JP3128275B2 - Reactive stabilized polyol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to reactive stabilized copolycarbonate diols which are liquid at room temperature and are useful in the production of polyurethanes.

[0002]

2. Description of the Related Art Polyols conventionally used in the production of polyurethanes include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as p-toluenesulfonic acid, and esters such as phosphoric acid esters and phosphites as reaction regulators. Had been added. However, there are problems such as the inability to obtain a sufficient effect with such a reaction modifier and the inability to obtain a polyol having an expected pot life. It was necessary to change the amount of the agent used, which was difficult.

[0003] Further, in the conventional method, if the amount of the regulator added is excessive, there are problems such as that it acts as an accelerator and that the residue in the urethane deteriorates the durability of the urethane. However, few attempts have been made to control the urethanization reactivity with the characteristics of a polyol alone without the addition of a reaction regulator, and the development of a polyol having such characteristics has been desired.

[0004]

DISCLOSURE OF THE INVENTION In view of such circumstances, the present inventors have developed a liquid which is liquid at ordinary temperature and has stable urethanization reactivity without using a reaction regulator.
It is to provide a polycarbonate diol as a urethane raw material.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that 60 to 90 mol% of 1,4-butanediol unit and one kind of diol having 5 to 20 carbon atoms are used as a copolymer component. Or, by using an aliphatic copolycarbonate diol containing 10 to 40 mol% of a repeating unit composed of two or more kinds, it was found that the composition had stable urethanization reactivity without using a reaction regulator, and completed the invention. I came to.

[0006] It is not clear why the conventionally used polyol causes an abnormal reaction in the urethanization reaction and causes gelation, etc., but the reaction rate at which the polyol is added to the isocyanate group is low. Crosslinking due to heat generation due to the large size and acceleration of the reaction due to a small amount of an alkali component contained therein are conceivable, all of which are due to the high reactivity of the polyol to the isocyanate group. Therefore, the reaction regulators which have been used have been studied for their effect of delaying the reaction, and are still used at present.

[0007] The present inventors have studied to impart this retarding effect to the polyol itself, and found that a polyol containing a 1,4-butanediol unit as a repeating unit in a high ratio has this retarding effect. . Although the theoretical interpretation of this delay effect has not been sufficiently clarified, analysis by NMR or the like shows that 1,4-butanediol and carbon atoms of 5 and
It can be interpreted that there is a clear difference in acidity from the above diols, and this is a difference in reactivity with the isocyanate group, resulting in a delay effect. That is, the terminal of the polyol is 1,
It is believed that a delay effect occurs when the 4-butanediol unit is formed.

A 1,4-butanediol unit having 5 carbon atoms
Examples of the polyol having a repeating unit of the above diol are disclosed in JP-A-51-144492 and JP-A-Heisei 2-2.
No. 89616, which has a low 1,4-butanediol unit ratio of 50% or less and a terminal of 1,4-butanediol.
Since it was other than 4-butanediol unit, the delay effect was extremely small, and it was difficult to stabilize the reaction.

In order to make the terminal a 1,4-butanediol unit, the charge ratio of 1,4-butanediol and an aliphatic diol having 5 to 20 carbon atoms during the synthesis of the polyol is as follows:
When the polymer is synthesized by disproportionation, 1,
The charge ratio of the polycarbonate diol composed of 4-butanediol units and the polycarbonate diol composed of aliphatic units having 5 to 20 carbon atoms is important. That is, 1,4
-If the reactivity of butanediol and its polycarbonate diol is the same as the reactivity of the aliphatic diol having 5 to 20 carbon atoms and its polycarbonate diol, the ratio at the time of synthesis becomes the ratio of the repeating unit of the produced polymer, and If the reactivity is different, the ratio at the time of synthesis and the ratio of the terminal diol unit of the resulting polyol change, and the ratio of the low reactivity, the diol at the terminal increases, so that the polymer has a blocking property. Is large.

[0010] Based on this, the present inventors have developed 1,4
Various compositions of -butanediol units were investigated, and as a result surprisingly, when the ratio of 1,4-butanediol units in the polymer was 60 mol% or more, most of the terminals were 1,4-butanediol units. It has been found that the present invention has been completed. That is, the present invention relates to an aliphatic copolycarbonate diol, the structural unit of which is represented by the following repeating units (I) and (II):
And the ratio of (I) and (II) is (I) / (II) =
60 / 40-90 / 10 Der is, the number-average molecular weight thereof is 5
00-20000 relates der Ru aliphatic copolycarbonate diol.

