DE102004044876A1 - Preparation of (poly)urea powder, useful as thickeners in lubricants, comprises reacting isocyanate with amine (e.g. ethylene diamine) in a solvent (e.g. toluol diisocyanate) in a reactor, powdering by using shear stress and drying - Google Patents

Abstract

Preparation of a (poly)urea powder (I) comprises reacting an isocyanate with an amine in a solvent in a reactor, powdering the formed (I) by using shear stress during its formation and drying in the reactor. Independent claims are also included for: (1) (I) (having an average particle diameter of 20-100 mu m) obtained by the method; and (2) a method for preparing a composition comprising suspending the obtained powder of (I) in at least a basis oil.

Description

The The present invention relates to a process for the preparation of (Poly) urea powders and compositions according to the method contained (poly) urea powder and the use of polyurea particles obtained by the process as thickeners, especially in lubricants, such as so-called polyurea fats.

So-called polyurea fats containing polyureas as thickeners in base oils are still produced almost exclusively by the so-called "in-situ" process according to the prior art By polyaddition of polyisocyanate dissolved in solvent or mineral oil and polyamines also dissolved in mineral oil or solvent, the resulting polyurea is present in dispersed, pre-swollen form and forms a gelatinous, structured paste after removal of the solvent in the base oil (mineral oil) This process has the disadvantage that the resulting product contains impurities due to the reaction, TDI being particularly critical, which requires special approval procedures to carry out the "in situ" process , Further disadvantages are that the control of the reaction is problematic due to the high viscosities in the "in-situ" process, which may lead to inhomogeneities within the reaction masses, as well as problems with temperature dissipation since the polyaddition reaction is exothermic so-called "in-situ" state of the art is described in detail in the EP 0534248 A1 referenced, to which reference is made.

The disadvantages of the above-mentioned prior art attempts the method of EP 0534248 A1 to be overcome, in which initially the polyaddition to polyurea in a solvent (including toluene, butanol, ethyl acetate, chloroform, etc.) or solvent-free by extrusion is performed. The recovered solid is subsequently further processed, ie dried (suction filtration or evaporation or removal of the solvent), then ground and finally converted to fat. In the in the EP 0534248 A1 polyureas are first prepared by reacting polyisocyanates with amines, these are then ground after thorough reaction in the dry state to give powders and the ground crude after pasting in a base oil in a high pressure homogenizer under pressures of more than 500 bar to a "PU fat" The disadvantage of this method is that the powders obtained by grinding are relatively coarse-grained, which leads to disadvantages in the incorporation of the polyurea powder into the base liquids, which makes the use of a high-pressure homogenizer compulsory Furthermore, the method of the EP 0534248 A1 the disadvantage that several reactors and several process steps is required. The solvent variant of EP 0534248 A1 also requires very large amounts of solvent, which must be distilled off again after the reaction. High amounts of solvent are therefore necessary, for example, so that the resulting reaction product can be transported on a suction filter for drying. All this leads to higher energy consumption and higher solvent recycling costs. The solvent-free variant by extrusion has the disadvantage that problems of heat dissipation (especially cracking) can occur. In both variants, a subsequent grinding of the dried reaction product is required, which is also very expensive.

Similarly required the method of WO 02/04579 with a polyurea fat with Low noise properties should be provided, first a separate process of preparation of the polyurea and then an additional one Scherverfahren with the particle size of the thickener particles at the incorporation into a base oil can be reduced to less than 500 nm, be preferred the particle sizes the shear process is reduced so much that all particles less as 100 μm with 95% of the particles having less than 50 microns. The production more finely divided polyurea suspensions are there after However, not described methods with reasonable energy input possible. WO 02/04579 also describes no finely divided dried polyurea powder, for example at the customer site in base oils can be incorporated.

Farther WO 02/02683 discloses rubber compositions which have a fine-particle polyurea filler contain. The polyurea filler particles used have a light microscopic particle size of 0.001 to 500 microns on. The However, polyurea particles are not isolated but preferred produced in the presence of the rubber. A dried finely divided Polyurea powder, a process for its preparation and its Application as thickener in so-called PU fats is not mentioned.

Surprisingly, the present inventors succeeded in producing particularly finely divided (poly) urea powder by the use of a process for the production of polyurea in a reactor with simultaneous shear stress and removal of the volatile contents. The process allows the preparation of finely divided, dry (poly) urea powder in a single reactor without additional grinding step. The obtained (poly) urea particles are sufficiently finely divided and allow incorporation into base oils for the production of (poly) urea fats without increased energy expenditure.

