Polyoxyalkylene-polyol production process (options)

FIELD: polymer production.

SUBSTANCE: polyoxyalkylene-polyols are obtained via direct polyoxyalkylenation of acid-sensitive low-molecular initiator with molecular weight below 400 Da in presence of double complex metal cyanide catalyst. Process comprises: (i) creation of appropriate conditions in reactor of polyoxyalkylenation in presence of double complex metal cyanide catalyst; (ii) continuously feeding into reactor alkylene oxide and above-mentioned initiator; and (iii) discharging polyether product. Loss of catalyst activity is reduced by performing at least one of the following operations: acidification of acid-sensitive low-molecular initiator before feeding it into reactor; and treatment of the same with effective amount of a substance other than acid, which reacts with base or absorbs base, before feeding it into reactor.

EFFECT: prevented catalyst from loosing its activity and essentially decreased high-molecular fraction and polydispersity of polyoxyalkylene-polyols.

21 cl, 2 dwg, 2 tbl, 3 ex

 

The scope to which the invention relates.

The present invention relates to the production of polyoxyethyleneglycol by direct oxyalkylene glycerin and other measurable oxyalkylated low molecular weight initiators (starters) with the use of double cyanide metal complex catalysts.

Background of invention

Oxyalkylene using basic catalysts have long been used to obtain polyoxyethyleneglycol. When oxyalkylene using basic catalysts suitable low-molecular hydrogen-containing initiator, for example propylene glycol or glycerol, oxyalkylene oxide alkylene, for example ethylene oxide or propylene oxide, resulting in quality product easy polyester - polyoxyalkylene. Due to the possibility of using low molecular weight initiator ratio of initiation (the mass ratio of polyol to the mass of the initiator) is relatively high and, thus, in the process effectively use the capacity of the reactor. When oxyalkylene using basic catalysts, as the last use of a strong base, for example sodium hydroxide or potassium hydroxide.

However, the majority of polyoxyethyleneglycol, useful for the synthesis of polyurethane polymers, and is also suitable for other purposes, contain significant amounts of oxypropylene groups. In the process of oxypropylation with the use of basic catalysts is a competing reaction is the rearrangement of propylene oxide to allyl alcohol, the result is the formation of monofunctional compounds, which also are oxyalkylene, forming polyoxyalkylene with a wide range of molecular mass lying in the range of the molecular weight of the allyl alcohol or a low molecular weight oxyalkylene oligomers to poliefirnaya very high molecular weight. In addition to increasing the molecular mass distribution of the product, continuing education of Manolov leads to a decrease in product functionality. For example, polyoxypropylene or polyoxypropylene with an equivalent weight of 2000 Da may contain from 30% to 40% (molar) monooly. The presence Mineola reduces the functionality of the obtained polyoxypropylene from its "nominal" or "theoretical" values of 2.0 to the "real" functionality, which lies in the range from 1.6 to 1.7. In the case of trolov functionality can be in the range of 2.2 to 2.4. In the process of further oxypropylation functionality continues to decline and the increase in molecular weight is slowing down. For these reasons, the practical upper limit of equivalen the Noah mass of polyoxypropyleneglycol, obtained with the use of basic catalysts, lies slightly above 2000 Da. Even at moderate values of the equivalent mass of the products are characterized by low real functionality and a wide molecular weight distribution.

The content of Manolov in polyoxyalkylene determine, usually by measurement of unsaturation, for example, in accordance with ASTM D-2849-69 Tests polyol as one of raw materials for urethane foams", because each molecule Mineola contains allyl end group. Typically, the level of unsaturation of polyols obtained by the use of basic catalysts, is to 0.060 mEq/g to 0.10 mEq/g or more. There have been numerous attempts to reduce unsaturation, but few of them were successful.

In the early 60-ies was found that the use of the double cyanide metal complex catalysts, such as non-stoichiometric glyoxime complexes hexacyanocobaltate zinc, allows you to get polyoxypropyleneamine with low content of Manolov expressed in the unsaturation in the range of 0.018 mEq/g to 0.020 mEq/g, which is a significant improvement compared with the contents of Manolov in products with basic catalysts. However, the problems of the activity of the catalyst in combination with its value is updated and the difficulty of the removal of residual catalyst from the obtained polyols prevented the industrial application of this method. In the 80's, interest in these catalysts increased again, and the emergence of improved catalysts of increased activity in combination with improved methods for removing catalysts ensured the rapid adoption of the method in the industry. Thus obtained polyols were characterized by several low content of Manolov, which was reflected in the values of unsaturation from 0.015 mEq/g to 0.018 mEq/g But the economic process indicators were low, and in many cases the expected increase in the quality of polymer products due to the increased functionality and high molecular weight polyols was not reached.

Recently researchers firm "ARCO chemical company (ARCO Chemical Company) catalysts have been developed based on the double-cyanide complexes (catalysts of the type "DCM"), far superior activity all previously known catalysts. These catalysts according to the information set forth in the U.S. patents 5470813 and 5482908 included this reference in the present description, also provided industrial application of polyether polyols under the trade name ACCLAIM. However, unlike polyols of low unsaturation (of 0.015-0.018 mEq/g), obtained with the use of old DCM catalysts, new polyols ultra-low unsaturation are characterized by a sharp improvement in the properties of polim the ditch, although used formulations are often different from those that were useful when using conventional polyols. Typically, the unsaturation of these polyols is from 0.002 mEq/g to 0.008 mEq/g

