SU321009A1 - METHOD OF OBTAINING POLYURETHANE - Google Patents

Description

This invention relates to the production of polyurethane and nolinisocyanate nolIurethanes.

A known method for producing polyurethane is by reacting compounds containing active hydrogen atoms, for example caprolactone, with polyisocyanates.

The invention provides for the use of compounds containing active hydrogen atoms, polyether polyols based on 6-hydroxy-caproic acids and their oligomers.

The starting materials used according to the invention include 6-acyloxykauronic acids or 6-hydroxycaproic esters. 6-acyloxycaproic acid can be characterized by the general formula

About N CSR (SP2) 5CUN

where R is hydrogen or lower alkyl, for example methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, etc. The derivatives substituted with lower alkyl may also be used according to the invention.

caironic acid with lower alkyl and can be characterized by the formula

HO (CH2) 5COOR

where R is lower alkyl, methyl, ethyl, propyl, isopronyl, butyl, etc., methyl is preferred. You can also use derivatives substituted lower alkyl.

It is known that 6-acyloxycaproic acids can be hydrolyzed. By heating b-acyloxycaproic acids with water, an equilibrium state is reached. Wherein

the system contains water, acyloxy acids, non-hydrolyzed 6-acyloxycaproic acids, 6-hydroxycaproic acids, or various oligomers. The proportion of each component in equilibrium depends on the initial ratio of water to β-a-cyloxycanronic acid, as well as temperature and other technological factors. Continuous release of hydrolyzed acyloxyacids can during the reaction and balance

until all the acyloxy acids have been substantially removed and all 6-acyloxycaproic acids have been hydrolyzed. The remaining hydrolysis product contains water, 6-hydroxycaproic acids and 6-hydroxycaproic oligomers.

As in the hydrolysis of β-acyloxycaproic acid, the hydrolysis of the esters of 6-hydroxycaric acid ACIDS is carried out in a similar manner in the presence of water. When this is done, the alkanol formed is continuously removed to obtain the desired mixtures of 6-hydroxycanropic acids and their various oligomers. These mixtures can be directly subjected to exchange decomposition reactions with organic functional compounds to break the cements in order to obtain polyester polyols that can be used to form polyurethanes.

According to the invention, the 6-hydroxycaproic slots and oligomers prefer not to be separated before the formation of polyesters. Another advantage of the irimenephen of these mixtures of starting materials is that the mixture reacts with chain-breaking agents to form polyether polyols, and metal catalysts are not required for the reaction, due to which the products obtained do not contain metallic catalysts or metallic impurities.

The method using hydrolysis is carried out by the reaction of the decomposition of 6-acyloxycaproic acid or 6-hydroxycaproic acid alkyl ester with water in the presence of an acidic catalyst or without it. The acyloxy acids or alkanols formed during the exchange decomposition reaction are removed to change the reaction equilibrium and to obtain the desired mixture of 6-hydroxycaproic acid and oligomers. It is advisable to remove acyloxy acids or alkanols, for example, by distillation as azeotrons.

Low molecular weight acyloxy acids should include, for example, formic acid, propionic acid, acetic acid, butyric acid, etc. If the 6-a to be hydrolyzed: cyloxycaproic acid is 6-formyloxycaproic, it is necessary to remove the formic acid. If the starting material is 6-acetoxycaproic acid, acetic acid is removed, etc., as the alkyl chain of the acid increases. Formyloxy and acetoxy derivatives are preferred.

