DE2136695A1 - Process for the production of stable polyurethane solutions - Google Patents

Description

DR. INC. A.VAN DERWERTH DR. FRANZ LEDERER

! 2I HAMBURG 90 ^a MONCHHN 80

· Τ «. SI · TIL «04lll 770861. LUCILE-GRAHN-STR. 3Ϊ ■ TEt. (0811.440846

Jul 22, 1971 FUJI SPINNING Co., Ltd.

Process for the production of stable polyurethane solutions

The present invention relates to a method of making stable polyurethane solutions, and more particularly to a process for the production of homogeneous and stable solutions by suppressing the growth of particularly long ones Molecular chains through a suitable control of the added Amounts of urethane prepolymers and chain extenders. The solutions of the substantially linear polyurethane are used in many applications as a starting material for production, for example of shaped products, threads, films, coatings, etc. used. *

The industrial use of the polyurethane solutions brings with it numerous problems, especially with regard to theirs

109887/1700

Tendency to wrap around the axles of the mixer, infoloe the r.elierungsphfinomene, the increase in viscosity in dependence of the time, etc., which occur in the course of their manufacture. The usual procedure for making a polyurethane solution consists in extending the chain of a bifunctional urethane prepolymer, which has isocyanate end groups and that by Reaction of a polyhydroxyl compound with terminal hydroxyl groups, such as a polyether glycol, polyester glycol, polyether ester glycol or polyacetal glycol with an excess amount of an organic diisocyanate is obtained with the aid of a Chain extender, which is a bifunctional compound that has two active hydrogen atoms associated with the isocyanate groups can react, for example a diamine, hydrazine or a glycol. This reaction takes place in the presence of a polar solvent instead, which is inert towards the reactive substances and can dissolve the polyurethane obtained. It is dimethylformamide, dimethylacetamide or Dimethyl sulfoxide.

In practice it is found that this chain extension reaction associated with a winding of the solution around the axis of the mixer due to a rapid local increase in viscosity which causes the so-called Weissenberg phenomenon, by which the solution climbs up the axis and gels, resulting in an incomplete mixture - which is difficult to achieve a homogeneous one To obtain polymer solution allows. Even if you have one Obtaining homogeneous polymer solution by addressing these difficulties

10 9887/1700 _ ₃ .

overcome by vigorous mixing, so is the solution obtained so unstable under the conditions that its viscosity increases in the time it takes for the solution to gel, which indicates the storage of the solution for very long periods of time makes impossible.

This phenomenon is a major disadvantage of this method of creation represent.

Various methods have been proposed to overcome these disadvantages to avoid. Mention should be made of the chain lengthening process at low temperature, the chain lengthening process with the help of two chain extenders with the possibility various peactions, the procedure based on the use of a stabilizer, e.g. acetone, in the course the chain extension is based, etc.

In all of these processes, the chain extender is added to the urethane prepolymer that is in the reactor or the urethane prepolymer is added to the chain extender located in the reactor. This fine process can effectively control the rapid reaction that occurs between the urethane prepolymer and the chain extender he follows.

The first of these manufacturing methods also has the disadvantage on that, for example, the isocyanate end groups of the urethane prepolymer in certain types of polar solvents be inactivated.

In addition to the above-mentioned method, it has been proposed in

109887/1700 - 4 -

a continuous process the urethane prepolymer, the Chain extender, the chain regulator and the polar solvent to be introduced into the peactor at a certain speed.

Part of the resulting polymer solution is used for dilution returned to the chain lengthening reaction to control. Hei takes this continuous process

k always the Mach part, the growth of extra-long molecular 'molecules due to the high concentration of Kettenverlängerunasmittels that vorlieat in the reactor no longer control to be able, however, the return rate of the semi-Polymerurethanlösung, and when the relative molar ratio of the urethane prepolymer to the chain extender is initially fixed at about 1: 1, the resulting urethane solution is unstable.
As a result, it turns out to be very difficult to

W knew.Methods of obtaining a polyurethane solution on an industrial scale which is stable and homogeneous and can be stored for a relatively long time and which does not have the disadvantages mentioned above.

It has now been found that the stability of the polyurethane solutions is strongly influenced by the reactions that occur in the course of the first phase of the chain extension reaction, and that a control of this initial reaction to stable polyurethane solutions can lead.

According to the invention, the control of the initial action can be made easy

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/ ßAO ORIGINAL

obtained v / ground by the reactor with the chain extender provided with a precisely determined initial concentration and then the additional amount of chain extender and urethane polymer with a specified one Speed is added.

According to the invention, stable polyurethane solutions are produced on a discontinuous basis? ⁷ else in the presence of a polar solvent and optionally in the presence of small amounts of a chain regulator by reaction

1. of a bifunctional urethane prepolymer with isocyanate end groups, by reacting a polyhydroxyl compound with terminal hydroxyl groups with a superstoichiometric one Amount of an organic diisocyanate is obtained with

2. a bifunctional chain extender, the active one Contains hydrogen atoms that react with the isocyanate groups and which is characterized by the fact that

ι of urethane prepolymer

\ 1) the degree of addition ^ expressed by χ and defined as a ratio in% of the molar amount of up to a certain

Urethane instant in the course of the> iPrepolymer added to the reaction. to the total molar amount of chain extender added and

2) The degree of chain extender, expressed by y and defined as the ratio in % of the molar amount of chain extender added up to a certain point in the course of the reaction to the molate