One of the disadvantages of oxyalkylene using DCM catalysts is the difficulty of the use of low molecular weight initiators in the synthesis of polyethers. Polyoxyalkylene low molecular weight initiators is generally slow and often accompanied by a decrease in the activity of the catalyst. Therefore, instead of directly using low molecular weight initiators previously in a separate process prepare oligomeric initiators by oxypropylation of low molecular weight initiator with the use of the main catalysts to the equivalent weight in the range from 200 Yes 700 Yes or more. Further oxyalkylene to the desired molecular weight is carried out with the use of DCM catalysts. However, strong bases cause a reduction in the activity of DCM catalysts. Thus, the basic catalyst used in the preparation of oligomeric initiator, it should be removed using various methods, for example, neutralization, absorption, ion exchange, etc. Some of these methods are associated with long filtering process viscous polyol. Also, high molecular weight initiator significantly decreases the ratio of initiation in the process, thus worsening the efficiency of the reactor. Another feature of oxyalkylene using DCM catalysts is the presence in the product components with a very high molecular weight. The molecular weight of the base molecules polyols obtained by the use of DCM catalyst, lie in a relatively narrow limits, so that the polyols obtained in DCM catalysts have a very low degree of polydispersity, as a rule, 1.20 or less. However, recently discovered that a very small proportion of the molecules, i.e. less than 1000 million-1has a molecular weight of more than 100,000 Da. It is believed that this very small but very high molecular weight fraction is responsible for some of the anomalous properties of polyols ultra-low unsaturation and high functionality. However, these molecules ultrahigh molecular weight does not cause significant changes in polydispersity, as are present in the product in very small amounts.

In the patent South Africa 9870987 included in the present description by reference, States that the content of the high molecular weight fraction ("tail") in polyoxypropyleneglycol can be minimized by continuous introduction of the initiator is in the process of oxyalkylene. In the periodic and semi-continuous processes instead of the introduction, the number of low-molecular initiator, for example propylene glycol or dipropyleneglycol, such an initiator is injected continuously as the passing polyoxyalkylene. Found that the constant presence in the mass of low-molecular substances leads to reduction of the resulting high molecular weight fraction, while also increasing the ratio of initiation, as a significant part of the finished polyol is formed from the low molecular weight initiator. An unexpected effect is the preservation of low-grade polydispersity, as opposed to expected expansion of the molecular mass distribution. In the case of continuous, not periodic accession process detected that the continuous addition of the initiator also leads to reduction in the content of high-molecular fraction, while ensuring the respect of initiation, approaching to that previously could only be achieved in a traditional semi-continuous process with the use of basic catalysts.

Unfortunately, it was also discovered that the use of glycerol - widespread trifunctional initiator - as in a periodic process with continuous introduction of the initiator, and in continuous% the SSE with the continuous introduction of the initiator, DCM catalyst gradually loses activity, and often a polyester of the desired molecular weight cannot be obtained or can be obtained with characteristics, such as the content of high molecular weight "tail", the polydispersity and the like, below the optimum. Found that this phenomenon occurs even at a relatively low speed injection of glycerol, but especially enhanced by increasing the speed that may occur in industrial production in the case of deviations from the nominal (within normal limits or beyond these limits), failure of pumps, etc.

It is desirable to provide the possibility of using low molecular weight initiator to obtain polyols using DCM catalysts. Further it is desirable to obtain polyols in DCM catalysts with minimal content of high molecular weight "tail" component. In addition, it is desirable to obtain polyols, spending polyoxyalkylene with the highest ratio of components. However, these objectives cannot be achieved if there is a decrease in catalyst activity.

A brief description of the invention

The present invention relates to a method of obtaining polyoxyethyleneglycol by oxypropylation of glycerol and other low molecular weight initiators using DCM catalysts in nepreryvnolitoy low molecular weight initiator in batch or continuous process. Unexpectedly, it was found that continuous and periodic processes, including continuous introduction of the initiator, can be made without loss of catalyst activity, if low molecular weight initiator or, alternatively, uterine mass in the reactor (the meaning of this term is explained below), processed to neutralize traces or residues of the grounds that have accumulated during synthesis or processing of some low molecular weight initiators, in particular glycerol.

Accordingly, it is proposed a method of obtaining polyoxyethyleneglycol by direct polyoxyalkylene kislotoustoichivoje low molecular weight initiator having a molecular weight of less than 400 Da, in the presence of a double metal complex cyanide catalyst, including:

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst;

(b) continuously introducing into said reactor oxide alkylene and kislotoustoichivoje initiator having a molecular weight of less than 400 Da; and

(c) challenging the polyester product oxyalkylene initiator,

in which the loss of activity of the double cyanide metal complex catalyst is reduced by performing one or more of the SL is blowing operations:

i) acidification mentioned kislotoustoichivoje initiator having a molecular weight of less than 400 Yes, before the introduction mentioned kislotoustoichivoje initiator in said reactor;

ii) processing mentioned kislotoustoichivoje initiator effective amount of acid substances reacting with a base or absorbing base, before the introduction mentioned kislotoustoichivoje initiator in said reactor.

Mentioned kislotoustojchivy initiator may include glycerol, and mentioned glycerin acidified by adding to it to reduce the loss of activity of the catalyst in the amount of one or more acids selected from organic and inorganic acids.

According to another aspect of the present invention, it is proposed a method of obtaining polyoxyethyleneglycol by direct polyoxyalkylene kislotoustoichivoje low molecular weight initiator having a molecular weight of less than 400 Da or lower oxyalkylene oligomers having a molecular weight of less than about 400 Da, in the presence of a double metal complex cyanide catalyst, including:

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst of Axia is melirovanie and polyoxyalkylene uterine weight;

(b) continuously introducing into said reactor kislotoustoichivoje initiator having a molecular weight of less than 400 Da, and oxide alkylene;

(c) the discharge of product further oxyalkylene kislotnoschelerngo initiator,

in which the amount of acid, effectively reducing the loss of catalyst activity, add to the above islamochristiana initiator or mentioned lower oxyalkylene the oligomers (uterine weight), or as mentioned in the reactor, and mentioned islamochristiana initiator or mentioned lower oxyalkylene the oligomers so as to reduce the loss of catalyst activity.

