LU83135A1 - REMOVER - Google Patents

Description

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description

The invention relates to compositions, especially those based on alkali for stripping paint.

5

When repainting, it is often desirable to remove the old layers of paint, either to have a good surface for the new coat of paint, or to expose the underlying surface. A fan flame is usually used to soften the old one

Paint is used, which is then removed with a scraper. However, this requires considerable skill and even experienced painters can scorch the surface below. This need not be serious, if the surface is repainted, but if, for example, a cleaned wooden surface is to remain uncoated, "scorched areas are unsightly.

'20 amateur painters therefore generally avoid flaming% and prefer to pickle the paint off with traditional means.

Generally weraer; these stripping agents are applied to the painted surface, whereupon they are applied to the paint so that it becomes soft.

2 c Then we rcer. oer paint and detergent removed with a scraper. Paint remover is used in two s * λ - Z -

Categories divided: those based on organic solvents and those based on aqueous alkaline.

Organic solvents, often together with an alkali, are used as the basis for the conventional paint strippers of the first 5 categories. These are very effective, but because of their solvent content they are extremely uncomfortable to use and the "thin" nature of the composition causes it to drip and run off.

Instead of the organic carrier, water was used for the preparation of aqueous compositions, which usually contains an alkali as the active ingredient 15 of the paint remover. These compositions are also uncomfortable to use because of their "thin" nature, furthermore the tendency of the composition to evaporate and run off on vertical surfaces means that the active ingredient is not in contact with the paint long enough for effective removal of the paint To achieve painting.

Aqueous paint strippers have recently been improved by adding a gel-containing agent and a filler, for example crock egg, to give them a paste-like consistency. This makes the coating of the Atbei zmi "ice on a painted Oc e - - _ 2 _% surface much easier and eliminates the problem of dripping, whereby the removal of the stripping agent and the softened paint from flat surfaces is considerably simplified since it can actually be lifted off the surface with a scratch 5. However, the layer of paint remover and paint has no lateral cohesion, so that to remove the scratches, the entire area between the layer formed and the surface below must be passed.

10 This is not difficult on flat surfaces. However, removing paintwork with a scratch from curved surfaces, such as chair legs or lasts, is not easy.

15 It has now been found that a remarkably good removal of paints, in particular oil-based paints, can be achieved with a paint remover which forms a peelable skin over the painted surface. The alkali is kept in contact with the paint that is so effectively softened, and the subsequent removal of the layer of paint remover and paint is made extremely easy, especially in the case of complicated shapes.

25 The Er f inour.g thus places one on tragoar e watery

Composition for removing paints available «

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- 4 - which contains an alkali in an amount which allows the paint to be stripped off, together with one or more components which promote skin formation. If this composition is applied as a layer to a painted surface to be stripped, a peelable skin is formed on it, which is sufficiently tear-resistant that it can be removed from the surface underneath and the adhesive strength of which is sufficient to prevent contact with the surface Soften the composition to separate 10 coats from the underlying surface and remove 2j.

The peelable skin can be removed from the underlying surface as a coherent gel. The 15 layer formed has such a lateral strength that it can be removed as an intact skin. For the advantages to be achieved, however, the lateral strength does not have to be high and, for example, the skin does not need to have any lateral elastic properties.

4 20 i The means to achieve the peeling is done by the

Skin can be diverse. According to a first embodiment of the invention, the composition can contain a fibrous mate-2 material as the skin-promoting component, which binds the aqueous alkaline composition together to form a peelable skin. These together - 5 -

Settlements generally contain a gel-forming agent in addition to the fiber material as a further skin-promoting component. According to a further embodiment of the invention, the composition can additionally contain a filler in order to thicken the composition and increase the absorption properties of the peelable skin.

According to an additional embodiment of the invention, no fiber material is used, but the peeling property is achieved by thickening the composition with a filler and using a special combination of gelling agents.

15

The first embodiment of the invention thus comprises a coatable aqueous composition which contains an alkali and an appropriate amount of fibrous material and is sufficiently alkaline to streak the paint.