Total amount of added chain leaning agent , where "" ■ ■ <* - * "■■ ·" ^v T09887 / 17Q0 ^{BAD 0RIG} ^ AL '~, s> ~

the total time is until the fat extender addition index reaches about 90 % , the following equation

enough:

loo χ + 35 \ y ^ - ~ ξ ^x or preferably

If reactive reagents other than those formed by the urethane prepolymer and chain extender are present, the equivalent amounts of these agents must be converted into molar amounts of the M-functional reactive agents and included in the molar amounts of urethane prepolymer and chain extender. Of these other reactive agents, the molar amounts of the latter having isocyanate groups (e.g. organic isocyanates), the molar amount of urethane prepolymer and the molar amounts of those having active hydrogen atoms are added. can react with the isocyanate groups (for example the monamines) are added to the molar amount of chain extender. If a chain regulator is used, its equivalent amount must be considered. This is true in compounds that contain a urea group and having a terminal Äiriinogruppe and which are obtained by reaction of a diamine with an organic monoisocyanate, and in compounds "which contain a urea group and having a terminal isocyanate group and prepared by reacting a Monamins with an organic Diisocyanate were obtained.

109887/1700 iao original " ⁷ "

According to one embodiment of the invention, the solvent is introduced into the reaction zone beforehand in a precisely determined Henge -on chain extender. Subsequently, the urethane prepolymers, the Kettenverlängerungsinittel and optionally chain regulators with the speed determined by the claimed above equations, and was calculated, was added, and in the moment when the addition level of Urethanprepolymerem 65 - _f 95%, preferably 70 - reaches 90% is one the total amount of chain extender and. Chain regulator too.
According to a variant of the process according to the invention, it is possible, instead of beforehand, to add the chain extender to the reaction

/ ^CS

zone to initiate _r / at a greater speed and at the same time with the urethane prepolymer under the addition conditions that satisfy the claimed conditions. The remaining urethane prepolymer is then added to the solution thus obtained while maintaining an excess of chain extender in relation to the prepolymer. In this way the solution reaches its specified viscosity. In the course of this last phase the reaction is not very different from the current batch polymerization method. The only advantage is that the rate of reaction can be more easily controlled by diluting the semi-polymer urethane, which has two active terminal carbon atoms.

What distinguishes the invention from previous methods,

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is the control of the addition conditions of each reactant in the first reaction phase until the rate of addition of the chain extender reaches about 90%. Are the nominal of the known methods in the course of the selected Anfanasreaktionsphase Fedingungen and if the rest of urethane prepolymers, such as anaeaeben above, is added, it is not possible to obtain stable polyurethane solutions.

ψ The relationship of the present invention between the addition levels of the urethane prepolymer and the chain extender is illustrated by the accompanying drawing. 1 shows the relationship between the percentages of a bifunctional urethane prepolymer which has isocyanate end groups and a bifunctional chain extender which has active hydrogen atoms which advise the isocyanate groups to react. The vertical axis represents the degree of addition of the chain extension agent and the waaaorech-

* th axis the addition wheel of the urethane prepolymer; the crades are calculated using the following formula:

added in a starry aurne look

Degree of addition (%) - ■ x'ioo

plus an additional ten molar total amount of chain extender

It should be understood that the molar amount ar. Kcttenverlengermittel is based on the reactive bifunctional entities that are involved in the reaction, as well as on their functionality. In other words, the functionality associated with the final

109887/1700 "

constant isocyanate groups of the urethane prepolymer reacts, used as a ^p echen base the nolar hen in such a way that they are taken into account when nan a chain regulator with active. Hydrogen atoms used, which react with the isocyanate groups. Penn nan infolaedessen uses a monofunctional P ^ ettenrerrler, two molecules of this latter correspond to one molecule of chain extender.

The polymer referred to in this invention includes all the compounds which have isocyanate end groups, as well as their intermediates. For example, if you have an organic Isocyanate is used as a chain regulator, this must be taken into account when calculating the molar plenum of urethane prepolymer will.

Referring to Fig. 1, v / ground χ and y which represent the respective levels of addition of urethane prepolymers and of chain extenders according to the definitions given above .sind through detects the zone lying between the straight oblique lines. As can be seen, according to the invention it is necessary that a Excess amount of chain extender always in the reaction system is present. If there is an excessive amount of the urethane prepolymer, the isocyanate end groups of the prepolymer become inactive in the solvent and their reaction with the chain extender can thereby be influenced. If, after the end of the chain-lengthening reaction, there are remaining Isocyanate groups that did not react are present / so represents one fast increase in the viscosity of the solution found what

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the addition of reactive compounds with the isocyanate groups, for example an aliphatic monamine, an aliphatic Mercaptan, etc., which is disadvantageous.

Before applying the method of the invention, two factors should be considered to draw attention to those who act on the chain extension process.

These two factors are usually essentially incompatible borrowed, but are compatible according to the invention.

The first of these factors is related to the dilution of the solution by lowering the concentration of chain extender per unit volume in the reaction medium. This causes the reaction of the chain extender with the urethane prepolymer, which contains isocyanate end groups, as well as the reaction of the semi-polymer urethane, which contains active terminal hydrogen atoms and which is formed in the chain extension reaction with the urethane prepolymer, which contains isocyanate end groups, at a moderate rate, which leads to homogeneity of the products obtained by this reaction. For this purpose, in addition to the amount required for diluting the extension agent and the urethane prepolymer, a solvent menu is introduced into the reactor and the semi-polymer urethane is also used in the course of the chain extension reaction, preferably to dilute the chain extension agent. The second factor is with increasing the reactive ratio of the chain extender to the urethane prepolymer

tied together? for example, the degrees of addition of chain extension 109887/1700 "_, - Il -

-iV ν BAD ORIGINAL

Nerunas materials and urethane prepolymers are chosen in such a way that specialist work prevents particularly long molecules and ensures homogeneous Solution of polyurethane is obtained, its Ilolekularcreweausgabe lieat in a separate area.

