DE3832828A1 - Coating composition, comprising fluoropolymers - Google Patents

Abstract

A coating composition is described which comprises fluoropolymers with a hydrophilicising action, the composition consisting of A) a copolymer which is composed of tetrafluoroethylene or chlorotrifluoroethylene, a comonomer which contains -COOM groups (M = alkali metal, ammonium group) and, if desired, a fluorine-containing vinyl ether, dissolved in a mixture of an aprotic solvent and water and mixed with B) a colloidal, aqueous dispersion of a fluoroolefinic or fluorochloroolefinic homo- or copolymer having a melting point of </= 200@C. The composition may also contain a diluent and conventional levelling agents, and is particularly suitable for coating fluorinated plastic sheets which can be employed as roof coverings, the purpose of such a coating being to promote the run-off of water.

Description

The invention relates to a coating composition Fluoropolymers with a hydrophilizing effect and their Use.

Fluorine-containing polymers which contain groups of the type -SO ₃ Ac or -COOAc (in which Ac here represents a group constituting the acid or an acid derivative) in appreciable proportions, in contrast to most other fluoropolymers, have a hydrophilic character. They have found widespread use as cation-permeable membranes in electrochemical processes. The films required for this are partly produced by casting solutions onto a substrate and peeling off the self-supporting film from this substrate. There has been no lack of attempts to provide suitable solutions for the production of such cast films. The preparation of such solutions is known from DE-OS 19 59 142, from DE-OS 29 05 457 and from EP-OS 50 447, it having been found that fluorine-containing polymers with -COOAc groups, depending on the type of Ac, have large differences in solubility. While, according to DE-OS 29 05 457, such polymers in the salt form (Ac = alkali metal or ammonium group) should be readily soluble in highly polar solvents, even in aprotic ones, corresponding polymers dissolve in the acid form (Ac = H) according to EP-OS 50 447 only when water is added. However, it has been found that addition of water also significantly enhances the solubility of such polymers when they are in the salt form, particularly when these polymers are of high molecular weight or equivalent weight. Such solutions are also known, for example, from EP-OS 2 45 144.

It has also been attempted to use such solutions of fluorine-containing polymers with -SO ₃ Ac or -COOAc groups for coating substrates, as described in particular in US Pat. No. 3,692,569 and in the abovementioned documents DE-OS 29 05 457 and EP-OS 50 447 mentioned. However, such coatings have the considerable disadvantage of unsatisfactory adhesion to the substrate. This is already noticeably noticeable when covering shaped articles with closed surfaces, for example made of metal or glass. This can be helped by mechanical or caustic pretreatment of the substrate. However, the adhesion to non-stick plastic surfaces, such as from all fluoropolymers, but also from polyolefins, polyimides or even PVC, is completely inadequate.

It was therefore the task of a Coating composition with improved Adhesion properties to all types of substrates create.  

This object is achieved according to the present invention by a coating composition with a hydrophilizing effect, consisting of
A) a fluorine-containing copolymer composed of

• a) 90 to 55 mol% of copolymerized units of a fluorine-containing olefin of the formula CF ₂ = CFX, where X = F or Cl,
• b) 10 to 45 mol% of copolymerized units of a fluorine-containing comonomer which contains -COOM groups, where M is an alkali metal or an ammonium group ⁺N (R) ₄ and R, the same or different, is an alkyl or cycloalkyl radical or hydrogen is, as well
• c) 0 to 25 mol% of copolymerized units of a fluorinated vinyl ether of the formula where Y = F, Cl or H, p = 0 to 2 and q = 1 to 3, with the proviso that b) + c) is at most 45 mol%,

mixed with
B) a polymer from the group of fluoroolefinic or fluorochlorolefinic homopolymers or those copolymers which contain at least one fluoroolefin or fluorochlorolefin as a comonomer, with a melting point of 200 ° C., determined by the maximum of the DSC curve, where A) before the mixing in Is in the form of a solution which contains 1 to 20% by weight of the copolymer in a mixture of aprotic solvent and water, and B) before mixing as a colloidal aqueous dispersion with a solids content of 5 to 40% by weight of B) is present and finally the ratio of polymer solids A: B in the mixture of water and aprotic solvent is 30:70 to 70:30.

