US2992186A - Detergent compositions - Google Patents

Description

f net-tn July 11, 19st 6 xm Marh Ed ir ii Q s it via e sten, romrna, oedemaselgnor m aknebohe t Becket-Helios, Stockholm, Swedur, a

tion of Sweden No Drawing. Filed Oct. 1, 1956, Ser. No. 612,976

Claims priority, application Sweden Oct. 3, 1955 4 Claims. (Cl. 252-435) The present invention relates detergent compositions and more particularly a detergent composition which is better suited for various purposes than prior art detergent compositions.

For many purposes it is desirable that detergent cornpositions when dissolved in water exhibit a pH value which is at or moderately above the neutral point, e.g. within the range of- 7 to 9. This applies e.g. in the case of dish-washing compositions, since at higher pH values fatty substances; lccithin's etc. present'in the skin are saponified, so that the skin becomes dry. Thus, a composition tending to give a lower pH value is milder to the hands of the user. Another case where a low pH is desirable is the washing of painted surfaces because more strongly alkaline agents may have a degrading effeet on substances present in the paint. Another application where a low pH. is favorable is thewashirrg of' garments made of wool and other proteinaceous fibres, which are washed at a relatively low temperature (usually not above 40' C.), since such fibres are sensitive to a higher alkalinity and furthermore dyes may be attacked at a higher pH. This is also true as regards the dyes in colored gan'nentsmzdc from other types of fibres than the aboverncntioned which are commonly washed at a temperature of about 40-60 C.

On the other hand, in the case of high temperature washing (washing of cotton and linen goods, and the like) it is desirable to have a higher pH value. The cellulosic fibres are less susceptible to attack by alkali, and furthermore the higher pH is advantageous for the' detergent action. .The dirt consists to a major portion of fatty acids, in which solid particles (soot and dust of various types) are embulded. The washing process consists primarily in a saponification of the fatty acids, whereby the solid dirt is also detached. The saponification occurs most readily at a pH of 9.5 or above but since the cellulosic fibres are not entirely insensitive to alkali a pH of about it is usually not surpassed.

The main obiectof the present invention is to provide a detergent composition which in aqueous solution at a lower temperature, eg. up to about 50 or 60 C., maintains a pH within the range of about 7.5 to 9.5, preferably about 8.5, during at least a substantial period of time, l' 'zrt'after some time of residence at a higher temperature (cfg. about 80 to 100' C.) obtains a pH within the range of about 9.5 to 11 preferably 10 to 10.5. This object is realized by incorporating magnesium oxide in the composition.

The invention is broadly applicable to detergent compositions corny-rising as the active detersive ingredient a synthetic detergent of anionic or nonionic type. Examples of anionic detergents which may be used in compositions embodying this invention, include alkyl aryl- "atoms, such as lruryl sulfate or lauryl' sulfonate; and higher fatty r-cio amides, in which the acyl group contains from 8 to 20 carbon atoms, such as tallow fatty facid amide, cocoa fatty acid amide and the like. fire .sulfonates and sulfates referred to above are commonly times the amount of magnesium oxide or to 40% by sodium sulfonates, although the corresponding salts of ammonium or organic bases, such as, e. ethanol amine,

triethanol amine and the like, may also be used. Ea

amples of nonionic detergents which may be included in compositions 'acoording to'this invention, include polyglycol others of higher aliphatic alcohols and polyglyc'ol others of higher fatty acids, inwhich thealcohol group and the fatty acid group respectively compr'ues from 8 to 20 carbon atoms and which contain to 50 ethylene oxide (CH,CH O) units per molecule. A great number of anionic and nonionic synthetic detergents of the above and other types and processes of preparing them are well-known in the art and described in the technical and patent literature. It will be understood that insofar as the present invention is concerned the type of detergent is not essential, since the pH increase centemplated by this invention is not dependent on the detergentused. ltistobenotedthatsoapsarenotsuitable since they tend to impart a toohigh pH value per se. The amount of nonionic or anionic synthetic detergent will usually be about to 50% by weight of the detergent composition, preferably about 15 to (on a dry basis).

