DE4338626A1 - Additive for glass bottle cleaning and its use to reduce glass corrosion - Google Patents

Abstract

The invention concerns an additive for alkaline aqueous washing solutions for use in bottle-washing plants, the additive containing a combination of hydroxyoligocarboxylic acids and phosphonic acids and resulting in a reduction of glass corrosion during washing. The invention also concerns the use of the additive in washing glass-bottles.

Description

The invention relates to a new additive for aqueous alkaline cleaning agents solutions for machine bottle cleaning systems for glass bottles, especially for beverage bottles. The additive has the task of the alkaline bottle cleaning usually occurs glass corrosion to reduce. Further aspects of the invention relate to the use of the Additives in aqueous cleaning solutions for machine cleaning of Glass bottles.

Before refilling reusable glass beverage bottles, the Labels are removed and the bottles are cleaned thoroughly. In the Bottle cleaning machines of the bottling plants are used for this usually strongly alkaline, sodium hydroxide-containing cleaning solutions set. The alkali metal hydroxide content is usually in the range 0.5 to 5, in particular 1 to 3% by weight. When using suitable products and processes achieve the desired cleaning effect. An un The desired effect in bottle cleaning is glass corrosion. Underneath it is understood that the surface of the glass bottles is chemically attacked becomes what leads to surface roughness. A sequela is common Fig. difficult cleaning of the rough surface and the risk of wax microorganisms in cracks and holes in the surface. From the Practice and laboratory tests have shown that the corrosiveness of Natri Umhydroxid-containing cleaning solutions through an increased proportion of Natri umcarbonate increases.

Given the number of possible refill cycles for reusable glass bottles is limited, among other things, by glass corrosion during cleaning, there is a need for additives that are used as additives in cleaning solutions  reduce glass corrosion. The invention therefore turns up gabe, a combination of active ingredients for aqueous alkaline cleaning solutions to provide for the mechanical cleaning of glass bottles, which, in addition to cleaning-enhancing properties, reduce the Glass corrosion contributes.

In a further aspect, the object of the invention is this Formulate active ingredient combination in the form of a concentrate that as Additive admixed on site to the aqueous alkaline cleaning solution that can.

Aliphatic hydroxymono-, hydroxydi- or hydroxytricarboxylic acids with 3 up to 6 carbon atoms and 1 to 5 hydroxyl groups are more technical as components Cleaner known. It is also known to use cleaning solutions geminale Di phosphonic acids of the general formula (I) given below, amino methylenephosphonic acids of the general formula (II) or phosphonocarbon add acids of the general formula (III). It is assumed that the acids or their anions complexing properties ins have special properties compared to the hardness-forming ions in water. The ge called phosphonic and phosphonocarboxylic acids also show so-called hardness-stabilizing (scale-inhibiting) properties.

For example, DE-C-23 25 829 describes a sequestering agent for 2- and 3-valent cations in the form of a mixture of 1-hydroxyethane-1,1- diphosphonic acid, aminotrimethylene phosphonic acid and 2-phosphonobutane 1,2,4-tricarboxylic acid or its water-soluble salts. This font ent holds detailed information about which geminal diphosphonic acids, Ami nomethylenephosphonic acids and phosphonocarboxylic acids as sequestering agents combination can be selected. The one in this document, the hereby is expressly made the subject of the present disclosure Given phosphonic acid types are also in the sense as phosphonic acid components of the present invention.

The use of hydroxyalkanoligocarboxylic acids as complexing agents in technical alkaline cleaners are also known. For example WO 92/08824 discloses an aqueous alkaline cleaner for aluminum  a pH between 10 and 12, which is an alkaline builder component, Aminoalkyl or hydroxyalkyldiphosphonic acids, surfactants and complexing agents for aluminum contains. As complexing agents for aluminum are under whose gluconates and tartates are given. From the unpublished deut The patent application P 42 32 612.5 is the use of a combination from a phosphonic acid, an oxidizing agent and at least one short chain organic carboxylic acid, selected from among others tartaric acid and citric acid, in acidic aqueous solutions, which have a pH in the loading range from 0 to 3 to remove magnetite deposits in water leading systems known.

