JP2991568B2 - Linear segmented polyurethane urea and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear segmented polyurethane urea and a method for producing the same. More specifically, useful for stably producing elastic fibers with high physical properties,
The present invention relates to a method for producing a linear segmented polyurethane urea having a remarkably small number of branched structures in a polymer and a highly concentrated solution thereof with high productivity.

[0002]

2. Description of the Related Art Polyurethane has entered a wide range of fields such as foams, adhesives, paints, elastomers, synthetic leathers, and fibers, and has produced many useful products. Among them, the polyurethane urea elastic fiber which requires particularly high elasticity is usually made of segmented polyurethane urea, and is a so-called "two-step method" shown in the following (1) and (2).
Manufactured in. (1) First, a diisocyanate component and a diol component are reacted in a molten state, and then dissolved as a molten prepolymer having isocyanate groups at both terminals in a solvent such as dimethylformamide or dimethylacetamide to obtain a prepolymer solution. (Melt synthesis method) or by directly reacting both components in the above solvent to obtain a prepolymer solution (solution synthesis method). (2) Then, the prepolymer is treated with an aliphatic diamine as described in US Pat. No. 2,929,804. The chain is extended to obtain a segmented polyurethane urea solution. Then, the solvent is removed from the solution to obtain a polyurethane urea elastic fiber. However, undesired side reactions (crosslinking reaction) are apt to occur during the production of the above-mentioned polymer, and the resulting final polymer has many branched structures. As a result, the polymer solution tends to gel at a high viscosity, and even if a method of ignoring productivity such as lowering the concentration of the polymer solution is used, the tendency of the polymer solution to gel is not completely eliminated. In addition, the solution viscosity decreases due to branch cutting in a subsequent step such as the subsequent compounding of a stabilizer,
Stable spinning and other molding are difficult, and the microgel in the polymer is accompanied by thread breakage. To solve this,
JP-B-41-3472, JP-B-44-22311 and JP-B-47-35317
As disclosed in Japanese Unexamined Patent Publication, there is a method of cutting a branched structure of a polymer to lower the viscosity to a level suitable for molding. In these methods, a long time is required for cutting, branch cutting is insufficient, time loss is large, and in some cases, the polymer solution is colored or devitrified. Furthermore, the microgel cannot be completely removed, and thread breakage still occurs during molding, for example, when spinning fine denier yarn or increasing the spinning speed. It is also possible to mold after adjusting the polymer solution having a viscosity that can be molded by lowering the polymer molecular weight and concentration without cutting the branch, but it is difficult to avoid a change in viscosity due to branch cutting in the subsequent process. Stable molding is difficult, a molded article with high physical properties cannot be obtained, and the productivity of the polymer solution also deteriorates as described above.

On the other hand, there has been an attempt to suppress a branching reaction (crosslinking reaction) to obtain a polymer having a small number of branched structures from the beginning. For example, "polyurethane resin" (by Keiji Iwata, sold by Nikkan Kogyo Shimbunsha) includes a prepolymer reaction in a neutral solvent such as toluene or in the absence of a solvent. It is stated that it can be suppressed. This is considered to be due to neutralization and deactivation of an alkali compound which is a catalyst for diol production remaining in the raw material diol component and promotes a crosslinking reaction by an acidic substance. On the other hand, dimethylformamide (pKa = -0.01) or dimethylacetamide (pKa = -0.18), which is a good solvent for the segmented polyurethane urea targeted in the present invention and is a basic solvent, Even if a small amount of an acidic substance is added, the effectiveness as an acid is reduced. Moreover, these solvents decompose into amines and carboxylic acids in the presence of the acidic substance, and as a result, the added acidic substance forms a neutral salt with the decomposed amine. The carboxylic acid remains later, but hardly acts as an acid in the solvent. Therefore, in such a basic solvent,
Unlike solvents that are neutral and do not decompose, such as toluene, it has been thought that acidic substances have no effect of suppressing the crosslinking reaction. However, surprisingly, as described above, when the prepolymer solution is prepared by the solution synthesis method or the bulk synthesis method in the basic solvent, if a small amount of an acidic substance is added in advance, the organic diamine is used. It was found that the chain was elongated, and the resulting polymer sometimes had significantly less branched structures. However, depending on the type and amount of the acidic substance to be added, the degree of the branched structure of the final polymer and the viscosity of the polymer solution are different. A low and devitrified polymer solution was obtained. As a result,
The spinnability of these polymer solutions was not stable, the physical properties of the resulting elastic fibers were low, and the fluctuations were large and unstable.

