FR2496107A1 - Stannous halide-alcohol complex gelling catalysts - for polyurethane prodn., low blowing activity, allowing prodn. of non-foamed prods. - Google Patents

Abstract

Prodn. of a polyurethane comprises reacting (i) an organic compsn. contg. at least two Zerewitinoff-active H atoms, and (ii) an organic polyisocyanate in the presence of, as gel catalyst, (iii) a stannous halide-alcohol complex. Pref. the alcohol is a polyether polyol, e.g. poly(oxyethylene)- or poly(oxypropylene)-glycol or triol, a monohydric alcohol or a glycol. (iii) is pref. of formula SnX2.aA (I) (where X is halide; A is an alcohol; a is not zero). Pref. X is Cl or Br. Blowing catalyst (iv) is opt. included. Cpd. (I) is novel when a is 1 or 2 and whenever X is Br. Also novel is (I) (X is Cl, A is polyoxyalkylene glycol (POAG)), as is a soln. of (I) (A is POAG) in excess POAG. Polymers can be used as sealants, cushions, filters, etc. The Sn complexes have high gelling but low blowing activity, and are non-toxic, permit use of "damp" charge to urethane elastomer prodn. and allow possible delay in gelation.

Description

The present invention relates to the preparation of novel products based on urethanes, and more particularly the use of a new catalytic system characterized by its ability to facilitate the formation of unexpanded urethane elastomers
Polyurethanes are prepared by reacting an organic polyfunctional polyisocyanate (generally an aliphatic isocyanate, as in the case of coatings, a polymeric isocyanate as in the case of rigid foams, or a tolylene diisocyanate as in US Pat. case of flexible foams) with an organic composition having at least two active hydrogels according to Zerewitinoff.

Examples of these latter compositions include various polyesters, polyester amides, polyoxyalkylene polyols, polyoxyalkylene ethers, polyacetals, polyoxyalkylene thioethers, and the like.

 When the desired product is to be an unexpanded urethane elastomer, the rection is carried out in an anhydrous medium and no blowing agent is added. When the desired product is to be an expanded urethane, water and an excess of isocyanate can be added to the mixture; the platinum reaction with the isocyanate groups forms carbon dioxide, and this gas is trapped in the reaction mixture.

In addition to (or instead of) these products, auxiliary blowing agents such as volatile haloalkanes may be added.

 When the desired product is expanded urethane, it is common to add an expansion catalyst which regulates the water-isocyanate reaction. A common expansion catalyst is N-ethyl morpholine.

 It is common commercial practice to add to either system a gelling catalyst which controls the reaction between the polyol, for example, and the isocyanate. In the case of unexpanded rethane elastomers, the expansion catalyst is omitted and a gelling catalyst is used.

 It has been found, however, that many prior art gelation catalysts are unsuitable in that they are characterized by excessive toxicity with the attendant environmental disadvantages. Another disadvantage of the catalysts of the prior art is their lack of specificity: although a catalyst of the prior art can be widely regarded as a gelling catalyst, it also serves to catalyze the reaction. 'expansion. This is undesirable since the gelling reaction and the expansion reaction can not be controlled independently. In the case of unexpanded urethane elastomers, in particular, it has been found that the gelling catalysts tested so far have the disadvantage of having a high capacity to catalyze expansion, so that they catalyze the reaction between the isocyanate and traces of water present in the system, giving products characterized by an excessive degree of expansion. In practice. this results in undesirable bubbles in the formed diurethane elastomer.

 Since formerly attempts have been made to provide gelling catalysts with only low expansion capacity, it has been attempted in industrial practice to produce elastomers from dry fillers in accordance with the present invention. severe requirements with regard to the water content.

 One of the aims of the invention is to provide a new process for the preparation of urethane polymers. Other objects will appear to the specialists on reading the description below.

In accordance with this aspect of the invention, the process for the preparation of the inventive emulsions consists in reacting (1) an organic composition having at least two active hydrogen atoms according to
Zerewitinoff, and (2) a polyfunctional polyisocyanate (including difunctional isocyanates) organic in the presence of a stannous alcohol halide complex as a catalyst.

 The polyfunctional organic polyisocyanates which can be used in the practice of the process of the invention may contain two or more isocyanate groups per molecule. Dan: the preferred embodiment preferably contains from 2 to 3, in general to 2.7 isocyanate groups. Suitable polyfunctional isocyanates are, for example, alkylene diisocyanates such as hexamethylene diisocyanate and decamethylene diisocyanate, arylene diisocyanates such as phenylene diisocyanates, tolylene diisocyanates, naphthalene diisocyanates, 4,4'-diphenylmethane diisocyanates, or their isomers or mixtures thereof. Triisocyanates, generally obtained by reacting 3 moles of arylene diisocyanate with 1 mole of hexanetriol or trimethylolpropane, can be used. When the formed polyurethane is an unexpanded elastomer (whether rigid or flexible), the preferred polyisocyanate may be a polymeric diisocyanate such as an isocyanate prepared from formaldehyde and aniline by phosgenation.When the product is a coating the preferred polyisocyanate may be an aliphatic diisocyanate such as isophorone diisocyanate. When the product is a soft foam, the preferred polyisocyanate may be a mixture of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate.

Substances having two or more active hydrogen atoms, as determined by the Zerewitinoff method, for example the polyoxyalkylene polyols which may be used in the practice of the invention, will be organic compounds having two or more reactive hydrogen atoms which will react. with organic polyfunctional isocyanates to give urethane polymers. These polyoxyalkylene polyols may include polyesters, polysocyanate modified polyesters, polyisocyanate modified amide polyesters. allenes glycols, polymercaptans, polyamines, alkylene glycols modified with polysilanates, etc .; it should be noted that these polyoxyalkylene polyols may carry active primary or secondary hydroxyl groups. The polyoxyalkylene polyol may be a hydroxylated polyether including glycerides of fatty acids. The polyesters, which are a preferred type of polyoxyalkylene polyol, can be obtained by an esterification reaction, for example an aliphatic dicarboxylic acid with a glycol or a triol or their mixtures in such proportions that the polyesters obtained can contain mainly terminal hydroxyl groups. The dicarboxylic acids suitable for preparing polyesters may include aliphatic and aromatic acids such as adipic acid, fumaric acid, sebacic acid, phthalic acid, and the like.
suitable alcohols are ethylene glycols, diethylene glycols, trimethylolpropane and the like. The glycerides of fatty acids can include those having a hydroxyl number of at least about 50 such as castor oil, hydrogenated castor oil or natural blown oils.

