EP3298064A1

EP3298064A1 - High-viscosity polyester with improved impact properties

Info

Publication number: EP3298064A1
Application number: EP16728066.8A
Authority: EP
Inventors: Nicolas JACQUEL; René SAINT-LOUP; Jean-Pierre Pascault; Françoise FENOUILLOT; Alain Rousseau
Original assignee: Roquette Freres SA
Current assignee: Roquette Freres SA
Priority date: 2015-05-22
Filing date: 2016-05-20
Publication date: 2018-03-28
Also published as: US11859046B2; FR3036400B1; WO2016189239A1; JP2018515666A; MX2017014990A; CN107636041A; KR20180011111A; CA2986103C; CA2986103A1; FR3036400A1; JP6937247B2; KR20240146110A; US20180155493A1

Abstract

The invention relates to a thermoplastic polymer comprising at least one 1,4:3,6-dianhydrohexitol unit (A), at least one alicyclic diol unit (B) other than the 1,4:3,6-dianhydrohexitol units (A) and at least one high-viscosity terephthalic acid unit (C).

Description

High viscosity polyester with improved impact properties Field of the invention

The present invention relates to a thermoplastic polyester of high viscosity, comprising at least one 1,4: 3,6-dianhydrohexitol unit, which can exhibit excellent properties of impact resistance and low coloring. The invention also relates to a method of manufacturing said polyester and the use of this polyester for the manufacture of different articles.

BACKGROUND OF THE INVENTION Because of their many advantages, plastics have become essential for the mass production of objects. Indeed, their thermoplastic nature allows these materials to be transformed at a high rate in all kinds of objects.

Some thermoplastic aromatic polyesters have thermal properties allowing them to be used directly for the manufacture of materials. They include aliphatic diol and aromatic diacid units. Among these aromatic polyesters, mention may be made of polyethylene terephthalate (PET), which is a polyester comprising ethylene glycol and terephthalic acid units, used for example for the manufacture of containers, packages, films or fibers.

"Monomeric units" means, according to the invention, units included in the polyester which can be obtained after polymerization of a monomer. With regard to the ethylene glycol and terephthalic acid units included in the PET, they may be obtained by esterification reaction of ethylene glycol and terephthalic acid, or by a transesterification reaction of ethylene glycol and terephthalic acid ester.

However, for certain applications or under certain conditions of use, these polyesters do not have all the required properties, in particular optical properties, impact resistance or heat resistance. Thus, PET modified glycols (PETg) have been developed. These are generally polyesters comprising, in addition to ethylene glycol and terephthalic acid units, cyclohexanedimethanol (CHDM) units. The introduction of this diol into the PET allows it to adapt the properties to the intended application, for example to improve its impact resistance or its optical properties, especially when the PETg is amorphous.

Other modified PETs have also been developed by introducing into the polyester units 1,4: 3,6-dianhydrohexitol, especially isosorbide (PEIT). These modified polyesters have higher glass transition temperatures than unmodified PETs or PETgs comprising CHDM. In addition, 1,4-3,6-dianhydrohexitols have the advantage that they can be obtained from renewable resources such as starch. These modified polyesters are particularly useful for the manufacture of bottles, films, thick sheets, fibers or articles requiring high optical properties. However, a problem encountered in the manufacture of polyesters comprising 1,4-3,6-dianhydrohexitol units, and in particular isosorbide units, is that these polyesters generally have a coloration. This coloration is explained until now by the sensitivity to the thermo-oxidation of isosorbide at high temperature. In this respect, reference may be made to the review by Fenouillot et al., Prog Polym. Sci., 2010, Vol 35, Pages 578 et seq. Which states: "the sentivity of isosorbide to thermooxidation at high temperature needed to polymerize polyesters is the cause for this yellowing". This very high sensitivity of isosorbide requires, in order to obtain low-staining polymers, to work in an atmosphere essentially free of oxygen, with a quantity of isosorbide generally limited and at a lower temperature.

It is to answer this problem that document US2006 / 0173154 A1 teaches a method for reducing this phenomenon of staining of polyesters related to the presence of isosorbide in the starting monomers. This document more particularly teaches a process for producing poly (ethylene-co-isosorbide) terephthalate comprising an esterification step and a polymerization step using a polycondensation catalyst and a secondary antioxidant in specified proportions. In addition, it is essential that in this process the esterification temperature be from 180 to 265 ° C and the polycondensation temperature be from 260 to 275 ° C.

An additional problem of polyesters comprising predominantly ethylene glycol and isosorbide is that they can be difficult to dry. However, during the melt processing of the polyester, the moisture can cause hydrolysis of said polyester. Thus, obtaining polyesters which are easier to dry could improve the stability of the polyester during its melt processing. Another problem with these PEITs is that they may have insufficient properties of impact resistance. In addition, the glass transition temperature may be insufficient for certain applications.

To improve the impact properties of polyesters, it is known from the prior art to use polyesters whose crystallinity has been reduced. With regard to the isosorbide-based polyesters, US2012 / 0177854, which describes polyesters comprising terephthalic acid units, and diol units comprising from 1 to 60 mol% of isosorbide and from 5 to 99 % 1,4-cyclohexanedimethanol which have improved impact properties. As indicated in the introductory part of this application, it is a question of obtaining polymers whose crystallinity is eliminated by the addition of comonomers, and thus here by the addition of 1,4-cyclohexanedimethanol. In the examples part, the manufacture of various poly (ethylene-co-1,4-cyclohexanedimethylene-co-isosorbide) terephthalates (PECIT) and also an example of poly (1,4-cyclohexanedimethylene-co-isosorbide) terephthalate is described. (PCIT).

However, the Applicant has found (see examples below) that the PCIT synthesized in this application US2012 / 0177854 has a reduced viscosity in solution which may be insufficient, for example, for the manufacture of films when they are produced by blowing sheath or for the manufacture of hollow bodies or son. In addition, if its impact resistance is presented as improved, it is not at all the case of its resistance to cold shock. Also, its glass transition temperature may be insufficient for certain applications (for example for hot filling or "hot-fill"). On the contrary, the PECITs described in this document have much higher glass transition temperatures. Note that this document also mentions the phenomenon of polyester staining related to the presence of isosorbide in the starting monomers.

It can also be noted that, while PECIT polymers have been the subject of commercial developments, this is not the case for ITCs. Indeed, their manufacture was hitherto considered complex, the isosorbide having a low reactivity as secondary diol. Yoon et al. (Synthesis and Characteristics of a Biobased High-Tg Terpolyester of Isosorbide, Ethylene Glycol, and 1,4-Cyclohexane Dimethanol: Effect of Ethylene Glycol as Chain Linker on Polymerization, Macromolecules, 2013, 46, 7219-7231) have thus shown that the synthesis of PCIT is much more difficult than that of PECIT. This document describes the study of the influence of the ethylene glycol content on the production kinetics of PECIT. In Yoon et al., An amorphous PCIT (which comprises about 29% isosorbide and 71% CHDM based on the sum of the diols) is manufactured to compare its synthesis and properties with those of PECIT polymers. The use of high temperatures during the synthesis induces a thermal degradation of the polymer formed if one refers to the first paragraph of the Synthesis part of page 7222, this degradation being notably related to the presence of cyclic aliphatic diols such as isosorbide . As a result, Yoon et al. used a process in which the polycondensation temperature is limited to 270 ° C. Yoon et al. have found that, even by increasing the polymerization time, the process also does not make it possible to obtain a polyester having a sufficient viscosity. Thus, without the addition of ethylene glycol, the viscosity of the polyester remains limited, despite the use of prolonged synthesis times. It should also be noted that in Yoon et al., The PCIT obtained is presented as an amorphous polyester.

