JP2016020494A - Manufacturing method of polycarbonate diol-containing composition and polycarbonate diol-containing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially useful manufacturing method of a polycarbonate diol-containing composition capable of providing a polycarbonate diol-containing composition having reduced residual amount of by-products without adding an additive or the like during manufacturing of the polycarbonate diol-containing composition by polymerizing a dihydroxy compound containing 1,4-butanediol and a carbonate compound as raw materials by a transesterification.SOLUTION: There is provided a manufacturing method of a polycarbonate diol-containing composition having a process of polymerizing a dihydroxy compound containing 1,4-butanediol and a carbonate compound as raw materials by transesterification in a reaction vessel equipped with a stirring device and a wing circumferential speed in the reaction is 0.3 to 10 m/s.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a polycarbonate diol-containing composition having a step of obtaining a polycarbonate diol by polymerizing a raw material dihydroxy compound and a carbonate compound by a transesterification reaction. A polycarbonate diol-containing composition comprising a step of polymerizing a dihydroxy compound containing butanediol and a carbonate compound by a transesterification reaction in a reactor having a stirring blade to obtain a polycarbonate diol-containing composition having a reduced residual amount of by-products And a polycarbonate diol-containing composition in which the residual amount of tetrahydrofuran (hereinafter sometimes abbreviated as THF) is reduced.

  Conventionally, it is known to produce a polycarbonate diol-containing composition by polymerizing a dihydroxy compound and a carbonate compound by a transesterification reaction. Industrially produced polycarbonate diol-containing compositions include polycarbonate diol-containing compositions using a dihydroxy compound containing 1,4-butanediol as the raw dihydroxy compound, and these polycarbonate diol-containing compositions are Generally, it is used as a raw material for polyurethane and polyurethane acrylate.

  When a polycarbonate diol-containing composition is polymerized by a transesterification reaction using a dihydroxy compound containing 1,4-butanediol as a raw material, dehydration cyclization of 1,4-butanediol and terminal units of the obtained polycarbonate diol It is known that by-carbonation of THF causes by-production of THF. There was a problem that the productivity of the polycarbonate diol-containing composition deteriorated as the amount of THF by-produced at this time increased.

In addition, when polyurethane or polyurethane acrylate is produced, if THF remains in the raw material polycarbonate diol-containing composition, the polyurethane solution used for coatings and the like also contains THF. There was also a problem that the adverse effect of.
In order to avoid these problems, various methods for reducing the amount of THF produced as a by-product in the production of a polycarbonate diol-containing composition using a dihydroxy compound containing 1,4-butanediol as a raw material have been conventionally used. Has been studied.

  For example, Patent Literature 1 and Patent Literature 2 describe a method for producing polytetramethylene carbonate diol using butanediol as a raw material and a method for producing thermoplastic polyurethane using polytetramethylene carbonate diol obtained using butanediol. However, in these patent documents, it is described that the generation of by-product THF is suppressed by adding a phosphate ester or an acidic compound when synthesizing polytetramethylene carbonate diol. .

  Patent Document 3 describes a method for producing a copolycarbonate diol mainly composed of 1,4-butanediol and a polyurethane resin. Patent Document 3 discloses a fat containing 1,4-butanediol as a raw material. In the production of copolycarbonate diol using a group glycol, it is described that the generation of by-product THF is suppressed by adding a compound having a 3,5-di-tert-butyl-4-hydroxyphenyl skeleton. .

Patent Document 4 discloses that by-product THF in a polycarbonate diol obtained by setting the temperature of a transesterification reaction to 90 to 175 ° C. when producing a polycarbonate diol having a tetramethylene group as a repeating unit using dialkyl carbonate. It is described that the content of can be reduced.
By the way, although patent document 5 is different from a polycarbonate diol containing composition, it describes about the manufacturing method of aromatic polycarbonate, and when superposing | polymerizing aromatic polycarbonate in the reaction apparatus provided with a stirring apparatus, per unit volume is described. A method is described in which the surface renewability at the gas-liquid interface is improved by controlling the stirring power and the by-product phenol (PHL) is efficiently removed.

Further, in Patent Document 6, although different from the polycarbonate diol-containing composition, 1,4-
A method is described in which when a polyester is polymerized using butanediol as a raw material, a by-product reaction of THF is suppressed by controlling a reaction temperature and a peripheral speed of a stirring blade.

Japanese Patent No. 3704137 Japanese Patent No. 3859241 Japanese Patent No. 4605491 JP 2010-126591 A JP 2008-50591 A JP 2005-194519 A

In the methods described in Patent Documents 1 to 3, since the additive for suppressing generation of by-product THF added during the transesterification reaction remains in the obtained polycarbonate diol-containing composition, the polycarbonate diol-containing composition When polyurethane is polymerized using this, there is a problem that the reactivity and the physical properties of the polyurethane are affected.
In the method described in Patent Document 4, there is no problem due to the additive remaining in the obtained polycarbonate diol-containing composition, but when the polycarbonate diol-containing composition is produced on an industrial scale, the reaction time is 20 hours. Since it is long, the production efficiency is poor and the minimum pressure is as high as 13.3 kPa, so that the residual amount of by-product THF in the obtained polycarbonate diol-containing composition cannot be sufficiently reduced.

  When the method described in Patent Document 5 is applied to a method for producing a polycarbonate diol-containing composition, by-products to be removed are different between PHL and THF, and reaction conditions are different. The by-product THF content in the resulting polycarbonate diol-containing composition cannot be removed during the reaction so that it can be reduced to a desired amount, and conversely, the by-product formation of THF and the resulting polycarbonate diol-containing composition are obtained. There was a risk of excessive increase in the molecular weight of the polycarbonate diol and by-product of terminal structure other than hydroxyl group.

  Regarding Patent Document 6, the by-product mechanism of THF is different between polyester and polycarbonate diol, and when the terminal unit is removed as THF in polyester, the terminal becomes a carboxyl group, so the by-product of THF does not proceed any further. On the other hand, in the polycarbonate diol, THF proceeds by decarboxylation cyclization, and thus the terminal has a structure derived from a dihydroxy compound even after THF is eliminated, and by-product of THF can proceed continuously. That is, THF is more likely to be a by-product of polycarbonate diol than polyester, and even if the technique described in Patent Document 6 is applied to a polycarbonate diol-containing composition, the content of THF in the resulting polycarbonate diol-containing composition is suppressed. It seems more difficult to do.

