This application claims priority from U.S. Provisional Application Serial No. 60/014,8-13,

filed April 4, 1996. Background of (he Invention

Certain amine catalysts arc known in the polyurethane industry such as propanamide, N,N-

dimethyl-3-[dimcthylamino] (DDPΛ, Structure 1), which is the simplest of a scries of catalysts, having no reactive functional groups, for the formation of polyurethane described in U.S. Patent No. 4,01 1 ,223.

A similar non-reactive analog that has been found useful as a polyurethane catalyst is propanamide, 3-[bis-(3-[dimcthylamino]propyl)]amino-N,N-dimcthyl as described in U.S. Patent No. 4,049,591.

Additionally, a number of hydroxyl, and primary/secondary amine containing tertiary amine polyurethane catalysts arc described in the article "Factors Affecting the Discoloration of

Vinyl That Has Been Molded Against Urcthane Foam," R. L. Zimmerman and T. L. Austin, Polyurethane World Congress 1987. Sept. 29-Oct. 2, pp. 693-697, 1987. However, all of these catalysts have deficiencies in cither activity, with the hydioxy substituted cases, or with volatility, such as in the unsubstituted case.

U.S. Patent No. 4,384,950 describes the use of a substituted form of DDPΛ as a demulsifier for breaking oil-in-water emulsions from tar-sand bitumen recovery. The reference, however, does not describe the use of this compound as a catalyst for urethanc systems. The reaction used in the preparation of the substituted compound involves addition/condensation of methacrylic or acrylic acid with dimcthylaminopropylamine. Methods of manufacture of said compound are disclosed in U.S. Patent Nos. 4,256,665 and 4,259,259. Summary of the Invention

The present invention provides amine/amide catalysts for use in catalyzing the formation

of polyurethane. The amine/amide catalysis have low volatility in the resulting polyurethane (i.e., low fogging) and reactivity at least as good as the most reactive component in the system [see Priester, R. D. Jr., R. D. Pefley and R. B. Turner, "High Resiliency Polyurea Foam - An Improved Flexible Foam Matrix, Journal of Cellular Plastics. 30(2) 1994, pp. 147, which is incorporated herein by reference]. These compounds are tertiary amine/amidcs that have similar base structures to DDPA, but contain secondary amine groups for reacting into the polymer matrix. Unexpectedly, these highly reactive compounds have a catalyhc activity which is very close to that of tlie completely unsubstituted catalyst DDPA.

The structure of the tertiary aminc/amidcs of the present invention is:

Q is C i ₊ j, or (CHj)„N(R ^J )kT and T is a divalent cyclic group, by which is ireant a group which is attached at both its ends to tl e nitrogen to foπn a cyclic group, or T ^■ * is a monovalent alkyl,

aminoalkyl or alkylaminoalkyl group, k = 0 or 1 , being 1 if T is a monovalent group and 0 if T is a divalent group; R ² = H or CIInn; each occurrence of R ^J = R ⁴ = H; R ⁵ = 11 or CH ₃ , n = 2 to 6; and each occurrence of z = 1 to 4. "n" is preferably 2 υr 3 and z is preferably 1. T when

monovalent may be an alkyl group of one to four carbons which may have one or more amines thereon (e.g., amino-Ci-C*- alkyl) or therein (e.g., mono- or di-C|-C ₄ - alkylamino-Cι-C ₄ - alkyl). T when divalent may be alkyl, amine substituted alkyl, alkylaminoalkyl, or alkoxyalkyl which

forms with the nitrogen atom shown in structure (2) to which T is attached a cyclic structure which incorporates up to 6 caibon atoms in the ring as well as the nitrogen atom shown in structure (2) and optionally a second nitrogen atom or an oxygen atom in the ring, e.g., moφholino, piperazmo. Said cyclic structures may include Ci to C ₄ alkyl substitutions on the

ring.

Another aspect of the present invention is methods of forming polyut ethane by combining the polyol and polyisocyanatc reactants in the presence of an effective amount of one or more than one compound of foπnula (2) to catalyze the reaction of said reactants.