Hydrolysis can be carried out in the presence or absence of catalysts. It is advisable, however, to conduct the reaction in the presence of catalytic amounts of catalysts for Tina of hydrogen ions, better in the presence of strongly acidic catalysts. A cation-exchange resin, which has a but at least partially hydrogen form, usually contains sulfonic groups, and is otherwise inert with respect to the reaction mixture, is very suitable for carrying out the proposed strong-acid process. This resin can be easily separated from the reaction mixture, as well as from the hydrolysis products formed. Preferred in hydrolysis. A universal catalyst, which can be easily separated from the resulting mixtures, is preferred — a strongly acidic cation exchange resin having at least partially the hydrogen form containing sulfonic or phosphoric acid groups; these include heat-resistant, sulfonated synthetic resins with basic polystyrene. cross-linked structure. The most preferred resins are those that can be used at elevated temperatures. In general, all cation exchange resins are effective catalysts.

The resin used as a catalyst can be simply added, carefully placed or dispersed in the initial reaction mixture, for example, by stirring. The resin concentration in the reaction mixture can be any, providing the necessary rate of hydrolysis under given conditions, for example, the molar ratio

ester: water, temperature, degree of unmixing, and particle size of the cation exchange resin. Typically, 2 grams of cation exchange resin per mole of ester is sufficient to provide rapid hydrolysis

elevated temperature.

For hydrolysis, other acidic catalysts that are volatile enough can also be used so that they can be distilled off during the subsequent polyester formation reaction.

the reaction mixture, and therefore, is thus effectively removed during the preparation of polyesters. Such catalysts that can be used alone or in combination with a cation exchange resin include highly volatile acids such as hydrogen chloride and trifluoroacetic acid, which do not form stable esters with hydroxyl primers contained in the reaction mixture to produce polyesters.

Hydrolysis can be carried out without catalysts, although the reaction in this case proceeds more slowly. Strong acids and other ion exchange resins may also be used. The use of a volatile strong acid is most desirable because the hydrolysis product is then used to obtain polyesters. It is established that the addition of approximately 0.1 to 0.3 weight. The% HC1, based on the mixture to be hydrolyzed, provides a rate of hydrolysis that is advantageously different from the rate observed when using an ion exchange resin. When using ion exchange resin, the reaction time is approximately 24 hours. Reactions and exchange decompositions are usually carried out at temperatures from 100 to approximately 300 ° C, in advance from 110 to 150 ° C. It should be borne in mind that the time required for the hydrolysis reaction can be reduced by increasing the amount of water and catalyst used. The reaction rate approximately doubles when the temperature rises by 10 ° C.

before and over temperature if the pressure is higher than atmospheric.

The hydrolysis of the alkyl esters of 6-hydroxycaproic acids is preferably carried out under conditions similar to the hydrolysis of 6-acyloxycaproic acids, i.e., at a temperature of 100 or less to 300 ° C or more, and it is preferable to apply a pressure at elevated temperatures at: 1 osfer. Hydrolysis is carried out using about 0.1 to 5 mol of water or more, preferably 0.5 to 2 mol, per 1 mol of 6-ayloxycaproic acid or 6-hydroxycaproic acid alkyl ester. Although the preferred temperature for hydrolysis of 6-acyloxycaproic acid in the presence of water, some of which may have a vapor form, as already indicated, ranges from 110 to 150 ° C, it is advisable to hydrolyze at elevated temperatures, for example, from 150 up to 300 ° C and more, in the presence of nara at a pressure above atmospheric. If low pressure narcotics are used, for example, from 4.92 to 12.7 / vg / cl, the reaction can be carried out at a temperature of from 150 to 180 ° C or slightly higher.

When carrying out the above reactions, the use of a large amount of water leads to the formation of a large number of monomers, the use of a small amount of hydrolyzing agent leads to an increased amount of oligomers. Since it is usually desired to obtain predominantly monomers, for the reaction it is advisable to use a small amount of hydrolyzing agents. In this case, the resulting mixture of products can be used without separation.

As noted, the formation of the acid during the reaction due to the hydrolysis of 6-acyloxycaproic acids should be non-periodically or neinpepbiBHo separated to achieve the progress of the equilibrium reaction in the desired niravlenin. It was found that the formic acid or acetic acid produced by the hydrolysis of low units of the series, for example 6-formyloxycaproic acid or 6-acetoxycanropic acid, can be removed as azeotron with water released from the system. These acids can also be isolated by non-steam distillation if the reaction is carried out in this way.

