JP4790104B2 - Segmented polyurethane with high rigidity and high elongation - Google Patents

Description

【００４０】
【表２】

【００４１】
【発明の効果】
本発明で得られるセグメント化ポリウレタンは、１，１２−ドデカンジオールを含有する脂肪族炭化水素とカーボネート化合物から合成される脂肪族ポリカーボネートジオールを用いているために、耐熱性、耐加水分解性、耐候性等に優れている上に、初期弾性率及び破断伸びが共に大きく、かつ常用温度域での力学物性の変化が小さいため、実使用時における材料としての信頼性が高く、高剛性及び高伸度を有するセグメント化ポリウレタンである。
【図面の簡単な説明】
【図１】セグメント化ポリウレタンの貯蔵弾性率（Ｅ’）温度依存性の結果を示したものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to segmented polyurethane. More specifically, the present invention relates to a segmented polyurethane having a high initial stiffness (elastic modulus at low strain) and 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]
[Prior art and its problems]
Segmented polyurethane is a block polymer-structured polyurethane that is synthesized from the three components of polyol, diisocyanate and chain extender, and has so-called hard and soft segment parts in its molecule. It is widely used because of its high physical properties. .
[0003]
Conventionally, polyether diols and polyester diols have been mainly used as polyols, but segmented polyurethanes using polycarbonate diols are attracting attention because they are excellent in heat resistance, hydrolysis resistance, weather resistance, and the like.
So far, polycarbonate diol-based segmented polyurethanes obtained by using lower alkyl diols such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and the like are known (Japanese Patent Publication No. 45). No. -9533, JP-A-2-170813, JP-A-4-7327, JP-A-5-51428, etc.). However, these have insufficient rigidity and elongation, and their improvement is required. Moreover, in the normal temperature range (-20 degreeC-+35 degreeC) at the time of actual use, the change of a mechanical physical property is large, and there existed a restriction | limiting in the use surface.
[0004]
For these problems, the composition ratio of polyol, diisocyanate and chain extender, which are the components of segmented polyurethane, or the type of diisocyanate and chain extender, the molecular weight of segmented polyurethane, etc. Although studies have been made, in particular, many studies have been made on the structure of a polyol, that is, a polycarbonate diol, which creates a soft segment portion.
For example, regarding the improvement of rigidity, methods using rigid alicyclic alkyl diols such as 1,4-cyclohexanedimethanol (Japanese Patent Publication No. 55-19249, Japanese Patent Publication No. 61-34448, etc.) are known. However, there is a problem that the elongation decreases.
[0005]
For improving 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. 158617, JP-A-4-31418, JP-A-4-332717, etc.), diethylene glycol, triethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,6-hexanediol, 1,7-heptane. Methods using ether diols such as ethers of aliphatic diols such as diol, 1,8-octanediol, 1,9-nonanediol (Japanese Patent Laid-Open No. 63-305127, Japanese Patent Laid-Open No. Hei 2-214713, Japanese Patent Laid-Open No. Hei 2) -240124, JP-A-2-25582 Publication, etc.) and the like have been proposed. No.. However, none of these methods can be expected to improve rigidity.
[0006]
In addition, segmented polyurethanes obtained by 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. 4-1764). And JP-A-3-72516, JP-A-3-140318, JP-A-4-342714, JP-A-5-43646, etc.) and long-chain dimer diols (36 carbon atoms). There are also known segmented polyurethanes (JP 10-251369 A, JP 10-273514 A, etc.), but they do not show satisfactory values in both rigidity and elongation.
[0007]
Furthermore, in any of the above proposals, the problem that the change in mechanical properties in the normal temperature range (−20 ° C. to + 35 ° C.) during actual use is not solved.
[0008]
[Problems to be solved by the invention]
The object of the present invention is to solve the above-mentioned problems that the prior art could not solve, that is, high rigidity and low initial mechanical modulus and elongation at break, and small change in mechanical properties in the normal temperature range. It is to provide a segmented polyurethane having high elongation.
[0009]
[Means for Solving the Problems]
  The present invention provides (A) 1,12-dodecandioeAndIt is achieved by a segmented polyurethane having high rigidity and high elongation, characterized in that it is produced from a component comprising a polycarbonate diol (B) chain extender synthesized from a carbonate compound and (C) a diisocyanate.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
  The (A) polycarbonate diol used in the present invention is 1,12-dodecandioe.AndIt is synthesized from carbonate compounds.
