MXPA00009473A - Molded and slab polyurethane foam prepared from double metal cyanide complex-catalyzed polyoxyalkylenepolyols and polyols suitable for the preparation thereof - Google Patents

Abstract

Copolymer DMC-catalyzed polyoxypropylene polyols which exhibit processing latitude similar to base-catalyzed copolymer analogs and homopolyoxypropylene analogs may be prepared by oxyalkylation with a mixture of propylene oxide and ethylene oxide such that a finite ethylene oxide content is maintained in the oxyalkylation reactor for the most substantial part of the oxyalkylation, the polyoxypropylene polyol having randomly distributed oxyethylene moieties which constitute 1.5 weight percent or more of the polyol product. Block copolymer polyols having external blocks containing lesser oxyethylene content than internal blocks and bicompositional compositions containing discrete multimodal and dissimilar and optionally multimodal polyols produced by a continuous addition of starter process are useful as polyols exhibiting greater processing latitude.

Description

MOLDED POLYURETHANE FOAM AND PLATE FROM POLYOLYL ALCOHOL POLYOLYL ALCOHOLS WITH A CYANIDE DOUBLE METAL COMPLEX AND THE APPROPRIATE POLYOLES FOR THE PREPARATION OF THEM Field of the Invention The present invention pertains to molded and plate foam prepared from polyether polyols catalyzed with the double metal cyanide complex exhibiting increased processing amplitude. The present invention furthermore pertains to multiblock and bicompositional polyoxyalkylene polyols prepared by the polymerization catalyzed by the double metal cyanide complex (DMC) of alkylene oxide blends to form the polyoxypropylene polyether polyols having properties that increase the freedom of processing suitable for use when preparing molded foam and polyurethane plate.

BACKGROUND OF THE INVENTION Polyurethane polymers are prepared by reacting a di- or polyisocyanate with an isocyanate-reactive compound, polyfunctional in REF .: 123286 in particular, polyether hydroxyl functional polyols. There are several classes of polyurethane polymers recognized in the art, for example, elastomers, for example molded elastomers, polyurethane RIM, microcellular elastomer, and molded and polyurethane plate foam. Each of these polyurethane varieties presents unique problems in formulation and processing.

Two of the largest volume categories of polyurethane polymers are molded foams and polyurethane plates. In molded foams, the reactive ingredients are supplied in a closed mold and foamed, whereas in the plate foam, the reactive ingredients are supplied in a mobile conveyor belt, or optionally in a discontinuous open mold, and it allows them to grow freely. The resulting foam board, often 6 to 8 feet (2 to 2.6 m) wide and high, can slide into narrow sections to be used as seat cushions, carpet base, and other applications. The molded foam can be used for limiting foam parts, for example, pads for automotive seats.

In the past the polyoxypropylene polyether polyols useful for plating and molding applications have been prepared by means of the oxypropylation with basic catalysis of suitable water initiators such as propylene glycol, glycerin, sorbitol, etc., producing the respective diols, triols , and polyoxypropylene hexols. As documented well now, an arrangement of propylene oxide with allyl alcohol occurs during basic catalyzed oxypropylation. The monofunctional, unsaturated allyl alcohol supports a hydroxyl group which can be converted to oxyalkyl, and its continuous generation and oxypropylation produces increasingly large amounts of unsaturated polyoxypropylene monools having a broad molecular weight distribution. As a result, the current functionality of the polyether polyols produced significantly decreases the "nominal" or "theoretical" functionality. However, the generation of monoi places a relatively low practical limit on the molecular weight that can be obtained. For example, a diol (equivalent weight of 2000 Da) molecular weight 4000 Da (Dalton) catalyzed with base may have a measured unsaturation of 0.05 meq / g, and therefore contain 30 mole percent of unsaturated polyoxypropylene onoi species. The resulting current functionality will be only 1.7 instead of the "nominal" functionality of 2 expected for a polyoxopropylenediol. As this problem is increased while molecular weight increases, the preparation of poly-oxypropylene polyols having equivalent weights greater than about 2200-2300 Da is not practical using conventional base catalysis.

Several attempts have been made over the years to reduce the monoi content of the polyoxypropylene polyols. The use of low temperatures and pressures causes some improvements, as illustrated by the published European application EP 0 677 543 Al. However, the onoi content only fell to the 10-15 mole range, and the reaction rate decreased to such a degree that the cost increased markedly due to the Increase in reaction time. The use of alternating catalysts such as calcium naphthenate, optionally in conjunction with tertiary amine cocatalysts, results in polyols having unsaturation levels of c.a. from 0.02 to 0.04 meq / g, which corresponds, again, to 10-20 mol percent of unsaturated monools.

The double metal cyanide catalysts such as zinc hexacyanocobalt complexes were found to be catalysts for oxypropylation in the 60's. However, its high cost, coupled with modest activity and difficulty in removing significant amounts of catalyst residues from the polyether product, prevented commercialization. The unsaturation of the polyoxypropylene polyols by means of these catalysts was found to be low, however, with c.a. of 0.018 meq / g. The improvements in the catalytic activity and the methods of removal of the catalyst originated a brief commercialization of the polyols catalyzed with DMC in the 80 's. However, the economic aspects were marginal at most, and the expected improvements due to the lower monoi content and unsaturation did not materialize.

Recently, as indicated by the researchers of the North American patents 5,470,813, 5,482,908 and 5,545,610, at ARCO Chemical Company they have produced the DMC catalysts with exceptional activity, which have also caused the decrease of unsaturation to unprecedented levels in the range of 0.002 to 0.007 meq / g. The polyoxypropylene polyols thus prepared were found to react quantitatively differently from before the polyols with "low" unsaturation in certain applications, notably the molded elastomers and microcellular foams.