According to another aspect of the present invention, it is proposed a method of obtaining polyoxyethyleneglycol by direct polyoxyalkylene glycerol in the presence of a double metal complex cyanide catalyst, including:

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst;

(b) continuously introducing into said reactor oxide alkylene and glycerol; and

(c) challenging the polyester product oxyalkylene glycerin,

in which the loss of activity of the double cyanide metal complex catalyst is reduced by the implementation of the program one or more of the following operations:

i) acidification mentioned glycerine before the introduction of the above glycerol in said reactor;

ii) processing the above-mentioned glycerol effective amount of a substance reacting with or absorbing base, before the introduction of the above glycerol in said reactor.

Brief description of drawings

Figure 1 presents a plot of the pressure of propylene oxide over time for two processes oxypropylation of glycerol using DCM catalyst: one using acidified glycerol, and the second using nepoddelnogo glycerin.

Figure 2 presents a plot of the pressure of propylene oxide to the two operations using acidified glycerol and one operation conducted without the use of acid.

A detailed description of the preferred embodiments

The method in accordance with the present invention includes a continuous introduction kislotoustoichivoje low molecular weight initiator in the process of oxyalkylene using double metal complex cyanide catalysts as a catalyst oxyalkylene. The method can be carried out in the regime of semi-continuous process or a continuous process. In any case supplied kislotoustojchivy low molecular weight initiator, maliciousness in the reactor or other substance flow in the process is acidified thus, to the impurity content of the main character was below the level that causes the lowering of the catalyst activity. The required amount of acid, usually is in the range of a few million-1with respect to the low molecular weight initiator.

According to the method in accordance with the present invention, polyoxyalkylene obtained by oxyalkylene one or more suitable for this purpose kislotoustoytchivi low molecular weight initiators, preferably glycerol, in the presence of a double metal complex cyanide catalyst (DCM-, or DMC catalyst). In the well-known periodic processes with the use of DCM catalysts initially introduced into the reactor all the initiator add DCM catalyst and add a small amount of oxide alkylene (catalyst may be introduced with the initiator, or (for example, in a tubular reactor) at various points along the flow of reagents). A sharp drop in pressure indicates the activation of the catalyst. In an alternative embodiment, can be used pre-activated uterine mixture of the catalyst initiator. The temperature in the reactor support, usually in the range from 70°to 150°and introduce the rest of propylene oxide at a relatively low pressure, for example, less than 0 pounds per square inch (69 kPa). In the traditional method is used, as a rule, oligomeric initiators with equivalent weight in the range from 200 Yes 700 Yes or more. For example, polyols based on glycerol is preferably used molecular weight of from 700 Da to 1500 Da. Values are equivalent and molecular weights, expressed in Daltons (Da), in the present description in the absence of special instructions refer to the numeric average values are equivalent and molecular weights.

In the traditional process, for example, polyoxypropylene glycerol with molecular weight of 3000 Da can be achieved by oxypropylation is used as the initiator of the oligomer of oxypropylated glycerol with molecular weight of 1500 Da to achieve a molecular weight of 3000 Da. The ratio of initiation, therefore, is 3000 Yes/1500 Da, or 2.0. This is a little regarding the initiation is not possible to effectively use the capacity of the reactor, since about 40% of the total volume of the reactor is initiated. In addition, the product contains a small but significant fraction of very high molecular weight (>100000 Yes). It is believed that this high molecular weight fraction ("tail") contributes to the falling foam in some polyurethane mixtures.

According to the method of continuous introduction of the initiator polyoxyalkylene is carried out by introducing a smaller amount of oligomeric initiator together with the catalyst and the initial number of oxide alkylene to activate, similarly to the traditional way. However, in the method with the continuous introduction of the initiator into the reactor, in addition to the oxide alkylene, introducing a low molecular weight initiator, preferably in the form of a mixed stream of the source material. As a non-restrictive example, will indicate that the number of low-molecular initiator may account for 1.8% (wt.) from the total amount of low molecular weight initiator and oxide Alikina. In the use of reduced amounts of oligomeric initiator and continuous injection of low molecular weight "Monomeric" initiator glycerin polyol with molecular weight of 3000 Da can be obtained with higher values of relationship initiation, for example 5. The efficiency of the process increases to almost 100% in the calculation of the consumed propylene oxide. The product also contains a smaller amount of high molecular weight "tail".

The above-described method with the continuous introduction of the initiator makes effective use of low molecular weight initiators such as propylene glycol and dipropyleneglycol. However, if a process with continuous introduction of initiator used glycerin, which is the usual trihydroxyphenyl the initiator, the catalyst often loses activity partially or completely, as can be seen from the increasing pressure of propylene oxide in the reactor. In this case reaccessed or almost stops and the product may not achieve the desired molecular weight. Discovered that the products are characterized by a wide polydispersity and a relatively high content of high molecular weight fraction.

It has been unexpectedly discovered that the addition of very small amounts of acid to the glycerol-initiator before introducing it into the reactor as a continuous input initiator allows the use of glycerol to produce high molecular weight polyols without lowering the activity of the catalyst, increasing the content of high molecular weight fraction or increasing the degree of polydispersity. The same or slightly better results can be obtained, podkisst not glycerin, and uterine weight in the reactor. Not considering any theoretical justification, we can assume that glycerol may contain impurities of the main character, whose origin is connected with the method of its production, which, as a rule, consists in the hydrolysis of triglycerides contained in animal fats or vegetable oils, using a basic catalyst. It is known that the base cause a loss of activity DCM catalysts. Thus, the addition of acid is the preferred way to prevent loss of activity DCM catalysts during catalytic oxyalkylene glycerin. Other ways is the pressure of glycerin substances the main character or other substances, reacts with acids, to prevent loss of catalyst activity is adsorption with the use of adsorbents acid character or ion exchange, or to neutralize these impurities, or to exchange them for the acid group. The preferred method of removing impurities of the main character is the addition of acid.