For higher acids, such as propionic, oil, etc., which do not form an azeotron with water, it is advisable to add a hydrocarbon, such as benzene, toluene, xylene, ethylbenzene, etc., in order to obtain a triple azeotrope with acid and water and thus remove acid. During the hydrolysis reaction, in which the esters of b-hydroxycaronic acid acids are converted into 6-hydroxycaproic acids to form alcohols, boiling, as a rule, at a low temperature, the latter can be isolated by distillation with water or water. Therefore, methyl esters are preferred, with methanol being separated. In addition to the above methods, other agents can be used to remove the acids and alcohols that form during the reaction. Removal of acids and alcohols is necessary to complete the reaction. Thus, hydrolysis of 6-formyloxcaproic acid, which is a preferred embodiment of the invention, corresponds to the following equation:

N-СОО (СН2) 5СООH + Н2О НО (СНг) бС soft + НСОО

proceeds not quite quantitatively, unless formic acid formed is removed. During this hydrolysis reaction, dimers of 6-hydroxycaproic acid are also formed, corresponding, for example, to

BUT {CH2) 5COO (CH2) 5COOH

as well as higher oligomers by condensation of b-hydroxycaproic acid either alone or with 6-formloxycaproic acid. If raw materials substituted with alkyl are used, corresponding derivatives are formed that are substituted by lower alkyl. The amount of dimers formed and higher oligomers depends on the hydrogen concentration (pH value), reaction temperature, catalysts, and other factors.

6-hydroxycaproic acids usually contain a significant amount of lower oligomers of hydroxy acids in the hydrolysis product, which is used to produce a polyether polyol, but this does not have a noticeable negative effect on the properties of the polyurethanes obtained from this polyol.

The 6-acyloxycanronic acids used as starting materials for the proposed method are prepared by known methods. Lower alkyl esters of 6-hydroxycanronic acids can be obtained by hydrolysis of os-caprolactones, 6-acyloxycanroic acids or another method.

As mentioned above, the second step of the method of producing polyurethanes is the conversion of the products of hydrolysis obtained in the aforementioned way to polyester full poly. For this purpose, the resultant hydrolysis mixture is exposed to means for breaking an active hydrogen chain, such as a polyol, polyamine, or ammonia alcohol, to regulate the functionality of the polyester polyol. To the most suitable

ethanol glycol, diethylene glycol, tri-ethylene glycol and higher polyethylene glycol, propylene glycol and its higher homologs, 1,3-pro-diol, tetra-, nenta- and hexamethylene glycols, 1,2-, 2,3- and 1,3-butanediols,

neopentylene glycol, 2-ethyl-2-methyl-1,3-propanediol, 1,4-cyclohexanediols, cis- and trans1, 4-cyclohexanedimethanol, 1,4-bis- (hydroxymethyl) -benzene, etc.

glycerin, 1,1L-trimethylolpropane, 1,1,1-trimethylol ethane monoethanolamine and diethanolamine, N-methylethanolamine and dipentaerythritol, pentaerythritol, sorbitol, a-methyl-O-glucopyranoside, sucrose, phenylene, toluene and toluene and diacyl diamine, sorbitol, a-methyl-O-glucopyranoside, sucrose, phenylene, toluene, and toluene-andylamine diamines; 2- and 1,3-propanediamine, ethylenediamine, hexamethylenediamine, isopropanolamine, diisopropanolamine, 1,2,4-and 1,2,6-hexanetriol, etc.