As described above, in the case where a prepolymer solution is obtained by a solution synthesis method or a melt synthesis method, and then a chain is extended with an organic diamine to produce a segmented polyurethane urea solution, a conventional technique requires stable products of high physical properties. In other words, it was not possible to stably produce a solution given as a solution, that is, a homogeneous and transparent solution of a segmented polyurethane urea having very few branched structures in a polymer with high productivity.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a linear segmented polyurethane urea having a very small number of branched structures in a polymer capable of stably forming a product having high physical properties and a homogeneous transparent solution thereof. An object of the present invention is to provide a method for producing a stable and high-concentration product with high productivity.

[0006]

According to the present invention, there are provided:
At least one stoichiometric excess diisocyanate component selected from the group consisting of 4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4-phenylene diisocyanate and a number average molecular weight of 50
A segmented polyurethane urea obtained by chain-extending a prepolymer having isocyanate groups at both ends comprising diol components of 0 to 6000 with an organic diamine in an organic solvent of dimethylformamide or dimethylacetamide. A linear segmented polyurethane urea having a degree of branching (Nb) of 3 or less is provided.

According to the present invention, there is also provided at least one stoichiometric excess diisocyanate component selected from the group consisting of 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4-phenylene diisocyanate. And the number average molecular weight is 500-6000
The diol component is reacted in the presence of dimethylacetamide or dimethylformamide as a solvent to form a prepolymer solution having isocyanate groups at both ends, or both components are reacted in a molten state in the absence of a solvent to form a melt. When a prepolymer solution is obtained by obtaining a prepolymer in the form of a solution, a prepolymer solution is obtained, and then the prepolymer is chain-extended with an organic diamine to produce a segmented polyurethane urea solution. 9 or less acidic substance in the range amount (mol / 1
kg of a prepolymer solution) to obtain a prepolymer solution, which is then chain-extended with an organic diamine.

X ≦ Amount of acidic substance to be added (mol / kg of prepolymer solution) ≦ A / 100 (where X = A × B × [1-e ^{(BA) kt} ) / [ ^AB ×
e ^{(BA) kt} ],

A is a value obtained by subtracting the initial concentration of both terminal hydroxyl groups in the diol component from the initial concentration of the isocyanate group in the diisocyanate component (mol / kg prepolymer solution) in the case of the synthesis of the prepolymer solution. In the case of melt prepolymer synthesis, which is a method, the concentration of isocyanate groups at both terminals of the prepolymer when the prepolymer is dissolved in a solvent (mol / kg prepolymer solution),

B is the initial concentration of the solvent (mol / 1 kg of the prepolymer solution) in the case of the synthesis of the prepolymer solution, and the concentration of the solvent used for dissolution (mol / 1 kg of the prepolymer solution) in the other case, and t is the prepolymer solution. In the case of solution synthesis, the prepolymer solution production time (min), in the other case, the prepolymer dissolution time (min), k = C × 10 ⁶ × e ^{(−E / RT)} ,

C (kg / mol / min) and E (kcal / mol)
Is the frequency coefficient and activation energy, respectively, T is the prepolymer solution production temperature in the case of prepolymer solution synthesis, and the prepolymer temperature (K) during dissolution in the other case, and R is the gas constant (1.99859). × 10 ^-3 kcal / mole
K)).

The inventors of the present invention have conducted intensive studies on the above problems, and as a result, the number of yarn breaks during spinning was remarkably reduced by a high-concentration linear segmented polyurethane urea solution having a degree of branching of 3 or less in a polymer. Is further improved than before, furthermore, the cause of accelerating the branching reaction is due to the substance generated during the production of the prepolymer solution, the amount of this branching reaction accelerating substance generated depends on the type, concentration and the like of the diisocyanate component and the solvent. In the solution synthesis method, it depends on the prepolymer solution production temperature, time and concentration, and in the melt synthesis method, it depends on the prepolymer dissolution temperature, time and concentration. When a prepolymer solution is produced, a linear segment having a degree of branching of a polymer of 3 or less is excellent not only in spinnability but also in quality (physical properties). The homogeneous clear solution of cement polyurethane urea stable found that can be produced with good productivity at a high concentration, thereby completing the present invention. Hereinafter, the contents of the present invention will be described in more detail.

The diol component used in the present invention has a number average molecular weight of 500 to 6000, preferably 900 to 25.
00 polyester diol, polyether diol,
It is a diol selected from the group consisting of polycarbonate diols.

As the polyester diol, one or a mixture of glycols such as ethylene glycol 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and the like, and succinic acid, glutaric acid, adipic acid, speric acid, mazelaic acid, etc. Polyester having a melting point of 60 ° C. or lower, preferably 40 ° C. or lower, which is produced from one or a mixture of aliphatic dicarboxylic acids and a dicarboxylic acid which may further contain an aromatic dicarboxylic acid such as terephthalic acid or isophthalic acid. Diol alone or 2
Mixtures of more than one species.

