JP2002030143A - Method for producing polycarbonate diol containing urethane-forming catalyst - Google Patents

Abstract

(57) [Problem] An object of the present invention is to provide a method for producing a urethane-containing catalyst-containing polycarbonate diol which can solve the conventional problems. That is, the present invention provides a urethane-forming catalyst-containing polycarbonate diol having a stable reactivity in urethane-forming reaction (urethane-forming reactivity), particularly a urethane-forming catalyst-containing polycarbonate diol having a stable and high reactivity in an urethane-forming reaction with an isocyanate compound. It is an object to provide a method that can be easily manufactured. The object of the present invention is solved by a method for producing a polycarbonate diol containing a urethanization catalyst, which comprises subjecting a polycarbonate diol containing a transesterification catalyst to heat treatment in the presence of a phosphite triester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polycarbonate diol containing a urethanization catalyst. More specifically, the production of a polycarbonate diol containing a urethanization catalyst, which has a stable reactivity (urethanization reactivity) in a urethanization reaction, that is, a polycarbonate diol containing a urethanization catalyst, which has a stable and high reactivity in a urethanization reaction with an isocyanate compound. About the law. Polycarbonate diol is a compound useful as a raw material for various urethane compounds. In the present invention, urethanization means "converting (polycarbonate diol) to urethane".

[0002]

2. Description of the Related Art Polycarbonate diols are produced by subjecting a carbonate compound and a diol compound to a transesterification reaction in the presence of a transesterification catalyst, but usually, the transesterification catalyst remains active unless deactivated. It is contained in.

[0003] For this reason, the polycarbonate diol (polyester diol containing a transesterification catalyst) obtained as described above promotes the urethanization reaction of the polycarbonate diol with an isocyanate compound. ,
The reactivity (urethanization reactivity) in the urethanization reaction by the isocyanate compound is not constant.

[0004] Therefore, when a urethane-forming reaction is carried out using such a polycarbonate diol, it is difficult or complicated to control the reaction (for example, when the reactivity is significantly reduced in the latter stage of the reaction, or when the reaction scale becomes large, This causes a problem such as rapid heat generation) or gelation of the reaction product during the reaction. Further, when an aliphatic isocyanate compound is used as the isocyanate compound, there is a problem that the urethane-forming reactivity of the polycarbonate diol is extremely low.

[0005] In order to solve such a problem, conventionally, the transesterification catalyst is previously deactivated with an acid, water, or the like.
Thereafter, a complicated operation of adjusting the urethanization reactivity of the polycarbonate diol by adding a new urethanation catalyst at the time of the urethanization reaction was required (Japanese Patent Publication No. Hei 8-8).
26140).

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a urethane-containing catalyst-containing polycarbonate diol which can solve the above-mentioned problems. That is, the present invention provides a urethane-forming catalyst-containing polycarbonate diol having a stable reactivity in urethane-forming reaction (urethane-forming reactivity), particularly a urethane-forming catalyst-containing polycarbonate diol having a stable and high reactivity in an urethane-forming reaction with an isocyanate compound. It is an object to provide a method that can be easily manufactured.

[0007]

An object of the present invention is to provide a process for producing a polycarbonate diol containing a urethanization catalyst, which comprises subjecting a polycarbonate diol containing a transesterification catalyst to heat treatment in the presence of a phosphite triester. Is solved by

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate diol containing a transesterification catalyst (polyester diol containing a transesterification catalyst) used in the present invention is obtained by subjecting a carbonate compound and a diol compound to a transesterification reaction in the presence of a transesterification catalyst. It is obtained. The polycarbonate diol produced by this transesterification reaction has a molecular terminal substantially a hydroxyl group as shown by the following formula.

[0009]

Embedded image (In the formula, R represents a residue of a diol compound. N represents an average degree of polymerization of the polycarbonate diol, and is not particularly limited and is a real number, preferably 1 to 100, and more preferably 1 to 50.) )

In the above-mentioned polycarbonate diol containing a transesterification catalyst, the transesterification catalyst in the transesterification reaction between the carbonate compound and the diol compound is contained as it is, and the content of the transesterification catalyst is 0 to 1 mol of the polycarbonate diol. .001-3
It is preferably 0 mmol, more preferably 0.001 to 15 mmol, particularly preferably 0.003 to 8 mmol. Also,
The transesterification catalyst-containing polycarbonate diol has a water content of 0 to 5000 ppm, preferably 0 to 3000 pp.
m, more preferably 0 to 2000 ppm. However, the water content is based on weight.

