Woven fabric made of polyester basic monofilament

Abstract

The present invention relates to a textile elementary monofilament made of polyester having a melting point Tm higher than or equal to 240° C., a tensile strength higher than or equal to 2.5 cN / tex and an elongation at break higher than or equal to 10%, as well as a process for producing such a monofilament.

Description

[Technical field]

[0001] The present invention relates to the field of polyester textile yarns and to a process for producing such yarns. [Background technology]

[0002] Polyesters have many applications in the industrial and textile fields, especially in the manufacture of clothing fibers. Due to the diversity of their applications, large quantities are produced every year. It is therefore interesting to synthesize polyesters from monomers derived from renewable resources, and such polyesters have technical characteristics that allow them to replace petroleum-based polyesters, such as polyethylene terephthalate (PET). Extensive research has been done on the production of polyesters from furandicarboxylate monomers. These monomers can be produced from natural sources such as sugars. The synthesis of polyesters typically involves esterification and polycondensation steps, which may be followed by crystallization and solid-state post-condensation steps to tailor the properties of the polyester. The structure, and therefore the characteristics, of the resulting polyester depend on how these various steps are carried out. For example, patent application WO 2015 / 137805 describes polyethylene furanoate (PEF)-based polyesters with a low content of diethylene glycol units, and a method for their synthesis. The synthesis includes, among other things, esterification and polycondensation steps in the presence of a compound that inhibits the formation of diethylene glycol. The presence of this inhibitor compound allows a very low amount of diethylene glycol units to be obtained in the PEF, thus improving the melting point and crystallinity of the resulting polyester. Patent application WO 2013 / 055860 describes polyesters containing dicarboxylic acid units and glycol units whose glass transition temperatures are relatively stable over a wide range of polyester compositions. The patent application mentions many potential uses of such polyesters, particularly as fibers, but does not teach how to impart desired mechanical properties to the fibers. Summary of the Invention

[0003] Continuing its research, the Applicant has found a textile base monofilament having a high melting point and high strength, which is particularly suitable for use in the production of fabrics, which can be obtained through a combination of steps and specific operating conditions that are improvements over the processes known in the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] The present invention relates to at least one of the following embodiments. 1) A woven basic monofilament made of a polyester of formula (I), [ka] (In the formula, m represents the total number of ethylene glycol furan dicarboxylate units, and n represents the total number of cyclohexane dimethanol furan dicarboxylate units, where n does not include zero and m+n≧25.) The molar ratio of ethylene glycol units represented by EG to cyclohexanedimethanol units represented by CHDM is in the range of 0 / 100 mol / mol to 20 / 80 mol / mol, and the woven basic monofilament has a melting point Tm higher than or equal to 240°C, a tensile strength higher than or equal to 2.5 cN / tex, and an elongation at break higher than or equal to 10%. Woven basic monofilament.

[0005] 2) A woven basic monofilament according to any preceding embodiment, wherein the furan rings account for at least 25% by weight of the polyester. 3) Woven elementary monofilament according to any of the preceding embodiments, in which the polyester has a weight-average molar mass in PMMA equivalent of greater than 45000 g / mol, preferentially greater than 55000 g / mol. 4) Woven elementary monofilament according to any one of the preceding embodiments, in which the polyester has an intrinsic viscosity greater than 0.7 dL / g, very preferentially greater than 0.8 dL / g. 5) Woven basic monofilament according to any one of the preceding embodiments, in which the polyester has a dispersity indicated as D and represents a ratio of the weight average molar mass to the number average molar mass (D=Mw / Mn) of less than 2.5, preferably less than 2.0. 6) The woven base monofilament according to any one of the preceding embodiments, wherein the molar ratio of ethylene glycol units to cyclohexanedimethanol units is in the range of 4 / 96 mol / mol to 15 / 85 mol / mol.

[0006] 7) A woven basic monofilament according to any one of the preceding embodiments, having a tensile strength greater than or equal to 3 cN / tex and an elongation at break greater than or equal to 15%. 8) A woven basic monofilament according to any one of the preceding embodiments, having a shrinkage percentage of less than 14%, preferentially less than 12%. 9) A woven base monofilament according to any one of the preceding embodiments coated with one or more layers of a non-metallic adhesive composition base coating. 10) A fabric comprising at least one woven elementary monofilament according to any one of the preceding embodiments. 11) A method for preparing a textile basic monofilament made of polyester, comprising the steps of: a step of transesterification of a composition comprising a compound of the furandicarboxylate type, designated RFC, of ​​general formula (II),

[0007] [ka] (wherein R represents an alkyl group having 1 to 3 carbon atoms or a hydrogen atom). The composition further comprises at least one glycol compound selected from 1,4-cyclohexanedimethanol and a mixture of 1,4-cyclohexanedimethanol and ethylene glycol; carrying out this transesterification step at a temperature ranging from 180° C. to 280° C., increasing with a gradient of at least 1° C. / min, in the presence of a Lewis acid catalyst, with a glycol compound / RFC molar ratio ranging from 1.1 to 2, preferentially from 1.1 to 1.2; a melt polycondensation step carried out at a temperature higher than or equal to 260° C. and at a pressure lower than 100 mbar, whereby a polyester is obtained, in which 1,4-cyclohexanedimethanol is present in the composition of the transesterification step in a content such that the molar ratio of ethylene glycol units to cyclohexanedimethanol units in the polyester, as a result of the polycondensation step, is in the range of 0 / 100 mol / mol to 20 / 80 mol / mol; - spinning polyester, thereby obtaining a textile basic monofilament; The method of claim 1,