In addin'on to the synthetic nonionic or anionic dotergent, the detergent compositions contemplated by this invention comprise an alkali metal phosphate which acts as a builder. As phosphates which may be used there may be mentioned sodium or potassium salts of ortho, meta, poly and pyro-phosphoric acids, e.g. sodium hemmetaphosphate, sodium pyrophosphate, sodium triwlyphosphate (Na l O disodiurn orthophosphate etc.

The amount of phosphate will usually be about 25 to I by weight of the detergent composition (on a dry basis).-

In accordance with the present invention it has been found that a detergent composition of the type above referred to containing anonionic or anionic synthetic deurgent ands phosphate and formulated so that its pH when dissolved in water is within the range of to 9.5 may be imparted the characteristic of rapidly obtaining a pH of 9.5 to 11 when the solution is heated (eg. to to (I), while no or at least only a slow increase in pH occursat room temperature or slightly elevated temper-attire (e.g. up to 60' C.), by incorporating magnesium oxide in the composition. When the solution is heated, the magnesium oxide reacts with the alkali metal phosphate to. form alkali and magnesium phosphate which is less dlmociated than the alkali metal phosphate, whereby pH will increase. Since this reaction occurs only slowly at a lower temperature, there will be only a slow increase in pH at room temperature. The amount of magnesium oxide may be about l to 10% by weight of the detergent esmpositiontcn a dry basis). t

It has also been found, inaccordance with two preferred embodiments of the invention, that the desired eficct may be improved with respect to the constancy of the pH value at a lower temperature in two difi'erent ways.

In one preferred embodiment, an alkali metal bicarbonate is incorporated in addition to the magnesium w p i g yr the alkali metal bicarbonate minimines the increase in pH at a lower temperature but doea not prevent the dsired pH increase at a higher temperature. The amount of bicarbonate may be about 5 to 20 weight of the detergent composition (on a dry basis).

- In the other preferred embodiment, the magnesium" oxide is added in the form of a powder the individual W particles of which are coatedwith a substance which melts and is dispersed or dissolved in the washing eoluat about $0 to 60 C, whereby the magnesium oxide ,L.

