Polyorganosiloxane emulsion with large particle size and preparation method thereof

Abstract

The present invention relates to a process for preparing a storage-stable aqueous polyorganosiloxane emulsion comprising (A) at least one polyorganosiloxane (B), at least one alkyl polyglycoside (C), water, optionally (D) an additional emulsifier different from (B), optionally (E) a thickener and optionally (F) an additional additive typically contained in the polyorganosiloxane emulsion, the present invention relates to a process for preparing an emulsifier, characterized in that (i) the total of 1.5 to 4.5 parts of (B) per 100 parts of (A), (ii) the total of 0 to 3 parts of (D) per 100 parts of (A), (iii) the total number of parts per 100 parts of (A), (B) and (D) is < = 4.5, and (iv) the process comprises the following steps: (1) preparing an emulsifier-water mixture comprising at least (B), water (C), optionally (D), optionally (E) and optionally (F); (2) preparing a pre-emulsion by adding at least one (A) to an emulsifier-water mixture, with the proviso that the preparation of the pre-emulsion is carried out by means of a stirring device having a maximum circumferential speed of 4.5 m / s under the action of low shear forces; optionally (3) diluting the pre-emulsion by adding additional water (C); and optionally (4) adding (F), wherein a polyorganosiloxane emulsion having a particle size D (50) of 1 [mu] m to 50 [mu] m is obtained by the method.

Description

Technical Field

[0001] The present invention relates to storage-stable aqueous polyorganosiloxane emulsions of relatively high-viscosity polyorganosiloxanes, which emulsions comprise alkyl polyglycosides as emulsifiers and have a large particle size, and to a process for preparing these emulsions. Background Art

[0002] Polyorganosiloxanes have a wide variety of uses. The terms "polyorganosiloxane" and "silicone" are used synonymously in the present invention. In order to facilitate application and metering, especially in the case of viscous products, for many applications, it is desirable that the organosilicon compound is in diluted form. For this purpose, organic solvents such as benzene or chlorocarbons can be used, which is however disadvantageous from an ecological and occupational health point of view. Therefore, it is mainly used in the form of aqueous emulsions or dispersions, usually as oil-in-water emulsions (which can be diluted with water). The oil phase is understood here to mean a water-immiscible organosilicon compound optionally dissolved in an organic solvent.

[0003] Emulsions comprising polyorganosiloxanes and other organosilicon compounds and processes for their preparation have long been known from the prior art and are described, for example, in the textbook W. Noll, Chemistry and Technology of Silicones, 1968, p. 428-431, Verlag Chemie Weinheim.

[0004] Emulsifiers for polyorganosiloxane emulsions are typically ethoxylated synthetic alcohols, ethoxylated fatty alcohols, ethoxylated triglycerides, ethoxylated fatty acids and mixtures thereof (eg in EP 200916 B1, EP 0463431 A2 and DE 19620405 B4).

[0005] Emulsifiers based on polyglycol ethers and esters are undesirable in particular in cosmetic applications due to potential skin irritation (eg in US2007178144 AA (corresponding to EP 1813251 A2)). Furthermore, there is an increasing demand for products containing emulsifiers based on renewable raw materials.

[0006] Alkyl polyglycosides are emulsifiers which are produced from renewable raw materials and do not contain any polyethylene glycol groups.

[0007] It is known that silicone oils, such as polydimethylsiloxane, can be emulsified with alkyl polyglycosides (for example in US 5133897A (corresponding to EP 0418479A1)). These emulsions can be prepared with low shear forces. 2 to 40 parts of emulsifier, preferably 5 to 30 parts of emulsifier, are used based on the oil phase. In these embodiments, silicone oils with a maximum of 2000 mPa·s are emulsified, and at least 11 parts of emulsifier are used per 100 parts of polyorganosiloxane to prepare a stable emulsion.

[0008] If silicone defoamers are to be emulsified, i.e. mixtures of silicone oil and finely divided silica, a relatively high surfactant content is required and the emulsion must additionally be stabilized with a thickener or an alcohol (see EP 0769548 A1 and EP 0774503 A1). EP 0769548 A1 uses at least 5 parts, preferably at least 28 parts, of an emulsifier based on silicone oil. EP 0774503 A1 also uses at least 5 parts, preferably at least 10 parts, of an emulsifier based on polyorganosiloxane. The examples of these patent specifications use 25 parts and 50 parts of emulsifier per 100 parts of silicone oil / SiO2, respectively.

[0009] However, high proportions of emulsifiers are economically disadvantageous, particularly for cost reasons.

[0010] DE 102014212725 A1 describes a method for preparing a particularly finely divided emulsion based on a high-viscosity silicone oil and an alkyl polyglycoside. A particle size of less than 300 nm is achieved by using high shear forces. Therefore, even at a relatively low emulsifier concentration of only about 12 parts of emulsifier per 100 parts of silicone oil, these emulsions are stable. However, this method has the following disadvantages: it requires a suitable unit that can generate high shear forces in the high-viscosity phase, which additionally means high energy consumption and is therefore ecologically and economically disadvantageous.

[0011] For specific applications in cosmetics, large particle sizes are preferred (eg in WO 03 / 092639 A1). However, according to Stokes' law, the tendency to segregate increases with particle size (in this respect see H. Schubert et al., Chem. Ing. Techn. 61, 1989, p. 701-711).

[0012] It was therefore an object to provide emulsions based on high-viscosity silicone oils and processes for producing these polyorganosiloxane emulsions which comprise emulsifiers based on renewable raw materials and have excellent stability even with very low emulsifier proportions and large particle sizes. Summary of the invention

[0013] This object is achieved by the present invention.

