mix the monomers with the alcohol initially. The alcohol may also be added at a later stage in the reaction, or both at the beginning and during the reaction, whenever necessary. In an embodiment, some amount of alcohol (c) is added to the process from the beginning, in addition a larger amount of alcohol (c) is continuously fed to the reaction mixture during the process. Preferably, the alcohol is added before or during the esterification step. The monohydric alcohol may act as a reactive diluent in the reaction mixture, which may be considered desirable or necessary under certain circumstances. If deemed suitable, in addition to the monohydric alcohol, further inert solvents may be added to the reaction, in particular diphenyl ether, dimethoxybenzene, etc.

[0033] Advantageously, when monohydric alcohols are used in the presently claimed process, and compared to polymerization processes known in the art starting from a mixture of monomers, less isosorbide is lost during polymerization and more isosorbide is incorporated in the resulting polyester copolymer.

[0034] As the process of the invention proceeds, the monohydric alcohol present in the reaction mixture is discharged from the reactor. The discharged material can be advantageously separated and purified and recycled. Therefore, another embodiment of the invention relates to the above polymerization process, further comprising, after a step of separating the monohydric alcohol and optionally the water present (for example by distillation), optionally purifying the separated material to recover purified monohydric alcohol, and preferably recycling the purified monohydric alcohol to the above process.

[0035] Preferably, the diols and / or dicarboxylic acids used in the current process are obtained and / or derived from renewable sources, such as sustainable biomass materials. "Biomass materials" are understood herein to be compositions of matter obtained and / or derived from biological sources, as opposed to compositions of matter obtained and / or derived from petroleum, natural gas or coal. Said biomass materials may be, for example, polysaccharides, such as starch, or cellulosic and / or lignocellulosic materials. "Sustainable" is understood herein to be materials harvested and / or obtained in such a way that the environment is not depleted or permanently damaged. Sustainable biomass materials may be sourced, for example, from forest waste, agricultural waste, waste paper and / or sugar processing residues. Isosorbide, isomannide and isoidide can be conveniently obtained by dehydrating sorbitol, mannitol and iditol, respectively. The synthesis of these 1,4:3,6-dianhydrohexitols is known per se in the art.

[0036] The amount of each separate monomer unit in a polyester copolymer is often determined by proton nuclear magnetic resonance spectroscopy ( 1The amount of each monomer unit in the polyester copolymer can be measured by H NMR (H NMR). A person skilled in the art will readily find analytical conditions for measuring the amount of each separate monomer unit in the polyester copolymer. Other analytical methods may include depolymerization followed by monomer quantification (relative to a standard). Polyesters can be depolymerized in water (hydrolysis), in alcohol, e.g., methanol (alcohololysis, e.g., methanolysis), or in glycols (glycolysis). An excess of depolymerization solvent ensures complete depolymerization, and a catalyst (e.g., base) can accelerate the depolymerization.

[0037] The polyester copolymers according to the present invention may be random copolymers or may have a more chunky microstructure.

[0038] The number average molecular weight (Mn) of the polyester copolymer may vary and may depend, for example, on the type and amount of added monomer, catalyst, reaction time and reaction temperature and pressure. Advantageously, the number average molecular weight of the polyester copolymer according to the invention is at least 15000 g / mol, preferably the number average molecular weight is 16500 g / mol or more, in particular 18000 g / mol or more, more preferably 20000 g / mol or more up to 100000 g / mol.

[0039] The weight average molecular weight (Mw) and number average molecular weight (Mn) can be measured by gel permeation chromatography (GPC) at 35° C. using poly(methyl methacrylate) (PMMA) or polystyrene (PS) standards as reference materials for calculation, and hexafluoro-2-propanol or dichloromethane as eluents, respectively. When monomer units derived from aromatic or heteroaromatic diacids are present in the (co)polymer, a combination of PMMA and hexafluoro-2-propanol is used, and when aliphatic diacid monomer units are present in the (co)polymer, a combination of PS and dichloromethane is used. All molecular weights herein are measured as described in the Analytical Methods section of the Examples.

[0040] Suitably, the polydispersity index (i.e. the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), i.e. Mw / Mn) of the polyester copolymer according to the invention may be in the range of ≧1.6 to ≦2.8, in particular ≧1.8 to ≦2.6.

[0041] The glass transition temperature of the polyester copolymers can be measured by conventional methods, in particular by differential scanning calorimetry (DSC) at a heating rate of 10° C. / min in a nitrogen atmosphere. All glass transition temperatures herein are measured as described in the Analytical Methods section of the Examples.

[0042] The process according to the invention may have several stages. Preferably, the process according to the invention has an esterification / transesterification stage and a polycondensation stage, said esterification / transesterification stage being carried out before the polycondensation stage. The esterification / transesterification stage may preferably be preceded by an introduction stage comprising the step of introducing suitable monomers into the reactor. During the esterification / transesterification reaction, condensation products, such as water, may be removed by distillation. The polycondensation stage may preferably be followed by a recovery stage, in which the polyester copolymer is recovered from the reactor.

[0043] The process according to the invention can be carried out in batch, semi-batch or continuous mode. The esterification / transesterification and polycondensation steps can conveniently be carried out in one and the same reactor, but can also be carried out in two separate reactors, for example the esterification / transesterification step can be carried out in a first esterification / transesterification reactor and the polycondensation step can be carried out in a second polycondensation reactor.

