MXPA98003525A - Compositions of aminometil pyrrolidine urea parala polyurette production - Google Patents

Abstract

The present invention relates to a method for preparing a polyurethane foam, which comprises reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition comprising a compound represented by the following formula I or II, or any mixture of compounds I and

Description

COMPOSITIONS OF AMINOMETRY PYRROLIDINE UREA FOR THE PRODUCTION OF POLYURETHANES BACKGROUND OF THE INVENTION The present invention relates to the use of tertiary amine catalysts, to produce polyurethanes, especially polyurethane foam. Polyurethane foams are widely known and are used in the automotive, home construction and other industries. The foams are produced by reaction of a polyisocyanate with a polyol in the presence of various additives. Such an additive is a chlorofluorocarbon blowing agent (CFC) which evaporates as a result of the reaction exotherm, causing the polymerization mass to foam. The discovery that CFCs deplete the ozone layer in the stratosphere has produced regulations that reduce the use of CFCs. The production of water-blown foams, where blowing is carried out with C02 generated by the reaction of water with the polyisocyanate, has consequently become increasingly important. Tertiary amine catalysts are typically used to accelerate blowing (the reaction of water with isocyanate to generate C02) and gelation (the polyol reaction with isocyanate) - The ability of the tertiary amine catalyst to selectively promote either blowing or gelling, is an important consideration in selecting a catalyst for the production of a particular polyurethane foam. If a catalyst promotes the blowing reaction to a very high degree, much of the C02 will be released before sufficient isocyanate reaction with polyol has occurred and the C02 will bubble away from the formulation, causing collapse of the foam. Poor quality foam will be produced. On the other hand, if a catalyst promotes the gelation reaction too strongly, a substantial portion of the CO 2 will be released after a significant degree of polymerization has occurred. Again, poor quality foam will be produced, this time characterized by high density cells, broken or poorly defined, or other undesirable characteristics. Tertiary amine catalysts are generally fetid or malodorous and offensive and many have high volatility due to low molecular weight. The release of tertiary amines during the foaming process can present significant safety and toxicity problems, and the release of residual amines from consumer products is generally undesirable. Amine catalysts containing ureido functionality (e.g., CONH2) have an increase in molecular weight and hydrogen bonds with reduced volatility and odor, when compared to related structures lacking these functionalities. In addition, catalysts containing ureido functionality chemically bound to the urethane during the reaction and do not detach from the finished product. The catalyst structures that incorporate this concept are typically of low to moderate activity and promote both blowing (isocyanate-water) and gelation (isocyanate-polyol) reactions in varying proportions. The patent of the U.S.A. No. 4,644,017 discloses the use of certain diffusion-stable amino alkyl ureas, which have tertiary amino groups in the production of a polyisocyanate addition product that do not discolor or change the constitution of surrounding materials such as PVC. The patent of the U.S.A. No. 4,007,140 discloses the use of N, N'-bis (3-dimethylaminopropyl) urea as a low odor catalyst for the manufacture of polyurethanes. The patent of the U.S.A. No. 4,194,069 describes the use of N- (3-dimethylaminopropyl) -N '- (3-morpholino-propyl) urea, N, N'-bis (3-dimethylaminopropyl) urea and N, N'-bis (3-morpholinopropyl) ) urea, as catalysts to produce polyurethanes.

