Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3947—Liquid compositions
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3945—Organic per-compounds

Definitions

• the present invention is in the field of oxidizing and bleaching agents and relates to aqueous suspensions of peroxycarboxylic acids.
• Peroxycarboxylic acids also known as percarboxylic acids or peracids
• percarboxylic acids or peracids are very effective oxidizing agents, and it has therefore been proposed early on to use these compounds as bleaching agents, as disinfectants or for other oxidation purposes.
• their low chemical stability often stands in the way of a practical use of the compounds, which manifests itself in low storage stability and in the tendency to explosive self-decomposition, in particular in pure form.
• the percarboxylic acids are therefore used together with stabilizing and desensitizing agents, with the aid of which resistance sufficient for practical use can be achieved.
• Examples of solid peracid formulations of this type are given, for example, in Belgian patent 560 389, which deals with mixtures of percarboxylic acids and hydrates of inorganic salts.
• Examples of liquid preparations of peroxycarboxylic acids are given in German Offenlegungsschrift DE 26 12 587 in the form of suspensions of water-insoluble peracids in an aqueous liquid, the viscosity of which has been increased using polymeric thickeners.
• European laid-open publications 160 342, 176 124, 201 958 and 240 481 describe suspensions of water-insoluble peroxycarboxylic acids in aqueous anionic surfactant solutions which are thickened with inorganic salts.
• the suspension form is a convenient form of percarboxylic acids.
• difficulties have arisen not only from the poor chemical stability of the peroxycarboxylic acids, which manifests itself as a more or less rapid self-decomposition of the compounds or as an interaction with the other suspension components, but also because of a lack of physical stability.
• Practically all previously proposed percarboxylic acid suspensions which are sufficiently liquid, tend to sink the peracid particles when standing for a long time, with the result that the suspensions have to be homogenized again before use and that the risk of exothermic self-decomposition increases again in the area of sediments. The task was therefore to look for possibilities for a more stable suspension of water-insoluble percarboxylic acids.
• the invention relates to a suspension of solid peroxycarboxylic acid in an aqueous surfactant solution, in which an ethoxylate of a long-chain aliphatic alcohol with an HLB value between 6 and 11 is contained as an essential component.
• the suspensions according to the invention are notable for exceptional chemical and physical resistance. Another important advantage is the low viscosity of the suspensions, which is retained even at high levels of suspended peracid.
• the suspensions according to the invention contain an essential constituent of a certain type of nonionic surfactants: they are ethoxylates of long-chain aliphatic alcohols, these alcohols preferably having 10 to 18 carbon atoms and preferably being primary and / or unbranched.
• the ethoxylates are obtained in a manner known per se from ethylene oxide and the alcohols in an addition reaction.
• the ethoxylates used according to the invention have an HLB value between 6 and 11, preferably between 7.5 and 10.5. This value, introduced by WC Griffin (Journal of the Society of Cosmetic Chemists, page 249 (1954)), is used today in general for the classification of surfactants, in particular nonionic surfactants.
• HLB E 5 where E indicates the proportion by weight of the ethylene oxide content in the surfactant molecule.
• nonionic surfactants suitable according to the invention are addition products from decanol and 2 to 4 moles of ethylene oxide (EO), addition products from dodecanol or tetradecanol and 2 to 5 moles of EO, addition products from hexadecanol and 3 to 6 moles of EO and addition products from octadecanol and 3 to 7 moles EO.
• EO ethylene oxide
• the ethoxylates are usually produced from mixtures of long-chain alcohols and are also present as mixtures of differently ethoxylated molecules; the average molecular weight (number average) and the average ethylene oxide content are used to determine the HLB value.
• Nonionic surfactants of the alcohol ethoxylate type are present in various phases in a mixture with water, depending on the concentration ratios and temperature.
• the occurrence of the individual phases can be followed by means of viscosity observations and with the aid of the polarizing microscope and is usually recorded in the form of a phase diagram draws.
• Particularly suitable for use in accordance with the invention are those nonionic surfactants of the alcohol ethoxylate type in which the melting point of the lamellar phase is higher than the melting point of the hexagonal phase.
• the melting point is the highest temperature at which the respective phase can still be observed.
• Those surfactants in which the melting point of the hexagonal phase is below 15 ° C. are particularly preferred.
