Polycarbonate diol and method for producing the same

Abstract

Provided are polycarbonate diol and a method for producing the same. A method for producing polycarbonate diol comprises the steps of mixing and heating a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a), a phosphoric acid diester represented by the following formula (b), and a phosphoric acid triester represented by the following formula (c), wherein the ratio of the number of moles of phosphorus to the number of moles of the ester exchange reaction catalyst is 0.1 to 5, and the mass ratio of the phosphoric acid monoester to the phosphoric acid diester to the phosphoric acid triester satisfies the relationship of 50 to 90: 3 to 25: 0.01 to 5 (phosphoric acid monoester: phosphoric acid diester: phosphoric acid triester). [Wherein, R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R 3 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms].

Description

Technical Field

[0001] The present invention relates to polycarbonate diols and a method for producing the same. Background Art

[0002] When polycarbonate diol is manufactured industrially with diol and carbonate compound as raw materials, ester exchange reaction catalyst is usually used. The ester exchange reaction catalyst used remains in the polycarbonate diol, so when the polycarbonate diol is used as a raw material for polyurethane, thermoplastic elastomer, urethane elastic fiber, etc., it will promote the reaction with isocyanate, and it is difficult to control the urethane reaction. For example, when using highly reactive isocyanate compounds such as diphenylmethane diisocyanate and naphthalene diisocyanate, the control of the urethane reaction becomes extremely difficult, resulting in high molecular weight and the generation of gel and other problems. In order to completely prevent this situation, there is a method of separating the ester exchange reaction catalyst using an adsorbent, but the process is complicated and there are problems when it is carried out industrially.

[0003] In order to reduce the influence of the transesterification catalyst on the carbamate reaction, various treatment methods are disclosed. For example, a method for producing aliphatic polycarbonate diol is known, characterized in that a phosphoric acid monoester and a phosphoric acid diester are used together in an aliphatic polycarbonate diol obtained by polymerization using a transesterification catalyst, the phosphoric acid monoester and the phosphoric acid diester are pre-dissolved in a polar solvent, and added in the form of a solution of the polar solvent (for example, refer to Patent Document 1). In addition, a polycarbonate diol product containing phosphoric acid and / or phosphorous acid is known, which is obtained by using a dihydroxy compound and a carbonate compound as raw material monomers and by an ester exchange reaction in the presence of an ester exchange catalyst (for example, refer to Patent Document 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 4749024

[0007] Patent Document 2: Japanese Patent No. 6526943 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, although the method of Patent Document 1 can suppress the influence of the transesterification catalyst on the carbamate reaction, depending on the ratio of the phosphoric acid monoester to the phosphoric acid diester, there is a case where the reactivity of the carbamate changes when more than 3 years have passed since production. In addition, the method of Patent Document 2 has the following problems: depending on the amount of phosphoric acid, the material of the reactor is limited due to its corrosiveness.

[0010] An object of the present invention is to provide a polycarbonate diol in which the influence of a transesterification catalyst used in the production of the polycarbonate diol on the urethanization reaction (that is, excessive promotion of the urethanization reaction) is reduced and the urethanization reactivity is less likely to change over time.

[0011] Solutions for solving problems

[0012] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that the above-mentioned problems can be solved by using a predetermined phosphorus compound in a predetermined amount and ratio.

[0013] That is, the present invention includes the following embodiments.

[0014] [1] A method for producing a polycarbonate diol, comprising the steps of mixing and heating a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a), a phosphoric acid diester represented by the following formula (b), and a phosphoric acid triester represented by the following formula (c),

[0015] The ratio of the number of moles of phosphorus to the number of moles of the above-mentioned transesterification catalyst is 0.1 to 5,

[0016] The mass ratio of the above-mentioned phosphate monoester to the above-mentioned phosphate diester to the above-mentioned phosphate triester satisfies the relationship of 50-90:3-25:0.01-5 (phosphate monoester: phosphate diester: phosphate triester),

[0017]

[0018] In the formula,

[0019] R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0020] R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0021] R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

[0022] [2] The production method according to [1], wherein the mixing further comprises the step of mixing phosphoric acid.

[0023] The mass ratio of the phosphoric acid monoester to the phosphoric acid diester to the phosphoric acid triester to the phosphoric acid satisfies the relationship of 50-90:3-25:0.01-5:3-25 (phosphoric acid monoester:phosphoric acid diester:phosphoric acid triester:phosphoric acid).

[0024] [3] The production method according to [1] or [2], wherein the heating is performed at 70°C to 170°C for 15 minutes to 5 hours.

