PROCESS FOR CHEMICAL CLEANING - Patent Review GB19720037743 19720814

Description

(54) PROCESS FOR CHEMICAL CLEANING

(71) We, CHEMISCHEFABRIK KREUSSLER & CO. GmbH, a

German body corporate organised under the laws of Germany of87-95 Rheingaustrasse, Wiesbaden-Biebrich 6202, Germany, do hereby declare the invention, for which we pray that a patent may be granted tous, and the method by which it is to be performed, to be particularly described in and by the followingstatement:

This invention relates to a chemical cleaning process, using organic solvents and surface-active compounds.

The use of organic solvents, e.g. chlorinated hydrocarbons, benzene or fluorinated carbon tetrachlorides, in conjunction with cleaning intensifiers, for cleaning textiles is well known. It is alsoknown that wet-fixed soiling effects cannot be satisfactorily removed by using such solvents above, for example, pigment soil, which adheres to the textile material by water-soluble substances, suchae sugar or salts, or water-soluble stains, such as stains from foods and beverages are not removed in practice by an organic solvent.

The usual commercial cleaning intensifiers contain between 4 and 30 30 � by weight, often 8 to 14% by weight of water, but it is only by addition of further quantities of water to cleaning solutions which contain cleaning intensifiers that the success of the cleaning as regards wet-fixed soiling is substantially improved. The addition of water is usually related to the weight of the material to be cleaned and amounts to 0.5 to 6% and in special cases up to 10% of the weight of the materials. In this connection, it is in principle immaterial whether the water is introduced into the system mixed with the cleaning intensifiers, or separately as pure water, or assteam.

The various known possible operating procedures only differ in the operation of the process as regards the quantities of the added water and the method in which the water is applied. Accordingly, different results are produced as regards the extent of the detachment of so-called wet soil.

The nature and extent of the water addition must be measured according to the properties of the material to be cleaned if disadvantageous effects of the water on the material are to be avoided. For this reason, the materials to be cleaned are usually sorted into several categories before cleaning takes place. Generally, with textiles, a distinction is made as regards at least three classes:

1. Textiles which must be cleaned in the absence of added water;

2. Textiles which tolerate a small quantity of added water without disadvan

tageous consequences, and

3. Textiles which can be cleaned with relatively large additions of water.

The sorting operation generally requires knowledge of materials and experience, and represents an expense as regards labour and equipment.

Those textiles which will only tolerate small or even no addition of water to the cleaning solution are cleaned less satisfactorily regarding wet soiling, than those textiles which permit higher additions of water. Such textiles consequently have to undergo a subsequenthand-treatment (stain-removal) in order to complete the cleaning. This represents additional expenditure of time and additional costs.

It is also pertinent that with some cleaning systems, such as self-operated and coin-operated cleaning arrangements, it is not possible to carry out a differential sort ing of the material depending on its degree of water sensitivity, and thus it is necessary to dispense with an addition of water. In these cases, as with the morewater tolerant textiles included in the load, it is necessary in certain circumstances to accept a lower standard of wet-fixed soil removal.

It is the object of the invention to provide achemical cleaning processwhere-oy wet-fixed soil is removed without the addition of water to the solvent, to the cleaning intensifiers or to the cleaning solution.

The invention provides a process for cleaning soiled articles comprising contacting the soiled article with an organic solvent containing at least one organic surfactant and at least one of the following compounds:

1. Glycerine

2. pentaerythritol

3. an aliphatic amine having 6 to 12 carbon atoms

4. benzoic acid ethoxylate having 2 to 7 mols of ethylene oxide

5. sodium or potassium toluene sulphonate.

There is also provided a composition for use in the chemical cleaning of soiled articles comprising an organic solvent at least one organic surfactant and at least one of glycerine, pentaerythritol, aliphatic amines having 6 to 12 carbon atoms, benzoic acid ethoxylene having 2 to 7 mols of ethylene oxide or sodium or potassium toluene sulphonate.

According to a preferred embodiment of the invention, in the process according to the invention the organic surfactant comprises a compound of one of the formulae.

Type I

Ethoxylated fatty acid amides of the general formula RCONH(CH2CHXO)sH in which R represents a hydrocarbon chain with 12 to 20 carbon atoms and s is an integer of from 1 to 15, e.g. oleic acid amide ethoxylated with 3 mols of ethylene oxide or lauric acid amide ethoxylated with 1.5 mols of ethylene oxide.