Polycondensation of a mixture of 6-hydroxycaproic acids with a diol, a triol, an amine, or other suitable compounds with active hydrogen to obtain a noliferal ioliol and is iripiently simple. The best results for polyurethane are obtained when using a polyester with a low acid number, for example, below 2. This acid value o the number corresponds to a carbonic acid equivalent weight of about 28,000. The higher the hydroxyl equivalent weight of the polyester polyol obtained, the more difficult it is to reduce the acid number to 2 or less. . The simplest method to achieve this effect is to use an esterification catalyst together with means to remove condensation water (since the reaction is reversible). Since catalysts for the formation of polyesters are often metal compounds, the remains of such catalysts usually have a catalytic effect on the subsequent reaction of these polyesters with isocyanates, which greatly reduces the viability and stability of the prepolymers.

If the polycondensation is carried out without a catalyst, the problem of removing water and terminating the reaction at the possible time is solved by creating special conditions.

It was found that a polyester with a low acid number with a hydroxyl equivalent weight of 1000 or more can be obtained by applying a high temperature (from 180 to 240 ° C) along with one or more of the following methods of water stripping: vacuum (210 mm Hg). azeotro pna-distillation (with toluene, benzene or xylene), mixed with excess polyol through vacuum distillation.

Polyether ioliol is usually obtained as follows. A predetermined amount of crude hydroxycaproic acid and compounds with active hydrogen, calculated according to the theory, is fed into the reaction vessel, with active hydrogen compounds being introduced in excess if it is envisaged to use mixed distillation of water with excess polyol through vacuum distillation. The reaction vessel should be equipped with a stirrer, heating devices, a thermometer, a nitrogen supply pipe and water distillation apparatus, preferably a distillation column. The stirred reaction mixture is rapidly heated to a temperature at which the distillation of water begins. As the reaction proceeds, the temperature rises so that continuous distillation of the water is maintained, preferably with some back flow through the distillation column, if a relatively volatile component is used. When the distillation of water stops, mainly at a temperature of about 180 ° C, the acid number of the product is checked. If the latter is too high, as is the case for lolyester olyloids with a hydroxyl equivalent weight of about 500 or more, use one of the methods described above to complete the reaction. If vacuum stripping of water is used, the pressure is slowly reduced to 10 mm Hg. Art. and below, and the reaction temperature is maintained at 180 ° C. When the water is distilled off, the acid value is again checked. If it is still high, the temperature is raised to approximately 240 ° C and maintained at that level until the knock does not receive the desired acid number. For

obtain polyester diol mol. weight. 2000 for several hours should maintain the temperature of 240 ° C and a pressure of 2 mm Hg. Art., to reduce the acid number to 1.5 less.

If azeotropic distillation of water is used, azeotronic distillation agent is introduced at the beginning of the reaction or later. Instead of the distillation nozzle on top of the distillation column, set

Dean-stark traps. The amount of toluene (or other azeotropic distillation agent) is taken so as to maintain the desired boiling rate at any given reaction temperature. End temperature

The reaction is often about 240 ° C. The solvent is recovered by vacuum distillation until a sufficiently low acid value is reached. Experiments have shown that the total time required to obtain a polyester diol using vacuum distillation of water is approximately the same as with other methods, but this method is the simplest.

The use of an esterification catalyst reduces the time and temperature required to produce low acid number polyether polyols. However, the catalyst often has a detrimental effect on the polyol, for example 5 hours of certain

1 million esterification catalysts can make a polyether diol relatively unsuitable for the production of molded polyurethane elastomers. In many cases, residues of esterification catalysts in polyols are permissible. In such cases, they can be advantageously used to make polyether polyols.

With the polycondensation of 6-hydroxycaproic acids in the presence of a catalyst and means

For chain termination, the process is conducted in much the same way as without a catalyst. The catalyst can be introduced before heating along with the reaction components. Some catalysts are deactivated, but partially or

water. The catalyst is preferably fed after the main amount of water is removed, for example, after distillation of water at 180 ° C and atmospheric pressure. Vacuum distillation, or azeotropic distillation, or mixed distillation of water can be used separately or in combination with each other, with vacuum distillation being preferred.