[0014] The present invention provides a method for preparing a storage-stable aqueous polyorganosiloxane emulsion, the emulsion comprising

[0015] (A) at least one polyorganosiloxane having the general formula

[0016] R 2 a (R 1 O) b SiO (4-a-b) / 2 (I)

[0017] in

[0018] R 1 may be the same or different and are a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group,

[0019] R 2 may be the same or different and are monovalent, substituted or unsubstituted hydrocarbon groups having 1 to 30 carbon atoms or hydrogen atoms,

[0020] a is 0, 1, 2, or 3,

[0021] b is 0, 1, 2, or 3,

[0022] The condition is that the sum of a+b is ≤3,

[0023] (B) at least one alkyl polyglycoside of the following general formula

[0024] AOG m (II)

[0025] in

[0026] A is a linear or branched, saturated or unsaturated alkyl group having 8 to 24 carbon atoms,

[0027] G is a glycosidic group, and

[0028] m is the degree of glycosylation and is an integer ranging from 1 to 5 on average,

[0029] (C) Water,

[0030] Optionally

[0031] (D) another emulsifier different from the alkyl polyglycoside (B),

[0032] Optionally

[0033] (E) Thickener

[0034] and optionally

[0035] (F) additional additives usually present in polyorganosiloxane emulsions, characterized in that

[0036] (i) a total of 1.5 to 4.5 parts of alkyl polyglycoside (B) are present per 100 parts of polyorganosiloxane (A),

[0037] (ii) a total of 0 to 3 parts of additional emulsifier (D) per 100 parts of polyorganosiloxane (A),

[0038] (iii) the total number of parts per 100 parts of polyorganosiloxane (A), alkyl polyglycoside (B) and additional emulsifier (D) is ≤ 4.5

[0039] as well as

[0040] (iv) The method comprises the following steps

[0041] (1) preparing an emulsifier-water mixture comprising at least one alkyl polyglycoside (B) and water (C) and optionally further emulsifiers (D), optionally thickeners (E) and optionally further additives (F),

[0042] (2) preparing a preliminary emulsion by adding at least one polyorganosiloxane (A) to an emulsifier-water mixture, provided that the preliminary emulsion is prepared under the action of low shear forces using a stirring device having a maximum peripheral speed of 4.5 m / s,

[0043] Optionally

[0044] (3) Dilute the pre-emulsion by adding additional water (C)

[0045] and optionally

[0046] (4) adding another additive (F),

[0047] Among other things, the process yields a polyorganosiloxane emulsion having a particle size D(50) of 1 μm to 50 μm.

[0048] The present invention further provides a storage-stable aqueous polyorganosiloxane emulsion comprising (A) at least one polyorganosiloxane having the general formula

[0049] R 2 a (R 1 O) b SiO (4-a-b) / 2 (I)

[0050] in

[0051] R 1 may be the same or different and are a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group,

[0052] R 2 may be the same or different and are monovalent, substituted or unsubstituted hydrocarbon groups having 1 to 30 carbon atoms or hydrogen atoms,

[0053] a is 0, 1, 2, or 3,

[0054] b is 0, 1, 2, or 3,

[0055] The condition is that the sum of a+b is ≤3,

[0056] (B) at least one alkyl polyglycoside of the following general formula

[0057] AOG m (II)

[0058] in

[0059] A is a linear or branched, saturated or unsaturated alkyl group having 8 to 24 carbon atoms, G is a glycoside group, and

[0060] m is the degree of glycosylation and is an integer ranging from 1 to 5 on average,

[0061] (C) Water,

[0062] Optionally

[0063] (D) another emulsifier different from the alkyl polyglycoside (B),

[0064] Optionally

[0065] (E) Thickener

[0066] and optionally

[0067] (F) further additives usually present in polyorganosiloxane emulsions,

[0068] Features

[0069] (i) a total of 1.5 to 4.5 parts of alkyl polyglycoside (B) are present per 100 parts of polyorganosiloxane (A),

[0070] (ii) a total of 0 to 3 parts of additional emulsifier (D) per 100 parts of polyorganosiloxane (A),

[0071] (iii) the total number of parts per 100 parts of polyorganosiloxane (A), alkyl polyglycoside (B) and additional emulsifier (D) is ≤ 4.5

[0072] as well as

[0073] (iv) preparing the emulsion by a method comprising the steps of:

[0074] (1) preparing an emulsifier-water mixture comprising at least one alkyl polyglycoside (B) and water (C) and optionally further emulsifiers (D), optionally thickeners (E) and optionally further additives (F),

[0075] (2) preparing a preliminary emulsion by adding at least one polyorganosiloxane (A) to an emulsifier-water mixture, provided that the preliminary emulsion is prepared under the action of low shear forces using a stirring device having a maximum peripheral speed of 4.5 m / s,

[0076] Optionally

[0077] (3) Dilute the pre-emulsion by adding additional water (C)

[0078] and optionally

[0079] (4) adding another additive (F),

[0080] Provided that the polyorganosiloxane emulsion has a particle size D(50) of greater than 1 μm to at most 50 μm.

[0081] In order not to create too many pages in the description of the invention, only preferred embodiments of individual features are given below.

[0082] However, the skilled reader should explicitly understand this disclosure in such a way that every combination of different preference levels is therefore also explicitly disclosed and explicitly intended.

[0083] Preferably, polydimethylsiloxanes having a viscosity (determined at 25° C. in accordance with DIN 53019) of from 10 000 mPa·s to 3 000 000 mPa·s are used as polyorganosiloxanes (A).

[0084] Preferably, an alkyl polyglycoside (B) having an average saturated alkyl group having 8 to 14 carbon atoms and an average degree of glycosidation m of 1.1 to 3.0 is used.

