WO2011095376A1

WO2011095376A1 - Sulfonated condensation product

Info

Publication number: WO2011095376A1
Application number: PCT/EP2011/050308
Authority: WO
Inventors: Rainer Packe-Wirth
Original assignee: Construction Research & Technology Gmbh
Priority date: 2010-02-08
Filing date: 2011-01-12
Publication date: 2011-08-11

Abstract

The invention relates to a sulfonated condensation product based on primary chain component aminoplast formers having at least two amino groups and (para)formaldehyde, wherein the condensation product comprises at least one ethyleneurea compound of the general formula (I) chemically bound. According to the invention, said condensation product develops its advantageous effect as a liquid additive for inorganic solids and in particular inorganic binding agents and as an additive for particle boards, and as an auxiliary in the tanning of leather, in particular in powder form, wherein the powder can comprise additional amounts of chemically unbound ethyleneurea.

Description

Sulfonated condensation product

The present invention is a sulfonated condensation product based on the main chain building blocks Aminoplastbildner with at least two amino groups and (para-) formaldehyde and its use.

It is well known that hydraulically setting binders, such as cement, lime, gypsum, CaSC hemihydrate and anhydrite can be liquefied by the addition of dispersants, which can be adjusted as desired low water / binder ratios. Long-established traditional dispersants include melamine-formaldehyde-sulfite (MFS) resins, which have been continually refined over the past few years to meet increased expectations. A disadvantage of these MFS resins is the content of free formaldehyde, which, not least for health reasons, precludes a continued high acceptance of such resins. There have therefore been numerous attempts to significantly reduce the content of free formaldehyde in MFS resins.

Several publications have shown that the addition of ethyleneurea and similar compounds can reduce the amount of free formaldehyde (see H. Petersen: "Relationships between Chemical Constitution, Hydrolysis Resistance and Equilibrium of N-Methylol Compounds", 3rd mid Textilveredelung 3 (1968), 4, pages 160 to 179, and DE-A 199 46 591).

For water-soluble sulfonated melamine-formaldehyde condensates, the z. For example, as powder dispersants in construction chemistry (see US 3,941,734), formaldehyde can be released by an equilibrium reaction in the aqueous medium. This process of equilibration typically lasts for several days. It has also been known that ethylene urea reacts by reaction with the formaldehyde which is freely present in the solution, thereby significantly lowering its content. Since the situation regarding the content of free formaldehyde in MFS resins is still unsatisfactory, it is an object of the present invention, as an alternative to the previous procedures, namely to add ethylene urea to the MFS resins, sulfonated condensation products on Basis of the main chain building blocks Aminoplastbildner with at least two amino groups and

To provide (para) formaldehyde, in which the content of free formaldehyde is significantly reduced. This object has been achieved with a corresponding sulfonated condensation product which comprises at least one ethyleneurea compound of the general formula I,

O

, c

(i) / \

H (OCH ₂ ) _n - N _N - _R 1

R ⁴ R ³ where n = 0 to 10,

R ¹ = [(CH ₂ ) _u -O] _v -R ⁶ -R ⁷ where u = 0 to 5 and v = 0 to 3000,

R ² , R ³ , R ⁴ , R ⁵ independently of one another are H or alkyl,

R ⁶ = [(CHR ⁸ -CHR ⁹ ) _u -0] _v with u and v as defined;

R ⁷ = H, alkyl, aryl, O-alkyl, O-aryl or OH and

R ⁸ = H or alkyl and

R ⁹ = H or alkyl.

wherein alkyl = Ci to Cio-alkyl and aryl = Ce - cis-aryl, both of which may be substituted,

mean,

contains chemically bound.

Surprisingly, it has been found in connection with the present invention that it is possible to prepare modified MFS resins which contain ethyleneurea and / or its derivatives chemically bonded, these condensation products having a significantly lower content of free formaldehyde and moreover Efficiency as a dispersant compared to the unmodified resins are at least equal. From the described prior art was hitherto known only that ethylene urea reacts by reaction with the free formaldehyde in the solution and thus lowers its content. However, it was not to be expected that ethyleneurea could react under certain reaction conditions with an MFS resin and thus be chemically bonded to this condensation product. Such ethylene-urea-modified MFS resins correspond to the present invention, are characterized in particular by the fact that the free formaldehyde content is significantly reduced compared to the unmodified variants, which is why practically no free ethyleneurea is detectable. In addition, the comparison of the dispersant effect of an ethyleneurea-modified MFS resin with the unmodified variant shows a far better effect in the modified variant. The expression of the benefits was not to be expected. The described advantages occur in particular in the case of condensation products according to the invention which contain the ethyleneurea compound in the side chain.

