US 3686127 A
Description (OCR text may contain errors)
AU 165 EX 27/66 Cl. 011a 7/18, 7/56 vs. CI. 2: 2- 9,
10 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula OCOR where X is C, preferably C alkyl or acyl; R is H or C alkyl; M is alkali metal, ammonium or substituted ammonium. The compounds undergo perhydrolysis with aqueous hydrogen peroxide to give percarboxylic acids which are good low-temperature bleaching agents. As well as being bleached precursors the compounds and their perhydrolysis products have detergent properties.
The compounds are therefore suited for incorporation in washing products.
This application is a division of our copending US. application Ser. No. 610,796, filed Jan. 23, 1967, now abandoned.
This invention relates to detergent and bleaching-aid compounds, and to detergent bleaching compositions, in particular to compositions suitable for washing textile materials and removing stains therefrom at relatively low temperatures.
Many detergent compositions contain an inorganic persalt, such as sodium perborate or percarbonate to provide bleaching properties. These persalts provide a satisfactory bleach when the composition is used at or near the boil, but at lower temperatures, e.g., 50-60 C., their action is rather slow, even too slow to be really efiective within the normal bleaching time. This is particularly disadvantageous when using washing machines which operate at this temperature range.
It is known that certain organic esters and acid anhydrides, such as those obtained by the acylation of phenol sulphonates, have the ability to enhance the bleaching action at low temperatures of the persalts. It has also been suggested to provide detergent bleaching compositions comprising such esters, an inorganic persalt and an organic detergent, which is either a soap or a soapless detergent, e.g., an alkylbenzene sulphonate or an alkyl sulphate. In such compositions the organic detergent must be incorporated in a sufficient amount in order that when the composition is used the product washes.
It is an object of the present invention to provide a new organic detergent and bleaching-aid compound of the general formula 3,686,127 Patented Au 22, 1972 in which X is a branched or straight chain alkyl or acyl v radical containing 6-17 carbon atoms, R is hydrogen or an alkyl radical having 17 carbon atoms and M is an alkali metal, ammonium or substituted ammonium radical.
The invention further provides a detergent bleaching composition containing a perhydrate or an inorganic persalt and the above-defined organic compound. By the term persalt is meant a compound, more precisely termed peroxyhydrate, containing hydrogen peroxide of crystallization which is liberated when the substance is dissolved in water. Suitable compountk are alkali metal perborates, percarbonates, perpyrophosphates and persilicates, and also urea peroxide.
It has been found that the compounds according to the invention not only enhance the bleaching action of persalts at low temperatures, but also possess detergent and emulsifying properties comparable to alkylbenzene sulphonate and hence they are detergent actives having simultaneously peracid precursor activity.
During the perhydrolysis reaction the compound according to our invention forms percarboxylic acid and the respective phenol sulphonate at relatively low temperature, of which products the former as distinct from sodium perborate or H O, has eflicient bleaching activity at low temperature and the latter has detergent properties, e.g.,
It has also been found that the solubility and hence the precursor activity of the new compounds according to the invention decreases with increasing chain length of the alkyl or acyl radical X.
On the other hand the washing etliciency increases with increasing chain length of the alkyl or acyl group X.
Suitable compounds giving satisfactory performance are those in'which the alkyl or acyl group X contains 6-17 carbon atoms. Compounds in which X C H or C H CO are almost or completely insoluble in water; compounds in which X C H or C H CO have poor washingefiiciency. The preferred compounds are those in which 'X is a branched or straight chain alkyl or acyl radical containing 8-14 carbon atoms.
It has further been found that the new compounds in which the X radical in the benzene nucleus is in the para positionv to the -OCOR group are particularly effective. Evidently, in compounds in which the X radical is in the ortho position to the -0COR group, the perhydrolysis of the acyl group is hampered by the X radical in the ortho position, probably because of the steric hindrance. This is also implied by the fact that the corresponding ,0- alkyl-phenol sulphonates are always more diflicult to acctylate than the corresponding para isomers.
Although it is known that percarboxylic acids in general are efiicient bleaching agents at lower temperatures, it was found that the best results are only obtained from those compounds which on perhydrolysis release performic to percaprylic acid, i.e., from those compounds in which R is H or an alkyl radical having 1-7 carbon atoms. The preferred compounds are those in which R is methyl, i.e., acetoxy alkylbenzene sulphonates or acetoxy acylbenzene sulphonates, since they are easy to prepare. They may be prepared by sulphonation of an alkylor acylphenol with either oleum, S0, or concentrated sulphuric acid and acetylating the sulphonate with acetyl chloride or acetic anhydride. The alkylphenol may be a commercially avilable alkylphenol, e.g., nonylphenol, octylphenol, etc. or may be prepared from phenol through acylation and Fries rearrangement to acylphenol followed by reduction. Acetoxy-acylbenzene sulphonates may be obtained by leaving out the reduction step.