20th

Most appropriately, the alkali consists of an alkali metal hydride, ca these lead to a strongly alkaline composition, are readily available and are inexpensive. Sodium and potassium hydroxide are preferred.

25 However, it is also possible ar.oere A.lk & iier, with a pH in aqueous solution before, more than 10, for example ί - 6 - i ί

Alkali silicates, such as sodium metasilicate and alkali phosphate! phate, for example to use trisodium phosphates.

Other strongly alkaline materials, preferably with a pH of more than 12 and especially with one. 5 pH values of more than 13 are known and can be used in the compositions according to the invention, i sodium hydroxide is generally the most; preferred alkali, since other compounds are more expensive and have a milder or slower effect. If desired, ; 10, sodium hydroxide can be produced using a mixture of sodium carbonate and calcium hydroxide.

For some applications, for example when there is a risk that the surface under the paint will discolour! } 15, it may be desirable to use a milder alkali, and in this case trisodium phosphate could be used.

The alkali concentration in the composition is set according to known criteria and is within the ability of the person skilled in the art. When sodium hydroxide is used as the alkali, concentrations of 25% by weight or more can be used. However, it is preferred not to use more than 12% sodium hydroxide, which means that there are 25 restrictions on use in accordance with the guidelines i for handling toxins in the United Kinadoms i; - 7 - can be avoided. The lower limit for the concentration is determined by the effect to be achieved in each case and could be only 1% or even lower. However, the usual concentration range for the sodium 5-hydroxide is 3 to 12% and in particular 3 to 7%. Within these preferred ranges, the particular concentration is selected in relation to the required removal rate and taking into account the costs for the removal agent.

10th

If other alkalis are used, the preferred concentrations are determined on a similar basis.

Potassium hydroxide can be used in concentrations up to 17%. Special measures according to the guidelines listed above are not required, so this alkali could be preferred if a higher concentration is required. A likely concentration range for the above-mentioned alkali salts is 30 to 40%.

20th

The compositions preferably contain a gel-forming mistletoe as a further component promoting autogenesis, which may be a natural or synthetic water-soluble polymer. These yellowing agents 2b are known. Examples of suitable agents are Pcly-; acrylic acid and its esters, starch, natural types of rubber, L; \> l!

Il l | - 2 - ï \ j like tragacanth or British rubber, cellulose ether,! Hydroxyethyl cellulose, xanthan gum and synthetic clays, such as montmorillite clays. Preferred gel-forming agents are! the xanthan gum and synthetic clays. An example of | i. 5 A commercially available xanthan gum is Kelzan, a high molecular weight natural polysaccharide, which is obtained in a pure cultivation process with the microorganism Xanthomonas campestris and is available from Kelco, which belongs to Merck and Co. Inc. A preferred synthetic clay is laponite, a synthetic one

Hectorite, namely a magnesium silicate that contains lithium, fluorine or hydroxide groups in a layer structure. This clay is available from Laporte Industries Limited.

15 The amount of the gel-forming agent is selected according to the thickness required for the composition, taking into account the properties of the gel-forming agent used in each case. It is not possible to specify general preferred ranges 20 for the agents forming the 1, since the different agents are used in different concentrations in order to achieve the same degree of gelation. Those skilled in the art can easily choose the appropriate amount of gelling agent. For illustrative purposes only, 25 it is unlikely that gel-forming agents will be used. is used in concentrations of more than 10% by weight.

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A convenient lower limit is 0.1%. The later examples illustrate suitable concentrations of yellowing agents in the special compositions.

5 The fibrous material in the first embodiment of the invention holds the gelled layers of the composition against the painted surface, thus making the layer peelable. The peelability can be imparted to the composition with a variety of organic and inorganic, natural and synthetic fibers, provided the fiber is not degraded by the other components of the composition in the concentrations used. The fibers can, for example, consist of ground paper, paper flakes, paper stampings, wool, textile fibers, asbestos, wood pulp or plastic fibers, such as viscose fibers or ground synthetic leather. These types of fibers are relatively inexpensive because they come from waste materials. In particular, ground paper is a cheap fiber source and is preferred for this reason.

