JP5432926B2 - Production method of intermediate molecular weight polyester and high molecular weight polyester - Google Patents

Description

  [0001] The present invention relates to the production of polyester.

  [0002] Linear polyesters generally react by transesterification of one or more dimethyl esters with one or more diols by directly reacting one or more dicarboxylic acids with one or more diols by esterification. Or oligomers obtained by performing both direct esterification and transesterification in a single reaction mixture. In the case of direct esterification, water is produced from the reaction mixture, and in the case of transesterification, methanol is produced from the reaction mixture. The oligomer thus obtained can be converted into a higher molecular weight polyester polymer by polycondensation. The branched polyester can be produced by introducing a tri- or higher functional reactant instead of a part of the dicarboxylic acid, diol, or dimethyl ester.

  [0003] Low molecular weight polyesters are typically produced in a one-step reaction that achieves both direct esterification and polycondensation. This reaction is generally carried out at atmospheric pressure and at a temperature near the normal boiling point for the diol (eg, at a temperature of about 170-210 ° C. for reactions using ethylene glycol). Usually a large excess of diol is used. A small amount (eg, about 3%) of xylene can be added near the end of the reaction to facilitate the distilling of water from the reaction mixture. The final product is a low molecular weight polyester that may become a liquid after cooling to room temperature, or in some cases an amorphous solid.

  [0004] Intermediate and high molecular weight polyesters are generally produced by a two-stage process. The first stage is usually a direct esterification or transesterification reaction to produce a low molecular weight oligomer in the liquid state, and the second stage is usually a polycondensation reaction to convert the oligomer to a polymer of the target molecular weight. is there. Considerable time may be required to complete these two stages. The first stage esterification reaction can be performed, for example, using conditions similar to the direct esterification reaction conditions for obtaining the above-described low molecular weight polyester. The second stage polycondensation reaction generally involves reduced pressure (eg, about 0.1-1 mm pressure) and elevated temperature (eg, higher than ambient temperature (eg, about 270-290 ° C. for polyesters derived from ethylene glycol). )] And melt polymerization or solid state polymerization. Depressurization and heating help to remove excess diol. The reaction mixture usually has a sufficiently high viscosity and is therefore very difficult to stir during the polycondensation reaction. The final product is an intermediate molecular weight polyester or a high molecular weight polyester and becomes a solid after cooling. The solid product is usually pelletized and then shipped to the end user. The end user uses an extruder or other equipment to melt the pellets and make the melt into a film or mold it into a solid object. For example, very large amounts of pelletized polyester resin are used to make containers (eg, bottles in the case of polyethylene terephthalate resin).

  [0005] The present inventors have discovered a method for producing intermediate or high molecular weight polyester syrups. That is, the method comprises: a) supplying or making an ester oligomer; b) mixing the oligomer in a non-reactive carrier capable of forming an azeotrope with water and converting the resulting solution to atmospheric and elevated temperatures. Converting the oligomer to a polyester polyol by stirring at; and c) removing water from the mixture by azeotropic reflux to give a syrup comprising an intermediate or high molecular weight polyester polymer in a non-reactive carrier. ;including.

  [0006] The disclosed manufacturing methods can result in rapid completion of the reaction and allow greater freedom in selecting the reactants. The liquid polyester product thus obtained can be used more easily than when pelletized solid polyester is used as a starting material to produce polyester paints and other liquid polyester products.

FIG. 1 is a schematic diagram of one embodiment of the disclosed process. FIG. 2 is a schematic diagram of another embodiment of the disclosed process. FIG. 3 is a perspective cutaway view of a transport container filled with the disclosed polyester syrup.

[0010] Like reference symbols in the various drawings indicate like elements. Elements in the drawings are not to scale.
[0011] Unless otherwise stated, the following terms shall have the meanings set forth below and shall be applicable to the singular and plural forms.

  [0012] "One (a)", "One (an)", "The", "At least one", and "One or more" The term “is used interchangeably. Thus, for example, a coating composition containing “an” additive means that the coating composition may include “one or more” additives.

[0013] By "azeotrope" is meant a mixture of two or more pure compounds that forms a constant boiling mixture.
[0014] "Elevated temperature" means a temperature of at least 120 ° C.

[0015] "Esterification" refers to direct esterification or transesterification.
[0016] As used with respect to polymers, "low molecular weight" means a polymer with Mn less than 4,000 amu, and "intermediate molecular weight" refers to a polymer with Mn of 4,000 to 7,000 amu. By “high molecular weight” is meant a polymer with Mn greater than 7,000 amu.

  [0017] "Non-reactive carrier" is a solvent or other carrier that can dissolve, disperse, or solubilize a medium or high molecular weight polyester to form the disclosed polyester syrup, It refers to a solvent or other carrier that is not a reactant to make (eg, not glycol) and does not react with the polyester (eg, does not transesterify with polyester) at the temperature of the polycondensation.

