JP2017025155A - Manufacturing method of polycarbonate diol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of polycarbonate diol capable of obtaining the polycarbonate diol hardly being colored even during high temperature storage.SOLUTION: There is provided a manufacturing method of polycarbonate diol having a process of heat treating polycarbonate diol obtained by transesterification of a carbonate compound and a diol compound in a presence of a transesterification catalyst, a hydroxyl group-containing phosphorus compound with molar ratio of 0.5 to 8.0 based on the transesterification catalyst and water with molar ratio of 10 to 3000.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a polycarbonate diol.

  Polycarbonate diol is used as a raw material for polyurethane and the like. At this time, it is desired to stabilize the urethanization reaction. For example, Patent Document 1 proposes reducing urethanization reactivity by adding water to polycarbonate diol and heating. Patent Document 2 also includes a urethanization catalyst having a stable urethanization reactivity by adding a phosphorous acid triester to a polycarbonate diol containing a transesterification catalyst that has not been subjected to a deactivation treatment. A manufacturing method for obtaining a polycarbonate composition is disclosed. Furthermore, Patent Document 3 proposes that the effect of the transesterification catalyst on the urethanization reaction can be efficiently reduced by adding a phosphoric acid monoester to the aliphatic polycarbonate diol and subjecting it to heat treatment.

  Moreover, when using polycarbonate diol as raw materials, such as a polyurethane, if the raw material polycarbonate diol is colored, the polyurethane etc. which are manufactured from this polycarbonate diol will also be colored, and a use application will be restrict | limited. For this reason, it is desired that the polycarbonate diol has good chromaticity. Patent Document 4 proposes a method for producing a polycarbonate diol with little coloration and excellent thermal stability by transesterification with a transesterification catalyst in the presence of phosphoric acid and / or phosphorous acid. .

Japanese Patent Publication No. 6-53794 JP 2002-30143 A JP 2006-298986 A JP 2014-201738 A

  Polycarbonate diol is often a solid or viscous liquid at room temperature. Therefore, it may be stored at a high temperature in order to improve the handleability. In this case, there was a problem that even if the chromaticity of the polycarbonate diol immediately after production was good, the polycarbonate diol colored over time when stored at a high temperature. And also by the manufacturing method of the said patent documents 1-4, there was still room for improvement in coloring prevention at the time of high temperature storage.

  Then, an object of this invention is to provide the manufacturing method of polycarbonate diol which can obtain polycarbonate diol which is hard to color even at the time of high temperature storage.

  As a result of earnest research to solve the above-mentioned problems of the prior art, the present inventor has heat-treated polycarbonate diol obtained in the presence of a transesterification catalyst, and a predetermined range of hydroxyl group-containing phosphorus compound and water. It has been found that a polycarbonate diol which is difficult to be colored during high-temperature storage can be obtained by using a method for producing a polycarbonate diol having a heat treatment step to achieve the present invention.

That is, the configuration of the present invention is as follows.
[1]
A polycarbonate diol obtained by transesterifying a carbonate compound and a diol compound in the presence of a transesterification catalyst;
A hydroxyl group-containing phosphorus compound having a molar ratio of 0.5 to 8.0 with respect to the transesterification catalyst, water having a molar ratio of 10 to 3000,
A process for producing a polycarbonate diol, which comprises a step of heat-treating.
[2]
The method for producing a polycarbonate diol according to [1], wherein a moisture content in the polycarbonate diol is 20 ppm or more and 2000 ppm or less after the heat treatment step.
[3]
In the said heat processing process, the temperature of heat processing is 50 degreeC or more and 200 degrees C or less, The manufacturing method of polycarbonate diol as described in [1] or [2].
[4]
A polycarbonate diol obtained by transesterifying a carbonate compound and a diol compound in the presence of a transesterification catalyst;
A hydroxyl group-containing phosphorus compound having a molar ratio of 0.5 to 8.0 with respect to the transesterification catalyst, water having a molar ratio of 10 to 3000,
A method for preventing coloration of polycarbonate diol during high-temperature storage, comprising a step of heat-treating.

  According to the method for producing a polycarbonate diol according to the present invention, a polycarbonate diol which is difficult to be colored even at high temperature storage can be obtained.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with various modifications within the scope of the gist.

