JP2001323042A - Segmented polyurethane having high stiffness and high elongation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a segmented polyurethane having high stiffness and high elongation having both high initial modulus of elasticity and high breaking elongation and having small change of mechanical properties within a normal temperature range. SOLUTION: This segmented polyurethane having high stiffness and high elongation is characterized in that the polyurethane is produced from components comprising (A) a polycarbonate diol synthesized from an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a polycarbonate compound, (B) a chain extender and (C) a diisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a segmented polyurethane. More specifically, the present invention relates to a segmented polyurethane having high initial elastic modulus (elastic modulus at low strain) and high elongation at break, and high rigidity and high elongation with little change in mechanical properties in a normal temperature range. Therefore, it can be used as an elastomer, elastic fiber, coating material and the like.

[0002]

2. Description of the Related Art Segmented polyurethanes are synthesized from three components, polyol, diisocyanate, and a chain extender, and have a block polymer structure having a so-called hard segment and a soft segment in the molecule. Widely used to indicate.

Conventionally, polyether diols and polyester diols have been mainly used as polyols. However, segmented polyurethanes using polycarbonate diols have attracted attention because of their excellent heat resistance, hydrolysis resistance, weather resistance and the like. I have. Heretofore, there has been known a polycarbonate diol-based segmented polyurethane obtained by using a lower alkyl diol such as 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol (Japanese Patent Publication No. Sho 45). JP-A-9533, JP-A-2-170813, JP-A-4-7327,
JP-A-5-51428). However, these have insufficient rigidity and elongation, and their improvement is required.
In addition, the normal temperature range during actual use (-20 ° C to + 35 ° C)
, Changes in mechanical properties were large, and there were cases where there were restrictions in terms of applications.

[0004] In order to solve these problems, the composition ratio of the polyol, diisocyanate and chain extender, which are the constituent components of the segmented polyurethane, is examined, or the type of the diisocyanate and the chain extender is examined. Although studies have been made from the aspect, many studies have been made particularly on the structure of a polyol, ie, a polycarbonate diol, which creates a soft segment portion. For example, regarding improvement in rigidity, 1,4
A method using a rigid alicyclic alkyl diol such as cyclohexanedimethanol (Japanese Patent Publication No. 55-1924)
No. 9 and Japanese Patent Publication No. 61-34448) are known, but there is a problem that the elongation is reduced.

In order to improve the elongation, a method using an alkyl diol having a side chain such as 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, etc. Kaihei 2-1
58617, JP-A-4-31418, JP-A-4-332717), diethylene glycol, triethylene glycol, polypropylene glycol, polytetramethylene ether glycol, or
A method using an ether diol such as an etherified aliphatic diol such as 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol and 1,9-nonanediol (JP-A-63-305127). ,
JP-A-2-214713, JP-A-2-24012
No. 4, JP-A-2-255822, etc.). However, none of these methods can be expected to improve rigidity.

In addition, segmented polyurethanes obtained using relatively higher alkyl diols such as 1,9-nonanediol and 2-methyl-1,8-octanediol (Japanese Patent Publication No. 3-54967, Japanese Patent Publication No. Hei 4-54967). -1764
JP, JP-A-3-72516, JP-A-3-14
0318, JP-A-4-342714, JP-A-5-43646, etc.) and a segmented polyurethane obtained by using a long-chain dimer diol (36 carbon atoms) (JP-A-10-251369, Kaiping 10
-273514) is also known, but does not show satisfactory values in both rigidity and elongation.

Further, none of the above proposals solves the problem of a large change in mechanical properties in a normal temperature range (−20 ° C. to + 35 ° C.) during actual use.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems which cannot be solved by the prior art, that is, both the initial elastic modulus and the elongation at break are large, and the temperature in the ordinary temperature range is high. An object of the present invention is to provide a segmented polyurethane having high rigidity and high elongation with a small change in mechanical properties.

[0009]

The present invention provides (A) 1,1
Polycarbonate diol synthesized from an aliphatic hydrocarbon diol containing 2-dodecanediol and a carbonate compound, which is produced from a component containing (B) a chain extender and (C) a diisocyanate, and has high rigidity and high elongation. Achieved by a segmented polyurethane with a degree.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate diol (A) used in the present invention is synthesized from an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a carbonate compound. Here, the aliphatic hydrocarbon diol containing 1,12-dodecanediol is
1,12-dodecanediol is used as a main component, and a part thereof can be substituted with another alkyldiol. Examples of such an alkyl diol include an aliphatic hydrocarbon diol having 11 or less methylene groups and an alicyclic diol having 12 or less carbon atoms. Specifically, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10 -Decanediol, 2-methyl-1,
3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-methyl-1,
Examples include 8-octanediol, 1,4-cyclohexanedimethanol, and the like, and mixtures thereof. The amount of these used is preferably 50 mol% or less of the whole diol since 1,12-dodecanediol is preferably used as a main component. It is more preferably at most 30 mol%.

