JP6914868B2 - Polyester manufacturing method - Google Patents

Description

The present invention relates to a method for producing a polyester. More specifically, the present invention relates to a method for producing a polyester by a condensation polymerization method.

Polyester resins are widely used as materials for fibers, films, bottles, paints, toner binders and the like.

As one of the polyester production methods, there is a direct polymerization method consisting of an esterification step of producing an oligomer by performing an esterification reaction of a dicarboxylic acid and a diol, and a polycondensation reaction of the produced oligomer.

In the esterification step and the polycondensation reaction step in such a direct polymerization method, the use of a catalyst is indispensable for increasing the production efficiency, and an organic titanium compound, an antimony compound, a tin compound or the like is used as the esterification catalyst. Among these, organic titanium compounds are widely used because they have high activity and high solubility in polyester.

However, when the organic titanium compound is polymerized, the catalyst may be decomposed due to condensed water generated in the first stage esterification step, high temperature conditions, etc., and the decomposed product may be insolubilized as a foreign substance.

Naturally, such decomposition of the catalyst causes a decrease in the reaction rate and a decrease in production efficiency, and the particles of the decomposition product often adversely affect the quality of the polyester. It causes uneven gloss.

As a method for producing a polyester resin for a toner binder, Patent Document 1 discloses a method in which an esterification step is performed under pressurized conditions and the production efficiency is enhanced by switching to reduced pressure conditions under certain conditions.

However, the reaction under pressurized and high temperature conditions as in Patent Document 1 accelerates the decomposition of the catalyst, especially when an organic titanium compound is used, resulting in a decrease in production efficiency, generation of foreign substances, coloring of polyester, etc. Invite.

In order to suppress such decomposition of the catalyst, Patent Document 2 proposes that the esterification reaction is carried out in the presence of a catalyst having a chelate ligand having high hydrolysis resistance. Quality deterioration due to foreign matter was insufficient, especially for toner binder applications.

JP-A-2010-155978 JP 2012-241111

The present invention has been made to solve the above-mentioned problems, and is a method for producing a polyester resin having high productivity and excellent quality with less foreign matter derived from the titanium-containing catalyst and less coloring in the presence of a titanium-containing catalyst. Is to provide.

As a result of diligently examining the reaction conditions in the first-step esterification reaction and the second-step polycondensation reaction, the present inventors set the temperature, pressure, and esterification rate of the esterification reaction within a specific range. As a result, we have found a polyester production method that has high production efficiency and less catalyst-derived foreign matter generation and coloring, and has reached the present invention.
That is, the present invention is a method for producing a polyester (A) containing an alcohol component (x) containing an aliphatic diol having 2 to 20 carbon atoms and a carboxylic acid component (y) as constituent components in the presence of an esterification catalyst. After the first step (a) and the first step (a), the reaction is carried out at a temperature of 100 ° C. to 180 ° C. and 10 to 70 kPa until the reaction rate is 50% or more and 95% or less, and then 140 ° C. to 240 ° C. A method for producing a polyester, which comprises a second step (b) of reacting at a temperature of ° C. and 6 kPa or less.

The method for producing a polyester of the present invention provides a method for producing a polyester which has the effects of high production efficiency, less generation of foreign substances derived from a catalyst, and less coloring.

Hereinafter, the present invention will be described in detail.
The polyester (A) of the present invention contains an alcohol component (x) and a carboxylic acid component (y) as constituent components.

The alcohol component (x) of the present invention includes diols (aliphatic diols having 2 to 20 carbon atoms, diols having 21 or more carbon atoms and aromatic diols), polyols having 3 to 8 valences or more, and other alcohol components. And so on. Of these, it is essential to contain an aliphatic diol having 2 to 20 carbon atoms.

Examples of the diol include the following.
Examples of the aliphatic diol having 2 to 20 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. 1,4-Cyclohexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1, , 13-Tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol and the like. Moreover, you may use these 2 or more types together.
From the viewpoint of polyester crystallinity, it is preferably an aliphatic diol having 2 to 10 carbon atoms, and more preferably an aliphatic diol having 2 to 6 carbon atoms.

