EP0547261B1 - Coated flat structure - Google Patents

Abstract

The invention describes a coated flat structure which contains a coating carrier, an at least partly cross-linked base layer applied thereon and a further layer applied on said base layer. The base layer comprises a plastics composition which does not flow under the effect of heat and a carboxylic acid having one carboxyl group and at least 18 carbon atoms in the molecule and, if appropriate, its salts of divalent or trivalent metals. This invention further describes a process for producing a flat structure of this kind, the aforementioned base layer being preferably applied by grid-like coating, and the further layer being applied thereon in excess and being uniformly distributed by vibration of the flat structure and the excess of this further layer not adhering to the print being removed by blowing and suction. Subsequently the carrier coated in this way is dried, sintered and condensed. The flat structure thus produced is suitable in particular as lining material in the textile industry, in particular for pieces of clothing with lightweight, thin exterior layers, such as blouses and shirts.

Description

This invention relates to a coated sheet-like structure, comprising a coating carrier, a base or base layer made of a plastic mass applied thereon and a further, second layer provided thereon. This invention further relates to a method for producing such a flat structure and a particularly favorable use for this flat structure.

A sheet with a single coating is known from US-A-4 602 057. This single coating consists of copolyamide and 0.3 to 15% by weight of behenic acid. A uniform mixture of behenic acid and copolyamide is produced; This is followed by a temperature treatment above the melting temperature of behenic acid, but below the melting temperature of copolyamide, whereby an even loading is achieved. The required amount of coating can be reduced by this individual coating.

Flat structures are also known which are provided with a base layer made of a plastic mass, which is preferably applied in the form of an aqueous paste to the flat structure in the form of a grid. The fabric is then vibrated with a rapidly rotating beater roller. A hot melt adhesive powder is sprinkled on the paste print.

The excess powder not adhering to this base layer is blown off and suctioned off, and the paste of the base layer with the powder adhering to it is then dried and sintered. The coating grid, which is preferably in the form of a dot, thus consists of a base layer made of this dried and sintered paste. The sintered hot-melt adhesive powder represents the further plastic layer sitting on it. The coated fabrics are laminated in sheets or as blanks with other sheets or cut sheets under the action of pressure and comparatively mild temperature to form composites with particularly high resistance to washing and cleaning.

DE-B-22 31 723 describes such flat structures which have two layers lying one above the other. According to this publication, a base layer is used which, after drying and sintering, has a higher melting point and a higher melt viscosity than the hot-melt adhesive layer scattered thereon. Double-layer coatings of this type result in improved adhesion, a softer grip and a reduced tendency to kickback when fixing, so that they are increasingly able to assert themselves over single coatings.

In addition to the double coating of paste and scattering powder mentioned, there are further double coating methods of combinations of paste with paste and powder with powder, which are described in DE-B-22 14 236, DE-B-25 36 911 and DE-B-32 30 579 .

For cleaning-resistant fixing inserts, copolyamides, copolyesters, low-pressure polyethylenes and polyurethanes are used as plastic masses for the base layer. Copolyamides and copolyesters are particularly suitable as materials for the hot-melt adhesive layer.

To suspend the pastes for the base layer, special suspending or dispersing agents are used, which are also used in single coatings, for example combinations of fatty acids, ammonia and water-soluble thickening agents. Suitable dispersants are, for example, in the publications DE-B-20 07 971, DE-B-22 29 308, DE-B-24 07 505, DE-B-25 07 504, EP-A-0 150 262 and DE-B -35 10 109.

In addition to double-layer coatings which contain hot-melt adhesive powder in the base layer, those are also already known whose base layer has no heat-sealing properties after drying and sintering and has been cured by chemical crosslinking, so that a thermoset is obtained. Information on this can be found in German utility model DE-GM 72 11 199, which specifies the use of crosslinked base layers made of polyacrylates, PVA, polyamide and polyurethane. According to DE-B-24 30 260, interlinked base layers are also used, which contain thermosets (= thermosets).

