DD297177A5 - THERMOPLASTIC POWDER MASSES, METHOD OF PREPARATION AND THEIR USE - Google Patents

Abstract

Thermoplastic powder compositions based on polyamide and / or polyetheresteramide, process for their preparation and their use for coating metal substrates. Powder compositions based on polyamide and / or polyetheresteramide, which additionally contain epoxy / sulfonamide resins and are suitable for coating metal substrates, are described.

Description

The invention relates to novel thermoplastic powder compositions based on polyamide and / or polyetheresteramide, the before

can all be used for coating metal substrates without having previously been treated with a primer or primer.

The polyamides are commonly used for coating metal substrates, mainly because of their goodness

mechanical properties such as abrasion resistance, impact resistance - and their chemical inertness numerous products, such as

Hydrocarbons, bases, mineral acids. However, it is known that the adhesion of the polyamides to metals is insufficient, due to poor wetting properties of the

molten polyamides that do not allow them to penetrate well into the rough surfaces and gaps of the metal to achieve mechanical adhesion. On the other hand, you wear a polyamide powder regularly on a

Total metal surface and brings this order to the appropriate melting temperature, so the film stretches

molten polyamide together and forms droplets that can fall off the metal support or the metal pad.

To overcome this disadvantage, the metal support is coated with a primer coat of a primer,

to ensure the adhesion and mechanical anchoring of the polyamide powder. Generally one uses one

Bonding agent based on thermosetting resins and brings it as a powder or as a solution or as a suspension in

organic solvents.

Therefore, additional facilities must be provided for the possibly necessary removal of Solvents and for baking, or curing of the primer layer, before the so-coated substrate Polyamide powder is applied. In addition, by curing and / or drying the primer jhicht the duration

the operations for coating or coating and thus increased their costs in a non-negligible way.

FR-A-7241484 describes polyamide-based powder compositions containing blocked phenols and none Require pretreatment with primer. However, the conditions of use are difficult and they do allow

improved, but not very powerful adhesion results.

The thermoplastic powder compositions based on polyamide and / or polyetheresteramide, the subject of the invention

are good wetting properties for metal substrates and provide high performance without the use of a primer

Adhesion results. The invention relates to thermoplastic powder compositions which are a mixture of polyamide and / or Polyothorostoramid

with epoxy resins / aromatic sulfonamides are or represent.

The weight ratio of Epoxldharzon / sulfonamides to polyamide and / or polyetheresteramide nllgomoin 0.5 to

20%, preferably 2 to 7%.

As polyamide, which is part of the thermoplastic powder mass 9 of the invention, are: aliphatic Polyamides obtained from lactams or amino acids whose carbon chain 4 bis

Contains 20 carbon atoms, such as caprolactam, enantholactam, dodecalactam, undocanolactam, 11-aminoundecanoic acid, 12-aminododecanoic acid, condensation products of a dicarboxylic acid and a diamine such as the polyamides (PA) 66,69,610,612.96, (condensation products of hexamethylenediamine and adipic acid,

Azelaic acid, sebacic acid, 1,12-dodecanedioic acid and nonamethylenediamine and adipic acid); Copolyamides by Polymerization of the various above mentioned. Monomers are obtained or the mixtures of several above

mentioned polyamides. Among these polyamides, special mention is made:

- Polyamide 11, obtained by polymerization of 11-aminododoic acid

Polyamide 12 obtained by polycondensation of 12-aminododecanoauroaurorododocanolactam and

Copolyamides obtained by polymerization of the above-mentioned monomers.

Generally, the inherent viscosity is (inherent viscosity) of the polyamide-measured at 2O ⁰ C with a solution from O, 5g polyamide 100g m-cresol - in the range from 0.20 to 2.0 preferably in the range of 0.60 to 1,30dl /G.

Also referred to as the polyamide are the amorphous semi-aromatic polyamides, especially those described in the following references: FR-A-1588130, FR-A-2324672 and FR-A-2575756, EP-A-OO53876 and JP-PSs 59015447 and 60217237. As Polyetheresteremid are both the random polyetheresteramides (caused by arbitrary linkage of the various monomeric constituents) and the Blockpolyetheresteramide consisting of blocks which have a certain chain length of their various components.

