MXPA97003941A - Catalyst for the low temperature cure of isocyanates block - Google Patents

Abstract

The present invention comprises a polyesternoxane catalyst, a composition containing the catalyst and a method for using the catalyst and curing the composition. The curable composition comprises: (1) a blocked isocyanate, (ii) a functional component containing active hydrogen, (iii) a poliestanoxane catalyst to promote the reaction of the blocked isocyanate with the functional component. A cocatalyst based on CU, Zn, Ni, Zr, Ce, Fe, Co, V, Sb and B1 and especially oxides, salts or chelates of these metals can also be used. The invention also relates to a method for curing a blocked isocyanate at a low reaction temperature which comprises combining the catalyst with the blocked isocyanate and the functional component and heating it to a temperature of less than about 180 ° to obtain a urethane cure

Description

CATALYST FOR THE LOW TEMPERATURE CURE OF BLOCKED ISOCYANATES CROSS REFERENCE WITH PENDING APPLICATIONS This application is a partial continuation of the United States Provisional Patent Application North America with serial number 60 / 018,438, entitled: "Catalyst for Low Temperature Cure of Blocked Isocyanates" filed on May 28, 1996. BACKGROUND OF THE INVENTION Field of the Invention The invention is directed to polysanoxane catalysts, useful for the low temperature cure of blocked isocyanates. Description of the Related Art In one part coating formulations, blocked isocyanates are preferred over unblocked isocyanates to obtain good stability for a shelf life. The blocked isocyanates are deblocked by heating the formulation to initiate the cure reaction usually with a polyol. The catalysts are used to promote the release and healing reactions to allow them to proceed at lower temperatures and / or faster healing times. It is difficult to find a catalyst that has little or no activity at room temperature for prolonged stability (shelf life) and also initiates rapid curing by heating the formulation to moderate temperatures. Achieving slight reductions in curing temperatures of only several degrees and at the same time retaining the stability at room temperature represents a significant improvement and an important inventive step as the curing temperatures approach the ambient temperature. The lower cure temperatures conserve energy, reduce the deformation of plastic substrates, and reduce color formation. Organic tin compounds, particularly diorganic tin such as dibutyl tin dilaurate and dibutyl tin oxide, are commonly used for the curing reaction of blocked isocyanates with hydroxyl-containing compounds. Some stanoxanes have also been used as catalysts to unlock polyisocyanates. Yutaka M. et al. In U.S. Patent No. 3,676,402 (1972) teaches octaalkylstanoxanes as catalysts for the regeneration of an isocyanate group in an isocyanate compound blocked at low curing temperatures. The nomenclature used in the present patent application refers to the octaalkylstanoxanes of the Yutaka patent described, polyesternoxane compounds of a general formula described hereinafter in which, N is equal to zero instead of a "dimer" of the formula represented in the Yutaka patent. This difference is only nomenclature. In the same way, the common, commercially available catalyst, dialkyl tin oxide, such as the dibutyl tin oxide described as the prior art in the Yutaka Patent, is herein characterized as a polyesternoxane of the general formula in which N is equal to infinity. The use of a single general formula in the present for the poliestanoxanes provides greater clarity to the description of the family of catalysts having values of N from 0 to infinity. The history of the preparation of poliestanoxanes is described in an article entitled "Polymeric stannoxanes" by Davis, Al and n et al., Which appeared in the Journal of Organometallic Chemistry, Vol 10 (1967) on pages 33 and 34. The authors describe the preparation of the diestanoxanes (compounds of the general formula used in the present with N equal to 0) and the preparation of the infinite polymer (N equal to infinity) as having been achieved by the hydrolysis of dialkyl tin dichlorides, but that no Recognized intermediate molecular weight compound could be prepared by that route. The authors discovered that the controlled size poliestanoxanes, that is, with values for N between 0 and infinity could be prepared by telomerization reactions between tin chlorides and dialkyl tin oxides. However, the use of these poliestanoxanes as catalysts is not mentioned. The authors elaborated this research in a later article entitled "Organotin Chemistry, Part VII, Functionally Substituted Distannoxanes and Oligostannoxanes", J. Chem. Soc. 1979, 2030. The Yutaka Patent discloses that the octaalkylstanoxane catalysts (N = 0) constitute an improvement over the closest catalyst of the prior art, dialkyl tin oxide (N equal to infinity) because the higher temperatures Low for catalysed unblocking of blocked isocyanates is achieved at N equal to 0. Therefore, Yutaka describes that the healing temperature is optimized by reducing the value of N to zero from infinity. On the contrary, the present invention is based on the surprising discovery that there is an anomaly in the correlation between the values of N and the temperatures to unblock the isocyanates. The minimum healing temperature is not achieved by reducing N to zero as Yutaka teaches. The applicants discovered that between N equal to 0 and N equal to infinity, there is a small range of values for N for which lower temperatures can still be reached to catalyze the release of the isocyanate groups, lower than that achieved with N equal to infinity. and still lower than that achieved by the Yutaka catalysts (N equal to zero). Yokoo, M. and co-workers in U.S. Patent Number 3,681,271 describe octaalkylstanoxane (N = 0) as a catalyst for polyurethane foam. Keshi A. and co-workers in U.S. Patent No. 3,703,484 is similar to the teaching of the previously mentioned Yutaka patent (3,676,402) with respect to octaalkylstanoxane (N = 0). "Novel Témplate Effects of Distannoxane Catalysts in Highly Efficient Transesterification and Esterification", by Junzo Otera et al., In the Journal of Organi c Chemistry, 1991, Vol. 56, No. 18 uses a slightly different nomenclature, disubstituted tetraorgano-diestanoxanes, for describe essentially the same molecule that Yutaka described as octaalkyl-stanoxanes and described herein by a general formula for stanoxanes with n = 0. A series of United States Patents of North America issued for Nichols. James D. and Dickenson. John B. including Numbers 5,149,814; 5,145,976; 5,089,645; 5,089,584; 5,089,583; and 4,987,244 describe organic tin catalysts for polyurethane and contain a good summary of the relevant art.