DE-A-36 03 579 describes acidic, phosphoric acid-containing cleaner concentrates te known as the essential ingredient of the invention ethoxylated fat contain amines of the general formula (V).

in the
n for an integer from 2 to 30,
Ra for a straight-chain or branched, saturated or unsaturated alkyl radical having 8 to 24 carbon atoms and R ^b for a group

- (CH₂-CH₂-O) _m -H

or a group

stands, where
R ^{c is} an alkylene radical having 2 to 6 carbon atoms,
m, x and y each represent an integer from 0 to 30.

The concentrates also contain a combination of different ones  Phosphonic acids represented by the general formulas given below I, II and III are writable, and partly gluconic acid. It is the total phosphonic acid content is greater than the gluconic acid content.

From the German patent application P 43 24 396.7, cleaning agents are included high wetting ability known, preferably for cleaning art fabric surfaces are used. As constituents essential to the invention they contain monoamino or diaminomono or dicarboxylic acids or their Amides in combination with longer chain carboxylic acids and non-ionic Surfactants. Optional components in these cleaners can be: Hy droxypolycarboxylic acids such as tartaric acid and citric acid, geminal diphos Phonic acids such as 1-hydroxyethane-1,1-diphosphonic acid, aminophosphonic acids and phosphonopolycarboxylic acids. These cleaners can also be used as Buil dersubstanzen contain alkali metal hydroxides.

Surprisingly, it was found that a combination of hydroxy oligocarboxylic acids and phosphonic acids known as sequestering agents in certain proportions by alkaline, carbonate Cleaner solutions caused glass corrosion significantly reduced. Because of the known complexing properties of these active ingredients would be rather one increased corrosion rate was expected.

In a first aspect, the invention describes an additive in the form of a aqueous solution for addition to alkaline cleaning baths for machine len cleaning of glass bottles consisting of

• a) 7 to 25 wt .-%, based on the free acid, one or more aliphatic hydroxymono-, hydroxydi- or hydroxytricarboxylic acids with 2 to 6 carbon atoms and 1 to 5 hydroxyl groups and / or aliphatic Monoamino or diaminomono or dicarboxylic acids with 2 to 6 carbon atoms or their water-soluble salts,
• b) 1 to 12% by weight, based on the free acid, of one or more mineral diphosphonic acids of the general formula (I) where R is an alkyl radical having 1 to 5 carbon atoms and Z is hydrogen, a hydroxyl or an amino group,
  and / or one or more aminomethylenephosphonic acids of the general formula (II) where X and Y independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms,
  R¹ and R² -PO₃H₂ or a group of the formula and R³ is -PO₃H₂,
  and / or one or more phosphonocarboxylic acids of the general formula (III) where R 'is hydrogen, an alkyl radical having 1 to 4 carbon atoms or a group -CH₂-CH₂-COOH,
  or their water-soluble salts,
• c) 63 to 92% by weight of water or an aqueous solution of further auxiliaries fe,

the total concentration of the carboxylic acids of group a) not less is the total concentration of group b) phosphonic acids.

The additive preferably contains 10 to 20% by weight, based on the free Acid, one or more of the carboxylic acids of group a) or what serially soluble salts, and / or, preferably and, 2 to 6 wt .-%, based on the free acid, one or more of the phosphonic acids of group b) or their water-soluble salts and 68 to 91% by weight, preferably 74 to 88 % By weight of water or an aqueous solution of further auxiliaries.

Since the additive is intended as an additive to an alkaline cleaning solution is in the application solution, the acid usable according to the invention Ren in the form of their anions, regardless of whether the additive them contains as free acids or as water-soluble salts. If you put the car group a) and / or group b) phosphonic acids as what a soluble salts, the alkali metal or ammonium salts are special suitable, preferably sodium salts are used. The term "Water-soluble" is to be understood to mean that the salts in the aqueous Phase of the additive in the concentration ranges mentioned above, based on the free acids, are soluble.