[0085] In a preferred embodiment, no additional emulsifier (D) is present.

[0086] Preferably, 0.1 to 1 part of xanthan gum is used as thickener (E) per 100 parts of polyorganosiloxane (A).

[0087] Preferably, the instability index of the polyorganosiloxane emulsion after centrifugation at 2300×g for 8 h is <0.1.

[0088] In a preferred embodiment, the polyorganosiloxane emulsion has a particle size D(50) of 3 μm to 20 μm.

[0089] Preferably, the polyorganosiloxane emulsion has an octamethylcyclotetrasiloxane (D4) content of less than 0.1% by weight, based on the total weight of the polyorganosiloxane emulsion.

[0090] The polyorganosiloxane emulsion according to the invention and the process according to the invention for preparing it are described in more detail below:

[0091] The components (A) to (F) used in the process according to the invention may each be one type of such component or a mixture of at least two types of the corresponding components.

[0092] Polyorganosiloxane (A)

[0093] The polyorganosiloxanes (A) of the general formula (I) used in the emulsions according to the invention are preferably liquid at 25° C. and preferably have a viscosity, measured to DIN ISO 53019 at 25° C. of 10 to 50 000 000 mPa·s and particularly preferably 10 000 to 3 000 000 mPa·s.

[0094] The polyorganosiloxanes (A) are preferably those which comprise 5 to 10,000 units of the formula (I), particularly preferably those which consist of units of the formula (I) having an average value a of 1.9 to 2.3 and an average value b of 0 to 0.2.

[0095] R 1 may be the same or different and are a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group, preferably a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom.

[0096] R 2 The may be the same or different and are monovalent, substituted or unsubstituted hydrocarbon groups having 1 to 30 carbon atoms or hydrogen atoms.

[0097] Preferably, in a unit of formula (I), at most one group R 2 Has the definition of a hydrogen atom.

[0098] Group R 2 Preferred is a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms, and particularly preferred is a hydrogen atom, a methyl group or a phenyl group.

[0099] In a preferred embodiment, in particular, 80 mol % or more of the groups R 2 The group R has the definition of methyl and 20 mol% or less 2 It has the definition of aminopropyl or aminoethylaminopropyl.

[0100] Hydrocarbon R1 or R 2 Non-exhaustive examples of are alkyl, such as methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, such as n-hexyl, heptyl, such as n-heptyl, octyl, such as n-octyl and isooctyl, such as 2,2,4-trimethylpentyl, nonyl, such as n-nonyl, decyl, such as n-decyl, dodecyl, such as n-dodecyl, octadecyl, such as n-octadecyl, cycloalkyl, such as cyclopentyl, cyclohexyl and cycloheptyl and methylcyclohexyl, alkenyl, such as vinyl, 1-propenyl and 2-propenyl, aryl, such as phenyl, naphthyl, anthracenyl and phenanthrenyl, alkaryl, such as o-, m-, p-tolyl, xylyl and ethylphenyl and aralkyl, such as benzyl and α- and β-phenylethyl.

[0101] Substituted group R 1 or R 2 Non-exhaustive examples of are hydrocarbon groups substituted by halogen, cyano, glycidyloxy, polyalkylene glycol or amino groups, such as hydrocarbon groups with trifluoropropyl, cyanoethyl, glycidyloxypropyl, polyalkylene glycol propyl and amino groups.

[0102] Amino substituted group R 2 A non-exhaustive example is:

[0103] H2N(CH2)2NH(CH2)3-

[0104] H2N(CH2)2-

[0105] H3CNH(CH2)3-

[0106] H2N(CH2)4-

[0107] H2N(CH2)5-

[0108] H(NHCH2CH2)3-

[0109] C4H9NH(CH2)2NH(CH2)2- and

[0110] Cyclo-C6H 11 NH(CH2)3-,

[0111] in

[0112] H2N(CH2)3- and

[0113] H2N(CH2)2NH(CH2)3- is particularly preferred.

[0114] In formula (I), the sum of a+b is ≦3 and has a value of preferably on average from 1.5 to 2.4, particularly preferably on average from 1.9 to 2.3 and very particularly preferably on average from 1.95 to 2.05.

[0115] Non-exhaustive examples of polyorganosiloxanes (A) used in the emulsions according to the invention are aminopropyldimethylsiloxy-, aminoethylaminopropyldimethylsiloxy-, vinyldimethylsiloxy-, trimethylsiloxy-, dimethylalkoxysiloxy- or dimethylhydroxy-terminated polydiorganosiloxanes, in particular polydimethylsiloxanes containing side aminopropyl, aminoethylaminopropyl or carboxyalkyl groups.

[0116] Preferred polyorganosiloxanes (A) are those of the formula:

[0117] R 2 3-c (R 1 O) c SiO(R 2 SiO) p Si(OR 1 ) c R 2 3-c (III)

[0118] in

[0119] R 1 and R 2 With the definitions given above,

[0120] c is 0, 1 or 2, preferably 0 or 1,

[0121] as well as

[0122] p is 1 to 100,000, preferably 5 to 10,000.