The above-mentioned transesterification catalyst includes tetraethoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, tetraphenoxytitanium and the like having 4 to 4 carbon atoms.
40 alkoxy or aryloxy titanium compounds,
Organic tin compounds having 2 to 40 carbon atoms, such as dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, and alkoxyaluminum compounds having 3 to 30 carbon atoms, such as triethoxyaluminum, triisopropoxyaluminum, and tri-s-butoxyaluminum. Are preferred. Among these transesterification catalysts, the titanium compounds are particularly preferable.

The transesterification catalyst may be used alone or in combination in the transesterification reaction, but may be used in an amount of 0.001 to 5 mmol, more preferably 0.001 to 3 mmol, per 1 mol of the diol compound. , Especially 0.00
It is preferably used in a proportion of 3 to 1 mmol.

The carbonate compound includes a dialkyl carbonate having 1 to 10 carbon atoms such as dimethyl carbonate, diethyl carbonate and dibutyl carbonate, and an aralkyl group having 7 to 10 carbon atoms such as dibenzyl carbonate. C6 such as diaralkyl carbonate and diphenyl carbonate
And dialkyl carbonates containing an alkylene group having 2 to 10 carbon atoms such as ethylene carbonate and propylene carbonate.

The carbonate compound may be used alone or in combination in the transesterification reaction.
It is preferable to use the diol compound at a ratio of 0.5 to 1.5 mol per 1 mol. In addition, it is preferable to appropriately select a carbonate compound that can efficiently extract by-product alcohol derived from this compound.

The diol compound may have 3 to 3 carbon atoms.
Diol compounds (aliphatic diols) having hydroxyl groups at both ends of 25 alkylene groups (residues of a diol compound) are preferred. This alkylene group contains various isomers, an alkyl group having 1 to 6 carbon atoms, an aralkyl group having 7 to 10 carbon atoms,
It may have at least one aryl group having 6 to 12 carbon atoms as a substituent. Further, the carbon chain of the alkylene group may contain at least one ether bond or may contain an alicyclic structure. The diol compound may be used alone or in combination.

Specific examples of the diol compound include the following compounds. That is, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-
Nonanediol, 1,10-decanediol, 1,11
-Undecanediol, 1,12-dodecanediol,
1,14-tetradecanediol, 1,20-eicosandiol and the like,

2-methyl-1,3-propanediol,
2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-
Butyl-2-ethyl-1,3-propanediol, 1,
3-butanediol, neopentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-
Pentanediol, 2,2,4-trimethyl-1,3-
Pentanediol, 1,5-hexanediol, 2-ethyl-1,6-hexanediol, 2-ethyl-1,3
-Hexanediol, 2,4-heptanediol, 2-
Alkylene groups such as methyl-1,8-octanediol are isomers or have an alkyl group as a substituent,

1,3-cyclohexanediol, 1,4
-Cyclohexanediol, 2,7-norbornanediol, 2,2'-bis (4-hydroxycyclohexyl) propane, 1,3-cyclohexanedimethanol,
1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol and the like, wherein the carbon chain of the alkylene group contains an alicyclic structure,

[0019] Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, polytetramethylene glycol and the like, wherein the carbon chain of the alkylene group contains an ether bond,

Tetrahydrofuranmethanol, 1,4
Examples thereof include those in which the carbon chain of an alkylene group such as -bis (hydroxyethoxy) cyclohexane contains an alicyclic structure and an ether bond.

The diol compound includes p-xylene diol, p-tetrachloroxylene diol,
1,4-bis (hydroxyethoxy) benzene, 2,2
A diol compound having an aromatic ring such as -bis [(4-hydroxyethoxy) phenyl] propane, or a polyol compound such as trimethylolethane, trimethylolpropane, hexanetriol, or pentaerythritol, alone or in combination with all diol compounds; On the other hand, it may be contained in a proportion of 25% by weight or less, further 20% by weight or less, particularly 15% by weight or less.

