GB1584864A - Catalyst compositions and their use in the production of polyurethanes - Google Patents

Description

(54) CATALYST COMPOSITIONS AND THEIR USE IN THE PRODUCTION OF POLYURETHANES (71) We, AIR PRODUCTS AND CHEMICALS, INC., a corporation organised and existing under the laws of the State of Delaware, United States of America, of P.O. Box 538, Allentown, Pennsylvania 18105, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the use of catalysts in the production of polyurethanes.

Polyurethanes, which are formed by reacting an isocyanate with a reactive hydrogen providing component, such as a polyol, have been widely used in preparing rigid and flexible foams, castings, adhesives and coatings. Typically, the reaction between the isocyanate and the polyol has been catalyzed by using various components such as amines, e.g. tertiary amines and organometallics, particularly organo tin compounds such as stannous octoate, dibutyl tin laurate, tin ethylhexanoate and so forth. The effectiveness of the catalyst is often measured by the cream time, which is the time required for the isocyanate and polyol syrup to turn from a clear solution to a creamy color; the gel time, which is the time required for polymer particles to form in the syrup; rise time, which is the time required for the syrup to rise to its maximum height; and cure time which is the time to reach a tack-free state.

In some applications for polyurethanes it is desirable to effect reaction in the shortest time possible and, therefore, catalysts having tremendous activity are desired. In some applications, though, as in the molding of intricate parts or large objects, it may be desirable to keep the polyurethane composition in a fluid state for an extended time to permit the composition to completely fill the mold or flow into the cracks and crevices of the mold. Then, once the mold is completely filled, it is desirable to effect polymerization of the polyurethane in the shortest time possible so that the finished parts can be removed and the mold recharged with new materials. In this regard, it is desirable to delay the initial reaction, but after reaction commences then catalyze the polymerization rate. To do this it is necessary to extend the cream time to permit the polyurethane composition to penetrate the cracks and crevices in the mold and to extend the gelation time as the polyurethane foam on gelling becomes intractable and resists molding. However, once the reaction begins, it is desirable to end up with a rise and cure time comparable to those achieved by active catalysts as this will permit greater productivity.

A number of compositions has been suggested in the prior art as being useful as delayed action catalysts (DAC), i.e. those which initially delay and then catalyze the isocyanate-hydroxyl reaction. For example, chelating agents, e.g. betadiketones and beta carbonyls with amine-free organometallics have been used.

Examples of beta-diketones useful as a delayed action catalyst in polyurethane chemistry include 2,4-hexanedione, acetylacetone, 1 ,cyclohexyl- 1,3 butanedione, beta-hydroxy ketones, e.g. beta hydroxy quinoline, I - hydroxy - 9 - fluorenone, and alpha-hydroxy ketones, e.g. benzoin, acetoin and others.

Another example of a delayed action catalyst for the preparation of foamed polyurethane resins discloses that amine salts of dicarboxylic acids and notably the hydroxy tertiary amine salts of oxalic acid are particularly effective in delaying the initial reaction between an isocyanate and hydroxyl group, but after an appropriate lapse of time, they become fully effective and cause the reaction to proceed to completion smoothly, rapidly and efficiently.

It has also been proposed to use quaternary ammonium salts of Mannich bases as a delayed action catalyst for the reaction between an isocyanate and polyol to form polyurethanes. Initially, the quaternary ammonium salt has little catalytic effect, but during the reaction it decomposes to form tertiary amine which can assist in catalyzing the reaction. Quaternary ammonium salts of Mannich bases are prepared by reacting a secondary amine with an aldehyde and a ketone such as cyclohexanone and then reacting the Mannich base with an organic halide to form the quaternary ammonium salt. This catalyst is not particularly effective as a delayed action catalyst when used in conjunction with organometallics.

Some of the problems with delayed action catalysts (DAC) in the past have been that not only did they delay cream time and gelation time, but also they delayed the rise and cure time. As a result, these DAC's resulted in lower production rates.

This invention relates to catalyst compositions containing a particular delayed action catalyst defined below in combination with an organometallic catalyst, and to a method for catalyzing the reaction between an isocyanate and a compound having at least two reactive hydrogen atoms, as determined by the Zerewitinoff method, to form polyurethanes.

The delayed action catalysts have the ability, particularly when combined with organometallics such as organo tin compounds to delay the initiation of the isocyanate reaction thereby extending the cream and gelation time and yet catalyze the reaction to give a cure time which is essentially the same as would be achieved if the organometallic compound were used alone.

Broadly, the delayed action catalyst comprises a compound represented by the formula:

wherein R, and R2 independently are hydrogen (wherein only one of R, and R2 is hydrogen at a time) alkyl or substituted alkyl groups having from I to 15 carbon atoms, or are combined to form a piperidinyl, piperazinyl, morpholino, imidazolo or imidazolino radical or substituted radical thereof; wherein R3 and R4 independently are alkylene groups having from 1-6 atoms, aralkylene groups with the alkylene portion having from 1 to 6 carbon atoms, substituted alkylene or substituted aralkylene groups; wherein R5 is hydrogen, an alkyl group having from I to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group or a substituted derivative of said alkyl, alkenyl or aryl groups, a cycloaliphatic or alkyl substituted cycloaliphatic group with the alkyl portion having from 1 to 6 carbons, or a keto alkyl group with the alkyl portion having from 1-6 carbon atoms; wherein R6 is-hydrogen, or a radical selected from alkyl, phenyl, furfuryl, napthyl, and substituted derivatives of such groups; wherein X is a carboxylic acid group, a quaternary ammonium salt of a carboxylic acid group or an amine salt of a carboxylic acid group; wherein Y is a carboxylic acid group, a nitrile group, a quaternary ammonium salt of a carboxylic acid group, or an amine salt of a carboxylic acid group; wherein m and n independently are 0 or 1; wherein q is 0 or 1; wherein p is 1 or 2; and wherein s is 0 or 1; and wherein p+q+s is 3.

