JP6526943B2 - Polycarbonate diol excellent in heat stability and method for producing the same - Google Patents

Description

  The present invention relates to a polycarbonate diol excellent in thermal stability and a method for producing the same. More specifically, the present invention relates to a polycarbonate diol which is less in molecular weight increase, compositional change and coloration due to heating, and a method for producing the same.

Polycarbonate diol is used as a raw material of polyurethane and urethane acrylate, but when the raw material polycarbonate diol is colored, the polyurethane etc. manufactured from this polycarbonate diol will also be colored, and the commercial value decreases, so polycarbonate Reduction of color is also desired for diols. In addition, when the molecular weight increase and the composition change due to heating, when the polyurethane and the like are used, the physical properties of the polyurethane change, so it is desirable that the change does not occur due to the heating.
Patent Documents 1 and 2 describe polycarbonate diols having high reactivity stabilized in the urethanization reaction by adding a phosphite to the ester exchange reaction catalyst-containing polycarbonate diol and heat treating the mixture.
Patent Document 3 describes that the polycarbonate diol produced without a catalyst is reduced in molecular weight and the like by heating, but the molecular weight and the like are maintained by the addition of the organic phosphoric acid ester compound.
Patent Document 4 reports that a phosphite diester is added to a polycarbonate polyol to deactivate the catalyst and to facilitate control of the reaction in the urethanization reaction.

Japanese Patent Application Laid-Open No. 2002-30143 Japanese Patent Laid-Open No. 2002-69166 Japanese Patent Application Laid-Open No. 61-151263 JP 2005-54034 A

  The previously known techniques disclose measures for effectively utilizing polycarbonate diol as a raw material of urethane, etc. However, in this technique, polycarbonate diol generated upon heating polycarbonate diol containing a specific metal component is disclosed. The suppression of color tone deterioration, suppression of molecular weight increase, and suppression of composition change were not satisfactory.

  An object of the present invention is to provide a polycarbonate diol which is less in molecular weight increase and composition change due to heating, less colored and highly transparent. Furthermore, another object of the present invention is to provide a method for producing the polycarbonate diol having the heat stability.

MEANS TO SOLVE THE PROBLEM As a result of repeating earnest research so that the said subject might be solved, the present inventors discover that the following invention corresponds with the said objective, and came to complete this invention.
That is, the gist of the present invention is as follows.
[1]
The number average molecular weight is 250 or more and 5500 or less,
Phosphoric acid and / or phosphorous acid is contained, and the total content of phosphoric acid and phosphorous acid is 0.1 mole times or more relative to the total content of metal elements derived from the transesterification catalyst in terms of phosphorus atom Polycarbonate diol characterized in that it is less than the molar ratio.
[2]
The polycarbonate diol according to [1], wherein the total content of metal elements derived from the transesterification catalyst in the polycarbonate diol is 0.1 ppm or more and 100 ppm or less. [3]
The metal element derived from the transesterification catalyst in the polycarbonate diol is at least one selected from the group consisting of a long period periodic table group 1 element (excluding hydrogen) and a long period periodic table group 2 element The polycarbonate diol as described in [1] or [2] containing an element.
[4]
The polycarbonate diol according to [1] to [3], wherein the polycarbonate diol is obtained by transesterification in the presence of a transesterification catalyst using a dihydroxy compound and a carbonate compound as raw material monomers.
[5]
The polycarbonate diol according to [4], wherein the carbonate compound is a diaryl carbonate.
[6]
The polycarbonate diol according to any one of [1] to [5], which has a turbidity of 2.0 ppm or less as measured by an integrating sphere type turbidimeter.
[7]
The polycarbonate diol according to any one of [1] to [6], having a Hazen color number of 60 or less measured according to JIS K0071-1 (1998).
[8]
A method of producing a polycarbonate diol having a number average molecular weight of 250 or more and 5500 or less by using a dihydroxy compound and a carbonate compound as a raw material monomer and performing polycondensation by a transesterification reaction in the presence of a transesterification catalyst.
An ester of phosphoric acid and / or phosphorous acid with respect to the polycarbonate diol whose ratio of the end group derived from a carbonate compound is 10 mol% or less with respect to the total amount of end groups among molecular chain ends of polycarbonate diol A method for producing a polycarbonate diol, which is added in an amount of 0.1 to 50 moles per mole of the exchange catalyst.
[9]
The manufacturing method of polycarbonate diol as described in [8] which has a refinement | purification process after phosphoric acid and / or phosphorous acid addition to the said polycarbonate diol.

  The polycarbonate diol of the present invention is excellent in thermal stability, and the color tone does not deteriorate even if the polycarbonate diol is heated for a long period of time, and changes in both molecular weight and composition are small. In this case, it is extremely useful industrially without any change in physical properties such as color tone of polyurethane.

  Hereinafter, although the form of the present invention is explained in detail, the present invention is not limited to the following embodiments, and can be variously deformed and carried out within the limits of the gist.

[1. Polycarbonate diol]
The polycarbonate diol of the present invention has a number average molecular weight of 250 or more and 5500 or less, and is at least selected from the group consisting of long period periodic group 1 elements (except hydrogen) and long periodic period periodic group 2 elements It is a polycarbonate diol containing one kind of element.
The polycarbonate diol is preferably obtained by transesterification using a dihydroxy compound and a carbonate compound as raw material monomers in the presence of a transesterification catalyst.

<1-1. Dihydroxy compound>
Although the dihydroxy compound of the raw material monomer is not particularly limited, it is preferable to contain a compound represented by the following formula (A) (hereinafter sometimes referred to as "dihydroxy compound (A)").
When the polycarbonate diol manufactured using the dihydroxy compound containing the dihydroxy compound (A) as a raw material monomer contains a specific metal, the thermal stability is excellent by containing a specific amount of phosphoric acid and / or phosphorous acid It becomes possible to set it as a polycarbonate diol.

  Examples of the dihydroxy compound (A) include 2,2-dimethyl-1,3-propanediol (hereinafter sometimes referred to as neopentyl glycol, sometimes abbreviated as "NPG"), 2-ethyl-2-butyl-1,3 2,2-dialkyl-substituted 1,3-propanediols such as propanediol, 2,2-diethyl-1,3-propanediol and 2-pentyl-2-propyl-1,3-propanediol (hereinafter referred to as 2 And 2-dialkyl-1,3-propanediols, provided that the alkyl group is an alkyl group having a carbon number of 15 or less), 2,2,4,4-tetramethyl-1,5- Tetraalkyl substituted alkylene diols such as pentanediol and 2,2,9,9-tetramethyl-1,10-decanediol; 3,9-bis (1,1-dime Diols containing a cyclic group such as 2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, 2,2-diphenyl-1,3-propanediol, 2,2 -Divinyl-1,3-propanediol, 2,2-diethynyl-1,3-propanediol, 2,2-dimethoxy-1,3-propanediol, bis (2-hydroxy-1,1-dimethylethyl) ether And bis (2-hydroxy-1,1-dimethylethyl) thioether as well as 2,2,4,4-tetramethyl-3-cyano-1,5-pentanediol and the like.

(In the above formula, n is 0 or 1, and R ₁ and R ₂ are each independently a group selected from the group consisting of an alkyl group having 1 to 15 carbon atoms, an aryl group, an alkenyl group, an alkynyl group and an alkoxy group, In the range of the carbon number, it may have an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom or a substituent containing these, and X is a divalent C 1-15 carbon atom which may contain a hetero atom Represents a group)
Among these, those in which n is 0 and R ₁ and R ₂ are an alkyl group having 1 to 5 carbon atoms are preferable. Specific raw material compounds giving the structure are, for example, 2,2-dimethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 2,2-diethyl-1, Mention may be made of 2,2-dialkyl-substituted 1,3-propanediols such as 3-propanediol and 2-pentyl-2-propyl-1,3-propanediol.
The dihydroxy compound of the raw material monomer is not particularly limited, but a dihydroxy compound having a structure represented by the following formula (B) (hereinafter sometimes referred to as "structure (B)") (hereinafter "dihydroxy compound (B)" It may be preferable to include the

(In the above formula (B), the site represented by the formula (B) excluding the case is part of _-CH 2 -O-H.)
When the polycarbonate diol manufactured using the dihydroxy compound containing the dihydroxy compound (B) as a raw material monomer contains a specific metal, the heat stability is excellent by containing a specific amount of phosphoric acid and / or phosphorous acid It becomes possible to set it as a polycarbonate diol.

