JP5168938B2 - Polyester production method and polyester - Google Patents

Description

  The present invention relates to a method for producing a polyester excellent in color tone and thermal stability. More specifically, the generation of foreign substances due to the catalyst used during polymerization and mold contamination during molding are reduced, the polymer has better thermal stability and color tone than conventional products, and color tone deterioration at high temperature melting is dramatic. The present invention relates to an improved polyester production method.

  Polyester is used for various purposes because of its usefulness of functionality. Among them, polyethylene terephthalate, which is excellent in versatility and practicality, is used for, for example, clothing, materials, medical, film, fiber or bottle. Widely used as a molded product.

  In general, polyethylene terephthalate is produced from terephthalic acid or an ester-forming derivative thereof and ethylene glycol. However, in a commercial process for producing a high molecular weight polymer, an antimony compound is widely used as a polymerization catalyst. However, polymers containing antimony compounds have some undesirable properties as described below.

  For example, when a polymer obtained using an antimony catalyst is melt-spun into a fiber, it is known that an antimony catalyst residue is deposited around the die hole. As this deposition progresses, it becomes a cause of defects in the filament, so that it needs to be removed in a timely manner. The deposition of the antimony catalyst residue is considered to be due to the antimony compound in the polymer being transformed in the vicinity of the die and partially vaporizing and dissipating, and then a component mainly composed of antimony remains in the die. In addition, the antimony catalyst residue in the polymer tends to be relatively large particles, and it becomes a foreign substance, causing an increase in the filtration pressure of the filter during molding, causing yarn breakage during spinning or film tearing during film formation, etc. It has undesirable characteristics and contributes to a decrease in operability.

  In view of the above background, there is a demand for polyesters that do not contain antimony. Therefore, germanium compounds are known when the role of a polymerization catalyst is required for compounds other than antimony compounds, but germanium compounds are difficult to use for general purposes because they have a small reserve and rare value. Further, studies using a titanium compound as a polymerization catalyst have been actively conducted. Since the titanium compound has a higher catalytic activity than the antimony compound, a desired catalytic activity can be obtained with a small amount of addition, and generation of foreign particles and contamination of the base can be suppressed. However, when a titanium compound is used as a polymerization catalyst, side reactions such as a thermal decomposition reaction and an oxidative decomposition reaction are promoted due to its high activity, resulting in a problem that the thermal stability is deteriorated and the polymer is colored yellow.

  In order to solve this problem, studies using an aluminum compound as a polymerization catalyst have been actively conducted. Since the aluminum compound has higher catalytic activity than the antimony compound, the desired catalytic activity can be obtained with a small amount of addition, and generation of foreign particles and contamination of the base can be suppressed. However, when an aluminum compound is used as a polymerization catalyst, a side reaction such as a thermal decomposition reaction or an oxidative decomposition reaction is promoted due to its high activity, resulting in a problem that the thermal stability is deteriorated and the polymer is colored yellow. It is not preferable that the polymer is yellowish, for example, when polyester is used as the fiber, since the commercial value of the fiber for clothing is impaired.

  In order to solve this problem, studies have been made to improve the heat resistance and color tone of a polymer by adding a phosphorus compound together with an aluminum compound (Patent Document 1). This method suppresses the activity of aluminum that is too high by the phosphorus compound, and improves the heat resistance and color tone of the polymer. For example, in a polyester production method using an aluminum compound as a catalyst, a phosphinic acid compound, a phosphine oxide compound, a phosphonous acid compound, a phosphinic acid compound, or a phosphine compound is added as a phosphorus compound (Patent Document 2). ) Is clearly stated. However, when these methods are used, a certain improvement in the heat resistance of the polymer can be seen. However, when a certain amount or more of the phosphorus compound is added, the polymerization activity of the aluminum compound is too suppressed, and the target degree of polymerization is reached. Or the polymerization reaction time is delayed, resulting in a problem that the color tone of the polymer deteriorates.

Therefore, as a result of intensive studies on improving the above problems in the present invention, the object of the present invention can be achieved by adding a specific phosphorus compound in the process of producing a polyester using an aluminum compound as a polymerization catalyst. Obtained knowledge.
JP-A-11-228682 (Claims) JP 2001-253941 A (Claims)

  The object of the present invention is to solve the above-mentioned conventional problems, that is, the generation of foreign matters due to the catalyst and the mold contamination during molding are reduced, and the thermal stability and color tone of the polymer are remarkably superior to those of conventional products. It is providing the manufacturing method of polyester.

  The object of the present invention is obtained by esterifying or transesterifying a dicarboxylic acid or an ester-forming derivative thereof with a diol or an ester-forming derivative thereof, and then performing a polymerization reaction in the presence of an aluminum-based polymerization catalyst. In the method for producing a polyester, it can be achieved by a method for producing a polyester characterized by adding a phosphorus compound represented by the following formula 1 or formula 2.