Detailed Description nf the Invention

A preferred subset of the aminc amidcs of the present invention is:

or more particularly

wherein R ¹ = (R ³ ) ₂ N(Cnj)„ or C lι,«; R ² , R ^J , R\ R ⁵ , T, k, n and z arc as above, "n" is

preferably 2 or 3 and z is preferably 1. Each may be the same or different, as may each value of n and z. One specific preferred range of structures for 2A and 2B is those in which R ^* is C _t Uι, _*\ . Preferred specific compounds are:

and

An example of such a cyclic terminated structures is:

These compounds may be manufactured as known in the art for the manufacture of amine/amide. Generally, the catalysts arc prepared from the direct reaction of

dimethylaminopropylamine (DMAPA) or other similar amines, with methyl acrylate (MA), dimethyl acrylainide (DMΛΛ) or similar unsaturated materials. The products of these reactions

arc substantially the aminopropionamidcs of the present invention containing lesser amounts oT

unreacted raw materials and other adducts such as:

Methods of manufacture of compounds of Structure 4 arc specifically disclosed in U.S. Patent

Nos. 4,256,665 and 4,259,259, which arc incorporated herein by reference.

These aminc/amidc catalysts arc used for the catalysis of the reaction to form polyurethane, i.e.,, catalyze the isocyanate/watcr and/or isocyanatc/alcohol reactions. Said polyurcthanes may be rigid, flexible slabslock, ester slabstock, molded microccllular elastomer or

other types of foams as arc known in the art. The aminc/amidcs of the present invention can be

used in amine prc-blcnds, i.e., mixtures with other amine catalysts, surfactants, or other additives or polyurethane components as arc known in the art.

Foam formulations with which the compounds of the present invention can be used as catalysts usually comprise (a) a polyether polyol containing an average of more than two hydroxyl groups per molecule; (b) an organic polyisocyanatc; (c) at least one catalyst for production of polyurethane foam; (d) water; (e) a surfactant, preferably any of the siiicone/polyclhcr copolymers known in this field for this purpose; and (0 an inert gas.

The polyois have an average number of hydroxyl groups per molecule of at least slightly

above 2 and typically 2.1 to 3.5. Generally, the polyol should have an equivalent weight of about 400 to 1500 or even 400 lo 3000 grams/cquivαleπl and nn ethylene oxide content of less than 20%. Useful polyois include but arc not limited to polyether polyois such as alkylene oxide adducts of polyhydroxyalkancs, alkylene oxide adducts of non-reducing sugars and sugar

derivatives, alkylene oxide adducts of polyphenols, and alkylene oxide adducts of polyamines and polyhydroxyamincs. The alkylene oxides are preferably based on ethylene oxide or propylene

S oxide.

The organic polyisocyanatcs contain at least two isocyanate groups, e.g., toluene

diisocyanates (TD1), and the index of the foam is typically 60 to 130.

The water generally comprises on the order of 1 to 12 php (paits by weight per hundred

parts of polyol). 0 Other additives may be added to the polyurethane foam lo impart specific properties to

the foam _, including, but not limited to. coloring agents, flame rctardanls, and GIϊOLITC® Modifier foam additives (available from Organo Siliconcs Group of Witco Coφoratiυn,

Greenwich, CT). The inert gas is one which is soluble in the foam formulation at elevated

pressures, but will come out of solution (i.e., blow) at atmospheric pressure. An exemplar ₎ ' such

gas is C0 ₂ , but nitrogen, air or other common gases, including hydrocarbon gases, such as methane and ethane may also be used. The inert gas may also comprise a volatile organic compound such as a pentane isomer or a hydrochlorocarbon that boils above ambient temperature but has a sufficiently high vapor pressure at ambient temperature that its vapor represents a substantial component of the gas in the cells of the foam.

The silicone copolymer surfactants should be capable of helping to form a stable foam and should be present in an amount effective to stabilize the polyurethane foam, i.e., an amount which is generally about 0.05 to 5 wt. percent of the total reaction mixture, preferably 0.2 to 1.5 wt. percent.