Examples of the diol having 21 or more carbon atoms include a linear aliphatic alcohol having 21 or more carbon atoms, a branched aliphatic alcohol having 21 or more carbon atoms, a polyether diol having 21 or more carbon atoms, a polyester diol, and a polycarbonate diol.

Examples of the aromatic diol include polyoxyalkylene ethers of bisphenols (number of AO units 2 to 30), aromatic polycarbonate diols, and the like.

Among these diols, a linear aliphatic diol is preferable from the viewpoint of the crystallinity of the polyester (A). More preferably, it is ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol and 1,12-dodecanediol.

The alcohol component (x) of the present invention may contain a polyol having a valence of 3 to 8 or more.
Examples of the 3- to 8-valent or higher polyol include 3- to 8-valent or higher polyhydric fatty alcohols, saccharides and derivatives thereof, trisphenols, novolak resins, acrylic polyols and the like.
Examples of the trihydric or higher polyhydric aliphatic alcohol include alkane polyols and intramolecular or intermolecular dehydrations thereof, and specific examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. , Sorbitan, polyglycerin and the like.
Examples of the saccharide and its derivative include sucrose and methylglucoside.
Examples of trisphenols include AO adducts such as trisphenol PA (additional number of moles 2 to 30).
Examples of the novolak resin include AO adducts (additional number of moles 2 to 30) of phenol novolac, cresol novolak, etc.
Examples of the acrylic polyol include a copolymer of hydroxyethyl (meth) acrylate and another vinyl-based monomer.
Of these, preferred are 3- to 8-valent or higher polyhydric aliphatic alcohols and novolak resin AO adducts, and more preferably novolak resin AO adducts.

Examples of other alcohol components include monohydric alcohols.
Examples of the monohydric alcohol include aliphatic alcohols and aromatic alcohols containing an alkyl group having 3 to 36 carbon atoms.

Examples of the aliphatic alcohol containing an alkyl group having 3 to 36 carbon atoms of the monohydric alcohol include 1-butanol, 1-octanol, 1-ethylhexanol, myristyl alcohol, lauryl alcohol, stearyl alcohol, behenyl alcohol and oleyl alcohol. Can be mentioned.

Examples of the aromatic alcohol of the monohydric alcohol include benzyl alcohol and the like.

Among other alcohol components, an aliphatic alcohol containing an alkyl group having 3 to 36 carbon atoms is preferable, and myristyl alcohol, behenyl alcohol and stearyl alcohol are more preferable.

As the other alcohol component, a diol having at least one group selected from the group consisting of a carboxylic acid (salt) group, a sulfonic acid (salt) group, a sulfamic acid (salt) group and a phosphoric acid (salt) group is a constituent unit. May be.
The "acid (salt)" in the present invention means an acid or a salt salt.

Examples of the diol having a carboxylic acid (salt) group include tartaric acid (salt), 2,2-bis (hydroxymethyl) propanoic acid (salt), 2,2-bis (hydroxymethyl) butanoic acid (salt) and 3-[. Bis (2-hydroxyethyl) amino] propionic acid (salt) and the like can be mentioned.

Examples of the diol having a sulfonic acid (salt) group include 2,2-bis (hydroxymethyl) ethanesulfonic acid (salt), 2- [bis (2-hydroxyethyl) amino] ethanesulfonic acid (salt) and 5-sulfo. -Isophthalic acid-1,3-bis (2-hydroxyethyl) ester (salt) and the like can be mentioned.

Examples of the diol having a sulfamic acid (salt) group include N, N-bis (2-hydroxyethyl) sulfamic acid (salt), N, N-bis (3-hydroxypropyl) sulfamic acid (salt), N, N-. Examples thereof include bis (4-hydroxybutyl) sulfamic acid (salt) and N, N-bis (2-hydroxypropyl) sulfamic acid (salt).

Examples of the diol having a phosphoric acid (salt) group include bis (2-hydroxyethyl) phosphate (salt) and the like.