Advantages of the delayed action catalysts used in this invention include: the ability to delay the initial reaction between an isocyanate and an active hydrogen containing compound in the formation of a polyurethane; the ability to form a polyurethane having excellent flow during initial cure by extending the cream and gelation time and yet ending up with a desirable rise and cure time which is comparable to conventional catalyst compositions; the ability to form an organometallic catalyzed polyurethane molding composition having excellent flow during initial stages by extending the cream and gelation time and yet end up with a desirable rise and cure time which often is close to those obtained with conventional catalyst compositions; the ability, by virtue of being thermally sensitive, to generate additional reactive amine for catalyzing and enhancing the cure rate; and the ability to delay amine and organometallic catalyzed urethane polymerization; and the ability to form thermally sensitive tertiary amine salts of tertiary amino acids which decompose on heating to generate additional tertiary amine for catalysis.

Broadly, the delayed action catalysts (DAC's) used in this invention can be visualized as Mannich adducts having at least monofunctionality in terms of tertiary amine and at least monofunctionality and preferably difunctionality in the form of acid, nitrile and amine salt. The Mannich adducts are formed by reacting a primary or secondary amine with an aldehyde and an organic compound having a hydrogen atom sufficiently active to undergo a Mannich condensation and having pendant carboxylic acid or nitrile functionality or functionality which can be subsequently converted to the carboxylic acid or nitrile.

The thus formed tertiary amino acid adduct can be reacted with an amine to form the salt.

In preparing the Mannich type adducts described, suitable amines generally are lower alkyl amines having from 1 to 15 carbon atoms, and preferably 1 to 3 carbon atoms, lower alkanol amines where the alkanol portion has from 2 to 4 carbon atoms; piperidine; piperazine; imidazole; aralkylene amines such as mono and dibenzylamine, e.g. ethylbenzylamine; heterocyclic amines, e.g. morpholine.

The amines can be substituted with various groups, e.g. alkyl, alkoxy, ether and hydroxyl so long as the substituted group does not interfere with the reaction or impart an adverse characteristic to the resulting polyurethane resin. The preferred substituted group is a hydroxyl group as it does not interfere with the reaction and tends to aid the delay in the initial urethane reaction and thereby lengthen the cream time. Those amines best suited for forming the Mannich type are morpholine, diethanolamine, ethanolamine, piperidine and piperazine.

The second component used in forming the Mannich adduct is an aldehyde.

Aldehydes and substituted aldehydes useful in forming the Mannich adducts are well known and can be used here. As taught in the art, these aldehydes must have a pendant aldehyde group which is sufficiently reactive to form the Mannich adduct.

Typically, these aldehydes are activated, as for example, by an unsaturated group in conjugated relationship with the carbonyl aldehyde. Examples of aldehydes best suited for practicing the invention are formaldehyde, benzaldehyde, furfuraldehyde, napthaldehyde, and substituted aldehydes such as nitrobenzaldehyde, nitrofurfural and cyanofurfuraldehyde. For reasons of efficiency and economy, formaldehyde is the preferred aldehyde used in forming the adduct.

The remaining component necessary for forming the Mannich adduct is an organic compound having at least one hydrogen atom sufficiently reactive for undergoing a Mannich reaction. Generally in such compounds, the hydrogen atom is positioned on a methylene group alpha positioned to a carbonyl group such as a ketone, a carboxylic acid ester or an acid group. Further, the organic compound should have a pendant carboxylic acid or nitrile group or a structure, e.g. ketone or ester which permits the formation of a carboxylic acid. The acid then can be neutralized with amine and converted to the salt. Examples of organic compounds having at least one active hydrogen atom, and in some instances, two active hydrogen atoms suited for practicing the invention include disubstituted saturated acids such as malonic acid, benzyl malonic acid, lower alkyl (C1-C3) malonic acids, furfuryl malonic acid, alkenyl malonic acids, e.g. allyl malonic acid; cyanoacetic acid and keto acids, e.g. 2-ketobutyric acid.

The amine salts used in this invention can be formed by reacting the amino acids with amines such as ethanolamine, diethanolamine, triethanolamine, tri-npropanolamine, methylamine, ethylamine, propylamine, benzylamine, triethylamine, or cyclohexylamine. Highly reactive tertiary amines such as bis (dimethylaminoethyl) ether and triethylenediamine can also be used to form the amine salts and these catalysts are particularly effective for enhancing the rate of the urethane reaction. Generally, the less active amines, such as ethanolamine and diethanol amine result in producing a less active catalyst. Because the tertiary amine is tied to the Mannich adduct, though, the cream time is lengthened substantially over that which is obtained by using tertiary amine alone.

Examples of amine salts of Mannich type adducts include: bis - tri - n propanolamine salt of bis(hydroxyethyl)amino methyl malonic acid, diethanolamine salt of hydroxyethylamino methyl malonic acid, monomethylamine salt of bis(hydroxyethyl)amino furfuryl malonic acid, bis - triethylenediamine salt of bis(hydroxyethyl)amino benzyl malonic acid, bis - triethylenediamine salt of morpholino benzyl malonic acid, bis - dimethylamine salt of morpholino methyl malonic acid, methylamine salt of bis(piperidinylmethyl)acetic acid, bis - tri - n propanolamine salt of diglycolamino methyl malonic acid, propanolamine salt of bis(piperidinylmethyl)acetic acid, triethanolamine salt of bis(imidazolo methyl)acetic acid, bis - trimethylamine salt of piperidinyl methyl malonic acid and triethylenediamine salt of morpholino benzyl cyanoacetic acid.

Quaternary ammonium salts of the acid substituted adducts or the amine salts thereof can be formed and used as delayed action catalysts. Generally, the quaternary ammonium functionality detracts from the delayed action of the catalyst vis-a-vis an organometallic catalyst as the acid or nitrile functionality is more effective in tying the metal portion than the quaternary ammonium salt. On the other hand, the increased amine content, which results on decomposition of the quaternary ammonium salt, can enhance the catalytic activity and reduce the rise and cure time. Although a cream time slightly less than the cream time for an organometallic catalyzed polyurethane may be observed for some tertiary amine salts of DAC's, the cream time is substantially longer than if the DAC were not present. For example, a tertiary amine-organometallic catalyzed reaction will have a much shorter cream time than the same urethane composition catalyzed with similar quantities of amine and organometallic, but including a DAC, i.e. the tertiary amino acid. Quaternary ammonium salts can be formed by reacting the acid substituted adducts with amines such as ethanolamine, dimethyl amine and tertiary amines, triethylenediamine, diethylenetriamine, trimethylamine, quinuclidine and a hydroxy substituted tertiary amine such as triethanolamine. The formation of quaternary ammonium salts of the acid Mannich Adducts can also serve a second purpose in that it often enhances the solubility of the delayed action catalyst in the polyurethane syrup as will be explained.

