TWI476227B - Process of producing polyester - Google Patents

Description

Polyester manufacturing method

The present invention relates to a method for producing a polyester, and more particularly to a reduction in the amount of by-produced tetrahydrofuran (hereinafter sometimes referred to as THF) when a polyester is produced using heated 1,4-butanediol as a raw material. A method of efficiently and stably producing a good quality polyester.

The polyester obtained by subjecting the reaction product to a polycondensation reaction by using a dicarboxylic acid component and a diol component as a raw material to carry out a reaction of one or more of the esterification reaction and the transesterification reaction, has been utilized in various various types. use. Polybutylene terephthalate or polybutylene succinate, which is a main component of diol, using 1,4-butanediol (hereinafter sometimes referred to as 1,4-BG), can be used as an engineering plastic or biological Decompose the polymer.

The polycondensation reaction, in particular, the melt-polycondensation reaction, is usually carried out under high temperature and reduced pressure, and has a vapor ejector in the decompression attachment device, and steam using 1,4-BG is known as a vapor (Patent Document 1) .

Patent Document 1: International Publication No. 2004/026938

However, according to the review by the inventors of the present invention, if an ejector using 1,4-BG vapor is used as a pressure reducing attachment device, the 1,4-BG vapor used in the ejector is condensed and used as a polycondensation. Reaction raw materials and long-term reaction In the inter-running operation, the thermal stability of 1,4-BG is lowered, and tetrahydrofuran is produced by-product, which causes a decrease in the original unit of 1,4-BG and a decrease in the degree of decompression, and the quality of the obtained polyester is lowered.

Therefore, an object of the present invention is to provide a method for producing a polyester, which is a vacuum reducing device including a 1,4-BG steam ejector, wherein 1,4-BG is prevented from being formed into THF by heating. In the case of the original unit and the reduction in the degree of pressure reduction, the polycondensation reaction of the polyester can be carried out for a long period of time, and a polyester of good quality can be obtained.

As a result of intensive studies on the above-mentioned problems, the inventors of the present invention have found that when 1,4-BG is heated to generate steam, the pH of 1,4-BG is adjusted to suppress the heating from 1,4-BG to THF. The invention is carried out to obtain the operation method of the stable pressure reducing attachment device, and the present invention has been achieved.

That is, the gist of the present invention is as follows [1] to [4].

[1] A method for producing a polyester by subjecting a diol component containing 1,4-butanediol to a dicarboxylic acid component to carry out one or more reactions in an esterification reaction and a transesterification reaction, thereby further producing the above reaction a method for continuously producing a polyester by performing a polycondensation reaction; wherein (a) the above polycondensation reaction is carried out under reduced pressure; (b) the above polycondensation reaction under reduced pressure, using 1,4-butyl a pressure reducing device for a vapor generating device for driving a diol and a steam generating device for driving a steam ejector; (c) using 1,4-butanediol which has passed through the above-described pressure reducing attachment device as the diol component; and (d) supplying 1,4-butanediol to the vapor generating device for driving the steam ejector The pH is 7.0 or more and 11.5 or less.

[2] The method for producing a polyester according to the above [1], wherein the 1,4-butanediol supplied to the steam generating device for driving the steam ejector contains 0.1 ppm by weight or more of a nitrogen compound in terms of a nitrogen atom. And 150 ppm by weight or less.

[3] The method for producing a polyester according to [1] or [2], wherein the 1,4-butanediol supplied to the steam generating device for driving the steam ejector contains an amine compound and an amino alcohol compound One or more of them.

[4] The method for producing a polyester according to any one of [1] to [3] wherein the 1,4-butanediol supplied to the steam generating device for driving the steam ejector is derived from a biomass resource.

According to the present invention, when a polyester having 1,4-BG as a main component of a diol is produced by using a pressure reducing attachment device having a 1,4-BG steam ejector, the pH of 1,4-BG is adjusted by adjusting Further, when 1,4-BG is formed into THF by heating, the original unit and the degree of pressure reduction are not caused to be lowered, and the polycondensation reaction of the polyester can be carried out for a long period of time, whereby a polyester having good quality can be produced.

Hereinafter, the embodiments of the present invention will be described in detail, but the description of the constituent elements described below is an example (representative example) of the embodiment of the present invention, and is not limited thereto. content.

Here, "ppm by weight", "% by weight" and "parts by weight" are synonymous with "ppm by mass", "% by mass" and "parts by mass".

<Polyester raw materials>

The polyester of the present invention refers to a polymer having a structure in which a dicarboxylic acid component and a diol component are used as a raw material and the raw material is ester-bonded.

In the present invention, a repeating structural unit of a polymer derived from a monomer is represented by the word "unit" in the name of the monomer. For example, the repeating structural unit derived from a dicarboxylic acid is represented by the term "dicarboxylic acid unit", and the repeating structural unit derived from a diol is represented by the term "diol unit".

The dicarboxylic acid component in the present invention contains at least one compound selected from the group consisting of a dicarboxylic acid, a dicarboxylic anhydride, and an alkyl dicarboxylate.

Specific examples of the dicarboxylic acid include citric acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, and 4,4'-di. An aromatic dicarboxylic acid such as phenylketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenylstilbene dicarboxylic acid or 2,6-naphthalene dicarboxylic acid An alicyclic dicarboxylic acid such as 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid or 1,4-cyclohexanedicarboxylic acid, malonic acid, succinic acid or pentane An aliphatic dicarboxylic acid such as diacid, adipic acid, pimelic acid, suberic acid, sebacic acid or sebacic acid. Among them, from the viewpoints of mechanical properties, breadth of use, ease of availability of raw materials, etc., as the aromatic dicarboxylic acid, citric acid and isononanoic acid are preferred, and as the aliphatic dicarboxylic acid, succinic acid is preferred. Adipic acid.

The dicarboxylic acid anhydride may, for example, be an anhydride of any of the above dicarboxylic acids.

The alkyl dicarboxylate may, for example, be an alkyl ester of any of the above dicarboxylic acids. Among the alkyl dicarboxylates, a dialkyl ester is preferred. The alkyl group is not particularly limited. However, if the alkyl group is too long, the boiling point of the alkyl alcohol formed during the transesterification reaction increases, and it is not volatilized from the reaction liquid. As a result, the terminal stopper acts to hinder the polymerization. Therefore, an alkyl group having 4 or less carbon atoms is preferred, and a methyl group is more preferred.

The dicarboxylic acid component is preferably a main component of p-citric acid or an ester derivative thereof, or succinic acid or an anhydride thereof. In the present specification, the main component means a component which is the most abundantly measured in terms of moles among the components (dicarboxylic acid component or diol component) containing the component.

In the present invention, the main component of the diol component is 1,4-BG. Examples of the component other than 1,4-BG include ethylene glycol, diethylene glycol, polyethylene glycol, 1,2-propylene glycol, 1,3-propanediol, polypropylene glycol, polybutylene glycol, and dibutyl. An aliphatic diol such as alcohol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,2-cyclohexanediol, 1,4- An alicyclic diol such as cyclohexanediol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, decanediol, 4,4'-dihydroxybiphenyl, Aromatic diols such as 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)anthracene, isosorbide, dehydrated mannitol, isoidide, red sul A glycol or the like derived from a plant material (biomass resource) such as a sugar alcohol. Further, as the ethylene glycol, 1,3-propanediol, 1,4-BG or the like, a material derived from a plant material can also be used.

Among the total diol components, 1,4-BG is preferably 70 mol% or more, more preferably 80 mol% or more, and particularly preferably 95 mol% or more.

In the present invention, a hydroxycarboxylic acid such as lactic acid, glycolic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 6-hydroxy-2-naphthalenecarboxylic acid or p-β-hydroxyethoxybenzoic acid, or an alkane may be further used. a monofunctional component (a component having one hydroxyl group or a carboxyl group) such as oxycarboxylic acid, stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t-butylbenzoic acid or benzamidine benzoic acid, 1,2,3-propanetricarboxylic acid, trimellitic acid, trimellitic acid, pyromellitic acid, gallic acid, malic acid, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, etc. A trifunctional or higher polyfunctional component (a component having three or more hydroxyl components and/or a carboxylic acid component) or the like is used as a copolymerization component.

Wherein, the dicarboxylic acid unit is 50 mol% or more, preferably 80 mol% or more, and particularly preferably 95 mol% or more, which is composed of a decanoic acid unit, and the diol unit is 70 mol% or more, preferably 80. More than or equal to 100% by mole, more preferably 95% by mole or more of polybutylene terephthalate composed of 1,4-BG units, or 50% by mole or more, preferably 80% by mole of the dicarboxylic acid unit. The above, particularly preferably 95 mol% or more is composed of succinic acid units, 70 mol% or more of the diol unit, preferably 80 mol% or more, and particularly preferably 95 mol% or more by 1,4-BG unit. The polybutylene succinate is suitable for use because of its large production scale and the effect of the present invention.