The transesterification catalyst-containing polycarbonate diol used in the present invention is obtained by transesterification of a carbonate compound and a diol compound in the presence of a transesterification catalyst. As long as it is obtained (polyester diol containing a transesterification catalyst), a commercially available polycarbonate diol can also be used.

The transesterification can be carried out in one, two or three steps according to a known method. For example, using a reactor equipped with a distillation apparatus (e.g., a distillation column), a carbonate compound and a diol compound are reacted until almost no alcohol is distilled out while extracting by-product alcohol by distillation in the presence of a transesterification catalyst. Thus, the polycarbonate diol may be produced in one step. At this time, the entire amount of the carbonate compound may be initially charged, or the carbonate compound may be continuously or sequentially added to the diol compound.

If necessary (for adjusting the molecular weight), the polycarbonate diol produced in one step is further condensed between the molecules while the transesterification catalyst is left as it is and the diol compound produced as a by-product is similarly extracted. A polycarbonate diol having a target molecular weight may be produced in two stages by a polymerization reaction. In the present invention, the whole reaction including the polycondensation reaction in this case is treated as a transesterification reaction.

If necessary (for adjusting the molecular weight), a diol compound is added to the polycarbonate diol produced in one step, and the transesterification catalyst is left as it is, and the polycarbonate diol and the diol compound are further esterified. The polycarbonate diol having the target molecular weight may be produced in two stages by an exchange reaction. Further, a diol compound may be added to the polycarbonate diol produced in the two steps including the above-mentioned condensation polymerization reaction, and further subjected to a transesterification reaction to produce a polycarbonate diol having a target molecular weight in three steps.

When the transesterification reaction is carried out in one stage, the reaction temperature is preferably 100 to 210 ° C., and the reaction pressure is not particularly limited, but it is normal pressure or 50 to 500 mm.
It is preferable to reduce the pressure to Hg. However, it is preferable that the reaction temperature and the reaction pressure are set so that the by-product alcohol is distilled off and the diol compound is not substantially distilled out. Note that the reaction can be performed in an atmosphere of air, carbon dioxide, or an inert gas (nitrogen, argon, helium, or the like) or in an air stream, but is preferably performed in an inert gas atmosphere or an air stream.

When the transesterification reaction is carried out in two stages by further subjecting the produced polycarbonate diol to a polycondensation reaction between molecules, the reaction temperature is 150 to 240 ° C.
Further, the temperature is preferably set to 150 to 230 ° C., and the reaction pressure is preferably reduced to about 0.1 to 50 mmHg. As the catalyst, the transesterification catalyst can be used as it is. The by-product diol compound is preferably extracted by distillation, and the reaction atmosphere and the like are preferably the same as described above. The extracted diol compound can be reused in a transesterification reaction with a carbonate compound.

When a transesterification reaction is carried out in two or three steps by adding a diol compound to the produced polycarbonate diol and further performing a transesterification reaction, the reaction conditions such as the reaction temperature and the reaction pressure are as described above. This is the same as when the reaction is performed in one stage.

After the transesterification reaction is completed in one, two, or three stages, the reaction solution is cooled as it is to obtain a transesterification catalyst-containing polycarbonate diol. The transesterification catalyst-containing polycarbonate diol has a substantially hydroxyl group at the molecular end as described above, and contains the transesterification catalyst and water in the above-described ratio.

In the present invention, obtained as described above,
A transesterification catalyst-containing polycarbonate diol (reactivity (urethane-forming reactivity) in a urethanization reaction with an isocyanate compound is unstable and causes various problems as described above) is subjected to heat treatment in the presence of a phosphite triester. Thereby, it can be converted into a urethane-forming catalyst-containing polycarbonate diol having stable urethanization reactivity. That is, the polycarbonate diol containing a urethanization catalyst of the present invention is obtained by heat-treating a polycarbonate diol containing a transesterification catalyst in the presence of a phosphite triester. The urethane-forming catalyst-containing polycarbonate diol having a stable urethane-forming reactivity has high urethane-forming reactivity at the same time.

As described above, in the present invention, the activity of the transesterification catalyst contained in the polycarbonate diol in the presence of the phosphite triester is reduced by heating the transesterification catalyst. It can be stabilized (maintained at high activity). And the conversion of the isocyanate compound (isocyanate group) in the urethanization reaction can be made high.