Often where a plurality of acid groups are present and the organo portion of the Mannich adduct or the amine salt thereof is relatively small or negated by the fact that a hydroxyl or other polar group is present, it may be necessary to use a solvent to disperse the delayed action catalyst in the syrup. Virtually any solvent may be used which does not compete with the isocyanate-active hydrogen to form a polyurethane, and which does not impart adverse effects to the resultant polyurethane can be used. Conventional solvents such as glycols, e.g. propylene glycol, ethylene glycol, dipropylene glycol, polar solvents such as dimethyl formamide; ethylene carbonate, amines (which form salts with the acid group) and other solvents are used. Amino-nitrile compositions such as cyanoethyldiethanolamine, which is also a catalyst, can also be used as a solvent.

Solvent selection is well within the skill of those in the art.

The second component used in forming the urethane catalyst of this invention is a conventional organometallic catalyst used for the catalysis of polyurethanes.

Typically, these organometallics have the formula RnM wherein R designates the organo moiety, M represents the metallic moiety and n is an integer sufficient to satisfy the valence of the metal component. Generally, the metals in the organometallic include antimony, tin, lead, manganese, mercury, cobalt, nickel, iron, vanadium or copper. From a commercial point of view, only a few of these metals are used in polyurethane synthesis as they have advantages of cost and they do not affect product quality. For example, iron, although it is effective for catalyzing the isocyanate-hydroxyl reaction, may cause discoloration. Of the metals listed, tin is probably the metal that is used in greatest proportion, and it is preferred in practicing this invention.

The organo portion of the organometallic component is present to provide solubility of the metal in the isocyanate syrup. The solubility of the organometallic should generally be at least about 1 gram per 100 grams of syrup at 500C and organo portions which provide the solubility are operable. Generally, the organo portion is an alkyl group having from 4--15 carbon atoms or an alkoxy group, although cyclic and cycloaliphatic groups can be used. Examples of organometallics suited for practicing this invention include dibutyl tin dilaurate, dibutyl tin diacetate, diethyl tin diacetate, dihexyl tin diacetate, dibutyl tin - di(2 ethyl hexanoate), stannous octoate, tin decanoate, di-N-octyl tin mercaptide, iron acetylacetonate, dioctyl tin oxide, dimethyl tin oxide and titanium acetyl acetonate Representative polyisocyanates suited for producing polyurethanes in practising this invention are the aliphatic and aromatic polyvalent isocyanates.

Examples of aliphatic isocyanates include alkylene diisocyanates such as tri, tetra and hexamethylene diisocyanates; arylene diisocyanates and their alkylation products such as phenylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, di and triisopropyl benzene diisocyanate and triphenylmethane triisocyanates; triesters of isocyanato-phenyltriphosphoric acid; triesters of para-isocyanato phenyl phosphoric acid; aralkyl diisocyanates such as 1 - (isocyanato phenyl-ethyl) isocyanate or xylene diisocyanate.

Suitable reactive Zerewitinoff compounds, e.g. polyols for forming the polyurethanes include aliphatic polyether polyols prepared from the reaction of ethylene or propylene oxides or mixtures thereof with a glycol; glycols such as ethylene glycol, propylene glycol, butylene glycol, tetramethylene glycol, hexamethylene glycol, and triols such as glycerol, trimethylolpropane, trimethylol ethane, and higher polyols such as pentaerythritol, sorbitol, castor oil, polyvinyl alcohol, sucrose, dextrose and methyl glycoside amino polyols made by the condensation of alkylene oxides and alkanol amines such as tetrahydroxyethylenediamine, tetrahydroxypropyl ethylenediamine; other organic compounds having an active hydrogen atom are amines such as.triethanolamine and diethanolamine.

The polyols also can be incorporated into a polymer and'reacted with the isocyanates as in the case of polyesters. A polyester, as is known, is prepared by the reaction between a dicarboxylic acid and a polyol, e.g. a glycol. Examples of conventional dicarboxylic acids suited for manufacturing polyester polyols include succinic, glutaric, adipic, sebacic, phthalic, terephthalic, maleic, fumaric, itaconic and citraconic. Glycols include, ethylene glycol, propylene glycol and butylene glycol.

In the preparation of polyurethanes, conventional additives can be utilized for their desired effect without departing or detracting from the advantageous aspects of the catalysts of this invention. For example, blowing agents such as water or a volatile organic compound such as dichlorodifluoromethane, dichlorofluoromethane, trichloromonofluoromethane, difluorodichloroethane, methylene chloride, carbontetrachloride, butane, or pentane can be used.

Foam stabilizers or surfactants are other additives which can be added for enhancing the retention of gas generated during the polymerization reaction and such stabilizers include silicone block polymers comprising polyalkylene glycol units, n-vinyl pyrrolidone, or n-vinyl pyrrolidone-dibutyl maleic copolymers, e.g. nvinyl pyrrolidone-dibutyl maleate-vinyl acetate copolymer.

In preparing the polyurethanes, the delayed action catalyst is added to the urethane composition in at least a sufficient or effective proportion for enhancing the cure rate of the urethane. Generally the catalyst is used in an amount of from about 0.1 to about 5 parts by weight per 100 parts by weight preferably about 0.5 to 1.5 parts per 100 parts by weight of reactive Zerewitinoff hydrogen compound, e.g. polyol. When less than about 0.1 parts are added to the composition, the catalyst is not present in sufficient proportion to substantially influence the cure rate of the polyurethane. When more than about 3.5 parts of the delayed action catalyst are added to the urethane composition, too much amine may be introduced and amine odor may be observed. For reasons of economy, the catalyst concentration is preferably from about 0.5 to about 1.5 parts by weight.