<Manufacture of polyester>

In the description of the method for producing the following polyester, polybutylene terephthalate (hereinafter sometimes referred to as PBT) using citric acid as the dicarboxylic acid and 1,4-BG as the diol is used. The production is described as an example, but the polyester of the present invention The manufacturing method is not limited to this.

In the present invention, the PBT is produced by performing a polycondensation reaction under reduced pressure, except that a steam ejector using a 1,4-BG having a specific pH range is used as an additional method of decompression in the polycondensation reaction, A known manufacturing method is carried out.

These known methods can be roughly classified into a so-called direct polymerization method using citric acid as a main raw material, and a transesterification method using a dialkyl phthalate as a main raw material by performing an esterification reaction and a transesterification reaction. One or more kinds of reactions are carried out, and the product of the reaction is subjected to a polycondensation reaction to produce PBT. The difference is that the former is produced by the initial esterification reaction, and the latter is formed by the initial transesterification reaction to produce alcohol. However, the stability of the raw material, the ease of treatment of the distillate, the height of the original unit of the raw material, or the present From the viewpoint of the improvement effect obtained by the invention, etc., a direct polymerization method is preferred.

As an example of the direct polymerization method, for example, a ratio of 1,4-BG to 1,4-BG with respect to phthalic acid is 1.0 to 2.5, preferably 1.1 to 2.0, in singular or plural. In the esterification reaction tank of the stage, an esterification reaction catalyst is used, and the temperature is 180 to 260 ° C, preferably 200 to 250 ° C, particularly preferably 210 to 245 ° C, and the pressure is 10 to 133 kPa, preferably 13 to 101 kPa. Preferably, the reaction time is 0.5 to 5 hours, preferably 1 to 3 hours, and the esterification reaction is continuously carried out. The oligomer of the obtained esterification reaction product is transferred to a polycondensation reaction tank, and the polycondensation reaction catalyst is continuously used at a temperature of 210 to 260 ° C, preferably 220 to 250 ° C, in a plurality of polycondensation reaction tanks. , especially good 220~245 °C, pressure 27kPa Hereinafter, it is preferably 20 kPa or less, particularly preferably 13 kPa or less, and at least one of the polycondensation reaction tanks is subjected to polycondensation under reduced pressure of preferably 2 kPa or less under stirring for 2 to 12 hours, preferably 2 to 10 hours. The method of reaction. The stirring time is the sum of the stirring time (residence time) in the polycondensation reaction tank of the plurality of stages.

On the other hand, as an example of the transesterification method, for example, dimethyl phthalate and 1,4-BG are contained in a single or multiple esterification reaction tank in the presence of a transesterification catalyst. According to the temperature of 110~260 °C, preferably 140~245 °C, especially good 180~220 °C, and the pressure is 10~133kPa, preferably 13~101kPa, especially good 60~90kPa, the reaction time is 0.5~5 hours, preferably 1~ The transesterification reaction was continuously carried out for 3 hours. The oligomer of the obtained transesterification reaction product is transferred to a polycondensation reaction tank, and continuously in the presence of a polycondensation reaction catalyst in the presence of a polycondensation reaction catalyst at a temperature of 210 to 260 ° C, preferably 220 °. 250 ° C, particularly preferably 220 ~ 245 ° C, a pressure of 27 kPa or less, preferably 20 kPa or less, particularly preferably 13 kPa or less under reduced pressure, at least one of the polycondensation reaction tanks is preferably under a reduced pressure of 2 kPa or less, under stirring A method of performing a polycondensation reaction for 2 to 12 hours, preferably 2 to 10 hours.

The PBT obtained by the polycondensation reaction is usually transferred from the bottom of the polycondensation reaction tank to the polymer pull-out mold and extracted into a strand shape. After water cooling or water cooling, the cutter is cut into pellets and small pieces ( Chip-like granular body. The granules can then be subjected to solid phase polycondensation by known methods to increase the intrinsic viscosity.

As the esterification reaction or transesterification reaction catalyst in the present invention, for example, three a ruthenium compound such as ruthenium oxide; a ruthenium compound such as ruthenium dioxide or osmium tetroxide; a titanium alkoxide such as tetramethyl titanate, tetraisopropyl titanate or tetra-n-butyl titanate; Titanium compound such as titanium phenolate such as titanate; dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethyltin oxide, dihexahexyl oxytin oxide, and di(12 Base) tin oxide, triethyltin hydroxide, triphenyltin hydroxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, three Tin compounds such as butyltin chloride, dibutyltin sulfide, butyl hydroxytin oxide, tin methyl phthalate, tin ethyl phthalate, tin butyl phthalate; magnesium acetate, magnesium hydroxide, magnesium carbonate, magnesium oxide A magnesium compound such as magnesium alkoxide or magnesium hydrogen phosphate; a calcium compound such as calcium acetate, calcium hydroxide, calcium carbonate, calcium oxide, calcium alkoxide or calcium hydrogen phosphate; and a manganese compound, a zinc compound or the like. Among them, from the viewpoint of catalyst activity, a titanium compound or a tin compound is preferable, and tetra-n-butyl titanate or tetraisopropyl titanate is particularly preferable.

The amount of the catalyst to be used is not particularly limited, and if it is too large, it is not only a cause of foreign matter, but also a deterioration reaction at the time of heat retention of PBT or a cause of gas generation. If the amount is too small, the main reaction rate is lowered. The tendency to cause a side reaction is usually 1 to 300 ppm by weight, preferably 5 to 200 ppm by weight, more preferably 5 to 150 ppm by weight, particularly preferably 10 to 100 ppm by weight, based on the metal concentration in the PBT. It is 20 to 90 ppm by weight, preferably 30 to 60 ppm by weight.

In addition, as a polymerization reaction catalyst, it can be followed by esterification or transesterification. The catalyst added during the reaction is used as a polycondensation reaction catalyst without adding a new catalyst, and the above catalyst may be further added. The amount of the polycondensation reaction catalyst to be used is not particularly limited, and if it is too large, it is 300 ppm by weight or less, preferably 200 ppm by weight or less, and more preferably 100 ppm by weight, based on the metal concentration in the PBT. Hereinafter, it is preferably 50 ppm by weight or less, and most preferably 30 ppm by weight or less.

Further, when an organic titanium compound is used as a catalyst, the concentration of the titanium metal in the final PBT is preferably 250 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 60 ppm by weight or less, from the viewpoint of suppressing foreign matter. Preferably 50 ppm by weight or less. The metal concentration in the PBT can be recovered by wet ashing or the like, and then measured by atomic light emission or inductively coupled plasma (ICP).

Further, in the esterification reaction, the transesterification reaction, and the polycondensation reaction, phosphorous acid such as orthophosphoric acid, phosphorous acid, hypophosphoric acid, polyphosphoric acid, or the like may be added in addition to the above catalyst. a reaction aid such as an alkali metal or an alkaline earth metal compound such as sodium hydroxide, sodium benzoate, lithium acetate, potassium hydroxide, potassium acetate, magnesium acetate or calcium acetate, 2,6-di-t-butyl-4 a phenolic compound such as octylphenol, pentaerythritol-indole [3-(3',5'-t-butyl-4'-hydroxyphenyl)propionate], dilauryl-3,3'-sulfur a thioether compound such as propionate, pentaerythritol-yttrium (3-lauryl thiodipropionate), triphenyl phosphite, decyl phenyl phosphite, phosphite (2, 4-) An antioxidant such as a phosphorus compound such as di-t-butylphenyl) or the like, which is a paraffin wax, a microcrystalline wax or a polyethylene wax. A long-chain fatty acid and an ester thereof represented by montanic acid or montanic acid ester, a release agent such as a polyoxygenated oil, and the like.

The esterification reaction tank or the transesterification reaction tank may be any one of a known type, or may be a type of a vertical stirring complete mixing tank, a vertical heat convection mixing tank, or a column type continuous reaction tank, or may be The singular groove may also be a plurality of grooves in which the same or different types of grooves are arranged in series. Among them, a reaction tank having a stirring device is preferable, and as the stirring device, a normal type composed of a power unit, a bearing, a shaft, and a stirring blade, or a turbine stator type high-speed rotary mixer, a disc grinding type mixer, and a grinding machine can be used. High-speed rotary type such as a mixer.

The form of stirring is not limited, and a general stirring method in which the reaction liquid in the reaction tank is directly stirred from the upper portion, the lower portion, and the horizontal portion of the reaction vessel, or a part of the reaction liquid is taken out from the outside of the reaction tank by piping or the like may be employed. A method in which the reaction liquid is circulated by stirring with a line agitator or the like.

