GB1561618A

GB1561618A - Polyurethane formation using high tertiary amine content catalysts

Info

Publication number: GB1561618A
Application number: GB2363578A
Authority: GB
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1976-10-18
Filing date: 1977-08-10
Publication date: 1980-02-27
Also published as: FR2367734B1; BR7706913A; GB1561617A; JPS5350110A; JPS5630340B2; FR2367734A1

Description

PATENT SPECIFICATION ( 11) 1 561 618

> ( 21) Application No 23635/78 ( 22) Filed 10 Aug 1977 ( 62) Divided out of No 1561617 ( 31) Convention Application No 733548 ( 32) Filed 18 Oct 1976 CD ( 31) Convention Application No 740991 ( 32) Filed 11 Nov 1976 ( 31) Convention Application No 746577 ( 32) Filed 1 Dec 1976 in ( 33) United States of America (US) ( 44) Complete Specification published 27 Feb: 1980 ( 51) INT CL 3 CO 8 G 18/18 ( 52) Index at acceptance C 3 R 32 BIB 32 B 1 X 32 B 2 A 2 32 B 3 B 32 D 10 32 DIIA 32 D 1 IC 32 D 16 A 32 D 16 B 32 D 16 C 32 D 16 D 32 D 1 32 D 6 A 32 D 6 C 32 D 6 D 32 D 6 J 32 D 6 K 32 D 6 M 32 D 9 B 1 32 D 9 BX 32 D 9 C 32 E 1 32 E 4 32 Gl Y 32 G 2 Y 32 H 10 32 H 1 32 H 2 32 H 5 B 2 32 H 5 BY 32 H 6 A 32 H 6 C 32 H 6 Y 32 H 8 32 H 9 A 32 J 2 C 32 J 2 E 32 J 2 F 32 J 2 Y 32 KD 32 PSA 2 32 P 5 AY C 2 C 20 Y 287288 30 Y 323 32 Y 456 45 Y 607 640 771 814 816 AA NW ( 54) POLYURETHANE FORMATION USING HIGH TERTIARY AMINE CONTENT CATALYSTS ( 71) We, TEXACO DEVELOPMENT CORPORATION, a corporation organised and existing under the laws of the State of Delaware, United States of America, of 135 East 42nd Street, New York, New York 10017, 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 5

described in and by the following statement:-

This invention relates to polyurethane formation using certain amines as urethane catalysts.

Catalysts are used to prepare polyurethanes by the reaction of a polyisocyanate, a polyol and perhaps other ingredients The catalyst is employed to 10 promote at least two, and sometimes three, major reactions that must proceed simultaneously and competitively at balanced rates during the process, in order to provide polyurethanes with the desired physical characteristics One reaction is a chain extending isocyanate/hydroxyl reaction, by which a hydroxylcontaining molecule is reacted with an isocyanate-containing molecule to form a urethane 15 This increases the viscosity of the mixture and provides a polyurethane that contains secondary nitrogen atoms in the urethane groups A second reaction is a cross-linking isocyanate/urethane reaction, by which an isocyanatecontaining molecule reacts with a urethane group containing a secondary nitrogen atom The third reaction which may be involved is an isocyanate/water reaction by which an 20 isocyanate-terminated molecule is extended and by which carbon dioxide is generated to blow, or to assist in the blowing of, a foam This third reaction is not essential if an extraneous blowing agent, such as halogenated, liquid hydrocarbon, or carbon dioxide, is employed, but is essential if all or even a part of the gas for foam generation is to be generated by this in-situ reaction (e g in the preparation of 25 "one-shot" flexible polyurethane foams).

The reactions must proceed simultaneously at optimum balanced rates relative to each other in order to provide a good foam structure If carbon dioxide evolution is too rapid in comparison with chain extension, the foam will collapse If the chain extension is too rapid in comparison with carbon dioxide evolution, foam 30 rise will be restricted, resulting in a high density foam with a high percentage of poorly defined cells The foam will not be stable in the absence of adequate crosslinking.

