EP3781658A1

EP3781658A1 - Corrosion protection for glassware in a dishwasher

Info

Publication number: EP3781658A1
Application number: EP19715457.8A
Authority: EP
Inventors: Thomas Doering; Thomas Weber
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2018-04-19
Filing date: 2019-04-02
Publication date: 2021-02-24
Also published as: DE102018205971A1; US11518959B2; US20210032571A1; WO2019201583A1

Abstract

The invention relates to a gel which is based on polysaccharide and which comprises glass protection additives selected from zinc salts, polyvinyl amide, polyvinyl amine, or combinations thereof. The invention additionally relates to the use of said gel for the corrosion protection of glassware during cleaning and/or rinsing processes, in particular in a dishwasher, and to a method for preventing the corrosion of glassware during cleaning and/or rinsing processes, in particular in a dishwasher.

Description

"Corrosion protection for glassware in a dishwasher"

The present invention relates to a polysaccharide-based gel comprising glass preservative additives selected from zinc salts, polyvinylamide and polyvinylamine, or combinations thereof. Furthermore, the present invention relates to the use of this gel for the corrosion protection of glassware in cleaning and / or rinsing operations, in particular in a dishwasher and a method for inhibiting the corrosion of glassware during cleaning and / or rinsing operations, in particular in a dishwasher.

The corrosion of glassware in cleaning and / or rinsing a dishwasher is a long-known problem. Glassware is subject to repeated strong rinsing in a dishwasher different degrees of corrosion. It comes after the leakage of minerals to a progressive hydrolysis of the silicate network. This can then lead to the formation of visible turbidity and streaks in the glass by deposition.

From the prior art, various approaches for overcoming the problems described are known.

For example, EP 1 141 190 A1 describes the use of water-soluble glass as corrosion protection for glassware. However, the production of water-soluble glass is both time and energy consuming, since this must be carried out at process temperatures of about 850 ° C.

It was therefore an object of the present invention to provide a system which can prevent or slow down the corrosion problems described above and is simple in its manufacture.

The inventors of the present invention have found in this respect that the object can be achieved by a polysaccharide-based gel comprising glass preservative additives selected from zinc salts, polyvinylamide or polyvinylamine or combinations thereof.

In a first aspect, the present invention therefore relates to a gel which is suitable for the

Corrosion protection of glassware is suitable and which

at least one polysaccharide polymer;

at least one glass protection additive selected from zinc salts, polyvinylamine, polyvinylamide or mixtures thereof;

optionally at least one solvent; and optionally at least one additive;

includes or consists of.

In a further aspect, the invention also relates to the use of the gel according to the invention for the corrosion protection of glassware, in particular during cleaning and / or rinsing operations in a dishwasher.

Finally, the invention also relates to methods for inhibiting the corrosion of glassware, in particular in cleaning and / or rinsing operations, comprising the steps:

i) contacting the glassware with the gel of the invention, the gel being dissolved in water, especially in a dishwashing machine;

ii) optionally carrying out a cleaning or rinsing step.

The weight-average molecular weight can be determined according to the present invention by means of

Gel permeation chromatography using polystyrene standards.

All in connection with the components of the gel described herein

Unless indicated otherwise, quantities are based on% by weight, based in each case on the total weight of the gel. Furthermore, such amounts referring to at least one ingredient always refer to the total amount of that type of ingredient contained in the gel, unless explicitly stated otherwise. This means that such quantity information, for example in connection with "at least one additive", to the

Total amount of additive contained in the gel.

"At least one" as used herein refers to 1 or more, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or more. In the context of constituents of the compositions described herein, this indication does not refer to the absolute amount of molecules but to the nature of the ingredient. "At least one additive" therefore means, for example, one or more different additives, i. one or more different types of additives. Together with quantities, the quantities refer to the total amount of the corresponding designated type of ingredient as defined above.

"Substantially free" as used herein means that the particular compound is present in less than 0.01% by weight, preferably 0.001% by weight, more preferably 0.0001% by weight, most preferably not at all respective component or composition is included. In particular, it also means that the respective compound was not deliberately added.

The term "gels" or "solid gels" as used interchangeably herein refers to preparations wherein, under standard conditions (25 ° C; 1013 mbar), a force of at least 0.03 mN is necessary to allow a 30 ° cone made of stainless steel to penetrate 5 mm deep into the respective product matrix (measured with the Texture Analyzer TA.XT plus).

