NZ335210A

NZ335210A - Room temperature catalyst suitable for use in polyurethane compositions comprising the reaction product of a titanium, zirconium, hafnium or aluminium orthoester and a beta-diketone or beta-ketoester and a complexing agent such as a mercapto compound

Info

Publication number: NZ335210A
Application number: NZ335210A
Authority: NZ
Inventors: Christopher John Skinner; John Ridland
Original assignee: Tioxide Specialties Ltd
Priority date: 1996-10-05
Filing date: 1997-09-19
Publication date: 2000-01-28
Also published as: CN1239484A; KR20000048918A; AU4312697A; AU735671B2; TR199901203T2; CZ118099A3; IL129303A0; CA2267773A1; EP0929585A1; TW394782B; WO1998015585A1; AR008869A1; PL332641A1; HUP0000438A2; ID17410A; NO991616D0; JP2001501534A; NO991616L; BR9711862A

Abstract

his catalyst, which is suitable for use in polyurethane compositions, comprises the reaction product of: (a) the reaction product of a titanium, zirconium, hafnium or aluminium orthoester and a 'beta'-diketone or 'beta'-ketoester and ( (b) a complexing agent selected from a mercapto compound, an oxazolidine or a tetrahydro-oxazine. The catalyst is particularly useful for preparing coating compositions which have a long pot life and can be cured at room temperature.