It has long been known that tertiary amines, such as trimethylamine and triethylamine are effective for catalyzing the second crosslinking reaction Other 35 typical tertiary amines are set forth in U S Patents No 3,925,268; 3,127, 436; and 3,243,389; and in German Offenlegungsschrifts 2,354,952 and 2,259,980 Some of the tertiary amines are effective for catalyzing the third, water/isocyanate reaction for carbon dioxide evolution Tertiary amines are, however, only partially effective as catalysts for the first chain extension reaction To overcome this problem, the so-called "prepolymer" technique has been developed, wherein a hydroxycontaining polyol component is partially reacted with the isocyanate component in 5 order to provide a liquid prepolymer containing free isocyanate groups This prepolymer is then reacted with additional polyol in the presence of a tertiary amine to provide a foam This method is still commonly employed in preparing rigid urethane foams, but has proven less satisfactory for the production of flexible urethane foams 10 For flexible foams, a one-step or "one-shot" process has been developed, wherein a tertiary amine, such as triethylenediamine, is employed in conjunction with an organic tin compound Triethylenediamine is particularly active for promoting the water/isocyanate reaction, and the tin compound is particularly active in synergenistic combination with the triethylenediamine for promoting the 15 chain extension reaction Even here, however, the results obtained leave much to be desired Triethylenediamine is a solid, and must be dissolved before use to avoid processing difficulties Also, triethylenediamine and other of the prior art amines can impart a strong amine odour to the polyurethane foam.

In addition to these problems of odour and handling, other tertiary amines 20 have still further defects For example, in some instances the compounds are relatively volatile, leading to obvious safety problems In addition, some catalysts of this type do not provide sufficient delay in foaming, which delay is particularly desirable in moulding applications to allow sufficient time to place the preform mix in the mould Other catalysts, while meeting specifications in this area, do not yield 25 foams with a desirable tack-free time.

Lastly, while certain tertiary amines do not have the defects mentioned above, they nevertheless do not have a sufficiently high tertiary amine content It is believed that the higher the tertiary amine content, the more rapid the catalytic activity 30 Our co-pending British Patent Application No 33618/77 Serial 1,561,617 provides a compound of the formula /N CH 2 CH 2 CH 2 N-R 1 (I) R 2 wherein R is alkyl 35 R' is a group of the formula -CH 2 CHR 2-Y, -CH 2 OR 3 or CHR' -N CH 2 CH 2 CH 2 N R 2 is hydrogen, alkyl, aryl, substituted aryl, alkaryl, substituted alkaryl, aralkyl or substituted aralkyl, R 3 is hydrogen or alkyl; R 4 is hydrogen, alkyl, aryl or substituted aryl; and Y is -OH, -CN, -CONR, -CO 2 R 4, or COR 4 40 The present invention provides a method for producing a polyurethane which comprises reacting an organic polyisocyanate with an organic polyester polyol or polyether polyol in the presence of a catalyst which is a compound of formula (I) in which R has the meaning given above, and in which R' has the meaning given above or is alkyl 45 One preferred group of compounds has the formula R N CH 2,CH 2 CH 2 NCH 2 CHR 2 -Y (I) R/ z wherein Y is -CN, -CONR 2, -CO 2 R 4 or COR 4 and R, R 2 and R 4 have the meanings given above Preferred compounds of this class are those in which R is so 50 methyl, in which Y is -CN and R 2 is hydrogen, and in which Y is CONH 2 50 Specific preferred compounds are N-cyanoethyl-N,N-bis-(dimethylamino propyl) amine and 3-lbis-(dimethylaminopropyl) amino 1 propionamide.

1,561,618 A second preferred group of compounds has the formula R R" /N CH 2 CHCH 2 C, i R)Z -CC 2 -N-CHR -N CH 2 CH 2 CH 2 N\j R 2 JI, wherein R is alkyl and R 4 is hydrogen, alkyl or aryl, for instance, bislbis-( 3dimethylaminopropyl)aminol methane.

A third preferred group of compounds has the formula 5 R\R N CH 2 CH 2 CH 2 -N CH 20 R OIV) R 2 wherein R is alkyl and R 3 is hydrogen or alkyl, for instance, lbis-( 3dimethylaminopropyl)amino methyll-methyl ether.

A fourth preferred group of compounds has the formula R 1 N -CH 2 CH 2 CH 2 INCH 2 CHR 2 _ OH ('V) 10 R/ 2 wherein R and R 2 have the meanings given above, for instance, bis-( 3dimethylaminopropyl) ( 2-hydroxypropyl) amine and bis-( 3dimethylaminopropyl) ( 2-hydroxyethyl) amine.

All these compounds of formulae II, III, IV and V are described and claimed in our co-pending British Patent Application No 33618/77 Serial No 1561617 The 15 compounds of formula (I) in which R' is alkyl are believed to be known compounds.