(The formula 1, in Formula _2, R 1 to R ₄ each independently represents a hydrocarbon group having 1 to 20 carbon atoms.)

  In the method of obtaining a polyester by polymerizing in the presence of an aluminum-based polymerization catalyst according to the present invention, by adding the phosphorus compound represented by Formula 1 or Formula 2, the color tone and heat resistance are dramatically improved as compared with conventional products. Can be obtained. This polyester can solve problems such as deterioration in color tone, base stain, increased filtration pressure, and thread breakage in the production of molded articles for fibers, films and bottles.

  The polyester production method of the present invention is a method in which a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof are esterified or transesterified and then polymerized and synthesized.

  Specific examples of the polyester obtained by such a production method include polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalene dicarboxylate, polyethylene. -1,2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate and the like. The present invention is suitable for polyethylene terephthalate or polyester copolymers mainly containing ethylene terephthalate units, which are most commonly used.

  In the method for producing the polyester of the present invention, it is essential to add the phosphorus compound represented by the formula 1 or 2 as a phosphorus compound at an arbitrary time. In the method of obtaining polyester by polymerizing in the presence of an aluminum-based polymerization catalyst, the addition of the phosphorus compound represented by Formula 1 or Formula 2 surprisingly improves the color tone and heat resistance of the resulting polymer. Is done. The coloring of the polyester and the deterioration of the heat resistance are caused by a side reaction of polyester polymerization as specified in the saturated polyester resin handbook (Nikkan Kogyo Shimbun, first edition, pages 178 to 198). In the side reaction of this polyester, carbonyl oxygen is activated by a metal catalyst, and β hydrogen is extracted, thereby generating a vinyl end group component and an aldehyde component. As a result of such a side reaction, the polymer is colored yellow, and since an aldehyde component is generated, the main chain ester bond is cleaved, resulting in a polymer having poor heat resistance. In particular, when an aluminum compound is used as a polymerization catalyst, a side reaction due to heat is strongly activated, so that a large amount of vinyl end group components and aldehyde components are generated, resulting in a yellow colored polymer having poor heat resistance. In the conventional phosphorus compound, the activity of the aluminum catalyst is adjusted by appropriately interacting the phosphorus compound with the aluminum compound. However, it has been unavoidable that the conventional phosphorus compound decreases the polymerization activity as well as the side reaction activity of the aluminum compound. However, in the phosphorus compound represented by Formula 1 or Formula 2 of the present invention, only the side reaction activity can be suppressed to a very small value while sufficiently maintaining the polymerization activity of the aluminum compound. The mechanism of this effect is currently not fully understood, but this is essentially different from the effect of conventional phosphorus compounds on aluminum compounds, or at least well achieved with conventional phosphorus compounds. It was not possible.

  Among these, when a phosphorus compound represented by Formula 3 is used, it is preferably used in polymerization of polyester because the phosphorus compound has high heat resistance and hydrolysis resistance.

(In the above formula _3, R 5 to R ₇ each independently represents a hydrocarbon group having 1 to 10 carbon atoms, an integer of a + b + c = 0~5. )
Examples of the phosphorus compound represented by the above formula 3 include, for example, a compound having a = 2, b = 0, c = 0, R ₅ = tert-butyl group, R ₅ = 2,4-position, tetrakis (2,4- Di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, which is IRGAFOS P-EPQ (Ciba Specialty Chemicals) or Sandostab P-EPQ (Clariant). (Available from Japan).

  Among these, the phosphorus compound represented by Formula 4 is preferable because the color tone and heat resistance of the obtained polyester are particularly good.

(In the above formula _4, R 8 _{to R 10} each independently represents a hydrocarbon group having 1 to 10 carbon atoms.)
As a phosphorus compound represented by the above formula 4, tetrakis (2,4-di-t-butyl-5 is used as a compound of R ₈ = tert-butyl group, R ₉ = tert-butyl group, R ₁₀ = methyl group. -Methylphenyl) [1,1-biphenyl] -4,4'-diylbisphosphonite, and this compound is available as GSY-P101 (Osaki Kogyo Co., Ltd.). These compounds may be used alone or in combination.

  The phosphorus compound of the polyester of the present invention may be added alone or in a state dissolved or dispersed in a diol component such as ethylene glycol.