Notwithstanding their perceived advantages, the substitution of these polyols with their base-catalyzed analogs in molded foam and plate formulations on a commercial scale has frequently led to catastrophic failure. In molded foams, for example, the stiffness of the foam is increased to a degree that the necessary crushing of the foams that follows the molding proved difficult if not impossible. In both the molded foams and the foams in plates, the loss of resistance of the foam occurred frequently, giving foams unable to produce. These effects occur even when the current high functionality of the polyols is usefully lower by the addition of the lower functionality polyols to achieve a current functionality similar to the base-catalyzed polyols.

The polyoxypropylene polyols catalyzed with DMC have exceptionally narrow molecular weight distribution, as can be seen from the gel penetration chromatograms of the polyol samples. The molecular weight distribution is often much narrower than base-catalyzed analog polyols, particularly in the larger equivalent weight range, for example. Polydispersities of less than 1.5 are obtained, and polydispersities in the range of 1.05 to 1.15 are common. In view of the low levels of unsaturation and low polydispersity, it is surprisingly, the DMC-catalyzed polyols did not prove to be "advantageous" replacements of the base-catalyzed polyols in polyurethane foam applications. Because oxypropylation with modern DMC catalysts is highly efficient, it is highly desirable to provide DMC-catalyzed polyoxypropylene polyols that can directly replace conventional polyols in plating and molding polyurethane foam applications.

A comparison of gel permeation permeation chromatograms of base catalyzed and DMC catalyzed polyols exposes differences that have not been recognized as the dependent result in the development of polyol. For example, as shown in Curve A of Figure 1, a base-catalyzed polyol exhibits a significant "major" portion of low molecular weight oligomers and polyoxypropylene monools before the main peak molecular weight. Passing the peak, the weight percentage of the higher molecular weight species falls rapidly. In curve B of Figure 1, a similar chromatogram of the DMC catalyzed polyol reveals a narrow centered peak with a "major" portion of very low molecular weight, but with a small portion of higher molecular weight species, which can be terminated with "high molecular weight tails". Due to the low concentration of the portion of the tail with high molecular weight, generally less than 2-3 weight percent of the total, the polydispersity remains low. Both curves are idealized for illustration purposes.

Brief Description of the Invention It has now been surprisingly discovered that polyboxypropylene polyols catalyzed by multiblock or bicompositional DMC can be obtained which mimics the behavior of the base-catalyzed analogues, yes during polyoxyalkylation, small but effective amounts of ethylene oxide or other comonomers Suitable modifiers that modify stability, as defined herein, are copolymerized with propylene oxide for the bulk of the oxypropylation, resulting in a copolymer of the random polyoxypropylene polyol. In both processes the conventional by batch and the continuous addition of the initiator of the processes of polyoxyalkylation, it is preferred that the amount of ethylene oxide in the external block is not disproportionately greater than the amount contained in the internal block. The bicompositional polyethers, as defined herein, are produced by the continuous addition of the process initiator. Both multiblock and bicompositional polyols have been found for use in molded foams or plate applications, and exhibit processing freedom similar to their base-catalyzed analogs.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 illustrates the hypothetical molecular weight distribution curves for a conventional base-catalyzed polyol (Curve A) and a DMC-catalyzed polyol (Curve B).

Detailed Description of the Invention Intensive research into the chemical and physical characteristics of polyoxypropylene polyols has led to the discovery showing the narrow distribution of molecular weight 1 and low polydispersity of polyols catalyzed by DMC, small fractions of high Molecular weight are largely responsible for the excessive stiffness of the foam (stabilization) and the loss of foam resistance. It has been conjectured that these high molecular weight species exert an effect similar to a surfactant which alters the solubility and hence the external growth phase of the polyurethane polymers during the isocyanate polyol reaction.

While the foam loses strength in plate foam formulations (destabilization) using DMC-catalyzed polyoxypropylene polyols that have been associated with the high molecular weight compounds, no explanation of the stiffness (excessive stabilization) experienced in the molded foam has been found. expressed so far. The inventors have surprisingly found that the high molecular weight tail compound present in the DMC-catalyzed polyoxypropylene polyols is responsible for the excessive stiffness in the molded foams as well as the loss of foam strength in the plated foam. This is the same cause that creates The opposite effects of destabilization on plaque foams and excessive stabilization in molded foams is more surprising.

Until now, methods not completely effective to avoid the production of high molecular weight compounds during polyoxypropylation using the DMC catalysts have been found. The present inventors have conjectured that the dissimilar processing of conventional polyols and DMC catalyzed polyols may reside in the differences exhibited by these polyols with respect to their content of lower weight and higher molecular weight species. Since the complex of the external phase of the hard and soft segments that occurs during polyurethane polymerization is known to be affected by the molecular weight of the polyol, this external phase was an aspect that was identified as a possible cause of the differences of the processing. It has surprisingly been found that the preparation of the polyoxypropylene polyols of the mixtures containing a minimum effective amount of monomers that can be copolymerized, preferably ethylene oxide, completely the most substantial of the DMC-catalyzed oxyalkylation, it produces polyols that are useful in the same way as their base-catalyzed polyoxypropylene counterparts in molded foam or plate applications while maintaining the same molecular weight distribution substantially as polyols of homopolymer polyoxypropylene catalyzed with DMC.

It is more surprising that the loss of foam resistance is experienced in the formulations of the DMC-catalyzed polyol-based foam (destabilization), while at the same time, the stiffness (excessive stabilization) is experienced in the molded foam. The inventors have surprisingly found that the incorporation of internal ethylene oxide randomly discussed previously in the DMC-catalyzed polyoxypropylene polyols cures the excessive stiffness in the molded foam as well as the loss of strength in the plated foam. It is surprising that these very different difficulties of processing can be cured with the same solution.

Although excessive stiffness of the foam and loss of foam strength can be avoided by the preparation of the DMC-catalyzed polyoxypropylene polyols as defined herein, the amount of the high molecular weight glue is not believed to be significantly altered, and therefore the unexpected and meritorious effects exhibited by the copolymerized products must be due to some other causes. It is believed that the high molecular weight species generated are also copolymers, and that the presence of more hydrophilic oxyethylene radicals, or of stereochemically different radials such as butylene oxides, etc., in these fractions alters the compatibility of these species with the hard and soft segments of the polymer chains that grow during polyurethane polymerization. The mechanism of this change is known. It can result, for example, from a change in the hydrophilic / lipophilic balance (HLB) of the high molecular weight fractions, they can create the polyether equivalent of hard and soft polyurethane segments, or can alter the crystallinity or stereoregularity, which in any case, can be defined as a change in "surfactance" of the high molecular weight tail, since it is believed that the effects are related to the surface.

