RU2793131C2 - Method for producing polyether polyol with a high ethylene oxide content - Google Patents

Abstract

FIELD: biochemistry.

SUBSTANCE: invention concerns a process for production of a polyether polyol used in the production of polyurethane foam. The process includes continuous feeding into a reactor which contains a composite metal cyanide complex catalyst and (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtained by the method invented, (a) ethylene oxide, (b) substituted alkylene oxide, (c) optionally, parent compound having a hydroxyl functionality of 1 to 8. The mass ratio of the total amount of ethylene oxide supplied to the total amount of substituted alkylene oxide supplied is from 50:50 to 95:5. The time-averaged ethylene oxide concentration is below 13,000 ppm by mass (ppm) per minute, the ethylene oxide concentration is averaged over a period of time T of continuous ethylene oxide supply, the ethylene oxide concentration being defined as the weight of ethylene oxide in the reactor based on the total weight of the reactor contents. EFFECT: method allows to produce a polyether polyol with a high ethylene oxide content using a composite metal cyanide complex catalyst, which can be used to produce a wide range of flexible polyurethane foams.

7 cl, 10 tbl, 2 ex

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The present invention relates to a method for producing a polyether polyol, a polyether polyol obtained by said method, a method for producing polyurethane foam using said polyether polyol, a polyurethane foam obtained by said method, and a molded article containing said polyurethane foam.

BACKGROUND OF THE INVENTION

Polyether polyols are widely used for the manufacture of polyurethane foams, such as flexible polyurethane foams. Elastic polyurethane foams are widely used in many fields. The main areas of application are the automotive and aviation industries, upholstered furniture and technical products. For example, foam-filled seats, seat tops, and back and head headrests, all made from flexible polyurethane foam, are widely used in automobiles and aircraft. Other applications include the use of flexible polyurethane foam as the base of carpets, bedding and mattresses, motorcycle foam saddles, gaskets between car body and headlights, engine air filter lip seals, and insulating layers on car parts and components. engine to reduce sound and vibration.

Polyether polyols are also often referred to as polyoxyalkylene polyols. Polyether polyols are typically prepared by reacting a parent compound or initiator having multiple active hydrogen atoms with one or more alkylene oxides. Typically, polyether polyols used in the manufacture of flexible polyurethane foams are prepared by adding (i) propylene oxide alone, or (ii) a mixture of propylene oxide with ethylene oxide having a high propylene oxide content, to a suitable hydroxy functional parent compound. However, for the production of a number of polyurethane foams, for example, soft, hypersoft foams and viscoelastic foams, in particular air viscoelastic foams, and for cell opening, polyether polyols with a high content of ethylene oxide are also used. US20110230581 discloses a process for the preparation of high ethylene oxide polyether polyols using a double metal cyanide catalyst (DMC).

An important property of a polyether polyol is its viscosity, especially its viscosity at a relatively low temperature. The lower the viscosity, the easier the polyether polyol can be processed (stored and transported), especially in countries where the ambient temperature is relatively low. It is particularly desirable that the polyether polyol does not solidify (remain liquid) at a relatively low temperature.

Furthermore, since polyether polyols are relatively expensive, especially polyether polyols that have a high ethylene oxide (EO) content, it is desirable that a relatively small amount of such polyether polyol can be used to make a particular polyurethane foam. Such an expensive polyol can then advantageously (partially) be replaced by a cheaper polyether polyol, such as a polyester polyol, which has a lower EO content.

It is particularly desirable to provide a polyether polyol such as mentioned above which would be suitable for use in the production of flexible polyurethane foams. It is especially desirable that such a polyol can be used in a wide variety of flexible polyurethane foam applications, including soft foams, super soft (hyper soft) foams and viscoelastic foams, in particular air viscoelastic foams, as well as for opening cells in molded foams.

The purpose of this invention is to provide a process for producing a polyether polyol with a high content of ethylene oxide using a composite metal cyanide complex catalyst, as well as a method for producing polyurethane foam from such a polyether polyol, and the specified method(s) has(s) has (are) one or more number of the above desired improvements.

SUMMARY OF THE INVENTION

Surprisingly, it has been found that the above object can be achieved by a method in which the concentration of ethylene oxide in the reactor is less than 13,000 ppm by weight (ppm) per minute.

Accordingly, this invention relates to a process for producing a polyether polyol, including:

a continuous feed to a reactor which contains a composite metal cyanide complex catalyst and (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtainable by the process of the invention:

(a) ethylene oxide,

(b) a substituted alkylene oxide according to formula (I)

where R1, R2, R3 and R4 independently of each other represent hydrogen, a C ₁ -C ₁₂ alkyl group and/or a phenyl group, provided that:

(I) at least one of R1-R4 is not hydrogen, and

(II) one or more methylene groups on any C ₁ -C ₁₂ alkyl radical may be replaced by an oxygen atom or a sulfur atom,

(c) optionally, a parent compound having a hydroxyl functionality of 1 to 8,

wherein the mass ratio of the total amount of ethylene oxide supplied to the total amount of substituted alkylene oxide supplied is from 50:50 to 95:5, and

wherein the ethylene oxide concentration is less than 13,000 ppm by weight (ppm) per minute during continuous ethylene oxide supply, the ethylene oxide concentration being defined as the weight of ethylene oxide in the reactor based on the total weight of the reactor contents.

In addition, the present invention relates to a polyether polyol obtained by the above method.

The present invention also relates to a method for producing polyurethane foam, which includes reacting a polyether polyol with a polyisocyanate in the presence of a blowing agent, wherein the polyether polyol is the polyether polyol obtained by the above method.

In addition, this invention relates to a polyurethane foam obtained by the above method, as well as to a molded product containing the specified polyurethane foam.

DETAILED DESCRIPTION OF THE INVENTION

Although the methods of this invention and the compositions used in these methods are described in terms of "comprising", "having in its composition" or "comprising" one or more of the various stages and components described, respectively, they can also "consist on essentially from" or "consist of" said one or more of the various steps and components described, respectively.

In the aforementioned method for producing a polyether polyol of the present invention, the following compounds are continuously fed into the reactor: (a) ethylene oxide, (b) substituted alkylene oxide, and (c) optionally, a starting compound. In this method, in the process of continuous supply of ethylene oxide, in particular, in the process of continuous supply of ethylene oxide, substituted alkylene oxide and optionally the parent compound, the concentration of ethylene oxide is less than 13,000 ppm by mass (ppm) per minute, preferably less than 12,000 ppm wt. per minute, more preferably less than 11000 ppm wt. per minute, more preferably less than 10,000 ppm wt. per minute, more preferably less than 9000 ppm wt. per minute, more preferably less than 8500 ppm wt. per minute, more preferably less than 8000 ppm wt. per minute, more preferably less than 7500 ppm wt. per minute, more preferably less than 7000 ppm wt. per minute, more preferably less than 6500 ppm wt. per minute, most preferably less than 6000 ppm wt. in a minute.

Preferably, during the entire period of continuous supply of ethylene oxide, in particular, during the entire period of continuous supply of ethylene oxide, substituted alkylene oxide and optionally the parent compound, the concentration of ethylene oxide is below one of the above values. In particular, it is preferred that during said period of continuous supply, the concentration of ethylene oxide does not amount to or exceed 13,000 ppm wt. per minute, more preferably, it does not amount to or exceed 12000 ppm wt. per minute, more preferably it does not amount to or exceed 11000 ppm wt. per minute, more preferably, it does not amount to or exceed 9000 ppm wt. per minute, more preferably, it does not amount to or exceed 8500 ppm wt. per minute, more preferably it does not amount to or exceed 8000 ppm wt. per minute, more preferably, it does not amount to or exceed 7500 ppm wt. per minute, more preferably it does not amount to or exceed 7000 ppm wt. per minute, more preferably it does not amount to or exceed 6500 ppm wt. per minute, most preferably it does not amount to or exceed 6000 ppm wt. in a minute.