Description

<div class="application article clearfix" id="description"> WO 98/15585 PCT/GB97/02565 CATALYSTS This invention relates to catalysts and in particular to catalysts for use in the preparation of polyurethanes There is currently much change in the industrial coatings market place 5 Coating applications are becoming increasingly more demanding in terms of performance, safety and environmental compliance. Many traditional coating chemistries are finding it impossible to survive in this rapidly changing climate Polyurethane coatings has been one technology that has enjoyed substantial growth in this field and their success lies in the fact that polyurethane coatings provide superior chemical resistance, flexibility, 10 abrasion resistance, weathering and impact resistance The protection afforded by such coatings is of particular significance in the automotive, construction, marine and chemical sectors Polyurethane coatings, films, sealants and foams are made by reacting hydroxyl containing polymers and polyisocyanates according to the isocyanate addition 15 polymerisation process. The reaction between the isocyanate groups and the active hydrogen atoms of the hydroxyl containing polymer is usually accelerated by the means of catalysts. Tertiary amines and metal compounds have been used as catalysts, examples being tnethylene diamine, tin(ll) octoate and di-n-butyl tin dilaurate However, the prior art catalysts have disadvantages. In the case of amines, this is manifested by lower catalytic 2 o activity mol per mol than metal based catalysts, odour and toxicity Many of the traditional metal catalysts also demonstrate an activity that is high but difficult to control appropriately for some apolications According to the invention, there is provided a catalyst comprising the reaction product of: 2 5 (a) the reaction product of a titanium, zirconium, hafnium or aluminium orthoester and a (1-diketone or 15-ketoester having the general formula 0 O where R\ R2 and R3 may be independently selected from the group consisting of hydrogen and alkyl, aryl, cycloalkyl, alkoxy, aryloxy, hydroxyalkyl, alkoxyalkyl and 3 o hydroxyalkoxyalkyl groups containing up to eight carbon atoms, and Printed from Mimosa WO 98/15585 PCT/GB97/02565 (b) a complexing agent selected from a mercapto compound or an oxazolidine or a tetrahydro-oxazine having the general formula (A) or (B) respectively, (A) (B) in which R10 is hydrogen or an alkyl group and X is a hydroxyalkyl group, or mixtures 5 thereof Preferably, the orthoester has the formula M(OR)4 in which M is titanium or zirconium and R is an alkyl group, a cyeloalkyl group or an aryl group. More preferably R contains 1 to 8 carbon atoms and particularly suitable orthoesters include tetra/sopropoxy titanium, tetra-n-butoxy titanium, tetra-n-propoxy zirconium and tetra-n-butoxy zirconium 10 Preferably the li-diketone or IJ-ketoester is selected from acetyiacetone, methylacetoacetate, ethylacetoacetate or terf-butylacetoacetate and the molar ratio of titanium, zirconium, hafnium or aluminium orthoester to the IJ-diketone or li-ketoester is from 1.0.5 to 1:4. Reaction products of mixtures of both types of ligand and of titanium, zirconium, hafnium or aluminium orthoesters containing more than one alkoxy group are 15 within the scope of the invention More preferably the fi-diketone or IJ-ketoester is acetyiacetone or ethylacetoacetate and the molar ratio of titanium, zirconium, hafnium or aluminium orthoester to acetyiacetone or ethylacetoacetate is from 1:1 to 1:4 A variety of mono-functional or poly-functional mercaptans can be used to advantage. Representative mercaptans include, for example, trimethylol propane 20 trithioglycolate, pentaerythritol fefra/as-(3-mercapto propionate), ethylene glycol jb/s-(3-mercapto propionate), ethylene glycol di-mercapto acetate, mercapto propionic acid and esters thereof, trimethylol propane Ms-(3-mercaptopropionate), toluene-3,4-dithiol, a, a'-dimercapto-p-xylene, dodecane dithiol, didodecane dithiol, 3,4-dimercaptotoluene, dimercapto benzothiazole, allyl mercaptan, methylthioglycolate, benzyl mercaptan, 25 1-octane thiol, para-thiocresot,cyclohexyl mercaptan, dith loeryth ritol, 6-ethoxy-2-mercaptobenzothiazole, 1,6-hexane dithiol, d-limonene dimercaptan, and the like and mixtures thereof In addition to monofunctional or polyfunctional mercaptans, monomer or oligomer compounds can be synthesised or modified to contain pendant mercaptan or thiol groups. 30 Preferably, the mercapto compound is selected from trimethylolpropane Printed from Mimosa WO 98/15585 PCT/GB97/02565 fr/s-(3-mercaptopropionate), pentaerythritol fefra/c/s-(3-mercaptopropionate), ethylene glycol jb/s-(3-mercaptopropionate) and pentaerythritol fe/ra/cfs-(2-mercaptoacetate) and mixtures thereof More preferably the mercapto compound is selected from pentaerythritol fefrak/s-(3-mercaptopropionate), ethylene glycol ib/s-(3-mercapto propionate) and 5 pentaerythritol fefra/c/s-^-mercaptoacetate) and mixtures thereof In one embodiment, the complexing agent is an oxazolidine or a tetrahydro-oxazine having the formula (A) or (B) respectively as hereinbefore defined Preferred complexing agents of this embodiment are oxazolidines having formula (A) In formula (A) or (B), R10 is hydrogen or an alkyl group preferably 10 containing up to 8 carbon atoms. Suitable alkyl groups include methyl, ethyl, propyl, isopropyl and butyl groups X is a hydroxyalkyl group preferably containing up to 6 and more preferably up to 4 carbon atoms Particularly preferred complexing agents are compounds in which X is a hydroxyethyl or a hydroxypropyl group. Sufficient complexing agent must be present relative to the reaction 15 product of a titanium, zirconium, hafnium or aluminium