To date, there is still a need to find new thermoplastic polyesters having a sufficiently high viscosity for use in more applications. There is also a need to obtain polymers which also have low color and / or good impact resistance properties, especially when cold.

In the present state of the art, it has not heretofore been possible to obtain a high viscosity polyester comprising 1,4-3,6-dianhydrohexitol (A) units, alicyclic diol (B) units other than (A) and terephthalic acid units (C), when this polyester comprises a small molar amount of non-cyclic aliphatic diol units such as ethylene glycol. These linear aliphatic diols are recognized as necessary in the polycondensation reaction to obtain high viscosity polymers.

There is also a misconception about the need to use limited temperatures in polyester manufacturing processes comprising 1,4: 3,6-dianhydrohexitol (A) units to achieve low polymer degradation, and therefore low coloring. To obtain these polymers, it was necessary to use particular processes using low esterification and polycondensation temperatures because of the high sensitivity to the thermooxidation of isosorbide.

By carrying out studies on the polyester production processes containing 1,4: 3,6-dianhydrohexitol units, the Applicant has succeeded in obtaining a new high-viscosity polyester, which polyester may also have excellent properties of resistance to shock, low staining and / or ability to be easily dried. This polyester can be used in very different temperature conditions since it has excellent cold impact resistance, while having a high glass transition temperature.

Summary of the invention

The subject of the invention is thus a thermoplastic polyester comprising: at least one 1,4-4,6-dianhydrohexitol (A) unit;

At least one alicyclic diol unit (B) other than the 1,4-3,6-dianhydrohexitol (A) units;

At least one terephthalic acid unit (C); said polyester being free from non-cyclic aliphatic diol units or comprising a molar amount of non-cyclic aliphatic diol units, based on all of the monomer units of the polyester, of less than 5%, and the reduced viscosity in solution (25 ° C; (50% m): ortho-dichlorobenzene (50% m), 5 g of polyester IL) of said polyester is greater than 50 ml / g.

Despite the fact that it can comprise large quantities of 1,4-3,6-dianhydrohexitol units known as coloring agents in polyesters during the polymerization, the Applicant has found that the polyesters according to the invention can surprisingly present together a high viscosity and low color.

This polymer may especially be obtained by a particular manufacturing process, comprising in particular a step of introducing into a monomer reactor comprising at least one 1,4: 3,6-dianhydrohexitol (A), at least one alicyclic diol (B). other than 1, 4: 3,6-dianhydrohexitols (A) and at least one terephthalic acid (C), said monomers being free from non-cyclic aliphatic diol or comprising a molar amount of non-cyclic aliphatic diol units of less than 5%, this amount being determined with respect to all the monomers introduced.

This process comprises a step of polymerization at a high temperature of said monomers to form the polyester, said step consisting in: a first oligomerization stage during which the reaction medium is stirred under an inert atmosphere at a temperature ranging from 265 to 280 ° C, preferably from 270 to 280 ° C, for example 275 ° C; ^■ a second stage of condensation of the oligomers in which the oligomers formed are stirred under vacuum at a temperature ranging from 278 to 300 ° C to form the polyester, preferably 280 to 290 ° C, e.g. 285 ° C;

^■ a polyester recovery step; wherein the molar ratio ((A) + (B)) / (C) is from 1.05 to 1.5.

The Applicant has found that by using a terephthalic acid as monomer (C), selected quantities of (A), (B) and (C) very specific and high temperatures during the polymerization (oligomerization and condensation of oligomers), it is quite possible to obtain new polyesters having a higher viscosity. Contrary to what was believed by those skilled in the art, 1,4-3,6-dianhydrohexitols (and in particular isosorbide) as sole diols are not responsible for the coloration of the polyesters during the polymerization, despite the high temperatures. used during the process. The Applicant has surprisingly found that the polyesters stain only if the diols used are mixtures of 1, 4: 3,6-dianhydrohexitols with non-cyclic aliphatic diols, and in particular when the molar amount of non-cyclic aliphatic diols is equal. at or above 5%. Without being bound by any particular theory, it appears that the degradation of 1,4: 3,6-dianhydrohexitols is increased during polymerization when non-cyclic aliphatic diols are included in the starting monomers. This would be explained by the fact that these non-cyclic aliphatic diols polymerize rapidly with terephthalic acid, which would slow down the polymerization of 1,4: 3,6-dianhydrohexitols with terephthalic acid; the 1,4: 3,6-dianhydrohexitols would then be subjected to higher temperatures for longer, which would induce a phenomenon of strong coloration of the polyester and a decrease in the viscosity of the polyester formed.

The polyester according to the invention has a reduced viscosity in high solution and can be used in many tools for converting plastics, and in particular be easily converted by blowing. It also has excellent impact properties. According to some embodiments of the invention, they can also have particularly high glass transition temperatures.

The invention also relates to different processes for manufacturing this polyester.

Detailed description of the invention The polymer that is the subject of the invention is a thermoplastic polyester comprising:

At least one 1,4-3,6-dianhydrohexitol (A) unit;

At least one terephthalic acid unit (C). The polyester according to the invention is free from aliphatic non-cyclic diol units or comprises a small amount.

By "low molar amount of non-cyclic aliphatic diol units" is meant in particular a molar amount of non-cyclic aliphatic diol units of less than 5%. According to the invention, this molar amount represents the ratio of the sum of the non-cyclic aliphatic diol units, these units being able to be identical or different, with respect to all the monomeric units of the polyester.

A non-cyclic aliphatic diol may be a linear or branched non-cyclic aliphatic diol. It can also be a saturated or unsaturated non-cyclic aliphatic diol. In addition to ethylene glycol, the saturated linear non-cyclic aliphatic diol may, for example, be 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-di- octanediol and / or 1,10-decanediol. As an example of saturated branched non-cyclic aliphatic diol, mention may be made of 2-methyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-2-butyl-1, 3-propanediol, propylene glycol and / or neopentyl glycol. Examples of unsaturated aliphatic diol include, for example, cis-2-butene-1,4-diol. This molar amount of non-cyclic aliphatic diol unit is advantageously less than 1%. Preferably, the polyester is free of non-cyclic aliphatic diol unit.

Despite the small amount of non-cyclic aliphatic diol, and thus ethylene glycol, used for the manufacture of the polyester, the polyester has a reduced viscosity in high solution.

This reduced viscosity in high solution allows the polyester to be used in many applications described below.

This reduced viscosity in solution may be greater than 50 ml / g, this viscosity can be measured using a Ubbelohde capillary viscometer at 25 ° C. in an equimassic mixture of phenol and ortho-dichlorobenzene after dissolving the polymer. 130 ° C with stirring, the introduced polymer concentration being 5g / L. This test of reduced viscosity in solution is, by the choice of solvents and the concentration of the polymers used, perfectly suitable for determining the viscosity of the viscous polymer of the present invention. According to the present invention, it is considered that a polyester of reduced viscosity in solution greater than 50 ml / g and up to 70 ml / g is a "high viscosity polyester".