The salts constituting the acid salt include ammonium salts and amine salts (methylamine salts, dimethylamine salts, trimethylamine salts, ethylamine salts, diethylamine salts, triethylamine salts, propylamine salts, dipropylamine salts, tripropylamine salts, butylamines). Salts, dibutylamine salts, tributylamine salts, monoethanolamine salts, diethanolamine salts, triethanolamine salts, N-methylethanolamine salts, N-ethylethanolamine salts, N, N-dimethylethanolamine salts, N, N- Diethylethanolamine salt, hydroxylamine salt, N, N-diethylhydroxylamine salt, morpholin salt, etc.), quaternary ammonium salt [tetramethylammonium salt, tetraethylammonium salt, trimethyl (2-hydroxyethyl) ammonium salt, etc.] and alkali Examples thereof include metal salts (sodium salt, potassium salt, etc.).

Of these, a diol having a carboxylic acid (salt) group and a diol having a sulfonic acid (salt) group are preferable.

The content of the aliphatic diol having 2 to 20 carbon atoms is preferably 70 mol% or more and 100 mol% or less based on the number of moles of the alcohol component (x) as a constituent component from the viewpoint of the crystallinity of the polyester (A). More preferably, it is 90 mol% or more and 100 mol% or less.

Examples of the carboxylic acid component (y) of the present invention include dicarboxylic acids, trivalent to hexavalent or higher polycarboxylic acids and the like.
Examples of the dicarboxylic acid include an alkanedicarboxylic acid having 2 to 50 carbon atoms (including carbon of a carbonyl group), an alkenedicarboxylic acid having 4 to 50 carbon atoms, an alicyclic dicarboxylic acid having 6 to 40 carbon atoms, and an alicyclic dicarboxylic acid having 8 to 36 carbon atoms. Aromatic dicarboxylic acid and the like can be mentioned.
Examples of the alkanedicarboxylic acid having 2 to 50 carbon atoms (including the carbon of the carbonyl group) include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid and decylsuccinic acid.
Examples of the alkenedicarboxylic acid having 4 to 50 carbon atoms include alkenylsuccinic acid such as dodecenyl succinic acid, pentadecenyl succinic acid and octadecenyl succinic acid, maleic acid, fumaric acid and citraconic acid.
Examples of the alicyclic dicarboxylic acid having 6 to 40 carbon atoms include dimer acid (dimerized linoleic acid) and the like.
Examples of the aromatic dicarboxylic acid having 8 to 36 carbon atoms include phthalic acid, isophthalic acid, terephthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid and 4,4'-biphenyldicarboxylic acid.
Two or more of these may be used in combination.

Of these, an alkanedicarboxylic acid having 2 to 50 carbon atoms (including carbon of a carbonyl group), an alkenedicarboxylic acid having 4 to 50 carbon atoms, and a terephthalic acid are preferable.

Examples of the tricarboxylic acid having a valence of 3 to 6 or more include an aromatic carboxylic acid having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, etc.) and an aliphatic acid having 6 to 36 carbon atoms (including an alicyclic type). Examples thereof include carboxylic acids (hexanetricarboxylic acid, decantrycarboxylic acid, etc.) and ester-forming derivatives thereof.
Of these, preferred are trimellitic acid, pyromellitic acid and ester-forming derivatives thereof.

As the carboxylic acid component (y), a monovalent carboxylic acid may be appropriately contained.
Examples of the monovalent carboxylic acid include an aliphatic carboxylic acid containing an alkyl group having 2 to 36 carbon atoms and an aromatic carboxylic acid.

Examples of the aliphatic carboxylic acid containing an alkyl group having 2 to 36 carbon atoms include acetic acid, lauric acid, myristic acid, stearic acid and behenic acid.

Examples of the aromatic carboxylic acid include benzoic acid, methyl benzoic acid, pt-butyl benzoic acid and the like.

Of these, an aliphatic carboxylic acid containing an alkyl group having 2 to 36 carbon atoms is preferable.

