Tioxide Specialties Limited

Imperial Chemical Industries Limited

Acma Limited

John Ridland

Brian Steven Jolly

Iain Wesley Hepplewhite

Bruno Frederic Stengel

Martin G Partridge

An organometallic composition is described which comprises a complex of at least one orthoester of a metal having a formula M(ROAcAc) (OR&prime;) in which M is selected from the group consisting of titanium, zirconium and hafnium; ROAcAc denotes an ester of an alochol ROH, in which R comprises an (optionally substituted) C cyclic, branched or linear, alkyl, alkenyl, aryl or alkyl-aryl group or a mixture thereof, with acetoacetic acid; OR&prime; is the residue of an alcohol R&prime;OH in which R&prime; comprises an (optionally substituted) C cyclic, branched or linear, alkyl, alkenyl, aryl or alkyl-aryl group or a mixture thereof, and x and y are each in the range 1-3. The composition is useful as a curing agent for polyurethanes used in various applications.

Organometallic compositions

An organometallic compound suitable for use as a catalyst for the preparation of an ester comprises the reaction product of an orthoester or condensed orthoester of titanium, zirconium or aluminum, an alcohol containing at least two hydroxyl groups, an organophosphorus compound containing at least one P&mdash;OH group and a base. A process for the preparation of an ester comprises carrying out an esterification reaction in the presence of the catalyst In a further embodiment the organometallic compound suitable for use as a catalyst in an esterification process comprises the reaction product of, in addition, a 2-hydroxy carboxylic acid.

Esterification catalysts

A process for the preparation of an ester comprises carrying out an esterification in the presence of a catalyst comprising the reaction product of an orthoester or a condensed orthoester of titanium or zirconium, an alcohol containing at least two hydroxyl groups, a 2-hydroxy acid and a base. The process can be a direct esterification or a transesterification and can be a polyesterification. The catalyst can effectively produce esters without leading to a haze in the final product and there is a reduced amount of yellowing of polyesters in comparison to known catalysts.

Esterification process

A method of curing a powder coating composition comprises reacting a polyester resin with an alkanolamine derivative of titanium or zirconium. This derivative is the reaction product of an orthoester or a condensed orthoester of titanium or zirconium with a trialkanolamine and with a dialkanolamine or a monoalkanolamine. In the reaction product the ratio of trialkanolamino radicals to Ti or Zr atoms is from 0.5:1 to 1.5:1 and the ratio of monoalkanolamino radicals or dialkanolamino radicals to Ti or Zr atoms is from 0.2:1 to 2.0:1. The reaction products are preferably derivatives of ethanolamines or isopropanolamines and can be used to cure carboxyl-rich resins or hydroxyl-rich resins.

Polyester resin powder coating compositions

The invention consists of a new method of curing a polyester powder coating composition. The resin is cured by the use of an organotitanium or organozirconium derivative of an alkanolamine having the formula M.sub.3 [(OR).sub.3 N].sub.4 or O[M(OR).sub.3 N].sub.2 or R.sup.1 [OM(OR).sub.3 N].sub.x where M represents Ti or Zr, R represents a divalent aliphatic radical, x is 1 to 4 and R .sup.1 is a saturated hydrocarbyl group or a group containing one or more ether linkages. The method is suitable for use with both hydroxyl-rich and carboxyl-rich polyester resins and the cured coatings have desirable physical properties.

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Durham, United Kingdom

John Ridland