The new compounds when combined with an inorganic persalt, such as sodium perborate, form detergent bleaching compositions which are suitable for bleaching and cleansing at relatively low temperatures, e.g., 40-60 C., as well as at higher temperatures.
The invention may also be applied to bleaching baths such as are used for treating textiles, to wash liquors, such as are usedin commercial or domestic laundering. Solid detergent hje'ac I compositions may contain, in addition to a persaltand "the compound according to the invention, inert sii ts g d alkaline agents. An additional amount of organic detergent, which may be soap and/or an organic anionic and/or nonionic type soapless detergent, may also be incorporated, but is not necessary.
The advantage of the detergent bleaching compositions according to the invention over compositions which contain mere esters as the bleach enhancer, is that the compound of the invention replaces partially or entirely the use of organic detergent substances, which means that more room is available for other ingredients. Besides, the perhydrolysis products from the compound of the invention are both valuable substances, as distinct from those obtained from the perhydrolysis of known esters of which the alcoholic part is more or less an inactive byproduct.
Detergent bleaching compositions according to the invention should preferably contain one or more alkaline substances in such amounts that similar compositions not containing esters would give a pH value within the range 9-11 when dissolved at the desired bleaching concentration. Suitable alkaline materials are, for instance, alkali metal carbonates, phosphates (including orthophosphates and water-soluble condensed phosphates, such as triphosphates and pyrophosphates) and silicates.
Compositions according to the invention may also contain any of the conventional adjuncts present in detergent compositions. As such may be mentioned supplementary builders, inert salts and organic materials such as alkali metal sulphates, chlorides, carboxymethylcellulose, fluorescent agents and germicidal compounds. The compositions must not contain water in a state and in an amount sufficient to permit appreciable chemical reaction between the components prior to use.
The proportion of the persalt to the new organic compound which may be present in compositions according to the invention will depend on the time and temperature of washing and bleaching, the degree of bleaching required and the concentration of the wash and bleaching solution.
In particular it is preferred to use a slight excess of persalt, but at least an equimolar ratio of persalt to the organic detergent and bleaching-aid compound used is desirable.
It is convenient to measure the precursor activity of compounds according to the invention in terms of peracid yield. The activity of various compounds according to the invention are given in the following Examples 1 to 7.
The determination is based on iodometric titration of the amount of peracetic acid which is formed in an aqueous solution at 20' C. from the precursor and hydrogen peroxide (as sodium perborate). The titration is carried out at C. after Larious periods of time. At this low temperature only the peracid present is titrated, and not the hydrogen peroxide of which an excess is present. As the perhydrolysis is carried out in alkaline medium the peracid formed decomposes during its formation. Therefore, a
maximum is found in the peracid formation as a function of time; this maximum is regarded as a measure for the precursor activity of the compound concerned.
Maxi- Maximum mum Boluperacid alter biiity yield (min- 20 Example percent utes) pH 8-9 1. Sodium 2-acetexy-6-hexylbenzene sulphonate 43 6 Good. 2. Shodlum Z-aeetoxy-G-isooctylbenzene sul- 60 30 Do.
onate. 3. Sodium z-acetoxy-b-nnnylbenzene sul- 45 7 Do.
honate. L odlum 4-acetoxy-3-dodecylbenzene sul- 13 20 Do.
honate. it sodlum 2-aeetnxy-6-dodecylbenzene sul- '26 Do.
This seemingly relatively low yield is partly caused by decomposition oi the formed peracid in alkaline medium during the long reaction time.
EXAMPLE 6 The activity of sodium 2-acetoxy 5 caproylbenzene sulphonate was determined by the same method as described above.
The maximum peracetic acid yield was 39%, which was reached after 10 minutes. The compound was found to have a good solubility at 20 C.
EXAMPLE 7 The activity of sodium Z-acetoxy-S-lauroylbenzene sulphonate was also determined and the maximum peracetic acid yield found was 65% after 10 minutes.
The compound was found to have a good solubility at 20 C.