In the coating composition of the invention the fluorine-containing copolymer composed of

• a) copolymerized units of a fluorine-containing olefin of the formula CF ₂ = CFX, where X = F or Cl; they are therefore copolymerized units of tetrafluoroethylene (hereinafter abbreviated to TFE) or chlorotrifluoroethylene (hereinafter abbreviated to CTFE),
• b) copolymerized units of a fluorine-containing comonomer containing -COOM groups, where M is an alkali metal, preferably sodium, or an ammonium group of the formula ⁺N (R) ₄ and R, the same or different, is an alkyl or cycloalkyl radical or hydrogen ; Usually, the comonomer b) is not copolymerized in this form, but in the form of a group Z, which can then be converted into -COOM in the copolymer formed; Z here means in particular COOH, COOR ′, COORf, CON (R ′ ′) ₂ , COF or CN, where R ′ is a short-chain alkyl radical, Rf is a short-chain perfluoroalkyl radical and R ′ ′ is a short-chain alkyl radical or hydrogen,
• c) and optionally copolymerized units of a fluorinated vinyl ether of the formula where Y = F, Cl or H, p = 0 to 2 and q = 1 to 3.

The proportions from a) are 90 to 55, preferably 85 to 70 mol%, of b) 10 to 45, preferably 15 to 30 mol% (based on the form -COOM) and from c) 0 to 25, preferably 0 to 10 mol%, where a), b) and optionally c) Add 100 mol%, but with the proviso that in In the presence of c) the sum of the proportions of b) and c) 45 mol%, in the preferred quantitative ratio  30 mol%.

The comonomer b) can be one of the formula

CF₂ = CF [CF₂] _m Z

be, where m = 0 to 10, preferably 0 to 5, and Z has the meaning given above from the preparation and takes on the meaning -COOM (defined as above) after hydrolysis in the coating composition. Perfluoroacrylic acid and its derivatives are preferred. Such copolymers and their preparation are described in British patent specification 11 10 007.

Likewise, b) can also be a comonomer of the formula

be in which n = 0 to 2, preferably 0 to 1, o = 1 to 10, preferably 1 to 5, and Z has the meaning given above from the preparation and after hydrolysis in the coating composition according to the invention the meaning -COOM (M defined as above). Copolymers A) in which the comonomer a) TFE and b) is one of the abovementioned formula with n = 0 and o = 2 are particularly preferred.

If necessary, the copolymer A) can be expanded by c) copolymerized units of a vinyl ether of the above-mentioned formula to the terpolymer, a fraction of 0.5 mol% being sufficient; this proportion can extend up to the above limit. Y = F, p = 0 to 1 and q = 1 to 3 are preferred. Perfluoropropyl vinyl ether (PPVE) is particularly preferred as comonomer c). A preferred terpolymer is one of a) 83 to 70 mol% TFE, b) 15 to 25 mol% CF ₂ = CF-O- (CF ₂ ) ₂ -COOM and c) 2 to 5 mol% PPVE.

The copolymers mentioned and their production are described, for example, in the US patents 41 16 888 and 41 38 373. The transfer to the Salt form -COOM takes place by treatment of the obtained  Copolymers with basic reagents, such as for example alkali hydroxides or carbonates, in aqueous medium at elevated temperatures.

Such copolymers can also be produced by the method described in US Pat. No. 4,471,076. A copolymer is first prepared from a) TFE, b) an -H-perfluoroalkyl vinyl ether or polyether and optionally c) a perfluoroalkyl vinyl ether and this copolymer is then treated with peroxodisulfuryl difluoride F-SO ₂ -OO-SO ₂ F, the - H atoms of the comonomer b) are converted into fluorosulfato groups. These are then converted into -COOM groups using appropriate basic reagents.