In the heat treatment, the transesterification catalyst-containing polycarbonate diol may be used alone or in combination. Further, the polycarbonate diol may be used as a lactone (butyrolactone, caprolactone, laurolactone, or the like) containing an alkylene group having 2 to 20 carbon atoms, or an alkylene carbonate containing an alkylene group having 2 to 20 carbon atoms (ethylene carbonate, 1, 2, or 3). -Propylene carbonate, 1,3-propylene carbonate, 2,2-dimethylpropylene carbonate, etc.)
Those obtained by further copolymerizing with a ring-opening polymer of these lactone or alkylene carbonate may be used. The alkylene group of the alkylene carbonate may have an isomer, a substituent, or the like, like the alkylene group in the diol compound.

The phosphite triesters used in the present invention include trimethyl phosphite, triethyl phosphite,
C1-2 such as tripropyl phosphite, tributyl phosphite, trihexyl phosphite, and trioctyl phosphite
Trialkyl phosphite containing an alkyl group having 7 to 20 carbon atoms, such as trialkyl phosphite containing an alkyl group of 0, tribenzyl phosphite, etc .; triphenyl phosphite, tricresyl phosphite, etc. And triaryl phosphite containing an aryl group having 6 to 20 carbon atoms. Further, phosphite triesters containing a mixture of an alkyl group, an aralkyl group and an aryl group can also be mentioned.

Among the phosphite triesters, trialkyl phosphites are preferred. Among them, trialkyl phosphite, tributyl phosphite, trihexyl phosphite, trioctyl phosphite and the like have 3 to 3 carbon atoms. Trialkyl phosphites containing 20 alkyl groups are particularly preferred.

In the heat treatment, the phosphite triester is used in an amount of 0.8 to 10 mol based on 1 mol of the transesterification catalyst (1 g atom of metal in the catalyst) used in the transesterification reaction between the carbonate compound and the diol compound. Furthermore, 0.
It is preferable to use 9 to 5 mol, particularly 1 to 2 mol.

The temperature at which the transesterification catalyst-containing polycarbonate diol is heat-treated in the presence of the phosphite triester is 70 to 145 ° C., more preferably 80 to 145 ° C.
Particularly, the temperature is preferably from 95 to 135 ° C. The atmosphere at the time of the heat treatment is preferably under an atmosphere of an inert gas such as helium, nitrogen, argon, or carbon dioxide or under an air stream. The pressure may be any of reduced pressure, normal pressure, and pressurized. The heat treatment time varies depending on the conditions, but is usually 0.5 to 24 hours.

After the completion of the heat treatment, the treatment liquid is cooled to obtain the polycarbonate diol containing the urethanization catalyst of the present invention. The polycarbonate diol containing the urethanization catalyst contains a transesterification catalyst, phosphite triester, And can be used as it is (without adding a new catalyst and containing phosphite triester) as it is in the urethanization reaction with an isocyanate compound. The urethanization reaction using an isocyanate compound can be performed according to a known method using, for example, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, or the like.

The polycarbonate diol containing a urethanization catalyst of the present invention thus obtained has a stable urethanization reactivity and a high urethanization reactivity. That is, it has a stable and high reactivity in the urethanization reaction with the isocyanate compound (the reaction rate constant of the urethanization reaction with the isocyanate compound is stable and high).

For example, in a urethanization reaction using diphenylmethane diisocyanate as an isocyanate compound (according to the method described in Examples described later), the polycarbonate diol containing a urethanization catalyst of the present invention has an average value in the latter half of the reaction (50 to 60 minutes after the start of the reaction). Is 0.7 times or more of the average reaction rate constant at the beginning of the reaction (10 to 20 minutes after the start of the reaction). Although the rate constant slightly decreases in the later stage of the reaction, the degree is not remarkable, and the reaction rate constant is It is stable. In terms of the whole reaction, the reaction rate is high when the average reaction rate constant is in the range of 4 to 5 g / mol · sec.

In the urethanization reaction using dicyclohexylmethane diisocyanate as an isocyanate compound (according to the method described in Examples described later), the average reaction rate constant in the latter half of the reaction (2 to 5 hours after the start of the reaction) is determined in the initial stage of the reaction. It is 0.6 times or more of the average reaction rate constant (10 to 60 minutes after the start), and although the rate constant slightly decreases in the latter stage of the reaction, the degree is not remarkable and the reaction rate constant is stable. In terms of the overall reaction, the reaction rate is high when the average reaction rate constant is in the range of 0.2 to 0.5 g / mol · sec.