Although such double-layer coatings with a crosslinked base layer seem to be particularly predestined to most effectively prevent the tendency of the hot-melt adhesive coating to recoil when heat sealing, which is still and especially in the case of the thin textile carriers that are frequently used today, they have so far been of virtually no importance because of this achievable grip too tight and the adhesion of the fixing compound with other fabrics is too low. The reason for this is that the crosslinkable polymer dispersions and solutions which offer crosslinking, even after thickening with thickening agents, have a much too high tendency to penetrate into the carrier and are also sucked up by the sprinkled hotmelt adhesive powder, enveloping the latter to a greater or lesser extent and therefore reduce its heat sealability to an unbearable level during the crosslinking process. In addition, the usual rapid passage through the drying plant during coating has obviously not hitherto allowed sufficient condensation to take place.

This invention is therefore based on the object of providing a flat structure of the type mentioned at the outset which does not have the disadvantages listed above. In particular, the tendency to penetrate into the carrier should be reduced to the required minimum and, when using hot-melt adhesive powder as the second layer, the tendency to suck should be reduced without the adhesive strength of the base layer to the carrier and the hot-melt adhesive scattering coating to the base layer suffering. In addition, the duration of exposure to temperature should ensure, even with the short throughput times customary in coating technology, that the base layer and the hot-melt adhesive sprinkling coating sitting thereon are anchored fully cleanable and washable.

Furthermore, a method for producing such a flat structure and a particularly favorable use of this flat structure are to be specified.

To achieve this object, a coated sheet is provided which has a coating carrier, a base layer applied thereon and a further layer provided thereon, the base layer which is no longer flowable under the action of temperature being applied in a grid pattern, at least partially crosslinked, and an aliphatic carboxylic acid with a carboxyl group and at least 18 Contains carbon atoms per molecule in an amount of 2 to 10% by weight and optionally salts of divalent or trivalent metals of this carboxylic acid in an amount of 0.1 to 2% by weight, the amounts given relating to the dry weight of the base layer. The at least partial crosslinking should extend to such an extent that the base layer does not flow at all temperatures to which the coated fabric is exposed in later laminations with other fabrics. Good results can be achieved if this aliphatic carboxylic acid in a Amount of preferably 2 to 8 wt.%, Particularly preferably 4 to 7 wt.%, Based on the dry substance, is contained. Behenic acid or oxystearic acid is preferably used as the carboxylic acid. In addition, wax acids, for example oxidized montan wax, which contains about 60% higher fatty acids, and other fatty acids with at least 18 carbon atoms per molecule can also be used.

Calcium, magnesium, zinc or aluminum salts can be used as salts of the carboxylic acid in the stated amount. This makes it possible to further reduce penetration.

The base layer can be produced from a crosslinkable, aqueous polymer dispersion, emulsion and / or solution which is thickened. The polymers used preferably have a film-forming temperature of at least 5 ° C. and are usually acidic in dispersion or emulsion form.

In some cases it has proven to be advantageous if aqueous dispersions of self-crosslinking acrylic polymers which can additionally contain carbamide, melamine, semi-reactant, reactant crosslinkers with = N-CH₂OH or = N-CH₂OR, also dissolved in water, where R is an alkyl, with an alkaline, preferably ammonia-alkaline, aqueous dispersion of carboxylic acids, preferably behenic acid or oxy-stearic acid and thickeners. Furthermore are Carboxylic acids can be used which, in addition to alkyl and carboxyl groups, also have other foreign groups in the molecule. In many cases it is advantageous to additionally add a crosslinking catalyst, for example ammonium tetrafluoroborate. Such a crosslinking catalyst is preferably used in an amount of 0.2 to 2.0% by weight, based on the dry weight of the base layer. The pH of the ready-to-use aqueous dispersion paste mixed with thickeners should be adjusted to 5.0 to 8.0, preferably 6.0 to 7.0.