  More specifically as the dihydroxy compound (B), oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4 -(2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) fluorene, 9,9-bis (4- (2- (2-hydroxyethoxy) -3-isobutylphenyl) fluorene Hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9 Bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis (4- (4) (2-hydroxyethoxy) -3-tert-butyl-6-methylphenyl) fluorene 9,9-bis (4- (3-hydroxy-2,2-dimethylpropoxy) phenyl) fluorene etc., aromatic group in side chain And a compound having an ether group bonded to an aromatic group in the main chain, and a compound having a cyclic ether structure. Further, among the compounds having a cyclic ether structure, a compound having a plurality of cyclic ether structures is more preferable, and a compound having two cyclic ether structures is more preferable. As the compound having a cyclic ether structure, an anhydrous sugar alcohol represented by a dihydroxy compound represented by the following formula (C) is particularly preferable. These may be used alone or in combination of two or more, depending on the required performance of the polycarbonate diol to be obtained.

  Among these dihydroxy compounds, it is preferable to use a dihydroxy compound having no aromatic ring structure from the viewpoint of the light resistance of the polyurethane obtained from polycarbonate diol, and among them, variously available as plant resources. Isosorbide (hereinafter sometimes abbreviated as "ISB") obtained by dehydration condensation of sorbitol produced from starch of the present invention is easy to obtain and manufacture, hardness, abrasion resistance, light resistance, carbon neutral Most preferable in terms of

As the polycarbonate diol of the present invention, a dihydroxy compound (may be referred to as another dihydroxy compound) other than the dihydroxy compound (A) and the dihydroxy compound (B) may be used as long as the effects of the present invention are not impaired. Other dihydroxy compounds include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octane Straight-chain terminal diols such as diol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol and 1,20-eicosanediol, diethylene glycol, trione Diols having an ether group such as ethylene glycol, tetraethylene glycol and polytetramethylene glycol, thioether diols such as bishydroxyethyl thioether, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propane Diol, 3-methyl-1,5 Dicyclic diols such as pentanediol and 2,4-diethyl-1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 4,4- Dicyclohexyldimethylmethanediol, 2,2'-bis (4-hydroxycyclohexyl) propane, 1,4-dihydroxyethylcyclohexane, isosorbide, 2,5-bis (hydroxymethyl) tetrahydrofuran, 4,4'-isopropylidenedicyclohexanol And diols having a cyclic group such as 4,2'-isopropylidenebis (2,2'-hydroxyethoxycyclohexane) in the molecule, nitrogen-containing diols such as diethanolamine and N-methyl-diethanolamine, and bis (hydroxyethyene) ) Sulfur-containing diols such as Suruhido, and the like can be given. These diols may be used alone as the component (B) or may be used in combination.

<1-2. Carbonate compound>
As a carbonate compound which can be used, it is not limited as long as the effect of the present invention is not impaired, and dialkyl carbonate, diaryl carbonate or alkylene carbonate can be mentioned. Among these, diaryl carbonate is preferable from the viewpoint of reactivity.
Specific examples of the carbonate compound which can be used for producing the polycarbonate diol of the present invention include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, ethylene carbonate and the like, and diphenyl carbonate (hereinafter abbreviated as "DPC") In some cases) is preferred.

<1-3. Use ratio of raw material monomer>
The amount of the carbonate compound to be used is not particularly limited, but the lower limit is preferably 0.35, more preferably 0.50, still more preferably 0.60 in molar ratio to 1 mol in total of the dihydroxy compounds. Preferably it is 1.00, More preferably, it is 0.98, More preferably, it is 0.97. If the amount of the carbonate compound used exceeds the above upper limit, the proportion of terminal groups of the obtained polycarbonate diol which is not a hydroxyl group may increase or the molecular weight may not fall within a predetermined range. There is a case.

<1-4. Transesterification catalyst>
In the case of producing the polycarbonate diol of the present invention, a transesterification catalyst (hereinafter sometimes referred to as a catalyst) can be used as needed to accelerate the polymerization. In that case, if too much catalyst remains in the obtained polycarbonate diol, the polycarbonate diol may become cloudy or may become easily colored by heating. Moreover, when manufacturing a polyurethane, reaction may be inhibited or reaction may be promoted excessively.
For this reason, the amount of catalyst remaining in the polycarbonate diol is not particularly limited, but is preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 30 ppm or less, particularly preferably 20 ppm or less, most preferably as a catalyst metal content Is less than 10 ppm.

On the contrary, since the polycondensation reaction of the dihydroxy compound and the carbonate compound does not proceed if the catalyst is excessively small, the content of the catalyst in terms of catalyst metal is preferably 0.1 ppm or more, more preferably 0.5 ppm or more, and further preferably Is 1 ppm or more.
As the transesterification catalyst, any compound generally regarded as having transesterification ability can be used without limitation.

  Examples of transesterification catalysts include compounds of long-period periodic table group 1 elements (excluding hydrogen) such as lithium, sodium, potassium, rubidium, cesium and the like; long-periodic periodic compounds such as magnesium, calcium, strontium, barium, etc. Compounds of group 2 elements; compounds of long period type periodic table 4 elements such as titanium and zirconium; compounds of long period type periodic table 5 elements of hafnium etc. long period periodic table 9 such as cobalt Compounds of group A elements; compounds of long period type periodic table group 12 elements such as zinc; compounds of long period type periodic table group 13 elements such as aluminum; long period type periodic table group 14 such as germanium, tin, lead etc. Compound of element; Compound of long period periodic table group 15 element such as antimony, bismuth, etc. Formation of lanthanide metal such as lanthanum, cerium, europium, ytterbium Thing, and the like. Among these, from the viewpoint of increasing the transesterification reaction rate, a compound of a long period type periodic table group 1 element (except hydrogen), a long period type periodic table group 2 element compound, a long period periodic table 4 Compounds of group elements, compounds of long group periodic table group 5 elements, compounds of long group periodic table group 9 elements, compounds of long group periodic table group 12 elements, long group periodic table group 13 elements Compounds of long period periodic table group 14 elements are preferable, compounds of long period periodic group group 1 elements (except hydrogen), compounds of long period periodic group group 2 elements are more preferable, long Compounds of the periodic table group 2 element are more preferred. Among the compounds of the long period periodic table group 2 element, compounds of magnesium, calcium and barium are preferable, compounds of calcium and magnesium are more preferable, and compounds of magnesium are more preferable. These metal compounds are mainly used as hydroxides, salts and the like. Examples of salts when used as salts include halide salts such as chloride, bromide and iodide; carboxylates such as acetate, formate and benzoate; methanesulfonic acid, toluenesulfonic acid, trifluoro Sulfonic acid salts such as lomethanesulfonic acid; acetylacetonate salts; and the like. The catalytic metal can also be used as an alkoxide such as methoxide or ethoxide.

  Among these, preferably, an acetate or nitrate, a sulfate, a carbonate, a hydroxide, a halide or an alkoxide of at least one metal selected from long-period periodic group group 2 elements is used. Preferably, acetates, carbonates and hydroxides of long period periodic group 2 elements are used, more preferably magnesium, acetates and carbonates of calcium and hydroxides are used, and particularly preferably magnesium, Calcium acetate is used, most preferably magnesium acetate is used.