[0123] Non-exhaustive examples of preferred polyorganosiloxanes (A) used in the process according to the invention are:

[0124] (CH3)3Si-O-[Si(CH3)2-O-] n -Si(CH3)3

[0125] HO(CH3)2Si-O-[Si(CH3)2-O-] n -Si(CH3)2OH

[0126] (CH3)3Si-O-[Si(CH3)2-O-] n -[Si(CH3)RO-] m -Si(CH3)3

[0127] HO(CH3)2Si-O-[Si(CH3)2-O-] n -[Si(CH3)RO-] m-Si(CH3)2OH

[0128] CH3O(CH3)2Si-O-[Si(CH3)2-O-] n -[Si(CH3)RO-] m -Si(CH3)2OCH3

[0129] C2H5O(CH3)2Si-O-[Si(CH3)2-O-] n -[Si(CH3)RO-] m -Si(CH3)2OC2H5,

[0130] in

[0131] n is 50 to 5000,

[0132] m is 1 to 100,

[0133] as well as

[0134] R is, for example, -C3H6NH2, -C3H6NH-C2H4NH2 or -C 10 H 20 COOH group.

[0135] If reactive polyorganosiloxanes (e.g. with vinyl or OH end groups) are preferably used as polyorganosiloxanes (A), chain extension, polycondensation or crosslinking in the presence of suitable reactants can be carried out, for example, in emulsion. Reactions of this type are known to those skilled in the art and lead to emulsions or crosslinked polyorganosiloxane elastomers prepared according to the invention comprising polyorganosiloxanes having a viscosity of more than 1,000,000 mPa·s (determined at 25° C. in accordance with DIN 53019).

[0136] The polyorganosiloxanes (A) used in the emulsions according to the invention are preferably prepared by relevant methods from the literature.

[0137] Alkyl polyglycoside (B)

[0138] In a preferred embodiment, the alkyl polyglycoside (B) is a compound of the general formula (II),

[0139] in

[0140] A has the definition given above,

[0141] G is a hexose or pentose unit or a mixture thereof

[0142] as well as

[0143] m has the definition given above.

[0144] Compounds of this type are described, for example, in US Pat. No. 5,133,897 A (corresponding to EP 0 418 479 A1).

[0145] Alkyl polyglycoside (B) can be obtained by 1 H NMR spectra, characterized, for example, on a Bruker Avance 500 MHz NMR spectrometer, can be obtained by, as known to the person skilled in the art and as described, for example, in the textbook “H. Friebolin, Ein-undzweidimensionale NMR-Spektroskopie [One- and Two-Dimensional NMR Spectroscopy], 5th Edition, 2013, p. 35, Wiley-VCH-Verlag” and as processed, for example, according to the operating instructions of the Bruker Topspin 3.2 NMR data analysis software. 1 The area under the H NMR signal is integrated to determine the average chain length of the alkyl groups A or the average degree of glycosylation m.

[0146] Preferably, the alkyl polyglycosides (B) are those having a saturated alkyl group having an average of 8 to 14 carbon atoms and an average degree of glycosidation of 1.1 to 3.0.

[0147] Particularly preferred are alkyl polyglycosides (B) based on fatty alcohols having 8 to 10 carbon atoms and having an average degree of glycosidation of from 1.4 to 2.0.

[0148] Non-exhaustive examples of alkyl polyglycosides (B) are D-pyranose, oligomers, decyloctyl glucoside (available from BASF SE under the trade name APG 215 or from Stockmeier GmbH under the trade name CG 110), D-glucopyranose, oligomers, C10-16-alkyl glycosides (available from BASF SE under the trade name 650EC and Available under GD 70).

[0149] Water (C)

[0150] The water (C) used may be all types of water which have also been used hitherto for preparing polyorganosiloxane emulsions.

[0151] The water (C) used is preferably partially or completely demineralized water, distilled or (repeatedly) redistilled water, water for medical or pharmaceutical purposes, such as purified water (Aqua purificata according to the European Pharmacopoeia (Pharm. Eur.)).

[0152] The water (C) used according to the invention preferably has an electrical conductivity of less than 50 μS / cm, particularly preferably less than 10 μS / cm and in particular less than 1.3 μS / cm, in each case at 25° C. and 1010 hPa.

[0153] The amount of water (C) used is preferably 10 to 1000 parts by weight, particularly preferably 40 to 500 parts by weight, based on 100 parts by weight of the polyorganosiloxane (A).

[0154] Additional emulsifier (D)

[0155] The polyorganosiloxane emulsions according to the invention may optionally contain further emulsifiers (D). In this case, all nonionic, anionic or cationic emulsifiers known to the person skilled in the art can be used. Preference is given here to emulsifiers based on renewable raw materials.

[0156] The further emulsifiers (D) are preferably commercially available emulsifiers.

[0157] Non-exhaustive examples of substance classes of further emulsifiers (D) are sorbitan esters, glycerol esters, polyglycerol esters, alkyl sulfates and alkyl phosphates.

[0158] Preferably, the further emulsifiers (D) optionally used according to the invention can be used in pure form or as a solution of one or more emulsifiers in water or an organic solvent.

[0159] Thickener (E)

[0160] As component (E), the emulsions according to the invention may optionally comprise thickeners; these are preferably cellulose ethers and polysaccharides, for example xanthan gum, particularly preferably xanthan gum.

[0161] If a thickener (E) is used, the amount used is preferably 0.01 to 2 parts based on 100 parts of polyorganosiloxane (A).

[0162] Additional additives (F)

[0163] In addition to components (A) to (E), further additives (F) which are usually added to silicone emulsions may optionally be used.

[0164] Non-exhaustive examples of further additives (F) are further siloxanes other than the polyorganosiloxanes (A), such as polyether siloxanes or silanes, in particular alkoxysilanes, fillers, additives such as preservatives, disinfectants, wetting agents, corrosion inhibitors, dyes and fragrances, and mixtures thereof.

[0165] If further siloxanes other than the polyorganosiloxane (A) are used, they are preferably used in an amount of 0.1 to 1 part, based on 100 parts of the polyorganosiloxane (A).

[0166] If silanes are used, they are preferably used in amounts of 0.1 to 50 parts, based on 100 parts of polyorganosiloxane (A).