To low molecular weight initiators suitable for the method in accordance with the present invention are initiators with a molecular weight less than about 400 Da, preferably less than 300 Da, containing impurities of the main character, decreasing the activity of DCM catalysts. Examples of such low molecular weight initiators that do not have a restrictive nature, are glycerin, diglycerin and polyglyceryl; all these substances receive, as a rule, with the use of strong bases. Glycerin is usually obtained by hydrolysis, or saponification, triglycerides, and diglycerin and polyglyceryl can be obtained by condensation of glycerol in the presence of basic catalysts. Other examples suitable for the purposes of the present invention low molecular weight initiators include the various metrafenone and similar products obtained by the reaction of formaldehyde with urea, phenol, cresol, etc. in the presence of basic catalysts.

Sentence is of specific low molecular weight initiator for use in accordance with the present invention can be set by holding polyoxypropyleneamine nepoddelnogo (and "raw", as described below) initiator using DCM catalyst under normal conditions of polyoxyalkylene, for example, when 110-120°and the excessive pressure of propylene oxide 10 psig (69 kPa). In the reactor enter oligomeric initiator, preferably one that was itself obtained using DCM catalyst or thoroughly cleaned to remove residual basic catalyst, add DCM catalyst and activate it as described in the present description and in the aforementioned patents, and slowly added to the reactor proposed by the initiator, through process polyoxyalkylene or mixed with oxide alkylene, either in the form of a separate stream of reagent, or in a mixture with another thread, for example with the stream returned in the product cycle.

If the pressure of the oxide alkylene greatly increased, which indicates the loss of catalyst activity, it is necessary to re-analyze low molecular weight initiator, followed by the destruction or neutralization of the grounds contained therein. For example, low molecular weight initiator can be acidified, as indicated in the present description, or to treat acidic ion-exchange resins, or remove the Foundation in other ways, for example by introducing the initiator into contact with substances that react with bases, for example with phosgene or chlorine is true tiomila. The alternative is the acidification of "uterine mass in the reactor, i.e. a mixture containing oligomeric initiator and used to start the reaction. If the same low molecular weight initiator, acidified or otherwise processed, as indicated in the present description, be oxyalkylene without premature lowering of the activity of the catalyst, this low-molecular initiator is considered "islamochristiana" initiated within the meaning of this term, as used in the present description.

Acids suitable for neutralization include inorganic acids and organic carboxylic acids, phosphonic acids, sulfonic acids and other acids. If oxyalkylene glycerin among the inorganic acids are preferred phosphoric acid, and organic acids, it is advisable to use citric acid and 1,3,5-benzotriazolyl acid. Useful are also derivatives of acids, reacts with bases, such as acid chlorides, anhydrides, acids, etc. Can also be used organic acids such as phosphonic acids, sulfonic acids, such as toluensulfonate, etc. are Examples of suitable inorganic acids are, among others, hydrochloric acid, Hydrobromic acid and sulfuric acid, and to polutrillionom acids and acidifying derived include formic acid, oxalic acid, citric acid, acetic acid, maleic acid, maleic anhydride, succinic acid, succinic anhydride, adipic acid, acid chloride of adipic acid, adipic anhydride, etc. In the present description, the precursors of inorganic acids, such as chloride thionyl, phosphorus trichloride, chlorosis carbon, sulfur trioxide, pathiakis phosphorus, phosphorus oxychloride, etc. are considered as inorganic acids. The above lists are illustrative and are not restrictive.

The adsorbents which can be used include adsorbents minor nature, i.e. absorbents that absorb basic connectivity and not leave polyols significant amounts of substances that occur in the adsorbents. As examples of adsorbents may be mentioned activated carbon, magnesium silicate, acidic alumina, acidic silicon dioxide and other Adsorbents should be used in quantities sufficient to remove impurities of the main character. In the case of some adsorbents, such as activated carbon, the required amount may be too high, although you can use them in smaller quantities in combination with other treatments. The adequacy of the applied amount of the adsorbent to achieve the objectives of this image is to be placed can be detected by tests for the suppression of the activity of the catalyst of low-molecular initiator in accordance with the above-described method.

Suitable ion exchange resins are preferably acidic ion exchangers of the type recovered by washing the resin strong acid in the intervals between cycles of use. You can use, for example, acrylic or styrene resin grafted by sulfo, fotogruppe or carboxyl groups, preferably in an acidic form. Suitable for the purpose, the resin produced by the industry, for example, firms Rohm & Haas or Dow Chemical. Low molecular weight initiator can be removed with an adsorbent or ion exchange resin and filter or, more preferably, to pass through a column filled with the adsorbent or resin.

However, preferred is the simple addition of an acid, more preferably conventional inorganic acid, glycerin with stirring. After adding acid glycerin is preferably subjected to Stripping to remove traces of water introduced with the acid or formed from the acid neutralization process. Adding acid is the preferred working method, is cheap and quick and requires no special tools. As a rule, you need to add less than 100 million-1acid relative to the total weight of the low molecular weight initiator, preferably from about 5 million-1up to 50 million-1, Nai is more preferably from approximately 10 million -1up to 30 million-1.

The term "continuous introduction of the initiator for this method means oxyalkylene in the presence of DCM catalyst, in which a low molecular weight initiator or a low molecular weight oligomeric product oxyalkylene such initiator having a molecular weight of less than about 400 Da, preferably less than 300 and most preferably less than 200 Da, impose almost continuously throughout a substantial portion of the length of operation oxyalkylene so that the reaction mass during the whole process oxyalkylene contains a minor proportion of a low molecular weight initiator. In General, approximately 30% (wt.) the final polyester product, more preferably more than 50% (wt.), most preferably 70% (wt.) or more, is formed from a low molecular weight initiator, instead of oligomeric initiator of increased molecular weight.

