DE19502892A1 - Process for the preparation of oil-in-water emulsions containing liquid alcohols - Google Patents

Abstract

In order to prepare stable liquid alcohol-containing oil-in-water emulsions, a mixture of (a) 1 part per weight of an oil component consisting of (i) maximum 70 parts per weight water-immiscible monofunctional alcohols with 6 to 30 C atoms liquid at temperatures from 5 to 15 DEG C and (ii) at least 30 parts per weight of another, non water-miscible organic compound; (b1) 0.1 to 0.5 parts per weight of a non-ionic emulsifier with an HLB value from 11 to 15; optionally (b2) up to 0.2 parts per weight of a co-emulsifier from the group of the saturated fatty alcohols with 16 to 22 C atoms or of the partial esters of polyols with 3 to 6 C atoms with saturated fatty acids with 14 to 22 C atoms; (c) 1 to 6 parts per weight water; and optionally (d) other usual releasing agents for hydraulic binders, is transformed into a finely dispersed oil-in-water emulsion of low viscosity at a temperature above or within the phase inversion temperature range.

Description

Field of the Invention

The invention relates to a method for producing oil-in-water emulsions and liquid alcohols their use as release agents for hydraulic binders.

State of the art

It is known that oil-in-water emulsions with non-ionic emulsifiers are produced when heated undergo phase inversion, d. that is, at higher temperatures The outer, aqueous phase becomes the inner phase can. This process is usually reversible, so that when cooling down the original emulsion type forms. F. Schambil, F. Jost and M. J. Schwuger report in "Progress in Colloid & Polymer Science 73", (1987), 37-47 on properties of cosmetic emulsions of paraffin oil and Paraffin oil-ester oil mixtures and also describe that Emulsions above the phase inversion temperature a lower viscosity and a high one Have storage stability.  

From DE-A-38 19 193 liquid oil-in-water emulsions are po larer oil components known at a temperature in the loading range of the phase inversion temperature interval or above were produced and therefore low viscosity, fine and are very stable. When using specially selected Such emulsions are emulsifiers and co-emulsifiers finely divided so that their particles are no longer visually visible are. Such emulsions that are transparent, bluish have an opalescent appearance, are also called microemulsi referred to.

The use of fatty alcohols as mold release agents for hy Draulic binders are known. GB 1 294 038 be writes mold release agents based on aliphatic, saturated or unsaturated alcohols and a cationic emulsifier.

EP-A 561 465 proposes emulsifiable mold release agents for hydraulic binders based on fatty acid esters from Polyols that do not have any H atoms in the β position to the OH group gen, before. The esters can also be higher aliphatic monofunctional alcohols are added.

The emulsions are prepared in that the form release agents with stirring units are emulsified in water. This method has several disadvantages; it can e.g. B. too Problems with emulsion stability are coming. The viscosity the emulsions can increase during storage, for example, or else the oil component can be removed by creaming separate. Some of these disadvantages can be overcome by doing so avoid using special emulsifying units that make it possible to produce particularly fine-particle emulsions.  

The operation of such units is time and expensive.

The object of the invention was to provide a method for ver to provide that avoids the disadvantages mentioned above and it allows stable, liquid alcohols as an oil component to provide containing emulsions available as Mold release agent for hydraulic binders use las sen.

Stability in this context means that the emulsion at least 1/2 year, better 1 year at room temperature neither cream still thickened. When storing and transporting the emul sions occur temperature fluctuations, which the stability also must not interfere. It is therefore wonderful it is worth it that the emulsions against short-term tempera fluctuations between 5 and 40 ° C are stable, i.e. neither cream still thicken.  

Description of the invention

The invention relates to a method for producing of oil-in-water emulsions by making a mixture of

• a) 1 part by weight of an oil component
  • i) at most 70% by weight of water-immiscible, monofunctional alcohols with 6 to 30 C atoms that are liquid at temperatures of 5 to 25 ° C.
  • ii) at least 30% by weight of another, water-immiscible organic compound
• b1) 0.05-0.5 parts by weight of a nonionic emulsifier with an HLB value of 10-16 and
• b2) if desired up to 0.2 parts by weight of a Coemul gators from the group of saturated fatty alcohols 16-22 carbon atoms or the partial ester of polyols 3-6 carbon atoms with saturated or unsaturated Fatty acids with 14-22 carbon atoms and
• c) 1-6 parts by weight of water,
• d) if desired, further, in mold release agents usual auxiliary materials for hydraulic binders

at a temperature above or within the phase version temperature range into a low viscosity, very fine oil-in-water emulsion transferred.