orthoester and a ft-diketone or IJ-ketoester in order that the hydroxyl containing polymer/ polyisocyanate reaction mixture containing the catalyst has a pot life suitable for the particular application The pot life of a reaction mixture is normally defined as the time required for the viscosity of the mixture in an open pot to double from its initial viscosity 2o The catalyst of the present invention provides the ability to formulate a catalysed reaction mixture which has a very long and useful pot life without the need for formulating specifically designed resins, curing agents, or the like A further advantage is that the catalysed reaction mixture need not be heated to achieve cure, although it can be heat cured if desired Furthermore it is often found that utilisation of the catalyst of this 25 invention will allow lower cure temperatures or shorter cure times when compared to standard catalyst technology. Yet another advantage is the ability to form harder and more corrosion resistant films than allowed by previous catalyst technology. The catalyst of the invention is usually added to the reaction mixture in an amount in the range 0.005 per cent to 0 5 per cent by weight with respect to weight of 3 o reaction mixture Conventional urethane coatings may be provided as two separate packages (a two-pack system) One component (Part 1), typically, is the hydroxyl containing polymer while the second component (Part 2) is the polyisocyanate. Solvents and other conventional paint additives may be added to each component in accordance 35 with conventional teachings The catalyst is often included in the hydroxyl containing Printed from Mimosa WO 98/15585 PCT/GB97/02565 4 polymer to avoid premature gelation of the polyisocyanate Occasionally, the catalyst package is not added to either Part 1 or Part 2 until just prior to application of the coating composition Application of conventional two-pack coating compositions typically takes place by the admixture of the two components just before application which may be by 5 conventional roll coat, reverse rollcoat, or other conventional tactile means, or can be by spray techniques. Regardless of the application technique, the two components are kept separate in order to prevent premature reaction with attendant viscosity increase which prevents effective application The applied coatings are often baked in order to speed the cure and ensure expulsion of solvent and gases from the applied film, lo The invention also provides for the use of the catalyst as hereinbefore defined in the reaction between a hydroxyl containing polymer or mixture of hyJroxyl containing polymers and an isocyanate containing compound or a mixture of isocyanate containing compounds. The hydroxyl containing polymers for use in the present invention include 15 in particular polyesters, polyesteramides, polyethers, siloxanes and/or silicones and copolymers of such materials having hydroxyl functionality within their structure. Examples of the polyesters are those predominately hydroxyl terminated polyesters prepared from dicarboxylic acids including, but not restricted to, succinic, glutaric, adipic, pimelic, azelaic and sebacic acids. Polybasic acids obtained by the 2 o polymerisation of unsaturated long-chain fatty acids obtained from naturally occurring oils may be used Mixtures of acids may also be used Suitable glycols for use in the preparation of polyesters include but are not restricted to ethylene glycol, 1,2-propyleneglycol, 1,3-butylene glycol, diethylene glycol, triethylene glycol and decamethylene glycol Mixtures of glycols may be used. Branching groups containing 25 more than two isocyanate reactive groups may also be used Suitable branching components include polyhydric alcohols such as glycerol, pentaerythritol, sorbitol and polycarboxylic acids such as tricarballylic acid and pyromelhtic acid and compounds containing mixed functional groups such as diethanolamme and dihydroxystearic acid. The polyethers may be any hydroxyl containing polymers or co-polymers 3 o made by the polymerisation or co-polymerisation of cyclic ethers such as epichlorohydrin, tetrahydrofuran, oxacyclobutane and substituted oxacyclobutanes and 1,2-alkylene oxides, for example, ethylene oxide and 1,2-propylene oxide Alternatively there may be used branched polyethers prepared, for example, by polymerising an alkylene oxide in the presence of a substance having more than two active hydrogen atoms, for example, Printed from Mimosa WO 98/15585 PCT/GB97/02565 glycerol, pentaerythritol and ethylene diamine Mixtures of linear and branched polyethers may be used Siloxanes may also be referred to as polyoxysilanes, and are sometimes simply referred to as polysilanes Herein, siloxane refers to compositions having the 5 formula R4 R5 Si — O k R7 where n is from 1 to 10 when no solvents are present in the composition When so'vents are included in the composition , n may be higher than 10 In this formula R4, R5 and R6 is independently selected from the group consisting of hydrogen and alkyl, aryl, cycloalkyl, 10 alkoxy, aryloxy, hydroxyalkyl, alkoxyalkyl and hydroxyalkoxyalkyl groups containing up to six carbons. R7 is selected from th? group consisting of hydrogen and alkyl and aryl groups In most cases, at least two of the R4, R5 and Re groups are hydrolysable oxy substituents which can form polymers by hydrolysis. Silicone refers to compositions having the formula r r- R'f-Si —O — R' I R» ! - K n 15 where each R9 is independently selected from the group consisting of the hydroxyl group and alkyl, aryl and alkoxy groups having up to six carbons, each R8 is independently selected from the group consisting of hydrogen and alkyl and aryl groups having up to twelve carbons and n is from 1 to 