For the purposes of this specification, the aforementioned "ethylene oxide concentration" is defined as the weight of ethylene oxide in the reactor, based on the total weight of the contents of the reactor. In addition, within the framework of this description, the specified concentration of ethylene oxide is expressed in units of parts per million by weight per minute (ppm wt./min). The specified ethylene oxide concentration is the time-averaged concentration of ethylene oxide, and the ethylene oxide concentration can be averaged over a period of time in the process of continuous supply of ethylene oxide, hereinafter referred to as the time period T. During the specified time period T, both (i) the ethylene oxide supply rate and (ii) the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate is constant.

Specifically, said ethylene oxide concentration can be calculated as follows with respect to the above-mentioned time period T starting from t0 and ending at time t1. First, the total ethylene oxide concentration over the entire time period T (hereinafter referred to as "C1") is calculated as follows:

C1 (expressed in ppmw) = [(total weight of ethylene oxide fed over time T)/(total weight of reactor contents at t0)]*1000000

Second, the time-averaged ethylene oxide concentration (hereinafter referred to as "C2") is calculated as follows:

C2 (expressed in ppmw/minute) = C1/(number of minutes in time period T)

In the present invention, the indicated (time-averaged) concentration of ethylene oxide "C2" should be less than 13,000 ppm by weight (ppm) per minute, as further described above.

In addition, during the aforementioned continuous supply period, the aforementioned ethylene oxide concentration may be at least 1000 ppm wt. per minute, or at least 2000 ppm wt. per minute, or at least 3000 ppm wt. per minute, or at least 4000 ppm wt. in a minute.

In addition, in the process of the present invention, the reactor into which ethylene oxide, substituted alkylene oxide and optionally the parent compound are continuously fed contains a composite metal cyanide complex catalyst. In addition, said reactor contains a polyol which is (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtainable by the method of this invention. Preferably, the reactor contains said catalyst and said polyol before starting said continuous feed to the reactor. Preferably, said poly(oxyalkylene) polyol referred to in (i) above has a weight ratio of ethylene oxide units to substituted ethylene oxide units (i.e. other than ethylene oxide units) that is within one of the ranges defined herein for weight the ratio of total ethylene oxide feed to total substituted alkylene oxide feed for a given polyol production process.

Preferably, the above polyol contained in the reactor is a polyether polyol obtainable by the process of the present invention as mentioned in (ii) above. In particular, said polyether polyol includes a finished polyether polyol obtained by the method of this invention. Such ready-made polyether polyol obtained by the method of this invention may be added to the reactor or formed in situ in the reactor before the continuous supply of ethylene oxide, substituted alkylene oxide and optionally the parent compound. In the latter case, which is preferred, such finished polyether polyol includes the polyether polyol obtained by the method of this invention, which remained in the reactor. Such finished polyether polyol remaining in the reactor is generally referred to as "minimum process residue". An easy way to ensure that there is minimal process residue in the reactor is to stop the removal of the polyether polyol before completely emptying the reactor.

The mass fraction of the aforementioned polyol contained in the reactor to which ethylene oxide, substituted alkylene oxide and optionally the parent compound are continuously fed, based on the total weight of the final product in the reactor, can vary within wide limits. The specified proportion may be from 1 to 80% wt., or from 3 to 70% wt., or from 5 to 60% wt., or from 7 to 50% wt., or from 8 to 40% wt. This proportion refers to the so-called "growth factor", which in this description is defined as the ratio of the total weight of the final product in the reactor to the weight of the specified polyol. That is, the mass fraction of (i) poly(oxyalkylene) polyol or (ii) polyether polyol obtained by the method of this invention, based on the total weight of the final product in the reactor, may be from 1 to 80 wt.%, or from 3 to 70% wt., or from 5 to 60% wt., or from 7 to 50% wt., or from 8 to 40% wt.

In the process of the invention, the ratio of ethylene oxide feed rate to substituted alkylene oxide feed rate may be increased during at least a portion of the continuous feed period, preferably during the initial continuous feed period. Within the framework of this description, the specified ratio is a molar ratio, unless otherwise indicated.

The above increase in the ratio of ethylene oxide feed rate to substituted alkylene oxide feed rate can be achieved in several ways, as indicated for 4 cases in the table below:

Ethylene oxide feed rate Substituted alkylene oxide feed rate 1 increases decreasing or constant 2 increases at a faster rate increases at a slower rate 3 decreasing at a slower rate decreasing at a faster rate 4 constant decreases

Cases 1 and 2 above are preferred. That is, in the continuous feed process for the process of this invention, the feed rate of ethylene oxide can be increased, and the feed rate of substituted alkylene oxide can be reduced or remain constant. Alternatively, and more preferably, in the continuous feed process for the process of this invention, both the ethylene oxide feed rate and the substituted alkylene oxide feed rate can be increased, with the ethylene oxide feed rate increasing at a faster rate than the substituted alkylene oxide feed rate.

It is preferable that at the beginning of the increase in the ratio of the feed rate of ethylene oxide to the feed rate of substituted alkylene oxide in the process of continuous supply of ethylene oxide and substituted alkylene oxide, this ratio was in the range from 1.0 to 3.0, more preferably from 1.3 to 2.5, most preferably from 1.5 to 2.3. Further, it is preferable that at the end of the increase in the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate in the process of continuously supplying ethylene oxide and substituted alkylene oxide, said ratio is in the range of 4.0 to 6.0. more preferably 4.3 to 5.5, most preferably 4.5 to 5.3.

In the above case, where the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate increases during at least part of the continuous feeding period, it is preferable that the aforementioned mass fraction of the polyol contained in the reactor into which ethylene oxide, substituted alkylene oxide and optionally feedstock are continuously fed the compound, based on the total weight of the final product in the reactor, was relatively low, preferably in the range from 1 to 50 wt.%, more preferably from 2 to 40 wt.%, more preferably from 3 to 30 wt.%, more preferably from 4 to 25% wt., most preferably from 5 to 20% wt.

In addition, in the process of the present invention, the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate can be kept constant during the continuous feed, preferably during the entire continuous feed period. This can be achieved in several ways, as indicated for the 3 cases in the table below, of which the first case is preferred:

Ethylene oxide feed rate Substituted alkylene oxide feed rate 1 constant constant 2 increases at the same rate increases at the same rate 3 decreasing at the same rate decreasing at the same rate

In the above case where the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate is kept constant in the continuous feeding process, it is preferable that the aforementioned mass fraction of the polyol contained in the reactor into which the ethylene oxide, the substituted alkylene oxide and optionally the starting compound are continuously fed, in terms of on the total weight of the final product in the reactor, was relatively high, preferably in the range from more than 50 to 80% wt., more preferably from more than 50 to 70% wt., most preferably from more than 50 to 60% wt.

In the process of this invention, ethylene oxide, a substituted alkylene oxide, and optionally a parent compound are continuously fed into a reactor that contains a composite metal cyanide complex catalyst. At least a portion of the catalyst may be fed into the reactor prior to said continuous feeding into the reactor. In addition, at least part of the catalyst may be contained in (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtainable by the process of the invention, the polyol being contained in a reactor continuously fed with ethylene oxide, a substituted alkylene oxide, and optionally original connection.

The method of this invention may further include continuously feeding to the reactor: (d) a composite metal cyanide complex catalyst. However, it is preferred that the catalyst is not fed continuously into the reactor.