[0025] [4] The production method according to [2] or [3], wherein, in the mixing, the phosphate monoester, the phosphate diester, the phosphate triester and the phosphoric acid are dissolved in a solution having an SP value of 8.0 to 11.0 (cal / cm 3 ) 1 / 2 The mixture is mixed in the form of a solution of a solvent.

[0026] [5] A polycarbonate diol comprising a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a), a phosphoric acid diester represented by the following formula (b), and a phosphoric acid triester represented by the following formula (c),

[0027] The ratio of the number of moles of phosphorus to the number of moles of the above-mentioned transesterification catalyst is 0.1 to 5,

[0028] The mass ratio of the above-mentioned phosphate monoester to the above-mentioned phosphate diester to the above-mentioned phosphate triester satisfies the relationship of 50-90:3-25:0.01-5 (phosphate monoester: phosphate diester: phosphate triester),

[0029]

[0030] In the formula,

[0031] R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0032] R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0033] R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

[0034] [6] The polycarbonate diol according to [5], further comprising phosphoric acid,

[0035] The mass ratio of the phosphoric acid monoester to the phosphoric acid diester to the phosphoric acid triester to the phosphoric acid satisfies the relationship of 50-90:3-25:0.01-5:3-25 (phosphoric acid monoester:phosphoric acid diester:phosphoric acid triester:phosphoric acid).

[0036] Effects of the Invention

[0037] According to the present invention, it is possible to provide a polycarbonate diol in which the influence of a transesterification catalyst used for producing the polycarbonate diol on the urethanization reaction is reduced and the urethanization reactivity is less likely to change over time. DETAILED DESCRIPTION

[0038] The following describes in detail a mode for implementing the present invention (hereinafter referred to as "this embodiment"). It should be noted that the present invention is not limited to the following embodiment, and can be implemented with various modifications within the scope of the gist thereof.

[0039] <Polycarbonate diol and method for producing the same>

[0040] One embodiment of the present invention relates to a method for producing a polycarbonate diol, and a polycarbonate diol produced by the method, the method comprising the steps of mixing and heating a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a) (hereinafter also referred to as “phosphoric acid monoester (a)”), a phosphoric acid diester represented by the following formula (b) (hereinafter also referred to as “phosphoric acid diester (b)”), and a phosphoric acid triester represented by the following formula (c) (hereinafter also referred to as “phosphoric acid triester (c)”),

[0041] The ratio of the number of moles of phosphorus to the number of moles of the above-mentioned transesterification catalyst is 0.1 to 5,

[0042] The mass ratio of the above-mentioned phosphate monoester to the above-mentioned phosphate diester to the above-mentioned phosphate triester satisfies the relationship of 50-90:3-25:0.01-5 (phosphate monoester: phosphate diester: phosphate triester),

[0043]

[0044] [Wherein,

[0045] R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0046] R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms,

[0047] R 3 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms].

[0048] According to the polycarbonate diol obtained by the production method of the present embodiment, the influence of the transesterification catalyst on the urethanization reaction can be reduced, and the change in the urethanization reactivity over time can be suppressed.

[0049] In this specification, phosphoric acid monoester (a), phosphoric acid diester (b) and phosphoric acid triester (c) are collectively referred to as "phosphoric acid ester", and phosphoric acid ester and other phosphorus-containing compounds are collectively referred to as "phosphorus compound".

[0050] R in formula (a) to (c)1 ~R 3 Each of them is independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, preferably an alkyl group having 3 to 12 carbon atoms, and more preferably an alkyl group having 3 to 8 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, n-hexyl, 2-ethylhexyl, octyl, lauryl, stearyl, isodecyl, etc. Specific examples of the aryl group include phenyl, etc.

[0051] The mass ratio of the phosphoric acid monoester (a) to the phosphoric acid diester (b) and the phosphoric acid triester (c) used in the production method of the present embodiment satisfies the relationship of 50 to 90: 3 to 25: 0.01 to 5. By making the phosphoric acid ester satisfy the above relationship, the influence of the ester exchange reaction catalyst on the carbamate reaction is reduced and the effect is sustained over time. The mass ratio of the phosphoric acid monoester (a) is preferably 60 to 85. The mass ratio of the phosphoric acid diester (b) is preferably 5 to 20.