Thiele and collaborators. Plaste und Kautschuk, 36, January 1989 (1) pp. 1-3, describe the reaction of phenyl isocyanate and butanol in the presence of bis, tributyl tin oxide as a model reaction for urethane polymers. Jerabek in U.S. Patent No. 4,031,050, Jerabek et al., in U.S. Patent No. 4,017,438 and Bosso et al., U.S. Patent No. 4,101,486, describe aqueous coating compositions based on blocked organic polyisocyanates, an amine adduct of a resin containing an epoxy group and a diorganic tin catalyst. Chung et al., In U.S. Patent No. 5,116,914 notes that dibutyl tin oxide, (N equal infinite, R equal to butyl) that is used as a catalyst in aqueous coatings, is difficult to disperse while that dibutyl tin dilaurate can be hydrolyzed which causes craterization problems in the deposited film. Patents describe the use of a dibutyl tin diacetylacetonate catalyst to avoid these problems. Treadwell and co-workers in US Pat. No. 4,032,468 disclose the use of a methyl or methoxymethyl tin oxide catalyst for the preparation of hydrolytically stable urethane foam precursors. The foam is formed by the reaction of the isocyanate component of the urethane foam with water. Weisfeld. L. et al., In Canadian Patent Number 79473, discloses diorganic tin oxides of various molecular configurations as compositions of matter and their use as stabilizers for resins. The use of esters of poliestanoxanediol and other complex organic tin compounds as stabilizers are also described in U.S. Patent Nos. 2,628,211, and 2,604,460 both by the inventor Gerry. Mack. The products of the organic tin-oxide reaction with up to five units of organic tin oxide per ester in the stanoxane polymer chain are described in U.S. Patent No. 2,783,632, by the inventor E.W. Johnson along with its use as stabilizers for resins. With respect to the polysiloxanes that catalyze, although tin-based catalysts have been used, polysanoxanes have not been taught for that use. For example, Belgian Patent 722,441, (1969) describes tetraorganic diestanoxanes as catalysts in organic polysiloxane compositions. See also British Patent 788,653, which discloses hexa-organic diestanoxanes as catalysts for silicone rubber. British Patent 845,651 and British Patent 930,470 also deal with the chemistry of a similar catalyst. SUMMARY OF THE INVENTION The present invention is directed to the use of a poliestanoxane of the following formula as a catalyst for the deblocking and curing of isocyanates, esterification and transesterification reactions and the curing of siloxanes: wherein each R is the same or different, and independently selected from alkyl groups having from 1 to 20 carbon atoms such as methyl, ethyl, propyl, butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, and the like ( preferably butyl or octyl), or aromatic groups such as phenyl, tolyl, xylyl, or benzyl; each X is the same or different and independently selected from halogen atoms (e.g., chlorine, bromine, iodine, etc.), hydroxyl groups, alkoxy groups (e.g., methoxy, ethoxy), propoxy, butoxy, etc.), carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic, acyloxy groups, for example formyloxy, acetoxy, propionyloxy, butyroyloxy, hexanolyloxy, lauroyloxy, oleoyloxy, palmitoyloxy, stearoyloxy, benzolyloxy, allylcarbonyloxy, cyanoacetoxy, benzyloyloxyalkyl , maleoyloxy, etc.), a mono-organic tin group of the formula R3 Sn-O- 0 I In which R3 is selected from the same group as R in the main formula, a triorganic tin group of the formula (R ^ SnO- in which each R2 is independently selected from the same group as R in the main formula; each Rj is the same or different and selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20 (the sum of n plus m is also referenced here as N) . These polysanoxanes are also excellent catalysts for the esterification and transesterification reactions as well as for catalyzing the silicone polymerization reactions. A curable composition is also provided which comprises: (i) a blocked isocyanate; (ii) a functional component reactive with the blocked isocyanate, the functional component containing reactive hydrogen, - and (iii) a polyesternoxane of the form defined above. The invention also includes a method for rapidly curing a blocked isocyanate at low reaction temperatures to release isocyanates. The method comprises heating a mixture of the polyesternoxane catalyst of the above formula, a blocked isocyanate and the functional component against a reaction temperature sufficient to initiate the release of the isocyanate and to produce a cured polyurethane. DETAILED DESCRIPTION This invention concerns polyestoxanes as catalysts for reacting or curing blocked isocyanates, especially blocked polyisocyanates of aliphatic alcohol, with a functional compound capable of reacting with an isocyanate and for catalysing esterification and transesterification reactions and silicone polymerization reactions. . With respect to the catalysts for reacting or curing blocked polyisocyanates, the present invention is based on the discovery that the polysanoxane catalysts of the above formula work at lower temperatures, (lower than about 180 ° C) than the poliestanoxanes of the same formula but having average values for the sum of n plus m of less than three or greater than 20, that is, approaching infinity as dibutyl tin oxide. The higher catalyst activity is particularly unexpected in view of the decrease in solubility of those poliestanoxanes as the value of N increases and the teaching in the closest prior art, the Yutaka patent, that the lowest temperatures are reached with N equal to zero against N equal to infinity. The polyesternoxane catalysts of the present invention are of the formula: X X R "-S -0 • S -O S" -R? R R X n m wherein each R is the same or different, and independently selected from alkyl groups having from 1 to 20 carbon atoms such as methyl, ethyl, propyl, butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, and the like ( preferably butyl or octyl), or aromatic groups such as phenyl, tolyl, xylyl, or benzyl; each X is the same or different and independently selected from halogen atoms (eg, chlorine, bromine, iodine, fluorine, etc.), hydroxyl groups, alkoxy groups (eg, methoxy, ethoxy, propoxy, butoxy, etc.), carbonate , phosphate, phosphinate, isocyanate, sulfonate, carboxylic, acyloxy groups, for example formyloxy, acetoxy, propionyloxy, butyroyloxy, hexanolyloxy, lauroyloxy, oleoyloxy, palmitoyloxy, stearoyloxy, benzolyloxy, allylcarbonyloxy, cyanoacetoxy, benzyloyloxyalkyl, maleoyloxy, etc.), a group of mono-organic tin of the formula R3 Sn-O- I In which R is selected from the same group as R in the main formula, a triorganic tin group of the formula (R2) 3SnO- in which each R2 is selected independently between the same group as R in the main formula; each Rj is the same or different and selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. However, to catalyze the esterification and transesterification reactions and the polymerization reactions of silicone, n is zero or an integer from 1 to infinity, m is zero or an integer from zero to infinity, and the sum of n plus m is zero or an integer from 1 to infinity. In the main formula O it is put for oxygen but sulfur would be equivalent. Mixtures, especially mixtures of two, three or four components of the above tin catalyst, can also be used.