The compounds set out above may be prepared by a wide variety of synthetic techniques Preferably, however, they are prepared by first making a bis(dialkylaminopropyl)-amine, (hereinafter referred to as "the bisamine") which 20 may itself be prepared by a variety of known techniques One excellent mode of preparation involves a reaction of a dialkylamine, such as dimethylamine, with acrylonitrile, followed by hydrogenation of the resultant condensate to produce dimethylaminopropylamine In producing dimethylaminopropylamine, one also produces the bis-dimethylaminopropylamine compound, which may be removed 25 from the monomolecule by conventional means such as distillation and the like.

The bis-amine then readily forms the compounds of formula (II) by reacting with a variety of monomers of the type CH 2 =CHR 2 Y where R 2 and Y have the meaning given above Typical reactants of this type include acrylamide, acrylonitrile, acrylic acid, and alkyl or aryl esters thereof, N,Ndisubstituted 30 acrylamide derivatives, and vinylketones such as methyl vinyl ketone.

Most preferred compounds are those where R in the above formulae is methyl.

Thus, greatly preferred compositions have the formula l(CH 3)2 NCH 2 CH 2 CH 2 l 2 NX where 35 X=I CH 2 CH 2 CN 2 CH 2 CH 2 CONH 3 CH 2 CH 2 CO 2 CH 3 4 CH 2 CH 2 CHO 5 CH 2 CH 2 CO 2 H 40 6 CH 2 CH 2 COCH 3 7 CH 2 CH(CH 3)Y where Y=CN, CO 2 CH 3, CO 2 H, CONH 2, CHO 8 CH 2 CH 2 CO 2 R 4 45 9 CH 2 CH 2 CO Na CH 2 CHR 2 CO 2 R 4 where R 2 is CH 3 or Et 11 CH 2 CHR 2 CONR 4 50 1,561,618 Compounds of the general formula (III) can be prepared by reacting the bisamine with a variety of aldehydes such as formaldehyde, and others of the type R 4 CHO where R 4 may be hydrogen, alkyl or aryl A greatly preferred reactant is formaldehyde Other preferred aldehydes are those in which R 4 is alkyl such as methyl, ethyl, propyl and butyl Thus R 4, preferably contains 1 to 4 carbon 5 atoms R 4 may also be phenyl or substituted phenyl, such as halosubstituted phenyl.

In order to produce the compounds of formula (IV) one merely reacts the bisamine with formaldehyde (if R 3 is H) or with formaldehyde and an alcohol if R 3 is alkyl The alcohol may be chosen from a wide variety of alkanols, including methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol 10 Another class of materials, which though not believed novel, were nevertheless shown to have excellent urethane catalyst activity, have the formula (I) where R and R' are both alkyl.

Again R' is preferably alkyl having 1 to 4 carbon atoms Materials of this type may be prepared by again reacting the bis-amine with an aldehyde and alcohol 15 combination Here, however, instead of removing excess alcohol by vacuum to prepare compounds of the formula (III), the reaction mixture is hydrogenated over conventional hydrogenation catalysts such as nickel to produce its desired compounds.

Compounds of the general formula (V) can be obtained by reacting the bis 20 amines with a variety of olefin oxides of the formula:

CH 2 CHR 2 0 where R' has the meaning given above Mixtures of olefin oxides may also be employed to form the catalysts used according to the invention.

The olefin oxides which may be employed as reactants, include ethylene oxide, 25 propylene oxide, butylene oxide, hexylene oxide, octylene oxide, dodecene oxide, styrene oxide, and cyclohexene oxide Alkyl, cyano, nitro, halo, and other additional substituents may also be present in the above olefin oxides.

Greatly preferred olefin oxide reactants are alkylene oxides having from 2 to 18 carbon atoms, most preferably, ethylene oxide and propylene oxide 30 The reaction of an olefin oxide, such'as an alkylene oxide, with an aminecontaining reactant as described above is well known to those skilled in the art.

Such a reaction is normally carried out under basic conditions established through the use of alkali metals, their hydroxides, oxides and hydrides and in some cases basic amines The reaction of the bis-amine with olefin oxides is substantially on a 35 mol per mol basis.