Another object of the invention is the use of Emulsions produced by the process according to the invention for the treatment of formwork material in concrete construction.  

For the purposes of the invention, are not mixed with water Alcohols understood those whose solubility in what ser at 20 ° C is less than 5 wt .-%.

Liquid at temperatures of 5 to 25 ° C means that the alcohols according to the invention or mixtures of alcohols fluids that are mobile at these temperatures represent. Alcohols are preferred within the meaning of these definitions nition that are liquid at temperatures of 5 to 15 ° C.

It has been found that higher alcohols from the class of unsaturated fatty alcohols, the Guerbet alcohols, the Oxo alcohols and saturated alcohols with 6 to 10 carbon atoms are particularly suitable in the sense of the invention.

The unsaturated fatty alcohols used are per se known compounds by partial hydrogenation of Fats or fatty acid methyl esters are available. As The raw materials used fats and oils are not pure chemical compounds, but their fatty acids a C chain distribution and can be saturated, simple or polyunsaturated form. Accordingly the fatty alcohols made from them also have one C chain distribution and can be saturated, simple or more polyunsaturated species.

The unsaturated fatty alcohols can be from 12 to 22, before preferably 16 to 18 carbon atoms exist and iodine numbers in the Be range from 40 to 170, preferably from 70 to 100. As a raw material base, fats and oils are vegetable and  used of animal origin, e.g. B. palm kernel oil, coconut oil, Tallow, rapeseed oil, soybean oil, palm oil and sunflower oil.

The use of an unsaturated is particularly preferred Fatty alcohol based on tallow, sunflower oil with a Oleic acid content <80 wt .-% and / or rapeseed oil, which also without De Stillation can be used.

Guerbet alcohols can also be used. Guerbet alcohols are known per se, catalyzed with alkali Condensation of aliphatic alcohols at temperatures of about 200 ° C available. Can in the condensation reaction Alcohols with 8 to 22 carbon atoms can be used. Prefers are linear alcohols with 8 to 14 carbon atoms for the Kon densation used, the preferred used Guerbet alcohols with 16 to 28 carbon atoms.

So-called oxo alcohols can also be used the. These are mostly primary, some ver branched higher alcohols obtained in oxo synthesis will. In this synthesis, the addition of Aldehydes of carbon monoxide from olefins with hydrogen reduced to alcohols with, for example, 8 to 15 carbon atoms.

Finally, the use of saturated alcohols is up native or synthetic base with 6 to 10 carbon atoms possible Lich.

The proportion of alcohol in the oil component is high at least 70% by weight, preferably at most 50% by weight, based on the oil component.  

As another, water-immiscible organic compound are all liquid at room temperature (20 ° C) water-insoluble, branched or linear hydrocarbon substances, ethers or esters as well as fatty oils (triglycerides) be set. But it can also be solid or higher melting such paraffins, esters, waxes or fats in such quantities be used that the mixture with the liquid oil components remains liquid at 20 ° C.

Are preferred as other, not water-miscible organic compound mineral oils and synthetically manufactured Hydrocarbons, e.g. B. liquid polyolefins or defi nated hydrocarbons, e.g. B. alkylcyclohexanes such. B. 1,3-diisooctylcyclohexane.

However, mono- and diesters of the formulas are also suitable

R¹-COOR² (I)
R²-OOC-R³-COOR² (II)
R¹-COO-R³-OOC-R¹ (III)

wherein R¹ and R² alkyl groups with 1-22 C atoms or alkene nyl groups with 8-22 carbon atoms and R³ alkylene groups with Are 2-16 carbon atoms and which contain at least 10 carbon atoms, and / or fatty acid triglycerides of fatty acids with 8-22 C atoms.

