WO1996014387A1

WO1996014387A1 - Clear rinsing agents with polyglucosan oxidation products

Info

Publication number: WO1996014387A1
Application number: PCT/EP1995/004246
Authority: WO
Inventors: Christian Nitsch; Willi Buchmeier; Peter Jeschke; Konrad Engelskirchen
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1994-11-07
Filing date: 1995-10-30
Publication date: 1996-05-17
Also published as: DE4439678A1

Abstract

The invention pertains to the use of polyglucosan oxidation products in clear rinsing agents and to clear rinsing agents containing polyglucosan oxidation products.

Description

"Rinse aid with polyqlucosan oxidation products"

Field of invention

The invention relates to the use of polyglucosan oxidation products in rinse aid for dishwashers.

State of the art

Commercially available rinse aids are mixtures of low-foaming fatty alcohol polyethylene / polypropylene glycol ethers, solubilizers (for example cumol sulfonate), organic acids (for example citric acid) and solvents (for example ethanol). The task of these agents is to influence the interfacial tension of the water in this way that it can run off the washware in a film that is as thin and coherent as possible, so that no water drops, streaks or films remain during the subsequent drying process. An overview of the composition of rinse aids and methods for checking performance can be found by W. Schirmer et al. in tens. Surf. Det. 28, 313 (1991).

When using modern phosphate-free and low-alkaline cleaners for automatic dishwashing, limescale or silicate deposits can also form on the items to be washed and in the interior of the machine. Disturbing lime or silicate deposits occur in particular if the washing water in the dishwasher is not or not sufficiently softened and a water hardness of 4 ° d is exceeded.

The object of the present invention is therefore to provide rinse aid, the use of which provides spotless dishes; In addition, the rinse aid should be low-foaming, have a high phase stability and be easily biodegradable. European patent application EP-Al-542496 discloses the use of oxidized starch as a builder in textile and dishwashing detergents. It has now been found that the addition of polyglucosan oxidation products to conventional rinse aid significantly improves the properties of this rinse aid with regard to the above criteria.

The present invention therefore relates to the use of oxidation products of polyglucosans in rinse aids.

In the context of the present invention, oxidation products of polyglucosans are understood to mean polymers of monosaccharides which at least partially consist of oxidized anhydroglucose units with one, two or three carboxyl groups per unit. These oxidized anhydroglucose units correspond to the constitutional formulas I, II or III:

For the production of such polysaccharide derivatives by oxidative treatment of, for example, cellulose, starch and dextrins extensive knowledge. Reference is made, for example, to Houben-Weyl "Methods of Organic Chemistry", Thieme-Verlag, Stuttgart (1987) Vol. E 20, Macromolecular Substances, here the subchapter "Polysaccharide Derivatives" edited by Dr. K. Engelskirchen, loc. Cit. P. 2042 ff, in particular p. 2124 ff (oxidation products of cellulose) and p. 2166 ff (oxidized starches). Reference is also made to the publication "Cellulose Chemistry and Its Applications" (1983), John Wiley & Sons, Chichester, GB, in particular TPNevell, "Oxidation of Cellulose" (Chapter 10), the extensive literature cited there, op. Cit. P. 262 to 265, as well as to the European patent applications EP 425369, EP 455522, EP 472042, EP 548 399 and in particular the German patent application DE 42 03 923, the older German application P 43 17 519.8 and the international application W092 / 18542.

Particularly preferred are those polyglucosan oxidation products which are produced by the processes described in German Offenlegungsschriften DE 4203 923 AI or DE 43 17 519 AI or by the processes described in European patent application EP 0 548 399 AI or international application WO92 / 18542 become.

According to German published patent application DE 4203923 A1, the production of polyglucosan oxidation products is carried out by oxidation of polysaccharides with nitrogen dioxide / dinitrogen tetroxide with conversion of at least part of the primary alcohol groups of the polysaccharides into carboxyl groups, the oxidation reaction being carried out at a temperature above room temperature in the presence of Oxygen is carried out. Temperatures of 30 ° to 70 ° C., in particular 40 ° to 60 ° C., are preferred. The reaction is preferably carried out in a closed reaction system at pressures of 1 to 10 bar, preferably 2 to 6 bar, measured at the reaction temperature, oxygen preferably in an inert carrier gas in an amount of 1 to 30% by volume, in particular 3 to 10 vol.% Is included.

