EP1401564A1

EP1401564A1 - Method for the production of surface active compounds in particulate form

Info

Publication number: EP1401564A1
Application number: EP02771641A
Authority: EP
Inventors: Peter-Roger Nyssen; Dietmar Fuchs; Hans-Peter Müller
Original assignee: Bayer Chemicals AG
Current assignee: Lanxess Deutschland GmbH
Priority date: 2001-05-22
Filing date: 2002-05-10
Publication date: 2004-03-31
Also published as: DE10124902A1; US6903065B2; WO2002094428A1; US20020177533A1

Abstract

The invention relates to particulate solids containing more than 90% by weight, preferably more than 98% by weight of natural or synthetic surface active compounds. The invention is characterized by the following: (a) the mean particle size of the solid particles is 10 - 3000 νm; (b) the surface active compounds are solid at room temperature and (c) the surface active compounds have a melting point of 25 to 250° C, preferably 30 - 130°C, more particularly 35 - 90°C. The invention also relates to a method for the production of particulate solids of surface active compounds, which is characterized in that the compounds are introduced in liquid form into a cryogenic gas forming droplets at a temperature above melting point, are cooled in solid state and separated from the cryogenic gas in the form of a particulate solid.

Description

METHOD FOR PRODUCING SURFACE-ACTIVE CONNECTIONS IN PARTICULAR FORM

The invention relates to particulate solids of surface-active compounds and to a process for their preparation.

Due to their chemical structure, many surface-active compounds occur as solid, usually wax-like, solid substances at room temperature.

In this form, the compounds cannot be used or handled efficiently and economically, for example as emulsifiers for aqueous systems; in particular, they are difficult to dose or require long dissolving times. Therefore, either less concentrated, possibly stabilized solutions (usually aqueous) are used or the solid substances are used as flakes or pellets. Disadvantages of aqueous solutions are often the low concentration, the presence of adjusting or stabilizing aids such as pH regulators and preservatives and in some cases the water itself.

Disadvantages of flakes or pellets are the still poor dissolving speed and also the mostly uneconomical production itself. Often, subsequent grinding, such as e.g. Cryo-grinding to powder is an additional complex work step.

Efforts are therefore being made to obtain easily flowable particulate solids, for example powders or granules of surface-active compounds, which can easily be found in the application systems, e.g. watery, dosed and as high as possible

They have dissolving speeds such as comparatively fluid settings or melting of the compounds.

The object of the invention is therefore a process for the economical production of particulate solids of surface-active compounds, characterized in that the compounds are at a temperature above their melting temperature be introduced liquid into a chamber charged with cryogas with the formation of drops, cooled to the solid state and separated from the cryogas as particulate solids, the separation vzw. can be made from the gaseous cryogas inside or outside the chamber.

Processes for producing powders from melts with the aid of atomization into low-boiling gases are known, for example, from DE 4132693 for metallic melts. EP 0 945 173 AI describes a similar process for plastics, waxes, pharmaceutical products or foods.

The substances mentioned, in particular waxes (see also Römpp) are generally synthetic or natural compounds that have no solubility in water and in particular no surface-active properties and are inert towards cryogases. The substances mentioned above are mostly characterized by a very high surface tension compared to an inert gas phase, in particular they have no surfactant-like character which lowers the surface tension in water.

Surprisingly, it has now been found that meltable surface-active substances, in the narrower sense in particular surfactants with a surface tension in aqueous solution of less than 40 mN / m, which are solid at room temperature, are processed, in particular economically, to particulate solids using the cryogas spray process mentioned can. It was surprisingly found in particular that droplet formation was achieved and clumping in the gas space or in the cryogas during cooling could be avoided to the extent that a free-flowing powder or granulate was obtained.