In order to achieve this goal, it is recommended to start the chain lengthening reaction introduce an amount of chain extender into the reactor that is 3 - 30% of the total amount added is equivalent to.

After this addition, chain extenders are used at the same time and urethane prepolymer.

The effects of the claimed method are dependent on the addition conditions of each reactant, up to the degree of addition of the chain extender reaches a value of 90%, where-

The effects under these conditions are no longer particularly noticeable

seem to change.

Thus, the method of adding the remaining reactants has no meaning if the addition conditions of each reactant are adapted to the claimed conditions, which are confirmed from the time of the first addition into the reaction zone nuts until the degree of addition of the chain extender is 90% of the total amount of chain extender added achieved.

According to one embodiment of the invention, a part of the used Solvent before the chain extension reaction with mixed with the urethane prepolymer to lower its viscosity and promote its reaction. The chain extension

1098 87/1700 '* ■' - 12 -

Gerunaspiittel and the chain regulator can be added separately, but they can also be mixed together and diluted with the solvent. However, it is not advisable to keep them under the dilute conditions for a very long time, because they can reversibly or irreversibly give rise to foreign substances according to the reactivity of the chain extender.

ψ In general, the chain regulator is used at the moment when the chain extension reaction has reached its end point. However, it is preferred to mix it with a chain extending agent and use it from the beginning of the chain extending reaction, taking its productivity into account and choosing an appropriate mixture.

By working this way, the chainreamer has one effective effect, so that a solution of the polyurethane is obtained, the molecular weight distribution of which is in a narrow range.

* The bifunctional urethane prepolymer used according to the invention, which has terminal isocyanate groups, can be produced by reaction of at least one polyglycol which contains terminal hydroxyl groups of a molecular weight which is usually in the range from 300 to 800 and preferably in the range from 800 to 3000, for example a polyether glycol, polyester glycol, Polyester ether glycol or a polyacetal glycol, with at least one organic diisocyanate in an excess amount, preferably 150-200 mol%, can be obtained.

The polyether glycols that have hydroxyl end groups and how

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BATH ORIGINAL

_ TO _

are used mentioned above, are preferably characterized by a melting point below 60 ⁰ C and a glass transition point below the ambient atmospheric temperature. Of these compounds, polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene-ethylene glycol, polyoxytctramethylene glycol, polvoxypentamethylene glycol, polyoxyhexamethylene glycol, etc. are named.

Of the polyesterolycols, those obtained by polycondensation of an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid with an aliphatic glycol are preferably used. One can also use as polyester glycol polycaprolactone, which is produced by the polymerization of lactone under. Ring opening is obtained, use. Of the aliphatic carboxylic acids that can be used, succinic acid, adipic acid, pimelic acid, tartaric acid, sebacic acid, etc. are mentioned, and of the aromatic dicarboxylic acids, terephthalic acid, kexahydroterephthalic acid, etc. Decamethylene glycol and neopentyl glycol etc .; named. The organic diisocyanates which may be used to prepare the urethane prepolymer are, for example, 1,6-hexamethylene diisocyanate, cyclohexylene diisocyanate, r-phenylene diisocyanate, naphthylene-l ^ -diisocyanst, toluyl diisocyanate-2,4 ~ _f diphenylmethane-4,4'- -diif5Ocyanat, azobenzene-4,4 ^l -diisocyanate, l-isopropylbenzene-S ^ -diisocyanate etc / .. Of these the diphenylmethane-4,4 ^l -diisocyanate is the preferred compound.

109887/1700 _1Δ

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The organic Dj isothiocyanate, the compounds mentioned above can also be used. Folalich extends the definition of isocyanate groups, from isocyanate and urethane also to isothiocyanate groups, isothiocyanate and thiourethane.

Of the polar solvents used according to the invention for example dimethylformamide, dimethylacetamide, dimethyl ^ sulfoxide, hexamethylphosphoramide, etc. called.

The chain extenders that have active hydrogen atoms and can react with isocyanate groups, v / earths selected from:

1. the glycols, such as 1,4-putanediol, 1,2-propanediol, phenylenedi (ß-hydroxymethyl ether) , Ethylene glycol, xylylene polycol etc /. ;

2. the hydrazines;

3. the amines, such as] \ thylenediamine, propylenediamine, hexamethylenediamine, Cyclohexylenediamine, methyliminobispropylamine, ° ipera-

^ zin, 2-methyl-piperazine, naphthylenediamine, diaminodiphenylmethylene, phenylenediamine, tolylenediamine, xylylenediamine, 3,3'-dichloro-4 _f 4'-diaminodiphenylmethane, carbodihydrazide, a hydrazide of a carboxylic acid, etc. ;

4. the amino alcohols, such as amino methyl alcohol, aminopropyl alcohol, Aminobenzyl alcohol, etc. and

5. water.

If you use water, it reacts with what is present Compound containing isocyanate groups to obtain the corresponding compound containing amino groups and used as

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_t **, '- ^' ^r - ' ■ "BAD ORIGINAL

Chain modification agent reaaaaaed. According to the present The chain regulator used in the invention is selected from those compounds which contain only one primary or secondary amino group, such as dimethylamine, diethylamine, dibutylamine, diethanolamine, TI, N-dimethyl-1,3-propanediamine etc.