The upper limit of the molar ratio (x / y) of the alcohol component (x) and the carboxylic acid component (y) is preferably 1.30 or less, more preferably 1.10 or less from the viewpoint of the amount of unreacted monomers, and the reaction From the viewpoint of speed, the lower limit is preferably 1.00 or more, and more preferably 1.03 or more.

Examples of the esterification catalyst of the present invention include titanium-containing catalysts, antimony-containing catalysts, tin-containing catalysts, aluminum-containing catalysts, zirconium-containing catalysts and the like.
Of these, it is essential to produce polyester (A) in the presence of a titanium-containing catalyst. Further, from the viewpoint of the reaction rate, an esterification catalyst is preferably added and reacted in the second step (b).
Titanium-containing catalysts include titanium alkoxide, potassium titanate oxalate, titanium terephthalate, titanium bistriethanol amine, titanium dihydroxybis (triethanol aminate), titanium monohydroxytris (triethanol aminate), and their molecules. Examples thereof include a polycondensate, titanium tributoxyterephthalate, titanium triisopropoxyterephthalate and titanium diisopropoxyditerephthalate.
Among these, titanium bistriethanolaminate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate, titanium monoisopropoxytriterephthalate and titanium terephthalate are preferable from the viewpoint of catalytic activity and hydrolysis resistance.

<Reaction temperature in step 1 (a)>
In the first step (a), the reaction temperature is 180 ° C. or lower, preferably 160 ° C. or lower from the viewpoint of suppressing the decomposition of the catalyst, and 100 ° C. or higher, preferably 120 ° C. from the viewpoint of the reaction rate.

<Reaction temperature in the second step (b)>
In the second step (b), the reaction temperature is 240 ° C. or lower, preferably 220 ° C. or lower, more preferably 210 ° C. or lower from the viewpoint of preventing coloration of the polyester, and 140 ° C. or higher from the viewpoint of the reaction rate. It is preferably 160 ° C. or higher, more preferably 190 ° C. or higher.

In the first step (a), the pressure is 70 kPa or less, preferably 60 kPa or less, more preferably 50 kPa or less from the viewpoint of suppressing the decomposition of the catalyst, and 10 kPa or more, preferably 15 kPa or more from the viewpoint of preventing diol scattering. It is more preferably 20 kPa or more.

In the second step (b), the pressure is 6 kPa or less, preferably 4 kPa or less, and more preferably 2 kPa or less from the viewpoint of the reaction rate.

In the present invention, the reaction is carried out in the first step (a) until the reaction rate is 50% or more and 90% or less, and then in the second step (b), the reaction is further reacted by 4% or more from the reaction rate of the first step (a).
This reaction rate represents the number of esterified acid components with respect to the total number of acid components as a percentage, and the amount of substance (mol) of the esterified acid components after the reaction is calculated from the acid value of polyester. The acid value is measured by the method specified in JIS K0070 (1992 edition).

The lower limit of the reaction rate in the first step (a) is essential to be 50% or more, more preferably 60% or more, from the viewpoint of preventing decomposition of the catalyst by the condensed water generated in the second step (b). Is 75%, and an upper limit of 90% or less is essential, more preferably 85%.

^{The SP value [solubility parameter: (cal / cm 3} ) ^1/2 ] of the mixture of the alcohol component (x) and the carboxylic acid component (y) is preferably 10.5 to 15.5 (solubility parameter: (cal / cm 3) 1/2] from the viewpoint of the solubility of the catalyst. It is cal / cm ³ ) ^1/2 , more preferably 11.0 to 13.0 (cal / cm ³ ) ^1/2 .
The SP value of the mixture referred to here is calculated from the SP value and weight fraction of each component of the alcohol component (x) and the carboxylic acid component (y), and is represented by the following formula (1) in detail.
σ _m = σ ₁ × x ₁ + σ ₂ × x ₂ ··· + σ _n × x _n (1)
Here, σ _m represents the SP value of the mixture, and σ _n represents the SP value of each component. For x _n, it represents the weight fraction of each component.
The SP value σn of each component represented here is calculated by the method described in the following document proposed by Fedors et al.
"POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (Pages 147-154)"