Various catalysts can be used to form polyesters, with tetraalkyl titanates being preferred, for example tetrabutyl titanate and tetraisopropyl titanate. Other suitable catalysts are zinc borate, porcine borate, lead oxide and dibutyl tin diacetate. The catalysts are used in an amount of from 5 to 20 hours per 1 million. At higher concentrations, the reaction time can be shortened, however, the reactivity of the products of the polyester polyols becomes too large during the subsequent process of producing polyurethanes.

Polyurethanes with good properties can also be obtained from a mixed polyester diol mol. weight. 2000, at which 35 weight. The oxycaproic acid radicals are replaced with an equimolar mixture of ethylene glycol and 1,4-butanediol together with adipic acid in an amount necessary to obtain a copolyester diol with the indicated molecular weight. Such a copolyetherdiol is maintained in a homogeneous liquid state for many days at 25 ° C, which facilitates its use and storage. This property is very valuable, in particular, in the production of microcellular polyurethane elastomers using a single-stage method, in which, in order to regulate the reactivity, it is ideal to mix the components at room temperature. The most suitable mixed polyethernol condensates contain from 50 to 90 weight. % of radicals of 6-hydroxycaproic acid, although a lower and higher number of them is suitable.

Polyols and other polyfunctional hydrogen compounds with active hydrogen can be used to prepare such copolyester polyols. If one wants to obtain trifunctional or higher polyfunctional (branched) mixed nylethernolol condensates, a small amount of triol or other polyfunctional compounds with active hydrogen is introduced into the mixture, which mainly contains diols or other bifunctional compounds with active hydrogen.

For the preparation of the above copolyether polyols, suitable dicarboxylic acids are alkane dicarboxylic acids of the formula

IEP (SP2) POOP

where R can range from about 1 to about 20. Other dicarboxylic acids, such as fumaric, maleic, phthalic, cyclohexane dicarboxylic, and so on can also be used. anhydrides, such as succinic, phthalic, glutaric and maleic anhydrides.

Preferred alkanedicarboxylic acids that contain from 4 to 10 carbon-rim atoms.

Branching can be achieved by introducing small amounts of polycarboxylic acids and their anhydrides, such as trimellitic

acid, pyromellitic acid dianhydride, 1,2,4-butanethricarboxylic acid, n. N. Hydroxy acid comonomers are suitable, for example, hydroxypivalic acid, 7-hydroxyheptane acid, and so on.

According to another embodiment, only the above described nicarboxylic acids can be used as a means for terminating the value. When using such bolutes, the acids are predominantly with terminal groups of carboxylic acids, due to which intermediate products are used, which are used to obtain derivatives of epoxy esters, which, in turn, are used to obtain polyurethane

derivatives of this tina.

As with the above described variants of polyester nolioles, the reaction can be carried out with or without an esterification catalysts.

Examples are given illustrating the proposed method, but not limiting it. In the nimers, the acid and hydroxyl numbers are determined by well-known methods.

Example 1. 1740 g (about 10.) Of 6-acetoxycanronic acid of 98.5% purity (determined by saponification of 0.5N. NaOPS) is mixed with 100 ° of water and fed into a vessel equipped with a stirrer, a thermometer, a nozzle

distillate and cooler for distillate. As catalyst, 100 g of Amberlite 200 sulfonic acid resin in hydrogen form is added to accelerate the hydrolysis of acetoxy compounds. Mixed components

heated to 110-120 ° C. Distillation of a mixture of water and acetic acid begins at this temperature.