In the present invention, the polyether polyol is a polyether polyol obtained by ring-opening polymerization of an alkylene oxide (ethylene oxide and a substituted alkylene oxide) in the presence of a composite metal cyanide complex catalyst. Preferably, in such a case, the composite metal cyanide complex catalyst is not removed after the production of the polyether polyol. Composite metal cyanide complex catalysts are often also referred to as double metal cyanide (DMC) catalysts. The amount of the composite metal cyanide complex catalyst may be from 5 to 100 ppm by weight (ppm), preferably from 10 to 40 ppm by weight. based on the final polyether polyol.

In the present invention, the composite metal cyanide complex catalyst may have the following formula (1):

(1) M ¹ _a [M ² _b (CN) _c ] _d .e(M ¹ _f X _g ).h(H ₂ O).i(R)

where each of M ¹ and M ² is a metal, X is a halogen atom, R is an organic ligand, and each of a, b, c, d, e, f, g, h and i is a number that is variables depending on the atomic equilibrium of metals, the number of coordinated organic ligands, etc.

In the above formula (1), M ¹ is preferably a metal selected from Zn(II), Fe(II), Fe(III), Co(II), Ni(II), Mo(IV), Mo(VI) , Al(III), V(V), Sr(II), W(IV), W(VI), Mn(II), Cr(III), Cu(II), Sn(II), and Pb(II) , particularly preferably Zn(II) or Fe(II). In the above formula, M ² is preferably a metal selected from Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn( III), Ni(II), V(IV) and V(V), particularly preferably Co(III) or Fe(III). II, III, IV and V between the above brackets denote the valencies of the atoms.

In the above formula (1), R is an organic ligand, and is preferably at least one compound selected from the group consisting of an alcohol, an ether, a ketone, an ester, an amine, and an amide. As such an organic ligand, a water-soluble ligand can be used. In particular, one or more compounds selected from tert-butyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-pentyl alcohol, isopentyl alcohol, N,N-dimethylacetamide, glyme (ethylene glycol dimethyl ether), diglyme (diethylene glycol dimethyl ether ), triglyme (triethylene glycol dimethyl ether), ethylene glycol mono-tert-butyl ether, isopropyl alcohol and dioxane can be used as the organic ligand(s). The dioxane may be 1,4-dioxane or 1,3-dioxane and is preferably 1,4-dioxane. Most preferably, the organic ligand or one of the organic ligands in the composite metal cyanide complex catalyst is t-butyl alcohol. In addition, a polyol, preferably a polyether polyol, can be used as the alcohol organic ligand. More preferably, poly(propylene glycol) having a molecular weight in the range of 500 to 2500 daltons, preferably 800 to 2200 daltons, can be used as the organic ligand or one of the organic ligands. Most preferably, such poly(propylene glycol) is used in combination with tert-butyl alcohol as organic ligands.

Composite metal cyanide complex catalyst can be obtained by known production methods. For example, it can be obtained by a method in which an organic ligand is coordinated with a reaction product obtained by reacting a metal halide with an alkali metal cyanomethalate in an aqueous solution, then the solid component is separated, and the separated solid component is washed with an aqueous solution containing the organic ligand. An alternative method is that the metal halide is reacted with an alkali metal cyanomethalate in an aqueous solution containing an organic ligand, and the resulting reaction product (solid component) is separated, and the separated solid component is washed with an aqueous solution containing an organic ligand.

As the metal for the metal halide, that exemplified above as M ¹ can be used, with Zn(II) or Fe(II) being particularly preferred. The most preferred metal halide is ZnCl ₂ . As the metal constituting the cyanomethalate, the one exemplified as M ₂ can be used, with Co(III) or Fe(III) being particularly preferred. A preferred specific example of an alkali metal cyanomethalate is Na ₃ [Co(CN) ₆ ] or K ₃ [Co(CN) ₆ ]. Moreover, instead of alkali metal cyanomethalate, H ₃ [Co(CN) ₆ ] can also be used.

In addition, the reaction product obtained by the above method can be washed and then subjected to filtration, and the precipitate (solid component) thus obtained can be dried to obtain a composite metal cyanide complex catalyst in the form of a powder. Alternatively, an aqueous solution containing the organic ligand and the composite metal cyanide complex catalyst after washing the reaction product may be dispersed in the polyol, and then excess water and organic ligand may be distilled off to form a composite metal cyanide complex catalyst in suspension.

As such a dispersant polyol, a polyether polyol can be used. The polyether polyol is preferably a polyether polyol having 2 to 12 hydroxyl groups and a molecular weight of 300 to 5000 daltons, which can be obtained by ring-opening polymerization of an alkylene oxide with a polyhydric alcohol, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylol propane or glycerin in the presence of an alkaline catalyst or a cationic catalyst. Such a polyether polyol can also be used as an initiator during the subsequent production of a polyether polyol using a composite metal cyanide complex catalyst in slurry form.

The number of hydroxyl groups in such a dispersant polyol is preferably 2 to 8, particularly preferably 2 to 3. Most preferably, said dispersant polyol is a poly(propylene glycol) having a molecular weight of 300 to 1500 daltons.

In the process according to the invention, the following alkylene oxides are continuously fed into the reactor:

(a) ethylene oxide,

(b) a substituted alkylene oxide corresponding to formula (I)

where R1, R2, R3 and R4 independently of each other represent hydrogen, a C ₁ -C ₁₂ alkyl group and/or a phenyl group, provided that:

(I) at least one of R1-R4 is not hydrogen, and

(II) one or more methylene groups on any C ₁ -C ₁₂ alkyl radical may be replaced by an oxygen atom or a sulfur atom.

Preferably, the aforementioned substituted alkylene oxide is selected from the group consisting of propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide and styrene oxide. Most preferably, the substituted alkylene oxide is propylene oxide.

During at least part of the period of continuous feeding in the method according to this invention, ethylene oxide and substituted alkylene oxide are simultaneously fed into the reactor. Therefore, the resulting polyether polyol contains a mixed epoxy block containing randomly distributed ethylene oxide units and substituted alkylene oxide units. Preferably, in such a mixed epoxy block, the weight ratio of ethylene oxide units to substituted alkylene oxide units is from 50:50 to 95:5, preferably from 55:45 to 90:10, more preferably from 60:40 to 85:15, most preferably from 70:30 to 80:20. In the case where the ratio of ethylene oxide feed rate to substituted alkylene oxide feed rate increases (over time) during the continuous feed process in the process of this invention, more ethylene oxide units are present at the chain end in the polyester polyol than there are substituted alkylene oxide units. In addition, for the same reason, there are relatively more primary terminal hydroxyl groups. Only when the ethylene oxide unit is a hydroxyl end group does this refer to the primary hydroxyl end group.

In the process of this invention, the weight ratio of total ethylene oxide feed to total substituted alkylene oxide feed is 50:50 to 95:5, preferably 55:45 to 90:10, more preferably 60:40 to 85:15, most preferably 70:30 to 80:20. The specified total amount of ethylene oxide supplied includes the amount of total ethylene oxide supplied continuously or not continuously, separately or not separately. In addition, the specified total amount of substituted alkylene oxide supplied includes the amount of all substituted alkylene oxide supplied continuously or not continuously, separately or not separately.

It is assumed that in the process of the present invention, in the step preceding the continuous supply of ethylene oxide and substituted alkylene oxide, resulting in the aforementioned epoxy mixed block, by supplying only ethylene oxide or substituted alkylene oxide, preferably by supplying only substituted alkylene oxide, a block consisting of said one type is formed. alkylene oxide. Furthermore, it is contemplated that in the process of the present invention, in the step following the continuous supply of ethylene oxide and substituted alkylene oxide leading to the aforementioned epoxy mixed block, by supplying only ethylene oxide or substituted alkylene oxide, preferably by supplying only ethylene oxide, a block is formed consisting of said one type of alkylene oxide.