[0044] At any stage of introduction, the monomers may be introduced into the reactor simultaneously, for example in the form of a feed mixture, or separately in portions. The monomers may be introduced into the reactor in the molten phase, or may be melted and combined after they are introduced into the reactor.

[0045] Any transesterification step is preferably carried out for a reaction time ranging from 0.5 hours or more, more preferably from 1.0 hours or more to 20.0 hours or less, preferably 10 hours or less, more preferably 6.0 hours or less. During the transesterification step, the temperature may be increased in steps or gradually.

[0046] Any polycondensation step is preferably carried out for a reaction time ranging from 0.5 hours or more, more preferably from 1.0 hours or more to 8.0 hours or less, more preferably 6.0 hours or less. During the polycondensation step, the temperature may be increased stepwise or gradually.

[0047] The polycondensation step may suitably be carried out at a temperature equal to or higher than the temperature at which the transesterification step is carried out or slightly lower, depending on the polymer. The transesterification step may for example be carried out at a temperature equal to or higher than 170°C, and depending on the desired polymer (e.g. a high Tg polymer), preferably equal to or higher than 210°C, even more preferably in the range of equal to or higher than 230°C to equal to or lower than 260°C. The polycondensation step may suitably follow the transesterification step, and may for example be carried out at a temperature equal to or higher than 220°C, and depending on the desired polymer (e.g. a high Tg polymer), more preferably equal to or higher than 265°C to equal to or lower than 300°C, more preferably equal to or lower than 285°C, most preferably equal to or lower than 275°C.

[0048] The polycondensation step can be followed by a recovery step, in which the polyester copolymer is recovered from the reactor. The polyester can be recovered, for example, by extracting the molten polymer in the form of threads from the reactor. The threads can be converted into granules using conventional granulation techniques.

[0049] The esterification / transesterification step is preferably carried out under an inert gas atmosphere, suitably at or slightly above ambient pressure, for example up to 5 bar. Preferably, the polycondensation step is carried out at reduced pressure.

[0050] A suitable and advantageous method for carrying out the process of the present invention comprises the following steps: (i) heating a mixture of diol monomers, dicarboxylic acid monomers and / or any esters thereof and monohydric alcohol in a reaction vessel at a certain temperature for a certain time until a clear melt is obtained; (ii) continuing the esterification / transesterification reaction at elevated temperature (under stirring) while removing condensation products (especially water) at a pressure of 1 to 5 bar; (iii) reducing the pressure of the vessel of step (ii) to a vacuum of less than 20 mbar, preferably less than 10 mbar, more preferably less than 5 mbar, in particular less than 1 mbar, while continuously stirring for a certain time, and optionally further increasing the temperature by 10 to 50° C. during step (iii) to facilitate removal of the remainder of the monohydric alcohol and condensation products from the reactor.

[0051] The process according to the invention may be carried out in the presence of one or more additives, such as stabilizers, for example light, UV and heat stabilizers, flow agents, flame retardants, ether formation inhibitors and antistatic agents. Phosphoric acid is one example of a stabilizer applied to PET. The additives may be added at the beginning of the process or during or after the polymerization reaction. Other additives include primary and / or secondary antioxidants. Primary antioxidants may be, for example, sterically hindered phenols, such as the compounds Hostanox® 0 3, Hostanox® 0 10, Hostanox® 0 16, Ultranox® 210, Ultranox® 276, Dovernox® 10, Dovernox® 76, Dovernox® 3114, Irganox® 1010 or Irganox® 1076. The secondary antioxidant may be, for example, a trivalent phosphorus-containing compound such as Ultranox® 626, Doverphos® S-9228, or Sandostab® P-EPQ.

[0052] The process according to the invention is preferably carried out in the presence of a catalyst, preferably a metal-containing catalyst. The catalyst is preferably used in an amount of 0.01 mol% to 0.5 mol% based on the total amount (in moles) of monomers. The metal-containing catalyst may, for example, comprise a derivative of tin (Sn), titanium (Ti), zirconium (Zr), germanium (Ge), antimony (Sb), bismuth (Bi), hafnium (Hf), magnesium (Mg), cerium (Ce), zinc (Zn), cobalt (Co), iron (Fe), manganese (Mn), calcium (Ca), strontium (Sr), sodium (Na), lead (Pb), potassium (K), aluminum (Al), and / or lithium (Li). Examples of suitable metal-containing catalysts include acetates and oxides, including salts of Li, Ca, Mg, Mn, Zn, Pb, Sb, Sn, Ge, and Ti, such as glycol adducts, and Ti alkoxides. Examples of the above compounds may be, for example, those given in sections

[0026] to

[0029] of US Patent Application Publication No. 2011282020 and on page 5 of International Patent Application No. 2013 / 062408. Preferably, the metal-containing catalyst is a tin-containing catalyst, such as a tin(IV)- or tin(II)-containing catalyst. More preferably, the metal-containing catalyst is an alkyltin(IV) salt and / or an alkyltin(II) salt. Examples include alkyltin(IV) salts, alkyltin(II) salts, dialkyltin(IV) salts, dialkyltin(II) salts, trialkyltin(IV) salts, trialkyltin(II) salts or mixtures of one or more of these. These tin(IV) and / or tin(II) catalysts may be used together with alternative or additional metal-containing catalysts. Examples of alternative or additional metal-containing catalysts that can be used include one or more of titanium (IV) alkoxides or titanium (IV) chelates, zirconium (IV) chelates or zirconium (IV) salts (e.g., alkoxides); hafnium (IV) chelates or hafnium (IV) salts (e.g., alkoxides); yttrium (III) alkoxides or yttrium (III) chelates; lanthanum (III) alkoxides or lanthanum chelates; scandium (III) alkoxides or chelates; and cerium (III) alkoxides or chelates.An example of a metal-containing catalyst is n-butyltin oxide hydroxide.