The foam is manufactured by mixing lhc ingredients (that is, ingredients (a) through (0) together such that byproduct gas generated during the reaction foams the polyurethane. The foam can also be made by the injection of inert gas, whereby the reactants arc put under high pressure (i.e., at least greater than atmospheric pressures) so that the inert gas is dissolved in the reactant mixture. Then the mixture is flashed, by releasing the pressure _, which causes the gas lo form bubbles at nuclcation sites in the foaming system and thus act as a blowing agent. This produces a reduced density foam. For a more complete description of this process and the equipment required therein, see European Patent Publication No. 0 645 226 Λ2. which is incorporated herein by reference.

The compounds of the present invention may also be used in non-foam polyurethane reactions, such as polyurethane elastomer formation. In such polyurcthanes, the water in the

formulation is often replaced with a chain extender, which is a low molecular weight (<400) active hydrogen containing compound with at least two reactive groups. Examples are 1 ,4-

butancdiol, ethylene glycol, diethylene glycol and ethylene diamine.

The conditions and formulations for these reactions arc known in the art, e.g.. "Polyurethane Handbook," 2nd ed., Gunter Ortel, ed., Hanser Publishers, Cincinnati, 1994, which is incoφorated herein by reference. Generally, these catalysts are used at a catalytically effective amount, i.e., in an amount to effectively catalyze the reaction to fonn the polyurethane. Generally

said effective amount is about 0.02 - 5.0 parts per hundred pails of polyol in the reaction formulation. In molded flexible foam, which is described in the examples below, these catalys ⁱ s

resulted in cream and exit times slightly faster than for DDPA. and the load properties (ILD) and

cure characteristics of the foams were at least as good as for DDPA.

EXAMPLES

Glossary: php: Parts of product per 100 parts of polyol in the formulation.

Polyol 1: An ethylene oxidc/propylcne oxide polyether sold by ARCO Chemical as ΛRCOL

Polyol E-656. Polyol 2: An ethylene oxide/propylene oxide polyether sold by ARCO Chemical as ΛRCOL

Polyol E-688.

Polyol 3*. A propylene oxide polyether sold by Dow Chemical as VORANOL 490.

Polyol 4: A propylene oxide polyether sold by Dow Chemical as VORANOL 800.

Polyol 5: A polyester polyol sold by Stepan Chemical as PS-3152.

Polyol 6: A polyester polyol sold by Wilco as FOMREZ 53.

Siliconc 1 : A siliconc surfactant sold by Witco as NIΛX surfactant L-3001.

Siliconc 2: Λ siliconc surfactant sold by Witco as NIΛX surfactant Y- 10829. Silicone 3: A siliconc surfactant sold by Witco as NIAX suifactant L-6900.

Silicone 4: A silicone surfactant sold by Witco as L-532.

Surfactant 1 : An organic surfactant sold by Union Carbide Corp. as NP-9.

Catalyst 1: An amine catalyst sold by Witco as NIAX catalyst A-l .

Catalyst 2: An amine catalyst sold by Witco as NIAX catalyst Λ-33. Catalyst 3: An amine catalyst sold by Witco as NIAX catalyst Λ-99.

Isocyanate 1 :Λ dipbcnyl methylene diisocyanate (MD1) variant sold by Dow Chemical as ISONATE 143-L

Isocyanate 2:Thc standard commercial mixture of 80% 2,4 and 20% 2.6 toluene diisocyanate.

Isocyanate 3:Λn MDI variant sold commercially by Dow Chemical as PΛPI 27. IFD: Foam load values as determined by ASTM D-3574 Test B 1

General Synthesis: Uncalalyzcd reaction nf certain primary amine containing tertiary amines with acrylates or methacrylates

The synthesis of the following tertiary aminc/amidcs was conducted in a 500 mL round- bottom four-neck flask. The flask was equipped with a pressure equalizing addition funnel,

mechanical stirrer, nitrogen purge, thermometer and heating mantle. Either one mole of DMAΛ and one mole of the amine of interest, or one mole of MA and two moles of the amine were used. If the amine it was primary, it was weighed into the flask and the DMΛΛ or MΛ was weighed

into the addition funnel. If the amine was not primary, the order was reversed (i.e., the amine was placed in the addition funnel and the DMΛA or MA in the flask). Specific details of reactions arc

outlined below. Example 1 - Synthesis of Amines/ Amides of the Present Invention Propanamide. 3-f3-dimethylaminopropynamino-N.N-dimcthvl - One mole of the DMΛPΛ

(dimclhylaminopropylaminc, 102.21 g) was weighed into the flask. The system was purged with nitrogen for several minutes. The DMAA was added (6 mlJmin.) to the flask while the mixture was being stirred and the temperature was being monitored. Tlie initial temperature was 24° C

and did not change during the addition. Once the DMAA addition was complete, the flask was heated lo 100°C and held for two hours with stirring. Structure H3 above was obtained al 90-* %

conversion..