The fibers used are preferably in Fct relatively short individual fibers, that is to say they are no longer than 10 mm. A preferred form: any 2 c grinded Papicf as & r n has fibers with length.

;; up to 2 mm.

"'ΐ · -,« - JO - i The fiber content of the composition is selected in such a way that, in combination with the selected gelling agent, it gives the composition the desired degree of peelability. Typically i - 5 the fibers no longer make than 25% by weight of the composition, and generally contains no more than 15% and preferably no more than 12% fiber material. Too much fiber material can cause the composition to become too thick to can be conveniently applied to the surface to be stripped. A preferred lower limit is about 5% fiber material, while excellent peelability is achieved with a fiber content I of not less than 8%.

i ί 15 The fiber material-containing compositions according to the invention can also contain a filler as a further skin-promoting component, that is to say a solid, particulate component which is essentially inert to the other components of the composition and (j 20 to the paint. This i: '= filler thickens the composition. In addition, when used with the composition | w 1', the filler absorbs the liquefied paint which has been attacked by the alkali | and thus helps prevent it from running off, suitable fillers such as chalk powder,

Clay, fly ash, vermiculite and wood flour. For cie erfin-— 5 j r c t v c t r purposes, k r e z c e r> u i v e r b e v c r r u c t - ΛΑ -

The filler should not be used in a concentration that makes the composition too thick for application. Of course, the amount of filler that can be used to achieve a distributable composition is influenced by the amount of fiber material present. In general, if filler is present, the amount of fibrous material can be reduced. It has been found that up to 64% filler can be used in conjunction with up to 20% fiber material, 1 ° furthermore that effective compositions with filler and fiber material can be obtained even if the amount of fiber material is below 5%, which is the preferred lower limit for fiber content in the absence of filler. It has also been found that the ratio of filler to fiber material is most suitably in the range from 6: 1 to 1: 1 and in particular in the range 4: 1.

It has also been found that peelable compositions are obtained without the use of fibers; know when using the filler in combination with a special combination of gel-forming agents. An alternative embodiment of the invention thus comprises a coatable composition of an alkali, filler, a xanthan gum and a synthetic. Fiector itton, which is sufficiently alkaline to. Paintings - a i:? ube i z er ..

* _ / 2. -! j; i j The alkali used in this embodiment is selected according to the above criteria and in! the concentrations previously proposed.

! . 5 The filler can also be obtained from the above

Materials are selected, but it is generally used in somewhat higher concentrations. In general, the filler is in an amount of at least! at least 25% by weight, preferably in an amount of up to 10 to 75% by weight. The amount of filler in the fiber-free compositions is best 50 to 70%. The amount of filler actually used is determined by the theological properties of the composition conditions determined, which in turn are determined by the nature i and concentration of the gel-forming agent. In terms of quality, this means that the amount of filler should not be so low that a slurry runs off the surface to be stripped, nor should the amount of filler be so high that the composition cannot be easily distributed on the surface.

According to a preferred embodiment, the composition is thixotropic, but even if it shows this property, it should be at ir-.rerr. Orders are sufficiently moved to be lent to. to allow a distribution.

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It has been found that a special combination of gel-forming agents is required in order to achieve peelability with a composition which contains filler but no fibers. The xanthan gum is preferably Kelzang gum and the clay is preferably laponite.

These gelling agents are preferably used in concentrations of 0.2 to 4% Kelzan and 0 to 2.0% Laponit, the ratio of Kelzan to Laponit being 5: 1 to 1: 1.

10th

Both types of the compositions according to the invention, that is to say whether they contain fiber material or not, can contain further standard constituents of stripping agents, for example wetting agents, dyes, preservatives and water-miscible organic solvents. All of these additives must of course be compatible with the other ingredients, in particular with the alkaline nature of the compositions, and they must also be miscible with water.

20 The selection of these conventional components in suitable concentrations is within the ability of the

Professional.

By incorporating a bleaching agent into the compositions according to the invention, an abrasion can age.

that the underlying surface bleaches.

i ΊΚ - A * - \ j! The conventional bleaching agents such as sodium chlorate or hydrogen peroxide can be used, typically in a concentration of 0 to 10% by weight of the composition.