Preferred catalysts of the invention are compounds with R which is butyl, octyl, phenyl or benzyl, or combinations thereof, where X OH, OOCR is the format or acetate or OR with R being butyl, octyl, phenyl or benzyl, and having N a value of 3 to 16. The catalytic activity seems to be better with N equal to 14 but those catalysts are difficult to dissolve. Although integers are set for n, m and N, the actual synthesis of those compounds results in a mixture so that n, m and N are actually average values for the mixture. Consequently, the values for n, m and N are not limited to whole cigars within the ranges established for m, n and N. In the same way a mixture of stanoxanes for which N has an average value of 3 is within the established range for N from 3 to 20 although some stanoxanes in the mixture have values for N of less than 3, for example, 2, while others have values of N greater than 3, for example 4. The compounds of the above formula can be producing by reflux in toluene for 15 to 30 minutes a mixture of a dialkyl tin oxide and a dialkyl tin (X) 2 in a molar ratio selected to produce the desired values for N, n and m. For example, starting with a mixture of 1.8 moles of dibutyl tin oxide and 0.3 moles of dibutyl tin dicarboxylate results in dibutylformyloxystanoxane with both N as n equal to 6 and m equal to 0 when the carboxylate is formate. The dibutylformyloxystanoxane produced in this way is a compound of the general formula, each R being butyl and each X being format. A synthetic route for polysanoxanes is also described in "Polimeric stannoxanes" by Davis, Alwyn, et al., Which appeared in the Journal of Organo etallic Chemistry, Vol. 10 (1967) and in "Organotin Chemistry, Part VII. Distannoxanes and Oligostannoxanes "J. Chem. Soc. 1970, 2030.) In another aspect of the present invention, it has been found that improved performance of polysanoxane catalysts such as reduced cure temperatures can be obtained by employing one or more cocatalysts with the catalyst of the present invention. These cocatalysts are preferably based on the elements of the VIIB Groups, VIII, IB, IIB, IVA or VA of the Periodic Table of the Elements such as manganese, cobalt, nickel, copper, zinc, zirconium, germanium, antimony or bismuth, especially compounds based on an element of the above groups of metals, such as bivalent metals, and particularly metal chelates, or oxides or salts of these metals and especially carbonate salts are preferred. Especially preferred metal elements are zinc, bismuth, and antimony, with zinc acetalacetate being the most preferred. Also included are combinations of the catalysts within the scope of the invention, especially combinations of two, three or four components. Representative salts of these cocatalyst metals are based on inorganic acids, carboxylic acids, hydroxy carboxylic acids, alcohols, glycols and phenols. Representative carboxylic acids include both mono- and dicarboxylic acids containing from 1 to about 20 carbon atoms and include saturated or unsaturated aliphatic and cycloaliphatic acids, and aromatic acids, and include formic, acetic, acrylic, methacrylic, propionic, butyric, hexanoic acids , octanoic, decanoic, stearic, oleic, eiconsanoic and benzoic. Examples of dicarboxylic acids include oxalic, malic, maleic, succinic, sebacic acids and the various phthalic isomeric acids. Typical carboxylic acids preferably contain from 2 to about 20 carbon atoms and include hydroxy, acetic, lactic, citric, tartaric, salicylic, and gluconic acids. Inorganic acids or mineral acids include carbonic acid, halogen acids such as hydrochloric acid, hydrobromic acid and hydroiodic acid, nitrogen acids, sulfur acids and phosphorus acids, all of which are known in the art. The alcohols comprise straight-chain or branched mono- or polyhydroxy chain alcohols, substituted or unsubstituted mononuclear or polynuclear mono- or polyhydroxy-cycloaliphatic alkyl alcohols and the like containing from 1 to about 20 carbon atoms. Phenols comprise mononuclear or polynuclear mono- or polyhydroxyphenols with substituted or unsubstituted alkyl. The carbonates of the above metals may exist as pure carbonates or as basic carbonates which are believed to be mixtures of the carbonate and the metal oxide or hydroxide in a single molecule and include metal carbonates such as basic zinc carbonate, basic copper carbonate and similar. The chelates of the aforementioned metals that can be employed can be based on any metal chelation compound known in the art but typically comprise beta-diketones such as acetylacetone to provide the acetylacetonates of the metals. Metal catalysts that are generally more suitable as cocatalysts are those that are soluble in the formulation especially if they are soluble in the functional compound, for example, the polyol resin, or soluble in the solvent if the formulation uses a solvent. Some specific metal catalysts that may be employed include zinc carbonate (basic), zinc acetylacetonate, zinc acetate, copper acetylacetonate, iron acetylacetonate, nickel acetylacetonate, zinc acetate, zinc lactate, and copper acetate. Those suitable metal cocatalysts are described in general terms, by Leiner and Bossert in U.S. Patent Number 4,395,528. The catalyst of the present invention can also be used in combination with other known urethane catalysts or catalysts for esterification, transesterification, or silicone polymerization, depending on the desired reaction to be catalyzed. The weight ratio of the polyesternoxane catalyst component to the metallic or non-metallic co-catalyst (s) is in the range of about 10: 1 to 1:10 and preferably 4: 1 to 1: 4. If the catalyst package comprises tin-containing catalysts alone or in combination with co-catalysts, the percentage by weight of tin is based on the weight of the resin components, ie, the blocked isocyanate, and the functional component containing the active hydrogen capable of reacting with the blocked isocyanate, should be in the range of about 0.02. % to 2%, preferably from 0.05% to 1% and ideally in the range of approximately 0.1% to 0.5%. These percentages and all other proportions used herein are by weight unless otherwise stated. In the present invention, the term "a blocked isocyanate" is used in its ordinary meaning for those skilled in the art, who understand that it means a compound containing blocked isocyanate groups in its structure obtained by the addition reaction of an isocyanate with an isocyanate blocking agent. The isocyanate compounds which can be blocked for stability and subsequently deblocked are well known and include both aliphatic isocyanates and aromatic isocyanates. Examples of aliphatic polyisocyanates are tetramethylene diisocyanate, hexamethylene diisocyanate. Examples of aromatic isocyanates are phenylene diisocyanate, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), diphenylethane