[0053] The process according to the invention may optionally further comprise, after the aforementioned recovery step (i.e. the polyester (co)polymer is recovered from the reactor), a polymerization step in the solid state, if the polymer is semi-crystalline. That is to say, said polyester (co)polymer recovered as described above can be further polymerized in the solid state to increase its chain length. Said polymerization in the solid state is also called solid state polymerization (SSP). Said solid state polymerization advantageously makes it possible to further increase the number average molecular weight of the polyester (co)polymer. Where applicable, SSP can also advantageously enhance the mechanical and rheological properties of the polyester copolymer before injection blow molding or extrusion. The solid state polymerization process preferably comprises a step of heating the polyester (co)polymer in the essential or complete absence of oxygen and water, for example by purging with a vacuum or an inert gas.

[0054] Advantageously, therefore, the method according to the invention comprises: - a melt polymerization step in which said (co)polymer is polymerized in the melt to produce a polyester copolymer melt product; - optional pelletization to convert the polyester copolymer melt product into pellets and optional drying of said pellets under vacuum or with the aid of inert gas purging; - an optional solid state polymerization step of the polyester copolymer melt product, optionally in pellet form, at a temperature above the Tg of the polyester copolymer melt product and below the melting temperature of the polyester copolymer melt product; may include.

[0055] In general, the solid state polymerization may suitably be carried out at a temperature in the range of 150° C. or more and 220° C. or less. The solid state polymerization may suitably be carried out at ambient pressure (i.e., atmospheric pressure of 1.0 bar, which corresponds to 0.1 megapascals) with purging with a flow of inert gas (such as nitrogen or argon), or may be carried out in vacuum, for example at a pressure of 100 mbar or less (corresponding to 0.01 megapascals). The solid state polymerization may suitably be carried out for a period of up to 120 hours, more suitably for a period of time in the range of 2 hours or more and 60 hours or less. The duration of the solid state polymerization may be adjusted so that the polyester copolymer reaches the desired final number average molecular weight.

[0056] In a further embodiment, the present invention relates to polyester (co)polymers obtainable or in particular obtainable by the process according to the invention, in particular having a number average molecular weight, measured by gel permeation chromatography, of 15,000 daltons or more, in particular 16,500 daltons or more, more in particular 18,000 daltons or more, in particular 20,000 daltons or more, and a polydispersity index of 1.8 or more to 2.8 or less, more in particular 2.6 or less, in particular isosorbide succinate, isosorbide glutarate, isosorbide adipate, isosorbide diglycolate, isosorbide thiodiglycolate, isosorbide 1,4-cyclohexanedicarboxylate, isomannide succinate, isomannide glutarate, isomannide adipate, isomannide diglycolate and polyester (co)polymers containing or consisting of repeat units selected from one or more of isosorbide-co-1,4-cyclohexanedimethylene furanoate, isosorbide-co-1,3-propylene terephthalate, isosorbide-co-1,3-propylene furanoate and isosorbide succinate-co-terephthalate, and having a number average molecular weight, as measured by gel permeation chromatography, of preferably 22,000 Daltons or more and containing or consisting of isosorbide-co-1,4-cyclohexanedimethylene terephthalate repeat units.

[0057] In particular, the polyester (co)polymer is Poly(isosorbide-succinate), especially those with Mn of 30,000 daltons or greater; Poly(isosorbide-glutarate), especially those with Mn of 35,000 daltons or greater; Poly(isosorbide-adipate), especially those with Mn of 27,000 daltons or greater; Poly(isosorbide-diglycolate), especially those with Mn of 20,000 daltons or greater; Poly(isosorbide-thiodiglycolate), especially those with Mn of 15,000 daltons or greater; Poly(isosorbide-1,4-cyclohexanedicarboxylate), especially those with Mn of 35,000 daltons or greater; Poly(isomannide-succinate), especially those with Mn of 23,000 daltons or greater; Poly(isomannide-glutarate), especially those with Mn of 35,000 daltons or greater; Poly(isomannide-adipate), especially those with Mn of 25,000 daltons or greater; Poly(isomannide-diglycolate), especially those with Mn of 16,000 daltons or greater; Poly(isomannide-1,4-cyclohexanedicarboxylate), especially those with Mn of 27,000 daltons or greater; Poly(isosorbide-co-1,4-cyclohexanedimethylene terephthalate) (PICT), especially those with a Mn of 22,000 Daltons or more and / or especially those with a glass transition temperature of 140° C. or more; Poly(isosorbide-co-1,4-cyclohexanedimethylene furanoate) (PICF), especially those with a Mn of 20,000 Daltons or more and / or especially those with a glass transition temperature of 120° C. or more; Poly(isosorbide succinate-co-terephthalate), preferably containing 10 to 90 mol % succinate (based on the total of units derived from dicarboxylic acids), especially those having an Mn of 16,000 Daltons or more; Poly(isosorbide succinate-co-furanoate), preferably containing 10 to 90 mol % succinate (based on the total of units derived from dicarboxylic acids); Poly(isosorbide adipate-co-furanoate), preferably containing 10 to 90 mol % adipate (based on the total of units derived from dicarboxylic acids); Poly(isosorbide-co-1,3-propylene terephthalate) (PIPT), especially those with Mn of 16,000 daltons or greater; and Poly(isosorbide-co-1,3-propylene furanoate) (PIPF), especially those with Mn of 16,000 daltons or more and the sum of monomer units derived from diols, selected from the group consisting of:

[0058] Particularly preferred are polyester (co)polymers containing monomer units derived from two different diols, in particular the specific polyester (co)polymers listed above, which contain 10 to 60 mol % (based on the sum of the diols), in particular 20 to 55 mol %, in particular 30 to 50 mol % of monomer units derived from the above (bi)cyclic secondary diols, in particular isosorbide. Particularly preferred are polyester (co)polymers having Mn of 22,000 Daltons or more and PI 10-60 CT, PI 10-60 C.F., P.I. 10-60 PT and PI 10-60 PF, and even more preferably PI 30-50 CT, PI 30-50 C.F., P.I. 30-50 PT and PI 30-50 PF is a polyester (co)polymer selected from the group consisting of

[0059] Since the polyester (co)polymers obtained or obtainable by the process of the present invention can be suitably combined with additives and / or further (co)polymers, the present invention further provides a composition comprising said polyester (co)polymer and in addition one or more additives and / or one or more additional further (co)polymers.

[0060] Said composition may, for example, contain nucleating agents as additives. These nucleating agents may be organic or inorganic in nature. Examples of nucleating agents are talc, calcium silicate, sodium benzoate, calcium titanate, boron nitride, zinc salts, porphyrins, chlorins and phlorins.

[0061] The composition according to the invention may also contain, as additives, fillers or fibers of nanometric (i.e. with nanometric particles) or non-nanometric and functionalized or non-functionalized organic or inorganic nature. They may be silica, zeolites, glass fibers or beads, clays, mica, titanates, silicic acids, graphite, calcium carbonate, carbon nanotubes, wood fibers, carbon fibers, polymer fibers, proteins, cellulose fibers, lignocellulosic fibers and non-destructed granular starches. These fillers or fibers may make it possible to improve the hardness, stiffness or permeability to water or gas. The composition may contain from 0.1% to 75% by weight, for example from 0.5% to 50% by weight, of fillers and / or fibers relative to the total weight of the composition. The composition may also be of composite type, i.e. contain a large amount of these fillers and / or fibers.

[0062] The composition may also contain, as additives, opacifiers, dyes and pigments, which may be selected from cobalt acetate and the following compounds: HS-325 Sandoplast® Red BB, a compound with an azo function, also known as Solvent Red 195, HS-510 Sandoplast® Blue 2B, an anthraquinone, Polysynthren® Blue R and Clariant® RSB Violet.

[0063] The composition may also contain, as additives, processing aids to reduce the pressure in the processing device. Mold release agents can also be used, which make it possible to reduce the adhesion of the polyester to the shaping device, for example the rollers of the mold or calendering device. These agents can be selected from fatty acid esters and amides, metal salts, soaps, paraffin or hydrocarbon waxes. Specific examples of these agents are zinc stearate, calcium stearate, aluminum stearate, stearamide, erucamide, behenamide, beeswax or candelilla wax.

[0064] The composition may also contain other additives, such as stabilizers, as described herein above.

[0065] In addition, the composition may contain, apart from the one or more polyester (co)polymers according to the invention, one or more additional (co)polymers, which may suitably be selected from the group consisting of polyamides, polystyrene, styrene copolymers, styrene / acrylonitrile copolymers, styrene / acrylonitrile / butadiene copolymers, polymethyl methacrylate, acrylic copolymers, poly(ether / imides), polyphenylene oxides, such as poly(2,6-dimethylphenylene oxide), polyphenylene sulfide, poly(ester / carbonates), polycarbonates, polysulfones, polysulfone ethers, polyether ketones and blends of these polymers.

[0066] The composition may also contain, as additional (co)polymers, polymers making it possible to improve the impact resistance of the polymer, in particular functionalized polyolefins, such as functionalized ethylene or propylene polymers and copolymers, core / shell copolymers or block copolymers.

[0067] The composition according to the invention may also contain, as additional (co)polymers, polymers of natural origin, such as starch, cellulose, chitosan, alginic acid, proteins, such as gluten, pea protein, casein, collagen, gelatin or lignin, these polymers of natural origin being physically or chemically modified or not. Starch may be used in destructured or plasticized form. In the latter case, the plasticizer may be water or a polyol, in particular glycerol, polyglycerol, isosorbide, sorbitan, sorbitol, mannitol or even urea. The application may in particular be for preparing the composition of the method described in the document WO 2010 / 010282.

[0068] These compositions can be suitably produced by conventional thermoplastic conversion methods. These conventional methods may include at least one stage of mixing of the molten or softened polymers and one stage of recovery of the composition. The mixing may be carried out, for example, in an internal blade or rotor mixer, an external mixer or a single-screw or co-rotating or counter-rotating twin-screw extruder. However, it is preferred to carry out the mixing by extrusion, in particular using a co-rotating extruder. The mixing of the constituents of the composition can be suitably carried out in the temperature range of 220 to 300° C., preferably under an inert atmosphere. In the case of an extruder, the various constituents of the composition can be suitably introduced by means of an introduction hopper arranged along the extruder.