  The present invention has been made in view of the problems that could not be solved by the above-described prior art, and a dihydroxy compound containing 1,4-butanediol as a raw material and a carbonate compound were subjected to a transesterification reaction in a reactor having a stirring blade. When producing a polycarbonate diol-containing composition by polymerization, an industrially advantageous polycarbonate diol-containing composition capable of obtaining a polycarbonate diol-containing composition with a reduced amount of by-products without adding additives or the like. An object of the present invention is to provide a polycarbonate diol-containing composition having excellent quality and a method for producing a product.

  As a result of intensive studies to solve the above problems, the present inventors have determined the shape of the reactor for performing the transesterification reaction, the rate at which byproduct THF generated in the reaction system flows out of the reaction system, Paying attention to the relationship between the rate of production of raw THF, and the by-product THF is scattered from near the reactor liquid level and distills out of the system, the shape of the stirring blade attached to the stirring device, the rotational speed, etc. It was found that there was a correlation between the rate of distillation of THF out of the reaction system. And, if the blade peripheral speed of the stirring device provided in the reactor is a certain amount, the residual amount of by-product THF in the product polycarbonate diol-containing composition is small, and the environmental load and health load of polyurethane are reduced. It has been found that a low polycarbonate diol-containing composition can be obtained and that it is an industrially advantageous production method from the viewpoint of operating cost, and the present invention has been completed.

That is, the gist of the present invention resides in the following [1] to [5].
[1] A method for producing a polycarbonate diol-containing composition comprising a step of polymerizing a dihydroxy compound containing 1,4-butanediol and a carbonate compound by a transesterification reaction in a reactor equipped with a stirrer to obtain a polycarbonate diol. A method for producing a polycarbonate diol-containing composition, wherein the peripheral speed of the stirring blade of the stirring device of the reactor during the transesterification reaction is 0.3 to 10 m / s.

[2] The method for producing a polycarbonate diol-containing composition according to [1], wherein the transesterification reaction temperature is 200 ° C. or lower.
[3] The method for producing a polycarbonate diol composition according to [1] or [2], wherein the carbonate compound contains diaryl carbonate.
[4] A polycarbonate diol-containing composition comprising a polycarbonate diol containing a structural unit represented by the following general formula (1) and having a number average molecular weight of 250 or more and 5500 or less, comprising tetrahydrofuran, A polycarbonate diol-containing composition, wherein the content of the tetrahydrofuran with respect to the content is 10 wtppm or more and 200 wtppm or less.

  [5] The polycarbonate diol-containing composition according to [4], wherein 99% or more of the terminal structure of the polycarbonate diol is a hydroxyl group, and the hydroxyl value is 20 to 230 mg-KOH / g or less.

According to the present invention, a polycarbonate diol in which the residual amount of THF is suppressed by controlling stirring during the reaction without requiring an additive that may affect the polymerizability and physical properties of the polyurethane. The containing composition can be advantageously produced industrially and economically.
In addition, if a polycarbonate diol-containing composition with a low residual amount of THF produced by the production method of the present invention is used, provision of products such as polyurethane and polyurethane acrylate with a low environmental and health burden can be expected.

It is a graph which shows transition of the residual amount of tetrahydrofuran in the polycarbonate diol containing composition with respect to the stirring time in manufacture of the polycarbonate diol containing composition of Example 4 and Comparative Example 3 of this invention.

Hereinafter, although the form of this invention is demonstrated in detail, this invention is not limited to the following embodiment, Various deformation | transformation can be implemented within the range of the summary.
<Dihydroxy compound>
In the method for producing a polycarbonate diol-containing composition of the present invention, the dihydroxy compound as a raw material is a dihydroxy compound containing 1,4-butanediol, but may contain a dihydroxy compound other than 1,4-butanediol. For example, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,3-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3 -Methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecane Diol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-eicosanediol, cyclohexanediol, cyclohexane Examples include dimethanol and isosorbide. Among these, 1,3-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, cyclohexanedimethanol, and isosorbide are preferably contained together with 1,4-butanediol. Neopentyl glycol, 1,10-decanediol 1,12-dodecanediol and isosorbide are particularly preferable. Dihydroxy compounds other than 1,4-butanediol may be contained alone or in combination of two or more. Further, the proportion of 1,4-butanediol contained in the raw material of all dihydroxy compounds is not particularly limited, but is preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably. Is 95 mol% or more.

<Carbonate compound>
In the method for producing a polycarbonate diol-containing composition of the present invention, examples of the carbonate compound used as a raw material include dialkyl carbonate, alkylene carbonate, and diaryl carbonate. Among these, it is preferable that diaryl carbonate is included from a reactive viewpoint.

Specific examples of the carbonate compound that can be preferably used in the method for producing the polycarbonate diol-containing composition of the present invention include dimethyl carbonate, diethyl carbonate, ethylene carbonate, and diphenyl carbonate, and diphenyl carbonate is particularly preferable.
<Use ratio of raw materials>
In the method for producing a polycarbonate diol-containing composition of the present invention, the amount of the carbonate compound used is not particularly limited, but is usually a molar ratio with respect to 1 mol of the total of dihydroxy compounds, and the lower limit is preferably 0.75, more preferably 0.00. 80, more preferably 0.84, and the upper limit is preferably 1.00, more preferably 0.98, and still more preferably 0.97. If the amount of carbonate compound used exceeds the above upper limit, the proportion of the polycarbonate diol end groups that are not hydroxyl groups may increase or the molecular weight may not fall within a predetermined range. If the amount is lower than the lower limit, polymerization may occur up to a predetermined molecular weight. May not progress.

<Transesterification catalyst>
In the manufacturing method of the polycarbonate diol containing composition of this invention, it can manufacture by polycondensing a dihydroxy compound and a carbonate compound by transesterification.
As the transesterification catalyst, any compound that is generally considered to have transesterification ability can be used without limitation.