The carbonate compound used for the synthesis of the aliphatic polycarbonate diol may be any of a linear / cyclic aliphatic compound having a carbonate group and an aromatic compound. For example, dialkyl carbonate, diaryl carbonate or alkylene carbonate, specifically dimethyl carbonate, diethyl carbonate,
Di-n-butyl carbonate, diisobutyl carbonate, diphenyl carbonate, ethylene carbonate,
Trimethylene carbonate and the like and mixtures thereof can be mentioned. In the present invention, the synthesis of the aliphatic polycarbonate diol can be performed by a known method. That is, an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a carbonate compound, as a catalyst, titanium compounds such as titanium tetrachloride, tetra-n-butyl titanate and tetraisopropyl titanate, metal tin, tin hydroxide, It is obtained by subjecting an aliphatic hydrocarbon diol containing 1,12-dodecanediol to a transesterification reaction with a carbonate compound using a transesterification catalyst such as a tin compound such as tin chloride. The use ratio of the aliphatic hydrocarbon diol containing 1,12-dodecanediol and the carbonate compound is not particularly limited, but both ends of the molecular main chain of the aliphatic polycarbonate diol obtained are almost completely hydroxyl groups. To achieve this, an aliphatic hydrocarbon diol containing 1,12-dodecanediol in a slight stoichiometric excess, preferably a 1 to 30 mol% excess, based on the amount of the carbonate compound used is used. The amount of the catalyst used is 10 ppm to 1000 ppm based on the weight of 1,12-dodecanediol.
The conditions of the transesterification reaction are not particularly limited, but the transesterification reaction is usually performed at 110 to 180 ° C for about 1 to 4 hours under normal pressure, and further reacted at normal pressure at about 110 to 280 ° C for several hours. It is desirable that the reaction be performed for several hours under a reduced pressure of 20 mmHg or less while gradually increasing the degree of vacuum. In addition, since this reaction is an equilibrium reaction, it is desirable to continuously extract and remove by-product alcohols or phenols to the outside of the system. For this purpose, it is preferable to provide a distillation column in the reactor. In order to assist the distillation of the by-products, the reaction can be carried out while passing a small amount of an inert gas such as nitrogen, argon or helium through the reaction system. The molecular weight of the aliphatic polycarbonate diol obtained in the present invention is not particularly limited, but is preferably about 500 to 3000 in number average molecular weight. If the number average molecular weight is too low, a segmented polyurethane having the properties described in the present invention cannot be obtained. Moreover, the synthesis itself of an aliphatic polycarbonate having an excessively high average molecular weight is difficult. In the present invention, if necessary, the reaction product whose molecular weight has been adjusted is preferably treated with a phosphorus-based compound such as dibutyl phosphate in substantially the same mole as the transesterification catalyst used, to obtain a transesterification catalyst. Can be obtained to obtain an aliphatic polycarbonate diol as a target product.

[0012] The chain extender (B) used in the present invention is one of the constituent components in order to vary from a hard one to a soft one according to the intended use of the segmented polyurethane of the present invention. And a low molecular weight compound having at least two hydrogen atoms that react with isocyanate groups. Generally, aliphatic polyols and aliphatic or aromatic polyamines can be mentioned. Preferably, aliphatic polyols having 11 or less carbon atoms and aliphatic polyamines or aromatic polyamines can be exemplified. These may be used alone or as a mixture. Specifically, 1,4-butanediol, 1,
5-pentanediol, 1,6-hexanediol,
1,8-octanediol, 1,9-nonanediol,
1,4-cyclohexanedimethanol, 1,4-dihydroxyethylcyclohexane, ethylenediamine, 1,
Examples thereof include 2-propylenediamine, p, p'-diaminodicyclohexylmethane, and meta (para) xylylenediamine, and more preferably 1,4-butanediol.