• the concentration of alcohol ethoxylate can be varied within wide limits.
• the viscosity of the suspension generally increases with the concentration of nonionic surfactant and, if desired, can be brought up to a pasty consistency.
• the concentration of alcohol ethoxylate in the suspensions is therefore preferably between about 5 and about 30 percent by weight, based on the total weight of the finished dispersion; the range from 5 to 20 percent by weight is particularly preferred. It is noteworthy that the suspensions have high physical stability even at relatively low viscosities.
• part of the nonionic surfactants is replaced by betaine-type surfactants.
• Betaine surfactants contain a hydrophobic part, a quaternary ammonium group and an anionic group in their molecule. They are usually prepared by reacting long-chain tertiary amines, which preferably have a linear alkyl radical having an average of 12 to 18 carbon atoms, by reaction with sultones, for example propane sultone, or, preferably, by reaction with halocarboxylic acids, for example chloroacetic acid.
• Examples of such betaine surfactants are: Dehyton (R) AB 30: Coconut alkyl-N + (CH3) 2-CH2-CO2 ⁇ Dehyton (R) K: Cocoacyl-NH- (CH2) 3-N + (CH3) 2-CH2-CO2 ⁇
• betaine surfactants By using the betaine surfactants it is possible to get by with less surfactant in the suspensions.
• the effect of the betaine surfactant becomes clear even at a weight ratio of betaine to nonionic surfactant of 1:10, even more above a weight ratio of 1: 4.
• a weight ratio of 4: 1, preferably 2: 1 and in particular, can be regarded as the upper limit 1: 1.
• the peroxycarboxylic acids suspended according to the invention can be aromatic, aliphatic, alicyclic or heterocyclic percarboxylic acids which are at least partially, preferably more than 50% and in particular more than 80% undissolved in the aqueous suspension liquor at room temperature.
• the percarboxylic acids should preferably have melting points above 50 ° C. in pure form. Particularly preferred are those peracids which are also solid in technical quality, ie with a clear content of the underlying carboxylic acid, up to 50 ° C.
• the aliphatic compounds and in particular the monopercarboxylic acids with 10 to 18 carbon atoms and the alpha, omega-diperoxycarboxylic acids with 9 to 13 carbon atoms are particularly preferred.
• the aliphatic compounds and in particular the monopercarboxylic acids with 10 to 18 carbon atoms and the alpha, omega-diperoxycarboxylic acids with 9 to 13 carbon atoms are particularly preferred.
• the amount of suspended peracid in the preparations according to the invention can be very high without an inadmissible increase in viscosity.
• Peracid levels in the suspensions of up to 30 percent by weight and also above, based on the total weight of the suspension, can easily be achieved. Amounts of peracid up to about 25 percent by weight are common.
• the lower limit of the peracid content in the suspensions is not critical and is primarily determined by economic factors. Peracid contents above 5, usually above 10 percent by weight, based on the total weight of the suspension, are customary, but in special cases, significantly lower concentrations, for example 1 or 2% by weight, can also be considered.
• a further advantage of the preparations according to the invention is that the particle size of the suspended peracid can vary within wide limits without the suspension stability being impaired. Particle sizes between approximately 1 and approximately 100 ⁇ m, in particular 5 to 50 ⁇ m, are customary. H. in general, the percarboxylic acid can be suspended in the particle size as it is obtained in the synthesis process.
• the suspensions additionally contain hydrogen peroxide, preferably in amounts between 0.1 and 20% by weight, in particular between 2 and 15% by weight.
• This additive can contribute to the chemical stabilization of the peracids and moreover provides a stronger effect, especially when the suspensions are used as bleaching agents, especially at elevated temperatures.
• the dispersions can contain auxiliaries and additives, provided these substances do not impair the stability of the dispersion. Special mention should be made of chelating agents to render harmless Heavy metal traces, which can be contained in the dispersions in amounts of up to 2 percent by weight, preferably 0.01 to 1 percent by weight. All complexing agents customary for the stabilization of peroxycarboxylic acids can be used; but preferably polyphosphonic acids, such as 1-hydroxyethane-1,1-diphosphonic acid or ethylenediaminetetramethylenephosphonic acid, and their salts are used.
• inorganic salts such as those that can be contained in technical products, in particular from the production of percarboxylic acids.
• the content of inorganic salts in the dispersions is preferably below 1.5 percent by weight, in particular between 0.1 and 1 percent by weight.
• Buffer substances can also be added to the suspensions with the aim of keeping the pH of the dispersions safely in the desired weakly acidic range, ie in a range of the pH between 1 and 7, preferably between 1.5 and 5.