The type of the agitating blades can also be selected from known ones. Specific examples of the agitating blades include, for example, a propeller, a spiral wing, a turbine wing, a fan turbine wing, a disk turbine wing, a Pfaudler wing, a full coverage wing, and a Max. Blend wing and so on.

The polycondensation reaction tank may, for example, be a known product such as a vertical agitation polymerization tank, a horizontal agitation polymerization tank, or a thin film evaporation polymerization tank. In the late stage of polycondensation in which the viscosity of the reaction liquid rises, the tendency of the substance to move becomes a dominant factor of the molecular weight increase compared with the reaction rate. Therefore, when the main reaction is promoted while suppressing the side reaction, the temperature is lowered as much as possible, and the surface is raised. The renewer is more advantageous for achieving the object of the present invention, and is preferably selected for surface renewal, plug flow, and self-purification. The more singular or plural horizontal agitating polymerization machine having a thin film evaporation function.

Further, the PBT obtained by the production method of the present invention may be subjected to solid phase polycondensation by a known method to increase the molecular weight.

Hereinafter, preferred embodiments of the method for producing a polyester of the present invention will be described by taking PBT as an example. Fig. 1 is an explanatory view showing an example of an esterification reaction step employed in the present invention, and Fig. 2 is an explanatory view showing an example of a polycondensation step employed in the present invention.

In Fig. 1, the raw material p-citric acid is usually mixed with 1,4-butanediol in a raw material mixing tank (not shown), and supplied to the reaction tank (A) in the form of a slurry from the raw material supply line (1). Further, the catalyst of the present invention is preferably supplied to a catalyst supply line (3) after being formed into a 1,4-butanediol solution in a catalyst adjusting tank (not shown). Fig. 1 shows a state in which a recycle line (2) for recycling 1,4-butanediol is connected to a catalyst supply line (3), and after mixing the two, it is supplied to a liquid phase portion of the reaction tank (A).

The gas distilled from the reaction tank (A) is separated into a high boiling component and a low boiling component in the rectification column (C) via a distillation line (5). Usually, the main component of the high boiling component is 1,4-butanediol, and the main component of the low boiling component is water.

The high-boiling component separated in the rectification column (C) is withdrawn from the extraction line (6), via the pump (D), partially recycled to the reaction tank (A) by the recycle line (2), and partly by the recycle line ( 7) Return to the distillation column (C). Further, the remaining portion is taken out to the outside by the extraction line (8). On the other hand, the light boiling component separated in the rectification column (C) is taken out from the gas extraction line (9), condensed by the condenser (G), and temporarily stored in the tank through the condenser condensate line (10). (F). Collected in the tank (F) In one part, the distillation line (11), the pump (E) and the circulation line (12) are returned to the rectification column (C), and the remainder is extracted to the outside via the extraction line (13). The condenser (G) is connected to an exhaust device (not shown) via an exhaust line (14). The oligomer produced in the reaction tank (A) is withdrawn through an extraction pump (B) and an extraction line (4) of the oligomer.

In the step shown in Fig. 1, although the catalyst supply line (3) is connected to the recirculation line (2), the two may be independent. Further, the raw material supply line (1) may be connected to the liquid phase portion of the reaction tank (A).

The compound of at least one metal selected from Groups 1 to 2 of the periodic table is prepared to a predetermined concentration in a preparation tank (not shown), and then connected to the 1,4-butyl group via a line (L7) in FIG. The diol supply line (L8) is further diluted with 1,4-butanediol and supplied to the extraction line (4) of the oligomer shown in Fig. 1 described above.

Then, the oligomer supplied to the first polycondensation reaction tank (a) is polycondensed under reduced pressure to form a prepolymer, and then supplied to the first via the extraction gear pump (c) and the extraction line (L1). 2 polycondensation reaction tank (d). In the second polycondensation reaction tank (d), the polycondensation is further carried out at a pressure lower than the pressure of the first polycondensation reaction tank (a) to form a polymer. The obtained polymer is supplied to the third polycondensation tank (k) via the extraction gear pump (e) and the extraction line (L3). The third polycondensation reaction tank (k) is composed of a plurality of stirring wing blocks, and belongs to a horizontal reaction tank having a twin-shaft self-cleaning type stirring blade. The polymer introduced into the third polycondensation reaction tank (k) from the second polycondensation reaction tank (d) by the extraction line (L3) After the polycondensation in one step, the gear pump (m) and the extraction line (L5) are extracted by the die (g) in the form of a molten strand, cooled by water or the like, and then rotated by a rotary cutter (h). Cut into particles. The symbols (L2), (L4), and (L6) are exhaust lines of the first polycondensation reaction tank (a), the second polycondensation reaction tank (d), and the third polycondensation reaction tank (k), respectively. The filters R, S, T, and U do not need to be provided at all, and may be appropriately set in consideration of the foreign matter removal effect and the operational stability.

<injector>

In the present invention, the decompression addition of the polycondensation reaction tank is carried out by a 1,4-BG steam ejector.

The vapor obtained by supplying 1,4-BG to the vapor generation device is used as the vapor for driving the injector. The ejector is used in combination with a condenser disposed in the downstream portion of the ejector and a hot water well cabinet connected to the condenser via a pneumatic vacuum column. According to this method, the organic component contained in the attracting gas can be condensed in the 1,4-BG belonging to the condenser sealing liquid, and the condensed liquid can be directly subjected to distillation purification or use as a polyester raw material. Alcohol content.

In the present invention, the use of a diol component as a polyester or 1,4-BG as a vapor for driving an ejector can be obtained by a known method. For example, an ethylene ethoxylation reaction is carried out by using a raw material of butadiene, acetic acid, and oxygen to obtain an intermediate of diethyloxybutene, and the diethyloxybutene is hydrogenated and hydrolyzed to obtain 1,4. -BG; 1,4-BG obtained by hydrogenation of maleic acid, succinic acid, maleic anhydride and/or fumaric acid as raw materials; using acetylene as a raw material and aqueous formaldehyde solution The butynediol is obtained by contact and hydrogenated Obtained crude 1,4-BG; 1,4-BG obtained by oxidation of propylene; 1,4-BG obtained by hydrogenation of succinic acid obtained by fermentation; direct fermentation by biomass such as sugar The obtained 1,4-BG and the like.

<1,4-BG from biomass resources>

The diol component used in the production of the PBT of the present invention is preferably supplied from a biomass resource to a vapor generation device from the viewpoint of environmental protection.

Biomass resources include those that are grown by converting photosynthesis into starch or cellulose by plant photosynthesis, animal bodies that are grown by eating plant bodies, or products that are processed from plant or animal bodies. Specific examples include wood, straw, rice husk, rice bran, old rice, corn, sugar cane, cassava, sago palm, bean dregs, corn cob, cassava residue, bagasse, vegetable oil residue, alfalfa, buckwheat, soybean, oil, Old paper, paper residue, water product residue, livestock excrement, sewage sludge, food waste, etc.

Among them, preferred are wood, straw, rice husk, rice bran, old rice, corn, sugar cane, cassava, sago palm, bean dregs, corn cob, cassava residue, bagasse, vegetable oil residue, alfalfa, buckwheat, soybean, fat Plant resources such as old paper, paper residue, etc., preferably wood, straw, rice husk, old rice, corn, sugar cane, cassava, sago coconut, alfalfa, oil, old paper, paper residue, etc., preferably corn, Sugar cane, cassava, sago coconut.

Biomass resources generally contain many alkali metals and alkaline earth metals containing nitrogen or Na, K, Mg, Ca, and the like.

The method of such biomass resources is not particularly limited, for example, via an acid or an alkali. The chemical treatment, the step of known pretreatment/saccharification using biological treatment such as microorganisms, physical treatment, and the like are derived as a carbon source. In the steps, most of the steps include miniaturization of the biomass resources by micro-processing, cutting, grinding, etc., and may further include a pulverization step by a grinder or a grinder. The thus miniaturized biomass resources are typically further derived as a carbon source via a pretreatment/saccharification step. As a specific method, for example, a chemical method such as an acid treatment by a strong acid such as sulfuric acid, nitric acid, hydrochloric acid or phosphoric acid, an alkali treatment, an ammonia freeze-cooking blasting method, a solvent extraction, a supercritical fluid treatment, or an oxidizing agent treatment; Physical methods such as micro-pulverization, retort, microwave treatment, electron beam irradiation, etc.; biological treatment such as hydrolysis by microorganism or enzyme treatment.