  Examples of the transesterification catalyst include lithium, sodium, potassium, rubidium, cesium and other periodic table long periodic table (hereinafter simply referred to as “periodic table”) Group 1 metal compounds; magnesium, calcium, strontium, Compounds of Group 2 metals of the periodic table such as barium; compounds of Group 4 metals of the periodic table such as titanium and zirconium; compounds of Group 5 metals of the periodic table such as hafnium; compounds of Group 9 metals of the periodic table such as cobalt; Periodic Table Group 12 metal compounds such as zinc; Periodic Table Group 13 metal compounds such as aluminum; Periodic Table Group 14 metal compounds such as germanium, tin and lead; Periodic Table Group 15 such as antimony and bismuth Metal compounds; lanthanide metal compounds such as lanthanum, cerium, europium, ytterbium and the like. Among these, from the viewpoint of increasing the transesterification reaction rate, compounds of Group 1 metal of the periodic table, compounds of Group 2 metal of the periodic table, compounds of Group 4 metal of the periodic table, compounds of Group 5 metal of the periodic table, Periodic table Group 9 metal compound, Periodic table Group 12 metal compound, Periodic table Group 13 metal compound, Periodic table Group 14 metal compound are preferred, Periodic table Group 1 metal compound, Periodic table A compound of Group 2 metal is more preferable, and a compound of Group 2 metal of the periodic table is more preferable. Among the compounds of Group 1 metals of the periodic table, lithium, potassium, and sodium compounds are preferable, lithium and sodium compounds are more preferable, and sodium compounds are more preferable. Among the compounds of Group 2 metals of the periodic table, magnesium, calcium and barium compounds are preferred, calcium and magnesium compounds are more preferred, and magnesium compounds are more preferred. These metal compounds are mainly used as hydroxides and salts. Examples of salts when used as a salt include halide salts such as chloride, bromide and iodide; carboxylates such as acetate, formate and benzoate; methanesulfonic acid, toluenesulfonic acid and trifluoro Examples thereof include sulfonates such as romethanesulfonic acid; phosphorus-containing salts such as phosphates, hydrogen phosphates, and dihydrogen phosphates; acetylacetonate salts. The catalyst metal can also be used as an alkoxide such as methoxide or ethoxide.

  Among these, preferably, acetate, nitrate, sulfate, carbonate, phosphate, hydroxide, halide, alkoxide of at least one metal selected from Group 2 metals of the periodic table is used, More preferred are group 2 metal acetates, carbonates, and hydroxides of the periodic table, more preferred are magnesium, calcium acetates, carbonates, and hydroxides, and particularly preferred are magnesium and calcium. Acetate is used, most preferably magnesium acetate.

<Reaction temperature>
In the method for producing a polycarbonate diol-containing composition of the present invention, the reaction temperature for the transesterification reaction is preferably 200 ° C. or lower. The reason for this is that deterioration of the color tone of polycarbonate diol, allyl terminal by-product and THF by-product can be suppressed. Moreover, More preferably, it is 190 degrees C or less, More preferably, it is 180 degrees C or less. On the other hand, the lower limit of the reaction temperature is 130 ° C. or higher, preferably 140 ° C. or higher, and more preferably 150 ° C. or higher. If the reaction temperature is too low, the residual amount of byproducts derived from carbonates such as phenol and methanol tends to increase, and polymerization does not proceed to a predetermined molecular weight.

<Reaction pressure>
In the method for producing a polycarbonate diol-containing composition of the present invention, the minimum reaction pressure during the transesterification reaction is not particularly limited, but is usually 1.0 kPa or less, preferably 0.5 kPa or less. On the other hand, the lower limit of the reaction pressure is 0.01 kPa or more, preferably 0.02 kPa or more, and more preferably 0.03 kPa or more. As the reaction pressure is lowered, the reaction time is shortened, and the color tone of the resulting polycarbonate diol-containing composition tends to be suppressed. As the reaction pressure is increased, the polymerization rate is stabilized and the distillation of raw materials is suppressed. For example, the molecular weight of the polycarbonate diol tends to be easily controlled.

<Reaction time>
In the method for producing a polycarbonate diol-containing composition of the present invention, the reaction time for the transesterification reaction is not particularly limited, but is usually 12 hours or less, preferably 10 hours or less, more preferably 8 hours or less. It is. On the other hand, the lower limit of the reaction time is 0.5 hours or longer, preferably 1 hour or longer, and more preferably 1.5 hours or longer. As the reaction time becomes longer, the residual amount of byproducts derived from carbonates such as phenol and methanol tends to be reduced, and as the reaction time becomes shorter, the deterioration of the color tone of the resulting polycarbonate diol-containing composition tends to be suppressed. is there.

<Reactor>
In the method for producing a polycarbonate diol-containing composition of the present invention, the shape of the reactor used for the transesterification reaction is not particularly limited, but reactors such as a tank type, a tube type, and a column type can be used. The polymerization reaction can be carried out batchwise or continuously. In the present invention, the polymerization reaction is preferably carried out continuously from the standpoint of product stability.

<Shape of stirring blade and stirring speed>
In the method for producing a polycarbonate diol-containing composition of the present invention, the reactor used for the transesterification reaction includes a stirrer, but the shape of the stirrer blade having the stirrer is not particularly limited, but is preferably a propeller blade or a turbine blade. , Paddle wing, anchor wing, ribbon wing, log bone (registered trademark) wing and the like can be used, and paddle wing, anchor wing and log bone (registered trademark) wing are more preferable.

  In the method for producing a polycarbonate diol-containing composition of the present invention, during the transesterification reaction, the polymerization reaction is performed while stirring the stirring blades of the above stirring device, but the stirring speed correlates with the size and shape of the reactor. In the present invention, it is preferably 30 to 250 rpm. In addition, as a more preferable stirring speed, it is 50-200 rpm, More preferably, it is 70-180 rpm. As the stirring speed increases, the efficiency of distilling off byproducts such as THF tends to improve, and as the stirring speed decreases, the power of the stirrer can be reduced, so the power cost tends to be reduced.