The polycarbonate diol containing a urethane-forming catalyst may be used alone or as a mixture of two or more. Further, the polycarbonate diol may be further copolymerized with the above-mentioned lactone or alkylene carbonate, or a ring-opening polymerization thereof. May be further copolymerized with the product and used in the urethanization reaction.

[0042]

Next, the present invention will be described specifically with reference to examples and comparative examples. In addition, the reactivity in the urethanization reaction of the polycarbonate diol with the isocyanate compound was evaluated by obtaining the reaction rate constant of the urethanization reaction as follows.

1. Determination of Isocyanate Group A reaction solution of 2 to 3 g of a urethane reaction of a polycarbonate diol with an isocyanate compound was sampled with time, and 10 ml of a dibutylamine-THF solution and TH
F20 ml of F was mixed and stirred, and then 50 ml of THF and a bromophenol blue solution of an indicator were added thereto, and unconsumed dibutylamine was titrated with 0.1 mol / L (liter) of hydrochloric acid. The isocyanate groups (molar number) remaining in the reaction solution were determined from the difference between the titration value and the blank experiment. In addition, THF represents tetrahydrofuran, and each solution is as follows.

Dibutylamine-THF solution: A solution obtained by diluting 3.23 g of dibutylamine with THF to 250 ml Bromophenol blue solution: a solution of 0.5 g of bromophenol blue in 50 ml in methanol

2. Measurement of Reaction Rate Constant of Urethane Reaction According to the following equation, x / a (ax) is plotted with respect to reaction time t, and from the slope, the reaction rate constant K of the urethane reaction is calculated.
I asked. Kt = x / a (ax)

However, each symbol is defined as follows. K: reaction rate = K [concentration of isocyanate group] [concentration of hydroxyl group contained in polycarbonate diol] Reaction rate constant t: reaction time a: initial concentration of isocyanate group (mol / g; measured by quantitative determination of isocyanate group) Ax: concentration of isocyanate groups after time t (mol / mol)
g; the number of moles of dibutylamine consumed per 1 g of the reaction solution after the time t, which is measured from the quantitative determination of the isocyanate group) x: the concentration of the isocyanate group consumed after the time t (mol / mol)
g)

The isocyanate group conversion was determined as follows. Isocyanate group conversion (%) = 100 × (mol number of charged isocyanate groups−mol number of remaining isocyanate groups) /
Number of moles of charged isocyanate groups

Example 1 [Production of polycarbonate diol (polyester diol containing transesterification catalyst)] 1 L equipped with a distillation column
(L) In a glass flask, 427 g (4.74 mol) of dimethyl carbonate, 560 g (4.74 mol) of 1,6-hexanediol, and 0.054 g (0.16 mmol) of tetrabutoxytitanium were placed, and the reaction was carried out. At a temperature of 100 to 200 ° C., a transesterification reaction was carried out at normal pressure for 5 hours while distilling off a mixture of methanol and dimethyl carbonate with stirring.

Next, the mixture of methanol and dimethyl carbonate was further distilled off under reduced pressure of 100 mmHg, and then at 160-200 ° C. under reduced pressure of 1-5 mmHg.
The mixture was further reacted for 8 hours while distilling off 1,6-hexanediol to obtain 537 g of polycarbonate diol (polyester diol containing a transesterification catalyst). This polycarbonate diol has a hydroxyl value of 56.1 mgK
OH / g, average molecular weight 2000, hue (APHA) 15
It was. The reaction operation was performed in a nitrogen stream,
The average molecular weight was determined from the hydroxyl value.

[Heat treatment] 100 g of the transesterification catalyst-containing polycarbonate diol obtained above (0.05 mol as the polycarbonate diol, titanium content 14 ppm, water content 700 ppm) was put into a 500 ml glass flask, and the mixture was added thereto. And 8.78 mg (0.0351 mmol; 1.2 mol based on 1 g atom of titanium) of tributyl phosphite were added thereto, and the mixture was heated for 2 hours while stirring at 130 ° C. in a nitrogen stream. After the completion of the heat treatment, the treatment liquid was cooled to obtain 100 g of a polycarbonate diol containing a urethane-forming catalyst. In addition, titanium content and water content are based on weight.