As a solvent for these copolymers A) has most suitable proved a mixture of an aprotic Solvent, that is, a solvent that does not possesses reactive protons, and water. examples for such aprotic solvents with water must be miscible are the N-alkyl and N, N-dialkylformamides, acetamides and propionamides with Alkyl radicals of 1 to 4 carbon atoms, Tetramethylene sulfoxide, ethylene carbonate, Propylene carbonate, tetramethyl urea, N, N'-dimethylimidazolidone-2, N, N'-dimethylpyrazolidone-2 and hexamethylphosphoric triamide. As special N, N-dimethylformamide and -acetamide, dimethyl sulfoxide and N-methylpyrrolidone-2. In addition to being as complete as possible with Water and easy availability is one possible  low boiling point another point of view for the Selection of the aprotic solvent because it is Removal after the coating process is favored. The water present in the solution promotes the Dissolution of the polymer and is said to coexist with the Polymer A) and the aprotic solvent form a clear homogeneous solution. The resolution is made by copolymers A) in the mixture from aprotic solvent and water to 90 to 160 ° C, preferably 95 to 130 ° C, heated. The The dissolving process takes 5 to 48 hours and can be done accelerate considerably by stirring.

The amount of the copolymer A) is such that it is Proportion, based on the total solution, 1 to 20% by weight, preferably 2 to 15% by weight. Here is the ratio of aprotic solvent to Water expediently 98: 2 to 30: 70, preferably 95: 5 to 60: 40 parts by weight.

The solution thus prepared is suitable for Casting self-supporting foils or for Coating and impregnating such substrates inherently have sufficient liability, for example, textile-like fabrics Mineral fibers or high temperature resistant fibers, like asbestos or aramid.

To improve liability, according to the added a polymer B) to the present invention, which is selected from the group of fluoroolefinic and fluorochlorefinic homopolymers or of those copolymers that have at least one fluoroolefin  or contain fluorochlorolefin as a comonomer. Essential selection criterion for this polymer B) is that because of its composition it has a Melting point of 200 ° C, preferably 180 ° C, should have. Furthermore, this polymer is said to be colloidal aqueous dispersion may be available or at least by means of suitable measures in one colloidal aqueous dispersion can be transferred.

For this come from the group of homopolymers for example in question the polyvinyl fluoride and Polyvinylidene fluoride, but also such Polytrifluorochlorethylene, which according to their Manufacturing conditions with relatively low Molecular weight arise.

Examples from the group of copolymers which contain at least one fluoroolefin or one fluorochlorolefin as a comonomer and have a melting point of 200 ° C. are:
Copolymers which contain copolymerized units of TFE and vinylidene fluoride and, in addition, copolymerized units of hexafluoropropylene or a perfluoroalkyl vinyl ether having 1 to 4 carbon atoms; it can also be quaterpolymers which contain the two last-mentioned comonomers together;
copolymers of TFE and 20 to 30 mol% of hexafluoropropylene;
Copolymers of TFE and 10 to 45 mol% of a perfluoroalkyl vinyl ether with 1 to 4 carbon atoms, in particular perfluoropropyl vinyl ether;
Copolymers of TFE, 10 to 25 mol% of hexafluoropropylene and 5 to 15 mol% of a perfluoroalkyl vinyl ether, preferably perfluoropropyl vinyl ether;
Copolymers of TFE or CTFE and ethylene, which can contain more than 10 mol% and up to 40 mol% of a third and optionally fourth comonomer, such as, for example, the copolymer of 20 to 30 mol known from US Pat. No. 3,817,951. % TFE, 40 to 60 mol% ethylene and 10 to 30 mol% hexafluoropropylene or the copolymer from TFE, ethylene and isobutylene or the copolymer from TFE or CTFE, ethylene and
Vinylidene fluoride or the copolymer of TFE, ethylene and vinyl acetate. Such copolymers which contain TFE or CTFE in approximately equal proportions and also third or fourth comonomers have been described in US Pat. Nos. 24 68 664 and 38 59 262 and in British Pat. No. 10 24 351. Copolymers of hexafluoroisobutylene and ethylene, which are also suitable are described in US Pat. No. 3,720,655.