The preferred method and a preferred device are described in principle in EP 945173 AI. It is characterized in particular in that an atomization or drop formation unit is arranged in the upper part of a solidification chamber or on a solidification tube, to which the surface-active compound in the form of its liquid melt is fed, if appropriate under excess pressure. Typically, the melt leaves the drop formation unit either in the form of discrete drops (e.g. when using a drop generator) or in the form of rays or fine threads, which disintegrate into drops with increasing distance from the drop formation unit due to laminar or turbulent jet decay and preferably fall down due to gravity. The cryogas, generally N2 or CO ₂ , is introduced into the chamber in a predominantly liquid state below the drop formation unit by means of a feed device and brought into contact with the melt jets or drops, a temperature gradient of the cryogas occurring in the chamber between the drop formation unit and the entry of the cryogas formed. The temperature gradient is preferably set up in such a way that in the area below the drop formation unit (“1st zone”) the jet decay (drop formation) is not impeded by solidification, so that a cooler zone (“2nd zone”) follows the drop formation area. in which the drops or melt particles solidify on the surface, so that they no longer stick and that is followed by an even colder zone ("3rd zone"), in which the drops or particles completely also in The particulate solids thus obtained can then be removed from the lower area of the chamber together with the cryogas, for example by means of a pneumatic discharge device, and then separated and collected by means of, for example, a filtration or cyclone separator according to the amount of particulate solid to be generated, the particle size and also the specific heat capacity of the melt. The temperature distribution described is monitored by means of temperature sensors in / at the zones mentioned in the chamber; The amount of cryogas is regulated either according to the desired temperature distribution in the chamber or in particular according to the exhaust gas temperature of the cryogas behind the chamber or the separator (in the case of stationary operation). According to the invention, the formation of the drop formation unit can be arbitrary, for example plate atomizers or nozzles are used, preferably high-pressure nozzles or swirl chamber nozzles. One or more nozzles can be used. After the beam decay, the droplets generated are initially out of round, but preferably take a spherical shape in the further course

Shape. Depending on the type and setting of the drop formation unit, drops or after their solidification of particulate solids with average diameters (volume-related) of 10 to 3000 μm, in particular 20 to 1000 μm, can be generated. In the context of the invention, the terms powder and granulate cannot be separated sharply, since, depending on the process, both particle forms or mixed forms can occur. Unless otherwise stated, the term particulate solids is therefore used. In the area of the larger diameters above 100 μm, granules can be spoken of both for individual particles (analogy to spray drying) and agglomerates; In particular for low-dust products, the granulate form in the form of light adhesion of very fine particles to one another or with coarser particles is not excluded or even desired.

In a preferred embodiment, the particulate solid contains more than 90% by weight, in particular more than 98% by weight, of the surface-active compound.

The preferred embodiment of the chamber is rotationally symmetrical. The cryogas is preferably introduced, preferably injected, from a plurality of individual feeds arranged on the circumference of the chamber.

In a special embodiment of the method takes place during or after

Solidification of the drops targeted agglomeration of particles into granules, for example by using a fluidized bed or so-called fluidized bed fluidized bed agglomeration, which is either integrated in the lower part of the chamber or downstream of the chamber. The fluidized bed agglomeration integrated in the chamber is preferred, at least part of the cryogas being used to generate the

Fluid bed can be used and the agglomeration by building fine or the finest individual particles on coarser, not yet fully solidified particles (so-called “raspberry granules”). Granules with particularly low dust are obtained. The typical average granule grain sizes are 50-3000 μm, in particular larger than 100 μm.

Surface-active compounds are preferably understood to mean emulsifiers, wetting agents, dispersants, defoamers or solubilizers which are completely soluble in the aqueous phase and which are solid at room temperature. In particular, they can be non-ionic, anionogenic, catogenic or amphoteric or monomeric, oligomeric or polymeric in nature. The selection of the surface-active compounds is not restricted according to the invention; in the broader sense, water-soluble surfactants such as, for example, emulsifiers, wetting agents, dispersing agents or defoamers, and also, if appropriate, water-insoluble compounds, in particular from the group of

Sorbitan esters such as SPAN®, ICI

Polymers, especially block and block copolymers based on ethylene and / or propylene oxide such as e.g. Pluronic®, BASF

Block and block copolymers of ethylene and / or propylene oxide on bifunctional amines such as e.g. Tetronic®, BASF

Block copolymers based on (poly) stearic acid and (poly) alkylene oxide such as e.g. Hypermer® B, ICI