By the use of the finely divided particles is especially at incorporation in base oils for the production of so-called PU fats the application of lower pressures homogenization possible, resulting in energy and material savings leads.

im Molekül aufweisen, wobei die freien Valenzen durch mindestens eine organische Gruppe abgesättigt sind, Harnstoff selbst also ausgenommen ist. Erfindungsgemäß bevorzugt sind jedoch die Polyharnstoff-Verbindungen, die mindestens zwei Gruppen

im Molekül aufweisen.The present invention thus relates to a process for the preparation of a (poly) urea powder, which comprises reacting at least one isocyanate with at least one amine in at least one solvent in a reactor and subjecting the resulting (poly) urea to shear under formation of a (poly) urea powder dries in said reactor. (Poly) urea according to the invention includes monourea compounds and polyurea compounds. Mono-urea compounds are those that have a group

have in the molecule, wherein the free valences are saturated by at least one organic group, urea itself is therefore excluded. According to the invention, however, the polyurea compounds which are at least two groups are preferred

in the molecule.

The The present invention preferably relates to a process for the preparation a polyurea powder, characterized in that at least a polyisocyanate with at least one polyamine and optionally reacted with at least one monoamine and the resulting polyurea under shear stress to form a polyurea powder dried in the reactor.

Prefers is the weight ratio the total weight of polyisocyanate and mono- or polyamine for Total weight of solvents from 10% to 50%. Most preferably, the ratio is from 15% to 35%. One relationship from bigger than 50% is disadvantageous because the thickening of the suspension during the Implementation increasingly the diffusion and reaction of the reactants with special needs. A relationship less than 10% is disadvantageous because the yield is uneconomical is.

The Solvent, that used in the invention Suspension is used, preferably from organic solvents selected. Particularly preferred is the solvent from organic solvents selected which is selected are from the group that consists of optionally substituted ones straight-chain, branched, cyclic aliphatic or aromatic Hydrocarbons, such as butane, pentane, n-hexane, cyclohexane, n-octane, Isooctane, petroleum ether, benzene, toluene, xylene, halogenated hydrocarbons, such as methylene chloride, chlorobenzene, ethers, such as diethyl ether, tetrahydrofuran, Ketones, such as acetone, esters, such as ethyl acetate, butyl acetate, etc.

Especially preferred solvents are n-hexane, n-heptane, petroleum ether, ethyl acetate.

It is possible, too, Mixtures of one or more solvents to use.

The Preparation of the polyurea can in a conventional manner the reaction of at least one polyisocyanate with at least one Polyamine in a suitable solvent respectively.

The Preparation of the polyureas is expediently carried out by reaction at least a polyisocyanate with at least one mono- or polyamine at Temperatures of -100 up to 250 ° C, preferably 20 to 80 ° C, in a solvent, such as those mentioned above, with precipitation of the polyurea.

The polyurea obtained preferably have melting or decomposition points of ≥ 180 ° C, be preferably ≥ 200 ° C, more preferably ≥ 240 ° C. Their glass transition temperatures, if present, are above 50 ° C., preferably above 100 ° C.

suitable Polyisocyanates for the preparation of the polyureas are e.g. Hexamethylene diisocyanate (HDI), Toluene diisocyanate (TDI), 2,2'-, 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI), polymethylene polyphenyl isocyanate (PMDI), naphthalene diisocyanate (NDI), 1,6-diisocyanato-2,2,4-trimethylhexane, Isophorone diisocyanate (3- (isocyanato-methyl) -3,5,5-trimethylcyclohexyl isocyanate, IPDI), tris (4-isocyanato-phenyl) -methane, phosphoric acid tris (4-isocyanato-phenylester), thiophosphoric acid tris- (4-isocyanato-phenylester) and oligomerization products obtained by reaction of said low molecular weight diisocyanates with diols or polyalcohols, in particular Ethylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, Pentaerythritol were obtained and a residual content of free isocyanate groups have. Furthermore, oligomerization products obtained by reaction of mentioned low molecular weight diisocyanates containing hydroxy groups Polyesters, e.g. Polyesters based on adipic acid and Butanediol and hexanediol with molecular weights from 400 to 3,000, or by reaction with hydroxyl-containing polyethers, such as polyethylene glycols, Polypropylene glycols, polytetrahydrofurans with molecular weights of 150 to 3,000, and a residual content of free isocyanate groups can own furthermore oligomerization products obtained by reaction of said low molecular weight diisocyanates with water or by dimerization or trimerization, e.g. dimerized toluene diisocyanate (Desmodur TT) and trimerized toluene diisocyanate, Isocyanatgruppenhaltige aliphatic polyuretdiones, e.g. obtained on Isophorondiisocyanatbasis and have a residual content of free isocyanate groups. Preferred levels of free isocyanate groups of the polyisoyanates are from 2.5 to 50 wt .-%, preferably 10 to 50 wt .-%, especially preferably at 15 to 50 wt .-%. Such polyisocyanates are known and commercially available. See Houben-Weyl, Methods of Organic Chemistry, Volume XIV, Pages 56-98, Georg Thieme Verlag Stuttgart 1963, Encyclopedia of Chem. Technol., John Wiley 1984, Vol. 13, pp. 789-818, Ullmann's Encyclopedia of Industrial chemistry, VCH, Weinheim, 1989, Vol. A 14, p. 61 1-625, as well as the commercial products of the Desmodur and Crelan series (Bayer AG).