Examples of the polyether diol include polytetramethylene ether glycol, polycaprolactone diol, polyethylene ether glycol, polypropylene ether glycol and the like.

As the polycarbonate diol, a dialkyl carbonate or the like and a hydroxy compound such as 1,4
-Butanediol, 1,3-pentanediol, 1,5
Poly (butane-1,4-carbonatediol), poly (pentane-1,5-carbonatediol), poly (pentane-1,3-carbonatediol) obtained by reaction with -pentanediol, 1,6-hexanediol, etc. ), Poly (hexane-1,6-carbonatediol) and their copolymers and polycarbonate diols.

In the present invention, it is preferable to prepare a prepolymer with the molar ratio of the diisocyanate component to the diol component in the range of 1.3 to 2.5. Outside this range, the inherent properties of the prepolymer functioning as a soft segment are impaired, which is not preferable.

As the organic diamine which is a chain extender of the prepolymer used in the present invention, known aliphatic, alicyclic and aromatic diamines can be used. For example, ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, cyclohexylenediamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylenediamine, 3,3′-dichloro-4,4′-biphenyldiamine, Consists of 2,6-diaminopyridine, 4,4'-diaminodiphenylmethane, hydrogenated m-phenylenediamine, p-phenylenediamine, tetrachloro-m-phenylenediamine, tetrachloro-p-phenylenediamine and mixtures thereof Selected from the group.

Further, Japanese Patent Application No. 4-16691 (April 1992
And a diaminourea compound comprising an organic diisocyanate and an organic diamine as described in US Pat. Such compounds include, for example, 4,4'methylene-bis [[[(2-aminoethyl) amino] carbonyl] aniline] [compound (1)], 4,4'methylene-bis [[(2- [Aminopropyl) amino] carbonyl] aniline] [compound (2)], 4,4'methylene-bis [[[(6-aminohexyl) amino] carbonyl]
Aniline] (compound (3)) or a compound represented by the following formula (4)
~ (13).

[0020]

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[0021]

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[0022]

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[0023]

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The amount of chain extender used in the present invention is preferably in the range from 80 to 98% (based on stoichiometric) of the prepolymer free isocyanate content. If it is less than this range, the polymer molecular weight will be too low to obtain high physical properties, and if it is more than this range, on the contrary, the polymer molecular weight will be too large to make molding impossible. On this occasion,
As the polymer molecular weight modifier, for example, a terminal terminator such as diethylamine or diethanolamine may be used.

The acidic substances suitable for the present invention include dimethylformamide, acid chloride having an acid dissociation index of 1 to 9 in dimethylacetamide solvent, phosphate ester, borate ester, phosphite ester, sulfonic acid, oxyacid , Sulfuric acid gas, inorganic acid and the like, for example, at least one acid selected from benzoyl chloride, alkyl phosphoric acid, benzenesulfonic acid, paratoluenesulfonic acid, sulfurous acid gas, hydrochloric acid, sulfuric acid and the like. An acidic substance having an acid dissociation constant of greater than 9 cannot completely neutralize the branching promoter present in the prepolymer solution, and therefore has a small branching suppressing effect. The acid dissociation index indicates the logarithm of the reciprocal of the acid dissociation constant (25 ° C.), and the measurement method is determined by the method described in Chemical Handbook Basic Edition II (Chemical Dojinsha).

Next, the amount of the acidic substance to be added must be within the range represented by the following formula.

X ≦ Amount of acidic substance to be added (mol / kg of prepolymer solution) ≦ A / 100 (where X = A × B × [1-e ^{(BA) kt} ) / [A−B ×
e ^{(BA) kt} ],

A is a value obtained by subtracting the initial concentration of both terminal hydroxyl groups in the diol component from the initial concentration of the isocyanate group in the diisocyanate component (mol / kg prepolymer solution) in the case of the synthesis of the prepolymer solution. In the case of melt prepolymer synthesis, which is a method, the concentration of isocyanate groups at both terminals of the prepolymer when the prepolymer is dissolved in a solvent (mol / kg prepolymer solution),

B is the initial concentration of the solvent (mol / 1 kg prepolymer solution) in the case of prepolymer solution synthesis, the concentration of the solvent used for dissolution (mol / 1 kg prepolymer solution) in the other case,

T is the prepolymer solution production time (min) in the case of prepolymer solution synthesis, and the prepolymer dissolution time (min) in the other case, k = C × 10 ⁶ × e ^{(-E / RT)} ,

T represents the prepolymer solution production temperature (K) in the case of synthesizing the prepolymer solution, and T represents the prepolymer temperature (K) during dissolution, and R represents the gas constant (1.985).
9 × 10 ⁻³ kcal / mol · K)

The C value (frequency coefficient, kg / mol) and E value (activation energy, kcal / mol) are constants determined by the combination of diisocyanate and solvent, and are shown in Table 1.