It has been found that the minimum amount of copolymerized ethylene oxide should be about 1.5 weight percent relative to the total feed of propylene oxide plus ethylene oxide. The amounts of 1 percent by weight or less exhibited substantially the same properties as the homopolyroxypropylene polyols catalyzed with DMC. The monomers instead of ethylene oxide which can be used to achieve the mysterious effects of the object of the invention include those monomers copolymerizable with propylene oxide or copolymerizable with mixtures of propylene oxide and ethylene oxide under the catalysis of DMC. These monomers include, but are not limited to, substituted, for example halogenated or unsubstituted C5 to C20 olefins oxides, especially C4 to Ci2, such as 1,2-oxide. butylene, 2,3-butylene oxide with α-olefins are preferred; oxetane, methyloxetane such as 3-methyloxetane, caprolatone, maleic anhydride, phthalic anhydride, halogenated propylene and butylene oxides, and a-olefin oxides. The effective amounts of these monomers in the preparation of polyols which are suitable for use in plaque foam can be easily determined by synthesis of a white polyol and evaluation of its development in the super critical foam test, as described above. In general, the amounts used will be similar to the amounts of ethylene oxide used, in a mol to mol basis. However, the copolymerizable monomers which cause great disruption of the polyol structure of the high molecular weight fractions can be used in smaller amounts. Mixtures of these monomers are also useful, particularly in conjunction with ethylene oxide. These monomers, effective to modify the effect of the high molecular weight glue, are referred to herein as comonomers that modify the stabilization. While ethylene oxide is used in discussions that continue, these discussions apply as well as in the comonomers that modify the stabilization, unless otherwise indicated.

The maximum amount of ethylene oxide that can be used successfully depends on the end use contemplated. While the amount of ethylene oxide is increased, the polyol becomes increasingly hydrophilic, and when the ethylene oxide is used in large amounts, the primary hydroxyl content is increased. This increase in the primary hydroxyl content is less important when the ethylene oxide (EO) ends with polyols that are subsequently prepared, or when a high EP / PO ratio is used in the final stage of polymerization, for example with the total purpose of increasing the content of primary hydroxyl for use in foam in plate with high strength and in the prepolymer or molded foam of a discharge. In these cases, the total oxyethylene content should be between 7% and 35% by weight, preferably between 7% and 30%, and more preferably between 7% and 25%. However, with the low primary hydroxyl content, homopolymers of polyoxypropylene mirrors are contemplated, the total oxyethylene content must, in most cases be less than 20 weight percent, more preferably less than 15 weight percent, even more preferably lower of 10 weight percent, and more preferably in the range of from about 2 weight percent to about 9 weight percent.

The polyols of the scope of the invention can be called "multiblock" and "bicompositional" "extended EO polyols", as "oxyethylene" radicals are "extended", or randomly distributed throughout the portion of the polyol prepared by oxyalkylation catalyzed with DMC , but in different proportions, as discussed below.

It has surprisingly been found that the effects of excessive stabilization as well as loss of foam resistance can be altered by changing the proportions of the ethylene oxide or the monomer modifying the stabilization contained in the interior and interior blocks. outside of the subject polyol. The alteration of the block composition in the multiblock polyols that affects the stabilization of the foam is not believed that until now it has been reported for any polyol prepared by any catalysis method.

The subject polyols of the invention further include extended EO polyols coated in multiblock and bicompositional which have been covered with an alkylene oxide or alkylene oxide mixtures in the presence of a catalyst without DMC. Extended coated EO polyols and expanded EO polyols include polyols prepared by oxyalkylation, in the presence of a DMC catalyst, a polyoxypropylene oligomer which is likewise prepared by oxyalkylation using a catalyst without DMC, for example, a basic catalyst such as potassium hydroxide.

It is important that the most substantial part of the polyoxyalkylation that takes place in the presence of DMC catalysts is carried out in the presence of ethylene oxide or other comonomers that modify the stabilization. While the ethylene oxide is fed into the polyoxyalkylation reactor it may occasionally be interrupted, the ethylene oxide will still be present in smaller amount but decrease the amounts during this interruption. By the term "most substantial part" with respect to this means that the ethylene oxide will be absent, for example, it will have a concentration in the polyoxyalkylation reactor of 0 percent by weight, for no more than 5% of the total oxyalkylation period when propylene oxide is fed to the reactor during the DMC catalysis, preferably not more than 3 5 of this period, and in particular not more than 1%. Thus, at least 95% of the resulting polyoxyalkylene portion of polyol will have randomly distributed oxyethylene or other radicals that modify the stabilization, with the total minimum oxyethylene or other monomer content being about 1.5 weight percent, including any "cover" of homopolioxypropylene.

The values discussed above reflect only the portion of oxyalkylation developed in presence of the DMC catalysts, but preferably also include the activation period (induction period) where the DMC catalyst is activated. Generally, DMC catalysts exhibit an initial induction period wherein the oxyalkylation rate is small or zero. This is very evident in batch-type processes, where followed by the addition of the catalyst to the initiator (s), the alkylene oxide is added to pressurize the reactor and monitor the pressure. The induction period is considered when the alkylene oxide pressure drops. This pressure drop is often rapid, and the activated catalyst then exhibits a high oxyalkylation rate. The concentration of the ethylene oxide during the induction period is desirably in the range of 1.5 to 15 weight percent. When propylene oxide is used to activate the catalyst in the absence of ethylene oxide, the length of time before it is fed mixed alkylene oxide containing ethylene oxide is introduced to the reactor containing the catalyst is minimized to reduce the homopolymerization of propylene oxide. A) Yes, since a mixed feed induction period is desired, the necessary induction period should not be taken into account when determining the portion of oxyalkylation catalyzed by DMC during which the presence of ethylene oxide or other comonomer that modifies stabilization is required .