suitable Polyisocyanates are also blocked polyisocyanates which are among the reaction conditions can react with the polyamines. this includes all the polyisocyanates already mentioned fall, the isocyanate groups are each blocked with suitable cleavage groups, the at higher Cleave the temperature again and release the isocyanate groups. Suitable cleavage groups are in particular caprolactam, malonic acid esters, Phenol and alkylphenols, e.g. Nonylphenol as well as imidazole and Sodium bisulfite. Particularly preferred are caprolactam, malonic esters and alkylphenol-blocked polyisocyanates, especially based on Toluene diisocyanate or trimerized toluene diisocyanate. preferred Levels of blocked isocyanate groups are 2.5 to 30%. Such blocked polyisocyanates are known and commercially available. See Houben-Weyl, Methods of Organic Chemistry, Vol XIV, pages 56-98, George Thieme Verlag Stuttgart 1963, as well as the commercial products of the Desmodur and Crelan series (Bayer AG).

preferred Polyisocyanates are hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI), polymethylene polyphenylisocyanate (PMDI), 1,6-diisocyanato-2,2,4-trimethylhexane, Isophorone diisocyanate (IPDI), and oligomerization products, the by reaction of said low molecular weight diisocyanates with Water or with diols or polyalcohols, in particular ethylene glycol, 1,4-butanediol, 1,6-hexanediol, Trimethylolpropane and penterythritol, were obtained and a residual content possess free isocyanate groups, as well as oligomerization products, by dimerization or trimerization, such as dimerized toluene diisocyanate (Desmodur TT) and trimerized toluene diisocyanate, containing isocyanate groups aliphatic polyuretdiones, e.g. isophorone diisocyanate-based, were obtained and a content of free isocyanate groups of 2.5 to 50 wt .-%, preferably 10 to 50 wt .-%, particularly preferably 15 to 35 wt .-%, possess. Very particular preference is given to 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI) hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI) and polymethylene polyphenyl isocyanate (PMDI).

Suitable polyamines are aliphatic di- and polyamines, such as hydrazine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1-amino-3-methylaminopropane, 1,4-diaminobutane, N, N'-dimeth-1-ethylenediamine , 1,6-diaminohexane, 1,12-diaminododecane, 2,5-diamino-2,5-dimethylhexane, trimethyl-1,6-hexanediamine, diethylenetriamine, N, N ', N''- trimethyldiethylenetriamine, triethylenetetramine, Tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine with molecular weights between 250 and 10,000, dipropylenetriamine, tripropylenetetramine, bis (3-aminopropyl) amine, bis (3-aminopropyl) methylamine, piperazine, 1,4-diaminocyclohexane, isophoronediamine, N-cyclohexyl-1, 3-propanediamine, bis- (4-amino-cyclohexyl) -methane, bis (4-amino-3-methyl-cyclohexyl) -methane bisaminomethyltricyclodecane (TCD-diamine), o-, m- and p-phenylenediamine, 1,2 Diamino-3-methylbenzene, 1,3-diamino-4-methylbenzene (2,4-diaminotoluene), 1,3-bisaminomethyl-4,6-dimethylbenzene, 2,4- and 2,6-diamino-3,5 -diethyltoluene, 1,4- and 1,6-diaminonaphthalene, 1,8- and 2,7 diam inonaphthalene, bis (4-ami no-phenyl) -methane, polymethylenepolyphenylamine, 2,2-bis (4-aminophenyl) -propane, 4,4'-oxibisaniline, 1,4-butanediol-bis (3-aminopropyl ether), hydroxyl-containing polyamines, such as (2-aminoethylamino) ethanol, carboxyl-containing polyamines, such as 2,6-diamino-hexanoic acid. Further, amino-containing liquid polybutadienes or acrylonitrile / butadiene copolymers having average molecular weights preferably between 500 and 10,000 and amino-containing polyethers, for example based on polyethylene oxide, polypropylene oxide or polytetrahydrofuran having a content of primary or secondary amino groups of 0.25 to about 8 mmol / g, preferably 1 to 8 mmol / g. Such amino group-containing polyethers are commercially available (eg, Jeffamine D-400, D-2000, DU-700, ED-600, T-403, and T-3000 from Texaco Chem. Co.).

Especially preferred polyamines are hydrazine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1-amino-3-methylaminopropane, 1,4-diaminobutane, N, N'-dimethyl-ethylenediamine, 1,6-diaminohexane, diethylenetriamine, N, N ', N' '- trimethyldiethylenetriamine, Triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenimine with molecular weights between 250 and 10,000, dipropylenetriamine, tripropylenetetramine, isophoronediamine, 2,4-diaminotoluene and 2,6-diaminotoluene, bis (4-amino-phenyl) -methane, polymethylene-polyphenylamine and amino group-containing liquid Polybutadiene or acrylonitrile / butadiene copolymers with middle Molweights preferably between 500 and 10,000 amino-containing Polyethers e.g. based on polyethylene oxide, polypropylene oxide with a content of primary or secondary Amino groups from 1 to 8 mmol / g.