Low molecular weight "kislotoustojchivy" initiator can also be mixed with initiators, are not sensitive to acid, for example, ethylene glycol, propylene glycol, dipropyleneglycol, trimethylolpropane, pentaerythritol, sorbitol, sucrose and others, with the aim of producing polyether polyols joint initiation. The reactions in the reactor is injected directly scolecite kislotoustoichivoje initiator or lower oligomer, are not processes with continuous introduction of the initiator. However, it should be borne in mind that the final stage of oxyalkylene, if necessary, can be performed without adding a low molecular weight initiator. This "finishing" stage allows you to lower the content of oligomers of moderate molecular weight by providing sufficient time for the reaction to oxyalkylene last added servings of low-molecular initiator with the formation of high molecular weight products and, thus, to minimize the polydispersity.

In the continuous version of the process with continuous introduction of the initiator, the reaction can be initiated by applying oligomeric initiator, but after the initial stage of its continuously initiate by further adding oligomeric initiator, preferably by returning to the cycle of the oligomer or polymer with the subsequent stage of the process. The oxide alkylene together with glycerin or a low molecular weight product oxyalkylene injected at various points along the reactor, which may represent for example, a tubular reactor ("multipoint introduction"). You can also use capacitive reactor with continuous stirring (ARND).

As in periodic and continuous process variants, with continuous introduction of a mandatory UN paid the Torah to initiate the reaction, you can use the "uterine mass in the reactor. This uterine weight in the case of a periodic process can be an oligomeric product prepared in advance with the use of DCM catalyst or other catalyst method, the product of intermediate molecular weight, taken from the reactor batch and stored for further use, or some completely oxyalkylation product. A unique feature of the process with continuous introduction of the initiator allows the use of polyols with a target value of molecular weight as a uterine mass without significant expansion of the molecular mass distribution of the product. Apparently, the speed oxyalkylene oxyalkylene substances is inversely proportional to the molecular weight or degree prior oxyalkylene these substances and thus, low molecular weight compounds oxyalkylated significantly faster products of higher molecular weight.

In continuous processes can be used uterine weight from a separate store, as in periodic variations, however, to take full advantage of the continuous process uterine mass is generated by selection and return to the loop part of the flow of intermediate or final product. So after continuous process within the how many days regarding the initiation can be reduced to values close to achievable with periodic oxyalkylene using basic catalysts, where the use of Monomeric initiators such as glycerine.

Instead of handling glycerin to acidification or remove impurities the main character can be acidified uterine mass, used in the process. In this case, the uterine weight should, as a rule, add an amount of acid equivalent to that which would be necessary to enter in the glycerin. In the periodic process all of the necessary amount of acid you can add to the beginning of the process, although it is also possible introduction in parts. In the continuous process, the amount of added acid and the frequency of its introduction can be varied depending on the number and type in the product cycle and the efficiency of mixing provided by the reactor. For example, in the reactor with the "piston flow" (with a predominantly diffusive mixing) may be the most appropriate continuous addition of acid to the uterine mass.

The foregoing General description of the invention for a better understanding of its nature is illustrated by the following examples with illustrative only and not considered as restrictive, unless otherwise stated.

Sample critical part foam

<> The presence or absence of harmful high-molecular fraction in polyoxypropyleneamine used for the preparation of foamed polyurethanes, can be set using the polyol in the tension of the foam composition, cooked by way of manual mixing. In this test, the foam prepared with the test polyol, is considered to be "settling"if its surface after stavki remains convex; in the case of the concave surface after stavki foam described as "falling". The degree of movement can be quantified in relative units by calculating the change (in percent) of the cross-sectional area of the foam. The composition of the foaming composition is the following: polyol 100 parts; water - 6,5; methylene chloride and 15 parts; amine catalyst type Niax® a-1 and 0.03 parts; the catalyst based on tin T-9 - 0.4 parts; surface-active agent L-550 on polysiloxane basis-0.5 parts. The foam is injected into the reaction with a mixture of 2,4-and 2,6-colordistance with an index of 110. It is convenient to pour the foam in the standard box cake with a capacity of 1 cubic feet (2.8 liters) or in a standard container for ice cream with a capacity of 1 gallon (3.8 l). As part of this composition polyols prepared in the traditional way, i.e. with the use of basic catalysts having a high content of secondary hydroxyl acids cause the subsidence of foam approx the tion by 5-10% while polyols obtained by the use of DCM catalysts containing high molecular weight "tail" faction, called "falling" foam with subsidence of about 40-70%, and even more.

Analytical methods for determination of high molecular weight "tail" faction

The method of analysis suitable for the quantitative determination of high molecular weight "tail" faction in particular polyols obtained by the use of DCM catalysts, based on the known method of high performance liquid chromatography (HPLC), which is easy to make a knowledgeable specialist. The molecular weight of the high molecular weight fraction can be estimated by comparing its elution from the column for gel permeation chromatography (GPC) with the same index for the standard sample of polystyrene with an appropriate molecular weight. For example, for most analyses, the appropriate standard is polystyrene with a molecular weight of 100,000. As you know, the high molecular weight fraction emerge from the column faster than low molecular weight; for maintaining the stability of the baseline is reasonable after elution of high molecular weight fractions to dump the rest of the eluate from the HPLC column to waste without having it pass through the detector, in order to avoid overload of the latter. Although you can use many types detec the Directors, appropriate type is evaporative detector svetorasseyanie, for example, one commercially available.

In the preferred method of analysis used column length 250 mm, diameter 10 mm with filler Jordi Gel DVB 103Angstrom (particle size 5 μm); mobile phase is tetrahydrofuran, the flow rate is 1.0 ml/min detection using evaporative detector svetorasseyanie company Varex model IIA; the heater temperature detector set 100°and an outlet temperature of 60°S; the flow rate of nitrogen is 40 ml/min Initial solution of polystyrene prepared, when 20 mg of polystyrene with a molecular mass of 591000 in a volumetric flask with a capacity of 100 ml volume of the solution up to the mark with tetrahydrofuran. This original solution was used for preparation of quantitative standards containing 2 mg/l 5 mg/l and 10 mg/l of polystyrene. Calibration sample for estimation of molecular weight prepared, when 2 mg of polystyrene with a molecular weight of 100,000 in a volumetric flask with a capacity of 100 ml volume of the solution up to the mark with tetrahydrofuran.