According to German Offenlegungsschrift DE 43 17 519 AI, the polyglucosan oxidation products from polysaccharides are oxidized with Nitrogen dioxide / dinitrogen tetroxide is produced by converting at least a portion of the primary alcohol groups of the polysaccharides into carboxyl groups, the oxidation reaction being carried out in a continuous process at a temperature above 80 ° C. in the presence or absence of oxygen and a residence time of the reaction mixture in the reaction zone of 1 to 30 min, preferably 5 to 30 min and in particular 10 to 30 min. The preferred reaction temperature is between 100 ° and 160 ° C., in particular 110 ° to 130 ° C., the preferred reaction pressure is 1 to 40 bar, in particular 3 to 15 bar.

According to European patent application EP 548 399 A1, polyglucosan oxidation products are produced by oxidation of carbohydrates with an oxygen-containing gas in an alkaline medium, the oxidation reaction being carried out by homogeneous catalysis of a salt of Cu, Cr, Co, Ni, Fe, V, Ti or Mn is catalyzed.

According to international application WO92 / 18542, polyglucosan oxidation products are obtained by oxidizing carbohydrates with an oxygen-containing gas in an alkaline aqueous medium in the presence of catalytically effective amounts of a salt of copper, silver or a metal from the group VIII of the periodic table and a metal ion ligand, e.g. B. a polydentate amine ligand.

In a nutshell: A large number of oxidizing agents are used for the oxidation of polyglucosans. Examples include (air) oxygen, hydrogen peroxide, sodium hypochlorite or bromite, periodic acid or periodates, lead (IV) acetate, nitrogen dioxide and cerium (IV) salts. These oxidizing agents react very differently with the anhydroglucose units, cf. for example the formula pictures in Houben-Weyl loc. cit. p. 2124. It is known that when nitrogen dioxide acts on cellulose, the oxidation of the primary alcohol group to the carboxy group is the predominant reaction. The oxidizing agent can be used in gaseous form or dissolved in an inert organic solvent, cf. here also Houben-Weyl op. cit. p. 2125 and the primary literature mentioned there in this connection. In terms of strength, too, they can be largely selective Carry out oxidations of the primary alcohol group of the anhydroglucose unit to the carboxyl group.

For example, monocarboxyl starches with a freely selectable degree of conversion of the primary alcohol groups can be produced by their selective oxidation with nitrogen dioxide at low temperatures even without auxiliary agents, for example solvents or catalysts. The almost quantitative and largely selective implementation of the building blocks of the starch molecule is also possible.

However, such a quantitative implementation is not necessary for the purpose according to the invention of using such natural product derivatives in the agents described. Rather, what is essential is the interplay of the following two parameters: adequate conversion of the primary alcohol groups to carboxy groups and, on the other hand, regulation of the average molecular weight of the natural polyglucosan molecule into adequately degraded sections. The first of these two parameters is likely to have functional significance for the interaction, for example with the hardness constituents, while the sufficiently restricted average molecular weight of the modified polyglucosan building blocks can be important, among other things, for the sufficient solubility under operating conditions.

The following applies to these two parameters:

The preferred lower limit for the content of oxidized anhydroglucose units according to formulas I, II and / or III in the polyglucosan derivatives is about 25 mol%, preferably at least about 35 mol% to 40 mol%. The almost quantitative conversion of one, two or three alcohol groups into carboxy groups is possible, so that the upper limit for the corresponding content of oxidized anhydroglucose units is 95 mol% to about 100 mol%. Corresponding oxidation products which are characterized by contents in the range from about 35 mol% to 80 mol% of oxidized anhydroglucose units may be particularly suitable for practical use, in one important embodiment of which their content is in the range from about 40 mol% is up to 60 mol%. - The statistical average of the oxidized polyglucosans to be used according to the invention preferably consist of at least 15 mol% of oxidized anhydroglucose units of the formula I and have average molecular weights below 15,000.

Rinse aids containing polyglucosan oxidation products show very low foaming, high phase stability and ensure spotless, shiny dishes.

Another subject of the invention are rinse aids containing polyglucosan oxidation products with organic carboxylic acids and certain surfactants.

The polyglucosan oxidation products are generally in rinse aid. in an amount of 0.1 to 10 wt .-%, preferably 1 to 5 wt .-%, based on the total rinse aid.

As organic carboxylic acids e.g. aliphatic hydroxy-di- and tricarboxylic acids such as malic acid (monohydroxysuccinic acid), tartaric acid (di-hydroxysuccinic acid); saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid; Gluconic acid (hexane-pentahydroxy-1-carboxylic acid), but preferably anhydrous citric acid. They are used in amounts of about 0.5 to 50, preferably about 1 to 20,% by weight.