It is also possible to add portions of a polyurethane dispersion that can be crosslinked to the base layer. In this case, the amount of the polyurethane dispersion is between 2 and 40% by weight, based on the dry weight of the base layer. Other, also suitable, self-crosslinking polymers that can be added are self-crosslinking polyvinyl esters, which are also present in dispersion form. Self-crosslinking copolymers, e.g. Styrene-acrylic or acrylic-vinyl ester copolymers can be used in dispersion form.

Rapidly crosslinking acrylic polymers with film formation temperatures above about 5 ° C. have proven to be particularly suitable, which allow a rapid coating speed in the presence of the carboxylic acids used according to the invention and the catalyst present, if any, and which already crosslink with cleaning and washing resistance with a short drying and condensation time.

It is also possible to use a self-crosslinking polymer dispersion paste, the previously was foamed. For this purpose, an ionogenic surfactant can be added to the paste in an amount of 0.1 to 1% by weight, preferably about 0.5% by weight. In addition, a foam stabilizer based on a fatty acid alkanolamide can be added. It is preferably foamed up to 2 to 3 times the volume.

The second layer, which is applied to this base layer, can either consist of hot-melt adhesive powder or of flock fibers. If this second layer is made from hot-melt adhesive powder, which can be charged with a crosslinking catalyst for the base layer, for example with oxalic acid or maleic acid, the sheet-like structure coated in this way is preferably suitable as a fixable interlining material, in particular for the clothing industry, for example as blouse or shirt inserts. The catalyst treatment of the hot-melt adhesive powder further accelerates the crosslinking of the base layer.

By using base layers of the type according to the invention, which are sprinkled with hot-melt adhesive powder, there is little imprint penetrating through the flat structure, which produce a soft feel and, above all, provide excellent adhesion, since the scattered powder is only anchored on the contact surface with the base layer and has no tendency to absorb and wrap around the moist base layer. By using the carboxylic acid additive, the cleaning and washing resistance is not adversely affected.

When drying and condensing, the base paste applied to the coating substrate goes under Admixing a thickened, preferably ammonia-alkaline aqueous dispersion, which is described above, into the ammonia or ammonium salt-free dry state. In the finished hot melt adhesive coating, the carboxylic acid is free of ammonium salts.