Of course, from an economic point of view, the production process of the condensation products is an important aspect. In this regard, the present invention provides a variant in which at least one pyrosulfite or sulfite and in particular sodium pyrosulfite and / or sodium sulfite have been used to sulfonate the condensation product. In principle, with regard to the main chain building blocks, the condensation product according to the invention is not subject to any restriction. However, it has proved to be advantageous if the aminoplast generator is melamine, urea, thiourea, dicyandiamide and / or a guanidine or one of its salts. The molar ratio of the respective building blocks, namely the aminoplast,

(Para) formaldehyde, the sulfonating component and the ethyleneurea or one of its derivatives, should be 1: 2.0 to 6.0: 1, 0 to 3.0: 0.001 to 5.0. A ratio of 1: 2.5 to 5.0: 1, 5 to 2.5: 0.01 to 3.0 is particularly advantageous. According to the invention, the claimed condensation product can be present as an aqueous solution having a solids content of between 5.0 and 60% by weight and preferably between 15 and 40% by weight, with a range between 20 and 35% by weight being considered to be particularly preferred. For certain applications, in particular as a dispersant, the condensation product should be present as a powder, which can be obtained according to the invention, in particular from an aqueous solution.

As already stated several times, the essential advantage of the sulfonated condensation products according to the invention is that the ethyleneurea compound is chemically incorporated into the resin. A not to be underestimated importance is therefore also the production process of corresponding condensation products. In this context, the present invention provides a process for the preparation in which, in process step a), the aminoplast-forming component, the (para) formaldehyde and the sulfonating component in a molar ratio of 1: 2.0 to 6.0: 1, 0 to 3.0 is heated in aqueous solution and at a temperature of 40 to 90 ° C and a pH of 7.5 to 13.0 until no more sulfite is detectable. Subsequently, in step b) after the sulfonation of the aminoplast generator in step a) a pH of 2.0 to 6.5 is set and the reaction mixture is condensed at temperatures between 20 and 100 ° C and preferably at 60 to 90 ° C. Possibly. can in process step c) finally set the resulting condensation product to a pH of 7.5 to 10.0 or a thermal post-treatment at a pH> 10.0 and a temperature of 60 to 100 ° C are performed. The pH should be adjusted advantageously with sulfuric acid, formic acid, sulphanilic acid and / or glyoxylic acid. The variability of the process according to the invention is also evident in that process step a) is carried out in the presence of at least one ethyleneurea compound of general formula (I) and / or in that at least one ethyleneurea compound of formula (I) in the condensation step b) is added. Thus, the desired ethyleneurea compound or a mixture thereof can be supplied to the proposed reaction both exclusively in process step a) or exclusively in process step b) or else in both process steps.

In order to realize the particularly advantageous mode of action of the condensation product according to the invention as a dispersant, according to a further variant of the invention, the aqueous solution obtained should be converted into a powder, which should preferably be effected by spray-drying.

In addition to the condensation product and a process for its preparation, the present invention also encompasses the use of the sulfonated condensation product, its main use being as a liquid additive for inorganic solids and in particular for inorganic binders, fillers and / or pigments containing (dry) mixtures. Furthermore, the condensation products of the invention are suitable as additives for chipboard and as an adjuvant in the tanning of leather.

The use of the condensation products in powder form has proved to be particularly favorable. The respective powders should be conveniently prepared in which by co-spray drying with a further solution containing an ethylene urea compound of the formula (I), or by admixing a predominantly dry and at least one ethyleneurea compound of the formula (I ) containing powder at least one additional additional ethylene urea compound has been supplied. The present invention thus comprises the variant of a condensation product in powder form, which contains an ethylene urea compound chemically bound. However, it also includes a variant in which the corresponding powder was prepared in a spray-drying together with another solution. This additional solution contains an ethylene urea compound of the general formula (I), wherein the ethylene urea compound is ideally the same compound which has already been reacted in the condensation product; However, the ethylene urea compound contained in the further solution may also be different from the unreacted compound or it may be any mixture of suitable ethylene urea compounds. The same variations Onsmöglichkeiten exist in the alternative of admixing a predominantly dry powder containing an ethylene urea compound of the formula (I). In this case too, the ethyleneurea compound may be the identical compound which has been reacted with the condensation product or else one of them which is different or mixtures of suitable ethyleneurea compounds. In this way, an additional ethyleneurea compound is added to the already ethylene-containing sulfonated condensation product, the term "additionally" referring to the chemical structure of the respective ethyleneurea compound, which may thus also differ structurally from the incorporated compound, or else to the amount of total ethylene urea, which is finally reacted in the powdered condensation product and mixed.