However, the copolymers mentioned above are preferred TFE, vinylidene fluoride and hexafluoropropylene or from TFE, vinylidene fluoride and perfluoropropyl vinyl ether or from TFE, vinylidene fluoride, hexafluoropropylene and Perfluoropropyl vinyl ether as far as it has a melting point of 200 ° C. This is generally then the case when the proportion of copolymerized Units of TFE in such copolymers at most 60 mol% and vinylidene fluoride at least 25 mol% is. Such copolymers are known to the person skilled in the art from German Offenlegungsschrift 26 35 402 US Pat. No. 3,235,537 and from European Patent 2 809.  

All of these homopolymers and copolymers are that Known specialist. You can use known methods in aqueous medium in the presence of known Dispersants, especially salts of Perfluoroalkanoic acids, polymerized or copolymerized become and fall as colloidal aqueous dispersions with 5 to 40 wt .-% solids. You can in this form with the fluorine-containing copolymer A) be mixed. The is preferably Solids content of the colloidal aqueous dispersion of the Polymers B) 10 to 25% by weight.

Of the flow and wetting properties of the it is coating composition according to the invention expedient, the dispersion of the polymer B) in one more concentrated range of solids content choose the water content during the coating process to keep low. On the other hand, when mixing the dispersion of B) with the solution of A) because of the Salt character of the fluorine-containing copolymer A) in Coagulation occurs to a small extent. The appearance this unwanted coagulation is also dependent on the type of polymer B) used. In this case it may be appropriate to the solution of the fluorine-containing Copolymers A) before mixing with the dispersion of polymer B) to add a diluent. The amount of this diluent should be measured in this way be that a coagulation of B) at and after the Mixing process is avoided and the coating composition according to the invention still is sufficiently stable in storage. This amount to be added depends on the type of polymer used B) and its tendency to coagulate in a colloidal  aqueous dispersion, from the solids content of this Dispersion and the salt character of fluorine Copolymers A). The addition of this diluent can be unnecessary in many cases, otherwise its share can fluctuate within wide limits, for example, it can be 0.1 to 5 times the volume the solution of A). The cheapest Quantity can easily be determined by a preliminary test determine. As diluents are in particular suitable alkanols with 1 to 3 carbon atoms, Ethylene glycol monoalkyl ether with an alkyl group of 1 up to 4 carbon atoms or one of the abovementioned aprotic ones Solvent. In the latter case, it is convenient uses the aprotic solvent already in the solution of A) is present, that is, the solution is further diluted.

Is the addition of such a diluent required, it becomes the solution of the fluorine-containing Copolymers A) before further mixing with the Polymers B) added. In any case, the - diluted or undiluted - solution of fluorine Copolymer A) with the colloidal aqueous dispersion of polymer B) mixed so that the ratio of Polymer solids A): B) 30: 70 to 70: 30, preferably 40:60 to 60:40. It has proven to be useful, the solution of A) in the stir in aqueous dispersion of B).

The coating composition according to the invention can still contain other common additives and ingredients, such as for example dyes and color toners, antioxidants as well as leveling agents that ensure the even  Film formation of the coating composition at Favor coating process. Such leveling agents are for example ethylene glycol mono- and also dialkyl ethers with alkyl groups of 1 to 4 carbon atoms and Alkanols of 1 to 4 carbon atoms. In any case, the leveling agent used with water and each unlimited use of aprotic solvents be miscible. If the mix is already a Contains diluent, which with the Leveling agent is identical, so is another part after mixing A) with B) added.

The thus prepared according to the invention Coating composition is applied using conventional methods applied the respective substrate, such as by spraying, dipping, brushing, coating with the Squeegee or on a roller mill. You can use a coating process layer thicknesses of up to 20 µm can be achieved. The coating is then at a temperature between 20 ° C and 70 ° C dried. If necessary, another layer can then be applied applied and dried and this process still can be repeated any number of times until the desired one Layer thickness is reached. Finally, the Then plating in a temperature range that differs from Temperatures a little above the melting point of the Polymers B) up to 220 ° C, preferably up to 200 ° C, stretches, baked for 5 to 15 minutes.