The polysaccharide based gel is in particular a gel based on a cationic

Polysaccharides, in particular selected from the group of cationic cellulose polymers and / or cationic guar derivatives.

In various embodiments, the at least one polysaccharide polymer is contained in 0.1 wt% to 3 wt%, preferably 0.2 to 1.5 wt%, based on the total weight of the gel.

The gels preferably contain as cationic polysaccharide polymer (s) - based on the weight of the gel - 0.1 to 3 wt .-%, preferably 0.15 to 2 wt .-%, more preferably 0.1 to 1, 5 wt .-% and in particular 0.15 to 0.8 wt .-% of at least one polymer from the group of cationic cellulose polymers and / or cationic guar derivatives.

Cationic cellulose polymers within the meaning of the invention are those which are present in at least one

Side chain carry more than one permanent cationic charge. Cellulose is composed of beta-1, 4-glycosidically linked D-glucopyranose units and forms unbranched,

water-insoluble chains. As a "side chain" of a cellulose, chemical substituents are defined which bind to the cellulose skeleton and do not belong to the native cellulose since they have been subsequently introduced, for example, by chemical synthesis.

Preference is given to quaternized cellulose polymers derived from hydroxy (C 2 -C 4) -alkylcelluloses, more preferably from hydroxyethylcelluloses.

Such polymers are known to those skilled in the art and commercially available from various companies. Particularly preferred are the cationic known under the INCI names Polyquaternium-4, Polyquaternium-10, Polyquaternium-24, Polyquaternium-67 and / or Polyquaternium-72

Cellulose derivatives. Very particular preference is given to polyquaternium-10, polyquaternium-24 and / or polyquaternium-67 and particular preference to polyquaternium-10.

Preferred gels of the invention contain as cationic polysaccharide polymer (s) - based on the weight of the gel - 0.01 to 3 wt .-%, preferably 0.05 to 2 wt .-%, more preferably 0.1 to 1, 5 wt .-% and in particular 0.15 to 0.8 wt .-% of at least one polymer from the group of Polyquaternium-4, Polyquaternium-10, Polyquaternium-24, Polyquaternium-67 and / or

Polyquaternium-72.

Particularly preferred gels of the invention contain as cationic polysaccharide polymer (s) - based on the weight of the gel - 0.01 to 3 wt .-%, preferably 0.05 to 2 wt .-%, more preferably 0.1 to 1, 5 wt .-% and in particular 0.15 to 0.8 wt .-% Polyquaternium-10. Suitable cationic guar derivatives for the purposes of the invention are cationic hydroxyalkyl guar derivatives, preferably cationic hydroxyethyltrimethylammonium guar and / or cationic hydroxypropyltrimethylammonium guar having weight-average molecular weights of between 100,000 and 2,000,000 g / mol.

Particularly preferred are the cationic guar polymers having a weight-average molecular weight of between 200,000 and 1,600,000 g / mol, which are known by the INCI name Guar Hydroxypropyltrimonium Chloride. The cationic charge density of these guar polymers is preferably at least 0.4 meq / g, preferably at least 0.5 meq / g and especially at least 0.6 meq / g. The determination can be carried out for example by means of titration. Their nitrogen content is preferably in the range of 1, 1 to 1, 8 wt .-% (based on their total weight).

Cationic guar derivatives, which are known by the INCI name Guar Hydroxypropyltrimonium Chloride, are known to the person skilled in the art and are available, for example, under the trade names Cosmedia® Guar, N-Hance® and / or Jaguar® from various suppliers.

Particularly preferred gels of the invention contain as cationic polysaccharide polymer (s) - based on the weight of the gel - 0.01 to 3 wt .-%, preferably 0.05 to 2 wt .-%, more preferably 0.1 to 1, 5 wt .-% and in particular 0.15 to 0.8 wt .-% guar hydroxypropyltrimonium chlorides.

The gel of the present invention also contains at least one glass protection additive selected from zinc salts, polyvinylamine, polyvinylamide or mixtures thereof.

In various embodiments, the at least one glass protection additive is contained in 0.1 to 15.0% by weight, preferably 2.0 to 10.0% by weight, based on the total weight of the gel.