Polyvinylpyrrolidone and copolymers with a molecular weight of> 100,000 g / mol, e.g. Luviskol K®, BASF

Preferred water-soluble surface-active compounds are those from a) to d): a) non-ionic or ionically modified compounds from the group of

Alkoxylates, alkylolamides, esters, amine oxides and alkylpolyglycosides, in particular reaction products of alkylene oxides with alkylatable compounds, such as e.g. Fatty alcohols, fatty amines, fatty acids, phenols, alkylphenols, carboxamides and resin acids. This is e.g. for ethylene oxide adducts from the class of reaction products of ethylene oxide with:

m) saturated and / or unsaturated fatty alcohols with 6 to 25 C-

Atoms or

n) alkylphenols with 4 to 12 carbon atoms in the alkyl radical or

o) saturated and / or unsaturated fatty amines with 14 to 20 C-

Atoms or

p) saturated and / or unsaturated fatty acids with 14 to 22 carbon atoms or

q) hydrogenated and / or unhydrogenated resin acids,

r) from natural or modified, optionally hydrogenated castor

Esterification and / or arylation products produced in the form of oil fats, which are optionally linked to repeating structural units by esterification with dicarboxylic acids,

b) ionic or non-ionic compounds from the group of the reaction products of alkylene oxide with sorbitan esters [Tween®, ICI], oxalkylated acetylenediols and glycols, oxalkylated phenols, in particular phenol / styrene polyglycol ethers according to formula I) and II) and ionic modified Phenol / styrene polyglycol ethers of the formula I) or II) as disclosed, for example, in EP-A 839 879 [or EP-A-764 695]. The term “ionic modification” is understood to mean, for example, sulfation, carboxylation or phosphating.

Ionic modified compounds can be present either in the form of their free acids or preferably as a salt, in particular as an alkali or amine salt, preferably a diethylamine salt.

in which

R 1 ¹ 5 ⁰ denotes hydrogen or CC ₄ alkyl,

R, 1'6 ° represents hydrogen or CH ₃ ,

R 17 denotes hydrogen, -CC ₄ -alkyl, C ₁ -C -alkoxy, -CC -alkoxycarbonyl or phenyl,

m is a number from 1 -4, n is a number from 14-120, in particular 20-100,

R ^{18 is the} same or different for each unit indicated by n and for

Is hydrogen, CH ₃ or phenyl, where in the case of the presence of CH ₃ in the various - (- CH -CH (R) -O -) -

Groups in 0 to 60% of the total value of n R represent CH and m 100 to 40% of the total value of n R ^{18 represent} hydrogen and where in the presence of phenyl in the various - (-CH ₂ -CH (R ¹⁸ ) -O -) - groups in 0 to 40% of the total value of n R ¹⁸ for phenyl and in 100 to 60% of the total value of n R ¹⁸ for

Hydrogen stands.

c) ionic or nonionic polymeric surface-active agents from the group of homopolymers and copolymers, graft and graft copolymers and statistical and linear block copolymers.

Examples of suitable polymeric surface-active agents are polyethylene oxides, polypropylene oxides, polyoxymethylenes, polytrimethylene oxides, polyvinyl methyl ethers, polyethyleneimines, polyacrylic acids, polyarylamides, polymethacrylic acids, polymethacrylamides, poly-N, N-dimethyl-acrylamides,

Poly-N-isopropylacrylamides, poly-N-acrylglycinamides, poly-N-methacrylic glycinamides, polyvinyloxazolidones, polyvinylmethyloxazolidones.

d) anionic non-polymeric surface-active agents, in particular from the group of alkyl sulfates, ether sulfates, ether carboxylates, phosphate esters,

Sulfosuccinatamides, (paraffin sulfonates), olefin sulfonates, sarcosinates, isothionates and taurates, especially alkyl sulfonates of the general formula

R- SO ₂ -OH

with R = alkyl, cycloalkyl, alkenyl, in particular the rest of a paraffin. The surface-active compounds have a melting point of 25-250 ° C., preferably 30-130 ° C. and in particular 35-90 ° C. The viscosity of the melt is less than 5000 mPas, preferably less than 1000 mPas and in particular less than 200 mPas.