Sometimes it is necessary to produce coated polyoxyalkylene polyols. With the base-catalyzed, coated polyols, the feed of propylene oxide or mixtures of propylene oxide / ethylene oxide and continuing only with ethylene oxide generally develops upon cessation. Thus the process produces polyols coated with polyoxyethylene, resulting in a high content of primary hydroxyl which increases the reactivity of the polyol. For some base catalyzed copolymer polyols, a "run" with all propylene oxide can be used to produce polyols with high secondary hydroxyl content, for example, a primary hydroxyl content of less than about 3 mole percent. With DMC-catalyzed polyols, the coating can be developed to produce polyols with both lower and higher hydroxyl content, but the ethylene oxide coating generally can not be developed using the DMC catalysts. Since the latter catalysts can be used to prepare a polyoxypropylene coating, this coating should be less than 5 weight percent, and preferably be absent when the coating is prepared using the DMC catalysts.

To coat a DMC-catalyzed polyol with any propylene oxide or ethylene oxide using a catalyst without DMC, the DMC catalyst must first be removed, destroyed or deactivated. This is more conveniently done by adding ammonia, an organic amine, or preferably an alkali metal hydroxide. When the latter, for example, excess KOH is added, the catalytic activity of the catalyst is destroyed, the excess KOH serves as a conventional basic catalyst for the coating. A "coated polyol" as this term is used herein is inclusive of DMC-catalyzed polyols which are further oxyalkylated in presence of a catalyst without DMC. This term does not include the fortuitous copolymers of PO / EO catalyzed with DMC which subsequently reacts with all the propylene oxide in the presence of a DMC catalyst; these polyols should consider the limitation discussed above that the total oxyalkylation includes no more than 5% polyoxypropylation alone, more preferably no more than 1%. Otherwise, the resulting products will not be processed well.

As previously notedIn addition, it has been found that the properties of the extended EO polyols and coated EO polyols can be altered by changing the relative amounts of ethylene oxide over several portions of the oxyalkylation. For example, in the preparation of the plate polyols, it has surprisingly been found that with the same total oxyethylene content, the polyols prepared by incorporating large amounts of ethylene oxide during the initial stages of the polyoxyalkylation and relatively minor amounts during the step end products produce polyols that exhibit less tendency towards loss of resistance in the foam plate systems than those prepared with the correspondingly lower amounts of ethylene oxide during the initial oxyalkylation.

Thus, the polyols of the subject invention are substantially polyoxypropylene, multiblock or bicompositional polyols containing minimally from 1.5 percent by weight of oxyethylene or other radicals derived from comonomers that modify the stabilization, these polyols produced in this way that no more than 5%, and preferably not more than 3% of the total oxypropylation is carried out only with propylene oxide. In conventional batch processes, in order to obtain the benefits of the objective of the invention, it is necessary that the random polyoxypropylene di-block polyols are minimally produced. For plate foam, it is generally desired that the outer portion of the polyol contain a lower amount of oxyethylene radicals in a base by weight than an inner portion. For example, in the batch process, a polyoxypropylene / polyoxyethylene triol with a molecular weight of 1500 Da containing 12 percent in The weight of oxyethylene radicals can further be oxyalkylated in the presence of a mixture containing a minor amount of ethylene oxide on a weight basis to prepare a polyol product having an oxyethylene content of less than 12% by weight. These products unexpectedly provide a superior development in plate foam systems compared to polyols with a similar oxyethylene content where the external fortuitous block contains the same or more amount of oxyethylene radicals than the internal block. However, in polyols for molded foam, improved processing of polyols is observed where the polyol tip contains a higher oxyethylene content than the interior of the polyol.

In continuous addition of the initiators, in both batch and continuous processes, it has been found that polyols with excellent properties can be obtained when the ratio of oligomeric initiating oxyethylene radicals to total oxyethylene radicals, in percent by weight, is greater than 0.30. In other words, the amount of ethylene oxide in the feed of propylene oxide / ethylene oxide should not be greater disproportionately than the weight percent of the oxyethylene radicals in the initiator. It is preferable that the ratio of initiating EO to the EO of the outer block is greater than 0.6, and more preferably 0.9 or greater.

In the continuous addition of the initial process, the oligomeric initiators can be base-catalyzed homopolyoxypropylene initiators, polyoxypropylene / polyoxyethylene random or block initiators catalyzed with bases of substantially any polyoxyethylene content, but preferably less than 20 percent by weight, or polyoxypropylene / polyoxyethylene random copolymer polyols may be provided with the latter containing at least 1.5 weight percent oxyethylene radicals, and preferably from 2 to about 20 weight percent, more preferably 2 to about 15, and more preferably 2 to about 10 weight percent of oxyethylene radicals.

The synthesis of the multi-block and bicompositional extended EO polyols and coated extended EO polyols can be performed using the catalysts and by the methods generally set forth in US Patents 5,470,813, 5,482,908, 5,545,601 and 5,689,012 and the Co-pending Application Series No. 08 / 597,781, are incorporated herein by reference. In general, any DMC catalyst can be used as the oxyalkylation catalyst, including those set forth in the aforementioned North American patents and patent applications and also in the US patents 5,100,997, 5,158,922 and 4,472,560. Activation of the catalysts is developed by the addition of propylene oxide, preferably together with small amounts of ethylene oxide.

In conventional batch processing, the DMC catalyst is introduced into the reactor together with the desired amount of initiator, which is generally an oligomer having an equivalent weight in the range of 200 to 700 Da. One or more primers used can have an average functionality of at least 1.5, preferably 2 to 8, hydrogen atoms that can be oxyalkylated. Significant amounts of monomeric initiators such as propylene glycol and glycerin tend to delay catalyst activation and may prevent activation altogether, or deactivate the catalyst while the reaction continues. The oligomeric initiator can be prepared by oxy-propylation catalyzed by a base, or by catalysis with DMC. In the latter case, but except the induction period should be performed in the presence of approximately 1.5 weight percent or more of ethylene oxide.