diisocyanate (EDI), naphthylene diisocyanate, diphenylmethane triisocyanate, dithylene diisocyanate, dianisidine diisocyanate, triphenylmethane triisocyanate, diphenylether triisocyanate, omega, dimethylbenzene diisocyanate (MXDI) and dimers and trimers of the above isocyanates. Also suitable are addition products having two or more terminal NCO groups obtained by reacting a surplus amount of the aforementioned isocyanates with lower molecular active hydrogen compounds such as ethylene glycol, propylene glycol, butylene glycol, propane. trimethylol, hexanetriol, glycerol, sorbitol, pentaerythritol, castor oil, ethylenediamine, hexamethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or with polymeric compounds having active hydrogen atoms such as polyether based or polyester based polyols. Also suitable are organic polyisocyanate prepolymers such as a prepolymer derived by the reaction of a polyol with a polyisocyanate in a proportion having a slight excess of isocyanate groups, so that the prepolymer contains isocyanate end groups. Of the polyisocyanate compounds, polyisocyanates such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), dimethylbenzene diisocyanate (MXDI) diphenylethane diisocyanate (EDI), and addition products having two or more NCO groups are preferred. terminals obtained by the addition of the excess amount of said aromatic polyisocyanate with the aforementioned low or high molecular weight compounds containing active hydrogen atoms. Examples of isocyanate blocking agents are those commonly employed in the art, such as various phenolic compounds, for example, phenol, thiophenol, chlorophenol, methylthiophenol, ethylphenol, ethylthiophenol, nitrophenol, cresol, xyleneol or resorcinol.; alcohols such as ethanol, methanol, propanol, isopropanol, butanol, tertiary butanol, tertiary pentanol, tertiary butanethiol or tertiary hexanol, or derivatives thereof such as ethylene chlorohydrin, omega-hydroperfluoroalcohols or 1,3-dichloro-2-propanol; aromatic amines such as diphenylamine, diphenylnaphthylamine or silidine; imides such as succinic acid imide or phthalic acid imide; active methylene compounds such as acetoacetic acid esters, acetylacetone or malonic acid diesters; mercaptans such as 2-mercapto benzothiazole or tertiary dodecyl mercaptan, -pyrazoles such as 3,5-dimethylpyrazole, lactams such as epsilon-caprolactam, delta-valerolactam, gamma-butyrolactam or beta-propyl-lactam, imines such as ethyleneimine, urea such as urea, thiourea or diethyleneurea, oximes such as acetoxime, methylethyl ketone oxime, or cyclohexanone oxime, diaryl compounds such as carbazole, phenylnaphthylamine or N-phenyl xylidine, bisulfates and borates. Of these blocking agents, phenolic compounds and ethanol are preferable. The blocked isocyanate can be easily prepared in a known manner, for example, by reacting a polyisocyanate compound with an equivalent or a slight excess amount of an isocyanate blocking agent in the presence or absence of a solvent that does not have a hydrogen atom active, such as ketones, esters or aromatic hydrocarbons at room temperature or at about 40 ° C to about 120 ° C. Preferred functional compounds for reacting with the blocked isocyanate are ester containing polyols and ether containing polyols. These compounds are well known in the art for making polyurethanes. Examples are polyols obtained by the polymerization by the addition of one or more alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, or styrene oxide, for one or more polyols, such as the initiator, such as ethylene glycol, diethylene glycol, propylene glycol, glycerol, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, sucrose, mannitol, sorbide, mannitol, or sorbitan, or for amines such as ethylenic diamine, propylenic diamine, and ethanolic amine under alkaline or acidic conditions. Polyether polyol resins are particularly suitable for use as the functional component mentioned as the preparations as described in the publication entitled "High Polymer Vol. XIII Polyethers Part 1" (1963) by Norman G. Gaylord published by Interscience Publishers, New York, NY the molecular weight of the polyether polyols can be varied depending on the purpose, and is generally selected from the range of about 300 to about 3,000, preferably about 400 to about 2,000. Ester-containing polyol resins are also preferred as the functional component such as those obtained by the reaction of a polyol with a polycarboxylic acid. For example, polyols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, butylene glycol, trimethylolpropane, glycerol, hexanetriol or pentaerythritol can be reacted with one or more polycarboxylic acids such as oxalic acid, succinic acid , glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, or their acid anhydrides. Acrylic polyester polyols are another commercially useful class of suitable polyols. The polyester polyols are prepared in a known manner as described in the publication entitled "Polyesthers and Their Application", April 1959, published by Bjorksten Research Lab., Inc., New York, N.Y. The molecular weight of the polyester polyols can vary depending on the desired purpose, and is generally selected from the range of about 300 to about 3000, preferably about 400 to about 2000. The functional compound or functional component may also comprise a resin that is an adduct of a primary and / or secondary amine with an epoxy-containing resin or a resin that is an amino acid salt adduct with a polyepoxide. The functional compounds or components containing reactive hydrogen suitable for practicing the present invention are well known and described in patents such as US Patents Numbers 3,084,177; 3,240,730; 3,392,128 and 3,392,153, from the inventors Hostettler et al. The invention also relates to a method for rapidly curing a blocked isocyanate at low reaction temperatures to release an isocyanate. The method comprises heating a mixture of the polyesternoxane catalyst, a blocked isocyanate and the functional component to a reaction temperature sufficient to initiate the release of the isocyanate and to produce a cured polyurethane. When the isocyanate is blocked with a 2-ethylhexyl group, the mixture is heated to a reaction temperature as low as about 150 ° C for deblocking and curing. When the isocyanate is a blocked oxime isocyanate, for example methyl ethyl ketoxime, said reaction temperature may be as low as about 110 ° C to 115 ° C provided there is a soluble metal co-catalyst such as zinc acetylacetonate is used in combination with the polyesternoxane of the present invention between 140 ° C to 150 ° C with dibutyl tin dilurate catalyst. When the isocyanate is blocked with a lactam group, said reaction temperature can be as low as about 135 ° C to 140 ° C when a soluble metal catalyst such as zinc acetylacetate is