[0167] Non-exhaustive examples of additives that can be used according to the invention are preservatives, dyes or fragrances known to the person skilled in the art, in particular preservatives such as methylisothiazolinone, chloromethylisothiazolinone, benzylisothiazolinone, phenoxyethanol, methylparaben, ethylparaben, propylparaben, butylparaben, isobutylparaben, alkali metal benzoates, benzoic acid, alkali metal sorbates, sorbic acid, iodopropynyl butylcarbamate, benzyl alcohol and 2-bromo-2-nitropropane-1,3-diol.

[0168] If additives are used, the amount used is preferably 0.0005 to 2 parts, based on 100 parts of polyorganosiloxane (A). Additives (F), in particular preservatives, are preferably used in the process according to the invention.

[0169] The emulsions according to the invention have a particle size (median of the volume distribution) of 1 μm to 50 μm, in particular of 3 μm to 20 μm, these figures being based on the D(50) value of the volume distribution measured according to the Fraunhofer diffraction principle (according to ISO 13320). The parameters assumed for the measurement were a spherical model with a refractive index of the continuous phase of 1.33, a refractive index of the dispersed phase of 1.39 and an absorption of 0.01.

[0170] The emulsions prepared according to the invention preferably have a content of non-volatile fractions, measured in accordance with DIN EN ISO 3251, of preferably 1 to 80% by weight, particularly preferably 50 to 70% by weight.

[0171] The pH of the emulsion prepared according to the invention is preferably from 3 to 10, particularly preferably from 3 to 8.

[0172] Storage-stable emulsions are those in which no visible separation into two phases occurs after storage at 50° C., preferably in a drying cabinet, for 30 days.

[0173] Preferably, the polyorganosiloxane emulsion according to the present invention can be prepared batchwise or continuously, for example according to US 2018193808 (equivalent to EP3349888 B1).

[0174] The peripheral speed v (the speed of a point on the edge of the rotor or disk) is calculated in meters per second by the following formula:

[0175] v=U·π·d R (IV),

[0176] in

[0177] U is the rotation speed (in revolutions per second)

[0178] as well as

[0179] d R is the diameter of the dispersing tool in meters.

[0180] The greater the peripheral speed v, the stronger the shear forces acting on the product to be dispersed.

[0181] According to the invention, a peripheral speed v of at most 4.5 m / s, preferably at most 3 m / s, particularly preferably at most 2 m / s and very particularly preferably at most 1 m / s should be chosen.

[0182] Preferably, the process according to the invention is carried out at the pressure of the surrounding atmosphere, ie at about 1010 hPa.

[0183] The process according to the invention is preferably carried out at a temperature of 0°C to 80°C, preferably at 2°C to 50°C and particularly preferably at 5°C to 30°C.

[0184] Preferably, the process according to the invention is carried out at room temperature, ie about 25° C., or at a temperature established on the combination of components at room temperature without additional heating or cooling.

[0185] The invention further provides the use of the polyorganosiloxane emulsions prepared by the process according to the invention in cosmetic compositions, such as body or hair care products.

[0186] The emulsions prepared according to the invention can in principle be used for all other purposes for which emulsions with polyorganosiloxanes have been used hitherto, for example in the processing of rubber and plastics or in metal processing as release agents, lubricants, hydrophobizing agents and for impregnation of textiles, and as hydrophobizing agents for glass and mineral building materials.

[0187] The process according to the invention has the advantage that despite very low proportions of emulsifier and low shear forces, very storage-stable and high-performance emulsions with average particle sizes of 1 μm to 50 μm, in particular 3 μm to 20 μm (D(50) value of the volume distribution), can be obtained. This makes the process according to the invention energetically and therefore economically and ecologically advantageous.

[0188] The large particle size of the polyorganosiloxane emulsions according to the invention obtainable by the process according to the invention further provides particular performance advantages in cosmetic hair care products.

[0189] The use of alkyl polyglycosides (B) as emulsifiers based on renewable raw materials is resource-friendly. In addition, the use of polysaccharide-based emulsifiers in cosmetic applications can minimize potential skin irritation and intolerance caused by conventional emulsifiers based on polyglycol ethers and esters.

[0190] Furthermore, the polyorganosiloxane emulsions according to the invention have excellent performance properties, such as good conditioning effects in hair care products, i.e. a significant reduction in the wet and dry combing forces, as well as good effects as release agents and lubricants, and good wetting ability on various substrates. DETAILED DESCRIPTION

[0191] Example

[0192] The subject matter of the invention will be illustrated by the following examples without restricting the invention to what is disclosed therein.

[0193] In the following examples, all figures for parts and percentages are based on weight, unless otherwise stated. Unless otherwise stated, the following examples were carried out at ambient atmospheric pressure, i.e. at about 1010 hPa, and at room temperature, i.e. at about 25° C., or at a temperature established on the combination of components at room temperature without additional heating or cooling. All viscosity figures given in the examples are based on a temperature of 25° C.

[0194] The particle size measurement of the polyorganosiloxane emulsions according to the invention was carried out using a Malvern Mastersizer 2000 (Malvern Instruments GmbH, Herrenberg, Germany; measuring principle: Fraunhofer diffraction according to ISO 13320). The parameters assumed for the measurement were a spherical model with a refractive index of the continuous phase of 1.33, a refractive index of the dispersed phase of 1.39 and an absorption of 0.01. The reported measured value is D(50), the median of the volume distribution.

[0195] To determine the oil viscosity, 20 g of polyorganosiloxane emulsion were mixed with 30 g of acetone and the emulsion was separated. The acetone-water phase was removed and the process was repeated again. Subsequently, the polymer was washed three times with water and dried at 110° C. while stirring until no water droplets were visible and then post-treated in a drying cabinet at 110° C. for a further 8 h.