• a) Der Teilchendurchmesser der vernetzbaren Polymerdispersionen liegt in der Regel zwischen 0,1 und 1 µm. Die Teilchen der Schmelzkleberpulver, die zum Einrühren benutzt werden, haben in der Regel Durchmesser von 30 - 40 µm. Im Teilchenvolumen liegt ein Verhältnis von 1:25.000 bis 1:25.000.000 vor. Die Polymerteilchen der Dispersionen sind also um viele Dimensionen kleiner.
• b) Die Teilchen der vernetzbaren Polymerdispersionen sind elektrische Ladungsträger, die sich gegenseitig abstoßen und auf diese Weise die Dispersion stabilisieren. Die Schmelzklebrpulver besitzen selbst keine Ladungen.
• c) Die Anmischungen der vernetzbaren Polymerdispersionen mit den angedickten alkalisch eingestellten Dispersionen der höheren Fettsäuren verändern beim Mischprozeß den pH-Wert erheblich. Die Alkalität verschwindet durch den Zusatz der in der Regel sauer eingestellten Polymerdispersionen. Das Mischprodukt soll einen pH-Wert von etwa 5 - 8, vorzugsweise 6 - 7 haben. Dagegen bleiben die Anmischungen mit dem Schmelzkleberpulver im pH-Wert über 8.
  Aufgrund der pH-Wert-Änderung muß angenommen werden, daß die im alkalischen Medium als Salze vorliegenden Fettsäuren bei Anmischen mit den vernetzbaren Polymerdispersionen nahezu vollständig in die freie Fettsäure überführt werden, wohingegen das Gleiche mit Schmelzkleberpulvern nicht stattfindet.
• d) Schließlich handelt es sich bei Schmelzkleberpulvern und bei vernetzbaren Polymerdispersionen um chemisch stark voneinander abweichende Substanzen. Die vernetzbaren Polymerdispersionen müssen, um wasch- und reinigungsfest zu werden, vernetzt werden, Schmelzkleberpulver nicht. Die Vernetzung muß in kürzester Zeit bei den in der Beschichtungspraxis üblichen kurzen Verweilzeiten und relativ milden Temperaturen im Trockner ablaufen. Es bestand ein großer Vorbehalt, daß dies bei Zusatz alkalisch eingestellter Produkte erreichbar ist, da durch Verschiebung des pH-Wertes in den alkalischen Bereich eine enorme Kondensationsverzögerung eintritt. Es war überraschend, daß eine pH-Wert-Änderung lediglich in die Nähe des Neutralbereiches bei Anwesenheit von Fettsäuren und besonders bei zusätzlicher Zugabe von Vernetzungskatalysatoren, wie Ammoniumtetrafluoroborat, die Kondensationsgeschwindigkeit nicht abgebaut, sondern sogar beschleunigt wird und gleichzeitig die Benetzungseigenschaften der Druckpasten zum Träger und aufgestreuten Schmelzkleberpulver trotz nahezu vollständigem Übergang der fettsauren Salze in die freien Fettsäuren, unter Erzeugung eines besonders weichen Griffes und einer hohen Fixierhaftung in der gewünschten Weise beeinflußt werden konnten. Offenbar wird die Penetrationsneigung bei vernetzbaren Polymerdispersionen nicht nur - wie bei Schmelzkleberpulveranmischungen - überwiegend durch die fettsauren Salze, sondern durch die freie Fettsäure abgebremst, die darüber hinaus auch die Vernetzung der angewandten vernetzbaren Polymerdispersionen beschleunigt und damit dem geforderten raschen Durchlauf durch den Trockner beim Beschichtungsvorgang entgegenkommt.

The admixtures of crosslinkable polymer dispersions with the addition of thickened alkaline dispersions of higher fatty acids differ in several ways from the comparable, known suspensions (dispersions) which contain hot-melt adhesive powder:

• a) The particle diameter of the crosslinkable polymer dispersions is generally between 0.1 and 1 μm. The particles of the hot melt adhesive powder that are used for stirring generally have a diameter of 30-40 μm. The particle volume has a ratio of 1: 25,000 to 1: 25,000,000. The polymer particles of the dispersions are therefore many dimensions smaller.
• b) The particles of the crosslinkable polymer dispersions are electrical charge carriers which repel one another and in this way stabilize the dispersion. The hotmelt adhesive powders themselves have no charges.
• c) The admixtures of the crosslinkable polymer dispersions with the thickened alkaline dispersions of the higher fatty acids significantly change the pH during the mixing process. The alkalinity disappears when the polymer dispersions, which are generally acidic, are added. The mixed product should have a pH of about 5-8, preferably 6-7. In contrast, the mixtures with the hot melt adhesive powder remain in the pH value above 8.
  Due to the change in pH, it must be assumed that the fatty acids present as salts in the alkaline medium are almost completely converted into the free fatty acid when mixed with the crosslinkable polymer dispersions, whereas the same does not take place with hot-melt adhesive powders.
• d) Finally, hot melt adhesive powders and crosslinkable polymer dispersions are chemically very different substances. The crosslinkable polymer dispersions have to be crosslinked in order to be washable and cleanable, but not hot melt adhesive powder. The crosslinking must take place in the shortest possible time with the short residence times and relatively mild temperatures which are customary in coating practice in the dryer. There was a great reservation that this can be achieved with the addition of alkaline products, since an enormous delay in condensation occurs by shifting the pH value into the alkaline range. It was surprising that a change in pH value only in the vicinity of the neutral range in the presence of fatty acids and especially with the addition of crosslinking catalysts, such as ammonium tetrafluoroborate, does not reduce the rate of condensation, but even accelerates it, and at the same time the wetting properties of the printing pastes to the carrier and sprinkled hot-melt adhesive powder despite the almost complete transition of the fatty acid salts into the free fatty acids, producing a special one soft grip and a high fixing adhesion could be influenced in the desired manner. Apparently, the tendency to penetration in crosslinkable polymer dispersions is not only slowed down by the fatty acid salts, as in the case of hotmelt adhesive powder mixtures, but also by the free fatty acid, which also accelerates the crosslinking of the crosslinkable polymer dispersions used and thus complies with the required rapid passage through the dryer during the coating process .

