DE2031165A1 - Bituminous wax emulsion - for coating metal esp for undersealing - ve - Google Patents

Abstract

Mixts. of bituminous materials and solidhydrocarbon producing waxes and resins are stirred in melt, then treated at melt with heated mixt. of amine and H2O (wt. ratio 1:1 to 1:10) using min. stirring rate to give Reynolds No. of 30, 000-150,000 pref. 44000-120,000, H2O is added at least 90 degrees C; charge is cooled to below m.p. stirring rate is adjusted to give above Reynolds No. then 15-30% pref. 16-20% (on total wt) of mixt. of water-sol. alcohol and H2O (wt. ratio at least 1:1) is added, with stirring and charge is cooled to room temp. by adding H2O. Used for surface protection of metal workpieces, machines and vehicles esp. for undersealing motor vehicles.

Description

Process for the preparation of coating-forming wax emulsions The invention relates to a process for the production of coating-forming wax emulsions for surface protection against corrosive influences during storage, use and transport of metallic materials, machines and vehicles, in particular for underbody protection of motor vehicles.

Such coating agents have been known for a long time.

There are dispersions of waxes, bitumen, pitch and other plastic ones Substances and their mixtures in solvents with different solids content and of different consistencies, some of which can be sprayed, some of which are applied manually Need to become. On the other hand, aqueous dispersions are also known in which the organic substance with the help of emulsifiers or organic or inorganic Protective colloids are dispersed in water. These sub-floor protection agents can also be used can be produced in different consistencies.

Both groups of the coating agents mentioned have disadvantages.

The solvent-based coating agents have an intense and offensive odor and are either flammable - or if non-flammable Solvents have been used - harmful or have an accotic Effect. Special protective measures are therefore required when processing these products necessary. It is also necessary to have the application surface, e.g. the sub-floor to dry a vehicle carefully before application.

In rubber parts and seals, they lead to the softener being released and to their rapid embrittlement. Sp -aggregate us spray contamination on vehicles and the workplace can only be cleaned with solvents, with the risk of a Fire or a health impairment of the workforce again and again consists.

Also, these detergents are indifferent to the Vehicle paint must be relatively tellers The drying process of these coating agents can usually only be followed by scanning the treated areas.

The aqueous dispersions dry very poorly and are bare Iron parts are not suitable, as they dry up with signs of rust The protective film does not adhere sufficiently to the appearance of rust. Even with the coating agents this group must be the drying process can be controlled manually. In addition, there is no way to determine when the protective film will be applied has reached its water resistance.

In addition, the aqueous dispersions are not sufficiently frost-proof. Attempts have been made to add water-soluble solvents, like low molecular weight mono-, di- and tri-alcohols to achieve frost protection, but which have remained unsuccessful because this addition is due to increasing instability of the dispersions had to remain limited to such low proportions that antifreeze protection was insufficient.

The object of the present invention is now to provide a method for the production of stable coating-forming, non-flammable wax emulsions to create that avoid the disadvantages of the known emulsions and are easy to process are. This includes good sprayability, opacity and frost resistance.

This object is achieved according to the invention in that a mixture of bituminous substances with hydrocarbon waxes and resins Stirred homogeneously above the melting temperature of the mixture and then above this melting temperature with a heated mixture of amines, preferably aminomethylpropanol, Diethylaminoethanol as well as monoethanolamine and water in a weight ratio of 1 : 1 to 1:10, preferably about 1: 7.5, offset at a minimum stirrer speed which has a Reynolds number in the range from 30,000 to 150,000, preferably 44,000 guaranteed up to 120,000; that then water of at least go ° c added and the approach to a temperature below the melting temperature of the mixture, is preferably cooled to approx. 600C, whereby a stirrer speed is set, that of the Reynolds number ensuring the emulsion stability in the range of 30,000 to 150,000, preferably 44,000 to 120,000; that subsequently at continued stirring a mixture of 15 - 30 ffi based on the total weight, preferably about 16-20 06, water-soluble alcohols, preferably Isopropanol, and water in a weight ratio of at least 1: 1, preferably about 1.6 ° 1, supplied and the approach by cooling and adding water to room temperature is brought.