• Anionic surfactants or cationic surfactants are not required as auxiliaries in the dispersions, but can be present in small amounts as long as they do not adversely affect the rheological properties of the dispersions and the stability of the peracids.
• the peracid dispersions can contain oxidation-stable dyes, viscosity-regulating substances, for example polymeric carboxylic acids, such as polyacrylic acid or acrylic acid-maleic acid copolymers, hygroscopic substances and others.
• the total amount of auxiliaries and additives in the dispersions is preferably not more than 10 percent by weight and is in particular between 0.01 and 5 percent by weight.
• the production of the suspensions according to the invention presents no problems.
• the suspensions can be obtained without extraordinary aids by mixing the components, and the order of addition can be chosen almost arbitrarily.
• the suspension medium composed of surfactant, water and, if appropriate, further constituents can first be mixed in and then the peracid can be stirred in. However, it is also possible to first mix the peracid with other constituents and then stir this mixture into water or a solution of the remaining constituents into water.
• premixes that are safe to handle, such as those obtained in the production of the percarboxylic acids.
• Such premixes contain, in addition to water, about 10 to 95 percent by weight of the solid peroxycarboxylic acid, in addition, if appropriate, portions of the underlying carboxylic acid (as a result of inadequate conversion during conversion into the peracid), traces of hydrogen peroxide, mineral acid and inorganic salts, in particular Na2SO4 and MgSO4.
• a particular advantage is that these peracid premixes do not have to be dried in order to prepare the dispersions according to the invention, but can be used in the moist form which is initially obtained in the preparation.
• the dispersions are filled into bottles, jugs or canisters or into tubes and similar containers after production.
• the dispersions according to the invention are easy to handle preparations of the peroxycarboxylic acids and can be used in almost all cases instead of solid percarboxylic acid preparations.
• the dispersions are mainly used as concentrated bleaching agents for hard surfaces and especially for textiles.
• the dispersions can be used in concentrated form or, if necessary, after dilution alone, but is it is often desirable to first add the dispersions to a treatment liquor which also contains other active ingredients, so that the bleaching or disinfecting action of the peracids can be used in one treatment course at the same time as the effects which this treatment liquor exerts alone.
• the suspension is preferably used in amounts such that the peracid concentration in the working solution is between 30 and 5000 ppm, in particular between 100 and 2000 ppm.
• a particularly preferred area of use for the peracid dispersions according to the invention is the addition as a bleaching agent to wash liquors for textile laundry in the household and in commerce. Due to their consistency, the peracid suspensions are not only suitable for manual dosing, but also for automatic dosing using suitable devices, as is preferred in the commercial sector.
• the suspension was stored in glass bottles at room temperature. The suspension proved to be extremely stable physically. After 190 days there was no visible decrease in the peracid particles and no sediment. The chemical stability of the peracid was determined on a separately stored sample after prior homogenization by potentiometric titration. The peracid content decreased very slowly and was: after days % By weight peracid 0 25th 71 24th 190 22
• Example 2 a suspension of 38.5 g of the technical peracid described therein was prepared in a solution of 4 g of dehydol (R) LS4 and 1 g of Dehyton (R) AB30 in 56.5 g of water.
• the viscosity of the suspension was 240 mPas (measuring conditions as in Example 1).
• the pH was 2.2.
• the suspension also showed very good stability: after 120 days of storage at room temperature, no decrease in the peracid particles and no sediment was discernible.
• the peracid content (potentiometric) had only decreased from 25 to 19% by weight.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Detergent Compositions (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (8)

Citations (2)

• 1989
  • 1989-03-06 DE DE3907131A patent/DE3907131A1/de not_active Withdrawn
• 1990
  • 1990-02-26 JP JP2504645A patent/JPH04503920A/ja active Pending
  • 1990-02-26 KR KR1019900702393A patent/KR920700281A/ko not_active Application Discontinuation
  • 1990-02-26 EP EP90904617A patent/EP0462186A1/fr active Pending
  • 1990-02-26 EP EP90103648A patent/EP0386566A1/fr not_active Withdrawn
  • 1990-02-26 WO PCT/EP1990/000317 patent/WO1990010688A1/fr not_active Application Discontinuation
  • 1990-03-05 PT PT93340A patent/PT93340A/pt not_active Application Discontinuation

Patent Citations (2)

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