It is possible to add hot-melt adhesive powder to the base layer, preferably in an amount of 2 to 50% by weight, based on the dry weight of the base layer. For example, copolyamide, copolyester or also low-pressure polyethylene powder can be added to the base layer in the stated amount.

The mixture of the polymer dispersion is first additionally thickened before application to the coating carrier, this thickening should be relatively strong, so that the base paste largely loses its flow properties. After thickening, the viscosity of the resulting base paste is, for example, in the range from 15000 to 35000 cP at 20 ° C. (SVI HAAKE viscometer VT 23) and 5.8 revolutions / min.

Suitable thickeners are, for example, ammonium salts of polyacrylic acids, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose ethers, starch ethers, alginates, polygalacton mannan (ether). A highly disperse silica can also be used as a thickener.

The carrier material on which the base layer and the second layer are applied can be any flat structure from the textile sector, for example a woven fabric, knitted fabric, non-woven fabric, woven fabric, knitted non-woven fabric, woven knitted fabric, plastic film, foam, synthetic leather or similar materials. Such carriers preferably have a weight in the range of 20 to 120 g / m².

According to the method according to the invention, the base layer is first prepared, which in addition to the polymer dispersion contains a carboxylic acid with a carboxyl group and at least 18 carbon atoms in the molecule, and which can optionally contain salts of divalent or trivalent metals of this carboxylic acid. For this purpose, an aqueous, thickened coating paste is produced, which is then applied to the coating carrier by means of a grid-shaped coating. The coating weight of the base layer is in the range of about 1 to 20 g / m², preferably 2 to 8 g / m². Then the further, second layer is applied, which can consist, for example, of the hot-melt adhesive powder already mentioned. Copolyamide powder or copolyester powder are particularly suitable as hot-melt adhesive powder. A hot-melt adhesive powder with a powder-grain fraction which has a particle size in the range from 5 to 160 μm, preferably 80 to 160 μm, is expediently used.

Instead of the hot-melt adhesive powder, flock fibers can also be applied to the base layer. Such flock fibers preferably consist of cellulose, cotton or synthetic fibers, which have a cutting length of 0.5 to about 5 mm.

A self-crosslinking, aqueous polyacrylate dispersion having a solids content of 45 to 60% by weight and a pH of 2.5 to 3.5, mixed about 200% by weight, is used in the production of the sheet-like structure according to the invention with a grid-like coating. Parts of this dispersion with about 100 parts by weight of a thickened ammoniacal behenic acid dispersion with a pH of 8.5 to 10 (behenic acid content 5 to 7% by weight). Polyacrylic acid ammonium is used as a thickening agent in an amount of 0.8 to 1.0% by weight. In addition, about 0.2 to 2.0% by weight of ammonium tetrafluoroborate, from which an approximately 10% aqueous solution has previously been prepared, are added. After thickening, the viscosity of the base paste is in the range of approximately 15000 to 35000 cP at 20 ° C. (SVI measuring device, HAAKE viscometer VT 23) and 5.8 revolutions / min.

The base paste is applied to a fine textile carrier web using a sieve template with a number of holes of 50 to 120 / cm², then, if necessary, crosslinking catalyst for the base layer is applied to hot-melt adhesive powder with a melting point of approximately 95 to 125 ° C. and with a grain size of approximately 80 to 160 µm scattered in excess. A subsequent beater roller vibrates the carrier and ensures an even distribution of the scattered powder. The excess of hot-melt adhesive powder is then removed by blowing and suction. Drying, sintering and condensation take place at 160 to 190 ° C in a time of 10 to 30 s.