Sample polyols prepared by otoshiana 0.1 g of polyester in a flask with a capacity of 1 ounce (30 ml) and added to the weighed sample tetrahydrofuran to the total weight of the polyol and tetrahydrofuran 10,0,

The peak areas is polistirolnyh standards were determined using an electronic integrator, and the peak areas for each participant polyol were averaged. Average peak areas were used to build the calibration curve of the dependence between the logarithm of the peak area and the logarithm of concentration. The concentration (C) of polymer with molecular weight of more than 100,000 Da in the sample polyol, expressed in million-1(Cppm), can be determined from the equation:

Withppm=(Cmg/lWt/Ws)/0,888,

where Cmg/lthe concentration of polymer in mg/l, Wt- the total weight of the polyol and solvent, Ws- weight polyol, and 0,888 - density of tetrahydrofuran. For example, if the concentration fraction of polymer with molecular weight of over 100,000, determined by analysis, is 1.8 mg/l and a concentration factor of Wt/Wsequal to 100, then Withppmequal to 203 million-1.

Examples 1, 2 and 3, comparative examples C1 and C2

The number of operations oxypropylation with continuous introduction of initiator was carried out in reactors with a capacity of 10 gallons (38 l) and 300 gallons (1100 l). In each case, into the reactor was introduced a number of oxypropylated glycerine initiator with a molecular mass of 1500 Yes, sufficient to provide for the relationship of initiation is equal to 5, together with a number of complex hexacyanocobaltate zinc as DCM catalyst, sufficient to ensure the horse is Noy concentration of the catalyst in the final product, 30 million-1. Oligomeric initiators with a molecular mass of 1500 Yes identified as initiators of the "second" or "third generation" (taken from the initiator, obtained after two or three cycles of treatment initiator, prepared using potassium hydroxide). Used purchase glycerin.

After the introduction of oligomeric initiator and a catalyst, the reactor was purged (otparyvali) by ozonation with nitrogen under a pressure of 5-30 mm RT. Art. for 30-40 minutes at a temperature in the reactor 130°C. Then introduced propylene oxide or a mixture of propylene oxide with ethylene oxide in an amount equivalent to 4-6% (wt.) initiator boot and monitor the pressure in the reactor to control the activation of the catalyst.

Until the resumption of the supply of propylene oxide was allowed pressure drop to below 500 Torr. After activation of the catalyst was applied to the reactor propylene oxide in an amount corresponding "control" relationship initiation. "Control" regarding the initiation is defined as the ratio of the amount of mass injected propylene oxide and the initial mass of the initiator to the initial weight of the initiator.

"Control" regarding the initiation it is necessary to ensure complete activation of the catalyst. After giving up "control" relationship initsiirovannoe the number of propylene oxide with the addition of 2.3% to 2.6% (wt.) glycerol was added to the reactor continuously during the 6-6,5 hours Joint filing of glycerin and propylene oxide was continued until completion of the reaction. In some examples, a reactor was jointly introduced glycerol, propylene oxide and ethylene oxide.

Hydroxyl number, degree of unsaturation and a viscosity of each of the obtained polyol was determined by standard methods. Molecular weight distribution and polydispersity polyols were measured and calculated using the standard method of gel permeation chromatography. The results are presented in Tables 1 and 2. The content of high molecular weight "tail" fraction was also determined by gel permeation chromatography.

TABLE 1
Example1C1
The target molecular weight (Da)30003000
The target hydroxyl number5656
The molecular mass of the original initiator (Yes)1500155
The generation of the initial initiator3rd2nd
Continuously injected initiatorGlycerinGlycerin
The ratio of initiation55
Check agains the initiation 1,51,5
The concentration of glycerol (%) (glycerin/propylene oxide+glycerin)2,62,6
The final concentration of catalyst in the product (million-1)3030
Mixing (horse. forces/million gallons)88
The concentration of phosphoric acid in the initiator (m-1)200
Pressure Stripping (mm RT. Art.)305
The temperature of the bog (°)130130
The duration of the Stripping unit (min)4030
Download for activating the catalyst (oxide/initiator), % (wt.)5,56
Duration of injection (h)6,56
The measured hydroxyl number54,768,2
High-molecular fraction (m-1)444568
Test critical foamwithstandsnot as well.
Unsaturation (mEq/g)0,00370,0035
Viscosity (cSt)624573
The polydispersity1,111,75

TABLE 2
Example2C3C2
The target molecular weight (Da)320032003200
The target hydroxyl number525252
The molecular mass of the original initiator (Yes)150015001500
The generation of the initial initiator3rd3rd2nd
Continuously injected initiatorglyceringlyceringlycerin
The ratio of initiation555
Controlling the ratio of initiation1,51,51,5
The concentration of glycerol (%) (glycerin/propylene oxide+glycerin)2,32,52,3
The final concentration of catalyst in the product (million-1)303030
Mixing (Loches. forces/million gallons)888
The concentration of phosphoric acid in the initiator (m-1)20200
Pressure Stripping (mm RT. Art.)303010
The temperature of the bog (°)130130130
The duration of the Stripping unit (min)404030
Download for activating the catalyst (oxide/initiator), % (wt.)5,5/EA*5,5/EA*4*
Duration of injection (h)6,56,56
The measured hydroxyl number51,3to 49.967.0
Unsaturation (mEq./g)0,00290,00260,0032
Viscosity (cSt)651665554
The polydispersity1,121,121,31
% of ethylene oxide1212,312,4
*) IS propylene oxide, EO is ethylene oxide

In Examples 1, 2 and 3 of glycerol introduced into the reactor together with propylene oxide, before mixing with the latter was acidified by adding 20 million-1FOS is ornago acid. In comparative examples C1 and C2 acidification is not produced. Registered dependence of the pressure of propylene oxide from time to time during the five operations; the resulting curves are presented in figures 1 and 2.