[0008] 12) The method according to the preceding embodiment, wherein in the compound of general formula (II), R represents an alkyl group containing 1 to 2 carbon atoms. 13) The method according to any of embodiments 11 and 12, wherein the transesterification step is carried out for a period ranging from 1 to 5 hours, preferentially from 1 to 3 hours. 14) The method according to any one of embodiments 11 to 13, wherein in the transesterification step, the temperature is continuously increased in the range of 180° C. to 280° C. with a gradient of less than or equal to +5° C. / min. 15) The method according to any one of embodiments 11 to 14, wherein the catalyst used in the transesterification step is selected from hafnium acetylacetonate, zirconium acetylacetonate, titanium tetraisopropoxide and titanium tetrabutoxide, preferentially titanium tetrabutoxide. 16) The method according to any one of embodiments 11 to 15, wherein the transesterification step is carried out at a pressure ranging from 1.5 to 8 bar, preferentially from 1500 to 8000 mbar.

[0009] 17) The method according to any one of embodiments 11 to 16, wherein the polycondensation step is carried out at a temperature higher than or equal to 270° C., preferably higher than or equal to 280° C. 18) The method according to any one of embodiments 11 to 17, wherein the polycondensation step is carried out at a pressure of less than 50 mbar. 19) The method according to any one of the embodiments 11 to 18, wherein the polycondensation step is followed by a forming step in which the polyester is quenched by contacting with water, then cut into granules, then dried under an inert atmosphere at a temperature ranging from 80° C. to 100° C. and at a pressure less than or equal to atmospheric pressure. 20) Following the formation step, a crystallization step is carried out at a temperature ranging from 120° C. to the melting point of the polyester, preferentially in the range of 130° C. to 150° C., for a time ranging from 15 minutes to 2 hours, if the composition used in the transesterification step does not contain ethylene glycol, or at a temperature ranging from 220° C. to the melting point of the polyester, preferentially in the range of 220° C. to 230° C., for a time ranging from 10 minutes to 2 hours, if the composition used in the transesterification step contains ethylene glycol, followed by a solid-state post-condensation step at an increasing temperature ranging from 200° C. to 260° C., for a time ranging from 1 to 60 hours.

[0010] 21) The method according to the preceding embodiment, wherein the solid-state post-condensation step is carried out under inert gas flow at increasing temperatures in the range of 210° C. to 260° C., preferentially in the range of 220° C. to 250° C., for a time period in the range of 24 h to 72 h, preferentially in the range of 10 h to 60 h. 22) The method according to the preceding embodiment, wherein the temperature of the solid-state post-condensation step is increased stepwise in the range of 2 to 10°C. 23) The method according to any one of embodiments 11 to 22, wherein the spinning step, which is carried out as the last step of the method, is carried out at a temperature above the melting point of the polyester, the pressure at the die inlet is adjusted to be between 3.3 and 10.0 MPa, and the drawing step is subsequently carried out on a series of drawing cups, each of which has a temperature in the range of 40°C to 160°C and a draw ratio in the range of 3 to 6. 24) The method of the preceding embodiment, wherein the spinning and drawing steps are carried out continuously, without intermediate winding. 25) The method according to any of the embodiments 23 and 24, in which the first stretching cup has a temperature between 90 ° C and 160 ° C, preferentially between 105 ° C and 145 ° C, and the temperature of the last stretching cup is in the range of 40 to 80 ° C, thereby carrying out the relaxation step. 26) The method according to any one of embodiments 23 to 25, in which the final winding speed is between 500 and 5000 m / min, preferentially between 1000 and 3000 m / min.

[0011] definition The carbon-containing compounds referred to herein may be of fossil or bio-based origin. In the latter case, they may be partially or completely derived from biomass or may be obtained from renewable starting materials derived from biomass. Polymers, plasticizers, fillers, etc. are particularly contemplated. Any range value expressed by the expression "between a and b" indicates a range of values ​​that is greater than a and less than b (i.e., the boundaries a and b are excluded), whereas any range value expressed by the expression "a to b" means a range of values ​​that ranges from a up to b (i.e., the exact boundaries a and b are included). Unless otherwise stated, pressures are expressed in absolute values.

[0012] Polyesters according to the invention The present invention relates to a textile basic monofilament made of a polyester of formula (I), [ka] It is derived from the condensation of ethylene glycol (denoted as EG) and cyclohexanedimethanol (denoted as CHDM) monomers and is shown in diagram (II):

[0013] [ka] (In the formula, m represents the total number of ethylene glycol furan dicarboxylate units, and n represents the total number of cyclohexane dimethanol furan dicarboxylate units, where n does not include zero, and m+n≧25, and preferentially m+n≧35. The molar ratio of ethylene glycol units to cyclohexanedimethanol units (CHDM) is in the range of 0 / 100 mol / mol to 20 / 80 mol / mol, and said textile basic monofilament has a melting point Tm higher than 240°C, preferentially higher than or equal to 245°C, a tensile strength higher than or equal to 2.5 cN / tex, preferentially higher than or equal to 3 cN / tex, and an elongation at break higher than or equal to 10%. The polyester of the woven basic monofilament according to the present invention may or may not contain ethylene glycol units. In the case where the polyester does not contain ethylene glycol units, it is poly(1,4-cyclohexanedimethylene 2,5-furandicarboxylate) and is designated PCF. In the case where the polyester contains ethylene glycol units, it is poly(ethylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate) and is designated PECF, where "co" means copolymer.