also used between 160 ° C to 175 ° C. with dibutyl tin dilurate catalyst. When the isocyanate is blocked with 2-ethylhexanol, the reaction temperature is low especially when a soluble metal cocatalyst such as zinc acetylacetate is also used between 180 ° C to 200 ° C with the dibutyl tin dilurate catalyst. When the isocyanate is blocked with 3,5-dimethylpyrazole, the temperature of the reaction is low, especially when a soluble metal catalyst such as zinc acetylacetate is also used between 140 ° C with dibutyl tin dilurate catalyst. When the isocyanate is blocked with diethyl malonate, the reaction temperature is low especially when a soluble metal cocatalyst such as zinc acetylacetate is also used between 120 ° C to 135 ° C with dibutyl tin dilurate catalyst. The following commercially available ingredients are preferred for practicing the present invention for polyurethane reactions: (a) Acrylic polyols - Desmophen A565 (Miles, Inc.), Joncryl 500 (SC Johnson), (b) Polyester polyols - Desmophen 680 -70 (Miles Inc.), K-Flex 188 (King Industries), Rucote 104 (Ruco), (c) Polyether polyols - Desmophen 1600 U (Miles, Inc.), (d) polybutadiene polyol - Poly bd R45HT (Elf Atochem), (e) blocked hexamethylene diisocyanate, Desmodur Bl 3175A (Bayer), (f) blocked isoperone diisocyanate caprolactam, Vestagon B 1530 (Huís). An improved process is also provided for catalyzing the making of a polyurethane from reagents containing an isocyanate and a catalyst wherein the improvement comprises using as a catalyst both to release the isocyanate and for the formation of polyurethane, a polyesternoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- II wherein R ^ is selected from the same group as R, or a triorganic tin group of formula (R ^ SnO- in which each R is selected from the same group as R, each Rj is the same or different and is selected between the same groups as R or X, n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. With respect to the esterification reactions and transesterification, the improved process uses conventional compounds capable of esterification or transesterification reactions and a catalyst for these reactions, the improvement comprises using as a catalyst, a poliestanoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- in which R is selected from the same group as R, or a triorganic tin group of formula (R2) 3SnO- in which each R is selected from the same group as R, - each Rj is the same or different and is selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. Likewise, with respect to the catalyzed polysiloxane reactions of the reactants that form polysiloxane, the improvement comprises using as a catalyst, a poliestanoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- in which R3 is selected from the same group as R, or a triorganic tin group of formula (R ^ SnO- in which each R2 is selected from the same group as R, each Rj is the same or different and is selected from the same groups as R or X, n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. The following examples illustrate The invention Commercially available chemicals in the examples are described more specifically as follows, Desmophen A565 is a polyacrylate having hydroxyl available as a 65 percent solution in xylene.It has an OH content of about 2.7 percent, an OH equivalent in weight of 600, an acid value less than 10, a density of 1.03 g / cm3 at 20 ° C and a viscosity of approximately 1000 mPa at 23 ° C and is available in the United States of America at Miles, Inc. ( Bayer) .Desmodur BL3175A is also available at Miles, Inc. and is a dii blocked hexamethylene socianate having a blocked NCO content of 11.3 percent, an average equivalent weight of 372 and a viscosity between 2000 and 4000 mPa.s at 23 ° C. In all examples the following procedures were used with a formulation consisting of a functional resin, a polyisocyanate crosslinker, solvent (s) and catalyst. The formulations were shaken well to ensure complete homogeneity before evaluation. With some solid catalysts it was necessary to heat the formulation at 50 ° C for 1-4 hours for complete solubility of the catalyst. In other cases a convenient mixture of solvents was used to dissolve previously the catalyst before incorporation. The ratio of NCO / OH in the formulation was between 1.1 to 1.2. The solids content was maintained between 50-60 percent. The comparison of catalyst activity was determined by monitoring the viscosity as a function of the cure time. A Brookfield viscometer adapted with a hot cell was connected to a strip graph register. An aliquot of 10 grams of the formulation with the desired catalyst was placed in the chamber and rapidly heated to the test temperature. A speed spindle # 27 was immersed in the solution and the initial viscosity was measured. The rate of increase in viscosity was monitored until a viscosity of 2500 cps was reached. In case of all the examples the formulation gelled at this viscosity. The time required to reach this viscosity was named "gel time" at the test temperature. This technique provides information on the time required to reach a target viscosity and on the rate of viscosity increase for a given system and compares the relative reactivity of different catalysts in a specific formulation at the same temperature. The variability in gel time is +/- 0.5-1.0 minutes and is limited by the precision of weighing the catalyst. The lower gel time shows better, that is, faster, catalytic activity. The gel time measurements correlated with the properties of the film. The properties of the film were evaluated by comparing the quality of the coating of the curing with a test of rubbing of solvent and an acid corrosion test. The formulations containing the catalyst coated 316 stainless steel panels and cured at different temperatures. The cured panel was subjected to solvent resistance and acid corrosion tests. The solvent resistance was determined with double rubs of methyl isobutyl ketone and the number of rubbed doubles was recorded to wear the film. The panel is examined at regular intervals during the rubbing test to determine if the surface has been damaged. The number of double rubs needed to damage the surface is recorded. If there is no effect on the surface after 100 rubs then the registered value is >100 rubbed doubles. Acid corrosion was measured by placing several drops of a 50 percent sulfuric acid solution on a coated panel, covering the panel with a glass jar and evaluating the panel for swelling, blistering or softening at regular intervals over a period of 24 hours. The films were also prepared in sheets of clear glass to monitor the development of color. Control experiments were carried out using dibutyl tin oxide (N = infinite) and tetrabutyl diacetoxiestanoxane (N = 0) as reference catalysts. The catalysts were compared on an equal Sn basis.