As the diisocyanate (C) used in the present invention, various known aliphatic, alicyclic or aromatic diisocyanate compounds and high-functional or high-molecular diisocyanates are used. Specifically, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl diisocyanate,
Tetraalkyldiphenylmethane diisocyanate,
1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene Diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,
Examples include 4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate and derivatives thereof. Preferred are 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, and more preferred is 4,4'-diphenylmethane diisocyanate. These diisocyanates can be used alone or in combination.

The segmented polyurethane having high rigidity and high elongation of the present invention comprises (A) a polycarbonate diol (B) chain synthesized from an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a carbonate compound. It can be produced from a component containing an extender and (C) a diisocyanate by a polyurethane reaction. In this case, (A) a part of the aliphatic polycarbonate diol synthesized from the aliphatic hydrocarbon diol containing 1,12-dodecanediol and the carbonate compound is replaced with a hydrocarbon diol having 11 or less carbon atoms and the carbonate compound. It is also possible to substitute with an aliphatic polycarbonate diol synthesized from Specific examples of the hydrocarbon diol having 11 or less carbon atoms include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, , 9-nonanediol, 1,10-decanediol, 2-methyl-1,3-propanediol,
3-methyl-1,5-pentanediol, neopentyl glycol, 2-methyl-1,8-octanediol,
Examples include 1,4-cyclohexanedimethanol and the like and mixtures thereof. The amount of the aliphatic polycarbonate diol synthesized from the hydrocarbon diol having 11 or less carbon atoms and the carbonate compound is 50% by weight or less based on the entire aliphatic polycarbonate diol.

The polyurethane-forming reaction can be carried out in the absence of a solvent or in the presence of an organic solvent inert to isocyanate groups.

In the case of a solvent-free system, the aliphatic polycarbonate diol (A) and the chain extender (B) are mixed, and the diisocyanate (C) is mixed therewith and reacted at once, or After the aliphatic polycarbonate diol of (A) is reacted with the diisocyanate of (C) to obtain a prepolymer having an isocyanate group, the chain extender of (B) is mixed and reacted to polymerize, or
The aliphatic polycarbonate diol (A) and the chain extender (B) are mixed, and a part of the diisocyanate (C) is mixed and reacted to obtain a prepolymer having an isocyanate group. It can also be produced by mixing the diisocyanate (C) and further reacting.

The temperature of the polyurethane conversion reaction is not particularly limited, but is preferably from 80 to 150 ° C.

When using an inert organic solvent system,
After dissolving the aliphatic polycarbonate diol of (A) in an inert organic solvent and further mixing the chain extender of (B), the diisocyanate of (C) is mixed therewith and reacted at once, or ( The aliphatic polycarbonate diol of A) is dissolved in an inert organic solvent, and
After mixing and reacting the diisocyanates of (A) and (B), a chain extender is further mixed and reacted to polymerize,
Alternatively, the aliphatic polycarbonate diol of (A) is dissolved in an inert organic solvent, and the chain extender of (B) and a part of the diisocyanate of (C) are mixed and reacted therewith, and the remaining (C) May be mixed and further reacted.

Examples of the inert organic solvent include methyl ethyl ketone, ethyl acetate, toluene, dioxane, dimethylformamide, dimethyl sulfoxide and the like.

The temperature of the polyurethane-forming reaction in an inert organic solvent system is not particularly limited, but is preferably from 20 to 100 ° C.

In order to accelerate the polyurethane reaction, known amine catalysts such as triethylamine and triethylenediamine and tin catalysts such as trimethyltin laurate and dibutyltin dilaurate may be used.

Next, regarding the mixing ratio of the aliphatic polycarbonate diol of (A), the chain extender of (B) and the diisocyanate of (C), the aliphatic polycarbonate diol of (A) and the chain of (B) The use ratio of the extender is not particularly limited, but the former is 1/10 mol and the latter is 1/10 to 1 mol.
A range of 0 mole is preferred. If this value is too small,
The resulting segmented polyurethane has too low a stiffness and is not practical. Also, if this value is too large,
The essential features derived from the aliphatic polycarbonate diol (A) are not exhibited, and the object of the present invention cannot be achieved.
The amount of the diisocyanate (C) used is not particularly limited by the molecular weight of the obtained segmented polyurethane, but when used as an elastomer, it is an active hydrogen group of the aliphatic polycarbonate diol (A). It is desirable that the number of moles of the isocyanate group of the diisocyanate (C) is approximately equimolar to the total number of moles of the hydroxyl group and the active hydrogen group contained in the chain extender (B). Preferably, the equivalent molar ratio of the hydroxyl group, which is the active hydrogen group of the aliphatic polycarbonate diol of (A), the total mole number of the active hydrogen groups contained in the chain extender of (B), and the isocyanate group of the diisocyanate of (C) is equivalent. 1: 0.
8 to 1: 1.2, more preferably 1: 0.95
１ ： 1: 1.05. If this value is too small, the molecular weight of the resulting segmented polyurethane will not be sufficiently increased. On the other hand, if this value is too large, the molecular weight of the obtained segmented polyurethane becomes too large, resulting in gelation or a side reaction due to excessive isocyanate groups, which is not preferable.

