DE4400272A1 - Release agent for hydraulic binder, esp. concrete or shell mould - Google Patents

Abstract

Release agent (I) for hydraulic binder is based on (a) a water-immiscible monofunctional alcohol (I) which is liquid at 5-15 deg C, selected from 12-22 C unsatd. fatty alcohols with an I2 no. of 40-170, 16-28 C Guerbet alcohols, 8-15 C oxo-alcohols and/or 6-10 C satd. alcohols and (b) opt. other water-immiscible organic cpds. as the oil components; (c) opt. other release agents normally used for these binders; and (d) water. The novelty is that (I) also contains (e) 0.5-5 wt.% emulsifier w.r.t. the oil components (a) and (b). Also claimed is a concentrate for the prepn. of (I).

Description

Field of the Invention

The invention is in the field of release agents for loading clay formwork and forms and describes new ones with water immiscible, liquid at temperatures of 5 to 15 ° C, agents containing monofunctional alcohols for this purpose.

State of the art

Release agents for concrete formwork and forms are e.g. B. from the corresponding guideline of the main committee "concrete techno of the German Concrete Association, Wiesbaden, from 1980 or from H. Reul, Handbuch Bauchemie, Verlag für chem. Indu strie, Ziolkowsky AG, Augsburg, 1991, pp. 319f. she are placed on the formwork before placing the fresh concrete applied. When stripping, the release agents should reduction between concrete and formwork and damage to avoid the concrete surface and formwork. The number the technically possible uses of the formwork material thereby be increased.  

The release agents generally contain an oil component, as well as various additives, e.g. B. rust inhibitor, Antioxidants, antipore agents, preservatives, mesh agents, adhesives and emulsifiers.

Different substance classes or their are used as oil components Mixtures used, e.g. B. mineral oils or white oils, waxes, Triglycerides based on vegetable or animal oils or fats or fat derivatives.

The use of the concrete release agent is particularly advantageous in the form of an aqueous emulsion. If this application is ge is desired, the release agents usually contain Emulsifiers such as soaps, ethoxylated fatty acids and ethoxylated alkylphenols or petroleum sulfonates in amounts of about 10 to 30% by weight based on the oil component. More common The release agents are delivered to the place of use not as an emulsion, but in the form of a concentrate, which is diluted immediately before use.

The release agents used today have different after parts. Mineral oils or white oils are unacceptable as an oil component sufficiently biodegradable. Native triglycerides, e.g. B. Turnip oil is biodegradable, but has relatively high viscosities that are unfavorable for use. It can also be caused by saponification of the oil by alkaline Components of the concrete come to precipitate Ca soaps, the so-called sanding, which occurs during the further processing of the Concrete can cause liability problems. Analog behavior show fatty acid esters. It has already been suggested by Use of fatty alcohol distillation residues Remedy to create, but it has been shown that this  Only use compounds in a proportionate form as an oil component can be det as z. B. in DD-A52 90 439 be is written. 80 to 90% by weight is used here as the oil component. Mineral oil used, the 4 to 10 wt.% Of a mixture of saturated and unsaturated wax esters with 32 to 36 Koh len atoms, saturated and unsaturated fatty alcohols with 24 to 32 carbon atoms and hydrocarbons, as in the distillation of fatty alcohols as a residue arises, is added. The ones present in the mixture Wax esters can also saponify and thereby the above trigger the liability problems described.

There is therefore an increasing need for an oil component for concrete release agents that are readily biodegradable without the disadvantages of previously known compounds such as high viscosity to show surface defects or sanding.

The requirements for an environmentally compatible concrete release agent are in the RAL UZ 64 "biodegradable lubricant fabrics and formwork oils "from June 1991.

Also used for the production of aqueous emulsions set emulsifiers are not application technology unproblematic. To date, the emulsions had to be prepared relatively large amounts of emulsifier are used, which but negatively affects the rain resistance of the release agents becomes. In addition, with a high emulsifier content at the limit re-emulsification to the alkaline cement with part of the release agent in the surface of the concrete penetrates. These release agent residues can then later become the  problems with the liability of paints already mentioned or cleaning.