  In addition, the phosphorus compound which is not represented by Formula 1 or Formula 2 can also be used together as a phosphorus compound. For example, phosphoric acid, trimethyl phosphate, triphenyl phosphate, phosphoric acid compounds such as sodium phosphate, phosphonic acid, phenylphosphonic acid, (3,5-di-t-butyl-4-hydroxyphenyl) methylphosphonic acid diethyl Phosphonic acid compounds such as esters and ethyl diethylphosphonoacetate, phosphinic acid compounds such as hypophosphorous acid, phenylphosphinic acid and sodium hypophosphite, phosphine oxides such as trimethylphosphine oxide and triphenylphosphine oxide, Phosphorous acid compounds such as phosphoric acid, triphenyl phosphite and sodium phosphite, phosphonites such as phosphonous acid and phenylphosphonous acid, phosphinic acids such as phosphinic acid and diphenylphosphinic acid Compounds, phosphine, phosphine such as triphenylphosphine Emissions based compounds. Phosphorus compounds not represented by Formula 1 or Formula 2 can also be added at any point in the production process, and may be added alone or in a state dissolved or dispersed in a diol component such as ethylene glycol. May be. Moreover, you may mix with the phosphorus compound represented by Formula 1 or Formula 2, or may add simultaneously.

  In the method for producing the polyester of the present invention, the aluminum compound is preferably added so as to be 1 to 300 ppm in terms of aluminum atoms with respect to the obtained polymer. When it is 10 to 250 ppm, the thermal stability and color tone of the polymer become better, and it is more preferably 20 to 150 ppm. Moreover, it is preferable that the manufacturing method of the polyester of this invention adds the phosphorus compound represented by Formula 1 or Formula 2 with an aluminum compound so that it may become 1-500 ppm in conversion of a phosphorus atom with respect to polyester. The amount of phosphorus added is preferably from 3 to 250 ppm, more preferably from 10 to 100 ppm, from the viewpoints of thermal stability and color tone of polyester during yarn production and film formation. In addition, when the aluminum atom of the aluminum compound has a molar ratio of Al / P = 0.1 to 30 as the phosphorus atom in the phosphorus compound, the thermal stability and color tone of the polyester are preferable. More preferably, Al / P = 0.5-18, and still more preferably Al / P = 1.0-14.

  Addition of at least one selected from the group consisting of magnesium compounds, manganese compounds, calcium compounds, and cobalt compounds is preferable because the reaction activity and the color tone of the polymer are improved. It is preferable to add at least one selected from the group consisting of magnesium compounds, manganese compounds, calcium compounds, and cobalt compounds so that the total is 1 to 100 ppm in terms of atoms relative to the polyesters of magnesium, manganese, calcium, and cobalt. More preferably, it is 3-75 ppm, Most preferably, it is 5-50 ppm. At this time, the molar ratio (Mg + Mn + Ca + Co) / P of the total amount of magnesium, manganese, calcium and cobalt in terms of atoms and the phosphorus atom of the phosphorus compound is preferably 0.1 to 5 in terms of color tone and thermal stability. More preferably, it is 0.1-4, More preferably, it is 0.3-3. Particularly when the atomic conversion amount of magnesium to polyester is 5 to 25 ppm, and when the molar ratio Mg / P of the phosphorus atom of the phosphorus compound to the total of magnesium atom is 0.3 to 3, both the color tone and thermal stability are good. It is.

  Specific examples of the magnesium compound include magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, and magnesium carbonate. Specific examples of the manganese compound include manganese chloride, manganese bromide, manganese nitrate, manganese carbonate, manganese acetylacetonate, and manganese acetate. Specific examples of the calcium compound include calcium oxide, calcium hydroxide, calcium alkoxide, calcium acetate, and calcium carbonate. Specific examples of the cobalt compound include cobalt chloride, cobalt nitrate, cobalt carbonate, cobalt acetylacetonate, cobalt naphthenate, and cobalt acetate tetrahydrate. Among these, a magnesium compound is preferable in terms of color tone and polymerization activity, and magnesium acetate is particularly preferable.

  The aluminum compound of the polymerization catalyst of the present invention is preferably at least one selected from inorganic aluminum compounds, aluminum alcoholates, aluminum chelates, and carboxylic acid aluminum salts from the viewpoint of thermal stability and color tone of the polymer. For example, examples of the inorganic aluminum compound include aluminum hydroxide, aluminum chloride, and aluminum hydroxide chloride. Examples of the aluminum alcoholate include aluminum ethylate, aluminum isopropylate, aluminum tri-n-butylate, aluminum tri-sec-butyrate, Examples include aluminum tri-tert-butyrate, mono-sec-butoxyaluminum diisopropylate, and the aluminum chelates include ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum Monoacetyl acetate bis (ethyl acetoacetate), aluminum tris (acetylacetate) Examples include aluminum monoisopropoxymonooroxyethyl acetoacetate and aluminum acetylacetonate. Examples of the carboxylic acid aluminum salt include aluminum acetate, aluminum benzoate, aluminum lactate, aluminum laurate, and aluminum stearate. Aluminum compounds are preferred, and aluminum hydroxide is particularly preferred. These aluminum compounds may be used alone or in combination.