[0052] In the manufacturing method of this embodiment, phosphoric acid can be mixed in addition to the mixed phosphate ester. When phosphoric acid is mixed, it is preferred that the mass ratio of the phosphoric acid monoester (a), the phosphoric acid diester (b), the phosphoric acid triester (c), and the phosphoric acid satisfy the relationship of 50 to 90: 3 to 25: 0.01 to 5: 3 to 25. If the mass ratio of phosphoric acid is 3 or more, it is possible to effectively reduce the effect of the ester exchange reaction catalyst on the carbamate reaction together with the phosphoric acid ester. If the mass ratio of phosphoric acid is 25 or less, the corrosion of the reactor is less. The mass ratio of phosphoric acid is preferably 5 to 20.

[0053] The ratio of the number of moles of phosphorus to the number of moles of the ester exchange reaction catalyst is 0.1 to 5, preferably 0.5 to 3.5, and more preferably 0.5 to 2.5. It should be noted that the phosphorus in the "number of moles of phosphorus" is not limited to phosphorus from phosphate esters, but also includes, for example, phosphorus from phosphoric acid. If the above ratio is greater than 0.1, the effect of the ester exchange reaction catalyst on the carbamate reaction can be reduced. If the above ratio is less than 5, the promotion of the carbamate reaction by excessive phosphorus can be suppressed. The above ratio can be calculated from the analytical values ​​of the catalyst metal and phosphorus obtained by elemental analysis based on inductively coupled plasma (ICP) described in the following examples.

[0054] The amount of the transesterification catalyst in the aliphatic polycarbonate diol can be calculated based on the amount of catalyst added when the aliphatic polycarbonate diol is produced and then heat-treated, or by determining the amount of catalyst metal contained in the polycarbonate diol when a commercially available polycarbonate diol is used.

[0055] The compatibility of phosphorus compounds with aliphatic polycarbonate diols is not always good. Depending on the added phosphorus compound, it is sometimes difficult to disperse in the aliphatic polycarbonate diol, and it is necessary to increase the heat treatment temperature or extend the heat treatment time. When the phosphorus compound is dissolved or dispersed in a solvent in advance and added, the phosphorus compound becomes easy to dissolve or disperse in the aliphatic polycarbonate diol, and the treatment can be carried out at a low heat treatment temperature and in a short time compared to the case where no solvent is used.

[0056] The solvent used preferably has a SP value (solubility parameter) of 8.0 to 11.0 (cal / cm 3 ) 1 / 2 Examples of the solvent used in the present invention include 1,4-dioxane, 1-butanol, butyl acetate, ethyl acetate, acetone, 2-ethylhexanol, diethylene glycol monobutyl ester, etc. From the viewpoint that the addition temperature is not easily restricted, the boiling point of the solvent is preferably 100° C. or higher, and more preferably 150° C. or higher.

[0057] In order not to affect the urethanization reaction, it is preferred to use a smaller amount of the solvent. The mass of the solvent used is usually 0.5 to 5 times, preferably 0.5 to 3 times, and more preferably 0.5 to 2 times the mass of the phosphorus compound.

[0058] Although the phosphorus compound may be added to the aliphatic polycarbonate diol in a state dispersed in a solvent, it is more preferred to add the phosphorus compound in a state dissolved in a solvent because a predetermined amount of the phosphorus compound can be added and the phosphorus compound is easily dissolved or dispersed in the aliphatic polycarbonate diol.

[0059] As a method for producing the aliphatic polycarbonate diol of the present invention, the aliphatic polycarbonate diol may be polymerized, followed by adding a phosphorus compound and performing a heat treatment. Alternatively, a phosphorus compound may be added to an aliphatic polycarbonate diol produced without taking measures such as adding a phosphorus compound to reduce the effect of the transesterification catalyst on the urethanization reaction and the heat treatment may be performed again.

[0060] The manufacturing method of the present embodiment is described by taking a method of polymerizing an aliphatic polycarbonate diol and then performing a heat treatment as an example. After reaching a predetermined degree of polymerization, a phosphorus compound in an amount calculated based on the amount of the added transesterification catalyst is added to the reactor, and heated and stirred. The heating treatment temperature is preferably 70°C to 170°C. As needed, the phosphorus compound is added after cooling from the temperature at the end of the polymerization to the predetermined heating treatment temperature. If the heating treatment temperature is 70°C or higher, the heating treatment time will not be long, which is more economical. If the heating temperature is below 170°C, the aliphatic polycarbonate diol is less colored, and the added phosphorus compound is less decomposed. If the heating treatment temperature is 75°C to 160°C, the possibility of the above-mentioned problems is reduced, and it is more preferably 75°C to 155°C. The heating treatment time is the time required to reach the predetermined urethanization reaction rate, which varies depending on the heating treatment temperature and the treatment method, and is usually 15 minutes to 5 hours. If the heating treatment time is 15 minutes or more, there are fewer cases of insufficient treatment, and if it is 5 hours or less, there is no problem with productivity.

