JPS62185776A - Ice removing and ice deposition preventing agent of airplane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aircraft de-icing and anti-icing agents based on glycols and water and containing cross-linked acrylic polymers as thickening agents.

Such an agent is known from US Pat. No. 4,358,389. In detail, it is composed essentially of the following components: (1) 40 to 65% by weight of alkylene glycols having 2 to 3 carbon atoms and oxyalkylene glycols having 4 to 6 carbon atoms; (2) 35 to 60% by weight of water; (3) 0.05 to 1.5% by weight of a 0.5% aqueous solution at 20°C; (7) +1) has a viscosity of 1,000 to 50°000 mPa s and has a viscosity of 0.1 to 1.
Thickeners from the group of crosslinked polyacrylates exhibiting laminar flow behavior at shear rates up to at least 20,000 s in a 5% strength by weight aqueous solution and at a pH value of 7.5, (4) 0.05 ~1% by weight of a water-insoluble component within the group of mixed base mineral oils, (5) 0.05-1% by weight of a surfactant within the group of alkali metal-alkylaryl sulfonates, (6)
0.01-1% by weight of at least one corrosion inhibitor;
and (7) at least one member of the group consisting of alkali metal carbonates, alkali metal hydrogen carbonates, alkali metal hydroxides and amines in an amount such that the entire agent has a pH value of 7.5 to 10. Alkaline Compound □ Provided that the amount of components a) and b) in this agent is at least 94% by weight based on the weight of the nucleating agent □.

This known aircraft de-icing and anti-icing agent has been found to be effective and is already often used. At present, this agent leaves much to be desired in its viscosity-temperature behavior at very low temperatures, such as those prevailing throughout the Arctic region (temperatures of about -20 to about -35°C). For example, under the winter temperatures prevailing in central Europe and its neighboring regions (temperatures from about 0 to about -15°C), low shear rates ("low shear The same is true for "viscosity"). However, temperatures below about -15°C, especially about -20 to about -35°C
At temperatures of , the viscosity is too high, especially at low shear rates.

For example, the viscosity of this product at -25°C using a Brookfield viscometer at 0.3 revolutions 7 minutes (upM) is 50,
000-60.000 mPa s (desired value is 10,0
00 to 40,000 mPa s). How this affects in practice is explained in detail below: for de-icing the surfaces of the aircraft, especially on aerodynamically important surfaces, and for de-icing the aircraft's body when the aircraft is stopped. ) The liquid preparations applied as protection against re-icing are, as is known, completely washed away during take-off and ensure the inherent aerodynamics (in particular lift) of the aircraft during the flight. In the case of the known agents, this occurs quite satisfactorily at all surface areas where high shear rates occur. That is, in this case the viscosity of the nucleating agent decreases rapidly, in effect becoming low viscosity and runs off quickly and completely. At surface areas where relatively low shear rates occur (aerodynamically relatively gentle areas, for example the back of an airplane), the known liquid preparations run off slowly, especially at arctic temperatures; Because the flow is too slow, it still exists in liquid form in the above area after takeoff. In addition to this, modern airplanes have blade structures that are particularly sensitive to icing or dirt, for example. Therefore, to ensure sufficient lift, an airplane should be free of ice and snow. In the case of such aircraft, therefore, it is necessary to provide icing protection even under critical conditions (+1 to -2 DEG C.) and even at the slightest level of frost. In this case, since sufficient lifting force can be obtained on the blades already at the time of startup □, that is, when the rotation starts □, the applied agent needs to exhibit optimal flow-down behavior.

From the above discussion, it can be seen that known aircraft de-icing and anti-icing agents have low Temperatures below -15°C, especially -20°C, to ensure good run-off even at shear rates (i.e. even at aerodynamically moderate locations).
It can be seen that even at temperatures of up to about -35 DEG C., the viscosity must be improved so that the increase is relatively small.

In other words, the direct relationship is the “remaining time” (□ the unavoidable downtime between de-icing and take-off □ the time during which re-icing due to freezing is prevented by the anti-icing agent) and its resting viscosity at a temperature of about In order to achieve the desired degree of agent run-off even in aerodynamically calm locations, it should be significantly reduced.

In short, an aircraft deicing and deicing solution that satisfies the high demands regarding viscosity during takeoff (due to the prevailing aerodynamic behavior) of the aircraft in the entire temperature range from about 0°C to about -35°C. I need to get some anti-ice cream.