Optionally, in the process of this invention, a starting compound having a hydroxyl functionality of 1 to 8, preferably 2 to 8, more preferably 2 to 6, more preferably 2 to 4, most preferably 2 to 3, is continuously fed into the reactor. When "hydroxyl functionality" is mentioned, reference is made to the number of hydroxyl groups in the molecule of the parent compound.

Preferably, if the feed compound is supplied continuously, the feed rate of such feed compound increases (over time) for at least a portion of the continuous feed period. In addition, it is preferable that during at least part of the period of continuous supply in the method according to this invention, ethylene oxide, substituted alkylene oxide and the source compound are simultaneously fed into the reactor.

As the above starting compound, a polyhydric alcohol preferably having a molecular weight of not more than 400, such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylolpropane or glycerin, or a polyether monool or a polyether polyol having 2 to 8 hydroxyl groups and a molecular weight of from 300 to 5000 daltons, which can be obtained by ring-opening polymerization of alkylene oxide with the above polyhydric alcohol in the presence of an alkaline catalyst or a cationic catalyst. The number of hydroxyl groups in the above polyhydric alcohol is preferably 2 to 8, particularly preferably 2 to 3. More preferably, propylene glycol (MPG), ethylene glycol (MEG), diethylene glycol (DEG), glycerin, or combinations of the above are used. Most preferably, propylene glycol (MPG), glycerin, or a combination thereof is used.

This method for producing polyols can be carried out at a temperature of from 50 to 200°C, preferably from 80 to 180°C, most preferably from 100 to 160°C.

In addition, the present invention relates to a polyether polyol obtained by the above method.

The polyester polyol of the present invention may have a hydroxyl value (OH number) of 15 to 300 mg KOH/g, more preferably 15 to 250 mg KOH/g, more preferably 15 to 200 mg KOH/g, more preferably 15 to 150 mg KOH/g, more preferably 20 to 100 mg KOH/g, more preferably 20 to 75 mg KOH/g, most preferably 25 to 60 mg KOH/g.

Moreover, the polyether polyol of the present invention may have a hydroxyl functionality that is the same as the hydroxyl functionality described above for the parent compound. Therefore, the above description of this property applies equally to the polyether polyol of this invention.

Further, the polyether polyol of the present invention may have a molecular weight in the range of 350 to 15000 Daltons, more preferably 500 to 6500 Daltons, more preferably 1500 to 6000 Daltons, most preferably 2500 to 5500 Daltons.

Further, the polyether polyol of the present invention may have a primary hydroxyl content in the range of 50 to 90%, more preferably 50 to 85%, more preferably 55 to 80%, most preferably 60 to 75%. The "primary hydroxyl content" referred to refers to the percentage of ethylene oxide (EO) end groups relative to the total number of end groups.

Preferably, the polyol contained in the reactor to which ethylene oxide, a substituted alkylene oxide and optionally a parent compound are continuously fed in accordance with the process for producing polyols of the present invention has properties similar to those described above for the polyether polyol of the present invention. Such properties include hydroxyl number, hydroxyl functionality, molecular weight, and primary hydroxyl group content. Therefore, the above description of these properties applies equally to said polyol contained in the reactor.

The present invention also relates to a method for producing a polyurethane foam, which includes reacting a polyether polyol with a polyisocyanate in the presence of a blowing agent, wherein the polyether polyol is a polyether polyol obtained by the above method for producing a polyether polyol.

In addition, this invention relates to a method for producing polyurethane foam, including:

obtaining a simple polyester polyol, including:

a continuous feed to a reactor which contains a composite metal cyanide complex catalyst and (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtainable by the process of the invention:

(a) ethylene oxide,

(b) a substituted alkylene oxide according to formula (I)

where R1, R2, R3 and R4 independently of each other represent hydrogen, a C ₁ -C ₁₂ alkyl group and/or a phenyl group, provided that:

(I) at least one of R1-R4 is not hydrogen, and

(II) one or more methylene groups on any C ₁ -C ₁₂ alkyl radical may be replaced by an oxygen atom or a sulfur atom,

(c) optionally, a parent compound having a hydroxyl functionality of 1 to 8,

wherein the mass ratio of the total amount of ethylene oxide supplied to the total amount of substituted alkylene oxide supplied is from 50:50 to 95:5, and

wherein the ethylene oxide concentration is less than 13,000 ppm by mass (ppm) per minute during the continuous supply of ethylene oxide, wherein the ethylene oxide concentration is defined as the mass of ethylene oxide in the reactor based on the total mass of the contents of the reactor,

and additionally including:

reaction of a polyether polyol with a polyisocyanate in the presence of a blowing agent.

In the aforementioned method for producing polyurethane foam according to the present invention, the first step for producing a polyether polyol corresponds to the method described above for producing a polyether polyol according to this invention. Therefore, the above description of the latter process applies equally to the first step of said process for producing polyurethane foam.

Preferably, the polyurethane foam to be produced in this process is a flexible polyurethane foam. Polyether polyols that are suitable for making flexible polyurethane foams from them (also called flexible polyether polyols) have a relatively high molecular weight (for example, from 3000 to 6500 daltons) and a relatively low nominal functionality (Fn; for example, from 2 to 3 hydroxyl groups per molecule ). Reference is made to "Chemistry and Technology of Polyols for Polyurethanes", Rapra Technology Ltd., 2005, in particular page 8.

In this process for producing polyurethane foam, a polyether polyol is reacted with a polyisocyanate in the presence of a blowing agent.

The polyisocyanate may be, for example, an aromatic polyisocyanate, such as toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI) or polymeric MDI (i.e., polymethylene polyphenyl isocyanate), an aliphatic polyisocyanate, such as hexamethylene diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate, lysine diisocyanate or tetramethylxylylene diisocyanate, an alicyclic polyisocyanate, for example, isophorone diisocyanate, or a modified product from the above. Tolylene diisocyanate (TDI) may be a mixture of 80% wt. 2,4-TDI and 20% wt. 2.6-TDI, which is sold as "TDI-80". In addition, the polyisocyanate may be any mixture of two or more of the polyisocyanates mentioned above. For example, the polyisocyanate may be a mixture of TDI and MDI, in particular a mixture in which the weight ratio of TDI:MDI varies from 10:90 to 90:10.

In this method for producing polyurethane foam, the molar ratio of isocyanate (NCO) groups in the polyisocyanate to hydroxyl (OH) groups in the polyester polyol can be such that the final polyurethane foam does not contain free terminal NCO groups. Typically, in this process, the isocyanate index (or NCO index) may vary over a wide range and may range from 60 to 150, preferably from 65 to 130. The isocyanate index is defined as:

[(actual isocyanate)/(theoretical isocyanate)]*100, where "theoretical isocyanate" is equal to 1 equivalent of isocyanate group (NCO) per 1 equivalent of isocyanate-reactive group.

Such "isocyanate-reactive groups" as defined above include, for example, OH groups from a polyol and from any water that can be used as a blowing agent. Isocyanate groups also interact with water, as discussed further below.