After removing approximately 500 g of distillate, the vessel temperature reaches

140-145 ° C. Next, another 2000 g of water is added to the mixture of the components, again heated to 110-120 ° C while the mixture of water and acetic acid is distilled. After removal of approximately 2-100 g of distillate, the distillate temperature of the vessel reaches 140-145 ° C. For the third time, 2000 g of water is added, the vessel is again heated to a PO-120 ° C temperature, at which the mixture of water and acetic acid is distilled from above. When will collect 6100 g of distillate consisting

from water and acetic acid, the distillate is analyzed to determine the content of acetic acid by titration with 0.5N. NaOH. Titration indicates that approximately 590 g of acetic acid has been collected. Further, at 110 ° C, while distillation is carried out. After removal of 500 g of distillate, the residual distillate is analyzed. Analysis shows that the acetic acid is no longer distilled. The ion exchange resin from the reaction mixture is filtered, washed with 200 e of water, the washing liquids and the filtrate are combined, the acid number of the filtrate is determined, which indicates that the hydrolysis product consists of approximately one-third of 6-hydroxycaproic acid, and two-thirds of the higher oligomers acid. The hydrolysis product also contains a very significant amount of water. Example 2. This example illustrates the preparation of polyester diol resin. weight. 2000 without the use of a catalyst, with 1,4-butanediol being used as a chain breaker and the hydrolysis product of Example 1 as the starting material. Approximately 2300 g of the mixture of the hydrolysis product and the washing liquids of Example 1 are fed into a reaction vessel with a stirrer, equipped with a thermometer, a short, filled distillation column and a nozzle for distillation on top of this column. 55 g of 1,4-butanediol are added to the hydrolysis product and washing liquids in the vessel. The reaction mixture is then heated to 7 ° C for 7 hours, during which time 1040 g of distillate containing mainly water are collected. Then, the pressure is gradually reduced by means of a vacuum pump as long as the constant sluggy distillation of water continues. While the pressure slowly decreases to 100 mm over 6 hours. Hg Art., the temperature is still rising to 240 ° C. The vacuum is adjusted to 3 mm Hg. the mixture components are kept for another 3 hours at a temperature of 240 ° C, during which time the distillation of water and another distillate is stopped. The total amount of distillate obtained is 1085 g. The polyester polpol product is cooled to room temperature; a waxy solid solid is obtained. The acid number of the product is about 1.5 and the hydroxyl number is about 55. Example 3. 100 g of the polyester described in example 2 with a hydroxyl number 55 and an acid number 1.5 are mixed with 9.5 g of 1,4-butanediol and heated to 120 ° C . At this temperature, 43 g of n, / g-diphenylmethane diisocyanate are added to the mixture of polyether polyol and diol and the components are intensively mixed for several minutes, gases are removed from them and poured into the water-heated form as soon as the mixture reaches 140-145 ° C. The closed mold is left for 1 hour at 120 ° C in an air circulation oven. After cooling the mold, the sample of the elastomer is removed, then cured for 12 hours at 100 ° C. After a week in the conditions described, the resulting elastomers have tensile strengths above 492 kg / cm with an elongation at break of about 600%. Shore A hardness of products is 85. The product is characterized by good elasticity and abrasion resistance. The elastomer can also be prepared using the prepolymer method, in which the polyether polyol is subjected to exchange decomposition reactions, first with diisocyanate and then with 1,4-butanediol. The resulting elastomer also has excellent tensile strength. Example 4. In a reaction flask equipped with a stirrer, a thermometer, a Dean-Stark trap with a cooler and a nitrogen inlet, 960 g (6 mol) of 6-formyloxycaproic acid of 97.9% purity determined by saponification were introduced. 0.5 n. NaOH, 432 g (24 mol) of water and 25.6 g of sulfonic acid ion exchange resin in the hydrogen form, which serves as a catalyst for the hydrolysis of the ester, are added. The components are heated to a temperature of about 100 ° C at which distillation of the mixture of water and formic acid begins. When the concept of hydrogen (pH value) decreases to such a point that the temperature of the reaction vessel rises to approximately 130-140 ° C, more water is added to the hydrolyzable mixture to hydrolyze the formic ester. The reaction is considered complete when by titration with 0.5 n. NaOn states that formic acid is not present in distilled water. For this purpose, 7426 g of a distillate of water and formic acid, which contains 269 g of formic acid, are distilled at a temperature of the reaction vessel between 100 and 145 ° C. After the release of 269 g of formic acid, an additional portion of the catalyst is introduced — about 25 g of the sulfonic acid resin in the hydrogen form. With an additional supply of water, it is often observed that the components involved in the reaction do not dissolve when the water content approaches 1 mole per mole of formic acid ester introduced at the beginning. This observation shows that the hydrolysis product contains not only hydroxycaproic acid, but mainly its oligomers, which are no longer soluble in water. The total duration of hydrolysis to formic acid in distillate is about 28 hours. At the end of the water distillation, 43.6 g (0.37 mol) of 1,6-hexanediol are added to the hydrolysis product, and the ion exchange resin is separated by filtration. 759 g of filtrate are obtained, which is introduced into a reaction flask equipped with a stirrer, a nitrogen inlet, a thermometer and a nozzle for azeotropic distillation. The components of the mixture are heated for 10 hours from 120 to and 79 g of aqueous distillate are isolated by forming an azeotrope with toluene. After release of toluene and single. Art. polyester analyzed. The polyester is a waxy solid with a hydroxyl number of 24.1 and a carboxyl of 1.9, which corresponds to a molecular weight of about 4655.