The compounds described above possess a number of useful characteristics making them exceptionally attractive as polyurethane catalysts For example, they have a high tertiary amine content and resultant rapid catalytic activity for forming polyurethane foams Tertiary amine content is calculated as the number of tertiary 40 amino groups divided by the molecular weight times 1,000 For example, the acrylonitrile adduct of bis-(dimethylaminopropyl)-amine has a tertiary amine content of 12 48 meq/g In addition, the compounds are also relatively nonvolatile and possess little if any odour There are no solids-handling problems such as are present with such well known polyurethane catalysts as triethylenediamine The 45 catalysts used according to the'invention are particularly desirable in foaming urethanes in that they provide a sufficient delay in the foaming operation to aid in processing Yet the catalysts also give good foams with desirable tackfree times.

As noted above, this delay time is particularly desirable in moulding applications to allow sufficient time to place the prefoam mix in the mould Lastly, the compounds 50 are easily prepared as typically described above, and are relatively inexpensive.

Any aromatic polyisocyanate may be used to prepare polyurethanes using the catalysts according to the invention Typical aromatic polyisocyanates include mphenylene diisocyanate, p-phenylene diisocyanate, polymethylene polyphenylisocyanate, 2,4-toluene diisocyanate, 2,6-tolylene diisocyanate, 55 dianisidine diisocyanate, bitolylene diisocyanate, naphthalene-1,4diisocyanate, and diphenylene-4,4 '-diisocyanate.

Suitable aliphatic-aromatic diisocyanates, include xylylene-1,4diisocyanate, xylylene-1,3-diisocyanate, bis( 4-isocyanatophenyl) methane, bis( 3methyl-4isocyanatophenyl) methane, and 4,4 '-diphenylpropane diisocyanate 60 Greatly preferred aromatic polyisocyanates used in the practice of the invention are 2,4 and 2,6-toluene diisocyanates and methylene-bridged polyphenyl 1,561,618 polyisocvanate mixtures which have a functionality of from 2 to 4 These latter compounds are generally produced by the phosgenation of corresponding methylene bridged polyphenyl polyamines, which are conventionally produced by the reaction of formaldehyde and primary aromatic amines, such as aniline in the presence of hydrochloric acid and/or other acidic catalysts Known processes for 5 preparing the methylene-bridged polyphenyl polyamines and corresponding methylene-bridged polyphenyl polyisocyanates therefrom are described in the literature in many patents, for example U S Patents No 2,683,730; 2,950, 263:

3,012,008: 3,344,162; and 3,362,979.

Most preferred methylene-bridged polyphenyl polyisocyanate mixtures used 10 according to this invention contain from 20 to 100 weight percent of methylene diphenyldiisocyanate isomers, with any remainder being polymethylene polyphenyli diisocyanates having higher functionalities and high molecular weights Typical of these are polyphenyl polyisocyanate mixtures containing 20 to 100 weight percent of methylene diphenyldiisocyanate isomers, of which 20 to 95 weight percent 15 thereof is the 4,4 '-isomer, with the remainder being polymethylene polyphenyl polyisocyanates of higher molecular weight and functionality that have an average functionality of from 2 1 to 3 5 The isocyanate mixtures are known commercially available materials and can be prepared by the process described in U S Patents No 3,362,979 20 The hydroxyl-containing polyol component which reacts with the isocyanate, may suitably be a polyester polyol or a polyether polyol having a hydroxyl number from 700 to 25 or even lower When it is desired to provide a flexible foam, the hydroxyl number is preferably in the range from 25 to 60 For rigid foams, the hydroxyl number is preferably in the range from 350 to 700 Semi-rigid foams of a 25 desired flexibility are provided when the hydroxyl number is intermediate to the ranges just given.

When the polyol is a polyester polyol, it is preferably a resin having a relatively high hydroxyl value and a relatively low acid value made from the reaction of a polycarboxylic acid with a polyhydric alcohol The acid component of the 30 polyester is preferably of the dibasic or higher polybasic type and is usually free of reactive unsaturation, i e ethylenic groups or acetylenic groups The unsaturation, such as occurs in the rings of such aromatic acids as phthalic acid, terephthalic acid, or isophthalic acid, is non-ethylenic and non-reactive Thus, aromatic acids may be employed for the acid component Aliphatic acids, such as succinic acid, 35 adipic acid, sebacic acid, and azelaic acid, may also be employed The alcohol component for the polyester should contain a plurality of hydroxyl groups and is preferably an aliphatic alcohol, such as ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, glycerol, pentaerythritol, trimethylolethane, trimethylolpropane, mannitol, sorbitol, or methyl glueoside Mixtures of two or 40 more of the above identified alcohols may be employed also if desired When a flexible urethane foam is desired, the polyol should preferably have an average functionality of from 2 to 4 and a molecular weight of from 2,000 to 4, 000 For rigid foams, the functionality of the polyol component is preferably from 4 to 7.