  The polymerization catalyst of the present invention is generally a series of reactions for synthesizing a polyester from a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. (1) A dicarboxylic acid component and a diol component An esterification reaction that is a reaction, or (2) an ester exchange reaction that is a reaction between an ester-forming derivative component of a dicarboxylic acid and a diol component, and (3) the ester reaction or transesterification reaction is substantially completed. In addition, it refers to a polymer having an effect that contributes to at least one of the polymerization reactions in which a low polymerization degree of polyethylene terephthalate is increased by a dediol reaction. Therefore, titanium oxide particles generally used as inorganic particles in fiber matting agents and the like have substantially no catalytic effect on the above reaction and can be used as the polymerization catalyst of the present invention. It differs from the aluminum compound that can be made.

  In the polyester production method of the present invention, the polymerization catalyst and additives may be added as they are to the polyester reaction system, but the compound contains a diol component that forms a polyester such as ethylene glycol or propylene glycol in advance. Is added to the reaction system after removing low-boiling components such as alcohol used at the time of synthesizing the compound, if necessary, and it is preferable because foreign matter formation in the polymer is further suppressed. The addition time includes a method of adding a catalyst immediately after the addition of the raw material as an esterification reaction catalyst or a transesterification reaction catalyst, and a method of adding the catalyst together with the raw material. When added as a polymerization reaction catalyst, it may be substantially before the start of the polymerization reaction, and may be added before the esterification reaction or transesterification reaction or after the completion of the reaction and before the start of the polymerization reaction catalyst. Good. The order of addition to the reaction system of at least one compound selected from the group consisting of aluminum compounds, phosphorus compounds, magnesium compounds, manganese compounds, calcium compounds, and cobalt compounds is not particularly limited. It is preferable to add to. By mixing the catalyst additive in advance, the thermal stability and the color tone can be improved, and the amount of carboxyl end groups can be suppressed. The above mixing conditions are carried out by stirring at a temperature of 0 to 200 ° C. for 1 minute or longer, preferably at a temperature of 10 to 100 ° C. for 5 minutes to 300 minutes. The reaction pressure at this time is not particularly limited, and may be normal pressure.

  In addition, in the polyester production method of the present invention, the addition of the phosphorus compound is performed after the polymerization catalyst is added and after the polymerization reaction is started by reducing the pressure in the reactor until the polymerization reaches the target degree of polymerization. By carrying out, a polyester having a good color tone and excellent heat resistance can be obtained. In the case of adding a phosphorus compound by the above method, if a large amount of a diol component such as ethylene glycol is brought in and added, depolymerization of the polyester (polyester main chain cleavage reaction) proceeds. A method of adding alone or adding a master pellet containing phosphorus at a high concentration is preferable. At this time, the phosphorus compound may be added in several portions, or may be continuously added with a feeder or the like. In addition, the above-mentioned method of adding a phosphorus compound is preferably added by filling a container made of a polymer having substantially the same component as the polymer obtained in the present invention, which can be dissolved or melted in the polymerization system. . When the phosphorus compound is added to the container as described above and added, the addition to the polymerization reactor under reduced pressure conditions can prevent the phosphorus compound from being scattered and flowing out to the reduced pressure line. At the same time, a desired amount of phosphorus compound can be added to the polymer. The container referred to in the present invention is not limited as long as it contains phosphorus compounds, and includes, for example, an injection-molded container having a lid or a stopper, or a sheet or film formed into a bag shape by sealing or sewing. More preferably, the container described above creates an air vent. When a phosphorus compound is added to a container that has been vented, even if it is added to the polymerization reactor under vacuum conditions, the container bursts due to air expansion and the phosphorus compound flows out to the decompression line, or the upper part of the polymerization reactor. The phosphorus compound can be added to the polymer in a desired amount without adhering to the wall surface. If the container is too thick, it takes longer to dissolve and melt, so it is better to make the container thinner. However, the container should be thick enough not to rupture when the phosphorus compound is sealed or added. For this purpose, a material having a thickness of 10 to 500 μm and uniform thickness is preferable. In particular, before starting depressurization in the polymerization reactor, the phosphorus compound is added to the obtained polyester in an amount of 0 to 50 ppm in terms of phosphorus atoms, and after the depressurization in the polymerization reactor is started, the polyester is the target. When the phosphorus compound is added in an amount of 10 to 500 ppm based on the polyester obtained until the degree of polymerization is reached, the color tone is particularly good and the polymerization delay can be extremely reduced.

  Moreover, in the manufacturing method of polyester of this invention, you may add a blue-type regulator and / or a red-type regulator as a color tone regulator.

