EP2480600A1

EP2480600A1 - Iron(iii)-complexing agent for stabilizing comb polymers in mineral binding agents

Info

Publication number: EP2480600A1
Application number: EP10754534A
Authority: EP
Inventors: Christian M. BÜRGE; André Peter; Christophe Kurz; Franz Wombacher
Original assignee: Sika Technology AG
Current assignee: Sika Technology AG
Priority date: 2009-09-21
Filing date: 2010-09-21
Publication date: 2012-08-01
Also published as: BR112012006112A2; CN102575054B; MX2012003366A; JP2013505317A; KR20120099417A; CN102575054A; US20120178854A1; AU2010297199A1; WO2011033127A1

Abstract

The invention relates to compositions comprising a comb polymer and a Fe(111)-complexing agent X, which is selected from the group comprising thiocyanates, condensed phosphates, amines, amino acetic acids, oxycarboxylic acids and compounds of the formula (V). In addition, the invention relates to a method for stabilizing comb polymers in the presence of Fe(III) using such Fe(111)-complexing agents X.

Description

IRON (III) COMPLEX BUILDER FOR STABILIZING COMPOUNDS IN MINERAL BINDS Technical Field

The invention relates to the field of additives for hydraulically setting compositions.

State of the art

It has long been known that the starting materials for the

Cement production may have a more or less high chromium content. In particular, the presence of water-soluble chromium (VI) in cement flour may result in prolonged skin contact

Rashes, especially the so-called Maurerekzem cause and is undesirable for this reason. Also known are methods and measures to reduce the unwanted soluble chromium (VI) content and fix it in the reduced stage. For this purpose, for example, iron (l l) sulfate is used, wherein the water-soluble

Chromatanteil in cements by iron (l l) sulfate is reduced to trivalent chromium and iron (l l) ions are oxidized to iron (l l l) ions.

By oxidation by means of atmospheric oxygen of iron (l l) sulfate to

However, admixtures of known iron (III) compounds to the dry cement powder can frequently lose their reducing action after a relatively short time, since they can already be oxidized to inactive iron (III) compounds when air is admitted. A particular disadvantage of the iron (III) compounds is that they are capable of damaging organic compounds present in the cement, in particular comb polymers, for example by iron (III) -catalyzed oxidation of the organic compound with atmospheric oxygen.

For these reasons, iron (l) compound in considerable

Quantities, typically 0.4% by mass of iron (II) compound based on the cement, are added to ensure safe chrome reduction guarantee. As a result, this leads to a considerable proportion of potential iron (III) compounds.

Comb polymers have long been used in concrete technology as a dispersant, especially as Hochleistungsverflussiger because of their strong water reduction.

Comb polymers are only conditionally stable at elevated temperature and are destroyed within days, so that they can no longer develop their effect. It has been shown in particular that the effect of

Comb polymers significantly decreases when in the presence of inorganic powders, in particular hydraulic binders, in conjunction with

Iron (III) compounds can be used at elevated temperature. Such problems occur, for example, in the storage of hydraulic

Binders or when grinding hydraulic binders.

During storage, the hydraulic binders are usually over

80 ° C, often even at over 120 ° C, stored in silos. In addition, high pressures are present in silos, especially in high silos, which place particular demands on the stabilization of polymers. Comb polymers are added to the binder beforehand, which is particularly useful in the production of

Ready mixes, such as ready-mixed cement, is desired, takes after storage at high temperatures, the mode of action of the comb polymers from strong.

Comb polymers are also used in part as grinding aids in the milling of hydraulic binders, for example clinkers, as described, for example, in WO 2005/123621 A1. Since the grinding also high temperatures, the comb polymers can

are largely destroyed and their effect no longer unfold.

Presentation of the invention

Object of the present invention is therefore, a

To provide composition and a method which comb polymers in the presence of iron (III) compounds, in particular in mineral binders, especially at elevated temperature, protects against damage by iron (III) compounds.

Surprisingly, it was found that this by a

Composition according to claim 1 can be achieved. It has now been found that by compositions comprising a

A comb polymer and at least one Fe (III) complexing agent X, which is selected from the group consisting of thiocyanates, condensed phosphates, amines, aminoacetic acids, oxycarboxylic acids and compounds of the formula (V) comb polymers can be protected from damage by iron (III) compounds and be able to maintain their effect over a longer period even at elevated temperature in the presence of iron (III) compounds.

In particular, it is surprising that a composition comprising a comb polymer and at least one Fe (III) complexing agent X, which additionally comprises an antioxidant, is particularly suitable for protecting comb polymers from damage by iron (III) compounds.

Furthermore, it has been shown that protected in this way

Comb polymers can still have their effect as grinding aids and / or as dispersants, in particular as plasticizers, after they have been exposed to high temperatures during the milling process or during long storage. Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

Way to carry out the invention

The present invention relates to a composition comprising a comb polymer and at least one Fe (III) complexing agent X which is selected from the group consisting of thiocyanates condensed Phosphates, amines, amino acetic acids, oxycarboxylic acids and compounds of formula (V).