Oil components of the type of the mono- and diesters of the formulas I, II and III are cosmetic and pharmaceutical oil components ten and known as lubricants and lubricants. Among the mono and diesters of this type comes the  Room temperature (20 ° C) liquid products the greatest importance tion to. Suitable as oil components monoesters (I) z. B. the methyl esters and isopropyl esters of fatty acids with 12-22 C atoms, such as B. methyl laurate, methyl stearate, methyl oleate, Methyl erucate, isopropyl palmitate, isopropyl myristate, isopro pylpalmitate, isopropyl stearate, isopropyl oleate. Other suitable nete monoesters are e.g. B. n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl palmitate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitate, oleyl oleate, Oleylerucat, erucyl oleate and esters, which are made from technical aliphatic alcohol mixtures and technical aliphatic Carboxylic acids are available, e.g. B. esters of saturated and unsaturated fatty alcohols with 12-22 carbon atoms and sown saturated and unsaturated fatty acids with 12-22 carbon atoms, such as they are accessible from animal and vegetable fats.

In particular, the esters can also be saturated and unsaturated saturated fatty acids with 12-22 carbon atoms and polyols from Neopentyl type, such as neopentyl glycol, trimethylol propane, tri methylolethane, pentaerythritol, ditrimethylpropane, dipentaery thritol and tripentaerythritol can be used.

However, the ethers of alcohols with more than are also suitable 6 carbon atoms, preferably up to 18 carbon atoms, such as. B. Di-n-hexyl ether, di-n-octyl ether or di-n-decyl ether.

Suitable dicarboxylic acids (II) are e.g. B. di-n-butyl adipate, Di-n-butyl sebacate, di- (2-ethylhexyl) adipate, di- (2-hexylde cyl) succinate and di-isotridecyl acelaate. Suitable diol esters (III) are e.g. B. ethylene glycol dioleate, ethylene glycol diol  isotridecanoate, propylene glycol di (2-ethylhexanoate), Butanediol di-isostearate and neopentyl glycol di-caprylate.

The proportion of other, non-water-miscible organic Connection to the oil component is at least 30% by weight, preferably at least 50% by weight based on the oil composition nente.

Suitable non-ionic emulsifiers are as emulsifiers (b1) characterized by a lipophilic, preferably linear alkyl or Acyl group and a hydrophilic, from low molecular weight Glycol, glucose and polyol ethers. Also ethoxylated castor oils are suitable nonionic Emulsifiers.

Nonionic ethylene oxide suitable as emulsifiers (b1) storage products on fatty alcohols with 16-22 carbon atoms customary. The technical products represent mixtures ho mologer polyglycol ether of the starting fatty alcohols, the average degree of oxyethylation of the added molar amount Corresponds to ethylene oxide. As emulsifiers (b2) can also Ethylene oxide addition products to partial esters from one Polyol with 3-6 C atoms and fatty acids with 14-22 C atoms be used. Such products are e.g. B. by ethoxy lation of glycerol monostearate, glycerol monopalmitate, or of mono- and di-fatty acid esters of sorbitan, e.g. B. from Sorbitan monostearate or sorbitan sesquioleate.

The emulsifiers suitable for the process according to the invention should have an HLB value of 10-16, preferably 11-15,  exhibit. Below the HLB value (hydrophile-lipophile balance) should be understood as a value that can be calculated according to

where L is the weight fraction of the lipophilic groups, i.e. H. of the Fatty alkyl or fatty acyl groups in percent by weight in the Ethylene oxide addition products.