[Production method of polycarbonate diol]
In the method for producing a polycarbonate diol of this embodiment, the molar ratio of the polycarbonate diol obtained by subjecting a carbonate compound and a diol compound to a transesterification reaction in the presence of a transesterification catalyst and the transesterification catalyst is 0.5. There is a heat treatment step of heat-treating the hydroxyl group-containing phosphorus compound of 8.0 or less and water having a molar ratio of 10 or more and 3000 or less. According to the method for producing a polycarbonate diol of the present embodiment, a polycarbonate diol that is difficult to be colored even at high temperature storage can be obtained. Moreover, according to the manufacturing method of the polycarbonate diol of this embodiment, the chromaticity of the obtained polycarbonate diol may recover compared with the chromaticity of the polycarbonate diol before the said heat processing.

（式（Ａ）中、Ｒは、炭素数２〜１５の二価の脂肪族又は脂環族炭化水素を表す。） [Polycarbonate diol]
The polycarbonate diol of this embodiment has a repeating unit represented by the following formula (A) and hydroxyl groups at both ends of the polycarbonate diol.

(In the formula (A), R represents a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

  In the formula (A), R represents a divalent aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms, and one or more of these can be selected in all repeating units. In the formula (A), when R is a divalent aliphatic hydrocarbon having no side chain, the chemical resistance and mechanical strength of the resulting polyurethane tend to increase.

  The number average molecular weight of the polycarbonate diol of the present embodiment varies depending on its use, but is preferably 300 or more and 20000 or less, more preferably 400 or more and 10,000 or less, and further preferably 500 or more and 3000 or less. When the number average molecular weight is 300 or more, the resulting thermoplastic urethane tends to have better flexibility and low-temperature characteristics, and when the number average molecular weight is 20000 or less, the resulting thermoplastic urethane is molded. Tend to be better. The number average molecular weight can also be calculated from the hydroxyl value of the polycarbonate diol as in the method described in the examples described later.

[Transesterification]
In the transesterification reaction of the present embodiment, a polycarbonate diol is obtained by reacting a carbonate compound such as alkylene carbonate, dialkyl carbonate, or diaryl carbonate with a diol compound in the presence of a transesterification catalyst.

<Carbonate compound>
Examples of the carbonate compound include, but are not limited to, ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 1,2-pentylene carbonate. And alkylene carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate and dibutyl carbonate, and diaryl carbonates such as diphenyl carbonate. In this, alkylene carbonate is preferable and ethylene carbonate is more preferable.

<Diol compound>
Examples of the diol compound include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7- Diols having no side chain such as heptanediol, 1,8-octanediol, 1,9-nanodiol, 1,10-dodecanediol, 1,11-undecanediol, 1,12-dodecanediol; 2-methyl-1 , 8-octanediol, neopentyl glycol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1 Diol having a side chain such as 1,5-pentanediol, 2,4-diethyl-1,5-pentanediol; Cyclic diols such as rhohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2-bis (4-hydroxycyclohexyl) -propane; p-xylenediol, p-tetrachloroxylenediol, 1,4 Examples include diols having an aromatic ring such as bis (hydroxyethoxy) benzene and 2,2-bis [(4-hydroxyethoxy) phenyl] propane. Of these, diols having no side chain are preferred, and 1,5-pentanediol and 1,6-hexanediol are more preferred.

  The polycarbonate diol of this embodiment may be a homopolycarbonate diol obtained from one kind of diol compound or a copolymerized polycarbonate diol obtained from two or more kinds of diol compounds.