As a carbon source derived from the above biomass resources, six-carbon sugars such as glucose, mannose, galactose, fructose, sorbose, tagatose, etc., arabinose, xylose, ribose, xylulose, ribulose are usually used. Five-carbon sugar such as sugar, disaccharide/polysaccharide such as polypentose, sucrose, starch, cellulose; butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid , stearic acid, oleic acid, linoleic acid, linoleic acid, monocutinic acid, citric acid, decenoic acid, arachidonic acid, azelaic acid, sinapic acid, docosapentaenoic acid, hydrazine Fats and oils such as diglycolic acid, perylenetetracarboxylic acid, and arachidonic acid; and fermented saccharides such as polyhydric alcohols such as glycerin, mannitol, xylitol, and ribitol. Among them, a hexose or a pentose sugar such as glucose, fructose or xylose is preferred, and glucose is particularly preferred. As a carbon source from plant resources in a broader sense, it belongs to the main component of paper. Cellulose is also preferred.

Generally, the use of such carbon sources, by a chemical conversion method including a fermentation step by microbial conversion or a hydrolysis/dehydration reaction/hydration reaction/oxidation reaction, and the like, and the fermentation and chemical conversion methods The combination of diols is synthesized. Among these, a fermentation method by microbial conversion is preferred.

The diol used in the production of PBT according to the present invention may be directly produced from a carbon source such as glucose by a fermentation method, or may be subjected to a reduction catalyst by a succinic acid, a succinic anhydride or a succinic acid ester obtained by a fermentation method. It is converted into a diol compound by hydrogenation, or 1,4-butanediol or the like can be produced from 1,3-butadiene obtained by a fermentation method.

A method of directly producing a diol by a fermentation method by a carbon source can be carried out, for example, according to the method described in JP-A-2010-521182. A method of hydrogenating a succinic acid, succinic anhydride, succinic acid ester or the like by a reduction catalyst to be converted into a diol compound can be carried out, for example, according to the method described in JP-A-2008-101143.

Examples of the catalyst for hydrogenating succinic acid include Pd, Ru, Re, Rh, Ni, Cu, Co, and a compound thereof. Specific examples thereof include Pd/Ag/Re, Ru/Ni/Co/ZnO, Cu/Zn oxide, Cu/Zn/Cr oxide, Ru/Re, Re/C, Ru/Sn, Ru/Pt/Sn, Pt/Re/base, Pt/Re, Pd/Co/Re, Cu/Si, Cu/Cr/Mn, ReO/CuO/ZnO, CuO/CrO, Pd/Re, Ni/Co, Pd/CuO/CrO ₃ , Ru, Ni/Co, Co/Ru/Mn, Cu/Pd/KOH, Cu/Cr/Zn, and the like. Among them, from the viewpoint of catalyst activity, Ru/Sn or Ru/Pt/Sn is preferred.

Further, a method of producing 1,4-BG by a combination of biomass resources and a reaction with a known organic chemical catalyst can be further used. For example, when a five-carbon sugar is used as a biomass resource, a diol such as butanediol can be easily produced by a combination of a known dehydration reaction and a catalyst reaction.

In the present invention, the pH of 1,4-BG supplied to the vapor generation device is 7.0 or more and 11.5 or less, and the lower limit is preferably 7.5 or more preferably 8.0. The upper limit is preferably 11.0, more preferably 10.5. When the pH is less than the lower limit, the amount of THF in the condensate increases, and the pressure-reducing ability of the ejector tends to decrease. When the upper limit is exceeded, the color tone of the polyester which uses the condensate as a diol component tends to deteriorate. By setting the pH to the extent of this case, even if it is operated for a long period of time, the reduction of the additional pressure-reducing ability is small, so that it can be stably operated to obtain a polyester having good quality.

In the present invention, the pH of 1,4-BG supplied to the steam generator for driving the steam ejector is measured by directly measuring the value of 1,4-BG by a pH meter using a glass electrode which is generally known. The pH measurement value obtained by using a pH meter of a glass electrode can directly measure the value of 1,4-BG of a target by the method according to JIS Z8802 (2011). More specifically, for example, 50 mL of 1,4-BG is used in a beaker, and a pH meter (HM-25R) manufactured by East Asia DKK Co., Ltd. is used, and the value measured by immersing the pH electrode at 25 ° C in the atmosphere.

The pH adjustment of 1,4-BG supplied to the vapor generating apparatus can be carried out by a method of adding an amine compound or an amino alcohol to 1,4-BG; and making 1,4-BG and an anion A method of contacting an exchange resin; a method of using 1,4-BG obtained by a fermentation method, and the like. The pH of 1,4-BG obtained by fermentation, For example, when succinic acid obtained by fermentation of biomass resources is hydrogenated to obtain BG, succinic acid can be hydrogenated by its fermentation conditions, neutralization conditions by ammonia, crystallization conditions of succinic acid, and crystallization of succinic acid. The purification conditions of 1,4-BG including distillation are adjusted. In addition, when 1,4-BG is directly obtained by fermentation of biomass resources, it is also possible to carry out refining including distillation by the fermentation conditions, neutralization conditions of ammonia, and the obtained 1,4-BG. Adjustments such as conditions.

Among the above, it is preferred to use a compound having one or more of an amine compound and an amino alcohol compound to adjust the pH, and it is preferable to invest in equipment such as an easy-to-use pH control and an unnecessary additional equipment.

The amine compound which adjusts the pH of 1,4-BG may, for example, be a primary amine, a secondary amine or a tertiary amine. Specifically, there are octylamine, mercaptoamine, 1-aminodecane, aniline, phenethylamine, dipentylamine, dihexylamine, diheptylamine, n-butylamine, isobutylamine , second butylamine, tert-butylamine, dibutylamine, tributylamine, N-methylaniline, tributylamine, tripentylamine, N,N-dimethylaniline, bicyclo Hexylamine, 1,3-propanediamine, N,N-dimethyl-1,6-hexanediamine, N-butylpyrrole, N-butyl-2,3-dihydropyrrole, N-butyl Pyrrolidine, 4-dimethylaminopyridine, 1,2,3,4-tetrahydroquinoline, 2,3-dihydro-1H-indole, 4-aminomethylpiperidine, 4-amino group -5,6-dihydro-2-methylpyrimidine, 2,3,5,6-tetramethylpyridyl ,3,6-dimethylhydrazine Among them, tributylamine and N-butylpyrrolidine are preferably used from the viewpoint of polymer color tone.

Examples of the amino alcohol include 4-amino-1-butanol and 2-amino-1-butanol. Amidoxime, ethanolamine, diethanolamine, triethanolamine, and amidoxime. Among them, 4-amino-1-butanol and guanamine are preferably used from the color tone of the polymer.

The anion exchange resin used for adjusting the pH of 1,4-BG in the present invention is not particularly limited, and any one having a low degree of crosslinking and a high degree of crosslinking can be used. Further, it may be in any form of a gel type, a porous type, or a super porous type. Specific examples include commercially available DIAION SA-10A, SA-12A, SA-11A, NSA100, SA-20A, SA-21A, PA306S, PA308, PA312, PA316, PA318L, PA408, PA412, PA418, HPA25 (Mitsubishi Chemical) Co., Ltd.), or other grades of products, etc., but are not limited thereto.

The nitrogen compound contained in the 1,4-BG after the pH adjustment is preferably 0.1 ppm by weight or more and 150 ppm by weight or less, more preferably 0.1 ppm by weight or more and 120 ppm by weight or less, more preferably in terms of nitrogen atom. 0.5 ppm by weight or more and 100 ppm by weight or less. When the nitrogen compound is less than the above lower limit, the amount of THF in the condensate increases, and the pressure-reducing ability of the ejector tends to decrease. Moreover, when it exceeds the said upper limit, the color tone of the polyester produced using the condensate as a diol component tends to deteriorate.

1,4-BG which is a vapor for driving the ejector can be separately prepared from 1,4-BG which is a diol component of polyester, and 1,4-BG which is a diol component of polyester can also be used. A part is used as the vapor for driving the injector.

Fig. 3 is an explanatory view showing an example of a pressure reducing attachment device.

This description will be described by way of an example in which the polycondensation reaction tank is the first to third tanks. The pressure of each polycondensation reaction tank (a, d, k) in Fig. 2 The control is performed using the pressure reducing attachment shown in FIG. In Fig. 3, 1,4-BG is continuously supplied to the 1,4-BG vapor generating device (K) for ejector driving by an external supply line (19), heated to 240 ° C and produced. The 1,4-BG vapor is supplied to each of the ejector through the supply line (20) (for the first polycondensation reaction tank: A1‧A3, and the second polycondensation reaction tank: B1‧B3‧B5, the third polycondensation reaction For tanks: C1‧C3‧C5).