  The weight average molecular weight / number average molecular weight (Mw / Mn), which is the molecular weight distribution of the polycarbonate diol of the present invention, is not particularly limited, but the lower limit is preferably 1.5, more preferably 1.8. The upper limit is preferably 3.5, more preferably 3.0. If the molecular weight distribution exceeds the above range, the physical properties of the polyurethane produced using this polycarbonate diol tend to be hard at low temperatures, the elongation decreases, etc., and it is attempted to produce a polycarbonate diol having a molecular weight distribution below the above range. Then, sophisticated purification operations such as removal of oligomers may be required.

  The weight average molecular weight is a weight average molecular weight in terms of polystyrene, and the number average molecular weight is a number average molecular weight in terms of polystyrene. The weight average molecular weight can be determined usually by gel permeation chromatography (sometimes abbreviated as GPC).

<1-6. Molecular chain end>
The molecular chain ends of the polycarbonate diol of the present invention are mainly hydroxyl groups. However, in the case of a polycarbonate diol obtained by the reaction of a dihydroxy compound and a carbonate compound, there is a possibility that some of the molecular chain terminals are not hydroxyl groups as impurities. As a specific example, the molecular chain end is an alkyloxy group or an aryloxy group, and many are structures derived from a carbonate compound.

For example, when a diphenyl carbonate is used as the carbonate compound, a phenoxy group (PhO-) as an aryloxy group, a methoxy group (MeO-) as an alkyloxy group when dimethyl carbonate is used, and an ethoxy group when diethyl carbonate is used When (EtO-) or ethylene carbonate is used, a hydroxyethoxy group (HOCH ₂ CH ₂ O-) may sometimes remain as the molecular chain end (here, Ph represents a phenyl group and Me represents a methyl group. , Et represents an ethyl group).

The ratio of the total number of the terminal number derived from the dihydroxy compound is preferably 90 mol% or more, more preferably 95 mol% or more, still more preferably the molecular chain terminals of the polycarbonate diol of the present invention to the total terminal number. Is 97 mol% or more, particularly preferably 99 mol% or more. By setting it as the said range, when it is set as a polyurethane, it becomes easy to set it as a desired molecular weight, and it becomes possible to become a raw material of the polyurethane excellent in the physical property balance.
The ratio of the number of end groups derived from the carbonate compound at the molecular chain end of polycarbonate diol is preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably 3 mol%, with respect to the total number of terminals. The content is particularly preferably 1 mol% or less.

  The lower limit of the hydroxyl value of the polycarbonate diol of the present invention is preferably 20 mg KOH / g, more preferably 25 mg KOH / g, still more preferably 30 mg KOH / g, most preferably 35 mg KOH / g. The upper limit is preferably 450 mg-KOH / g, more preferably 230 mg-KOH / g, and still more preferably 150 mg-KOH / g. If the hydroxyl value is less than the above lower limit, the viscosity may be too high, and handling during polyurethane formation may be difficult. When the above upper limit is exceeded, physical properties such as flexibility and low temperature properties may be insufficient when polyurethane is used.

<1-7. Metal content>
In the polycarbonate diol of the present invention, the element derived from the transesterification catalyst may remain in the polycarbonate diol. Moreover, it may be mixed as an impurity of a dihydroxy compound, a carbonate compound, or other additives. Furthermore, elements may be mixed into the polycarbonate diol from a reaction apparatus that performs a transesterification reaction. The invention applies in all those cases.

The total content of the elements derived from the transesterification catalyst in the polycarbonate diol is preferably 0.1 ppm to 100 ppm, and the lower limit is more preferably 0.5 ppm, and still more preferably 1 ppm. The upper limit is more preferably 50 ppm, still more preferably 30 ppm, particularly preferably 20 ppm, and most preferably 10 ppm. When the total content of the elements is excessively large, the polycarbonate diol may be clouded, control of the reaction may be difficult during polyurethane formation reaction, and polyurethane reaction may be promoted more than expected to cause abnormal reaction. In addition, even if phosphoric acid and / or phosphorous acid is contained, prevention of deterioration of color tone may be insufficient, and it may be difficult to control increase in molecular weight. If the amount is too small, the polycondensation reaction between the dihydroxy compound and the carbonate compound does not proceed, which is not preferable. The method of controlling the total content of the elements is, for example, using a preferable range of amount of transesterification catalyst, using a purified raw material monomer, selecting an appropriate temperature, residence time in transesterification reaction, etc. Can be mentioned.

<1-8. Phosphoric acid, phosphorous acid>
The polycarbonate diol of the present invention contains phosphoric acid and / or phosphorous acid. Specifically, the total content of phosphoric acid and phosphorous acid with respect to the total content of the long-period periodic table group 1 element (excluding hydrogen) and the long-period periodic table group 2 element in the polycarbonate diol The content is, in terms of phosphorus atom, 0.1 to 50 mole times. The lower limit is preferably 0.2 molar times, more preferably 0.3 molar times, still more preferably 0.4 molar times, particularly preferably 0.5 molar times, and most preferably 0.6 molar times. The upper limit is preferably 10 molar times, more preferably 5 molar times, still more preferably 3 molar times, particularly preferably 2 molar times, and most preferably 1.5 molar times. If the total content of phosphoric acid and phosphorous acid is low, heating the polycarbonate diol may deteriorate the color tone, and the molecular weight of the polycarbonate diol may increase and the composition may change. When the total content of phosphoric acid and phosphorous acid is large, when the polycarbonate diol is used as a raw material for polyurethane, the polyurethane is easily hydrolyzed and there is a possibility that phosphoric acid and phosphorous acid may bleed out. .

  By containing phosphoric acid and / or phosphorous acid, it is possible to obtain polycarbonate diol which is less in increase in molecular weight, composition change and color tone due to heating. Among them, phosphoric acid is more preferable from the viewpoints of suppressing the deterioration of the color tone of polycarbonate diol and having little influence on the reactivity and color tone at the time of polyurethane formation.

  The method of adding phosphoric acid and / or phosphorous acid to polycarbonate diol is added to the reactor at 0.2 mole-fold or more and 50 mole-fold or more with respect to 1 mole of transesterification catalyst used for producing polycarbonate diol. The addition conditions can be carried out even at room temperature, but the heat treatment makes the effect more efficient. The temperature of the heat treatment is not particularly limited, but the upper limit is preferably 180 ° C., more preferably 150 ° C., still more preferably 120 ° C., and the lower limit is preferably 50 ° C., more preferably 60 ° C., more preferably Is 70 ° C. If the temperature is lower than this, the onset of the effect may be insufficient. On the other hand, at temperatures exceeding 180 ° C., the obtained polycarbonate diol may be colored by heat. Although the reaction time with phosphoric acid and / or phosphorous acid is not particularly limited, it is usually 0.1 to 5 hours.