EXAMPLES 1 to 8 from A to J In the comparative examples from A to J and operating examples 1 to 8, a master batch of the following mixture was prepared. The components were stirred to ensure complete solubility usually from 2 to 4 hours. - Desmophen A565 (215 grams, 42.9 percent by weight) - Desmodur BL 3175 A (140 grams, 27.9 percent by weight) - methylamyl ketone (58.5 grams, 11.7 percent by weight) - methyl isobutyl ketone (58.5 grams, 11.7 percent by weight) - propylene glycol methyl ether acetate (29.0 grams, 5.8 percent by weight) For each evaluation, a 10 gram aliquot of this masterbatch was removed and the appropriate catalyst was added. The results of Examples 1-8 and A-J are shown in Table 1.

EXAMPLES 9 to 12 and K In comparative example K and operating examples 9 to 12, a master batch of the following mixture was prepared. The components were stirred to ensure complete solubility usually from 2 to 4 hours. - Desmophen A565 215 grams - Desmodur BL 3175 A 140 grams - methylisobutyl ketone 146.4 For each evaluation, a 10 gram aliquot of this masterbatch was removed and the appropriate catalyst was added. The formulations chosen for the examples were designated for comparison of catalyst performance. The results are summarized in Tables II to IV. In the examples the organic tin catalysts of the present invention were synthesized, evaluated and compared with dibutyl tin oxide (N = infinite) and tetrabutyldiacetoxiestanoxane (N = 0) to represent the closest organic tin catalyst of the prior art and with commercial catalysts dibutyl tin diacetate and dibutyl tin dilurate. The catalysts of the present invention demonstrated improved performance characteristics in blocked HDI oxime-acrylic polyol systems compared to butyl diastane dilaurate and tetrabutyl diacetoxannoxane. Gel time measurements show reactivity at least 20 percent faster with the catalyst of the present invention. The films were prepared using a 0.1 millimeter extraction bar (dry film of 0.05 millimeters) and cured at 130 ° C. Again, this temperature was selected to demonstrate the performance differences between catalysts. The panels were cured at 130 ° C with a catalyst of the present invention with 0.16 percent Sn giving very good film properties. The cured formulation resists 75 double rubs with methyl ethyl ketone and is not attacked by 50 percent sulfuric acid solution or xylene solution while 100 double rubs of methyl ethyl ketone at 130 ° C were achieved with the catalyst with 0.25 percent Sn in the formulation. Under the same conditions, the cured coating of dibutyl tin dilaurate is immediately attacked by methyl ethyl ketone and by 50 percent sulfuric acid. Complete cure (> 100 rubs with methyl ethyl ketone) with dibutyl tin dilaurate would require a curing temperature of 140 ° C. This reduced cure temperature could not be achieved simply by increasing the level of use of dibutyl tin dilaurate (requires 140 ° C for complete cure). The ability to perform complete cure at a lower -10 ° C temperature is significant as it allows one-component urethane formulations to compete with other coating technologies particularly on temperature-sensitive substrates. The coating compositions used in the examples were formulated without any pigment or filler so as not to add an unnecessary variable in the comparison. However, the compositions of the present invention can be used in mixtures and coating formulations that have additional additives such as pigments and fillers, or additives that are intended to impart other functional activities to coatings such as biocides., fungicides or the like according to well-known practices in the coating art. When selecting a polyisocyanate catalyst of the present invention for use in a specific formulation it is preferred to use a liquid catalyst or a catalyst that is soluble in the solvent system employed in the coating composition. The liquid organic tin catalysts are preferably used because the dispersion of the catalyst in the formulation is more easily obtained. Preferred solvents for use in the formulation are methyl ethyl ketone (MEK), methyl amyl ketone (MAK), methyl isobutyl ketone (MIBK) and mixtures of pentadione and methanol or propylene glycol with methylethylacetate. In addition, the resin or other polyol can act as a solvent for the catalyst. The coating compositions of the present invention can be applied to metal or polymeric substrates including both thermoplastic and thermoset polymers, especially polyolefins, phenolics, polyvinyl chlorides, polyvinylidine chlorides and fluorides, polyesters, ABS polymers, acrylics, epoxies, polyamides, Teflon® and the like. It will be apparent to those skilled in the art that various modifications and variations can be made to the curable composition containing a catalyst for the low temperature cure of the blocked isocyanates as well as to the method of the invention to obtain these reactions at low temperature without departing of the spirit or scope of the invention. It is intended that these modifications and variations of this invention be included as part of the invention, as long as they fall within the scope of the appended claims or their equivalents. The best mode known at present for practicing the present invention is with a poliestanoxane of the formula which is soluble in a component of the curable composition or in a solvent which is also solvent for one of the components in the composition. Particularly convenient are dibutyl diacetoxannoxane, especially with n = 6. Dibutyldiformyloxyphenoxanes are also very convenient, especially when used with a cocatalyst. Zinc acetylacetonate is the preferred cocatalyst. The preferred ratio of dibutyldiacetoxiestanoxane (n = 6) to zinc acetylacetonate is 1.13: 1, with 0.07% stannoxane based on the combined weight of isocyanate and polyol. Variations in the selection of polysanoxane catalyst, cocatalyst and solvent should be made based on the blocked polyisocyanate and the polyol used.

