Alkoxyalcohol adduct of rare earth monocarboxylate

1. A process for preparation of an alkoxyalcohol adduct of rare earth monocarboxylate, represented by the formula (I):

M(R 2 —COO) 3 .(R 1 O(CH 2 ) n OH) p   (I)

in which M is at least one rare earth element selected from the group consisting of Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; R 1 is an aliphatic hydrocarbon group having 1 to 4 carbon atoms or a substituted aliphatic hydrocarbon group having 3 to 6 carbon atoms; R 2 is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms which has or does not have a substituent; n is 2 or 3; and p is a number in the range of 0.5 to 3 comprising the step of:

heating a rare earth carboxylate represented by the formula (II):

M(R 2 —COO) 2 .mH 2 O  (II)

in which M and R 2 are the same as those defined above and

m is a number satisfying the condition 0<m<4,

together with an alkoxyalcohol represented by the formula (III):

R 1 —O—(CH 2 ) n OH  (III)

in which R 1 and n are the same as those defined above, to remove water together with the alkoxyalcohol by distillation.

2. The process of claim 1 , wherein R 2 in the formula (II) is methyl.

3. The process of claim 1 , wherein the alkoxy-alcohol represented by the formula (III) is at least one compound selected from the group consisting of 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 1-ethoxy 2-propanol and 3-ethoxy-1-propanol.

4. The process of claim 1 , wherein the rare earth carboxylate is a rare earth acetate and the rare earth acetate is heated together with ethoxyethanol so that water is distilled off together with the ethoxyethanol.