The term "Fe (III) complexing agent" is used throughout

present text understood a neutral molecule and / or ion, which is suitable as a so-called ligand on a Fe (III), the so-called central ion, and to form a complex compound, as described in CD Römpp Chemie Lexikon, 9th Edition, version 1 .0, Georg Thieme Verlag, Stuttgart.

It is advantageous if the Fe (II) complexing agent X is a

Complexation constant for Fe (l l l), which is 10 times, in particular 1000 times, greater than the complexation constant for Fe (l l). This is particularly advantageous when complexing Fe (II) complexing agent X with Fe (I) is disadvantageous.

The term "complex formation constant" throughout the present text means the equilibrium constant Ki for the formation of a complex compound of Fe (III), respectively Fe (II), (central ion) and a Fe (III) complexing agent X (ligand), measured in Water at room temperature.

As thiocyanates, 2-nitro-4-thiocyanatoaniline and benzyl thiocyanate, in particular benzyl thiocyanate, are preferred.

As condensed phosphates pyrophosphate, tripolyphosphate and polyphosphate are preferred.

Amines and aminoacetic acids are advantageous because they can form very stable complex compounds with Fe (II).

As amines are triethanolamine (TEA), ethylenediamine (EDA), 1 - [2- (bis (2-hydroxypropyl) amino) ethyl (2-hydroxypropyl) amino] propan-2-ol

(Quadrol), N, N-di- (hydroxyethyl) -glycine (DHEG), diethylenetriamine (DETA), tetraethylenepentamine (TEPA), triethylenetetramine (TETA) are preferred.

As aminoacetic acids are nitrilotriacetic acid (NTA),

Ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CDTA), diethylenetriamine pentaacetic acid (DTPA), ethylene glycol bis (amino- ethyl ether) -N, N, N'N'-tetraacetic acid (EGTA), N- (2-hydroxyethyl) -ethylenediamin-N, N, N'-triacetic acid (HEDTA), triethylenetetraminehexaacetic acid (TTHA), glycine, glutamic acid, or their salts, preferably.

Glycine has a stability constant for Fe (III) of 6.3 × 10 ¹⁰ and for Fe (II) of 2 × 10 ⁴ . Glutamate has a stability constant for Fe (II) of 6.3 x 10 ¹³ and for Fe (II) of 4 x 10 ⁴ . NTA has a stability constant for Fe (II) of 8 x 10 ¹⁵ . EDTA has a stability constant for Fe (III) of 1 .3 x 10 ²⁵ and for Fe (II) of 2 x 10 ¹⁴ .

As the oxycarboxylic acids, 2,3-dihydroxybutanedioic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid (citric acid), gluconic acid, α-hydroxybutyric acid, hydroxysuccinic acid are preferable.

Glycolates have a stability constant for Fe (III) of 5 × 10 ³ and for Fe (II) of 8 × 10 ¹ . Malonates have a stability constant for Fe (III) of 2 × 10 ⁹ and for Fe (II) of 5 × 10 ⁵ . Citrate has a stability constant for Fe (II) of 3.2 × 10 ¹³ and for Fe (II) of 5 × 10 ⁵ . Tartaric acid has a stability constant for Fe (III) of 7.2 x 10 ¹¹ . of the formula (V)

R ¹⁰ and R ¹¹ independently of one another represent H, halogen atom, NO 2 or an optionally branched, saturated or unsaturated alkyl radical having 1 to 25 C atoms or an aryl radical having 6 to 14 C atoms or an acyl radical having 1 to 10 C Atoms or a carbonyl radical having 1 to 10 C atoms or a carboxyl radical having 1 to 10 C atoms, or

R ¹⁰ and R ^{1 1} are part of an aromatic or cycloaliphatic ring, in particular an aromatic 6-membered ring.

Examples of compounds of the formula (V) are 2-amino-5-bromothiazole, 2-amino-5-chlorothiazole, 2-amino-5-nitrothiazole, 2-aminothiazole, 2-aminothiazole-5-carboxaldehyde, 2-amino-4 thiazolecarboxylic acid, 2-amino-5- methylthiazole, 2-amino-4- (trifluoronormethyl) thiazole-5-carboxylic acid, 2-amino-4-thiazoleacetic acid, 2-amino-4,5-dinethylthiazole, 2-amino-α- (methoxyimino) -4-thiazoleacetic acid, 5 Acetyl-2-amino-4-methylthiazole, 5-acetyl-2-amino-4-methylthiazole, methyl 2-amino-4-thiazole acetate, methyl 2-amino-4-thiazole acetate, 2-amino-4,6 -difluorobenzothiazole, 2-amino-5-bromo-benzothiazole, 2-amino-6-bromobenzothiazole, 2-amino-4-chlorobenzothiazole, 2-amino-6-chlorobenzothiazole, 2-amino-6-fluorobenzothiazole, 2-amino-6 -nitrobenzothiazole, 2-aminobenzothiazole, ethyl 2-amino-α- (hydroxyinnino) -4-thiazole acetate, ethyl 2-amino-4-methylthiazole-5-carboxylate, ethyl 2-aminothiazole-4-acetate, ethyl-2 - aminothiazole-4-acetate, 2-amino-4,5,6,7-tetrahydrobenzothiazole, 2-amino-6- (trifluoromethyl) benzothiazole, 2-Amino-6-thiocyanatobenzothiazole, 2-Amino 4-methoxybenzothiazole, 2-amino-6-methoxybenzothiazole, 2-amino-4-methylbenzothiazole, 2-amino-6-methylbenzothiazole, 2-amino-4- (3,4-difluorophenyl) thi azole, 2-amino-4- (4-bromophenyl) thiazole, 2-amino-4- (4-chlorophenyl) thiazole, 2-amino-4- (4-nitrophenyl) thiazole, 2-amino-4-phenylthiazole, 2 -Amino-4-phenylthiazole, 2-Amino-6-ethoxybenzothiazole, 2-amino-5,6-dimethylbenzothiazole, 2-amino-4- (p-tolyl) thiazole, 2-amino-5-methyl- 4-phenylthiazole, 4- (4-acetamidophenyl) -2-aminothiazole, ethyl 2-amino-4- (4-bromophenyl) thiazole-5-carboxylate, ethyl 2-amino-4-phenylthiazole-5-carboxylate, 2 -Amino-4-phenyl-5-tetradecylthiazole.