[0061] When the phosphorus compound is dissolved in a solvent in advance and added to the aliphatic polycarbonate diol, the heat treatment temperature can be as low as 70 to 150°C. Even at 70 to 125°C, the effect can be exhibited by heat treatment for 30 minutes to 4 hours.

[0062] Since the aliphatic polycarbonate diol may be colored during the heat treatment, it is preferred to replace the inside of the treatment container with an inert gas such as nitrogen.

[0063] The treatment method of the present invention is not particularly limited. For example, heating and stirring may be performed using a reactor equipped with a heater and a stirrer, or heating treatment may be performed continuously using an in-line mixer or a static mixer.

[0064] The aliphatic polycarbonate of the embodiment of the present invention is obtained from a dihydroxy compound and a carbonate compound using an ester exchange reaction catalyst.

[0065] The dihydroxy compound used in the method for producing the polycarbonate diol of the present embodiment is not particularly limited, and examples thereof include dihydroxy compounds having no side chain, such as 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-dodecanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, and 1,15-pentadecandiol. Alcohols; diols having side chains such as 2-methyl-1,8-octanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol; cyclic diols such as 1,4-cyclohexanedimethanol, 2-bis(4-hydroxycyclohexyl)-propane, and 1,4-cyclohexanediol. One or more of these diols may be used as the dihydroxy compound. When one or more diols without a side chain are used as dihydroxy compounds, the chemical resistance and mechanical strength of the coating film are improved, so it is preferred, and more preferred, to use one or more of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 1,9-nonanediol as dihydroxy compounds. It is further preferred to use two diols selected from 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol as raw materials for polycarbonate diol. It is particularly preferred to use 1,5-pentanediol and 1,6-hexanediol as dihydroxy compounds.

[0066] When two or more diols are used as dihydroxy compounds, the ratio of these diols is not particularly limited, and it is preferred to set the ratio of the raw materials used so that the obtained polycarbonate diol is liquid at room temperature. When two diols are used as raw materials, it is preferred to set the feed amount between 20 / 80 and 80 / 20 in terms of molar ratio. If it is within this range, the obtained polycarbonate diol is liquid. It is further preferred to set it to 30 / 70 to 70 / 30, and more preferably to set it to 40 / 60 to 60 / 40, because it is also liquid below 0°C.

[0067] Furthermore, it is also possible to use a compound having more than 3 hydroxyl groups in one molecule, such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, etc. as a raw material for polycarbonate diol within the range that does not damage the performance of the polycarbonate diol of the present embodiment. If the compound having more than 3 hydroxyl groups in one molecule is used as a raw material for polycarbonate diol excessively, crosslinking will occur in the polymerization reaction of polycarbonate and gelation will occur. Therefore, when using a compound having more than 3 hydroxyl groups in one molecule as a raw material for polycarbonate diol, it is preferred that the molar ratio of the compound relative to the diol used as a raw material for polycarbonate diol is set to 0.1 to 5 mol%. The ratio is more preferably 0.1 to 1 mol%.

[0068] The carbonate compound used in the method for producing the polycarbonate diol of the present embodiment is not particularly limited, and examples thereof include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; alkylene carbonates such as ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate. One or more of these carbonates can be used as raw materials for polycarbonate diol. From the viewpoint of easy acquisition and easy setting of polymerization reaction conditions, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, dibutyl carbonate, and ethylene carbonate are preferably used.

[0069] In the method for producing polycarbonate diol of the present embodiment, a catalyst for transesterification reaction is added. The catalyst is not particularly limited, and examples thereof include: alkali metals such as lithium, sodium, potassium, and alkaline earth metals such as magnesium, calcium, strontium, and barium, alkoxides, hydrides, oxides, amides, carbonates, hydroxides, and nitrogen-containing borates; and basic alkali metal salts and alkaline earth metal salts of organic acids. In addition, the above-mentioned catalyst is not particularly limited, and examples thereof include: metals, salts, alkoxides, and organic compounds of aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten, rhenium, osmium, iridium, platinum, gold, thallium, lead, bismuth, and ytterbium. One or more of these catalysts can be selected and used. When one or more catalysts selected from metals, salts, alkoxides, and organic compounds of sodium, potassium, magnesium, potassium, titanium, zirconium, tin, lead, and ytterbium are used, the polymerization of polycarbonate diol proceeds well and the influence on the urethane reaction using the obtained polycarbonate diol is small, so it is preferred. It is more preferred to use metals, salts, alkoxides, and organic compounds of titanium, ytterbium, tin, zirconium, and magnesium as the above catalyst.