The molecular end of the segmented polyurethane obtained in the present invention may be either a hydroxyl group or an isocyanate group. A partially crosslinked structure can also be introduced by reacting a urethane bond and / or a urea bond with an isocyanate group or using a low molecular compound having at least three hydrogen atoms that react with the isocyanate group.

The segmented polyurethane obtained by the present invention can be further reacted with a low molecular compound having at least two hydrogen atoms that react with isocyanate groups or a low molecular compound having at least two isocyanate groups to increase the molecular weight. Alternatively, it can be reticulated.

Various known additives may be added to and mixed with the segmented polyurethane obtained in the present invention as long as the effects of the present invention are not impaired.

The segmented polyurethane obtained in the present invention is excellent in heat resistance, hydrolysis resistance, weather resistance, etc., has a large initial elastic modulus and a large elongation at break, and has good mechanical properties in a normal temperature range. Since the change is small, the segmented polyurethane has high reliability as a material in actual use, and has high rigidity and high elongation. Therefore, it can be used as a polyurethane elastomer, polyurethane elastic fiber, polyurethane coating material and the like for rolls, solid tires, casters, shoe soles, tubes, hoses, belts, films and various injection molded parts.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but these do not limit the present invention in any way. In addition, various physical properties of the aliphatic polycarbonate diol were measured by the following methods. (1) Hydroxyl value (OH value) A fixed amount of a sample is weighed into an esterification flask, 25 ml of a pyridine solution of phthalic anhydride is accurately added with a whole pipette, and an air condenser is attached to the reaction flask. Heated for 2 hours with gentle shaking. After the reaction, the reaction mixture was allowed to stand at room temperature, and unreacted phthalic anhydride was titrated with N / 2 sodium hydroxide using the indicator phenolphthalein. The OH value was calculated by the following equation. OH number (mgKOH / g) = 28.05 (BA) f
/ S where S is the sampled amount (g), A is the amount of N / 2 sodium hydroxide solution required for sample titration (ml), and B is the N / 2 sodium hydroxide required for blank test titration. Solution volume (m
l) and f are factors of N / 2 sodium hydroxide solution. (2) Number average molecular weight (Mn) Calculated by the following equation. Mn = 112200 / OH number (3) Glass transition temperature (Tg) Measured using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation) in a nitrogen gas atmosphere at a heating rate of 10 ° C./min. (4) Melting point (Tm) The melting point (Tm) was measured using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation) in a nitrogen gas atmosphere at a heating rate of 10 ° C./min.

The physical properties of the segmented polyurethane were measured by the following methods. (5) Tensile properties According to JIS K7311, a tensile tester (manufactured by Orientec, Tensilon UCT-5T) was used at 23 ° C and 50 ° C.
% RH. Initial modulus, stress (100
%, 200%, 300% and elongation at break (ie tensile strength)
) And elongation at break. (6) Dynamic viscoelasticity Using a dynamic viscoelasticity measuring device (manufactured by Rheometrics, RSAII), frequency 1 Hz, strain amount 0.05%, -100 to 2
The measurement was performed in a tensile mode in a temperature range of 00 ° C.

Example 1 Synthesis of Aliphatic Polycarbonate Diol 1,12-Dodecane was placed in a 2 L glass reaction vessel equipped with a stirrer, a thermometer, and a distillation column equipped with a distillation tube, a reflux head and a condenser at the top of the column. 0.85 mol of diol (manufactured by Ube Industries, Ltd.), 0.81 mol of dimethyl carbonate (manufactured by Ube Industries, Ltd.) and 100 ppm of tetra-n-butyl titanate as a catalyst (1,1 by weight)
12-dodecanediol), heated, and refluxed with methanol and dimethyl carbonate azeotroping with methanol by transesterification.
Hold at 0 ° C. for 3 hours. Next, the temperature was gradually raised to 190 ° C. over 5 hours while distilling off the formed azeotrope of methanol and dimethyl carbonate. Then 190 ° C
Over 4 hours, the pressure was gradually increased by a vacuum pump, and finally the reaction was performed at a pressure of 20 mmHg for 2 hours to obtain a polycarbonate diol as a reaction product. Next, to the thus obtained polycarbonate diol, dibutyl phosphate in an equimolar amount to tetra-n-butyl titanate was added, followed by stirring at 110 ° C. for 2 hours. Table 1 shows the physical properties of the obtained polycarbonate diol.
This polycarbonate diol is hereinafter referred to as polycarbonate diol A.