The surfactant base of the rinse aid according to the invention is formed from a nonionic surfactant which is present in an amount of 0.5 to 50% by weight, preferably 2 to 20% by weight, and which is selected from the group of mixed ethers of the formula I. , the fatty alcohol polypropylene glycol / polyethylene glycol ether of the formula II, the alkyl polyglycosides of the formula III and their mixtures, where in the mixed ethers of the formula I,

(I) R1 for a linear or branched, aliphatic alkyl and / or alkenyl radical with 8 to 14 carbon atoms, R2 for a linear or branched alkyl radical with 1 to 4 carbon atoms or a benzyl radical, a for 0 or numbers from 1 to 2 and b represents numbers from 5 to 15,

in the fatty alcohol polypropylene glycol / polyethylene glycol ethers of the formula (II),

R ^{3 represents} a linear or branched, aliphatic alkyl and / or alkenyl radical having 8 to 16 carbon atoms, c represents 0 or numbers from 1 to 3 and d represents numbers from 1 to 5,

and in the alkyl polyglycosides of the formula (III),

⁴ 0- [G] _p (III)

R ^{4 stands} for an alkyl radical with 8 to 22 carbon atoms, G stands for a sugar residue with 5 or 6 carbon atoms, preferably a glucose residue, and p stands for numbers from 1 to 10.

Mixed ethers of the formula I are to be understood as meaning known end group-capped fatty alcohol polyglycol ethers which can be obtained by the relevant methods of preparative organic chemistry. Fatty alcohol polyglycol ethers are preferably reacted in the presence of bases with alkyl halides, in particular butyl or benzyl chloride. Typical examples games are mixed ethers corresponding to formula (I) in which Rl is a technical Cι ₂ / i4 cocoalkyl, a is 0, b is 5 to 10 and R is a butyl group (Dehypon ^(R) LS-54 or LS-104, from Henkel KGaA). The use of mixed ethers blocked with butyl or benzyl groups is particularly preferred for technical reasons. The fatty alcohol polypropylene / polyethylene glycol ethers of the formula II are known nonionic surfactants which are obtained by adding initially propylene oxide and then ethylene oxide or exclusively ethylene oxide to fatty alcohols. Typical examples are polyglycol ethers of the formula (II) in which R ^{3 represents} an alkyl radical having 12 to 18 carbon atoms, c represents 0 or 1 and d represents numbers from 2 to 5 (dehydrol ( ^R ) LS- 2, LS-4, LS-5, Henkel KGaA, Düsseldorf / FRG). However, the fatty alcohols are preferably only ethoxylated, ie c is zero.

Alkyl polyglycosides (APG) are known substances which can be obtained by the relevant processes in preparative organic chemistry. As representative of the extensive literature, reference is made here to the documents EP-A1-0301 298 and WO 90/3977.

The alkyl polyglycosides can be derived from aldoses or ketoses with 5 or 6 carbon atoms, preferably glucose. The preferred alkyl polyglycosides are thus alkyl polyglucosides.

The index number p in the general formula (III) indicates the degree of oligomerization (DP degree), i.e. the distribution of mono- and oligoglycosides is present and stands for a number between 1 and 10. While p must always be an integer in a given compound and can in particular assume the values p = 1 to 6, the value p is for a specific alkyl oligoglycoside an analytically determined arithmetic size, which usually represents a broken number. Alkyl polyglycosides with an average degree of oligomerization p of 1.1 to 3.0 are preferably used. From the point of view of application technology, preference is given to those alkyl polyglycosides whose degree of oligomerization is less than 1.7 and in particular between 1.2 and 1.6.

As further surfactants, the agents according to the invention can contain nonionic substances such. B. contain the type of fatty acid N-alkylglucamides. Solubilizers, for example cumene sulfonate, and colorants and fragrances are suitable as further additives, and in a preferred embodiment, the agents according to the invention dispense with solubilizers. The following examples are intended to explain the subject matter of the invention in more detail without restricting it.