Table 1 ───────────────────────────Solvent Isocyanate ─────────────Dimethylphodimethyla Lumamide Cetamide ４ ， 4,4'-diphenyl C value 20.0 2.5 Lumethane diisocyanate ─────── ───────── Nate E value 16.8 17.9 ２ ， 2,4-Toluenedi value C value 30.0 3.5 Socyanate ──────────────── E value 16.9 18.1 ─────────────────────────── 1, 4-phenylene C value 40.0 4.5 Isocyanate ──────────────── E value 13.9 14.9 ───────────────────── ──────

When the amount of the acidic substance added is less than this range (X or less in the formula), the degree of branching of the polymer increases, and the polymer solution becomes a gel with high viscosity. As a result, a high-concentration polymer solution cannot be obtained, resulting in poor productivity, and in a subsequent step such as compounding of a stabilizer, a decrease in solution viscosity due to branch cutting occurs, and stable molding becomes difficult. In addition, microgels in the polymer cause breakage during molding, such as spinning. Conversely, it is larger than this range (A / 100 in the formula)
Above) and the excess acidic substance present during chain elongation reduces the functional group ability of the organic diamine, which is a chain extender, so that a desired polymer molecular weight cannot be obtained and a polymer solution that gives a molded article with high physical properties can be obtained. Absent. In addition, the polymer solution is easily devitrified with time, causing various troubles in the process. The timing of adding the acidic substance is preferably at the start of the reaction, but may be at the time when the conversion of isocyanate groups to urethane groups reaches 95%.

In the present invention, the prepolymer solution production temperature is preferably 5 to 70 ° C. in the case of prepolymer solution synthesis.
If the temperature is lower than 5 ° C., the production time is significantly increased,
If the number exceeds 3, reactions other than the above side reactions, for example, trimerization of isocyanate groups, etc., become remarkable, which is not desirable. The prepolymer production temperature in the case of melt synthesis is 30 to
120 ° C. is preferred. Temperature conditions outside this range are not preferred for the same reasons as in the prepolymer solution synthesis.

The chain extension reaction is preferably carried out at 0 to 30 ° C. If it is less than this, the solubility of the prepolymer deteriorates and the system becomes non-uniform, and if it is more than this, the reaction between the isocyanate group and the amino group becomes abnormally fast, making it difficult to control the reaction. .

The thus obtained linear segmented polyurethane urea of the present invention has a degree of branching (Nb) of 3 or less, and its homogeneous transparent solution shows almost no decrease in viscosity even in the steps after production. Because it is stable and has low viscosity, the polymer solution concentration can be made higher than before,
Productivity is improved. Furthermore, since it is uniform and transparent, it is excellent in molding stability such as spinning, and the number of times of yarn breakage during spinning is significantly reduced as compared with the conventional case. Further, the product after molding shows high physical properties and is satisfactory.

In the production of the linear polyurethane urea described above, the prepolymer reaction and the chain extension reaction were performed in a batch system. When manufacturing a prepolymer in a batch mode, the isocyanate group concentration in the prepolymer solution may be reduced due to a shift in the raw material charging ratio for each batch or a reaction temperature unevenness in the system often observed in a large-capacity reactor. May fluctuate. Furthermore, when the prepolymer stays in the kettle, side reactions leading to a crosslinked structure are likely to occur.
When the chain extension reaction is carried out batchwise, the reaction between the isocyanate group and the amino group is extremely fast, so that the reaction occurs before the prepolymer solution and the amine solution are uniformly mixed, and a polymer having desired properties is obtained. Solution may not be obtained. These problems are due to the use of high-precision scales,
The shape of the stirring blades can be considerably improved from the engineering aspect, such as devising the shape of the stirring blade so that the solution in the kettle can be mixed as uniformly as possible.However, it is difficult to say that it is not enough. Frogs are more preferred.

The continuous synthesis of the prepolymer solution and the polymer solution can be achieved by the method described below. That is, as shown in FIG. 1, after each raw material flow of the stoichiometric excess of diisocyanate component A, diol component B and solvent C is continuously supplied and mixed by a quantitative pump, urethanation reaction is carried out in reactor 2, A prepolymer solution having isocyanate groups at both ends is obtained, or a diisocyanate component A and a diol component B are continuously mixed, and after a urethanization reaction, the flow of the solvent C is continuously fed to the molten prepolymer. In addition, after mixing in the mixer 3 to form a prepolymer solution, the solution flow is continuously supplied to the flow of the organic diamine D using a metering pump, respectively.
To extend the prepolymer to obtain a polymer solution E.