The type of blowing agent required to produce the polyurethane foam of this invention is not essential. For example, suitable blowing agents include water, acetone, carbon dioxide gas or liquid, halogenated hydrocarbons, aliphatic alkanes, and alicyclic alkanes. Due to the ozone depleting effects of fully chlorinated fluorinated alkanes (CFCs), the use of this type of blowing agent is generally not preferred, although it is possible to use them within the scope of this invention. Halogenated alkanes in which at least one hydrogen atom has not been replaced by a halogen atom (so-called HCFCs) have little or no ozone depleting effect and are therefore the preferred halogenated hydrocarbons for use in physically blown foams. A very suitable blowing agent of the HCFC type is 1-chloro-1,1-difluoroethane. The use of water as a (chemical) blowing agent is also well known. The water reacts with the isocyanate groups according to the well-known NCO/H ₂ O reaction, resulting in the release of carbon dioxide, which leads to foaming. Finally, aliphatic and alicyclic alkanes have been developed as alternatives to CFC blowing agents. Examples of such alkanes are n-pentane and n-hexane (aliphatic), as well as cyclopentane and cyclohexane (alicyclic). It is understood that the above blowing agents may be used singly or as a mixture of two or more. The amounts in which blowing agents are to be used are those which are commonly used, i.e. in the range between 0.1 and 10 php (mass fractions per hundred mass fractions of polyether polyol), preferably from 0.1 to 5 php in the case of water and between about 0.1 and 20 php for halogenated hydrocarbons, aliphatic alkanes and alicyclic alkanes.

In addition, other components may also be present in the process for making the polyurethane of this invention, for example one or more polyurethane catalysts, surfactants and/or crosslinkers.

Polyurethane catalysts are known in the art and include many different compounds. For the purpose of this invention, suitable catalysts include tin, lead or titanium based catalysts, preferably tin based catalysts such as tin salts and dialkyltin salts of carboxylic acids. Specific examples are tin octoate, tin oleate, dibutyltin dilaurate, dibutyltin acetate and dibutyltin diacetate. Other suitable catalysts are tertiary amines, for example bis(2,2'-dimethylamino)ethyl ether, trimethylamine, triethylamine, triethylenediamine and dimethylethanolamine (DMEA). Examples of commercially available tertiary amine catalysts are those sold under the trademarks NIAX, TEGOAMIN and DABCO (all trademarks). The catalyst is typically used in an amount of 0.01 to 2.0 mass fractions per one hundred mass fractions of polyether polyol (php). Preferred amounts of catalyst are from 0.05 to 1.0 php.

The use of foam stabilizers (surfactants) is well known. Silicone surfactants are most traditionally used as foam stabilizers in the production of polyurethanes. A wide variety of such silicone surfactants are commercially available. As a rule, such a foam stabilizer is used in an amount of up to 5% wt. based on the reaction mixture of polyol reagent and polyisocyanate reagent.

The use of crosslinkers in the manufacture of polyurethane foams is also well known. Polyfunctional glycolamines are known to be suitable for this purpose. The polyfunctional glycolamine most commonly used and also applicable in the preparation of the flexible polyurethane foams of this invention is diethanolamine, often abbreviated as DEOA. If used at all, the crosslinker is used in amounts up to 3.0 php, but the most appropriate amount is in the range of 0.2 to 1.5 php.

In addition, other well known additives such as colorants, flame retardants and fillers can also be used in the process for making the polyurethane of this invention.

In addition, this invention relates to a polyurethane foam obtained by the above method, as well as to a molded product containing the specified polyurethane foam.

The present invention is further illustrated by the following examples.

Examples

In the examples, polyether polyols (also referred to as "polyols") were prepared using a double metal cyanide (DMC) catalyst. The DMC catalyst contained zinc(II) hexacyanocobaltate(III), tert-butyl alcohol and polypropylene glycol (PPG). Said PPG had a molecular weight of about 1000 Daltons. The DMC catalyst was prepared according to Example 6 of WO200180994.

In Examples 1 and 2 below, polyol B and polyol C, respectively, were prepared in accordance with the present invention. In the preparation of polyol B, glycerol (starting compound) was not used. In the preparation of polyol C, glycerol was used.

A) Example 1: Polyol B

Polyol B was prepared in the presence of polyol A. Polyol A had a hydroxyl functionality of 3.0 and an OH number of 250 mg KOH/g and was prepared by adding propylene oxide to glycerol.

393.6 g of polyol A and 0.243 g of the above DMC catalyst in 63.2 g of polypropylene glycol having a molecular weight of 400 g/mol were placed in a 5.5 L laboratory autoclave under a nitrogen atmosphere. The autoclave was closed and the contents were distilled off at 130° C. for 1 hour at a stirrer speed of 300 rpm and a pressure of 800 mbar while passing through 50 ml of nitrogen per minute. Once the reaction temperature stabilized at 130° C., the stirrer speed was increased to about 1000 rpm. Then, 22.62 g of propylene oxide (PO) was added to activate the catalyst. The start of the polymerization reaction was manifested in an accelerated pressure drop 5 minutes after the introduction of propylene oxide. Once the pressure stabilized, the reactor was pressurized to about 1.9 bar using nitrogen.

The propylene oxide (PO) stream was then fed into the reactor at a feed rate of 107 g/hr. Two minutes after the start of the PO stream, the ethylene oxide (EO) stream began to be fed at a rate of 150 g/h. Both the PO feed rate and the EO feed rate were increased gradually during the initial continuous feed period. The EO feed rate was increased more than the PO feed rate, thus the ratio of the EO feed rate to the PO feed rate increased gradually in the initial continuous feed period. The EO stream was stopped 223 minutes after the start of the PO stream. The PO flow was stopped 232 minutes after the start of the PO flow.

EO and PO feed rates, molar ratio of EO feed rate to PO feed rate, and EO concentration over time are presented in Table 1 below. The EO and PO feed rates were kept constant between successive time points shown in Table 1.

Table 1

Time ⁽¹⁾ (min) PO feed rate (g/h) EO feed rate (g/h) Molar ratio of EO feed rate to PO feed rate Concentration ⁽²⁾ EO (ppm w/min) 0 107 0 0 0 2 107 150 1.8 0 10 107 175 2.2 5174 20 107 225 2.8 5636 thirty 107 250 3.1 6643 40 107 275 3.4 6722 50 112 300 3.5 6747 60 112 350 4.1 6730 70 112 400 4.7 7187 80 150 450 4.0 7502 90 150 500 4.4 7700 100 158 550 4.6 7759 110 170 600 4.7 7753 120 185 650 4.6 7690 130 200 700 4.6 7583 140 215 750 4.6 7441 150 230 775 4.4 7277 160 240 800 4.4 6875 190 245 800 4.3 6516 200 245 825 4.4 5196 210 245 850 4.6 5018 223 245 0 0 4854 232 0 0 0 0

(1) Count from the start of the PO stream.

(2) The EO concentration is determined and calculated as described above in the section preceding the Examples section:

C1 (expressed in ppm wt.) = [(total mass of ethylene oxide fed during the time period T between two successive times shown in Table 1)/(total mass of the contents of the reactor at the beginning of the time period T)]*1000000 ;

EO concentration (expressed in ppmw/min) = C1/(number of minutes in time T);

during each of the consecutive time periods T shown in Table 1, both (i) the EO feed rate and (ii) the ratio of the EO feed rate to the PO feed rate were constant.

As can be seen from table 1, during the entire period of continuous supply of ethylene oxide to the reactor, the concentration of ethylene oxide was below 8000 parts by weight (ppm) per minute.

A total of 2033.3 g of ethylene oxide and 679.7 g of propylene oxide was added to the reactor during the continuous feeding phase of this experiment. Thus, the weight ratio of total ethylene oxide to total propylene oxide fed during said continuous feeding phase was 75:25.

After 0.75 h after the interaction, the mixture was cooled to 110°C and distilled off with nitrogen under vacuum at a pressure of 800 mbar for 0.5 h, and then cooled to 60°C.