Surprisingly, the inventors have found that specific mixtures of crosslinked acrylic acid homopolymers and selected crosslinked acrylamide/acrylic acid copolymers or acrylamide/alkali metal acrylate copolymers are used as thickening agents. and three different and identical compounds as basic (alkaline) compounds for adjusting the pH value of this agent, namely ammonia, monoethanolamine, jetanolamine and/or triethanolamine (the first base known de-icing and anti-icing effects when specific amounts of potassium hydroxide (second basic component), potassium hydroxide (second basic component) and another alkali metal hydroxide (third basic compound) are used. It has been found that the drawbacks of the agent can be eliminated and an agent having the desired properties mentioned above is obtained. The above three types of alkaline compounds of the acrylic polymers are additionally present simultaneously, which have a special influence on both acrylic polymers, e.g. with respect to swelling properties, viscosity and temperature behavior. It has been found that with special combinations the desired viscosity and the desired flow behavior of the nucleating agent can be achieved even at very low temperatures and low shear rates.

New aircraft de-icing and anti-icing agents based on glycol and water and containing cross-linked acrylic polymers as thickening agents have substantially a) 40-70 if weight, especially 50-60 % by weight of glycols from the group consisting of alkylene glycols having 2 to 3 carbon atoms and oxyalkylene glycols having 4 to 6 carbon atoms, b) 0.1 to 1 % by weight, in particular 0.2 to 0. 7% by weight,
A crosslinked copolymer of acrylic acid or alkali metal acrylate and acrylamide (this product contains 10 to 10 copolymerized units of acrylic acid or alkali metal acrylate)
90% by weight, in particular from 20 to 80% by weight and an amount of copolymerized units of acrylamide from 10 to 90fi amount χ, in particular from 20 to 8
0% by weight) and crosslinked homopolymers of acrylic acid or alkali metal acrylates 1 to 10
parts by weight, especially from 3 to 8 parts by weight of a crosslinked acrylic polymer, provided that each of the homopolymers and copolymers contains 5 parts by weight.
．． 000-70. OQQmPa s, especially 10.00
0-50. has a viscosity of OOOmr'a s and O
A prerequisite is a laminar behavior under a shear rate of ~20,000 s-' (this viscosity and laminar behavior are respectively c) 0.05-1% by weight, in particular 0.1-0 .7% by weight
d) 0.01 to 1% by weight, in particular 0.03 to 0.5% by weight, of at least one corrosion inhibitor; e) this removal; Ice and anti-icing agent pif-value of 7.5
~11. In particular, the following basic compounds els eZ and e are used in the following amounts to adjust the pH to 8-10.

e + ) 0, 01-1% by weight, especially 0.05-0
．． 5% by weight of ammonia, monoethanolamine, jetanolamine or triethanolamine or mixtures thereof (first basic component), e2) 0.05-0
．． 7% by weight, in particular 0.07-0.4% by weight of potassium hydroxide (second basic component) and eZ) 0.01-0.5% by weight, especially 0.03-0.
15 parts iiχ of another alkali metal hydroxide (third basic component), and f) remaining water in an amount of % by weight (% by weight is based on the weight of the de-icing and anti-icing agent) (The weight of the finished agent or the entire mixture - the sum of components a) to r) □ is 100% by weight).

Component a) of the deicing and anti-icing agents according to the invention is advantageously ethylene glycol, propylene glycol (1°2-propylene glycol or 1,3-propylene glycol) and/or diethylene glycol.

Component b) comprises specific weight proportions of two selected crosslinked acrylic polymers, namely crosslinked homopolymers of acrylic acid or alkali metal acrylates (in particular sodium or -potassium acrylate) and 10 ~90
% by weight of copolymerized acrylamide, in particular 20-80 wt.
% by weight, in particular from 20 to 80% by weight (wt. % based on the copolymer) of copolymerized acrylic acid or copolymerized alkali metal acrylate (in particular sodium or -potassium acrylate). based on 1 part by weight of copolymer, 1 to 10 parts by weight, in particular 3 to 8 parts by weight, of homopolymer are present. Both crosslinked acrylic polymers also have a specific viscosity and specific flow behavior, i.e. 5,000-70,000 mP.
a s , especially 10. OOO~50.000mPas
Viscosity (by Brookfield viscometer at 20 revolutions/min in a 0.5χ aqueous solution with a pH of 7 at 20°C)
and O ~ 20,000 in a rotational viscometer (high shear rotational viscometer) in a 0.5χ aqueous solution with a pH value of 7 at 20°C.
A fluid exhibiting laminar flow behavior under a shear rate of s-1 is used. The flow curves (viscosity profile) obtained at shear rates from 03-1 to high values of 20,0 OOS −' indicate whether laminar or non-laminar flow occurs.