The patent of the U.S.A. No. 4,094,827 describes the use of certain alkyl substituted ureas, which provide less odor and a delay in the foaming reaction, which help in the production - of polyurethane foam. The patent of the U.S.A. No. 4,330,656 describes the use of N-alkyl ureas as catalysts for the reaction of 1,5-naphthylene diisocyanate with polyols or for the chain extension of prepolymers based on 1,5-naphthylene diisocyanates without accelerating atmospheric oxidation. DE 30 27 796 A1 discloses the use of dialkyl aminoalkyl ureas of higher molecular weight, as reduced odor catalysts, for the production of polyurethane foam. CA 2,061,168 A (EP 0 499 873 A) describes the preparation and use of pyrrolidines as catalysts for the polyisocyanate polyaddition process. COMPENDIUM OF THE INVENTION The present invention provides a composition for catalyzing the trimerization of an isocyanate and / or the reaction between an isocyanate and a compound containing a reactive hydrogen, e.g., the blowing reaction and the reaction of the urethane to produce polyurethane. The catalyst composition comprises an aminomethyl pyrrolidine urea represented by formulas I or II: The catalyst composition may comprise the compound I, the compound II, or a mixture of the compounds I and II in any proportion by weight. The advantage of these catalyst compounds is their high activity and gelation selectivity. Additionally, they contain a ureido group that will react with isocyanate and chemically bond to the urethane during the reaction; consequently, the catalyst compound is not released from the finished product. The compositions are somewhat viscous and have minimal odor. DETAILED DESCRIPTION OF THE INVENTION The catalyst compositions according to the invention can catalyze (1) the reaction between an isocyanate functionality and an active hydrogen-containing compound, i.e. an alcohol, a polyol, an amine or water, especially the reaction of urethane (gelling) of the polyol hydroxyl with isocyanate to produce polyurethanes and also the reaction of blowing water with isocyanate to release carbon dioxide to produce foamed polyurethanes, and / or (2) trimerization of the isocyanate functionality to form polyisocyanurates. The polyurethane products are prepared using any convenient organic polyisocyanates well known in the art, including for example, hexamethylene diisocyanate, phenylene diisocyanate, toluene diisocyanate ("TDI") and 4,4 'diphenyl methane diisocyanate ("MDI"). 2,4- and 2,6-TDI are particularly convenient individually or together as their commercially available mixtures. Other suitable isocyanates are mixtures of diisocyanates commercially known as "crude MDI", also known as PAPI containing about 60% of 4,4'-diphenylmethane diisocyanate together with other isomeric polyisocyanates and higher analogues. Also suitable are "prepolymers" of these polyisocyanates comprising a partially pre-reacted mixture of a polyisocyanate and a polyether or polyester polyol. Illustrative of suitable polyols as a component of the polyurethane composition are polyalkylene ether and polyester polyols. Polyalkylene ether polyols include poly (alkylene oxide) polymers such as polymers and copolymers of poly (ethylene oxide) and poly (propylene oxide) with terminal hydroxyl groups derived from polyhydric compounds, including diols and triols; for example, among others, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, pentaerythritol, glycerol, diglycerol, trimethylol propane and low weight polyols. similar molecular In the practice of this invention, a single high molecular weight polyether polyol can be used. Also, mixtures of high molecular weight polyether polyols such as mixtures of di- and trifunctional materials and / or materials of different molecular weight or different chemical composition can be used. Useful polyester polyols include those produced by reacting a dicarboxylic acid with an excess of a diol, for example, adipic acid with ethylene glycol or butanediol, or reacting a lactone with an excess of a diol such as caprolactone with propylene glycol. In addition to polyether and polyester polyols, master batches or premix compositions often contain a polyol polymer. Polymer polyols are used in polyurethane foam to increase the foam deformation resistance, i.e. Increase the foam's load-bearing properties. Currently, two different types of polymer polyols are used to achieve load bearing improvement. The first type, described as a graft polyol, consists of a triol in which the vinyl monomers are copolyzed by grafting. Styrene and acrylonitrile are the usual monomers of choice. The second type, a polyurea modified by polyurea, is a polyol containing a polyurea dispersion formed by the reaction of a diamine and TDI. Since TDI is used in excess, some of the TDI can react with both the polyol and the polyurea. This second type of polyol polymer has a variant called PIPA polyol which is formed by the in situ polymerization of TDI and alkanolamine in the polyol. Depending on the load support requirements, the polymer polyols may comprise 20 to 80% of the polyol portion of the masterbatch. Other typical agents found in polyurethane foam formulations include chain extenders such as ethylene glycol and butanediol; crosslinkers such as diethanolamine, diisopropanolamine, triethanolamine and tripropanolamine; blowing agents such as water, CFCs, HCFCs, HFCs, pentane and the like; and cell stabilizers such as silicones. A general formulation of flexible foam based on polyurethane having a density of 16 to 48 kg / m3 (1 to 3 lb / ft3) (eg, for automotive seats) contains a gelation catalyst such as the catalyst composition according to the invention and a blowing catalyst such as bis (dimethylaminoethyl) ether (BDMAEE), will comprise the following components in parts by weight (pbw = parts by weight): Formulation of flexible foam pbw Polyol 20-100 Polyol Polyol 80-0 Silicone Surfactant 1 - 2.5 Blowing agent 2-4.5 Interleaver 0.5-2 Catalyst 0.2-2 Isocyanate Index 70-115 The gelation catalyst composition comprises a compound represented by the formula I or II, and any combination of% by weight of the compounds I and II. Mixtures of compounds I and II may comprise 50 to 95% by weight of compound I and 5 to 50% by weight of compound II. As a result of the preparation process, the catalyst composition can also contain up to 20% by weight of the unreacted urea III. lll Compounds I and II are prepared by reacting urea and N-methyl-3-aminomethyl pyrrolidine in the appropriate molar proportions under an inert atmosphere at elevated temperatures. The compounds I and II can be isolated individually by chromatography. Any of the blowing catalysts known in the polyurethane art can be used with the catalyst compounds of the invention. Illustrative of convenient blowing catalysts are BDMAEE, pentamethyldiethylenetriamine and related mixtures (U.S. Patent No. 5,039,713), higher permethylated polyamines (U.S. Patent No. 4,143,003), branched polyamines (U.S. Patent No. 3,836,488), 2- [N- (dimethylaminoethoxyethyl) -N-methylamino] ethanol and the related structures (U.S. Patent No. 4,338,408), and alkoxylated polyamines (U.S. Patent No. 5,508,314). A catalytically effective amount of the catalyst composition is used in the polyurethane formulation. More specifically, convenient amounts of the catalyst composition may be in the range from about 0.01 to 10 parts per 100 parts of polyol (phpp = parts per hundred (100) parts poiyol) in the polyurethane formulation, preferably 0.1 to 1 phpp. The catalyst composition can be used in combination with, or also comprise, other tertiary amine, organotin and urethane carboxylate catalysts (gelling and / or blowing) well known in the urethane art. EXAMPLE -1 Mixture of 1- (N-Methyl-3-pyrrolidino) methyl urea (I) and 1,3-Bis (N-methyl-3-pyrrolidino) methyl urea (II) A 3-necked round bottom flask, with capacity of one liter, it was adapted with the following: mechanical agitator, reflux condenser, nitrogen sparger, and controlled temperature heating mantle. The flask was charged with 45.75 g (0.762 mol) of urea (CH4N20) and 86. 84 g (0.762 mol) of N-methyl-3-aminomethyl pyrrolidine (IV), (C6H14N2). Compound IV can be prepared according to Example 3 below.