10 when no solvents are present in the composition 20 When solvents are included in the composition , n may be higher than 10 Isocyanate containing compounds crosslink with the hydroxyl groups of the resin or polymer under the influence of the metal catalyst to cure the coating. Aromatic, aliphatic, or mixed aromatic/aliphatic isocyanates may be used Further, alcohol-modified and alternatively modified isocyanate compositions can be used Poly-isocyanates 25 preferably will have from about 2 to 4 isocyanate groups per molecule. Suitable poly-isocyanates include, for example, hexamethylene diisocyanate, polymethyl polyphenyl isocyanate (Polymeric MDI or PAPI), 4,4'-toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), m- and p-phenyiene dusocyanates, Printed from Mimosa WO 98/15585 PCT/GB97/02565 6 fns-(4-isocyanatophenyl) thiophosphate, triphenylmethane trusocyanate, dicyclohexylmethane diisocyanate (H12MDI), cyclohexane diisocyanate (CHDI), bis-isocyanatomethyl cyclohexane (H6XDI), trimethylhexane diisocyanate, dimer acid diisocyanate (DDI), trimethyl hexamethylene diisocyanate, dicyclohexylmethane 5 diisocyanate and dimethyl derivatives thereof, lysine diisocyanate and its methyl ester, isophorone diisocyanate, methyl cyclohexane diisocyanate, 1,5-naphthalene diisocyanate, triphenyl methane trusocyanate, xylene diisocyanate and methyl and hydrogenated derivatives thereof, polymethylene polyphenyl isocyanates, chlorophenylene-2,4-dnsocyanate, and mixtures thereof Aromatic and aliphatic 10 polyisocyanate dimers, trimers, oligomers, polymers (including biuret and isocyanurate derivatives) and isocyanate functional prepolymers are often available as preformed packages and such packages are also suitable for use The ratio of isocyanate equivalents of the polyisocyanate cross-linking agents to the hydroxyl groups of the hydroxy materials preferably should be greater than 1 1 and can range from 1 2 up to 2.1. 15 The precise intended application of the coating composition will often dictate this ratio which is known as the isocyanate index A solvent or vehicle may be included as part of the coating composition. Volatile organic solvents may include ketones and esters for minimising viscosity, though some aromatic solvent may be used and typically such solvents are part of the volatiles 20 contained in commercial isocyanate polymers Representative volatile organic solvents include, for example, methyl ethyl ketone, acetone, butyl acetate, methyl amyl ketone, methyl isobutyl ketone, ethylene glycol monoethyl ether acetate (sold under the Trademark Cellosolve acetate) and the like. Organic solvents commercially utilised in polyisocyanate polymers include, for example, toluene, xylene and the like. The effective 25 non-volatile solids content of the coating composition can be increased by incorporation of a plasticiser ester which is non-volatile or has a relatively low volatility (high boiling point) and which is retained for the most part in the cured film Such suitable plasticiser esters include, for example, di-(2-ethylhexyl) phthalate (DOP) and the like. If used, the proportion of plasticiser ester should not exceed 10% by weight; otherwise loss of mar 30 resistance can occur Typically, the proportion of plasticiser ester, when used, is in the range 5 to 10% by weight. The coating composition can additionally contain opacifying pigments and inert extenders such as, for example, titanium dioxide, zinc oxide, clays such as kaolinite clays, silica, talc, carbon or graphite (e g. for conductive coatings) and the like Additionally, the coating compositions can contain tinctorial pigments, 35 corrosion-inhibiting pigments, and a variety of agents typically found in coating Printed from Mimosa WO 98/15585 PCT/GB97/02565 7 compositions Such additional additives include, for example, surfactants, flow or levelling agents, pigment dispersants and moisture scavengers based on systems such as oxazolidines and the like Using the catalyst of the invention, a coating composition can be 5 formulated to have a minimum pot life of at least 2 hours in an open pot and generally the coating can be formulated to have a pot life which is in the range 2 to 8 hours Such extended pot life is desirable and means that refilling the pot at the plant during shifts is not usually required. After storage of the coating composition, the stored composition can be modified to application viscosity with suitable solvent (if required) and such a 10 composition retains all the excellent performance characteristics which it initially possessed Heat curing of coatings generally involves baking the applied coating composition at temperatures ranging from 50°C to 150°C or higher for time periods ranging from 1 to 30 minutes. Heating of the coated substrate can be beneficial for 15 solvent expulsion from the film as well as ensuring that the film is non-blocking for rapid handling of the coated substrate. The heating schedules needed for the catalyst of this invention tend to be rather mild in terms of temperature and time compared to conventional heat-cured urethane systems. A variety of substrates can be coated with the coating compositions 20 prepared according to the present invention. Substrates include metal, such as, for example, iron, steel, aluminium, copper, galvanised steel, zinc, and the like. Additionally, the coating composition can be applied to wood, glass, concrete, fibreboard, RIM (reaction injection moulded urethanes), SMC (sheet moulding compound), vinyl, acrylic, polyolefine and other polymeric or plastic material, paper and the like Since the coating 2 5 compositions can be cured at room temperature, thermal damage to thermally-sensitive substrates is not a limitation on use of the coating compositions