[0014] The furan rings preferentially make up at least 25% by weight of the polyester of the textile basic monofilament according to the invention. The weight average molar mass of the polyester of the textile basic monofilament according to the invention, measured after granulating the polyester in the manner described herein, is preferentially greater than 45 000 g / mol, very preferentially greater than 55 000 g / mol in PMMA equivalent. The polyester of the textile basic monofilament according to the invention has an intrinsic viscosity, measured after granulating the polyester in the manner described herein, preferentially greater than 0.7 dL / g, very preferentially greater than 0.8 dL / g. The polyester of the textile basic monofilament according to the invention preferentially has a dispersity, expressed as D, measured after granulating the polyester in the manner described herein, which represents a ratio of the mass average molar mass to the number average molar mass of less than 2.5, preferably less than 2.0. The enthalpy of fusion of the polyesters according to the invention is preferentially greater than 40 J / g.

[0015] According to the invention, the molar ratio of ethylene glycol units to cyclohexanedimethanol units in the polyester ranges from 0 / 100 mol / mol to 20 / 80 mol / mol. Such a ratio, in combination with other characteristics of the polyester, makes it possible to obtain particularly useful thermomechanical properties in the monofilament, such as melting point, tensile strength and elongation at break. Preferably, the polyester is PECF, the molar ratio of ethylene glycol units to cyclohexanedimethanol units ranges from 4 / 96 mol / mol to 15 / 85 mol / mol. Preferably, the textile base monofilament has a shrinkage rate of less than 14%, preferentially less than 12%, which is lower than the shrinkage rates of prior art PEF filaments, which are typically around 15% to 30%, before any thermal coagulation step. The term "elementary monofilament" refers to an element having a length at least 10 times greater than the maximum dimension of its cross section, regardless of the shape of said cross section, be it circular, elliptical, oblong, polygonal, in particular rectangular or square, or oval. In the case of a rectangular cross section, the monofilament has the shape of a band. The textile elementary monofilaments may be coated with one or more layers of a non-metallic adhesive composition based coating, for example obtained by melt spinning, solution spinning or gel spinning. Each textile elementary monofilament has a substantially circular cross section, for example with a diameter in the range of 2 μm to 100 μm.

[0016] The textile thread element may be an assembly of a plurality of textile elementary monofilaments as defined above, sometimes called a strand, which preferably comprises more than 10 textile elementary monofilaments, preferably more than 100 textile elementary monofilaments, more preferentially more than 500 textile elementary monofilaments. The textile yarn element may also be an assembly of several strands as defined above, which may be produced by a twisting step or a succession of twisting steps, which may be composed solely of elements of the filaments of the invention or may be composed partially of these filaments which are thus constituents of a heterogeneous assembly. In one embodiment, the non-metallic adhesive composition base layer is formed by a layer of an adhesive primer, which allows for example to improve the adhesion of the thread elements to the elastomeric matrix. Such adhesive primers are those commonly used by those skilled in the art for pre-sizing certain textile fibers, in particular polyester, e.g. PET, aramid fibers, aramid / nylon fibers. For example, epoxy-based primers may be used, in particular polyglycerol polyglycidyl ether-based primers. Blocked isocyanate-based primers may also be used.

[0017] In another embodiment, the non-metallic adhesive composition base layer is formed by a base layer of resin and elastomeric latex. Reference may be made to RFL (resorcinol-formaldehyde-latex) based adhesive compositions as well as to adhesive compositions such as those described in WO 2015 / 118041. In yet another embodiment, the thread elements may be coated with a layer of adhesion primer, which is itself coated with a base layer of resin and elastomeric latex. fabric The present invention further relates to a fabric comprising at least one woven elementary monofilament according to the invention. Within the fabric, woven basic monofilaments are used preferentially in the form of threads, which comprise one or more woven basic monofilaments according to the invention. As used herein, the term "fabric" means a cloth made up of a plurality of yarns brought together by weaving, knitting, bonding, or any other means known to those skilled in the art.

[0018] Process according to the invention for synthesizing polyesters Transesterification Step The process according to the invention comprises a step of transesterification of a composition comprising a compound of the furandicarboxylate type, designated RFC, of ​​general formula (II), [ka] (In the formula, R represents an alkyl group containing 1 to 3 carbon atoms or hydrogen atoms; the composition further comprises at least one glycol compound selected from 1,4-cyclohexanedimethanol and a mixture of 1,4-cyclohexanedimethanol and ethylene glycol; This transesterification step is carried out at a temperature ranging from 180° C. to 280° C. with a ramp of at least 1° C. / min, in the presence of a Lewis acid catalyst, with a glycol compound / RFC molar ratio ranging from 1.1 to 2, preferentially from 1.1 to 1.2.

[0019] The term "transesterification" is used herein to refer both to transesterification, when R represents an alkyl group containing 1 to 3 carbon atoms, and to esterification, when R represents a hydrogen atom. The transesterification step allows the preparation of oligomers of general formula (I), which are 1,4-cyclohexanedimethylene 2,5-furandicarboxylate oligomers if the composition does not contain ethylene glycol (hence m=0), or ethylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate oligomers if the composition contains ethylene glycol. The operating conditions for this step have a decisive influence on the structure of the polyester obtained. In the composition used in this step, the glycol compound / RFC molar ratio ranges from 1.1 to 2, preferentially from 1.1 to 1.2. Preferably, R independently represents an alkyl group containing 1 to 2 carbon atoms. The compound of general formula (II) then corresponds to dimethyl 2,5-furandicarboxylate or diethyl 2,5-furandicarboxylate. The use of such a compound makes it possible to significantly reduce the dispersity D of the resulting polyester.