Synthesis of Segmented Polyurethane and Evaluation of Its Physical Properties In a 1 L internal volume glass reaction vessel equipped with a stirrer, thermometer and cooling tube, polycarbonate diol A60 was prepared.
g (0.0284 mol) and 1,4-butanediol
5.15 g (0.0572 mol) was completely dissolved in N, N'-dimethylformamide 202 g at 60 ° C. Next, about 1 g of this solution was withdrawn with a syringe, and the moisture content was measured with a Karl Fischer moisture meter.
It was 7 ppm (0.0039 mol). The amount of 4,4'-diphenylmethane diisocyanate (21.93 g (0.04 g)) was substantially equal to the total amount of each of the polycarbonate diol A, 1,4-butanediol and water.
877 mol, NCO / OH = 0.98 (molar ratio)) was added to the above solution. Subsequently, the temperature was reset to 80 ° C., and heating / reaction was started. Since the solution viscosity increases with the progress of the reaction, the solution viscosity was measured every hour using an E-type viscometer, and the reaction was stopped 5 hours after the increase in the viscosity was almost no longer observed. As a result, the final viscosity of this solution was 62.0 Pa · sec at 40 ° C.
Therefore, after heating this segmented polyurethane solution to 60 ° C., it was cast on a glass plate with releasability, and
Heat at 0 ° C for 1 hour, then at 120 ° C for 2 hours,
A film having a thickness of 00 μm was obtained. The physical properties of this film are shown in Table 2 and FIG.

Example 2 In Example 1, polycarbonate diol A 90
g (0.0426 mol) and 1,4-butanediol
3.86 g (0.0429 mol) was completely dissolved in N, N'-dimethylformamide 202 g at 60C. Next, about 1 g of this solution was withdrawn with a syringe, and the moisture content was measured using a Karl Fischer moisture meter.
pm (0.0043 mol). 22 g of 4,4′-diphenylmethane diisocyanate (0.088 mol, N 2) was set to be approximately equal to the total amount of each of the polycarbonate diol A, 1,4-butanediol and water.
CO / OH = 0.98 (molar ratio)), and the physical properties of the segmented polyurethane film obtained in the same manner as described below are shown in Table 2.

Example 3 In Example 1, polycarbonate diol A 36
g (0.017 mol) and 1,4-butanediol
6.18 g (0.0686 mol) was completely dissolved in N, N'-dimethylformamide 202 g at 60C. Next, about 1 g of this solution was withdrawn with a syringe, and the moisture content was measured using a Karl Fischer moisture meter.
pm (0.0036 mol). 21.85 g of 4,4'-diphenylmethane diisocyanate (0.0874 g) was set to be substantially equal to the total amount of each mole number of polycarbonate diol A, 1,4-butanediol and water.
Mol, NCO / OH = 0.98 (molar ratio)),
Table 2 below shows the physical properties of the segmented polyurethane films obtained in the same manner.

Comparative Example 1 Synthesis of Aliphatic Polycarbonate Diol Example 1 was prepared in the same manner as in Example 1 except that 1,6 hexanediol (manufactured by Ube Industries, Ltd.) was used instead of 1,12-dodecanediol. The physical properties of the obtained polycarbonate diol are shown in Table 1. This polycarbonate diol is hereinafter referred to as polycarbonate diol B.

Synthesis and Physical Properties of Segmented Polyurethane 60 g (0.0299 mol) of polycarbonate diol B and 5.39 g (0.00.0 g) of 1,4-butanediol
599 mol) with N, N'-dimethylformamide 205
g was completely dissolved at 60 ° C. Next, about 1 g of this solution was withdrawn with a syringe, and the water content was measured with a Karl Fischer water content meter. As a result, 537.4 ppm (0.008
1 mol). Polycarbonate diol B, 1,
23.98 g of 4,4'-diphenylmethane diisocyanate (0.0959 mol, NCO / O) was almost equal to the total amount of each mole of 4-butanediol and water.
H = 0.98 (molar ratio)), and the reaction was stopped 6 hours after the increase in viscosity was almost no longer observed. The final viscosity of this solution is 46.5P at 40 ° C.
a · sec. The physical properties of the obtained segmented polyurethane film are shown in Table 2 and FIG.