All particularly preferred polyamines are ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diethylenetriamine, Triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenimine with molecular weights between 250 and 10,000, 2,4-diaminotoluene and 2,6-diaminotoluene, Bis- (4-amino-phenyl) -methane and polymethylene polyphenylamine and amino group-containing polyethers, e.g. based on polyethylene oxide, polypropylene oxide, with a content of primary or secondary Amino groups from 1 to 8 mmol / g and molecular weights between 250 and 2000th

In addition to the polyamines even more opposite the polyisocyanates reactive compounds are added, in particular Chain terminators such as monoamines such as ammonia, C1 to C18 alkylamines and di (C1 to C18 alkyl) amines, as well as aryl amines such as aniline, C1-C12 alkylarylamines, and aliphatic, cycloaliphatic or aromatic mono-, di-, or poly-C1 to C18 alcohols, aliphatic, cycloaliphatic or aromatic mono-, di- or C 1 -C 18 -carboxylic acids, aminosilanes, such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane, and carboxyl, epoxy or hydroxyl group-containing liquid Polybutadiene or acrylonitrile / butadiene copolymers with middle Molar weights preferably between 500 and 10,000 and polyether and Polyesters with molecular weights between 200 and 10,000, compared to the Polyisocyanates have reactive hydroxyl and / or carboxyl groups, be used. example for this in addition monomains to be used are ammonia, methylamine, dimethylamine, Dodecylamine, octadecylamine, oleylamine, stearylamine, ethanolamine, Diethanolamine, beta-alanine or aminocaproic acid. The amount of these extra Amines, alcohols, carboxylic acids, hydroxyl- andoder carboxyl-containing polyether and polyester depends on their content compared to the polyisocyanate-reactive groups and is from 0 to 0.5 mol of reactive group per isocyanate equivalent.

The polyurea particles according to the invention can - as mentioned - through Reaction of at least one polyisocyanate with at least one Mono- or polyamine at temperatures of -100 to 250 ° C, preferably 20 to 80 ° C, in a solvent under precipitation of the polyurea. Preferred solvents are in particular organic, preferably aprotic with isocyanates non-reactive, solvents, especially optionally substituted straight-chain, branched, cyclic aliphatic or aromatic hydrocarbons, such as Butane, pentane, n-hexane, petroleum ether, cyclohexane, n-octane, isooctane, Benzene, toluene, xylene, halogenated hydrocarbons, such as methylene chloride, Chlorobenzene, ethers, such as diethyl ether, tetrahydrofuran, ketones, such as Acetone, esters such as ethyl acetate, butyl acetate, etc.

The Monourea compounds are made according to the polyurea compounds in particular by reaction of monofunctional isocyanates with monofunctional Amines produced. These are expediently such compounds, which has a thickening effect on the base oils similar to the polyureas exhibit.

In contrast to the so-called "in-situ" state of the art described above, according to the invention, the preparation of the (poly) urea particles does not take place in the so-called base or base oil of the lubricant, as described below: The solvents used for the preparation of the polyureas and which are present in the suspensions subjected to spray drying, differ from the so-called base oils in particular by their viscosity and their molecular weight average is about 1 cSt (40 ° C), while it is at least about 4 cSt (40 ° C) for the base oils at least about 4 preferred. Base oils have a molecular weight distribution which results from the refining / distillation production. In contrast, solvents have a defined molecular weight.

The Reaction of polyisocyanate with mono- or polyamine is preferred so performed that the polyisocyanate is initially introduced in the solvent and then polyamine admixed or by mixing the mono- or polyamine in the solvent submitted and added to the polyisocyanate. The amounts of polyisocyanate, Mono- or polyamine depend on the desired properties of the polyurea particles. By Use of a surplus on mono- or polyamine these contain, for example, still bound amino groups, or when using a surplus of polyisocyanate still bound isocyanate groups. preferred Amounts ratios of polyisocyanate and polyamine are from 0.5 to 2.0, more preferred 0.7 to 1.3, in particular 0.8 to 1.2 moles of isocyanate group per mole Amino group.

Become Monoamine, like stearylamine used as a chain stopper, can do this the ratios of polyamine to polyisocyanate influence accordingly.

Next Mono- or polyamines can According to the invention further across from Isocyanates reactive polyfunctional compounds are used such as in particular polyols, so that it is used to form Polyurea urethanes comes. Such polyols may also include polyether groups exhibit. The polyols may be, for example, those above mentioned Polyl alcohols used for the preparation of oligomeric Polyisoyanaten act.

aufweisen. Besonders bevorzugt sind erfindungsgemäß Polyharnstoffe, die im Mittel zwei, drei oder vier solcher Harnstoffgruppen aufweisen. For controlling the polyurea particle size, as already mentioned above, emulsifiers and dispersants may be added before or during the production process. According to the invention, the polyureas are those which contain at least two urea repeat units of the formula

exhibit. Polyureas which on average have two, three or four such urea groups are particularly preferred according to the invention.

