JP2003503588A - Surfactant emulsions and structural surfactant systems - Google Patents

Abstract

  (57) [Summary] A mixture of an ethoxylated nonionic surfactant having an average of 20 to 100 ethyleneoxy groups per molecule and 0.1 to 150 parts by weight of a water-soluble thiocyanate. Particularly peptized surfactants by increasing the lamellar / L2 phase transition temperature.

Description

Detailed Description of the Invention

The present invention relates to the formulation of nonionic surfactant emulsions and structured surfactant suspension systems. In particular, it relates to laundry detergents, especially formulations of laundry detergents used in industrial and commercial washing.

Structural Surfactants Suspending solids in liquids presents problems. If solids differ in density from liquids, they will tend to settle or float. Increasing the viscosity of the liquid can delay, but not prevent, such separation, and high viscosity is generally undesirable. A colloidal system that is small enough (eg, less than 1 micron) for the suspended particles to undergo Brownian motion may be kinematically stable. However, it is difficult or undesirable to mill to such sizes for some solids, and many of them are incapable of holding at this level at the crystal growth or agglomeration planes. , The use of colloidal suspensions is limited.

Adjusting the density of one phase to match that of another is usually not feasible. Moreover, such systems are almost always temperature-labile due to the differential rate of thermal expansion.

[0004] One method of suspension that allows even relatively large particles to be stably suspended is a structural surfactant. This term refers to any suspension of a surfactant mesophase, usually in the lamellar or G phase, alone or more commonly interspersed with an aqueous phase, when the system is at rest. Includes systems that provide a yield stress that is also sufficient to immobilize the particles, but low enough that the system is poured like a normal liquid. Such systems may exhibit a very low apparent viscosity when agitated, pumped or poured, and also suspend particles, sometimes particles of millimeter or larger size. It may be possible to hold infinitely inside.

Three main types of suspension systems have been used in practice, all of which have a surfactant bilayer with a hydrophobic part of the molecule on the inside of the bilayer and a hydrophilic part on the outside of the bilayer. With G phase arranged with (or vice versa). The dual phases are in a side-by-side, eg parallel or concentric arrangement, sometimes separated by an aqueous layer. The G phase (also known as the L _α phase) is identified by its characteristic structure, usually under a polarizing microscope, and / or by X-ray diffraction, which can often detect evidence of lamellar symmetry. can do. Such evidence is for a simple integer ratio 1: 2: 3 and d-spacing (
2π / Q, where Q is the momentum transfer vector) and may include peaks of the first, second and sometimes third order. Other types of symmetry give different ratios, which are usually not whole numbers.

Most surfactants form the G phase at ambient or somewhat higher temperatures when mixed with water in certain proportions. However, such phase G cannot normally be used as a structural suspension system. Useful amounts of solids prevent them from pouring, smaller amounts tend to settle.

The main types of structural systems used in practice are based on dispersible lamellar, spherulite and extended lamellar phases. The dispersible layer plate-like phase is a two-phase system in which the surfactant bilayers are arranged as parallel plates to form G phase domains interspersed with an aqueous phase, forming an opaque gel-like system. They are described in EP 0 086 614.

The spherulitic phase comprises well- delimited spheres, commonly referred to in the art as spherulites, in which the surfactant bilayers are arranged as concentric shells. Spherulites usually have diameters in the range 0.1 to 15 microns and disperse in the aqueous phase in the manner of a classical emulsion, but interact to form a structural system. The spherulite system is EP
0 151 884 in more detail.

Many structural surfactant systems are intermediate between dispersible layered slabs and spherulites and include both types of structures. Systems with more spherulitic nature are generally preferred as they tend to have lower viscosities. Variations on the system of spherulites include spheroids or rod-shaped bodies (sometimes called batonets).

A third type of structural surfactant system comprises an extended G phase. It differs from the other two types of structural systems in that it is essentially a single phase and differs from conventional G phases in that it has a wider d-spacing. The conventional G phase has a d-spacing of about 5-7 nanometers. Attempts to suspend the solid in such a phase cannot be poured or
This results in a hard paste that is unstable and / or both. When the electrolyte is added to the aqueous surfactant, especially the surfactant in the M phase, at a concentration just below that required to form a normal G phase, a d-spacing of 8-20, eg 10-15 nanometers is achieved. An expanded G phase having is formed. The M phase contains aligned surfactant molecules and forms a cylindrical rod of indefinite length. It shows hexagonal symmetry and a unique structure under a polarizing microscope. The typical M phase shows a very high viscosity and therefore appears to be a curdled solid. The M phase near the lower concentration limit (L ₁ / M phase boundary) is pourable but has a very high viscosity and often a viscous appearance. Such systems tend to readily form an expanded G phase, especially with the addition of a sufficient amount of electrolyte.