Particularly preferred is 2-aminothiazole.

Preferably, the Fe (III) complexing agent X is a compound of the formula (V).

It is furthermore particularly advantageous if the Fe (III) complexing agent X is not substances which, when used in mineral binders, lead to an odor nuisance. It is particularly advantageous if the Fe (III) complexing agent X causes a reduction of Fe (III) to Fe (II). The ferrous compound for reducing soluble chromium (VI) may be added to the cement either as a cement additive during cement production or as a concrete admixture in concrete production. When used as Mahlzusatzmittel the dosage can be adapted to the soluble chromium (VI) content. As a rule, 0.4% by mass (based on the cement) of iron (II) sulfate is added, so that the cements produced meet the requirements of Directive 2003/53 / EC. When used as a concrete admixture in concrete production, the addition of iron (II) compounds can not be adjusted to the chromium (VI) content of the cement, as is usually the chromium (VI) content of the cement

Cements are not known. In Germany, the chromium (VI) content can be up to 2 mg / kg.

Iron (II) compound is typically iron (II) sulfate, but other iron (II) compounds, especially iron (II) salts, are also possible.

The iron (III) ions are typically formed by oxidation of iron (II) ions of the mentioned iron (II) compound, in particular by atmospheric oxygen or by chromium (VI) ions. However, iron (III) ions can also be of other origin. For example, iron (III) ions can be derived from iron (III) compounds, in particular iron (III) salts.

In the present document, the term "comb polymer" is understood as meaning a comb polymer consisting of a linear polymer chain (= main chain) to which side chains are linked via ester or ether groups.

The at least one comb polymer is preferably a comb polymer KP having side chains attached via ester or ether groups to the main chain.

Suitable comb polymers KP are, on the one hand, comb polymers with side chains bonded via ether groups to the linear polymer backbone. Bonded via ether groups to the linear polymer backbone

Side chains can be introduced by polymerization of vinyl ethers or allyl ethers.

Such comb polymers are described, for example, in WO 2006/133933 A2, the content of which is hereby incorporated by reference in particular

is disclosed. The vinyl ethers or allyl ethers have in particular the formula (II).

Here, R 'is H or an aliphatic hydrocarbon radical having 1 to 20 C atoms or a cycloaliphatic hydrocarbon radical having 5 to 8 C atoms or an optionally substituted, aryl radical having 6 to 14 C atoms. R "is H or a methyl group and R '" is an unsubstituted or substituted aryl radical, in particular a phenyl radical.

Furthermore, p is 0 or 1; m and n are each independently 2, 3 or 4; and x and y and z are each independently for values in the range of 0 to 350.

The sequence of those designated in formula (II) as s5, s6 and s7

Substructure elements can be alternating, block-like or random

be arranged.

In particular, such comb polymers are copolymers of

Vinyl ethers or allyl ethers with maleic anhydride, maleic acid, and / or

(Meth) acrylic acid.

On the other hand, comb polymers having side chains bonded via ester groups to the linear polymer backbone are suitable as the comb polymer KP. This type of comb polymer KP is preferred over the comb polymers with side chains attached via ether groups to the linear polymer backbone. Particularly preferred comb polymers KP are copolymers of the formula (I).

M independently of one another represents H ⁺ , alkali metal ion,

Alkaline earth metal ion, divalent or trivalent metal ion, ammonium ion, or organic ammonium group. The term "independently of one another" in the present document in each case means that a substituent can have different meanings available in the same molecule: Thus, for example, the copolymer of the formula (I) can simultaneously have carboxylic acid groups and sodium carboxylate groups, ie for M in this Trap H ⁺ and Na ^{+ are} independent of each other.

It is clear to the person skilled in the art that on the one hand it is a carboxylate to which the ion M is bound, and on the other hand that in the case of polyvalent ions M the charge must be balanced by counterions.

Furthermore, the substituents R independently of one another represent hydrogen or a methyl group.