Generally, organometallic components are included in polyurethane manufacture in a proportion of from about 0.005 to about 0.5, and preferably 0.01 to 0.2 parts by weight per 100 parts by weight of active Zerewitinoff hydrogen compound. Variations within this broad range are found particularly when high and low density polyurethanes are prepared and these variations are observed in practicing this invention. Generally, in formulating high density polyurethanes, from about 0.03 to about 0.07 parts by weight organometallic, e.g. organo tin, compound are used. In formulating low density polyurethanes from about 0.08 to about 0.2 parts by weight organometallic compound are used. Naturally, as the proportion of organometallic compound is increased in the urethane composition, the proportion of the delayed action catalyst should be increased if one wants to delay substantially the urethane reaction or inhibit other adverse effects of the organometallic catalyst. However, the formulator can adjust the concentration of organometallic catalyst and the delayed action catalyst as desired within the above range to achieve desired conditions for his line of products.

In visualizing the delayed action catalyst, and the organometallic catalyst as a catalyst composition for urethane catalysis, approximately from about 0.1 to about 100 parts of delayed action catalyst (DAC) are generally present per part by weight of organometallic catalyst. Preferably, the catalyst composition comprises 0.660 and most preferably from about 2 to about 20 parts by weight of DAC per part by weight of organometallic catalyst. Thus, when the catalyst composition comprising the DAC and organometallic catalyst are combined in suitable proportion for catalyzing the urethane reaction, then both components of the catalyst will be present in the reaction mixture in the desired range to achieve desired results.

When less than about 0.1 part of DAC are included per part of organometallic catalyst, and the catalyst composition is added to the urethane composition, then there generally is insufficient DAC in the urethane composition to counteract the catalyst activity of the organometallic catalyst or adverse effect of the organometallic catalyst. On the other hand, as the proportion of DAC is increased above 20 parts/part organometallic catalyst, the benefits become less distinctive.

When levels above 100 parts/part organometallic catalyst are employed, no significant enhancement of catalytic activity or of other desired features in the urethane composition are observed to warrant the additional expenditure and usage of the catalyst.

The following Examples are provided to illustrate preferred embodiments of this invention and are not intended to restrict the scope thereof. All parts are parts by weight and all percentages are weight percentages, and all temperatures are in "C unless otherwise specified.

Example 1 Bis(morpholinomethyl)acetic acid was prepared conventionally in a flask equipped with a stirrer and reflux condenser by first charging 0.1 moles of malonic acid, 0.2 moles morpholine, and 100 cc water. The contents were warmed to a temperature of about 20"C and then 0.2 moles formaldehyde as a 40 /" aqueous solution were added to the flask and the reaction commenced. When the evolution of carbon dioxide ceased, the water was removed from the reaction mixture by coupling the flask to a vacuum source and heating to a temperature of about 50"C.

The syrupy residue remaining in the flask then was triturated in acetone and the resulting white crystalline solid isolated by filtration. The melting point of the product was about 129--130"C.

Examples 2-12 In the following examples a variety of tertiary amino acids were prepared in accordance with the method of Example I except that the various amines, aldehydes, and acids or nitriles listed and proportions thereof were substituted for the respective components in Example 1. The product produced is set forth in Table I.

TABLE I Exmple amine Aldehyde Acid Amine Product Ex. 2 0.1 m diethanolamine 0.1 m formaldehyde 0.1 m malonic acid - bis(hydroxyethyl)amino methyl malonic acid Ex.3 0.2 mdiethanolamine 0.2 m formaldehyde 0.1 m malonic acid - bis[bis(hydroxyethyl)amino methyl] acetic acid Ex.4 0.1 m diethanolamine 0.1 m furfuraldehyde 0.1 m malonic acid - bis(hydroxyethyl)amino furfuryl malonic acid Ex.5 0.1 m diethanolamine 0.1 m benzaldehyde 0.1 m malonic acid 0.2 m TEDA trithylenediamine salt of bis (hydroxyethyl)amino benzyl malonic acid Ex.6 0.1 m morpholine 0.1 m benzaldehyde 0.1 m malonic acid - morpholino benzyl malonic acid Ex.7 0.2 m piperidine 0.2 m formaldehyde 0.1 m malonic acid - bis(piperidinylmethyl) acetic acid Ex.8 0.2 m methyl piperazine 0.2 m formaldehyde 0.1 m malonic acid - bis(methylpiperazinomethyl) acetic acid Ex.9 0.2 m imidazole 0.2 m formaldehyde 0.1 m malonic acid - bis(imidazolo methyl)acetic acid Ex.10 0.1 m piperidine 0.1 m formaldehyde 0.1 m malonic acid - piperidinyl methyl malonic acid Ex.11 0.1 m morpholine 0.1 m benzaldehyde 0.1 m cyanoacetic 0.1 m TEDA triethylene diamine salt of morpholino benzyl cyanoacetic acid Ex.12 0.2 m morpholine 0.2 m formaldehyde 0.1 m malonic acid - bis(morpholinomethyl)acetic acid Example 13 Bis - (hydroxyethyl)amino benzyl malonic acid was prepared conventionally in a flask equipped with a stirrer and reflux condenser by first charging 0. I mol of malonic acid, 0.1 mol of diethanol amine and 100 cc methanol. The contents were warmed to a temperature of about 20"C and then 0.1 mol benzaldehyde were added to the flask and the reaction commenced. After refluxing the reaction mixture for 1 hour, the methanol was removed from the reaction mixture by coupling the flask to a vacuum source and heating to a temperature of about 50"C.

The residue remaining in the flask then was triturated in acetone and the resulting acid isolated by filtration.

The bis - triethylenediamine salt of the acid was prepared by mixing 0.1 m of the methanolic solution of the acid with 0.2 m triethylene diamine at room temperature (250C) for 30 minutes, after which the methanol was removed under reduced pressure.

Example 14 Morpholino benzyl cyanoacetic acid was prepared in the same manner as the acid of Example 13 except that morpholine was substituted for diethanolamine and cyanoacetic acid for malonic acid. The monotriethylenediamine salt of the cyanoacetic acid adduct was prepared in the same manner as the amine salt of Example 13.