The extended G phase is described in more detail in EP 0 530 708. In the absence of suspended matter, they are translucent, unlike the opaque dispersive plate lamella or spherulitic phase which is necessarily opaque. They are optionally optically anisotropic and have a shear dependent viscosity. In this case, they are distinct from the L ₁ phase, which is a micellar solution and contains a microemulsion. The L ₁ phase is transparent, optically isotropic and substantially Newtonian. They are non-structural and cannot suspend solids. Some L ₁ phases show narrow angle X-ray diffraction spectra showing evidence of hexagonal symmetry.
Such phases usually have a concentration near the L ₁ / M phase boundary and the addition of electrolytes can form an expanded G phase.

Most structural surfactant systems require the presence of an electrolyte and a surfactant and water to form a structural system capable of suspending solids. However, certain relatively hydrophobic surfactants, such as isopropylamine alkylbenzene sulfonate, are capable of forming spherulites in water in the absence of an electrolyte. Such surfactants are capable of suspending solids in the absence of electrolytes, as described in EP 0 414 549.

[Aggregation] A problem associated with two-phase structural surfactant systems, especially spherulitic systems, is the aggregation of dispersible surfactant structures. This tends to occur at high surfactant and / or high electrolyte concentrations. It has the effect of separating the dispersible surfactant from the aqueous phase, making the composition very viscous and / or unstable.

It has been found that certain amphiphilic polymers act as peptizers for structural surfactants. One type of deflocculant polymer exhibits a comb structure with a hydrophilic backbone and hydrophobic side chains or vice versa. A typical example is a random copolymer of acrylic acid and fatty alkyl acrylate. Comb peptizers are described in a number of patents, for example WO-A-9106622.

A more effective type of peptizer has a surfactant, rather than a comb structure, that attaches a hydrophilic polymeric group at one end to a hydrophobic group. Such peptizers are typically telomers formed by telomerizing hydrophilic monomers with hydrophobic telogens. Examples of surfactant peptizers include alkyl thiol polyacrylates and alkyl polyglycosides. Surfactant peptizer is E
It is described in more detail in P 0 623 670.

A disadvantage of both surfactants and comb peptizers is that the concentration required to peptize to optimum viscosity is critical within a fairly narrow range and varies with temperature.
Too little or too much peptizer causes instability and / or excessive viscosity. As a result, peptized systems tend to separate if the temperature changes significantly. In particular, it tends to form a pronounced bottom layer upon prolonged standing.

One approach to the problem of temperature stability has been to add highly crosslinked polyacrylates (see US Pat. No. 5,602,092). They are difficult to disperse in structural liquids. Our co-pending application of the same date discloses the use of certain copolymers to prevent this bottom separation.

[Use of Structural Surfactant] Structural surfactants include water-insoluble or sparingly soluble builders in laundry detergents, defoamers and enzymes in laundry detergents and other surfactant systems. Abrasives in hard surface cleaners, pesticides and oils in pesticide preparations (EP O 388 239 and E.
P O 498 231) in rocky water (EP O 430 602)
), A dye (EP O 472 089) in the dyebath concentrate and printing ink,
It has been applied to the task of suspending talc, oils and other cosmetic ingredients in personal care formulations.

PROBLEMS An additional type of temperature instability is often observed with more concentrated structural surfactants, especially peptized structural surfactants. It typically involves the sedimentation of suspended solids when the composition is stored under warm conditions. We currently believe that this separation may be due to the tendency of the dispersible lamellae or spherulites to L ₂ at higher temperatures to undergo a phase change in the surfactant. There is.

Similar problems may arise when attempting to prepare nonionic surfactant emulsions at high concentrations.

Specific problems arise in connection with industrial and commercial laundry such as factories, hospitals and hotels, especially liquid detergents suitable for use in automatic washing machines.