In addition to the emulsifier can be used to manufacture the Oil-in-water emulsions according to the inventive method Coemulsifier (b2) in amounts of up to 0.2, preferably 0.1 up to 0.2 parts by weight can be used. The co-emulsifier is due to its hydrophilicity itself not for the production of Oil-in-water emulsions are suitable, together with the above de Finished emulsifiers can, however, be particularly stable and fine-particle emulsions of the polar oil components put. According to the invention, coemulsifiers are those of Type of saturated fatty alcohols with 16-22 carbon atoms, e.g. B. Cetyl alcohol, stearyl alcohol, arachidyl alcohol or Behenyl alcohol or mixtures of these alcohols are suitable, such as them in the technical hydration of vegetable and tie organic fatty acids with 16-22 carbon atoms or the equivalent The resulting fatty acid methyl ester can be obtained. Still own are partial co-emulsifiers made from a polyol 3-6 carbon atoms and saturated and / or unsaturated fat acids with 14-22 carbon atoms. Such partial esters are e.g. B. the monoglycerides of palmitic, stearic and oleic acid, the sorbitan mono- and / or diesters of myristic acid,  Palmitic acid, stearic acid or mixtures of these fats acids, the monoesters from trimethylolpropane, erythritol or Pentaerythritol and saturated fatty acids with 14-22 C atoms. Technical monoesters also become monoesters understood that by esterification of 1 mole of polyol with 1 mole Fatty acid are obtained and which is a mixture of monoesters, Represent diesters, triesters and possibly unesterified polyol.

It is particularly preferred if the the method according to the invention initially forms an emulsion, which is so finely divided that the emulsion droplets are submicroscopic and the emulsion is a transparent has a bright, bluish opalescent appearance. Such emul Sions are also called microemulsions. Microemulsions are obtained if the type and proportions of Ölkom components emulsifiers and co-emulsifiers in the preferred Are coordinated.

As nonionic emulsifiers (b1) are in a before preferred embodiment addition products of 8-25 mol Ethylene oxide to saturated fatty alcohols with 16-22 carbon atoms used.

In a further preferred embodiment of the invention are used as nonionic emulsifiers ethoxylated castor oils used by adding 5 to 50, preferably 5 to 20 moles of ethylene oxide (EO) per mole of triglyceride were obtained.

In a further preferred embodiment of the invention are used as nonionic emulsifiers with polyfunctional Alcohols, preferably ethylene glycol, ring-opened α-epoxides  with 8 to 18, preferred 12 to 14 carbon atoms, the following with 5 to 25, preferably 7 to 15 moles of ethylene oxide per mole α-epoxy were used.

In a further preferred embodiment of the invention are preferred as nonionic emulsifiers with 5 to 50 7 to 15 mol of ethylene oxide reacted saturated or unsaturated saturated fatty alcohols with 8 to 18, preferably 10 to 14 C atoms.

In a further preferred embodiment of the invention are used as nonionic emulsifiers with mixtures of 1 to 10, preferably 3 to 7 mol ethylene oxide and 1 to 5, preferred 1 to 3 mol of propylene oxide (PO) reacted fatty alcohols with 8 to 18, preferably 10 to 14 carbon atoms.

In a further preferred embodiment of the invention are used as nonionic emulsifiers with 5 to 15 mol Ethylene oxide converted fatty acids with 8 to 22, preferably 10 up to 18 carbon atoms.

In a further preferred embodiment of the invention are used as nonionic emulsifiers with 5 to 15 mol Ethylene oxide converted fatty acid alkanolamides with 8 to 22, preferably 10 to 18 carbon atoms used.

In a further preferred embodiment of the invention are used as nonionic emulsifiers, esters of sorbitan or with up to 40 mol ethoxylated sorbitan with fatty acids with 12 to 22 carbon atoms.  

The method according to the invention can be carried out in this way be determined that the phase inversion temperature by taking a sample of the usual way prepared emulsion using a conductivity meter heated and determined the temperature at which the Conductivity decreases sharply. The specific conductivity The oil-in-water emulsion that was initially present takes a lot usually over a temperature range of 2-8 ° C from initially over 1 millisiemens per cm (mS / cm) to values below 0.1 mS / cm. This temperature range is called phases called inversion temperature range.

Now that the phase inversion temperature range is known, you can either the method according to the invention in the way carry out that one initially manufactured as usual Emulsion subsequently heated to a temperature which is in within or above the phase inversion temperature range lies, or in such a way that one is already in the manufacture the emulsion chooses a temperature that is within or above is half the phase inversion temperature range.

The emulsions prepared according to the invention can be one Solids content of 5 to 60% by weight, preferably 20 to 40% by weight exhibit. The emulsions thus produced are thin liquid to viscous and have water as a continuous pha se.