This invention is explained in more detail below with reference to the following examples.

example 1 a) Dispersion of behenic acid :

1000 parts by weight of water
130 parts by weight of LATECOLL AS (ammonia-alkaline polyacrylate thickener, 10%, pH = 11, supplier BASF)
72 parts by weight of behenic acid
24 parts by weight of zinc 12-oxystearate
pH: 10.0

b) Base paste:

100 parts by weight of behenic acid dispersion according to Example 1a)
200 parts by weight of aqueous self-crosslinking polyacrylate dispersion based on ethyl acrylate / methyl methacrylate, solids content 50%, film formation at 27 ° C., pH = 2.5
20 parts by weight of ammonium tetrafluoroborate 10% in water
8-10 parts by weight of polyacrylic acid thickener, partially neutralized with NH₃, 30%,
pH = 5.0
pH of the finished paste: 6.0
Application quantity paste: 7 g / m² (dry weight)
Grid: 25 mesh (= 110 dots / cm²)

c) Scattering powder:

94 parts by weight of copolyamide,
Melting point 110 ° C, grain size 80-160 µm,
MFI value 160 ° C, approx. 35 g / 10 min, applied with
2 parts by weight of oxalic acid, dissolved in
4 parts by weight of water
intensely mixed
Application quantity: 8 g / m²

d) Carrier:

elastic synthetic fabric
Weight: 38 g / m²

e) Drying:

Condensation and
Sintering: 180 ° C / 20 s

Example 2

Replacement of behenic acid from Examples 1a) and 1b) with 12-oxy-stearic acid

Example 3

Replacement of behenic acid from examples 1a) and 1b) with HOECHST wax S
(= oxidized montan wax with 60% fatty acid content)

Example 4

50 parts by weight of an aliphatic
Polyurethane dispersion (40%) are added to the batch according to Example 1b) and further processing is carried out according to 1c) to 1e).

Instead of the hot-melt adhesive powder, according to Example 5 below, fiber cut flakes can be connected to the base layer for other purposes. The flock fibers made of cellulose, cotton or synthetic fibers with a cutting length of 0.5 to approx. 5 mm are advantageously shot onto the base layer in an electrostatic field. The drying and wash-resistant anchoring of the cut flock fibers can take place under the conditions of Examples 1 to 4. The grid-like imprint of the base layer also gives a very soft feel.

Example 5

A paste for the base layer with a dry application weight of 25 g / m² is pressed onto a closed textile carrier in a 25 mesh grid. The paste has the following composition:
100 parts by weight of behenic acid dispersion from Example 1a)
200 parts by weight of Plextol DV 240 (self-crosslinking soft polyacrylate dispersion, 60%, pH = 2.1 damping maximum according to DIN 53445 at -40 ° C; Supplier: Röhm GmbH)
20 parts by weight of ammonium tetrafluoroborate solution 10% in water
10 parts by weight of polyacrylic acid thickener, partially neutralized with NH₃, 30%, pH = 5.0
100 parts by weight of Impranil DLV (= anionic aliphatic polyester-polyurethane dispersion 40%,
networkable;
Supplier: Bayer)
pH of the finished paste: 6.0
Cellulose cut flakes with a length of 1 mm are shot onto the print in an electrostatic field (40,000 volts). Drying is particularly washable and cleanable within 120 to 180 s at 160 ° C. The handle is very soft.

It is also possible to print the paste according to the invention as described in Example 6 below onto the coating carrier. In this way it is possible to obtain laminations with a particularly soft feel and absolute resistance to kickback and to reduce the coating weights even further without the adhesion falling in the same proportion. For inserts for lightweight, thin outer fabrics, e.g. In the case of blouse inserts, such particularly soft laminates are of great interest.