 Polyethers, another preferred type of polyoxyalkylene polyol may comprise polyoxyalkylene glycols, for example polyethylene glycols and polypropylene glycols preferably having a molecular weight of at least 200. For convenience, the terms "polyol" or "polyoxyalkylene polyol" "may be used to designate substances having two or more active hydrogen atoms, as determined by the Zerewitinoff method, which may be used in the practice of the invention.

The preferred non-expanded trethanelastomer elastomers of the invention are prepared by reacting (1) an organic composition having at least two active hydrogen atoms assayed by the method of
Zerewitinoff and (2): In organic polyfunctional polyisocyanate in the presence of a stannous halide alcohol complex as a catalyst.

 According to the invention, the product can be obtained by using an isocyanate and an organic composition (i.e. a polyol) in a proportion giving an isocyanate index in the reaction medium of 0.7 to 1, Preferably from 0.9 to 1.2, for example 1.1. The isocyanate index is the ratio of equivalents of isocyanate groups to Zerewitinoff active hydrogen equivalents in the total composition. The catalyst is present in a proportion of 0.01 to 5% by weight, preferably 0.1 to 2% by weight, for example 1% by weight of the polyol.

 Various other ingredients including fillers, pigments, reinforcing agents, flow control agents, flame retardants, etc. can be incorporated into the composition.

 It may be desirable in one embodiment to use the method of the invention in a prepolymer technique using as a filler a prepolymer prepared from an excess of isocyanate and a polyol which is can then react with a polyol supplement.

 The preparation of an unexpanded urethane elastomer by the process of the invention may consist in introducing the constituents plus the catalyst into a reaction vessel at 20-dDOC, preferably at 20-500 ° C., for example at 250 ° C. and mixing. the components.

The gel time can be varied by changing the amount of catalyst and the constituents of the system.

 The elastomer can then be vulcanized at 50-2000C, preferably at 80-100OC, for example at BOOC for 1 to 90 minutes, for example for 60 minutes.

 By Shore hardness test or by naked eye examination of the presence of surface bubbles in a sample of 8 cm diameter and 50 mm thickness after vulcanization, it is found that the unexpanded elastomers thus prepared are substantially free of heat. 'expansion.

 One of the features of the process of the invention is that the gelling catalyst used has virtually no ability to function as an expansion catalyst. Accordingly, it is not necessary to use anhydrous reagents as is the case for the unexpanded elastomer systems of the prior art. It is found, for example, that it is necessary in many systems of the prior art to maintain the water content of the introduced polyol at less than 0.10% by weight, and preferably less than 0.01% by weight. Fillers, when used in prior art elastomer compositions, typically require additional drying prior to use to a water content of less than 0.01% by weight.

In view of the fact that the sannene-alcohol halide complex gelation catalysts of the invention do not show any notable ability to function as an expansion catalyst, the constituents of the elastomer-forming mixture need not be exempt. of water. In particular, they can be used "as is" without having to ensure that they are dry. In practice, this means that a water content of up to 0.1% by weight can be found.
The elastomer preparation is effected by reacting (1) an organic composition having at least two active hydrogen atoms assayed by the Zerewitinoff method, (2) an organic polyfunctional polyisocyanate, and (3) as a so-called catalyst. gelification, a stannous halide-alcohol complex. In the preferred embodiment, there may also be fillers, pigments, reinforcing agents, flow control agents, flame retardants, etc.

The preparation of an expanded urethane product is carried out by reacting (1) an organic composition having at least two active hydrogen atoms assayed by the method of Zerewitinoff5 (2) an organic functional polyisocyanate, (3) an agent expansion agent, usually water, (4) a cell-modifying agent such as a silicone such as dimethyl polysiloxane with trimethyl radical-blocked moieties sold by Union Corporation
Carbide under the trade name L-520, (5) an expansion catalyst and (6) as a gelling catalyst, a stannous halide-alcohol complex.

In a typical "one-step" formula these constituents are generally added to the reaction mixture in the parts by weight proportion indicated in the following table (specialists will be aware that the parts by weight can vary with the molecular weight or the number functional groups)
TABLE constituting interval interval Value
Typical preferred polyol 12 - 250 60 - 250 100 isocyanate 10 - 500 25 - 200 50 Cell modifying agent 0.01 - 10 0.2 - 4 1 blowing agent 0 - 10 1 - 5 3 Expansion catalyst 0 , 1 - 5 0,5 - 2 1 gelling catalyst 0,1 - 5 0,5 - 2 1
The expansion catalyst that can be used may be a typical expansion catalyst such as an amine such as N-ethyl morpholine etc.

 In this typical one-stage formula, the components are introduced into a reaction vessel at 20 ° C to 80 ° C, preferably at 0 ° C to 500 ° C, for example 20 ° C, and mixed thoroughly.

 In the case of expanded uretha, the catalyst of the invention is found to have a clear advantage in that since it is substantially free of the ability to catalyze the expansion reaction, it allows a very high degree of separate control of the reactions. expansion and gelation, that is to say that each of them can be regulated independently by changing the type and amount of catalyst without affecting the other in an unfavorable direction.

The gelling catalysts of stannous halide-alcohol complex which can be used in the practice of the process of the invention are characterized by the formula
Sn X2. A.