The polyester (A) in the present invention is preferably a crystalline polyester from the viewpoint of catalyst solubility.
The crystalline polyester described in the present invention is not particularly limited as long as it is a crystalline polyester. The crystalline polyester in the present invention is a polyester having one or more endothermic peaks in the second heating process in the analysis by a differential scanning calorimeter.
The differential scanning calorimeter is measured using, for example, "DSC210" [manufactured by Seiko Instruments Inc.], and the temperature rise / cooling conditions for the measurement are from 30 ° C to 180 ° C at 10 ° C / min. The temperature is raised (the first temperature raising process). Then, after leaving it at 180 ° C. for 10 minutes, it is cooled to 0 ° C. under the condition of 10 ° C./min (first cooling process). Then, after leaving it at 0 ° C. for 10 minutes, the temperature is raised to 180 ° C. under the condition of 10 ° C./min (second temperature raising process).

The metal-containing component other than titanium is not particularly limited, but the tin compound is regulated as an environmental pollutant, and the content is preferably 30 ppm or less. More preferably, it is 20 ppm or less.

The timing of adding the catalyst is preferably during the second step (b) in order to prevent deactivation of the catalyst, and more preferably when the reaction rate in the second step (b) is 85% to 100%.

From the viewpoint of suppressing coloring of the produced polyester resin, it is desirable to replace it with an inert gas before the first step (a). The inert gas referred to here is a gas that does not affect the esterification reaction, and specific examples thereof include nitrogen, argon, and helium.
Among these, nitrogen and argon are preferable from the viewpoint of preventing coloring.

The polyester produced in the present embodiment is processed into toner by adding a colorant, a mold release agent, a charge control agent, or the like as a binder resin for toner, for example.

The polyester produced in the present embodiment may be subjected to yet another reaction and modified if necessary. Specific reactions include a urethanization reaction and an epoxidation reaction.

Examples of the polyfunctional isocyanate compound to be reacted with polyester include aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbons in NCO groups; the same applies hereinafter), aliphatic diisocyanates having 2 to 18 carbon atoms, and aliphatic diisocyanates having 4 to 15 carbon atoms. Alicyclic diisocyanates, aromatic aliphatic diisocyanates having 8 to 15 carbon atoms and modified products of these diisocyanates (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group and oxazolidone). Group-containing modified products, etc.) and mixtures of two or more of these. Further, if necessary, a polyisocyanate having a valence of 3 or more may be used in combination.

Examples of the polyfunctional epoxy compound to be reacted with polyester include bisphenol A type or -F type epoxy compound, phenol novolac type epoxy compound, cresol novolac type epoxy compound, hydrogenated bisphenol A type epoxy compound, and bisphenol A or -F AO adduct. Diglycidyl ether, diglycidyl ether of AO adduct of hydrogenated bisphenol A, diols (ethylene glycol, propylene glycol, neopentyl glycol, butanediol, hexanediol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, etc.) Glycidyl ether, trimethyl propanedi, triglycidyl ether, pentaerythritol tri, tetraglycidyl ether, sorbitol hepta, hexaglycidyl ether, resorcin diglycidyl ether, dicyclopentadiene phenol-added glycidyl ether, methylenebis (2,7-dihydroxynaphthalene) ) Tetraglycidyl ether, 1,6-dihydroxynaphthalenediglycidyl ether, polybutadiene diglycidyl ether and the like can be mentioned.

Among these, modification by urethanization reaction is preferable from the viewpoint of reactivity with polyester, and modification by urethanization reaction using an aliphatic diisocyanate having 2 to 18 carbon atoms is more preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. The methods for measuring the physical properties and evaluation items adopted in the following examples are as follows. In addition, Example 3 is Reference Example 1, and Examples 8 to 11 are Reference Examples 2-5.