For certain purposes, the hydrophilic Properties of the coating formed still improved if at least on the surface -COOM groups are converted into those in which  M is a metal of II. Or III. Main group is. This is achieved by using a solution of hydroxide or a salt of the metal in question, preferably the Calcium, magnesium or aluminum for a while allows the surface of the coating to act. Depending on Duration and temperature of the solution used the effect is limited to the surface or extend deeper layers of the coating.

The coating compositions of the invention can can be applied to a variety of substrates. These are, for example, substrates with closed ones and hard or porous surfaces like for example metals, glass, porcelain or ceramics, also fabrics, fleeces or other textile Flat structures made of mineral fibers, such as asbestos or Glass fibers, or from high temperature resistant Synthetic fibers, for example from polyimides, Polyesters, polyether ketones, polyether sulfones, Polytetrafluoroethylene and others.

Particularly suitable because of its high adhesive strength are the coating compositions of the invention for the coating of moldings and foils of all Kind of fluorine-containing polymers, their melting point above, but at most slightly below that of the each of the polymers B) used, and also from other plastics with largely hydrophobic Surfaces, such as polyimides, polyamides or also polypropylene. On fluoropolymers that are suitable for a coating with the invention Suitable coating compositions include PTFE, even if this with small portions of others  Comonomer is modified, but not yet out belongs to the melt processable type; Copolymers of the TFE with hexafluoropropylene or with Perfluoroalkyl vinyl ethers, or both, which due to their low comonomer content a high one Have melting point; Copolymers of the type TFE / ethylene, which only minor shares in third and optionally have other comonomers and therefore are high-melting; also polychlorotrifluoroethylene, Polyvinyl fluoride and polyvinylidene fluoride.

The from the coating compositions of the invention coatings obtained are absolutely clear and transparent. They have outstanding adhesive strength on the substrate and have an excellent UV permeability and high chemical and Temperature resistance. You own one in particular high water wettability, which is sometimes essential is better than that of glass, so that on it separated water droplets run off easily.

Because of these properties they are coated Formations particularly suitable for roofing with coated films, the hydrophilic layer can be attached both inside and outside. The Interior coating is particularly important for the Use in greenhouses and other damp rooms, in which are on the inner surface of the canopy Separates condensed water. If you consider a fabric as Wants to use a canopy according to the invention has a hydrophilic outer layer, so the fabric expediently beforehand with a watertight barrier layer from one  Provided fluoropolymers and then the invention Coating composition applied as an outer layer. Other applications are for example medical devices, membranes for filtration purposes, Diaphragms and coatings on so-called Zero distance electrodes for electrolysis, in which the Layer of the invention Coating composition as a cation exchange membrane acts on the metal.

The following examples further illustrate the invention explains:

Example 1

A) First, a solution of a fluorine-containing Copolymers copolymerized from 76 mol% Units of the TFE and 24 mol% of a comonomer formula

CF₂ = CF-O- [CF₂] ₂-COONa

is made by 150 g of this copolymer in 1000 g of a mixture of N, N-dimethylformamide and water (weight ratio 90:10) will. 150 ml of this solution are removed and with 300 ml of ethylene glycol monomethyl ether diluted.

B) Then 75 ml of a colloidal, aqueous Dispersion of a terpolymer consisting of 57.4 mol% of copolymerized units of the TFE,  12.7 mol% of hexafluoropropylene and 29.9 mol% of Vinylidene fluoride (melting point 180 ° C), with a Solids content of 24.0% by weight slowly with stirring given to A). Finally 175 ml of isobutanol added with stirring.