The gas containing tetrahydrofuran and water distilled from the first polycondensation reaction tank (a) shown in Fig. 2 is introduced into the ejector (A1) through the line (21) shown in Fig. 3, at this time by spraying The 1,4-BG vapor discharged from the device (A1) is condensed by a gas pressure condenser (A2), and the condensed liquid is collected into the hot water well cabinet (H2) through a pneumatic vacuum column (25). On the other hand, the component that has not been condensed by the air pressure condenser (A2) is sent to the ejector (A3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (26) to the hot water well cabinet (H3). Similarly to the first stage, the components that are not condensed by the air pressure condenser (A4) are discharged from the line (24) to the outside of the system using a vacuum pump (A5). The pipelines (22, 23) are supply lines of 1,4-BG, and the entire amount is circulated and supplied by the hot water well cabinets (H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the second polycondensation reaction tank (d) shown in Fig. 2 is introduced into the ejector (B1) through the line (31) shown in Fig. 3, at this time by spraying The 1,4-BG vapor discharged from the vessel (B1) is condensed by a gas pressure condenser (B2), and the condensate is collected into the hot water well cabinet (H1) through a pneumatic vacuum column (36). On the other hand, the component that is not condensed by the air pressure condenser (B2) is sent to the ejector (B3) of the second stage, and the condensate is collected by the pneumatic vacuum column (37). Collected to the hot water cabinet (H2). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (B4) is sent to the ejector (B5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (38) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (B6) are discharged from the line (35) to the outside of the system using a vacuum pump (B7). The pipelines (32, 33, 34) are supply lines of 1,4-BG, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the third polycondensation reaction tank (k) shown in Fig. 2 is introduced into the ejector (C1) through the line (41) shown in Fig. 3, at this time by spraying The 1,4-BG vapor discharged from the vessel (C1) is condensed by a gas pressure condenser (C2), and the condensate is collected by a pneumatic vacuum column (46) to the hot water well cabinet (H1). On the other hand, the component that has not been condensed by the air pressure condenser (C2) is sent to the ejector (C3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (47) to the hot water well cabinet (H2). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (C4) is sent to the ejector (C5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (48) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (C6) are discharged from the line (45) to the outside of the system using a vacuum pump (C7). The pipelines (42, 43, 44) are supply lines of 1,4-BG, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The liquid containing 1,4-BG as the main component collected in the hot water well cabinet (H1, H2, H3) is sent to the buffer tank (H5) through the pipeline (54) and the pump (H4), and the whole amount is passed through the pump. (H6) and the line (55) are directly transferred to the raw material slurry preparation tank in an unpurified state as a part of the polyester raw material diol.

The lines (51, 52, 53) are supply lines for the 1,4-BG from the outside to the hot water well cabinets (H1, H2, H3). Further, in the operation of the continuous polycondensation process, only the line (19) and the lines (51, 52, 53) are supplied from the external 1,4-BG, and are set to a constant flow rate.

(Example)

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples. Moreover, the physical properties and the measurement methods of the evaluation items used in the following examples are as follows.

<Amount of THF generated in a reduced pressure generating device>

The 1,4-BG vapor vaporized in the supply line (20) of the vapor 1,4-BG of the ejector was collected into a SUS cylinder, cooled and condensed, and then subjected to Shimadzu capillary gas chromatography (GC- 2025), the amount of THF produced was calculated. The column was DB-1 (inner diameter: 0.25 mm, length: 30 m, film pressure: 1.0 μm) of J&W Co., Ltd. The injection portion and the detector temperature were maintained at 50 ° C for 7 minutes at 240 ° C and the column temperature, and then the temperature was raised to 230 ° C at 10 ° C / min. Nitrogen (100 kPa) was used in the capillary gas. As a method of quantitative analysis, a THF aqueous solution was used as a standard curve in advance, and the amount of THF in 1,4-BG was derived from the Area value at the time of GC measurement.

<Intrinsic viscosity (Polymer IV)>

Use a Ukrainian viscometer to obtain the following essentials. That is, a mixed solvent of phenol/tetrachloroethane (weight ratio of 1/1) was used, and a polymer solution having a concentration of 1.0 g/dL and a solvent were measured at 30 ° C in the case of polybutylene terephthalate. second The number of seconds of dropping the polymer solution having a concentration of 0.5 g/dL and the solvent in the case of polybutylene succinate was determined by the following formula (1).

IV=((1+4K _H η _SP ) ^0.5 -1)/(2K _H C) (1) (where η _SP =(η/η ₀ )-1, η is the number of seconds the polymer solution falls, η ₀ For the solvent to drop the number of seconds, C is the polymer solution concentration (g / dL), K _H is the Huggins constant. K _H is 0.33.)

<terminal carboxyl group concentration (polymer AV)>

After pulverizing the sample, it was dried in a hot air dryer at 140 ° C for 15 minutes in the case of polybutylene terephthalate, and dried in a desiccator at 60 ° C for 30 minutes in the case of polybutylene succinate. To the room temperature, 0.1 g of the sample was weighed into a test tube, and 3 ml of benzyl alcohol was added thereto, and while drying with nitrogen gas, the solution was dissolved at 195 ° C for 3 minutes, and then 5 ml of chloroform was slowly added thereto, followed by cooling to room temperature. . To the solution, 1 to 2 drops of a phenol red indicator were added dropwise, and while stirring with dry nitrogen gas, the solution was titrated with a 0.1 N sodium hydroxide benzyl alcohol solution, and it was considered to be completed when it turned from yellow to red. In addition, as a blank group, the same operation was carried out without dissolving the polyester resin sample, and the amount of terminal carboxyl groups (acid value) was calculated by the following formula (2).

The amount of terminal carboxyl groups (equivalent/ton) = (ab) x 0.1 xf / w (2) (where a is the amount of benzyl alcohol solution (μl) of 0.1 N sodium hydroxide required for titration, and b is a blank group The amount (μl) of the benzyl alcohol solution of 0.1 N sodium hydroxide required for titration, w is the sample amount (g) of the polyester resin, and f is the valence of the benzyl alcohol solution of 0.1 N sodium hydroxide.

Further, the valence (f) of a 0.1 N sodium hydroxide benzyl alcohol solution was determined by the following method. 5 ml of methanol was collected in a test tube, and 1 to 2 drops of phenol red ethanol solution was added as an indicator, and titrated with 0.4 ml of a 0.1 N sodium hydroxide benzyl alcohol solution until the discoloration point, and then 0.2 ml of known price was taken. A 0.1 N aqueous hydrochloric acid solution was added as a standard solution, and titrated again with a 0.1 N sodium hydroxide benzyl alcohol solution to a color point (the following operation was carried out under a dry nitrogen gas injection). The force price (f) is calculated by the following formula (3).

The amount of force (f) = 0.1 N of aqueous hydrochloric acid solution x 0.1 N of aqueous hydrochloric acid solution (μl) / 0.1 N of sodium hydroxide benzyl alcohol solution titration (μl) (3)

<Particle tone (polymer Co-b)>

The granular polyester was filled in a cylindrical powder measuring tank having an inner diameter of 30 mm and a depth of 12 mm, and a colorimetric color difference meter Z300A (manufactured by Nippon Denshoku Industries Co., Ltd.) was used, and JIS Z8730 (2009) was used as a reference. The Lab value described in Example 1 indicates the b value obtained by the Hunter color difference color coordinate in the system, and the reflection value is obtained by measuring the simple average value of the values of four places by rotating the measurement tank by 90 degrees. .

<solution fog value>

After dissolving PBT 2.70 g at 110 ° C for 30 minutes in 20 mL of a mixed solvent of phenol/tetrachloroethane = 3/2 (weight ratio), the mixture was cooled in a constant temperature bath at 30 ° C for 15 minutes, and turbid with Japanese electric color (stock). The meter (NDH-300A) was measured by a groove length of 10 mm. The lower the value, the better the transparency.

<pH of 1,4-BG>

50 mL of 1,4-BG was collected in a beaker, and it was measured by immersing in a pH electrode at 25 ° C in the atmosphere using a pH meter (HM-25R) manufactured by Toago Corporation, DKK.

<Method for Measuring Nitrogen Atom Content (ppm by Mass) in 1,4-BG>

A sample of 15 mg was collected in a quartz boat, and a sample was burned using a trace total nitrogen analyzer ("TN-10 type" manufactured by DIA INSTRUMENTS Co., Ltd.), and quantified by a combustion/chemiluminescence method. Further, the standard sample used at this time was obtained by dissolving aniline in toluene and producing 0, 0.5, 1.0, and 2.0 μg/mL in terms of nitrogen.

[Example 1] (Manufacture of polybutylene terephthalate)

Polybutylene terephthalate was produced by the esterification step shown in Fig. 1 and the polycondensation step shown in Fig. 2 and the pressure reducing attachment device of Fig. 3 as follows.