<1-9. Turbidity>
For the turbidity of the polycarbonate diol of the present invention, a 50% solution of polycarbonate diol in methylene chloride is placed in a 10 mm cell with an integrating sphere-type turbidity meter PT-200 manufactured by Mitsubishi Chemical Co., Ltd. The value measured using the calibration curve is preferably 2.0 ppm or less, more preferably 1.0 ppm or less, and particularly preferably 0.5 ppm or less. When the turbidity is more than 2.0 ppm, the transparency of the polyurethane obtained from polycarbonate diol as a raw material may be deteriorated to reduce the commercial value or the mechanical physical properties. The turbidity is considered to be mainly due to aggregation and precipitation of catalyst components, aggregation and precipitation of additives, and formation of cyclic oligomers with low solubility, etc. In order to reduce turbidity to 2.0 ppm or less, at the time of polycarbonate diol production It is necessary to comprehensively control the selection of the type and amount of the catalyst, additives, thermal history, concentration of monohydroxy compound during polymerization and after completion of polymerization, and concentration of unreacted monomer. For example, when the solubility of the catalyst itself in the polycarbonate diol is low, precipitation of the catalyst is likely to occur, and when the concentration is high, precipitation is promoted. On the other hand, in order to suppress the formation of a cyclic oligomer having poor solubility, it is also important to select and combine a dihydroxy compound as a monomer. For example, in the case of homopolymers, cyclic oligomers tend to be formed, but copolymerization makes it difficult to form a stable cyclic structure and tends to lower turbidity. In addition, if the temperature at the time of polycarbonate diol production is high, cyclic oligomers are thermodynamically easily formed, so it is effective to lower the polymerization temperature. However, if the amount is too low, productivity may be impaired, or it may take an excessive amount of time to cause deterioration in color tone, or deterioration in turbidity, which is not preferable.

<1-10. APHA value>
The color of the polycarbonate diol of the present invention is the Hazen color number (JIS-K0071-1
: 60 or less, preferably 50 or less, more preferably 30 or less, and still more preferably 20 or less in terms of the value (hereinafter referred to as "APHA value") when expressed as 1998. . When the APHA value exceeds 60, the color tone of the polyurethane obtained from polycarbonate diol as a raw material is deteriorated, the commercial value is lowered, or the heat stability is deteriorated. In order to make the APHA value 60 or less, selection of the type and amount of catalyst and additive in polycarbonate diol production, heat history, concentration of monohydroxy compound during polymerization and after completion of polymerization, and concentration of unreacted monomer Need to be controlled. In addition, light shielding during and after polymerization is also effective. Further, setting of the molecular weight of polycarbonate diol and selection of a dihydroxy compound species which is a monomer are also important. In particular, polycarbonate diols having an aliphatic dihydroxy compound having an alcoholic hydroxyl group as a raw material exhibit various excellent properties such as flexibility, water resistance, light resistance, etc. when processed into polyurethane, but an aromatic dihydroxy compound is a raw material In this case, the thermal history and the coloration by the catalyst tend to be more remarkable than in the above case, and it is not easy to make the APHA value 60 or less.

<1-11. Residual monomers etc>
When an aromatic carbonate compound 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, for example, when producing polyurethane using the polycarbonate diol as a raw material, phenols may be an inhibitor of the reaction, and urethane bonds formed by phenols are Since the bond strength is weak, it is dissociated by heat in a subsequent step or the like, and the isocyanate and phenols may be regenerated to cause a failure. Moreover, since phenols are also irritating substances, the residual amount of phenols in polycarbonate diol is preferably as small as possible. Specifically, the weight ratio to the polycarbonate diol is preferably 1000 ppm or less, more preferably 500 ppm or less, still more preferably 300 ppm or less, and preferably 100 ppm or less. In order to reduce phenols in the polycarbonate diol, as described later, the pressure of the polymerization reaction of the polycarbonate diol is a high vacuum of 1 kPa or less as an absolute pressure, or a purification process such as thin film distillation is performed after the polycondensation reaction of the polycarbonate diol. It is effective to do.

  In polycarbonate diol, the carbonate compound used as a raw material at the time of manufacture may remain. Although the residual amount of the carbonate compound in the polycarbonate diol is not limited, the smaller one is preferable, and the upper limit is preferably 5% by weight, more preferably 3% by weight, still more preferably 1% by weight as the weight ratio to the polycarbonate diol. is there. If the carbonate compound content of the polycarbonate diol is too high, the reaction during polyurethane formation may be inhibited.

  In the polycarbonate diol, the dihydroxy compound used at the time of manufacture may remain. The residual amount of the dihydroxy compound in the polycarbonate diol is not limited, but is preferably small, and is preferably 1% by weight or less, more preferably 0.1% by weight or less, as a weight ratio to the polycarbonate diol. Is less than 0.05% by weight. When the residual amount of the dihydroxy compound in the polycarbonate diol is large, the molecular length of the soft segment part in forming the polyurethane may be insufficient, and a desired physical property may not be obtained.

The polycarbonate diol may contain a cyclic carbonate (cyclic oligomer) by-produced in the production. For example, when 2,2-dimethyl-1,3-propanediol is used as the compound represented by the formula (A), 2,2-dimethyl-1,3-dioxane-2-one or two molecules of these are further used. Further, a cyclic carbonate or the like may be generated and contained in the polycarbonate diol. Since these compounds may cause side reactions in the polyurethane formation reaction and cause turbidity, the pressure of the polymerization reaction of polycarbonate diol is set to a high vacuum of 1 kPa or less as an absolute pressure, or synthesis of polycarbonate diol is performed. It is preferable to carry out thin film distillation etc. later and to remove as much as possible. The content of these cyclic carbonates contained in the polycarbonate diol is not limited, but is preferably 3% by weight or less, more preferably 1% by weight or less, still more preferably 0.5% by weight or less as a weight ratio to the polycarbonate diol .

[2. Method for producing polycarbonate diol]
The method for producing the polycarbonate diol of the present invention uses a dihydroxy compound and a carbonate compound as raw material monomers, and is polycondensed by a transesterification reaction in the presence of a transesterification catalyst and has a hydroxyl value of 20 mg KOH / g or more and 450 mg KOH / g or less The method for producing a polycarbonate diol, wherein the proportion of end groups derived from a carbonate compound among molecular chain ends of the polycarbonate diol is 10 mol% or less based on the total amount of end groups. And a method of producing a polycarbonate diol in which phosphoric acid and / or phosphorous acid is added in an amount of 0.1 to 50 moles per mole of the transesterification catalyst.

<2-1. Dihydroxy compound>
The dihydroxy compound is not particularly limited, but preferably contains at least one selected from the group consisting of the dihydroxy compound (A) and the dihydroxy compound (B).

2-2. Carbonate compound>
As a carbonate compound, a diaryl compound is preferable.

<2-3. Transesterification catalyst>
Any transesterification catalyst can be used without limitation as long as it is a compound generally considered to have transesterification ability, but from the viewpoint of increasing the transesterification reaction rate, long period periodic table group 1 element (excluding hydrogen The compound of long period type periodic table group 2 element, the compound of long period type periodic table group 4 element, the compound of long period type periodic table group 5 element, the long period type periodic table group 9 element Preferred is a compound, a compound of a long period periodic table group 12 element, a compound of a long period periodic table group 13 element, a compound of a long period periodic table group 14 element, a long period periodic table group 1 element ( The compounds of hydrogen except for) and the compounds of long period periodic table group 2 elements are more preferable, and the compounds of long period periodic table group 2 elements are more preferable.

  The upper limit of the weight ratio of the specific element to the weight of the raw material monomer dihydroxy compound is preferably 100 ppm, more preferably 50 ppm, and still more preferably 30 ppm. Preferably 20 ppm is preferred, and 10 ppm is most preferred. On the other hand, the lower limit is preferably such an amount that sufficient polymerization activity can be obtained, that is, 0.1 ppm, more preferably 0.5 ppm, still more preferably 1 ppm, and particularly preferably 3 ppm.

<2-4. Molecular weight / molecular weight distribution>
The lower limit of the number average molecular weight (Mn) of the polycarbonate diol of the present invention determined from NMR is 250, preferably 500, and more preferably 750. On the other hand, the upper limit is 5,500, preferably 4,500, more preferably 3,500, still more preferably 3,000. When the Mn of the polycarbonate diol is less than the above lower limit, sufficient flexibility may not be obtained when it is urethane. On the other hand, if the above upper limit is exceeded, the viscosity may be increased, which may impair the handling during the polyurethane formation. The number average molecular weight can be determined by nuclear magnetic resonance (NMR).