Example 15 Approximately 100 cc of water and 0.2 moles (21.1 grams) of malonic acid and 0.4 mols (27.4 grams) of imidazole were charged to a round bottom flask. Then 0.4 mols formaldehyde as a 35% aqueous solution were added over a period of time to the mixture of water, malonic acid and imidazole. The resulting mixture was stirred for about 36 hours at 250C after which the contents were heated to a temperature of 50"C and the water removed by vacuum. The resulting product was bis (imidazolomethyl)acetic acid.

Example 16 Approximately 100 cc of methanol, 0.1 mols of malonic acid, 0.1 mols of diethanolamine, and 0.1 mols of furfuraldehyde were charged to a round bottom flask. The contents were refluxed for two hours, and then the methanol removed by evacuation. The product obtained was bis - (hydroxyethyl)amino furfuryl malonic acid.

The triethylaminediamine salt of the above product is prepared in the same procedure as the composition in Example 1.

Example 17 Conventional high density rigid polyurethane foams were prepared from the basic formulation below in conventional manner. In preparing these polyurethane foams, the catalyst, comprising an amine or tertiary amino acid (as indicated) or an amine salt of a Mannich adduct (as indicated), and organometallic catalyst (as indicated) and the concentration of each catalyst component were varied to determine the overall effect on the foam for (1) Mondur (Trade Mark) MR Isocyanate is chide 4,4'methylene bisphenylisocyanate having an isocyanate equivalent of about 133, a functionality of about 2.7-2.9 and a viscosity of about 15250 cps.

(2) NIAX (Trade Mark) DAS-361 Polyol is a sucrose/amine polyol having a hydroxyl number of 360.

(3) Thano (Trade Mark) G-400 Polyol is a glycerol polyol having a hydroxyl number of 400.

(4) Polylite (Trade Mark) 34-400 Polyol is an amino polyol having a hydroxyl number of 790.

(5) In the examples to follow where a previous example is given, as the catalyst used but a different amine indicated as a solvent, that amine was used in place of the particular amine in the previous example; TEDA refers to triethylenediamine; DEA refers to diethanolamine; MEA refers to monoethanolamine; EC refers to ethylene carbonate; DPG refers to dipropylene glycol; DMF refers to dimethyl formamide; EG refers to ethylene glycol, PG refers to propylene glycol; T-9 refers to stannous octoate; T-12 refers to dibutyl tin dilaurate; PbAc refers to lead acetate; Co naphthenate refers to cobalt naphthenate; MnA refers to manganese acetate; the catalyst referred to by Ex. corresponds to the product of the Example having the same number; php refers to the total amount of catalyst (including solvent if used) per 100 parts polyol.

The results of the formulation testing is set forth in Tables II through V.

TABLE II High Density Rigid Foam Organo Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec.

TEDA (0.7) (70 /,, PG) 34 81 106 - - T-12(0.04) 44 78 87 TEDA (0.7) (70% PG) Lead Acetate 12 32 43 (0.04) TEDA (0.7) (70% PG) T-12 (0.04) 29 42 49 Ex. 2 (0.5) (neat) T-12 (0.04) 55 98 111 Ex. 2(1.0 (neat) T-12(0.04) 57 104 120 Ex.2(l.5) (neat) T-12(0.04) 57 118 139 Ex. 3 (0.5) (neat) T-12 (0.04) 55 98 111 Ex.3(1.0) (neat) T-12 (0.04) 57 104 120 Ex. 3 (1.5) (neat) T-12 (0.04) 57 118 139 Ex. 3 (0.5) (33% in DPG) T-12 (0.04) 58 95 104 Ex.3(1.0) (33% in DPG) T-12 (0.04) 59 108 124 Ex.4(0.5) (neat) T-12 (0.04) 76 118 138 Ex.4(1.0) (neat) T-12 (0.04) 80 129 150 Ex.4(0.5) (neat) T-12 (0.05) 68 105 117 Ex.4(1.0) (neat) T-12 (0.05) 75 110 128 Ex. 5 (0.5) (neat) - 61 132 176 Ex.5(0.7) (neat) - 53 113 160 Ex.5(1.0) (neat) - 44 93 125 Ex. 5 (0.5) (neat) T-12 (0.03) 48 77 86 Ex. 5(1.0) (neat) T-12 (0.03) 43 69 79 Ex. 5 (0.5) (neat) T-12 (0.04) 46 71 78 Ex.5(1.0) (neat) T-12(0.04) 40 64 72 Ex. 5 (0.5) (neat) T-12 (0.05) 44 63 69 Ex.5(1.0 (neat) T-12 (0.05) 37 61 65 TABLE III High Density Rigid Foam Organo- Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec.

Ex.6 (0.5) (33% in DMF) T-12(0.03) 61 110 132 Ex.6 (0.5) (33% in DMF) T-12(0.04) 59 103 124 Ex.6 (1.0) (33% in DMF) T-12(0.04) 65 122 153 Ex.6 (0.5) (33% in DMF) T-12(0.05) 55 94 110 Ex.2 (0.5) (33% in DPG) T-12(0.04) 58 95 104 Ex.2 (1.0) (33% in DPG) T-12(0.04) 59 108 124 Ex.7 (0.5) (33% in ethylene T-12(0.04) 48 76 86 carbonate) Ex.7 (1.0) (33% in ethylene T-12 (0.04) 41 71 82 carbonate) Ex.8 (0.5) (33% in EG) T-12(0.04) 49 82 91 Ex.8 (1.0) (33% in EG) T-12(0.04) . 49 81 90 Ex.9 (0.5) (33% in ethylene T-12 (0.04) 49 97 114 carbonate) Ex.9 (1.0) (33% in ethylene T-12(0.04) 50 98 116 carbonate) Ex.10(0.5) (33% in ethylene T-12(0.04) 54 102 117 carbonate) Ex. 10(1.0) (33% in ethylene T-12(0.04) 54 121 145 carbonate) TABLE IV High Density Rigid Foam Organo- Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec. ethylene diamine - 60 197 > 6' (0.4) diethanolamine - 68 244 > 6 min.