[0011]
  The carbonate compound used for the synthesis of the aliphatic polycarbonate diol may be any of a linear / cycloaliphatic compound having a carbonate radical 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 do. In the present invention, the synthesis of the aliphatic polycarbonate diol can be performed by a known method. That is, 1,12-dodecandioeAndUsing a carbonate compound as a catalyst, a transesterification catalyst such as a titanium compound such as titanium tetrachloride, tetra-n-butyl titanate, tetraisopropyl titanate, or a tin compound such as metal tin, tin hydroxide, tin chloride, etc. , 12-DodecandioLeObtained by a transesterification reaction with a carbonate compound. 1,12-DodecandioAndThe use ratio of the carbonate compound is not particularly limited, but in order for both ends of the molecular main chain of the resulting aliphatic polycarbonate diol to be almost completely hydroxyl groups, the stoichiometric amount relative to the use amount of the carbonate compound. A theoretically slight excess, preferably a 1-30 mol% excess of 1,12-dodecandioeLeUsed. The amount of the catalyst used is 10 ppm to 1000 ppm based on the weight of 1,12-dodecanediol. The conditions for the transesterification reaction are not particularly limited, but the transesterification reaction is usually performed at 110 to 180 ° C. for 1 to 4 hours under normal pressure, and further reacted at 110 to 280 ° C. for several hours under normal pressure, and then at the same temperature. It is desirable to carry out the reaction for several hours under a reduced pressure that finally becomes 20 mmHg or less while gradually increasing the degree of vacuum. Further, since this reaction is an equilibrium reaction, it is desirable to continuously extract and remove alcohols or phenols produced as a by-product from the system. For this purpose, it is preferable to provide a distillation column in the reactor. Further, in order to help the by-product to be distilled off, the reaction can be carried out while passing a small amount of 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 the number average molecular weight is preferably about 500 to 3,000. If the number average molecular weight is too low, a segmented polyurethane having the properties described in the present invention cannot be obtained. Also, it is difficult to synthesize an aliphatic polycarbonate having an excessively high average molecular weight. In the present invention, if necessary, the reaction product having the molecular weight adjusted as described above is preferably treated with a phosphorus compound such as dibutyl phosphate, which is approximately the same mole as the transesterification catalyst used. It is also possible to obtain an aliphatic polycarbonate diol as a target product by inactivating.
[0012]
The (B) chain extender used in the present invention is blended as one of the constituent components in order to change from a hard one to a soft one depending on the intended use of the segmented polyurethane of the present invention. It is a low molecular weight compound having at least two hydrogen atoms that react with isocyanate groups.
Usually, aliphatic polyols and aliphatic polyamines or aromatic polyamines can be mentioned. Preferred examples include aliphatic polyols and aliphatic polyamines or aromatic polyamines having 11 or less carbon atoms. These may be used alone or in combination.
Specifically, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, 1, Examples include 4-dihydroxyethylcyclohexane, ethylenediamine, 1,2-propylenediamine, p, p'-diaminodicyclohexylmethane, and meta (para) xylylenediamine. More preferred is 1,4-butanediol.
[0013]
As the (C) diisocyanate used in the present invention, various known diisocyanate compounds such as aliphatic, alicyclic or aromatic, 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-4,4′-diisocyanate, 1,3-bis ( Socia sulphonate methyl) 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.
[0014]
  The segmented polyurethane having high rigidity and high elongation according to the present invention comprises (A) 1,12-dodecandioe.AndPolycarbonate diol synthesized from carbonate compounds,(B) It can manufacture by a polyurethane-ized reaction from the component containing a chain extension agent and (C) diisocyanate.
[0015]
This polyurethane-forming reaction can be performed in the absence of a solvent, or can be performed in the presence of an organic solvent inert to the isocyanate group.
[0016]
In the case of a solvent-free system, the aliphatic polycarbonate diol (A) and the chain extender (B) are mixed, and the (C) diisocyanate is mixed and reacted at once, or (A) The aliphatic polycarbonate diol of (C) is reacted with the diisocyanate of (C) to obtain a prepolymer having an isocyanate group, and then the polymer is polymerized by mixing and reacting with the chain extender of (B), or (A) The aliphatic polycarbonate diol of (B) and the chain extender of (B) are mixed, and a part of the (C) diisocyanate is mixed and reacted to obtain a prepolymer having an isocyanate group, and then the remaining (C) It can also be produced by mixing and further reacting.
[0017]
The temperature of the polyurethane reaction is not particularly limited, but is preferably 80 to 150 ° C.