Furthermore, the substituents R ¹ independently of one another are - [AO] _q -R ⁴ . The substituents R ² independently of one another are a C 1 - to C 20 -alkyl group, -cycloalkyl group, -alkylaryl group or - [AO] _q -R ⁴ . The substituent A in both cases independently of one another is a C ₂ - to C ₄ -alkylene group and R ^{4 is} a C 1 - to C 20 -alkyl group, -cyclohexyl group or -alkylaryl group, while q is from 2 to 250, in particular from 8 to 200, more preferably from 1 to 150 represents.

Furthermore, the substituents R ^{3 are} independent of each other

-NH ₂ , -NR ⁵ R ⁶ , -OR ⁷ NR ⁸ R ⁹ . Here, R ⁵ and R ^{6 are} independent of each other is a C 1 to C 20 alkyl group, cycloalkyl group or alkylaryl group or aryl group, or a hydroxyalkyl group or an acetoxyethyl (CH 3 -CO-O-CH 2 -CH 2 -) or a hydroxy-isopropyl- (HO-CH (CH 3) 2) ₃ ) -CH ₂ -) or an acetoxyisopropyl group (CH ₃ -CO-O-CH (CH ₃ ) -CH ₂ -); or R ⁵ and R ⁶ together form a ring of which the nitrogen is a part to form a morpholine or imidazoline ring.

The substituent R ⁷ is a C ₂ -C ₄ -alkylene group.

Furthermore, the substituents R ⁸ and R ⁹ each independently represent a C 1 - to C 20 -alkyl group, -cycloalkyl group, -alkylaryl group, -aryl group or a hydroxyalkyl group.

The sequence of the substructure elements designated as s1, s2, s3 and s4 in formula (I) can here be arranged alternately, blockwise or randomly.

Finally, the indices a, b, c and d represent molar ratios of the structural units s1, s2, s3 and s4. These structural elements are in a ratio of

a / b / c / d = (0.1 - 0.9) / (0.1 - 0.9) / (0 - 0.8) / (0 - 0.3), especially a / b / c / d = (0.1 - 0.9) / (0.1 - 0.9) / (0-0.5) / (0-0.1), preferably a / b / c / d = (0.1-0.9) / (0.1-0.9) / (0-0.3) / (0-0.06), with the proviso that a + b + c + d = 1. The sum c + d is preferably greater than 0.

The preparation of the comb polymer KP of the formula (I) can on the one hand by free radical polymerization of the corresponding monomers of the formula (III _a ), (III _b ), (III _c ) or (IIId), which then leads to the structural elements s1 s4 s4

R

^{3 /} ) or on the other hand, by a so-called polymer-analogous reaction Pol carboxylic acid of the formula (IV) take place

In the polymer-analogous reaction, the polycarboxylic acid of the formula (IV) is esterified or amidated with the corresponding alcohols, amines and then at most neutralized or partially neutralized (depending on the nature of the radical M, for example with metal hydroxides or ammonia). Details of the polymer-analogous reaction are disclosed, for example, in US 2002/0002218 A1 on page 5 in section [0077] to and with [0083], as well as in its examples or in US Pat. No. 6,387,176 B1 on page 5, line 18 to line 58 and in US Pat examples. In a variant thereof, as described in US 2006/0004148 A1 on page 1 in section [001 1] to and with [0055] on page 3 and in its examples, the comb polymer KP of the formula (I) in solid

State of aggregation can be produced. The disclosure of these just mentioned patents is hereby incorporated by reference in particular.

It has been found that a particularly preferred

Embodiment of the comb polymers KP of the formula (I) are those in which c + d> 0, in particular d> 0, are. As the radical R ³ , in particular -NH-CH ₂ -CH ₂ -OH has proved to be particularly advantageous.

Comb polymers KP, such as those manufactured by Sika Schweiz AG under the trade name series ViscoCrete®, have proven to be particularly advantageous

be sold commercially.

The weight fraction of the Fe (III) complexing agent X is typically from 0.01 to 50% by weight, preferably from 0.05 to 20% by weight, particularly preferably from 0.1 to 5% by weight, based on the total weight of the comb polymer. It is further advantageous that the composition further comprises at least one antioxidant, in particular in an amount of 0.01 to 50 wt .-%, preferably 0.05 to 10 wt .-%, particularly preferably 0.1 to 5 wt .-%, based on the total weight of the comb polymer.

Suitable antioxidants are, for example, selected from the group consisting of substituted phenols, in particular sterically hindered phenols; substituted hydroquinones, in particular sterically hindered hydroquinones; sterically hindered aromatic amines such as diarylamines; Arylamine-ketone condensation products; Organosulfur compounds such as dialkyl dithiocarbamic acids or dialkyl dithiophosphites; Organophosphorus compounds such as phosphites or phosphonites;

Tocopherols and their derivatives; Gallic acids and their derivatives and vanillin.

Particularly suitable are antioxidants which comprise at least one substituted phenol, substituted hydroquinone or a substituted aromatic amine. Particularly suitable are sterically hindered phenols, sterically hindered hydroquinones or sterically hindered

aromatic amines.