[0011]

Embedded image (R is a group having 5 to 20 carbon atoms and one hydroxyl group at each of two terminals.
A diol residue obtained by removing two terminal hydroxyl groups from an aliphatic alkylene diol, an aliphatic alkylene ether diol, or an aliphatic alkylene polyether diol having one by one)

Hereinafter, the present invention will be described in detail. In the present invention, the diol having an aliphatic alkylene group satisfying the structural unit (II) is defined as an ether having an aliphatic alkylene group.
Derived from toluene compounds and polyether compounds
Compounds are also included, and examples thereof include 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, and 2-ethyl-
1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2,2 -bis (4-hydroxycyclohexyl)-
Propane, 1,4-dimethylolcyclohexane, dipropylene glycol, polytetramethylene glycol,
2,6′-dihydroxyethylhexyl ether, 2,
4'-dihydroxyethyl butyl ether, 2,5'-
Examples thereof include dihydroxyethylpentyl ether and 2,3′-dihydroxy-2,2′-dimethylpropyl ether, and are preferably aliphatic diols having 5 to 8 carbon atoms, for example, 1,5-pentanediol, 1,
6-hexane diol, up to 1,7-butanediol,
There are 1,8-octanediol and isomers of these diols. One or more of these diols can be selected and used.

In the aliphatic copolycarbonate diol of the present invention, when the repeating unit composed of 1,4-butanediol is 50% or less, a terminal other than 1,4-butanediol is terminated, so that the reactivity is stabilized and the polycarbonate diol is stabilized. If the ratio is greater than 90%, the polycarbonate diol becomes a solid at ordinary temperature, handling is not required, and the physical properties such as flexibility when made into urethane are undesirably reduced. The aliphatic polycarbonate diol of the present invention preferably contains a repeating unit composed of 1,4-butanediol in an amount of 60 to 90 mol%.

The polycarbonate diol thus obtained is a viscous liquid at room temperature and has a number average molecular weight of 50
It is a polymer of 0 to 20,000. The method for producing the polycarbonate diol in the present invention is described in Schnell's "P.
Polymer Reviews “Vol. 9 (196)
4) p. As described in 9-20, it can be synthesized by reacting a carbonylating agent with an aliphatic diol in the presence or absence of a transesterification catalyst.

For example, details when ethylene carbonate is used as the carbonylating agent will be described below. That is, a mixture of 1,4-butanediol and an aliphatic diol having 5 to 20 carbon atoms in a predetermined ratio and ethylene carbonate are mixed in a molar ratio of 20: 1 to 1:20 in the presence or absence of a catalyst. The reaction is carried out at a temperature of 100 ° C. to 280 ° C. under reduced pressure or reduced pressure to distill off by-produced ethylene glycol and unreacted ethylene carbonate to obtain 2 to 10 units of low molecular weight polycarbonate diol.
At 0 ° C to 280 ° C, the unreacted diol and ethylene carbonate are distilled off, and the low molecular weight polycarbonate diol is polymerized. During this time, the diol formed continues to evaporate to obtain a polycarbonate diol having a predetermined molecular weight.

Similarly, in a method using ethylene carbonate, a low-molecular-weight polycarbonate diol of 2 to 10 units is formed, and then ethylene carbonate is further added to increase the molecular weight by a chain extension reaction to recover unreacted ethylene carbonate. A method for obtaining a polycarbonate diol having a predetermined molecular weight may be used. Next, details when dimethyl carbonate is used as the carbonylating agent will be described. That is, this method uses a predetermined ratio of 1,
A mixture of 4-butanediol and an aliphatic diol having 5 to 20 carbon atoms and dimethyl carbonate are mixed in a ratio of 1:20 to 20: 1 in the presence or absence of a catalyst.
The method is characterized in that the reaction is carried out while distilling off the methanol at a temperature of from 280 ° C. to 280 ° C. under normal pressure or under pressure, and the reaction is further carried out while distilling off the methanol at a temperature of from 120 ° C. to 280 ° C. under reduced pressure.

In any of the methods, the temperature is from 100 ° C.
A temperature of 280 ° C. is suitable. If the temperature is lower than 100 ° C., the reaction rate is slow.
More preferably, the temperature is from 130C to 250C. In order to carry out these reactions efficiently, a method of continuously extracting ethylene glycol or methanol as a by-product using a reactor equipped with a fractionation tower may be used. Further, in addition to the above-mentioned carbonylating agent, 1,2-propylene carbonate, 1,2
-Butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, diethyl carbonate, dibutyl carbonate may be used depending on the conditions.

As another synthesis method, a polycarbonate diol of 1,4-butanediol and a polycarbonate of an aliphatic diol having 5 to 20 carbon atoms are synthesized by the above-described synthesis method, and are prepared in a predetermined ratio. After mixing, a disproportionation method of heating at 150 ° C. to 25 ° C. under nitrogen at normal pressure in the presence or absence of a catalyst may be used. Catalysts that can be used in the synthesis of the polycarbonate diol of the present invention are ordinary transesterification catalysts, such as lithium,
Sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, cobalt, germanium,
There are metals such as tin, lead, antimony, arsenic, and cerium, as well as salts, alkoxides, and organometallic compounds. Particularly preferred are compounds of titanium, tin, and lead. The amount of the catalyst used is 0.00001% to 1% of the total weight of the starting materials.
Is appropriate.