The mixture is stirred at constant speed while slowly heating to 120 ° C. The reaction is monitored at 120 ° C for two hours until all signs of NH3 release (as evidenced by bubbling in the N2 pressure relief device). The pale yellow liquid is cooled to 80 ° C and the flask containing the liquid is evacuated by the vacuum pump and replenished with N2 three times to remove any volatiles present. Quantitative 13 C NMR showed that the product is as follows in Table 1. Table 1 Reaction product of Example 1% in mol 1- (N-Methyl-3-pyrrolidino) methyl urea (I) 81.7 1, 3-Bis (N-methyl-3-pyrrolidino) methyl urea (II) 7.0 Urea 11.3 EXAMPLE 2 In this example, a polyurethane foam is prepared in a conventional manner. The formulation of polyurethane in parts by weight (pbw): COMPONENT PARTS E-648 60 E-519 40 DC-5043 1.5 Diethanolamine 1.49 Water 3.5 TDI 80 index 105 E-648 - a polyether polyol with a conventional ethylene oxide tip, marketed by Arco Chemical Co. E-519 - a polyether polyol filled with styrene acrylonitrile copolymer marketed by Arco Chemical Co. silicone surfactant DABCOR DC-5043 marketed by Air Products and Chemicals, Inc. TDI 80 - a mixture of 80% by weight of 2,4-TDI and 20% by weight of 2,6-TDI For each foam, the catalyst (Table 2) was added to 202 g. of the above premix in a 951 ml (32 oz.) paper cup and the formulation is mixed for 20 seconds at 5000 RPM using a top agitator coupled with a 2.5 cm (2 in.) diameter stirrer blade. TDI Enough was added to produce a foam with Index 105 [index = (mol of NCO / mol of active hydrogen) x 100] and the formulation was mixed well for 5 seconds using the same top agitator. The 951 ml (32 oz.) Beaker was dropped through a hole in the bottom of a 3804 ml (128 oz.) Paper cup placed on a shelf. The hole is dimensioned to trap the lip of the smaller vessel. The total volume of the foam container was 4755 ml (160 oz.). Foams approach this volume at the end of the foaming process. The maximum foam height and time to reach the top of the mixing vessel (T0C1) and the top or top of the 3804 ml (128 oz) vessel (TOC2) were recorded (see Table 2). Table 2 CATALYZER COMPOSITION TOC1 TOC2 Height Height (sec) (sec) Complete of (sec) Foam (mm) 0. 25 pp-hp of DABCO 33LV / 12.88 39.14 132.60 420.79 0.10 pphp of DABCO BL-11 0.48 pphp of catalyst 13.75 39.68 117.49 422.92 of Ej.l * / 0.10 pphp of DABCO BL-11 catalyst DABCO 33LVR - 33% by weight of TEGA in dipropylene glycol from Air Products and Chemicals, Inc. DABCO catalyst BL-11 - 70% by weight of BDMAEE in dipropylene glycol from Air Products and Chemicals, Inc. * 50% by weight of catalyst of Example 1 and 50% by weight of dipropylene glycol. The data in Table 2 shows that the use of the catalyst composition of Example 1 gave a slower initial reactivity profile, indicated by a longer T0C1, which improves the fluidity, followed by a shorter time for it to grow completely, which indicates demolding times will not be longer than the control ones. The catalyst composition of Example 1 also has low odor and low volatility. EXAMPLE 3 This process for producing N-methyl-3-aminomethyl pyrrolidine is Example lc of CA 2,061,168 A (EP 499 873 A). A mixture of 300 g of N-methylglycine, 300 g of acrylonitrile, and 3 liters of toluene are introduced into a 3-neck, 4-liter capacity flask equipped with stirrer, reflux condenser, dosing funnel, and a water separator. which has a capacity of approximately 70 ml. The mixture is heated to vigorous reflux at a bath temperature from 120 to 140 ° C. A total of 105 g of paraformaldehldo is then added in 3 g portions, with no added portions until the evolution of water from the previous addition has ceased. A homogeneous, slightly yellowish solution is obtained at the end of the reaction. The solvent is distilled off and the residue fractionated in vacuo to give 315 g of N-methyl-3-cyanopyrrolidine (e.g. 83-85 ° C, 22 mm Hg).