First, a slurry of 60 ° C in which 1,4-butanediol was mixed with respect to a ratio of 1.80 moles of citric acid was used, and the slurry preparation tank was passed through the raw material supply line (1) to become 40 kg/ In an hourly manner, it was continuously supplied to an esterification reaction tank (A) having a screw type mixer which was previously filled with a low molecular weight bulk oligomer having an esterification ratio of 99%. At the same time, the bottom component (98% by weight or more of 1,4-butanediol) of the rectification column (C) at 185 ° C is supplied from the recycle line (2) at 13.2 kg/hr, and is connected to the recycle line. The catalyst supply line (3) of (2) supplied a catalyst solution of 60 ° C prepared into a 3.0 wt% 1,4-butanediol solution at 345 g/hr. The catalyst system uses tetra-n-butoxy titanate.

The internal temperature of the reaction tank (A) was 230 ° C, the pressure was 70 kPa, and the produced water, tetrahydrofuran and the remaining 1,4-butanediol were distilled off from the distillation line (5) in a rectification column (C). ) is separated into a high boiling component and a low boiling component. 98% by weight or more of the high-boiling component of the bottom of the system after stabilization is 1,4-butanediol, and a part of the distillation column (C) is drawn to the liquid phase in a certain manner, and is extracted to a part via the extraction line (8). external. On the other hand, the low-boiling component mainly composed of water and THF is extracted from the top of the tower by gas, and is condensed by a cooler (G). The liquid level of the tank (F) is in a certain manner, and the extraction line is used. ) Pull out to the outside.

A certain amount of the oligomer formed in the reaction tank (A) is extracted by the extraction line (4) of the oligomer using the extraction pump (B), and the unit of the tannic acid in the reaction tank (A) is used. The average residence time of the conversion meter is 3 hours to control the liquid level. The oligomer extracted from the oligomer extraction line (4) is continuously supplied to the first polycondensation reaction tank (a). After the system was stabilized, the esterification rate of the oligomer collected at the outlet of the reaction tank (A) was 97.5%.

The internal temperature of the first polycondensation reaction (a) was 246 ° C, the pressure was 2.4 kPa, and the liquid level control was carried out so that the residence time became 120 minutes. The initial polycondensation reaction is carried out while extracting water, tetrahydrofuran or 1,4-butanediol from an exhaust line (L2) connected to a pressure reducer (not shown). The extracted reaction liquid is continuously supplied to the second polycondensation reaction tank (d).

The internal temperature of the second polycondensation reaction (d) was 239 ° C, the pressure was 150 Pa, and the liquid level control was carried out so that the residence time became 90 minutes, and the exhaust line connected to a pressure reducer (not shown) L4), while extracting water, tetrahydrofuran, 1,4- Butanediol is further subjected to a polycondensation reaction. The obtained polymer is continuously supplied to the third polycondensation reaction (k) via the extraction line (L3) by the gear pump (e) for extraction. The internal temperature of the third polycondensation reaction (k) was 238 ° C, the pressure was 130 Pa, and the residence time was 60 minutes, and the polycondensation reaction was further carried out. The obtained polymer was continuously drawn into a strand shape from a die (g) via a filter (U), and cut by a rotary cutter (h). Further, the pressure of each of the polycondensation reaction tanks (a, d, k) was controlled using a pressure reducing attachment device as shown in Fig. 3 .

As the vapor for driving the ejector, 1,4-butanediol (pH = 9.3) prepared by adding 4-amino-1-butanol was added in an amount of 20 ppm by weight. The 1,4-butanediol is continuously supplied to the vapor generating device (K) of the 1,4-butanediol for driving the ejector through the supply line (19), and is heated to 240 ° C to produce 1, The 4-butanediol vapor is supplied to each of the ejector through the supply line (20) (for the first polycondensation reaction tank: A1‧A3, and for the second polycondensation reaction tank: B1‧B3‧B5, the third polycondensation reaction For tanks: C1‧C3‧C5). At this time, the amount of THF generated in the steam generating device (K) was 2,300 ppm by weight.

The gas containing tetrahydrofuran and water distilled from the first polycondensation reaction tank (a) is introduced into the ejector (A1) via the line (21), and the effluent (A1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (A2), and the condensed liquid is collected into a hot water well cabinet (H2) through a pneumatic vacuum column (25). On the other hand, the component that has not been condensed by the air pressure condenser (A2) is sent to the ejector (A3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (26) to the hot water well cabinet (H3). Similarly to the first stage, the components that are not condensed by the air pressure condenser (A4) are discharged from the line (24) to the outside of the system using a vacuum pump (A5). The line (22, 23) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinet (H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the second polycondensation reaction tank (d) is introduced into the ejector (B1) via the line (31), and the effluent (B1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (B2), and the condensed liquid is collected into the hot water well cabinet (H1) through a pneumatic vacuum column (36). On the other hand, the component that has not been condensed by the air pressure condenser (B2) is sent to the ejector (B3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (37) to the hot water well cabinet (H2). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (B4) is sent to the ejector (B5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (38) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (B6) are discharged from the line (35) to the outside of the system using a vacuum pump (B7). The line (32, 33, 34) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the third polycondensation reaction tank (k) is introduced into the ejector (C1) via the line (41), and the effluent (C1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (C2), and the condensate is collected into the hot water well cabinet (H1) through a pneumatic vacuum column (46). On the other hand, the component that has not been condensed by the air pressure condenser (C2) is sent to the ejector (C3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (47) to the hot water well cabinet (H2). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (C4) is sent to the ejector (C5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (48) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (C6) are discharged from the line (45) to the outside of the system using a vacuum pump (C7). The line (42, 43, 44) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The liquid containing 1,4-butanediol as the main component in the hot water well cabinet (H1, H2, H3) is sent to the buffer tank (H5) through the pipeline (54) and the pump (H4), and the total amount thereof is taken. The pump (H6) and the line (55) are directly transferred to the raw material slurry preparation tank in an unpurified state as a part of the polyester raw material diol.

The line (51, 52, 53) is a supply line of 1,4-butanediol from the outside to the hot water well cabinet (H1, H2, H3), and is supplied with 20 mass ppm of 4-amino-1-butanol. 1,4-butanediol solution. Further, in the operation timing of the continuous polycondensation process, the external 1,4-butanediol solution is supplied with a line (19) and a line (51, 52, 53), and is set to a constant flow rate.

The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Embodiment 2]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 10.8) prepared by adding 4-amino-1-butanol as a vapor for driving the ejector was added in an amount of 100 ppm by weight. get on. The steam generating device (K) had a THF production amount of 2,300 ppm by weight, and the polymer color tone was good. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Example 3]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 8.9) prepared with tributylamine was added as a vapor for driving the initiator in an amount of 20 ppm by weight. The amount of THF produced by the steam generating device (K) was 2,600 ppm by weight, and the color tone of the polymer was good. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Example 4]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 10.7) prepared with tributylamine was added as a vapor for driving the initiator in an amount of 1000 ppm by weight. The amount of THF produced by the steam generating device (K) was 2,100 ppm by weight. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Example 5]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 9.3) prepared by adding 2-guanamine was added as a vapor for driving the eliminator in an amount of 20 ppm by weight. The amount of THF produced by the steam generating device (K) was 2,200 ppm by weight, and the color tone of the polymer was good. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Comparative Example 1]

The same procedure as in Example 1 was carried out except that commercially available 1,4-butanediol (pH = 5.2) was used as the vapor for driving the ejector. The steam generating device (K) produced THF in an amount of up to 4,900 ppm by weight. Will gather after 1 week of operation The results of quality evaluation of the ester granules are shown in Table 1.

[Comparative Example 2]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 11.9) prepared by adding 4-amino-1-butanol as a vapor for driving the ejector was added in an amount of 1000 ppm by weight. get on. The amount of THF generated by the steam generating device (K) was as small as 2,100 ppm by weight, but the color tone of the polymer was deteriorated. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Comparative Example 3]

The same procedure as in Example 1 was carried out except that 1,4-butanediol (pH = 5.5) prepared with 2-pyrrolidone was added as a vapor for driving the injector in an amount of 20 ppm by weight. The amount of THF generated by the steam generating device (K) was 3,800 ppm by weight, and the color tone of the polymer deteriorated. The quality evaluation results of the polyester pellets one week after the start of the operation are shown in Table 1.