<2-5. Reaction temperature>
The reaction temperature in transesterification can be arbitrarily selected as long as a practical reaction rate can be obtained. In general, the lower limit of the reaction temperature is preferably 70 ° C., more preferably 100 ° C., and still more preferably 130 ° C. The upper limit of the reaction temperature is usually preferably 220 ° C., more preferably 200 ° C., and still more preferably 180 ° C. By setting the upper limit of the reaction temperature to the above value, it is possible to prevent quality problems such as coloring of the obtained polycarbonate diol and formation of an ether structure.

  Furthermore, the reaction temperature is preferably 180 ° C. or less, more preferably 170 ° C. or less, and still more preferably 160 ° C. or less throughout the entire steps of the transesterification reaction for producing a polycarbonate diol. By setting the reaction temperature to 180 ° C. or less throughout the above-described steps, it is possible to prevent easy coloring due to the conditions.

<2-6. Amount of hydroxyaryl in reaction>
In polycarbonate diol, the content of phenols contained in the solution during the reaction (hereinafter sometimes referred to as "the concentration of hydroxyaryl contained in the polymerization reaction component") is preferably 45 wt% or less, preferably 30 wt% It is more preferable to make it to the following, and it is further preferable to make it 20 wt% or less.

  In particular, it is preferable to maintain the content of phenols contained in the solution in the reaction throughout the entire process of the transesterification reaction to the above-mentioned upper limit or less. By setting the content to the above upper limit or less, the amount of phenols can be limited under high temperature conditions at the time of transesterification, and it becomes difficult to color.

In addition, as a method of making content of phenols into upper limit value or less, reaction is performed under pressure reduction from reaction initial stage, for example, Distilling off the produced phenols etc. are mentioned, for example.
Also, the content of the phenols can be measured, for example, by extracting a part of the reaction solution from the reactor at regular intervals and quantifying it by NMR, GPC and LC.

<2-7. Reaction pressure>
Although the reaction can be carried out under normal pressure, the transesterification reaction is an equilibrium reaction, and the reaction can be biased to a production system by distilling off the light boiling components to be produced out of the system. Therefore, in the latter half of the reaction, the reaction is preferably carried out while distilling off the light boiling components under reduced pressure conditions.

Or it is also possible to make it react, distilling off the light-boiling component which lowers | hangs a pressure gradually from the middle of reaction, and produces | generates. In particular, it is preferable to carry out the reaction by increasing the degree of reduced pressure at the end of the reaction, since the by-produced monoalcohol, phenols, cyclic carbonate and the like can be distilled off.
The upper limit of the reaction pressure at the end of the reaction is preferably 10 kPa, more preferably 5 kPa, and still more preferably 1 kPa. In order to effectively distill these light-boiling components, the reaction can also be carried out while flowing an inert gas such as nitrogen, argon and helium into the reaction system.

When a low-boiling dihydroxy compound or carbonate compound is used in the transesterification reaction, the reaction is carried out near the boiling point of the dihydroxy compound or carbonate compound at the initial stage of the reaction, and the temperature is gradually raised as the reaction proceeds. It is also possible to adopt a method of advancing the reaction. In this case, it is preferable because distillation of unreacted carbonate compound can be prevented at the initial stage of the reaction.
Furthermore, in order to prevent evaporation of these raw materials, it is also possible to carry out the reaction while refluxing the dihydroxy compound and the carbonate compound by attaching a reflux pipe to the reactor, in which case the amount of the charged raw materials is not lost. It is preferable because the ratio can be accurately adjusted.

<2-8. Reaction method>
The polymerization reaction can be carried out batchwise or continuously, but in the present invention it is preferable to carry out continuously from the viewpoint of product stability and the like. The apparatus to be used may be any of a tank type, a tube type and a column type, and a known polymerization tank or the like equipped with various stirring blades can be used. The atmosphere during the temperature rise of the apparatus is not particularly limited, but from the viewpoint of product quality, it is preferable to be carried out in an inert gas such as nitrogen gas under normal pressure or reduced pressure.

<2-9. Addition of phosphoric acid and / or phosphorous acid>
As the transesterification proceeds, the ratio of end groups derived from the carbonate compound to the total end groups of the formed polycarbonate diol decreases. Then, after the proportion of end groups derived from the carbonate compound becomes 10 mol% or less with respect to the total amount of end groups, 0.1% of phosphoric acid and / or phosphorous acid with respect to 1 mol of transesterification catalyst The molar amount is added and the 50 molar amount or less. As for the addition time of phosphoric acid and / or phosphorous acid, the ratio of the end group originating in a carbonate compound is more preferably 5 mol% or less, further preferably 3% or less, and particularly preferably 1% or less.

  Phosphoric acid and / or phosphorous acid may be added directly, but from the viewpoint of corrosion of the material of the reaction tank, it is preferable to add it by dissolving preferably in a solvent or the like. Examples of the solvent and the like include water, an organic solvent, a dihydroxy compound, a polycarbonate diol and the like, and it is more preferable to dissolve in a dihydroxy compound and a polycarbonate diol to be added. The addition of phosphoric acid and / or phosphorous acid dissolved in water is not preferable because corrosion of the material of the reaction vessel is likely to occur, and it is not preferable immediately after completion of the transesterification reaction. In the case of adding, since the temperature in the tank is high and the water is vaporized, there is a high possibility that phosphoric acid and / or phosphorous acid is not added to the polycarbonate diol, which is not preferable. As for the organic solvent, when phosphoric acid and / or phosphorous acid is added immediately after the end of the transesterification reaction, the temperature in the tank is high and the organic solvent is vaporized, so phosphoric acid and / or phosphorous acid is polycarbonate It is not likely to be added to the diol, which is not preferable.

  The lower limit of the addition amount of phosphoric acid and / or phosphorous acid is preferably 0.2 molar times, more preferably 0.3 molar times, still more preferably 0.4 molar times, particularly preferably 0.5 molar times, most Preferably, it is 0.6 molar times. The upper limit is preferably 10 molar times, more preferably 5 molar times, still more preferably 3 molar times, particularly preferably 2 molar times, and most preferably 1.5 molar times. By being in the said range, it becomes possible to deactivate a transesterification catalyst efficiently. Therefore, when removing residual monomers or adjusting molecular weight after transesterification, it becomes possible to produce polycarbonate diol stable in quality without coloration due to heating and change in molecular weight and the like.

<2-10. Purification step>
It is preferable to have a purification step after addition of phosphoric acid and / or phosphorous acid to the polycarbonate diol. In the purification process, purification is carried out for the purpose of removing raw material dihydroxy compounds, raw material carbonate compounds, low-yielding cyclic carbonates by-produced in the polycarbonate diol product, alcohols by-produced from carbonate compounds, phenols and added catalysts, etc. Examples of the process include vacuum distillation, steam distillation and thin film distillation. Among them, thin film distillation is effective.
Although there is no restriction | limiting in particular as thin film distillation conditions, It is preferable that an upper limit is 250 degreeC and the temperature at the time of thin film distillation is 200 degreeC. Further, the lower limit is preferably 120 ° C., and more preferably 150 ° C.

  By setting the lower limit of the temperature at the time of thin film distillation to the above value, the light boiling component removal effect becomes sufficient. Further, by setting the upper limit to 250 ° C., it is possible to prevent the polycarbonate diol obtained after thin film distillation from being colored.

The upper limit of the pressure during thin film distillation is preferably 500 Pa, more preferably 150 Pa, and still more preferably 50 Pa. By making the pressure at the time of thin film distillation below the above-mentioned upper limit, the removal effect of a light boiling ingredient is fully acquired.
The upper limit of the temperature for keeping the temperature of the polycarbonate diol just before thin-film distillation is preferably 250 ° C., and more preferably 150 ° C. In addition, the lower limit is preferably 80 ° C., and more preferably 120 ° C.