Comparative Example 2 Synthesis of Aliphatic Polycarbonate Diol A polycarbonate diol obtained in exactly the same manner as in Example 1 except that diethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) was used instead of 1,12-dodecanediol. Table 1 shows the physical properties. This polycarbonate diol is hereinafter referred to as polycarbonate diol C.

Synthesis and Properties of Segmented Polyurethane 60 g (0.0266 mol) of polycarbonate diol C and 4.79 g (0.06 g) of 1,4-butanediol
532 mol) with N, N'-dimethylformamide 198
g was completely dissolved at 60 ° C. Next, about 1 g of this solution was withdrawn with a syringe, and the moisture content was measured with a Karl Fischer moisture meter. As a result, 311.7 ppm (0.004 ppm) was obtained.
6 mol). Polycarbonate diol C, 1,
21.42 g of 4,4'-diphenylmethane diisocyanate (0.0857 mol, NCO /
OH = 1.015 (molar ratio)), and the reaction was stopped 7 hours after the viscosity increase was almost no longer observed. As a result, the final viscosity of this solution was 29.15 Pa · sec at 40 ° C. The physical properties of the obtained segmented polyurethane film are shown in Table 2 and FIG.

Comparative Example 3 Synthesis of Aliphatic Polycarbonate Diol In Example 1, instead of 1,12-dodecanediol, a mixture of 1,9-nonanediol and 2-methyl-1,8-octanediol (1,9 -Nonanediol / 2
-Methyl-1,8-octanediol = 65/35 mol% ratio (manufactured by Kuraray Co., Ltd.), and physical properties of the obtained polycarbonate diol are shown in Table 1. This polycarbonate diol is hereinafter referred to as polycarbonate diol D.

Synthesis and Properties of Segmented Polyurethane Polycarbonate diol D (60 g, 0.0296 mol) and 1,4-butanediol 5.32 g (0.06 g)
591 mol) in N, N'-dimethylformamide 200
g was completely dissolved at 60 ° C. Next, about 1 g of this solution was withdrawn with a syringe, and the moisture content was measured using a Karl Fischer moisture meter to be 370 ppm (0.0055 mol). Polycarbonate diol D, 1,4-
23.31 g of 4,4'-diphenylmethane diisocyanate (0.0933 mol, NCO / OH) was almost equal to the total amount of each mole of butanediol and water.
= 0.99 (molar ratio), and the reaction was stopped 7 hours after the increase in viscosity was almost no longer observed. As a result, the final viscosity of this solution was 68.0 Pa · sec at 40 ° C. Table 2 shows the physical properties of the obtained segmented polyurethane film.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

The segmented polyurethane obtained according to the present invention uses an aliphatic polycarbonate diol synthesized from an aliphatic hydrocarbon containing 1,12-dodecanediol and a carbonate compound, so that the heat resistance,
In addition to excellent hydrolysis resistance, weather resistance, etc., the initial elastic modulus and elongation at break are both large, and the changes in mechanical properties in the ordinary temperature range are small, so the reliability as a material in actual use is high. Is a segmented polyurethane having high rigidity and high elongation.

[Brief description of the drawings]

FIG. 1 shows the results of temperature dependence of storage elastic modulus (E ′) of segmented polyurethane.

Claims (3)

[Claims] 1. A polycarbonate diol synthesized from (A) an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a carbonate compound, (B) a chain extender, and (C) a component containing a diisocyanate. A segmented polyurethane having high rigidity and high elongation characterized by the above-mentioned. 2. A chain extender (B) per mole of a polycarbonate diol (A) synthesized from an aliphatic hydrocarbon diol containing 1,12-dodecanediol and a carbonate compound.
(C) The cyanate group of the diisocyanate is produced from a component containing 0.8 to 1.2 equivalents to 1 equivalent of the active hydrogen group of (A) + (B), using / 10 to 10 times mol. The segmented polyurethane having high rigidity and high elongation according to claim 1. 3. The high rigidity and high rigidity according to claim 1, wherein (B) 1,4-butanediol is used as a chain extender and (4) 4,4′-diphenylmethane diisocyanate is used as a diisocyanate. Segmented polyurethane with elongation.