[0018]
When an inert organic solvent system is used, the aliphatic polycarbonate diol (A) is dissolved in an inert organic solvent, and the chain extender (B) is further mixed, and then the diisocyanate (C). The aliphatic polycarbonate diol of (A) is dissolved in an inert organic solvent, and the diisocyanate of (C) is mixed and reacted therewith, and then the chain of (B) is further mixed. The extender is mixed and reacted to polymerize, or the aliphatic polycarbonate diol (A) is dissolved in an inert organic solvent, and this is combined with one of the chain extender (B) and the diisocyanate (C). After the parts are mixed and reacted, the remaining diisocyanate (C) may be mixed and further reacted.
[0019]
Examples of the inert organic solvent include methyl ethyl ketone, ethyl acetate, toluene, dioxane, dimethylformamide, dimethyl sulfoxide and the like.
[0020]
The temperature of the polyurethane reaction in an inert organic solvent system is not particularly limited, but is preferably 20 to 100 ° C.
[0021]
In order to accelerate the polyurethane reaction, a known amine catalyst such as triethylamine or triethylenediamine, or a tin catalyst such as trimethyltin laurate or dibutyltin dilaurate may be used.
[0022]
Next, regarding the blending ratio of the (A) aliphatic polycarbonate diol, the (B) chain extender and the (C) diisocyanate, the aliphatic polycarbonate diol (A) and the chain extender (B) The use ratio is not particularly limited, but the latter is preferably in the range of 1/10 to 10 mol with respect to 1 mol of the former. If this value is too small, the resulting segmented polyurethane will be too rigid and impractical. On the other hand, if this value is too large, the original characteristics derived from the aliphatic polycarbonate diol (A) cannot be expressed, and the object of the present invention cannot be achieved.
The amount of (C) diisocyanate used is not particularly limited depending on the molecular weight of the resulting segmented polyurethane, but when used as an elastomer, it is the active hydrogen group of the aliphatic polycarbonate diol (A). It is desirable that the number of moles of the isocyanate group of the (C) diisocyanate is approximately equimolar with respect to the total number of moles of active hydrogen groups contained in the hydroxyl group and the chain extender (B). Preferably, the equivalent molar ratio of the total number of moles of the active hydrogen group contained in the chain extender of (B) and the isocyanate group of the diisocyanate of (C) is the active hydrogen group of the aliphatic polycarbonate diol of (A). 1: 0.8 to 1: 1.2, more preferably 1: 0.95 to 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 resulting segmented polyurethane becomes too large, causing gelation or side reactions due to excess isocyanate groups, which is not preferable.
[0023]
The segmented polyurethane obtained in the present invention may have either a hydroxyl group or an isocyanate group at the molecular end. A partially crosslinked structure can also be introduced by the reaction between a urethane bond and / or urea bond and an isocyanate group, or the use of a low molecular weight compound having at least three hydrogen atoms that react with the isocyanate group.
[0024]
In addition, the segmented polyurethane obtained in 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 or form a network. You can also
[0025]
In the segmented polyurethane obtained by the present invention, various known additives may be added and mixed within a range not impairing the effects of the present invention.
[0026]
The segmented polyurethane obtained by the present invention is excellent in heat resistance, hydrolysis resistance, weather resistance, etc., and has both a large initial elastic modulus and elongation at break, and a small change in mechanical properties in a normal temperature range. Therefore, it is a segmented polyurethane that has high reliability as a material in actual use, and has high rigidity and high elongation.
Therefore, it can be used as polyurethane elastomer, polyurethane elastic fiber, polyurethane coating material, etc. such as rolls, solid tires, casters, shoe soles, tubes, hoses, belts, films and various injection molded parts.
[0027]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but these do not limit the present invention.
Various physical properties of the aliphatic polycarbonate diol were measured by the following methods.
(1) Hydroxyl value (OH value)
A certain amount of sample was weighed in an esterification flask, 25 ml of a phthalic anhydride solution in pyridine was accurately added with a whole pipette, an air condenser was attached to the reaction flask, and heated for 2 hours while gently shaking at 98 ± 2 ° C. . 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 an indicator phenolphthalein.
The OH value was calculated by the following formula.
OH value (mgKOH / g) = 28.05 (BA) f / S
Here, S is the amount of sample collected (g), A is the amount of N / 2 sodium hydroxide solution required for the sample titration (ml), and B is the N / 2 sodium hydroxide solution required for the titration of the blank test. Amount (ml), f is a factor of N / 2 sodium hydroxide solution.
(2) Number average molecular weight (Mn)
It was calculated by the following formula.
Mn = 112200 / OH value
(3) Glass transition temperature (Tg)
A differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) was used, and the measurement was performed in a nitrogen gas atmosphere at a temperature rising rate of 10 ° C./min.