Hydroxyacetic acids in particular come as group a) hydroxycarboxylic acids right, lactic acid, gluconic acid, tartronic acid, malic acid, tartaric acid and Ci tronic acid into consideration. Furthermore, amino carboxylic acids are according to the invention of group a). The naturally occurring alpha amino acids or Amino acid derivatives are generally tra with respect to the amino group chiral carbon atom and are in the L-form. Although for the chiral L-amino acids for the technical purpose according to the invention offer no particular advantage, they are considered natural or natural identical active ingredients are preferably used. Accordingly, as amino acids In the form of their racemates or in optically active form, for example, use Find: glycine, alanine, valine, leucine, isoleucine, beta-alanine, gam ma-aminobutyric acid, epsilon-aminocaproic acid, glutamine, glutamic acid,  Aspartic acid, aminomalonic acid, aminoadipic acid and 2-amino-2-methyl pentanedioic acid. The amino acids can also carry hydroxyl groups. Examples include serine and threonine.

It is particularly advantageous if the additive is 2 to 4, preferably 3 different carboxylic acids and especially hydroxy carboxylic acids from Grup pe a) contains, the combination of gluconic acid, lactic acid and Ci tronic acid leads to particularly positive results. It's cheap there when the additive is gluconic acid, lactic acid and citric acid or their water-soluble salts in a weight ratio of 1: (0.5 to 1.5): (0.5 to 1.5), preferably in a weight ratio of 1: (0.7 to 1.0): (0.8 to 1.2) contains.

Suitable phosphonic acids are listed in DE-C-23 25 829. Therefore can the phosphonic acids of group b) or their water-soluble salts are preferably selected from the following groups:

Formula (I): 1-aminoethane-1,1-diphosphonic acid and 1-hydroxyethane-1,1-diphosphonic acid,
Formula (II): ethylenediaminetetramethylenephosphonic acid, diethylenetriamine pentamethylenephosphonic acid, aminotri- (2-propylene-2-phosphonic acid), amino trimethylenephosphonic acid,
Formula (III): phosphonosuccinic acid, methylphosphonosuccinic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid.

It is again advantageous if the additive or phosphonic acids whose water-soluble salts of the general formula (I) and / or (III) ent holds, preferably at least one phosphonic acid of the formulas (I) and (III), especially 1-hydroxyethane-1,1-diphosphonic acid and 2-phos phonobutane-1,2,4-tricarboxylic acid can be used.

A preferred additive is characterized in that it is a Phos phonic acid or its water-soluble salts of the general formulas (I) and  (III) in a weight ratio of 1:10 to 10: 1, preferably 1: 1 to 10: 1, in particular 6: 1 to 9: 1 contains.

It has proven to be advantageous to use certain weight ratios between the total content of the carboxylic acids of group a) and the total content the phosphonic acids of group b). Particularly favorable values The glass corrosion was found when the weight ratio of the carbon acids of group a) to the phosphonic acids of group b) in the range between 1: 1 to 5: 1, preferably in the range 2: 1 to 4: 1.

The effect according to the invention is already achieved if the additive is except the above-mentioned components from groups a) and b) only Contains water. Depending on the application conditions, however, it can be advantageous be to add other additives to the water phase of the additive. Here in particular defoamers fall under the cleaning of egg glass bottles containing white contaminants often arise Fight foam. Accordingly, an aqueous solution c) is preferably one Defoamer solution used, it being recommended in the context of the invention is that the defoamer has a proportion based on the total additive from 1 to 25, preferably 10 to 20 and in particular 13 to 18% by weight matters.

Depending on the type of contamination of the glass bottles, the defoamer can be empirical to be chosen. Those polyglycol ethers which have proven themselves in EP-B-124 815 as foam-suppressing additives in low-foam cleaning agents recommended. Accordingly, the defoamer is preferably turned off chooses from the group of polyethylene glycol ethers of the general formula (IV)

R⁴-O- (CH₂-CH₂-O) _n -R⁵ (IV)

in the R⁴ a straight-chain or branched alkyl or alkenyl radical 8 to 18 carbon atoms, n is a number from 7 to 12, preferably from 8 to 10, and R⁵ is an alkyl radical with 4 to 8 carbon atoms, in particular with 4 carbon atoms mean.  