[Urethanation reaction] 100 g of the urethane-forming catalyst-containing polycarbonate diol obtained above and 225 g of 2-butanone were placed in a 500 ml glass flask, and heated and stirred at a bath temperature of 70 ° C (liquid temperature of 65 ° C). .
Then, 12.51 g (0.05 mol) of 4,4'-diphenylmethane diisocyanate was added, and the mixture was continuously heated and stirred at the same temperature. The reaction operation was performed in a nitrogen stream.

When the reaction solution was sampled with time and the amount of isocyanate groups remaining in the reaction solution was quantified, the average reaction rate constant of the urethanization reaction was at the beginning of the reaction (10 to 20 minutes after the start of the reaction; hereinafter, omitted). 4.81 g / mole-second,
2. Late in the reaction (50 to 60 minutes after the start of the reaction; hereinafter omitted).
At 67 g / mol · sec, the decrease in the rate constant in the late stage of the reaction was small (reaction rate constant ratio: 0.76), and the reactivity was stable. The average reaction rate constant for the entire reaction was 4.44 g / mol · sec. The conversion of the isocyanate group after one hour was 82.4%. The average reaction rate constant is determined by the least-squares method, and the reaction rate constant ratio means “average reaction rate constant in the latter half of the reaction: average reaction rate constant in the initial stage of the reaction”.

Comparative Example 1 [Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 1 except that 100 g of the transesterification catalyst-containing polycarbonate diol was used without any heat treatment. As a result, the average reaction rate constant of the urethanization reaction was 2.94 g / mol · sec in the early stage of the reaction and 1.88 g / mol · sec in the late stage of the reaction, and the rate constant gradually decreased in the late stage of the reaction (reaction rate Constant ratio: 0.64), and the reactivity was unstable. The average reaction rate constant for the entire reaction was also 2.7.
It was low at 3 g / mol · sec. The conversion of the isocyanate groups after one hour was 65.6%.

Example 2 [Heat treatment] In addition to using 100 g of a transesterification catalyst-containing polycarbonate diol (0.05 mol as a polycarbonate diol, 14 ppm of titanium and 300 ppm of water) obtained in Example 1 and having a different moisture absorption. Was subjected to a heat treatment in the same manner as in Example 1.

[Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 1 except that 100 g of the urethane-containing catalyst-containing polycarbonate diol obtained above was used. As a result, the average reaction rate constant of the urethanization reaction was 4.83 g / mol · sec in the early stage of the reaction, and 3.69 g in the late stage of the reaction.
At g / mol · sec, the decrease in the rate constant in the latter half of the reaction was small (reaction rate constant ratio: 0.76), and the reactivity was stable. The average reaction rate constant for the entire reaction was 4.43 g / mol · sec. The conversion of the isocyanate group after one hour was 82.3%.

Example 3 [Heat treatment] A heat treatment was carried out in the same manner as in Example 2 except that the heating temperature was changed to 100 ° C.

[Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 1 except that 100 g of the urethane-containing catalyst-containing polycarbonate diol obtained above was used. As a result, the average reaction rate constant of the urethanization reaction was 4.77 g / mol · sec in the early stage of the reaction, and 3.62 in the late stage of the reaction.
At g / mol · sec, the decrease in the rate constant in the latter half of the reaction was small (reaction rate constant ratio: 0.76), and the reactivity was stable. The average reaction rate constant for the entire reaction was 4.38 g / mol · sec. The conversion of the isocyanate group after one hour was 81.9%.

Comparative Example 2 [Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 2 except that 100 g of the transesterification catalyst-containing polycarbonate diol was used without any heat treatment. As a result, the average reaction rate constant of the urethanization reaction was 4.57 g / mol · sec in the early stage of the reaction, and 2.36 g / mol · sec in the late stage of the reaction. : 0.52), and the reactivity was unstable. The average reaction rate constant for the entire reaction was 4.12. After one hour, the conversion of isocyanate groups was 8
It was 6.8%.

Example 4 [Heat treatment] This was carried out in the same manner as in Example 1.