A health-related one: there is no impairment of the workforce available. The dispersion can be sprayed on, brushed on or by dipping Parts to be treated are applied, although spraying is preferable is because, due to the thixotropic setting of the dispersion, on the one hand low-air pressure spray units or airless spray guns are sufficient and, on the other hand, the dispersion also in high Layer thickness can be applied without the fear of dripping. The dispersion can be applied to parts that are still wet. Signs of rust do not occur. Parts and seals made of rubber are not attacked. Impurities at the vehicle, at the workplace and at the spraying units can be done very easily and cost-effectively cleaned with water or

to be washed off. Into the petrol separators of petrol stations and business premises Any dispersion coagulates so quickly due to the excess water present, that water pollution does not occur.

Through a combination of specially selected organic solids a very low film-forming temperature can be achieved, so that drying the dispersion and the incipient water resistance of the protective film are easily visible can be observed by a color change of the protective film from light brown to black can.

The solid of the dispersion consists of a mixture of bituminous Substances with hydrocarbon gauges and resins.

The bituminous substances are petroleum bitumens with a softening point (Ring and ball) from 27 - 50 ° C, preferably from 37 - 44 ° C and a break point according to Fraass from -15 to -200C or blown bitumen with a softening point (Ring and ball) from 80 - 90 ° C and a Fraass breaking point of -15 down to -200C, the hydrocarbon waxes are produced by deasphalting mineral oil estiZation residues obtained hydrocarbon waxes (so-called petrolatum) or by de-oiling the Hydrocarbon waxes obtained from petrolatum (so-called micro waxes), which are also refined can be, with a solidification point of 40-95 ° C, preferably 65-85 ° C according to DIN 51556 and a penetration at 250C of 3 - 200, preferably of 6 - 70 according to DIN 51579. The resins are products that can be mixed with these substances in the melt e.g. hydrocarbon resins, rosins and montan resins with a softening point from 40 - 140 ° C, preferably from 65 - 800C according to DIN 53180 and an acid number of 0-150, preferably from 10-80 mg KOH / g according to ASTM D 465. These mixtures can a chlorinated paraffin to improve adhesion to metallic surfaces with a chlorine content of 40 - 70, preferably 63 - 65% according to DIN 63474 added will. The ammonium salts are used as emulsifiers from oxidized waxes, e.g. oxidized Montan wax with a solidification point of 60 - 85 ° C according to DIN 51556 and an acid number from 80 - 160 mg KOH / g according to ASTM D 465 and the aforementioned volatile amines used. The emulsifier is formed during the manufacturing process of the dispersion.

The mixture of bitumen, hydrocarbon waxes, resins, chlorinated paraffin and oxidized waxes are kept in a mixing vessel and at one above the melting temperature temperature of the mixture, which can be e.g. 110 - 1200C, homogeneous touched. Then it is also above the melting temperature of the mixture a heated mixture of the aforementioned amines and water in a weight ratio from 1 t 1 to 1:10, but preferably in a weight ratio of 1 t under 7.5 Stirring added as quickly as possible and stirred for another 15 minutes. The minimum speed the stirrer is set according to the Reznolds number required for emulsification. Condensate water at approx. 90 ° C is then added and the mixture is heated for a further 15 minutes. stirred and the batch then cooled to about 6000 as quickly as possible.

A mixture of isopropanol and water in a weight ratio of 1: 1 to 2 t 1, but preferably in a weight ratio of 1.6: 1, is used in a Added stirrer speed that depends on the Reynolds number that ensures the stability of the emulsion depends. The dispersion is cooled to room temperature and a residual amount of Stirred in cold water.

The dispersion can also be prepared so that the higher Temperature added water with a temperature of approx. 90 ° C in two sub-steps is added (see embodiment 2).

Embodiment 1 The dispersion according to the invention has, for example the following composition.

7.0 parts by weight of standard bitumen B 200 according to DIN 1995 (softening point 37 - 44 ° C) 4.0 "microwax (solidification point 82 ° C, I penetration 8) 5.0 nontane resin 3.0" oxidized Montan wax 1.0 "chlorinated paraffin 1.5 parts by weight diethylaminoethanol II. 10.0" condensate water III 20.0 parts by weight of condensate water IV 25.0% by weight of isopropanol 15.0 "of condensate water V 8.5 parts by weight of condensate water In a heated stirred reactor with a diameter of 770 mm, which is equipped with a cross bar stirrer with a diameter of 400 mm, the Components I are charged and melted at 110 ° C. With stirring at 168 rpm the homogeneous melt cooled to 100 ° C and components II are added, resulting in a Reynolds number of approx. 45,000. With the same Speed is III added at a temperature of about 90 ° C and then is the mixture cooled to about 6006. Then the Components IV and V added.