It is known the cleaning solutions for machine bottle cleaning plants to add further surface-active auxiliaries, which are found in for example, have a favorable effect on the detachment behavior of the labels. Here for nonionic surfactants based on ethoxylation and / or pro Use poxylation products of fatty alcohols or fatty amines. A Particularly suitable product group from ethoxylated fatty amines is in the DE-A-36 03 579 cited above. The ones described there Fatty amine ethoxylates are also used as auxiliary substances to increase cleaning performance of the additives according to the invention suitable. In particular come as surface-active auxiliaries reaction products of fatty amines with 10 to 18 carbon atoms with 8 to 16 mol ethylene oxide into consideration. It is favorable if that or the nonionic surfactants in the aqueous solution c) in a are present in such an amount that they relate to the total additive Make up proportion of 1 to 6, preferably from 2 to 4 wt .-%.

The polyether chain obtained by alkoxylation of the defoaming and of the surface-active auxiliaries can be conventional or so-called called "narrowed" homolog distribution. A way to manufacture development of alkoxylation products with a narrow homolog distribution for example in DE-A-38 43 713.

For analytical control and adjustment of the active ingredient concentration lightening in the detergent bath, it is helpful if the application Finished cleaning solution or the concentrated additive for this analytically contains easily identifiable key substances. As such a key substance For example, a soluble iodide, especially potassium iodide, comes in Consider its content in the bath solution by iodometric titration can be easily determined. Accordingly, it is preferred that the additive contains such a lead substance in a concentration that is in the diluted bath solution can be easily determined, but not too application or wastewater problems. For example, the fiction moderate additive 0.1 to 0.5 wt .-% potassium iodide.

In a further aspect, the invention relates to the use of the addi tivs in an aqueous cleaning solution containing alkali metal hydroxide mechanical cleaning of glass bottles. The use is known  records that the cleaning solution has an active ingredient content of is adjustable in that the additive described above in such amounts to the cleaning solution that the content of the cleaning solution solution of carboxylic acids of group a) 100 to 1,000 mg / l, preferably 200 up to 800 mg / l, in particular 300 to 600 mg / l and of phosphonic acids Group b) is 50 to 400 mg / l, preferably 75 to 200 mg / l. Of the NaOH content of the cleaning solution is in the technically usual range of 0.5 to 5% by weight, preferably 1 to 3% by weight.

The use according to the invention can advantageously be carried out in this way leads that the additive described above, which is an active represents substance concentrate in the appropriate dosage of the alkali cleaning solution containing tall hydroxide. The Ver can of course also be done by one individual active ingredients in the above-mentioned concentration range of the Reini solution separately. From the comparison of the concentrations of the Active substances of groups a) and b) in the finished cleaning solution and in Additive can be made by diluting the additive accordingly resulting concentrations of the other excipients nonionic surfactants, defoaming mer and lead substances can be easily calculated.

The use is further characterized in that the bottles with the cleaning solution at temperatures between 40 and 90 ° C, preferably between 55 and 85 ° C for a period of 1 to 30 minutes preferably in contact for 3 to 20 minutes.

Embodiments

The invention is illustrated by the examples shown below tert. To check the relative corrosion rate of glass bottles with cleaning solutions according to the invention and with comparison solutions brand new 0.33 liter glass bottles (so-called Vichy bottles) for 24 Immersed in the respective solutions at 80 ° C for hours and the weight ver lust in grave removal per bottle determined. Even if this test condition not the conditions on a technical bottle washer correspond, however, the relative corrosion effect of the individual Determine solutions.  

To standardize the conditions, the test solutions included (except Cf. 1) 2 wt .-% sodium carbonate to the conditions in technical Approximately simulate baths. In practice, the sodium carbonate The content of the cleaning solutions fluctuate widely. All test solutions included 2.5% by weight of NaOH, the components listed in Table 1 and water ad 100%. Comparative solution 1 was free of carbonate.