Type II

Ethoxylated or non-ethoxylated sugar esters of the general formula (R,--COO),,--B- [(CH,--CH,,-O),OHI.

in which B represents a cyclo-semiacetal of theformula (CHOH)n1, R1 is a hydrocarbon chain having 8 to 19 carbon atoms; n is an integer from 0 to 15; m is an integer from 5 to 7; p is an integer from 1 to 4 and s=(m-2)-p e.g. heptaoxyethylene-sorbitan-monooleate, heptaoxyethylene-sorbitan-trioleate, sorbitan-monolaurate.

Type III

Sulphosuccinic acid esters of the general formula

EMI2.1

in which A represents a hydrocarbon chain with 3 to 18 carbon atoms or an aliphatic amine radical with 3 to 18 carbon atoms, B represents a hydrocarbon chain with 3 to 18 carbon atoms or a monovalent metal ion, M is a monovalent metal ion; e.g. 2ethylhexyl sulphosuccinate-sodium salt semi-ester, monolauryl sulphosuccinic diethylamine-sodium salt

Type IV

Phosphoric acid esters or amidoesters of the general formula

EMI2.2

in which R1 represents an alkyl radical with 2 to 13 carbon atoms or a hydrogen atom, R2 is an alkyl radical with 2 to 13 carbon atoms, a monovalent metal ion or a dialkanol ammonium radical, R3 is an alkyl radical with 2 to 13 carbon atoms or a dialkanol ammonium radical, n represents an integer from 0 to 5, provided that n represents 1 to 5 whenR2 is not an alkyl radical, e.g. phosphoric acid monononyl ester-diethanol ammonium sodium salt phosphoric acid-dinonyl ester diethanol ammonium sodium salt, phosphoric acid monononyl ester-bis-diethanol ammonium salt, phosphoric acid-dinonyl ester-monosodium salt.

Organic surfactants can in principle be added by themselves to organic solvents, but they are however, generally the active principle in "cleaning intensifiers". Cleaning intensifiers are surfactant preparations consisting of organic surfactants with solution promoters and organic solvent diluents. Monohydric and/or polyhydric aliphatic or cycloaliphatic alcohols are typical solution promoters, and hydrocarbons and/or chlorinated hydrocarbons with boiling points above1800C are typical diluents. The proportion of organic surfactants in the compositions according to the invention is preferably from 15 to95%.

It has been found that by using the processes of the invention it is not necessary to add additional water to the solvents either as emulsified with the cleaning intensifier or as free water to the solvent or to the cleaning solution, or in the form of steam before or during the treatment in the solvent and in the cleaning machine. Water which is possibly contained in the cleaning intensifier or the natural water content of the materials to be cleaned, is not considered as a positive addition for the purpose of the invention.

It has also been found that cleansing action of the Types I to IV with respect to water-soluble substances which are insoluble in organic solvents can be increased beyond a purely additive effect (synergistic effect) by mixing more than one of such chemical compounds in the cleaning material. The compounds may also be used with other organic surfactants, e.g.alkylaryl sulphonates, alkyl sulphonates,alkyl sulphates, fatty acid polyglycol ethers, alkylol polyglycol ethers, oralkylphenol polyglycol ethers. The combination of the compounds with other organic surfactants may also be done to influence the consistency of the cleaning intensifiers in order to produce a homogeneous form which is easy to handle, transport and store and which is resistant to temperature change.However, such mixing can also produce certain other desired properties or improve such properties for example, prevent greying, improve the soil carrying power in the cleaning solution, provide a good filtering capacity, a favourable foam behaviour, miscibility and solubility in the solvents used for the chemical cleaning, consistency of the distillation residue, prevention of corrosion on parts of the machines.

The following test results are given to illustrate the effectiveness of the cleaning materials of the invention.

l(a) Solubility of common salt in anhydrous perchlorethylene with a concentration of 3.5 g/l of the hereinafter specified organic surfactant in perchlorethylene, indicated in percent by weight, related to the surfactant.

Oleic acid amide ethoxylated with 3 mols ofEO (Type I) 0.4%

sorbitan monooleate ethoxylated with 7 mols ofEO (Type II) 0.5 %

2-ethylhexyl sulphosuccinate-sodium salt, semi-ester (Type III)0.5%

phosphoric acid semi-ester, mixture of equal parts of monoesters

and diesters with equal parts of nonyl alcohol and di

ethanolamine (Type IV) 0.6%

equal parts of the foregoing surface-active agents

(Type I+III) 0.7%

equal parts of the foregoing surface-active agents

(Type11+111) 1.2%

equal parts of the foregoing surface-active agents

(Type IV+III) 1.3% (b) by comparison: :

nonylphenol polyglycol ether with 3 mols ofEO produced

less than0.1%

nonylphenol polyglycol ether with 5 mols of EO produced

less than0.1%

nonylphenol polyglycol ether with 7 mols of EO produced

less than0.1% (c) a normal commercial cleaning intensifier based onalkylaryl

sulphonate and alkylphenol polyglycol ethers0.3 ,0

EO=ethylene oxide.