  The color tone adjusting agent of the present invention is a dye used for a resin or the like. Specifically, in COLOR INDEX GENERIC NAME, blue color tone adjusting agents such as SOLVENT BLUE 104, SOLVENT BLUE 122, SOLVENT BLUE 45, SOLVENT RED 111, SOLVENT RED 179, SOLVENT RED 195, SOLVENT RED 135, PIGMENT RED 263, VAT RED 41, etc. Examples thereof include system color adjusting agents. Among them, SOLVENT BLUE 104, SOLVENT BLUE 45, SOLVENT RED 179, SOLVENT RED 195, SOLVENT RED 135, which do not contain halogen that tends to cause corrosion of equipment, have relatively good heat resistance at high temperatures and excellent color development, SOLVENT VIOLET 49 is preferably used.

  Further, one or more of these color tone adjusting agents can be used depending on the purpose. In particular, it is preferable to use one or more blue-type adjusting agents and red-type adjusting agents, since the color tone can be finely controlled. Furthermore, in this case, the color tone of the resulting polyester is particularly preferable when the ratio of the blue-based regulator is 50% by weight or more with respect to the total amount of the color-tone regulator to be added.

Finally, the content of the color tone adjusting agent with respect to the polyester is preferably 30 ppm or less in total.
The polyester obtained by the method for producing a polyester of the present invention preferably has an intrinsic viscosity (IV) of 0.4 to 1.0 dlg ⁻¹ when measured at 25 ° C. using orthochlorophenol as a solvent. More preferably from 0.5~0.8dlg ^-1, particularly preferably from 0.6~0.7dlg ^-1.

  Moreover, in order to improve the thermal stability which is the object of the present invention, the terminal carboxyl group concentration of the polyester is preferably in the range of 1 to 30 equivalents / ton. As the terminal carboxyl group concentration is lower, the thermal stability is improved, and the dirt adhering to the mold during molding and the dirt adhering to the die during yarn production are significantly reduced. When the terminal carboxyl group concentration exceeds 30 equivalents / ton, the effect of reducing dirt adhering to the mold or die may be reduced. The terminal carboxyl group concentration is preferably 25 equivalent / ton or less, particularly preferably 20 equivalent / ton or less.

  The polyester obtained by the method for producing a polyester of the present invention preferably has a diethylene glycol (DEG) content of 0.1 to 1.5% by weight with little mold contamination during molding. More preferably, it is 1.3 weight% or less, Most preferably, it is 1.1 weight% or less.

  Moreover, since the polyester obtained by the manufacturing method of the polyester of this invention is 1-15 ppm in content of acetaldehyde, since the bad influence to the flavor in a molded object and a fragrance is suppressed, it is preferable. More preferably, it is 13 ppm or less, Most preferably, it is 11 ppm or less.

  The color tone of the chip shape is a hunter value, and the L value is in the range of 60 to 95, the a value is in the range of -6 to 2, and the b value is in the range of -5 to 5. To preferred. More preferably, the L value ranges from 70 to 90, the a value ranges from -5 to 1, and the b value ranges from -3 to 3.

  The polyester obtained by the method for producing a polyester of the present invention was dried under reduced pressure at 150 ° C. for 12 hours and then increased in carboxyl end groups after being melted at 290 ° C. for 60 minutes in a nitrogen atmosphere. It is preferably in the range of tons. The smaller this value is, the higher the thermal stability is, and the dirt that adheres to the mold during molding and the dirt that adheres to the die during yarn production are reduced. Preferably it is 13 equivalent / ton or less, Most preferably, it is 8 equivalent / ton or less.

  The polyester obtained by the method for producing a polyester of the present invention was dried under reduced pressure at 150 ° C. for 12 hours, and after being melted at 290 ° C. for 60 minutes in a nitrogen atmosphere, the change in color tone b value Δb value 290 was −5 to 5 It is preferable that it is the range of these. The smaller this value, the less the decomposition and coloring due to thermal deterioration, and the better the thermal stability. Preferably it is 4 or less, particularly preferably 3 or less.

  The polyester obtained by the method for producing a polyester of the present invention is useful as a fiber by forming into a filament shape by, for example, melt extrusion molding or the like and then stretching or spinning.

  A method for producing the polyester of the present invention will be described. Although the example of a polyethylene terephthalate is described as a specific example, it is not limited to this.

  Polyethylene terephthalate is usually produced by one of the following processes.