Table 1 shows the test results.

Examples 14 to 18

There were additive concentrates in the form of aqueous solutions for addition to aq alkaline cleaning solutions for machine bottle cleaning made by submitting the required amount of water and the others Components were dissolved therein with stirring at room temperature. A to K have the same meaning as in Table 1, L means potassium iodide. Ange the active substance and auxiliary substance contents in the additive are given in% by weight; the dif 100% by weight is water.

*) Footnote to Table 1

A) Gluconic acid
B) lactic acid
C) Citric acid
D) glycine
E) Glutamic acid
F) 2-phosphonobutane-1,2,4-tricarboxylic acid
G) 1-hydroxyethane-1,1-diphosphonic acid
H) aminotrimethylenephosphonic acid
I) fatty alcohol × 9.6 ethylene oxide-butyl ether (Dehypon® LT104, Henkel KGaA)
K) Cocosamine × 12 ethylene oxide

Claims (19)

1. Additive in the form of an aqueous solution for addition to alkaline cleaning baths for machine cleaning of glass bottles, consisting of

• a) 7 to 25 wt .-%, based on the free acid, one or more aliphatic hydroxymono-, hydroxydi- or hydroxytricarboxylic acids with 2 to 6 carbon atoms and 1 to 5 hydroxyl groups and / or aliphatic monoamino or diaminomono- or dicarboxylic acids with 2 to 6 carbon atoms or their water-soluble salts,
• b) 1 to 12% by weight, based on the free acid, of one or more geminal diphosphonic acids of the general formula (I) where R is an alkyl radical having 1 to 5 carbon atoms and Z is hydrogen, a hydroxyl or an amino group,
  and / or one or more aminomethylenephosphonic acids of the general formula (II) where X and Y independently of one another are hydrogen or an alkyl group having 1 to 4 carbon atoms,
  R¹ and R² -PO₃H₂ or a group of the formula and R³ is -PO₃H₂,
  and / or one or more phosphonocarboxylic acids of the general formula (III) where R 'is hydrogen, an alkyl radical having 1 to 4 carbon atoms or a group -CH₂-CH₂-COOH,
  or their water-soluble salts,
• c) 63 to 92% by weight of water or an aqueous solution of further auxiliaries,