Any water present in the aforesaid commercial surfactants was removed before the test byazeotropic distillation.

The removal of the water from the materials for the foregoing tests was only carried out so as to obtain analytical conditions which could be exactly compared.

However, where water was unavoidably present (e.g. natural water content) this has been proved by corresponding technical tests in use to be a harmless principal.

2. Tests under controlled conditions with poplin jackets consisting of cotton-polyester mixed fabrics, in a perchlorethylene cleaning installation confirmed the results of Test I. Lemonade and common salt solution, which were dried on the fabric were used as test stains. The textile material was then conditioned with65"it relative air humidity and cleaned for 15 minutes with cleaning solutions of the concentrations indicated in Test I. The removal of the stains by the materials listed in 1(a) was much better than with the use of a normal commercial cleaning intensified based on alkaryl sulphonate and alkylphenol polyglycol ethers. The comparison was made by visual sampling.

Inthe process of the invention in which cleaning solution comprises an organic surfactant and a compound numbered 1 to 5 typical surfactants include alkaryl sulphonates, alkyl sulphonates, alkyl sulphates, fatty acid polyglycol ethers, alkylol polyglycol ethers, and alkyl phenol polyglycol ethers.

The following test results illustrate the effectiveness of such cleaning materials of the invention.

3. The solubility of common salt in anhydrous perchlorethylene in the presence of a conventional cleaning intensifier (organic surfactant) based on alkaryl sulphonate and alkylphenol polyglycol ether in a concentration of 3.5 g/l to 10.5 mg/l was investigated.

If such a cleaning intensifier contained one of the five aforementioned substances, substantially higher water-solubility values were found, namely: aforesaid cleaning intensifier with a content of:

mg/l

15% by weight glycerine 85

8% by weight pentaerythritol 42

5% by weight dodecylamine 55

15% by weight benzoic acid ethoxylate with 5

mols of ethylene oxide 65

15% by weight toluene sulphonate 60

It has also been found that the chemical cleaning properties can be further enhanced by including organic surfactants and compounds of the Type I to IV, together with aforementioned compounds numbered 1 to 5.

The increase in efficiency is illustrated in the following Examples.

EXAMPLES 1. Substance A

5.0 parts by weight of sodium dilauryl sulphosuccinate

EMI4.1

10.0 parts by weight of ethoxylated sugar ester of the formula

EMI4.2

15.0 parts by weight of ethoxylated fatty acid amide carboxylic acid with 16 carbon atoms with 7 mols of ethylene oxide,

5.0 parts by weight of phosphoric acid ester of 1 mol of phosphoric acid and 2 mols of 2-ethylhexanol, neutralised with diethanolamine,

10.0 parts by weight of dodecylbenzenesulphonic acid, potassium salt,

15.0 parts by weight glycerine,

5.0 parts by weight of isopropanol (solution promoter component),

30.0 parts by weight of perchlorethylene (standardising agent).

2. Substance B

As Substance A, but having 5.0 parts by weight of dodecylamine instead of 15 parts by weight of glycerine.

3. Substance C

As Substance A, but having 15.0 parts by weight of sodium toluene sulphonate instead of 15 parts by weight of glycerine.

4. Substance D

As Substance A, but having 15.0 parts by weight of benzoic acid ethoxylate with 5 mols of ethylene oxide instead of 15 parts by weight of glycerine.

5. Substance E

10.0 parts by weight of nonylphenol polyglycol ether with 9 mols of ethylene oxide,

8.0 parts by weight isopropanol,

8.0 parts by weight pentaerythritol,

22.0 parts by weight ethoxylated sugar ester, as defined in Substance A,

12.0 parts by weightsulphosuccinic acid ester, as defined in Substance A,

40.0 parts by weight perchlorethylene.