[0018] "Non-viscosity measurement method" means a method for measuring and managing the progress of a polymer formation reaction without the need to perform viscosity measurement.
[0019] "Polycondensation temperature" means a temperature of 200 ° C or higher.

[0020] "Polyester" refers to linear polyester and branched polyester.
[0021] "Polyester syrup" means a liquid that can be poured easily at room temperature and contains an intermediate or high molecular weight polyester in a non-reactive carrier.

  [0022] "Preferred" or "preferably" refers to an embodiment of the invention that may provide a particular merit under certain circumstances. However, other embodiments may be preferred under the same or other circumstances. Furthermore, the listing of one or more preferred embodiments does not indicate that other embodiments are not useful, and is intended to exclude other embodiments from the scope of the invention. I'm not doing it.

  [0023] When used in reference to a component present in a mixture, "substantially free" means containing less than about 5% by weight of the component, based on the weight of the mixture. .

  [0024] The recitation of numerical ranges using endpoints includes all numbers subsumed within that range (eg 1 to 5 is 1, 1.5, 2, 2.5, 2.75, 3, 3.80, 4, and 5 etc.).

  [0025] FIG. 1 shows an exemplary schematic diagram of one embodiment of the disclosed process in which a two-stage reaction is performed. The apparatus 10 includes an esterification reactor 12 for producing ester oligomers by direct esterification or transesterification. The reactor 12 is fitted with an impeller 14 which is mounted on a shaft 16 and driven by a motor 18. The fractional distillation column 20 makes it possible to remove water through the outlet 22. Inert gas source 24 is regulated by valve 26 and sent to reactor 12 via conduit 28. The carboxylic reactant (usually in the solid state) stored in vessel 30 can be melted using extruder 32 and sent to reactor 12 via conduit 34. In the case of reactants (eg, isophthalic acid or terephthalic acid) that can be decomposed in the extruder and can be easily added to the reactor 12 in the solid state, the extruder 32 can be omitted. The extruder 32 is further omitted in the case of reactants (eg, phthalic anhydride) that have a melting behavior that can be melted in the vessel 30 and sent directly to the reactor 12 via a conduit 34. can do. The glycol reactant (usually in the liquid state) stored in vessel 36 is regulated by valve 38 and sent to reactor 12 via conduit 40. The catalyst solution stored in vessel 42 is regulated by valve 44 and sent to reactor 12 via conduit 46. When esterification is complete, oligomeric or low molecular weight polyester product 50 is removed from reactor 12 by opening valve 52 and sent to polycondensation reactor 60 via conduit 54. The reactor 60 is fitted with an impeller 62 that is mounted on a shaft 64 and driven by a motor 66. The reflux distillation column 68 removes reaction by-products and vaporized non-reactive carrier from the reactor 60 and sends them to the condenser 72 via the conduit 70. Condensed non-reactive carrier 73 is collected at the bottom of condenser 72 and reaction by-products are removed via port 74. Extraction conduit 76, pump 78, and return conduit 80 allow condensed non-reactive carrier 73 to be returned to column 68. Non-reactive carrier stored in vessel 84 is regulated by valve 86 and sent to reactor 60 via conduit 88. The catalyst solution stored in vessel 90 is regulated by valve 92 and sent to reactor 60 via conduit 94. The progress of the polycondensation reaction can be monitored in various ways (eg, by withdrawing a sample at sampling port 96 when valve 98 is open). When it is determined that the polycondensation reaction is complete, the polycondensation reaction product syrup 100 is removed from the reactor 60 by opening the valve 102 and sent to the shipping drum 106 via the conduit 104.

  [0026] The esterification and polycondensation reactions outlined with respect to FIG. 1 can be referred to as the first stage involving oligomerization and the second stage involving polymer formation, respectively. It goes without saying to those skilled in the art that it is somewhat difficult to delineate between oligomerization and polymerization, some polymer formation may occur in reactor 50, and some in reactor 60. May occur.

  [0027] The reaction outlined with respect to FIG. 1 can be performed in a single reactor. FIG. 2 shows an exemplary schematic of a single reactor embodiment of the disclosed process. The apparatus 200 includes a reactor 202 mounted on a shaft 206 and fitted with an impeller 204 driven by a motor 208. The fractional distillation column 210 allows water to be removed via the outlet 212. Inert gas source 214 is regulated by valve 216 and sent to reactor 202 via conduit 218. The reflux distillation column 220 removes reaction by-products and vaporized non-reactive carrier from the reactor 202 and sends them to the condenser 224 via the conduit 222. Condensed non-reactive carrier 225 is collected at the bottom of condenser 224 and reaction by-products are removed via port 226. Extraction conduit 228, pump 230, and return conduit 232 allow condensed non-reactive carrier 225 to be returned to column 220. Carboxylic acid reactant stored in vessel 240 is melted using extruder 242 and sent to reactor 202 via conduit 244. As in the embodiment of FIG. 1, the extruder 242 is omitted for carboxylic reactants that can be added directly to the reactor 202 in the solid state or can be melted in the vessel 240. can do. The glycol reactant stored in vessel 246 is regulated by valve 248 and sent to reactor 202 via conduit 250. The esterification catalyst solution stored in vessel 252 is regulated by valve 254 and sent to reactor 202 via conduit 256. When the esterification reaction is complete, an oligomeric or low molecular weight polyester product is obtained, which is further reacted to produce a polyester syrup. Non-reactive carrier stored in vessel 258 is regulated by valve 260 and sent to reactor 202 via conduit 262. The polycondensation catalyst solution stored in vessel 264 is regulated by valve 266 and sent to reactor 202 via conduit 268. The progress of the polycondensation reaction can be monitored by drawing a sample at the sampling port 270 when the valve 272 is open. Polycondensation reaction product syrup 274 is removed from reactor 202 by opening valve 276 and sent to shipping tote 280 via conduit 278.