Further, with the ability to use the vaporous amine catalyst spray method, the flexibility in use of the coating compositions is enhanced even further It should be understood, however, that heating of the coating composition following application (eg to a temperature between about 50°C 3 o and 150°C) is often recommended for enhancing solvent expulsion The coatings which are made available by this invention can be used as primers, intermediate coats, and top coats and the cure is substantially independent of film thickness Printed from Mimosa WO 98/15585 PCT/GB97/02565 8 The invention will be more readily understood from the following examples in which all percentages and proportions are by weight, unless otherwise expressly indicated Printed from Mimosa WO 98/15585 PCT/GB97/02565 9 EXAMPLE 1 Preparation of Catalyst A 0 1 mol of tetra-n-propoxy zirconium (Tilcom® NPZ from Tioxide Specialties Ltd) was added to a 1 litre flask placed in a cold water bath and 0 1 mol of 5 ethylacetoacetate was added over a period of one hour whilst the mixture was stirred The resulting product was a pale yellow liquid The zirconium content of the catalyst was measured at 15 85% 4 mmol of this product was added to a 50 ml flask placed in a cold water bath and 40 mmol of pentaerythritol fefra/c/s-(mercapto- propionate) was added The 10 resulting product was a clear mobile liquid The zirconium content of the catalyst was measured at 1 54% Comparative Catalyst Dibutyl tin dilaurate (source Aldrich Chemicals) was used as the comparative catalyst 15 Testing of the Catalysts in Film Formation (at an addition level to give molar% Zr equal to molar% Sn) 108 g of an acrylic resin (Joncryl 500 from S C. Johnson Polymer b v.), 40.93 g of methyl n-amyl ketone and the calculated amount of catalyst were thoroughly mixed. To this container 39 42 g of an isocyanate (Desmodur® LS2025 from Bayer) was 2 o added From the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were made. Each plate was then cured and the hardness of the resulting film measured The viscosity of the remaining mixture was then measured using a Brookfield viscometer every 0 5 hr Printed from Mimosa WO 98/15585 PCT/GB97/02565 10 Viscosity of Hvdroxvl Containing Polymer I Isocyanate Mixture vs. Time Time (hrs) Comparative Catalyst (0 06g) Catalyst A (0 73g) 0 260 138 3 05 Gelled 153.3 1 176 7 1 5 181.7 2 185 2.5 185 3 191 7 3.5 191.7 4 191 7 Film Hardness by Pendulum Testing of Resulting Films Cure Schedule Comparative Catalyst Catalyst A ambient 120hrs 64 s 79 s EXAMPLE 2 The same catalyst and comparative catalyst as in Example 1 were used 5 Testing in Film Formation of the Catalysts (at an addition level to give molar % Zr equal to molar % Sn> 108 g of an acrylic resin (Joncryl 500 from S.C. Johnson Polymer b.v), 40 93 g of methyl n-amyl ketone and the calculated amount of catalyst were thoroughly mixed To this container 39 42 g of an isocyanate (Desmodur® LS2025 from Bayer) was added 10 From the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were made. Each plate was then cured and the hardness of the resulting film measured The viscosity of the remaining mixture was then measured using a Brookfield viscometer every 0 5 hr Printed from Mimosa WO 98/15585 PCT/GB97/02565 11 Viscosity of Hvdroxvl Containing Polymer I Isocyanate Mixture vs Time Time (hrs) Comparative Catalyst (0 006g) Catalyst A (0 073g) 0 138 3 135 05 156 7 146 7 1 233 156 7 1.5 226.7 156 7 2 256 7 156 7 2.5 ' 306 7 156 7 3 390 156.7 3.5 425 156.7 Film Hardness by Pendulum Testing of Resulting Films Cure Schedule Comparative Catalyst Catalyst A ambient 264hrs 137 s 144 s ambient 336hrs 146 s 160 s EXAMPLE 3 The same catalyst and comparative catalyst as in Example 1 were used. 5 Testing in Film Formation of the Catalyst (at an addition level to give molar % Zr equal to % Sn) 109.4g of an acrylic resin (Joncryl 907 from S. C. Johnson Polymer b v.), 46.1g butyl acetate and the calculated amount of catalyst were thoroughly mixed To this container, 24.4g of an isocyanate (Tolonate® HDT from Rhone Poulenc) was added From 10 the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were made Each plate was then cured and the hardness of the resulting film measured. The viscosity of the remaining mixture was then measured using a Brookfield viscometer every 0.5hr Printed from Mimosa WO 98/15585 PCT/GB97/02565 12 Viscosity of Hvdroxvl Containing Polymer I Isocyanate Mixture vs. Time Time (hrs) Comparative Catalyst (0 005g) Catalyst A (0 061 g) 0 163 165 05 178 165 1 197 165 1.5 212 165 2 237 165 2.5 300 173 3 383 173 35 405 173 Film Hardness bv Pendulum Testing of Resulting Films Cure Schedule Comparative Catalyst Catalyst A Ambient 192h 171 s 180 s EXAMPLE 4 Preparation of Catalyst B 5 1 mol of tetra-n-propyl zirconium (Tilcom® NPZ from Tioxide Specialties Ltd ) was added to a 1 litre flask placed in cold water bath and 1 mol of acetyiacetone was added over a period of one hour whilst the mixture was stirred. The resulting product was a pale yellow liquid. 