The ideal laundry detergent for commercial use has high surfactant levels, especially high levels of nonionic surfactants, which have been found to be particularly effective in removing soil. , High alkalinity for saponifying greasy soils, and high levels of builders, which improve the performance of surfactants by offsetting the effects of calcium in water. The composition must be homogeneous, pourable, and as concentrated as possible. Unfortunately, combining surfactants with high concentrations of electrolytes to form stable compositions is generally difficult. Nonionics that are incapable of forming stable solutions at high alkalinity or in the presence of electrolytes, except at very low concentrations that are too low to be commercially unacceptably low. This has been found to be particularly difficult to achieve with surfactants. Therefore, it was customary in commercial machines to use two separate solutions, one for the supply of surfactant and the other as the alkalinity source.

Attempts to combine the above two in a single formulation have hitherto not been successful.
Even with the use of peptizers such as the peptizers described in EP-A-0 623 670 or EP-A-0 346 995, commercially stable concentrations of sufficiently stable homogeneous phases are formed. However, its formation has only occurred over a very limited temperature range.

SOLUTION: We now find that mixtures of highly ethoxylated nonionic surfactants and alkali metal thiocyanates are temperature stable and the temperature of peptized structural surfactants. It has been disclosed that highly concentrated emulsions can be formed which improve stability. It disperses readily in water systems, which makes them less sensitive to temperature changes.

The mixture is particularly useful for controlling instability in concentrated industrial and commercial detergents. We have found that the mixture has a G by increasing the phase transition temperature.
It is considered to suppress the transition from the phase or structural system to the L ₂ phase.

[Invention] According to the first embodiment, the invention of the inventors of the present invention is 20 to 10 on average per molecule.
An ethoxylated nonionic surfactant having 0 ethyleneoxy groups, and 0.1-1
A mixture with 50 parts by weight of water-soluble thiocyanate is provided.

According to a second embodiment, our invention comprises water and a concentration of the above mixture adapted to form an emulsion or phase G at temperatures below 40 ° C. A concentrated nonionic surfactant emulsion is provided.

[0028]   According to a third embodiment, our invention is that at some temperature below 50 ° C., L ₂ Dispersible layer capable of forming a phase plate-like and / or spherulite structural surfactant
The structural surfactant, water and the necessary proportions in relative proportions adapted to form the system.
Electrolyte then, and optionally, a sufficient amount of peptizer to inhibit aggregation of the system.
A structural surfactant composition capable of suspending a solid containing the composition.
The product has a relative molar ratio (i) :( ii) of 1: 200-20: 1, (i) 20-1.
An ethoxylated nonionic surfactant having an ethyleneoxy group of 00, (ii)
It is characterized by containing an effective amount of a phase stabilizer which is a mixture with a water-soluble thiocyanate.
A composition is provided.

Preferably, the structural surfactant is a high amount of nonionic surfactant, typically an ethoxylate having 1 to 15, for example 2 to 10, ethylene oxide,
And optionally consisting of small amounts of anionic and / or amphoteric surfactants. Preferably, the water is present in a proportion of 20-60%. Preferably, the electrolyte contains an alkali.

[Phase Stabilizer] The stabilizer is an ethoxylated C _8-20 linear or branched alcohol or fatty acid,
It may contain fatty amines, sorbitan or glycerol esters, alkylpolypropoxy groups or alkylphenyl groups. The number of ethoxy groups is 20-100
, For example 30-80, preferably 40-60. The molar ratio of (i) :( ii) may preferably be 1: 100 to 10: 1, for example 1:50 to 5: 1. When the surfactant is added to the structural surfactant system, the surfactant (i) is present in an amount of 0.1-3% by weight of the total composition, preferably 0.2-2% by weight. We prefer that. The maximum concentration depends on the amount of structural surfactant present, but higher levels are preferred for higher concentrations of structural surfactant. Excess destroys the structure. The thiocyanate is preferably greater than 0.05%, more preferably 0.
． It is present in an amount above 1%, for example above 0.5%. The upper limit is not critical, but concentrations above about 10% are not preferred to provide additional benefit. 2%
Concentrations above 1 are generally uneconomical.

The thiocyanate may be any water-soluble thioisocyanate, but is preferably alkali metal isothiocyanate or ammonium isothiocyanate, most preferably potassium isothiocyanate.