[0070] The polycarbonate diol of the present embodiment can be produced by various methods described in, for example, Schnell, Polymer Reviews, Vol. 9, pp. 9 to 20 (1994).

[0071] A specific example of the method for producing the polycarbonate diol of the present embodiment is shown below. The method for producing the polycarbonate diol of the present embodiment is not particularly limited, and can be carried out in two stages, for example. A dihydroxy compound and a carbonate compound are mixed in a molar ratio (dihydroxy compound: carbonate compound) of, for example, 20:1 to 1:10, and the first stage reaction is carried out at 100 to 250° C. under normal pressure or reduced pressure. When dimethyl carbonate is used as the carbonate compound, the generated methanol is removed in the form of a mixture with dimethyl carbonate, thereby obtaining a low molecular weight polycarbonate diol. When diethyl carbonate is used as the carbonate compound, the generated ethanol is removed in the form of a mixture with diethyl carbonate, thereby obtaining a low molecular weight polycarbonate diol. In addition, when ethylene carbonate is used as the carbonate compound, the generated ethylene glycol is removed in the form of a mixture with ethylene carbonate, thereby obtaining a low molecular weight polycarbonate diol. Next, in the second step of the reaction, the reaction product of the first step is heated at 120 to 250° C. under reduced pressure to remove unreacted diol and carbonate and condense low molecular weight polycarbonate diol to obtain polycarbonate diol of a predetermined molecular weight.

[0072] The number average molecular weight of the polycarbonate diol obtained by the manufacturing method of this embodiment is preferably 300 to 5000. If the number average molecular weight of the polycarbonate diol is 300 or more, the low temperature characteristics of the obtained polyurethane become good. If the number average molecular weight of the polycarbonate diol is 5000 or less, when used as a constituent material of a coating, the solid content concentration of the coating is not limited, and the molding processability of the obtained polyurethane will not decrease, so it is preferred. The number average molecular weight of the polycarbonate diol is more preferably 450 to 3000.

[0073] Example

[0074] Hereinafter, the present invention will be described by way of Examples and Comparative Examples.

[0075] The following examples are described to illustrate the present invention, and are not intended to limit the scope of the present invention at all.

[0076] The physical property values ​​shown in the following Examples and Comparative Examples were measured by the following methods.

[0077] 1) Reaction rate of polycarbonate diol

[0078] 75 g of polycarbonate diol was added to a 1 L separable flask equipped with a stirrer, a condenser, and a thermometer. The polycarbonate diol was dried by heating and stirring at 80°C for 3 hours while reducing the pressure at about 2.5 kPa. After confirming that the temperature of the polycarbonate diol in the flask reached 80°C, diphenylmethane diisocyanate was added in an amount twice the molar amount of the aliphatic polycarbonate diol. After reacting at 80°C for 30 minutes, the reaction rate was measured from the reaction rate of the isocyanate.

[0079] 2) Stability over time

[0080] The polycarbonate diol is added to a container, the inside of the container is replaced with nitrogen, and then sealed, and allowed to stand in a thermostat at 50°C for 4 weeks. Thereafter, the reaction rate is measured by the method 1) above, and the carbamate reaction rate ratio is calculated by the following formula (1) as an indicator of the stability of the inhibitory effect on the ester exchange catalyst. It should be noted that 4 weeks at 50°C is equivalent to about 3 years at room temperature (23°C). In addition, when the inhibitory effect on the ester catalyst does not change over time at all, the reaction rate ratio of formula (1) is 1. If the reaction rate ratio is 0.85 to 1.15, there is basically no need to change the carbamate reaction conditions regardless of the storage time. If it is 0.90 to 1.10, there is almost no need to change the carbamate reaction conditions. The reaction rate ratio is more preferably 0.95 to 1.05.

[0081] Reaction rate ratio = B / A (1)

[0082] A: Reaction rate when using aliphatic polycarbonate diol that has been left standing for 4 weeks at 50°C

[0083] B: Reaction rate when using aliphatic polycarbonate diol after standing at 50°C for 4 weeks

[0084] 3) Determination of the number average molecular weight of polycarbonate diol

[0085] The hydroxyl value (OH value) was determined by the "neutralization titration method (JIS K0070-1992)" using acetic anhydride and pyridine and titrating with an ethanol solution of potassium hydroxide, and the number average molecular weight of the aliphatic polycarbonate diol was calculated using the following formula (2).