Denote the graphs in the figures correspond to the numbering of the examples. As can be seen from the graphs C1 (Figure 1) and C2 (Figure 2), corresponding to operations using nepoddelnogo glycerol pressure of propylene oxide begins to increase almost immediately after the start of the giving of glycerol. In comparative example C1 of approximately 5 h after the beginning of the bargain glycerin absolute pressure reached 48 pounds per square inch (330 kPa), which indicates the loss of catalyst activity. In comparative example C2, the pressure reached 43 psi (296 kPa), which also indicates the loss of catalyst activity. Submission oxide was discontinued and the catalyst is, ultimately, provided the expenditure of oxide. Then feed oxide in comparative example 2 was resumed, and the pressure quickly reached 33 psi (227 kPa) after only 30 min; thereafter, the operation was terminated due to loss of catalyst activity.

In examples 1, 2 and 3 of the glycerol prior to feeding into the reactor (joint with oxide) was acidified. It is easy to see that the pressure of propylene oxide remained constant throughout the operation, AB is alumnae its value was approximately 5 pounds per square inch (35 kPa). The drawings illustrate the dramatic improvement provided by acidification fed glycerol. Note that a small spike on the graph approximately 3.5 h after start of the reaction, corresponds to the beginning of contact of the second impeller stirrer with the reaction mass, which increases the intensity of mixing.

In addition to these sharp differences between the processes conducted by acidification and without acidification glycerol, polyols derived from acidified glycerol differ significantly from products produced without the use of acid. Polyol in example 1 (from acidified glycerol) has a polydispersity (Mw/Mn) just to 1.11 and the content of the high molecular weight fraction (average of two measurements) is approximately 444 million-1. Hydroxyl number is 54,7, and the degree of unsaturation, typical products obtained with the use of high-level DCM catalysts, approximately 0,0037 mEq/g Polyol obtained in example 1, tested on critical foam with an acceptable degree of settling of the foam.

On the contrary, in comparative example C1, where acidification has not been performed, the results are completely different. In this example, the loss of catalyst activity is so significant that the specified molecular weight is not achieved, as evidenced by the high hydroxyl number 68,2. Even at this low molecular weight carried high hydroxyl number, the polydispersity is very high and is 1.75. The content of the high molecular weight fraction is significantly higher than in example 1, and an average of 573 million-1i.e. increases by approximately 30%. Further, the polyol does not stand the test of critical foam, showing excessive settling of the foam.

The polyols obtained in examples 2 and 3 (acidification of glycerol), have almost the same properties. The polydispersity (Mw/Mn) is just 1,12, and the viscosity is within 651-665 cSt. The hydroxyl number of the product according to example 2 is 51,3, and the product from example 3, accounting for 49.9, then as specified hydroxyl number 52,0. Indicators of unsaturation products according to examples 2 and 3 also typical levels of unsaturation achieved when using high-level DCM catalysts, and lie within 0,0026-0,0029 mEq/g

On the contrary, in comparative example C2, where acidification has not been performed, the results are completely different. In this example, the loss of catalyst activity is so significant that the specified molecular weight is not achieved, as evidenced by the high hydroxyl number 67,0. Even at this low molecular weight, the polydispersity is high and is 1.31. The viscosity of the product on FOSS is twittername example C2 is reduced in comparison with examples 2 and 3 due to the low molecular weight polyol.

The above examples and comparative examples show that acidification introduced into the reactor glycerol leads to a significant difference in the processes of oxyalkylene glycerol in DCM catalysts performed with continuous introduction of low-molecular initiator. As the content of the high molecular weight fraction, and the polydispersity is significantly reduced, and the loss of activity of the catalyst is substantially prevented. It should again be emphasized that the contribution of the high molecular weight fraction in the overall polydispersity negligible. The greatest influence on the difference in polydispersity products of example 1 and comparative example C1 has a distribution of molecules in the range of lower molecular masses, i.e., near the numeric average value of the target molecular weight (approximately 3000 Yes).

Although the method which is the subject of the present invention described with reference to glycerin as such, it is also applicable to other low molecular weight initiators, which are produced, processed or stored in such a way that the polyol contains impurities core nature that may cause loss of activity DCM catalyst, preferably for initiators with a molecular mass of less than 300 Da, more preferably less than 200 Da. Neogranichenniy is an example of such an initiator is diglycerin. To identify such "kislotoustoytchive" initiators can be as described above.

The term "establishing conditions oxyalkylene in the reactor oxyalkylene shall be deemed not to require special explanation. Such conditions are established, when the temperature in the reactor, the pressure of the oxide alkylene, amount of catalyst, the degree of activation of the catalyst, the presence oxyalkylene compounds in the reactor, etc. such that when introduced into the reactor unreacted oxide alkylene is oxyalkylene. As a non-restrictive example, let us point out that the periodic version of the method with continuous introduction of initiator conditions oxyalkylene first set, follow the procedures described in examples above. The term "continuous introduction" in relation to the introduction of oxide alkylene and low molecular weight initiator means is either true continuous introduction or periodic dosed introduction, giving the same results, which are achieved with the continuous introduction of these components. The term "oxyalkylene low molecular weight polyester initiator" means polyoxyalkylene prepared by oxyalkylene kislotoustoichivoje low molecular weight initiator or mixture of initiators containing kolotoc the responsive low molecular weight initiator. For example, if islamochristiana low-molecular initiator is glycerol, oxyalkylated low molecular weight polyester initiator is polyoxypropylene triol, glycerine initiated. The terms "starter" and "initiator" in the present description in the absence of special clauses have the same value.

For knowledgeable specialist who has a real full description of the invention, it is clear that the process can be made a variety of changes and modifications without changing the essence of the invention without going beyond its scope.