Moreover, in the manufacturing method of the polycarbonate diol containing composition of this invention, it is preferable that the stirring power per unit volume is 0.01-5 kW / m < ³ > in this invention. In addition, as a more preferable stirring speed, it is 0.025-4kW / m < ³ >, More preferably, it is 0.05-3kW / m < ³ >. As the stirring power per unit volume increases, the efficiency of distilling out by-products such as THF tends to improve, and as the stirring power decreases, the power of the stirring device can be reduced, so that the power cost tends to be reduced. Here, the “stirring power per unit volume” means that the net stirring power (P) for stirring the polymerization reaction liquid charged in the reactor equipped with the stirring blades was charged in the reactor. It means the value (P / V) divided by the volume (V) of the polymerization reaction solution. The net stirring power (P) is the stirring power value under the same operating condition in the absence of the polymerization reaction liquid from the stirring power value (P1) when the polymerization reaction liquid is in the operating state. It means a value obtained by subtracting (P0).

In the method for producing a polycarbonate diol-containing composition of the present invention, the blade peripheral speed of the stirring device during the reaction is 0.3 to 10 m / s. The blade peripheral speed in the present invention is the tip speed of the stirring blade, and is a numerical value calculated by the following formula (a).
Blade peripheral speed (tip speed of stirring blade) = π × D × N ÷ 60 (a)
(D: Blade diameter (m), N: Number of revolutions (rpm))
The higher this value, the lower the content of by-product THF in the polycarbonate diol-containing composition obtained by polymerization. On the other hand, the lower this value is, the smaller the power required for the agitator is, so there is an advantage that the power cost can be reduced. The blade peripheral speed is 0.3 to 10 m / s, preferably 0.4 to 8 m / s, more preferably 0.5 to 5 m / s, and particularly preferably 0.6 to 3 m. / S.

  In the method for producing a polycarbonate diol-containing composition of the present invention, in order to reduce the content of by-product THF, the overall transfer substance capacity coefficient (hereinafter sometimes abbreviated as kLa) may be increased. preferable. kLa can be expressed by the stirring power per unit volume (P / V), the volume (V) of the polymerization reaction solution charged in the reactor, and the surface area (S) of the polymerization reaction solution charged in the reactor. .

kLa = A / V × (P / V) ^0.25
(A: surface area (m ² ), V: volume (m ³ ), P: stirring power (kW))
The higher the kLa, the lower the content of by-product THF in the polycarbonate diol-containing composition obtained by polymerization. On the other hand, the lower the kLa, the lower the power required for the stirrer. kLa is usually 1 to 100, preferably 5 to 80, more preferably 10 to 75, still more preferably 20 to 70, and particularly preferably 30 to 60. In the calculation of kLa in the examples described later, the surface area of A uses the volume of V as the surface area and volume of the polymerization reaction liquid remaining at the end of the reaction, and the stirring power of P determines the stirring power during the polymerization reaction. Power values were used.

<Viscosity>
In the method for producing a polycarbonate diol-containing composition of the present invention, the viscosity of a reaction product (including polycarbonate diol) at 80 ° C. is preferably 100 to 40000 mPa · s, more preferably 200 to 30000 mPa · s. More preferably, it is 400-20000 mPa · s. Higher viscosity tends to improve physical properties such as tensile strength when polyurethane is used, and lower viscosity tends to be superior in handling properties when used for synthesis of polyurethane and the like. The viscosity of the polycarbonate diol-containing composition can be measured by using an E-type viscometer (Cone: CPE-52) after the polycarbonate diol-containing composition is heated to 80 ° C. and melted.

  In the production of the polycarbonate diol-containing composition of the present invention, a transesterification catalyst (hereinafter sometimes referred to as “catalyst”) can be used to promote the transesterification reaction. In that case, if an excessive amount of catalyst remains in the obtained polycarbonate diol-containing composition, the reaction is inhibited or excessively promoted when a polyurethane is produced using the polycarbonate diol-containing composition. Sometimes.

For this reason, the amount of catalyst remaining in the polycarbonate diol-containing composition is not particularly limited, but is preferably 100 ppm or less, more preferably 50 ppm or less, and still more preferably 10 ppm or less as the content in terms of catalyst metal.
As the transesterification catalyst, any compound that is generally considered to have transesterification ability can be used without limitation.

<Catalyst deactivator>
As described above, when a catalyst is used in the transesterification reaction, the catalyst may remain in the usually obtained polycarbonate diol-containing composition, and the polyurethane formation reaction may not be controlled by the remaining catalyst. In order to suppress the influence of the remaining catalyst, it is preferable to add a substantially equimolar amount of, for example, a phosphorus compound or the like to the transesterification catalyst used to inactivate the transesterification catalyst. Further, after the addition, the transesterification catalyst can be efficiently inactivated by heat treatment or the like as described later.

Examples of phosphorus compounds used for inactivating the transesterification catalyst include inorganic phosphoric acid such as phosphoric acid and phosphorous acid, dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, And organic phosphate esters such as triphenyl phosphate.
These may be used alone or in combination of two or more.

  The amount of the phosphorus compound used is not particularly limited, but as described above, it may be approximately equimolar with the transesterification catalyst used, and specifically, with respect to 1 mol of the transesterification catalyst used. The upper limit is preferably 5 mol, more preferably 2 mol, and the lower limit is preferably 0.7 mol, more preferably 0.85 mol, and still more preferably 1.0 mol. When a smaller amount of the phosphorus compound is used, the transesterification catalyst in the reaction product is not sufficiently deactivated, and the obtained polycarbonate diol-containing composition is used as a raw material for polyurethane production, for example. The reactivity of the polycarbonate diol with respect to the isocyanate group may not be sufficiently lowered. Moreover, when the phosphorus type compound exceeding this range is used, the obtained polycarbonate diol containing composition may color.

  The inactivation of the transesterification catalyst by adding a phosphorus compound can be performed at room temperature, but it is more efficient when heat-treated. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 150 ° C., more preferably 120 ° C., still more preferably 100 ° C., and the lower limit is preferably 50 ° C., more preferably 60 ° C., even more preferably. Is 70 ° C. When the temperature is lower than this, it takes time to inactivate the transesterification catalyst, which is not efficient, and the degree of inactivation may be insufficient. On the other hand, at a temperature exceeding 150 ° C., the obtained polycarbonate diol-containing composition may be colored.