(4) Melting point (Tm)
A differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50) was used, and the measurement was performed in a nitrogen gas atmosphere at a temperature rising rate of 10 ° C./min.
[0028]
Various physical properties of the segmented polyurethane were measured by the following methods.
(5) Tensile properties
According to JIS K7311, measurement was performed at 23 ° C. and 50% RH using a tensile tester (Orientec, Tensilon UCT-5T). The initial elastic modulus, stress (values at 100%, 200%, 300% and elongation at break (ie, tensile strength)) and elongation at break were determined.
(6) Dynamic viscoelasticity
Using a dynamic viscoelasticity measuring device (Rheometrics, RSAII), measurement was performed in a tensile mode at a frequency of 1 Hz, a strain amount of 0.05%, and a temperature range of −100 to 200 ° C.
[0029]
Example 1
Synthesis of aliphatic polycarbonate diol
1,12-dodecanediol (manufactured by Ube Industries, Ltd.) 0.85 in a 2 L glass reaction vessel equipped with a stirrer, thermometer and distillation tower equipped with a fractionation tube, reflux head and condenser at the top of the tower Mole, 0.81 mol of dimethyl carbonate (manufactured by Ube Industries, Ltd.) and 100 ppm of tetra-n-butyl titanate as catalyst (value relative to 1,12-dodecanediol on a weight basis) are heated, heated, and transesterified. Methanol and dimethyl carbonate azeotroped with methanol were maintained at 130 ° C. for 3 hours while refluxing. Next, the temperature was gradually raised to 190 ° C. over 5 hours while distilling off the azeotrope of methanol and dimethyl carbonate produced. Thereafter, while maintaining the temperature at 190 ° C., the degree of pressure reduction was gradually increased with a vacuum pump over 4 hours, and the reaction was finally carried out at a pressure of 20 mmHg for 2 hours to obtain a polycarbonate diol as a reaction product.
Next, tetra-n-butyl titanate and an equimolar amount of dibutyl phosphate were added to the polycarbonate diol thus obtained, and the mixture was stirred at 110 ° C. for 2 hours. The physical properties of the obtained polycarbonate diol are shown in Table 1. This polycarbonate diol is hereinafter referred to as polycarbonate diol A.
[0030]
Synthesis of segmented polyurethane and evaluation of its properties
In a glass reaction vessel having an internal volume of 1 L equipped with a stirrer, a thermometer and a cooling tube, 60 g (0.0284 mol) of polycarbonate diol A and 5.15 g (0.0572 mol) of 1,4-butanediol were mixed with N, It was completely dissolved in 202 g of N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 263.7 ppm (0.0039 mol).
21.93 g (0.0877 mol, NCO / OH = 0.98 mol) of 4,4′-diphenylmethane diisocyanate so as to be approximately equal to the total amount of each of the polycarbonate diol A, 1,4-butanediol and water. Ratio)) was weighed and added to the above solution. Subsequently, the temperature was reset to 80 ° C., and heating and reaction were started. Since the solution viscosity increased 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 almost no increase in viscosity was 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 releasable glass plate and heat-treated at 70 ° C. for 1 hour and then at 120 ° C. for 2 hours to form a film having a thickness of about 200 μm. Obtained. The physical properties of this film are shown in Table 2 and FIG.
[0031]
Example 2
In Example 1, 90 g (0.0426 mol) of polycarbonate diol A and 3.86 g (0.0429 mol) of 1,4-butanediol were completely dissolved in 202 g of N, N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 260 ppm (0.0043 mol).
22 g of 4,4′-diphenylmethane diisocyanate (0.088 mol, NCO / OH = 0.98 (molar ratio)) so as to be approximately equal to the total amount of each of the number of moles of polycarbonate diol A, 1,4-butanediol and water. Table 2 shows the physical properties of segmented polyurethane films obtained in the same manner.
[0032]
Example 3
In Example 1, 36 g (0.017 mol) of polycarbonate diol A and 6.18 g (0.0686 mol) of 1,4-butanediol were completely dissolved in 202 g of N, N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 265 ppm (0.0036 mol).
21.85 g (0.0874 mol, NCO / OH = 0.98 mol) of 4,4′-diphenylmethane diisocyanate so as to be approximately equal to the total amount of each of the polycarbonate diol A, 1,4-butanediol and water. Table 2 shows the physical properties of the segmented polyurethane film obtained in the same manner.
[0033]
Comparative Example 1
Synthesis of aliphatic polycarbonate diol
Table 1 shows the physical properties of polycarbonate diol obtained in the same manner as in Example 1 except that 1,6-hexanediol (manufactured by Ube Industries) was used instead of 1,12-dodecanediol. This polycarbonate diol is hereinafter referred to as polycarbonate diol B.