In this formula, X can be a halide. Although it is possible to form complexes where X is a fluoride or an iodide, it is preferred that the halide be a bromide or a chloride. In the preferred embodiment, the halide, the halide is a chloride. Although it is possible to form complexes in which the two X groups are not identical (for example in which one is a chloride and the other a fluoride), these will ordinarily be identical.

 As will be noted below, it is possible to obtain deliberately different results depending on the halide present, for example the chloride may give results different from those obtained with the bromide.

 When the above complex is a stannous halide-alcohol complex, the symbol A can represent an alcohol, that is to say an organic hydroxyl compound whose type is an alcohol proper, a glycol, a polyol, a polyether polyol etc. In the preferred embodiment the alcohol, i.e. the organic hydroxy compound will be a polyol (such as ethylene glycol, propylene glycol etc.) and preferably a polyoxyalkylene polyol (such as dipropylene glycol). diethylene glycol etc.) In the stannous halide complex, preferably a stannous glycol chloride complex, the molar ratio of the alcoholic compound (eg alcohol or glycol) to the stannous halide may be 1: 1 at 2: 1, for example 1: 1. it may generally be desirable to use the complex in an excess of an alcohol, preferably identical to that of the complex. In this case, the alcohol may be present in an amount such that it gives molar ratios of 1: 1 to 100: 1, preferably 1: 1 to 5: 1, for example 4: t.

 The symbol a can represent a number which is ordinarily between 1 and 2. One of the features of the products of the invention is that a is generally an integer such as 1 or 2.

 When the organic hydroxy compound is a monoalcohol it can be characterized by the formula ROH.

In the formula R0H, R may be a hydrocarbon radical chosen from alkyl, aralkyl, cycloalkyl, aryl and alkaryl radicals optionally substituted with inert substituents. When R is an alkyl radical it may for example be a methyl, ethyl, n-propyl, iso-propyl, n-butyl, i-butyl, sec-butyl, amyl, octyl, decyl, octadecyl, etc. radical. When R is an aralkyl group, it may for example be a benzyl, beta-phenylethyl, and the like. When R is a cycloalkyl radical, it may for example be a cyclohexyl, cycloheptyl, cyclooctyl, 2-methylcycloheptyl, 3-butylcyclohexyl or 3-methylcyclohexyl radical, etc. When R is an aryl radical, it may for example be a phenyl or naphthyl radical. etc. When R is an alkaryl radical, it may for example be a tolyl, sylyl, etc. radical may carry inert substituents, that is to say it may carry a non-reactive substituent such as an alkyl or aryl radical. , cycloalkyl, ether, halogen, etc. For example, R groups carrying inert substituents may be 3-chloropropyl, 2-ethoxyethyl, carboethoxymethyl, 4-methylcyclohexyl, p-chlorophenyl, p-chlorobenzyl, 3-chloro-5-methylphenyl, and the like. In one aspect of the invention, the preferred R groups may be lower alkyl radicals, ie, C 1 to C 2 alkyl radicals, such as methyl, ethyl, n-propyl, propyl, butyls, amyls, hexyls, octyls, decylates, etc. The radicals R of a given composition may be identical or different.

As examples of monohydroxy compounds which can be used to form the complexes of the invention, mention will be made of the following
BOARD
methanol
ethanol
n-propanol
i-propanol
bu tanols
hexanol
octanols
dodecanol
phenol
benzyl alcohol
cyclohexyl alcohol
When the alcohol or the organic hydroxylated composition is a polyhydric alcohol, they may be characterized by the formula R '(OH) x wherein x is an integer greater than 1 and R' is selected from the same radicals as R, with the exception of that x hydrogen atoms
R 'have been replaced by an equal number of hydroxyl groups.

 In a preferred embodiment, the R group of ROH may be a radical of a polyol, in which case the R group may be of the form -R '(OH) y-. In this case, the ROH may be a glycol such as ethylene glycol HOCH 2 CH 2 OH, wherein y is 2 and R 'is -CH 2 CH 2 -. It will be seen that R ', in this case, is selected from the same group as R, except that R' carries X hydroxyl groups in place of an equal number of hydrogen radicals.

Examples of polyols include
BOARD
ethylene glycol
propylene glycol-1,2
propylene glycol-1,3
sorbitol
trimethylol propane
pentaerythritol
tetramethylene qlycol
Gold will also find that the radical R may comprise an ether part as in the case of the following compounds
BOARD
diethylene glycol
triethylene glycol
dipropylene glycol
In the practice or method of the invention, to prepare alcoholic complexes of the stannous halide, one mole of Sn X 2 is reacted with the desired amount (moles, where a is 1-2 moles, for example 1 mole). alcohol.

 Although one of the features of the process of the invention is that it is possible to use reagents which contain water for the preparation of complexes, it is desirable to use dry reagents so that the reaction mixture contains less than 1% by weight of water. If the mixture contains much more than 5% water by weight, it is desired (at least if the product is to be used as a urethane catalyst) that the water is extracted from the reaction mixture.

 If it is desired to use the product of the reaction in situ, it may be desirable to add to the reaction mixture the equivalent amount of alcohol (eg glycol) to form the product, which can ordinarily be a product containing ( per mole of Sn X2) an integer number of moles of alcohol groups.

More commonly, however, it may be desirable to use an excess of ROH, in which case the product may be a solution (of the complex) or a suspension (of the complex) in the excess of alcohol, for example glycol, d glycolic ether etc.

 In the preferred embodiment, the introduced alcohol, if not dry (when it is a high molecular weight alcohol, for example a glycol), can be dried before the reaction by heating at a temperature of 100 to 150.degree. C., for example 1000.degree. C., and 0.5 to 50 mmHg, generally at 2.5 mmHg, typically for 0.5 to 5 hours, for example for 1 hour, to eliminate the water. The preferred filler is an anhydrous stannous halide such as anhydrous stannous chloride.

 The reaction is preferably carried out at a temperature of 25 to 2000 ° C., for example 100 ° C. and at a pressure of 0.5 to 2000 mmHg, preferably 0.5 to 50 mmHg, for example about 1.5 mm Hg, for 0.5 to 4 hours, for example for 1 hour.