The time for reacting with the phosphorus compound is not particularly limited, but is usually 1 to 5 hours.
<Residual monomers, etc.>
In the method for producing a polycarbonate diol-containing composition of the present invention, residual monomers may be contained in the obtained polycarbonate diol-containing composition. When diaryl carbonate such as diphenyl carbonate is used as a raw material, phenols are by-produced during the production of polycarbonate diol. Since phenols are monofunctional compounds, they may be an inhibitory factor in the production of polyurethane, and the urethane bonds formed by phenols are weak in their bonding strength, so they are heated by subsequent processes. It may dissociate, causing isocyanates and phenols to be regenerated and causing problems. Moreover, since phenols are also stimulating substances, it is preferable that the residual amount of phenols in the polycarbonate diol-containing composition is smaller. Specifically, the weight ratio with respect to the polycarbonate diol-containing composition is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 300 ppm or less, and particularly preferably 100 ppm or less. In order to reduce the phenols in the polycarbonate diol-containing composition, it is effective to set the pressure of the polymerization reaction of the polycarbonate diol to a high vacuum of 1 kPa or less as an absolute pressure, or perform thin film distillation after the polymerization of the polycarbonate diol. It is.

  In the polycarbonate diol-containing composition, the carbonate compound used as a raw material during production may remain. The remaining amount of the carbonate compound in the polycarbonate diol-containing composition is not limited, but a smaller amount is preferable, and the upper limit of the weight ratio with respect to the polycarbonate diol-containing composition is preferably 5% by weight, more preferably 3% by weight, Preferably it is 1 weight%. If the carbonate compound content in the polycarbonate diol-containing composition is too large, the reaction during polyurethane formation may be inhibited. On the other hand, the lower limit is not particularly limited, but is preferably 0.1% by weight, more preferably 0.01% by weight, and still more preferably 0% by weight.

  The dihydroxy compound used at the time of manufacture may remain in the polycarbonate diol-containing composition. The residual amount of the dihydroxy compound in the polycarbonate diol-containing composition is not limited, but a smaller amount is preferable, and the weight ratio to the polycarbonate diol is preferably 1% by weight or less, more preferably 0.5% by weight or less. More preferably, it is 0.1% by weight or less. If the residual amount of the dihydroxy compound in the polycarbonate diol-containing composition is large, the molecular length of the soft segment portion when polyurethane is used may be insufficient, and desired physical properties may not be obtained.

  The polycarbonate diol-containing composition may contain a cyclic carbonate (cyclic oligomer) by-produced during production. For example, when 1,3-propanediol is used, 1,3-dioxan-2-one or a compound in which two or more of these molecules form a cyclic carbonate is formed and contained in the polycarbonate diol-containing composition. May be. These compounds may cause side reactions in the polyurethane formation reaction and cause turbidity. Therefore, the pressure of the polymerization reaction of the polycarbonate diol is set to a high vacuum of 1 kPa or less as an absolute pressure, or the synthesis of the polycarbonate diol is performed. It is preferable to remove as much as possible by performing thin film distillation or the like later. The content of these cyclic carbonates contained in the polycarbonate diol-containing composition is not limited, but is preferably 3% by weight or less, more preferably 1% by weight or less, and still more preferably 0.8% as a weight ratio with respect to the polycarbonate diol-containing composition. It is 5% by weight or less, particularly preferably 0.1% by weight or less.

  When a polycarbonate diol-containing composition is polymerized using a dihydroxy compound containing 1,4-butanediol, a by-product is formed by dehydration cyclization of 1,4-butanediol and decarboxylation cyclization of the terminal unit of the obtained polycarbonate diol. The remaining THF remains in the polycarbonate diol-containing composition. If THF remains, it is volatilized when producing polyurethane or the like, and there is a problem that adverse effects on the environment or health occur. Therefore, it is preferable to remove as much as possible. By performing the method for producing a polycarbonate diol-containing composition of the present invention, it is possible to reduce the amount of THF remaining.

  The content of THF contained in the polycarbonate diol-containing composition is preferably 10 wtppm to 200 wtppm, more preferably 12 wtppm to 150 wtppm, and particularly preferably 15 wtppm to 120 wtppm, as a weight ratio to the polycarbonate diol in the composition. It is.

  The polycarbonate-containing composition obtained by the method for producing a polycarbonate diol-containing composition of the present invention and the polycarbonate-containing composition of the present invention contain 95 wt% or more containing polycarbonate as a main component. The amount of substances and compounds that may be contained in addition to the main component polycarbonate is preferably 0.01 to 5 wt%, more preferably 0.01 to 2 wt%, and 0.01 to It is especially preferable that it is 1 wt%.

  The polycarbonate-containing composition obtained by the method for producing a polycarbonate diol-containing composition of the present invention and the polycarbonate-containing composition of the present invention usually have a hydroxyl value of 20 mg-KOH / g or more and 230 mg-KOH / g or less. The lower limit is preferably 25 mg-KOH / g, more preferably 30 mg-KOH / g, and still more preferably 35 mg-KOH / g. The upper limit is preferably 140 mg-KOH / g, more preferably 115 mg-KOH / g, and still more preferably 60 mg-KOH / g. If the hydroxyl value is less than the above lower limit, the viscosity of the polycarbonate diol-containing composition becomes too high, and handling when making the polyurethane using the polycarbonate diol-containing composition may be difficult. When a product is made into polyurethane, physical properties such as flexibility, low temperature characteristics, and elastic recovery may be insufficient.

<Structural features>
The polycarbonate-containing composition obtained by the method for producing a polycarbonate diol-containing composition of the present invention and the polycarbonate-containing composition of the present invention include a polycarbonate containing a structural unit represented by the following general formula (1). .