As an apparatus that is used for the application of the process according to the invention can be used, an ordinary reactor can be used to mix the high efficiency liquid is equipped with a stirrer. A stirrer, the chain extender and the urethane prepolymer are preferably used mixes effectively, thereby rapidly dispersing these compounds in the reactor. Such a stirrer is special useful because it can generate violent currents in the first polymerization phases which are characterized by a low viscosity of the solution. In any case, a sufficient one Emotion necessary to the malevolent effects of the rapid. Reaction between the chain extender and the urethane prepolymer to disturb and so obtain a homogeneous solution. The polymerization temperature is usually the ambient temperature, however, a temperature of about 10 C in the first polymerization phases may be suitable if the viscosity of the Lösuna is low, and a temperature of about 30 ° C. may be preferred be used in the last polymerization phases provided that the chain lengthening reaction to this time has ended.

The polyurethane obtained by the process according to the invention

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109887/1700

The solution is similar to that of tteigunn, an increase in viscosity as a function of the from the time to show, to gel, a transparency of the weaker solutions result in a lowering of the spinnability cause and the phenomenon of phase separation between. see the solvent and the polymer. The application of the claimed method also rarely causes the rise phenomenon to occur along the axis of the stirrer which often occurs in the course of the chain-lengthening reaction when the other methods are used. There is an advantage also in a smaller amount of chain regulator opposite the known methods.

The use of the method according to the invention also leads to stable polyurethane solutions of the same concentration and viscosity. The polyurethane solutions are homogeneous and also have has a molecular weight distribution which is in a narrow range.

The polyurethane solutions obtained according to the invention are known in corresponding products are converted using known processes, which do not work with desolvation. For example, elastic polyurethane threads can be carried out based on these solutions the known methods of dry and wet spinning can be obtained. Spinning a spinning solution 30 days after Their manufacture also gives FMden no difference with those obtained by instantly spinning the spinning solution. A publisher is also provided the suspension time of the filters and. the period of use

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«AD ORIGINAL

the spinnerets as well as a reduction in thread breakage, which takes place immediately after leaving the spinneret. These advantages completely overcome the various technical ones Difficulties that arise when using the previously known methods. The method according to this invention is particularly important in the production of a spinning liquid advantageous in which the reactivity of the polyurethane is particularly high and contains the urethane urea groups that cause coagulation favor the solution. The procedure also enables to increase the concentration of the spinning liquid while maintaining the same degree of stability of the solution. The invention can also be applied to corresponding other than "an elastic threads carried out, for example on shaped products such as threads, coatings, etc.

The following examples illustrate the invention. The amounts given are parts or% by weight, unless otherwise stated will.

FIGS. 2, 3 and 4 relate to various examples according to the invention and the comparative examples to non-inventive examples. The values χ and γ given on the abscissa and ordinate represent the respective degree of addition of the urethane prepolymer and of the chain extender in accordance with the definitions given above. 1 corresponds. The straight lines outside this range correspond to the comparative examples not according to the invention.

109887/1700 '»ad original" ¹⁸ "

example 1

1. Preparation of the prepolymer solution

In a stainless steel reactor equipped with a stirrer, a Thermometer and a nitrogen supply line is provided, 601.8 parts of a polyester with one molecular weight are added of 2030, the reaction of adipic acid with a> 'ethylene glycol-propylene glycol mixture with a molar ratio of 9: 1 ^ was obtained, too.

148.2 parts of diphenylmethane-4,4'-diisocyanate are then added at 60.degree and brings the temperature to 90 ° C within 30 minutes.

The reaction is continued at this temperature for 60 minutes to obtain an isocyanate-terminated prepolymer. Man finally diluted with 250 parts of dimethylformamide to one To obtain 75% prepolymer solution, its content of isocyanate groups Is 2.365%.

2. Manufacture of the flmin solution

This solution, which is used for chain extension, is used by mixing 3.50 grams of methyliminobispronylamine, 11.59 grams of ethylenediamine and 0.46 g of diethanolamine with such an amount of dimethylformamide that a volume of 100 ml is obtained.

3. Chain extension reaction

In a reactor equipped with a stirrer, a thermometer, feed lines for the solution of the chain extension belt and for If nitrogen is provided, 2106 g of dimethylformamide are first added and 5 ml of amine solution. This is then added with stirring

^ 09887/1700 " ¹⁹ "

Mix the amine and prepolymer solution at one temperature of 10 - 30 ° C and with precisely defined addition rates.

At the beginning, the rate of addition of the amine solution is 2.0 ml / min, and that of the prepolymer solution is 15.6 g / min. The addition is continued for 47.5 minutes, which makes it possible to obtain a degree of addition for the prepolymer of 95%. The rate of addition of the prepolymer is then reduced to 7.8 g / min until the rate of addition of prepolymer reaches 97.5%. The rate of addition is reduced again until the total addition of prepolymer reaches 775 g, which corresponds to an addition rate of 99.5% at the moment the process is stopped.

The solution obtained in this way is not colored, transparent, has a viscosity of 400 poise and a solids content of 20.1%. The specific viscosity of this solution, measured in dimethylformamide at 30 ^° C., is 1.25.

The conditions of this example are the same as the method according to the invention adapted and correspond to A of FIG.