Commercial and Industrial Formulations According to a preferred embodiment, the present invention relates to 10 to 50% by weight of water of the composition (A) and at least 3% by weight of the composition (B). A nonionic surfactant having an average HLB of more than 50%, preferably greater than 50%, based on the total weight of the surfactant, of 8 to 15, and optionally a smaller proportion of anionic and / or amphoteric surface. A structural surfactant containing an active agent, (C) at least 10% by weight of the builder by weight of the composition, and (D) at least 7% by weight of the composition, at least partially in solution. A soluble non-micelle-forming salt containing any soluble part of the builder and a base that dissociates into ions, (E) a total free alkali content of at least 0.5 N, and (F) the above components AE 25 A detergent composition containing a peptizer in an amount sufficient to provide a pourable composition that does not separate after 1 month at 0 ° C, further comprising a water-soluble thiocyanate, preferably potassium thiocyanate, average per molecule consisting C _{8 to 20} alcohol ethoxylate having an ethyleneoxy group 25 to 100 and provides a composition 0.01 to 5 wt% of co-stabilizer is present.

The amount of water is typically above 15%, preferably above 20%, especially above 25% and usually above 30%, based on the total weight of the composition.

In some applications, it is preferred that the structural surfactants be all nonionic, as the inclusion of anionic surfactants adversely affects performance. However, if an anionic surfactant is acceptable, its inclusion has the advantage that higher total surfactant concentrations can be achieved more easily. Typically, as a whole, nonionic formulations contain from 7 to 30% by weight, more typically from 10 to 25% by weight of surfactant, while a small proportion of anionic surfactant is used. The composition containing the agent may comprise up to 50% by weight, for example 15-40% by weight, in particular 20-35% by weight.

The nonionic surfactant is preferably composed of 60 to 100% by weight of alkoxylates, preferably ethoxylates or mixed ethoxylates / propoxylates. Typically it comprises alkoxylated _C8-20 , especially _C10-18 , natural or synthetic alcohols. The alcohol is typically first or second straight chain or branched chain saturated or unsaturated. Also useful are alkoxylated fatty acids, fatty amines, alkylphenols, glycerol mono- and dialkyl esters and sorbitan esters.

The ethoxylates typically contain 1-10 alkoxy groups on average, depending on the alkyl chain length, to give a HLB of 10-15, preferably 12-14.

Nonionic surfactants may include mono- or diethanolamides or amine oxides. The surfactant may optionally contain a minor proportion (ie less than 50% based on the total weight of surfactant) of an anionic surfactant such as soap and / or alkylbenzene sulfonate. Other anionic surfactants that may be used include alkyl ether sulphates, alkyl sulphates, olefin sulphonates, paraffin sulphonates and alkyl phosphates.

The builder is preferably sodium tripolyphosphate, but may alternatively be or include sodium or potassium pyrophosphate, sodium or potassium citrate, sodium or potassium carbonate or a zeolite. Other builders include EDTA, nitrilotriacetate, phosphonates and polyelectrolytes such as polyacrylates and polymaleates. The term "builder" as used herein excludes any hydroxide used to provide free alkali, but includes carbonates and silicates. The builder is greater than 10% by weight, based on the total weight of the composition,
It is preferably present in an amount greater than 15 weight. The level of builders may be above 20%, but the excess over solubility in the system is present as suspended particles.
Builder concentrations generally do not exceed 50% by weight and are usually below 40%, for example below 30%.

The composition contains at least 7% by weight of salts and bases which reduce the solubility of the dissolved surfactant. This includes any soluble part of the builder and any alkali required to provide the free alkalinity.

It excludes micelle-forming components such as anionic surfactants. Soluble salts and bases are preferably 10-40% by weight of the composition, for example 15-30% by weight.
And constitutes a sufficient amount to form a multiphase system in which the aqueous phase is interspersed with the surfactant or surfactant mesophase.

The total free alkali should be sufficient to neutralize at least an equal amount of 0.5N HCl. Preferably, the free alkalinity is 0.7-2 normal, for example 0.
It is 8 to 1.5 rules.

We particularly like that the compositions of the invention contain a peptizer. Peptizers include polycarboxylates having one or more alkyl groups, such as _C8-20 alkyl thiol polycarboxylates (eg, polyacrylates or polymaleates), or those with _C8-20 alkyl esters of unsaturated carboxylic acids. It may also be a copolymer of saturated carboxylic acids (eg a copolymer of acrylic acid and / or maleic acid with a small proportion of C _8-20 alkyl acrylate and / or alkyl maleate ester). Alternatively it may comprise an alkyl polyglycoside. The alkyl polyglycosides are preferably polyglucosides and typically have an average degree of polymerization of 1.3 to 10, more usually 1.5 to 3.