Both acrylic polymers used according to the invention are known and commercially available. It is important to have the above characteristics and properties. Suitable are crosslinked acrylic polymers which are commercially available under the name polyfunctionally statistically crosslinked acrylic polymers. Homopolymers - e.g. U.S. Pat. No. 2,798.053 and U.S. Pat.
m- as described in detail in No. 23.692
, acrylic acid or alkali metal acrylates are polymerized in the presence of a radical initiator (catalyst) and a crosslinking agent having at least a molecular photopolymerization agent, in particular CII z , 7J, and the polymer dispersion is processed into powder form. Manufactured by obtaining a polymer. For the polymerization of acrylic acid, water-immiscible organic solvents such as benzene, toluene, hexane,
Heptane and their analogs are used and for the polymerization of the acrylate water or water-like liquids are used.

Of both crosslinked homopolymers □, i.e. acrylic acid homopolymer and alkali metal acrylate homopolymer □,
The former polymers are particularly advantageous in the present invention. The copolymer is produced by copolymerizing acrylamide and acrylic acid or alkali metal acrylate in the presence of a radical initiator and the above-mentioned crosslinking agents and obtaining a powdered copolymer from the copolymer dispersion. This copolymerization is also carried out using suitable solvents (see, for example, both US patents mentioned above). Another method of making this copolymer is described in detail in US Pat. No. 4,237,249. According to this, acrylamide is polymerized in a water-miscible alcohol in the presence of a radical initiator and the crosslinking agent mentioned above, and the resulting polymer dispersion is treated with an alkali metal hydroxide, especially sodium or potassium hydroxide. The treatment saponifies the appropriate amount of amide to obtain the desired alkali metal acrylate groups, and then obtains a powdered acrylamide/alkali metal acrylate copolymer. Both crosslinked copolymers - namely the copolymer of acrylic acid and acrylamide and the copolymer of alkali metal acrylate and acrylamide - are prepared in the present invention by the method of U.S. Pat. No. 4,237,249. Particular preference is given to alkali metal acrylate/acrylamide copolymers prepared according to the method.

Common crosslinking agents are described in U.S. Pat. Nos. 2,798,053, 2,923,692 and 4,23.
7.249, hydrocarbons having a plurality (especially two to five) of unsaturated bonds, such as the group of vinylbenzene, divinylnaphthalene, and polybutadiene; Esters with ~5) unsaturated bonds, such as allyl acrylate, crotyl acrylate, ethylene glycol diacrylate, glycerin diacrylate, glycerin triacrylate, diallyl phthalate, diallyl oxalate, diallyl citral and triallylicitral, and correspondingly methacrylates and methallyl esters and ethers with multiple (in particular 2 to 5) unsaturated bonds, such as diallyl ether, diallyl ethylene glycol ether, diallyl propylene glycol ether, trimethylolethane or trimethylol. Di- or triallyl ether of propane, di- or triallyl ether of glycerin (also polyglycerin, especially di-decaglycerin), tetraallyloxyethane and
di-, tri-, tetra- or penta-allyl ethers of sugar alcohols, such as erythritol, pentaerythol, arabitol, xylitol, dulcitol, mannitol, sorbitol, di-, tri-, tetra- or penta-allyl ethers of glucose and sucrose; There are corresponding members of the group of meta-allyl ethers. Particularly preferred crosslinkers are those from the group of ethers with multiple unsaturations, among them diallyl ethers, di- or triallylglycerol ethers, di- or triallyltrimethylolethane ethers, di- or triallyl- Particularly suitable are trimethylolpropane ether, tetraallyloxyethane and the di-, tri-, tetra- or pentaallyl ethers of sugar alcohols and the corresponding metaallyl ethers.

The amount of crosslinking agent in the homopolymer and in the copolymer is generally from 0.1 to 10% by weight, in particular from 1 to 5% by weight, based on the homopolymer or copolymer.

The crosslinked homopolymer used according to the invention therefore consists essentially of polymerized alkali metal acrylates (advantageously alkali metal acrylates or Na).
or polymerized acrylic acid and 0.1 to 10% by weight, in particular 1 to 5% by weight, based on the polymer, of a polymerized crosslinking agent. In other words, from 90 to 99.9% by weight, especially from 95 to 99% by weight of polymerized alkali metal acrylate or polymerized acrylic acid and from 0.1 to 10% by weight, especially from 1 to 5% by weight of polymerized crosslinking agent. (% by weight based on polymer). Of both polymers, as mentioned above, a polymer containing acrylic acid as a main component (acrylic acid homopolymer) is advantageous.