Although in general no hydrogen halide is released during the reaction, it is preferred to purge with nitrogen during the reaction.

 The alcohol complexes formed are generally soluble in the alcohol from which they are formed and they are not normally isolated until further use.

Examples of alcohol complexes that can be prepared by the process of the invention include the following:
BOARD
SnCl2. 2 HO (CH2CH2O) 3H
SnCl2. 2 HOCH-CH2-O-CH2-CH-OH
CH3 CH3
SnCl2. 1 C2H50H
SnCl2. 1 C (CH 2 OH) 4
SnCl2. 2 n-C12H250H
SnCl2. 2 HOCH2CH20H
SnBr2. 2 HO (CH2CH2O) 3H
SnBr2. 2 C (CH 2 OH) 4 SnF 2. 1 HO (CH2CH2O) 50H
SnI2. 2 HOCH2CH20H
The complexes prepared by the process of the invention, for example the complex of a stannous chloride molecule and a dipropylene glycol molecule, are characterized by properties which clearly distinguish them, for example from other compositions containing the separate charge components, for example stannous chloride and dipropylene glycol. For example, if this complex is analyzed by infra-red spectroscopy, it is found that the bands of the spectrum of the complex are very different from those of the charge.

 Thus, this complex taken as an example has peaks with the following wave numbers: 7.73; 8.08; 8.83; 9.28; 11.83 and 12.10. On the contrary, there are no predominant peaks at these points in the stannous chloride and dipropylene glycol feedstock.

Dipropylene glycol, for example, has peaks at the following wave numbers: 7.65; 7.97; 8.75; 9.20 11.65 and 11.90. Those skilled in the art will find that these significantly different spectra correspond to the formation of the desired new complex or ligand,
It should also be noted that the maximum peak intensity is very different. it is clear that the peaks for the complex are different in location and intensity from those observed for glycol.

 Similar conclusions can be drawn from the study of Mosebaner spectra. For example, if one compares (1) a stannous halide and (2) a complex of a stannous halide and an alcohol, the spectrum of the latter presents important modifications of the values of the chemical shift and the splitting of the quadrupoles, which clearly indicate the formation of a Wu, * plex rather than a simple mixture or a simple solution.

 The novel products of the invention are characterized by (1) surprisingly high activity as a gelling catalyst in urethane systems, accompanied by low activity as expansion catalysts, (2) their low toxicity relative to prior art gelling catalysts containing lead, mercury etc., (3) their ability to permit the use of a "wet" charge in the production of urethane elastomers without adverse effect on the product, (4) and their ability to provide more accurate and independent control of expansion and gelification reactions in expanded urethane systems and the like.

Of particular interest, when used as catalysts in the formation of elastomers, they make it possible to achieve the desired gelation delay, ie it is possible to retard gelation for such long periods of time. as desired, for example, in one case, up to 24 hours. At the end of the desired delay time, the elastomer may be gelled by heating, for example at 800 ° C. it is clear that the duration of the delay is a function of the amount of catalyst used, the use of smaller amounts of catalyst giving greater delays.

 The urethane elastomers of the invention can be used as sealants, sealants and the like. Expanded urethanes can be used as padding, filters, etc.

 The practice of the method of the invention will emerge from the following description of preferred embodiments, in which as in 1 rest of this specification, all parts are by weight unless otherwise indicated.

In some of the examples below, the following properties are measured
Viscosity (cps); it is measured with a Brookfield LVT viscometer
Working time (min.): The time after which an elastomer being vulcanized has a viscosity measured in a Brookfield LVT viscometer of 20,000 cps at the reaction temperature
Gel time (sec or min): the time after which the elastomer or foam has hardened to such a degree that after scratching or contact with a spatula or glass rod, it no longer flows and resoude more into a continuous structure
Shore Hardness A-2: It is determined by the ASTM D 2240 test;
Bending under a compressive load (bar): it is determined by the ASTM D 575 test;
Compression set (%): determined by ASTM D 395, method B
Resilience (%): determined by ASTM D 2632
Tensile strength (bar): It is determined by the ASTM D 368 test
Module at 100 7D (bar): it is determined by the test ASTM D 412
Elongation at break (%): determined by ASTM D 412
Tear (kg / cm): determined by ASTM D 624
Initial tears (kg): determined by ASTM D 1938; and
Maximum tear (kg): determined by ASTM D 1938.

Example I
In this example illustrating the preparation of a stannous chloride complex, it is introduced into a 250 ml round bottom flask equipped with a mechanical stirrer, a thermometer and a vacuum connection orifice. 92 grams (0.6 mole) of triethylene glycol. It is dried by heating at 1000 ° C. under 2.5 mmHg for 1 hour and then allowed to cool to 30 ° C. Anhydrous stannous chloride (24 g, 0.12 mol) is added. A nitrogen purge tube is also introduced into the system. The reaction mixture is heated to 1500C and maintained at this temperature for 1 hour under a vacuum of 1.7 mmHg with a nitrogen purge. The solution obtained is yellow. The product is formed with a substantially stoichiometric yield in solution in 0.36 moles of triethylene glycol.

Example
In this example, illustrating the preparation of a stannous chloride complex, reaction is carried out in a 250 ml 3-neck flask equipped with a mechanical stirrer, a thermometer and a reflux condenser with a connection port. of the vacuum Dipropylene glycol (90 g) is added and heated to 100 ° C. under 1 mm Hg for 1 hour After cooling the glycol at 50 ° C., 24 g of anhydrous stannous chloride are added. The nitrogen is heated to 1150 ° C. at 1.5 mm Hg and maintained at this temperature and pressure for 1 hour, the solution being of a very light yellow.

 The product is formed with a practically stoichiometric yield (in solution in the excess of glycol).