[0069] The present invention also relates to a molded article containing the polyester (co)polymer according to the invention or a composition containing the polyester (co)polymer according to the invention and one or more additives and / or additional (co)polymers. Said polyester (co)polymers can be easily used for the production of films, fibers, injection molded parts and packaging materials, such as containers. The use of polyester (co)polymers is particularly advantageous for said films, fibers, injection molded parts or packaging materials that need to have heat or cold resistance.

[0070] The shaped article may also be a fiber, for example for use in the textile industry. These fibers may or may not be woven to form a fabric.

[0071] The molded article may also be a film or sheet. These films or sheets may be produced by calendaring, cast film extrusion or film blown extrusion techniques. These films may be used to produce labels or insulators.

[0072] The molded article may in particular be a container for use in hot-fill and recycling applications. The molded article may be produced from the polyester (co)polymer or a composition containing the polyester (co)polymer and one or more additives and / or additional (co)polymers using conventional conversion techniques. The molded article may also be a container for transporting gases, liquids and / or solids. Possible containers may be baby bottles, flasks, bottles, such as carbonated or non-carbonated water bottles, juice bottles, soda bottles, carboys, alcoholic beverage bottles, pharmaceutical or cosmetic bottles, tableware, such as prepared food tableware or microwave tableware, or lids. These containers may be of any size.

[0073] The molded article can be suitably produced by, for example, extrusion blow molding, thermoforming or injection blow molding.

[0074] The present invention therefore also comprises the use of one or more polyester (co)polymers according to the invention and preferably provides a method for producing a molded article comprising the steps of: 1) providing a polyester (co)polymer obtainable according to the method of the present invention, 2) producing a polymer melt by melting said polyester (co)polymer and, optionally, one or more additives and / or one or more additional (co)polymers, and 3) extrusion blow molding, thermoforming and / or injection blow molding the polymer melt into a molded article.

[0075] The molded article can also be produced according to a method comprising the step of applying a polyester layer in the molten state onto an organic polymer-based layer, onto a metal, or onto an adhesive composition in the solid state, which can be carried out by pressing, lamination, extrusion lamination, coating or extrusion coating.

[0076] The invention is further illustrated by the following non-limiting examples. EXAMPLES

[0077] List of abbreviations CH2Cl2 = dichloromethane CD2Cl2 = dideutero-dichloromethane (or DCM-d2) DSC = Differential Scanning Calorimeter EP = 4-ethylphenol FDCA = 2,5-furandicarboxylic acid GPC = gel permeation chromatography HFIP = hexafluoro-2-propanol IPA = Isophthalic Acid ISO = Isosorbide MA = monohydric alcohol MOP = 4-methoxyphenol 4-MP = 4-methylphenol (p-cresol) Mn=number average molecular weight Mw=mass average molecular weight PDI=polydispersity index PICF = Poly(isosorbide-co-1,4-cyclohexanedimethylene-furanoate) PICT = poly(isosorbide-co-1,4-cyclohexanedimethylene terephthalate) PIPF = Poly(isosorbide-co-1,3-propylene-furanoate) PIPT = Poly(isosorbide-co-1,3-propylene terephthalate) PISA = poly(isosorbide succinate) PISAT = poly(isosorbide succinate-co-terephthalate) PMMA = poly(methyl methacrylate) PS = Polystyrene TPA = terephthalic acid TCE = 1,1,2,2-tetrachloroethane TCE-d2 = 1,2-dideutero-1,1,2,2-tetrachloroethane Tg = glass transition temperature

[0078] Analysis method: In the examples below, weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) using two different methods.

[0079] (1) For the samples of Examples 1 to 5 and Table 1 to 5: GPC measurements were carried out at 35°C. PS standards were used as reference materials for calculations. Dichloromethane was used as the eluent at a flow rate of 1 ml / min. GPC measurements were carried out under these conditions using an Agilent HPLC system with a 1260 Infinity II refractive index detector equipped with two PLgel 5μm MIXED-C (300×7.5mm) columns. Molecular weight calculations were carried out using Agilent GPC / SEC software. (2) For the samples of Examples 6 to 7 and Tables 6 to 7: GPC measurements were performed at 35° C. PMMA standards were used as reference materials in the calculations. HFIP was used as the eluent at 1 mL / min. GPC measurements were performed under these conditions using a Hitachi Chromaster 5450 with an Agilent HPLC system equipped with two PFG 7 micrometer (μm) Linear M (300×7.5 mm) columns. Molecular weight calculations were performed with Astra6 software.

[0080] The glass transition temperatures of the polyester polymers and copolymers of the following examples were measured using a differential scanning calorimeter (DSC) at a heating rate of 10° C. / min in a nitrogen atmosphere. During the second heating cycle, the glass transition, (Tg), was recorded.

[0081] The content of monomer units in the polyester polymers and copolymers in the following examples was determined by proton nuclear magnetic resonance spectroscopy ( 1 The contents of diol and diacid monomer units were measured using dideutero-dichloromethane (CD2Cl2), tetrachloroethane (TCE-d2) or dimethylsulfoxide-d6 as solvents and dichloromethane (CH2Cl2), tetrachloroethane (TCE) or dimethylsulfoxide as references.