Polyol B had a hydroxyl functionality of 2.8, an OH number of 39.0 mg KOH/g and a viscosity at 25°C of 902 mPa·s. At 5° C., polyol B was still liquid and had a viscosity of 3700 mPa·s. Polyol B was clear at 25°C and cloudy at 5°C. In addition, the weight ratio of ethylene oxide to propylene oxide in polyol B was 74:26. And its growth ratio (the ratio of the mass of the final product to the mass of polyol A) was 8.1. This corresponds to the proportion of polyol A, based on the weight of the final product, which is 12.3% wt. The molecular weight of polyol B was 4363 g/mol. The amount of DMC catalyst in the final polyol was 75 ppm wt.

B) Example 2: Polyol C

Polyol C was prepared in the same manner as polyol B (in Example 1), provided that:

1) 407.5 g of polyol B was used. The amount of polyol B indicated was the amount of polyol B remaining in the reactor ("minimum process residue") after the experiment of example 1 was completed.

2) 0.225 g DMC catalyst in 51.5 g polypropylene glycol was used.

3) 23.13 g of propylene oxide (PO) was added to activate the catalyst.

4) Two minutes after the start of the PO stream, the glycerol stream was started at a feed rate of 9.1 g/h.

5) Four minutes after the start of the PO stream, the ethylene oxide (EO) stream was started. During the continuous feed phase, the ratio of the EO feed rate to the PO feed rate increased in a similar manner as in Example 1. The EO stream was stopped 245 minutes after the start of the PO stream. The PO flow was stopped 253 minutes after the start of the PO flow. See also table 2 below. As can be seen from table 2, during the entire period of continuous supply of ethylene oxide to the reactor, the concentration of ethylene oxide was below 6500 parts by weight (ppm) per minute.

6) The glycerol feed rate was increased gradually by 0.22 g/h every 10 minutes until a maximum feed rate of 19 g/h was reached 218 minutes after the start of the glycerol flow, after which the glycerol feed rate was kept constant. Glycerol in a total amount of 43.0 g was added over 3.72 hours.

7) A total of 1873.3 g of ethylene oxide and 615.9 g of propylene oxide were added to the reactor during the continuous feeding phase of this experiment. Thus, the weight ratio of total ethylene oxide to total propylene oxide fed during said continuous feeding phase was 75:25.

8) After 0.52 h after the reaction, the mixture was cooled to 110°C and distilled with nitrogen under vacuum at a pressure of 800 mbar for 1 h, and then cooled to 60°C.

9) Polyol C had a hydroxyl functionality of 2.8, an OH number of 36.4 mg KOH/g and a viscosity at 25°C of 1217 mPa.s. At 5° C., polyol C was still liquid and had a viscosity of 5400 mPa·s. Polyol C was clear at 25°C and cloudy at 5°C. In addition, the weight ratio of ethylene oxide to propylene oxide in polyol C was 75:25. And its growth ratio (the ratio of the mass of the final product to the mass of polyol B) was 7.4. This corresponds to a proportion of polyol B, based on the weight of the final product, of 13.5% wt. The molecular weight of polyol C was 4363 g/mol. The amount of DMC catalyst in the final polyol was 75 ppm wt.

table 2

Time ⁽¹⁾ (min) PO feed rate (g/h) EO feed rate (g/h) Molar ratio of EO feed rate to PO feed rate Concentration ⁽²⁾ EO (ppm w/min) 0 107 0 0 0 4 107 150 1.8 0 10 107 175 2.2 4853 20 107 200 2.5 5188 thirty 107 225 2.8 5435 40 107 250 3.1 5608 50 112 275 3.2 5722 60 112 300 3.5 5782 80 112 325 3.8 5376 90 112 350 4.1 5401 100 112 375 4.4 5402 110 112 400 4.7 5383 120 117 425 4.8 5349 130 124 450 4.8 5299 140 131 475 4.8 5236 150 138 500 4.8 5163 160 152 550 4.8 5082 170 165 600 4.8 5218 180 179 650 4.8 5307 190 193 700 4.8 5357 200 205 750 4.8 5373 210 220 800 4.8 5364 220 228 830 4.8 5333 245 228 0 0 4703 253 0 0 0 0

See explanation in table 1 above.

B) Comparison with Example 4 US20110230581

The results of Examples 1 and 2 above were compared with those of US20110230581 Example 4. The relevant parameters are shown in Table 3 below.

Table 3

Etc. 1 - Polyol B (according to the invention) Etc. 2 - Polyol C (according to the invention) Etc. 4 US20110230581 Addition of glycerin No Yes Yes Extension factor ⁽¹⁾ 8.1 7.4 8.1 The proportion of the original polyol ⁽¹⁾ (%) 12.3 13.5 12.3 Mass ratio of EO:PO (in the final product) 74:26 75:25 76:24 Hydroxyl functionality 2.8 2.8 3.0 OH number (mg KOH/g) 39.0 36.4 36.6 Viscosity at 25°C (mPa s) 902 1217 1541 Viscosity at 5°C (mPa s) 3700 5400 -

(1) Build-up ratio=weight ratio of final product to weight of starting polyol; Share of original polyol = [1/growth factor]*100%

Advantageously, the viscosity (at 25°C) of polyols B and C (according to the invention) was unexpectedly significantly lower (902 mPa s and 1217 mPa s, respectively) compared to the viscosity of the polyol obtained in example 4 of US20110230581 (1541 mPa s ).

D) Production of polyurethane foams

Advantageously, the polyurethane foam experiments described below show that the polyols produced by the process of this invention can be successfully used in a wide range of polyurethane foam applications, including: 1) airborne viscoelastic foams; 2) soft foam; 3) super soft foams; and 4) as antifoam agents in molded foams.

This will be described in more detail in the following sections, where the polyol C prepared in Example 2 above was used. The materials (polyols, polyisocyanates, and other components) used in the polyurethane foam experiments are described in Table 4 below.

Table 4

POLYOLS Caradol SA34-05 Polyether polyol commercially available from Shell Chemicals; MM=4700 g/mol; OH number=34.0 mg KOH/g Caradol SA36-02 Polyether polyol commercially available from Shell Chemicals; MM=4600 g/mol; OH number=36.0 mg KOH/g; EO content >60% Caradol SA250-06 Polyether polyol commercially available from Shell Chemicals; MM=675 g/mol; OH number=250.0 mg KOH/g Caradol SC48-08 Polyether polyol commercially available from Shell Chemicals; MM=3500 g/mol; OH number=48.0 mg KOH/g; EO content <15% Caradol SC56-16S Polyether polyol commercially available from Shell Chemicals; MM=3000 g/mol; OH number=56.0 mg KOH/g Caradol MD22-40 Styrene-acrylonitrile polymeric polyester polyol, commercially available from Shell Chemicals; OH number=22.0 mg KOH/g POLYISOCYANATES Desmodur 3133 Polymeric MDI commercially available from Covestro; free NCO content=32% Suprasec 2721 Prepolymerized MDI commercially available from Huntsman; free NCO content=29.8% TDI-80 An 80:20 mixture (by weight) of the 2,4 and 2,6 TDI isomers commercially available from Mitsui; free NCO content=48.3% OTHER COMPONENTS Dabco 33LV Solution 33% wt. triethylenediamine in dipropylene glycol, commercially available from Air Products and Chemicals Dabco T-9 Tin octoate catalyst commercially available from Air Products and Chemicals DeoA Diethanolamine (98%; crosslinker) Niax A33, A1, C225 Amine based catalysts available from Momentive Performance Materials Niax L3627, L618, L417, L627, L580 Silicone based surfactants commercially available from Momentive Performance Materials Tegostab B4900, BF2370 Silicone based surfactant commercially available from Evonik

MDI=methylene diphenyl diisocyanate;

TDI=toluene diisocyanate

One or more of the following properties of the thus obtained foams were measured:

1) Crushing Force (FTC): The foam should be handled in such a way that it does not break/deform at all, so all closed cells in the foam should be intact at the start of the test. 55 seconds after demoulding, the foam is placed under the indenter leg such that the center of the indenter leg is perpendicular to the foam, just above the center point of the molded foam. 60 seconds after removal from the mold, the compression of the foam by the indenter leg begins. When the foam becomes depressed to 75% of its original height, the indenter changes direction. The highest force measured during the compression cycle is taken as the FTC value.