Preferred zinc salts are zinc acetate, zinc chloride, zinc oxide, zinc sulfide, zinc stearate, zinc carbonate, and zinc ricinoleate, particularly preferred are zinc chloride, zinc acetate and zinc ricinoleate.

Polyvinylamine compounds in the context of the invention are polyvinylamine polymers.

Polyvinylamide compounds in the context of the invention are polyvinylamide polymers.

The polyvinylamine and / or polyvinylamide-containing polymers preferably to be used according to the invention can be prepared by free-radical polymerization of N-vinylcarboxamides, such as N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N- methylacetamide, N-vinyl-N-ethylformamide, N-vinyl-Nn-propylformamide, N-vinyl-N-isopropylformamide, N-vinyl-N-isobutylformamide, N-vinyl-N-methylacetamide, N-vinyl-Nn-butylacetamide and N-vinyl-N-methylpropionamide, preferably N-vinylformamide, and preferably subsequent complete or, in particular, partial hydrolysis of the amide functions to amine functions.

The hydrolysis can be carried out under alkaline or acidic conditions, preferably in an aqueous medium and at a temperature of 70 to 90 ° C is used. However, it is also possible to use inert organic solvents, such as dioxane or aliphatic or aromatic hydrocarbons, or alcohols, e.g. tert. Butanol, to use as a reaction medium.

The polymers to be used according to the invention may additionally contain in copolymerized form a monoethylenically unsaturated comonomer. Of course, several comonomers can be copolymerized. Suitable comonomers are anionic, nonionic and cationic monomers.

Examples of suitable anionic comonomers are:

a, b -unsaturated monocarboxylic acids, preferably having from 3 to 6 carbon atoms, such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid and vinylacetic acid, and their alkali metal and ammonium salts;

unsaturated dicarboxylic acids preferably having 4 to 6 carbon atoms, such as itaconic acid and maleic acid, their anhydrides, such as maleic anhydride, and their alkali metal and ammonium salts;

Half esters of unsaturated dicarboxylic acids with C1-C6 alcohols, such as itacon and

Maleic acid haibester.

Preferred anionic comonomers are acrylic acid and its salts, especially sodium acrylate.

Suitable nonionic comonomers are, for example:

Esters of monoethylenically unsaturated C 3 -C 6 -carboxylic acids, in particular of acrylic acid and methacrylic acid, with monohydric C 1 -C 22 -alcohols, in particular with C 1 -C 6 -alcohols; and also hydroxyalkyl esters of monoethylenically unsaturated C 3 -C 6 -carboxylic acids, especially of acrylic acid and methacrylic acid, with bivalent C 2 -C 4 -alcohols, such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec. Butyl (meth) acrylate, tert-butyl (meth) acrylate, ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate;

Amides of monoethylenically unsaturated C3-C6 carboxylic acids, especially of acrylic acid and methacrylic acid, with primary and secondary C1-C12 amines, such as (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide and N butyl (meth) acrylamide;

Vinyl esters of saturated C1-C11 carboxylic acids, such as vinyl acetate and vinyl propionate;

aliphatic and aromatic olefins, such as ethylene, propylene, C4-C24-α-olefins, in particular C4-C16-α-olefins, for example butylene, isobutylene, diisobutene, styrene and α-methylstyrene, and also diolefins having an active double bond, for example butadiene ; unsaturated alcohols such as vinyl alcohol and allyl alcohol; unsaturated nitriles, such as acrylonitrile and methacrylonitrile.

As suitable cationic comonomers are e.g. called:

N-vinyl lactams of 5- to 7-membered-ring lactams such as N-vinylpyrrolidone, N-vinylcaprolactam and N-vinyl oxazolidone;

Vinylimidazole and vinylimidazoline units containing monomers and their alkyl derivatives, in particular C1-C15-alkyl derivatives, and their quaternization, such as N-vinylimidazole, N-vinyl-2-methylimidazole, N-vinyl-4-methylimidazole, N vinyl-5-methylimidazole, N Vinyl 2-ethylimidazole, N-vinylimidazoline, N-vinyl-2-methylimidazoline and N-vinyl-2-ethylimidazoline;