By setting the temperature for keeping the temperature of the polycarbonate diol just before the thin film distillation to the above lower limit or more, it is possible to prevent the flowability of the polycarbonate diol just before the thin film distillation from being lowered. On the other hand, by setting the upper limit or less, it is possible to prevent the polycarbonate diol obtained after thin film distillation from being colored.
In addition, in order to remove water-soluble impurities, it may be washed with water, alkaline water, acidic water and a solution of a chelating agent. In that case, the compound to be dissolved in water can be arbitrarily selected.

EXAMPLES The present invention will be more specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.
Below, the evaluation method of each physical-property value is as follows.

[Evaluation method: polycarbonate diol]
<Quantification of phenoxy group content, dihydroxy compound content and phenol content by NMR and measurement of number average molecular weight of polycarbonate diol>
A polycarbonate diol is dissolved in CDCl ₃ and 400 MHz ¹ H-NMR (AL-400 manufactured by Nippon Denshi Co., Ltd.) is measured, phenoxy group, dihydroxy compound, and phenol are identified from the signal position of each component, and each is integrated The content of was calculated. The lower detection limit at that time is 100 ppm as the weight of phenol based on the weight of the whole sample, and 100 ppm as the dihydroxy compound. 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 lower limit of detection of the phenoxy group is 0.1% with respect to the whole terminal is there. Further, the number average molecular weight of polycarbonate diol was calculated from the integral value of polycarbonate.
Each integral value was calculated according to the following chemical shift. Since the chemical shift value may slightly differ depending on the composition, in such a case, the method of obtaining the integral value may be changed as appropriate.

[Composition analysis (ISB / 1,6-hexanediol copolymer polycarbonate / polycarbonate diol)]
The integral value of the following chemical shift value was acquired by said ¹ H-NMR. In addition, 1, 6 hexanediol may be abbreviated as "16 HD".
Integral value of δ 5.207 to 4.973 ppm = a
Integral value of δ 4.697 to 4.599 ppm = b
Integral value of δ 4.599 to 4.464 ppm = c
Integral value of δ 3.686-3.501 ppm = d
Integral value of δ 2.764 to 2.717 ppm = e
Integral value of δ 1.493 to 1.295 ppm = f

There are two types of structures of chain ends derived from ISB, which are respectively referred to as "ISB end 1" and "ISB end 2". Further, the ISB-derived structural portion in the polycarbonate diol other than the end is referred to as “in ISB”. Similarly, for 16HD, "16HD end" and "in 16HD" are used. The composition ratio was calculated by calculating the respective numbers according to the following equation in consideration of the respective proton numbers.
(ISB) terminal 1 = b−e
(ISB) in = c-(ISB) terminal 1
(ISB) terminal 2 = a-(ISB) terminal 1-(ISB) x 2
(16 HD) end = (de- (ISB) end 1) / 2
(16 HD) in = (f-(16 HD) end x 4) ÷ 4

[Composition analysis (NPG / 16HD copolymer polycarbonate / polycarbonate diol)]
The integral value of the following chemical shift value was taken by said ¹ H-NMR.
Integral value of δ 4.25 to 4.05 ppm = g
Integral value of δ 4.05 to 3.87 ppm = h
Integral value of δ 3.70 to 3.57 ppm = i
Integral value of δ 3.41 to 3.30 ppm = j
Integral value of δ 1.15 to 1.12 ppm = k

The end derived from NPG is referred to as "NPG end". Further, the NPG-derived structural moiety in the polycarbonate diol other than the end is referred to as "in NPG". Similarly, for 16HD, "16HD end" and "in 16HD" are used. The composition ratio was calculated by calculating the respective numbers according to the following equation in consideration of the respective proton numbers.
NPG terminal = j ÷ 2
In NPG = (h-j) ÷ 4
16 HD end = i ÷ 2
In 16 HD = (g-16 HD terminal x 2-k ÷ 6 x 4) ÷ 4

[Composition analysis (other polycarbonate diol)]
As in the case of other ISB / 16HD and NPG / 16HD copolymer polycarbonate diols, structures derived from each terminal and each dihydroxy compound other than the terminal were specified, and the composition ratio was calculated from the integral value and the number of protons.

<Quantitative analysis of the amount of ISB in polycarbonate diol by LC>
1 g of polycarbonate diol was precisely weighed in a 10 mL volumetric flask, acetonitrile was added, and the volume was adjusted to 10 mL. 100 μL of the solution was collected, 900 μL of pure water was added to precipitate polycarbonate diol, and the precipitated polycarbonate diol was removed by filtration. It measured by the quantitative analysis by LC using the solution after filtration.

(Analysis conditions)
Column: Synergi 4 μm Hydro-RP 250 mm L × 4.6 mm I. D.
Injection volume: 50 μL
Eluent: 0.1% aqueous formic acid solution
Flow rate: 0.8 mL / min
Column temperature: 40 ° C
Detector: RI

<Quantitative analysis of the amount of NPG and the amount of neopentyl carbonate (NPC) in polycarbonate diol by LC>
1 g of polycarbonate diol was precisely weighed in a 10 mL volumetric flask, acetonitrile was added, and the volume was adjusted to 10 mL. 100 μL of the solution was collected, 900 μL of pure water was added to precipitate polycarbonate diol, and the precipitated polycarbonate diol was removed by filtration. It measured by the quantitative analysis by LC using the solution after filtration.

(Analysis conditions)
Column: CADENZA CD-C18 3 μm 250 mm × 4.6 mm I. D.
Injection volume: 50 μL
Eluent: water / acetonitrile = 95/5 (volume ratio)
Flow rate: 0.8 mL / min
Column temperature: 40 ° C
Detector: RI

<Quantitative analysis of the amount of phenol in polycarbonate diol by LC>
1 g of polycarbonate diol was precisely weighed in a 10 mL volumetric flask, acetonitrile was added, and the volume was adjusted to 10 mL. It measured by the quantitative analysis by LC using the solution.

(Analysis conditions)
Column: CAPCELL PAK 3 μm 75 mm L × 4.6 mm I. D. MG
Eluent: water / acetonitrile = 95/5 to 0/100 (volume ratio)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detector: UV

<APHA value>
According to JIS K0071-1 (1998), it measured comparing with the standard solution put into the colorimetric tube. The reagent used the color standard solution 1000 degree | times (1 mgPt / mL) (Kishida Chemical). Moreover, the solution was adjusted and judged in 5 steps until APHA50.

<Turbidity>
A 50% methylene chloride solution of polycarbonate diol was placed in a 10 mm cell with an integrating sphere-type turbidity meter PT-200 manufactured by Mitsubishi Chemical Co., Ltd., and measurement was performed using a polystyrene calibration curve set in advance in the device.

<Analysis of phosphoric acid and phosphorous acid content>
1 g of polycarbonate diol was precisely weighed and dissolved in 10 mL of acetonitrile, and then pure water was dropped and the volume was adjusted to 100 mL, and the precipitated polycarbonate diol was removed by filtration. Phosphoric acid and phosphorous acid in the solution after filtration were analyzed by ion chromatography. The phosphoric acid and phosphorous acid concentrations of acetonitrile used as a solvent were measured as blank values, and the value obtained by subtracting the phosphoric acid and phosphorous acid concentrations of the solvent was taken as the phosphoric acid and phosphorous acid concentration of the polycarbonate diol. The measurement conditions are as shown in Table 1 below.

<Analysis of metal element (metal element derived from transesterification catalyst, phosphorus element) amount>
1 g of polycarbonate diol was precisely weighed, 10 mL of 89% sulfuric acid was added, and heating was performed to 200 ° C. to 400 ° C. on a high temperature hot plate. After cooling to room temperature, 1 mL of 69% nitric acid was added, and heating was again performed from 200 ° C. to 400 ° C. on a high temperature hot plate. The operations of nitric acid addition and heating were repeated until the decomposition solution became transparent. After cooling to room temperature, the solution obtained above was quantified using ICP-OES Vista-Pro (manufactured by Agilent) to calculate the molar concentration of the metal element in the polycarbonate.

