Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Patent
1997-06-09
1998-12-08
Shippen, Michael L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C07C 4311
Patent
active
058472290
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a process for the production of end-capped nonionic surfactants by forming an alcoholate between a fatty alcohol polyglycol ether and a solid base, reacting the alcoholate with a dialkyl sulfate and adding water to initiate phase separation.
2. Statement of Related Art
For a number of industrial processes, the presence of foam is extremely undesirable. For example, both in the machine washing of beer or milk bottles and in the spray cleaning of automobile panels, not only is the cleaning or degreasing effect of the surface-active formulations used an important factor, the avoidance of foam which can seriously interfere with the operation of machinery is of equal importance. This is all more the so inasmuch as, in many cases, highly active but also high-foaming anionic surfactants are used.
The problem of controlling foam has been known for some time and, accordingly, various more or less convincing solutions to the problem are known from the prior art and may be divided into two groups.
The first group comprises processes involving the addition of defoamers which are often paraffinic hydrocarbons or silicone compounds. For the described applications, however, this is mostly undesirable. The second group of processes involve the use of surface-active formulations which are themselves low-foaming and which may additionally exhibit defoaming properties. The surfactants used are generally nonionic surfactants or surfactant-like systems such as, for example, fatty alcohol propylene glycol ethers or block polymers of ethylene and propylene glycol which, unfortunately, are not sufficiently biodegradable.
End-capped fatty alcohol polyglycol ethers, so-called "mixed ethers", which are described for example by R. Piorr in Fat. Sci. Technol. 89, 106 (1987), have established themselves on the market as particularly effective low-foaming surfactants. These products are generally butyl-end-capped nonionic surfactants which are known, for example, from EP-A 0 124 815, EP-B 0 303 928, EP-B 0 324 340, EP-A 0 420 802, DE-A 3 928 600 and DE-C 4 243 643.
Methyl mixed ethers occupy a special position. They are end-capped by methyl groups and are normally obtained by reaction of the corresponding 4,587,365, BASF! or dimethyl sulfate.
In this connection, a one-pot process for the production of end-capped nonionic surfactants is known from EP 0 302 487 B1 (BASF). In this process, fatty alcohol polyglycol ethers are reacted with dialkyl sulfates in the presence of aqueous alkali metal hydroxides, the reaction taking place at a temperature in the range from 20.degree. to 60.degree. C. and the concentration of alkali metal hydroxide having to be kept above 35% by weight, based on the aqueous phase, throughout the reaction. However, the products contain up to 25% by weight of unreacted starting product and are unacceptable from the point of view of color.
Accordingly, the problem addressed by the present invention was to provide an improved process for the production of end-capped nonionic surfactants of the methyl mixed ether type which would be distinguished by a reduced content of unreacted starting material and by improved color quality.
DESCRIPTION OF THE INVENTION
The present invention relates to a process for the production of end-capped nonionic surfactants corresponding to formula (I): ##STR1## in which R.sup.1 is an alkyl and/or alkenyl group containing 6 to 22 carbon atoms, n1 and n2 independently of one another stand for 0 or for numbers of 1 to 10 and m stands for numbers of 1 to 20, by reaction of alcohol alkoxylates with dialkyl sulfates, in which
(a) fatty alcohol polyglycol ethers corresponding to formula (II): ##STR2## in which R.sup.1, n1, n2 and m are as defined above, are reacted with solid substantially water-free bases (III),
(b) the alcoholates formed are etherified with dialkyl sulfates (IV),
(c) water is added to the crude ethers in such a quantity that phase separation occurs and
(d) the organic valuable phases are removed b
REFERENCES:
patent: 4548729 (1985-10-01), Schmid et al.
patent: 4587365 (1986-05-01), Anchor
patent: 4624803 (1986-11-01), Balzer et al.
patent: 4922029 (1990-05-01), Birnbach et al.
patent: 4942049 (1990-07-01), Schmid et al.
patent: 4973423 (1990-11-01), Geke et al.
patent: 5484553 (1996-01-01), Guth, et al.
Fat. Sci. Technol., 89 (1987) p. 106.
Bigorra Llosas Joaquim
Bonastre Nuria
Pi Subirana Rafael
Trius Oliva Antonio
Henkel Kommanditgesellschaft auf Aktien
Jaeschke Wayne C.
Millson Jr. Henry E.
Shippen Michael L.
Szoke Ernest G.
LandOfFree
Process for the production of end-capped nonionic surfactants does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the production of end-capped nonionic surfactants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the production of end-capped nonionic surfactants will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-179379