[0086] Number average molecular weight = 2 / (OH value × 10-3 / 56.1) (2)

[0087] 4) Analysis of contained elements (catalyst metals and phosphorus) using inductively coupled plasma (ICP)

[0088] The elements contained in the aliphatic polycarbonate diol were analyzed as follows. First, the sample was weighed into a Teflon (registered trademark) decomposition container, high-purity nitric acid (manufactured by Kanto Chemical) was added, and decomposed using a microwave decomposition device (manufactured by Milestone General KK, ETHOS TC). It should be noted that the sample was completely decomposed and the resulting decomposition liquid became colorless and transparent. Pure water was added to the decomposition liquid as a test liquid. For the obtained test liquid, an inductively coupled plasma analyzer (manufactured by Thermo Fisher Scientific KK, iCAP6300 Duo) was used to quantify based on the standard solution of each element.

[0089] [Preparation of Phosphate Ester Composition]

[0090] A phosphate ester composition was prepared according to the ratios shown in Table 1 below.

[0091]

Table 1

[0092] Table 1

[0093]

[0094] [Example 1]

[0095] 10.6 kg (90 mol) of 1,6-hexanediol and 7.9 kg (90 mol) of ethylene carbonate were added to a 20 L reactor equipped with a heating jacket and equipped with a regular packing and a theoretical plate number of 10, a condenser, and a stirrer, and 1.6 g of titanium tetraisopropoxide was added as a catalyst. The reactor was depressurized to 1 kPa, and nitrogen was introduced to return to atmospheric pressure three times to replace the inside of the reactor with nitrogen.

[0096] Heating was started by flowing a heat medium into the jacket, and the pressure was adjusted to 7 to 8 kPa, and heating was performed for 3 hours at a reaction temperature of 160° C. At this time, extraction from the fractionator was not performed.

[0097] Then, the mixture of ethylene glycol and ethylene carbonate produced was taken out and reacted for 15 hours. Furthermore, the reaction was carried out for 5 hours while taking out all the distilled components at a pressure of 0.3 to 0.6 kPa and a reaction temperature of 160 to 175°C without using a distillation tower. After returning to normal pressure, a solution prepared by adding 1.5 g of the phosphate composition 1 to 1.8 g of 2-ethylhexanol and stirring uniformly was added, and the mixture was stirred at 120°C for 3 hours while flowing nitrogen, thereby obtaining an aliphatic polycarbonate diol (hereinafter referred to as PC-1) having a number average molecular weight of 1987 and being a white solid at room temperature.

[0098] [Examples 2 to 7]

[0099] Aliphatic polycarbonate diols (hereinafter referred to as PC-2 to PC-7, respectively) were obtained by the method shown in Example 1 except that the phosphate ester composition shown in Table 2 was used and the amounts shown in Table 2 were added.

[0100] In addition, the amount of 2-ethylhexanol was adjusted so that the weight ratio with respect to the phosphoric acid ester composition shown in Example 1 might be achieved.

[0101] [Comparative Examples 1 to 6]

[0102] Aliphatic polycarbonate diols (hereinafter referred to as PC-21 to PC-26, respectively) were obtained by the method shown in Example 1 except that the phosphate ester composition shown in Table 2 was used and the amounts shown in Table 2 were added.

[0103] In addition, the amount of 2-ethylhexanol was adjusted so that the weight ratio with respect to the phosphoric acid ester composition shown in Example 1 might be achieved.

[0104] [Example 8]

[0105] 10.6 kg (90 mol) of 1,6-hexanediol, 7.9 kg (90 mol) of ethylene carbonate, and 0.9 g of titanium tetrabutoxide as a catalyst were added to the apparatus used in Example 1. The reactor was depressurized to 1 kPa, and nitrogen was introduced to return to atmospheric pressure, and the inside of the reactor was replaced with nitrogen by repeating three times.

[0106] A heat medium was flowed into the jacket to start heating, and the pressure was adjusted to 7 to 8 kPa, and heating was performed at a reaction temperature of 160° C. for 3 hours. At this time, extraction from the fractionator was not performed.

[0107] After that, the mixture of ethylene glycol and ethylene carbonate produced was taken out and reacted for 15 hours. Furthermore, the reaction was carried out for 5 hours at a pressure of 0.3 to 0.6 kPa and a reaction temperature of 160 to 175° C. without using a distillation tower while taking out all the distilled components. After returning to normal pressure, a solution prepared by adding 0.6 g of the phosphate composition 9 to 0.7 g of 2-ethylhexanol and stirring uniformly was added, and the mixture was stirred at 120° C. for 3 hours while flowing nitrogen to obtain an aliphatic polycarbonate diol (hereinafter referred to as PC-8).