4. Experiments on the viscosity of the solutions and the properties of the threads

The polyurethane solution obtained by the process described above has been stored at a temperature of 30 ° C and the changes in viscosity as a function of time were measured using a rotational viscometer. The results obtained, shown in Table I, show that the solution was over

109887/1700 ^ Oo /? _tol ., .. " ²⁰ "

is stable for a very long period of time.

The solution is in an aqueous dimethylformamide bath with the aid a spinneret with 60 holes with a diameter of 0.11 mm immediately after its manufacture, 5 days after and 10 days was subsequently spun and the properties of the threads thus obtained were measured.

The results of these measurements, which are shown in Table I, show that all the properties obtained have excellent properties exhibit.

Example 2

The polyurethane solution is produced using the same apparatus, the same amine solution and the same prepolymer solution been. The reactor is first charged with 2106 g of dimethylformamide and 20 ml of amine solution. The prepolymer solution is then added at a rate of 15.6 g / min by adding 10 ml of the Amir solution every 5 minutes. The degree of addition of the prepolymer is 80% at the moment when all the amine solution has been added. Analogously to Example 1, the Prepolymer solution until a total amount of 771 α is reached, which corresponds to a final degree of addition of 98.9% for the prepolymer.

In this way, an uncolored, transparent T ¹ polyurethane solution with a solids content of 20.0% and a viscosity of 39Ο poise is obtained.

The working procedure of this example corresponds to B of Fin. 2.

109887/170 0 _gAD " ²¹ "

Example 3

The same is used analogously to the previous examples Device and the same amine solution and the same prepolymer solution.

The reactor is first charged with 2106 g of dimethylformamide and 25 ml of amine solution. The amine solution is added to this mixture at a rate of 2.0 ml / Hin and the prepolymer solution at a rate of 15.6 g / min. The addition of the amine solution is ended after 37.5 minutes. At this moment the degree of addition of the prepolymer solution is 75%. As in Example 1, the addition of the prepolymer solution is continued until the total amount added is 774 g, which corresponds to an addition rate of 99.3 % . The working conditions of this example correspond to C of FIG. 2.

The polyurethane solution obtained in this way is undyed, transparent and has a viscosity of 380 poise and a solid content of 20.1%.

The specific viscosity of the solution, measured in dimethylformamide at 30 ° C, is 1.2O.

The test results, which have the purpose of improving the stability of the To determine the solution and the properties of the threads are in Table I listed and considered excellent.

Comparison game 1 ■ ■■

The Vorriehtung, the amine solution and di @ Prep © Xym © rXösung are the same " as those given in Example 1" Since, © Eiigabebeäin-

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However, conditions deviate from the conditions of the claim of the patent away.

The reactor is charged with 2106 g of dimethylformamide and one releases the amine solution and prepolymer solution at one rate of 20 ml / min and 15.6 g / min, respectively. The whole amount of amine is after Added 50 minutes. At this point in time, the degree of addition of prepolymer solution is 97.5%. The prepolymer solution is then used until a total of 762 g is reached, which corresponds to a final degree of addition of 97.8%. V7enn nan after the working conditions specified above, the polyurethane

solution has a solids content of 19.8%, has a viscosity range from 100 - 420 poise and calls according to the cefr'lle excessive winding of the solution around the axis of the stirrer. If this solution is under the same conditions as the of Example 1 is stored, it gels by becoming whitish after 2 days, which no longer affects the viscosity and allows their spinnability. The working conditions of this comparative example 1 are indicated under D in FIG.

Comparative example 2

The device, amine and prepolymer solutions are the same

like that of example 1.

2106 g of dimethylformamide and 70 cm of amine are added to the reactor. The amine and prepolymer solution are added to this mixture at eugabe speeds of 2 ml / min and 15.6 g / min . The addition of the amine solution is ended after 15 minutes . Der Zuvw <* « '^ 1 0 9 8 8 _{7/17 0 0 flAD 0R) älNAL} ·" ^2S "

The degree of prepolition at this point is 30%. The prepolymer solution is then added analogously to Example 1 until a total of 767 g is reached, which is a Final degree of prepolymer of 98.4%. In this way, a polyurethane solution with a solids content is obtained of 19.9% / a viscosity of 3 50 poise with a surprise finish Tendency to rise along the axis of the stirrer. The spinnability of this solution is after storage of 10 days because of her gelieruna impossible. Working conditions correspond to F of FIG. 2.

Comparative example 3

In this example, the addition of the amine and prepolymer solution is not carried out at the same time. The reactor is first provided with the total amount of amine solution _f, for example 100 ml. The prepolymer solution is then added at the rate of addition given in Example 1. After a total amount of prepolymer solution of 760 g has been added, the degree of prepolymer added increases to 97.5%.

In this way, a solution is obtained with a solids content of 19.8% and a viscosity of 150 poise. The solution exhibits, to an excessive extent, the cook-off phenomenon about the axis of the stirrer. After 5 days it gels and can no longer be spun.
The working conditions of this example are described under F of

Fig. 2 indicated.

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Table I cribt "for the inventive examples 1, 2 and 3 and the non-inventive comparative examples 1, 2 and 3 the changes in viscosity as a function of time and the properties of the filaments obtained by spinning the polyurethane solutions immediately after their manufacture, again after 5 and 10 days.

9AD OWGINAL ²⁵

10 9 8 8 7/1700

Table I.