The amount of the alcohol component (x) scattered is determined by 1H-NMR (nuclear magnetic resonance) spectroscopy of the condensed water generated in the first step (a) and the second step (b) and the condensed water to which the internal standard substance is added. Can be obtained from the spectrum of. That is, the alcohol contained in the condensed water is based on the peak ratio of 3.0 to 4.0 ppm derived from -CH-proton adjacent to the hydroxyl group of the alcohol component (x) contained in the condensed water and the peak ratio and concentration of the added internal standard substance. The weight ratio of the component (x) can be calculated, and the amount of the alcohol component (x) scattered can be calculated from the weight of the condensed water.

The deuterated solvent and the internal standard substance used for the measurement are preferably those having no peak at 3.0 to 4.0 ppm. For example, deuterated chloroform as the deuterated solvent and dimethylformamide (DMF) as the internal standard substance should be used. Can be done.

Regarding the scattering rate of the alcohol component (x), the scattering amount of the diol with respect to the charged amount of the diol is expressed as a weight percentage.

The scattering rate of the alcohol component (x) is, for example, preferably 5% or less, more preferably 4% or less, still more preferably 3% or less, from the viewpoint of process stability.

Regarding the degree of coloring of polyester, it was dissolved in DMF so that the mass percent concentration was 6%, and L * a * b was used using a quartz cell with an optical path length of 10 mm using a color tester OME2000 (Nippon Denshoku Kogyo). * Was measured and evaluated by the value of the color difference ΔE represented by the formula 2.
ΔE = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2 (2)

The ΔE value is preferably 4.0 or less when used as a toner binder, for example. It is more preferably 3.0 or less, still more preferably 2.0 or less.

Regarding the process time of polyester, from the viewpoint of production efficiency, the sum of the process times of the first step (a) and the second step (b) is preferably 24 hours or less, more preferably 18 hours or less, still more preferably. Within 12 hours.

Example 1
(Synthesis of polyester (a-1))
690 parts of sebacic acid, 432 parts of 1,6-hexanediol and 1 part of titanium diisopropoxyditerephthalate are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and the inside of the reactor is pressurized with nitrogen. , The operation of returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 170 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out under a reduced pressure of 1.0 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.3% or more. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-1). The reaction rate of (a-1) was 99.3%, no foreign matter was observed in the appearance of the polyester, the ΔE of the DMF solution of the polyester was 0.82, and almost no coloring was observed.

Example 2
(Synthesis of polyester (a-2))
769 parts of sebacic acid and 367 parts of 1,4-butanediol and 1 part of titanium diisopropoxyditerephthalate as a condensation catalyst were placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and nitrogen was inside the reactor. The operation of pressurizing with and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 150 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 50%. Then, the reaction was carried out under a reduced pressure of 1.2 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.3% or more. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-2). (A-2) The reaction rate was 99.4%, no foreign matter was observed in the appearance of the polyester, the ΔE of the DMF solution of the polyester was 0.63, and almost no coloring was observed.

Example 3
(Synthesis of polyester (a-3))
690 parts of sebacic acid, 432 parts of 1,6-hexanediol and titanium diisopropoxyditerephthalate part are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and the inside of the reactor is pressurized with nitrogen. , The operation of returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 10 kPa at 160 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out under a reduced pressure of 1.1 kPa while gradually raising the temperature to 190 ° C., and the mixture was taken out when the reaction rate reached 99.3% or more. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-3). The reaction rate of (a-3) was 99.3%, no foreign matter was observed in the appearance of the polyester, the ΔE of the DMF solution of the polyester was 0.74, and almost no coloring was observed.

Example 4
(Synthesis of polyester (a-4))
827 parts of adipic acid, 376 parts of ethylene glycol and 1.0 part of titanium bistriethanolaminate as a condensation catalyst were placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and the inside of the reactor was pressurized with nitrogen. , The operation of returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 120 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 75%. Then, the reaction was carried out under a reduced pressure of 1.0 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.3%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-5). The reaction rate of (a-5) was 99.3%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 0.94, and almost no coloring was observed.