Example 6

On a synthetic knitted fabric with weft insertion (= woven fabric) of 38 g / m², approx. 2.5 g / m² will be 2.5 times the volume in a 25 mesh grid foamed paste from Example 1b), which comprises 0.5% of an ionic surfactant, which contains a small amount of a foam stabilizer based on a fatty acid alkanolamide, printed and sprinkled with copolyamide powder according to Example 1c). The total dry coating is 5 to 6 g / m²
Compared to an unfoamed double coating quantity, the adhesion after lamination has only dropped to approx. 75%.

Claims (18)

1. Coated flat structure comprising a coating support, a base layer applied to this and a further layer sitting on top of this, characterised in that the base layer incapable of flowing applied in the form of a raster is at least partially cross linked and contains an aliphatic carboxylic acid with a carboxyl group and at least 18 carbon atoms per molecule in a quantity of 2 to 10 wt % and if necessary its salts of bivalent or trivalent metals in a quantity of 0.1 to 2 wt %, the specification of quantities relating to the dry weight of the base layer.
2. Flat structure according to claim 1, characterised in that the carboxylic acid is behenic acid or oxystearic acid.
3. Flat structure according to claim 1 or 2, characterised in that the salt of the carboxylic acid is a calcium, magnesium, zinc or aluminium salt.
4. Flat structure according to claims 1 to 3, characterised in that the base layer is produced with an aqueous polymer dispersion, emulsion and/or solution capable of cross linking.
5. Flat structure according to claim 4, characterised in that the polymer exhibits a film formation temperature of at least 5C°.
6. Flat structure according to claim 4 or 5, characterised in that the polymer is a self cross-linking polyacrylate.
7. Flat structure according to any of the claims 4 to 6, characterised in that the polymer dispersion additionally contains, dissolved in water, carbamide, melamine, semi-reactant , reactant cross-linking agents with =N-CH₂OH or =N-CH₂OR , where R means an alkyl group.
8. Flat structure according to any of the claims 4 to 7, characterised in that the polyacrylate dispersion additionally contains a polyurethane dispersion in a quantity of 2 to 40 wt % with respect to the dry weight of the base layer.
9. Flat structure according to any of the claims 1 to 8, characterised in that the base layer additionally contains fusion adhesive based on copolyamides, copolyesters or low-pressure polyethylene in a quantity of 2 to 50 wt % with respect to the dry weight of the base layer.
10. Flat structure according to any of the claims 1 to 9, characterised in that ammonium tetrafluoroborate as cross-linking catalyst is contained in the base layer during impression in a quantity of 0.2 to 2.0 wt % with respect to the dry weight of the base layer.
11. Flat structure according to any of the claims 1 to 10, characterised in that the base layer is foamed before impression.
12. Flat structure according to any of the claims 1 to 11, characterised in that the further layer consists of a fusion adhesive powder made of copolyamides or copolyesters.
13. Flat structure according to claim 12, characterised in that the further layer consists of a fusion adhesive powder which is acted on with cross-linking catalysts for the base layer.
14. Flat structure according to any of the claims 1 to 11, characterised in that the further layer consists of flock fibres made of cellulose, cotton or synthetic fibres.
15. Process for manufacturing a flat structure according to any of the claims 1 to 14, in which on a base layer applied in raster form, which contains a carboxylic acid with a carboxyl group and at least 18 carbon atoms in the molecule and if necessary a salt of it with bivalent or trivalent metals, a further layer is applied with which the excess of the further layer not adhering to the imprint is removed by blowing and suction and that the support thus coated is then dried, sintered and condensed.
16. Process according to claim 15, characterised in that the base layer is manufactured from a self cross-linking polymer dispersion with a pH of 5.0 to 8 which contains 2 to 10 wt % of the carboxylic acid and if necessary 0.2 to 2.0 wt % of ammonium tetrafluoroborate.
17. Process according to claim 15 or 16, characterised in that the base layer is applied to the support by dot raster coating.
18. Use of a flat structure according to any of the claims 1 to 14 as a fixable inlay material for articles of clothing, in particular such with light-weight, thin outer materials, such as blouses and shirts.