[Embodiment 6] <Modulation of polymerization catalyst>

100 parts by mass of magnesium acetate. tetrahydrate was placed in a glass eggplant type flask equipped with a stirring device, and 1500 parts by mass of absolute ethanol (purity of 99% by mass or more) was further added. Further, 65.3 parts by mass of dihydrogen phosphate (mixed mass ratio of monoester to diester) of 45:55 was added, and the mixture was stirred at 23 °C. After confirming that the magnesium acetate was completely dissolved after 15 minutes, 122 parts by mass of tetra-n-butyl titanate was added. Stirring was continued for another 10 minutes to obtain a homogeneous mixed solution. The mixed solution was transferred to an eggplant type flask, and concentrated under reduced pressure in an oil bath at 60 ° C by an evaporator. After 1 hour, almost all of the ethanol was distilled off to obtain a translucent viscous liquid. The oil bath temperature was further raised to 80 ° C, and further concentrated under reduced pressure of 5 Torr to obtain a viscous liquid. This liquid catalyst was dissolved in 1,4-butanediol to prepare a titanium atom content of 3.36 mass%. The catalyst solution had good storage stability in 1,4-butanediol, and no catalyst was found to be formed at least 40 days after the catalyst solution stored at 40 ° C in a nitrogen atmosphere. Further, the pH of the catalyst solution was 6.3.

(Manufacture of polybutyl succinate)

The polybutylene succinate was produced by the esterification step shown in Fig. 1 and the polycondensation step shown in Fig. 2 and the pressure reducing attachment shown in Fig. 3 as follows. First, 50 ° C mixed with 1.00 mol of succinic acid containing 0.18 wt% of malic acid, 1,4-butanediol of 1.30 mol and a total amount of malic acid of 0.0033 mol. Slurry, from the slurry brewing tank (not As shown in the figure, the raw material supply line (1) is continuously supplied to an esterification reaction tank having a stirrer filled with a low molecular weight bulk oligomer having an esterification ratio of 99% by weight in a nitrogen atmosphere in a manner of 45.5 kg/hour. (A).

The internal temperature of the esterification reaction tank (A) was 230 ° C and the pressure was 101 kPa, and the produced water, tetrahydrofuran and the remaining 1,4-butanediol were distilled off from the distillation line (5) in the distillation column. (C) is separated into a high boiling component and a low boiling component. The high boiling component of the bottom of the system after stabilization of the system is extracted in a certain manner according to the liquid level of the distillation column (C), and a part thereof is taken out to the outside via the extraction line (8). On the other hand, the low-boiling component mainly composed of water and tetrahydrofuran is extracted from the top of the tower by gas, and is condensed by a cooler (G). The liquid level of the tank (F) is in a certain manner, and the extraction line is taken. ) Pull out to the outside. At the same time, the total amount of the bottom component (98% by weight or more of 1,4-butanediol) of the distillation column (C) of 100 ° C is supplied by the recycle line (2), and the catalyst supply line is used ( 3), and is supplied in combination with 1,4-butanediol such as tetrahydrofuran produced in the esterification reaction tank to adjust the molar ratio of 1,4-butanediol to succinic acid in the esterification reaction tank. It is 1.30. The supply amount is 3.8 kg/hour in combination with the recycle line (2) and the catalyst supply line (3).

The esterification reaction product formed in the esterification reaction tank (A) is continuously pumped out from the extraction line (4) of the esterification reactant using a pump (B), and the liquid in the esterification reaction tank (A) is amber. The liquid level is controlled by an acid unit conversion meter with an average residence time of 3 hours. The esterification reactant extracted from the extraction line (4) is continuously supplied to the first polycondensation reaction tank (a). After the system is stabilized, the esterification rate of the esterification reactant collected at the outlet of the esterification reaction tank (A) is 92.4%, and the terminal carboxyl group is concentrated. The degree is 884 equivalents/ton.

The catalyst solution prepared by the above-mentioned method is prepared into a catalyst solution diluted with 1,4-butanediol in a catalyst preparation tank so that the concentration of the titanium atom is 0.12% by weight. The supply line (L8) was continuously supplied to the extraction line (4) of the esterification reactant at 1.4 kg/hr (the catalyst was added to the liquid phase of the reaction liquid). The supply is stable during the operation period.

The internal temperature of the first polycondensation reaction (a) was 240 ° C, the pressure was 2.7 kPa, and the liquid level control was carried out so that the residence time became 120 minutes. The initial polycondensation reaction is carried out while extracting water, tetrahydrofuran or 1,4-butanediol from an exhaust line (L2) connected to a pressure reducer (not shown). The extracted reaction liquid is continuously supplied to the second polycondensation reaction tank (d).

The internal temperature of the second polycondensation reaction (d) was 245 ° C, the pressure was set to 400 Pa, and the liquid level control was performed so that the residence time became 150 minutes, and the exhaust line connected to a pressure reducer (not shown) L4) Further, a polycondensation reaction is carried out while extracting water, tetrahydrofuran, and 1,4-butanediol. The obtained polyester is continuously supplied to the third polycondensation reaction (k) via the extraction line (L3) by the gear pump (e) for extraction. The internal temperature of the third polycondensation reaction (k) was 245 ° C, the pressure was 130 Pa, and the residence time was 180 minutes, and the polycondensation reaction was further carried out. The obtained polyester was continuously drawn into a strand shape by a die (g), and cut by a rotary cutter (h).

Further, the pressure of each of the polycondensation reaction tanks (a, d, k) was controlled using a pressure reducing attachment device as shown in Fig. 3 .

As the vapor for driving the ejector, 1,4-butanediol (pH = 9.3) prepared by adding 4-amino-1-butanol was added in an amount of 20 ppm by weight. The 1,4-butanediol solution is continuously supplied to a vapor generating device (K) for 1,4-butanediol for driving the ejector through a supply line (19), and heated to 240 ° C to produce 1 The 4-butanediol vapor is supplied to each of the ejector through the supply line (20) (for the first polycondensation reaction tank: A1‧A3, and for the second polycondensation reaction tank: B1‧B3‧B5, the third polycondensation For the reaction tank: C1‧C3‧C5). At this time, the amount of THF generated in the steam generating device (K) was 2,300 ppm by weight.

The gas containing tetrahydrofuran and water distilled from the first polycondensation reaction tank (a) is introduced into the ejector (A1) via the line (21), and the effluent (A1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (A2), and the condensed liquid is collected into a hot water well cabinet (H2) through a pneumatic vacuum column (25). On the other hand, the component that has not been condensed by the air pressure condenser (A2) is sent to the ejector (A3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (26) to the hot water well cabinet (H3). Similarly to the first stage, the components that are not condensed by the air pressure condenser (A4) are discharged from the line (24) to the outside of the system using a vacuum pump (A5). The line (22, 23) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinet (H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the second polycondensation reaction tank (d) is introduced into the ejector (B1) via the line (31), and the effluent (B1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (B2), and the condensed liquid is collected into the hot water well cabinet (H1) through a pneumatic vacuum column (36). on the other hand, The component that has not been condensed by the air pressure condenser (B2) is sent to the ejector (B3) of the second stage, and the condensate is collected to the hot water well cabinet (H2) through the pneumatic vacuum column (37). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (B4) is sent to the ejector (B5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (38) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (B6) are discharged from the line (35) to the outside of the system using a vacuum pump (B7). The line (32, 33, 34) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The gas containing tetrahydrofuran and water distilled from the third polycondensation reaction tank (k) is introduced into the ejector (C1) via the line (41), and the effluent (C1) is discharged at 1, 4 The butanediol vapor is condensed by a gas pressure condenser (C2), and the condensate is collected into the hot water well cabinet (H1) through a pneumatic vacuum column (46). On the other hand, the component that has not been condensed by the air pressure condenser (C2) is sent to the ejector (C3) of the second stage, and the condensed liquid is collected by the pneumatic vacuum column (47) to the hot water well cabinet (H2). Similarly to the first stage, the component that has not been condensed by the air pressure condenser (C4) is sent to the ejector (C5) of the third stage, and the condensed liquid is collected by the air pressure vacuum column (48) to the hot water well cabinet (H3). Similarly to the second stage, the components that are not condensed by the air pressure condenser (C6) are discharged from the line (45) to the outside of the system using a vacuum pump (C7). The line (42, 43, 44) is a supply line of 1,4-butanediol, and the entire amount is circulated and supplied by the hot water well cabinets (H1, H2, H3) (not shown).

The liquid containing 1,4-butanediol as a main component collected in the hot water well cabinet (H1, H2, H3) is sent to the buffer tank (H5) through the line (54) and the pump (H4), and is The entire amount is directly transferred to the raw material slurry preparation tank by the pump (H6) and the line (55) in an unpurified state as a part of the polyester raw material diol.

The line (51, 52, 53) is a supply line of 1,4-butanediol from the outside to the hot water well cabinet (H1, H2, H3), and is supplied with 20 mass ppm of 4-amino-1-butanol. 1,4-butanediol solution. Further, in the operation timing of the continuous polycondensation process, only the line (19) and the lines (51, 52, 53) are supplied from the external 1,4-butanediol solution, and are set to a constant flow rate.