[0082] Example 1 Preparation of poly(isosorbide succinate) (PISA) on a lab-scale using 4-methylphenol Succinic acid (7.085 g, 60 mmol), isosorbide (8.768 g, 60 mmol) and 4-methylphenol (9.732 g, 90 mmol) were weighed into a 100 ml three-neck flask. Butyltinoxide hydroxide hydrate (0.013 g, 0.06 mmol) was added as a suspension in 0.5 ml toluene. The flask was equipped with a nitrogen gas inlet, overhead stirrer, and a distillation head fitted with a thermometer and a receiving flask. A constant nitrogen gas flow of 40 ml / min was maintained throughout the first step (esterification) of the experiment. The reaction mixture was heated to 240° C. in a silicon oil bath. As soon as the oil bath temperature reached 150° C., stirring was started at a speed of 100 rpm. After 5 h at 240° C., the reactor was removed from the oil bath and cooled to room temperature under nitrogen flow. The reactor was then heated to 220°C under a nitrogen flow of 40 ml / min. As soon as the oil bath temperature reached 150°C, stirring was started at a speed of 100 rpm. The second step of the experiment (polycondensation) started when the oil bath temperature reached 220°C. The nitrogen flow was stopped and a cold trap was connected to the receiving flask. A vacuum of 400 mbar was applied to the reactor and the pressure was reduced by half every 15 minutes. After 105 minutes, full vacuum (between 0.3 and 0.9 mbar) was reached. After stirring the reaction for 60 minutes under full vacuum, the reactor was flushed with nitrogen. The distillation head and overhead stirrer were removed from the flask and the reaction product was scraped out of the reactor under a positive nitrogen flow.

[0083] Comparative examples were carried out with the "non-reactive" version, i.e., a compound with no reactive substituents, in which no monohydric alcohol is present.

[0084] The results are shown in Table 1.

[0085] [Table 1]

[0086] Example 2 Preparation of poly(isosorbide succinate) using 4-methylphenol in a 2-liter autoclave To demonstrate the industrial feasibility of the process of Example 1, the synthesis of poly(isosorbide succinate) was scaled up from a 100 ml glass reactor to a 2 liter stainless steel autoclave.

[0087] procedure Isosorbide (453.0 g, 3.1 moles), succinic acid (366.1 g, 3.1 moles), 4-methylphenol (502.8 g, 4.65 moles), butyltin hydroxide hydrate (0.647 g, 3.1 mmoles), and tris(2,4-di-tert-butylphenyl)phosphite (0.351 g, 0.5 mmoles) were weighed into a 2-liter stainless steel autoclave. The reactor was closed and heated to 220° C. under constant nitrogen flow. Stirring was started at 100 rpm when the oil temperature reached 150° C. After 1 hour at 220° C., the oil temperature increased to 240° C. This temperature was held for 5 hours until water was no longer collecting in the reactor receiving flask. A molten sample of the reaction mixture was removed under positive nitrogen flow to determine the alcohol to ester end group ratio, and the reactor was cooled to room temperature. Next, 5.49 g of succinic acid was added to the reaction mixture and stirred at 240° C. for another 1.5 hours. The temperature of the oil was then reduced to 220° C. and pre-polycondensation was started by slowly applying a vacuum of 400 mbar. The pressure in the reactor was reduced by half (200, 100, 50, 25, 12.5 and 6.5 mbar) every 15 minutes until a pressure of 0.05 to 0.5 mbar was reached. After 1 to 1.5 hours at 0.05 to 0.5 mbar, polycondensation was complete. The reactor was flushed with nitrogen and a pressure of 2.3 bar was applied in the reactor. The polymer product was extruded through a nozzle at the bottom of the reactor into a water bath and chipped.

[0088] The results are summarized in Table 2.

[0089] [Table 2]

[0090] Example 3 Preparation of PISA using 2-methoxyphenol Succinic acid (7.085 g, 60 mmol), isosorbide (8.768 g, 60 mmol), 2-methoxyphenol (11.173 g, 90 mmol) and tris(2,4-di-tert-butylphenyl)phosphite (6.8 mg, 0.01 mmol) were weighed into a 100 ml three-neck flask. Butyltin hydroxide hydrate (0.013 g, 0.06 mmol) was added as a suspension in 0.5 ml toluene. The flask was equipped with a nitrogen gas inlet, overhead stirrer, and a distillation head fitted with a thermometer and a receiving flask. The reactor was heated to 80° C. and four vacuum / nitrogen cycles were performed to deoxygenate the reaction mixture. A constant nitrogen gas flow of 40 ml / min was maintained throughout the first step (esterification) of the experiment. The reaction mixture was heated to 240° C. in a silicon oil bath. As soon as the oil bath temperature reached 150°C, stirring was started at a speed of 100 rpm. After 5 hours at 240°C, the reactor was removed from the oil bath and cooled to room temperature under nitrogen flow. The reactor was then reheated to 240°C under nitrogen flow of 40 ml / min. As soon as the oil bath temperature reached 150°C, stirring was started at a speed of 100 rpm. After another 4 hours at 240°C, the reactor was removed from the oil bath and cooled to room temperature under nitrogen flow. The reactor was then heated to 220°C under nitrogen flow to start the second step of the experiment (polycondensation). The nitrogen flow was stopped and a cold trap was connected to the receiving flask. A vacuum of 400 mbar was applied to the reactor and the pressure was reduced by half every 15 minutes. After 105 minutes, full vacuum (between 0.3 and 0.9 mbar) was reached. After stirring the reaction for 90 minutes under full vacuum, the reactor was flushed with nitrogen. Under positive nitrogen flow, the distillation head and overhead stirrer were removed from the flask and the reaction product was scraped out of the reactor. The results are summarized in Table 3.