Prefers The polyurea particles consist of polyurea with a mass-average molecular mass determined by gel permeation chromatography against polystyrene as Standard, from 500 to 20,000.

Especially preferred polyureas are reaction products of 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI) and Polymethylenepolyphenylisocyanate (PMDI) and ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 2,4- 1,6-diaminohexane, diaminotoluene and 2,6-diaminotoluene, bis (4-amino-phenyl) -methane and polymethylene polyphenylamine and / or monoamines, such as ammonia, C1 to C18-alkylamines and di- (C1 to C18-alkyl) -amines, as well as arylamines, such as aniline, C1-C12 alkylarylamines, as well as polyureas with molecular weights from 500 to 3000.

To the conversion to the (poly) urea is completed takes place the drying of the (poly) urea powder by stripping off the solvent and the rest possibly existing volatile Ingredients from the reaction reactor. The drying is preferably carried out at a temperature in the range of 40 to 80 C °. In a preferred variant the drying is carried out under reduced pressure of preferably less as 300 mbar. Particularly preferably, the drying takes place at a Pressure in the range of 10 to 180 mbar.

The inventive method is characterized in that at least the drying step under shear stress. shear stress means that shear forces are applied to the (poly) urea particles in the reactor. Preferably, the shear stress is also ready during the Reaction of the polyisocyanate with the polyamine applied, thereby the formation of larger particles or agglomerates is avoided from the outset.

The shear stress exerted in the reactor is preferably from 1 to 10 ⁴ s ^-1 .

The shear stress during drying or optionally also during the reaction is expediently chosen so that the particle size ranges given below for the obtained (Po ly) urea powder can be achieved.

suitable Reactors in which the production and drying of the (poly) urea powder under shear stress, preferably include horizontal single shaft mixers one.

The according to the inventive method dry polyurea powder obtained preferably have one Residual content of volatile Ingredients (those having a boiling point of less than 250 ° C), less than 5 wt%, more preferably less than 3 wt%, still more preferably less than 1% by weight.

The according to the inventive method obtained dry (poly) urea powder preferably have medium Particle sizes of less than 150 μm, preferably less than 100 microns and more preferably less than 80 microns. The lower limit of the mean grain or particle size is preferably at more than about 20 microns. Grain sizes of more than 150 μm are less preferred because these are a homogeneous incorporation of the (poly) urea particles in basic or base oils difficult. Mean particle sizes of less than 20 μm are less preferred because they require too much shear effort would on the other hand, the finely divided powder then too much dust inclines.

The mean grain size means here the weight average particle size, and it is determined by coherent light scattering (Laser method). This method gives a mean particle size including the agglomerates. The size of the primary particles can be significantly lower, for example at about 1 to 10 microns. By the use of high pressure homogenizers on the inventively prepared PU fats can be largely deagglomerated according to the invention Polyurea particles are achieved.

Prefers have more than 90% of the particles of the obtained (poly) urea powder a particle size of less 100 μm.

The The present invention further relates to dry (poly) urea powders, those by the method according to the invention available and especially the dried (poly) urea powder, which has a mean particle diameter of 20 to 150 microns, preferably from 20 to 100 μm and their solvent content preferably less than 0.5% by weight, more preferably less than 0.3% by weight even more preferably less than 0.2% by weight.

Of the Advantage of the invention produced dry (poly) urea powders consists in particular, for the first time a possibility To have found customers to the production of so-called PU fats enable, without this from the point of view of occupational safety problematic "in-situ" use to have to do or that this is a high pressure homogenization at high pressures of must use more than 500 bar. It is therefore to be expected. that according to the inventive method available (Poly) urea particles open up application areas or customer groups for which one the use of (poly) ureas due to the disadvantages described not yet considered moved.

The (poly) urea powders obtainable by the process according to the invention are, in particular, those having a high specific surface area. Such high specific surface areas are not obtainable by other prior art drying methods and subsequent milling. The (poly) urea powders according to the invention have a specific surface area of from 15 to 50 m ² / g, preferably from 35 to 45 m ² / g (measured by Hg porosimetry).

The The present invention further relates to a process for the preparation a composition containing the (poly) urea powders described above suspended in at least one base oil.

Base oils close in principle any, preferably organic liquid, which is opposite to the (Poly) urea powder is inert. These are especially those Liquids, which can be thickened by means of the (poly) urea powder.