  When the average number of carbon atoms of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol is 3 or more and 5.5 or less, good chemical resistance and heat resistance can be obtained when polyurethane is used. The upper limit of the average carbon number is 5.5, preferably 5.3, more preferably 5.0, particularly preferably 4.7, and most preferably 4.5. The lower limit of the average carbon number is 3, preferably 3.2, more preferably 3.4, and particularly preferably 3.5. If it is less than the above lower limit, the flexibility and low-temperature characteristics of polyurethane may be insufficient, and if it exceeds the above upper limit, chemical resistance and heat resistance may be insufficient.

  The average carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol in the present invention is determined from the result of gas chromatography analysis of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol by heating in the presence of an alkali. be able to. Specifically, it is calculated from the carbon number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol and the molar ratio of the dihydroxy compound to the total dihydroxy compound.

The dihydroxy compound obtained by hydrolyzing the polycarbonate diol may be one kind or plural kinds. In the case of a plurality of types, it may be a copolymer or a mixture of different types of polycarbonate diols, but a copolymer is preferred because the properties of polyurethane such as low-temperature characteristics are improved. In the case of a copolymer, a block copolymer or a random copolymer may be used, but the polycarbonate diol of the random copolymer is more preferable because of low temperature characteristics and flexibility.

  The dihydroxy compound obtained by hydrolyzing the polycarbonate diol is preferably an aliphatic dihydroxy compound. Examples of the aliphatic dihydroxy compound include 1,3-propanediol, 2-methyl-1,3-propanediol, and neopentyl glycol. 1,3-butanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol 1,14-tetradecanediol, 1,16-hexadecanediol, 1, 8 octadecanediol, 1,20- Eiko Sanji ol, cyclohexanediol, cyclohexanedimethanol, isosorbide and the like. Further, at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol as the dihydroxy compound having a small carbon number that provides good chemical resistance and heat resistance properties. It is preferable to contain a seed, and it is more preferable to include any one of 1,3-propanediol and 1,4-butanediol. Furthermore, since the chemical resistance and heat resistance are good, the polycarbonate diol-containing composition preferably has high crystallinity. Therefore, the dihydroxy compound obtained by hydrolyzing the polycarbonate diol contains 1,4-butanediol. It is preferable.

  The proportion of 1,4-butanediol contained in the dihydroxy compound obtained by hydrolyzing the polycarbonate diol is preferably 25 to 100 mol%. The upper limit of the proportion of 1,4-butanediol is 100 mol%, preferably 90 mol%, more preferably 80 mol%, still more preferably 75 mol%. The lower limit of the proportion of 1,4-butanediol is 25 mol%, preferably 30 mol%, more preferably 40 mol%, still more preferably 50 mol%. If it is less than the above lower limit, chemical resistance and heat resistance may be insufficient, and if it exceeds the upper limit, flexibility and low temperature characteristics of polyurethane may be insufficient.

<Molecular chain end>
The molecular chain terminal of the polycarbonate diol of the present invention is mainly a hydroxyl group. However, in the case of a polycarbonate diol obtained by the reaction of a dihydroxy compound and a carbonate compound, there are cases where some of the molecular chain terminals are not hydroxyl groups as impurities. As specific examples thereof, the molecular chain terminal is an alkyloxy group or an aryloxy group, and many have a structure derived from a carbonate compound.

For example, when diphenyl carbonate is used as the carbonate compound, phenoxy group (PhO-) is used as the aryloxy group, methoxy group (MeO-) is used as the alkyloxy group when dimethyl carbonate is used, and ethoxy group is used when diethyl carbonate is used. (EtO-), when using ethylene carbonate which may hydroxyethoxy group _(HOCH 2 _CH 2 O-) remains as a molecular chain terminal (here, Ph represents a phenyl group, Me represents a methyl group Et represents an ethyl group).

  The molecular chain terminals other than hydroxyl groups in the polycarbonate diol of the present invention are preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably 3 mol% or less, particularly preferably 1 mol%, based on the total number of terminals. It is as follows.

<Molecular weight and molecular weight distribution>
The ratio of the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (hereinafter sometimes abbreviated as “GPC”) of the polycarbonate diol of the present invention to the number average molecular weight in terms of polystyrene is 1.5 to 3. 0 is preferred. The lower limit is more preferably 1.7, and still more preferably 1.8. The upper limit is more preferably 2.5, and still more preferably 2.3. When the ratio exceeds the above range, the properties of the polyurethane produced using this polycarbonate diol tend to become hard at low temperatures, decrease in elongation, etc., and when trying to produce a polycarbonate diol having a molecular weight distribution less than the above range. In some cases, advanced purification operations such as removal of oligomers may be required.

  Further, the number average molecular weight of the polycarbonate diol can be determined from the hydroxyl value, and the lower limit of the number average molecular weight (Mn) is preferably 500, more preferably 800, still more preferably 1,000, and particularly preferably 1,500. It is. On the other hand, the upper limit is preferably 5,500, more preferably 4,500, and still more preferably 3,500. When Mn of the polycarbonate diol is less than the lower limit, flexibility, low temperature characteristics, and elastic recovery may not be sufficiently obtained when urethane is used. On the other hand, if the upper limit is exceeded, the viscosity increases, and handling during polyurethane formation may be impaired. In particular, within the above preferred range, the polyurethane is particularly excellent in flexibility, low-temperature characteristics and elastic recovery, and also has good physical properties with respect to chemical resistance and heat resistance.

<APHA value>
The color of the polycarbonate diol-containing composition of the present invention is 60 or less in terms of value (hereinafter referred to as “APHA value”) expressed in terms of Hazen color number (based on JIS K0071-1: 1998). Is preferably 50 or less, more preferably 30 or less, and still more preferably 20 or less. When the APHA value exceeds 60, the color tone of the polyurethane obtained using the polycarbonate diol-containing composition as a raw material is deteriorated, and the commercial value is lowered or the thermal stability is deteriorated. In order to reduce the APHA value to 60 or less, the catalyst during the production of the polycarbonate diol-containing composition, the selection of the type and amount of the additive, the thermal history, the concentration of the monohydroxy compound during and after the polymerization, and the unreacted monomer It is necessary to comprehensively control the concentration of. Further, light shielding during and after the polymerization is effective. It is also important to set the molecular weight of the polycarbonate diol and to select the dihydroxy compound species that is a monomer. In particular, a polycarbonate diol-containing composition using an aliphatic dihydroxy compound having an alcoholic hydroxyl group as a raw material exhibits various excellent performances such as flexibility, water resistance, and light resistance when processed into polyurethane. Heat history and coloration due to the catalyst tend to be more remarkable than when the compound is used as a raw material, and it is not easy to make the APHA value 60 or less.