Embodiment 2 The dispersion according to the invention has, for example the following composition.

7.0 parts by weight of blown bitumen (softening point 80 - 90 ° C) 3.0 parts by weight T microwax (solidification point 70 ° C, penetration 25) I 5.0 wt 3.0% by weight of oxidized polyethylene 2.0% by weight of chlorinated paraffin 1.5% by weight of diethylaminoethanol II 1.5% by weight of water III 30.0% by weight of water IV 17.0% by weight of water V. 18.0 parts by weight isopropanol 12.0 parts by weight of water In a heated stirred reactor of 1080 mm diameter, which is with is equipped with a frame stirrer with a diameter of 1000 mm, the components I charged and melted it at 1200C. While stirring at a stirrer speed from 88 rpm, the homogeneous melt is cooled to 950C, and components II are admitted. The mixture is then stirred for approx. 15 min. Maintained at about 90 ° C for a long time and then III at a temperature of about 90 ° C added, resulting in a Reynolds number of approx. 120,000.

IV is added with further stirring and the batch is increased to approx. 6000 cooled down. Then the components V are mixed in.

The dispersions according to Examples 1 and 2 are from light brown in color, perfectly homogeneous with a thixotropic tendency, like the ones below Show run-out times.

Production according to embodiment 1 2 Solids content in% by weight 21.5 25.0 isopropanol content in% by weight 24.6 17.8 flow time according to 4 DIN 53 211 (according to 10-hour storage) 28 sec. 33 sec.

Flow time according to 4 DIN 53 211 (immediately after vigorous stirring) 22 sec. 23 sec.

The advantages of the dispersions over the dispersions known per se for the intended use can be derived from the following numerical values remove.

Preparation according to embodiment 1 2 Drying time of the dispersion with a wet film thickness of 60 my 30 min. 40 min.

with a wet film thickness of 100 my 60 min. 70 min.

Freezing point of the dispersion -18 ° C-14 ° C pour point of the dispersion -220C -20 ° C The drying process can be recognized by the color change from light brown to black Water resistance of the immediately after the color change, the film dried Wax film can no longer be re-emulsified with water.

The excellent properties of the protective film, which by drying the dispersion arises and which make it suitable as an underbody protection agent, result from the following numerical values.

Production according to embodiment 1 2 Melting point of the wax film 76 ° C 800C temperature resistance of the wax film (drainage of the wax film 7000 7500 from sheet metal) Low-temperature flexibility of the wax film given at -35 a given corrosion protection (Salt spray chamber) at least 240 h at least 240 h stone chip resistance with a dry film thickness from 30 my no carbon copies

Claims (6)

Claims 1) Process for the production of coating-forming Wax emulsions, indicated that a mixture of bituminous Substances with hydrocarbon waxes and resins representing solid above The melting temperature of the mixture is stirred homogeneously and then above this Melting temperature with a heated mixture of amines and water in weight ratio is offset from 1 s 1 to 1:10 at a minimum stirrer speed, which is a Reynolds number in the range of 30,000 to 150,000, preferably 44,000 to 120,000; that then added water of at least 90 ° C and the approach to a below the melting temperature of the mixture, preferably about 60 ° C is set, a stirrer speed is set, which depends on the emulsion stability Ensuring Reynolds number in the range from 30,000 to 150,000, preferably 44 000 to 120,000 depends; that then, with continued stirring, a mixture from 15-30% based on the total weight, preferably about 16-20%, water-soluble Alcohols and water in a weight ratio of at least 1: 1 and the Approach is brought to room temperature by cooling and adding water. 2) The method according to claim 1, characterized in that g e k e n n -z e i c h n e t that amines are preferably aminomethylpropanol, diethylaminoethanol and monoethanolamine and isopropanol is preferably used as the water-soluble alcohol. 3) Method according to claim 1 or 2, characterized in that g e k e n n -z e i c Note that the heated mixture is preferably amines and water in a ratio 1: 7.5 and that the water-soluble alcohol with water is preferably in a weight ratio 1.6: 1 is added. 4) Method according to one of the preceding claims, characterized in that g e k It is noted that the mixture of bituminous substances with hydrogen waxes and chlorinated paraffin is added to resins. 5) Method according to one of the preceding claims, characterized in that g e k It is noted that some of the amines are being replaced by ammonia. 6) Method according to one of the preceding claims, characterized in that g e k Note that the after adding the mixture of amines and water added amount of water is added in two chronologically staggered geilschrittw, between which the batch is stirred.