<Transesterification catalyst>
The transesterification catalyst of this embodiment is a catalyst for obtaining polycarbonate diol by transesterification. The transesterification catalyst can be freely selected from known transesterification catalysts. Examples of the transesterification catalyst include, but are not limited to, for example, alkali metals such as lithium, sodium, and potassium, and alkaline earth metals such as magnesium, calcium, strontium, and barium, hydrides, oxydo, amides, carbonates, Examples include hydroxides, nitrogen-containing borates, and basic alkali metal salts and alkaline earth metal salts of organic acids. Examples of transesterification catalysts using metals other than alkali metals and alkaline earth metals include aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, zirconium, and niobium. , Molybdenum, ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten, rhenium, osmium, iridium, platinum, gold, thallium, lead, bismuth, and ytterbium metals, salts, alkoxides, and organic compounds. . One or more transesterification catalysts can be selected and used from them. Among these, polycarbonate diols are obtained when one or more transesterification catalysts are used from metals, salts, alkoxides, and organic compounds of sodium, potassium, magnesium, potassium, titanium, zirconium, tin, lead, and ytterbium. The transesterification reaction is favorably performed, and the use of the obtained polycarbonate diol is preferable because it has little influence on the urethane reaction. More preferably, magnesium, titanium, ytterbium, tin, or zirconium is used as the transesterification catalyst. Specific examples of the transesterification catalyst include lead acetate trihydrate, which is an organic compound of lead, and titanium tetra-n-butoxide, which is an organic compound of titanium.

  The amount of the transesterification reaction catalyst used is preferably 0.00001% by mass or more and 0.1% by mass or less, and 0.0001% by mass or more and 0.05% by mass with respect to the total amount of raw materials (100% by mass). The following is more preferable.

  The transesterification catalyst used in the transesterification reaction is not consumed in the transesterification reaction when heat treatment is carried out subsequent to the production of the polycarbonate diol, and therefore can be calculated based on the amount of transesterification catalyst used. In the case of using a commercially available polycarbonate diol, the amount of metal in the transesterification catalyst contained in the polycarbonate diol is determined by measuring by ICP (Emission Spectroscopy, Inductively Coupled Plasma).

[Heat treatment process]
The heat treatment step of this embodiment is a step of heat-treating the polycarbonate diol obtained by the transesterification reaction, a predetermined amount of the hydroxyl group-containing phosphorus compound, and water. Hereinafter, a method of performing the heat treatment step following the transesterification will be described as an example. Based on the amount of transesterification catalyst charged in the transesterification reaction, polycarbonate diol having a predetermined degree of polymerization in the transesterification reaction is added to the reactor with a predetermined range of hydroxyl-containing phosphorus compound and water, and heated. Stir. If necessary, after cooling from the temperature at the end of the transesterification reaction to the temperature of the predetermined heat treatment, the hydroxyl group-containing phosphorus compound and water are added.

  In the heat treatment step, the temperature of the heat treatment is not particularly limited, but is preferably 50 ° C or higher and 200 ° C or lower, more preferably 50 ° C or higher and 160 ° C or lower, and 50 ° C or higher and 140 ° C or lower. Is more preferable. When the heat treatment temperature is 50 ° C. or higher, the heat treatment time is not excessively long and tends to be economically preferable. If heating temperature is 200 degrees C or less, since decomposition | disassembly of the polycarbonate diol by heat | fever is suppressed, it exists in a preferable tendency.

  The heat treatment time varies depending on the heat treatment temperature and the heat treatment method, but is preferably 15 minutes or more and 8.0 hours or less. When the heat treatment time is 15 minutes or longer, the reaction tends to proceed sufficiently. On the other hand, when the heat treatment time is 8.0 hours or less, the productivity tends to be good.

  In the heat treatment step, the polycarbonate diol may be colored. Therefore, it is preferable to replace the heat treatment container with an inert gas such as nitrogen. Although the processing method of this embodiment is not specifically limited, it may be heat-stirred in a reactor equipped with a heating device and a stirrer, or may be heat-treated continuously with an in-line mixer or a static mixer. Good.

<Hydroxyl-containing phosphorus compound>
The hydroxyl group-containing phosphorus compound of the present embodiment is not limited to the following, but examples thereof include phosphoric acids such as phosphoric acid, phosphorous acid, phosphonic acid, phosphonous acid, phosphinic acid, and phosphinic acid; monomethyl phosphate, phosphorus Phosphoric monoesters such as monoethyl phosphate, monobutyl phosphate, mono-2-ethylhexyl phosphate, monophenyl phosphate; phosphoric acids such as dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate, diphenyl phosphate Diesters; Phosphorous monoesters such as monooctyl phosphite and monophenyl phosphite; Sublimates such as diethyl phosphite, dipropyl phosphite, dibutyl phosphite, dioctyl phosphite and diphenyl phosphite Phosphoric acid diesters; phosphonic acids such as dibutylphosphonic acid, dioctylphosphonic acid, diphenylphosphonic acid; Phosphonate monoester such Honsan monobutyl; phosphinic acids such as phenyl phosphinic acid is preferably exemplified. More preferred are phosphoric acids, phosphoric monoesters, and phosphoric diesters, and further preferred are phosphoric acid, phosphorous acid, mono-2-ethylhexyl phosphate, and di-n-butyl phosphate.