The crosslinked copolymers used according to the invention as described above contain substantially 10 to 90% by weight, especially 20 to 80% by weight of polymerized alkali metal acrylates (advantageously alkali metal or Na) or polymerized acrylic acid and 10
Consisting of ~90% by weight, in particular 20-80% by weight, of polymerized acrylamide and 0.1-10% by weight, in particular 1-5% by weight of polymerized crosslinking agent (% by weight based on the polymer □ That is, the total of polymerized alkali metal acrylate or acrylic acid, acrylamide and crosslinking agent is 100% by weight □). In other words, the crosslinked copolymer essentially contains, for example, from 10 to 89.9% by weight2, in particular from 20 to 75% by weight of polymerized alkali metal acrylate or acrylic acid, from lO to 89.9% by weight, in particular It consists of 20-75% by weight of polymerized acrylamide and 0.1-10% by weight, in particular 1-5% of polymerized crosslinking agent (% by weight based on the polymer). Of both polymers, particular preference is given to the polymer prepared by the process of US Pat. No. 4,237,249, which consists of an alkali metal acrylate, acrylamide and a crosslinker.

Component C) of the deicing and anti-icing agents according to the invention contains - or several, in particular one or two, sulfonate groups (S
03 - or SO, Na- group), - or several, in particular 1 or 2, carbon atoms from 5 to 18, especially from 12 to
Preference is given to potassium and/or sodium alkylarylsulfonates having 18 alkyl groups and one or more, in particular one or two, benzene rings.

Particular preference is given to potassium and/or sodium alkylbenzenesulfonates having 12 to 18 carbon atoms in the alkyl group. This one is - 803 = or S
It has O, Na- groups and one alkyl group. Since the production of alkylaryl sulfonates also starts from hydrocarbon mixtures, such as those which occur, for example, as fractions in the distillation of crude oil, the alkyl radicals can also be mixtures of this type. In this case, the number of carbon atoms is 12 to 1B (i.e.,
Advantageously, the average number is 15). The alkali metal alkylaryl sulfonates used as component C) are known and commercially available (U.S. Pat. No. 4,358,
(See specification No. 389).

Component d) includes corrosion inhibitors such as glycols and water-based liquids, which are customary. Suitable corrosion inhibitors include alkali metal salts of fatty acids, especially lauric acid,
Group consisting of potassium or sodium salts of palmitic, stearic, benzoic and oleic acids; mono-
and dialkylamines (sometimes alkoxylated) and their salts with mineral acids or fatty acids,
Especially butyl-, hexyl-, octyl-, isononyl-
, oleyl-, dipropyl- and diptyl-amines; and l-lyazoles, especially those in the group of benztriazoles and tolyltriazoles. Of the abovementioned corrosion inhibitors, particular preference is given to using triazoles. Particular preference is given to benztriazole.

The pH value of the deicing and anti-icing agent of the present invention is 7°5 to 1.
1, in particular from 8 to 10, consists of representatives of each of the three groups of alkaline compounds. The three groups are el) ammonia, monoethanolamine, jetanolamine or triethanolamine or mixtures of two or more of these compounds: e") KOII
and e'') different alkali metal hydroxides from KOII, especially NaOH. Representatives of the three groups of alkaline compounds are used in fixed amounts of each (based on the weight of the final agent), as described above. It is also important to achieve the above ρ11 value.In short, for example, when using the minimum amount of each of the three representative components at the above pH value, If the value is not achieved, at least one of them should be added in a suitably larger amount. If values occur, it is necessary to use at least one of the three representatives in correspondingly smaller amounts.
a0H) is advantageously used within the abovementioned amount ranges in a weight ratio of at least 2:1. In short, 1 part by weight of Na0
Advantageously, at least 2 parts by weight of KOII are present per 1 l (other alkali metal hydroxide). Amine and ammonia and alkali metal hydroxide are 10~
Advantageously, it is used in the form of an aqueous solution with a concentration of 40% by weight.

component) is water. It is advantageous to use water that has been desalinated, for example by treatment with an ion exchanger or by distillation.

In principle, the production of the deicing and anti-icing agent of the present invention is as follows:
This is done by mixing the individual components together in any order. This can be carried out, for example, in a vessel equipped with a stirrer, optionally with heating up to about 60°C.