  [0028] FIG. 3 shows another exemplary transport container 300 for transporting the disclosed polyester syrup. Railroad tanker 302 contains polyester syrup 304 as a non-reactive carrier solution of polyester. Syrup 304 can be conveniently used to form polyester paints and other initially non-solid products, or other suitable liquid components without having to be melted or mixed with a carrier. Alternatively, it can be easily mixed with a solid component (for example, using a stirrer or a static mixer).

  [0029] Various dicarboxylic acids, or anhydrides or esters thereof, can be used in the disclosed process. Representative dicarboxylic acids for use in direct esterification reactions include, but are not limited to, saturated carboxylic acids, unsaturated carboxylic acids, anhydrides of these carboxylic acids, and combinations of these compounds. The polyester may be a saturated polyester or an unsaturated polyester. The dicarboxylic acid may be an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, or an alicyclic dicarboxylic acid. Representative dicarboxylic acids include maleic acid, chloromaleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, malic acid, succinic acid, glutaric acid, d-methylglutaric acid, adipic acid, sebacic acid, pimelic acid O-phthalic acid, isophthalic acid (IPA), terephthalic acid (TPA), dihydrophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrachlorophthalic acid, chlorendic acid, decanedicarboxylic acid, cis-5-norbornene-2 , 3-dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, dimethyl-2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and anhydrides of these acids There are but limited to these Not. Preferred dicarboxylic acids include terephthalic acid, isophthalic acid, o-phthalic acid, glutaric acid, adipic acid, 1,4-cyclohexanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, hexahydrophthalic acid, adipic acid, and these There are anhydrides and esters. Any ester of the above dicarboxylic acid (eg methyl ester) can be used in the transesterification reaction. The reaction mixture is optionally mixed with a small amount of monocarboxylic acid or ester thereof, or a small amount of tri- or higher carboxylic acid or ester thereof (eg, ethylhexanoic acid, propionic acid, trimellitic acid, benzoic acid, 4- Methyl benzoic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and esters thereof, but are not limited thereto.

[0030] Various glycols can be used in the disclosed process. Exemplary glycols for use in direct esterification reactions include linear diols, cyclic diols, and branched diols having 2 or more (eg 2 to about 8) carbon atoms; 4 or more (eg 4 To, but not limited to, aliphatic ether glycols and aromatic ether glycols having from about 20 to about 20 or 4 to about 10 carbon atoms; and combinations thereof. Typical glycols include ethylene glycol (also called EG, boiling point 195 ° C. at atmospheric pressure), 1,2-propanediol (propylene glycol or PG, boiling point 188 ° C.), 1,3-propanediol (boiling point 214 ° C.). ), 2-methyl-1,3-propanediol (MP diol, boiling point 212 ° C.), 2,2-dimethyl-1,3-propanediol (neopentyl glycol or NPG, boiling point 208 ° C.), 2,2,4 Trimethyl-1,3-pentanediol (TMPD glycol, initial boiling point 220 ° C.), 2-butyl-2-ethyl-1,3-propanediol (BEPG, boiling point 262 ° C.), 3-hydroxy-2,2-dimethyl Propyl-3-hydroxy-2,2-dimethylpropanate, , 3-butylene glycol (boiling point 204 ° C.), 1,4-butanediol (boiling point 230 ° C.), 3-methyl-1,5-pentanediol (MPD, boiling point 249 ° C.), 1,6-hexanediol (boiling point 250) ° C), 1,2-cyclohexanediol (118-120 ° C at a boiling point of 10 mmHg), 1,4-cyclohexanediol (150 ° C at a boiling point of 50 mmHg), 1,4-bis (hydroxymethyl) cyclohexane (cyclohexanedimethanol or CHDM, boiling point 283 ° C), 2,2-dimethylheptanediol, 2,2-dimethyloctanediol, diethylene glycol (DEG, boiling point 245 ° C), triethylene glycol (TEG, boiling point 285 ° C), dipropylene glycol (boiling point 229- 232 ° C.), tripropylene glycol (boiling) Point 273 ° C.), propylene glycol (PEG), hydroquinone bis (2-hydroxyethyl) ether, diethylene ether glycol (boiling point 197 ° C.), poly (ethylene ether) glycol, 2,2-bis- (p-hydroxycyclohexyl)- Examples include, but are not limited to, propane, 5-norbornene-2,2-dimethylol, and 2,3-norbornenediol. The reaction mixture can be prepared without or substantially without EG and PG, and instead, in conventional polyester polyol synthesis, it has a higher boiling point that is not normally used alone. It can be prepared using glycol. For example, the reaction mixture can be prepared using only glycols having an atmospheric boiling point of about 196 ° C or higher, about 200 ° C or higher, about 204 ° C or higher, or about 208 ° C or higher. This makes it possible to obtain particularly desirable physical properties (eg, change in crystallinity, glass transition temperature, softening point, or melt flow rate that are not or are not readily obtainable with polyester polymers derived from EG and PG. ) Can be synthesized. Preferred glycols include 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. There is. The reaction mixture is optionally mixed with a small amount of a monofunctional alcohol or a small amount of a trifunctional or higher polyfunctional alcohol (for example, 2-ethylhexyl alcohol, 2-cyclohexylethanol, 2,2-dimethyl-1-propanol, lauryl alcohol, Benzyl alcohol, cyclohexanol, glycerol, trimethylolpropane, trimethylolethane, di-trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol, but are not limited thereto.