Propanamide. 3-f3-dimcthvlaminopropvl)amino-N-r3-dimcthylaminopropvn - The synthesis of the

MA/DMAPΛ version of the amine was conducted by the procedure above using two moles of DMΛPΛ (204.42 g) and one mole of MA (86.10 g). During the addition of the MA the

temperature increased from and initial temperature of 24°C to a final temperature of 75°C. The

temperature was held at 75 ^β C for Iwo hours. The sample was then stripped on a rotary

evaporator for four hours at 70°C, 5 mm llg to remove methanol. Structure ll'\ above was

obtained at 92 % conversion. p _rnpnnπrrι i _c lp _| 3-[- -dimethylaminonronvnamino-N-r3-dimethylamiπopronvn. 2-mcthyl - The

synthesis of the mcthylmcthacrylate (MMA)/DMΛPΛ version of the amine was conducted by the

procedure listed above using two moles of DMAPΛ (204.42 g) and one mole orm Λ (86.10 g). During the addition of the MMΛ the temperature did not change from the initial temperature of

24° C. The temperature was increased to 120°C for a total of twcnly-four hours. The sample

was stripped on a rotary evaporator for four hours at 70°C, 5 mm Hg to remove methanol. The following structure was obtained at approximalcly 80% conversion:

Eiample 2 - Synthesis of Comparative Catalysts Propanamide, 3-[dimelhyl]amino-N,N-dimclhyl was made, stalling from DMΛΛ (one

mole) was added to a stirred reactor under nitrogen. Dimcthylaminc (one mole) was added at

such a rate as to keep the temperature in the reactor <35°C. When all of the dimcthylaminc was added, the reactor was held between 35 and 45°C for about two hours. After that time, temperature was increased to 60 ^β C for an additional 5 hours. After cooling to 25 °C, the reaction

was complete and tl e product analyzed. The analysis confirmed the anticipated structure of DDPA at 99+% conversion. Similarly, propanamide, 3-[3-mclhyl-3-hydroxyelhyl]amino-N,N- dimcthyl (9) was made from DMAΛ and MEOΛ (N-melhylcthanolaininc).

Additionally, propanamide, 3-[bis(2-hydiOxycthv ^, )amuιo]-N,N-dimclhyl (10) was made from DMΛΛ and DEOΛ (diclhanolamine).

Propanamide, 3-[3-mclhyl-3-hydroxycthyl]amino-N-mcthyI-N-hydroxyclhyl (1 1) was made from

MA and MBOA.

Propanamide, 3-[bis(2-hydroxyethyl)aminol-N,N-[bis(2-hydroxycthyl)] (12) was made from MΛ

and DEOA.

Example 3 - Evaluation in a Simple Water Blown Urclhanc Foam

Each of the reactive DDPA catalysts was evaluated in tcπns of its blow and gel

capabilities relarive to DDPA. To obtain blow capabilities a simple system or 97.22 php (0.049 eq.) of Polyol I , 1.79 php (0.195 eq.) of water, 1 php of Surfactant I and Isocyanate 1 al 103

index was used. A total of 50 grams of premadc polyol, water, surfactant blend was weighed into a lined one pint paper cup. The catalysts were evaluated by adding 0.25g (0.5 php) or 0.5g ( 1.0 php) to this mixture. Isocyanate was added and the mixture stirred on a drill press for 5 seconds.

Blow capabilities were deteπnined by measuring top-of-cup and blow-off times as compared lo DDPA. Data arc presented in Table 1.