B e i s p i e l e

A polyglucosan oxidation product was used, which was produced as follows in accordance with DE 4203923:

275.2 g of potato starch (1.6 mol based on anhydroglucose unit) with a moisture content of approx. 6% by weight were suspended in 825 g of carbon tetrachloride and transferred to a 2 l stirred autoclave. After evacuating the autoclave and flushing with nitrogen, 73.6 g of condensed nitrous oxide (0.8 mol) were added. The reaction mixture was heated to 50 ° C. within 30 minutes. The internal pressure in the autoclave was 0.5 bar (adjusted with nitrogen). By pressing in oxygen, an internal pressure of 2 bar was maintained within the first hour of the reaction, which was raised to 6 bar within the next hour. After a reaction time of 4.5 hours, oxygen consumption was no longer noticeable, noticeably from the drop in pressure. The autoclave was cooled to room temperature, let down and the reaction mixture with

1 1 of demineralized water are added. The suspension of the oxidation product was filtered through a glass suction filter. The product was first washed with acetone, then with water until the washing liquid had a neutral reaction, dewatered with acetone and dried (70 ° C., vacuum drying cabinet). 256 g of white, powdery, oxidized starch with an acid number of 324 were obtained, corresponding to an average content of about 1 carboxyl group per anhydroglucose unit. The product had a reduced viscosity (n _red ) of 3 ml / g, measured on the

2% by weight solution of the sodium salt in 1N aqueous sodium nitrate solution at 20 ° C.

Surfactants used:

A) Cι ₂ / i4-coconut fatty alcohol-5 EO-butyl ether dehypon ( ^R ) LS-54

B) Cι ₂ / i4-coconut fatty alcohol-10 EO-butyl ether dehypon ( ^R ) LS-104 C) Ci2 / l4 coconut fatty alcohol-4 EO adduct dehydol (R) LS-4

D) Cg / io-alkyl oligoglucoside, DP 1.6 plantars ( ^R ) APG 225

All surfactants are sales products from Henkel KGaA, Düsseldorf / FRG.

Rinse aid formulations of compositions 1 to 6 were produced, compositions 2, 3, 5, 6, 8 and 9 are according to the invention, 1 (V), 4 (V) and 7 (V) are used for comparison.

Application performance testing of rinse aid formulations:

I. Checking the foam behavior of the rinse aid formulations:

The foam development of the rinse aid was determined with the aid of a circulating pressure measuring device. The rinse aid (3 ml) was dosed by hand in the rinse aid at 50 ° C.

Here mean:

0 points = no foam development

1 point = weak foaming

2 points = medium foam development (still acceptable)

3 points = strong foaming

II. Drying:

15 minutes after the end of the washing program, the door of the dishwasher was opened completely. After 5 minutes the drying was determined by counting the remaining drops on the dishes listed below. Rating:

0 points = more than 5 drops

1 point = 5 drops

2 points = 4 drops

3 points = 3 drops 4 points = 2 drops

5 points = 1 drop

6 points = 0 drops (optimal drying)

III. Rinse aid effect:

After the drying had been assessed, the crockery parts were placed outside the dishwasher for 30 minutes to cool and then visually inspected under lighting in a black box. The dried residual drops, streaks, deposits, cloudy films, etc. remaining on the dishes and cutlery were assessed.

Rating:

0 points = bad rinse aid effect 8 points = optimal rinse aid effect

For the performance test III. The tests were carried out in the dishwasher (Miele G 590) with softened water (1.6 ° dH) and with non-softened water (13.8 ° dH). The 65 ° C normal program was selected for this. 30 g of Somat ^R cleaner (Henkel) were dosed in the cleaning cycle. The amount of rinse aid - the rinse aid composition given in each case in Table 1 - was 3 ml and was dosed by hand at 50 ° C. in the rinse aid cycle. The salt load in the water was between 600 and 700 mg / 1. 3 rinse cycles were carried out for each rinse aid formulation.

The following dishes were used to assess the drying and the rinse aid effect:

- "Neckar-Becher" glasses (Schott-Zwiesel), 6 pieces

- Stainless steel knife "Brasilia" (from WMF), 3 pieces

- White porcelain dinner plates (from Arzberg), 3 pieces

- red plastic plate "Valon dinner plate" (Fa. Haßmann), 3 pieces Table 1

KV) 2 3 4 (V)

Dehypon LS 54 15.0 15.0 15.0 -

Dehydol LS 4 - - - 9.0

Dehypon LS 104L _ _ _ 5.9

(85% aqueous (5% AS)

Solution)

APG 225 (70% _ _ _ _ aqueous solution)