Thin-film distillation apparatus
An internal condenser with a diameter of 50 mm, a height of 200 mm, and an area of 0.0314 m 2, a jacketed Kamata Scientific Co., Ltd. molecular distillation apparatus MS-300 special type was used.

Synthesis Example 1
(Step 1 reaction)
In a 180 L polymerization reaction tank equipped with a heat medium jacket, a stirrer, a reflux condenser, a condenser, a distillate tank, a cold trap, and a vacuum pump, 14.518 kg of 1,6-hexanediol (16HD), isosorbide (ISB) 17. 954 kg, 37.528 kg of diphenyl carbonate, 5.27 mL of an aqueous solution of magnesium acetate tetrahydrate (concentration: 200 g / L) were charged, and the atmosphere was purged with nitrogen gas. Steam was not fed to the reflux, and hot water of about 45 ° C. was fed to the condenser as a refrigerant. First, the oil was circulated to the jacket of the polymerization reaction tank to heat and dissolve the contents, and it was confirmed that the contents were almost completely dissolved at an internal temperature of 100 ° C., and stirring was started. Thereafter, when the internal temperature reached 146 ° C., the pressure was lowered to 18.0 kPa over 5 minutes to start distilling off by-produced phenol. Thereafter, while maintaining the internal temperature at 162 ° C. and distilling out the by-product phenol, the pressure was lowered to 8.00 kPa over 120 minutes, and the by-product phenol was further distilled. The amount of distillation at this stage was 80% of the theoretical amount of phenol.

(2nd step reaction)
The reaction liquid obtained in the first step was transferred to a 180 L polymerization reaction tank equipped with a heat medium jacket, a stirrer, a reflux condenser, a condenser, a distillate tank, a cold trap, and a vacuum pump under a nitrogen atmosphere. Heat medium oil at 180 ° C. was circulated in the polymerization reaction vessel jacket, steam at about 100 ° C. was passed as a refrigerant in the reflux condenser, and hot water at about 45 ° C. was passed as the refrigerant in the condenser. After transferring the reaction liquid of the first stage, the pressure was lowered to 8.00 kPa over 5 minutes. At that stage, the temperature of the reaction solution reached 165 ° C., and by-produced phenol began to be distilled. Thereafter, while the pressure was lowered to 0.40 kPa over 60 minutes, the reaction was carried out while distilling off and removing the phenol and the unreacted dihydroxy compound. Thereafter, the reaction was continued at 166 ° C. and 0.40 kPa for 115 minutes, followed by filtration with a filter to obtain a polycarbonate diol. The results are shown in Table 2 below.

(Result of reaction)
The obtained polycarbonate diol product is a transparent liquid at normal temperature, molecular weight 819, APHA 45, overall ratio 16 HD / ISB = 54/46, content of dihydroxy compound isosorbide is 8.7% by weight, phenol-containing The amount was 0.37% by weight, and ether bonds other than phenoxide terminal and isosorbide skeleton were not detected. Moreover, the residual diphenyl carbonate was below the quantitative limit (0.01 weight% or less). Furthermore, the terminal group derived from the carbonate compound was not detected.

[Synthesis examples 2, 6, 8]
A reaction was performed in the same manner as in Synthesis Example 1 except that the raw materials, the reaction temperature, and the reaction time described in Table 2 were changed. The reaction results are shown in Table 2.

Synthesis Example 3
The raw materials, reaction temperature, and reaction time described in Table 2 were changed to a pressure of 5 minutes after the start of pressure reduction in the first step reaction of 20.0 kPa, and a pressure of 120 minutes after that of 9.3 kPa, the second step The reaction was carried out in the same manner as in Synthesis Example 1 except that the pressure 5 minutes after the start of pressure reduction in the reaction (a) was changed to 9.3 kPa.

(Thin film distillation)
Furthermore, thin film distillation (jacket oil temperature: 180 ° C., pressure: 0.027 kPa) was performed at a flow rate of 20 g / min for the obtained product.
Physical properties of the polycarbonate diol product after thin film distillation are described in Table 2.

Synthesis Example 4
A reaction was performed in the same manner as in Synthesis Example 1 except that the raw materials, the reaction temperature, and the reaction time described in Table 2 were changed.
(Thin film distillation)
Furthermore, thin film distillation (jacket oil temperature: 160 ° C., pressure: 0.027 kPa) was performed at a flow rate of 20 g / min for the obtained product.
Physical properties of the polycarbonate diol product after thin film distillation are described in Table 2.

Synthesis Example 5
A reaction was performed in the same manner as in Synthesis Example 1 except that the raw materials, the reaction temperature, and the reaction time described in Table 2 were changed.
(Phosphoric acid added)
The polycarbonate diol of Synthesis Example 1 prepared in advance after confirming that the ratio of the end group derived from the carbonate compound to the molecular chain end of the polycarbonate diol in the reaction is undetected by NMR 609 g of phosphoric acid-containing polycarbonate diol to which phosphoric acid was added so as to be 0.040 wt% was pumped and added to the polycarbonate diol in the reaction. The reaction results are shown in Table 2. The yield was calculated by the amount excluding the polycarbonate diol added.

Synthesis Example 7
A reaction was performed in the same manner as in Synthesis Example 1 except that the raw materials, the reaction temperature, and the reaction time described in Table 2 were changed.
(Phosphoric acid added)
Before thin-film distillation of Synthesis Example 4 prepared in advance after confirmation that the ratio of the terminal group derived from the carbonate compound to the molecular chain terminal of the polycarbonate diol in the reaction was undetected by NMR The phosphoric acid-containing polycarbonate diol 472 g in which phosphoric acid was added to 0.040 wt% of the polycarbonate diol of the above was transferred by a pump and added to the polycarbonate diol in the reaction. The reaction results are shown in Table 2. The yield was calculated by the amount excluding the polycarbonate diol added.

Synthesis Example 9
(Step 1 reaction)
In a 180 L polymerization reaction vessel equipped with a heat medium jacket, stirrer, reflux condenser, condenser, distillate tank, cold trap, vacuum pump, 11.478 kg of 1,4-butanediol (14BG), isosorbide (ISB) 18. 613 kg, diphenyl carbonate 39.615 kg, and magnesium acetate tetrahydrate aqueous solution 5.46 mL (concentration: 200 g / L) were charged, and nitrogen gas substitution was carried out. Steam was not fed to the reflux, and hot water of about 45 ° C. was fed to the condenser as a refrigerant. First, the oil was circulated to the jacket of the polymerization reaction tank to heat and dissolve the contents, and it was confirmed that the contents were almost completely dissolved at an internal temperature of 100 ° C., and stirring was started. After that, when the internal temperature reached 146 ° C., the pressure was lowered to 21.3 kPa over 5 minutes to start distilling off by-produced phenol. Thereafter, while maintaining the internal temperature at 160 ° C., by-product phenol was distilled at 21.3 kPa for 30 minutes, the pressure was lowered to 12.0 kPa over 90 minutes, and further by-product phenol was distilled off. The amount of distillation at this stage was 80% of the theoretical amount of phenol.