ο co

CD

O O

Work indicated in Fig. 2
aedinqunaen Immediately after manufacture 2 days
5 days Fineness (denier) A. example
2 example
3 Veraleichsbeisniel
1 2 E. gelled 3 i U
O after
after 10 days
20 days Strength (g / d) 4X E. C. D. 3 50 420 i
F. example
1 φ
fC + J β
SO -H
CP--
β -H
3 CC tr · «- ^ after
after Strain (%)
Module at 300%
(g / d) 405
420 390 380 100-420 gelled, 420
v / is verrelich
850 1.083 150 y .U O β Φ
Φ Ai S CD
Ό ta cn -η
CtICO
ic>, j p. X fc
υ ß Fineness (denier)
Strength (g / d) 446
460 400
42Ο 390
420 595
0.155 700 '
gelled j ß -H
rl Solution Strain (%) 427 450
480 470
510 415 418
'0.817 immediately
Herste mg of Module at 3OO %
(g / d) 1.137 425 425 0.621 563 412 ί C. φ <->
rl Fineness (denier)
Strength (g / d)
Strain (%)
Module at 3OO%
(g / d) 602
0.153 1,110 1.109 483
0.108 0.138 0.803 ir fade X KJ
O Ε · < first 424
1,140 600
0.150 612
0.149 not ver
spinnable not ver
spinnable 517
. ί
1
0.127 (C.
ß in According to the H 611 423
1.121 421
1.122 not ver
spinnable aften after
10 days 0.155 610 614 Property 420
1,132
600
0.157 0.151 0.153 421
1.115
602
0.154 418
1.127
619
0.154

N) _ä U) CD cn (D cn

Example 4

1. Preparation of the prepolymersolution

"The reactor of the same type as that of Example 1 is provided with a mixture containing 278.6 parts of a polyester glycol with a molecular weight of 1526, which is obtained by the reaction of adipic acid and a mixture of 1,6-hexanediol and 2 , 2-dimethyl-1,3-propanediol was obtained in a molar ratio of 7: 3, contains fc and 278.6 parts of polyoxytetramethylene glycol with a molecular weight of 1324. 184.7 parts of diphenylmethane-4,4 are added at 50.degree diisocyanate and 8.2 parts of 2,4-tolylene-2,4-diisocyanate containing 20% 2,6-isomer to. Within 30 Hinuten the temperature rises to 80 ⁰ C, which retains one 60 minutes. 250 parts of dimethylformamide are added to the reaction product obtained in this way in order to obtain a 75% strength prepolymer solution, the isocyanate group content of this solution increasing to 3.136%.

2. Preparation of the amine solution

ψ The amine solution required for the chain lengthening reaction is obtained by mixing 4 g methylpiperazine, 14.4 g ethylenediamine, 0.722 g dibutylamine (as a chain regulator) and such an amount of dimethylacetamide that a total volume of 100 ml is achieved.

3. Chain extension reaction

The reactor is initially filled with 2062 σ dimethylacetanide and 10 ml Ainin solution provided, which at the same time at 10 ° C an amine and adding prepolymer solution.

The rate of addition of the amine solution is 2.0 ml / min, and ,, -v ^v 109887/1700 ~ ²⁷ "

iAD ORiGJNAL

2136

the prepolymer solution 15.1 σ / min .. The addition of the amine solution is finished after 45 minutes. At this point in time, the degree of addition is reached of prepolymer 90%. The addition of the prepolymer solution is then continued at a rate of 15.1 g / min. until the addition level reaches 95%. At this point the speed is changed to 7.6 g / min, and maintained, until. the degree of prepolymer addition is 97.5%. It is reduced again until the total amount of prepolymer added 755 g, which corresponds to a final addition rate of 99.7%.

The conditions of the example correspond to G of Fin. 3. In this way, an uncolored and transparent polyurethane solution is obtained which contains 20.1% solids and has a viscosity of 420 poise. The specific viscosity of this solution, measured in dimethylformamide at 30 ° C., is 1.27. 4. Experiments on the viscosity of the solutions and the properties of the threads

As for Example 1, the changes in the viscosity of the solutions depending on the time and the properties of the threads that were spun from these solutions, immediately after production, measured after 5 and 10 days. The results are shown in Table II and are found as excellent.

Example 5

The amine and prepolymer solution are the same as that of the two

109887/1700 _βΑΛ ^ - 28 -

game 4 and are used under the same reaction conditions.

Only the addition conditions are different. The peactor is with 2062 g of dimethylacetamide and 30 ml of amine solution are provided. One cribbes then the amine solution and the prepolymer solution with the the same rate of addition as that of Example 4. The addition of the amine solution is ended after 35 minutes, which is a Corresponds to the degree of addition of prepolymer solution of 70%. The prepolymer solution is then under the conditions of the example 4 is added until the total amount of prepolymer added is 751 α, which corresponds to an addition rate of 99.1%. The operating conditions of this example are listed under H in FIG.

The polyurethane solution obtained is uncolored, transparent and has a solids content of 20.0% and a viscosity of 410 poise at 30 ° C. The stability of this solution and the properties of the threads are measured analogously to Example 1. As shown in Table II, the results are excellent.

Comparative example 4

The amine solution is not in the course of the first reaction phase

added.

The reactor is charged all at once with 2062 α dimethylacetamide, the amine solution and prepolymer solution with the same addition rate as that indicated in Example 4 at the same time clogs. The addition of the amine solution is ended after 50 minutes.

1098 87/1700 sad original

At this point in time, the degree of addition of the prepolymer solution would be 97.5%. The prepolymer solution is then added analogously to Example 4. After adding the total amount of prepolymer solution (735 g) the final prepolymer addition rate is 99.7%. the The resulting polyurethane solution has a solids content of 19.7% with a viscosity that varies from area to area varies from 100-525 poise, causing the solution to rise excessively around the axis of the stirrer. Gelled after 2 days this solution and becomes whitish, which makes it impossible to spun. The working conditions of this comparative example correspond I of FIG. 3.