A piece of film (25 × 30 cm) from a copolymer of Type tetrafluoroethylene / ethylene (48.0 mol% TFE, 48.4 mol% ethylene, 3.0 mol% hexafluoropropylene, 0.6 mol% perfluoropropyl vinyl ether) is mixed with 6 ml coated above mixture, dried at 50 ° C. and then 5 minutes at 185 ° C in the drying cabinet heated. The coating obtained is complete transparent and hardly recognizable. That so coated piece of film is regarding its Wettability tested by water. Doing so following test methodology applied:

The tester does not consist of a plate rusting steel which, adjustable in inclination and lockable, in a support frame via two pins is anchored. The plate has a rectangular one Cutout (20 × 20 cm) in which the coated film to be tested is clamped. Under the plate is a tube system over which the film is steamed from below; the top is blown over with air, i.e. cooled. So foggy the test snippet keeps on going for hours Water vapor and you can see the formation of drops whose Recognize association, process behavior and crashes well and compare. By simply turning the Transverse axis can be any desired angle of inclination reproducible setting.  

The amount of steam applied is 0.6 g / h · cm ² in all examples, and the angle of inclination is 15 °.

In the present example, the temperature at the Top on 35 to 40 ° C, on the bottom on 55 held up to 60 °.

Optical assessment: During the vaporization Flat drops of one spread over the entire surface Size from 0.5 to 1 cm. In the further course of the Steaming run continuously to the edge.

Example 2

A) 200 ml of a solution of 100 g of a copolymer, consisting of 80 mol% of copolymerized Units of the TFE and 20 mol% of

CF₂ = CF-O- [CF₂] ₂COONa,

in 1000 g of a mixture of N, N-dimethylformamide and water (weight ratio 85:15) are diluted with 45 ml of dimethyl sulfoxide.

B) Then 90 ml of that in Example 1 used dispersion (solid 20 wt .-%) under Stir added to A). At the end you add 150 ml of isopropanol and 200 ml of isobutanol are added.

A piece of film (25 × 30 cm) made of a copolymer, consisting of 88 mol% of copolymerized units of the TFE and 12 mol% of the hexafluoropropylene, with 5 ml of the above mixture as in Example 1 described, coated. You get one perfectly transparent film.  

The test methodology for assessing water wetting is identical to that in Example 1.

In the present example, the temperature at the Foil top at 40 ° C, on the bottom at 55 to Kept at 65 ° C.

Optical assessment: During the vaporization flat drops with a size of 0.5 to 1 cm. in the a further course of vaporization is formed Water film that runs to the edge.

Example 3

A) 250 ml of the polymer solution used in Example 1 are made with 100 ml of a mixture N, N-dimethylformamide and water (weight ratio 75: 25) diluted.

B) Then 50 ml of an aqueous dispersion of a Terpolymers consisting of 39.8 mol% copolymerized units of TFE, 11.8 mol% of Hexafluoropropylene and 48.4 mol% of Vinylidene fluoride (melting point 120 ° C), with a Solids content of 31% by weight slowly with stirring given to A). Finally, 150 ml of n-propanol and 200 ml of isobutanol added with stirring.

A piece of film (25 × 25 cm) made of a terpolymer, consisting of 57.4 mol% of copolymerized units of TFE, 12.7 mol% of hexafluoropropylene and 29.9 mol% of vinylidene fluoride, with 6.5 ml of  coated above mixture, dried at 50 ° C. and then heated to 140 ° C for 10 minutes.

In the test to assess water wetting according to Example 1 is the temperature on the top of the film kept at 25 ° C, on the underside at 40 to 45 ° C.

Optical assessment: Evaporation forms a transparent, full-surface water film that up to runs to the edge.

Example 4

A) 200 ml of a solution of 120 g of a copolymer, consisting of 72 mol% of copolymerized Units of the TFE and 28 mol% of

CF₂ = CF-O- [CF₂] ₂COONa,

in 1000 g of a mixture of N, N-dimethylformamide and water (weight ratio 90: 10) with 220 ml Ethylene glycol monoethyl ether diluted.

B) Then 110 ml of an aqueous dispersion of a Terpolymers consisting of 51.5 mol% copolymerized units of TFE, 1.6 mol% of PPVE and 46.9 mol% of the vinylidene fluoride (Melting point 173 ° C), with a solids content of 26% by weight added to A) with stirring. Subsequently add 70 ml of ethanol, 60 ml of propanol and 60 ml Isobutanol added.