Preferred base oils are, for example, conventional base oils used in lubricants, such as customary mineral oils used, synthetic hydrocarbon oils or synthetic or natural ester oils, or mixtures thereof. Generally, these have a viscosity in the range of about 4, preferably 5 to about 400 cSt at 40 ° C, although typical applications have a viscosity in the range of about 10 to about 200 cSt at 40 ° C. Mineral oils which may be used in the present invention may be conventional refined base oils derived from paraffinic, naphthenic or mixed crudes. Synthetic base oils include ester oils such as esters of glycols such as a C13 oxo diester of tetraethylene glycol, or complex esters such as those of 1 of sebacic acid and 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid.

Natural ester oils include saturated and unsaturated natural Esteröle, like vegetable or animal oils and fats which are naturally occurring triglycerides Fatty acids, and their hydrogenated products or transesterification products. preferred such natural Esteröle are of plant origin, especially vegetable oils, which consisting essentially of mixed glycerol esters of higher fatty acids with an even number of Carbonates, such as apricot kernel oil, avocado oil, cottonseed oil, borage oil, thistle oil, peanut oil, hardened peanut oil, corn oil, hemp oil, hazelnut oil, pumpkin seed oil, coconut oil, linseed oil, bay oil, poppy oil, macadamia oil, corn oil, almond oil, evening primrose oil, olive oil, hydrogenated Palm oil, Palm oil, Pistachio oil, Rapeseed oil, Castor oil, Sea Buckthorn Oil, Sesame oil, soybean oil, sunflower seed oil, grapeseed oil, walnut oil, wheat germ oil, wild rose oil, coconut oil, Palm fat, palm kernel fat or rapeseed oil, preferably are sunflower oil, soybean oil and rapeseed oil.

Other synthetic oils shut down a: synthetic hydrocarbons such as poly-alpha-olefins, alkylbenzenes, such as alkylate bottoms from the alkylation of benzene with tetrapropylene, or the copolymers of ethylene and propylene; Silicone oils, e.g. ethyl phenyl polysiloxanes, Methyl polysiloxanes, etc., polyglycol oils, e.g. such receive Condensation of butyl alcohol with propylene oxide; carbonate ester, e.g. the product of the reaction of C8 oxo alcohols with ethyl carbonate to form a half ester, followed by reaction with tetraethylene glycol, etc. Other suitable synthetic oils include polyphenyl ethers, such as those about 3 to 7 ether bonds and about Have 4 to 8 phenyl groups. Other base oils include perfluorinated polyalkyl ethers such as those described in WO 97/477710.

The base oils preferably have a boiling point of more than 100 ° C, more preferably more than 150 ° C, yet more preferably more than 180 ° C on.

preferred base oils are conventional refined base oils that differ from paraffinic, Derive naphthenic or mixed crude oils, synthetic Hydrocarbons such as poly-alpha-olefins, alkylbenzenes and ester oils.

Prefers contains the inventively prepared Composition of 2 to 25 wt .-%, preferably from 5 to 15 wt .-% of the (poly) urea according to the invention based on the total amount of the base oil.

The Process for the preparation of the o.g. Composition suitably includes the Suspending the inventively prepared (Poly) urea powder in at least one base oil. Suspending the (poly) urea powder in the base oil can be done in a conventional manner, for example in a homogenizer, by means of a roller mill or high-speed dissolvers and others for the Preparation of such dispersions of known devices, such as corundum disks, colloid mills, pin mills etc .. The incorporation of the powder is carried out by pasting at elevated temperatures from about 100-170 ° C, and then until repeated homogenization in the o. g. Equipment. Before homogenizing turns out to be the cooling the pasted mass as appropriate. As mentioned above, if necessary, it is possible the invention obtained (Poly) urea particles in the production of PU fats by sole or additional Application of a high-pressure homogenizer to deagglomerieren further and thereby further decreasing the mean particle sizes in the primary particle size range.

By the use of the invention especially requires finely divided (poly) urea powder with high specific surface area the incorporation of the polyurea powder substantially less energy as the incorporation of a ground (poly) urea powder. Furthermore To achieve the same viscosities lower amounts of the polyurea powder required.

The The present invention further relates to the use of the inventively prepared (Poly) urea powder as thickener. The (poly) urea powder according to the invention can For example, used as a thickener in the following applications are: paints, varnishes, adhesives, pastes, greases, solutions etc.

Particular preference is given to the (poly) urea powders prepared according to the invention as Verdi used in lubricants.

The produced according to the invention Polyurea powder are preferred in amounts of about 5 to 25 wt .-%, based on the total amount of the base oil used.

The The present invention further relates to lubricants containing the produced according to the invention Polyurea powder, at least one base oil and optionally further typical for lubricants and additives. These usual auxiliaries and additives shut down For example: corrosion inhibitors, high-pressure additives, antioxidants, Friction modifier, wear protection additives.

A Description of the additives used in greases can be found for example in Boner, "Modern Lubricating Greases ", 1976, chapter 5.

In a particular embodiment For example, the invention relates to a composition especially for use as a lubricant comprising at least one (poly) urea powder according to the invention, at least one base oil and at least one further thickener or thickener contains. typical other thickeners used in grease formulations or thickener in particular the alkali metal soaps, clays, polymers, asbestos, carbon black, silica gels and aluminum complexes.