The Applicant has also succeeded in obtaining a polyester having an even higher viscosity, hereinafter called "very high viscosity polyester". According to the invention, the term "polyester of very high viscosity" means a polyester having a reduced viscosity in solution of greater than 70 ml / g, advantageously greater than 75 ml / g, preferably greater than 85 ml / g, and preferably greater than 85 ml / g. at 95 mL / g.

In the case where the polyester according to the invention is a polyester of very high viscosity, it has excellent impact properties at room temperature but also good properties of cold impact resistance. As this polyester can be used and mechanically stressed at low temperature, this allows it to be used in many applications, in various industries such as for example automotive or household appliances.

The monomer (A) is a 1,4: 3,6-dianhydrohexitol. As previously explained, the 1,4: 3,6-dianhydrohexitols have the disadvantage of being secondary diols that are not very reactive in the manufacture of polyesters. 1,4: 3,6-Dianhydrohexitol (A) may be isosorbide, isomannide, isoidide, or a mixture thereof. Preferably, 1,4: 3,6-dianhydrohexitol (A) is isosorbide.

Isosorbide, isomannide and isoidide can be obtained respectively by dehydration of sorbitol, mannitol and iditol. As regards isosorbide, it is marketed by the Applicant under the brand name POLYSORB® P. The alicyclic diol (B) is also called aliphatic and cyclic diol. It is a diol which can be chosen in particular from 1, 4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol or a mixture of these diols. Most preferably the alicyclic diol (B) is 1,4-cyclohexanedimethanol. The alicyclic diol (B) may be in the configuration c / ^'s, in the trans configuration or may be a mixture of diols configuration c ^/' s and trans.

The polyester of the invention may for example comprise: A molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 1 to 54%;

A molar amount of alicyclic diol units (B) other than the 1,4-, 3,6-dianhydrohexitol (A) units ranging from 1 to 54%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%. The quantities in different units in the polyester may be determined by H NMR or by chromatographic analysis of the monomer mixture resulting from a methanolysis or complete hydrolysis of the polyester, preferably by H.sym.

Those skilled in the art can easily find the conditions of analysis to determine the amounts in each of the patterns of the polyester. For example, from an NMR spectrum of a poly (1,4-cyclohexanedimethylene-co-isosorbide terephthalate), the chemical shifts relating to 1,4-cyclohexanedimethanol are between 0.9 and 2.4 ppm and 4. At 0 and 4.5 ppm, the chemical shifts relative to the terephthalate ring are between 7.8 and 8.4 ppm and the chemical shifts relative to isosorbide are between 4.1 and 5.8 ppm. The integration of each signal makes it possible to determine the quantity of each pattern of the polyester. The polyester according to the invention can be semi-crystalline or amorphous. The semicrystalline nature of the polymer depends mainly on the amounts of each of the units in the polymer. Thus, when the polymer according to the invention comprises large quantities of 1,4-3,6-dianhydrohexitol (A) units, the polymer is generally amorphous, whereas it is generally semi-crystalline in the opposite case. Preferably, the polyester according to the invention has a glass transition temperature ranging from 85 to 200 ° C.

According to an advantageous embodiment, the polyester according to the invention comprises:

A molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 1 to 20%, advantageously from 5 to 15%;

A molar amount of alicyclic diol units (B) other than the 1,4, 3,6-dianhydrohexitol (A) units ranging from 25 to 54%, advantageously from 30 to 50%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

According to this advantageous mode, the polyester is generally semi-crystalline. The Applicant has succeeded in obtaining polyesters having semi-crystalline properties, even when the molar amount of 1,4-3,6-dianhydrohexitols reaches 20%. This polyester has surprisingly excellent properties of impact resistance. In addition, the crystallization rate of these new polyesters is higher than that of PEIT and PEICT, which allows to transform them into articles with improved application properties. In particular, this semi-crystalline polyester has a particularly high thermomechanical behavior, due to its high glass transition temperature and the presence of crystallinity reinforcing the mechanical properties at high temperature.

Preferably, when the polyester according to the invention is semi-crystalline, it has a melting point ranging from 210 to 295 ° C., for example from 240 to 285 ° C.

Preferably, when the polyester according to the invention is semi-crystalline, it has a glass transition temperature ranging from 85 to 140 ° C., for example from 90 to 115 ° C.

The glass transition and melting temperatures are measured by conventional methods, especially using differential scanning calorimetry (DSC) using a heating rate of 10 ° C / min. The experimental protocol is detailed in the examples section below.

Advantageously, when the polyester according to the invention is semi-crystalline, it has a heat of fusion greater than 10 J / g, preferably greater than 30 J / g, the measurement of this heat of fusion consisting in subjecting a sample of this polyester heat treatment at 170 ° C for 10 hours and then evaluate the heat of fusion by DSC by heating the sample to 10 ° C / min.

According to another embodiment of the invention, the polyester comprises: · a molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 20 to 54%;

A molar amount of alicyclic diol units (B) other than the 1,4, 3,6-dianhydrohexitol (A) units ranging from 1 to 35%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

According to this other embodiment, the polymer is generally amorphous. Preferably, when the polyester according to the invention is amorphous, it has a glass transition temperature ranging from 120 to 200 ° C., for example from 140 to 190 ° C.

The polyester according to the invention may be of low color and in particular have a clarity L * greater than 50. Advantageously, the clarity L * is greater than 55, preferably greater than 60, most preferably greater than 65, for example greater than 70 . The L * parameter can be determined using a spectrophotometer, using the CIE Lab model.

The polyester according to the invention, especially that of very high viscosity, has a very good impact resistance, in particular a very good resistance to cold impact. The polyester according to the invention, in particular that of very high viscosity, advantageously has a non-notched Charpy impact strength greater than 100 kJ / m ² (25 ° C, ISO 179-1 / 1 eU: 2010).

The polyester according to the invention, especially that of very high viscosity, advantageously has a Charpy impact strength with a notch greater than 5 kJ / m ² , advantageously greater than 10 kJ / m ² (-30 ° C., ISO 179-1 / 1 eA: 2010).

These properties of very high impact resistance could be obtained, even when the polyester according to the invention is semi-crystalline. This is contrary to the teaching of the application US2012 / 0177854 which teaches to decrease the crystallinity of the polyester in order to improve its impact resistance properties. The invention also relates to a method of manufacturing the polyester according to the invention.

According to a first variant of the process of the invention, the Applicant has succeeded in obtaining a polyester, which may have a reduced viscosity in high solution, by a manufacturing process comprising:

A step of introducing into a monomer reactor comprising at least one 1, 4:

3,6-dianhydrohexitol (A), at least one alicyclic diol (B) other than the 1,4, 3,6-dianhydrohexitols (A) and at least one terephthalic acid (C), the molar ratio ((A) + (B)) / (C) ranging from 1.05 to 1.5, said monomers being free from non-cyclic aliphatic diol or comprising, with respect to all the monomers introduced, a molar amount of non-cyclic aliphatic diol units less than 5%;

A step of introducing into the reactor a catalytic system;

A step of polymerizing said monomers to form the polyester, said step consisting of:

^■ a first oligomerization stage during which the reaction medium is stirred under inert atmosphere at a temperature ranging from 265 to 280 ° C, preferably from 270 to 280 ° C, e.g. 275 ° C; ^■ a second stage of condensation of the oligomers in which the oligomers formed are stirred under vacuum at a temperature ranging from 278 to 300 ° C to form the polyester, preferably 280 to 290 ° C, e.g. 285 ° C; • a polyester recovery step.