40x; erases uponinaeaseinamperatureabouethemcitingpointof the coating substance, will be releasedand will provide thedesiredpI-Iincrease. Asthiscoatingsubstanceitis mainsimdivcermaskedatalowutempentmbjut mlfmieacidareaddedtomlitcaoiu Water 4 the withagltatiommkgof per ee possible to us my fo with I will-bk 5 solution followed by 850 kg. of an aqueous piste com- 8 P -l- P -m n is pfl ke 9 33% of a detergent mixture consisting of 5 parts P I ma which is )dvlnmgwu! for of sodium dodecylbenzene sulfonate and 2 parts of sodium W 8 n. since such an inert subs nce Pinfin cetyl alcohol sulfate, to which paste there have previi molly 1 load for the deterrent wmposmonr ously been added kg. of a technical sodium carboxy i reason it i p erred to use as the coating substance 10 methylcellulose (67% of NaCMC, the remainder being u y 10011015 blvinl I lmhini 9 Wimin by-produot salts and water), 14 kg. of a 40% aqueous som "fund -l- W W e lution of ethylene diamine tetraacetic acid and 0.76 g. of which p n: ind dissolution in the detergent solu- '4.4' bis-(Zl-diaminotriazinylkamino)stilbene-2.2'-disu1- tion exhibit a certain dirt dispsrsinz action- Other hfonic acid as an optical brightener. The resulting slurry stances having a similar effect areiethylene oxide nddt- 18 i mym 0 f Md tion products of the above-mentioned fatty alcohols com- 250 k; of h powder are mixed i h 57 k; f 4m 1 G -2- 1 l0 4 l Oxide mils W perbontte and 36 kg. of a masked magnesium oxide molecule of fatty alcohol. The coated magnesium oxide Powder comprising 55% of magngsjum oxide d 45% W suitably P 9 y i l magnesium cetyl alcohol: This masked magnesium oxide powder d P with 1110K"! coating submu- Hi- W a9 is obtained by stirring magnesium oxide powder into 1001101. Ind spraying the fl into 6014 i that molten eetyl alcohol and spraying the mixture into cold the molten coating substance solidifies and forms a film i Hound magflcsium p P p 12 kg. of washing were added to a washing machine of mbslallm may such that 1 together with 50 liters of water and 210 g. of the powder der contains to 757 of MgO and 75 to 25% of the 25 prcparcd as above 1 m h H f h incoating material. by s m y. the composition a 25' c. was 8.2. The contents of the machine were is 40 60% 0f and-60 40% of the coming heated to 85' C. in minutes whereupon the pH had stance, by weight. The magnesium 0 6 9 be in increased to 9.2. After 15 minutes at 85' C. pH was 9.8. such a coated form even when bicarbonate is present, al- In moth washing a 40- C, h H bm though the importance of the coating is less in this case. 30 daily m To obtain the lower pH value desired at the lower tem- Example 2 perature, it may in many cases be desirable to admix acidic substances. To this end it is known to use as the g f a g gg a phosphate sodium acid pyrophosphate e,H,P,o, pfragrap amp e m which may also be used in compositions wrdinzlo drum perborate and 0.72 of a masked magnesium this invention. Since however this salt has a relatively (cmainmg 40% of M30 and of hol). The m'mure was dissolved in 2 liters of water and strong bufiering action, which may counteract the desired m 1 w boiled in a to cum, with 200 of PH x g f l giff #551332: isl iich ias heavily s i l ed 51m fatty acids The not comcasmar'e as can emmanyeaseatmny in certain cases be more advantageous to employ a small q PH g f zg i? ;c o o c amount of a strong acid, such as sulfuric acid, to obtain (10 mmmcs) ct fgi' gz g gf i zg 10% by neg fizi itie fige zn wfiit 1 2 we: 0 e rem eona asts.

in addition to the above mentioned ingredients the de- P PH was hciftmg mo wgwt compositions of this invcnfinn may contain my 5 minutes) it was 8.1 and after 15 minutes at 100 C. it other desired ingredients which are common in detergent 1 compositions of thetype here contemplated. Thus, the Gi d f p gg of WE-11 g conposmon tflually comlprises a $1gh-molecularu1wc1t gg; g ig ms 1 p rustanee,su asaceuoseeenln car e sodium salt of carboxymethyl cellulose, rg ol vi lw tions may be prepared in substantially the same manner pyrrolidone, e.g. in an amount of 0.5 to 2% by weight the mpqsmon P i 1, y makmg an M 9" of the mixture (on a dry basis). Other additives which of QHPERdWHlS 9 f i gfl are frequently present are silicates, such as water and blcarbmmm any), p y s' c (e.g. 2 .to 1% other alkali metal salts, such as Sodium q a n d blending the pp with p sulfate (e.g. s to 20%), a perborate (e.g. s to 20% or hom a m y bwarbona-te- T other bleaching agents, stabihzers forthe pcrborate, e.g. Optical bughknfi mmfiomd m the p bclfw 1! ethylenediamine tetrafhcetie acid, amlgcucirsientodges fi ozdfitamge 1. th'lhueistetrcm iitOgxand (so-ceded o tical bri, tenors; e.g. 0. o et 9 n 1 ca S= W1 1m in additives of of course posn'hle without departin from pics 4, 5 and 7 shows the number of ethylene mode the spmt and scope of the invention. It will noted, 5 111113 Present P" mplecule 0f the 9 however, that greater amounts of substances which tend Pound R i P given an 2 to give high pH values already at a low temperature will 1: solution: mwnmz 4 c P" hm of the compositions not be included, as also substances which would tend to 5:45p]: 3 interfere with thereactiondesired at the higher temperam me compositions of this invention are preferably prov 3 {limit 20 pared in the form of a powder, althoughthey may also lf w be prepared in the form of liquids. When used 21 wash 2 clzg l fglg 10 ingpurposeganamountofnboutltologot eoom- 1mm!!! Y positions (on a dry basis) will be dissolved in 1 liter of Sodium silicatxeldiwater glass, NaO-3.3S iO;) water. Magnesium o 'lhe hxventionillusnated, but not restricted by the Sodium perborate '1 folio p e L Sodiumsulfate 2o Example 1 Optical-brighten: 0.06