The deflocculant is generally added in an amount sufficient to provide interspersing of the aqueous phase with the surfactant phase at 25 ° C. and not separating within one month. This may typically require from 0.5 to 10% by weight, more usually from 1 to 5% by weight, for example from 2 to 4.5% by weight, based on the weight of the composition. The amount is preferably adjusted to obtain a spherulite composition containing the surfactant vesicles, which usually have a multi-layer lamellar or G-phase structure dispersed in the aqueous phase.

The costabilizer is up to 5% by weight, usually 0.01-3% by weight, for example 0.02.
It may be present in a proportion of ˜2% by weight, in particular 0.01 to 1% by weight. The combination of two or more costabilizers is sometimes particularly effective.

The detergent composition of the present invention is also preferably an antifoaming agent such as a silicone antifoaming agent, a stain suspending agent such as carboxymethyl cellulose, an optical brightener, a stain removing agent such as an enzyme, and perboric acid. Bleach containing salt metaborate mixtures, phosphonates, and especially aminotrimethylene phosphonate, ethylenediamine tetrakis (methylene phosphonate), diethylene triamine pentakis (methylene phosphonate)
And sequestrants such as aminophosphonates, perfumes, colorants, preservatives, corrosion inhibitors, bleach activators such as TAED and / or fabric conditioners, including others of the like series and the like. Contains conventional minority detergent ingredients.

All of the above minority components may be present in conventional amounts and will generally constitute less than 5% by weight of the composition, typically less than 1% by weight. The anionic component of the ionic components may typically be sodium, potassium or a mixture of the two. Potassium is preferred if a very high solids content is desired.

The invention is illustrated by the following examples, in which all percentages are by weight of the composition. The total material amounts to 100% by weight.

[0048]

[Table 1]

The product was an effective industrial and commercial laundry detergent. In the absence of alkyl polyglycoside, the composition aggregated vigorously, resulting in rapid separation.
In the absence of potassium thiocyanate and / or 50 mole ethoxylate,
The products separated at temperatures above 30 ° C.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, MZ, SD, SL, SZ, TZ, UG , ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, BZ, C A, CH, CN, CR, CU, CZ, DE, DK, DM , DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, K E, KG, KP, KR, KZ, LC, LK, LR, LS , LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, RO, R U, SD, SE, SG, SI, SK, SL, TJ, TM , TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW

Claims (7)

[Claims] 1. A mixture of an ethoxylated nonionic surfactant having an average of 20 to 100 ethyleneoxy groups per molecule and 0.1 to 150 parts by weight of a water-soluble thiocyanate. 2. A concentrated nonionic surfactant emulsion containing water and a concentration of said mixture adapted to form an emulsion or phase G at temperatures below 40 ° C. 3. At a temperature below 50 ° C., in a relative proportion adapted to form a dispersible layer platy and / or spherulitic surfactant system capable of forming the L ₂ phase. A structure capable of suspending a solid, containing a structural surfactant, water and, if necessary, an electrolyte and, optionally, a deflocculant in an amount sufficient to suppress the aggregation of the system. Surfactant composition, wherein the composition is from 1: 200 to 20: 1.
A relative phase ratio (i): (ii) of a phase stabilizer which is a mixture of (i) an ethoxylated nonionic surfactant having 20 to 100 ethyleneoxy groups and (ii) a water-soluble thiocyanate. A composition comprising an effective amount. 4. The composition according to claim 3, wherein the structural surfactant contains a large amount of nonionic surfactant and a small amount of anionic and / or amphoteric surfactant. 5. The composition of claim 1 or 2 wherein the stabilizer comprises an ethoxylated _C8-20 fatty alcohol. 6. A water content of 10 to 50% by weight of the composition (A) and at least 3% by weight of the composition (B) of 50% based on the total weight of the surfactant.
A nonionic surfactant having an average HLB of 8 to 15 and optionally,
A structural surfactant containing a smaller proportion of anionic and / or amphoteric surfactant, (C) at least 10% by weight of builder, based on the weight of the composition, and (D) at least based on the weight of the composition. 7% of a soluble non-micelle forming salt containing any soluble part of said builder, which dissociates at least partially into ions in solution, and a base, and (E) a total free alkali content of at least 0.5 normal. And (F) a combination of the above-mentioned components A to E, and a peptizer in an amount sufficient to provide a pourable composition that does not separate after one month at 25 ° C. Te, further from 0.01 to 5 wt%, together with a water soluble thiocyanate, an auxiliary stabilizer consisting of C _{8 to 20} alcohol ethoxylate having an ethyleneoxy group 25-100 average per molecule exist Composition. 7. The composition according to claim 6, wherein the thiocyanate is potassium thiocyanate.