  [0031] Various catalysts can be used for esterification, and these catalysts are well known to those skilled in the art. Typical catalysts include titanium, tin, lanthanum, zinc, copper, magnesium, calcium, manganese, iron, and cobalt inorganic and organic compounds (oxides, carbonates, phosphorus compounds, alkyl compounds, aryl compounds, and Aryl derivatives, as well as combinations of two or more thereof), but not limited thereto. Typical catalysts include titanium catalysts (eg, tetraisopropyl titanate and tetraisobutyl titanate); titanium / zirconium mixed catalysts; lanthanum acetylacetonate; cobalt acetate; organic titanium compounds and organic zirconium compounds (eg, US Pat. Compounds disclosed in US Pat. Nos. 056,818, 3,326,965, 5,981,690, and 6,043,335); and n-butyl stannic acid, octyl stannic acid, and US Pat. No. 6,281. , 325 and 6,887,953, tin catalysts containing other tin compounds; The catalyst can be used in an amount sufficient to promote the desired direct esterification or transesterification reaction (eg, from about 5 to about 10,000 ppm catalyst based on the weight of the polyester).

  [0032] The hydroxyl to acid molar ratio for the direct esterification reaction (or the hydroxyl to ester molar ratio in the case of transesterification reactions) may be, for example, from about 0.5: 1 to about 2: 1; 5: 1 to about 1.5: 1, about 0.8: 1 to about 1.2: 1, about 0.9: 1 to about 1.1: 1, about 0.95: 1 to about 1.05 1 or about 0.98: 1 to about 1.02: 1. An excess of hydroxyl is preferably used, and the hydroxyl to acid molar ratio or hydroxyl to ester molar ratio is about 1: 1 to about 2: 1, about 1: 1 to about 1.5: 1, about 1: 1 to Preferably, it is about 1.2: 1, about 1: 1 to about 1.1: 1, about 1: 1 to about 1.05: 1, or about 1.1 to about 1.02: 1. The preferred ratio may be well below the ratio normally used for direct esterification (generally a significant excess of glycol is used). Therefore, the disclosed production method makes it possible to reduce the amount of glycol used at the start of the esterification reaction and to carry out the reaction using a glycol having a boiling point higher than 196 ° C., which is the boiling point of ethylene glycol. is there. This may speed up the reaction, change the number of side reactions, or make it easier to achieve the target number average molecular weight for the ester oligomer or for the final polyester. For example, a hydroxyl to acid molar ratio of about 1.025: 1 may result in a final polyester product of about 10,000 amu, and a hydroxyl to acid molar ratio of about 1.01: 1 is about 20,000 amu. May result in a final polyester product. The number average molecular weight of the final product increases rapidly as the hydroxyl to acid molar ratio or hydroxyl to ester molar ratio approaches 1: 1, so it is important to carefully monitor the molar ratio in the course of the esterification reaction as the target number average Helps avoid over-extending the molecular weight.