[0034]
Synthesis and properties of segmented polyurethane
60 g (0.0299 mol) of polycarbonate diol B and 5.39 g (0.0599 mol) of 1,4-butanediol were completely dissolved in 205 g of N, N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 537.4 ppm (0.0081 mol).
23.98 g (0.0959 mol, NCO / OH = 0.98 mol) of 4,4′-diphenylmethane diisocyanate so as to be approximately equal to the total amount of each of the number of moles of polycarbonate diol B, 1,4-butanediol and water. The ratio)) was weighed, and thereafter the reaction was stopped in the same manner 6 hours after almost no increase in viscosity was observed. The final viscosity of this solution was 46.5 Pa · sec at 40 ° C. The physical properties of the obtained segmented polyurethane film are shown in Table 2 and FIG.
[0035]
Comparative Example 2
Synthesis of aliphatic polycarbonate diol
Table 1 shows the physical properties of 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. This polycarbonate diol is hereinafter referred to as polycarbonate diol C.
[0036]
Synthesis and properties of segmented polyurethane
60 g (0.0266 mol) of polycarbonate diol C and 4.79 g (0.0532 mol) of 1,4-butanediol were completely dissolved in 198 g of N, N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 311.7 ppm (0.0046 mol).
21.42 g (0.0857 mol, NCO / OH = 1.015 mol) of 4,4′-diphenylmethane diisocyanate so as to be approximately equal to the total amount of each of the number of moles of polycarbonate diol C, 1,4-butanediol and water. The ratio)) was weighed, and thereafter the reaction was stopped in the same manner 7 hours after almost no increase in viscosity was 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.
[0037]
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- Table 1 shows the physical properties of polycarbonate diol obtained in exactly the same manner except that octanediol = 65/35 mol% ratio (made by Kuraray Co., Ltd.) was used. This polycarbonate diol is hereinafter referred to as polycarbonate diol D.
[0038]
Synthesis and properties of segmented polyurethane
60 g (0.0296 mol) of polycarbonate diol D and 5.32 g (0.0591 mol) of 1,4-butanediol were completely dissolved in 200 g of N, N′-dimethylformamide at 60 ° C. Next, about 1 g of this solution was extracted with a syringe, and the moisture content was measured with a Karl Fischer moisture measuring device. As a result, it was 370 ppm (0.0055 mol).
23.31 g of 4,4′-diphenylmethane diisocyanate (0.0933 mol, NCO / OH = 0.99 (mol) so as to be approximately equal to the total amount of polycarbonate diol D, 1,4-butanediol and each mole of water. The ratio)) was weighed, and thereafter the reaction was stopped in the same manner 7 hours after almost no increase in viscosity was observed. As a result, the final viscosity of this solution was 68.0 Pa · sec at 40 ° C. The physical properties of the obtained segmented polyurethane film are shown in Table 2.
[0039]
[Table 1]

[0040]
[Table 2]

[0041]
【The invention's effect】
Since the segmented polyurethane obtained in the present invention uses an aliphatic polycarbonate diol synthesized from an aliphatic hydrocarbon containing 1,12-dodecanediol and a carbonate compound, it has heat resistance, hydrolysis resistance, and weather resistance. In addition to excellent properties, the initial elastic modulus and elongation at break are both large, and the change in mechanical properties in the normal temperature range is small, so it is highly reliable as a material in actual use, and has high rigidity and high elongation. It is a segmented polyurethane having a degree.
[Brief description of the drawings]
FIG. 1 shows the results of temperature dependence of storage elastic modulus (E ′) of segmented polyurethane.

Claims (3)

(A) 1,12 Dodekanjio polycarbonate diol synthesized from Le and a carbonate compound, a high stiffness and high elongation, characterized in that it is manufactured from components comprising (B) a chain extender, and (C) a diisocyanate Having segmented polyurethane. (A) 1,12 Dodekanjio Le and a carbonate compound to polycarbonate diol 1 mole synthesized from, using (B) a chain extender 1 / 10-10 times by mol, the activity of (A) + (B) per 1 equivalent of the hydrogen groups, a high stiffness and high elongation according to claim 1, characterized in that it is manufactured from components comprising (C) iso cyanate groups 0.8 to 1.2 equivalents of a diisocyanate Having segmented polyurethane.   The segment having high rigidity and high elongation according to claim 1 or 2, wherein (B) 1,4-butanediol is used as a chain extender and (4) 4,4'-diphenylmethane diisocyanate is used as a diisocyanate. Polyurethane.

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