The reactor is heated, for example at 110 ° C, and propylene oxide, or a mixture of propylene oxide containing a minor amount of ethylene oxide is added to pressurize the reactor, generally at about 10 psig. A rapid decrease in pressure indicates that the induction period is over, and the catalyst is active.

A mixed feed of propylene oxide and ethylene oxide is then added until the desired molecular weight is obtained. The relationship of PO / EO will change during the reaction when the polyols are prepared with two blocks.

In a continuous conventional process, a pre-activated initiator / catalyst mixture is continuously fed into the continuous reactor such as a continuously stirred tank reactor (CSTR) or tubular reactor. The same catalyst / initiator is limited as described in the batch process applied. An associated feed of propylene oxide and ethylene oxide is introduced into the reactor, and the product is continuously stirred. A subsequent feed associated, for example, another point together with a continuous tubular reactor, which contains a concentration of ethylene oxide different from the initial feed.

In the continuous addition of the initiating process, batch operation or continuous operation can be practiced, the catalyst and the DMC catalyst are activated as in the conventional batch process. However, a small molar amount of initiator is used relative to the desired molar amount of product. The molar deficiency of the initiator is preferably supplied gradually in the feed of PO / EO, with the low molecular weight initiator such as propylene glycol, dipropylene glycol, glycerin, etc.

In the continuous process, the continuous addition of the initiating process, following the activation of the catalyst, the continuous addition of monomeric initiator accompanies the PO / EO feed. It is also continuous to remove the product, as is, in general, the introduction of the additional catalyst. Preferably, a removal stream from the reactor is used to activate the catalyst with additional DMC. In this way, the products can be obtained following the departure from the initial line that are completely composed of random PO / EO, with EO spread across the entire molecule.

The initial molecules useful for preparing the extended EO polyols are dependent on the nature of the process. In a batch process, the oligomeric initiator is preferred. These include homopolymeric and copolymer PO / EO polyols prepared by the catalysis with a base, preferably having equivalent weights in the range of 200 Da to 700 Da, or PO / EO copolymer polyols catalyzed with DMC that have been prepared using propylene oxide and ethylene oxide fed in association with the most substantial part of the oxyalkylation instead of the induction period , and normally contains 1.5 percent by weight of oxyethylene radicals.

In the continuous addition of the initiator, in the batch and continuous process, the initiator can be the same as what was previously described; it can be a low molecular weight oligomer; a monomeric initiator molecule such as, in a non-limiting sense propylene glycol, dipropylene glycol, glycerin, sorbitol, or mixtures of the monomeric initiators; or may comprise a mixture of monomeric and oligomeric initiators, optionally in conjunction with a recycle stream from the same process, this recycle stream contains white weight polyols, or preferably polyols that are oligomeric relative to the white weight of the polymer.

The polyols of the subject invention have functionalities, molecular weights and hydroxyl numbers suitable for use in molded and plated foams. The range of the nominal functionalities is generally from 2 to 8. In general, the average functionality of the polyol blends ranges from approximately 2.5 to 4.0. Equivalent polyol weights generally have ranges from about 800 Da to about 5000 Da when the unsaturation of the polyol is less than 0.02 meq / g. The unsaturation is preferably 0.015 meq / g or less, and more preferably in the range from 0.002 to about 0.008 meq / g. The number of hydroxyls can range from 10 to about 60, with the hydroxyl number in the range of 24 to 56 being more preferred. In the molded foam derived from the prepolymer, a lower number of hydroxyls is generally preferred, for example, in the range of about 20 to about 35, advantageously from 24 to about 28. A terminal block contains 30 weight percent excess of oxide of ethylene, more preferably about 50 weight percent of ethylene oxide or greater is particularly useful. The mixtures can, of course, contain polyols of functionalities, equivalent weight, and number of low and high hydroxyls. Any mixture preferably should not contain more than 20 weight percent of undistorted EO DMC-catalyzed polyols, for example, homopolymer polyols of DMC-catalyzed polyoxypropylene or polyols of the copolymer of. polyoxypropylene / polyoxyethylene catalyzed with DMC having more than 5 weight percent of all oxypropylene blocks.

The development of multi-block and bicompositional extended EO polyols and polyols of EO coated coats intended for use in plate foams can be evaluated by testing these polyols in the "Supercritical Foam Test" (SCFT). The polyols that pass this test have been found to perform well in commercial applications, without loss of foam resistance. The SCFT consists of preparing a polyurethane foam using the formulation that is expressly designated to magnify the differences in behavior of the polyol. For molded foam polyols, loss of strength openings and crushing are factors that can be used to evaluate the development of the polyol alone or a set with SCFT.

In the SCFT, a foam prepared from a given polyol was reported as "settled" if the surface of the foam appears convex after stopping expansion and is reported as loss of strength if the foam surface is concave after stopping the expansion . The amount of loss of strength can be reported relatively quantitatively by calculating the percent change in the area of the cross section taken through the foam. The formulation of the foam is as follows: polyol, 100 parts; water, 6.5 parts; methylene chloride, 15 parts; Niax® amine type catalyst A-1, 0.10 parts; tin catalyst T-9, 0.34 parts; silicone surfactant L-550, 0.5 parts. The foam is reacted with a mixture of 80/20 of 2,4- and 2,6-toluene diisocyanate with an index of 110. The foam can conveniently be be emptied into a standard 1-cubic-foot cake box, or a standard 1-gallon ice-cream container. In this formulation, suitably prepared, for example, polyols catalyzed by a base having a large amount of hydroxyl causes the foam to settle approximately 15% ± 3%, while polyols prepared from DMC catalysts exhibit tails with high substantially homopolyioxypropylene molecular weight causing loss of strength in about 35-70%.

Having described this invention, another understanding can be obtained with reference to certain specific examples that are provided herein for purposes of illustration only and are not intended to limit unless otherwise specified.