the total concentration of the carboxylic acids of group a) not is less than the total concentration of the group's phosphonic acids b). 2. Additive according to claim 1, characterized in that it consists of 10 to 20 wt .-%, based on the free acid, of one or more of the carboxylic acids of group a) or their water-soluble salts,
and / or, preferably and
2 to 6% by weight, based on the free acid, of one or more of the phosphonic acids of group b) or their water-soluble salts
and
68 to 91 wt .-%, preferably 74 to 88 wt .-% water or an aqueous solution of other auxiliaries. 3. Additive according to one or both of claims 1 and 2, characterized records that as water-soluble salts of the carboxylic acids of group a)  and / or the phosphonic acids of group b) alkali metal or ammonium salts, preferably sodium salts, are used. 4. Additive according to one or more of claims 1 to 3, characterized ge indicates that the hydroxycarboxylic acids of group a) are selected are made of hydroxyacetic acid, lactic acid, gluconic acid, tartronic acid, Malic acid, tartaric acid and citric acid. 5. Additive according to one or more of claims 1 to 3, characterized ge indicates that the amino carboxylic acids of group a) are selected from glycine, alanine, ß-alanine, valine, leucine, isoleucine, gamma-amino butyric acid, epsilon-aminocaproic acid, glutamine, glutamic acid, Aspa Ragic acid, aminomalonic acid, aminoadipic acid and 2-amino-2-methyl pentanedioic acid. 6. Additive according to one or more of claims 1 to 3, characterized ge indicates that the amino acids of group a) additional hydroxyl bear groups and are preferably selected from serine and threo nin. 7. Additive according to one or more of claims 4 to 6, characterized ge indicates that there are 2 to 4, preferably 3 different carboxylic acids ren, preferably hydroxycarboxylic acids, especially gluconic acid, Lactic acid and citric acid, or their water-soluble salts. 8. Additive according to claim 7, characterized in that it is gluconic acid, Lactic acid and citric acid or their water-soluble salts in Ge weight ratio 1: (0.5 to 1.5): (0.5 to 1.5), preferably in Weight ratio 1: (0.7 to 1.0): (0.8 to 1.2) contains. 9. Additive according to one or more of claims 1 to 8, characterized in that the phosphonic acids of group b) or their water-soluble salts are selected from the following groups: Formula (I): 1-aminoethane-1,1-diphosphonic acid and 1-hydroxyethane-1,1-diphosphonic acid,
Formula (II): ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, aminotri- (2-propylene-2-phosphonic acid), aminotrimethylenephosphonic acid,
Formula (III): phosphonosuccinic acid, methylphosphonosuccinic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid. 10. Additive according to claim 9, characterized in that it is phosphonic acids or their water-soluble salts of the general formula (I) and / or (III) contains, preferably in each case at least one phosphone acid of the formulas (I) and (III), in particular 1-hydroxyethane-1,1-di phosphonic acid and 2-phosphonobutane-1,2,4-tricarboxylic acid become. 11. Additive according to claim 10, characterized in that it is a Phos phonic acid or its water-soluble salts of the general formulas (I) and (III) in a weight ratio of 1:10 to 10: 1, preferably 1: 1 to 10: 1, in particular 6: 1 to 9: 1 contains. 12. Additive according to one or more of claims 1 to 11, characterized ge indicates that the weight ratio of the carboxylic acids of the group a) to the phosphonic acids of group b) 1: 1 to 5: 1, preferably 2: 1 to 4: 1. 13. Additive according to one or more of claims 1 to 12, characterized ge indicates that a defoamer solution is used as the aqueous solution c) is set. 14. Additive according to claim 13, characterized in that the defoamer a proportion of 1 to 25 based on the total additive, preferably makes up 10 to 20, in particular 13 to 18 wt .-%. 15. Additive according to one or both of claims 13 and 14, characterized in that the defoamer is selected from the group of polyethylene glycol ethers of the general formula (IV) R⁴-O- (CH₂-CH₂-O) _n -R⁵ (IV) in which R⁴ is a straight-chain or branched alkyl or alkenyl radical with 8 to 18 C atoms, n is a number from 7 to 12, preferably from 8 to 10, and R⁵ is an alkyl radical with 4 to 8 C atoms, in particular with 4 C- Mean atoms. 16. Additive according to one or more of claims 1 to 15, characterized ge indicates that the aqueous solution c) additionally one or more Nonionic surfactants based on ethoxylation and / or propoxylation pro products of fatty alcohols or fatty amines, preferably ethoxylation products of fatty amines, in particular reaction products of fatty amines contains with 10 to 18 carbon atoms with 8 to 16 moles of ethylene oxide, where the nonionic surfactant or surfactants has a proportion based on the total additive make up from 1 to 6, preferably 2 to 4 wt .-%. 17. Use of the additive according to one or more of claims 1 to 16 to reduce glass corrosion in aqueous, an alkali metal have hydroxide content of 0.5 to 5, preferably 1 to 3 wt .-% the cleaning solutions for the mechanical cleaning of glass bottles, characterized in that the cleaning solutions contain Have active ingredients, which is adjustable in that the Addi tiv in such quantities to the cleaning solution that the content of Cleaning solution on carboxylic acids of group a) 100 to 1,000 mg / l, preferably 200 to 800 mg / l, in particular 300 to 600 mg / l and an Group b) phosphonic acids 50 to 400 mg / l, preferably 75 to 200 mg / l. 18. Use according to claim 17, characterized in that the fla with the cleaning solution at temperatures between 40 and 90 ° C, preferably between 55 and 85 ° C for a period of 1 to 30 Minutes, preferably 3 to 20 minutes.