[0020] The transesterification step is preferentially carried out for a period ranging from 1 to 5 hours, preferably from 1 to 3 hours. According to the invention, the transesterification step is carried out at a continuously increasing temperature in the range of 180° C. to 280° C. The term "continuously increasing in the range of 180° C. to at least 280° C." means that the transesterification step is carried out at a temperature in the range of 180° C. to 280° C., and that the operating temperature increases during the transesterification step without any drop. By using an increasing temperature profile, any premature crystallization, possibly detrimental to the final product, can be avoided. In a preferred configuration, the temperature is increased continuously with a slope of less than or equal to +5° C. / min in the range of 180° C. to 280° C. When the maximum temperature is achieved, a plateau can be maintained until the degree of transesterification exceeds 80%. Preferably, the time between the minimum and maximum temperatures of the transesterification step in the case of a continuous temperature increase is at least equal to 30 minutes, preferentially at least equal to 45 minutes. The transesterification step is preferentially carried out at a pressure ranging from 1.5 to 8 bar. Preferably, this step is carried out under an inert atmosphere. Preferentially, operating at a pressure ranging from 1500 to 8000 mbar makes it possible to carry out the transesterification step in the liquid phase, while at the same time removing the reaction products, such as alcohols (when R is other than H) or water (when R is a hydrogen atom).

[0021] The transesterification step is carried out in the presence of a Lewis acid catalyst. Preferably, the Lewis acid catalyst is selected from hafnium acetylacetonate, zirconium acetylacetonate, titanium tetraisopropoxide (TIS) and titanium tetrabutoxide (TTB). Preferably, the Lewis acid catalyst is titanium tetrabutoxide (TTB). The transesterification step is carried out with a catalyst content ranging from 100 to 1000 ppm, preferentially from 150 to 500 ppm and very preferentially from 200 to 450 ppm. These operating conditions, at temperatures increasing stepwise over the mentioned ranges and in the presence of Lewis acid catalysts, in particular those of titanium tetrabutoxide (TTB), make it possible to obtain transesterification degrees of more than 80%, even more than 90%, with the amount of ester functions located at the chain ends of the resulting polyester prepolymers at the end of the transesterification being less than 100 meq / kg, preferably less than 80 meq / kg, preferably less than 30 meq / kg, while at the same time avoiding premature crystallization of certain oligomers. The degree of transesterification is determined by dividing the mass of alcohol (or water, if R=H) resulting from the transesterification step by the theoretical mass of alcohol (or water, if R=H) produced, assuming that all the ester functions (or acid functions, if R=H) of the RFC compound have reacted.

[0022] Polycondensation Step The process according to the invention comprises a melt polycondensation step carried out at a temperature higher than or equal to 260° C. and at a pressure lower than 100 mbar, thereby obtaining a polyester of general formula (I). As a result of this step, the sum of m+n is preferentially between 25 and 200. As a result of the transesterification step, the pressure is gradually reduced, over a period of between 60 and 120 minutes, preferentially between 80 and 100 minutes, to achieve the operating pressure of the polycondensation step. When the pressure is below 400 mbar, preferably below 300 mbar, very preferably below 200 mbar, the temperature of the reaction medium is increased until the initial operating temperature of the polycondensation step is achieved. The increase in temperature to the initial operating temperature of the polycondensation step occurs over a period ranging from 15 to 45 minutes. The use of low operating pressures, and in particular reduced pressure phases, allows the gradual removal of ethylene glycol and cyclohexanedimethanol present in the reaction system, and allows an increase in the molar mass of the polymer. Preferably, the polycondensation step is carried out at a temperature higher than or equal to 270° C., preferably higher than or equal to 280° C. Preferably, the polycondensation step is carried out at a pressure lower than 50 mbar, preferably as low as possible, for example preferentially lower than 1 mbar.

[0023] The polycondensation step is preferentially carried out for a time ranging from 10 minutes to 5 hours, preferably from 10 minutes to 2 hours. The polycondensation step is carried out with a catalyst content ranging from 100 to 1000 ppm, preferentially from 150 to 500 ppm, very preferentially from 200 to 450 ppm. The catalyst is generally added to the reaction system before the transesterification step. If necessary, the catalyst used in the polycondensation step may be topped off with a catalyst that is the same as or different from the catalyst used in the transesterification step. The polyester resulting from this step is called polycondensate and can then be formed into either granules, threads, or thin films. The threads may be formed using a spinning system, as known to those skilled in the art, to obtain threads that can be used as is or as a collection of threads. The threads may be formed, for example, by passing the thread through a series of temperature-controlled spools that can stretch the thread to the desired diameter. Formation into a thin film can be achieved by passing the polycondensate through a series of cooling rollers, thereby forming a thin film.

[0024] Preferably, the polycondensate is quenched by contacting with water and chopped into granules. This rapid placement of contact limits the agglomeration of the granules. A granulation step is carried out to form granules that are substantially uniform in size, thereby facilitating subsequent operations. In this preferred arrangement, the granules are then dried at a temperature in the range of 80° C. to 100° C. at sub-atmospheric pressure in an inert atmosphere, for example a nitrogen atmosphere. The polyester resulting from the polycondensation step is partially crystallized. The polyester resulting from the polycondensation step has an intrinsic viscosity greater than or equal to 0.50 dL / g, which is related to the molar mass of the polyester, the higher the molar mass of the polyester, the greater the intrinsic viscosity. The weight-average molar mass of the polyester resulting from this step, expressed in PMMA equivalent, is therefore preferentially greater than 35000 g / mol. Preferably, the intrinsic viscosity of the polyester is greater than or equal to 0.55 dL / g.