Thus, contrary to what was expected because of the use of high temperatures during the oligomerization and condensation stages of the oligomers, it is quite possible with the aid of the first variant of the process according to the invention. obtain polyesters of high viscosity and low color. Without being bound to any theory, the Applicant explains this weak coloration by the fact that it is only when using quantities of important non-cyclic aliphatic diol in combination with 1, 4: 3,6-dianhydrohexitol that this the latter is degraded in the reactor during the polymerization. Quite unexpectedly, according to the process of the invention which uses low molar quantities of non-cyclic aliphatic diol (less than 5%), or even does not use this monomer, it is quite possible to obtain polymers having both a high viscosity and a low color.

The polymer obtained can thus have at least a reduced viscosity in solution of greater than 50 ml / g.

This first stage of this variant of the process is carried out in an inert atmosphere, that is to say under an atmosphere of at least one inert gas. This inert gas may especially be dinitrogen. This first stage can be done under gas flow. It can also be done under pressure, for example at a pressure of between 1.05 and 8 bar.

Preferably, the pressure ranges from 3 to 8 bar, most preferably from 5 to 7.5 bar, for example 6.6 bar. Under these preferred pressure conditions, the reaction of all the monomers with each other is facilitated by limiting the loss of monomers during this stage.

Prior to the first oligomerization step, a deoxygenation step of the monomers is preferably carried out. It can be done for example by performing, after introducing the monomers into the reactor, a vacuum and then introducing an inert gas such as nitrogen into the reactor. This empty cycle-introduction of inert gas can be repeated several times, for example 3 to 5 times. Preferably, this vacuum-nitrogen cycle is carried out at a temperature between 60 and 80 ° C. so that the reagents, and in particular the diols, are totally melted. This deoxygenation step has the advantage of improving the coloring properties of the polyester obtained at the end of the process.

The second stage of condensation of the oligomers is carried out under vacuum. The pressure can decrease during this second stage continuously using pressure drop ramps, stepwise or using a combination of pressure drop ramps and bearings. Preferably, at the end of this second stage, the pressure is less than 10 mbar, most preferably less than 1 mbar.

According to this first variant of the process, the first stage of the polymerization stage preferably has a duration ranging from 20 minutes to 5 hours. Advantageously, the second stage has a duration ranging from 30 minutes to 6 hours, the beginning of this stage consisting of the moment when the reactor is placed under vacuum, that is to say at a pressure lower than 1 bar.

The method of this first variant comprises a step of introducing into the reactor a catalytic system. This step may take place before or during the polymerization step described above. The term "catalytic system" means a catalyst or a mixture of catalysts, optionally dispersed or fixed on an inert support.

The catalyst is used in suitable amounts to obtain a high viscosity polymer according to the invention.

Advantageously, during the oligomerization stage, an esterification catalyst is used. This esterification catalyst may be chosen from tin, titanium, zirconium, hafnium, zinc, manganese, calcium and strontium derivatives, organic catalysts such as para-toluenesulphonic acid (APTS ), methanesulfonic acid (AMS) or a mixture of these catalysts. By way of example of such compounds, mention may be made of those given in application US2011282020A1 in paragraphs [0026] to [0029], and on page 5 of application WO 2013/062408 A1.

Preferably, during the first stage of transesterification, a titanium derivative, a zinc derivative or a manganese derivative is used.

By way of example of mass quantities, it is possible to use from 10 to 500 ppm of catalyst system during the oligomerization stage, with respect to the amount of monomers introduced. At the end of transesterification, the catalyst of the first step may be optionally blocked by the addition of phosphorous acid or phosphoric acid, or else as in the case of tin (IV) reduced by phosphites such as phosphite triphenyl or phosphite tris (nonylphenyl) or those cited in paragraph [0034] of US201 application 1282020A1. The second stage of condensation of the oligomers may optionally be carried out with the addition of a catalyst. This catalyst is advantageously chosen from tin derivatives, preferably tin, titanium, zirconium, germanium, antimony, bismuth, hafnium, magnesium, cerium, zinc, cobalt, iron, manganese, calcium, strontium, sodium, potassium, aluminum, lithium or a mixture of these catalysts. Examples of such compounds may be, for example, those given in EP 1882712 B1 in paragraphs [0090] to [0094].

Preferably, the catalyst is a derivative of tin, titanium, germanium, aluminum or antimony.

By way of example of mass quantities, it is possible to use from 10 to 500 ppm of catalyst system during the condensation stage of the oligomers, with respect to the amount of monomers introduced.

Most preferably, a catalyst system is used in the first stage and the second stage of polymerization. Said system advantageously consists of a tin-based catalyst or a mixture of catalysts based on tin, titanium, germanium and aluminum. By way of example, it is possible to use a mass quantity of 10 to 500 ppm of catalyst system, relative to the quantity of monomers introduced.

According to the method of the first variant, an antioxidant is advantageously used during the monomer polymerization step. These antioxidants make it possible to reduce the coloring of the polyester obtained. The antioxidants may be primary and / or secondary antioxidants. The primary antioxidant can be a sterically hindered phenol such as the compounds Hostanox® 0 3, Hostanox® 010, Hostanox® 016, Ultranox® 210, Ultranox®276, Dovernox® 10, Dovernox® 76, Dovernox® 3114 Irganox® 1010, Irganox® 1076 or a phosphonate such as Nrgamod® 195. The secondary antioxidant may be trivalent phosphorus compounds such as Ultranox® 626, Doverphos® S-9228, Hostanox® P-EPQ, or the Irgafos 168. It is also possible to introduce as polymerization additive into the reactor at least one compound capable of limiting spurious etherification reactions, such as sodium acetate, tetramethylammonium hydroxide, or tetraethylammonium hydroxide.

The method of the first variant comprises a step of recovering the polyester at the end of the polymerization step. The polyester can be recovered by extracting it from the reactor in the form of a melted polymer rod. This ring can be converted into granules using conventional granulation techniques.

The polyester thus recovered has a reduced solution viscosity of greater than 50 ml / g and generally less than 70 ml / g. According to a second variant of the process of the invention, the method of manufacturing the polyester comprises a step of increasing the molar mass by post-polymerization of a polymer of reduced viscosity in weaker solution, which comprises at least one unit 1, 4: 3,6-dianhydrohexitol (A), at least one alicyclic diol unit (B) other than the 1,4-3,6-dianhydrohexitol units (A) and at least one terephthalic acid unit (C), said lower viscosity in lower solution being free from non-cyclic aliphatic diol units or comprising a molar amount of non-cyclic aliphatic diol units, based on all the monomer units of the polymer, less than 5%.

According to this second advantageous variant of the invention, it is possible to obtain a polyester having a reduced viscosity in particularly high solution, for example greater than 70 ml / g.