[Urethanation reaction] The amount of 2-butanone was changed to 56.6 g, and the isocyanate compound was changed to 4,4'-
13.12 g of dicyclohexylmethane diisocyanate
(0.05 mol), except that the urethanization reaction was carried out in the same manner as in Example 1. As a result, the average reaction rate constant of the urethanization reaction was in the initial stage of the reaction (10 to 60 minutes after the start of the reaction;
In the following, the rate constant was 0.497 g / mol · sec, and in the latter stage of the reaction (2 to 5 hours after the start of the reaction; hereinafter, omitted), 0.369 g / mol · sec. Ratio: 0.74), and the reactivity was stable. The average reaction rate constant for the entire reaction was 0.421 g / mol · sec. The conversion of the isocyanate group after 5 hours was 8
2.8%.

Example 5 [Heat treatment] The same procedure as in Example 1 was carried out except that the phosphite triester was replaced by 4.35 mg (0.0351 mmol) of trimethyl phosphite.

[Urethanization reaction] A urethanization reaction was carried out in the same manner as in Example 4 except that 100 g of the urethane-forming catalyst-containing polycarbonate diol obtained above was used. As a result, the average reaction rate constant of the urethanization reaction was 0.360 g / mol · sec in the initial stage of the reaction, and 0.2 in the late stage of the reaction.
At 38 g / mol · sec, the decrease in the rate constant in the latter half of the reaction was small (reaction rate constant ratio: 0.66), and the reactivity was stable. The average reaction rate constant for the entire reaction was 0.290 g /
Mole-seconds. The conversion of the isocyanate groups after 5 hours was 78.9%.

Example 6 [Heat treatment] The same procedure as in Example 1 was carried out except that the phosphite triester was replaced by 10.9 mg (0.0351 mmol) of triphenyl phosphite.

[Urethanization reaction] A urethanization reaction was carried out in the same manner as in Example 4 except that 100 g of the urethane-containing catalyst-containing polycarbonate diol obtained above was used. As a result, the average reaction rate constant of the urethanization reaction was 0.342 g / mol · sec at the beginning of the reaction and 0.242 g / mol · sec at the end of the reaction.
At 34 g / mol · sec, the decrease in the rate constant in the latter half of the reaction was small (reaction rate constant ratio: 0.68), and the reactivity was stable. The average reaction rate constant for the entire reaction was 0.283 g /
Mole-seconds. After 5 hours, the conversion of the isocyanate groups was 73.2%.

Comparative Example 3 [Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 4, except that 100 g of the transesterification catalyst-containing polycarbonate diol was used without any heat treatment. As a result, the average reaction rate constant of the urethanization reaction was 0.114 g / mol · sec in the early stage of the reaction and 0.055 g / mol · sec in the late stage of the reaction. : 0.48), and the reactivity was unstable. The average reaction rate constant for the entire reaction was also 0.066.
g / mol · sec. The conversion of the isocyanate groups after 5 hours was 39.8%.

Example 7 [Heat treatment] This was carried out in the same manner as in Example 2.

[Urethanation reaction] The amount of 2-butanone was changed to 56.6 g and the isocyanate compound was changed to 4,4'-
13.12 g of dicyclohexylmethane diisocyanate
(0.05 mol), except that the urethanization reaction was carried out in the same manner as in Example 2. As a result, the average reaction rate constant of the urethanization reaction was 0.383 g / mol.
Second, the rate constant in the latter half of the reaction is 0.326 g / mol · sec, and the rate constant in the latter half of the reaction is less reduced (reaction rate constant ratio: 0.8
5) The reactivity was stable. The average reaction rate constant for the entire reaction was 0.351 g / mol · sec. Also, 5
The conversion of the isocyanate groups after 7 hours was 79.7%.

Comparative Example 4 [Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 7, except that 100 g of the transesterification catalyst-containing polycarbonate diol was used without any heat treatment. As a result, the average reaction rate constant of the urethanization reaction was 0.191 g / mol · sec in the early stage of the reaction and 0.067 g / mol · sec in the late stage of the reaction. : 0.35), and the reactivity was unstable. The average reaction rate constant for the entire reaction was also 0.090.
g / mol · sec. The conversion of the isocyanate groups after 5 hours was 58.2%.