Examples of hindered phenols are 2-t-butyl-4,6-dimethylphenol, 2,6-di (t-butyl) -4-methylphenol (butylhydroxytoluene, BHT), 2-t-butyl-4-methoxyphenol (butylhydroxyanisole, BHA), pentaerythrityl tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate] (Irganox® 1010), 2,6-dioctadecyl-4-methylphenol, 2,4,6-tri -t-butylphenol, ortho-tert-butylphenol, 3,5-bis (1,1-dimethylethyl) -4-hydroxybenzene-propionic acid ester of C4-C22 alcohols, 4,4'-butylidene-bis (6-t-butyl) butyl-3-methylphenol), 4,4'-methylidene-bis (2,6-di-t-butylphenol), 3,5-bis (1,1-di-tert-butyl) -4-hydroxyphenyl-propion acid esters of C4-C22 alcohols, 2,2'-methylenebis (6-tert-butyl-4-methylphenol), 2,2-bis (4-hydroxyphenyl) -propane (bisphenol A), 4,4 Methylene bisphenol (bisphenol F), 1,1-bis (5-t-butyl-4-hydroxy-2-methylphenyl) butane, 2,2'-methylenebis [4-methyl-6- (1 -methylcyclohexyl) phenol], tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] - methane, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamic acid amide), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1, 3 , 5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 1,1,3-tris (5-t-butyl-4-hydroxy-2-methylphenyl) butane, 1, 3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) nnesitylene, ethylene glycol bis [3,3-bis (3'-t-butyl-4'-hydroxyphenyl) butyrate], di (3-t-butyl-4'-hydroxy-5-methylphenyl) dicyclopentadiene, 2,2'-methylenebis (4-methyl-6-cyclohexylphenol), 1, 3,5-tri- (3, 5-di-t-butyl-4-hydroxybenzyl) -2,4,6-trin-ethylbenzene (Irganox® 1330), 1, 3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl ) isocyanurate, 3,5-di-t-butyl-4-hydroxyphenyl-propionic acid ester, 5-t-butyl-4-hydroxy-3-methylphenyl-propionic acid ester, 3,5-di-t-butyl-4- hydroxyphenylpropionic acid amides, 3,5-di (1,1-dimethylethyl) -4-hydroxybenzenepropionic acid ester, 1,6-hexanediol bis (3,5-di-t-butyl-4-hydroxyphenyl) propionate, triethylene glycol bis-3- (t-butyl-4-hydroxy-5-methylphenyl) propionate, 2,2-bis (4-h ydroxyphenyl) propane, 2,2'-thio-bis (4-methyl-6-t-butylphenol), 2-methyl-4,6-bis ((octylthio) methyl) phenol (Irganox® 1520), 4 , 4'-Thio-bis (6-t-butyl-3-methylphenol), 2,2'-thiodiethyl-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate.

Preferred are 2,6-di-t-butyl-4-methylphenol (BHT), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis ( 4-methyl-6-cyclohexylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol), triethylene glycol bis-3- (t-butyl-4-hydroxy-5-methylphenyl ) propionate, 2,2-bis- (4-hydroxyphenyl) -propane, and tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) -propionate] methane, or antioxidants, as is typical marketed under the trade name Irganox® from Ciba Spezialitätenchemie, in particular 2-methyl-4,6-bis ((octylthio) methyl) phenol (Irganox® 1520), pentaerythrityl tetrakis [3- (3,5-di-tert. -butyl-4-hydroxyphenyl) -propionate] (Irganox® 1010), or 1, 3,5-tri- (3,5-di-t-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene (Irganox ® 1330).

Examples of hindered hydroquinones are 2,6-di-t-butyl-4-methoxyphenol, 2,5-di-t-butyl-hydroquinone.

Examples of sterically hindered aromatic amines and arylamine-ketone condensation products are N, N'-bis (1,4-dimethyl-pentyl) -p-phenylene- diamine, N, N'-diphenyl-p-phenylenediamine, 4- (p-toluene-sulfonamido) -diphenylamine, 4-n-butylaminophenol, 4,4'-di-t-octyldiphenylamine, 4,4'-di- ( alpha, alpha -dimethylbenzyl) diphenylannin, phenyl-beta-naphthylamine, N-isopropyl-N'-phenyl-p-phenylenediamine, and / or phenyl-2-aminonaphthalene.

Examples of organosulfur compounds are 2,2'-thio-bis (4-methyl-6-t-butylphenol), 2-methyl-4,6-bis ((octylthio) methyl) phenol (Irganox® 1520), 4, 4'-thio-bis (6-t-butyl-3-methylphenol), 2,2'-thiodiethyl-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,4 Bis (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1, 3,5-triazine, di-lauryl-3,3'-thiodipropionate, di-stearyl 3,3'-thiodipropionate, nathium dithionite, toluenesulfinic acid or derivatives thereof,

For example, sodium hydroxymethanesulfinate dihydrate (Rongalit® C).

Examples of organophosphorus compounds are dioctadecyl 3,5-di-t-butyl-4-hydroxybenzylphosphonic acid, trimethyl phosphite, triethyl phosphite, triphenyl phosphite, distearyl pentaerythritol diphosphite, tris (nonylphenyl) phosphite, tetrakis (2,4-di-t butylphenyl-4,4'-biphenylene diphosphonite, tris (2,4-di-t-butylphenyl) phosphite, neopentyl glycol triethylene glycol diphosphite, diisodecyl pentaerythritol diphosphite, tristearyl phosphite, trilauryl phosphite, Na hypophosphite or triphenyl phosphite.