The temperature of the melt is particularly advantageously set such that the ratio of surface tension of the melt to viscosity assumes a value of> 0.005, in particular> 0.01 [m / s].

The invention also relates to powders and / or granules containing more than 90% by weight, preferably more than 98% by weight, of natural or synthetic surface-active compounds, characterized in that

a) the average particle size of the particulate solid particles is 10 to 3000 μm, b) the surface-active compounds are solid at room temperature (20 ° C.), and c) the surface-active compounds have a melting point of 25 to 250 ° C., preferably from 30 to 130 ° C, especially 35 to 90 ° C.

In addition, other common additives such as Anti-caking agents (e.g. Aerosil®), preservatives, stabilizers, fillers, water and / or organic solvents may be included. The powders or granules according to the invention can be produced by the process according to the invention. The same preferred embodiments apply.

The individual particles from which the particulate solids such as powders and / or granules are composed have any structure, preferably a predominantly spherical structure, in particular a spherical structure.

The invention is explained in more detail below using an exemplary embodiment. example

The example is based on a method execution as can be seen in principle from FIG. 1.

Liquid nitrogen was placed in the container (5) and evaporated by means of controlled passage of air (RT) through the heat exchanger tube (6). As a result, a stationary temperature profile was set in the solidification tube (3) above it over a height of 10 m. The temperature at the top of the solidification tube was varied between + 10 ° C and - 105 ° C, directly above the

Liquid nitrogen surface is equal to the boiling temperature (-190 ° C) of liquid nitrogen.

100 g each of a wax of a surface-active compound based on an oleyl alcohol-polyethylene glycol ether (Avolan® IW,

Bayer AG) with a melting point of 45 ° C was heated in the receiver (1) to a temperature of 75 ° C and fed to a frequency-supported above the solidification tube (3) using a slight excess pressure of <0.3 bar nitrogen. The drop formation unit (2) had a bore with a diameter of 0.5 mm, the drop size achieved by frequency superimposition of> 500 Hz was about 0.8 to

1 mm (based on spherical shape). The melt first entered the solidification channel (3) in a thread-like manner and could be collected in the form of discrete particles in the collecting basket (4) within the container (5).

Depending on the setting of the temperature profile over the height of the solidification channel (3), different particle shapes were achieved:

At a head temperature of - 70 ° C there were irregularly shaped particles with poor pouring properties. At a head temperature of -20 to + 10 ° C, especially at 0 ° C, regular spherical particles with an average diameter of 0.8 to 1.0 mm and very good pouring properties could be obtained.

Under otherwise identical conditions, however, with a nozzle of 0.2 mm in diameter, free-flowing, non-sticky particles with an average diameter of <0.4 mm were also obtained.

Claims

claims

1. Particulate solids containing more than 90% by weight, preferably more than 98% by weight, of natural or synthetic surface-active compounds, characterized in that

a) the average particle size of the particulate solid particles is 10-3000 μm, b) the surface-active compounds are solid at room temperature, and c) the surface-active compounds have a melting point of 25 to 250 ° C, preferably 30 - 130 ° C, in particular 35 - Have 90 ° C.

2. Particulate solids according to claim 1, characterized in that the surface-active compounds are selected from the group

a) non-ionic or ionically modified compounds from the group of alkoxylates, alkylolamides, esters, amine oxides and alkylpolyglycosides, in particular

Reaction products of alkylene oxides with alkylatable compounds, e.g. Fatty alcohols, fatty amines, fatty acids, phenols, alkylphenols, carboxamides and resin acids. This is e.g. to ethylene oxide adducts from the class of reaction products of ethylene oxide with:

m) saturated and / or unsaturated fatty alcohols with 6 to 25 carbon atoms or

n) alkylphenols with 4 to 12 carbon atoms in the alkyl radical or o) saturated and / or unsaturated fatty amines with 14 to 20 carbon atoms or

p) saturated and / or unsaturated fatty acids with 14 to 22 carbon atoms or

q) hydrogenated and / or unhydrogenated resin acids,

r) from natural or modified, optionally hydrogenated

Castor oil fatty bodies produced esterification and / or arylation products, which are optionally linked to recurring structural units by esterification with dicarboxylic acids.