Comparative example 5

The amine and prepolymer solutions are the same as those of Example 4 and are used under the same reactive conditions. Only the amine previously added to the reactor has been modified.
The reactor is charged with 2062 α-dimethylacetamide and 50 ml of amiri solution. The amine and prepolymer solution are then added

the
with speeds similar to those of Example 4. The addition of the amine solution is ended within 25 minutes. After this point in time, the degree of addition of the prepolymer solution is finally continued in the same way as that indicated in Example 4. After the total amount of prepolymer solution (747 g) has been added, the rate of addition of prepolymer is 98.6%. The resulting polymer solution with a solids content of 19.9%

- 30 -109887/1700 sad original

and a viscosity at 30 ° C of 38O poise, has an excessive Neigunn to wrap around the axis of the stirrer. After 10 days the Lösuna gels, which makes it impossible to spun. The working conditions of this comparative example are below J in Fig. 3 listed.

Comparative example 6

The whole amount of dinethylacetainide and the areine solution are given beforehand (100 ml) into the reactor and then the prenolvmer solution at the same rate of addition as that in example 4 specified. The total amount of prepolymers added is 724 g, which corresponds to a final addition rate of prepolymer of 95.6%.

The solution obtained has a solids content of 19.5% an excessive tendency to move around the axis of the guide too wrap·. After 5 days the solution gels, which makes it impossible to spun.

Table II below gives the changes in viscosity for Examples A and 5 and Comparative Examples 4 to 6

. depending on the time, the properties of the threads obtained when spinning the solutions immediately after their production, again after 5 and 10 days.

- 31 -

109887/1700

Table II

Example Example Example 4 5

Comparative example 4 5 * 6

Working conditions indicated in Fig. 3

u <%
ο
• υ -ρ c

«J -H

c + »-

C -H

j3 (ß t

U 0 C

G) X S.

• cw α
as.> 1-3

a-

Immediately after production after 2 days

after 5 days
after 10 days
after 20 days

100 -

gels, becomes white

380 475

925 crelated

75 850

aelated

(U

• σ

O -P

χ:
υ
to ε:

-H

O β

IU 3

C H

• Η

■ Ρ (U H + » O m

ο ω

Λ ω ο B

tr

SC

H O) -P

CQ

Fineness (Denier) 430

Strength (g / d) 1.217

Elongation (%) 585

Modulus at 300% (g / d) 0.226

426 1.201 578 0.230

417 0.685 492 0.136

421 1.118 555 0.221

Fineness (Denier) 432

Strength (g / d) 1.223

Elongation (%) 590

Modulus at 300% (g / d) 0.224

1,214

0.231

not spinnable

424

0.847

560

0.189

410 0.574 520 0.121

not spinnable

Fineness (Denier) 4 24

Strength (a / a) 1.225

Elongation (?) 591

Modulus at 3OO% (g / d) 0.223

1.197

0.226

not spinnable

Example 6

1. Preparation of the prepolymer solution

The reactor of the same type as that of Example 1 is provided with 527.4 parts of polytetramethylene glycol with a molecular weight of 1516. 168.7 parts of diphenylmethane-4,4'-diisocyanate and 3.9 parts of p-xylylene diisocyanate are then added at 50.degree. The temperature is brought within 25 Hinuten to 65 ° C and the reaction is followed by 60 minutes fortae- \ sets. 300 parts of dimethylacetamide are then added in such a way that a 70% prepolymer solution is obtained. The prepolymer solution obtained in this way has an isocyanate group content of 2.774%.

2. Preparation of the amine solution

Mix 20.0 g of 1,2-propylenediamine, which is called Kettenverlenaerunns = medium is used, and 0.697 g of dibutylamine, which is used as a chain regulator, and diluted with 100 ml of dimethylacetamide «

3. Chain extension reaction

The reactor is charged with 1667 g of dimethylacetamide and 15 ml of amination. This mixture is kept at 10 ° C. and at the same time the amine and prepolymer solution are added at an addition rate of 1.79 ml / min and 16.5 g / min, respectively, and the entire amine solution is added after 47.5 minutes. At this point in time the degree of prepolymer addition is 95%. The addition of the prepolymer solution is then continued at a rate of 8.3 g / min until the degree of addition of prepolymer reaches 97.5%. The rate of addition of prepolymer is from

- 33 -10 9 8 8 7/1700 ' ^iAD original

new and reduced at the moment when the total (823 g) is added, the final degree of prepolymer addition is 99.6%.

The polyurethane solution obtained is uncolored, transparent and has a solids content of 22.9% and a viscosity at 30 ° C of 750 poise.

The working conditions of this example are listed under L of the figure.

4. Experiments on the viscosity of the solution and the properties of the threads

The viscosity of the polyurethane solutions is changed analogously to Example 1 measured as a function of time and the properties of the threads obtained by dry spinning. The results, shown in Table III, show the stability of the solutions and excellent properties the threads.

Example 7

The conditions are the same as those of Example 6 except that the rate of addition of the amine solution is 2.13 ml / min. The addition of the amine solution is complete after 40 minutes. At this point the prepolymer addition rate is 80%. The addition of the prepolymer solution is continued. After adding 820 g of prepolymer solution, the final degree of prepolymer addition is 99.2%.
The solution obtained with a solids content of 22.9 % and

109887/1700 B _AD """

a viscosity of 725 poise is uncolored and transparent. This solution proves to be extremely stable and the threads obtained by dry spinning have excellent properties (see Table III).
The working conditions correspond to M of FIG. 4.