Examples 1-5 and Comparative Examples C1-C3 These examples illustrate the significant and surprising differences between the polyols of homopolyoxypropylene, and expanded EO polyols catalyzed with a base, catalyzed with DMC. The base-catalyzed polyol is ARCOL® 5603, a polyoxypropylene homopolymer polyol initiated with glycerin with a hydroxyl number of 56 whose preparation catalyzed conventionally with a base was KOH. The relatively low equivalent weight resulted with a c.a. 8.2 percent mol, and the functionality of 2.83. The polyols catalyzed with DMC are prepared from the initiators containing glycerin and propylene glycol in order to obtain current functionalities close to the current functionality of the base-catalyzed control, as well as to give comparisons of the polyol processing as close as possible. possible. The addition of the initiator in batch and continuous processes. It was used to make the polyols catalyzed with DMC, the last process indicated in Table 1 as "continuous" and produced a bicompositional polyol. The liberated processing of the polyols in the SCFT previously described was evaluated, and compared with the control in terms of the settlement cent. The foams catalyzed with KOH routinely exhibited a settling degree of 15% ± 3%. The data was summarized in Table 1. Examples 1, 3 and 4 do not fall within the scope of the claimed invention, but are presented to illustrate the problems associated with plate polyols and DMC catalyzed moldings.

TABLE 1 Examples with a preceding "C", for example, "Cl" are comparative examples.

NA = not available. 3 # OH nominal.

The preceding examples and comparative examples illustrate the importance of preparing the expanded EO-containing polyoxyalkylene polyols as well as critically the minimum amount required to produce a polyol suitable for foam production without loss of strength. In the comparative example Cl, the KOH catalyzed polyol developed in the SCFT, with a settlement of 13%. The polyols. catalyzed with DMC that exhibit settlement of 15-20% have been found to circulate perfectly in commercial production. Foams that exhibit settlement greater than 35% almost always experience loss of strength. Foams with settlement in SCFT greater than 25% are not suitable for low density foams, but may be suitable for some higher density applications.

Comparative examples C2 and C3 are polyols catalyzed with DMC produced batchwise and continuously analogously with the polyol of Comparative Example Cl, for example, for all propylene oxide. These foams exhibited considerable settlement, 32% and 36%, about three times higher than the control polyol catalyzed with KOH. In comparative examples C4 and C5, both batch-produced polyols catalyzed with DMC, associated feed of small amounts of ethylene oxide, 0.5% and 1.0% by weight, was made with propylene oxide, generating random copolymers. However, the foams prepared from these polyols exhibited severe settling, even more, with 43% and 40% respectively, in all the polyols catalyzed with ethylene oxide DMC of Comparative Examples C2 and C3.

In Example 1, however, a batch-produced polyol catalyzed with DMC containing 1. 75 percent by weight of uniformly copolymerized ethylene oxide produces foams with a settling degree virtually the same as the control catalyzed by KOH (19% v. 18%). Note that it is the current value for the control polyol KOH which was made the same day as the foam derived from Example 1. The excellent similar development was achieved in 2.4 to 6.4 weight percent in the DMC catalyzed polyols of Examples 2-5. Note that the bicompositional polyol of Example 2 was better developed in the SCFT than any of the "monocompositional" extended EO polyols of Examples 1 and 3 having less or more extended EO, respectively.

Example 6 and Comparative Example Cß and C7 Bicompositional polyols were prepared using the addition of the initiator in the process batch-wise or continuously. The polyoxyalkylated glycerin initiator of 1.5Kda was added to the reactor with the DMC catalyst, the catalyst was activated and the oxyalkylation was continued with a mixture of propylene oxide and ethylene oxide containing glycerin while continuously adding the initiator. The resulting polyol is bicompositional, having a first population of molecules (polybiblock multiblock) derived from the 1.5 kDa initiator, thus having an internal block with an EO content identical to the initiating EO content, and an external block with an EO content identical with the composition of EO in the diet. The second population of molecules. { polyol copolymer) is a monoblock polyol derived from oxyalkylating glycerin added continuously, and has an EO content that is completely identical to the EO content of the EO / PO feed. Comparative Example C7 is a polyol conventionally catalyzed with a base.

TABLE 2 As can be seen from Example 6 mentioned above and Comparative Examples C6-C7, in the addition of the initiator of the continuous process, where a bicompositional population of molecules is obtained, oxyalkylating a high content of oxyalkylene starter to achieve the same content of white oxyalkylene unexpectedly produces polyols that have improved processing freedom, as evidenced by their low percentage of relative settlement with the catalyzed counterparts with a base. In comparative example C6, where the ratio of the initiator EO to the total EO is less than 0.3, the loss of resistance was observed. The ratio must be maintained greater than 0.3.

Examples 7-15 and Comparative Examples C8 to C12 DMC-catalyzed polyols with different numbers of hydroxyls were prepared using the addition of initiator in the continuous process, using polyoxyalkylated glycerin oligomeric initiators having different oxyalkylene contents, the total oxyalkylene content white remains constant at adjust the ethylene oxide content of the alkylene oxide mixture in the oxyalkylation. The polyols prepared in this way are compared to standard plate polyols catalyzed with a base having the same oxyalkylene content. The polyols catalyzed with a base of Comparative Example C8 and C9 contain a percent polyoxypropylene coating with lower primary hydroxyl content. The results are presented in Table 3.

TABLE 3 The results presented in Table 3 illustrate the beneficial results obtained when the ratio of the initiating oxyethylene content to the total oxyethylene content is at least 0.30. In Example 7, with a ratio of 0.31, the seated foam is acceptable, but higher than desired. In the Comparative Examples CIO and C12, where the ratio is less than 0.30, unacceptable settling occurs (loss of foam resistance).