Vinylpyridines and their quaternization products such as 4-vinylpyridine, 2-vinylpyridine, N-methyl-4-vinylpyridine and N-methyl-2-vinylpyridine;

basic esters of ethylenically unsaturated carboxylic acids, in particular the esters of a, b-unsaturated C3-C6 monocarboxylic acids, especially of acrylic acid and methacrylic acid, with

Amino alcohols, especially N, N-di (C 1 -C 4 -alkyl) amino-C 2 -C 6 -alcohols, and their

Quaternization products such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl acrylate, diethylaminopropyl acrylate, dimethylaminobutyl acrylate and

diethylaminobutyl acrylate;

basic amides of ethylenically unsaturated carboxylic acids, in particular the N, N-di (C 1 -C 4 -alkyl) amino (C 2 -C 6 -alkyl) amides of a, b-unsaturated C 3 -C 6 monocarboxylic acids, especially of acrylic acid and methacrylic acid, and their quaternization products, such as

Dimethylaminoethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide,

Dimethylaminopropyl (meth) acrylamide and diethyleminopropyl (meth) acrylamide.

When the polymers to be used according to the invention comprise comonomers in copolymerized form, their content is generally 0.1 to 80 mol%, in particular up to 50 mol%, based on the polymer.

The polymers to be used according to the invention can be present in water-soluble form, but they can also be crosslinked and thus water-insoluble. The polymers are preferred

water-soluble polymers.

The crosslinking can be carried out by thermal treatment of the polymer and / or by reaction with formic acid derivatives, targeted amidines being formed. However, the crosslinking is preferably carried out by copolymerizing a further, at least two ethylenically unsaturated, non-conjugated double bonds containing, crosslinking comonomer.

Suitable crosslinkers are, for example:

Alkylenebisacrylamides such as methylenebisacrylamide and N, N'-acryloylethylenediamine

Divinylalkylene ureas such as N, N'-divinylethyleneurea and N, N'-divinylpropyleneurea; Ethylidene bis-3- (N-vinylpyrrolidone), N, N'-divinyldimido-azolyl (2,2 ') butane and 1,1'-bis (3,3-vinylbenzimidazolite-2-one) 1,4-butane;

Alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate and tetraethylene glycol di (meth) acrylate;

aromatic divinyl compounds such as divinylbenzene and divinyltoluene; vinyl acrylate,

Allyl (meth) acrylate, triallylamine, divinyldioxane and pentaerythritol triallyl ether.

The polymers according to the invention preferably have weight-average molecular weights Mw of from 1000 to 6,000,000 g / mol, preferably from 45,000 to 450,000 g / mol.

Particularly preferred is a copolymer of vinylamine and N-vinylformamide. Since vinylamine itself is not accessible, copolymers of vinylamine and N-vinylformamide are prepared by polymerization of N-vinylformamide and subsequent alkaline hydrolysis as described above. In this case, products with different degrees of hydrolysis can be produced. Copolymers of vinylamine and N-vinylformamide are commercially available, for example, under the name "Lupamin®" from BASF.

In various embodiments of the invention, the gels are characterized in that the at least one glass protection additive is selected from zinc chloride, zinc acetate, zinc ricinoleate,

Polyvinylamine, polyvinylamide and mixtures thereof, preferably polyvinylamine and at least one zinc salt selected from zinc chloride, zinc acetate, Zinkricinoleat included.

In preferred embodiments, the at least one zinc salt, in particular zinc chloride, zinc acetate, zinc ricinoleate, in 0.5 to 15.0 wt .-%, preferably 2 to 10 wt .-%, based on the total weight of the gel; and / or the polyvinylamine in 0.1 to 10 wt .-%, preferably 1 to 5 wt .-%, based on the total weight of the gel.

The gel may further contain at least one solvent. The at least one solvent is preferably an organic solvent, in particular a mixture of a polar and a nonpolar solvent. The polar solvent is particularly preferably an organic solvent having at least one hydroxyl group, in particular alkanolamines, polyols, such as

Ethylene glycol, 1, 2-propylene glycol and 1, 2-glycerol, especially 1, 2 propylene glycol. That at least one nonpolar organic solvent is preferably an oil, especially a vegetable naturally occurring oil such as castor oil, castor oil, coconut oil, corn oil, linseed oil, cottonseed oil, sesame oil, palm oil, olive oil, sunflower oil, soybean oil, especially castor oil.