The nreoarea complex is analyzed in this example II using Mossbauer spectra measured on the product in solid form at 77 k (and also in liquid form) with respect to a standard of
Ba119 SRO3 at room temperature. The results obtained are compared to the spectrum of an anhydrous stannous chloride powder under comparable conditions.

 In separate runs, the Mossbauer spectra of the product of this Example II were also measured against alpha tin.

 The table below gives the isomeric shifts b and the split of the quadrupole. All inputs are + 0.04 mm / s; and the units are millimeters per second. The values indicated in the complex column are each the average of two readings on the same sample (one liquid and the other frozen) made on two consecutive days.

BOARD
SnCl Complex split quadrupole # O 1,745 isomeric shift # with respect to BaSnO3 4,16 3,565 isomeric shift s versus tin CC 2,07 1,475
It is apparent from the above table that the isomeric shift 6 (whether measured against the barium stannate standard or the alpha tin standard) decreased by 0.595 mm / sec. Likewise, the split of the quadrupole # has gone from 0 to 1.745 mm / s. These shifts show the composition of the invention is a complex and not merely a mixture of fillers.

Example III
In this example which illustrates the preparation of a mixed stannous chloride-glycol complex, is introduced into a 250 ml 3-necked flask with a vacuum connection port, 50 g (0.39 mole) of dipropylene glycol, 58.6 g. g (0.39 moles) of triethylene glycol and 14.8 g (0.078 moles) of anhydrous stannous chloride. The reaction mixture was heated at 1000C under 5 mmHg for 2 hours. A clear solution such as water is obtained.

Example IV
In this example, the procedure of Example I is followed except that the reactants are one mole of anhydrous stannous chloride and one mole of anhydrous ethylene glycol.

Example IV
In this example which illustrates the preparation of an unexpanded urethane elastomer by the process of the invention, 1.0 g of the catalyst of Example I and 150 g of the catalyst are introduced into a 283.5 g cup. an uncatalyzed, non-catalyzed, "component 1" containing a polynyl, containing
(1) 61.06% by weight of the polyoxypropylene glycol (about 2000 molecular weight) sold under the trade name of Thanol PP6 2000.

 (2) 2.85% by weight of an ethylene glycol monomethyl ether starch-initiated polyether chain blocker (about 1580 molecular weight) see U.S. Pat. No. 3,875 t16.

 (3) 33.58% by weight of a filler-containing calcined clay as the main constituent.

 (4) 1.43% by weight of 2-hydroxyethyl 2-hydroxypropyl carbanate.

 (5) 1.10% by weight of 2,6-di-t-butyl-p-cresol as antioxidant.

 After mixing for 1 minute and adjusting the temperature to 250C, is added 19.6 g of the polymeric isocyanate sold under the trade name PAPI 901. The mixture is stirred for 1 minute.

 A portion of the reaction mixture is then poured into a lid 8 cm in diameter and a second portion into a cup of 141.7 g. The lid is placed in an oven at 80 ° C. for 30 minutes. The cup is allowed to stand at room temperature while monitoring its viscosity and temperature. The elet has a working time of 4.8 minutes and a gel time of 7.2 minutes.

Shore hardness A-2 on the cup: 1.5 h: 45/0, 37/5; 25 hours: 50/0, 46/5; and 5 days: 53/0, 51/5. The lid has a Shore A-2 hardness of 45/0, 45/5 to 0.5 hours. Elastol, lere shows no signs of bubbles due to the water-isocyanate reaction.

 This example shows that the use of the catalyst of the invention allows the formation of urethane elastomers which have the advantage of being free of bubbles.

Example VI *
In a control example, the procedure of Example V is repeated, except that in place of the catalyst of Example I, 0.8 g of finely ground anhydrous stannous chloride is added.

 The gelation of the elastomer is carried out much more slowly than in Example V, and the elastomer obtained is of inferior quality. This shows the advantages of using the complex of the invention.

Example VII
In this example which illustrates the preparation of an unexpanded urethane elastomer by the process of the invention, 150.8 g of a non-catalyzed "component B" having the same composition as that of the invention are introduced into the reaction vessel. Example V. The temperature is adjusted to 25 C.

 0.8 g of the catalyst of Example II is added with 20.5 g of a polymeric isocyanate (sold under the trade name PAPI 901). The mixture, at 250 ° C., is stirred for 1 minute and poured into an 8 cm lid and a 41.7 g cup. The lid is placed in an oven at 80 ° C. for 1/2 hour. The cup is allowed to stand at room temperature according to its temperature and viscosity. There is a working time of 4.5 minutes and a gel time of 7.25 minutes.

The Shore A-2 hardness of the cup at 80 minutes is 37%; 31/5. The Shore A-2 hardness of the lid after 0.5 hours is 47/0, 47/5.

Example VIII
In this example, which illustrates the preparation of an unexpanded urethane elastomer (in the presence of added water), by the process of the invention, 150 g of component B containing 0.01% are introduced into a reaction vessel. by weight of water. 1 g of the catalyst of Example II and 0.1 g of water are added. After mixing and adjusting the temperature to 25 ° C., 19.6 g of polymeric isocyanate (sold under the trade name of
PAPI 901) and mixed for one minute.

 The reaction mixture is poured into an 8 cm lid and a 141.7 g cup. The lid is placed in an oven at 600 ° C. for 0.5 hours. The cup is allowed to cure at room temperature. The Shore A-2 hardness measured on the cup is 51/0, 50/5; on the lid, it is 43/0, 43/5 after 0.5 hours.

 No expansion is observed which shows that the catalyst is a gelling catalyst and not an expansion catalyst, even when the formula contains a quantity of water which would otherwise be sufficient to form an expanded product. If the formulation were modified by adding, for example, 1 g of N-ethyl morpholine, a commercial expansion catalyst, the formation of an expanded rethane would be avoided.

Examples IX, X *, XI
In this series of comparative examples, the procedure of Example VIII is followed, with the exceptions indicated. In each example, 1.0 g of water (instead of 0.1 g in Example VIII) is added.