0.01 moi of the product was added to a 50ml flask placed in a cold water bath and 10 0-1 mol of pentaerythritol fefrafas-(mercaptopropionate) was added. The resulting product was a clear mobile liquid. The zirconium content of the catalyst was measured at 1.63%. Printed from Mimosa WO 98/15585 PCT/GB97/02565 13 Preparation of Catalyst C 1 mol of tetra-n-propyl zirconium (Tilcom® NPZ from Tioxide Specialties Ltd ) was added to a 1 litre flask placed in cold water bath and 1 mol of ethylacetoacetate was added over a period of one hour whilst the mixture was stirred The resulting product was a pale 5 yellow liquid 0 01 mol of the product was added to a 50ml flask placed in a cold water bath and 0 2 mol of pentaerythritol fefratas-(-nercaptopropionate) was added The resulting product was a clear mobile liquid The zirconium content of the catalyst was estimated at 0 77% Testing in Film Formation of the Catalyst /at an addition level to oive equal 10 molar % of Zr) 104 4g of an acrylic resin (Joncryl 902 from S C Johnson Polymer b v ), 48 1g butyl acetate and the calculated amount of catalyst were thoroughly mixed To this container, 30 34g of an isocyanate (Tolonate® HDT from Rhone Poulenc) was added From the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were 15 made. Each plate was then cured and trfS hardness of the resulting film measured The viscosity of the remaining mixture was then measured using a Brookfield viscometer every 0.5hr Viscosity of Hvdroxvt Containing Polvmer / Isocyanate Mixture vs. Time Time (hrs) Catalyst B (0 62g) Catalyst C (1.31g) 0 185 177 0.5 185 177 1 185 177 1.5 211 192 2 231 192 2.5 280 213 3 315 213 Printed from Mimosa WO 98/15585 PCT/GB97/02565 Film Hardness bv Pendulum Testing of Resulting Films Cure Schedule Catalyst B Catalyst C 100°C/ 0 5hr 191 s 180 s Ambient 168hr 171 s 180 s EXAMPLE 5 Preparation of Catalyst D A flask was charged with 449 6g of n-propyl zirconate (Tilcom® NPZ from 5 Tioxide Specialties Limited, 20 3% Zr content) and placed in a cold water bath Ethylacetoacetate (130g) was added over a period of one hour whilst the mixture was stirred The resulting product was a pale yellow liquid A separate flask was then charged with 289.8g of this mixture and 2-isopropyl-hydroxyethyl-1,3-oxazolidine (lncozol®3 from Industrial Copolymers Ltd) 10 (159g) was added to the mixture whilst the mixture was stirred. The released solvent (n-propanol) was then removed by rotary evaporation under reduced pressure to leave a pale yellow oil. The zirconium content of the product was measured at 13.4% Preparation of Catalyst E A flask was charged with 449 6g mole of n-propyl zirconate (Tilcom® NPZ 15 from Tioxide Specialties Limited, 20 3% Zr content) and placed in a cold water bath. Ethylacetoacetate (130g) was added over a period of one hour whilst the mixture was stirred. The resulting product was a pale yellow liquid A separate flask was then charged with 145 2g of this mixture and 2-isopropyl-N-hydroxyethyl-1,3-oxazolidine (Incozol® 3 from Industrial Copolymers Ltd.) 2 o ("159g) was then added to the mixture whilst the mixture was stirred The released solvent (n-propanol) was then removed by rotary evaporation under reduced pressure to leave a pale yellow oil. The zirconium content of the product was measured at 9 34%. Comparative Catalyst Dibutyl tin dilaurate (source Aldrich Chemicals) was used as the 2 5 comparative catalyst. Testing in film formation of the catalysts at an addition levels to give eouivalent % Zr to % Sn (molari 104.4g of a acrylic resin (Joncryl 902 from S.C. Johnson Polymer b.v.), 48.1g of butyl acetate and the calculated amount of catalyst were thoroughly mixed. To this Printed from Mimosa WO 98/15585 PCT/GB97/02565 15 container 30 34g of an isocyanate (Tolonate® HDT from Rhone Poulenc) was added From the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were made Each plate was then cured and the hardness of the resulting film measured The viscosity of the remaining mixture was then measured using a Brookfield viscometer at 5 time periods of 0 5 hrs Viscosity of Hvdroxvl Containing Polvmer / Isocyanate Mixture vs. Time Time (hrs) Comparative Catalyst (0 054g) Catalyst D (0 06g) Catalyst E (0 086g) 0 180 158 3 165 05 445 161 7 170 1 1000 180 196 7 1 5 196 7 213.3 2 211.7 248 3 2.5 238.3 280 3 293 3 343.3 3.5 311 7 368.3 4 331.7 406.6 Film Hardness bv Pendulum Testing of Resulting Films Cure schedule 168 hrs, ambient. Dibutyl tin dilaurate 199 s Catalyst D 182 s Catalyst E 197 s EXAMPLE 6 10 Preparation of Catalyst F A flask was charged with 449 6g of n-propyl zirconate (Tilcom® NPZ from Tioxide Specialties Limited; 20.3% Zr content) and placed in a cold water bath. Ethylacetoacetate (130g) was added over a period of one hour whilst the mixture was stirred. The resulting product was a pale yellow liquid. 15 A separate flask was then charged with 289 8g of this mixture and 2-isopropyl-N-hydroxyethyl-1,3-oxazolidine (incozol® 3 from Industrial Copolymers Ltd.) Printed from Mimosa WO 98/15585 PCT/GB97/02565 16 (159g) was added to the mixture whilst the mixture was stirred The released solvent (n-propanol) was then removed by rotary evaporation under reduced pressure to leave a pale yellow oil The zirconium content of the product was measured at 13 4% Comparative Catalyst 5 Dibutyl tin dilaurate (source Aldnch Chemicals) was used as the comparative catalyst Testing in Film Formation of the Catalysts at an addition level to give equivalent % Zr to % Sn (molari 96g of a acrylic resin (Joncryl 922 from S.C Johnson Polymer b v.), 0 53g of 10 BYK 320 (BYK-Chemie GmbH), 47 47g of butyl acetate and the calculated amount of catalyst were thoroughly mixed To this container, 39 19g of an isocyanate (Tolonate® HDT LV from Rhone Poulenc) was added From the mixture, drawdowns (wet film thickness 60 micrometre) on glass plates were made Each plate was then cured and the hardness of the resulting film measured The viscosity of the remaining mixture was then 15 measured using a Brookfield viscometer at time periods of 0 5 hrs Viscosity of Hvdroxvl Containing Polvmer / Isocyanate Mixture vs. Time Time (hrs) Comparative Catalyst F Catalyst (0.073g) (0 079g) 0 73.3 83 3 0.5 160.0 113.3 1 1093 295 Film Hardness bv Pendulum Testing of Resulting Films Cure Schedule Comparative Catalyst Catalyst F 100°C / 0 5 hr 166 s 175 s 100°C/0 5hr then 168 hrs ambient 199 s 206 s 168 hrs ambient 208 s 210 s Printed from Mimosa $ow amende® WO 98/15585 PCT/GB97/02565 17 </div>