(0.4) diethylene triamine - 59 228 > 6 min.

(0.4) dibenzyl amine - 52 253 > 6 min.

(0.4) n-butyl amine - 61 244 > 6 min.

(0.4) Ex.6 (0.5) 33% in DMF T-12(0.04) 59 103 124 Ex.6 (1.0) 33% in DMF T-12(0.04) 65 122 153 - - T-12(0.01) 80 147 180 Ex. 11(0.5) (50% DPG) - 75 157 227 Ex.11(1.5) (50% DPG) - 50 107 154 Ex.11(0.5) (50% DPG) T-12(0.01) 53 100 125 Ex.11(1.5) (50% DPG) T-12(0.01) 43 82 105 - - T-12(0.03) 46 82 94 Ex.11(1.5) - T-12(0.03) 33 90 111 Ex. 12(1.0) - T-9 (0.04) 32 78 109 - - T-9 (0.04) 26 54 64 TABLE V High Density Rigid Foam Organo- Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec.

Ex.13(0.5) (neat) - 61 132 176 Ex.13(0.7) (neat) - 53 113 160 Ex.13(1.0 (neat) - 44 93 125 Ex.13(0.5) (neat) T-12(0.03) 48 77 86 Ex. 13(1.0) (neat) T-12(0.03) 43 69 79 Ex. 13(0.5) (neat) T-12(0.04) 46 71 78 Ex. 13(1.0) (neat) T-12(0.04) 40 64 72 Ex. 13(0.5) (neat) T-12(0.05) 44 63 69 Ex. 13(1.0) (neat) T-12(0.05) 37 61 65 Ex.14(0.5) (50% DPG) - 75 157 227 Ex.14(1.5) (50% DPG) - 50 107 154 Ex.14(0.5) (50% DPG) T-12(0.01) 53 100 125 Ex. 14(1.5) (50% DPG) T-12(0.01) 43 82 105 Ex. 14(1.5) (50%DPG) T-12(0.03) 33 90 111 ethylene diamine 60 197 > 6 min.

(0.4) diethanolamine 68 244 > 6 min.

(0.4) diethylenetriamine 59 228 > 6 min.

(0.4) n-butylamine 61 244 > 6 min.

TEDA (0.23) 67% DPG - 34 81 106 - - T-12(0.030 46 82 94 - - T-12(0.04) 44 78 87 - - T-12(0.05) 33 61 68 In reviewing the results from Tables Il-V, it is readily observed that the delayed action catalysts used in this invention act as a delayed action catalyst in that the cream time is extended in virtually every case where the catalyst is added to a tin catalyzed high density polyurethane formulation. Although the tack free or cure time is slightly extended in most cases as compared to an organometallic catalyzed polyurethane composition, the percentage of increase in cream time in the DAC catalyzed polyurethane composition generally is higher than the percentage increase in the tack free or cure time. Also, a formulator may not object to the extended cure time as delayed initiation may be of higher priority.

Delayed action is also shown in the triethylene diamine salts of the tertiary amino acid over a corresponding triethylene diamine-organo tin catalyzed polyurethane composition thus showing the ability of the delayed action catalyst to tie either the amine or tin, or both, during the initial stages of polymerization.

Example 18 Conventional low density rigid polyurethane foam formulations utilizing the components set forth below were prepared in conventional manner. In these polyurethane foams, the catalysts comprising an amino acid and organometallic and the concentration were varied. The basic formulation used for the low density rigid polyurethane foam was as follows: Component Amount, parts Hylene TIC"' 105 RS-6460 Polyol(2) 109 DC193(3) Surfactant 1.5 R1194) Blowing Agent 47 (1) Hylene (Trade Mark) TIC is an undistilled, technical grade of tolylene diisocyanate typically having an isocyanate content of 38.75 to 39.73%, an amine equivalent of 105.5 to 108 and a viscosity at 250C of 15 to 75 cps.

(2) RS-6406 Polyol is a sucrose amine polyol having a hydroxyl number 475.

(3) DC-193 Surfactants are polysiloxane polyoxalkylene block copolymers.

Examples are shown in U.S. Pat. 2,834,748 and 2,917,480.

(4) R-ll Blowing Agent is trichloromonofluoromethane.

(5) See paragraph (5) of Example 17 for an explanation of additional terms.

The results of the formulation testing is set forth in Table VI thru VIII.