Example 5
(Synthesis of polyester (a-5))
In a reactor equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 724 parts of dodecanedioic acid, 401 parts of 1,6-hexanediol and 1.0 part of titanium bistriethanolaminate as a condensation catalyst were placed in the reactor. Was pressurized with nitrogen and returned to normal pressure several times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 180 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out under a reduced pressure of 1.1 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.3%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-5). The reaction rate of (a-5) was 99.3%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 1.02, and almost no coloring was observed.

Example 6
(Synthesis of polyester (a-6))
695 parts of sebacic acid, 413 parts of 1,6-hexanediol and 22 parts of behenyl alcohol, 0.5 parts of titanium diisopropoxyditerephthalate as a condensation catalyst, and titanium in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube. The operation of adding monoisopropoxytriphthalate, pressurizing the inside of the reactor with nitrogen, and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 160 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 90%. Then, the reaction was carried out under a reduced pressure of 2.5 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.5%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-6). The reaction rate of (a-6) was 99.5%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 0.90, and almost no coloring was observed.

Example 7
(Synthesis of polyester (a-7))
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 725 parts of dodecanoic acid, 380 parts of 1,6-hexanediol and 17 parts of stearyl alcohol, 0.5 part of titanium diisopropoxyditerephthalate as a condensation catalyst, 0.5 part of titanium monoisopropoxytriphthalate was added, and the inside of the reactor was pressurized with nitrogen to return to normal pressure several times. Then, the reaction was carried out under a reduced pressure of 30 kPa at 160 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 90%. Then, the reaction was carried out under a reduced pressure of 2.0 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.8%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-7). The reaction rate of (a-7) was 99.8%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 0.85, and almost no coloring was observed.

Example 8
(Synthesis of polyester (a-8))
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 636 parts of dodecanoic acid, 450 parts of 1,9-nonanediol, 15 parts of stearyl alcohol and 0.5 part of titanium monoisopropoxytriphthalate were placed and reacted. The operation of pressurizing the inside of the vessel with nitrogen and returning it to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 20 kPa at 180 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 95%. Then, the reaction was carried out under a reduced pressure of 4.0 kPa while gradually raising the temperature to 210 ° C., and the mixture was taken out when the reaction rate reached 98.7%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-7). The reaction rate of (a-7) was 98.7%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 2.10, which was slightly colored.

Example 9
(Synthesis of polyester (a-9))
In a reactor equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 552 parts of dodecanenic acid and 533 parts of 1,12 dodecanediol and 0.5 part of titanium monoisopropoxytriphthalate as a condensation catalyst were placed in the reactor. The operation of pressurizing with nitrogen and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 15 kPa at 140 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 95%. Then, the reaction was carried out under a reduced pressure of 6.0 kPa while gradually raising the temperature to 220 ° C., and the mixture was taken out when the reaction rate reached 99.3%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-7). The reaction rate of (a-7) was 99.3%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 3.30, which was slightly colored.

Example 10
(Synthesis of polyester (a-10))
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 496 parts of adipic acid, 191 parts of ethylene glycol, 433 parts of a bisphenol A ethylene oxide 2 mol adduct, and titanium bistriethanolamine 1.0 as a condensation catalyst. The operation of putting in a part, pressurizing the inside of the reactor with nitrogen, and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 60 kPa at 150 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 90%. Then, the reaction was carried out under a reduced pressure of 1.8 kPa while gradually raising the temperature to 140 ° C., and the mixture was taken out when the reaction rate reached 99.8%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-10). The reaction rate of (a-10) was 99.8%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 1.80, and almost no coloring was observed.

Example 11
(Synthesis of polyester (a-11))
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 444 parts of adipic acid, 141 parts of ethylene glycol, 517 parts of a bisphenol A ethylene oxide 2 mol adduct, and titanium bistriethanolamine 1.0 as a condensation catalyst. The operation of putting in a part, pressurizing the inside of the reactor with nitrogen, and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a reduced pressure of 70 kPa at 150 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out under a reduced pressure of 0.4 kPa while gradually raising the temperature to 180 ° C., and the mixture was taken out when the reaction rate reached 99.8%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a-11). The reaction rate of (a-11) was 99.8%. No foreign matter was observed in the appearance of the polyester, and the ΔE of the DMF solution of the polyester was 1.52, and almost no coloring was observed.