2) Density according to ASTM D3574 (sample size 100*100*50 mm ³ , 2 foam samples).

3) Resilience according to ASTM D3574 - Test H (sample size 100*100*50 mm ³ , 2 foam samples) which involves dropping a 16 mm diameter steel ball bearing on the sample and measuring the percentage height that the ball bearing rebounded .

4) Hardness under compression strain load at 40% compression (CLD40%) according to DIN 53577 (sample size 100*100*50 mm ³ , 2 foam samples), which includes the measurement of the force required to compress the sample by 40% .

5) Indentation hardness at 25%, 40% or 65% compression (ILD25%, ILD40% or ILD65%) according to DIN 53577 (sample size 380*320*50 mm ³ , 1 foam sample) which includes includes measuring the force required to compress a sample by 25%, 40%, or 65%. In these examples, the specified sample size has been changed to 325*375*75 mm ³ .

6) The hardness index was determined by dividing ILD65% by ILD25%.

7) Porosity was determined using an "IDM" foam porosity tester (ASTM D3574 - test G) in which a 50*50*25 mm ³ foam sample was placed in the cavity of the vacuum chamber and the automatic constant pressure drop of the applied air was determined (125 Pa) . Air volume readings are recorded in liters/min.

8) Recovery time was determined using ASTM D3574 - Test M with 100*100*50 mm ³ foam samples (smaller than specified in the test method). The recovery time to 2 N or the recovery time to 4.5 N was measured (as in the test method).

D.1) Viscoelastic foams

D.1.1) MDI air viscoelastic foam

The non-isocyanate components shown in Table 5 below were placed in a beaker and the mixture stirred for 40 seconds. The isocyanate (MDI) component was then added and the mixture was stirred for 5-10 seconds and then poured into an aluminum mold which had been preheated at 50°C. The mold was opened after 8-10 minutes and the resulting foam was cured for 24 hours before cutting. The foam was additionally held at 23° C. for at least 18 hours prior to testing.

Table 5

According to the invention Comparative Compound Caradol SC48-08 (wt. %) 20 20 Caradol SA36-02 (wt %) 0 80 Polyol C (% wt.) 80 0 Water (php) 3.6 3.6 Niax C225 (php) 0.28 0.28 Niax L618 (php) 0.32 0.32 Niax L417 (php) 1.5 1.5 Desmodur 3133 (index) 75 75 Properties Density (kg/ ^m3 ) 41 41 ILD25% (N) 36.0 36.4 ILD40% (N) 46.6 46.9 ILD65% (N) 75.0 74.6 Hardness index 2.1 2.1 Recovery time up to 2 N (s) 10 9

% wt. = mass fraction

pphp=parts per 100 parts polyol (by weight)

index = isocyanate index

In both experiments, stable air molded viscoelastic foams with comparable properties were formed. This is surprising since different polyols were used in these experiments: Caradol SA36-02 (comparative) versus polyol C (according to the invention). Good foam stability was obtained with both of these polyols. This good foam stability was confirmed by observing that no shrinkage occurred, no collapse occurred, and no foam collapse occurred.

D.1.2) TDI viscoelastic foam

The non-isocyanate components shown in Table 6 below were placed in a beaker and the mixture stirred for 40 seconds. The isocyanate (TDI) component was then added and the mixture was stirred for 5-10 seconds and then poured into a carton. The resulting foam was cured for 24 hours before cutting. The foam was additionally held at 23° C. for at least 18 hours prior to testing.

In both series of experiments 1-3 and 4-6 (experiments 1 and 4 may be comparable; experiments 2 and 5 may be comparable; experiments 3 and 6 may be comparable), viscoelastic foams with comparable properties were formed. This is surprising since different polyols were used in these experiments: Caradol SA36-02 (comparative) versus polyol C (according to the invention). For example, both of these polyols gave comparable cell opening efficiency (as indicated by the same porosity) and the same recovery time.

In addition, in the series of experiments 4-6 (according to the invention) it can be seen that the use of an increasing amount of polyol With mainly leads to an increase in the porosity of the foam.

D.2) Soft foams

The non-isocyanate components shown in Table 7 below were mixed in a high speed mixer at about 2000 rpm for 40 seconds. The isocyanate (TDI) component was then added and the mixture was stirred for 7 seconds and then poured to form a foam. After completion of the foaming process, approximately 12 minutes after pouring, the foam was kept in an oven at 70° C. for about 6 minutes. The foam was then removed from the oven and cured. Approximately 24 hours later, the foam was cut as required and its physical properties were measured.

Table 7

According to the invention Comparative Compound Caradol SC48-08 (wt. %) 90 90 Caradol SA36-02 (wt %) 0 10 Polyol C (% wt.) 10 0 Water (php) 3.1 3.1 Niax A33 (pphp) 0.1 0.1 Tegostab B4900 (php) 1 1 Niax A1 (pphp) 0.05 0.05 Dabco T-9 (php) 0.25 0.25 TDI-80 (index) 100 100 Properties Density (kg/ ^m3 ) 28.9 28.6 Porosity (l/min) 102 98 CLD40% (kPa) 2.57 2.54 Elasticity (%) 48 46

As can be seen from table 7 above, the foam obtained in accordance with this invention is characterized by low hardness. Generally, if the CLD value for a foam is between 1.5 and 2.7, then the foam is classified as soft.

Both experiments produced soft foams with comparable properties. This is surprising since different polyols were used in these experiments: Caradol SA36-02 (comparative) versus polyol C (according to the invention).

D.3) Super soft foams

The non-isocyanate components shown in Tables 8 and 9 below were mixed in a high speed mixer at about 2000 rpm for 40 seconds. The isocyanate (TDI) component was then added and the mixture was stirred for 7 seconds and then poured to form a foam. After completion of the foaming process, approximately 12 minutes after pouring, the foam was kept in an oven at 70° C. for about 6 minutes. The foam was then removed from the oven and cured. Approximately 24 hours later, the foam was cut as required and its physical properties were measured.

Table 8

According to the invention Comparative Compound Caradol SC48-08 (wt. %) 40 25 Caradol SA36-02 (wt %) 0 75 Polyol C (% wt.) 60 0 Water (php) 4.5 4.5 Niax A33 (pphp) 0.1 0.1 Tegostab BF2370 (php) 1.2 1.2 Dabco T-9 (php) 0.05 0.05 Niax A1 0.1 0.1 TDI-80 (index) 96 96 Properties Density (kg/ ^m3 ) 22.8 21.3 CLD40% (kPa) 0.71 0.63

As can be seen from table 8 above, the foam obtained in accordance with this invention is characterized by a very low hardness. Generally, if the CLD value for a foam is less than 1.5, then the foam is classified as super soft foam (or hyper soft foam).

In both experiments, ultra-soft foams with comparable properties were formed. This is surprising since different polyols were used in these experiments: Caradol SA36-02 (comparative) versus polyol C (according to the invention).