Claims (36)

1. A curable coating composition comprising: (i) a blocked isocyanate; (ii) a functional component containing at least one active hydrogen reactive with the blocked polyisocyanate; and (iii) a polyesternoxane catalyst for the reaction of the blocked polyisocyanate with the functional component, of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- in which R3 is selected from the same group as R, or a triorganic tin group of formula (R 3SnO- in which each R2 is selected from the same group as R; each R i is the same or different and is selected from the same groups as R or X, - n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer of 3 to 20. The curable composition of claim 1 wherein the R is independently selected from the group consisting of methyl, ethyl, propyl, butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, phenyl, tolyl, xylyl , and benzyl, and the sum of n plus m is from 3 to 16. 3. The curable composition of claim 2 wherein each X is independently selected from the group consisting of -OH, formate, acetate or -OR4 being R butyl , octyl, phenyl or benzyl, and the sum of n plus m is from 3 to 16. 4. The composition of claim 3, wherein the R is independently selected from the group consisting of methyl, ethyl, propyl, butyl, isopropyl. , amyl, hexyl, heptyl, lauryl, octyl, phenyl, tolyl, xylyl, or benzyl. 5. The curable composition of claim 4, wherein each R is butyl or octyl, and each X is formyloxy acetoxy. The composition of claim 1, wherein each X is independently selected from the group consisting of halogen, methoxy, ethoxy, propoxy, butoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, formyloxy, acetoxy, propionyloxy, butyroyloxy, hexanolyloxy , lauroyloxy, oleoyloxy, palmitoyloxy, stearoyloxy, benzolyloxy, allylcarbonyloxy, cyanoacetoxy, maleoyloxy, a mono-organic tin group of the formula R3 Sn-O-II In which RJ is selected from the group consisting of methyl, ethyl, propyl , butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, phenyl and benzyl, and a triorganic tin group of the formula (R2) 3SnO- in which each R 2 is selected from the group consisting of methyl, ethyl, propyl , butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, phenyl and benzyl. The composition of claim 6 wherein X is independently selected from the group consisting of chlorine, bromine, iodine, hydroxyl, methoxy, ethoxy, propoxy, butoxy, carbonate, phosphate, isocyanate, sulfonate, acetoxy, formyloxy, propionyloxy and butyroxy . The composition of claim 2, wherein the blocked isocyanate is a blocked polyisocyanate and the reactive functional component with the blocked polyisocyanate comprises a polyfunctional component containing at least one hydroxyl hydrogen. 9. The curable composition of claim 2, wherein the catalyst is a liquid at room temperature. The composition of claim 2 wherein the polyesternoxane catalyst constitutes 0.02 percent to 2 percent of the total weight of the blocked isocyanate and the functional component. The composition of claim 10 wherein the polyesternoxane catalyst constitutes 0.1 percent to 0.5 percent of the total weight of the blocked isocyanate and the functional component. The curable composition of claim 1, further comprising a cocatalyst containing a metal element selected from the group consisting of manganese, cobalt, nickel, copper, cerium, zirconium, iron, zinc, germanium, antimony, or bismuth. The composition of claim 12, wherein the polyesternoxane catalyst constitutes 0.1 percent to 0.5 percent of the total weight of the blocked isocyanate and the functional component, each R is butyl, each X is formyloxy or acetoxy, the sum of n plus m is from 3 to 14, the cocatalyst is selected from the group consisting of zinc acetylacetonate, copper acetylacetonate, iron acetylacetonate, nickel acetylacetonate, zirconium acetylacetonate, bismuth acetyl acetonate, zinc acetate and zinc lactate, and the weight ratio of the poliestanoxane catalyst against the cocatalyst is in the range of 4: 1 to 1: 4. The curable composition of claim 12, wherein the metal-containing cocatalyst is a chelate, oxide or salt of the metal element. 15. The curable composition of claim 14, wherein the metal-containing cocatalyst is a salt. The curable composition of claim 15, wherein the metal salt is a salt of an inorganic acid, a carboxylic acid or a hydroxycarboxylic acid, or based on an alcohol, glycol or phenol. The curable composition of claim 16, wherein the metal-containing cocatalyst is a salt of a mono or dicarboxylic acid containing from 1 to about 20 carbon atoms. The curable composition of claim 17, wherein the mono or dicarboxylic acid is selected from the group consisting of acetic, acrylic, methacrylic, propionic, butyric, hexanoic, octanoic, decanoic, stearic, oleic, eicosanoic, benzoic, oxalic acids , malic, maleic, succinic, sebacic and phthalic. 19. The curable composition of claim 15, wherein the metal-containing cocatalyst is a salt of a hydroxycarboxylic acid containing from 2 to 20 carbon atoms. The curable composition of claim 18, wherein the hydroxycarboxylic acid is selected from the group consisting of hydroxyacetic, lactic, citric, tartaric, salicylic, and gluconic acid. The curable composition of claim 15, wherein the metal-containing salt is a salt of an inorganic acid selected from the group consisting of carbonic, hydrochloric, hydrobromic, hydriodic, nitric, sulfuric and phosphoric acids. 2