When the hydroxyl-containing component is a polyether polyol for use in 45 flexible polyurethane foam, the polyol may be an alkylene oxide adduct of a polyhydric alcohol with a functionality of from 2 to 4 The alkylene oxide may suitably be ethylene oxide, propylene oxide, or 1,2-butylene oxide, or a mixture of some or all of these The polyol will suitably have a molecular weight within the range of from 2000 to 7000 For flexible polyether polyurethane foams, the alkvlene 50 oxide is preferably propylene oxide or a mixture of propylene oxide and ethylene oxide.

For rigid polyether polyurethane foams, the polyol should have a functionality of from 4 to 7 and a molecular weight of from 300 to 1200 Polyols for rigid polyether polyurethane foams may be made in various ways, including the addition 55 of an alkylene oxide as above to a polyhydric alcohol with a functionality of from 4 to 7 These polyols may also be, for example, Mannich condensation products of a phenol, an alkanolamine, and formaldehyde, which Mannich condensation product is then reacted with an alkylene oxide See U S Patent No 3,297, 597.

The amount of hydroxyl-containing polyol compound to be used relative to 60 the isocyanate compound in both polyester and polyether foams normally should be such that the isocyanate groups are present in at least an equivalent amount, and preferably, in slight excess, compared with the free hydroxyl groups Preferably, the ingredients will be proportioned so as to provide from 1 05 to 1 5 mol equivalents of isocyanate groups per mol equivalent of hydroxyl groups However, 65 1,561,618 for certain shock absorbing foams we have found that by using the catalysts of our invention the mole equivalent of isocyanate to hydroxyl groups can be as low as 0 4.

When water is used, the amount of water, based on the hydroxyl compound, is suitably within the range of 0 05 to 5 0 mol per mol equivalent of hydroxy compound 5 It is within the scope of the present invention to utilize an extraneously added inert blowing agent, such as a gas or gas-producing material For example, halogenerated low-boiling hydrocarbons, such as trichloromonofluoromethane and methylene chloride, carbon dioxide, or nitrogen, may be used The inert blowing agent reduces the amount of excess isocyanate and water that is required in 10 preparing flexible urethane foam For a rigid foam, it is preferable to avoid the use of water and to use exclusively the extraneous blowing agent Selection of the proper blowing agent is well within the knowledge of those skilled in the art See, for example, U S Patent No 3,072,082.

The catalysts according to the invention, when used in the preparation of rigid 15 or flexible polyester or polyether polyurethane foams are preferably employed in an amount of from 0 05 to 4 0 weight percent, based on the combined weight of the hydroxyl-containing compound and polyisocyanate, preferably, the amount of catalyst used is 0 1 to 1 0 weight percent.

The catalysts of this invention may be used either alone or in admixture with 20 one or more other catalysts, such as other tertiary amines, or with an organic tin compound or other polyurethane catalysts The organic tin compounds, particularly useful in making flexible foams may suitably be a stannous or stannic compound, such as a stannous salt of a carboxylic acid, a trialkyltin oxide, a dialkvltin dihalide, or a dialkyltin oxide, wherein the organic groups of the organic 25 portion of the tin compound are hydrocarbon groups containing from I to 8 carbon atoms For example, dibutyltin dilaurate, dibutyltin diacetate, diethyltin diacetate, dihexyltin diacetate, di-2-ethylhexyltin oxide, dioctyltin dioxide, stannous octoate, stannous oleate, or a mixture thereof, may be used.

Such other tertiary amines include trialkyl-amines (e g trimethylamine or 30 triethylamine); heterocyclic amines, such as N-alkylmorpholines (e g Nmethylmorpholine or N-ethylmorpholine), 1,4-dimethylpiperazine, or triethylenediamine: or aliphatic polyamines, such as N,N,N'N'-tetramethyl1,3butanediamine.