5! When used, the assemblies according to the invention are i.

i Settlements typically applied as a layer with a thickness of 3 to 4 mm on the painted surfaces. It is advisable to apply with a spatula or a similar tool. The composition is then left to act until the paint is softened. A period of 1 to 6 hours is normally required for this, although longer contact times may also be desirable if many coats of paint are to be removed. If the layer of the composition dries out during this time, it can be sprayed with water to moisten it and ensure maximum contact of the alkali with the paint.

20 The layer is then with a scraper or similar; tools removed as peelable skin, although a real scraping of the surface lying on the surface should not be necessary. The skin is peeled off together with the softened paint in front of the surface, 25 and complicated shapes, more easily stripped in this way, without having to scrape off paint from each bar # - -v.

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The invention also encompasses a paint stripping process which consists of applying an effective amount of a composition of the invention to the layer (s) of paint, the composition, together with the paint softened by the action of the composition, of a peelable paint Forms skin, lifts the skin and pulls it from the underlying surface. The compositions according to the invention can also be in the form of dry powder in the form ready for use, which can be advantageous for storage and transport. When mixed with water, these dry powders result in an aqueous paint stripper that can be applied. The dry powder, apart from water, can have the same composition as the coatable aqueous composition. However, since at least some of the alkaline materials described above are not easy to handle in dry form, it is preferred to formulate the dry composition with a mixture of calcium hydroxide (quicklime) and an alkali metal salt, the anion of the alkali metal salt being combined with the calcium forms insoluble salt.

Mixing the components of such a mixture with water produces an alkali metal hydroxide, for example sodium hydroxide. Such compositions are easier to handle in dry form than dry compositions containing the corresponding alkali metal hydroxide.

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Preferably, the alkali metal salt and calcium hydroxide are used in substantially stoichiometric amounts; is used, the percentage of each of these components j in the dry composition being selected so that a corresponding percentage of alkali metal hydroxide is formed according to the above statements, preferably 3 to 12% by weight of hydroxide.

Since the dry powder composition is particularly useful for a do-it-yourself product, it can, | if necessary, be formulated with an increased amount of filler, I if there is one, i to facilitate mixing with water. To add! can play if a filler and fiber material together j Γ | 15 be used, the ratio filler to Fasei, material up to about 7: 1.

The following examples illustrate the invention.

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example 1

Stripping agent containing fibers and filler Composition of this agent: g

Xanthan gum (Kelzan) 26.2 48% (w / w) sodium hydroxide solution 104.6 ground paper 104.6

Chalk 104.6

Water 660.0 1000.0

Example 2

Stripping agent containing fibers Composition of this agent: g

Xanthan gum (Kelzan) 26.2

Laponit S 10.7-46% (w / w) sodium hydroxide solution 104.6 ground paper 104.6

Water 753.9% i I * # - Ai -: j Example 3 i ij filler-containing paint stripper I Composition of this agent: 9.5 xanthan gum (Kelzan) 10.5

II

Laponit S 4.3 46% (w / w) sodium hydroxide solution 83.3 i i II chalk 640.0 if water 261.9

Li; 10 1000.0 *! | ; i i j! ;.! Example 4; i Pickling agent containing filler and fibers I "f 15 This composition was thixotropic and was composed ii of the following components: ;; kg

Xanthan gum (Kelzan) 1.00

Laponit S 0.50 J 20 46% w / w sodium hydroxide solution 10.45

Chalk 3 ^, 83 1.6 mm gerr, aehien paper 7.46 100, Ci 25 $ ï

Water 45.77 - / 3%

Example 5 Pickling agent containing filler and fibers Composition of this agent: kg i 5 xanthan gum (Kelzan) 0.871

Laponit S 0.435 46% (w / w) sodium hydroxide solution 10.45

Chalk 37.31 3.2 mm paper flakes 8.71 10 water 42.226 100.00

Example 6 15 pickling agent containing filler and fibers

Composition of this agent:% w / w.

Xanthan gum (Kelzan) 2.6 'sodium hydroxide 5.0 20 3.2 mm ground paper 10.5

Wood flour with a particle size corresponding to a clear diameter of 53 microns (300 mesh) 10.5 l

Water 71.4 c%

Example 7 - Zo -; Paint remover containing filler and fibers!