The term "reduced viscosity polymer in weaker solution" means a polyester having a reduced viscosity in solution which is lower than that of the polyester obtained at the end of the post-polymerization stage. This polymer can be obtained according to the processes described in documents US2012 / 0177854 and Yoon et al., Using methods of manufacture using as monomers diols and diesters of terephthalic acid, or by using the method of the first variant described. previously.

The post-polymerization step may consist of a solid state polycondensation (PCS) step of the reduced viscosity polymer in a lower solution or a reactive extrusion step of the reduced viscosity polymer in a lower solution in the presence of at least one chain extender. According to a first particularly preferred embodiment of this second variant of the process, this post-polymerization step is carried out by PCS.

PCS is generally performed at a temperature between the glass transition temperature and the polymer melting temperature. Thus, to achieve PCS, it is necessary that the reduced viscosity polymer in lower solution be semi-crystalline. Preferably, the latter has a heat of fusion greater than 10 J / g, preferably greater than 30 J / g, the measurement of this heat of fusion consisting in subjecting a sample of this reduced viscosity polymer to a lower solution. heat treatment at 170 ° C for 10 hours and then evaluate the heat of fusion by DSC by heating the sample to 10 K / min.

Preferably, the reduced viscosity polymer in lower solution comprises:

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

Advantageously, according to this embodiment of the method, the PCS step is carried out at a temperature ranging from 190 to 300 ° C., preferably from 200 to 280 ° C.

The PCS step can be carried out in an inert atmosphere, for example under nitrogen or under argon or under vacuum.

According to a second embodiment of the process of the invention, the post-polymerization step is carried out by reactive extrusion of the reduced viscosity polymer in a lower solution in the presence of at least one chain extender.

The chain extender is a compound comprising two functions capable of reacting, in reactive extrusion, with functions, alcohol, carboxylic acid and / or carboxylic acid ester of the reduced viscosity polymer in a lower solution. The chain extender may, for example, be chosen from compounds comprising two isocyanate, isocyanurate, lactam, lactone, carbonate, epoxy, oxazoline and imide functions, said functions possibly being identical or different. Reactive extrusion may be carried out in an extruder of any type, such as a single-screw extruder, a twin-screw co-rotating extruder or a twin-screw counter-rotating extruder. However, it is preferred to perform this reactive extrusion using a co-rotating extruder. The reactive extrusion step can be done in:

Introducing the reduced viscosity polymer into a lower solution in the extruder so as to melt said polymer;

• then introducing into the molten polymer the chain extender;

And then reacting in the extruder the polymer with the chain extender;

Then recovering the polyester obtained in the extrusion stage.

During extrusion, the temperature inside the extruder is set to be at a temperature above the glass transition temperature if the polymer is amorphous and greater than the melting temperature if it is semi -cristallin. The temperature inside the extruder can range from 150 to 320 ° C. The invention also relates to the polyester obtainable by the method of the invention.

The invention also relates to a composition comprising the polyester according to the invention, this composition may comprise at least one additive or at least one additional polymer or at least one mixture thereof. The polyester composition according to the invention may comprise the polymerization additives possibly used during the process. It may also comprise other additives and / or additional polymers which are generally added during a subsequent thermomechanical mixing step.

As an example of an additive, there may be mentioned charges or fibers of organic or inorganic nature, nanometric or non-functional, functionalized or not. It can be silicas, zeolites, fibers or glass beads, clays, mica, titanates, silicates, graphite, calcium carbonate, carbon nanotubes, wood fibers, carbon fibers, polymer fibers, proteins, cellulosic fibers, lignocellulosic fibers and non-destructured granular starch. These fillers or fibers can improve the hardness, rigidity or permeability to water or gases. The composition can comprise from 0.1 to 75% by weight of filler and / or fibers relative to the total weight of the composition, for example from 0.5 to 50%. The additive useful for the composition according to the invention may also comprise opacifying agents, dyes and pigments. They can be selected from cobalt acetate and the following compounds: HS-325 Sandoplast® RED BB (which is a compound carrying an azo function also known as Solvent Red 195), HS-510 Sandoplast® Blue 2B which is an anthraquinone, Polysynthren® Blue R, and Clariant® RSB Violet.

The composition may also include as an additive a process agent, or processing aid, to reduce the pressure in the processing tool. A release agent to reduce adhesion to polyester forming materials such as molds or calender rolls can also be used. These agents can be selected from esters and fatty acid amides, metal salts, soaps, paraffins or hydrocarbon waxes. Specific examples of these agents are zinc stearate, calcium stearate, aluminum stearate, stearamide, erucamide, behenamide, beeswax or candelilla waxes.

The composition according to the invention may also comprise other additives such as stabilizing agents, for example light stabilizing agents, UV stabilizing agents and heat stabilizing agents, fluidifying agents, flame retardants and antistatic agents. The composition may further comprise an additional polymer, different from the polyester according to the invention. This polymer may be chosen from polyamides, polyesters other than the polyester according to the invention, polystyrene, styrene copolymers, styrene-acrylonitrile copolymers, styrene-acrylonitrile-butadiene copolymers, polymethyl methacrylates and acrylic copolymers. poly (ether-imides), polyphenylene oxide such as (2,6-dimethylphenylene) polyoxide, phenylene polysulfate, poly (ester-carbonates), polycarbonates, polysulfones, polysulfone ethers, polyether ketone and mixtures of these polymers.

The composition may also comprise, as additional polymer, a polymer making it possible to improve the impact properties of the polymer, in particular functional polyolefins such as functionalized ethylene or propylene polymers and copolymers, core-shell copolymers or block copolymers. The composition according to the invention may also comprise polymers of natural origin, such as starch, cellulose, chitosans, alginates, proteins such as gluten, pea proteins, casein, collagen, gelatin, lignin, these polymers of natural origin may or may not be physically or chemically modified. The starch can be used in destructured or plasticized form. In the latter case, the plasticizer may be water or a polyol, in particular glycerol, polyglycerol, isosorbide, sorbitans, sorbitol, mannitol or else urea. In order to prepare the composition, use may especially be made of the process described in document WO 2010/010282 A1.

The composition according to the invention can be manufactured by conventional methods of blending thermoplastics. These conventional methods include at least one step of melt blending or softening of the polymers and a step of recovering the composition. This method can be carried out in internal mixers with blades or rotors, external mixers, co-rotating or counter-rotating twin screw extruders. However, it is preferred to carry out this mixture by extrusion, in particular by using a co-rotating extruder. The mixture of the constituents of the composition can be carried out under an inert atmosphere.

In the case of an extruder, the various constituents of the composition can be introduced by means of introducing hoppers located along the extruder.

The invention also relates to a plastic article, finished or semi-finished, comprising the polyester or the composition according to the invention. This article can be of any type and be obtained using conventional transformation techniques.

This may be, for example, fibers or yarns useful for the textile industry or other industries. These fibers or yarns can be woven to form fabrics or nonwovens.

The article according to the invention may also be a film or a sheet. These films or sheets can be manufactured by calendering, cast film extrusion, duct extrusion extrusion techniques followed or not by monoaxial or polyaxial drawing or orientation techniques. These sheets can be thermoformed or injected to be used for example for parts such as portholes or machine covers, the body of various electronic devices (telephones, computers, screens), or as impact-resistant windows. The article can also be processed by extrusion profiles which can find their application in the fields of building and construction.