TABLE VI Low Density Rigid Foam Organo- Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec. Friability Shrinkage N,N-dimethylcyclo- - - 18 77 168 None None hexaylamine(0.8) - - T-12(0.08) 36 107 184 Moderate-Severe Moderate-Severe - - T-12(0.10) 32 91 137 Moderate Moderate - - T-12(0.15) 27 78 111 Slight-Moderate Slight-Moderate - - T-12(0.20) 23 57 93 Slight Slight N-dimethylcyclo- - T-12(0.06) 15 68 105 None None hexylamine (0.8) - T-12(0.08) 14 55 94 None None Ex.2"(0.5) (64% in DPG) T-12(0.08) 40 137 241 Very slight Very slight Ex.2 (1.0) (64% in DPG) T-12(0.08) 38 140 251 None None Ex.2 (0.5) (64% in DPG) T-12(0.1) 39 133 216 None None Ex.2 (1.0 (64% in DPG) T-12(0.1) 36 136 220 None None Ex.2 (1.0 (64% in DPG) T-12(0.2) 31 106 155 None None Ex.2 (1.5) (64% in DPG) T-12(0.3) 28 85 136 None None Ex.5 (0.5) (neat) T-12(0.08) 30 80 98 Very slight Very slight Ex.5 (1.0 (neat) T-12(0.08) 27 71 89 None None Ex.5 (0.5) (nat) T-12(0.1) 28 78 96 None None Ex.5 (1.0) (neat) T-12(0.1) 24 62 85 None None Ex.5 (1.0) (neat) T-12(0.2) 20 53 77 None None Ex.5 (1.5) (neat) T-12(0.3) 15 41 58 None None Ex.5 (1.0) (neat) - 33 98 151 Very slight None Ex.12(0.5) (33% in chloro- T-12(0.08) 28 138 218 Very silight Very slight acetonitrile) Ex.12(1.0 (33% in chloro- T-12(0.08) 32 123 193 None Slight acetonitrile) TABLE VII Low Density Rigid Foam Organo- Cream Tack Free Catalyst metallic Time Gel Time Cure Time php Solvent php Sec. Sec. Sec. Shrinkage Friability Ex.4(0.5) - T-12(0.08) 43 128 220 moderate-severe slight-moderate Ex.4(1.0) - T-12(0.2) 35 85 121 slight slight-moderate Ex.4(1.5) - T-12(0.1) 41 121 178 moderate slight-moderate Ex.4(1.5) - T-12(0.3) 31 79 115 slight slight-moderate Ex.8(0.5) (33% in EC) T-12(0.08) 24 106 183 OK OK Ex.8(1.0) (33% IN EC) T-12(0.08) 24 110 186 OK OK TABLE VIII Low Density Rigid Foam Cream Gel Tack Free Catalyst Organometallic Time Time Cure Time php Solvent php Sec. Sec. Sec. Shrinkage Friability dimethylcyclohexyl- - 18 77 168 none none amine (0.8) TEDA(0.17) 67% DPG - 30 106 164 slight moderate TEDA(0.43) 67% DPG - 11 50 75 none none - T-12(0.2) 38 70 98 moderate moderate bis-DEA salt of T-12(0.08) 39 117 230 slight-moderate very slight malonci acid (0.05) " (1.0) T-12(0.08) 36 123 237 moderate slight " (0.5) T-12(0.1) 37 115 241 moderate slight " (1.0) T-12(0.1) 34 117 245 moderate-severe slight mono DEA salt of T-12(0.08) 36 114 221 slight-moderate very slight malonic acid (0.5) " (1.0) T-12(0.08) 34 133 259 svere slight " (0.5) T-12(0.1) 36 103 187 slight-moderate slight " (1.0) T-12(0.1) 33 111 208 slight slight In analyzing the data for the low density polyurethane formulations, it is noted that the DAC's by themselves act as a delayed action catalyst, and to some extent, act to delay the initial catalytic effect of the tin catalyst. Although they also delay the overall reaction time, they do provide benefits in that there is a little odor (musty to slight) as compared to conventional amine catalyzed polyurethane compositions and the friability and shrinkage is generally better than non-DAC containing urethanes.

It is believed that the poor shrinkage of those low density polyurethanes catalyzed by a DAC dissolved in DMF is due to the solvent itself. As is known, DMF is a solvent for the polyurethane and its presence can lead to breakdown of the structure. This is not a problem in high density formulations.

Example 19 Conventional semi-flexible polyurethane foam formulations were prepared from the components listed below in conventional manner. In these polyurethane foam formulations, the catalyst comprising an aminoacid and organometallic and the concentrations were varied as indicated and the foams evaluated.

Amount Component parts by weight PAPI 901 Isocyanate(1 34 NIAX 34-28 Polyol'2' 50 TPE-4542 polyol(3 30 SA-1874 Polyol'4' 15.0 P-355 Polyol(5 5.0 Water 1.0 CaCO3 60 R-l IB Blowing Agent 4.0 Carbon Black 1.0 '''PAPI (Trade Mark)--901 Isocyanate is crude 4,4'methylenebisphenylisocyanate which has an isocyanate equivalent of about 132 and a functionality of about 2.2.

'21NIAX-34-28 polyol is a polymer polyol having a molecular weight of 5000, approximately 75% primary hydroxy groups, and a hydroxyl number of about 77.2.

'3'TPE-4542 polyol is a triol having a molecular weight of about 4500 and a hydroxyl number of about 37.5.

4SA-1874 polyol is a cross-linking agent having a hydroxyl number of about 450. It is primarily used as a cross-linking agent.

'5'P-355 polyol is an amine-based tetrol having a hydroxyl number of about 450.

It is primarily used as a cross-linking agent.

When the above semi-flexible polyurethane formulation was catalyzed with 0.1 parts bis(2 - dimethylamino ethyl)ether (control) and 0.05 parts T-12 per 100 parts polyol, a cream time of 22 seconds, a gel time of 85 seconds and a cure time of 135 seconds was recorded. When the same formulation was catalyzed with 0.1 parts of Example 1 catalyst, and 0.07 parts T- 12 a cream time of 34 seconds, a gel time of 98 seconds and a cure time of 135 seconds was recorded. When the same polyurethane formulation was catalyzed with 0.33 parts of Example 10 catalyst, and 0.09 parts of T-12, a cream time of 32 seconds, a gel time of 101 seconds, and a cure time of 136 seconds was recorded.

The results show that the bis(morpholino methyl)acetic acid (Example 1) and the piperidino-methyl malonic acid (Example 10) catalysts are effective as a delayed action catalyst. Extended cream times were reported, but the cure time for the formulations were essentially the same as the control. What is surprising is that the level of tin in the formulation, even though substantially higher than the control, did not result in a shorter cream time than the control.

Example 20 Conventional microcellular polyurethane foam formulations were prepared in the usual manner by mixing 87 parts of CP-4701 polyol, 13 parts of 1,4-butanediol, 1.00 parts of L-5303 Silicone Surfactant and 0.30 parts of water to form a polyol premix.

Then the tertiary amino acid (DAC) and organometallic catalyst were added and the type and concentration of each was varied as indicated.

After the catalysts were blended with the premix, 50 parts Mondur MR isocyanate were added to the premix and the resulting syrup poured into a container and evaluated as indicated in Tables IX and X. Terms used in the table correspond to Example 17, paragraph (5) for the high density formulations.

In addition: (1)CP-4701 Polyol-is a polyol made from glycerin and propylene and ethylene oxides and is marketed by the Dow Chemical Company, and '2'L-5303 Silicone-is a surfactant supplied by Union Carbide Corporation.

TABLE IX Microcellular Foam Organo- Cream Gel Tack Free Catalyst metallic Time Time Cure Time php Solvent php Sec. Sec. Sec.