[0025] Crystallization Step Following the formation of the polyester into granules, a crystallization step can be carried out continuously for 15 minutes to 2 hours at a temperature ranging from 120°C to the melting point of the polyester, preferentially in the range of 130°C to 150°C, if the composition used in the transesterification step does not contain ethylene glycol, or for 10 minutes to 2 hours at a temperature ranging from 220°C to the melting point of the polyester, preferably in the range of 220°C to 230°C, if the composition used in the transesterification step contains ethylene glycol. Solid-state post-condensation step In order to increase the weight-average molar mass and the melting point of the polyester obtained, it is useful to carry out a solid-state post-condensation step after the crystallization step, which is carried out by heating the polyester under a stream of inert gas, preferentially under a stream of nitrogen, to a temperature close to but below its melting point. In this way, the solid-state post-condensation step is carried out for a time in the range of 1 to 60 hours at a temperature increasing in the range of 200° C. to 260° C. Preferentially, the solid-state post-condensation step is carried out for a time in the range of 24 to 72 hours, preferentially 24 to 60 hours, at a temperature increasing in the range of 210° C. to 260° C., preferentially 220° C. to 250° C. Preferably, the temperature of the solid-state post-condensation step is increased stepwise in the range of 2 to 10° C.

[0026] By carrying out this step at an increasing temperature in the range of 210° C. to 260° C., preferentially in the range of 220° C. to 250° C., preferably by increasing this temperature in a step by 2 to 10° C., preferentially in the range of 3 to 5° C., the increase in molar mass and the increase in melting point of the resulting polyester are maximized. Thereby, the resulting polyester preferably has a melting point above 240° C. In addition, surprisingly, the melting zone, i.e. the temperature range visible on a thermogram obtained by DSC using the method described later in this document where melting is observed, drops significantly compared to polyesters obtained via prior art methods. As a result of the solid post-condensation step, the intrinsic viscosity of the polyester increases, preferably greater than or equal to 0.7 dL / g, more preferably greater than or equal to 0.8 dL / g. Thus, the weight-average molar mass of the polyester is preferentially greater than 45000 g / mol in PMMA equivalent. In the preferred case where R is other than a hydrogen atom in formula (II), the polyester has a low dispersity D, preferentially less than 2.5.

[0027] Formation Step The polyester resulting from this post-condensation step can then be formed into, among other things, yarn. The formation into yarns is carried out via a polyester spinning step. The polyester is placed in the extrusion screw at a temperature above the melting point of the polyester and the pressure at the die inlet is adjusted to between 3.3 and 10.0 MPa. On leaving the die, the flowing polyester is cooled in a vertical chamber and is received in a pair of room temperature cups rotating at a circumferential speed of 100-5000 m / min, preferentially 300-3000 m / min, very preferentially 300-500 m / min, the circumferential speed being understood as the distance travelled by the point of contact with the yarn on the outer surface of the cup per unit of time. The drawing step is then carried out in a row on a series of drawing cups, each at a temperature ranging from 105°C to 145°C, the last at a temperature ranging from 40°C to 80°C, the draw ratio being measured in a manner known to the skilled artisan, and the ratio of the speed of the last cup and the first receiving cup before winding being strictly greater than 3 and up to 6, preferentially between 3.1 and 5, very preferentially between 3.5 and 5. Preferentially, the final winding speed is between 500 and 5000 m / min, preferentially between 1000 and 3000 m / min, this speed corresponding to the speed of the monofilament leaving the last cup. The unit filament size is between 1 and 25 dpf (denier per filament), 1 denier corresponding to 1 g per 9000 m of filament.

[0028] A draw ratio strictly greater than 3, preferentially greater than or equal to 3.1 and very preferentially greater than 3.5 makes it possible to obtain monofilaments having particularly useful mechanical characteristics and, in particular, tensile strength. As a result of the forming step, the yarn obtained has a tensile strength greater than or equal to 2.5 cN / tex, preferentially greater than or equal to 3.0 cN / t, and an elongation at break greater than or equal to 10%, measured according to ASTM standard D885-03. Measurement method Shrinkage rate The shrinkage measurement is carried out by placing the textile basic monofilament, or, where appropriate, an assembly of textile basic monofilaments, in the form of a multifilament yarn, under a tension of 0.5 cN / tex, then measuring the initial length L0 of the filament at room temperature and its length L1 after 2 minutes at 180° C. in a preheated chamber. The shrinkage is calculated by (L0-L1) / L0 and is expressed in %. This measurement makes it possible to define the dimensional stability of the textile fabric. For many applications, it is important that the textile fabric does not deform when exposed to temperature changes (during use or washing operations). In this particular case, the applicant found that the yarn obtained had an inherently very low shrinkage of less than 12%, or even less than 10%, even before an additional thermal setting operation.

[0029] Amount of ester functional groups at the chain ends The amount of ester functions located at the chain ends is determined by NMR spectroscopy. This is carried out either in HFIP-d (deuterated hexafluoro-2-propanol) to look at the alcohol chain ends, or in a 25 / 75 vol. / vol. mixture of TFA-d / CDCl3 to look at the ester chain ends, the decarboxylated ends, and determine the DEG content, where TFA-d denotes deuterated trifluoroacetic acid and CDCl3 denotes deuterated chloroform. The mole percentage of chain ends per unit is calculated as follows:

number

[0030] Methods for the determination of the content of DEG units The amount of DEG units is measured by NMR spectroscopy. A value of 200 is given to the furan signal and integrated between 7.28 and 7.37 ppm (number of furan protons per 100 repeat units) and then the following formula is applied:

number

[0031] The Tg, low and high crystallization temperatures, crystallinity and Tm were measured by DSC using the following cycle: An increase from 30° C. to 280° C., a 2 min isotherm at 280° C., followed by a decrease in temperature from 280° C. to 30° C., then a 2 min isotherm at 30° C., and finally a final increase from 30° C. to 280° C. The rate was always set at 10° C. / min for both the increase and decrease. Intrinsic viscosity (IV) The intrinsic viscosity (IV) is measured in solution in a phenol / ortho-dichlorobenzene mixture. The polymer is dissolved in a phenol / ortho-dichlorobenzene mixture by weight at a concentration C equal to 5 g / L. To promote dissolution, the mixture of solvent and granules is placed at 120° C. for several minutes under vigorous stirring. Finally, the solution is filtered using a 0.45 μm PTFE filter paper before being introduced into the Ubbelohde capillary viscometer.