The object of the invention is to provide concrete release agents To make available whose oil components are monofunctional, immiscible with water, at temperatures from 5 to 15 ° C contain liquid alcohols and the disadvantages for these purposes of known compounds such as sanding, surface deficiencies and liability problems, which in part ent stand that the native oils used are not saponifying are stable, do not have. Another task of the Er is a concrete release agent whose oil components are monofunk tional, immiscible with water, at temperatures of Contain 5 to 15 ° C liquid alcohols place, possibly in the presence of small amounts Emulsifiers also stable in the temperature range from 0 to -5 ° C Form emulsions. The viscosity of the emulsions must go on be so low that they can be sprayed easily can. Uniform wetting must also be combined with a good adhesion to the most diverse Scha materials are guaranteed.

Description of the invention

The invention relates to mold release agents for concrete, the are characterized by the fact that they

• a) a water-immiscible, at temperatures of  5 to 15 ° C liquid, monofunctional Alcohol component with 6 to 30 carbon atoms,
• b) other, if not water-miscible organic compounds, where a) and b) form the oil component,
• c) if desired, an emulsifier,
• d) if desired, further, in mold release agents for Concrete auxiliaries,
• e) and, if desired, water contain.

Another object of the invention relates to the use of unsaturated fatty alcohols 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 C atoms and / or saturated alcohols with 6 to 10 C atoms as preferably the only oil component for concrete release agents.

Oil component

It has been found to be monofunctional, with water immiscible, liquid at temperatures of 5 to 15 ° C Allow alcohols to emulsify particularly easily. The emulsification already works without the need to add an emulsifier; by adding small amounts of emulsifiers, the quali emulsions are significantly improved.  

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

Liquid at temperatures of 5 to 15 ° C means that the alcohols according to the invention or mixtures of alcohols fluids that are mobile at these temperatures represent.

It has been found that higher alcohols from the class of unsaturated fatty alcohols, Guerbet alcohols, 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 according to the invention are known compounds that are characterized by partial Hy Fats or fatty acid methyl esters available are. The fats and oils used as the raw material base are not pure chemical compounds, but their fatty acids have a C chain distribution and can be used in saturated, mono- or polyunsaturated form. Dement speaking also have the Fettal made from them kohole a C chain distribution and can be saturated, simple or contain 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 tie Rischen origin used, for. B. palm kernel oil, tallow, rapeseed oil, Soybean oil, palm oil and sunflower oil.  

The use of an unsaturated is particularly preferred Fatty alcohol based on tallow and / or rapeseed oil, which too can be used without distillation.

Guerbet alcohols can also be used according to the invention. Guerbet alcohols are known per se, with alkali catalyzed condensation of aliphatic alcohols Temperatures of around 200 ° C available. In the condensate Onsreaktion alcohols with 8 to 22 carbon atoms can be used become. Linear alcohols with 8 to 14 carbon atoms are preferred. Atoms used for condensation are preferred among those 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 become. 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 oil components described above can be given if necessary after adding the expert for these purposes known additives, e.g. B. rust inhibitors, antioxidants, Antipore agents, preservatives, wetting agents and Adhesives can be used as concrete release agents.  

In addition to the alcohols according to the invention, the oil component - in minor amounts up to 15% by weight - also others for oils suitable for this purpose, such as fatty acid esters, triglycerides and - although not preferred - contain mineral oil.

If an emulsion application is desired, emulsifiers can also be added.

Emulsifier

The oil components according to the invention can be surprising therefore more suitable already by adding small amounts Convert emulsifiers into stable emulsions.

The known W / O and are suitable as emulsifiers O / W emulsifiers, such as. B. ethoxylates of fatty alcohols or Alkylphenols, ethoxylates of fatty acids, fatty acid monogly cerinester, soaps of fatty or resin acids and the like. The sodium or potassium soaps from are particularly suitable saturated or unsaturated fatty acids with 12 to 22 carbon atoms, e.g. B. sodium stearate or potassium oleate. For the production the concrete release agents according to the invention are the emulsifiers in amounts of 0.5 to 10% by weight, if desired, preferred 0.5 to 3% by weight, based on the oil component, is added.