The diisocyanate component, diol component, solvent and organic diamine used as the raw materials in the present invention are the same as those used in the case of the above-mentioned batch (batch) method for producing both prepolymer and polymer solutions. Can be used. Further, the molar ratio of the diisocyanate component and the diol component, the amount of the chain extender and the type of the acidic substance,
The amount is the same as in the case of the batch production method. Further, the prepolymer solution production temperature and the chain extension reaction temperature are the same as those in the batch production method.

In the continuous production method of both the prepolymer and polymer solutions according to the present invention, the continuous mixing of the raw material flows of the diisocyanate component, the diol component and the solvent and the mixing of the prepolymer solution and the organic diamine solution flow are sufficient. If a mixing effect can be obtained, either a static type mixer or a dynamic type mixer may be used.

The reactor used for continuous production of the prepolymer solution is a pipeline type hollow tube reactor, a pipeline type reactor equipped with a static mixer, a complete mixing tank row type reactor, and a polymer type reactor. Extrusion (Chris Ra
uwendeal, Hanser Publishers, 1986), and a single-screw or multi-screw extruder type reactor.

The degree of branching of the linear segmented polyurethane urea of the present invention obtained in this manner is further smaller than that obtained by a batch-type production method, and the polymer solution is uniformly transparent. Therefore, the molding stability such as spinning and the product after molding exhibit high physical properties, and are more satisfactory than those obtained by a batch method.

The degree of branching (Nb) is an index indicating the number of allophanate and burette bonds in the prepolymer, and can be determined as follows using a chemical decomposition method with n-butylamine. DMAc having a concentration of 0.005 g / ml of the segmented polyurethane urea of interest in the present invention.
0.1% by volume of n-butylamine was added to the solution, and its reduced viscosity (ηsp / C) was measured at 25 ° C.
g. The reduced viscosity (ηsp ′ / C) after treating this solution at 50 ° C. for 4 hours is defined as Eml / g. The degree of branching (Nb) defined by the following equation is calculated from the change in reduced viscosity before and after heating.

Nb = (DE) / D × 100

This method quantitatively cleaves only the allophanate and biuret branch bonds.
o (Macromol.Chem., 98, 148 (1966)) and Furukawa and Yo
Koyama et al. (J. Polym Sci., Po
lym.lett.Ed., 17,175 (1979)).

Further, that the polymer solution is uniform and transparent is the following 2
Judgment was made from the two measurement results. (I) Permeability of a 30% by weight dimethylformamide or dimethylacetamide solution of the polymer is 90% or more. However, the transmittance was measured using a turbidity meter (manufactured by Nissan Sangyo, model: LT-11) after aging the polymer solution at 20 ° C. for 2 weeks. (ii)
Microgels and macrogels large enough to allow visual judgment are not observed in the polymer solution aged at 20 ° C. for 2 weeks after production. However, the absence of a microgel means that there is no particle of 50 μm or more in a dimethylformamide or dimethylacetamide solution containing 1% by weight of the polymer. There are various methods for measuring microgel particles, but here we use a coulter counter (Coulter Ele
ctronics. Model: TA-2) was used.

[0048]

Next, the embodiments of the present invention will be described specifically with reference to examples. The parts in the examples relate to weight (g) unless otherwise specified.

Regarding the molding stability of the polymer solution, the difference between the viscosity after stirring the polymer solution at 80 ° C. for 5 hours (shear rate is ¹ sec ⁻¹ ) and the initial viscosity before stirring was measured using a rotary cylindrical rheometer. The polymer solution was subjected to dry spinning of a yarn of 40 denier / 4 filaments at a speed of 500 m / min for 10 hours continuously at a speed of 500 m / min, and the number of yarn breakage during the spinning was evaluated from two results. However, “+” indicates that the decrease in the polymer viscosity is small and the number of yarn breaks during spinning is extremely small, and “−” indicates that the decrease in the polymer viscosity is large and the number of yarn breaks during spinning is extremely large. Is set to “±”.

The physical properties of the obtained yarn were ASTM-D-273.
Measured by the general method of -72. 5cm for each measurement
The sample is stretched once at a constant pulling rate of 1000% per minute using five yarns with a gauge length of 100%, and the 100% modulus (g), elongation at break (%) and strength (g) are measured. did.