[0091] [Table 3]

[0092] Example 4 Other aliphatic polyesters containing isosorbide with 4-methylphenol Synthesis procedure of poly(isosorbide glutarate): Glutaric acid (23.782 g, 180 mmol), isosorbide (26.305 g, 180 mmol), 4-methylphenol (29.195 g, 270 mmol) and butyltin hydroxide hydrate (0.075 g, 0.36 mmol) were weighed into a 100 ml three-neck flask. The flask was equipped with a nitrogen gas inlet, overhead stirrer, and a distillation head fitted with a thermometer and a receiving flask. A constant nitrogen gas flow of 40 ml / min was maintained throughout the first step (esterification) of the experiment. The reaction mixture was heated to 240° C. in a silicon oil bath. As soon as the oil bath temperature reached 150° C., stirring was started at a speed of 100 rpm. After 6 hours at 240° C., the reactor was removed from the oil bath and cooled to room temperature under nitrogen flow. The reactor was then reheated to 240° C. under nitrogen flow of 40 ml / min. As soon as the oil bath temperature reached 150°C, stirring was started at a speed of 100 rpm. After 2 hours at 240°C (i.e., a total of 8 hours of esterification time), the oil bath temperature was reduced to 220°C and the second step of the experiment (polycondensation) was started. The nitrogen flow was stopped and a cold trap was connected to the receiving flask. A vacuum of 400 mbar was applied to the reactor and the pressure was reduced by half every 15 minutes. After 105 minutes, full vacuum (between 0.3 and 0.9 mbar) was reached. After stirring the reaction for 140 minutes under full vacuum, the reactor was flushed with nitrogen. The distillation head and overhead stirrer were removed from the flask and the reaction product was scraped out of the reactor under positive nitrogen flow.

[0093] Additional experiments with different diacids (adipic acid, 1,4-cyclohexanedicarboxylic acid, diglycolic acid, and thiodiglycolic acid, respectively) were also carried out on a 180 mmol scale (180 mmol of diacid, 180 mmol of diol, and 270 mmol of 4-methylphenol in a 100 ml reactor).

[0094] The specific conditions and results are summarized in Table 4.

[0095] [Table 4]

[0096] Example 5 Aliphatic polyesters containing isomannide using 4-methylphenol The procedure of Example 4 was followed for polyesters prepared from isomannide and succinic acid, glutaric acid, adipic acid, and diglycolic acid, respectively.

[0097] The specific conditions and results are summarized in Table 5.

[0098] [Table 5]

[0099] Example 6 Preparation of poly(isosorbide-co-1,4-cyclohexanedimethylene) terephthalate (PICT) using 4-ethylphenol In a 100 ml glass reactor, based on 24.1 g of terephthalic acid (1.0 equiv., 145 mmol), 10.6 g of isosorbide (0.5 equiv., 72.5 mmol), 10.4 g of 1,4-cyclohexanedimethanol (0.5 equiv., 72.5 mmol), 21.2 g of 4-ethylphenol, and 43 mg of catalyst (butyltin hydroxide hydrate, 500 ppm) were added before heating. In the first phase, the reaction system was heated in an oil bath at 240 °C under a nitrogen flow of 30 mL / min for 9.5 h. The second phase was started, the temperature of the oil was increased to 260 °C, the nitrogen flow was stopped, and a vacuum of 500 mbar was applied. The vacuum was gradually reduced and the solvent (4-ethylphenol) was collected in a distillation flask. The temperature was gradually increased up to 285 °C as the polymer became more viscous. The torque recorded by the mechanical stirrer increased from 16 N.cm up to 34 Ncm as the polymer became more viscous. The vacuum was slowly reduced over 2 hours, after which the system was kept below 1 mbar (to 0.4 mbar) for 1 hour. The final polymer has a Tg of 144.3° C., a weight average molecular weight (Mw) of 60.4 kg / mol, and is pale yellow in color.

[0100] The results and conditions are shown in Table 6.

[0101] Example 7 Other polyisosorbide-co-polyesters PICF, PIPT, PIPF and PISAT [poly(isosorbide-co-1,4-cyclohexanedimethylene furanoate), poly(isosorbide-co-1,3-propylene terephthalate), poly(isosorbide-co-1,3-propylene furanoate) and poly(isosorbide succinate-co-terephthalate, respectively] were synthesized in a similar manner with the differences summarized in Table 6. The reaction times of the first and second phases were not kept constant. Instead, after the above reaction, 1H-NMR, visual appearance (homogeneity), water collection and torque progression (during polycondensation) were followed and these techniques were used to determine when to terminate the two phases (nitrogen flow and vacuum).

[0102] [Table 6]

[0103] The preparation of PICT was investigated in more detail using different monohydric alcohols, see Table 7. Catalyst: BuSnOOH, 0.14 mol % with respect to TPA.

[0104] [Table 7]

Claims

1. A chemical process for the preparation of polyester (co)polymers starting from monomers and / or oligomers, comprising at least (a) one or more diol monomers, and (b) one or more dicarboxylic acid monomers and / or esters thereof; and / or One or more oligomers containing monomer units (a) and (b) reacting a mixture of at least one diol monomer (a) is a secondary diol monomer; (c) A monohydric alcohol having a boiling point of 175°C or higher at ambient pressure and an acid dissociation constant measured in water at 25°C of 12.0 or less and 7.0 or more. is further added in an amount of 2.5 to 100% by weight based on the total weight of the monomers and / or oligomers.