Example 5. In a reaction flask equipped with a stirrer, a thermometer, a Dean-Stark trap with a cooler and a nitrogen inlet tube, 960 g (6 mol) of 6-formyloxycaproic acid of 97.9% purity determined by saponification 0.5 are added. n NaOH. Into the hydrolyzable mixture, 1000 g of water and 25 g of sulfonic acid resin are introduced in hydrogen form, which is heated to the temperature at which distillation of the mixture of water and formic acid begins. By separating 850 g of distillate through a dropping funnel, fresh water is supplied at such a rate that the volume of liquid in the vessel while continuously removing the distillate is approximately constant. The rate of distillation and the supply of fresh water is controlled so that at a temperature of about 120 and 130 ° C to obtain a homogeneous phase. In this way, a total of 6900 g of distillate, including the first 850 g, are removed, the distillate containing 270 g of formic acid, determined by elution by titration with 0.5N. NaOH. Obsh, and the duration of hydrolysis to the absence of formic acid in distillate is about 20 hours.

Hydrolysis can be accelerated if it is conducted at a higher temperature and under pressure, and formic acid can be distilled off with water vapor.

From the above-described hydrolysis product, containing a small amount of 6-hydroxycaproic acid and very large amounts of higher oligomers, as can be seen from the insolubility of the hydrolysis product upon dilution with water, the ion exchange resin is removed by filtration. The filter cake is washed with 300 g of water, and the filtrate and washings are collected and loaded into the reactor. The reactor is equipped with a stirrer, a thermometer filled with a distillation column with a height of 300 ml1 and a distillation head on top of the column.

35 g of 1,4-butanediol are added to the hydrolysis product and the washing liquids. The reaction mixture is heated for 5 hours to 220 ° C while excess water and condensation water are removed through the column. The column should hold 1,4-butanediol in the vessel.

Next, the reaction mixture is slowly heated to 240 ° C for 5 hours, and only 3 mm Hg vacuum is maintained. Art. The resulting polyester at room temperature is a waxy solid with a carboxyl number of 1.7 n hydroxyl 56.5, which corresponds to a calculated molecular weight of about 1930.

300 g of this polyester are subjected to an exchange decomposition reaction with 59.4 g of an isomeric mixture of 2,4- and 2,6-toluene isocyanates in a ratio of 80:20 at a temperature of 80 ° C for 3 hours

in a dry nitrogen environment. The resulting solid reaction product with isocyanate end groups contains 4.1 weight. % NCO.