  That is, (A) using terephthalic acid and ethylene glycol as raw materials, obtaining a low polymer by direct esterification reaction, and further obtaining a high molecular weight polymer by subsequent polymerization reaction, (B) using dimethyl terephthalate and ethylene glycol as raw materials, In this process, a low polymer is obtained by a transesterification reaction, and a high molecular weight polymer is obtained by a subsequent polymerization reaction. Here, the esterification reaction proceeds even without a catalyst, but the aforementioned aluminum compound may be added as a catalyst. In the transesterification reaction, a compound such as magnesium, manganese, calcium, cobalt, zinc, or lithium or the above-described aluminum compound is used as a catalyst, and after the transesterification reaction is substantially completed, it is used for the reaction. In order to inactivate the catalyst, the phosphorus compound is added.

  The polyester of the present invention is used as a polymerization catalyst in any stage of the series of reactions (A) or (B), preferably to the low polymer obtained in the first half of the series of reactions (A) or (B). After adding at least one compound selected from aluminum compounds, phosphorus compounds, magnesium compounds, manganese compounds, calcium compounds, and cobalt compounds, and, if necessary, titanium oxide particles and a color tone adjusting agent, a polymerization reaction is performed to obtain a high molecular weight. To obtain polyethylene terephthalate.

  Further, the above reaction can be applied to a batch, semi-batch, or continuous system.

  The color tone adjusting agent is preferably added to the polyester at any time after the esterification reaction or transesterification reaction is completed and until the polymerization reaction is completed. In particular, it is preferably added after completion of the esterification reaction or transesterification reaction and before the start of the polymerization reaction, because the dispersion in the polyester is good.

  It is also possible to add the color tone adjusting agent to the polyester after the polymerization reaction is substantially completed. In this case, a method of directly melting and kneading the color tone adjusting agent on the chip using a single screw or twin screw extruder, or preparing a polyester containing the color tone adjusting agent at a high concentration separately in advance, You may blend with the chip which does not contain.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the physical-property value in an Example was measured by the method described below.
(1) Intrinsic viscosity of polymer IV
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.
(2) Carboxyl terminal group amount of polymer The measurement was carried out by titrating with an automatic titrator (Hiranuma Sangyo Co., Ltd., COM-550) using orthocresol as a solvent and a 0.02 N aqueous NaOH solution at 25 ° C.
(3) Color tone of polymer Using a color difference meter (SM color computer model SM-T45, manufactured by Suga Test Instruments Co., Ltd.), it was measured as a Hunter value (L, a, b value).
(4) Diethylene glycol (DEG) content of polymer Using monoethanolamine as a solvent, a 1,6-hexanediol / methanol mixed solution was added, cooled, neutralized, centrifuged, and the supernatant was subjected to gas chromatography (Shimadzu). It was measured by Seisakusho Co., Ltd., GC-14A).
(5) Polymer acetaldehyde content Polyester and pure water were heated and extracted at 160 ° C. for 2 hours under a nitrogen seal, and the amount of acetaldehyde in the extract was gas chromatographed using isobutyl alcohol as an internal standard (“Shimadzu” GC-14A ").
(6) Δ carboxyl end group 290, Δb value 290
After the polyester was dried under reduced pressure at 150 ° C. for 12 hours and then heated and melted at 290 ° C. for 60 minutes in a nitrogen atmosphere, the amount of carboxyl end groups and the color tone were measured by the methods (2) and (3) and heated. Differences before and after melting were measured as Δ carboxyl end group 290 and Δb value 290, respectively.
(7) Observation of deposits in the die The amount of deposits around the die holes 72 hours after spinning of the fibers was observed using a long focus microscope. The state in which deposits were hardly recognized was judged as ◯, the state in which deposits were recognized but operable was judged as Δ, and the state in which deposits were found and yarn breakage frequently occurred was judged as ×.

Example 1
About 100 kg of bis (hydroxyethyl) terephthalate is charged in advance, 82.5 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals) and ethylene glycol are added to an esterification reaction tank maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 ⁵ Pa. (Made by Nippon Shokubai Co., Ltd.) 35.4 kg of slurry was sequentially supplied over 4 hours, and after completion of the supply, an esterification reaction was further carried out over 1 hour, and 101.5 kg of the obtained esterification reaction product was placed in a polymerization tank. Transferred.