The absorbance of the absorption at 1688 cm ^-1 (Aν (C =
O, 1688 cm ^-1 )) and derived from the stretching vibration of the benzene ring
The value at 1610 cm ^-1 (Aν (C = C, 1610 cm ^-1 )) was measured as follows. A polymer film having a thickness of 10 μm is obtained from a 20% by weight solution of the polymer by a casting method (film formation conditions: under reduced pressure (2 Torr), 50 ° C., 24 hours). BIO-RAD FT-IR, Model FTS-
By using a 60A and a permeation method, 1750 cm ^-1
The infrared absorption in the region of 1600 cm ^-1 is measured. Yamamoto et al. (Po
lymer J., Vol. 21, No. 11, 1989), the infrared spectrum in this region is separated into nine types of waveforms by curve fitting (the peak position of each waveform is
1737, 1730, 1709, 1685, 166 from high wave number side
5, 1638, 1633, 1610 and 1592 cm ^-1 ). From the absorbances at 1688 and 1610 cm ^-1 after the waveform separation, the ratio of both absorbances, that is, Av (C = O, 1688 cm ^-1 ) / Aν '(C = C, 1610c
m ^-1 ) is obtained.

Example 1 A minimum amount X of 2
An example of producing a prepolymer solution by adding a double amount of 1.1 × 10 ⁻⁴ mol and then producing a polymer solution by a chain extension reaction will be described. First, 570 parts of dimethylacetamide (DMAc) is placed in a reaction vessel equipped with a stirrer, a thermometer, a nitrogen seal tube, and the like, and then 470 parts of polytetramethylene ether glycol (PTMG, number average molecular weight Mn =
2000) and finally 100 parts of 4,4'-diphenylmethane diisocyanate (MDI)
15.4 mg of benzoyl chloride (1.
(1 × 10 ^-4 mol) was precisely weighed and added to the reaction vessel. At the end of the reaction, the residual isocyanate group concentration was 0.271 mol. However, the residual isocyanate group concentration is An
alytical Chemistry of Polyurethanes (New York, Wile
y-Interscience, 1969) Polyurethanes, Sect. III. After that, 7.
A 514 parts DMAc solution containing 6 parts ethylenediamine (EDA) and 1.3 parts diethylamine (DEA) was prepared (moles of EDA / moles of DEA = 7.12, polymer concentration = 35% by weight), and 15 At C the solution was quickly added into the rapidly stirred prepolymer solution. When the absorption of the isocyanate group in the solution at 2260 cm ^-1 was no longer observed, the chain extension reaction was terminated. The degree of branching (Nb) of this polymer was 2.5, the properties of the polymer solution were uniform and transparent, the molding stability was extremely good, and the elastic yarn (4
The modulus (0d), elongation at break (100%), elongation at break and elongation at 3.2%, 72g and 750%, respectively, were extremely high. Furthermore, the infrared absorption ratio of the carbonyl group and the benzene ring = heavy bond in the obtained polymer

[0053]

(Where Aν (C = O, 1688 cm ⁻¹ ): absorbance of polymer at 1688 cm ⁻¹ , Aν ′ (C = C, 1610
cm ^-1): absorbance at 1610 cm ^-1 of the polymer) 0.1
It was below. Table 2 shows the physical property values of the elastic yarn.

Comparative Examples 1 and 2 In Comparative Example 1, the amount of benzoyl chloride added at the time of the reaction of the prepolymer solution was set to 1.7 × 10 ⁻⁵ mol, which is ３ of the minimum required amount X. In Comparative Example 2, the amount of benzoyl chloride was decreased. Upper limit A / 1
Example 1 except that it was 5.6 × 10 ^-3 mol twice as large as 00.
Under the same conditions as above, a polymer solution was obtained. Table 2 shows the results.

Comparative Example 3 A polymer solution was obtained under the same conditions as in Example 1 except that the prepolymer solution was prepared without adding any benzoyl chloride during the reaction of the prepolymer solution. Table 2 shows the results.

Comparative Example 4 Here, except that acetic acid having an acid dissociation constant of 9 or more in dimethylacetamide during the reaction of the prepolymer solution was added (1.1 × 10 ⁻⁴ mol, twice the minimum required amount X). A polymer solution was obtained under the same conditions as in Example 1. Table 2 shows the results.

Example 2 Here, the kind of the acidic substance added at the time of the reaction of the prepolymer solution was changed. Concentrated sulfuric acid (97 instead of benzoyl chloride)
%) (1.1 × 10 ⁻⁴ mol) (2 of minimum required amount X).
Except that the polymer solution was obtained under the same conditions as in Example 1. Table 2 shows the results.

Comparative Examples 5 and 6 In Comparative Example 5, concentrated sulfuric acid (97%) was used during the prepolymer solution reaction.
%), Which is 1/3 of the minimum required amount X and 1.7 × 10 ^-5 mol, and in Comparative Example 6, the amount of concentrated sulfuric acid is 5.6 × 10 ^-3 mol twice as large as the upper limit A / 100. A polymer solution was obtained under the same conditions as in Example 1 except for the above. Table 2 shows the results.