In a preferred embodiment, the antioxidant is a substituted phenol, especially a hindered phenol. Such antioxidants are available, for example, under the name Irganox® from Ciba. Preferably, the substituted phenol is selected from the group consisting of butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), bisphenol A, bisphenol F, salicylic acid, hydroquinone, vanillin,

Biphenyldiol, for example 4,4'-biphenyldiol or 2,2'-biphenyldiol, gallates and phenol polycondensates.

The composition as described above, both in liquid and in solid form, either alone or as part of a further composition, as a dispersant, especially as condenser; be used as a grinding aid, as a thickener or as a cement refiner.

The composition as described above may contain other ingredients. Examples of other ingredients are

Solvents or additives, such as grinding aids, for example glycols or alkanolamines such as triisopropanolamine (TIPA) or triethanolamine (TEA);

Contaminants, for example lignosulfonates, sulfonated naphthalene-formaldehyde condensates, or sulfonated melamine-formaldehyde condensates; Accelerator; retarder; shrinkage; defoamers; Foaming agents or components which reduce segregation of the fresh concrete, in particular the separation of water (bleeding), and improve the holding power of the fresh concrete. If the composition is used in liquid form, a solvent is preferably used for the reaction. preferred

Solvents are, for example, alcohols, especially ethanol or isopropanol, and water, with water being the most preferred

Solvent is. Depending on the nature of the composition, a dispersion or solution is formed. A solution is preferred.

The composition may also be in solid state. For the purposes of the invention, a composition in the solid state of aggregation is understood as meaning compositions which are in the solid state at room temperature and are, for example, powders, flakes, pellets, granules or plates and can be easily transported and stored in this form.

In a further aspect, the present invention relates to a composition comprising a comb polymer, a mineral

A binder and a complex of Fe (III) with at least one Fe (III) complexing agent X and optionally other complexing agents, wherein it is wherein Fe (III) complexing agent X is a Fe (III) complexing agent X, as previously described.

The mineral binder typically a hydraulic binder, a latent hydraulic binder or a non-hydraulic binder, in particular a cement, preferably a Portland cement, or mixtures thereof with fly ash, silica fume, blast furnace slag and limestone filler. Typically, the weight fraction of the comb polymer is 0.01 to 10 wt .-%, preferably 0.2 to 2 wt .-%, based on the total weight of the mineral binder.

In a further aspect, the present invention relates to

A method for stabilizing comb polymers in the presence of Fe (I l l), wherein the comb polymers at least one Fe (l l l) complexing agent X.

is added. The comb polymer and the Fe (II) complexing agent X are comb polymers and Fe (II) complexing agents X, as previously described.

The term "stabilization" is understood to mean, in particular, that the comb polymers are not degraded over a prolonged period of time and thus their effect, for example as dispersants, grinding aids, thickeners or cement refiners, is maintained

Stabilization of the comb polymer over at least one week, preferably at least 4 weeks.

Preferably, the Fe (II) complexing agent X in an amount of 0.01 to 50 wt .-%, preferably 0.05 to 20 wt .-%, based on the

Total weight of the comb polymer used.

It is also advantageous if in addition at least one

Antioxidant is added. As an antioxidant Compounds suitable as previously described as suitable as antioxidant.

Preferably, the at least one antioxidant is used in an amount of 0.01 to 50% by weight, preferably 0.05 to 10% by weight, based on the total weight of the comb polymer.

Preferably, the process is a process at a temperature of at least 40 ° C, preferably 80-160 ° C. Preferably, the method is a method for

Stabilization of polymers in the presence of Fe (III) in a mineral binder. As a mineral binder compounds are suitable, as they have previously been described as suitable as a mineral binder. For example, cement clinker after the firing process at over 1000 ° C usually cooled to a temperature of about 100 to 200 ° C and normally stored at a temperature of about 80 to 150 ° C, in particular at about 80 to 120 ° C, for example in silos. Thus, in the process temperatures of at least 40 ° C, preferably from 80 to 160 ° C, during milling, especially when grinding the cement clinker to cement occur. Furthermore, in the subsequent storage and / or transport of the mineral binder, in particular by

Solar radiation-induced heating of warehouses, transport or

Packaging containers. Therefore, it is preferably a

A method for stabilizing comb polymers in the presence of Fe (III) in mineral binders and at a temperature of at least 40 ° C, preferably from 80 to 160 ° C, wherein this temperature during grinding of the mineral binder and / or subsequent storage occurs.

The addition of the comb polymer and / or the Fe (III) complexing agent X and / or the antioxidant to the mineral binder can take place simultaneously or with a time delay. The addition of the comb polymers and / or the Fe (III) complexing agent X and / or the antioxidant to the mineral binder can be applied to the mineral binder during transport of the mineral binder, in particular when conveying cement. Preferably, the mineral binder, in particular cement, during the production process, for example in transport channels to the deposit, for example to silo or transport such as a truck, the comb polymers and / or the Fe (III) complexing agent X and / or the antioxidant added ,

The addition of the comb polymers and / or the Fe (III) complexing agent X and / or the antioxidant to the mineral binder can be further added to the mineral binder prior to grinding the mineral binder, in particular before and / or during the grinding of the cement clinker.