[0019]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. The hydroxyl value in the examples was measured by an acetylation method. The number average molecular weight in the examples was measured by the method described below. The terminals of the polycarbonate diol of the present invention were substantially all hydroxyl groups by NMR measurement. Further, the acid value in the polymer was measured by titration with KOH, and all the polymers were 0.01 or less.
Therefore, the number average molecular weight of the polymer is determined by the following equation.

Number average molecular weight = 2 / (OH value / 56110) A calibration curve was created based on this molecular weight, and the
, The number average molecular weight was measured.

[0021]

Example 1 Dixon packing filled diameter 10
Ethylene carbonate (EC) 880 in a 2 l flask equipped with a distillation column having a length of 300 mm and a length of 300 mm, a thermometer and a stirrer.
g (10 mol), 1,4-butanediol (BDL) 5
40 g (6 mol), 1,6-hexanediol (HD
L) 470 g (4 mol) was added, and the mixture was heated and stirred under a reduced pressure of 20 Torr, and the internal temperature was controlled to 150 ° C. The reaction was carried out for 18 hours while distilling EC and ethylene glycol having an azeotropic composition from the top of the distillation column.

Next, the distillation column was removed and the pressure was reduced to 7T.
Unreacted EC and diol were recovered at orr. After the completion of the distillation of the unreacted substances, the internal temperature was set to 190 ° C., and the diol was distilled while maintaining the temperature to carry out a self-condensation reaction. Four hours later, 700 g of a colorless and transparent liquid having a number average molecular weight of 2000 was obtained by GPC analysis. The hydroxyl value was 56 mgKOH / g. This polymer was converted to PC-a
Abbreviated. In order to measure the terminal purity of this polymer, the polymer was heated to 190 ° C. under a reduced pressure of 2 Torr to increase the molecular weight, and the diol formed by transesterification of the terminal was analyzed. As a result, the distillate component was 99 mol% of 1,4-butanediol and 1% or less of 1,6-hexanediol, and a polymer having a terminal of almost 1,4-butanediol component was obtained.

[0023]

Examples 2 and 3 1,6-hexanediol and 1,5-pentanediol were used as aliphatic diols having 5 to 20 carbon atoms, and their ratios to 1,4-hexanediol are shown in Table 1. Copolycarbonate diols (PC-b to PC-b) were prepared in the same manner as in Example 1 except that the reaction was carried out as described above.
PC-c) was obtained. Table 1 shows the respective number average molecular weights.

[0024]

Comparative Examples 1 and 2 1,6-hexanediol and 1,5-pentanediol were used as aliphatic diols having 5 to 20 carbon atoms, and their ratios to 1,4-hexanediol are shown in Table I. The polycarbonate diols (PC-d to PC-P) were prepared in the same manner as in Example 1 except that the reaction was carried out as described above.
Ce) was obtained. Table 1 shows the respective number average molecular weights.

[0025]

[Table 1]

[0026]

REFERENCE EXAMPLE 1 20 g of PC-a and 70 g of dimethylformamide obtained in Example 1 were charged into a reactor equipped with a stirrer, a thermometer and a cooling tube, and heated and stirred at 50 ° C. When the internal temperature reached 50 ° C., 5 g of diphenylmethane diisocyanate was added, and the remaining isocyanate groups were titrated while sampling on the way, and the time until the conversion of the isocyanate groups became 80% was measured. The time required for PC-a was about 60 minutes.

[0027]

Reference Example 2 PC-b as a polycarbonate diol
Was carried out in the same manner as in Reference Example 1 except that 19.5 g of was used. The required time in this case was 62 minutes.

[0028]

[Reference Comparative Example 1] PC as polycarbonate diol
The required time was measured in the same manner as in Reference Example 1 except that -d was used. This required 20 minutes.

[0029]

[Reference Comparative Example 2] PC as polycarbonate diol
The measurement was performed in the same manner as in Reference Example 1 except that 20.1 g of -e was used. This required 19 minutes.

[0030]

[Application Example 3] PC-c as a polycarbonate diol
Was measured in the same manner as in Application Example 1 except that 19.5 g of the compound was used. The required time in this case was 59 minutes.

[0031]

[Application Comparative Example 3] Polycaprolactone polyol as a polyol [Placcel 2 manufactured by Daicel Chemical Industries, Ltd.]
20, the molecular weight of 2000]. The required time in this case was 15 minutes.

[0032]

The copolycarbonate diol of the present invention is liquid at normal temperature, has stable urethanization reactivity without adding a reaction regulator, and is expected to be widely used as a raw material for polyurethane.

Claims (1)

(57) [Claims] 1. An aliphatic copolycarbonate diol whose structural unit comprises repeating units (I) and (II) represented by the following formula 1, wherein the ratio of (I) and (II) is (I) / (II) = 60/40 to 90/10
Ri a number average molecular weight of Der Ru aliphatic copolycarbonate diol 500 to 20,000. Embedded image (R is a group having 5 to 20 carbon atoms and one hydroxyl group at each of two terminals.
A diol residue obtained by removing two terminal hydroxyl groups from an aliphatic alkylene diol, an aliphatic alkylene ether diol, or an aliphatic alkylene polyether diol having one by one)