[0032] Intrinsic viscosity (IV) is measured at 25° C. and calculated using the following formula:

number

[0033] Size Exclusion Chromatography (SEC) Measurements SEC analysis was carried out in hexafluoroisopropanol (HFIP). Solutions were prepared at a concentration of 1 mg / mL. Prior to analysis, samples were filtered using 0.45 μm PTFE filter paper. The samples to be analyzed are introduced into the APC XT column using an automatic sample injector (Sample Manager pFTN) and a Waters Acquity Advanced Polymer Chromatography (APC) pump. The autosampler (Sample Manager pFTN) allows the next sample to be taken. SEC method for expressing Mn in PMMA equivalents The molar masses were evaluated using a refractive index detector (Waters RI detector) and the relative molar masses of our polymers can be determined from a calibration curve made from PMMA standards at 35° C., the eluent used is hexafluoroisopropanol (HFIP). EXAMPLES

[0034] (Example 1) The transesterification step is fed with a composition comprising dimethyl furan dicarboxylate (DMF) and 1,4-cyclohexane dimethanol (CHMD) in a glycol / DMF molar ratio equal to 1.15, which is placed in the presence of 200 ppm of titanium tetrabutoxide (TTB) catalyst. The transesterification step is carried out at 1.7 bar at a temperature ranging from 180° C. to 260° C. with a temperature ramp of +4° C. / min for 20 min, and once the maximum temperature is reached, it is maintained until the degree of transesterification is 90%. This step results in a prepolymer in which the presence of DEG units is undetectable. The degree of transesterification is 90%. The pressure of the reaction medium is then gradually reduced while the temperature is maintained at 260° C. When the pressure achieves a value of P<200 mbar, the temperature is increased to 280° C. over 20 minutes. After reducing the vacuum for 1 hour 30 minutes, the pressure is maintained below 1 mbar and the temperature at 280° C. for 90 minutes.

[0035] As a result of the polycondensation step, the polycondensate is quenched by contacting it with water and chopped into granules. The PCF polyester resulting from the polycondensation step has the following characteristics: ·Intrinsic viscosity (IV): 0.57dL / g Integrated EG / CHDM mole ratio: 0 / 100mol / mol Amount of ester functional groups at the ends of the chain: 11meq / kg Number average molar mass Mn (PMMA equivalent): 21100g / mol Mass average molar mass Mw (PMMA equivalent): 40090 g / mol ·Degree of dispersion (D): 1.9 Melting point: 271°C The granules obtained are then dried at 100° C. for 5 hours and then subjected to a crystallization step in which they are maintained at a temperature of 130° C. for 30 minutes. As a result of the crystallization, a solid post-condensation step is carried out by maintaining the granules at a temperature of 225° C. for 25 hours under a nitrogen flow. The polyester resulting from this step has the following characteristics: ·Intrinsic viscosity (IV): 0.81dL / g Glass transition temperature: 90.6℃ Melting point: 258.4℃ Heat of fusion: 68.3J / g Mass average molar mass Mw (PMMA equivalent): 60000g / mol Number average molar mass Mn (PMMA equivalent): 27200g / mol ·Dispersion degree: 2.2

[0036] (Example 2) The transesterification step is fed with a composition comprising dimethyl furan dicarboxylate (DMF), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHMD) in a glycol / DMF molar ratio equal to 1.2 and an EG / CHDM molar ratio equal to 15 / 85 mol / mol, this composition being placed in the presence of 200 ppm of titanium tetrabutoxide (TTB) catalyst. The transesterification step is carried out at 6.8 bar at a temperature ranging from 180° C. to 260° C. with a temperature ramp of +4° C. / min for 20 min, and once the maximum temperature is reached, it is maintained until the degree of transesterification is 90%. This step results in a prepolymer in which the presence of DEG units is undetectable, the degree of transesterification being greater than 90%. The pressure of the reaction medium is then gradually reduced while the temperature is maintained at 260° C. When the pressure achieves a value of P<200 mbar, the temperature is increased to 280° C. over 20 minutes. After reducing the vacuum for 1 hour 30 minutes, the pressure is maintained below 1 mbar and the temperature at 280° C. for 30 minutes.

[0037] As a result of the polycondensation step, the polycondensate is quenched by contacting it with water and chopped into granules. The PECF polyester resulting from the polycondensation step has the following characteristics: ·Intrinsic viscosity (IV): 0.62dL / g Integrated EG / CHDM molar ratio: 4 / 96mol / mol Amount of ester functional groups at the ends of the chain: 8meq / kg Number average molar mass Mn (PMMA equivalent): 22000g / mol Mass average molar mass Mw (PMMA equivalent): 39600 g / mol ·Degree of dispersion (D): 1.8 Glass transition temperature: 81.4℃ ·Low temperature crystallization temperature: 130℃ Heat of crystallization: 30J / g Crystallinity: 14% Melting point: 265℃ Heat of fusion: 49J / g