ionic or non-ionic compounds from the group of the reaction products of alkylene oxide with sorbitan esters, oxalkylated acetylenediols and glycols, oxalkylated phenols, in particular phenol / styrene-polyglycol ethers according to formula I) and II) and ionically modified phenol / styrene polyglycol ether of the formula I) or II)

embedded image in which

R, 1 ° 5 is hydrogen or C ₁ -C ₄ alkyl,

R, 1 ¹ 6 ° represents hydrogen or CH ₃ ,

R ^{17 is} hydrogen, -CC alkyl, Cr alkoxy, C _! -C denotes alkoxycarbonyl or phenyl,

m is a number from 1-4,

n is a number from 14-120, in particular 20-100,

R ^{1 is the} same or different for each unit indicated by n and represents hydrogen, CH ₃ or phenyl, where in the presence of CH in the various - (- CH -CH (R ¹⁸ ) -O -) - groups in 0 up to 60% of the total value of n R ^{18 stands} for CH and in 100 to 40% of the total value of n R ¹⁸ stands for hydrogen and where in the presence of phenyl in the various - (- CH ₂ -CH (R ¹⁸ ) -O -) - groups in 0 to 40% of the total value of n R ^{lδ are} phenyl and in 100 to 60% of the total value of n R ^{18 is} hydrogen, c) ionic or nonionic polymeric surface-active agents from the group of homopolymers and copolymers, graft and graft copolymers and statistical and linear block copolymers,

e) anionic non-polymeric surface-active agents, in particular those from the group of alkyl sulfates, ether sulfates, ether carboxylates, phosphate esters, sulfosuccinatamides, (paraffin sulfonates), olefin sulfonates, sarcosinates, isothionates and taurates, in particular alkyl sulfonates of the general formula

R- SO ₂ -OH

With R = alkyl, cycloalkyl, alkenyl, especially the rest of a paraffin.

3. Particulate solids according to claim 1, characterized in that the surface-active compounds are selected from the group of water-insoluble compounds, in particular from the group of

- sorbitan esters,

Polymers, in particular block and block copolymers based on ethylene and / or propylene oxide

Block and block copolymers of ethylene and / or propylene oxide on bifunctional amines,

Block copolymers based on (poly) stearic acid and (poly) alkylene oxide,

- Polyvinylpyrrolidone and - Copolymers with a molecular weight of> 100000 g / mol.

4. A process for the production of particulate solids of surface-active compounds, characterized in that the compounds are introduced at a temperature above the melting temperature in liquid form into a cryogas with drop formation, cooled to the solid state and separated from the cryogas as a particulate solid.

5. The method according to claim 4, characterized in that the molten surface-active compounds are introduced into a chamber in a cryogas, preferably N ₂ or CO, by means of a drop formation unit and cooled to the solid state after the drop formation, as particulate solids from the Chamber discharged and separated from the cryogas.

6. The method according to at least one of claims 4 to 5, characterized in that the molten surface-active compounds are introduced by atomization by means of pressure nozzles or centrifugal atomizers and thereby produce drops or particles with an average diameter of 10 to 3000 μm, in particular 20-1000 μm become.

7. The method according to at least one of claims 4 to 6, characterized in that the cryogas is introduced liquid into a zone below the drop formation unit by means of nozzles in the chamber.

8. The method according to at least one of claims 4 to 7, characterized in that during or after the solidification of the droplets, an agglomeration of the particles into a particulate solid, in particular granules, with an average particle size of 100-3000 μm, preferably by means of fluidized bed agglomeration.

9. The method according to at least one of claims 4 to 8, characterized in that the agglomeration is carried out by means of a fluidized bed below the drop formation zone within a common chamber.

10. The method according to at least one of claims 4-9, characterized in that the liquid surface-active compounds having a viscosity of <5000 mPas, preferably <1000 mPas, in particular <200 mPas are fed to the drop formation unit.

11. The method according to at least one of claims 4-10, characterized in that the temperature of the melt is adjusted so that the ratio of surface tension to the viscosity of the melt is> 0.005, in particular> 0.01 m / s.