The article according to the invention may also be a container for transporting gases, liquids and / or solids. It may be bottles, gourds, bottles, for example bottles of sparkling water or not, bottles of juice, bottles of soda, bottles, bottles of alcoholic beverages, vials, for example bottles of medicine, bottles of cosmetic products, these bottles being aerosols, dishes, for example for ready meals, microwave dishes or lids. These containers can be of any size. They can be manufactured by extrusion blow molding, thermoforming or injection blow molding.

These articles can also be optical articles, that is to say articles requiring good optical properties such as lenses, disks, transparent or translucent panels, light-emitting diode (LED) components, optical fibers, films for LCD screens or windows. These optical articles have the advantage of being able to be placed near sources of light and therefore of heat, while maintaining excellent dimensional stability and good resistance to light.

Among the applications of the article, it is also possible to mention protective parts where the impact resistance is important, such as cell phone protections, spherical packaging, but also in the automotive field bumpers as well as the elements of the board. on board.

The articles may also be multilayer articles, at least one layer of which comprises the polymer or the composition according to the invention. These articles can be manufactured by a process comprising a coextrusion step in the case where the materials of the different layers are brought into contact in the molten state. By way of example, mention may be made of tube coextrusion techniques, coextrusion of profiles, coextrusion blow molding (in English "blowmolding") of bottles, flasks or tanks, generally grouped under the term coextrusion blow molding of hollow bodies, coextrusion inflation also called blowing of sheath (in English "film blowing") and co-extrusion flat ("in English" cast coextrusion "). They can also be manufactured according to a process comprising a step of applying a layer of polyester in the molten state to a layer based on an organic polymer, metal or adhesive composition in the solid state. This step may be carried out by pressing, overmolding, lamination or lamination, extrusion-rolling, coating, extrusion-coating or coating.

The invention will now be illustrated in the examples below. It is specified that these examples do not limit the present invention.

Examples:

The properties of polymers have been studied with the following techniques:

The reduced viscosity in solution is evaluated using a Ubbelohde capillary viscometer at 25 ° C. in an equimassic mixture of phenol and ortho-dichlorobenzene after dissolution of the polymer at 130 ° C. with magnetic stirring. For these measurements, the polymer concentration introduced is 5 g / l.

The color of the polymer was measured on the granules (25 grams of granules in the measuring cell) using a Konica Minolta CM-2300d spectrophotometer.

The mechanical properties of the polymers were evaluated according to the following standards: Bending test: ISO 178

Tensile test: ISO 527

Charpy Impact Test: ISO 179-1: 2010 (Not Notched: ISO 179-1 / 1eU, Notched: EN ISO 179-1 / 1 eA)

The impact strengths were determined as follows:

In a first step, the test is carried out according to the ISO 179-1 1 eU standard at 25 ° C .;

• if, during this first test, the resistance is greater than 155 kJ / m ² , the ISO 179-1 / 1eA test is carried out at 25 ° C .;

· If, during this second test, the resistance is greater than 155 kJ / m ² , the ISO 179-1 / 1eA test is carried out at -30 ° C.

HDT Test Method B stress 0.45MPa ISO 75

Vicat Method B50 ISO 306 DSC The thermal properties of the polyesters were measured by differential scanning calorimetry (DSC): The sample is first heated under a nitrogen atmosphere in an open crucible of 10 to 320 ° C (10 ° C. min-1). cooled to 10 ° C. (10 ° C.min -1) and then heated to 320 ° C. under the same conditions as the first step. The glass transition temperatures were taken at the midpoint of the second heating. The possible melting temperatures are determined on the endothermic peak (onset of the peak) in the first heating. In the same way the determination of the enthalpy of fusion (area under the curve) is carried out at the first heating. For the illustrative examples presented below the following reagents were used:

Ethylene glycol (purity> 99.8%) of Sigma-Aldrich

1,4-Cyclohexane dimethanol (99% purity, mixture of cis and trans isomers)

Isosorbide (purity> 99.5%) Polysorb® P from Roquette Frères

Terephthalic acid (purity 99 +%) from Acros

Germanium dioxide (> 99.99%) from Sigma Aldrich

Irganox 1010 from BASF AG

Dibutyltin oxide (98% purity) from Sigma Aldrich

Carbonylbiscaprolactam (Allinco CBC) from DSM. Tritan TX2001: performance copolyester marketed by Eastman®

Preparation of the polyesters:

Example 1

In a 7.5L reactor are added 1680 g (11.6 mol) of 1,4-cyclohexanedimethanol, 233 g (1, 6 mol) of isosorbide, 2000 g (12.0 mol) of terephthalic acid, 1 65 g of Irganox 1010 (antioxidant) and 1.39 g of dibutyltinoxide (catalyst). To extract the residual oxygen from the isosorbide crystals, 4 nitrogen-vacuum cycles are carried out once the temperature of the reaction medium is between 60 and 80 ° C. The reaction mixture is then heated to 275 ° C (4 ° C / min) under 6.6 bar pressure and with constant stirring (1 50 rpm). The esterification rate is estimated from the amount of distillate collected. Then, the pressure is reduced to 0.7 mbar in 90 minutes along a logarithmic ramp and the temperature brought to 285 ° C. These conditions of vacuum and temperature were maintained until a torque increase of 15 nm with respect to the initial torque. Finally, a polymer rod is poured through the bottom valve of the reactor, cooled in a thermo-regulated water tank at 15 ° C and cut into granules of about 15 mg.

The resin thus obtained has a reduced solution viscosity of 69.9 ml / g ¹ . The H-NMR analysis of the polyester shows that the final polyester contains 3.2 mol% of isosorbide with respect to all the monomeric units. With regard to the thermal properties (recorded at the second heating), the polymer has a glass transition temperature of 91 ° C., a melting temperature of 276 ° C. with a melting enthalpy of 44.5 J / g. The mechanical properties of the polymer obtained are collated in Table 1. The clarity L * is 53.2. Example 1a

The polyester of Example 1 is used in a post-condensation step in the solid state. First, the polymer is crystallized for 2 hours in a vacuum oven at 170 ° C. The crystallized polymer is then introduced into an oil bath rotavapor equipped with a fluted balloon. The granules are then subjected to a temperature of 248 ° C. and a nitrogen flow of 3.3 L / min.

After 23h, the polymer reaches a reduced solution viscosity of 106.5 ml / g. Finally, after 54 hours of post-condensation, the polymer will have a solution viscosity of 121.3 ml / g. The mechanical properties of the polymer obtained are collated in Table 1.

Example 1b

According to another process according to the invention, the polymer of ex 1 was extruded in a bi-visDSM micro-extruder in the presence of 1% of carbonylbiscaprolactam (Allinco CBC). The extrusion was carried out on 12 g of polymer for 2 min at 300 ° C. The polymer has a solution viscosity of 85.5 mL / g.