[0038] The granules obtained are then dried at 100° C. for 5 hours and then they are subjected to a crystallization step in which they are maintained at a temperature of 220° C. for 20 minutes. As a result of the crystallization, a solid post-condensation step is carried out by maintaining the granules at a temperature of 235° C. for 20 hours under a nitrogen flow. The polyester resulting from this step has the following characteristics: ·Intrinsic viscosity (IV): 0.83dL / g Glass transition temperature: 89℃ Melting points: 257° C. and 265° C., indicating that a portion of the mass resulting from the polycondensation step is not lost. Number average molar mass Mn (PMMA equivalent): 30000g / mol Mass average molar mass Mw (PMMA equivalent): 63000g / mol ·Degree of dispersion: 2.1 Heat of fusion: 65J / g

[0039] (Example 3) The transesterification step is fed with a composition comprising dimethyl furan dicarboxylate (DMF), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHMD) in a glycol / DMF molar ratio equal to 1.2 and an EG / CHDM molar ratio equal to 20 / 80 mol / mol, this composition being placed in the presence of 200 ppm of titanium tetrabutoxide (TTB) catalyst. The transesterification step is carried out at 6.8 bar at a temperature ranging from 180° C. to 260° C. with a temperature ramp of +4° C. / min for 20 min, and once the maximum temperature is reached, it is maintained until the degree of transesterification is 90%. This step results in a prepolymer in which the presence of DEG units is undetectable, the degree of transesterification being greater than 90%. The pressure of the reaction medium is then gradually reduced while the temperature is maintained at 260° C. When the pressure achieves a value of P<200 mbar, the temperature is increased to 280° C. over 20 minutes. After reducing the vacuum for 1 hour 30 minutes, the pressure is maintained below 1 mbar and the temperature at 280° C. for 10 minutes.

[0040] As a result of the polycondensation step, the polycondensate is quenched by contacting it with water and chopped into granules. The PECF polyester resulting from the polycondensation step has the following characteristics: ·Intrinsic viscosity (IV): 0.61dL / g Integrated EG / CHDM molar ratio: 8 / 92mol / mol Amount of ester functional groups at the ends of the chain: 17meq / kg Number average molar mass Mn (PMMA equivalent): 22500g / mol Mass average molar mass Mw (PMMA equivalent): 40500g / mol ·Degree of dispersion (D): 1.8 Glass transition temperature: 78℃ Melting point: 258℃ The granules obtained are then dried at 100° C. for 5 hours and then subjected to a crystallization step in which they are maintained at a temperature of 220° C. for 20 minutes.

[0041] As a result of the crystallization, a solid post-condensation step is carried out by maintaining the granules at 232° C. under a nitrogen flow for 14 hours. The polyester resulting from this step has the following characteristics: ·Intrinsic viscosity (IV): 0.83dL / g Glass transition temperature: 87℃ Melting points: 249°C and 258°C, indicating that a portion of the mass resulting from the polycondensation step is not lost. Heat of fusion: 57.5J / g Number average molar mass Mn: 27700g / mol Mass average molar mass Mw: 55400g / mol ·Dispersion degree: 2.2

[0042] (Example 4) The transesterification step is fed with a composition comprising dimethyl furan dicarboxylate (DMF), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHMD) in a glycol / DMF molar ratio equal to 1.2 and an EG / CHDM molar ratio equal to 25 / 75 mol / mol, this composition being placed in the presence of 200 ppm of titanium tetrabutoxide (TTB) catalyst. The transesterification step is carried out at 6.8 bar at a temperature ranging from 180° C. to 260° C. with a temperature ramp of +4° C. / min for 20 min, and once the maximum temperature is reached, it is maintained until the degree of transesterification is 90%. This step results in a prepolymer in which the presence of DEG units is undetectable, the degree of transesterification being greater than 90%. The pressure of the reaction medium is then gradually reduced while the temperature is maintained at 260° C. When the pressure achieves a value of P<200 mbar, the temperature is increased to 280° C. over 20 minutes. After reducing the vacuum for 1 hour 30 minutes, the polymer is directly cast. As a result of the polycondensation step, the polycondensate is quenched by contacting it with water and chopped into granules.

[0043] The PECF polyester resulting from the polycondensation step has the following characteristics: ·Intrinsic viscosity (IV): 0.61dL / g Amount of ester functional groups at the ends of the chain: 20meq / kg Integrated EG / CHDM molar ratio: 14 / 86mol / mol Number average molar mass Mn (PMMA equivalent): 22300g / mol Mass average molar mass Mw (PMMA equivalent): 42370 g / mol ·Degree of dispersion (D): 1.9 Glass transition temperature: 75℃ Melting point: 248℃ The granules obtained are then dried at 100° C. for 5 hours and then subjected to a crystallization step in which they are maintained at a temperature of 220° C. for 20 minutes.

[0044] As a result of the crystallization, a solid post-condensation step is carried out by maintaining the granules at a temperature of 225° C. for 14 hours under a nitrogen flow. The polyester resulting from this step has the following characteristics: ·Intrinsic viscosity (IV): 0.83dL / g Glass transition temperature: 84℃ Melting point: 248℃ Heat of fusion: 53.9J / g Number average molar mass Mn (PMMA equivalent): 27600g / mol Mass average molar mass Mw (PMMA equivalent): 58000 g / mol ·Degree of dispersion: 2.1

[0045] (Example 5) Spinning of polyester obtained in Examples 1 to 4 Spinning tests were carried out using the four materials described in the preceding examples. The polymers prepared as described in Examples 1, 2, 3 and 4 above are formed by single-row extrusion spinning into the form of yarns (monofilaments) having the following process characteristics: -Die temperature is 275℃~280℃ - The speed of the first pair of receiving cups ranges between 300 and 600 meters per minute - The winding speed after drawing is between 1500 and 1800 m / min. -The ratio between these two speeds results in a stretch ratio in the range of 3 to 5 -The cup temperatures of the first three pairs range from 105 to 145°C, and the cup temperature of the fourth pair ranges from 45°C to 75°C.