In Example X *, the polyol formulation also contains 0.3 g of a commercial gelling catalyst
(Phenylmercury propionate) which is not present in Examples IX and XI.

 The polymeric isocyanate of Example VIII is present in Examples IX and XI in the amount of 19.6 g and in Example X * in the amount of 18.6 g. This difference in weight is not important enough to explain the results below.

 The gelling catalyst of Example I is used in Example IX, that of Example II is used in Example XI.

 It is observed that the experimental systems of Examples IX and XI have the advantage of foaming only slightly, despite an abnormally high water content. The control system of Example X * foams significantly more due to the presence of the prior art gelling catalyst.

The sag under a compressive load
(in bar) and the remanent strain (%) were determined and are given in columns A and B below.

BOARD
Example AB
IX 0.65 43.4
X + 0.29 67.6
XI 0.68 45.8
it is apparent from the examples and the table above that the use (in Examples IX and XI) of the stannous chloride complex catalysts of the invention provides the following advantages:
(1) the experimental product is characterized by very low foaming compared with Comparative Example X *, in which foaming is much more important.

 (2) the experimental product is characterized by a higher compression load deflection which is more than twice that of the product obtained in Comparative Example X *.

 (3) the experimental product is characterized by significantly lower compression set compared to the product of Comparative Example X *.

Example XII
In this example, which illustrates the preparation of a stannous chloride-glycol complex, is introduced into a 100 ml round bottom flask equipped with a magnetic stirrer, a thermometer and a vacuum connection port 46 g of the triol known under the trade name THANOL G 400 (glycerol-based polyoxypropylene triol having a molecular weight of about 400). The system is dried by heating at 1000 ° C. under 4 mmHg for 1 hour and then cooled. Anhydrous stannous chloride is added and the mixture is heated at 1500C under 0.3 mm of lg for 45 minutes.

 The product is formed in substantially stoichiometric amounts (in excess triol).

Example XIII
In this example, the procedure of Example VII is followed except that only 20% of the polymeric isocyanate is used and the catalyst (1 g) is that of Example XII.

 The unexpanded urethane elastomer has a working time of 5.2 minutes and a gel time of 7.25 minutes. Hardness Shore A-2: on cup after 1.5 hours 41 / O, 36/5; on the lid after 1/2 hour at 80 C, 51/0, 51/5.

No signs of foaming are observed.

Example XIV
In this example, which illustrates the preparation of an unexpanded urethane elastomer by the process of the invention, 887 g of a commercial uncatalyzed polyol containing a component B are introduced into a 2 1 resin flask. similar to that of Example V.

 Catalyst from Example I is added, the mixture is stirred, degassed and brought to 250 ° C.

118.3 g of the polymeric isocyanate sold under the trade name PAPI 901 are added and the mixture is stirred for 30 seconds.

The reaction mixture is poured into an 8 cm lid which is placed in an oven at 800 ° C. for 30 minutes in two circular molds of 25 mm diameter and in a 203 × 203 mm sheet mold. stand at room temperature for 2 hours and then place in an oven at BO L for 1 1.5 hours
Example XV
In this example, the procedure of Example XIV is repeated, except that the isocyanate is a polymeric isocyanate sold under the trade name of
THANATE P 220, which answers the formula

The properties of the elastomers of the examples
XIV to XV are the following
Properties Example XIV Example XV Hardness Shore A-2 Sm Disc 62/0 56/0 Resilience% 48.5 44.0 Tensile Strength, Bars 40.9 34.6 Modulus at 100%, Bars 20.0 15.9 elongation at break,% 266 293 tear, kg / cm 14.1 12.9 initial tear, kg 4.49 72.0 maximum tear, kg 4.46 7.13 compression set,% 13.7 16 , 4 deflection under compressive load, bars 7.37 5.35
Examples XVI to XIX
In each of the examples of this series, a urethane elastomer formulation is prepared containing (1) as polyol, 52.3 g of a glycerol-based polyol formed by reacting glycerol, ethylene and propylene oxide. It is mainly a polyoxypropylene triol having an average molecular weight of about 3000. Also 16.8 g of the aniline adduct are added to 2.5 moles of ethylene oxide. 32.3 g of a diphenylmethane diisocyanate sold under the name ISONATE 143 L and 0.02 g of the following catalysts are
catalyst example
XVI * dibutyl tin dilaurate
XVI 1 * 2-ethylhexanoate zinc
XVI II * 2-ethylhexanoate stannous at 50%
in diisooctyl phthalate
XIX Catalyst of Example I
In these examples, two round molds of 8 cm are used, one at room temperature, the other in an oven at 800 ° C., and a thin sheet vulcanized in an oven at 800 ° C. The formulations and the results are given in the table below
BOARD
Hardness Sore A-2 to 2 days
Formation 8 cm 8 cm sheet
Example of foam temp. Ord. 8O0C 800C
XVI * yes - 43/0 XVI 1 * yes 43/0 42/0 44/0
XVIII * slight 63/0 64/0 64/0
XIX no 63/0 70/0 70/0
The above table shows that only the product of Example XIX prepared in accordance with the invention is satisfactory. It does not foam as the products of the comparative examples do. In addition, the hardness of the product is better than that of the products prepared by the comparative processes.

Example XX
In this example illustrating the preparation of a stannous chloride complex, the reaction is carried out in a 3-neck flask equipped with a thermometer, a mechanical stirrer and a vacuum connection port. 500 g of a polyoxypropylene glycol having a molecular weight of about 2000, sold under the trade name THANOL PPG 2000 Polyol, are introduced therein. The system is dried by heating at 1000 ° C. under 1 mmHg for 1 hour, cooled to 300 ° C. and then 25 g of anhydrous stannous chloride are added thereto. The reaction mixture was heated at 120 ° C. under a vacuum of 14.4 mmHg for 1 hour.

 The product is obtained in practically stoichiometric amounts.