In a preferred embodiment, the Fe (III) complexing agent X is precoated with the comb polymer (and optionally with a

Antioxidant) and this mixture is then at a desired time during the manufacturing process of the mineral binder, especially the cement, for example, before grinding, or when conveying the mineral binder before storage, mixed with the mineral binder, or applied to the mineral binder so that, for example, a mineral binder is formed, which is coated with the mixture of Fe (III) complexing agent X and comb polymer (and possibly antioxidant). The transport or transport of the mineral binder can be carried out by means of devices known to the person skilled in the art, for example via air-conveying troughs, where the transport takes place pneumatically and gravimetrically. The grinding process is usually carried out in a cement mill, for example in a ball mill. However, in principle, other mills, such as are known in the cement industry, can be used. In a further aspect, the present invention relates to a use of a Fe (III) complexing agent X for the stabilization of

Comb polymers in the presence of Fe (III).

The comb polymer and the Fe (III) complexing agent X are comb polymers and Fe (III) complexing agents X, as previously described.

The invention will now be explained in more detail by way of examples.

1 . Used raw materials

2. Mortar tests

The effectiveness of the inventive compositions tested mortar.

In a first step, Portland cement (Swiss CEM I 42.5R), by mixing in a kitchen blender (Moulinex), with 1 wt .-% comb polymer (Sika® ViscoCrete® 1 10 CH, available from Sika Switzerland AG), by weight of the Portland cement, and optionally additionally with an amount (in relation to the total weight of the comb polymer) of an Fe (III) complexing agent X (KB), indicated in Table 2

Antioxidant (AntO) or a Fe (III) complexing agent X together with an antioxidant coated. The thus coated cement was either used immediately or placed in a transport container at 60 ° C for the in Table 2, before being used to prepare

Mortar mixtures was used.

The following mortar mixture was produced from the coated cement:

The sands, filler and coated cement were dry blended for 1 minute in a Hobart mixer. Within 30 seconds, the mixing water was added and mixed for another 2.5 minutes. The water / cement value (w / c value) was 0.46. To determine the effectiveness, the slump (ABM) (Table 2) of the mortar was determined in accordance with EN 1015-3 after 0 minutes. The used determination of the

Slurry differs from EN 1015-3 in that it did not lift or drop the spreading table.

Examples 6 to 6 represent examples according to the invention, while examples 7 to 12 represent comparative examples.

11% AntO 0.5% by weight 3 184

12% AntO 0.5% by weight 7 146

Table 2: Slump (ABM) of a mortar mixture in mm after 0 minutes

(min), using the coated cement immediately or storing the coated cement at 60 ° C for 2, 3 and 7 days (d). The results in Table 2 show that the inventive

Compositions are suitable for stabilizing comb polymers even at elevated temperature (60 ° C).

3. Chromate reduction

The effectiveness of chromate reduction by ferrous sulfate

Heptahydrate (F2S) in the presence of 2-aminothiazole (KB-1) was tested in the concrete.

20 g of cement (CEM II / A-LL 42.5N), 40 g of water and optionally listed in Table 3 additives were mixed for 15 minutes with vigorous stirring on a magnetic stirrer and then filtered through a Whatman 597 Vi folded filter. The Cr (VI) content of the effluent was determined reflectometrically by means of a chromate test from Merck, Germany, according to the manufacturer's instructions.

Table 3: Cr (VI) content in ppm of the filtered flow.

Table 3 shows that the effect of Cr (VI) reduction by ferrous sulfate heptahydrate is not affected by the addition of 2-aminothiazole. 4. Reduction of Fe (III) to Fe (II)

40 g of water and 0.2 g of Fe (III) sulfate hydrate (F3S solution) and, if appropriate, 0.6 g of 2-aminothiazole (KB-1) were allowed to stand for 15 minutes mixed with vigorous stirring on a magnetic stirrer, the pH was adjusted to 5 and then carried out after 2 min, respectively 17 hours, an iron (II) detection. The iron (II) detection was carried out by means of a

Reflectoquant iron (II) tests from Merck, Germany, according to the

Instructions from the manufacturer.

Table 4: Detection of Fe (II).

From Table 4 it can be seen that 2-aminothiazole causes a reduction of Fe (III) to Fe (II). 5. Selectivity

In a first experiment, 0.2 g of Fe (II) sulfate were dissolved in 40 g of water

Heptahydrate (F2S) dissolved with vigorous stirring on a magnetic stirrer.

Subsequently, the iron (II) content was determined. In a second experiment, 0.2 g of Fe (II) sulfate heptahydrate (F2S) were dissolved in 40 g of water with vigorous stirring on a magnetic stirrer. Thereafter, 0.6 g of 2-

Aminothiazole (KB-1) added. Subsequently, the iron (II) content was determined.