  [0033] Esterification can be performed using a batch process or a continuous reaction process. Heating can be performed before supply, at the time of supply, at the time of mixing, or a combination thereof. The temperature can be maintained at a constant value or can be changed as the esterification proceeds. It is desirable to maintain the reactants at a temperature sufficient to promote rapid reaction and formation of water, methanol, or other by-products while avoiding degradation of the oligomer. For polyesters derived from ethylene glycol, a reaction temperature of about 210-235 ° C is recommended. The esterification reaction may be carried out at atmospheric pressure or higher pressure [eg, about 34 KPa (5 psi) to about 100 Kpa (15 psi), about 34 KPa (5 psi) to about 200 Kpa (29 psi), or about 34 KPa (5 psi) to about 300 Kpa (44 psi). ) Can be easily performed. The use of high pressure results in an increase in reaction rate, and the use of a lower temperature than that used in the absence of pressure with high pressure may reduce the number of side reactions. The esterification reaction preferably forms hydroxyl functional and optionally acid functional oligomers having a hydroxyl number greater than the acid number. Unlike typical methods for producing solid polyester products, the disclosed esterification reaction can be carried out using a carrier that may be present in the final product but is not preferred. If a carrier is added during oligomer formation, it becomes difficult to use the intrinsic viscosity measurement method commonly used to monitor the progress of the reaction. However, by using a non-viscosity measurement method (details below) to monitor one or both of the oligomerization reaction and the polycondensation reaction, monitoring is possible despite the presence of a carrier that changes the viscosity of the reaction mixture. It can be carried out.

  [0034] A variety of carriers can be used, including non-reactive carriers described in detail below. Fractional distillation can be used to remove water, methanol, and other by-products from the esterification reactor and to return glycol (and non-reactive carrier, if used) back to the reactor. In the production setting, the esterification reaction can be carried out, for example, less than about 8 hours, including the time required to heat the reactants (but not including time to cool the product), It can be performed in less than 7 hours, or less than about 6 hours. The oligomer product thus obtained can be immediately converted to higher molecular weight polyesters still at high temperatures, or can be cooled or stored in any convenient manner required and subsequently converted.

  [0035] The polycondensation reaction can be performed in a different reactor than the reactor used for esterification (eg, as in FIG. 1) or used to perform the esterification. It can also be carried out in the same reactor (for example as in FIG. 2). The oligomer is mixed with a suitable catalyst and non-reactive carrier at ambient pressure and elevated temperature. Water and glycol are removed by azeotropic reflux with a non-reactive carrier. The final product is preferably a syrup rather than a solid. By avoiding the formation of a solid end product, a variety of diol reactants can be used, including higher boiling diols where unreacted residues are difficult to remove using reduced pressure and heat. . For example, the disclosed process can use diols whose boiling point is close to or higher than the temperature at which the polyester product can decompose. The final product usually contains a substantial amount (eg, 5% by weight or more) of non-reactive carrier. The addition of a carrier is not desirable in conventional methods for producing intermediate or high molecular weight polyester resins. This is because the added carrier must be removed to obtain the normally required solid end product. The addition of a viscosity reducing carrier during polycondensation further makes it difficult to use intrinsic viscosity measurements to monitor polymer formation reactions. However, by using a non-viscosity measurement method, monitoring can be performed despite the presence of a carrier that changes the viscosity of the reaction mixture. The target number average molecular weight for the intermediate molecular weight polyester may be, for example, 4,000 to 7,000 amu, 5,000 to 7,000 amu, 5,000 to 6,000 amu, or 6,000 to 7,000 amu. The target number average molecular weight for the high molecular weight polyester is, for example, larger than 7,000 amu (for example, 7,001 amu or more), 7,001 to 30,000 amu, 7,001 to 25,000 amu, 7,001 to 20,000 amu, 8 , 3,000 to 30,000 amu, 8,000 to 25,000 amu, 8,000 to 20,000 amu, 10,000 to 25,000 amu, 10,000 to 20,000 amu, 10,000 to 18,000 amu, or 10, 000 to 16,000 amu.

  [0036] As noted above, it is desirable to use a hydroxyl: acid molar ratio or hydroxyl: ester molar ratio close to 1: 1. Under such circumstances, the number average molecular weight of the polymer may increase rapidly. When making high molecular weight polyesters, or when using viscometry to monitor the progress of the reaction, everything is too simple to go too far to the desired reaction endpoint. Alternative monitoring methods (eg, using gel permeation chromatography to measure number average molecular weight, or titration to measure hydroxyl number) are similarly too much when the polymer formation reaction is ongoing. take time. To determine whether one or both of the disclosed ester oligomerization reaction and polycondensation reaction is ongoing or complete, it is preferred to use a non-viscosity monitoring method. A variety of such methods can be used, but the main criteria are that measurement results are obtained quickly and that the accuracy is as good as that obtained using intrinsic viscosity measurements. Or preferably better. The use of near infrared analysis to monitor the disappearance of hydroxyl and acid groups is a particularly preferred method. Nuclear magnetic resonance described in US Pat. No. 6,887,953B2 can also be used. Additional starting materials (eg, additional dibasic acids or glycols) during the ester oligomerization reaction or polycondensation reaction in order to use the measurement results to modify the reaction mixture and make it easier to reach the target number average molecular weight Can be determined whether or not must be added to the reactor. The ester oligomerization reaction and the polycondensation reaction can also be monitored by combining a non-viscosity measurement method and a viscosity measurement method (for example, measurement of intrinsic viscosity or monitoring of stirrer torque).