Stable emulsions can be obtained by emulsifying in water produce, even at low temperatures from 0 ° C to -5 ° C are stable. An improvement in cold stability can through measures known per se, such as the addition of water soluble polyacrylates in amounts of 0.05 to 0.5% by weight,  preferably 0.1 to 0.2% by weight, based on the emulsion be enough.

The manufactured from the concrete release agents according to the invention Emulsions can have a solids content of 5 to 55% by weight, preferably have 20 to 40% by weight. The so produced Emulsions are thin to viscous and have water as continuous phase.

It is also possible to use the concrete release agents according to the invention in the form of highly viscous pastes in the form of a water-in-oil emulsion to formulate by adding the amount of water added dimensioned so that pastes with a solids content of 60 to 85 wt.%, Preferably 70 to 80 wt.% Arise.

Additives

In addition to the oil component and the emulsifiers, the concrete release agents according to the invention are also conventional additives such as rust inhibitors, antioxidants, antipore agents, Kon preservatives, stabilizers, wetting agents and adhesives in amounts up to 15% by weight - based on the total agent without water - included.

Manufacturing

The release agents are produced in that the oil component with the emulsifier and, if necessary, the additive substances are intimately mixed. This so-called concentrate  can be used directly or after emulsification in water the.

The emulsification is preferably carried out so that the concentrate un ter stirring is incorporated into water.

application

The release agents can be in pure form or in the form of their Emulsion by spraying, spraying, brushing, brushing or Brushes are applied to the formwork surfaces. The low-viscosity emulsions are so stable that they have no Pro are sprayable. Highly viscous pastes can also pass through Spatulas are applied.

The concrete release agents according to the invention can be used alone or in Form their aqueous emulsions for steel, plastic or Wooden formwork can be used in concrete construction. The application can be done with the usual units.  

Examples

All percentages in the examples are understood, provided not otherwise stated, in percent by weight.

example 1 Manufacture of a concrete release agent concentrate

990 g of an unsaturated fatty al alcohols (C chain distribution 1% C12, 4% C14, 12% C16, 82% C18, 1% C20, iodine number 92.6) at 100 ° C with 10 g sodium stearate mixes and stirred for 10 minutes.

1000 g of a homogeneous, were obtained at room temperature gel-like concentrate.

emulsion

300 g of this concentrate were stirred into 700 g of lei given water. A milky emulsion was obtained, the stable against over 4 weeks at room temperature (approx. 23 ° C) Sedimentation or creaming remained.

The viscosity was 1700 cPs (centiPoise), determined with the Brookfield viscometer, spindle 4, at 23 ° C.

Emulsion concentrate

500 g of this concentrate and 500 g of tap water were included a high-speed agitator to a milky, viscous Emulsion stirred. The emulsion had a viscosity of 3200 cPs, determined with the Brookfield viscometer, Spindle 4, at 23 ° C.  

This emulsion concentrate can be mixed with further tap water by simply stirring into stable emulsions with solids kept from 5 to 40 wt.% are transferred.

Further examples are shown in Table 1.  

Table 1

Composition and behavior of concrete release agents

Oil component A is an unsaturated fatty alcohol with a C chain distribution 1% C12, 4% C14, 12% C16, 82% C18, 1% C20 and an iodine number of 92.6, determined according to the Method C V 11b of the German Society for Fat Research.

Oil component B is an unsaturated fatty alcohol with a C chain distribution 1% C12, 2% C14, 8% C16, 87% C18, 2% C20 and an iodine number of 95.1, determined according to the Method C V 11b of the German Society for Fat Research.

Oil component C is a Guerbet alcohol with 16 carbon atoms.

Oil component D (not according to the invention) is a mixture of saturated fatty alcohols with an iodine number of <0.5 and the following C chain distribution:
1% C10, 54% C12, 23% C14, 10% C16 and 12% C18.

The experiments show that only with the fat according to the invention alcohols and Guerbet alcohols stable, sprayable emulsi onen are producible.

With a solids content of 70%, a highly viscous product is produced Paste that can either be applied with a spatula or with Dilute a low-viscosity emulsion to 30% solids results.