  The hydroxyl group-containing phosphorus compound has a molar ratio to the transesterification catalyst of 0.5 or more and 8.0 or less, preferably 0.8 or more and 6.0 or less, more preferably 1.0 or more and 5.0 or less. is there.

<Water>
The water of this embodiment has a molar ratio with respect to the transesterification catalyst of 10 or more and 3000 or less, preferably 10 or more and 2000 or less, and more preferably 10 or more and 1000 or less.

  From the viewpoint of sufficiently exhibiting the effects according to this embodiment, the molar ratio of the hydroxyl group-containing phosphorus compound is 0.5 or more, and the molar ratio of water is 10 or more. Moreover, when manufacturing a polyurethane using the polycarbonate diol obtained after a heat processing process, the molar ratio of a hydroxyl-containing phosphorus compound is 8. from a viewpoint which prevents that a urethanation reaction is inhibited or accelerated too much. The molar ratio of water is 0 or less and 3000 or less.

  In the heat treatment step, a plurality of hydroxyl group-containing phosphorus compounds may be mixed and used at an arbitrary ratio. In that case, the sum of the molar ratios of the total hydroxyl group-containing phosphorus compound added to the transesterification catalyst may be in the above range.

  After the heat treatment step, the water content of the polycarbonate diol is preferably 20 ppm or more and 2000 ppm or less, more preferably 20 ppm or more and 1800 ppm or less, and further preferably 20 ppm or more and 1500 ppm or less. By containing 20 ppm or more of water, it tends to be difficult to color even during high-temperature storage. Moreover, if water is 2000 ppm or less, it exists in the tendency not to inhibit a urethanation reaction or to accelerate too much. The water content can be measured by the method described in Examples described later. Here, “ppm” is based on mass.

  The method for preventing coloration of the polycarbonate diol of this embodiment during high-temperature storage is based on a polycarbonate diol obtained by subjecting a carbonate compound and a diol compound to a transesterification reaction in the presence of a transesterification catalyst, and a molar amount relative to the transesterification catalyst. It has a heat treatment step of heat-treating a hydroxyl group-containing phosphorus compound having a ratio of 0.5 or more and 8.0 or less and water having a molar ratio of 10 or more and 3000 or less. According to the coloring prevention method at the time of high-temperature storage of the polycarbonate diol of this embodiment, it is possible to obtain a polycarbonate diol that is difficult to be colored even during high-temperature storage.

  Hereinafter, the present embodiment will be described more specifically with specific examples and comparative examples. However, the present embodiment is not limited to these examples and comparative examples unless they exceed the gist thereof. Absent. Evaluation and physical properties in Examples and Comparative Examples described later were evaluated and measured by the following methods.

(Evaluation) Chromaticity Using the polycarbonate diol obtained in the polymerization examples, examples and comparative examples as samples, the chromaticity of the polycarbonate diol was measured using the following apparatus and the light transmittance value of wavelength 430 nm and the wavelength of 550 nm It calculated | required with the following formula | equation from the value of the transmittance | permeability of light. It was confirmed that there were no bubbles during the measurement. Furthermore, the chromaticity of the sample after storing at 60 ° C. for 2 months was determined again (chromaticity after storage).
Apparatus: Product name “V-650” manufactured by JASCO JASCO Corporation
Cell: Glass 2 cm square cell chromaticity (%) = 10 ^{[log (A) -log (B)]} × 100
A: Value of transmittance of light having a wavelength of 430 nm (%)
B: Value of transmittance of light having a wavelength of 550 nm (%)
A chromaticity of less than 95% was evaluated as x (strong coloring), 95% or more and less than 96% was evaluated as Δ (slightly colored), and 96% or more was evaluated as ◯ (good chromaticity).