  [0037] Polyester polymers can be formulated so that target properties other than molecular weight can be obtained, or properties with a predetermined number average molecular weight that cannot be obtained with commercially available polyester polymers. One preferred subclass of polyester polymers is a linear polyester polymer having a number average molecular weight (Mn) of 6,000 to 20,000 amu and a hydroxyl number of 5 to 20 (the polymer backbone contains ethylene oxide groups and propylene oxide groups). Not or substantially free). Also preferred are linear polyester polymers within such subclasses having a number average molecular weight greater than 6000 amu, less than 15,000 amu, or less than 12,000 amu. Another preferred subclass of polyester polymers has a Tg of greater than 20 ° C. and less than 40 ° C. and a number average molecular weight of 7,001-20,000. Also preferred are polyester polymers within such a subclass and above 25 ° C. and below 35 ° C. For example, Tg is selected to yield a polyester polymer that is non-tacky at room temperature, but that the paint produced using the polyester polymer is sufficiently flexible to resist cracks and microcracks when bent. can do. Yet another preferred subclass of polyester polymers is derived from at least some aromatic dicarboxylic acids, anhydrides, or esters.

  [0038] A variety of catalysts can be used in the polycondensation reaction, and these catalysts are well known to those skilled in the art. Exemplary catalysts include, but are not limited to, those described above for the esterification reaction, such as an amount sufficient to promote the polycondensation reaction (eg, about 5 to about 10,000 ppm based on the weight of the polyester). Catalyst).

  [0039] Various non-reactive carriers can be used. Exemplary non-reactive carriers include, but are not limited to, hydrocarbons, fluorocarbons, ketones, and mixtures thereof. Selected carriers may have azeotropic characteristics when mixed with water, consideration for intended subsequent processing steps or storage, consideration for volatile organic compounds (VOC), or intended end use for products that can be produced from the disclosed polyester syrup Can be selected based on various parameters including: Non-reactive carriers can be, for example, temperatures at or above the temperature at which the polyester product can decompose (eg, temperatures up to 250 ° C., 260 ° C., 275 ° C., or 300 ° C., or higher). The polyester syrup can be stored up to a temperature higher than the estimated maximum temperature (eg, about 60 ° C. or higher). For example, the non-reactive carrier may have a boiling point of about 60 ° C to about 300 ° C, about 140 ° C to about 300 ° C, about 150 ° C to about 300 ° C, or about 175 ° C to about 300 ° C. The non-reactive carrier preferably has a boiling point equal to or higher than that of xylene (140 ° C.), more preferably higher than that of kerosene (150 ° C.). Typical non-reactive carriers include alkanes such as heptane (boiling point 98 ° C.), octane (boiling point 126 ° C.), mineral spirits (boiling point 140-300 ° C.), and mixtures thereof; toluene (boiling point 110 ° C.), xylene (Boiling point 140 ° C.), ligroin (boiling point 60 to 90 ° C.), “Aromatic” series fluids (eg, Aromatic 150 and Aromatic 200) available from ExxonMobil, and shell sols available from Shell Chemical (SHELLSOL) (TM) series fluids (for example, shell sol A100 and shell sol A150) and commercially available materials such as mixtures thereof; aromatic hydrocarbons; petroleum naphtha, VM & P naphtha, Stoddard solvent, kerosene (boiling point 150 ° C.), And a mixture of these A petroleum-derived solvent and a plant-derived solvent containing turpentine (boiling point 150 to 180 ° C.); methyl ethyl ketone (boiling point 80 ° C.), methyl isobutyl ketone (boiling point 117 ° C.), methyl isoamyl ketone (boiling point 144 ° C.), methyl amyl ketone (boiling point 150) C), cyclohexanone (boiling point 156 ° C.), isobutyl ketone (boiling point 168 ° C.), methyl hexyl ketone (boiling point 173 ° C.), methyl heptyl ketone (boiling point 192 ° C.), and mixtures thereof; and such A mixture of different classes of non-reactive carriers; Aromatic hydrocarbons are preferred non-reactive carriers. A sufficient amount of non-reactive carrier must be used to obtain a stirrable reaction mixture and to obtain the final product in the form of a polyester syrup. Non-reactive carriers are present in relatively high proportions (eg, about 5% or more, about 10% or more, about 15% or more, about 20% or more, about 30% or more, about 40% or more of the weight of the final polyester syrup, Or in an amount corresponding to about 50% or more). The non-reactive carrier may be a greater amount, for example, about 95%, about 90%, about 85%, about 80%, about 70%, about 60%, or about 50% of the weight of the final polyester syrup. . A large amount of non-reactive carrier generally serves to increase the polycondensation reaction rate, to shorten the polycondensation reaction cycle time, or to reduce the required stirring torque.