100 g of this reaction product with isocyanate end groups are heated to and thoroughly mixed for 2 min with 13 g of 4,4-methylene - bis - (o-chloroaniline), preheated to 121 ° C. During this time, the reaction mixture is subjected to a vacuum of 2 mm.

Hg Art., so that before the gas was removed from it. The reaction mixture is quickly poured into a metallic form, heated to. The elastomer is cured for 10 hours at 100 ° C. The determination of physical properties shows a Shore A 85 hardness and a tensile strength of 422 kg / cm, an elongation at break of about 500%.

Example 6. In a reaction flask equipped with a stirrer, thermometer, pipe

For admission of nitrogen and a Dean-Stark trap having a reflux condenser, 2423 g of 6-hydroxycaproic acid methyl ester Ub, 7% pure, 576 g of water and 60 g of ion-exchange sulfonic resin are fed.

acid in hydrogen form.

The reaction mixture is heated to a temperature of 100 ° C, and the combined distillation of water and methanol begins. After separation of distillation water and methanol, add

fresh water and hydrolysis is carried out at a temperature of 100-125 ° C with simultaneous continuous removal of water and methanol. The presence of methanol in the distillate is monitored by chromatographic analysis of the vapor phase. After adding 5472 grams of water, including 576 grams of feed at the beginning, and a total of 5796 grams of continuous distillate, the amount of methanol in the distillate determined by chromatographic apalysis of the vapor phase is still insignificant under these conditions. The hydrolysis of the above described experiment lasts approximately 24 hours.

During hydrolysis, a relatively small amount of 6-hydroxycaproic acid is formed, with the main product of hydrolysis being higher oligomers, which is confirmed by the insolubility in water of this product. The crude mixture of oligomers is suitable for conversion to polyester without further purification.

Next, the ion exchange resin is removed from the hydrolysis product with a filter, and only 1950 g of the product, 1900 g of the above-mentioned hydrolysis product, 191 g of diethylene glycol and 0.01 g of catalyst are collected, which corresponds to 5 parts per 1 million based on the weight of the components of the mixture. is then introduced into a reactor equipped with a stirrer, a thermometer, a nitrogen inlet, and a reverse trap.

a fridge.

The mixture is heated for 8 hours to 240 ° C to obtain 134 g of distillate, preferably water. According to the analysis, the resulting polyester at room temperature is

15

acid number 0.5 and hydroxyl 88.4, which corresponds to a molecular weight of about 1270.

300 g of the above described polyester with a temperature of 95 ° C for 1 hour in a dry nitrogen medium are subjected to an exchange decomposition reaction with 75 g of an isomeric mixture of 2,4- and 2,6-toluene diisocyanates in a 80:20 ratio. The resulting reaction product with isocyanate groups contains 4.15 weight. % NCO.

110 g of the above described reaction product with isocyanate end groups is subjected to an exchange decomposition reaction with 13 g of 4,4-methylene bis (o-chloroaniline) as in Example 6 and poured into a mold to obtain an elastomer. This sample is incubated for 45 ° C at 120 ° C, and then Yes, eV 1V4 h at 100 ° C, maintained for 72 hours at room temperature.

The elastomer has the following physical properties:

Shore A85 hardness

Module (in kg / slg) at elongation,%: 10046.9

20062,5

sixteen

39.4

300 164 400 500 328

Tensile strength, kg1cm 392 Strength at tensile strength, kg / cm 437 Elongation at break,% 576 Thickness, mm 1.83 / min), tensile strength - D 624-54 form C, tensile strength and elongation strength - D 412-61Т (according to ASTM).

Subject invention

A method of producing polyurethanes by reacting compounds containing their active hydrogen atoms with niisocyanates in the presence of targeted additives, characterized in that nylether polyols based on 6-hydroxycanronic acids and nth olgomers are used as compounds that contain their active hydrogen atoms.