Conventional formulation ingredients are also employed, for example, foam 35 stabilizers e g silicone oils, or emulsifiers The foam stabilizer may be an organic silane or siloxane For example, compounds may be used having the formula:

R SilO (R 2 Si O)n,-(oxyalkylene)m Rl 3 wherein R is alkyl having I to 4 carbon atoms; N is from 4 to 8; m is from 20 to 40; and the oxyalkylene groups are derived from propylene oxide and/or ethylene 40 oxide See, for example, U S Patent No 3,194,773.

In preparing a flexible foam, the ingredients may be intimately mixed with each other by the so-called "one-shot" method In this instance, water should comprise at least a part (e g 10 % to 100 %) of the blowing agent The foregoing methods are known to those skilled in the art, as illustrated by the following 45 publication: du Pont Foam Bulletin, "Evaluation of Some Polyols in OneShot Resilient Foams", March 22, 1960.

When it is desired to prepare rigid foams, the "one-shot" method or the socalled "quasi-prepolymer method" may be employed, wherein the hydroxylcontaining component preferably contains an average of from 4 to 7 reactive 50 hydroxyl groups per molecule.

In accordance with the "quasi-prepolymer method", a portion of the hydroxyl-containing component is reacted in the absence of a catalyst with the polyisocyanate component in proportions so as to provide from 20 to 40 percent of free isocyanate groups, based on the polyol in the reaction product To prepare a 55 foam, the remaining portion of the polyol is added and the two components are allowed to react in the presence of catalytic systems, such as those discussed above, and other appropriate additives, such as blowing agents, foam stabilizing agents, and fire retardants The blowing agent (e g a halogenated aliphatic hydrocarbon), the foam-stabilizing agent, and the fire retardant may be added to either the 60 prepolymer or remaining polyol, or both, before the mixing of the component.

Urethane elastomers and coatings may be prepared by known techniques wherein a tertiary amine according to this invention is used as a catalyst See, for 1.561,618 example, du Pont Bulletin PB-2, by Remington and Lorenz, entitled "The Chemistry of Urethane Coatings".

The invention will be illustrated further with respect to the following specific examples, which are given by way of illustration and not as limitations on the scope of this invention 5 EXAMPLE I

This example illustrates the utility of the catalysts of Examples I and 2 of our co-pending Application No 33618/77 Serial No 1,561,617 in a flexible urethane formulation A high speed stirrer was used to mix 48 4 parts of toluene diisocyanate with the following blend of components and with the amount of test catalyst 10 indicated below Thanol F-3520 Polyol ') 100 parts Water 4 parts Silicone surfactant I part Tin catalyst 0 6 parts 15 (Thanol is a Registered Trade Mark) The catalysts tested are (A) N-cyanoethyl-N,N-bis(dimethylaminopropyl)amine and (B) 3-lbis-(dimethylaminopropyl)aminol propionamide.

The blended components were poured into a standard mould and allowed to 20 rise The observed properties are recorded below:

Test Amount Cream Time Rise Time Foam Expt Catalyst (parts) (sec) (sec) Appearance 1 A 0 1 12 100 Good 2 A 0 13 83 Good 25 3 B 0 1 13 97 Good 4 B 0 2 85 Good ( 1) A glycerine based polyether polyol of 3500 molecular weight containing o% ethylene oxide available from Jefferson Chemical Co, Houston, Texas.

EXAMPLE 2 30

Here catalyst A was employed in another formulation to produce a packaging foam The formulation was as follows:

Foam Ingredients Parts Thanol SF-2750 m' 100 Water 20 35 Chlorotrifluoromethane blowing agent 35 Silicone surfactant 1 5 Catalyst A 3 0 Dibutyl tin dilaurate 0 02 Mondur MR Polyisocyanate'2) 140 5 40 NCO/OH 0 4 (Thanol SF-2750 is a polyether polyol Mondur is a Registered Trade Mark).

Details Cream time, sec 12 Rise Time, sec 50 45 Gel Time, sec 55 (I) A packaging foam polyol available from Jefferson Chemical Co Inc, Houston, Texas.

( 2) Polyphenylmethylene polyisocyanate of average functionality of 2 7, a product of Mobay Chemical Corp 50 As can be seen above cream, rise and gel times are all acceptable.