According to the invention preferred are the so-called soap fats. These are in particular Metal salts of particular monovalent, optionally substituted preferably higher (> C8) carboxylic acids, wherein It is also possible to use mixtures of metal salts of the carboxylic acids. There are in particular metal salts of carboxylic acids with alkali and alkaline earth metals, such as sodium, potassium, lithium, calcium, magnesium, barium or strontium but also with other metals such as aluminum and Zinc, lithium and calcium soaps are the most common. easy Soap lubricating greases are longer-chained from the alkali metal salts fatty acids (at least C8), with lithium 12-hydroxystearate, the most common, from 12-hydroxystearic acid, lithium hydroxide monohydrate, and mineral oil is formed. Complex soap greases are also widely used and include metal salts of a mixture of organic acids. One typical complex soap grease used today is a complex lithium soap grease consisting of 12-hydroxystearic acid, lithium hydroxide monohydrate, azelaic acid and mineral oil is made. The lithium soaps are disclosed in many patents including US-A-3 758,407, US-A-3,791,973, US-A-3,929,651 and US-A-4,392,967, in which examples are given.

The weight ratio Weight soap fats to weight Polyureas can according to the invention of 100 : 1 to 1: 100. The attractiveness of the invention produced (Poly) urea powder when mixed with soap fats especially in that one is different than in the via in situ method PU fats produced here the isolated dry polyurea powder into soap soap formulations and their properties can influence it in a targeted way. Experiments show that by the Adding 2% polyurea fat to lithium soap greases surprisingly decreases Penetration and thus an improvement in the consistency of the fat reached. Furthermore, the dropping point is compared to the pure lithium soap grease elevated.

The The present invention is illustrated by the following examples.

EXAMPLES

Polyurea 1:

To a mixture of 44.58 g of diethyltolylenediamine and 99.3 g of coconut fatty amine in 1350 g of petroleum ether with constant stirring 128.43g of a methylene-4,4'-diphenyldiisocyanats with an NCO content of 32.68% added.

The solvent the resulting suspension is after completion of the reaction Shear stress removed, and the resulting powder in the applied Vacuum dried.

It is a 15% suspension of the resulting powder in naphthenic mineral oil at about 150 ° C 1h, chilled and subsequently homogenized in a three-roll mill 3 ×. Dripping point and consistency of the fat obtained are determined. As a comparison serves a fat, which of polyurea powder identical Composition and same base oil was made. The underlying lying powder of the reference fat was prepared in the kneading extruder and subsequently ground conventionally.

Results:

The The consistency of a fat is determined by the cone penetration according to ISO 2137 on a sample of fat is determined. The cone penetration corresponds to the penetration depth of a cylindrical cone in the Fat sample after 5s, measured in 1 / 10mm, - the higher the value, the larger the Penetration depth, the lower the fat consistency. It makes a difference one between the rest penetration Pu and the walk penetration Pw, 60 or Pw, 60,000. The resting penetration is determined on the untreated fat. The walk penetration is determined after the sample has 60 strokes (Pw, 60). or 60,000 strokes (Pw, 60,000) was drummed. The difference between both Walkpenetrationen represents a proven in practice Measure of fat stability under continuous load. The smaller the difference, the more stable is the fat sample against stress.

Polyurea 2:

2 moles of 2,4-, 2,6-tolylene diisocyanate were added to a mixture of 1 mole of 1,6-hexamethylenediamine and 2 moles of stearylamine in ethyl acetate. The solvent of the resulting suspension is removed after completion of the reaction under shear stress. The resulting, powdery polyurea 2 is dried in vacuo. The light micrograph ( 1 ) shows that the particle diameter is well below 100μm. This is confirmed by a particle size analysis by means of coherent light scattering. The weight average of the measurement is D [v, 0.5] = 30.79 μm.

A 15% suspension of the dried polyurea 2 in naphthenbasischem oil is stirred at 170 ° C for 1h, then cooled and homogenized in a three-roll mill 3 ×. The consistency to a "in-situ" prepared reference fat became more identical Composition determined.

Result:

blends of lithium soap fats with polyurea powder prepared according to the invention.

It was to be ascertained whether admixing polyurea powder produced according to the invention leads to a change in penetration and drop point of commercially available lithium soap fats. For this purpose, three different commercially available lithium soap grease were investigated with and without the addition of polyurea powder. The lithium soap greases were heated to 170 ° C heated for one hour and then added 3 × via a roller mill with and without the addition of polyurea powder. The results were as follows:

The Experiments show that by adding 2% polyurea fat surprising to lithium soap fats a reduction of penetration and thus an improvement of the Consistency of the fat achieved. Furthermore, the dropping point is opposite to the pure lithium soap grease increased.