2. 2. The method of claim 1, wherein the at least one secondary diol (a) is selected from cyclic or bicyclic secondary diols.

3. 3. The method according to claim 1 or 2, wherein the one or more dicarboxylic acid monomers and / or esters thereof (b) are selected from (hetero)aromatic dicarboxylic acids and C2 to C18 aliphatic dicarboxylic acids, which may be linear, cyclic or branched, and / or their monoesters and / or diesters.

4. 4. The method of claim 3, wherein the one or more dicarboxylic acid monomers and / or esters thereof (b) are selected from terephthalic acid, terephthalic acid monoesters, terephthalic acid diesters, furandicarboxylic acid, furandicarboxylic acid monoesters, and furandicarboxylic acid diesters.

5. 5. The method of claim 4, wherein in addition to the secondary diol monomer (a), at least one further diol selected from C2 to C18 aliphatic diols is added.

6. 4. The method according to claim 3, wherein the one or more dicarboxylic acid monomers and / or esters thereof (b) are selected from aliphatic dicarboxylic acids.

7. 2. The method of claim 1, wherein the alcohol (c) is an optionally substituted phenol.

8. 10. The method of claim 1, wherein the total amount of monohydric alcohol (c) is added at the beginning of the reaction.

9. 2. The process of claim 1, wherein a certain amount of alcohol (c) is added to the process from the beginning, and in addition, a larger amount of alcohol (c) is continuously fed to the reaction mixture during the process.

10. A polyester (co)polymer obtainable by the process according to claim 1.

11. poly(isosorbide succinate), Poly(isosorbide-glutarate), Poly(isosorbide adipate), Poly(isosorbide-diglycolate), Poly(isosorbide-thiodiglycolate), Poly(isosorbide-1,4-cyclohexanedicarboxylate), poly(isomannide-succinate), Poly(isomannide-glutarate), Poly(isomannide-adipate), Poly(isomannide-diglycolate), Poly(isomannide-1,4-cyclohexanedicarboxylate), Poly(isosorbide-co-1,4-cyclohexanedimethylene terephthalate), Poly(isosorbide-co-1,4-cyclohexanedimethylene furanoate), Poly(isosorbide succinate-co-terephthalate), Poly(isosorbide succinate-co-furanoate), Poly(isosorbide adipate-co-furanoate), Poly(isosorbide-co-1,3-propylene terephthalate), and Poly(isosorbide-co-1,3-propylene furanoate) 11. The polyester (co)polymer according to claim 10, wherein the polyester (co)polymer is selected from the group consisting of polyester (co)polymers containing a total of dicarboxylic acid-derived monomer units and a total of diol-derived monomer units in a ratio of 1:

1.

12. 10. A polyester (co)polymer obtainable by the method of claim 1, having a number average molecular weight Mn of 15,000 Daltons or more and a polydispersity index of 1.8 to 2.8, measured by gel permeation chromatography under the following conditions: using poly(methyl methacrylate) or polystyrene standards as reference material and hexafluoro-2-propanol or dichloromethane as eluent, respectively (when monomer units derived from aromatic diacids or heteroaromatic diacids are present in the (co)polymer, a combination of poly(methyl methacrylate) and hexafluoro-2-propanol is used, and when aliphatic diacid monomer units are present in the (co)polymer, a combination of polystyrene and dichloromethane is used).

13. Isosorbide succinate, Isosorbide glutarate, Isosorbide adipate, Isosorbide diglycolate, Isosorbide thiodiglycolate, Isosorbide 1,4-cyclohexanedicarboxylate, Isomannide succinate, Isomannide glutarate, Isomannide adipate, Isomannide diglycolate, Isomannide thiodiglycolate, Isomannide 1,4-cyclohexanedicarboxylate, Isomannide 13. The polyester (co)polymer of claim 12, comprising or consisting of repeat units selected from one or more of isosorbide-co-1,4-cyclohexanedimethylene terephthalate, isosorbide-co-1,4-cyclohexanedimethylene furanoate, isosorbide-co-1,3-propylene terephthalate, isosorbide-co-1,3-propylene furanoate, and isosorbide succinate-co-terephthalate.

14. poly(isosorbide succinate), Poly(isosorbide-glutarate), Poly(isosorbide adipate), Poly(isosorbide-diglycolate), Poly(isosorbide-thiodiglycolate), Poly(isosorbide-1,4-cyclohexanedicarboxylate), poly(isomannide-succinate), Poly(isomannide-glutarate), Poly(isomannide-adipate), Poly(isomannide-diglycolate), Poly(isomannide-1,4-cyclohexanedicarboxylate), Poly(isosorbide-co-1,4-cyclohexanedimethylene terephthalate), Poly(isosorbide-co-1,4-cyclohexanedimethylene furanoate), Poly(isosorbide succinate-co-terephthalate), Poly(isosorbide succinate-co-furanoate), Poly(isosorbide adipate-co-furanoate), Poly(isosorbide-co-1,3-propylene terephthalate), and Poly(isosorbide-co-1,3-propylene furanoate) 14. The polyester (co)polymer according to claim 12 or 13, wherein the polyester (co)polymer is selected from the group consisting of a polyester (co)polymer containing a total of dicarboxylic acid-derived monomer units and a total of diol-derived monomer units in a ratio of 1:

1.

15. A composition comprising a polyester (co)polymer according to claim 10 and additionally one or more additives and / or one or more additional other (co)polymers.