Microencapsulation of detergent enzymes
Publication Date: 2014-Nov-02
The IP.com Prior Art Database
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MICROENCAPSULATION OF DETERGENT ENZYMES
FIELD OF THE INVENTION
This invention relates to stabilization of enzymes in detergents using microcapsules. 5
This invention relates to enzyme containing particles wherein the enzyme can be controllably retained within the particles despite migration of other materials through the walls of the particles. In particular, the invention relates to liquid detergent concentrates which contain particles which contain an enzyme whereby the enzyme is protected in the concentrate
but is released when the concentrate is diluted in wash water. In particular it preferably relates to such concentrates which contain two enzymes wherein one would normally deactivate the other but which are protected from each other in the concentrate and which are available upon dilution in wash water.
There is extensive prior art on encapsulating active ingredients in polymeric particles so
as to attempt to protect the active ingredient from the environment during storage but to permit release when required. In some processes the active ingredient is distributed through a polymeric matrix. In other processes the active ingredient is present in the core of a particle which has a polymeric shell. In some processes there is a polymeric shell surrounding a core containing a polymeric matrix and the active ingredient.
It is known to be desirable to include detergent enzymes in liquid detergent concentrates. There have been many proposals in the literature to protect the enzyme from the continuous phase of the concentrate and/or water by providing a continuous shell and/or a matrix which is intended to protect the enzyme from the concentrate but to release it when the detergent concentrate is added to water to provide wash water. Examples are given in EP 356,239 and
WO 92/20771, and the prior art discussed in those. These, and other known methods, generally involve forming the shell by coacervation.
Unfortunately it is very difficult to select a coacervation polymer and its conditions of use on the one hand, and a polymeric or other core composition on the other, so as to obtain in particles of high specific area the optimum protection and release performance that is required.
In general, either the shell is too impermeable to give effective release when required or the shell permits premature release.
A particular problem seems to arise in liquid detergents because of the tendency of the enzyme to permeate during storage through the high surface area of the coacervate shell, if the shell is capable of giving full release when required. This is probably due in part to the
rather low molecular volume of the enzyme (since detergent enzymes typically have a molecular weight of the order of 20 to 100 kDa) combined with the fact that many polymer films
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are likely to be permeable or semi-permeable to molecules of this size. Accordingly on prolonged storage a significant amount of the...