(Physical property 1) Water content Using the polycarbonate diol obtained in each of Examples and Comparative Examples as a sample, the water content of the polycarbonate diol was measured using the following apparatus.
Apparatus: Trade name “MKC-510N” manufactured by KEM Kyoto Electronics Industry Co., Ltd.
Catholyte: KEM Kyoto Electronics Co., Ltd. trade name “Chem Aqua Catholyte CGE”
Anolyte: Trade name “AQUAMICRON AKX” manufactured by Mitsubishi Chemical Corporation

(Physical Property 2) Hydroxyl Value Using the polycarbonate diol obtained in the polymerization example as a sample, the hydroxyl value of the polycarbonate diol was measured by the following method. Using a measuring flask, pyridine was added to 12.5 g of acetic anhydride to make 50 mL, and an acetylating reagent was prepared. The sample was accurately weighed in an amount of 2.5 to 5.0 g in a 100 mL eggplant flask. After adding 5 mL of acetylating reagent and 10 mL of toluene with a whole pipette, a condenser tube was attached, and the mixture was stirred and heated at 100 ° C. for 1 hr. Add 2.5 mL of distilled water with a whole pipette and stir for 10 min. After cooling for 2 to 3 min, 12.5 mL of ethanol was added, and after adding 2 to 3 drops of phenolphthalein as an indicator, titration was performed with 0.5 mol / L ethanolic potassium hydroxide. An acetylating reagent (5 mL), toluene (10 mL), and distilled water (2.5 mL) were placed in a 100 mL eggplant flask, heated and stirred for 10 minutes, and then titrated in the same manner (blank test).

Based on the above results, the hydroxyl value was calculated by the following formula (1).
Hydroxyl value (mg-KOH / g) = {(DC) × 28.05 × f} / E (1)
C: Sample titration (mL)
D: Titrate of blank test (mL)
E: Sample weight (g)
f: Factor of titrant

(Physical property 3) Number average molecular weight The number average molecular weight of polycarbonate diol is calculated using the following formula (2).
Number average molecular weight = 2 / (G × 10−3 / 56.11) (2)
G: Hydroxyl value (mg-KOH / g)

[Polymerization Example 1]
After charging 520 g of 1,6-hexanediol and 410 g of ethylene carbonate into a 2 L reactor equipped with a stirrer, 0.009 g of lead acetate trihydrate (molecular weight: 379) is added as a catalyst and filled with regular packing. Connected to the rectifying tower. The reactor was immersed in an oil bath at 210 ° C. and reacted for 20 hours at a reaction temperature of 170 ° C. while part of the distillate was extracted. Thereafter, the reactor was directly connected to a condenser, the temperature of the oil bath was lowered to 190 ° C., and the pressure was gradually lowered to further carry out the reaction for 8.0 hours. As a result, 517 g of polycarbonate diol which was a white solid at room temperature was obtained. It was. The hydroxyl value was measured and found to be 57.4. The obtained polycarbonate diol was dissolved at 80 ° C., and the chromaticity was determined to be 94.2%.

[Example 1]
The polycarbonate diol obtained in Polymerization Example 1 was dissolved at 80 ° C., and 250 g (48% by mass of the total amount obtained in Polymerization Example 1) was charged into a 500 mL container equipped with a stirrer. 0.0024 g of mono-2-ethylhexyl phosphate (molecular weight: 210) and 0.5000 g of water (molecular weight: 18) were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 185 ° C. and heat-treated at a temperature of 175 ° C. for 1.0 hr. The obtained polycarbonate diol was dissolved at 80 ° C., and the chromaticity and water content were determined. The determined chromaticity and water content are shown in Table 1.

[Example 2]
The polycarbonate diol obtained in Polymerization Example 1 was dissolved at 80 ° C., and 250 g (48% by mass of the total amount obtained in Polymerization Example 1) was charged into a 500 mL container equipped with a stirrer. 0.0097 g of mono-2-ethylhexyl phosphate and 0.0125 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 170 ° C. and heat-treated at a temperature of 155 ° C. for 3.0 hours. The obtained polycarbonate diol was dissolved at 80 ° C., and the chromaticity and water content were determined. The determined chromaticity and water content are shown in Table 1.