The comparative experiments with the saturated fatty alcohol were found ben despite increasing the amount of emulsifier and reducing the Solid a thickened, highly viscous emulsion that is not can be sprayed.  

Example 12 Cold stability test

The emulsion prepared according to Example 1 was on Cooled down to -5 ° C. The emulsion remained up to this temperature stable.

Example 13 Application attempt

The emulsion prepared according to Example 1 was with sprayed on vertical structural steel surfaces using a sprayer. A uniform oil film with good adhesion was obtained.

Example 14 Testing for separating effects

A form of formwork boards was made with the one according to Example 1 produced emulsion sprayed and poured with concrete. After curing, the formwork could easily be removed become. The wood structure was good on the concrete surface detect. Sanding or other surface defects could cannot be determined.

Claims (13)

1. mold release agent for concrete, characterized in that it

• a) a water-immiscible, monofunctional alcohol component which is liquid at temperatures of 5 to 15 ° C. and has 6 to 30 carbon atoms,
• b) if desired, other, water-immiscible organic compounds, a) and b) forming the oil component,
• c) if desired, an emulsifier,
• d) if desired, other auxiliaries customary in mold release agents for concrete,
• e) and, if desired, contains water.

2. Mold release agent for concrete according to claim 1, characterized in that it

• a) from 68 to 100% by weight of a water-immiscible, monofunctional alcohol component which is liquid at temperatures of 5 to 15 ° C. and has 6 to 30 carbon atoms,
• b) if desired up to 12% by weight of other, water-immiscible organic compounds, a) and b) forming the oil component,
• c) if desired up to 8% by weight of an emulsifier,
• d) if desired up to 12% by weight of further auxiliaries customary in mold release agents for concrete, the sum of a) + b) + c) + d) being equal to 100% by weight,

consists.   3. Mold release agent for concrete according to claim 1, characterized in that it consists of
5-85% by weight of an organic phase composed of oil component, auxiliaries and emulsifier and
95-15% by weight water,
consists. 4. mold release agent for concrete according to claim 1 and 3, characterized in that it consists of
15-55% by weight of an organic phase composed of oil component, auxiliary substances and emulsifier and
85-45% by weight water,
consists. 5. mold release agent for concrete according to claims 1 to 4, characterized in that not with water miscible, liquid at temperatures from 5 to 15 ° C, monofunctional alcohol component unsaturated Fatty alcohols 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 C atoms and / or saturated alcohols with 6 to 10 Represents carbon atoms. 6. mold release agent for concrete according to claims 1 to 5, characterized in that not with water miscible, liquid at temperatures from 5 to 15 ° C, monofunctional alcohol component unsaturated  Fatty alcohols with predominantly 16 to 18 carbon atoms as well Represents iodine numbers in the range of 70 to 100. 7. mold release agent for concrete according to claims 1 to 6, characterized in that the emulsifiers in quantities from 0.5 to 10% by weight, preferably 0.5 to 3% by weight on the oil component from alcohol component and other, not water-miscible organic Connections - are included. 8. mold release agent for concrete according to claims 1 to 7, characterized in that the emulsifying agent soaps of saturated or unsaturated fatty acids with 12 to Represent 22 carbon atoms. 9. mold release agent for concrete according to claims 1 to 8, characterized in that the auxiliary rust preservatives, antioxidants, antipore agents, preservatives Curing agents, stabilizers, wetting agents and Represent adhesive. 10. mold release agent for concrete according to claims 1 and 3 to 8, characterized in that the stabilizers represent water-soluble polyacrylates and in amounts of 0.05 to 0.5% by weight, based on the emulsion be used. 11. mold release agent for concrete according to claims 1 to 10, characterized in that the others are not water-miscible organic compounds fat represent acid esters, triglycerides and / or mineral oil.   12. Using unsaturated fatty alcohols with 12 to 22 carbon atoms and iodine numbers in the range of 40 to 170 and / or Guerbet alcohols with 16 to 28 C atoms and / or oxo alcohols with 8 to 15 carbon atoms and / or alcohols with 6 to 10 carbon atoms as Oil component, preferably as the sole oil component for concrete release agents.