solution there are added,

sodium tripolyphosphate (Na,P,O,,), the temperature being kept below 70' C. .Therwpon, 350 kg. of sodium sulfate are added to the NUlhem compositionwhen dissolved in w... of

temperatnrehasnpHofSJ. Afterhalfanhourntzs' C.,thepH is 8.9,after nnhourstSO' C. 9.5, nnddta haltsnhouratl'dO'C. 10.0.

Example 4 Pence Sodium dodecylbenzenesulfonste g Nonylphenol polyglycol ether (20130) Sodium u'ipolyph'osphote 30 Sodium bicarbonate 25 Sodium carboxymethylcelluloae 1 Sodium silicate (water glass) 4 Sodium perbcnte 12 Masked magnesium oxide (50% MgO, 50$

cetyl alcohol) 3 Sodium sulfate 2.5 Optical brightener 0.06 Water Remainder When dissolved in water of room temperature and up to 60' C., this composition gives a pH of about 9.0. After half an hour of boiling of the solution, its pH increases to 10.0.

Example 5 Percent Stcaryl alcohol polyglycol ether (30Et0) 15 Sodium tripolyphosphate 35 Sodium bicarbonate 25 Magnesium oxide 2 Sodium earboxymethylcellulose 1 Sodium silicate (water glass) 6 Sodium pe'rborate 8 Sodium sulfate 5 Optical brightener 0.05 Water Remainder This composition, when dissolved in water of 25' C. has a pH of 9.3. After heating to 100' C. the pH increases to 10.3.

Masked" magnesium oxide (50% MgO, 50%

stearyl alcohol) Sodium sulfate 15 Water 7 Remninda' E'her-dissolvedinwatercfZS'Qthiscnmpcsiticn shows pH 9.4, after heating to 100' C. 911 10.5.

What is claimed is: 1

1. A detergent composition comprising to 50% d at least one alkali metal phosphate selected from fin group consistingof sodium and potassium salts of orthophosphoric acid, metaphosphoric acid, polypbospboric acid and pyropbosphorie acid, 1 to 10% of magnesium oxide, and 15 to 50% of a detergent selected from the group consisting of a nonionic non'soap synthetic org'am'c detergent and an anionic non-soap synthetic organic dctergent, said compodtion having a pH within the range of 7.5 to 9.5 when admixed with water at a temperature below approximately 60' C, said magnesium oxide being Water glass 5 Sodium carboxymethylcellulose 0.5 Sodium perborate 14 Sulfuric acid 4 Sodium sulfate 12 Optical brigbtener 0.06 Water Remainder When dissolved in water of 25' C., this composition had pH 8.5, after heating to 100' C. pH 10.0.

Examp e 7 I Percent Tall oil acid polyglycol ester (ZSEtO) 17. Sodium tripolyphosphate 20 Sodium hexametaphosphate 10- Sod um bicarbonate 20 Masked magnesium oxide (60% MgO, 40% ccty alcohol) Polyvinylpyrrolidone Sodium perborate 10 prescnt in an amount providing a pH within the range of 9.5 to 11 when said composition is admixed with water at a temperature between approximately 80 and 100' C., said magnesium oxide being present in the form of a powder the particles of which are coated with an organic coating substance which is solid and insoluble in water at a temperature below approximately 60 C. to prevent said magnesium oxide from dissolving in said solution at a temperature below the last mentioned temperature, said organ'iocoating substance melting at a temperature of to C. to provide for dissolving c! said magnesium oxide in water at a temperature above approximately 60 C., said organic coating substance being present on the particles of magnesium oxide in an amount between 25 and by weight of the coated magnesium oxide.