Example 8

The conditions of Example 6 are repeated with the exception that the rate of addition of the amine solution is 2.62 ml / min. amounts to. The addition of the amine solution is complete after 32.5 minutes. At this point in time the degree of addition of Prepol ° yrnerem would be 65%. The total amount of prepolymer solution is analogous to Example 6 819 g, which corresponds to a final degree of prepolymer of 99.1% is equivalent to.

The uncolored and transparent polyurethane solution has a solids content of 22.9% and a viscosity of 720 poise. The solution is very stable and the threads obtained by dry spinning have excellent properties (see table III).

The operating conditions of this example are listed under N in FIG.

Comparative Example 7

The reactor, which was previously charged with 1667 g of dimethylacetamide and 40 ml of amine solution, is fed with amine and prepolymer solution at a rate of 2.0 ml / min and 16.5 g / min, respectively.

- ^{; i%} 109887/1700

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-35- 21361

see. The approach. The TVmin solution ends after 30 minutes. At this point in time, the degree of prepolymer addition is 60 %. You then set the. Continue adding the prepolymer as in Example 6 until 817 g of solution have been added. The final degree of prepolymer addition at this point in time is 98.8%. The solution never obtained, with a solids content of 22.8% and a viscosity of 710 poise, is uncolored and transparent. As shown in Table III, this solution gels after 10 days and is

spinnable.

under

The working conditions of this example are shown in FIG.

Comparative example 8

The reactor is previously charged with 100 cm as in Example G Amine solution and 1667 g dimethylacetamide. You then bet 810 g of the prepolymer solution under the conditions of the example 6 to. The final degree of prepolymer addition is 98.0%. The received Polyurethane solution has a solids content of 27.7 % and an excessive tendency to wrap around the axis of the stirrer. After 5 days the solution gels and cannot be spun (see Table III).

The working conditions are listed under P in FIG. Table III shows the changes in viscosity for Examples 6 to 8 and Comparative Examples 6 and 8 Solutions as a function of time and the properties of the threads obtained by spinning the solutions immediately

109887/1700

their position and after 5 and 10 days.

- 37 'AD ORIGINAL 109387/1700

Table III

ο co

00 00

co

O O

r-

co

Poise Immediately 2 after manufacture example
6th example
7th example
8th Veraleichsbeisniel
7 8. P. after 5 Days ι M. N 0 690 after IC
2C Days 750 725 720 710 1,700 after
after
.C, _! ) Days
► days 760 725 750 1,150 gelled ΙΟ! 3
C Λ t Fineness (denier) 780 735 760 1,600 Work indicated in Fig. 4
bedincTunaen • Η
4J φ 3
(0
: C Strength (g / d) 790
820 755
780 780
840 gelled 415 K
U Ό O cc
Il ι | i Stretch (%) 423 422 422 420 1.074 O-PG O Φ and the Module at 300% (ct / cI) 1.378 1.381 1.366 1.121 518 tr +> * - *
C - ^
3rd cr . s
tr-
Xl ιό rH
•H
0) Fineness (denier)
Strength (g / d) 550 547 545 537 0.223! hOC
φ ^; 3
Ό 03 CO
«:>» J OH
rs
C ΙΛ 4Y
Eat Strain (%) 0.259 0.226 0.268 0.233 not ver
spinnable j after the her Module at 3OO% (a / d) 420
1,382 419
1.374 417
1,370 418
1.373 after
10 days Fineness (denier)
Strength (g / d)
Strain (%)
Modulus at 3OO% (g / d) 560 549 553 510 0.265 0.258 0.276 0.185 _β 418
l, 38O
550
0.261 416
1.375
551
0.260 417
1.369
527
0.272 not ver
spinnable he fade Ό φ
yy Property

CO CD <J) CO cn

Claims (4)

Claims Process for the production of stable polyurethane solutions by reacting a bifunctional urethane prepolymer with isocyanate end groups with a bifunctional chain modifier which has active hydrogen atoms which can react with the isocyanate groups in the presence of a solvent, characterized in that
1. the degree of addition of the urethane prepolymer, expressed by χ and defined as the ratio in% of the molar amount of until
Urethane prepolymers that ^ at a certain moment in the The course of the reaction is added to the total molar amount of the chain extender to be added and W 2. the degree of addition of the chain extender, expressed by y and defined as the ratio in% of the molar amount until of the chain extender, the Y at a given moment is added in the course of the reaction, to the total molar amount of the chain extender to be added in the time interval starting from the beginning of the addition of the chain extender and at the corresponding moment v / o the degree of addition of the chain extender reaches about 90%. is calculated using the following equation: LQO 95 x + 35 ^. y # - 39 - 109887/1700 ^8AD original 2. The method ate ^ ß claim 1, characterized in that the / Zunabegrad χ of the urethane prepolymer and the degree of addition y of the Kcttenverlönaerunasmittels as defined above, preferably satisfies the following equation: χ + 30> y> - χ 3. The method according to claim 1 and 2, characterized in that _r is used a mixture with at least two chain extenders. 4. The method according to claim 1-3, characterized in that a chain extender is used that has two primary. Has amino groups and at least one tertiary amino group, which favors the dyeing affinity of the corresponding products originating from these solutions. 109887/1700