Example XXI
In this example which illustrates the preparation of a stannous chloride-alcohol complex, the reaction is carried out in a 250 ml 3-neck flask equipped with a magnetic stirrer, a thermometer and a reflux condenser with an orifice. vacuum connection. 90 g of lauryl alcohol are introduced therein and the drying is carried out by heating under reflux under a vacuum of 1.2 mmHg. After cooling to 30 ° C., 24 g of anhydrous starchy chloride are added. The mixture is heated at 113 ° C. at 0.7 mmHg for 1 hour.

 The product is obtained in substantially stoichiometric amounts.

Examples XXII to XXII I
These examples show that a polyester can be used as the polyol. The polyester is a diethylene glycol adipate polyester having a hydroxyl number of 103. The catalyst is that prepared in Example II. The catalyst is mixed with the polyester, then the isocyanate is added, and then mixed.

The reaction mixture is poured into two 8 cm round molds. One of them is placed in an oven at 80 ° C., and the other is left at room temperature.

In Example XXII, the amount of catalyst is 0.1 g, it is 1.0 g in Example XXIII. The polyisocyanate is a modified diphenyl methane diisocyanate, sold under the tradename dISOP.ATE 143 L.

BOARD
Ex. Catal - Polyester Polyester - Gel. in Gelif. at
cyanate the temp. 800C
ambient
XXII 0.1 g 77.4 g 22.6 g 4 h 11 min
XXIII 1.0 g 77.4 g 24.6 g 5.5 mm 4.5 m
The table above shows that polyesters can be used as polyols. Example XXII also shows that when the catalyst is present without a quartit as low as 0.1 3, the reaction is sensitive to heat the gelation time
at a temperature of about 25 ° C is about 4 hours, while it is only 11 minutes at 80 ° C.

Examples XXIV and XXV
In these examples, a prepolymer formulation is prepared in the ordinary manner by mixing 1125 parts of 4,4'-methylene diphenyl diisocyanate with 1,500 parts of a polytetramethylene glycol having a molecular weight of about 1,000, for 2.5 hours. 80 ° C.. The product is found to have an equivalent weight of 450.4. This prepolymer (90 parts) is mixed with 8.8 parts of 1,4-butanediol and with the catalyst of Example II. The procedure is also in accordance with that of Examples XXII and XXIII using the catalyst of Example II.

BOARD
Catalyst Gélif. at the temp. ambient Gélif. at 800C min. min. min.

0.1 g 10.25 5.4
1.0 g 2.75 2.25
Examples XXVI and XXVII *
In these two examples, the urethane elastomer is prepared in a manner comparable to the procedure of Example V. The isocyanate used is an aliphatic diisocyanate, isophorone diisocyanate (12.3 g in Example XXVI and 10.8 g in Example XXVII). As the polyol, 89.2 g of the triol of Example XVI, sold under the trade name THANOL F-3014 POLYOL, are used.

As a catalyst, 1.0 g of the product of Example III is used in Example XXVI. In Example XXVII, the catalyst is a commercial catalyst, dibutyltin dilaurate.

 It is found that the product of the invention prepared in Example XXVI is free of bubbles, while the control product of Example XXVII * has the disadvantage of containing many bubbles.

Examples XXVI He and XXIX
In these two examples, the procedure of Examples XXVI and XXVII is generally followed.

As the polyol, 89.1 g of a triol with a molecular weight of about 300, sold under the trade name of THANOL TE 3000 are used. The polyisocyanate is isophorone diisocyanate (12.4 g in Example XXVII I and 13.9 g in Example XXIX). The catalyst is that prepared in Example II (1.0 g in Example XXVIII and 2.0 g in Example XXIX).

The gelling properties of the products determined as in Examples XXVI to XXVI 1 *, are as follows
BOARD
Example Gelif. at the temp. ambient Gélif-. at 800C
XXVII I 5 h 29 min
XXIX 4:14 mn
The above table shows that by using aliphatic isocyanates, satisfactory urethane elastomers can be obtained that can be cured 10 to 15 times faster at 800 ° C than at room temperature.

Results comparable to the results above can be obtained if SnX2 is
Example
XXX SnSr2
XXXI SnF2
XXXII SnI2
It will be observed that comparable results are obtained using as catalysts for the urethane elastomers glycol complexes of SnBr 2. Systems containing bromine, however, are less resistant to the catalysis of the water-isocyanate expansion reaction than are the corresponding chlorine-containing systems.

 Thus, the alcohol complex of SnBr2 and triethylene glycol gives elastomers containing few bubbles. This system is satisfactory, although it is less preferred for this reason than the corresponding system containing chloride which is free of bubbles.

 It therefore appears that the bromide-containing system may be advantageous in that it provides better delayed reaction characteristics.

In comparable tests on a urethane elastomer system, the following results were obtained:
Example System Working time Frost time.

mn ~~~~~~~~ mn mn
XXXIII bromide 14.25 20.25
XXXIV chloride 14.25 greater than 30
This table shows that the use of the bromide system has the advantage of allowing a shorter gel time to be obtained when the working time is equal to that of a corresponding chloride system.

Example XXXV
In this example, a flexible foam is prepared which is suitable for a carpet backing.

In the pot of a model Hobart mixer
K5-A equipped with a wire arm, the following materials are placed
Parts Constituting 100 Propoxylated Ethoxylated Addition Product of
glycerol with a molecular weight of 3500, 11.45 1,4-bu + 3nediol, 6 silicone surfactant (Product sold
by Union Carbide Corp. under the name of
of L 5612), 31.280% by weight of Z, 4-toluene diisocyanate
20% by weight of 2,6-toluene isocyanate.

 They are mixed for 10 minutes at four speed of the mixer. Then 0.25 part of the catalyst of Example II (SnCl2-dipropylene glycol complex) is added, whereupon another 2 minutes are mixed at four speed of the mixer. The froth is poured into a 203 x 203 mm mold and placed in an oven at 110 ° C. It is devoid of stickiness after fourteen minutes. At room temperature, it can be worked for about 8 minutes.