<Application>
Polyurethane using the polycarbonate diol obtained by the production method of the present invention is excellent in chemical resistance, low temperature characteristics, heat resistance, etc., so artificial leather, synthetic leather, water-based polyurethane, elastomer, adhesive, elastic fiber, medical material It can be suitably used in general applications where polyols are usually used, such as raw materials such as flooring materials, paints, coating agents, and active energy ray-curable resin compositions.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited to these Examples, unless the summary is exceeded.
Below, the evaluation method of each physical property value is as follows.
[Evaluation method: Polycarbonate diol]
<Analysis of polycarbonate diol molecular weight and PHL residual amount>
The polycarbonate diol-containing composition was dissolved in CDCl3, 400 MHz 1H-NMR (AL-400 manufactured by JEOL Ltd.) was measured, and each unit of polycarbonate diol, terminal phenoxy group, and phenol were identified from the signal position of each component. From the integrated value, the content of phenol and terminal phenoxy group and the molecular weight of polycarbonate diol were calculated.

The detection limit in that case is 100 ppm as the weight of phenol with respect to the weight of the whole sample. The ratio of the phenoxy group is determined from the ratio of the integral value of one proton of the phenoxy group to the integral value of one proton of the whole terminal, and the detection limit of the phenoxy group is 0.05% with respect to the whole terminal. .
<Analysis of residual amount of THF>
A solution prepared by adding 250 mg of monochlorobenzene to 500 mL of N-methylpyrrolidone was used as an internal standard solution. 0.5 g of the polycarbonate diol-containing composition was precisely weighed and dissolved in 5 mL of the above internal standard solution weighed with a whole pipette. The obtained solution was analyzed by gas chromatography (GC). A concentration curve of THF was calculated in advance from an area ratio obtained by gas chromatography (GC) by preparing a calibration curve from known THF as a standard substance.

(Analysis conditions)
Apparatus: Agilent 6850 (manufactured by Agilent Technologies)
Column: Agilent J & W GC column DB-WAX
Inner diameter 0.25mm, length 60m, film thickness 0.25mm
Detector: Hydrogen flame ionization detector (FID)
Temperature rising program: 150 ° C → 190 ° C (5 minutes) 190 → 245 ° C (40 minutes)
Injection volume: 1 μL
Inlet temperature: 200 ° C
Detector temperature: 245 ° C. (FID detector)

[Example 1]
(Production of polycarbonate diol-containing composition)
1,5-butanediol: 955.0 g, 1,10-decanediol as a raw material in a 5 L glass separable flask equipped with a stirrer having a paddle type stirring blade, a distillate trap, and a pressure adjusting device : 405.4 g, diphenyl carbonate: 2639.7 g, magnesium acetate tetrahydrate aqueous solution: 6.6 mL (concentration: 8.4 g / L, magnesium acetate tetrahydrate contained: 55 mg), and nitrogen gas replacement .

  Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Subsequently, the pressure was lowered to 9.3 kPa over 90 minutes and further lowered to 0.7 kPa over 30 minutes to continue the reaction. Thereafter, the internal temperature was raised to 170 ° C., and the reaction was carried out for 120 minutes while removing phenol and unreacted dihydroxy compound out of the system to obtain a polycarbonate diol-containing composition.

During the reaction, a paddle type stirring blade was stirred at a stirring speed of 150 rpm (blade peripheral speed: 0.79 m / s).
In the obtained polycarbonate diol-containing composition, the number average molecular weight of the polycarbonate diol was 2980, the residual THF amount was 0.009 wt%, and the residual PHL amount was 0.10 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Example 2]
In Example 1, the stirring blade of the stirring device was changed to a Logbone (registered trademark) type stirring blade, and everything was the same as in Example 1 except that stirring was performed at a stirring speed of 150 rpm (blade peripheral speed: 0.94 m / s). In this way, a polycarbonate diol-containing composition was produced.
The resulting polycarbonate diol-containing composition had a polycarbonate diol number average molecular weight of 3000, a residual THF content of 0.012 wt%, and a residual PHL content of 0.11 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Example 3]
In Example 1, the stirring blade of the stirring device was changed to an anchor-type stirring blade, and everything was the same as in Example 1 except that stirring was performed at a stirring speed of 150 rpm (blade peripheral speed: 0.94 m / s). A polycarbonate diol-containing composition was prepared.
The obtained polycarbonate diol-containing composition had a polycarbonate diol number average molecular weight of 2900, a residual THF amount of 0.013 wt%, and a residual PHL amount of 0.09 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Example 5]
In a 5 L glass separable flask equipped with a stirring device having a paddle type stirring blade, a distillate trap, and a pressure adjusting device, 1,4-butanediol: 1219.1 g, diphenyl carbonate: 2780.9 g Magnesium acetate tetrahydrate aqueous solution: 6.9 mL (concentration: 8.4 g / L, magnesium acetate tetrahydrate contained: 58 mg) was added, and the atmosphere was replaced with nitrogen gas.

  Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Subsequently, the pressure was lowered to 9.3 kPa over 90 minutes and further lowered to 0.7 kPa over 30 minutes to continue the reaction. Thereafter, the internal temperature was raised to 170 ° C., and the reaction was carried out for 120 minutes while removing phenol and unreacted dihydroxy compound out of the system to obtain a polycarbonate diol-containing composition.