2. A detergent composition as in claim 1 which also comprises an alkali metal bicarbonate.

3. A detergent composition as in claim 1 in which said magnesium oxide particles are coated with s. flit! alcohol melting at 50 to 60 C.

4. A detergent composition as in claim 3 in which said fatty alcohol is cetyl alcohol.

References Gted the tile of this patent UNITED SIA'IES PATENTS 856,672 Best et a1. June 11, 1907 871,612 Nesfield Nov. 19, 1907 980,936 Federer Ian. 10, 1911 1,155,102 Schmidt Sept. 28, 1915 2,196,901 Ham Apt. 9, 1940 2,218,031 Reicbert ct x1. Oct. 15, 1940 2,338,268 Stossel Ian. 4, 1944- 2,372,402 Stokes Mar. 27, 1945 2,497,057 Pepe et aL- Feb. 7, 1950 2,498,343 Rider et a1. Feb. 21, 1950 2,498,344 Rider eta]. Feb. 21, 1950 2,513,997 Gibb July 4, 1950 2,678,303 Bonewitz et al. May 11, 1954' 2,763,618 Hendrix Sept. 18, 1956 2,765,239 ,Siegrist Oct. 1956 OTHER REFERENCES HandbookofChemistrymdPh'ysics, 37thed..pp.542, 543, pub. by Chemical Rubber Pub. (Jo-I Cleveland (1955).

Mil/IMMMMMYPLQQ-

Claims (1)

1. A DETERGENT COMPOSITION COMPRISING 25 TO 50% OF AT LEAST ONE ALKALI METAL PHOSPHATE SELECTED FROM THE GROUP CONSISTING OF SODIUM AND POTASSIUM SALTS OF ORTHOPHOSPHORIC ACID, METAPHOSPHORIC ACID, POLYPHOSPHORIC ACID AND PYROPHOSPHORIC ACID, 1 TO 10% OF MAGNESIUM OXIDE, AND 15 TO 50% OF A DETERGENT SELECTED FROM THE GROUP CONSISTING OF A NONIONIC NON-SOAP SYNTHETIC ORGANIC DETERGENT AND AN ANIONIC NON-SOAP SYNTHETIC ORGANIC DETERGENT, SAID COMPOSITION HAVING A PH WITHIN THE RANGE OF 7.5 TO 9.5 WHEN ADMIXED WITH WATER AT A TEMPERATURE BELOW APPROXIMATELY 60*C., SAID MAGNESIUM OXIDE BEING PRESENT IN AN AMOUNT PROVIDING A PH WITHIN THE RANGE OF 9.5 TO 11 WHEN SAID COMPOSITION IS ADMIXED WITH WATER AT A TEMPERATURE BETWEEN APPROXIMATELY 80 AND 100*C., SAID MAGNESIUM OXIDE BEING PRESENT IN THE FORM OF A POWDER THE PARTICLES OF WHICH ARE COATED WITH AN ORGANIC COATING SUBSTANCE WHICH IS SOLID AND INSOLUBLE IN WATER AT A TEMPERATURE BELOW APPROXIMATELY 60* C. TO PREVENT SAID MAGNESIUM OXIDE FROM DISSOLVING IN SAID SOLUTION AT A TEMPERATURE BELOW THE LAST MENTIONED TEMPERATURE, SAID ORGANIC COATING SUBSTANCE MELTING AT A TEMPERATURE OF 50 TO 60*C. TO PROVIDE FOR DISSOLVING OF SAID MAGNESIUM OXIDE IN WATER AT A TEMPERATURE ABOVE APPROXIMATELY 60*C., SAID ORGANIC COATING SUBSTANCE BEING PRESENT ON THE PARTICLES OF MAGNESIUM OXIDE IN AN AMOUNT BETWEEN 25 AND 75% BY WEIGHT OF THE COATED MAGNESIUM OXIDE.