Complexes of metal salts of organic acids and beta-diketones and methods for producing same
View Patent ↗Metal salts of organic acids complexed with β-diketone compounds are multifunctional complexes useful in the formulation of stabilizers for halogenated resins. These complexes may be used jointly with other low toxicity intermediates, such as zinc or magnesium intermediates, to form effective stabilizers that are non-toxic and exhibit better performance than other known stabilizers, including those containing toxic heavy metals such as cadmium or lead. The complex is prepared utilizing a Claisen condensation reaction and precipitation with water and heptane.
1. A method of preparing a stabilizer complex which comprises reacting:
a) a ketone of the structure:
where R 1 and R 2 are selected from the group consisting of H, methyl, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, aryl, aryl that is mono or poly substituted with C 1 -C 15 alkyl, C 1 -C 4 alkoxy, and phenylalkyl;
b) an ester of the structure:
where R 4 is selected from the group consisting of C 1 -C 5 alkyl, aryl, and aryl that is substituted with C 1 -C 4 alkyl, and R 3 is selected from the group consisting of aryl, substituted aryl, C 1 -C 20 alkyl, and C 2 -C 20 alkenyl;
c) a base selected from the group consisting of calcium oxide, calcium hydroxide, barium oxide, barium hydroxide, potassium hydroxide, potassium oxide, sodium hydroxide and sodium oxide in the presence of a solvent selected from the group consisting of an aromatic hydrocarbon, alkyl or aryl ether, dialkylsulfoxide, or the same ester used for the reaction, to form a reaction mixture containing a stabilizer complex,
d) contacting the reaction mixture containing the stabilizer complex with water, organic solvent or combination thereof to precipitate the stabilizer complex from the reaction mixture; and
e) recovering the stabilizer complex, which is a salt of a metal selected from the group consisting of sodium, potassium, calcium and barium.
2. The method according to claim 1 wherein the reaction mixture containing the stabilizer complex is contacted with water to dissolve unreacted components and precipitate the stabilizer complex from the reaction mixture.
3. The method according to claim 1 wherein the reaction mixture containing the stabilizer complex is contacted with organic solvent to remove unreacted components and to precipitate the stabilizer complex from the reaction mixture.
4. The method according to claim 3 wherein the organic solvent is heptane.
5. A method of preparing a stabilizer complex which comprises:
a) reacting acetophenone with methyl benzoate and calcium oxide to provide a stabilizer complex precipitate;
b) contacting the reaction mixture containing the stabilizer complex with water to dissolve unreacted calcium oxide as Ca(OH) 2 and precipitate additional stabilizer complex from the reaction mixture;
c) contacting the reaction mixture containing the stabilizer complex with organic solvent to remove methyl benzoate present on the stabilizer complex and precipitate additional the stabilizer complex from the reaction mixture; and,
d) recovering the stabilizer complex which is substantially free of unreacted Ca(OH) 2 and methyl benzoate.
6. The method according to claim 5 wherein the organic solvent is heptane.
7. The method according to claim 1 wherein the reaction mixture containing the stabilizer complex is contacted with water and organic solvent.