Table 1 - Water Blown Foam Examples

a The top-of-cup time rcpresenls Ihc time (seconds) al which lhc rising fonm reached lhc hcighl of lhc cup. b t he Krcl DDPΛ value represents the relative activity of the catalyst and was obtained by dividing the top- of-cup lime for the αminc-Bmidc by the top-of-cup lime for lhc DDPΛ at a given use level. For Run 3; 157 sec/168 sec = 0.93 = Krel DDPA at 0.5 php. c The blow lime represents the time (seconds) al which gasscs visibly escaped from the foam.

Table 1 shows this comparison in a simple water blown urclhanc foam formulation. Each catalyst

was evaluated at levels of 0.5 and 1.0 php, and rise (lop-of cup) and blow-off times noted. It is clear that the candidates break down into two families, those with activities reasonably close to that of the control DDPA (Runs 2-6) and those with significantly poorer activity (Runs 7- 14). The foams of Runs 3-6 contain the preferred catalysts nolcd above (Slnicturcs 3 and 4), while

Runs 7- 14 were catalyzed with the poorer pcrfoπning hydroxyl containing candidates (Slnicturcs 9-12). The difference in overall performance is significant, suggesting unique catalytic behavior of the preferred structures.

Example 4 - Evaluation in a Urcthane Elastomer

A similar experiment was used to evaluate the gel capabilities of the reactive DDPΛ

catalysts relative to DDPΛ. The resin blend consisted or 94 php (0.047 cq.) or Polyol 1 and 6 php (0.1 3 eq.) of ethylene glycol. Isocyanate 1 was used at 103 index. Λ total of 100 grams of the resin blend was weighed into a lined pint-size paper cup. Isocyanate was added and stirred by hand. The catalysts were evaluated al 3 php. Gel capabilities were determined by measuring gel time (point at which mixture was too viscous to stir by hand) and tack-frcc time as compared to DDPΛ. Data are presented in Table 2.

Table 2 - Urethanc Elastomer Examples

All catalysts were evaluated at 3.0 parls. Λtninc equiva ents ased only on tertiary amine content @

3.0 part use level.

The gel time rcpresenls lhc lime al which the mixture is lo viscous to be stirred by hand.

The Krcl DDPΛ value rcpresenls Ihe relative activity of the corresponding catalyst as compared to

DDPΛ. (gel time of aminc-amidc of interest/gel li e of DDPΛ).

1 he tack-frcc tune represents the time at which the mixture is hick free to Ihc touch.

Runs 2 and 3 confirm that Structures 3 and 4 have activities reasonably close to that or DDPΛ, while all of die other candidates are very much slower. This significant difference in this elastomer system confirms the unique catalytic character of these compounds and the broad scope

of their utility.

Example 5 - Evaluation in a Molded Flexible Foam Formulation

The catalysts were then evaluated in a molded flexible foam foπnulation. The control formulation contained 80 php of Polyol 1, 20 php of Polyol 2, 1.2 php Siliconc 2, 1.5 php of DEOΛ, 3.56 php of water, 0.23 php or Catalyst 2, 0.1 php of Catalyst 1 , and 0.25 php of "DDPΛ blend" (sec Table 3). Isocyanate 2 was used at an index of 100. The reactive DDPΛ catalysis were blended exactly like the "DDPΛ blend", replacing the DDPΛ with each catalyst to be evaluated. The new blends were used in place of the "DDPA blend" at equal parts in the formulation. The mixture was mixed (drill press) for 55 seconds, the isocyanate was added and

mixed for another 5 seconds after the isocyanate addition. The foams were made in an alu iminiim mold with 1/16 inch vents. The mold temperature was 150°F (tempered water heating) with a demold time of 3.5 minutes. Foams made were compared by measuring cream and exit limes, 50% or 75% ILD values, and cure response. Data arc presented in Table 3.

