Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Patent
1992-05-14
1993-11-09
Killos, Paul J.
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
564204, 564207, C07C 6952
Patent
active
052604802
DESCRIPTION:
BRIEF SUMMARY
The present invention relates o a process for the preparation of aqueous solutions of unsaturated quaternary ammonium salts corresponding to the following formula (I): (R.sub.1)(R.sub.2)(R)X.sup.-
A is an oxygen atom or an NH group,
R.sub.3 is a hydrogen atom or a methyl radical,
R.sub.4 is a linear or branched alkyl radical with 1 to 6 carbon atoms,
R.sub.1, R.sub.2 and R, which are different or identical, are an alkyl radical or an aryl radical,
X is chosen from Cl, Br, I, CH.sub.3 -CO.sub.3 or CH.sub.3 -SO.sub.4.
There is a known process, described in European Application 250,325, for the preparation of aqueous solutions of unsaturated quaternary ammonium salts (I) according to which, in the presence of at least one polymerization inhibitor:
in a first stage (a) at least one (meth)acrylic monomer (II) of formula H.sub.2 C=C(R.sub.3)--C(O)--A--R.sub.4 --N(R.sub.1)(R.sub.2) (in which R.sub.1, R.sub.2, R.sub.3, R.sub.4 and A have the meaning referred to above) is reacted with 5 to 20% by weight of the quantity necessary for the reaction of a quaternising agent (III) of formula RX (with R and X having the abovementioned meaning), or, instead of RX, with 5 to 20% by weight of an aqueous solution of unsaturated quaternary ammonium salts (I) (given in relation to the weight of (meth)acrylic monomers (II)), this solution comprising 50 to 85% by weight of quaternary ammonium salts (I),
in a second stage (b) water and the quaternising agent (III) are added continuously until the desired concentration of unsaturated quaternary ammonium salts is obtained in the water.
During the stages (a) and (b), the temperature is maintained between 30.degree. and 60.degree. C. Furthermore, during the stages (a) and (b) and in particular as the end of the reaction approaches, a stream of oxygen-containing gas is maintained in the reaction mixture, such that the volume ratio (or volumetric flow rate) of total gas at the exit of the reactor to the volume (or volumetric flow rate) of oxygen introduced at the entry of the same reactor is lower than 100.
The process according to European Application 250,325 makes it possible to prepare aqueous solutions of unsaturated quaternary ammonium salts (I) which have a room temperature stability of more than a year. However, the presence of impurities is found in these solutions, in particular of CH.sub.2 =C(R.sub.3)--C(O)--A--R(IV), CH.sub.2 =C(R.sub.3)--C(O)--AH (V) and of (meth)acrylic monomers (II). The content of these impurities is particularly high when R.sub.3 is a hydrogen atom and when A denotes an oxygen atom; it can then be up to values of 3000-5000 ppm, 0.69% and 1.3% by weight respectively in the case of the impurities. (IV), (V) and (II).
The Applicant Company has found a process for the preparation of aqueous solutions of unsaturated quaternary ammonium salts (I) enabling the formation of the impurities to be considerably reduced during the quaternization reaction, this process also having the advantage of yielding solutions whose room temperature stability exceeds a year.
More precisely, the subject of the present invention is a process for the preparation of aqueous solutions of unsaturated quaternary ammonium salts (I) corresponding to the following formula: (R.sub.1)(R.sub.2)(R)X.sup.- C=C(R.sub.3)--C(O)--A--R.sub.4 --N(R.sub.1)(R.sub.2) and from at least one quaternizing agent (III) of formula RX, in which formulae R, R.sub.1, R.sub.2, R.sub.3, R.sub.4, A and X have the abovementioned meaning, in the presence of at least one polymerization inhibitor, in which process the reaction is carried out at a temperature of between 10.degree. C. and 80.degree. C., and in which
(a) in a first stage, all or a part of the quaternizing agent (III) necessary for the reaction is introduced into the reactor, this agent (III) being in the liquid state in the reaction conditions,
(b) then, at least one (meth)acrylic monomer (II) is added, and
(c) as soon as 0 to 30% of the stoichiometry of the (meth)acrylic monomer(s) has been introduced into the reactor, the remainder of the quaternizing a
REFERENCES:
patent: 4745214 (1988-05-01), Hess et al.
Hess Raymond
Lacroix Christian
Killos Paul J.
Norsolor
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