2. The curable composition of claim 12, wherein the metal-containing cocatalyst is a chelate. 2

3. The curable composition of claim 22, wherein the metal chelate is selected from the group consisting of zinc acetylacetonate, copper acetylacetonate, iron acetylacetonate, zirconium acetylacetonate, bismuth acetylacetonate, nickel acetylacetonate, zinc acetate, and zinc lactate. 2

4. The curable composition of claim 23, wherein the metal chelate is a metal acetylacetonate. 2

5. The curable composition of claim 1, wherein the catalyst is soluble in another component of the curable composition or in a solvent for at least one component of the composition. 2

6. The curable composition of claim 12, wherein the metal-containing cocatalyst is soluble in another component of the curable composition or in a solvent for at least one component of the composition. 2

7. The curable composition of claim 26, wherein the metal-containing cocatalyst is soluble in the functional compound. The composition of claim 12 wherein the weight ratio of the polyesternoxane catalyst against the cocatalyst is in the range of 10: 1 to 1:10. 29. The composition of claim 28 wherein the weight ratio of the poliestanoxane catalyst against the cocatalyst is in the range of 4: 1 to 1: 4. 30. A process for curing a blocked isocyanate at a temperature below about 180 ° C comprising forming a mixture of: (i) a blocked isocyanate; (ii) a functional component containing at least one active hydrogen reactive with the blocked isocyanate; and (iii) a polyesternoxane catalyst for the reaction of the blocked polyisocyanate with the functional component, of the formula: wherein each R is the same or different, and is independently selected from the group consisting of methyl, ethyl, propyl, butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, phenyl, tolyl, xylyl, and benzyl groups; each X is the same or different and independently selected from the group consisting of chlorine, bromine, iodine, hydroxyl, methoxy, ethoxy, propoxy, butoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, formyloxy, acetoxy, propionyloxy, butyroyloxy, hexanolyloxy , lauroyloxy, oleoyloxy, palmitoyloxy, stearoyloxy, benzolyloxy, allylcarbonyloxy, cyanoacetoxy, benzyloyloxyalkyl, maleoyloxy, a mono-organic tin group of the formula R3 Sn-O- I in which RD is selected from the same group as R, and a triorganic tin group of the formula (R) 3SnO- in which each R2 is selected from the same group as R; each Rj is the same or different and selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20; and the mixture is cured at a temperature below about 150 ° C. The process of claim 30, wherein the blocked isocyanate is a blocked polyisocyanate and the reactive component functional with the blocked polyisocyanate is a polyol. 32. The process of claim 30, wherein the catalyst is liquid at about room temperature. 33. A process for coating a substrate comprising: (a) contacting the substrate with a curable coating composition comprising: (i) a blocked isocyanate, - (ii) a functional component containing at least one active hydrogen and reactive with the blocked reactive component, - and (iii) a catalyst for promoting the reaction of the reactive component with the functional component, comprising a poliestanoxane of the formula: wherein each R is the same or different, and is independently selected from the group consisting of methyl, ethyl, propyl, butyl, isopropyl, amyl, hexyl, heptyl, lauryl, octyl, phenyl, tolyl, xylyl, and benzyl groups; each X is the same or different and independently selected from the group consisting of chlorine, bromine, iodine, hydroxyl, methoxy, ethoxy, propoxy, butoxy, carbonate, formyloxy, acetoxy, propionyloxy, butyroyloxy, hexanolyloxy, lauroyloxy, oleoyloxy, palmitoyloxy, stearoyloxy , benzolyloxy, allylcarbonyloxy, cyanoacetoxy, benzyloyloxyalkyl, maleoyloxy, a mono-organic tin group of the formula R3 Sn-O-0 in which R3 is selected from the same group as R, and a triorganic tin group of the formula ( R2) 3Sn0- in which each R2 is selected from the same group as R; each R i is the same or different and selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20; and the coating is cured at a temperature above ambient and below about 180 ° C. 34. An improved process for catalyzing the making of a polyurethane from reagents containing a blocked isocyanate and a catalyst wherein the improvement comprises using as a catalyst to release the isocyanate and for the formation of the polyurethane, a polyesternoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O-II or wherein R3 is selected from the same group as R, or a triorganic tin group of formula (R2) 3SnO- in which each R2 is selected from the same group as R; each Rj is the same or different and is selected from the same groups as R or X; n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. 35. An improved process of the esterification or transesterification reaction from reactants capable of to enter an esterification or transesterification reaction and a catalyst for these reactions where the improvement comprises using as the catalyst, a polyesternoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- 0 wherein R3 is selected from the same group as R, or a triorganic tin group of formula (R2) 3SnO- in which each R2 is selected from the same group as R; each Rj is the same or different and is selected from the same groups as R or X; n is an integer of 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20. 36. An improved process to catalyze the making of a polysiloxane from reagents that form poliestanoxane and a catalyst for this reaction wherein the improvement comprises using as a catalyst, a poliestanoxane of the formula: wherein each R is the same or different, and is independently selected from an alkyl group having from 1 to 20 carbon atoms and an aromatic group, each X is the same or different and is independently selected from halogen, hydroxyl, alkoxy, carbonate, phosphate, phosphinate, isocyanate, sulfonate, carboxylic acid, acyloxy, a mono-organic tin group of formula R3 Sn-O- wherein R3 is selected from the same group as R, or a triorganic tin group of formula (R2) 3SnO- in which each R is selected from the same group as R; every R? is the same or different and is selected from the same groups as R or X, - n is an integer from 1 to 20, m is an integer from zero to 19, and the sum of n plus m is an integer from 3 to 20 . TABLE I blocked HDI + acrylic polyol + MIBK + MAK Table II blocked HDI + acrylic polyol + MIBK + MAK TABLE III Sn salts as blocked HDI cocatalysts + acrylic polyol * acet acetonato e z nc TABLE IV PROPERTIES OF THE FILM