In the following examples, the molded polyurethane foams were prepared to evaluate the effects of the EO content and the location in the polyoxypropylene polyols in the molded foam. The foams were prepared by the method described in U.S. Patent 5,700,847. The isocyanate-terminated prepolymer is an NCO-terminated prepolymer prepared by reacting 58 parts of a 80/20 mixture of TDI / MDI with 75 parts of the base polyol under consideration, and 25 parts of a polyol polymer containing 43 percent. by weight of acrylonitrile / styrene solids as the dispersed phase. They are added to 158 parts of prepolymer 1 part silicone foam control agent DC 5043. { surfactant), 0.25 parts of the NIAX® Al amine catalyst, and 5 parts of water. The foams were prepared by introducing the reactive compounds intensively mixed into a standard mold, closing the mold, and allowing the ingredients to react and foam to form. The loss of resistance of the vent is noted, and the force required to crush the foam is noted for every three crushing cycles.

Examples 16 and 17 and Comparative Example C13 and C14 The polyol of Example 16 and Comparative Example C13 were prepared by the addition of the initiator in the continuous process by incorporating a small amount of water as a feed associated with glycerin continuously added with the initiator.

As a result, polyols have a similar functionality current to their counterparts catalyzed with a base, for example, in the vicinity of 2.7. Both polyols are catalyzed with DMC, and have equivalent weights of c.a. 2000 Da The polyol of Comparative Example C13 without internal EO block, the initial polymerization to prepare the "main chain" is carried out only with PO. The "tip" or "coating" of the C13 polyol was prepared using DMC catalysis with an EO / PO ratio. The total EO content is 15 percent by weight, where 100% is placed in the outer block (tip). The polyol of Example 16 was prepared by incorporating ethylene oxide during the preparation of the main chain, followed by the alteration of the EO / PO ratio to 45/55 such that the main chain contained 25% of the total EO, with 75 % of total EO at the tip. The polyol of Example 17 is prepared similarly as with the polyol of Example 16, but without the continuous addition of water, and with a slightly lower content of EO. Thus, the polyol of Example 16 contains a 15 percent coating, similar to the 15 percent coating of the polyol of Comparative Example C13, but contains 5% internal EO. The polyol of Example 17 contains the same total EO as the C13 and C14 polyols. The details of the base polyol and the properties of the foam (loss of resistance to venting, force to crush) are summarized in Table 4. TABLE 4 The results presented in Table 4 indicate that the incorporation of ethylene oxide during the preparation of the polymer backbone of the casting polyol shows that it has no possible effect on the reactivity, while the polyols used in the prepolymer formulations in where the polyol fully reacts, however the results in the molded foam require considerably little force to crush, while maintaining the foam's venting stability.

Example 18-21 In a manner similar to Examples 16 and 17, blown with water, prepolymer-derived foams were prepared from a prepolymer consisting of the isocyanate-terminated reaction product of 75 parts of the base polyol, 25 parts of the polyol and 42 parts of a 80/20 mixture of TDI / MDI. The prepolymer was thoroughly mixed with 0.25 parts of NIAX® catalyst to the amine containing 3.5 parts of water. The properties of the base polyol and the properties of the foam are given in Table 5 below.

TABLE 5 The results in Table 5 illustrate how the distribution of ethylene oxide can be used to alter foam processing. In Examples 18-20, altering the percentage of oxide of ethylene in the main chain and the results in the tip with considerable variations in the crushing force. All the foams had good quality. Particularly noteworthy is the low value of the crushing force of Example 18.

Example 22 and Comparative Examples C15 and C16 Three polyols were prepared for use in one shot molded foams. The # major chain of Example 22 was prepared using a DMC catalyst and an associated feed of ethylene oxide and propylene oxide. Then a polyoxyethylene coating was added using KOH catalysis, while the DMC catalysts are not effective in polymerizing all ethylene oxide in an acceptable manner. The polyol of Comparative Example C15 was prepared in a similar manner, but did not contain random EO in the DMC catalyzed polymer backbone. The polyol of Comparative Example C16 was a KOH catalyzed polyol conventionally, the main chain and the coating. Each 75 parts of base polyol was mixed with 25 parts of polyol polymer, 4. 25 parts of water (swelling agent), 1.5 parts of diethylamine, 0.1 parts of NIAX® Al amine catalysts and 0.3 parts of NIAX® A-33, and 1.0 parts of DC 5043 silicone surfactant, and reacted with TDI with an index of 105 in the closed mold. The base polyol composition and the results of the molded foam are presented in Table 6.

TABLE 6 The results presented in Table 6 illustrate the substantial differences between the purpose of the polyols of the invention and the comparative polyols. In one-shot systems, different prepolymer systems, the reactivity of the polyol is important, and for this reason, polyols with high primary hydroxyl content are required. Past attempts to prepare the DMC-catalyzed polyols have been made after their KOH-catalyzed analogs, for example, the backbones were homopolyproxypropylene polyols which were then coated with EO in the presence of KOH to provide a polyol with high primary hydroxyl content coated with polyoxyethylene. However, as illustrated in Table 6, these polyols are not suitable for molded foams. Although the reactivity is acceptable, the DMC catalyzed polyol, which contains a homopolyxypropylene backbone (Comparative Example C15) is weakened to produce acceptable foam. Although the values of the crushing force appear to be desirably low, the cell size is very granular, with approximately 1 cm cells of size that has formed. Thus, the values of the crushing force are those expected for a product that looks like a sponge instead of the foam with fine cells, with uniformity required. Adding a portion of ethylene oxide during the preparation of the main chain catalyzed with DMC produces a foam formed with fine cells, normal.

The polyols of the subject invention can be used to prepare the polyol polymers that do not contribute to the loss of strength or excessive stabilization of the foam. These polyol polymers are prepared by the polymerization in itself by one or more vinyl monomers is a base polyol which is a polyol of the object of the invention. Vinyl polymerization in itself is a well-known process, and can, for example, employ developed stabilizers or stabilizing precursors. Preferred vinyl monomers are styrene, acrylonitrile, methyl methacrylate, vinylidene chloride, and the like. The contents of solids as prepared preferably in the range from 30 percent by weight to 50 percent by weight or greater.