The results of quality evaluation of the polyester pellets one week after the start of the operation are shown in Table 2.

[Comparative Example 4]

The same procedure as in Example 6 was carried out except that 1,4-butanediol (pH = 5.2) of a commercial product was used as the vapor for driving the ejector. The steam generating device (K) produced THF in an amount of up to 4,900 ppm by weight. The results of quality evaluation of the polyester pellets one week after the start of the operation are shown in Table 2.

The present invention has been described with reference to the particular embodiments of the present invention.

The present application is based on Japanese Patent Application No. 2011-163558, filed on Jan.

(industrial availability)

The method of producing the polyester of the present invention is efficient and has less conversion to THF. Further, the polyester obtained by the production method of the present invention has a good color tone and contributes to the efficient use of biomass resources.

1‧‧‧Material supply pipeline

2‧‧‧Recycling pipeline

3‧‧‧catalyst supply pipeline

4‧‧‧ oligomer extraction line

5‧‧‧Distillation line

6‧‧‧Extracted pipeline

7‧‧‧Circular pipeline

8‧‧‧Extracted pipeline

9‧‧‧ gas extraction pipeline

10‧‧‧Condenser Condensate Line

11‧‧‧Extracted pipeline

12‧‧‧Circular pipeline

13‧‧‧Extracted pipeline

14‧‧‧Exhaust line

15‧‧‧catalyst supply pipeline

16‧‧‧catalyst supply pipeline

19, 51, 52, 53‧‧‧ supply lines from external 1,4-butanediol

20‧‧‧Vapor 1,4-BG supply line for injectors

21‧‧‧Exhaust line from the first polycondensation reaction tank

31‧‧‧Exhaust line from the second polycondensation reaction tank

41‧‧‧Exhaust line from the third polycondensation reaction tank

Supply lines for 22, 23, 32, 33, 34, 42, 43, 44‧‧‧ 1,4-BG

24, 35, 45‧‧‧Sewage gas lines from vacuum pumps

25, 26, 36, 37, 38, 46, 47, 48‧‧‧ gas vacuum columns for air pressure condensers

54‧‧‧Extraction line of condensate from the hot water well cabinet to the buffer tank

55‧‧‧1,4-BG supply line from the buffer tank to the raw material slurry preparation tank

56‧‧‧ 1,4-BG supply line from the buffer tank to the distillation refining tower

57‧‧‧Low-boiling component extraction line

58‧‧‧ 1,4-BG supply line from the distillation refining tower to the raw material slurry preparation tank

59‧‧‧Extraction line for high boiling components

A‧‧‧reaction tank

B‧‧‧Extraction pump

C‧‧‧Rectifier

D, E‧‧ pump

F‧‧‧ slot

G‧‧‧Condenser

L1, L3‧‧‧ withdrawal pipeline

L2, L4, L6‧‧‧ exhaust lines

L5‧‧‧ polymer extraction pipeline

L8‧‧‧1,4-butanediol supply line

L7‧‧‧ metal compound supply pipeline

A‧‧‧1st polycondensation reaction tank

D‧‧‧2nd polycondensation reaction tank

K‧‧‧3rd polycondensation reaction tank

c, e, m‧‧‧ gear pump for extraction

G‧‧‧die

h‧‧‧Rotary cutter

R, S, T, U‧‧‧ filters

A1, A3, B1, B3, B5, C1, C3, C5‧‧‧ injectors

A2, A4, B2, B4, B6, C2, C4, C6‧‧‧ air pressure condenser

A5, B7, C7‧‧‧ vacuum pump

H1, H2, H3‧‧‧ hot water well cabinet

H4, H6, J2, J4‧‧ pump

H5‧‧‧buffer tank

J1‧‧‧Distillation and purification tower

J3‧‧‧Remelting tower re-boiler

K‧‧‧Vapor generator for 1,4-butanediol for injector drive

Fig. 1 is an explanatory view showing an example of an esterification reaction step employed in the present invention.

Fig. 2 is an explanatory view showing an example of a polycondensation reaction step employed in the present invention.

Fig. 3 is an explanatory view showing an example of a pressure reducing attachment device used in the present invention.

19‧‧‧Supply pipeline from external 1,4-butanediol

20‧‧‧Vapor 1,4-BG supply line for injectors

21‧‧‧Exhaust line from the first polycondensation reaction tank

22‧‧‧ 1,4-BG supply pipeline

23‧‧‧ 1,4-BG supply pipeline

24‧‧‧Spray gas line from vacuum pump

25‧‧‧ gas vacuum column for air pressure condenser

26‧‧‧ gas vacuum column for air pressure condenser

31‧‧‧Exhaust line from the second polycondensation reaction tank

32‧‧‧ 1,4-BG supply pipeline

33‧‧‧ supply line for 1,4-BG

34‧‧‧ supply line for 1,4-BG

35‧‧‧Spray gas line from vacuum pump

36‧‧‧ gas vacuum column for air pressure condenser

37‧‧‧ gas vacuum column for air pressure condenser

38‧‧‧ gas vacuum column for air pressure condenser

41‧‧‧Exhaust line from the third polycondensation reaction tank

42‧‧‧ supply line for 1,4-BG

43‧‧‧ supply line for 1,4-BG

44‧‧‧ supply line for 1,4-BG

45‧‧‧Spray gas line from vacuum pump

46‧‧‧ gas vacuum column for air pressure condenser

47‧‧‧ gas vacuum column for air pressure condenser

48‧‧‧ gas vacuum column for air pressure condenser

51‧‧‧Supply pipeline from external 1,4-butanediol

52‧‧‧Supply pipeline from external 1,4-butanediol

53‧‧‧Supply pipeline from external 1,4-butanediol

54‧‧‧Extraction line of condensate from the hot water well cabinet to the buffer tank

55‧‧‧1,4-BG supply line from the buffer tank to the raw material slurry preparation tank

56‧‧‧ 1,4-BG supply line from the buffer tank to the distillation refining tower

57‧‧‧Low-boiling component extraction line

58‧‧‧ 1,4-BG supply line from the distillation refining tower to the raw material slurry preparation tank

59‧‧‧Extraction line for high boiling components

A1‧‧‧Injector

A2‧‧‧ air pressure condenser

A3‧‧‧Injector

A4‧‧‧ air pressure condenser

A5‧‧‧vacuum pump

B1‧‧‧Injector

B2‧‧‧ air pressure condenser

B3‧‧‧Injector

B4‧‧‧Air Pressure Condenser

B5‧‧‧Injector

B6‧‧‧Air Pressure Condenser

B7‧‧‧vacuum pump

C1‧‧‧Ejector

C2‧‧‧ air pressure condenser

C3‧‧‧Injector

C4‧‧‧ air pressure condenser

C5‧‧‧Injector

C6‧‧‧ air pressure condenser

C7‧‧‧vacuum pump

H1‧‧‧hot water cabinet

H2‧‧‧Water well cabinet

H3‧‧‧Water well cabinet

H4‧‧‧ pump

H5‧‧‧buffer tank

H6‧‧‧ pump

J1‧‧‧Distillation and purification tower

J2‧‧‧ pump

J3‧‧‧Remelting tower re-boiler

J4‧‧‧ pump

K‧‧‧Vapor generator for 1,4-butanediol for injector drive

Claims (4)

A method for producing a polyester by subjecting a diol component containing 1,4-butanediol to a dicarboxylic acid component to carry out one or more reactions in an esterification reaction and a transesterification reaction, and further polymerizing the product of the reaction a method for continuously producing a polyester by a condensation reaction; wherein (a) the above polycondensation reaction is carried out under reduced pressure; (b) the above polycondensation reaction under reduced pressure, using 1,4-butanediol (v) using 1,4-butanediol which has passed through the above-mentioned pressure reducing attachment device as the above-mentioned diol component; and (d) supplying The pH of the 1,4-butanediol to the vapor generator for driving the steam ejector is 7.0 or more and 11.5 or less. The method for producing a polyester according to the first aspect of the invention, wherein the 1,4-butanediol supplied to the vapor generator for driving the steam ejector contains 0.1 ppm by weight or more of a nitrogen compound in terms of a nitrogen atom. And 150 ppm by weight or less. The method for producing a polyester according to the first or second aspect of the invention, wherein the 1,4-butanediol supplied to the vapor generator for driving the steam ejector contains an amine compound and an amino alcohol compound. More than one type. The method for producing a polyester according to claim 1 or 2, wherein the 1,4-butanediol supplied to the steam generating device for driving the steam ejector is derived from a biomass resource.