A peeling film (25 × 25 cm) made of a copolymer, which contains 99.95 mol% of copolymerized units of  Contains TFE and 0.05 mol% of the PPVE, with 6 ml of the Coated mixture described above, at 50 ° C. dried and then 10 minutes at 185 ° C heated. A homogeneous, smooth coating is obtained.

In the test to assess water wetting according to Example 1 shows the temperature at the top 40 ° C, kept at the bottom at 50 ° C.

Optical assessment: During the vaporization Flat drops of one spread over the entire surface Size of 1 cm. In the further course of vapor deposition they run continuously to the edge.

Claims (10)

1. Coating composition with a hydrophilizing effect, consisting of

• A) a fluorine-containing copolymer composed of
  • a) 90 to 55 mol% of copolymerized units of a fluorine-containing olefin of the formula CF ₂ = CFX, where X = F or Cl,
  • b) 10 to 45 mol% of copolymerized units of a fluorine-containing comonomer which contains -COOM groups, where M is an alkali metal or an ammonium group ⁺N (R) ₄ and R, the same or different, is an alkyl or cycloalkyl radical or hydrogen is, as well
  • c) 0 to 25 mol% of copolymerized units of a fluorinated vinyl ether of the formula where Y = F, Cl or H, p = 0 to 2 and q = 1 to 3, with the proviso that b) + c) is at most 45 mol%, mixed with
• B) a polymer from the group of the fluoroolefinic or fluorochlorolefinic homopolymers or those copolymers which contain at least one fluoroolefin or fluorochlorolefin as comonomer, with a melting point of 200 ° C., determined by the maximum of the DSC curve,

where A) before mixing in the form of a solution is present, the 1 to 20 wt .-% of the copolymer in a mixture of aprotic solvent and Contains water, and B) before mixing as one colloidal aqueous dispersion with a Solids content of 5 to 40 wt .-% of B) is present and finally the ratio of Polymer solids A: B in the mixture of water and aprotic solvent 30:70 to 70:30 is. 2. Coating composition according to claim 1, characterized in that the fluorine-containing comonomer b) in the copolymerized units within A) is one of the formula where n = 0 to 2 and o = 1 to 10. 3. Coating composition according to one or more of claims 1 and 2, characterized in that the fluorine-containing copolymer A) from 85 to 70 mol% on copolymerized units from a), 15 to  30 mol% of copolymerized units of b) and 0 to 10 mol% of copolymerized units of c) with the proviso that b) + c) at most 30 Mol% makes up. 4. Coating composition according to one or more of claims 1 to 3, characterized in that the solution of A) from 1 to 20 wt .-% of Copolymers consists of, dissolved in a mixture of aprotic solvent and water ratio from 98: 2 to 30: 70 parts by weight. 5. Coating composition according to one or more of claims 1 to 4, characterized in that the aprotic solvent is one from the group N, N-dimethylformamide, N, N-dimethylacetamide, Is dimethyl sulfoxide or N-methylpyrrolidone-2. 6. Coating composition according to one or more of claims 1 to 5, characterized in that the polymer B) from a fluorine-containing copolymer at most 60 mol% of copolymerized units of tetrafluoroethylene, at least 25 mol% copolymerized units of vinylidene fluoride and from copolymerized units of Hexafluoropropylene, the perfluoropropyl vinyl ether or from these two comonomers. 7. Coating composition according to one or more of claims 1 to 6, characterized in that it contains a diluent that the group the alkanols with 1 to 3 carbon atoms, the Ethylene glycol monoalkyl ether with an alkyl group  of 1 to 4 carbon atoms or that for the dissolution of the fluorine-containing copolymers A) suitable aprotic Solvent is selected. 8. Coating composition according to one or more of claims 1 to 7, characterized in that the melting point of polymer B) at 180 ° C. lies. 9. Use of the coating composition according to one or more of claims 1 to 8 for coating of foils or moldings made of fluorine-containing Polymers.