By the terms "improved processing freedom" and "increased freedom of processing" and the like terms mean that the polyol in question exhibits the development in the superior supercritical foam test exhibited by the homopolyproxypropylene analogue, catalyzed with DMC , with a settlement percent less than 35%, preferably less than 25%, and more preferably has the same or lower degree of settlement than a catalyzed polyol with a comparative base when it is intended for use in the foam formulations in plate.

By the term "major" or "minor" if used herein, it means 50% or more and less than 50%, respectively, unless otherwise indicated. The terms "initiator" and "starter" are used here interchangeably and have the same meaning unless otherwise specified. By the term "a" or "in the terms here means one or more unless the language clearly indicate otherwise. By the term "unitary" it is applied to the EO composition of the bicompositional molecule populations and that means that the polybial multiblock and the polyether monoblock both contain a block having an EO / PO ratio or co-oromer / PO ratio. Modifies the stabilization which are identical by virtue of being polymerized in the same vessel with the same alkylene oxide feed. The molecular weights and equivalent weights herein are average molecular numbers and equivalent weights unless otherwise indicated. The term "white ethylene oxide content" and similar terms mean the total percentage on a weight basis of the oxyethylene content of the polyol produced.

Any modality described or claimed herein may be used for the exclusion of any modality or feature is not discussed and / or claimed, provided that the necessary features of the invention are present. Necessarily the features of the invention include performing oxypropylation in the presence of ethylene oxide minimally 95% and preferably 97% of the oxyalkylation catalyzed with DMC; a minimum oxyethylene content of 1.5 weight percent relative to the weight of the polyol exclusive of any coating added in the presence of an effective coating catalyst with respect to the polyoxypropylene coatings and not more than 5 weight percent of a polyoxypropylene coating prepared in the presence of a catalyst; and the presence of the multiple block structure and / or a bicompositional population.

Having now fully described the invention, it will be apparent to a person with ordinary knowledge in the art that changes and modifications may be made thereto without departing from the perspective or scope of the invention as set forth herein.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (10)

1. A polyol catalyzed with muliblock DMC, characterized in that it comprises units comprising: i) an internal block comprising oxypropylene units and copolymerized comonomer units wherein the internal block can be prepared by oxyalkylating one or more initiators, in the presence of a catalyst DMC or a catalyst without DMC, with a first oxyalkylation mixture comprising propylene oxide and at least one copolymerizable comonomer within; and ii) at least one external block comprising oxypropylene units and copolymerized comonomer units within wherein the outer block can be prepared by oxyalkylation in the presence of the DMC catalyst i) with a second oxyalkylation mixture comprising propylene oxide and minus a comonomer that can be copolymerized within it: • the concentration and the nature of at least one comonomer in the second mixture differs from the first mixture; and • at least 95% of the polymerizable oxypropylene units are randomly copolymerized into units of the comonomer in the internal block and the external blocks; Y • the content of copolymerizable comonomer in the external block is lower than in the internal block.

2. A bicompositional DMC catalyzed polyol, characterized in that it comprises: a) a first multi-block polyol, the polyol has a first block comprising: i) a catalyzed oxypropylene-containing block without DMC; or ii) a DMC catalyzed oxypropylene-containing block further comprises copolymerized comonomers selected from the group consisting of ethylene oxide, comonomers that modify the stabilization, and mixtures thereof, with the proviso that when the oxyethylene radicals are present as a comonomer, they are present in an amount greater than 1.5% by weight, and at least one second, external block comprising: iii) a mixture catalyzed with DMC of propylene oxide and an amount of effective stabilization of one or more of the ethylene oxide and a comonomer that modifies the stabilization; and b) a random polyoxypropylene polyol copolymer having no internal block derived from an oligomeric starter molecule with equivalent greater than 200 Da, and containing a monomer distribution which is the same as the monomer distribution of a) iii).

3. A polyol catalyzed with bicompositional DMC in accordance with the Claim 2, characterized in that the weight ratio of the copolymerized comonomer in the oligomeric initiator to the content of Total copolymerized comonomer is the polyol is at least 0.34.

A polyol catalyzed by bicompositional DMC in accordance with the Claims 2 6 3, characterized in that the oligomeric initiator has an equivalent weight from 200 to 700 Da.

5. A bicompositional DMC catalyzed polyol according to any of Claims 2 or 4, characterized in that the first multi-block polyol comprises from 1 to 60% by weight of the bicompositional polyol.

6. A polyol according to any of the preceding claims, characterized in that from 5 to 40% by weight of the total copolymerized comonomer is located in the internal blocks.

7. A polyol according to any of the preceding claims, characterized in that the comonomer comprises a substituted or unsubstituted C to C20 alkylene oxide, oxetane, methyloxetane, an internal carboxylic ester or copolymerizable internal carboxylic anhydride; or a mixture of these.

8. A process for the preparation of a DMC catalyzed polyol according to any of the preceding claims, characterized in that the process comprises: a) supplying an activated mixture of DMC catalyst / initiator to a reactor; b) polyoxyalkylating the initiator with a mixture of oxyalkylation containing propylene oxide and at least one polymerizable comonomer with it such that the concentration of the comonomer during oxyalkylation is greater than zero for at least 95% of the total oxyalkylation to produce a copolymer of intermediate polyol; c) polyoxyalkylating the intermediate polyol copolymer with a mixture of oxyalkylation containing propylene oxide and at least one polymerizable comonomer with it such that the concentration and / or nature of at least a comonomer in step (c) differs from step (b); d) recovering a polyol wherein the copolymerizable comonomer content is at least 1.5% by weight.

9. A process in accordance with the Claim 8, characterized in that it is a continuous process in which the initial initiator molecules are added continuously or increasingly to the reactor.

10. A process for the preparation of foamed or molded polyurethane foam by means of the reaction of a di- or polyisocyanate with a polyether polyol in the presence of customary additives and incrustation aids, where the process comprises: selecting the minus a portion of the polyol compound a polyol according to any of Claims 1 to 17 and reacting the polyol with a di- or polyisocyanate to produce polyurethane foam in plate or molding.