Claims (32)

Process for the preparation of a (poly) urea powder, characterized in that at least one isocyanate is reacted with at least one amine in at least one solvent in a reactor and drying the resulting (poly) urea under shear to form a (poly) urea powder in said reactor. Method according to claim 1, characterized in that that the (poly) urea from a monourea compound and a polyurea compound is selected. Process for the preparation of a polyurea powder according to claim 1 or 2, characterized in that at least a polyisocyanate with at least one polyamine and optionally with at least one monoamine in at least one solvent reacted in a reactor and the resulting polyurea under Shear stress to form a polyurea powder in said The reactor dries. Method according to claim 3, characterized that the weight ratio the total weight of polyisocyanate and mono- or polyamine for Total weight of solvents from 10% to 50%. Method according to one of claims 1 to 4, characterized that the solvent from organic solvents selected becomes. Method according to one of claims 1 to 5, characterized that the solvent from organic solvents selected is selected from the group consisting of: optionally substituted straight-chain, branched cyclic aliphatic or aromatic hydrocarbons. A process according to any one of claims 3 to 5, wherein the polyisocyanates selected from the group which consists of: 2,4'- and 4,4'-diisocyanatodiphenylmethane (MDI) Hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), polymethylene polyphenyl isocyanate (PMDI), naphthylene diisocyanate (NDI), dicyclohexyl-4,4'-diisocyanate and Isophorone diisocyanate (IPDI). Method according to one of claims 1 to 7, wherein the mono- or polyamines the group selected consisting of: ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diethylenetriamine, Triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenimine with molecular weights between 250 and 10,000, 2,4-diaminotoluene and 2,6-diaminotoluene, bis (4-amino-phenyl) -methane, polymethylene polyphenylamine and amino group-containing polyethers containing primary or secondary Amino groups from 1 to 8 mmol / g and molecular weights between 250 and 2000, phenylenediamine, diethyltoluylenediamine, 2-methylpentamethylenediamine and butylamine, Hexylamine, octylamine, stearylamine, oleylamine, tridecylamine, coconut fatty amine, Aniline, isopropylaniline, N, N-diethylaniline, p-toluidine, cyclohexylamine, dioctyldiphenylamine. Method according to one of claims 1 to 8, characterized that in addition to mono- or polyamines further isocyanate-reactive polyfunctional Connections are used. Method according to one of claims 1 to 9, characterized that the resulting (poly) urea powder of polyurea with a mass-average molecular mass from 500 to 20,000 determined by gel permeation chromatography against polystyrene as standard, consists of 200 to 2,000,000. Method according to one of claims 1 to 10, characterized that the reaction of the polyisocyanate with the mono- or polyamine at a temperature in the range of 20 to 120 ° C is performed. Method according to one of claims 1 to 11, characterized drying at a temperature in the range of 40 to 80 C ° is performed. Method according to one of claims 1 to 12, characterized drying at a pressure in the range of 100 to 300 mbar carried out becomes. Method according to one of claims 1 to 13, characterized in that the shear stress of 1 to 10 ⁴ s ^-1 . Method according to one of claims 1 to 14, characterized that the reactor is selected from horizontal single shaft mixers. Method according to one of claims 1 to 15, characterized the resulting (poly) urea powder has an average particle size of less 150 microns. Method according to Claims 1 to 16, characterized the resulting (poly) urea powder has an average particle size of less 100 microns. Method according to claim 16 or 17, characterized that the obtained (poly) urea powder has an average particle size of more than 20 μm having. The method of claims 1 to 18, wherein more than 90% of the particles of the obtained (poly) urea powder have a particle size of less 100 microns have. (Poly) urea powder, obtainable according to claim one the claims 1 to 19. (Poly) urea powder that has an average particle diameter from 20 to 100 μm having. (Poly) urea powder according to claim 20 or 21, that has a volatile content Ingredients, such as solvents, of less than 0.5% by weight. (Poly) urea powder according to any one of claims 20 to 22, that has a specific surface area of more than 15 m ² / g (measured by Hg porosimetry). Process for the preparation of a composition, that suspending the (poly) urea powder obtained after a the claims 1 to 19 in at least one base oil. The method of claim 24, wherein the suspension of the (poly) urea powder in at least one base oil of the treatment in a high pressure homogenizer. Method according to claim 25, characterized in that that the base oil selected is from the group consisting of mineral oils and synthetic or natural oils. A method according to claim 24, 25 or 26, wherein the Amount of (poly) urea powder from 2 to 25 wt .-%, based on the total amount of base oil is. A method according to any one of claims 24 to 27, wherein at least another for Lubricant more usual Auxiliary and additive is mixed. A method according to any one of claims 24 to 28, wherein at least another thickener is added. Use of the (poly) urea powder obtained after one of the claims 1 to 19 as a thickener. Use of the (poly) urea powder obtained after one of the claims 1 to 19 in lubricants. Use of the composition obtained after one the claims 24 to 29 as lubricant, paint, varnish, glue, paste, solution etc.