  [0040] The polycondensation reaction can be conducted at any convenient high temperature as long as the polymer is produced at an appropriate rate and does not decompose in an undesirable manner. The reaction temperature can be, for example, about 200 ° C. to about 260 ° C., about 215 ° C. to about 250 ° C., or about 225 ° C. to about 235 ° C. (by measuring the temperature of the reactant itself rather than the headspace above the reactants). Be determined). The polycondensation reaction proceeds more rapidly at higher temperatures. For polyesters derived from ethylene glycol, reaction temperatures of about 210 ° C to about 250 ° C are preferred, with reaction temperatures of about 210 ° C to about 235 ° C being more preferred. In the production setting, the polycondensation reaction can be conducted, for example, in less than about 10 hours, less than about 9 hours, or less than about 8 hours (not including the time to heat the reactants or cool the product). These times are considerably shorter than those required for conventional solid state polyester polycondensation.

  [0041] Since the final product is preferably a polyester syrup rather than a solid (eg pelletized) polyester, there are few disadvantages and in fact some advantages associated with the disclosed process. There is. For example, as described above, the disclosed polyester syrup can be used much more easily to produce polyester paints than when starting from pelletized solids. The polycondensation reaction mixture can be stirred, thus reducing cycle time. The polycondensation reaction of the present invention can be carried out at a temperature lower than that of the conventional polycondensation reaction, and therefore the occurrence of side reactions is suppressed. The use of ambient pressure rather than reduced pressure during the polycondensation reaction may also reduce overall capital and operating costs. This is because vacuum reactors are more expensive to build up or are more difficult to operate than ambient pressure reactors. However, using the disclosed process to produce high molecular weight polyesters (compared to producing intermediate molecular weight polyesters) requires the use of a larger polycondensation reaction kettle stirring motor, resulting in longer reaction cycle times Or the reaction temperature is higher, the flow rate of nitrogen or other purge gas through the reactor is increased, the progress of the polycondensation reaction is measured more quickly, or a combination of these measures is required, You must understand this point.

  [0042] The polyester syrup thus obtained may contain, for example, from about 5 to about 95% by weight polyester solids and from about 95 to about 5% by weight non-reactive carrier, wherein the polyester and non-reactive carrier The desired amount usually depends somewhat on the number average molecular weight of the polyester. Intermediate molecular weight polyester syrups are, for example, from about 40 to about 95% by weight polyester solids and from about 60 to about 5% by weight non-reactive carrier, or from about 50 to about 80% by weight polyester solids and from about 50 to about 20%. It may contain% by weight of non-reactive carrier. The high molecular weight polyester syrup includes, for example, about 5 to about 80 weight percent polyester solids and about 95 to about 20 weight percent non-reactive carrier, about 10 to about 70 weight percent polyester solids and about 90 to about 30 weight percent. % Non-reactive carrier, or about 20 to about 60% by weight polyester solids and about 80 to about 40% by weight non-reactive carrier. After the polycondensation reaction is complete, it can be added to additional carrier (including non-reactive carrier) polyester syrup as needed. For example, a reactive carrier (eg, an ester) can be added once the syrup has cooled sufficiently so that it does not react with the polyester. However, in one preferred embodiment, the syrup substantially contains an alcohol, glycol, or ester that can react with the polyester at the polycondensation temperature (eg, at the actual temperature at which the polycondensation reaction occurred). do not do.

  [0043] The syrup can be used to make a product, stored, or shipped for use at another time or location. Drums (eg, drum 106 shown in FIG. 1), totes (eg, tote 280 shown in FIG. 2), railroad tank cars (eg, tank car 300 shown in FIG. 3), truck tank trailers, trucks, bottles, cans, sachets, and those skilled in the art Various transport containers can be used, including other transport containers that are well known or readily known. The selected transport container should comply with applicable requirements for interstate transport and applicable fire regulations for storage.

  [0044] Products that can be made from polyester syrup include the first such as paints and primers (eg, corrosion resistant primers containing high molecular weight polyester), coil coatings, sheet coatings, packaging coatings, sealants, and adhesives, etc. Is a solid product, but is not limited thereto. Carriers for paint preparation, fusion aids, pigments, dyes, fillers, thickeners, dispersants, flow modifiers, viscosity modifiers, antifoaming agents, UV absorbers, inhibitors, binders, crosslinkers, and initiation Additives including agents (including photoinitiators) can be mixed with the polyester syrup. The amount and type of such additives are well known or readily known to those skilled in the art.

  [0045] The present invention will now be described in further detail with reference to examples. Unless otherwise indicated, all parts and percentages are by weight.