[0196] The viscosity of the polyorganosiloxane emulsions and the removed oil for determining the oil viscosity was determined at 25° C. using an MCR 302 rheometer from Anton Paar GmbH Graz according to DIN 53019. A CP50-2 cone-plate system was used and the flow curves were measured using shear rates in the range from 0.1 to 100 / s. In the examples, the viscosity is reported as 10 / s.

[0197] To determine the content of octamethylcyclotetrasiloxane (D4), 0.5 g of sample was mixed with 10 ml of ultrapure acetone containing 120 ppm of n-dodecane as internal standard. After 16 hours of shaking, two phases were formed. 10 μl of the clear supernatant phase was injected into the gas chromatograph. A double determination was performed. The content of D4 in the emulsion was determined based on a pre-recorded calibration curve. The D4 content can then be calculated from this.

[0198] To determine the instability index, use The emulsion was centrifuged for 8 h at 4000 rpm (corresponding to about 2300 × g) using a 110.2-69 (LUM GmbH Berlin) and a cuvette with a path length of 2 mm. The stability was characterized by the instability index output by the device software. If this is 0, the emulsion is stable; if it is 1, the emulsion is completely separated (in this regard see Dispersion Letters Technical, T4 (2013) 1-4, Update 2014). This means that the smaller the value, the more stable the emulsion.

[0199] The wet hair combing forces were determined using tresses from damaged Caucasian hair (tress damage degree B, double tension) from Kerling International Haarfabrik GmbH with a weight of 2 g and a length of 20 cm. The combing forces were measured by the double combing method using an Instron 3343 tensile tester according to YK Kamath and Hans-Dietrich Weigmann, J. Soc. Cosmet. Chem., 37, 111-124, 1986. First, the wet combing forces were determined along the measuring section on an untreated tress. The tress was then treated with a cosmetic composition according to the invention and the force absorption during the combing procedure was determined. The reported measured value is the reduction in combing force along the measuring section (working) that occurs between the treated and untreated tresses. An average value was formed from five tresses. The reduction in combing force is reported as a percentage.

[0200] Raw materials used

[0201] Polyorganosiloxane A1: trimethylsiloxy-terminated polydimethylsiloxane having a viscosity of 60,000 mPa·s

[0202] Polyorganosiloxane A2: a mixture of trimethylsiloxy-terminated polydimethylsiloxanes having viscosities of 300 000 mPa·s and 1000 mPa·s; the mixture had a viscosity of 60 000 mPa·s.

[0203] Polyorganosiloxane A3: Hydroxyl-terminated polydimethylsiloxane having a viscosity of 80 000 mPa·s

[0204] Polyorganosiloxane A4: trimethylsiloxy-terminated polydimethylsiloxane having a viscosity of 20 000 mPa·s

[0205] Polyorganosiloxane A5: trimethylsiloxy-terminated polydimethylsiloxane having a viscosity of 330 000 mPa·s

[0206] Alkyl polyglycoside B1: A 63% aqueous solution of octyl / decyl polyglycoside having a surface tension of 29 mN / m (1 g / l) and a pour point of less than 0° C., available from BASF SE under the name APG 215 is available

[0207] Alkyl polyglycoside B2: A 53% aqueous solution of alkyl polyglycoside C10-16 having a surface tension of 28 mN / m (1 g / l) and a pour point of 5° C., available from BASF SE under the name 600CSUP available

[0208] Alkyl polyglycoside B3: A 50% aqueous solution of decyloctyl polyglycoside having a surface tension of 29 mN / m (1 g / l) and a pour point of 0° C., available from Stockmeier Chemie GmbH Co KG Bielefeld under the name CG-50 available

[0209] Additional emulsifier D1: Sorbitan monolaurate, available from Croda GmbH Nettetal under the name 20 can be obtained

[0210] Additional emulsifier D2: Octadecyl phosphate (acid value 330 mg KOH / g), from Croda GmbH Nettetal under the name 810A available

[0211] Thickener E: Xanthan gum, available from Jungbunzlauer Ladenburg GmbH Ladenburg under the name Xanthan FN

[0212] Additional additives (preservatives) F1: Potassium sorbate, benzoic acid and sodium benzoate, from CSC GmbH & Co. KG Nuremberg is available

[0213] Additional additives (preservatives) F2: phenoxyethanol, available from Thor GmbH Speyer

[0214] Preparation of polyorganosiloxane emulsion

[0215] In an anchor stirrer with a scraper, from Werke GmbH & Co. KG Staufen The emulsions were prepared in a magic PLANT laboratory mixer. The batch size was in each case 1500 g at 25° C. The formulations of Examples 1 to 9 according to the invention and Comparative Examples C1 to C3 can be found in Table 1 below.

[0216] First add 82.5g deionized water (C), and add component (B) and optionally (D) and optionally (E). With 75 / min agitator speed (corresponding to the peripheral speed of 0.63m / s), they are mixed for 10 minutes. In the process of 60 minutes, component (A) is metered in and further mixed for 60 minutes with 75 / min. In the process of 60 minutes, add remaining water and stir with 75 / min. In all experiments, finally add 1.5g potassium sorbate, 1.95g benzoic acid and 4.5g sodium benzoate as component (F) (preservative F1) and stir for 30 minutes.

[0217] Table 1: Formulations of Examples 1 to 9 and Comparative Examples C1 to C3 for components (A), (B), (D) and (E) 1)

[0218]

[0219]

[0220] 1) The amount of preservative F1 used was as described above; water (C) had to be added to 100% in each case.