Example 2

7.5 g (9.9 mol) of 1,4-cyclohexanedimethanol, 484 g (3.3 mol) of isosorbide, 2000 g (12.0 mol) of terephthalic acid are added to a 7.5 L reactor. 65 g of Irganox 1010 (antioxidant) and 1.39 g of dibutyltinoxide (catalyst). To extract the residual oxygen from the isosorbide crystals, 4 nitrogen-vacuum cycles are carried out once the temperature of the reaction medium is between 60 and 80 ° C. The reaction mixture is then heated to 275 ° C. (4 ° C./min) under 6.6 bars of pressure and with constant stirring (150 rpm). The esterification rate is estimated from the amount of distillate collected. Then, the pressure is reduced to 0.7 mbar in 90 minut.es according to a logarithmic ramp and the temperature brought to 285 ° C. These conditions of vacuum and temperature were maintained until a torque increase of 12.1 Nm compared to the initial torque. Finally, a polymer rod is poured through the bottom valve of the reactor, cooled in a tank of thermo-regulated water at 15 ° C and cut into granules of approximately 15 mg.

The resin thus obtained had a reduced solution viscosity of 80, 1 mL / g ^~ H NMR analysis of the polyester shows that the final polyester contains 8.5 mole% isosorbide with respect to all monomer units. With regard to the thermal properties, the polymer has a glass transition temperature of 96 ° C, a melting temperature of 253 ° C with a melting enthalpy of 23.2 J / g. The clarity L * is 55.3.

Example 2a

The polyester of Example 2 is used in a post-condensation step in the solid state. First, the polymer is crystallized for 2 hours in a vacuum oven at 170 ° C. The crystallized polymer is then introduced into an oil bath rotavapor equipped with a fluted balloon. The granules are then subjected to a temperature of 230 ° C. and a nitrogen flow of 3.3 L / min.

After 31 hours of post condensation, the polymer will have a solution viscosity of 18.3 ml / g. The mechanical properties of the polymer obtained are collated in Table 1.

Example 2b

According to another process according to the invention, the polymer of ex 2 was extruded in a DSM bi-screw micro-extruder in the presence of 1% carbonylbiscaprolactam (Allinco CBC). The extrusion was carried out on 12 g of polymer for 2 min at 300 ° C. The polymer has a solution viscosity of 92.8 ml / g.

Example 3

7.5 g (8.3 mol) of 1,4-cyclohexanedimethanol, 726 g (5.0 mol) of isosorbide, 2000 g (12.0 mol) of terephthalic acid are added to a 7.5 L reactor. 1.65 g of Irganox 1010 (antioxidant) and 1.39 g of dibutyltinoxide (catalyst). To extract the residual oxygen from the isosorbide crystals, 4 nitrogen-vacuum cycles are carried out once the temperature of the reaction medium is between 60 and 80 ° C. The reaction mixture is then heated to 275 ° C (4 ° C / min) at 6.6 bar pressure and with constant stirring (150 rpm). The esterification rate is estimated from the amount of distillate collected. Then, the pressure is reduced to 0.7 mbar in 90 minut.es according to a logarithmic ramp and the temperature brought to 285 ° C. These conditions of vacuum and temperature were maintained until a torque increase of 1 1, 1 Nm compared to the initial torque. Finally, a polymer rod is poured through the bottom valve of the reactor, cooled in a tank of thermo-regulated water at 15 ° C and cut into granules of approximately 15 mg.

The resin thus obtained had a reduced solution viscosity of 66.2 mL / g ^~ H NMR analysis of the polyester shows that the final polyester contains 15.1 mole% isosorbide with respect to all monomer units. With regard to the thermal properties (recorded at the second heating), the polymer has a glass transition temperature of 109 ° C. The clarity L * is 51.5.

Example 3a

The polyester of Example 3 is used in a post-condensation step in the solid state. First, the polymer is crystallized for 8:30 in a vacuum oven at 170 ° C. The crystallized polymer is then introduced into an oil bath rotavapor equipped with a fluted balloon. The granules are then subjected to a temperature of 210 ° C. and a nitrogen flow of 3.3 l / min.

After 33 hours of post condensation, the polymer will have a solution viscosity of 94.2 ml / g. The mechanical properties of the polymer obtained are collated in Table 1.

Example 3b

According to another process according to the invention, the polymer of ex 2 was extruded in a DSM bi-screw micro-extruder in the presence of 1% carbonylbiscaprolactam (Allinco CBC). The extrusion was carried out on 12 g of polymer for 2 min at 300 ° C. The polymer has a solution viscosity of 85.4 mL / g.

Against Example 1

This example was made according to the embodiment recommended by the patent application US 2012/0177854 A1.

In a 7.5L reactor is added 3038 g (21.0 mol) of 1,4-cyclohexanedimethanol, 440 g (3.0 mol) of isosorbide, 2000 g (12.0 mol) of terephthalic acid, and 0.38 g of carbon dioxide germanium. To extract the residual oxygen from the isosorbide crystals, 4 nitrogen-vacuum cycles are carried out once the temperature of the reaction medium is between 60 and 80 ° C. The reaction mixture is then heated at 250 ° C. (4 ° C./min) under 6.6 bars of pressure and with constant stirring (150 rpm). The esterification rate is estimated from the amount of distillate collected. Then, the pressure is reduced to 0.7 mbar in 90 minut.es according to a logarithmic ramp and the temperature brought to 280 ° C. These conditions of vacuum and temperature were maintained for 210 minutes without obtaining a torque increase. The casting of the reactor did not allow to extrude a rod of polymer to effect granulation.

The resin thus obtained has a reduced solution viscosity of 16.4 ml / g under the conditions as defined in the present invention, that is to say a much lower viscosity than that of the polymer according to the invention. This polymer has insufficient properties to evaluate its mechanical properties.

Against Example 2

7.59 g (13.8 mol) of ethylene glycol, 546 g (3.7 mol) of isosorbide, 2656 g (16.0 mol) of terephthalic acid, 1.65 g are added to a 7.5 L reactor. g of Irganox 1010 (antioxidant) and 1.39 g of dibutyltinoxide (catalyst). To extract the residual oxygen from the isosorbide crystals, 4 nitrogen-vacuum cycles are carried out once the temperature of the reaction medium is between 60 and 80 ° C. The reaction mixture is then heated to 275 ° C. (4 ° C./min) under 6.6 bars of pressure and with constant stirring (150 rpm). The esterification rate is estimated from the amount of distillate collected. Then, the pressure is reduced to 0.7 mbar in 90 minut.es according to a logarithmic ramp and the temperature brought to 285 ° C. These conditions of vacuum and temperature were maintained until a torque increase of 15.0Nm compared to the initial torque. Finally, a polymer rod is poured through the bottom valve of the reactor, cooled in a tank of thermo-regulated water at 15 ° C and cut into granules of approximately 15 mg.

The resin thus obtained had a reduced solution viscosity of 58.8 mL / g ^~ H NMR analysis of the polyester shows that the final polyester contains 8.7 mole% isosorbide with respect to all monomer units. With regard to the thermal properties (recorded at the second heating), the polymer has a glass transition temperature of 97 ° C. The clarity L * is 46.2.

