Method for impregnating a support matrix with solid and/or liquid compounds using compressed gases, and matrials impregnated in this manner

Abstract

The invention relates to a method for impregnating a support matrix with solid and/or liquid compounds using a compressed gas or a compressed mixture of gases at densities ranging from 0.15 to 1.3 kg/l and at least two unsymmetrical pressure changes (pulsations). The method is further charcterized in that both a multitude of impregnating substances such as biologically active compounds, technical materials or metal-organic compounds, as well as support matrices of biological origin and organic or inorganic substances can be used that have large inner surfaces and/or inner surfaces that are difficult to access.

1 . Method of impregnating a carrier matrix with solid and/or liquid compounds using compressed gas(mixtures), characterized in that the solid and/or liquid compound(s) (impregnating material) and the insoluble carrier matrix are brought into contact with a compressed gas(mixture) at gas(mixture) densities of at least 0.15 to 1.3 kg/l under at least two unsymmetrical pressure-change cycles (pulsations) in such a manner that, per individual pulsation of a duration of at least 5 s to 60 min, the respective time period to achieve the pressure maximum is greater than the time period for pressure reduction to the minimum.  
     
     
         2 . Method according to  claim 1 , characterized in that the impregnating material is a biologically active compound, in particular a pharmaceutical, agrochemical or cosmetic active compound, technical substance, in particular surface-active or surface-modifying composition, or organometallic compound.  
     
     
         3 . Method according to  claim 2 , characterized in that the impregnating material is a vitamin, nutraceutical, plant-treatment agent, biocide, phytohormone, aroma substance, pigment, dispersant, emulsifier or chemically reactive compound, in particular a surface-reactive compound.  
     
     
         4 . Method according to one of  claims 1  to  3 , characterized in that the carrier matrix is of biological origin, in particular a food, feed, seed material, or organic or inorganic carrier matrix, all of which preferably have large and/or poorly accessible internal surface areas.  
     
     
         5 . Method according to one of  claims 1  to  3 , characterized in that the carrier matrix is a synthetic, semisynthetic or natural organic polymer, in particular a polyethylene, polypropylene, polyglycolic acid or carbohydrate, or inorganic carrier material, in particular a silicone dioxide, in particular precipitated or pyrogenic silicic acid or silica gel, alumosilicate or other catalyst base material, in particular zeolite, and aluminium oxide, activated carbon, titanium dioxide or bentonite.  
     
     
         6 . Method according to one of  claims 1  to  5 , characterized in that gas(mixtures) are used in the near-critical and/or supercritical pressure range, preferably at process pressures of at least 5 to 800 bar, and particularly preferably of at least 50 to 500 bar.  
     
     
         7 . Method according to one of  claims 1  to  6 , characterized in that it is carried out using compressed carbon dioxide, propane, butanes, ethane, ethylene, dimethyl ether, ammonia, halogenated hydrocarbons or their mixtures.  
     
     
         8 . Method according to one of  claims 1  to  7 , characterized in that the process temperature is above the critical temperature of the gas(mixture) used, preferably at least 31° C. to 200° C.  
     
     
         9 . Method according to one of  claims 1  to  8 , characterized in that the gas(mixture) density is at least 0.4 to 1.0 kg/l.  
     
     
         10 . Method according to one of  claims 1  to  9 , characterized in that the durations of the individual pulsations differ from one another.  
     
     
         11 . Method according to one of  claims 1  to  10 , characterized in that the time periods for the pressure increase and/or the time periods for the pressure reduction of the individual pulsations differ among one another from one another.  
     
     
         12 . Method according to one of  claims 1  to  11 , characterized in that aids, in particular for changing the solubility, in particular water or organic solvents selected from the group consisting of short-chain alcohols, ketones and esters, and/or having surface activity, preferably in concentrations up to 20% by weight, are added to the gas(mixture).  
     
     
         13 . Method according to one of  claims 1  to  12 , characterized in that entrainers, preferably organic amines, in particular triethylamine or ammonia, are added to the gas(mixture).  
     
     
         14 . Method according to one of  claims 1  to  13 , characterized in that the aids and/or entrainers are added to the impregnating material, particularly preferably under atmospheric pressure.  
     
     
         15 . Method according to one of  claims 1  to  14 , characterized in that it is carried out batchwise.  
     
     
         16 . Method according to one of  claims 1  to  15 , characterized in that a carrier material is used that is precoated with impregnating materials.  
     
     
         17 . Method according to one of  claims 1  to  16 , characterized in that the components, before the pulsation, are brought to the process pressure to which the impregnating materials exhibit their optimum solubility behaviour, then the gas(mixture) is recirculated in the supercritical range in such a manner that the impregnating materials are distributed on the carrier material and then the process pressure is reduced in such a manner that the impregnating materials settle on the surfaces of the carrier material.  
     
     
         18 . Impregnated material obtainable by a method according to one of  claims 1  to  17 .