Example 3 Here, an example is shown in which the reaction temperature and the reaction time are changed to 50 ° C. and 50 minutes, respectively, among the prepolymer solution reaction conditions of Example 1. A polymer solution was produced under the same conditions as in Example 1 except that the amount of benzoyl chloride was changed to 3.8 × 10 ^-4 mol (twice the minimum required amount X) in accordance with the change in the conditions. Table 3 shows the results.

Example 4 Here, an example is shown in which the prepolymer solution concentration is changed to 70% by weight among the prepolymer solution reaction conditions of Example 1.
Accordingly, the prepolymer production time is reduced to 70 minutes, and the amount of benzoyl chloride is adjusted to 5 × 10 ^-5 mol (twice the minimum required amount).
A polymer solution was produced under the same conditions as in Example 1 except for the above. Table 3 shows the results.

Example 5 The solvent used in Example 1 was changed from DMAc to DMF.
The production temperature and time of the prepolymer solution were 30 ° C and 70 min.
A polymer solution was obtained under substantially the same conditions as in Example 1 except that 2.1 × 10 ⁻³ mol of benzoyl chloride was added (the minimum required amount). Table 3 shows the results.

Example 6 Here, an example of the method for synthesizing a molten prepolymer of the present invention will be described. 100 parts of solid MDI is placed in a reaction vessel equipped with a stirrer, a thermometer and a nitrogen sealed tube, and dissolved at 45 ° C. Next, 470.0 parts of PTMG (Mn = 2000)
Was added and a prepolymer reaction was performed at 80 ° C. for 150 minutes. After the completion of the reaction, the molten prepolymer was cooled to 30 ° C., 570 parts of DMAc was added, and dissolved under stirring for 90 minutes. At this time, 15.4 mg (1.1 × 10 ⁻⁴ mol) of benzoyl chloride, which was twice the minimum required amount, was precisely weighed and added to the reaction vessel. The concentration of residual isocyanate groups at the end of dissolution was 0.323 mol. Next, 7.6 parts of ethylenediamine (EDA) and 1.3 parts of diethylamine (D
514 parts of a DMAc solution containing EA) was prepared, and a polyurethane solution was obtained in the same manner as in Example 1. Table 4 shows the results.

Comparative Examples 7 and 8 In Comparative Example 7, when dissolving the molten prepolymer in DMAc, the amount of benzoyl chloride was reduced to 1/3 of the minimum required amount.
A polymer solution was obtained under the same conditions as in Example 7 except that 7 × 10 ⁻⁵ and 5.6 × 10 ⁻³ mol in Comparative Example 8 were added. Table 3 shows the results.

The symbols in each table are as follows. 1) A small amount and a large amount indicate that the amount of the added acidic substance is small and large, respectively, as compared with the claimed amount. 2) 100% modulus (%) of 40 denier yarn 3) 強度 Strength at break (g) 4) 〃 Elongation at break (g)

Comparative Example 9 As described in JP-B-47-35317, the polymer produced in Comparative Example 1 was heated and stirred at 70 ° C. for 10 hours.
A branch cut was obtained (the degree of branching after processing was 5.3). Table 2 shows the results.

EXAMPLE 7 As shown in FIG. 1, a flow of 100 parts / min of 4,4'-diphenylmethane diisocyanate, a flow of 470 parts / min of tetramethylene ether glycol and a flow of 570 parts / min
Of dimethylacetamide (containing 2.7 × 10 ^-2 % by weight benzoyl chloride) through a metering pump
Continuously guided into a forced stirring mixer (average residence time 1
Minutes). Thereafter, the solution after mixing is introduced into a pipeline type reactor, and reacted under the condition of an average residence time of 100 minutes and 30 ° C. to continuously obtain a prepolymer solution. Next, the solution flow (1140 parts / min) and the amine solution flow (514 parts / min, consisting of 7.6 parts of ethylenediamine, 1.3 parts of diethylamine and 505.1 parts of dimethylacetamide) are continuously applied. The mixture was guided into a forced stirring mixer (average residence time: 3 seconds), and the chain was extended at 15 ° C. to obtain a polymer solution. The completion of the chain extension reaction was confirmed in the same manner as in Example 1. The results are shown in Table 2.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3]

[0071]

As can be seen from the results shown in Table 2, the linear segmented polyurethane urea of the present invention has no acidic substance added at all during the reaction of the prepolymer solution (Comparative Example 3) or a small amount (Comparative Example 1, Comparative Example 1). 5) and a case where an acid substance having an acid dissociation constant in DMAc of 9 or more was added (Comparative Example 4), and conversely, a case where the amount was large (Comparative Examples 2 and 6).
Furthermore, as compared with a product obtained by branch-cut in the subsequent step (Comparative Example 9), the polymer of the present invention has a degree of branching of 3 or less and its solution is uniformly transparent, so that it has excellent molding stability. It can be seen that the high physical properties that could not be obtained by the method, that is, the modulus is improved, and that high elongation and high strength can be exhibited. The same can be said for the synthesis of a molten prepolymer (Table 3). Furthermore, as can be seen from the results in Table 4, it can be seen that the effects of the present invention were sufficiently discovered even when the conditions for producing the prepolymer solution were significantly changed. In addition, it can be seen that the physical properties (Example 7) of the polymer obtained by making all the processes from prepolymer synthesis to polymerization continuous in the polymer production method are more preferable than those obtained by the batch method.