[0108] [Example 9]

[0109] 5.0 kg of 1,5-pentanediol, 5.5 kg of 1,6-hexanediol, and 8.3 kg of ethylene carbonate were added to the apparatus used in Example 1, and 1.6 g of titanium tetraisopropoxide was added as a catalyst. The reactor was depressurized to 1 kPa, and nitrogen was introduced to return to atmospheric pressure three times to replace the interior of the reactor with nitrogen.

[0110] A heat medium was flowed into the jacket to start heating, and the pressure was adjusted to 7 to 8 kPa, and heating was performed at a reaction temperature of 160° C. for 3 hours. At this time, extraction from the fractionator was not performed.

[0111] After that, the mixture of ethylene glycol and ethylene carbonate produced was taken out and reacted for 15 hours. Furthermore, under the condition of pressure of 0.3-0.6 kPa, reaction temperature of 160-175°C, and without using a distillation tower, the reaction was carried out for 5 hours while taking out all the distilled components. After returning to normal pressure, a solution prepared by adding 1.4 g of phosphate composition 10 to 1.7 g of 1-butanol and stirring uniformly was added, and the mixture was stirred at 120°C for 3 hours while flowing nitrogen, thereby obtaining an aliphatic polycarbonate diol (hereinafter referred to as PC-9).

[0112] [Example 10]

[0113] 6.9 kg of 1,4-butanediol, 3.0 kg of 1,6-hexanediol, and 8.9 kg of ethylene carbonate were added to the apparatus used in Example 1, and 1.8 g of titanium tetrabutoxide was added as a catalyst. The reactor was depressurized to 1 kPa, and nitrogen was introduced to return to atmospheric pressure three times to replace the interior of the reactor with nitrogen.

[0114] A heat medium was flowed into the jacket to start heating, and the pressure was adjusted to 7 to 8 kPa, and heating was performed for 3 hours at an internal temperature of the reactor of 140° C. At this time, extraction from the distillation column was not performed.

[0115] After that, the mixture of ethylene glycol and ethylene carbonate produced was taken out and reacted for 15 hours. Furthermore, the reaction was carried out for 5 hours at a pressure of 0.3 to 0.6 kPa and a reaction temperature of 160 to 175° C. without using a distillation tower while taking out all the distilled components. After returning to normal pressure, a solution prepared by adding 1.8 g of the phosphate composition 9 to a mixed solvent of 2.0 g of 2-ethylhexanol and 0.1 g of 1-butanol and stirring uniformly was added, and the mixture was stirred at 120° C. for 3 hours while flowing nitrogen, thereby obtaining an aliphatic polycarbonate diol (hereinafter referred to as PC-10).

[0116] <Stability over time>

[0117] The stability over time was evaluated for PC-1 to 5, PC-8 to 10, PC-21 to 23, and PC-26 by the method of "2) Stability over time".

[0118] <Reaction speed>

[0119] For PC-2, PC-6, PC-7, PC-24, and PC-25, the reaction rate was measured by the above-mentioned method of "1) Reaction rate of polycarbonate diol". When the effect of the ester exchange reaction catalyst on the urethanization reaction is not reduced, when the reaction rate is measured by the method of "1) Reaction rate of polycarbonate diol", the reaction rate of isocyanate within 10 minutes will exceed 45% (when all the hydroxyl groups of the polycarbonate react, the reaction rate of isocyanate is 50%), and the control of the urethanization reaction becomes difficult. On the other hand, if the isocyanate reaction rate within 30 minutes is 8 to 20%, the urethanization reaction is easy to control, which is preferred. When PC-2 is used, the isocyanate reaction rate is within the above-mentioned range, which can reduce the effect of the ester exchange reaction catalyst on the urethanization reaction. Table 2 summarizes the results when the reaction rate of PC-2 is set to 1. The reaction rate is preferably 1.3 or less.

[0120]

Table 2

[0121]

Table 2

[0122] Table 2

[0123]

[0124] [Reference Example 1]

[0125] Aliphatic polycarbonate diol PC-1110g, diphenylmethane-4,4-diisocyanate 55g, N,N-dimethylformamide 100g, and dibutyltin dilaurate 0.02g as a catalyst were added to a separable flask, and reacted at 80°C for 2 hours to obtain a urethane prepolymer. Then, 1,4-butanediol 9.9g and N,N-dimethylformamide 308g as a chain extender were added dropwise, and further reacted for 4 hours to obtain a polyurethane resin solution. The obtained polyurethane resin solution was cast on a glass plate, left at room temperature for 30 minutes to volatilize the solvent, and then placed in a 100°C dryer for 2 hours to dry it to obtain a polyurethane film.