To the esterification reaction product, 7.6 g of cobalt acetate (20 ppm in terms of cobalt atom relative to the polymer), 12.0 g of magnesium acetate (15 ppm in terms of magnesium atom relative to the polymer) ethylene glycol solution, and the polymer Aluminum hydroxide equivalent to 50 ppm in terms of aluminum atoms (manufactured by Kishida Chemical Co., Ltd.), tetrakis (2,4-di-t-butyl-5-methylphenyl) equivalent to 289 ppm (15 ppm in terms of phosphorus atoms) with respect to the polymer [1 , 1-biphenyl] -4,4′-diylbisphosphonite (Osaki Kogyo Co., Ltd., GSY-P101) 30 minutes before adding in a separate mixing tank and stirring at room temperature for 30 minutes The mixture was added. After 5 minutes, an ethylene glycol slurry of titanium oxide particles was added to the polymer in an amount of 0.3% by weight in terms of titanium oxide particles. After another 5 minutes, the reaction system was decompressed to initiate the reaction. The reactor was gradually heated from 250 ° C. to 290 ° C., and the pressure was reduced to 40 Pa. The time to reach the final temperature and final pressure was both 60 minutes. Thereafter, the phosphorus compound was formed by injection molding a polyethylene terephthalate sheet at the time when it reached 85% of the predetermined stirring torque (at the time of 2 hours and 30 minutes from the start of pressure reduction), and the content Tetrakis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4,4′- equivalent to 289 ppm (15 ppm in terms of phosphorus atom) with respect to the polymer in a 500 cm ³ container Diylbisphosphonite (Osaki Kogyo Co., Ltd., GSY-P101) was packed and added from the top of the reaction can. When a predetermined stirring torque was reached, the reaction system was purged with nitrogen and returned to normal pressure to stop the polymerization reaction, discharged in a strand form, cooled, and immediately cut to obtain polymer pellets. The time from the start of decompression to the arrival of the predetermined stirring torque was 2 hours and 45 minutes.

  The obtained polymer was excellent in color tone and heat resistance.

  The polyester was vacuum-dried at 150 ° C. for 12 hours, then subjected to a spinning machine, melted by a melter, discharged from the spinning pack portion, and taken up at a speed of 1000 m / min. In the melt spinning process, almost no deposits around the nozzle holes and no increase in filtration pressure were observed during spinning.

Examples 2-9
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the addition amounts of the magnesium compound, manganese compound, calcium compound, cobalt compound, and color tone modifier (Solvent Blue 104) were changed. In Example 9, although the color tone b value was slightly poor, the obtained polymer was excellent in color tone and thermal stability was also excellent. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 10-15
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the addition amounts of the aluminum compound and the magnesium compound were changed. In Example 15, the color tone was slightly poor, and in Examples 12, 13, and 15, the heat resistance was slightly poor, but it was at a level with no problem in terms of product. In other examples, both the color tone and heat resistance were good. Further, the deposit around the base hole and the increase in the filtration pressure during spinning were slightly contaminated and broken in Example 13, but at a level that does not interfere with the operation. In the other examples, almost no deposits around the nozzle holes and no increase in filtration pressure were observed during spinning.

Examples 16-18
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the addition amount of the phosphorus compound was changed. In Example 16, although the color tone and heat resistance were slightly poor, they were at a level with no problem on the product. In other examples, both the color tone and heat resistance were good. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 19-20
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the mixing time of the aluminum compound, cobalt compound, and magnesium compound was changed. The obtained polymer was excellent in color tone and excellent in thermal stability. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Example 21
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the aluminum compound, cobalt compound, and magnesium compound were not pre-mixed. In addition, the addition of an aluminum compound, a phosphorus compound, a cobalt compound, and a magnesium compound to the reaction system first adds the cobalt compound and the magnesium compound to the polymerization reaction tank after the esterification reaction product is transferred, and 5 minutes later. An aluminum compound was added. The obtained polymer was excellent in color tone and excellent in thermal stability. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 22-23
In Example 22, polyester was added in the same manner as in Example 1 except that a part of the phosphorus compound (amount corresponding to 5 ppm in terms of phosphorus atom with respect to the polymer) was added to the premixed aluminum compound, cobalt compound, and magnesium compound. Polymerized and melt spun. The remaining phosphorus compound (amount corresponding to 10 ppm in terms of phosphorus atom relative to the polymer) was added to the reaction system at the time when 85% of the predetermined stirring torque was reached (reduced pressure was reduced). 2 hours and 35 minutes after the start). Further, in Example 23, before starting the polymerization reaction, all phosphorus compounds (amount corresponding to 15 ppm in terms of phosphorus atoms with respect to the polymer) were added after being premixed with the aluminum compound, cobalt compound, and magnesium compound. The polyester was polymerized and melted in the same manner as in Example 1 except that no phosphorus compound was added after the polymerization reaction was started by reducing the pressure in the reactor until the polymerization reached the target degree of polymerization. Spinned.
The obtained polymer was excellent in color tone and excellent in thermal stability. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 24-25
Instead of tetrakis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, Example 24 uses tetrakis (2,2) as the phosphorus compound. 4-di-t-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite (manufactured by Ciba Specialty Chemicals, IRGAFOS P-EPQ). A polyester was polymerized and melt-spun in the same manner as in Example 1 except that bis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4-ylphosphonite was used as . The obtained polymer was excellent in color tone and excellent in thermal stability. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Example 26
In addition to tetrakis (2,4-di-t-butyl-5-methylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphonite, as a phosphorus compound, in terms of phosphorus atoms relative to the polymer Polyester was polymerized in the same manner as in Example 1 except that 15 ppm equivalent of (3,5-di-t-butyl-4-hydroxyphenyl) methylphosphonic acid diethyl ester (Ciba Specialty Chemicals, IRGANOX 1222) was used. And melt spun. The obtained polymer was excellent in color tone and excellent in thermal stability. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 27-29
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that aluminum isopropylate, aluminum tris (acetyl acetate), and aluminum lactate were used instead of aluminum hydroxide as the aluminum compound. In Example 29, although the heat resistance was somewhat poor, it was at a level that was not a problem at all on the product. In other examples, both the color tone and heat resistance were good. In addition, almost no deposits and increase in filtration pressure around the nozzle holes during spinning were observed.