Example XXXVI
This example shows that the catalysts of the invention can be used to prepare a flexible foam which can remain for 5 minutes at room temperature without reacting, but which foam and vulcanize when placed in a hot oven.

Constituent B parts 100 molecular weight 5000, glycerol propo
ethoxylated sylé with a high content of
primary hydroxyls 0.1 silicone surfactant (L-5303
Union Carbide) 0.33 catalyst of Example II (SnCl 2
dipropylene glycol) 0.3 amine JEFFAMINE AP-22, aromatic amine
of functionality 2.2 prepared by
condensation of aniline and
formaldehyde 2.9 THANOL TR-380, ethoxylated aniline 24 trichlorofluoromethane
Component A 11.3 polymethylene polyphenyl isocyanate,
about 2.7 functionality, prepared
by phosgenation of the reaction product
resulting from the condensation of
aniline and formaldehyde (Mondur MR
sold by the Mobay Company).

 Components A and B are mixed by means of a stirrer at high speed and then poured into a mold. The reaction mixture, left standing for 5 minutes at room temperature, does not cream. At the end of this time, it is placed in an oven at 80 C. The mixture is transformed in the oven into a flexible foam.

Example XXXVI I
This example shows that it is possible to obtain a rigid foam having a very long cremation time.

Constituent B parts 33.4 propoxylated sorbitol, molecular weight
average 700 3.7 styrene-allyl alcohol polymer,
equivalent mass 200 1.5 silicone surfactant (DC-193
of Dow Corning) 1.3 trichlorofluoromethane 1 catalyst of Example II (SnCl 2
dipropylene glycol)
Component A 47.4 prepolymer (90% by weight of an iso
Polymer cyanate (Mondur MR), 10%
by weight of a phosphoric polyol,
of hydroxyl 205, 11.3% of P), the
Vircol 82 sold by Mobil Chemical Co.

 Components A and B are mixed for 30 seconds by means of a high speed stirrer and then poured into a box mold. The cream mousse in 4 minutes, rises in 12 minutes and is free of stickiness in 9 minutes.

TEST density ASTM D-1622 34.7 kg / m3 K-factor hot plate 0.0149 k cal./
protected modi
from Du Pont compressive strength ASTM D-1621 in direction of foam rise 2.51 bars in transverse direction 1.03 bar friability (weight loss) ASTM D-421-71 12.8% closed cells % ASTM D-2856 91.91% dimensional stability ASTM D-2126 Variations.

 dvol Àpds Along.

70 C / 100% RH + 10.9% -1.3% + 5.4% 93.3 C / sec. + 4.8% -0.7% + 3.7% -28.9 C / sec. -3.9% + 0.3% -2.0%
Example XXXVII I
This example illustrates the use of the catalyst to prepare a coating.

Constituent B parts 27.5 polyester diethylene glycol-acid
adipic (average equivalent weight 1000) 12.7 propoxylated glycerol (molecular weight
average 260) 0.03 catalyst of Example II (SnCl 2 -
dipropylene glycol)
Constituent 25,2 modified methylene diphenyl diisocyanate
(Isonate 1431, sold by Upjuhn Co.)
having an equivalent mass of 143 e = viron.

 Components A and B are mixed for 30 seconds and allowed to cool for 13 minutes at room temperature. Part of the mixture is then spilled onto a 101.6 x 101.6 mm metal plate and degassed. After 20 minutes (from the moment of mixing), the plate is placed in an oven at 80 ° C. The coating obtained St limpid and free of bubbles.

 A Taber abrasion test (ASTM D-1044-56) gives the following results: 1000 9, 1000 cycles, CS-17 wheel coating. The weight loss is 2.5 mg only.

Example XXXIX
This example illustrates the use of the catalyst in an adhesive
Constituent B parts 19.35 diethylene glycol-acid polyester
adipic acid (hydroxyl number 103) 0.02 catalyst of Example II (SnCl 2
dipropylene glycol)
Component A 5.65 modified methylene diphenyl diisocyanate
(Isonate 143 L)
Components A and B are mixed for 30 seconds, then brushed onto pretreated fiberglass plates (wiped with a 5% methylene diphenyl diisocyanate solution, modified in methylene chloride and dried at room temperature). room temperature for 15 minutes). Then the material is degassed. After 10 minutes, the plates are attached to each other and placed in an oven at 120 C to vulcanize.

Tensile shear strength: 48.2 bar (ASTM D-1002).

Example XL
In this example, the catalyst of Example II (SnCl2-dipropylene glycol) is used in a conventional flexible foam.

Constituents B parts 100 ethoxylated and propoxylated glycerol,
propoxylated ends, molecular weight
average eye. 3500 4 water 1 silicone surfactant (L-520
Union Carbide) 0.9 catalyst of Example II
Component A 32.5 toluene diisocyanate
Components A and B are mixed by means of a high speed stirrer and then poured into a mold. A foam is obtained.

Claims (6)

 A process for the preparation of a polyurethane in which (1) an organic composition having at least two active hydrogen atoms according to Zerewinitoff is reacted and (2) a polyfunctional organic polyisocyanate in the presence of a gelling catalyst, characterized in that this gelation catalyst is (3) a stannous halide-alcohol complex.  2. Method according to claim 1, characterized in that this complex is a complex of a stannous halide and a monoalcohol, a glycol or a polyether polyol.  3. Method according to any one of claims 1 and 2, characterized in that the stannous halide complex meets the formula  SnX2. wherein X is a halide ion, A is an alcohol and a is a positive number.  4. Method according to any one of claims 1 to 3, characterized in that the polyurethane is an unexpanded polyurethane elastomer.  5. Method according to any one of claims 1 to 3, characterized in that the polyurethane is an expanded polyurethane prepared in the presence of a blowing agent and / or an expansion catalyst.  6. Process according to any one of claims 1 to 5, characterized in that the stannous halide-alcohol complex is used in the form of solution and / or suspension in the alcohol.