In addition to the oil component and the emulsifiers, the emulsions still in mold release agents for hydraulic binders  usual auxiliaries such as rust inhibitors, antioxidants, Antipore agents, preservatives, protective colloids, Sta bilisators, wetting agents, defoamers and adhesives in quantities up to 15% by weight - based on the total agent without water - contain.

If the release agent according to the invention for hydraulic bin can be used for steel formwork material the use of an anti-rust agent is recommended as an additive to prevent corrosion on the formwork material to avoid.

One comes as rust preventive or corrosion inhibitor Series of connections in question.

A group of anti-rust agents according to the invention form for example the amines, e.g. B. octylamine, tridecylamine, Dibutylamine, tributylamine, dimethylalkylamines with 8 to 18 Carbon atoms in the alkyl chain or diamines such as ethylenediamine, 1,2-propylenediamine, diethylenetriamine and - preferably - Alkanolamines such as ethanolamine, diethanolamine, triethanolamine, 1-amino-2-propanol, diisopropanolamine, triisopropanolamine, Methylethanolamine, dimethylethanolamine, aminoethylethanol amine, ethylethanolamine, and diethylethanolamine, the one corrosion-inhibiting effect, especially on iron or have ferrous alloys.

Make another group of effective compounds anionic compounds such as sodium, potassium or amine soaps of fatty acids, preferably having 6 to 10 carbon atoms, of Dimer fatty acid or the corresponding compounds of  aromatic mono- or dicarboxylic acids, such as. B. Benzoin or Phthalic acid.

Also the alkali or amine salts of acidic phosphoric acid esters with alcohols with 6 to 18 carbon atoms or phosphoric acid Resalt such as trisodium phosphate are rust inhibitors in the sense of the invention.

Another group of corrosion inhibiting compounds that can be used according to the invention, the amides of fatty acids or dimeric fatty acids with alkanolamines such as Monoethanolamine or diethanolamine, monopropanolamine or Dipropanolamine, or diamines such as ethylenediamine, 1,3-propylenediamine, 1,2-propylenediamine or diethylenetriamine. The latter amidoamines can be used in acids such as Lactic acid neutralized form can be used. Prefers the monoethanolamides become more saturated and unsaturated Fatty acids with 16 to 20 carbon atoms used, especially be prefers the ethanolamide of oleic acid or linoleic acid or technical mixtures of these fatty acids.

Compounds from the triazole class also act such as B. benzotriazole or toluyltriazole corrosioninhi biting.

Because the various corrosion inhibitors are also synergistic can act, it is also possible to mix the pre use named connections.

The amount of added rust inhibitor is 0.01 to 2 wt .-%, preferably 0.1 to 1.0 wt .-% based on the entire means without water.  

The rust preventives can be incorporated into the oil component if they are soluble in it. It is also possible, the rust inhibitor in the for emulsifying the release agent water required for hydraulic binders or after the emulsification into the finished emulsion.

Add the excipients and mix with the previously produced fine-particle, liquid emulsion or micro emulsion is best done in such a way that the Auxiliaries and the emulsion to a mixing temperature of Bring 30-80 ° C and then given with vigorous stirring if using static or dynamic Mixing or emulsifying devices.

Hydraulic binders are mineral Substances that harden like stone under water and after hardening are water-resistant. Preferred hydraulic The binder is concrete.

Various methods are possible to apply the emulsions apply the formwork material to thereby set it of the hydraulic binder to effect the demoulding.

The emulsions can e.g. B. by spraying, spraying, Brush, brush or brush on the formwork surfaces be applied. The low viscosity emulsions are like this stable that they can be sprayed without problems.  

The emulsions can be used to treat steel, plastic or Wooden formwork can be used in concrete construction. The Appli cation can be done with the usual aggregates.