Examples 30-31
Similar to Example 1 except that the setting of the predetermined agitation torque was changed (in Example 30, the intrinsic viscosity of the polyester obtained was lowered, and in Example 31, the intrinsic viscosity of the obtained polyester was increased). The polyester was polymerized and melt-spun. The obtained polyester had good color tone and heat resistance, and almost no deposits around the nozzle holes and no increase in filtration pressure were observed during spinning.

Comparative Example 1
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that no phosphorus compound was added. The color tone was strongly yellowish, and contained a lot of DEG and acetaldehyde, and was a polymer with poor heat resistance.

Comparative Examples 2 to 21
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that the phosphorus compound to be added was changed.

  In either case, the time until the predetermined stirring torque was reached was significantly increased, and the polymer was inferior in color. Further, the polymer was a polymer having a large Δ carboxyl end group 290 and Δb value 290 and inferior heat resistance.

Comparative Example 22
A polyester was polymerized and melt-spun in the same manner as in Example 1 except that antimony trioxide, an antimony compound, was added as a polymerization catalyst instead of the aluminum compound. Although the polymer had good time, polymer color tone and heat resistance until reaching a predetermined stirring torque, deposits were observed around the mouthpiece holes during melt spinning, and the filtration pressure increased and yarn breakage occurred.

Claims (7)

In a method for producing a polyester obtained by esterifying or transesterifying a dicarboxylic acid or an ester-forming derivative thereof with a diol or an ester-forming derivative thereof and then polymerizing in the presence of an aluminum-based polymerization catalyst, At least 1 sort (s) is added among the phosphorus compounds represented by following formula 1 or formula 2, The manufacturing method of polyester characterized by the above-mentioned.

(The formula 1, in Formula _2, R 1 to R ₄ each independently represents a hydrocarbon group having 1 to 20 carbon atoms.)   2. The polyester according to claim 1, wherein the molar ratio Al / P of the aluminum atom in the aluminum-based polymerization catalyst and the phosphorus atom in the phosphorus compound represented by Formula 1 or Formula 2 is 0.1-30. Production method.   At least one compound selected from the group consisting of a magnesium compound, a manganese compound, a calcium compound, and a cobalt compound is added, and the total in terms of atoms in the magnesium compound, the manganese compound, the calcium compound, and the cobalt compound and Formula 1 or Formula 2 3. The method for producing a polyester according to claim 1, wherein a molar ratio (Mg + Mn + Ca + Co) / P of a phosphorus atom in the represented phosphorus compound is 0.1 to 5. 5. The method for producing a polyester according to any one of claims 1 to 3, wherein the phosphorus compound represented by Formula 2 is a compound represented by Formula 3.

(In the above formula _3, R 5 to R ₇ each independently represents a hydrocarbon group having 1 to 10 carbon atoms, a + b + c is an integer of 0-5.) The method for producing a polyester according to any one of claims 1 to 3, wherein the phosphorus compound represented by formula 2 is a compound represented by formula 4.

(In the above formula _4, R 8 _{to R 10} each independently represents a hydrocarbon group having 1 to 10 carbon atoms.)   The aluminum-based polymerization catalyst contains at least one selected from the group consisting of inorganic aluminum compounds, aluminum alcoholates, aluminum chelates, and carboxylic acid aluminum salts, according to any one of claims 1 to 5. A method for producing polyester.   In the process for producing a polyester obtained by polymerizing a dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof in the presence of a polymerization catalyst, the compound represented by the formula 1 is used before starting the pressure reduction in the polymerization reactor. Alternatively, the phosphorus compound of formula 2 is added in an amount of 0 to 50 ppm in terms of phosphorus atoms with respect to the obtained polyester, and after the pressure reduction in the polymerization reactor is started, the polyester reaches the target degree of polymerization. The method for producing a polyester according to any one of claims 1 to 6, wherein the phosphorus compound of the formula 1 or the formula 2 is added in an amount of 10 to 500 ppm based on the obtained polyester.