It has already been pointed out that the condensation products according to the invention are particularly suitable as liquid additives for inorganic binders. In this context, the present invention provides that it is preferably a hydraulically setting binder and preferably cement, lime, calcium sulfate hemihydrate and / or anhydrite. The construction chemical systems can thus be concretes, mortars, gypsum compounds, tile adhesives, screeds, plasters etc.

Claims

claims

1 . Sulfonated condensation product based on the main chain building blocks Aminoplastbildner with at least two amino groups and (para) formaldehyde, characterized in that it contains at least one ethylene urea compound of the general formula (I)

O

(I)

H (OCH ₂ ) _n

where n = 0 to 10,

R ¹ = [(CH ₂ ) _u -O] _v -R ⁶ -R ⁷ where u = 0 to 5 and v = 0 to 3000,

R ² , R ³ , R ⁴ , R ⁵ independently of one another are H or alkyl,

R ⁶ = [(CHR ⁸ -CHR ⁹ ) _u -0] _v with u and v as defined;

R ⁷ = H, alkyl, aryl, O-alkyl, O-aryl or OH and

R ⁸ = H or alkyl and

R ⁹ = H or alkyl.

mean,

contains chemically bound.

Condensation product according to claim 1, characterized in that it contains the ethylene urea compound in the side chain.

Condensation product according to one of claims 1 or 2, characterized in that at least one pyrosulfite or sulfite and preferably sodium pyrosulfite and / or sodium sulfite have been used for its sulfonation.

Condensation product according to one of claims 1 to 3, characterized in that the aminoplast generator is melamine, urea, thiourea, dicyandiamide and / or a guanidine (salt).

5. Condensation product according to one of claims 1 to 4, characterized in that the molar ratio of aminoplast generator: (para) formaldehyde: sulfo nierungskomponente: ethylene urea (derivative) 1: 2 to 6: 1 to 3: 0.001 to 5.

6. Condensation product according to one of claims 1 to 5, characterized marked, that it as an aqueous solution with a solids content between 5 and

60 wt .-% and preferably between 15 and 40 wt .-% is present.

7. Condensation product according to one of claims 1 to 6, characterized in that it is present as a powder, preferably obtained from an aqueous solution.

Process for the preparation of the sulfonated condensation product according to one of Claims 1 to 7, characterized in that, in process step a), the aminoplast-forming component, the (para) formaldehyde and the sulfonation component are in a molar ratio of 1: 2.0 to 6.0: 1, 0 to 3.0 in aqueous solution at a temperature of 40 to 90 ° C and a pH of 7.5 to 13.0 until heated until no sulfite is detectable, then in process step b) after Sulfonation of Aminoplastbildners in step a) is adjusted to a pH of 2.0 to 6.5 and the reaction mixture is condensed at temperatures between 20 and 100 ° C and preferably at 60 to 90 ° C, and optionally in process step c) Finally, the condensation product thus obtained is adjusted to a pH of 7.5 to 10.0 or a thermal aftertreatment at a pH> 10.0 and a temperature of 60 to 100 ° C is performed.

9. The method according to claim 8, characterized in that the pH is adjusted with sulfuric acid, formic acid, sulfanilic acid and / or glyoxylic acid. 10. The method according to any one of claims 8 or 9, characterized in that the method step a) is carried out in the presence of at least one ethylene urea compound of the formula I, and / or that at least one ethylene-urea compound of the formula I in the condensation step b) is added. 1 1. Method according to one of claims 8 to 10, characterized in that the resulting aqueous solution is converted into a powder.

12. The method according to any one of claims 9 to 1 1, characterized in that the powder is obtained by spray drying.

13. Use of the sulfonated condensation product according to one of claims 1 to 12 as a liquid additive for inorganic solids, in particular organic binders, fillers and / or pigments containing (dry) mixtures, as an additive for chipboard and as an adjuvant in the tanning of leather. 14. Use according to claim 13, characterized in that a condensation product is used in powder form, which was prepared by co-spray-drying with a further solution containing at least one ethylene-urea compound of formula I, and / or by admixing of a powder which is predominantly dry and contains at least one ethyleneurea compound of the formula I at least one additional ethyleneurea

Connection has been supplied.

15. Use according to one of claims 13 or 14, characterized in that it is the inorganic binder is a hydraulically setting binder and preferably cement, lime, calcium sulfate hemihydrate and / or anhydrite.