Starch Oxidation _ 2.5 4.0 _ Product

Citric acid 3.0 3.0 3.0 3.0 anhydrous

Na cumene sulfonate 14.0 14.0 14.0 10.0

(40% aqueous (5.6% AS) (5.6% AS) (4% AS) (4% AS)

Solution)

Perfume oil 0.5 0.5 0.5 0.5

demineralized 67.5 65.0 63.5 67.6

water

Foam rating 0 0 0 0

(AS: active substance) Continuation Table 1

5 6 7 (V) 8 9

Dehypon LS 54 - - - - -

Dehydol LS 4 9.0 9.0 6.0 6.0 6.0

Dehypon LS 104L 5.9 5.9 1.2 1.2 1.2

(85% aqueous (5% AS) (5% AS) (1% AS) (1% AS) (1% AS)

Solution)

APG 225 (70% - _ 11.4 U.4 11.4 aqueous solution) (8% AS) (8% AS) (8% AS)

Starch Oxidation 2.5 4.0 _ 2.5 4.0 product

Citric acid 3.0 3.0 3.0 3.0 3.0 anhydrous

Na cumene sulfonate 10.0 10.0 1.0 1.0 1.0

(40% aqueous (4% AS) (4% AS) (0.4% AS) (0.4% AS) (0.4% AS)

Solution)

Perfume oil 0.5 0.5 0.5 0.5 0.5

demineralized 65.1 63.6 76.9 74.4 72.9

water

Foam rating 0 0 0 0

⁰⁰

(AS: active substance)

Examples 2, 3, 5, 6, 8 and 9 are according to the invention, Examples 1 (V), 4 (V) and 7 (V) serve for comparison. - Results of the rinse aid effect studies

The results of the investigations of the rinse aid effect show that rinse aid formulations containing polyglucosan oxidation product, depending on the type of surfactants used and the items to be washed (glasses, knife blades, porcelain plates, plastic plates), consistently at least equally good to significantly better rinse aid effects, in particular on steel surfaces (Mes ¬ sern), as corresponding polyglucosan oxidation product-free formulations.

Claims

Patent claims

1. Use of oxidation products of polyglucosans and / or their water-soluble salts in rinse aid.

2. Use according to claim 1, characterized in that the oxidation product is a polymer of anhydroglucose units, which is at least partially composed of oxidized anhydroglucose units of the formulas I, II and / or III,

with one, two or three carboxyl groups and / or their soluble salts per unit.

3. Use according to claims 1 and 2, characterized in that the content of oxidized anhydroglucose units according to formulas I, II and / or III in the polyglucosan derivatives is at least 25 mol%, in particular at least 35 mol% and preferably at least 40 mol%, the upper limit of the content being about 100 mol%, in particular 95 mol%.

4. Use according to claims 1 to 3, characterized in that the oxidation products of polyglucosans and / or their soluble salts consist on average at least 15 mol% of oxidized anhydroglucose units of the formula I and have average molecular weights below 15,000.

5. Use according to claim 1, characterized in that the oxidation products of polyglucosans are prepared according to the methods disclosed in German laid-open patent applications DE 42 03 923 AI or DE 43 17 519 AI.

6. Use according to claim 1, characterized in that the oxidation products of polyglucosans are prepared according to the methods disclosed in European patent application EP 0 548 399 AI or international application WO92 / 18542.

7. containing rinse aid,

0.1 to 10% by weight, preferably 1 to 5% by weight, oxidation products of polyglucosans according to Claims 1 to 6,

- 0.5 to 50 wt .-%, preferably 1 to 20 wt .-%, organic carboxylic acids, especially citric acid and

0.5 to 50% by weight, preferably 2 to 20% by weight, of a nonionic surfactant selected from the group of the mixed ethers of the formula I, the fatty alcohol polypropylene glycol / polyethylene glycol ethers of the formula II, the alkyl polyglycosides of the formula III and their Mixtures, in which case in the mixed ethers of the formula I,

Rl for a linear or branched, aliphatic alkyl and / or alkenyl radical with 8 to 14 carbon atoms, R ² for a linear or branched alkyl radical with 1 to 4 carbon atoms or a benzyl radical, a for 0 or numbers from 1 to 2 and b stands for numbers from 5 to 15,

and in the alkyl polyglycosides of the formula (III),

R ⁴ 0- [G] _p (III)

R ^{4 is} an alkyl radical having 8 to 22 carbon atoms, G is a sugar radical having 5 or 6 carbon atoms, preferably a glucose radical, and p is a number from 1 to 10.