EXAMPLE 3

This example illustrates use of catalysts A and B in a rigid urethane formulation The components below were blended with a high speed stirrer, then poured into a standard mould and allowed to rise 55 1,561 618 Mondur MR polyisocyanate 46 6 parts 2500 parts Thanol RS-700 polyolm' 34 parts silicone surfactant 52 4 parts 880 parts fluorocarbon blowing agent Catalyst tested (see below) 5 ( 1) A nine mol propoxylate of sorbitol The rise characteristics observed were recorded below:

Catalyst Amount Cream Time Tack Free Rise Time Tested (parts) (sec) Time (sec) (sec) A 1 40 145 150 10 A 1 25 35 110 120 B 1 41 140 150 B 1 25 37 105 120 EXAMPLE 4

This example illustrates utility of the urethane catalysts of Examples 3 and 4 of 15 our co-pending Application No 33618/77 Serial No 1,561,617, and of an additional catalyst, in a flexible urethane formulation These catalysts are (C) lbis( 3)dimethylaminopropyl)aminomethyll methyl ether: (D) lbis( 3dimethylaminopropyl)aminol methane, and (E) bis-(dimethylaminopropyl)methylamine The procedure of Example I was followed and the observed 20 properties are recorded below:

Test Amount Cream Rise Foam Catalyst (Parts) Time Time Appearance C 0 1 12 sec 96 sec Good C 0 13 12 sec 84 sec Good 25 D 0 1 94 sec Good D 0 17 88 sec Good E 0 1 90 sec Good Compound E, bis-(dimethylaminopropyl)methylamine was produced as follows 30 A 500 ml reactor equipped with a stirrer, thermometer, and addition funnel was charged with 100 ml of methanol and 30 g of paraformaldehyde 187 g of bis(dimethylaminopropyl)amine was added dropwise over 45 min with stirring and the reaction mixture was allowed to remain overnight at room temperature This entire procedure was conducted with a nitrogen atmosphere 35 EXAMPLE 5

This example illustrates use of catalysts C, D and E in a rigid urethane formulation The procedure of Example 3 was followed and the rise characteristics observed are recorded below:

Catalyst Amount Cream Tack Free Rise 40 Tested (Parts) Time Time Time C 1 33 sec 85 sec 115 sec C 0 75 41 sec 105 sec 125 sec D 1 40 sec 95 sec 105 sec D O 75 37 sec 125 sec 140 sec 45 E I 31 sec 97 sec Il O 1 sec E 0 75 37 sec 120 sec 135 sec EXAMPLE 6

This example illustrates use of bis-( 3-dimethylaminopropyl)( 2hydroxypropyl)amine the urethane catalyst of Example 5 of co-pending 50Application No 33618/77 Serial No 1,561,617 in a flexiable urethane formulation.

The procedure of Example I was followed and the product had a cream time of 12 seconds, a rise time of 95 seconds and a good foam appearance.

EXAMPLE 7

This example illustrates the use of the urethane catalyst used in Example 6 55 above in a rigid urethane formulation The procedure of Example 3 was followed and the product had a cream time of 41 seconds, a tack free time of 128 seconds, and a rise time of 160 seconds.

1,561,618 9 1,561 618

Claims

WHAT WE CLAIM IS:

1 A method for producing a polyurethane which comprises reacting an organic polyisocyanate with an organic polyester polyol or polyether polyol in the presence of a catalyst of the formula R N CH 2 CH 2 CH 2 N-R 1 (I) 5 R 2 wherein R is alkyl:

R 1 is alkyl or a group of the formula -CH 2 CHR 2-Y, -CH 2 OR 3 or -CHR' -N CH 2 CH 2 CH 2 N\ R 2 R 2 is hydrogen, alkyl, aryl, substituted aryl, alkaryl substituted alkaryl, aralkyl or substituted aralkyl, R 3 is hydrogen or alkyl: 10 R 4 is hydrogen, alkyl, aryl or substituted aryl: and Y is -OH, -CN, CONR 42.

-CO 2 R 4 or -COR 4.

2 A method as claimed in Claim I wherein the catalyst is a compound of the formula:

R N -CH 2 CH 2 CH 2 NCH 2 CHR -Y (Y 15 2 15 R / wherein Y is -CN, -CONR 4, -CO 2 R 4 or -COR 4 and R, R 2 and R 4 have the meanings given in Claim 1.

3 A method as claimed in Claim 2 wherein R is methyl.

4 A method as claimed in Claim 2 or 3 wherein Y is CN and R 2 is hydrogen.

5 A method as claimed in Claim 2 or 3 wherein Y is CONH 2 20 6 A method as claimed in Claim 2 wherein the catalyst is N-cyanoethyl-N,Nbis-(dimethylaminopropyl) amine.