[Polymerization Example 2]
Using an apparatus similar to that used in Polymerization Example 1, 458 g of 1,5-pentanediol, 500 g of 1,6-hexanediol and 760 g of ethylene carbonate were charged, and then titanium tetra-n-butoxide (molecular weight: molecular weight: 340) was added in an amount of 0.0860 g. The reactor was immersed in an oil bath at 190 ° C. and reacted for 12 hours at a reaction temperature of 170 ° C. while part of the distillate was withdrawn. Thereafter, the reactor was directly connected to a condenser, the temperature of the oil bath was raised to 200 ° C., and the reaction was further carried out for 3.0 hours by gradually reducing the pressure. As a result, 910 g of a copolymerized polycarbonate diol that was liquid at room temperature was obtained. Obtained. The hydroxyl value was measured and found to be 56.3. When the chromaticity of the obtained polycarbonate diol was determined, it was 94.2%.

[Example 3]
200 g (22% by mass of the total amount obtained in Polymerization Example 2) was charged in a 500 mL container equipped with a stirrer with the polycarbonate diol obtained in Polymerization Example 2. 0.0093 g of di-n-butyl phosphate (molecular weight: 210) and 0.0200 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 130 ° C. and subjected to heat treatment at 120 ° C. for 6.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Example 4]
208 g of the polycarbonate diol obtained in Polymerization Example 2 (23% by mass of the total amount obtained in Polymerization Example 2) was charged into a 500 mL container equipped with a stirrer. 0.0115 g of phosphoric acid (molecular weight: 98) and 0.208 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in a 100 ° C. oil bath and heat treated at 95 ° C. for 5.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Example 5]
205 g (mass of 23% of the total amount obtained in Polymerization Example 2) was charged in a 500 mL container equipped with a stirrer with the polycarbonate diol obtained in Polymerization Example 2. 0.0143 g of phosphorous acid (molecular weight: 82) and 0.1435 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 120 ° C. and heat-treated at a temperature of 115 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Example 6]
130 g of the polycarbonate diol obtained in Polymerization Example 2 (14% by mass of the total amount obtained in Polymerization Example 2) was charged into a 500 mL container equipped with a stirrer. 0.0456 g of di-n-butyl phosphate and 0.1950 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 120 ° C. and heat treated at 115 ° C. for 1.0 hr. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Example 7]
130 g of the polycarbonate diol obtained in Polymerization Example 2 (14% by mass of the total amount obtained in Polymerization Example 2) was charged into a 500 mL container equipped with a stirrer. 0.0608 g of di-n-butyl phosphate and 0.0390 g of water were added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 150 ° C. and heat-treated at a temperature of 130 ° C. for 0.5 hr. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Polymerization Example 3]
Using an apparatus similar to that used in Polymerization Example 1, 458 g of 1,5-pentanediol, 500 g of 1,6-hexanediol, and 760 g of ethylene carbonate were added, and then titanium tetra-n-butoxide was added as a catalyst in an amount of 0. We put 0859g. The reactor was immersed in an oil bath at 190 ° C., and a reaction was carried out for 12 hours at a reaction temperature of 170 ° C. while extracting a part of the distillate. Thereafter, the reactor was directly connected to a condenser, and the temperature of the oil bath was raised to 200 ° C., followed by further reducing the pressure for 3 hours. As a result, 916 g of a copolymerized polycarbonate diol that was liquid at room temperature was obtained. It was. It was 56.1 when the hydroxyl value was measured. The chromaticity of the obtained polycarbonate diol was determined to be 94.8%.

[Comparative Example 1]
100 g of the polycarbonate diol obtained in Polymerization Example 3 was charged in a 500 mL container equipped with a stirrer (mass 11% of the total amount obtained in Polymerization Example 3). 0.0145 g of di-n-butyl phosphate was added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 120 ° C. and heat-treated at 115 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Comparative Example 2]
100 g of the polycarbonate diol obtained in Polymerization Example 3 was charged in a 500 mL container equipped with a stirrer (mass 11% of the total amount obtained in Polymerization Example 3). 0.1000 g of water was added, and the inside of the reactor was replaced with nitrogen. It was immersed in an oil bath at 110 ° C. and heat-treated at a temperature of 100 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Polymerization Example 4]
545 g of the polycarbonate diol obtained in Polymerization Example 3 was charged into a 1 L container equipped with a stirrer. After charging 54.7 g of 1,5-pentanediol and 61.9 g of 1,6-hexanediol, the reactor was immersed in an oil bath at 180 ° C., and the depolymerization was carried out at a reaction temperature of 165 ° C. for 20 min. 657 g of polycarbonate diol was obtained.
When the chromaticity of the obtained polycarbonate diol was determined, it was 94.5%.