As regards the solubility of common salt in anhydrous perchlorethylene with a concentration of 3.5 g/l of the following substance, the following solubility values were produced:

Normal commercial cleaning intensifier based on

alkaryl sulphonates and alkylphenol poly

glycol ethers 10.5 mg/l

Substance A 168.0 mg/l

Substance A without glycerine 88.0 mg/l

Substance B 112.0 mg/l

Substance C 98.0 mg/l

Substance D 102.0 mg/l

Substance E 91.0 mg/l

Substance E without pentaerythritol 63.0 mg/l

Tests under controlled conditions in a 12 kg perchlorethylene cleaning machine were conducted on 10 kg of woollen stockings and stained test fabrics with stains consisting of valerian, meat sauce, cola, cocoa, mayonnaise, milk, make-up, blackcurrant juice, and red wine.With the addition of 5 g/l of substance A to the cleaning solvent, stain removal was20% less than with the conventional procedure with addidon of water.

In the control test, the operation was carried out with the same machine loading, with the same test staining, but with a conventional cleaning intensifier in a concentration of 5 g/l and with an addition of 2% of water, based on the weight of the material to be cleaned.

Practical tests in a 50 kg cleaning machine in an industrial cleaning plant over a period of one week, using 3 g/l of substance A as compared with the use of 3 g/l of a conventional cleaning intensifier with an addition of2% of water, based on the weight of material, and using woollen stockings, showed that the proportion of stain removal for the cleaning with substance A was15% less.

White garments were cleaned in a 30 kg cleaning machine containing perchlorethylene containing 5 g/l of Substance B. For comparison purposes, the same material for cleaning was cleaned by the steam-spraying method, using a conventional cleaning intensifier with a corresponding working concentration and with an addition of3% of water, based on the weight of material. The material after cleaning with solvent containing Substance B was cleaner and had a clearer colour. The proportion for stain removal was considerably less than with the control method.

Corresponding results can be produced with the substances C, D and E.

Furthermore, corresponding results can also be produced if the aforesaid substances A to E contain only onecomponent of the Types I to IV.

The process of the invention has been developed for the chemical cleaning of textiles; it is also equally suitable for the chemical cleaning of leather and fur garments.

WHAT WE CLAIM IS:

1. A process for chemically cleaning soiled articles, comprising contacting the soiled article with an organic solvent containing at least one organic surfactant and at least one of the substances glycerine, pentaerythritol, an aliphatic amine containing 6 to 12 carbonatoms, benzoic acid ethoxylate having 2 to 7 mols of ethylene oxide, or sodium or potassium toluene sulphonate but does not contain additional water.

2. A process as claimed in Claim 1 in which the organic surfactant is a compound of any of the formulae: R-CO-NH(CH,-CH-O),H in which R represents a hydrocarbon chain with 12 to 20 carbon atoms and s is an integer of from 1 to 15,

II (R1-COO)1,-B L(CH,--CH,,-O),OH], in which B represents a cyclo-semiacetal of theformula --(CHOH),,-, R1 is a hydrocarbon chain having 8 to 19 carbon atoms, m is an integer of from 5 to 7; p is an integer of from 1 to 4; n is an integer of from 0 to 15 and s=(m-2)-p,

EMI6.1

in which A is a hydrocarbon chain with 3 to 18 carbon atoms or an aliphatic amine radical with 3 to 18 carbon atoms, B is a hydrocarbon chain with 3 to 18 carbon atoms or a monovalent metal ion, Me is a monovalent metal ion,

EMI6.2

in whichRi is an alkyl radical with 2 to 13 carbon atoms or a hydrogen atom,Ro.

is an alkyl radical with 2 to 13 carbon atoms or a monovalent metal ion,R3 is an alkyl radical with 2 to 13 carbon atoms or adialkanol ammonium radical, n is an integer from 0 to 5, but represents 1 to 5, whenR2 does not represent an alkyl radical.

3. A process as claimed in Claim 1 or Claim 2, in which the organic solvent is perchlorethylene.

4. A process as claimed in any of claims 1 to 3, in which at least one solution promoter and/or organic solvent diluent is present in the solvent.

5. A process as claimed in Claim 4, in which the solution promoter is a monohydric or polyhydric aliphatic or cycloaliphatic alcohol.

6. A process as claimed in Claim 4, in which the diluent is a hydrocarbon or chlorinated hydrocarbon with a boiling point above1800C.

7. A process as claimed in any of Claims 1 to 6, in which the article is a textile, or is made of leather or fur.

8. A process as claimed in Claim 1 substantially as herein described.

9., A process as claimed in Claim 2 substantially as herein described.

**WARNING** end of DESC field may overlap start of CLMS **.