Composition of this agent:% w / w.

i -! Î. 5 xanthan gum (Kelzan) 2.6 t j sodium hydroxide 5.0! [Vermiculite with a particle size corresponding to a clear j mesh size of ... mm (500 mesh) 10.5 j j 3.2 mm ground paper 10.5 10 water 71.4 i i

Example 8 Pickling agent containing filler and fibers 15 Composition of this agent:% w / w.

Xanthan gum (Kelzan) 2.0

Laponite 0.8

Sodium hydroxide 5.0 i - j s 20 chalks 21.0

Vermiculite with a particle size corresponding to a clear mesh size of ... mm <505 mesh> 10.5 i i j 1.6 mm ground paper 5.0 i 21 _ ^! Water 55.7 - -

Example 9 Pickling agent containing filler and fibers Composition of this agent:% w / w.

5 xanthan gum (Kelzan) 1.0

Laponite 0.5

Potassium hydroxide 5.0

Chalk 35.0 3.2 mm paper flakes 7.5 10 water 51.0

Example 10 Pickling agent containing filler and fibers 15 Composition of this agent:% w / w.

Xanthan gum (Kelzan) 2.6

Sodium hydroxide 5.0

Chalk 10.5 20 viscose fibers 10.5

Water 71.4 2 5; - ζι - ί.

; j; jj Example 11 ii

Paint remover containing fibers and filler h 1 - 1 - - - - | Composition of this product:! % W / w.

j ii, 5 water 58.2! | Chalk 15.7! 6.4 mm paper flakes 15.7 48% (w / w) sodium hydroxide solution 10.4 100.0;! 10th

The pH of the compositions of Examples 1 to 11 was in the range from 13 to 14.

! ; Example 12; ) i1 15 pickling agent containing fibers and filler

Composition of this agent: I% w / w.

Xanthan gum (Kelzan) 1.0

Laponite S 0.5 20 trisodium phosphate 10.0. \ Chalk 34.8 1, t mm ground paper 7.5

Water 46.2 25 The pK value of this composition was ν ', 8.

··· *? "

Example 13 9 - zi -

Stripping agent containing fibers and filler Composition of this agent:% w / w.

5 xanthan gum (Kelzan) 1.0

Laponite S 0.5

Sodium metasilicate 10.0

Chalk 34.8 3.2 mm ground paper 7.5 10 water 46.2

The pH of this composition was 12.7.

The following experimental results obtained with a conventional paint remover and with paint remover according to the invention also serve to illustrate this.

Procedure

The drugs were tested for their effectiveness in removing a four-layer paint * based on Cl from a wooden surface. The painted area was subdivided into test areas measuring approximately 15 cm x 10 cm using the stick-on adhesive tape. The paint remover used in each case was given a thickness with a spatula. applied about I 2 mm. The composition was a certain * - IH ~

Time left in contact with the test area and then removed with a spatula. The constitution of the composition at the time of removal, the ease of removal and the amount of paint 5 removed were evaluated. The results obtained are summarized later.

I results

For comparison, a conventional paint remover was searched under-10. This paint remover had the following composition:% w / w.

gelling agent (Viscalex HV30 - an acrylic copolymer emulsion from Allied * 15 Colloids Ltd.) 3.0

Sodium hydroxide 4.0

Chalk 66.5

Anti-foaming agent 0.2: »water 26.2 1 4 20; j * _ In separate tests, this composition was left 2/3

Hours and 2 hours with test areas ir, constant. i · The results obtained are summarized in Table 1 posed.

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Table 1 Condition

Together - contact time at the distant

Settling hours removal of paint

Known 5 composition 2/3 pasty 80% known composition 2 pasty 100% * 10 In each case the composition was made of paint and

Paint remover pasty. It was not connected and not removable. It was therefore necessary to scrape the paste off the stripped surface, which was a dirty and time-consuming job. After a contact time of 2/3 hours, the removal was 80%, ie all four layers of the paint were removed from 80% of the test area. After a contact time of 2 hours, the removal was 100%, ie all, four layers of the paint were off the test area; 20 removed.