[Comparative Example 3]
142 g of the polycarbonate diol obtained in Polymerization Example 4 was charged in a 500 mL container equipped with a stirrer (mass of 13% of the total amount obtained in Polymerization Example 3). 0.0207 g of di-n-butyl phosphate and 0.0284 g of water were added, and the inside of the reactor was replaced with nitrogen. It was treated for 8.0 hours without heating (at a temperature of 25 ° C.). The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Polymerization Example 5]
Using an apparatus similar to that used in Polymerization Example 1, 458 g of 1,5-pentanediol, 500 g of 1,6-hexanediol, and 760 g of ethylene carbonate were added, and then titanium tetra-n-butoxide was added as a catalyst in an amount of 0. We put 0859g. The reactor was immersed in an oil bath at 190 ° C., and a reaction was carried out for 12 hours at a reaction temperature of 165 ° C. while extracting a part of the distillate. Thereafter, the reactor was directly connected to a condenser, and the temperature of the oil bath was raised to 185 ° C., and then the pressure was gradually lowered and the reaction was further carried out for 3.0 hours. As a result, 915 g of copolymer polycarbonate diol that was liquid at room temperature was obtained. Obtained. When the hydroxyl value was measured, it was 56.0. When the chromaticity of the obtained polycarbonate diol was determined, it was 96.6%.

[Example 8]
200 g of the polycarbonate diol obtained in Polymerization Example 5 was charged into a 500 mL container equipped with a stirrer (mass of 22% of the total amount obtained in Polymerization Example 5). 0.0290 g of di-n-butyl phosphate and 0.0140 g of water were added, and the inside of the reactor was replaced with nitrogen. It was treated at 115 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Comparative Example 4]
200 g of the polycarbonate diol obtained in Polymerization Example 5 was charged into a 500 mL container equipped with a stirrer (mass of 22% of the total amount obtained in Polymerization Example 5). 0.0290 g of di-n-butoxide phosphate was added, and the inside of the reactor was replaced with nitrogen. It was treated at 115 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

[Comparative Example 5]
200 g of the polycarbonate diol obtained in Polymerization Example 5 was charged into a 500 mL container equipped with a stirrer (mass of 22% of the total amount obtained in Polymerization Example 5). 0.0140 g of water was added, and the inside of the reactor was replaced with nitrogen. It was treated at 115 ° C. for 3.0 hours. The chromaticity and water content of the obtained polycarbonate diol were determined. The determined chromaticity and water content are shown in Table 1.

  In Table 1, P represents a hydroxyl group-containing phosphorus compound, and M represents a transesterification catalyst.

  The polycarbonate diol produced by the method for producing polycarbonate diol according to the present invention is suitably used in the fields of polyurethane, thermoplastic elastomer, urethane elastic fiber and the like.

Claims (4)

A polycarbonate diol obtained by transesterifying a carbonate compound and a diol compound in the presence of a transesterification catalyst;
A hydroxyl group-containing phosphorus compound having a molar ratio of 0.5 to 8.0 with respect to the transesterification catalyst, water having a molar ratio of 10 to 3000,
A process for producing a polycarbonate diol, which comprises a step of heat-treating.   The manufacturing method of the polycarbonate diol of Claim 1 whose water content in the said polycarbonate diol is 20 ppm or more and 2000 ppm or less after the said heat processing process.   The manufacturing method of the polycarbonate diol of Claim 1 or 2 whose temperature of heat processing is 50 degreeC or more and 200 degrees C or less in the said heat processing process. A polycarbonate diol obtained by transesterifying a carbonate compound and a diol compound in the presence of a transesterification catalyst;
A hydroxyl group-containing phosphorus compound having a molar ratio of 0.5 to 8.0 with respect to the transesterification catalyst, water having a molar ratio of 10 to 3000,
A method for preventing coloration of polycarbonate diol during high-temperature storage, comprising a step of heat-treating.