The following examples are intended to illustrate the subject matter of the invention explain without restricting him to this:  

Examples 1. Production of the emulsions according to the invention

The oil components, emulsifiers and co-emulsifiers were ge mixes and to a temperature above the melting point the mixture warmed and homogenized. Then the Melt with stirring in the water, which is about the was heated to the same temperature, given and then briefly (approx. 1 minute) to a temperature in the phase inversion temperature temperature range or slightly above (in all cases play 95 ° C). Then the emulsions were rapidly, i. H. With a cooling rate of approx. 2 ° C per minute, with stirring Cooled to room temperature. After 24 hours the flow was ability and the yield point. All according to Table I, Example 1.1-1.8 microemulsions produced were fluid sig, d. H. movable under the influence of gravity. The yield point was well below 0.1 Pa (20 ° C).

The composition of the emulsions can be found in Table 1 to take.  

Table 1

2. Determination of the phase inversion temperature

Using a conductivity measuring bridge (Radiome ter, Copenhagen) the electrical conductivity of the Emulsions determined depending on the temperature. To for this purpose, the emulsion was first removed to + 20 ° C cools. At this temperature the emulsions showed one  Conductivity greater than 1 millisiemens per cm (mS / cm), d. H. they were in the form of oil-in-water emulsions. By slow Warm up with a heating rate of approx. 0.5 ° C / min using a temperature programmer in conjunction with a Cryostat was controlled, a conductivity diagram was created created. The temperature range within which the guide ability dropped below 0.1 mS / cm was considered Phase inversion temperature range noted. All in Ta belle 1 listed emulsions this temperature range below 100 ° C (Table 1, phase inversion).

Claims (10)

1. Process for the preparation of oil-in-water emulsions by making a mixture of

• a) 1 part by weight of an oil component
  • i) at most 70% by weight of water-immiscible, monofunctional alcohols with 6 to 30 carbon atoms that are liquid at temperatures of 5 to 25 ° C.
  • ii) at least 30% by weight of another, water-immiscible organic compound
• b1) 0.05-0.5 parts by weight of a nonionic emulsifier with an HLB value of 10-16 and
• b2) if desired up to 0.2 part by weight of a co-emulsifier from the group of saturated fatty alcohols with 16-22 carbon atoms or the partial esters of polyols with 3-6 carbon atoms with saturated or unsaturated fatty acids with 14-22 carbon atoms and
• c) 1-6 parts by weight of water,
• d) if desired, further auxiliaries customary in mold release agents for hydraulic binders

at a temperature above or within the Pha seninversion temperature range in a low vis loose, very finely divided oil-in-water emulsion. 2. The method according to claim 1, characterized in that the alcohols from the group of unsaturated fatty alcohol with 12 to 22 carbon atoms and iodine numbers in the range from 40 to 170
and / or Guerbet alcohols with 16 to 28 carbon atoms
and / or oxo alcohols with 8 to 15 carbon atoms,
and / or saturated alcohols with 6 to 10 carbon atoms. 3. The method according to claims 1 and 2, characterized records that the alcohols with unsaturated fatty alcohols predominantly 16 to 18 carbon atoms and iodine numbers in the Be range from 70 to 100. 4. The method according to claims 1 to 3, characterized records that the other, not water-miscible orga a mineral oil, an ether from Alko fetch one ester with more than 6 carbon atoms Dicarboxylic acid, an ester of fatty acids with monofunctional alcohols or an ester of fat acids with neopentyl type polyols or a mixture of the compounds mentioned. 5. The method according to claims 1 to 4, characterized shows that as a nonionic emulsifier (b1) Addition product of 8-25 moles of ethylene oxide on one saturated fatty alcohol with 16-22 carbon atoms becomes. 6. The method according to claims 1 to 5, characterized records that the auxiliaries rust preventive, Antioxidants, antipore agents, preservatives, Protective colloids, stabilizers, wetting agents, defoamers and represent adhesives.   7. The method according to claims 1 to 6, characterized records that the rust inhibitor compounds from the Groups of amines, alkanolamines, fatty acid salts, salts of acidic phosphoric acid esters, phosphoric acid salts and Represent amides of fatty acids. 8. The method according to claims 1 to 7, characterized records that the rust preventive in amounts of 0.01 up to 2% by weight, preferably from 0.1 to 1% by weight on the entire medium without water - are present. 9. Use of emulsions prepared according to the process ren according to claims 1 to 8 for the treatment of Formwork material in concrete construction.