An advantageous method by which a relatively rapid dissolution of each component can be achieved is carried out as follows: in a container with water at room temperature (
The thickening agent (component b) is introduced first, without stirring.
) is added. This addition is preferably followed by further stirring for some time until a homogeneous solution is obtained. The alkylaryl sulfonate (component C) and the corrosion inhibitor (component d) are then added thereto with stirring, and then the glycol (component a) is introduced, also with stirring. Now add the neutralizing agent (component e), again with stirring. Potassium hydroxide is then added as the last component of the three neutralizing agents in order to achieve the aforementioned pH values.

The deicing and anti-icing agents of the invention are characterized by long residence times, good viscosity behavior, optimal rheological properties, good thermal stability and high shear stability. It also has a relatively high freezing point depression, good wetting action, very little hydrophilicity, high temperature stability, very long shelf life □even at high temperatures□ and good corrosion protection. ing.

Generally, this material is used in the production of airplanes.
It has excellent compatibility with all aircraft materials.

Furthermore, when applied to airplanes, they are distinguished by very good sprayability and very good run-off properties during takeoff of the airplane. Furthermore, the new de-icing and anti-icing agent also satisfies the requirements mentioned at the beginning when used at temperatures of -15 DEG C. and below. It can be used successfully even in arctic regions and has the special properties required at such low temperatures. In particular, it has an optimal viscosity behavior even at low temperatures and low shear rates and therefore guarantees the desired rapid run-off even under such severe conditions during take-off.

When using the de-icing and anti-icing agent of the present invention, the nucleating agent is further diluted with water, preferably 75 (agent): 25 (
It is advantageous to dilute with water) or in a ratio of 50:50.

In such diluted form, it is applied to the surface to be treated using commonly used equipment. When deicing an airplane, the diluted solution is generally warmed to 50-95°C before being sprayed. To protect de-iced surfaces, it is advantageous to use undiluted agents.

The invention will be explained in more detail by the following example: ``Scattered Box'' The agent of the invention is prepared by mixing the following ingredients: a) 40.00% by weight of diethylene glycol and hyaluronic acid.
o, 00 ff1itχ propylene glycol b) 0
．． 03% by weight of substantially 20% by weight of polymerized sodium acrylate, 78% by weight of polymerized acrylamide and 2% by weight of polymerized (produced by the process of U.S. Pat. No. 4,237,249) 0.20% by weight of substantially 98% polymerized acrylic acid and 2% by weight polymerized crosslinker. acid polymer (in short, the weight ratio of both polymers is 1)
: 1.66); both polymers were heated at 20°C,
0.5 weight x at pH value 7: 45.00 in aqueous solution state
having a Brookfield viscosity (20 revolutions/min) of 0 mPa s and exhibiting laminar flow behavior up to a shear rate of 20.000 s-'; c) 0.15% by weight with an average number of carbon atoms in the alkyl group of 15; Sodium-alkylbenzene sulfonate, d) 0.03% by weight benztriazole, e) 0.0
5×1× triethanolamine, 0.03% by weight of sodium hydroxide and 0.11% by weight of potassium hydroxide and f) 49.40% by weight of water.

All mixing of components a) to r) is carried out at room temperature in a container equipped with a stirrer. Most of the water is introduced first and the thickening agent, ie both crosslinked acrylic polymers, is added under stirring. After this addition is complete, the solution is further stirred until a homogeneous solution is obtained. Now the alkylbenzene sulfonate, glycol, corrosion inhibitor and neutralizing agent are mixed in and further stirred until a homogeneous solution is obtained.

The three neutralizing agents are mixed in the above order, using sodium hydroxide and potassium hydroxide in an aqueous solution with a concentration of about 30 times Ix prepared with the remaining water.

The final mixture has a pH value of 8. The de-icing and anti-icing agent of the present invention has the following properties: The residual time according to the high humidity residual test (described in Test 1 below) is 8 hours or more. The residual time according to the freezing and rain durability test (described in Test 2 below) is 37 minutes (see page 1 for instructions on how to perform both tests).