Claims

1. CLAIMS 1 A catalyst comprising the reaction product of (a) the reaction product of a titanium, zirconium, hafnium or alumj/ium orthoester and a (J-diketone or fi-ketoester having the general formula R1 0 A w x R where R1, R2 and R3 may be independently seleptfed from the group consisting of hydrogen and alkyl, aryl, cycloalkyl, alkoxy, ac^loxy, hydroxyalkyl, alkoxyalkyl and hydroxyalkoxyalkyl groups containing up to eight/carbon atoms, and (b) a complexing agent selected frorrya mercapto compound or an oxazolidine or 10 a tetrahydro-oxazme having the (general formula (A) or (B) respectively N--X R (B) or mixtures thereof

2. A catalyst according to claim 1 characterised in that the orthoester has the formula M(ORfc in which M is titanium or zirconium and R is an alkyl group, a cycloalkyl 15 group or aiyaryl group. 3 / catalyst according to claim 1 or 2 characterised in that the li-diketone or IJ-ketafester is acetyiacetone, methylacetoacetate, ethylacetoacetate or fe^Riutylacetoacetate A catalyst according to any one of the preceding claims characterised in that the orthoester of titanium, zirconium, hafnium or aluminium and the R-diketone or B-ketoester are present in the reaction product in a molar ratio in the range 1 0 5 to 1 • 4, orthoester to R-diketone or B-ketoester. Printed from Mimosa 04/19/1999 15 28 48 page -19- AS AMENDED ■Sj 17 CLAIMS