1. The method of receiving polyoxyethyleneglycol by direct polyoxyalkylene kislotoustoichivoje low molecular weight initiator having a molecular weight of less than 400 Da, in the presence of a double metal complex cyanide catalyst, including:

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst;

(b) continuously introducing into said reactor oxide alkylene and kislotoustoichivoje initiator having a molecular weight of less than 400 Da; and

(c) challenging the polyester product oxyalkylene initiator,

in which the loss of activity of the double cyanide metal complex cat who lyst is reduced by performing one or more of the following operations:

i) acidification mentioned kislotoustoichivoje initiator having a molecular weight of less than 400 Yes, before the introduction mentioned kislotoustoichivoje initiator in said reactor;

ii) processing mentioned kislotoustoichivoje initiator effective amount of acid substances reacting with a base or absorbing base, before the introduction mentioned kislotoustoichivoje initiator in said reactor.

2. The method according to claim 1, characterized in that the said kislotoustojchivy initiator includes glycerin, and mentioned glycerin acidified by adding to it to reduce the loss of activity of the catalyst in the amount of one or more acids selected from organic and inorganic acids.

3. The method according to claim 2, characterized in that the said one or more acids include inorganic acid, present in an amount of from 1 to 100 million-1in relation to the mass of glycerin.

4. The method according to claim 2, characterized in that the acid comprises phosphoric acid in an amount of 5 to 100 million-1in relation to the mass of glycerin.

5. The method according to claim 1, characterized in that said operation of continuous injection of glycerol accompany introduction into said reactor at least one additional axially is imago initiator, other than glycerin.

6. The method according to claim 1, characterized in that said reactor is a continuous action.

7. The method according to claim 6, characterized in that said reactor continuous action includes tubular reactor.

8. The method according to claim 7, characterized in that the operation of the continuous introduction of oxide alkylene and kislotoustoichivoje initiator includes multipoint introduction.

9. The method according to claim 8, characterized in that the said kislotoustojchivy initiator contained in the above oxide alkylene as a component of the mixed stream is fed to the reactor.

10. The method according to claim 9, characterized in that the said kislotoustojchivy initiator includes glycerin.

11. The method of receiving polyoxyethyleneglycol by direct polyoxyalkylene kislotoustoichivoje low molecular weight initiator having a molecular weight of less than 400 Da or lower oxyalkylene oligomers having a molecular weight of less than about 400 Da, in the presence of a double metal complex cyanide catalyst, including

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst oxyalkylene and polyoxyalkylene uterine weight;

(b) the non-is-going introduction into said reactor kislotoustoichivoje initiator, having a molecular weight of less than 400 Da, and oxide alkylene;

(c) the discharge of product further oxyalkylene kislotnoschelerngo initiator,

in which the amount of acid, effectively reducing the loss of catalyst activity, add to the above islamochristiana initiator or mentioned lower oxyalkylene the oligomers (uterine weight), or as mentioned in the reactor, and mentioned islamochristiana initiator or mentioned lower oxyalkylene the oligomers so as to reduce the loss of catalyst activity.

12. The method according to claim 11, characterized in that the acid includes an inorganic acid, and the inorganic acid is added to the above islamochristiana initiator in an amount of from 1 to 100 million-1in relation to the weight of kislotoustoichivoje initiator having a molecular weight of less than 400 Da.

13. The method according to item 12, characterized in that the said inorganic acid comprises phosphoric acid in an amount of 5 to 100 million-1in relation to the weight mentioned kislotoustoichivoje initiator.

14. The method according to claim 11, characterized in that said acid is an inorganic acid, and it is added to the mentioned uterine weight referred to the continuous introduction of the mentioned acid is locustville initiator.

15. The method according to claim 11, characterized in that the said reactor oxyalkylene is a reactor oxyalkylene continuous action, and mentioned uterine weight gain by returning to the cycle selected flow coming from the above-mentioned reactor.

16. The method according to claim 11, characterized in that the said kislotoustojchivy initiator includes glycerin.

17. The method according to claim 11, characterized in that said reactor is a continuous action.

18. The method according to 17, characterized in that said reactor is a tubular reactor.

19. The method according to p, characterized in that the operation of the continuous introduction of oxide alkylene and kislotoustoichivoje initiator includes multipoint introduction.

20. The method according to claim 19, characterized in that the said kislotoustojchivy initiator contained in the above oxide alkylene as a component of the mixed stream is fed to the reactor.

21. The method of receiving polyoxyethyleneglycol by direct polyoxyalkylene glycerol in the presence of a double metal complex cyanide catalyst, including:

(a) establishing conditions oxyalkylene in the reactor oxyalkylene in the presence of a double metal complex cyanide catalyst;

(b) the continuous introduction of UE is mentioned reactor oxide alkylene and glycerol; and

(c) challenging the polyester product oxyalkylene glycerin,

in which the loss of activity of the double cyanide metal complex catalyst is reduced by performing one or more of the following operations:

i) acidification mentioned glycerine before the introduction of the above glycerol in said reactor;

ii) processing the above-mentioned glycerol effective amount of a substance reacting with or absorbing base, before the introduction of the above glycerol in said reactor.



 

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FIELD: polymer production.

SUBSTANCE: polyoxyalkylene-polyols are obtained via direct polyoxyalkylenation of acid-sensitive low-molecular initiator with molecular weight below 400 Da in presence of double complex metal cyanide catalyst. Process comprises: (i) creation of appropriate conditions in reactor of polyoxyalkylenation in presence of double complex metal cyanide catalyst; (ii) continuously feeding into reactor alkylene oxide and above-mentioned initiator; and (iii) discharging polyether product. Loss of catalyst activity is reduced by performing at least one of the following operations: acidification of acid-sensitive low-molecular initiator before feeding it into reactor; and treatment of the same with effective amount of a substance other than acid, which reacts with base or absorbs base, before feeding it into reactor.

EFFECT: prevented catalyst from loosing its activity and essentially decreased high-molecular fraction and polydispersity of polyoxyalkylene-polyols.

21 cl, 2 dwg, 2 tbl, 3 ex

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