[Brief description of the drawings]

FIG. 1 is a drawing showing an example of a flow of a continuous production method of a linear segmented polyurethane urea solution according to the present invention.

[Explanation of symbols]

 A ... diisocyanate component B ... diol component C ... solvent D ... amine component E ... polymer component 1 ... mixer 2 ... prepolymer synthesis reactor 3 ... mixer 4 ... mixer 5 ... metering pump

Continuation of the front page (56) References JP-A-49-97097 (JP, A) JP-A-47-15498 (JP, A) JP-A-48-20895 (JP, A) JP-A-3-128413 (JP) , A) JP-B-48-19719 (JP, B1) JP-B-46-14473 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 18/65-18/66 C08G 18/32 C08G 18/40-18/48 C08G 18/10

Claims (4)

(57) [Claims] 1. A method according to claim 1, wherein 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4
A stoichiometric excess diisocyanate component selected from the group of phenylene diisocyanates and a number average molecular weight of 5
A segmented polyurethane urea obtained by chain-extending a prepolymer having isocyanate groups at both ends comprising a diol component of 00 to 6000 with an organic diamine in an organic solvent of dimethylformamide or dimethylacetamide, wherein Branching degree (Nb)
Is 3 or less. 2. The linear segmented polyurethane urea according to claim 1, wherein the absorbance of the carbonyl group in the linear segmented polyurethane urea by infrared spectroscopy satisfies the following relationship. In the formula, Aν (C = O, 1688 cm ⁻¹ ): 1688 cm ^{−1 of} polymer
Av '(C = C, 1610 cm ^-1 ): absorbance of polymer at 1610 cm ^-1 3. 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4
A stoichiometric excess diisocyanate component selected from the group of phenylene diisocyanates and a number average molecular weight of 5
A diol component of from 0.00 to 6000 is reacted in the presence of dimethylacetamide or dimethylformamide as a solvent to form a prepolymer solution having isocyanate groups at both ends, or the components are reacted in a molten state in the absence of a solvent. Then, after obtaining a molten prepolymer, it is dissolved in a solvent to obtain a prepolymer solution, and then, when the prepolymer is chain-extended with an organic diamine to produce a segmented polyurethane urea solution, the acid in both solvents is used. An acidic substance having a dissociation index of 9 or less is present in the amount shown in the following formula (mol / 1 kg of a prepolymer solution) to obtain a prepolymer solution, and then linear segmentation is performed by chain extension with an organic diamine. A method for producing a polyurethaneurea solution. X ≦ Amount of acidic substance to be added (mol / kg prepolymer solution) ≦ A / 100 (where X = A × B × [1-e ^{(BA) kt} ) / [A−B ×
e ^{(BA) kt} ], where A is the value obtained by subtracting the initial concentration of both terminal hydroxyl groups in the diol component from the initial concentration of isocyanate groups in the diisocyanate component (mol / kg prepolymer solution) In the case of the synthesis of a molten prepolymer, which is the other method, the concentration of isocyanate groups at both terminals of the prepolymer when the prepolymer is dissolved in a solvent (mol / kg of a prepolymer solution). Is the initial concentration of the solvent (mol / kg of the prepolymer solution); in the other case, the concentration of the solvent used for dissolution (mol / kg of the prepolymer solution); min), in the case of other prepolymers dissolution time (minutes), a ^{k = C × 10 6 × e} (-E / RT), C (kg / mol / min) and E (kcal / mol) T represents the prepolymer solution production temperature in the case of prepolymer solution synthesis, and T represents the prepolymer temperature (K) at the time of dissolution in the case of prepolymer solution synthesis, and R represents the gas constant (1.99859 × 10 ⁻³ kcal / mol · K)). 4. A stoichiometric excess of a diisocyanate component, a diol component and a raw material flow of a solvent are continuously mixed and reacted by urethanation to obtain a prepolymer solution having isocyanate groups at both ends, or a diisocyanate. The components and the diol component are continuously mixed, and after the urethanization reaction, the solvent flow is continuously added to obtain the prepolymer solution.The solution flow is continuously mixed with the organic diamine flow, 4. The method for continuously producing a linear segmented polyurethane urea solution according to claim 3, wherein a prepolymer chain extension reaction is carried out.