The results achieved with compositions according to the invention are summarized in Table 2. The number of the examples is given for the compositions, in which their formulation is described.

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Table 2 quality; Together - contact time, at distant hours removal paint - | 1 peelable skin 100% l '' 5 2 1 "100%; 3 1” 100% 41 "100% | 4 2/3 "100% 51” 100% j • 10 6 1 "100% 7 1" 100% 8 1 "100% 9 1 * '100% 10 1" 100% 15 11 10 dry peelable skin 100 %! 12 5 peelable skin * 13 5 ”** i

Vr; "A completely removed layer, a second layer that can be removed by scratching. ^

t m 7Γ TT

i · 20 About 90% removal by scratching i i | Jece examined composition formed a peelable

Skin softened from the test area along with that by the alkali. Painting in one. Piece lifted off! Could be 2c. The compositions that sodium hyörc> ic! ir * - 47 “or potassium hydroxide, allowed 100% removal without scratching. It was only necessary to wash off the stripped area after removing the skin in order to obtain a clean wooden surface. The 5 compositions with trisodium phosphate and sodium metasilicate are milder, so that they can be applied to sensitive workpieces or if only the upper layers of the paint are to be removed selectively. A complete removal of all four layers 10 of the paint was not achieved with these alkalis, but these compositions showed the property sought according to the invention to form a peelable skin which facilitates the stripping.

15 Example 14

Pickling agent containing fibers and filler in dry powder form Composition of this powder:

Parts by weight 20 sodium carbonate 5.0

Calcium hydroxide 3.5

Chalk '34.0 3.2mm granulated paper 5.0

Kelzan 0.7o

25 Laponite S G, 3E

il

K

a t- λ; -Μ-

This composition is suitable for transport, storage and sale in dry form. When mixed with water to 100 parts by weight / weight a water-based paint stripper was applied, which. 5 formed a peelable skin when used and allowed 100% removal of the paint i without scratching, such as compositions containing sodium hydroxide.

i | 10 Example 15

Stripping agent containing fibers and filler in dry powder form

The compositions of Examples 12 and 13 were i; formulated without water as a dry powder. For the i; ! In use, these compositions were mixed with water to 100% w / w. They acted in the same way as the composition of Example 14.

' 1' ; '20' See: ko eL w

Claims (34)