[0221] 2) Amount based on 100% active content

[0222] 3) Corresponding to 0.2 parts (D) for every 100 parts (A)

[0223] In Table 2 below, for the measurement of the instability index after 8 h at 2300×g, Examples 1 to 9 according to the invention show only very slight signs of the onset of separation (instability index less than 0.1), whereas Examples C1 to C3 not according to the invention with a higher emulsifier ratio exhibit similar viscosities but show significant signs of separation with an instability index greater than 0.3 or even greater than 0.5.

[0224] Table 2: Tests of emulsion properties

[0225]

[0226]

[0227] Example 10: Emulsion polymerization using the polyorganosiloxane emulsion of the present invention

[0228] First add 82.5g deionized water (C) and add 60g B1 (corresponding to 37.8g active content) and 5.25g E, mix for 10 minutes with a stirrer speed of 75 / min (corresponding to a peripheral speed of 0.63m / s). In the process of 60 minutes, 895.65g of component A3 are metered in and further mixed for 60 minutes at 75 / min. Therefore, 4.22 parts of (B) are used for every 100 parts of (A). In the process of 60 minutes, the remaining water is added and stirred at 75 / min. Then 1.79g component D2 is added and stirred for 30 minutes. The emulsion is stored at 4°C for 48h and neutralized with 31.5g of triethanolamine. Then 13.5g phenoxyethanol is added as component (F) (preservative F2).

[0229] Comparative Example C4: Emulsion Polymerization Using a Polyorganosiloxane Emulsion Not According to the Invention

[0230] First, 82.5 g of deionized water (C) was added and 375 g of B1 (corresponding to 236.2 g of active content) was added, and mixed for 10 minutes at a stirrer speed of 75 / min (corresponding to a peripheral speed of 0.63 m / s). 895.65 g of component A3 was metered in over a 60-minute period and further mixed at 75 / min for 60 minutes. Therefore, 26.37 parts of (B) were used for every 100 parts of (A). The remaining water was added over a 60-minute period and stirred at 75 / min. Then 35 g of component D2 was added and stirred for 30 minutes. The emulsion was stored at 4° C. for 48 h and neutralized with 31.5 g of triethanolamine. Then 13.5 g of phenoxyethanol was added as component (F) (preservative F2).

[0231] Table 3: Tests on emulsion properties of Example 10 and Comparative Example C4

[0232]

[0233]

[0234] As shown in Table 3, the inventive polyorganosiloxane emulsion of Example 10 is able to form a very high viscosity oil without compromising the stability of the emulsion and without forming a significant amount of octamethylcyclotetrasiloxane (D4).

[0235] The non-inventive polyorganosiloxane emulsion of comparative example C4 has only a slight increase in oil viscosity. Therefore, the D4 content was not tested either. Despite the much smaller particle size and slightly higher viscosity, the instability index is significantly worse.

[0236] Example 11: Application example as a hair care product

[0237] The shampoo was prepared from the components shown in Table 4:

[0238] Table 4: Shampoo formulation components

[0239]

[0240] * International Nomenclature of Cosmetic Ingredients

[0241] The starting materials given in Table 4 are available under the following trade names:

[0242] 1) Citric acid, Sigma

[0243] 2) CAB 818 30%, Clariant

[0244] 3) LRO 26,5%,Clariant

[0245] 4) BF 13, Ashland

[0246] 5) K 12G, BASF

[0247] 6) 980, Lubrizol

[0248] 7) L-(+)lactic acid, 90%, Bernd Kraft GmbH

[0249] 8) Phenoxyethanol, Ethylhexylglycerin: PE 9010, Schülke&Mayr

[0250] 9) Ceraphyl TM 41 Ester, Ashland

[0251] 10) Sodium hydroxide, Sigma-Aldrich

[0252] 11) Ultrapure Sodium ChlorideBernd Kraft GmbH

[0253] Wet combing force on Caucasian hair was reduced by 30% compared to a shampoo without silicone emulsion.

[0254] If the non-inventive emulsion from example C2 is used instead of the inventive emulsion from example 2, the wet combing force decreases by only 10%.

Claims

1. A method for preparing a storage-stable aqueous polyorganosiloxane emulsion, the emulsion comprising (A) at least one polyorganosiloxane having the general formula: R 2 a (R 1 O) b SiO (4-a-b) / 2 (I), in R 1 may be the same or different and are a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group, R 2 may be the same or different and are monovalent, substituted or unsubstituted hydrocarbon groups having 1 to 30 carbon atoms or hydrogen atoms, a is 0, 1, 2, or 3, b is 0, 1, 2, or 3, The condition is that the sum of a+b is ≤3, (B) at least one alkyl polyglycoside of the following general formula: AOG m (II) in A is a linear or branched, saturated or unsaturated alkyl group having 8 to 24 carbon atoms, G is a glycosidic group, and m is the degree of glycosylation and is an integer ranging from 1 to 5 on average, (C) Water, Optionally (D) another emulsifier different from the alkyl polyglycoside (B), Optionally (E) Thickener and optionally (F) additional additives usually present in polyorganosiloxane emulsions, characterized in that (i) a total of 1.5 to 4.5 parts of alkyl polyglycoside (B) are present per 100 parts of polyorganosiloxane (A), (ii) a total of 0 to 3 parts of additional emulsifier (D) per 100 parts of polyorganosiloxane (A), (iii) the total number of parts per 100 parts of polyorganosiloxane (A), alkyl polyglycoside (B) and additional emulsifier (D) is ≤ 4.5, and (iv) the method comprises the following steps: (1) preparing an emulsifier-water mixture comprising at least one alkyl polyglycoside (B) and water (C) and optionally further emulsifiers (D), optionally thickeners (E) and optionally further additives (F), (2) preparing a preliminary emulsion by adding at least one polyorganosiloxane (A) to the emulsifier-water mixture, provided that the preliminary emulsion is prepared under the action of low shear forces using a stirring device having a maximum peripheral speed of 4.5 m / s, Optionally (3) diluting the preliminary emulsion by adding further water (C), and optionally (4) adding another additive (F), Therein, the method produces a polyorganosiloxane emulsion having a particle size D(50) of 1 μm to 50 μm.