The flow behavior in a rotational viscometer at a shear rate of 20.000 s-' is laminar. The viscosity values at various temperatures and very low shear rates (Brookfield viscosity at 0.3 revolutions minutes corresponds to a shear rate of 0.08 s-') are summarized below: +20 9.000 3 15.000 -10 20.000 -25 30.000 -35 45.000 The agent according to the invention is prepared by mixing the following components: a) 58.00% by weight of diethylene glycol b) 0.00% by weight.
08 wt 2, substantially 37% by weight of polymerized sodium acrylate, 60 wt. a crosslinked sodium acrylate/acrylamide copolymer comprising a crosslinking agent and 0.62% by weight of a crosslinked acrylic acid comprising substantially 97% by weight of polymerized acrylic acid and 3% by weight of a polymerized crosslinker. polymer (in short, the weight ratio of both polymers is 1)
(near, 8); both polymers were each incubated at 20°C, p
15,000m in the state of a 0.5% concentration aqueous solution with an H value of 7
c) 0.50% by weight with an average number of carbon atoms in the alkyl group of 15; Sodium-alkylbenzene sulfonate, d) 0.10% by weight of benztriazole, e) 0.
40% by weight triethanolamine, 0.08% by weight sodium hydroxide and 0.35% by weight potassium hydroxide and f) 39.87% by weight water.

The mixing of components a) to f) takes place as in Example 1.

This final mixture has a pH value of 9.5.

This de-icing and anti-icing agent according to the invention has the following properties: Residence time according to test 1 is more than 8 hours. The residence time according to test 2 is 33 minutes. At shear rates up to 20.000 s-', the flow behavior in the rotational viscometer is laminar. The viscosity values measured in the same manner as in Example 1 are summarized below: +20 11.00
0 0 15.000 -10 17.000 -25 25.000 -3540.000 The agent according to the invention is prepared by mixing the following components: a) 40.00% by weight of propylene glycol, b) 0
．． 04% by weight, substantially 10w 1χ polymerized sodium acrylate, 89w! Crosslinked sodium acrylate/acrylamide consisting of tx polymerized acrylamide and 1% by weight of polymerized crosslinker (prepared by the method of U.S. Pat. No. 4,237,249)
copolymer and 0.10% by weight of a crosslinked acrylic acid polymer consisting of substantially 97% by weight of polymerized acrylic acid and a triple itx polymerized crosslinker (in short, the weight ratio of both polymers is l: 2.5); both polymers were heated at 20°C,
8.000 m in the state of a 0.5% concentration aqueous solution with a pH value of 7.
Pa s and a Brookfield viscosity (20 revolutions/min) of 50,000 mPa s and 20.000
c) 0.07% by weight, average number of carbon atoms in the alkyl group is 1;
5 sodium-alkylbenzenesulfonate, d) 0.02 mWlχ benztriazole, e) 0
．． 03% by weight monoethanolamine, 0.02% by weight
of sodium hydroxide and 0.10% by weight of potassium hydroxide and f) 59.62% by weight of water.

The mixing of components a) to f) takes place as in Example 1.

This final mixture has a pH value of 8. This de-icing and anti-icing agent according to the invention has the following properties: Residence time according to test 1 is more than 8 hours. The residence time according to test 2 is 32 minutes. The flow behavior in the rotational viscometer is laminar at shear rates up to 20,000 s-'. The viscosity values measured in the same manner as in Example 1 are summarized below: +20 9,000 0 17.000 -1021.000 -2536.000 -35 47.000 Example 4 Produced by mixing the ingredients: a) 45.00% by weight diethylene glycol and 2
4.00% by weight propylene glycol, b) 0.15
% by weight of substantially 48% by weight polymerized sodium acrylate, 50% by weight polymerized acrylamide and 2% by weight polymerized sodium acrylate (prepared by the process of U.S. Pat. No. 4,237,249). a crosslinked sodium acrylate/acrylamide copolymer comprising a crosslinker and 0.75% by weight of a crosslinked acrylic acid polymer comprising substantially 95% by weight of polymerized acrylic acid and 5% by weight of a polymerized crosslinker. Coalescence (in short, the weight ratio of both polymers is 1)
:5); both polymers were each in the state of a 0.5 wt % aqueous solution at 20°C% pH value 7 at 60.000 mPa.
c) 0.80% by weight of sodium with an average number of carbon atoms in the alkyl group of 15 - having a Brookfield viscosity (20 revolutions/min) of s and exhibiting laminar flow behavior up to a shear rate of 20° 000 s -' alkylbenzene sulfonate, d) 0.04% by weight benztriazole, e) 0.8
0 wt 2 jetanolamine, 0.12 wt Nz sodium hydroxide and 0.30 wt 2 potassium hydroxide and f) 28.04 wt % water.

The mixing of components a) to f) takes place as in Example 1.

This final mixture has a pH value of 10.5.