Table 3 - Catalyst Comparison in a Flexible Molded Foam

a The cxil time represents the lime at which Ihe first amount of foam was visible in the mold vents. b ILD indicates indentation load deflection. c Indicated aminc-amidc catalyst. 33.5% / TERGITOL 15-S-7 surfactant (Union Carbide Cotp.) 66.5%. d nm indicates that (his value was not measured. c si set indicates that Ihe cure was slow

The performance of the preferred catalysts is given in Runs 2-5. These catalysis resulted in cream and exit times slightly faster than those for the DDPA control blend, and the load

properties (ILD) and cure characteristics of the foams were at least as good as the control. This is additioi 1 evidence that the typical catalytic activity of these tertiary amine/amide compounds is very close to that of DDPA . The performance of tlie hydroxyl containing candidates is shown in

Runs 6-13. While similar to DDPΛ, they tend lo give somewhat longer exit times (i.e., arc slower lo react) and lower load properties. Example 6 - Confirmation of the reactivity of amine/amide with isocyanate Structure 4 (0.315g, 0.00265m) was added lo a small reactor followed by phenyl isocyanate (0.684g, 0.00265m). Immediately upon mixing, there was a significant cxothcrm Rnd a notable increase in the viscosity of the mixture suggesting a fast reaction. After about three minutes, a sample of the mixture was taken which confirmed that all of the phenyl isocyanate had been consumed. This result confirms that these compounds react readily with isocyanate, supporting the concept that they will react into the roam and be non- volatile.

Example 7 - Evaluation in Rigid Foam Formulation

The catalysts were evaluated in a rigid oam rormulation containing 60 php of Polyol 3. 1 php of Polyol 4, 25 php or Polyol 5, 2 php Silicone 3, 1.0 php o water, 36 php or i lCFC-141b blowing agent. Isocyanate 3 was used al an Index o 120. Structure 4 was used as lhc catalyst for evaluation. All components except the isocyanate were premixed in a pint-size lined paper

cup. lhc mixture was mixed (drill press) for 1 seconds, the isocyanate was added and mixed for another 3 seconds. The mixture was then transferred to a lined paper bucket and cream, string

and gel, and final rise times were measured. Data represented in Table 4 demonstrate that catalyst 4, of the present invention yielded good rigid foam.

Table 4 - Catalyst Evaluation in Rigid Foam

Example 8 - Evaluation in Polyester Foam Formulation

Structure 4 was also evaluated in a polyester foam formulation. Two foams were made: a control and a foam using structure 4 as a replacement for DDPA at equal amine equivalents. The

formulations are listed in Table 5 below. The TDI was added to the polyol and the mixture was

hand mixed until it was clear. Then, the polyol/TDI mixture was mixed at 1000 rpm for 8 seconds. The water, amine, surfactant premix was added with a syringe and mixing was continued for 7 seconds. The mixture was then immediately poured into a card box (20 x 20 x 20 cm) and cream aud blow limes were monitored along with the rise profile. Cream times of lhc control foam and experimental foam were 13 seconds each. Blow times for the two foams were 1 19 seconds and 121 seconds, respectively. No differences in the two foams were observed.

Table 5 - Catalyst Evaluation in Polyester Foam Formulation

Example 9 - Verification orNonfugitivity

Fugitivity studies were also performed on a scries of polyester foams made using each of the following catalysts: N-ethyl moφholine, N-mcthyl morpholine, N,N-dimcUιyl benzylamine, n- hcxadccyldimcthylamine, and Structure 4. The following rormulation was used: Polyol 6,

water, silicone 4, surfactant 1, Isocyanate 2 at 103 index. Each of the catalysts was evaluated at the use level required to give a blow time of 41 seconds. The Polyol was weighed into a 32 oz. paper cup. The TDI was added to the polyol and the mixture was hand mixed until it was

clear. Then, the polyol/TDI mixture was mixed at 1000 φin for 8 seconds. The water,

amine, surfactant premix was added with a syringe and mixing was continued for 7 seconds. The mixture was then immediately poured into a paper bucket and top-of-cup limes were

recorded.

Then, approximately 0.2 gram samples of each of the foams were taken from the center of a foam sample cut from the second inch from the bottom of the bucket. These samples were placed in glass vials and scaled and were analyzed on a DB-l (30 meter x 0.32

mm) column using a Varian 3760 Gas Chromalograph equipped with a Perkin Elmer HS-40 Hcadspace Λutosamplcr. Data arc shown below.

Table 6 - Fugilivlty Data

a Required php to give a top-of-cup time of 1 sec. b Less than detection limit (< 1 , 000,000).

The above data confirm that Stmcture 4 has no detectable volalility. Tims, we anticipate that Structure 4 would be nonfugitivc in foam applications.