Example 1
Production of high molecular weight polyester resin
[0046] A mixing vessel equipped with a stirrer, distillation column, condenser, thermometer, and inert gas inlet was charged with 3.2 moles of 2-methyl-1,3-propanediol, 3.06 moles of 1,3. -Benzene dicarboxylic acid and 0.8 g FASTCAT (TM) 4201 dibutyltin oxide catalyst (commercially available from Arkema) were charged. The reaction had a hydroxyl: acid molar ratio of 1.046: 1. The reactor was flushed with inert gas and heated to 235 ° C. for 4 hours while removing water. [Aromatic 150 Fluid (commercially available from ExxonMobil) is added to dilute and cool the sample until an acid number of 18-25 is achieved, then use 0.1N methanolic KOH solution to reach pH 12 endpoint] Measured by titration] The bath temperature was kept at 235 ° C. Add additional aromatic 150 fluid to a further sample, dilute and cool, react OH groups with excess anhydride to convert anhydride groups to acid groups, then use 0.1N methanolic KOH solution. The batch hydroxyl value was measured within 30 minutes by titrating to pH 12 endpoint. The reaction temperature was lowered to 180 ° C. and additional 1,3-benzenedicarboxylic acid was added to adjust the hydroxyl: acid molar ratio to 1.01: 1. Atmospheric azeotropic distillation and sufficient amount of aromatic 150 fluid (as a non-reactive carrier) to obtain a reactor content of 17% aromatic hydrocarbons and 83% non-volatiles in the distillation mixture. The polycondensation reaction was used to raise the reaction temperature to 215 ° C. The batch temperature was held at 215 ° C. until an acid number of less than 3.0 was achieved. The final acid value was 2.2. The final Gardner bubble viscosity was Z (measured using a 40% solution of the polycondensation product in a 50/50 blend of Aromatic 150 Fluid / EKTASOLVE PM Acetate (commercially available from Eastman Chemical). ]. The color measured on the Gardner scale was 1 and no haze was observed in the resin. The number average molecular weight of the product was Mn = 17,355 as measured by gel permeation chromatography.

(Example 2)
Production of intermediate molecular weight polyester resin
[0047] In a mixing vessel equipped with a stirrer, distillation column, condenser, thermometer, and inert gas inlet, 4.02 moles of 2-methyl-1,3-propanediol, 3.84 moles of 1,3 -Benzene dicarboxylic acid and 0.8 g Fastcat 4201 dibutyltin oxide catalyst (commercially available from Arkema) were charged. The reaction had a hydroxyl: acid molar ratio of 1.046: 1. The reactor was flushed with inert gas and heated to 235 ° C. for 4 hours while removing water. Batch until acid number of 18-25 is achieved (measured by adding aromatic 150 fluid to dilute and cool sample, then titrate to pH 12 endpoint using 0.1N methanolic KOH solution) The temperature was kept at 235 ° C. Add additional aromatic 150 fluid to a further sample, dilute and cool, react OH groups with excess anhydride to convert anhydride groups to acid groups, then use 0.1N methanolic KOH solution. The batch hydroxyl value was measured within 30 minutes by titrating to pH 12 endpoint. The reaction temperature was lowered to 180 ° C. and additional 1,3-benzenedicarboxylic acid was added to adjust the hydroxyl: acid molar ratio to 1.03: 1. Atmospheric azeotropic distillation and sufficient amount of aromatic 150 fluid (as a non-reactive carrier) to obtain a reactor content of 17% aromatic hydrocarbons and 83% non-volatiles in the distillation mixture. The polycondensation reaction was used to raise the reaction temperature to 215 ° C. The batch temperature was held at 215 ° C. until an acid number of less than 3.0 was achieved. The final acid value was 1.6. The final Gardner bubble viscosity was J (measured using a 40% solution of the polycondensation product in a 50/50 blend of aromatic 150 fluid / Ectasolv PM acetate). The color measured on the Gardner scale was 1 and no haze was observed in the resin. The number average molecular weight of the product was Mn = 5,598 as measured by gel permeation chromatography.

  [0048] While preferred embodiments of the invention have been described, the disclosure herein may be applied to still other embodiments that fall within the scope of the appended claims. Needless to say to those skilled in the art. The entire disclosure of all patents, patent documents, and publications are incorporated herein by reference.

Claims (6)

A method for producing a high molecular weight polyester syrup comprising:
a) supplying or making ester oligomers;
b) stirring the oligomer reaction mixture in a non-reactive carrier of 5 wt% or more capable of forming an azeotrope with water and having a boiling point of 140 ° C. or higher at atmospheric pressure and elevated temperature to Converting to a polyester polyol; and c) removing water from the mixture by azeotropic reflux to obtain a syrup containing the high molecular weight polyester polymer in the non-reactive carrier, wherein in the non-reactive carrier The polyester polymer has a number average molecular weight (Mn) of 17,355 to 25,000 amu.
The manufacturing method of the said high molecular weight polyester syrup. The process according to claim 1, wherein the syrup does not contain an alcohol, glycol or ester that can react with the polymer at the polycondensation temperature. The production method according to claim 1 or 2, wherein the non-reactive carrier comprises an alkane, an aromatic hydrocarbon, a petroleum solvent, a plant-derived solvent, a ketone, or a mixture thereof. The process according to any one of claims 1 to 3, comprising forming a polymer with a hydroxyl: acid molar ratio or hydroxyl: ester molar ratio of 0.9: 1 to 1.1: 1. The manufacturing method in any one of Claims 1-4 whose high temperature is 200 to 260 degreeC. The process according to any one of claims 1 to 5, further comprising forming an ester oligomer in a non-reactive carrier.

Images