This deicing and anti-icing agent according to the invention has the following properties: Residence time according to test 1 is more than 8 hours. The residence time according to test 2 is 36 minutes. The flow behavior in the rotational viscometer is laminar at shear rates up to 20,000 s-'. The viscosity values measured in the same manner as in Example 1 are summarized below: +20 1
1.0000 18.000-
10 22.000-25
32.000-35
48.000 Example 5 Repeat Example 2. However, as component b) substantially 78
% by weight of polymerized sodium acrylate, 20% by weight of acrylamide and 2% by weight of (U.S. Pat. No. 4.23)
7.249) and 0.40 as component e).
The difference is that % by weight of ammonia, 0.08% by weight of sodium hydroxide and 0.35% by weight of potassium hydroxide are used.

The final mixture has the same values and the same properties as the mixture of Example 2 with respect to ρ11 value, residence time and flow behavior in a rotational viscometer. The viscosity values measured as in Example 1 are summarized below: +20 10.000 0 14.000 -10 16.000 -25 20.000 -35 32.000 Example 4 is repeated. However, as component b) substantially 88
% polymerized sodium acrylate, 10% acrylamide and 2x 1z (U.S. Pat. No. 4.23)
7.249) and a crosslinked sodium acrylate/acrylamide copolymer consisting of a polymerized crosslinker) and as component e) 0.8-
The difference is that 0% by weight of azonia, 0.12% by weight of sodium hydroxide and 0.30% by weight of potassium hydroxide are used.

The final mixture has the same values and the same properties as the mixture of Example 4 with respect to pH value, residence time and flow behavior in a rotational viscometer.

The viscosity values measured in the same manner as in Example 1 are summarized below: +20 9,000 0 16.000 -10 20.000 -25 25.000 -35 32.000 U.S. Patent No. 4,358,389 The agent according to the specification is prepared by mixing the following ingredients:

a) 58.00% by weight diethylene glycol b) 0.
A crosslinked acrylic acid polymer consisting of 70% by weight, essentially 97% by weight of polymerized acrylic acid and 3% by weight of polymerized crosslinker;
It has a Brookfield viscosity of 15,000 mPa s (20 revolutions/min) in a 5% strength aqueous solution state and 2
exhibiting laminar flow behavior up to a shear rate of 0.000 s-', c
) 0.50% by weight, average number of carbon atoms in alkyl group 15
Thorium-alkylbenzene sulfonate, d) 0.10% by weight benztriazole, e) 0.4
3% by weight of potassium hydroxide and f) 40.27% by weight of water.

The mixing of components a) to ") is carried out in the same manner as in Example 1.

This final mixture has a pH value of 9.4.

This de-icing and anti-icing agent has the following properties: Residence time according to test 1 is more than 8 hours. The residence time according to test 2 is 36 minutes. The flow behavior in the rotational viscometer is laminar at shear rates up to 20,000 s-'. Various temperatures and very low shear rates (Brookfield viscosity at 0.3 revolutions 7 minutes is 0.08 s-'
The viscosity values at shear rates (corresponding to the shear rate of method, i.e. “
Association of European Airlines
＾1rlein3) (AEA)” published by “Recommendations for de-Icing/Anti-Icing on Aircraft on 3 Grand” (AEA)”
icing/anti-icinHof aircra
ft on ground)”, second board, September 1983
1st day of the month, i.e. “Material 5specification Day/Anti-Icing Fluid, Aircraft
de-/anti-icing fluid, airc
According to this, in the case of liquids of type II (de-icing and anti-icing fluids), the residual time is determined by the so-called "high humidity residual".
y 1loldover)”-Test and “Ice Rain Endurance C
Freezing Ra1n Endurance)”
- Determined by test. The first test is satisfactory if the residence time is at least 8 hours and the second test is satisfactory if the residence time is at least 30 minutes.

The inventive and comparative examples show the results summarized below: The deicing and anti-icing agent known from U.S. Pat. No. 4,358,389 certainly meets the needs. It shows laminar flow behavior and good residence time and also 0,08 s-'
very low shear rate (0 on Brookfield viscometer)
．． 3 revolutions per minute) and the currently required viscosity at low temperatures down to about -15°C. However-
Its viscosity at temperatures below 15 DEG C., particularly from about -20 DEG to about -35 DEG C., and at the low shear rates mentioned above, is significantly higher than the required value. For example, this known agent has a temperature of 50.000 mPa5 at -25°C and the low shear rate mentioned above.
(Association of
According to the abovementioned regulations of European Airlines, this viscosity is a maximum of 50,000 mPa5. ).