2. The method according to claim 1, characterized in that: As polyorganosiloxane (A) used are polydimethylsiloxanes having a viscosity of 10 000 mPa·s to 3 000 000 mPa·s (determined at 25° C. in accordance with DIN 53019).

3. The method according to claim 1 or 2, characterized in that: Alkyl polyglycoside (B) having an average saturated alkyl group having 8 to 14 carbon atoms and an average glycosylation degree m of 1.1 to 3.0 is used.

4. The method according to claim 1, 2 or 3, characterized in that: No additional emulsifier (D) was present.

5. The method according to any one of claims 1 to 4, characterized in that As thickener (E), 0.1 to 1 part of xanthan gum is used per 100 parts of polyorganosiloxane (A).

6. The method according to any one of claims 1 to 5, characterized in that The instability index of the polyorganosiloxane emulsion after centrifugation at 2300×g for 8 h was <0.

1.

7. The method according to any one of claims 1 to 6, characterized in that The polyorganosiloxane emulsion has a particle size D(50) of 3 μm to 20 μm.

8. The method according to any one of claims 1 to 7, characterized in that The polyorganosiloxane emulsion has an octamethylcyclotetrasiloxane (D4) content of less than 0.1% by weight, based on the total weight of the polyorganosiloxane emulsion.

9. Storage-stable aqueous polyorganosiloxane emulsions, including (A) at least one polyorganosiloxane having the general formula: R 2 a (R 1 O) b SiO (4-a-b) / 2 (I), in R 1 may be the same or different and are a hydrogen atom or a monovalent, substituted or unsubstituted hydrocarbon group, R 2 may be the same or different and are monovalent, substituted or unsubstituted hydrocarbon groups having 1 to 30 carbon atoms or hydrogen atoms, a is 0, 1, 2, or 3, b is 0, 1, 2, or 3, The condition is that the sum of a+b is ≤3, (B) at least one alkyl polyglycoside of the following general formula: AOG m (II) in A is a linear or branched, saturated or unsaturated alkyl group having 8 to 24 carbon atoms, G is a glycosidic group, and m is the degree of glycosylation and is an integer ranging from 1 to 5 on average, (C) Water, Optionally (D) another emulsifier different from the alkyl polyglycoside (B), Optionally (E) Thickener and optionally (F) further additives usually present in polyorganosiloxane emulsions, Features (i) a total of 1.5 to 4.5 parts of alkyl polyglycoside (B) are present per 100 parts of polyorganosiloxane (A), (ii) a total of 0 to 3 parts of additional emulsifier (D) per 100 parts of polyorganosiloxane (A), (iii) the total number of parts per 100 parts of polyorganosiloxane (A), alkyl polyglycoside (B) and additional emulsifier (D) is ≤ 4.5, and (iv) the emulsion is produced by a method comprising the following steps: (1) preparing an emulsifier-water mixture comprising at least one alkyl polyglycoside (B) and water (C) and optionally further emulsifiers (D), optionally thickeners (E) and optionally further additives (F), (2) preparing a preliminary emulsion by adding at least one polyorganosiloxane (A) to the emulsifier-water mixture, provided that the preliminary emulsion is prepared under the action of low shear forces using a stirring device having a maximum peripheral speed of 4.5 m / s, Optionally (3) diluting the preliminary emulsion by adding further water (C), and optionally (4) adding another additive (F), Provided that the polyorganosiloxane emulsion has a particle size D(50) of 1 μm to 50 μm.

10. The polyorganosiloxane emulsion according to claim 9, characterized in that: As polyorganosiloxane (A) used are polydimethylsiloxanes having a viscosity of 10 000 mPa·s to 3 000 000 mPa·s (determined at 25° C. in accordance with DIN 53019).

11. The polyorganosiloxane emulsion according to claim 9 or 10, characterized in that: Alkyl polyglycoside (B) having an average saturated alkyl group having 8 to 14 carbon atoms and an average glycosylation degree m of 1.1 to 3.0 is used.

12. The polyorganosiloxane emulsion according to claim 9, 10 or 11, characterized in that No additional emulsifier (D) was present.

13. The polyorganosiloxane emulsion according to any one of claims 9 to 12, characterized in that As thickener (E), 0.1 to 1 part of xanthan gum is used per 100 parts of polyorganosiloxane (A).

14. The polyorganosiloxane emulsion according to any one of claims 9 to 13, characterized in that The instability index of the polyorganosiloxane emulsion after centrifugation at 2300×g for 8 h was <0.

1.

15. The polyorganosiloxane emulsion according to any one of claims 9 to 14, characterized in that The polyorganosiloxane emulsion has a particle size D(50) of 3 μm to 20 μm.

16. The polyorganosiloxane emulsion according to any one of claims 9 to 15, characterized in that The polyorganosiloxane emulsion has an octamethylcyclotetrasiloxane (D4) content of less than 0.1% by weight, based on the total weight of the polyorganosiloxane emulsion.

17. Use of the polyorganosiloxane emulsion according to any one of claims 9 to 16 or prepared according to any one of claims 1 to 8 in cosmetic preparations.

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