The iron (II) content determination was carried out by means of a reflectoquant iron (II) test from Merck, Germany, according to the manufacturer's instructions.

Table 5: Fe (II) content in mg / l.

In Table 5, especially in comparison to Table 4, it can be seen that 2-aminothiazole hardly forms complexes with Fe (II) in contrast to Fe (III) and thus represents a selective Fe (III) complexing agent compared to Fe (II). 6. complex formation

0.2 g of Fe (III) sulfate hydrate (F3S) were dissolved in 40 g of water with vigorous stirring on a magnetic stirrer and the pH was adjusted to 5. Subsequently, in a first experiment, 1 g

Sodium thiocyanate (NaSCN) added, after 1 min, the solution for a possible color change out, 1 g of 2-aminothiazole (KB-1) was added, after 1 min, the solution re-examined for a possible color change out. In a second experiment, (NaSCN) and (KB-1) were added in reverse order.

Table 6: Detection of Fe (II).

From Table 6 it can be seen that 2-aminothiazole is suitable as Fe (III) complexing agent and forms stronger Fe (III) complexes over sodium thiocyanate.

Of course, the invention is not limited to the embodiments shown and described.

Claims

claims

1 . A composition comprising a comb polymer and at least one Fe (III) complexing agent X which is selected from the group consisting of thiocyanates, condensed phosphates, amines, aminoacetic acids, oxycarboxylic acids and compounds of the formula compounds of the formula (V)

R ¹⁰ and R ¹¹ independently of one another represent H, halogen atom, NO ₂ or one, if necessary branched, saturated or unsaturated alkyl radical having 1 to 25 C atoms or an aryl radical having 6 to 14 C atoms or an acyl radical having 1 to 10 C Atoms or a carbonyl radical having 1 to 10 C atoms or a carboxyl radical having 1 to 10 C atoms,

R ¹⁰ and R ^{1 1} part of an aromatic or cycloaliphatic ring, especially a 6-aromatic ring.

2. A composition according to claim 1, characterized in that the Fe (III) complexing agent X has a complexing constant for Fe (III), which is 10 times, in particular 1000 times, greater than that

Complexing constant for Fe (II).

3. Composition according to one of the preceding claims, characterized in that the Fe (III) complexing agent X causes a reduction of Fe (III) to Fe (II).

4. Composition according to one of the preceding claims, characterized in that the proportion by weight of Fe (III) - Complexing agent X 0.01 to 50 wt .-%, preferably 0.05 to 20 wt .-%, based on the total weight of the comb polymer is.

5. Composition according to one of the preceding claims, characterized in that the composition further

has at least one antioxidant, in particular in an amount of 0.01 to 50 wt .-%, preferably 0.05 to 10 wt .-%, based on the total weight of the comb polymer.

6. A composition according to claim 5, characterized in that the antioxidant is selected from the group consisting of substituted phenols, in particular sterically hindered phenols; substituted hydroquinones, in particular sterically hindered hydroquinones; sterically hindered aromatic amines such as

diarylamines; Arylamine-ketone condensation products; Organosulfur compounds such as dialkyldithiocarbamic acids or

Dialkyldithiophosphiten; Organophosphorus compounds such as phosphites or phosphonites; Tocopherols and their derivatives; Gallic acids and their derivatives and vanillin.

7. A composition comprising a comb polymer, a mineral binder and a complex of Fe (III) with at least one Fe (III) complexing agent X and optionally other complexing agents, wherein the Fe (III) complexing agent X is an Fe (III ) Complexing agent X as described in the composition according to any one of claims 1-4.

8. A composition according to claim 7, characterized in that the mineral binder is a hydraulic binder, a latent hydraulic binder or a non-hydraulic binder, in particular a cement, preferably a Portland cement, or mixtures thereof with fly ash, silica fume, blast furnace slag and limestone filler ,

9. A composition according to claim 7 or 8, characterized in that the weight fraction of the comb polymer 0.01 to 10 wt .-%, preferably 0.2 to 2 wt .-%, based on the

Total weight of the mineral binder is.

10. A method for stabilizing comb polymers in the presence of Fe (III), characterized in that at least one Fe (III) complexing agent X is added to the comb polymers, wherein the Fe (III) complexing agent X is an Fe (III ) Complexing agent X is as it is in the composition according to one of claims 1-4

is described.

1 1. A method according to claim 10, characterized in that

at least one antioxidant is added.

12. The method according to any one of claims 10 or 11, characterized

characterized in that the process is a process at a temperature of at least 40 ° C, preferably from 80 to 160 ° C.

13. The method according to any one of claims 10 to 12, characterized

characterized in that the method is a method in a mineral binder.

14. The method according to claim 10 or 1 1, characterized in that it is in the method to a method for the stabilization of

Comb polymers in the presence of Fe (III) in mineral binders and at a temperature of at least 40 ° C, preferably from 80 to 160 ° C, wherein this temperature during grinding of the mineral

Binder and / or subsequent storage occurs. Use of a Fe (III) complexing agent X for stabilizing comb polymers in the presence of Fe (III), characterized in that the Fe (III) complexing agent X is a Fe (III) complexing agent X, as described in US Pat the composition according to any one of claims 1-4 is described.