[0126] [Reference Example 2]

[0127] PC-940g of aliphatic polycarbonate diol, 0.75g of BYK-331 (manufactured by BYK Chemicals) as a leveling agent, 1.25g of a dibutyltin dilaurate solution dissolved in a diluent (xylene / butyl acetate = 70 / 30 (mass ratio)) at 2 mass %, and 40g of the diluent were mixed and stirred to obtain a coating base. 7.5g of an organic polyisocyanate (DURANATE TPA-100, manufactured by Asahi Kasei Chemicals, isocyanate (NCO) content: 23.1%) was added to the obtained coating base to prepare a coating composition coating liquid.

[0128] Industrial Applicability

[0129] The polycarbonate diol of the present invention is suitable as a raw material for polyurethane, thermoplastic elastomer, urethane elastic fiber and the like.

Claims

1. A method for producing a polycarbonate diol, comprising the steps of mixing and heating a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a), a phosphoric acid diester represented by the following formula (b), and a phosphoric acid triester represented by the following formula (c), In the mixing, a step of further mixing phosphoric acid is included, The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, i.e., phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 3-25: 0.01-5: 3-25, The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.1 to 5, In the formula, R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

2. The manufacturing method according to claim 1, wherein: R 1 , R 2 , R 3 Each independently represents an alkyl group having 3 to 12 carbon atoms.

3. The manufacturing method according to claim 2, wherein: R 1 , R 2 , R 3 Each independently represents an alkyl group having 3 to 8 carbon atoms.

4. The manufacturing method according to claim 3, wherein: The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 60-85: 3-25: 0.01-5: 3-25.

5. The manufacturing method according to claim 3, wherein: The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 5-20: 0.01-5: 3-25.

6. The manufacturing method according to claim 3, wherein: The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.5 to 2.

5.

7. The manufacturing method according to claim 1, wherein: The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.5 to 2.

5.

8. The manufacturing method according to claim 1, wherein: The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 3-25: 0.01-5: 5-20.

9. The manufacturing method according to claim 3, wherein: The heating is performed at 70° C. to 170° C. for 15 minutes to 5 hours.

10. The manufacturing method according to claim 1, wherein: The heating is performed at 70° C. to 170° C. for 15 minutes to 5 hours.

11. The manufacturing method according to claim 1, wherein: In the mixing, the phosphate monoester, the phosphate diester, the phosphate triester and the phosphoric acid are dissolved in a solution having an SP value of 8.0 to 11.0 (cal / cm 3 ) 1 / 2 The mixture is mixed in the form of a solution of a solvent.

12. The manufacturing method according to claim 1, wherein: R 1 , R 2 , R 3 Each independently is an alkyl group having 3 to 8 carbon atoms, and the mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, i.e., phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 60 to 85: 5 to 20: 0.01 to 5: 3 to 25.

13. A polycarbonate diol obtained by mixing and heating a polycarbonate diol obtained by polymerization using an ester exchange reaction catalyst, a phosphoric acid monoester represented by the following formula (a), a phosphoric acid diester represented by the following formula (b), a phosphoric acid triester represented by the following formula (c), and phosphoric acid, The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.1 to 5, The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, i.e., phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 3-25: 0.01-5: 3-25, In the formula, R 1 is an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R 2 are each independently an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, R 3 Each independently represents an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms.

14. The polycarbonate diol according to claim 13, wherein R 1 , R 2 , R 3 Each independently represents an alkyl group having 3 to 12 carbon atoms.

15. The polycarbonate diol according to claim 14, wherein R 1 , R 2 , R 3 Each independently represents an alkyl group having 3 to 8 carbon atoms.

16. The polycarbonate diol according to claim 15, wherein The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 60-85: 3-25: 0.01-5: 3-25.

17. The polycarbonate diol according to claim 15, wherein The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 5-20: 0.01-5: 3-25.

18. The polycarbonate diol according to claim 15, which has a number average molecular weight of 300 to 5000.

19. The polycarbonate diol according to claim 15, wherein The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.5 to 2.

5.

20. The polycarbonate diol according to claim 13, wherein The ratio of the number of moles of phosphorus to the number of moles of the transesterification catalyst is 0.5 to 2.

5.

21. The polycarbonate diol according to claim 13, wherein The mass ratio of the phosphate monoester to the phosphate diester to the phosphate triester to the phosphoric acid, that is, phosphate monoester: phosphate diester: phosphate triester: phosphoric acid satisfies the relationship of 50-90: 3-25: 0.01-5: 5-20.

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