7 A method as claimed in Claim 2 wherein the catalyst is 3-lbis(dimethylaminopropyl)aminol propionamide.

8 A method as claimed in Claim I wherein the catalyst is a compound of the 25 formula:

t/ N-CH 2 CH 2 CH -N-CHRN CH 2 CH 2 CHN\ wherein R is alkyl and R 4 is hydrogen alkyl or aryl.

9 A method as claimed in Claim 8 wherein the catalyst is bis-lbis-( 3dimethylaminopropyl)aminol methane 30 A method as claimed in Claim I wherein the catalyst is a compound of the formula:

R' N -CH 2 CH 2 CH 2-N-CH 2 R 3 V) R 2 where R is alkyl and R 3 is hydrogen or alkyl.

11 A method as claimed in Claim 10 wherein the catalyst is bis-( 3 35 dimethylaminopropyl)aminomethyl-methyl ether.

12 A method as claimed in Claim I wherein the catalyst is a compound of the formula:

N CH 2 CH 2 CH 2NC Hz CHR 2 _ OH (V) R / 2 where R is alkyl and R 2 is hydrogen, alkyl, aryl, substituted aryl, alkaryl 40 substituted alkaryl, aralkyl, or substituted aralkvl.

13 A method as claimed in Claim 12 wherein R is methyl.

14 A method as claimed in Claim 12 wherein the catalyst is bis-( 3dimethylaminopropyl) ( 2-hydroxypropyl) amine.

A method as claimed in Claim 12 wherein the catalyst is bis-( 3dimethylaminopropyl) ( 2-hydroxyethyl) amine 5 16 A method as claimed in any preceding Claim wherein the organic polyisocyanate has a functionality of from 2 to 4, and the organic polyester or polyether polyol has a hydroxyl number of from 25 to 700.

17 A method as claimed in any of Claims I to 15 wherein a flexible polyether polyurethane foam is provided by reacting, in the presence of a blowing agent, the 10 organic polyisocyanate, in the presence of the catalyst, with a polyether polyol having a molecular weight within the range of 2000 to 7000, formed by the addition of a polyhydric alcohol having a functionality of from 2 to 4 with an alkylene oxide of 2 to 4 carbon atoms the organic polyisocyanate being employed in an amount sufficient to provide 0 4 to 1 5 mol equivalents of isocyanate groups per mol 15 equivalent of hydroxyl groups.

18 A method as claimed in any of Claims 1 to 15 wherein a rigid polyether polyurethane foam is provided by reacting, in the presence of a blowing agent, the organic polyisocyanate with a hydroxy terminated polyether in the presence of the catalyst, said polyisocyanate being employed in an amount sufficient to provide 0 4 20 to 1 5 mol equivalents of isocyanate groups per mol equivalent of hydroxy group in the hydroxy terminated polyether, and the polyether having from 4 to 7 hydroxy groups per molecule, a molecular weight within the range from 300 to 1200 and a hydroxyl number within the range of 350 to 700.

19 A method as claimed in any of Claims I to 15 wherein a flexible polyester 25 polyurethane foam is prepared by reacting, in the presence of the catalyst and a blowing agent, a toluene diisocyanate with a hydroxyl terminated condensation product, of a polycarboxylic acid and a polyhydric alcohol, the toluene diisocyanate being employed in an amount sufficient to provide 1 0 to 1 5 mol equivalents of isocyanate groups per mol equivalent of hydroxyl groups, the 30 condensation product having a functionality of from 2 to 4, a molecular weight from 2,000 to 4,000 and a hydroxyl number of from 25 to 60.

A method as claimed in Claim 1 substantially as hereinbefore described with reference to any of Examples I to 3.

21 A method as claimed in Claim I substantially as hereinbefore described 35 with reference to Example 4 or 5.

22 A method as claimed in Claim 1 substantially as hereinbefore described with reference to Example 6 or 7.

23 Polyurethane when produced by a method as claimed in any of the preceding Claims 40 MICHAEL BURNSIDE & PARTNERS, Chartered Patent Agents, Hancock House, 87 Vincent Square, London SWIP 2 PH Agents for the Applicants.

Printed for Her Majesty's Stationery Office, by the Courier Press, Leamington Spa 1980 Published by The Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.

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