The at least one solvent is contained in various embodiments in amounts of 20.0 to 90.0 wt .-%, preferably 50.0 to 85 wt .-%, particularly preferably in 70.0 to 80.0 wt .-%, in each case based on the total weight of the gel. The gel may further contain at least one additive. The additives are preferably selected from alkali and alkaline earth metal salts, such as sodium sulfate, fillers, such as silica or Aerosil, builders, corrosion inhibitors, enzymes, builders, such as Aerosil, foam inhibitors, surfactants,

Bittering agents, sequestering agents, electrolytes, perfumes, antimicrobial agents and dyes.

In various embodiments, the at least one additive is contained in an amount of 0.1 to 40 wt .-%, preferably 5 to 30 wt .-%, more preferably 15 to 25 wt .-%, each based on the total weight of the gel

In preferred embodiments, the gel is substantially phosphate and / or phosphonate free.

In further preferred embodiments, the gel is bleach-free. Essentially

"Phosphate-free" and "phosphonate-free" as used herein means that the subject gel is substantially free of phosphates or phosphonates, i. in particular phosphates or

Phosphonates in amounts less than 0.1 wt .-%, preferably less than 0.01 wt .-%, based on the total weight of the gel.

Suitable builders include aminocarboxylic acids and their salts, carbonates, organic cobuilders and silicates.

Aminocarboxylic acids and / or their salts represent another important class of builders. Particularly preferred members of this class are methylglycinediacetic acid (MGDA) or its salts, and glutamic diacetic acid (GLDA) or its salts or ethylenediamine diacetic acid or its salts (EDDS). Also suitable are iminodisuccinic acid (IDS) and iminodiacetic acid (IDA). The content of these aminocarboxylic acids or their salts may, for example, be between 0.1 and 15% by weight, preferably between 0.5 and 10.0% by weight, and in particular between 0.5 and 6% by weight , Aminocarboxylic acids and their salts can be used together with the abovementioned builders, in particular also with the phosphate-free builders.

Particularly suitable organic co-builders are polycarboxylates / polycarboxylic acids, polymers

Carboxylates, aspartic acid, polyacetals and dextrins to call.

Suitable organic builders are, for example, the polycarboxylic acids which can be used in the form of the free acid and / or their sodium salts, those of polycarboxylic acids being those

Carboxylic acids are understood to carry more than one acid function. These are, for example, citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartaric acid, maleic acid, fumaric acid, sugar acids, aminocarboxylic acids, nitrilotriacetic acid (NTA), if such use of NTA is not objectionable for ecological reasons, and mixtures of these. It is also possible, for example, the use of carbonate (s) and / or bicarbonate (s), preferably alkali metal carbonate (s), more preferably sodium carbonate. Alkali carbonates, especially sodium carbonate, can also be used as pH adjusters and in various embodiments of the invention are preferably present in an amount of from 15 to 40% by weight, more preferably from 20 to 30% by weight, based on the gel.

Further suitable builders are polymeric polycarboxylates, for example the alkali metal salts of polyacrylic acid or polymethacrylic acid, for example those having a weight-average molecular weight of 500 to 70,000 g / mol.

Suitable polymers are in particular polyacrylates, which are preferably a weight-average

Have molecular weight of 2000 to 20,000 g / mol. Because of their superior solubility, this group can again be the short-chain polyacrylates that form a weight-average

Molecular weight of 2000 to 10,000 g / mol, and more preferably from 3000 to 5000 g / mol, be preferred.

The gels can be used as builder further crystalline layered silicates of the general formula NaMSix0 _{2x + i} ^* y H2O, where M is sodium or hydrogen, x is a number from 1, 9 to 22, preferably from 1, 9 to 4, with particularly preferred values for x is 2, 3 or 4, and y is a number from 0 to 33, preferably from 0 to 20. It is also possible to use amorphous sodium silicates having a modulus Na 2 O: SiO 2 of from 1: 2 to 1: 3.3, preferably from 1: 2 to 1: 2.8 and in particular from 1: 2 to 1: 2.6, which are preferably delayed in dissolution and secondary wash properties.

In preferred gels, the content of silicates is limited to amounts below 10% by weight, preferably below 5% by weight and in particular below 2% by weight. Particularly preferred gels are silicate-free.