Furthermore, it is preferable that when using a polyol produced by the process for producing a polyol according to the present invention (such as said polyol C), only a relatively small amount (in this document: 60% by weight) of such a polyol needs to be used in order to produce super soft foam compared to the higher amount (here: 75% by weight) of Caradol SA36-02 used in the Comparative Example to make an ultra soft foam with the same softness. This is advantageous because polyether polyols are relatively expensive, especially polyether polyols which have a high EO content (as mentioned polyol C and Caradol SA36-02). Therefore, as explained above, it is desirable that a relatively small amount of such a polyether polyol can be used to make the foam. Such an expensive polyol can then be advantageously (partly) replaced by a cheaper polyether polyol, for example a polyether polyol which has a lower EO content (as mentioned by Caradol SC48-08).

In addition, when compared with the foam obtained in Example 18 of US20110230581, it appears that the above foam obtained in accordance with the present invention is advantageously excellent in softness. This can be seen from the lower CLD40% value of only 0.71 kPa, while the compressive strength for the foam obtained in Example 18 of US20110230581 was 1.3 kPa. These 2 foams were obtained in a similar way, except that in example 18 US20110230581 used 75% wt. polyol obtained in accordance with example 4 US20110230581, instead of 60% wt. polyol C, as in the example of this invention. This is an advantage because polyether polyols having a high EO content (like the above 2 polyols; see table 3 above) are generally relatively expensive.

Table 9

Fig. Fig. Comp. Fig. Comp. Fig. 1 2 3 4 5 6 Compound Caradol SC48-08 (wt. %) 40 35 35 40 40 35 Caradol SA36-02 (wt %) 0 0 65 0 60 0 Polyol C (% wt.) 60 65 0 60 0 65 Water (php) 2.45 2.45 2.45 2.45 2.45 2.45 Niax A33 (pphp) 0.4 0.4 0.4 0.4 0.4 0.4 Niax L580 (php) 1 1 1 1 1 1 TDI-80 (index) 105 105 105 110 110 110 Properties Density (kg/ ^m3 ) 35.4 34.7 - 34.8 - 34.8 CLD40% (kPa) 0.61 0.79 - 0.71 - 0.92 Elasticity (%) 46 50 - 45 - 45

Fig. = according to the invention; Comp. = comparative

The experiments shown in Table 9 above differ from the experiments in Table 8 in that the former were run at a higher isocyanate index: Experiments 1-3 (index=105) and Experiments 4-6 (index=110). In table 8 experiments, the isocyanate index was 96.

In both of these sets of experiments from Table 9, it was found that it was not possible to measure the physical properties on foams made using Caradol SA36-02 (comparative), while this was possible with polyol C (according to the invention). In comparative experiments 3 and 5 using Caradol SA36-02, the foam had an irregular cell structure with a wide cell size distribution.

D.4) Evaluation as an antifoam agent in molded foam formulation

The components listed in table 10 below were kept at a temperature of about 21°C. The non-isocyanate components shown in Table 10 were then mixed in a high speed mixer. In addition, a mold release agent (RCTA1211, commercially available from Chem Trend) was applied to a mold having a size of 32*38*7.5 cm and preheated to about 50°C. The isocyanate (MDI) component was then added and the resulting mixture was poured into a mould. Demoulding occurred six minutes after pouring. The resulting foam was then subjected to a crush force (FTC) measurement 60 seconds after demolding. In addition, the foam samples were left to cure at room temperature for at least 24 hours before being cut, after which they were further analyzed.

Table 10

According to the invention Comparative Compound Caradol SA34-05 (wt. %) 87.8 87.8 Caradol MD22-40 (wt. %) 4.6 4.6 Caradol SA36-02 (wt %) 0 2.3 Polyol C (% wt.) 2.3 0 Water (% wt.) 3.5 3.5 Niax A33 (wt. %) 0.2 0.2 Niax L3627 (wt. %) 0.7 0.7 Niax C225 (wt %) 0.4 0.4 DeoA (wt %) 0.5 0.5 Suprasec 2721 (index) 66.5 66.5 Properties FTC (H) 2145 2220 ILD40% (N) 385 379 Density (kg/ ^m3 ) 45.9 45.9 CLD40% (kPa) 7.5 7.4 Elasticity (%) 49 49

An important property of an antifoam agent is an increase in the friability of the foam, which affects the dimensional stability of the foam. In particular, the defoamer leads to a decrease in the FTC value. As can be seen from the above table 10, the FTC value for the foam obtained in accordance with this invention is advantageously reduced compared to the foam obtained in the comparative experiment.

Claims (19)

1. A method for producing a simple polyester polyol, including: continuous feed to a reactor which contains a composite metal cyanide complex catalyst and (i) a poly(oxyalkylene) polyol or (ii) a polyether polyol obtainable by the process of the invention: (a) ethylene oxide, (b) a substituted alkylene oxide according to formula (I)

where R1, R2, R3 and R4 independently of each other represent hydrogen, a C ₁ -C ₁₂ alkyl group and/or a phenyl group, provided that: (I) at least one of R1-R4 is not hydrogen, and (II) one or more methylene groups on any C ₁ -C ₁₂ alkyl radical may be replaced by an oxygen atom or a sulfur atom, (c) optionally, a parent compound having a hydroxyl functionality of 1 to 8, wherein the mass ratio of the total amount of ethylene oxide supplied to the total amount of substituted alkylene oxide supplied is from 50:50 to 95:5, and wherein the time-averaged concentration of ethylene oxide (C2) is less than 13,000 ppm by mass (ppm) per minute, wherein the ethylene oxide concentration is averaged over a time period T of continuous ethylene oxide supply, the ethylene oxide concentration being defined as the mass of ethylene oxide in the reactor based on the total weight of the contents of the reactor. 2. The method according to p. 1, characterized in that the time-averaged concentration of ethylene oxide is less than 12000 ppm wt. per minute, preferably less than 11000 ppm wt. per minute, more preferably less than 10,000 ppm wt. per minute, more preferably less than 9000 ppm wt. per minute, more preferably less than 8500 ppm wt. per minute, more preferably less than 8000 ppm wt. per minute, more preferably less than 7500 ppm wt. per minute, more preferably less than 7000 ppm wt. per minute, more preferably less than 6500 ppm wt. per minute, most preferably less than 6000 ppm wt. in a minute. 3. The method according to claim 1 or 2, characterized in that the mass fraction of (i) poly(oxyalkylene) polyol or (ii) polyether polyol obtained by the method according to this invention, based on the total mass of the final product in the reactor, is from 1 up to 80 wt.%, or from 3 to 70 wt.%, or from 5 to 60 wt.%, or from 7 to 50 wt.%, or from 8 to 40 wt.%. 4. The method according to claim 1 or 2, characterized in that the substituted alkylene oxide is selected from the group consisting of propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide and styrene oxide, while preferably the substituted alkylene oxide is propylene oxide. 5. Process according to claim 1 or 2, characterized in that the ratio of the ethylene oxide feed rate to the substituted alkylene oxide feed rate is increased during at least a portion of the continuous feed period, preferably during the initial continuous feed period. 6. Process according to claim 1 or 2, characterized in that the weight ratio of the total amount of ethylene oxide supplied to the total amount of substituted alkylene oxide supplied is from 55:45 to 90:10, preferably from 60:40 to 85:15, most preferably from 70 :30 to 80:20. 7. A method for producing polyurethane foam, including obtaining a simple polyester polyol by the method according to any one of paragraphs. 1-6, and reaction of a polyether polyol with a polyisocyanate in the presence of a blowing agent.