The subsequent reduction to N-methyl-3-aminomethyl pyrrolidine is carried out by dissolving the cyano compound in an equal volume of methanol. After the resulting solution is introduced into a 2 liter autoclave, 20 g of Raney cobalt and 130 g of ammonia are injected. The hydrogenation is then carried out at 90 ° C under a hydrogen pressure from 90 to 100 bars for about 3 hours. The solution is depressurized, filtered, and concentrated by evaporation. The resulting residue is fractionated in vacuo to give 310 g of N-methyl-3-aminomethyl pyrrolidine (e.g., 61 ° C, 22 mbar). DECLARATION OF INDUSTRIAL APPLICATION The present invention provides a catalyst composition for preparing polyurethane products, especially polyurethane foams.

Claims (14)

1. CLAIMS 1. 1- (N-methyl-3-pyrrolidino) methyl urea.
2. 2. 1, 3-Bis (N-methyl-3-pyrrolidino) methyl urea.
3. 3. A catalyst composition comprising compound I or compound 11, or a mixture of compounds I and II
4. 4. The catalyst composition of claim 1, comprising
5. 5. The catalyst composition of claim 1, comprising
6. 6. The catalyst composition of claim 1, comprising a mixture of
7. 7. A method for catalyzing the trimerization of an isocyanate and / or the reaction between an isocyanate and a compound containing a reactive hydrogen characterized by using a catalyst composition consisting essentially of compound I or compound II, or a mixture of compounds I and II
8. 8. The method of claim 7, wherein the catalyst composition comprises
9. 9. The method of claim 7, wherein the catalyst composition comprises
10. 10. The method of claim 7, wherein the catalyst composition comprises a mixture
11. 11. A method for preparing a polyurethane foam comprising reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition consisting essentially of compound I or compound II, or a mixture of compounds I and II
12. 12. The method of claim 11, wherein the catalyst composition comprises
13. 13. The method of claim 11 wherein the catalyst composition comprises
14. 14. The method of claim 11, wherein the catalyst composition comprises a mixture of