1. Applicable aqueous composition for stripping paints with an alkali content which enables stripping of paint 5 and one or more components which promote skin formation, so that when the aqueous composition is applied as a layer to a painted surface to be stripped, a peelable skin is formed, the tensile strength of which -10 is enough to peel them off the underlying surface and their adhesive strength is sufficient to separate and remove the paint softened by contact with the composition from the underlying surface. 15 2. Composition according to claim 1, characterized in that it has a pH of at least 10. 3. Composition according to claim 2, characterized in that it has a pH of at least 12. 4. Composition according to claim 3, characterized in that it has a pH of at least 13. 2a 5. Composition according to one of claims 1 to 4, characterized in that the alkali is an alkali metal hydride. * 6. The composition according to claim 5, characterized in that the alkali is sodium or potassium hydroxide. - δο- 57. Composition according to claim 6, characterized in that it contains 3 to 12% by weight of sodium hydroxide. i i 8. The composition according to claim 7, characterized in that it contains 3 to 7 wt.% Sodium hydroxide. 10th 9. Composition according to one of claims 1 to 8, characterized in that it contains a fibrous material as a component promoting skin formation. 10. Composition according to one of claims 1 to 9, j characterized in that it contains a gel-forming j as a further component which promotes skin formation. j "means. 1 v 'V- i 11. The composition according to claim 10, characterized gekennzeich- i. net that the gel-forming agent Folvac ryI acid or an ester of polyacrylics, starch, a natural oil rubber, a cellulose ether, Hroxroxyethyl cellulose, a xanthan gum or a synthetic gate. is. 25th 12. The composition according to claim 11, characterized in that the gel-forming agent is a natural polysaccharide. «-SA- 13. The composition according to claim 12, characterized in that the natural polysaccharide was obtained in a pure cultivation process with the microorganism Xantho-monas campestris. "1 ° 14. Composition according to claim 11, characterized in that the gel-forming agent is a synthetic hectorite clay. 15. The composition according to any one of claims 10 to 14, 15, characterized in that it contains 0.1 to 10% by weight of gel-forming agent. 16. Composition according to one of claims 9 to 15, ^ characterized in that the fibrous material 20 consists of ground paper, paper flakes, paper punch parts, wool, textile fibers, asbestos, wood pulp or synthetic fibers. 17. The composition according to any one of claims 9 to 16, characterized ocduroh that the fibers are not longer than 10 mm. - 32- 18. The composition according to claim 17, characterized in that it contains any milled paper fibers with fiber lengths of up to 2 mm. * 19. Composition according to one of claims 9 to 18, y characterized in that it contains up to 25% by weight of fiber material. | 20. The composition according to claim 19, characterized in that it contains 5 to 15% by weight of fiber material. 21. The composition according to claim 20, characterized in that it contains 8 to 12% by weight of fiber material. ! 15 22. Composition according to one of claims 1 to 21, Î characterized in that it also contains an essentially inert particulate filler as a further component promoting skin formation. j '20 23. Composition according to claim 22, characterized; * net that the filler from chalk powder, clay, flight! ash, vermiculite or wood flour. 24. The composition according to claims 22 and 23, characterized in that it contains up to 64% by weight of filler together with up to 20% by weight of fiber material. -53- 25. The composition according to claim 24, characterized in that the weight ratio of filler to fiber material is in the range from 6: 1 'to 1: 1. fr 26. The composition according to claim 25, characterized; net that the weight ratio of filler to fiber material is essentially 4: 1. 27. The composition according to claim 1 to 8, 10 to 15 or Ί0 22 or 23, characterized in that it contains an alkali, a filler, a xanthan gum and a synthetic hectorite clay as components which require skin formation. 28. The composition according to claim 27, characterized in that it contains 25 to 75% by weight of filler. 29. The composition according to claim 28, characterized in that it contains 50 to 70% by weight of filler. 20th 30. Composition according to one of claims 27 to 29, characterized in that it is thixotropic. 31. Composition according to one of claims 27 to 25 3G, characterized in that it contains 0.2 to 4% by weight of xanthan gum and up to 2% by weight of synthetic hectorite. 4 » 32. Composition according to claim 31, characterized in that the weight ratio of xanthan gum to synthetic hectorite clay is 5: 1 to 1: 1. - 2> V- 33. Dry powder composition; that when mixed with water is an applicable aqueous paint stripper according to one of claims 1 to! i results in 32. 34. Dry powder according to claim 33, characterized in that it contains calcium hydroxide and an alkali metal salt, wherein the anion of the alkali metal salt forms a water-insoluble salt with the calcium and thereby releases a paint-stripping amount of alkali, further releases one or several components that promote skin formation, so that when the aqueous paint remover is applied as a layer over a painted surface to be stripped: ù a peelable skin is formed, the tensile strength of which is sufficient to pull it off the surface underneath and the adhesive strength of which is sufficient to prevent contact with the surface Separate and remove the composition of softened paint from the underlying surface. I 21 "j 35. Composition according to claim 34, characterized in that the alkali metal salt is sodium carbonate. «R -3S- 7 5 36. Composition according to claim 34 and 35, characterized in that the calcium hydroxide and the alkali metal salt together release 3 to 12% by weight of alkali metal hydroxide in the aqueous paint stripper. 37. Composition according to one of claims 34 to 36, characterized in that the constituents and / or their percentages and / or their proportions correspond to those given in Examples 9 to 32. 38. Applicable aqueous paint remover from a mixture of water and a composition according to claim 34 to 37. Γ 39. Process for stripping paints from a 20 surface, characterized in that an effective amount of a composition μ according to claim 1 to 32 or 3c is applied to the paint, the composition together with the paint softened by the composition allows a peelable skin to be formed, 25 the skin formed is lifted and turned into Removal of paint from the surface below / peels off. - —------------------