The above examples clearly show that the compounds in which the alkyl group is in an ortho position in respect of the acetoxy group having a smaller activity than the corresponding para isomers. It should be noted that the above tests were carried out at 20 C. and it is clear that with increasing temperature, e.g., 40-60" C., the maximum peracid yield is reached after a shorter time and the solubility of the compounds increases as well.
EXAMPLE 8 To 63 parts of a spray-dried detergent powder base containing the following materials in parts by weight:
were added 11 parts of sodium perborate tetrahydrate and 26 parts of sodium Z-acetoxy-S-nonylbenzene sulphonate. The resulting composition was thoroughly mixed.
Test swatches stained with immedial black" were washed three times with a solution containing 5.75 g./l. of the above composition during 10 minutes at a temperature of 60 C. with a heating-up time of 20 minutes. As compared with the results obtained with the above composition without sodium Z-acetoxy-S-nonylbenzene sulphonate there was an increase of 5 in whiteness degree.
The sodium 2-acetoxy-5-nonylbenzene sulphonate was prepared as follows:
A mixture of 94.7 g. (0.43 mol) commercial nonylphenol and 48.5 g. (0.475 mol) 96% sulphuric acid was stirred for 5 hours at 60-65 C. After neutralization with 10% sodium hydroxide solution, extraction with ether of the non-converted nonylphenol and evaporation to dryness of the sulphonate solution, the sulphonate was isolated by extracting the evaporation residue with boiling ethanol.
A mixture of 40 g. crystallized sulphonate and 160 ml. acetic anhydride was stirred at C. for 2 hours and excess acetic anhydride was then evaporated under vacuum, followed by sequential extractive evaporation with ether and carbon tetrachloride.
EXAMPLE 9 Washing tests were carried out in a laboratory washing machine at a dosage of 3 g./l. Cotton test swatches soiled with carbon black stain were washed, using a bath ratio of 1:50 at temperatures of 60 and 95 C., respectively, for 30 minutes per wash. The following whiteness degrees were measured after three washes:
whiteness degree at- Composition with sodium elkylbenzene sulphonate. Composition with sodium 2-aeetoxy-5-nony1benzene suiphonate What is claimed is:
1. A detergent bleaching composition which contains 1) an inorganic persalt selected from the group consisting of alkali metal perborates, alkali metal percarbonates, alkali metal perpyrophosphates and alkali metal persilicates, and (2) a conjoint organic detergent and bleach precursor compound of the general formula in which X is a branched or straight chain alkyl or alkanoyl radical containing 6-17 carbon atoms, R is a hydrogen or alkyl radical having 1-7 carbon atoms, and M is an alkali metal or ammonium radical; said inorganic persalt being present in at least an equimolar ratio to the said conjoint organic detergent and bleach precursor compound, and said composition being substantially free of water.
6 2. The detergent bleaching composition defined by claim 1 which further contains (3) an alkaline material selected from the group consisting of alkali metal car bonates, alkali metal orthophosphates, alkali metal triphosphates, alkali metal pyrophosphates and alkali metal silicates.
3. The detergent bleaching composition defined by claim 1 wherein the inorganic persalt is sodium perborate.
'4. The detergent bleaching composition defined by claim 1 wherein in the general formula of the conjoint organic detergent and bleach precursor compound the R radical is methyl and the X radical in the benzene nucleus is in the para position to the OCOR group.
5. The detergent bleaching composition defined by claim 2 wherein the alkaline material is a water-soluble pentasodium triphosphate or tetrasodium pyrophosphate.
6. The detergent bleaching composition defined by claim 2 wherein the alkaline material is a water-soluble sodium silicate.
7. The detergent bleaching composition defined by claim 2 which further contains (4) an organic detergent selected from the group consisting of organic nonionie nonsoap detergents, organic anionic nonsoap detergents and soap.
8. The detergent bleaching composition defined by claim 4 wherein the OCOCH group is in the 2-position and the X radical is in the 5-position in the benzene nucleus.
9. The detergent bleaching composition defined by claim 8 wherein the conjoint organic detergent and bleach precursor compound is an alkali metal or ammonium salt of 2-acetoxy-5-nonylbenzene sulphonic acid.
10. The detergent bleaching composition defined by claim 9 wherein the conjoint organic detergent and bleach precursor compound is sodium 2-acetoxy-5-nonylbenzene sulphonate.
References Cited UNITED STATES PATENTS 3,532,634 10/1970 Woods 202-99X FOREIGN PATENTS 963,135 12/1961 Great Britain 202-99 MAYER WEINB-LATI, Primary Examiner US. Cl. X.R.