(2nd step reaction)
The reaction liquid obtained in the first step was transferred to a 180 L polymerization reaction tank equipped with a heat medium jacket, a stirrer, a reflux condenser, a condenser, a distillate tank, a cold trap, and a vacuum pump under a nitrogen atmosphere. Heat medium oil at 180 ° C. was circulated in the polymerization reaction vessel jacket, steam at about 100 ° C. was passed as a refrigerant in the reflux condenser, and hot water at about 45 ° C. was passed as the refrigerant in the condenser. After transferring the reaction liquid of the first stage, the pressure was reduced to 12.0 kPa over 5 minutes. At that stage, the temperature of the reaction solution reached 165 ° C., and by-produced phenol began to be distilled. Thereafter, while the pressure was lowered to 0.40 kPa over 40 minutes, the reaction was carried out while distilling off and removing the phenol and the unreacted dihydroxy compound. Thereafter, the reaction was continued at 170 ° C. and 0.40 kPa for 15 minutes, followed by filtration with a filter to obtain a polycarbonate diol. The results are shown in Table 3 below.

(Result of reaction)
The properties of the obtained polycarbonate diol product are shown in Table 3.

Synthesis Examples 10 and 11
A reaction was performed in the same manner as in Synthesis Example 9 except that the raw materials listed in Table 3 (110DD represents 1,10-decanediol), the reaction temperature, and the reaction time were changed. The reaction results are shown in Table 3.

Synthesis Example 12
In a 5 L glass separable flask equipped with a stirrer, a distillate trap, and a pressure regulator, as a raw material, 1,4-butanediol (14BG): 1.378 kg, 1, 10-decanediol (110 DD): 0 It filled with 585 kg, ethylene carbonate (EC): 1.584 kg, tetrabutyl titanate: 0.159 g, and replaced it with nitrogen gas. Under stirring, the internal temperature was raised to 80 ° C. to heat and dissolve the contents. Thereafter, the internal temperature was heated to 140 ° C., the pressure was lowered to 4.7 kPa over 3 minutes, and then the reaction was performed for 600 minutes. Next, 0.380 kg of ethylene carbonate was added, and reaction was performed for 450 minutes at an internal temperature of 180 ° C. and a pressure of 16.7 kPa. Furthermore, after raising the internal temperature to 190 ° C. and reducing the pressure to 0.40 kPa over 270 minutes and continuing the reaction, the remaining raw materials and byproducts are removed from the system at an internal temperature of 190 ° C. and a pressure of 0.40 kPa for 150 minutes. To give polycarbonate diol.

(Result of reaction)
The properties of the obtained polycarbonate diol product are shown in Table 3.
The polycarbonate diols prepared in Synthesis Examples 1 to 12 were designated PCD-A to L, respectively.

[Examples 1 to 18, Comparative Examples 1 to 12]
A heating study was conducted using an organic synthesizer Chemist Plaza CP-100 series Chemi Chemi-100 (manufactured by Shibata Scientific Co., Ltd.). The polycarbonate diols listed in Tables 4, 5 and 6 and additives are placed in a test tube, a cruciform stirrer is inserted, and the temperature of the block heater is set to 160 ° C. and heated for 4 hours at the chemist plaza warmed. went. The results are shown in Table-4, Table-5 and Table-6.

From the results of Tables 4 to 6, it is understood that the addition of a small amount of phosphoric acid and phosphorous acid to the polycarbonate diol can prevent the deterioration of the color tone and can suppress the increase of the molecular weight and the residual monomer. By containing a specific amount of phosphoric acid and phosphorous acid with respect to the specific element contained in the polycarbonate diol, it is possible to lower the APHA value (minus notation in the table before and after the heating of APHA). Also when used as a raw material, a thing with little coloring is obtained. On the other hand, according to the conventional methods such as phosphite esters, color tone deterioration, molecular weight fluctuation and residual monomer amount tend to increase, and the effect of the present invention is clear.

[Examples 19 and 20, Comparative Examples 13 and 14]
Thin film distillation was performed using the polycarbonate diol described in Table-7 and Table-8 at a flow rate of 20 g / min, a pressure of 0.027 kPa, and a jacket oil temperature described in the table. The results are shown in Tables 7 and 8.

From the results of Tables 7 and 8, compared to the case where polycarbonate diol after addition of phosphoric acid is not added, molecular weight increase and coloration by thin film distillation can be suppressed, and the amount of residual monomers can be further reduced. It is useful.
[ Reference Examples 21-24, Comparative Examples 15-18]
About 50 g of polycarbonate diol was added to a 300 mL test tube equipped with a stirring stirrer, sealed with a silicone rubber stopper, and heated at an internal temperature of 170 ° C. under a reduced pressure of 0.40 kPa. After comparative example 15-17 of 3 hours as in Reference Example 21 to 23, Comparative Example 18 and Reference Example 24 was then heated for 6 hours. The results are shown in Table 9.

  From the results of Table 9, polycarbonate diol after addition of phosphoric acid is useful because molecular weight increase and coloring can be suppressed and the amount of residual monomer can be further reduced as compared with the case where it is not added.

  The polycarbonate diol of the present invention has little increase in molecular weight, compositional change and coloration due to heating, and when the polycarbonate diol is used as a raw material of polyurethane, physical properties such as color tone of polyurethane obtained even if reaction conditions for polyurethane are changed. Industrially, it can be used very usefully, without change.

Claims (6)

The number average molecular weight of the polycarbonate diol contained is 250 or more and 5500 or less,
The polycarbonate diol is obtained by transesterification using a dihydroxy compound and a carbonate compound as raw material monomers in the presence of a transesterification catalyst,
Phosphoric acid and / or phosphorous acid is contained, and the total content of phosphoric acid and phosphorous acid is 0.1 mole times or more relative to the total content of metal elements derived from the transesterification catalyst in terms of phosphorus atom Less than the molar ratio,
The metal element derived from the transesterification catalyst in the polycarbonate diol product contains at least one element selected from the group consisting of a long period periodic table group 2 element and a long period periodic table group 4 element ,
The total content of metal elements derived from the transesterification catalyst in the polycarbonate diol product is 0.1 ppm or more and 100 ppm or less,
Turbidity was measured by an integrating sphere turbidity meter Ri der less than 2.0ppm,
Hazen color number was determined according to the following 4 hours heating JIS K0071-1 (1998) at 160 ° C. is a polycarbonate diol product that the Der Rukoto wherein 45 or less. The polycarbonate diol product of claim 1, wherein the metal element derived from the transesterification catalyst in the polycarbonate diol product comprises magnesium and / or titanium . A polycarbonate diol product according to claim 1 or 2 , characterized in that the carbonate compound is a diaryl carbonate. The polycarbonate diol product according to any one of claims 1 to 3 , which has a Hazen color number of 60 or less measured according to JIS K0071-1 (1998). The dihydroxy compound is selected from the group consisting of a compound represented by the following formula (A), a compound represented by the following formula (B), a linear terminal diol, and a diol having a branched chain.
5. A polycarbonate diol product according to any one of the preceding claims, characterized in that it comprises at least one dihydroxy compound.

(In the above formula (A), n is 0 or 1, R ₁ And R ₂ Are each independently a group selected from the group consisting of an alkyl group having 1 to 15 carbon atoms, an aryl group, an alkenyl group, an alkynyl group and an alkoxy group, and an oxygen atom, a sulfur atom, a nitrogen atom or It may have a halogen atom or a substituent containing these. X represents a divalent C1-15 group which may contain a hetero atom. )

(In the above formula (B), the site represented by the above formula (B) is —CH ₂ Except in the case of being part of -OH. ) The dihydroxy compound is at least one dihydroxy selected from the group consisting of a compound represented by the following formula (A), 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and isosorbide 5. The polycarbonate diol product of any one of claims 1 to 4 comprising a compound.

(In the above formula (A), n is 0 or 1, R ₁ And R ₂ Are each independently a group selected from the group consisting of an alkyl group having 1 to 15 carbon atoms, an aryl group, an alkenyl group, an alkynyl group and an alkoxy group, and an oxygen atom, a sulfur atom, a nitrogen atom or It may have a halogen atom or a substituent containing these. X represents a divalent C1-15 group which may contain a hetero atom. )