Comparative Example 1
(Synthesis of polyester (a'-1))
690 parts of sebacic acid, 432 parts of 1,6-hexanediol and 1 part of titanium diisopropoxyditerephthalate are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and the inside of the reactor is pressurized with nitrogen. , The operation of returning to normal pressure was performed multiple times. Then, the reaction was carried out under a pressure of 100 kPa at 170 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out under a reduced pressure of 1.0 kPa while gradually raising the temperature to 200 ° C., and the mixture was taken out when the reaction rate reached 99.3%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a'-1). The reaction rate of (a'-1) was 99.3%. In the appearance of polyester, foreign matter that seems to be derived from the brown catalyst was confirmed. The reaction time also increased. The ΔE of the polyester DMF solution was 1.05, and almost no coloring was observed.

Comparative Example 2
(Synthesis of polyester (a'-2))
724 parts of dodecanedioic acid, 401 parts of 1,6-hexanediol and 1 part of titanium diisopropoxyditerephthalate were placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and the inside of the reactor was added with nitrogen. The operation of pressing and returning to normal pressure was performed multiple times. Then, the reaction was carried out under a pressure of 30.0 kPa at 210 ° C., and the reaction was carried out while distilling off the produced water until the reaction rate reached 85%. Then, the reaction was carried out at 210 ° C. under a reduced pressure of 1.0 kPa, and the mixture was taken out when the reaction rate reached 99.3%. The removed resin was cooled to room temperature and then pulverized into particles to obtain a crystalline polyester (a'-2). The reaction rate of (a'-2) was 99.3%. No foreign matter was found in the appearance of the polyester, but the ΔE of the DMF solution of the polyester was 5.60, and the coloration was clearly visible. Furthermore, the amount of the alcohol component (x) scattered increased to 5.6%.

The above implementation results are shown in Table 1. The polyesters of Examples 1 to 11 are excellent in quality because catalyst deactivation is suppressed, production efficiency is high, and there are few foreign substances and coloring derived from the catalyst. Further, since the amount of the alcohol component (x) scattered is suppressed, the process stability is also excellent.
On the other hand, the polyesters of Comparative Examples 1 and 2 are inferior in at least one evaluation result in terms of production efficiency, catalyst-derived foreign matter and coloring.

The polyester production method of the present invention is a method for producing a polyester resin having excellent production efficiency and excellent quality, and the obtained polyester resin is useful as a material for fibers, films, bottles, paints, toner binders and the like.

Claims (6)

A method for producing a polyester (A) in which an alcohol component (x) containing an aliphatic diol having 2 to 20 carbon atoms and a carboxylic acid component (y) are reacted by melt polymerization in the presence of a titanium-containing catalyst, at 120 ° C. After the first step (a) of reacting at a temperature of ~ 180 ° C. and 20 to 50 kPa until the reaction rate becomes 50% or more and 90% or less, and after the first step (a), the temperature of 140 ° C. to 240 ° C., 6 kPa or less. A method for producing a polyester, which comprises the second step (b) of reacting with. The method for producing a polyester according to claim 1, wherein the alcohol component (x) contains 70 to 100 mol% of an aliphatic diol having 2 to 20 carbon atoms. The method for producing a polyester according to claim 1 or 2, wherein the polyester (A) is a polyester containing a crystalline polyester. The method for producing a polyester according to any one of claims 1 to 3, wherein the tin content of the polyester (A) is 30 ppm or less in terms of tin element based on the weight of the polyester (A). The invention according to any one of claims 1 to 4, wherein the solubility parameter (SP value) of the mixture of the alcohol component (x) and the carboxylic acid component (y) is 10.5 to 15.5 (cal / cm ³ ) ^1/2. Polyester manufacturing method. The method for producing a polyester according to any one of claims 1 to 5, wherein in the second step (b), an esterification catalyst is added and reacted.