This sample does not have sufficient crystallinity and crystallization speed to allow the realization of a post-condensation step in the solid state (it has a zero heat of fusion after heat treatment for 10 hours at 170 ° C.). Table 1. Mechanical properties

Impact resistance

Constraint

(kJ / m ² ) Module Module Deformation Hardness at the

Without Notch Notch Flexion Tensile Break at Vicat HDT Shore Break

Notch 2 mm 2 mm (MPa) (MPa) (%) D

(MPa)

at 25 ° C to 25 ° C to -30 ° C

No

Ex1 rupture 10 NM 1512 71 1 36 247 100 84 76 (> 155)

No steps

Ex1a. rupture rupture 23 1459 736 43 200 100 88 77 (> 155) (> 155)

No steps

Ex2a. rupture rupture 22 1523 760 44 203 107 95 81 (> 155) (> 155)

No steps

Ex3a. rupture rupture 19 1608 798 40 164 115 103 81 (> 155) (> 155)

ECx2 9.6 NM NM 2400 1 1 10 39 4 96 86 81

No

Tritan

rupture 94 NM 1480.9 44.7 147.4 1 17.9 103.8 79 TX2001

(> 155)

Conclusions of the tests:

Comparative polyester 1, which is that described in application US 2012/0177854 A1, has a very low viscosity, compared with the polyester according to the invention of Example 1. These two examples show that, surprisingly, It is quite possible to form viscous polymers using the process of the first variant of the invention.

The polyesters according to the invention, produced under the same conditions as the comparative polyester of the counterexample 2 (polyester further comprising a linear aliphatic diol) exhibit a lower coloration, as well as properties of impact resistance that are much greater.

The polyesters according to the invention have a high viscosity, or even a very high viscosity when performing a step of increasing the molecular weight by PCS or reactive extrusion.

The semicrystalline polyesters whose molecular weight has been increased by PCS have a higher viscosity than polyesters whose molar mass has been increased by reactive extrusion.

Polyesters of very high viscosity have excellent resistance to impact, at room temperature as well as cold.

The polyesters according to the invention have excellent mechanical properties, similar to Tritan ™ performance copolyesters marketed by Eastman®. Their impact properties are even superior.

Claims

1. Thermoplastic polyester comprising:

At least one 1,4-3,6-dianhydrohexitol (A) unit;

At least one alicyclic diol unit (B) other than the 1,4: 3,6-dianhydrohexitol (A) units;

At least one terephthalic acid unit (C); said polyester being free from non-cyclic aliphatic diol units or comprising a molar amount of non-cyclic aliphatic diol units, based on all the monomeric units of the polyester, of less than 5%, characterized in that the reduced viscosity in solution (25 ° C. Phenol (50% m): ortho-dichlorobenzene (50% m), 5 g of polyester IL) of said polyester is greater than 50 ml / g.

Polyester according to Claim 1, characterized in that its reduced viscosity in solution is greater than 70 ml / g, advantageously greater than 75 ml / g, preferably greater than 85 ml / g, and most preferably greater than 95 ml / g.

Polyester according to either of Claims 1 and 2, characterized in that the alicyclic diol (B) is a diol chosen from 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol or a mixture of these diols, very preferably 1,4-cyclohexanedimethanol.

Polyester according to any one of claims 1 to 3, characterized in that 1,4: 3,6-dianhydrohexitol (A) is isosorbide.

Polyester according to any one of claims 1 to 4, characterized in that the polyester is free from non-cyclic aliphatic diol unit or comprises a molar amount of non-cyclic aliphatic diol units, based on all the monomeric units of the polyester, lower at 1%, preferably the polyester is free of non-cyclic aliphatic diol unit.

6. Polyester according to any one of claims 1 to 5, characterized in that the polyester comprises:

A molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 1 to 54%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

7. Polyester according to any one of claims 1 to 6, characterized in that the polyester comprises:

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

8. Polyester according to any one of claims 1 to 6, characterized in that the polyester comprises:

A molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 20 to 54%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

9. Polyester according to one of claims 1 to 7, characterized in that it is semi-crystalline, advantageously has a heat of fusion greater than 10 J / g, preferably greater than 30 J / g, the measurement of this Heat of fusion comprising subjecting a sample of the polyester to heat treatment at 170 ° C for 10 hours and then evaluating the heat of fusion by DSC by heating the sample to 10 ° C / min.

10. Polyester according to one of the preceding claims characterized in that it has an impact resistance greater than an impact resistance greater than 100 kJ / m ² (25 ° C, ISO 179-1 / 1 eU: 2010).

1 1. Process for producing the polyester according to one of the preceding claims, comprising:

A step of introducing into a monomer reactor comprising at least one 1, 4:

A step of introducing into the reactor a catalytic system;

^■ a first oligomerization stage during which the reaction medium is stirred under inert atmosphere at a temperature ranging from 265 to 280 ° C, preferably from 270 to 280 ° C, e.g. 275 ° C;

A second stage of oligomer condensation during which the oligomers formed are stirred under vacuum at a temperature of from 278 to 300 ° C to form the polyester, preferably 280 to 290 ° C, for example 285 ° C;

• a polyester recovery step.

12. The method of manufacturing the polyester according to one of claims 1 to 10, comprising a step of increasing the molar mass by post-polymerization of a reduced viscosity polymer in a lower solution, said polymer of reduced viscosity in solution more composition comprising at least one 1,4-3,6-dianhydrohexitol (A) unit, at least one alicyclic diol unit (B) other than the 1,4-3,6-dianhydrohexitol (A) units and at least one acidic unit terephthalic material (C), characterized in that it is free from non-cyclic aliphatic diol units or comprises a molar amount of non-cyclic aliphatic diol units, based on all the monomer units of the polymer, of less than 5%.

13. The method of claim 12, characterized in that this postpolymerization step is carried out by solid state polycondensation (PCS) of the reduced viscosity polymer in a lower solution.

14. The method of claim 13, characterized in that the PCS step is carried out at a temperature ranging from 190 to 300 ° C, preferably from 200 to 280 ° C.

15. Method according to one of claims 12 to 14, characterized in that the reduced viscosity polymer in weaker solution comprises:

A molar amount of 1,4-3,6-dianhydrohexitol (A) units ranging from 1 to 20%;

A molar amount of alicyclic diol units (B) other than the 1,4, 3,6-dianhydrohexitol (A) units ranging from 25 to 54%;

A molar amount of terephthalic acid (C) units ranging from 45 to 55%.

16. Method according to one of claims 12 to 15, characterized in that the reduced viscosity polymer in lower solution is semi-crystalline, advantageously has a heat of fusion greater than 10 J / g, preferably greater than 30 J g / g, the measurement of this heat of fusion consisting in subjecting a sample of the reduced viscosity polymer in lower solution to a heat treatment at 170 ° C. for 10 hours and then evaluating the heat of fusion by DSC by heating the sample at 10 K / min.

17. The method of claim 12, characterized in that this postpolymerization step is performed by reactive extrusion of the reduced viscosity polymer in lower solution in the presence of at least one chain extender.

18. The method of claim 17, characterized in that the chain extender is selected from compounds comprising two functions isocyanate, isocyanurate, lactam, lactone, carbonate, epoxy, oxazoline and imide, said functions may be identical or different.

19. Polyester obtainable by the method according to one of claims 1 1 to 18.

20. A polyester composition comprising a polyester according to one of claims 1 to 10 or 19.

21. A plastic article comprising a polyester according to one of claims 1 to 10 or 19 or a composition according to claim 20.