During the reaction, a paddle type stirring blade was stirred at a stirring speed of 150 rpm (blade peripheral speed: 0.79 m / s).
The obtained polycarbonate diol-containing composition had a number average molecular weight of 2940, a residual THF amount of 0.009 wt%, and a residual PHL amount of 0.10 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Example 6]
In Example 5, a polycarbonate diol-containing composition was produced in the same manner as in Example 1 except that stirring was performed at a stirring speed of 90 rpm (blade peripheral speed: 0.47 m / s).
The obtained polycarbonate diol-containing composition had a polycarbonate diol number average molecular weight of 2920, a residual THF content of 0.020 wt%, and a residual PHL content of 0.17 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Comparative Example 1]
In Example 1, a polycarbonate diol-containing composition was produced in the same manner as in Example 1 except that the paddle type stirring blade was stirred at a stirring speed of 43 rpm (blade peripheral speed: 0.23 m / s).
The obtained polycarbonate diol-containing composition had a number average molecular weight of 2,800, a residual THF amount of 0.028 wt%, and a residual PHL amount of 0.64 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Comparative Example 2]
In Example 1, all the same as Example 1 except that the stirring blade of the stirring device was changed to a Logbone (registered trademark) type stirring blade and stirred at a stirring speed of 43 rpm (blade peripheral speed: 0.27 m / s). By the method, a polycarbonate diol-containing composition was produced.
The resulting polycarbonate diol-containing composition had a polycarbonate diol number average molecular weight of 2940, a residual THF content of 0.025 wt%, and a residual PHL content of 0.44 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

[Comparative Example 4]
In a 5 L glass separable flask equipped with a stirrer having a paddle type stirring blade, a distillate trap, and a pressure adjusting device, 1,4-butanediol: 774.3 g, isosorbide: 837.0 g, Diphenyl carbonate: 2388.7 g, magnesium acetate tetrahydrate aqueous solution: 7.3 mL (concentration: 8.4 g / L, contained magnesium acetate tetrahydrate: 61 mg) were added, and the nitrogen gas was replaced.

  Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Subsequently, the pressure was lowered to 9.3 kPa over 90 minutes and further lowered to 0.7 kPa over 30 minutes to continue the reaction. Thereafter, the internal temperature was raised to 170 ° C., and the reaction was carried out for 90 minutes while removing phenol and unreacted dihydroxy compound out of the system to obtain a polycarbonate diol-containing composition.

During the reaction, a paddle type stirring blade was stirred at a stirring speed of 43 rpm (blade peripheral speed: 0.79 m / s).
In the obtained polycarbonate diol-containing composition, the number average molecular weight of the polycarbonate diol was 660, the residual THF amount was 0.061 wt%, and the residual PHL amount was 0.20 wt%. The phenoxy end was below the detection limit. The results are shown in Table-1.

  It can be seen from Table 1 that Examples 1 to 3 and Example 6 have a large amount of residual THF in the polycarbonate-containing composition produced in Comparative Examples 1 and 2 having a low blade peripheral speed. Moreover, from Example 1 and Example 5, it turns out that the amount of THF remaining can be reduced irrespective of the ratio of the structure of Formula (1) in the polycarbonate containing composition manufactured. On the other hand, it can be seen from Comparative Example 4 that even if the ratio of the structure of the formula (1) in the polycarbonate-containing composition is low, the residual amount of THF in the polycarbonate-containing composition is large when the blade peripheral speed is low.

[Example 4]
Into a 5 L glass separable flask equipped with a stirrer (stirring blade: paddle, blade peripheral speed: 0.79 m / s), a distillate trap, and a pressure adjusting device, 1,4-butanediol: 1219. 1 g, diphenyl carbonate: 2780.9 g, magnesium acetate tetrahydrate aqueous solution: 6.9 mL (concentration: 8.4 g / L, contained magnesium acetate tetrahydrate: 58 mg), and nitrogen gas substitution was performed.

  Under stirring, the internal temperature was raised to 160 ° C., and the contents were dissolved by heating. Thereafter, the pressure was lowered to 24 kPa over 2 minutes, and then reacted for 90 minutes while removing phenol out of the system. Subsequently, the pressure was lowered to 9.3 kPa over 90 minutes and further lowered to 0.7 kPa over 30 minutes to continue the reaction. Thereafter, the internal temperature was raised to 170 ° C., and the reaction was carried out for 120 minutes while removing phenol and unreacted dihydroxy compound out of the system to produce a polycarbonate diol-containing compound. The reaction solution was extracted at 0, 30, 60, and 120 minutes during the reaction time, and the number average molecular weight of the polycarbonate diol and the residual amounts of THF and PHL in each reaction solution were analyzed. The results are shown in Table-2 and FIG.

[Comparative Example 3]
In Example 4, a polycarbonate diol-containing composition was produced in the same manner as in Example 4 except that the blade peripheral speed was changed to 0.23 m / s. The results are shown in Table-2 and FIG.

  As can be seen from Table-2 and FIG. 1, when the reaction time is extended to remove PHL, which is a byproduct derived from carbonate, and to increase the molecular weight of polycarbonate diol, THF is by-produced and the residual amount tends to increase. is there. The increase rate of THF can be suppressed by increasing the blade peripheral speed.

Claims (5)

  A method for producing a polycarbonate diol-containing composition comprising a step of polymerizing a dihydroxy compound containing 1,4-butanediol and a carbonate compound by a transesterification reaction in a reactor equipped with a stirrer to obtain a polycarbonate diol, A method for producing a polycarbonate diol-containing composition, wherein a peripheral speed of a stirring blade of the stirring device of the reactor during the transesterification reaction is 0.3 to 10 m / s.   The method for producing a polycarbonate diol-containing composition according to claim 1, wherein a reaction temperature of the transesterification reaction is 200 ° C. or lower.   The manufacturing method of the polycarbonate diol composition of Claim 1 or 2 with which the said carbonate compound contains a diaryl carbonate. A polycarbonate diol-containing composition comprising a structural unit represented by the following general formula (1) and containing a polycarbonate diol having a number average molecular weight of 250 or more and 5500 or less, comprising tetrahydrofuran, and the content of the polycarbonate diol A polycarbonate diol-containing composition, wherein the tetrahydrofuran content is 10 wtppm or more and 200 wtppm or less.

  The polycarbonate diol-containing composition according to claim 4, wherein 99% or more of the terminal structure of the polycarbonate diol is a hydroxyl group, and the hydroxyl value is 20 to 230 mg-KOH / g or less.

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