In contrast, the deicing and anti-icing agents of the invention have good residence time values, the required laminar flow behavior and very good (
Not only does it have a low viscosity value, but it also satisfies all the other requirements mentioned at the beginning as well as the ASA requirements to an unexpectedly high level. For example, the de-icing and anti-icing agents of the present invention exhibit significantly higher than 50.000 mPa s at -25°C and a shear rate of 0.08 s-' (corresponding to 0.3 revolutions/min on the Brookfield viscometer). It has a low viscosity (low shear viscosity at -25°C). A particularly advantageous feature of the agent according to the invention is its relatively low shear rate at -35°C (a temperature which is no longer mentioned at all in the ASA regulations) and at very low shear rates of 0.085-' viscosity, i.e., even under these extreme conditions, its viscosity is 50,000 m
This is slightly lower than Pas. Therefore, the de-icing and anti-icing agent of the present invention ensures safe take-off of airplanes even at temperatures up to -35°C.

Claims (1)

Claims: 1) A de-icing and anti-icing agent for airplanes based on glycol and water and containing a cross-linked acrylic polymer as a thickening agent, comprising: substantially a) 40-70% by weight; % of glycols from the group consisting of alkylene glycols having 2 to 3 carbon atoms and oxyalkylene glycols having 4 to 6 carbon atoms; b) 0.1 to 1% by weight of acrylic acid or alkali metal acrylates and acrylamide; 1 part by weight of a crosslinked copolymer with 10 to 90% by weight of copolymerized units of acrylic acid or alkali metal acrylate and 10 to 90% by weight of copolymerized units of acrylamide and 1 part by weight of acrylic acid or alkali A crosslinked acrylic polymer consisting of 1 to 10 parts by weight of a crosslinked homopolymer of a metal acrylate, provided that each of the homopolymer and copolymer contains 5,000 to 70 parts by weight.
,000 mPas and a viscosity of 0 to 20,000 mPas
The prerequisite is laminar behavior under a shear rate of s^-^1 (this viscosity and laminar behavior are each 20
in a Brookfield viscometer at 20 revolutions/min with a 0.5% strength aqueous solution with a pH value of 7 or 20.0 °C.
c) 0.05 to 1% by weight of a surfactant from the group of alkali metal alkylaryl sulfonates, d) 0. 01~
1% by weight of at least one corrosion inhibitor; e) the pH value of this de-icing and anti-icing agent is from 7.5 to
The following basic compound e_1 in the following amount to adjust to 11,
e_2 and e_3 e_1) 0.01 to 1% by weight of ammonia, monoethanolamine, diethanolamine or triethanolamine or mixtures thereof, e_2) 0.05 to 0.7% by weight of potassium hydroxide and e_3) 0.01 ~0.5% by weight of another alkali metal hydroxide and f) the remaining amount of water (% by weight is based on the weight of the deicing and anti-icing agent). and anti-icing agents. 2) The crosslinked copolymer contains 20 to 80% by weight of acrylic acid or alkali metal acrylate copolymerized units;
A de-icing and anti-icing agent according to claim 1, comprising 0 to 80% by weight of copolymerized units of acrylamide. 3) The de-icing and anti-icing agent according to claim 1 or 2, wherein 3 to 8 parts by weight of the crosslinked homopolymer is present per 1 part by weight of the crosslinked copolymer. 4) Deicing and icing according to any one of claims 1 to 3, in which the crosslinked homopolymer and the crosslinked copolymer each have a viscosity of 10,000 to 50,000 mPas. Inhibitor. 5) Any one of claims 1 to 4, wherein the crosslinked homopolymer is a crosslinked acrylic acid homopolymer and the crosslinked copolymer is a crosslinked alkali metal acrylate/acrylamide copolymer. The de-icing and anti-icing agent described in . 6) Any of claims 1 to 5, wherein the crosslinked homopolymer and crosslinked copolymer contain 0.1 to 10% by weight of a crosslinking agent based on the single or copolymer. The de-icing and anti-icing agent according to any one of the above. 7) Any one of claims 1 to 5, wherein the crosslinked homopolymer and crosslinked copolymer contain 1 to 5% by weight of a crosslinking agent based on the single or copolymer. The de-icing and anti-icing agent described in . 8) Components a) to f) in the following amounts: a) 50.00 to 60.00% by weight b) 0.20 to 0.70% by weight c) 0.10 to 0.70% by weight d) 0.03-0.50% by weight e_1) 0.05-0.50% by weight e_2) 0.03-0.10% by weight e_3) 0.07-0.40% by weight and f) the remaining amount of water The de-icing and anti-icing agent according to any one of claims 1 to 5, which contains the following.