Comparative Example 5 [Heat treatment] A heat treatment was carried out in the same manner as in Example 1 except that the phosphite triester was replaced by 7.37 mg (0.0351 mmol) of dibutyl phosphate.

[Urethanation reaction] A urethanization reaction was carried out in the same manner as in Example 1 except that 100 g of the urethane-containing catalyst-containing polycarbonate diol obtained above was used. As a result, the average reaction rate constant of the urethanization reaction was 0.051 g / mol · sec at the initial stage of the reaction, and 0.0
At 43 g / mol · sec, the decrease in the rate constant in the latter half of the reaction was small (reaction rate constant ratio: 0.84), but the average reaction rate constant for the whole reaction was very low at 0.045 g / mol · sec. Was. The conversion of the isocyanate groups after one hour was only 4.0%.

[0071]

[Table 1]

[0072]

Industrial Applicability According to the present invention, a method for producing a polycarbonate diol containing a urethanization catalyst having a stable reactivity (urethanization reactivity) in a urethanization reaction, that is, having a stable and high reactivity in a urethanization reaction with an isocyanate compound. A method for easily producing a polycarbonate diol containing a urethanization catalyst can be provided. Also,
According to the present invention, a transesterification catalyst-containing polycarbonate diol which is unstable in urethanization reaction with an isocyanate compound (urethanization reactivity) and causes various problems, has a stable urethanization reactivity and the reactivity is high. It can be converted to a high urethanization catalyst-containing polycarbonate diol. That is, by subjecting the transesterification catalyst contained in the polycarbonate diol to a heat treatment in the presence of phosphite triester, the urethanization catalyst activity of the transesterification catalyst is stabilized (maintained at a high activity). Can be. At the same time, the conversion of the isocyanate compound (isocyanate group) in the urethanization reaction can be increased. The urethane-forming catalyst-containing polycarbonate diol of the present invention has a stable and high reactivity in the urethane-forming reaction with an isocyanate compound (that is, the reaction rate constant of the urethane-forming reaction with the isocyanate compound is stable). And high)
The reaction control becomes difficult or complicated (for example, the reactivity is significantly reduced in the latter stage of the reaction, or the reaction scale becomes large, causing rapid heat generation) or without causing a problem such as the reaction product gelling during the reaction. In addition, the urethanization reaction with the isocyanate compound can be performed smoothly. Further, the urethanization reaction by the aliphatic isocyanate compound can be smoothly performed by overcoming the problem that the reactivity is very low.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4J029 AA09 AB04 AC02 BA02 BA04 BA05 BA07 BA09 BA10 BB04B BD02 BD03A BD04A BD06A BF09 BF10 BF18 BF25 BG05X HC03 HC04A HC05A HC06 JB131 JC751 JE182 JF221 JF321 J034 DB03 DF16 DF17 HA01 HA07 HC12 HC17 HC22

Claims (7)

[Claims] 1. A process for producing a polycarbonate diol containing a urethanization catalyst, comprising subjecting a polycarbonate diol containing a transesterification catalyst to a heat treatment in the presence of a phosphite triester. 2. The polycarbonate diol containing a urethanization catalyst according to claim 1, wherein the polycarbonate diol containing a transesterification catalyst is obtained by subjecting a carbonate compound and a diol compound to a transesterification reaction in the presence of a transesterification catalyst. Manufacturing method. 3. A transesterification catalyst comprising an alkoxy or aryloxy titanium compound, an organotin compound, or
3. The composition according to claim 1, which is an alkoxyaluminum compound.
A method for producing the polycarbonate diol containing a urethanization catalyst according to the above. 4. The process for producing a polycarbonate diol containing a urethane-forming catalyst according to claim 1, wherein the phosphite triester is heat-treated in the presence of 0.8 to 10 moles per mol of the transesterification catalyst. 5. The heat treatment temperature is 70 to 145 ° C.
A method for producing a polycarbonate diol containing a urethanization catalyst according to any one of claims 1 to 4. 6. A urethane-forming catalyst-containing polycarbonate diol obtained by heat-treating a polycarbonate diol containing a transesterification catalyst in the presence of a phosphite triester. 7. A method for stabilizing the activity of a urethanization catalyst, comprising subjecting a transesterification catalyst contained in a polycarbonate diol to a heat treatment in the presence of a phosphite triester.