As perfume oils or perfumes, within the scope of the present invention, individual fragrance compounds, e.g. the synthetic products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type are used. Preferably, however, mixtures of different fragrances are used, which together produce an attractive fragrance. Such perfume oils may also contain natural fragrance mixtures such as are available from vegetable sources, e.g. Pine, citrus, jasmine, patchouli, rose or ylang-ylang oil. The perfumes / perfume oils can be encapsulated, for example in microcapsules, or used in free form or both.

When used, the gel according to the invention can be introduced directly into the washing compartment or the dishwasher. For example, the metering can take place via a metering chamber of an automatic dishwashing machine. The addition may be at any time during the

Wash program done. The gel according to the invention may be present in pre-portioned form as a single portion, in particular in the form of a water-soluble pouch, preferably with a polyvinyl alcohol-based coating, usually in the form of a water-soluble PVA film.

All (preferred) embodiments described herein in connection with the gels according to the invention are also applicable to the use according to the invention and corresponding methods, and vice versa.

Examples:

Gels were prepared from the following compositions:

Claims

claims:

1. A gel suitable for the corrosion protection of glassware, which

at least one polysaccharide polymer;

optionally at least one solvent; and

optionally at least one additive;

includes or consists of.

2. Gel according to claim 1, characterized in that the at least one

Polysaccharide polymer is a cationic polysaccharide polymer, in particular selected from the group of cationic cellulose polymers and / or cationic guar derivatives.

3. Gel according to one of claims 1 or 2, characterized in that

(A) the at least one polysaccharide polymer in 0.1 wt .-% to 3 wt .-%, preferably 0.2 to 1, 5 wt .-%, based on the total weight of the gel is included; and or

(B) the at least one glass protection additive in 0.1 to 15.0 wt .-%, preferably 2.0 to 10.0% by weight, based on the total weight of the gel is included.

4. Gel according to one of claims 1 to 3, characterized in that the at least one glass protection additive is selected from zinc chloride, zinc acetate, Zinkricinoleat, polyvinylamine, polyvinylamide and mixtures thereof, preferably polyvinylamine and at least one zinc salt selected from zinc chloride, zinc acetate, Zinkricinoleat included ,

5. Gel according to one of claims 1 to 4, characterized in that the at least one zinc salt, in particular zinc chloride, zinc acetate, Zinkricinoleat, in 0.5 to 15.0 wt .-%, preferably 2 to 10 wt .-%, based is contained on the total weight of the gel and / or

in that the polyvinylamine is contained in 0.1 to 10% by weight, preferably 1 to 5% by weight, based on the total weight of the gel.

6. Gel according to one of claims 1 to 5, characterized in that

(A) the at least one solvent is an organic solvent, in particular a mixture of a polar and a nonpolar solvent, particularly preferably an organic solvent having at least one hydroxyl group, such as 1, 2-propylene glycol and / or a nonpolar organic solvent, such as Oils, in particular castor oil; and or

(B) the at least one solvent is contained in 20.0 to 90.0 wt .-%, preferably 50.0 to 85 wt .-%, particularly preferably in 70.0 to 80.0 wt .-%, based on the total weight of the gel.

7. Gel according to one of claims 1 to 6, characterized in that the gel further comprises at least one additive selected from alkali and alkaline earth metal salts, such as sodium sulfate, fillers, such as silica or Aerosil, builders, corrosion inhibitors, enzymes, builders, Schauminihibtoren, surfactants, Contains bittering agents, sequestering agents, electrolytes, fragrances, antimicrobial agents and dyes.

8. Gel according to one of claims 1 to 7, characterized in that the at least one additive in an amount of 0, 1 to 40 wt .-%, preferably 5 to 30 wt .-%, more preferably 15 to 25 parts by weight. %, in each case based on the total weight of the gel.

9. Use of the gel according to one of claims 1 to 8 for the corrosion protection of glassware, in particular during cleaning and / or rinsing operations in a dishwasher.

A method of inhibiting the corrosion of glassware, especially in cleaning and / or rinsing operations, comprising the steps of:

i) contacting the glassware with the gel according to any one of claims 1 to 8, wherein the gel has been dissolved in water, in particular in a dishwashing machine;

ii) optionally carrying out a cleaning or rinsing step.