3. 1. A catalyst comprising the reaction product of: (a) the reaction product of a titanium, zirconium, hafnium or aluminium orthoester and a R>-diketone or B-ketoester having the general formula where R\ R2 and R3 may be independently selected from the group consisting of hydrogen and alkyl, aryl, cycloalkyl, alkoxy, aryloxy, hydroxyalkyl, alkoxyalkyl and hydroxyalkoxyalkyl groups containing up to eight carbon atoms; and (b) a complexing agent selected from a mercapto compound or an oxazolidine or 2 q a tetrahydro-oxazine having the general formula (A) or (B) respectively N—X in which R10 is hydrogen or an alkyl group and X is a hydroxyalkyl group, or mixtures thereof. 2. A catalyst according to claim 1 charactensed in that the orthoester has the formula M(OR)4 in which M is titanium or zirconium and R is an alkyl group, a cycloalkyl 15 group or an aryl group 3 A catalyst according to claim 1 or 2 charactensed in that the B-diketone or B-ketoester is acetyiacetone, methylacetoacetate, ethylacetoacetate or tert-butylacetoacetate.

4. A catalyst according to any one of the preceding ciaims characterised in that the 2 o orthoester of titanium, zirconium, hafnium or aluminium and the 0,-diketone or B-ketoester are present in the reaction product in a molar ratio in the range 1 • 0.5 to 1 :4, orthoester to B-diketone or B-ketoester. INTELLECTUAL PROPERTY OFFICE OF N.Z. 2 2 NOV 2000 — ■—> n - *• r i r WO 98/15585 PCT/GB97/02565 33 5

5. A catalyst according to any one of the preceding claims characterised in that the mercapto compound is tnmethylolpropane fns-(3-mercaptopropionate), pentaerythritol fe/ra/c/s-(3-mercaptopropionate), ethylene glycol Jb/s-(3-mercaptopropionate) or pentaerythritol fefra/(/s-(2-mercaptoacetate).

6. 56. A catalyst according to any one of the preceding claims characterised in that the complexing agent is an oxazolidine of formula (A) in which R10 is hydrogen or an alkyl group containing up to 8 carbon atoms and X is a hydroxyalkyl group containing up to 6 carbon atoms.

7. A method of curing a composition comprising reacting a hydroxyl containing 10 polymer or mixture of hydroxyl containing polymers with an isocyanate containing compound or a mixture of isocyanate containing compounds characterised in that the reaction is catalysed by a catalyst according to any one of the preceding claims .

8. A method according to claim 7 characterised in that the catalyst is present in an amount in the range 0.005 per cent to 0.5 per cent by weight with respect to weight of the 15 composition.

9. A method according to claim 7 or 8 characterised in that the hydroxyl containing polymer is a polyester, a polyesteramide, a polyether, a siloxane as herein defined or a silicone as herein defined having hydroxyl functionality or a copolymer thereof.

10. A method according to any one of claims 7 to 9 characterised in that the 20 isocyanate containing compound is an aromatic, aliphatic or mixed aliphatic/aromatic isocyanate.

11. A method according to any one of claims 7 to 10 charactensed in that the composition contains isocyanate groups and hydroxyl groups in the range 1 : 2 to 2 : 1, isocyanate groups to hydroxyl groups. 2$

12. A method according to any one of claims 7 to 11 characterised in that a solvent or a plasticiser is present in the composition.

13. A method according to any one of claims 7 to 12 charactensed in that a plasticiser ester is present in the composition in an amount in the range 5 to 10% by weight

14. A method according to any one of claims 7 to 13 characterised in that the 3 0 composition contains an opacifying pigment or an extender.

15. A method according to any one of claims 7 to 14 characterised in that the composition is cured by heating at a temperature in the range 50°C to 150°C for a penod of 1 to 30 minutes 16 A catalyst according to claim 1 substantially as hereinbefore described with particular reference to any one of Examples 1 and 4 to 6 17 A method according to claim 7 substantially as hereinbefore described with particular reference to any one of Examples 1 to 6 pNfLiECTuF™p!n^7T: ofnzl " 2h END