TEDA (0.6) (66.6 /" PG) T-12 (0.03) 27 36 49 - (66.6% PG) T-12(0.2) 28 39 54 50 EG Ex.12(1.0 (33% in) T-12(0.2) 39 52 65 50 acetonitrile 50 EG Ex.12(1.0) (33% in) T-12(0.3) 34 42 51 50 acetonitrile - - T-12(0.3) 22 29 36 Ex.11(1.0 (50% DPG) - 272 400 600 Ex. 11(2.0) (50% DPG) 155 255 320 Ex.11(0.5) (50% DPG) T-12(0.04) 81 100 125 Ex.11(1.0) (50% DPG) T-12(0.04) 72 90 110 Ex.11(2.0) (50% DPG) T-12(0.04) 71 90 105 - - T-12(0.04) 360+ - TEDA (0.6) (67% DPG) T-12 (0.03) 40 52 68 TABLE X Microcellular Foam Tack Free Catalyst Organometallic Cream Time Gel Time Cure Time php Solvent php Sec. Sec. Sec.

TEDA(0.2) (66.6% DPG) T-12(0.03) 27 36 49 - T-12(0.25) 30 35 43 Ex.14(1.0) (50% DPG) - 272 400 600 Ex.14(2.0) (50% DPG) - 155 255 320 Ex.14(0.5) (50% DPG) T-12(0.04) 81 100 125 Ex.14(1.0) (50% DPG) T-12(0.04) 72 90 110 Ex. 14(2.0) (50 / DPG) T-12 (0.04) 71 90 105 - - T-12 (0.04) 360+ - The results for the microcellular formulation in Tables IX and X show that the DAC is effective for delaying the cream time of tertiary amine-tin catalyzed formulations and high tin catalyzed formulations. On the other hand, the DAC is more reactive than low tin catalyzed formulations.

Claims (19)

WHAT WE CLAIM IS:-

1. In a process for polymerizing a urethane forming composition comprising an organopolyisocyanate and an organic compound having at least two reactive hydrogen atoms as determined by the Zerewitinoff method in the presence of a delayed action catalyst and an organometallic catalyst, the improvement which comprises utilizing as the delayed action catalyst a compound represented by the formula:

wherein in the formula R, and R2 independently are hydrogen (wherein only one of R, or R2 is hydrogen at a time), alkyl or substituted alkyl groups having from 1 to 15 carbon atoms, or are combined to form a piperidinyl, piperazinyl, morpholino, imidazolo or imidazolino radical or substituted radical thereof; wherein R3 and R4 independently are alkylene groups having from 1-6 atoms, aralkylene groups with the alkylene portion having from 1 to 6 carbon atoms, substituted alkylene or substituted aralkylene groups; wherein R is hydrogen, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group or a substituted derivative of said alkyl, alkenyl or aryl groups, a cycloaliphatic or alkyl substituted cycloaliphatic group with the alkyl portion having from I to 6 carbons, or a keto alkyl group with the alkyl portion having from 1-6 carbon atoms; wherein R6 is hydrogen, or a radical selected from alkyl, phenyl, furfuryl, naphthyl, and substituted derivatives of such groups; wherein X is a carboxylic acid group, a quaternary ammonium salt of a carboxylic acid group, or an amine salt of a carboxylic acid group; wherein Y is a carboxylic acid group, a nitrile group, a quaternary ammonium salt of carboxylic acid group, or an amine salt of a carboxylic acid group; wherein m and n are 0 or 1; wherein q is 0 or 1; wherein p is 1 or 2; wherein s is 0 or 1; and wherein p+q+s is 3.

2. The process of Claim 1, wherein said delayed action catalyst is present in a proportion of from 0.1 to 5 parts by weight per 100 parts by weight of the organic compound having at least two active hydrogen atoms.

3. The process of Claim 1 or 2, wherein said organic compound is a polyol.

4. The process of Claim 3, wherein from 0.005 to 0.5 parts by weight of an organometallic catalyst per 100 parts by weight of polyol are included.

5. The process of Claim 1, 2, 3 or 4, wherein the organometallic catalyst is an organo tin compound.

6. The process of any preceding claim, wherein s in the formula is 1.

7. The process of Claim 6, wherein Yin the formula is a carboxylic acid group.

8. The process of any preceding claim, wherein Rl and R2 in the formula are selected from alkanol groups having from 2 to 4 carbon atoms, and alkyl groups having from 1 to 3 carbon atoms, or are combined to form a morpholino, imidazolo, or piperidinyl group.

9. The process of any preceding claim, wherein n and m in the formula are 0.

10. The process of any preceding claim, wherein R6 in the formula is hydrogen or a phenyl group.

11. A catalyst composition suitable for catalyzing the reaction between an organic polyisocyanate and an organic compound having at least two sufficiently reactive hydrogen atoms for forming a polyurethane which comprises: a delayed action catalyst of the formula given in Claim 1, and an organometallic catalyst, with the delayed action catalyst of the formula being present in a proportion of from 0.1 to 100 parts by weight per part by weight of the organometallic catalysis.

12. The catalyst composition of Claim 11, wherein the delayed action catalyst is present in a proportion of from 2 to 20 parts by weight per part by weight of organometallic catalyst.

13. The catalyst composition of Claim Il, wherein X and Y are carboxylic acid groups and s is 1, m and n are 0, R5 is hydrogen and q is 1.

14. The catalyst composition of Claim 11, wherein R, and R2 are selected from alkyl groups having from 1 to 3 carbon atoms, alkanol groups having from 2 to. 4 carbon atoms, or are combined to form a morpholino, piperidinyl or imidazolo radical, and R6 is selected from hydrogen, phenyl and furfuryl radicals.

15. The catalyst composition of Claim 11 wherein the organometallic catalyst is an organo tin compound.

16. The catalyst composition of Claim 15 wherein X and Y are triethylene diamine salts of carboxylic acid groups.

17. A catalyst composition as claimed in claim 11, substantially as described in any one of the experiments set out in any one of Examples 17 to 20.

18. A process for polymerising a urethane forming composition as claimed in claim 1, substantially as described in any one of the experiments set out in any one of the foregoing Examples 17 to 20.

19. A polyurethane composition, whenever produced by the process claimed in any one of claims 1 to 10 and 18.