[0046] The results obtained under various conditions are summarized in Table 1 below. Examples 11, 12, 13 are carried out using the polymer made as described in Example 1, Examples 21, 22, 23 are carried out using the polymer described in Example 2, Examples 31, 32, 33, 34 and 35 are carried out using the polymer described in Example 3, and Examples 41, 42, 43 and 44 are carried out using the polymer described in Example 4.

[0047] [Table 1]

[0048] After spinning under the above conditions, the strands are characterized and the results are presented in Table 2 below. [Table 2]

[0049] Tests carried out with four example polymers with molar ratios of EG / CHDM diol of 0 / 100, 4 / 96, 8 / 92 and 14 / 86 show that it is possible to obtain multistrands with a tensile strength greater than or equal to 2.5 cN / tex when a draw ratio of greater than 3 is applied. These characteristics allow to obtain multifilaments containing biosourceable furan monomers with a high melting point (>240° C.), usable in the textile industry and with the advantages of good mechanical strength, high elongation and low heat shrinkage.

Claims

1. A textile basic monofilament made of polyester of formula (I), 【Chemistry 1】 (In the formula, m represents the total number of ethylene glycol furan dicarboxylate units, and n represents the total number of cyclohexane dimethanol furan dicarboxylate units, provided that n does not include zero and m+n≧25.) the molar ratio of ethylene glycol units, denoted EG, to cyclohexanedimethanol units, denoted CHDM, ranges from 0 / 100 mol / mol to 20 / 80 mol / mol, said textile elementary monofilament has a melting point Tm higher than or equal to 240° C., a tensile strength higher than or equal to 2.5 cN / tex, and an elongation at break higher than or equal to 10%, said polyester having a weight-average molar mass in PMMA equivalent higher than 45000 g / mol, preferentially higher than 55000 g / mol, Woven basic monofilament.

2. 2. Woven basic monofilament according to claim 1, in which the polyester has an intrinsic viscosity greater than 0.7 dL / g, very preferentially greater than 0.8 dL / g.

3. 2. The woven basic monofilament according to claim 1, having a tensile strength greater than or equal to 3 cN / tex and an elongation at break greater than or equal to 15%.

4. A fabric comprising at least one woven elementary monofilament according to any one of claims 1 to 3.

5. 1. A method for preparing a textile base monofilament made of polyester, comprising the steps of: A step of transesterification of a composition comprising a compound of the furandicarboxylate type, designated RFC, of ​​general formula (II), 【Chemistry 2】 (wherein R represents an alkyl group containing 1 to 3 carbon atoms or a hydrogen atom). the composition further comprises at least one glycol compound selected from 1,4-cyclohexanedimethanol and a mixture of 1,4-cyclohexanedimethanol and ethylene glycol; said transesterification step being carried out at a temperature ranging from 180° C. to 280° C., increasing at a rate of at least 1° C. / min, in the presence of a Lewis acid catalyst, with a glycol compound / RFC molar ratio ranging from 1.1 to 2, preferentially from 1.1 to 1.2; a melt polycondensation step carried out at a temperature higher than or equal to 260° C. and at a pressure lower than 100 mbar, thereby obtaining a polyester, in which the 1,4-cyclohexanedimethanol is present in the composition of the transesterification step in a content such that the molar ratio of ethylene glycol units to cyclohexanedimethanol units in the polyester, as a result of the polycondensation step, ranges from 0 / 100 mol / mol to 20 / 80 mol / mol; - spinning said polyester, thereby obtaining a textile basic monofilament; In turn, The process according to claim 1, wherein the polycondensation step is carried out at a pressure of less than 50 mbar.

6. 6. The method according to claim 5, wherein in the transesterification step the temperature is increased continuously in the range of 180°C to 280°C with a gradient of less than or equal to +5°C / min.

7. 6. The method according to claim 5, wherein the polycondensation step is followed by a forming step in which the polyester is quenched by contacting it with water, then cut into granules, then dried under an inert atmosphere at a temperature ranging from 80° C. to 100° C. and at a pressure less than or equal to atmospheric pressure.

8. 8. The method according to claim 7, characterized in that the formation step is followed by a crystallization step, carried out at a temperature ranging from 120° C. to the melting point of the polyester, preferentially in the range of 130° C. to 150° C., for a time ranging from 15 minutes to 2 hours, if the composition used in the transesterification step does not contain ethylene glycol, or at a temperature ranging from 220° C. to the melting point of the polyester, preferentially in the range of 220° C. to 230° C., for a time ranging from 10 minutes to 2 hours, if the composition used in the transesterification step contains ethylene glycol, followed by a solid-state post-condensation step, at increasing temperatures ranging from 200° C. to 260° C., for a time ranging from 1 to 60 hours.

9. 9. The process according to claim 8, wherein said solid-state post-condensation step is carried out at an increasing temperature ranging from 210° C. to 260° C., preferentially from 220° C. to 250° C., for a time ranging from 24 h to 72 h, preferentially from 10 h to 60 h, under a flow of inert gas.

10. 10. The method according to any one of claims 5 to 9, wherein the spinning step, which is carried out as the last step of the method, is carried out at a temperature above the melting point of the polyester, the pressure at the die inlet is adjusted to be between 3.3 and 10.0 MPa, and a drawing step is subsequently carried out on a series of draw cups, each draw cup having a temperature in the range of 40°C to 160°C and a draw ratio in the range of 3 to 6.

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