The polyetheresteramides are products of the copolymerization of reactive earth polyamides and reactive end-capped polyethers such as: sequences of dicarboxylic acid terminated polyamides and of blocks of polyether diols. Such products have already been z. In FR-A-7418913 and FR-A-77 26678, the contents of which are incorporated herein by reference. The number average molecular weight of these polyamide blocks is generally from 500 to 10,000 and preferably from 600 to 5,000. The polyamide blocks of the polyetheresteramides are preferably formed from the polyamides 6,66,612,11 or 12 or from copolyamides formed by polycondensation of their monomers.

The number average molecular weight of the polyethers is generally 200 to 6000, preferably 600 to 3000. The polyether blocks are preferably made of polytetramethylene glycol (PTMG), polypropylene glycol (PPG) or polyethylene glycol (PEG). The intrinsic viscosity of the polyetheresteramides is advantageously 0.8 to 2.05, preferably 0.80 to 1.20.

The intrinsic viscosity is measured in m-cresol at 20 ⁰ C with an initial concentration of 0.5 g per 100 g of m-cresol and / gange give in dl.

The polyesteretheramides provided according to the invention may consist of 5 to 85% by weight of polyether and of 95 to 15% by weight of polyamide. Preferably, they consist of 30 to 80% by weight of polyether and 70 to 20% by weight of polyamide. The epoxy resins are solid or liquid compounds containing at least one epoxy group, singly or as a mixture. The mixtures may consist of compounds containing a different number of epoxy groups, and very often their content of functional epoxy groups is not represented overall by an integer. There are currently a very large number of examples of organic compounds in the marketplace and in the scientific and technical literature that correspond to this definition and whose structures are very different. The most common compounds are derived from the reaction of bisphenol A and epichlorohydrin, especially the compounds obtained in the addition of 2 moles of epichlorohydrin to 1 mole of bisphenol A (DGEBA). However, one can use a variety of other epoxy resins, for example, those resulting from the attachment of an epoxy group to both ends of a paraffinic hydrocarbon chain (the butanediol-derived diepoxides) or to a polyether chain, such as the polypropylene g / κO-α, ω-diepoxide. It is also possible to use more specific diepoxides, such as 3-epoxyvinylcyclohexene dioxide, 3,4-epoxycyclohexylmethyl-4-cyclohexane monocarboxylate, 3- {3,4-epoxycyclohexyl) -8,9-epoxy-2,4-dioxa- (5.5 ) -spiroundecane, bis (2,3-adipatepoxycyclopentyl) ether, bis (3,4-epoxy-6-methylcyclohexyl) and resorcinol diglycidyl ether.

If an end product with a high degree of crosslinking is desired, it may be advantageous to use epoxy compounds which contain more than two epoxy groups per molecule, such as the epoxidized soybean oils, polyglycidyl ethers of novolak-type phonol resins, p-aminophenol triglycidyl ethers or 1,1,2 , 2-tetra- (p-hydroxyphenyl) (ethane tetraglycidyl ether). The epoxy equivalent weight may generally be in the range of 43 to 5000, preferably in the range of 150 to 1000. The epoxy resins preferred according to the invention are those whose total functionality or total number of functional groups is 1.9 to 2.1 and advantageously equal to 2.

The aromatic sulfonamide compounds can be selected from the monosulfonamide compounds of optionally halogenated benzene such as benzenesulfonamide, nitrobenzenesulfonamide, o-, m- or p-toluenesulfonamide, aminoalkyl-borosulfonamides, naphthalene or xylenesulfonamide.

The inventively provided epoxy / sulfonamide resins can be obtained by reacting the sulfonamide compounds with the epoxy compounds. The respective proportion of epoxy compounds and sulfonamide compounds should be such that the number of epoxy groups is at least equal to the number of sulfonamide groups. However, for reasons of reaction kinetics and / or the quality of the end product, the stoichiometric ratio of the number of sulfonamide groups to the number of epoxy groups 1 may preferably be 0.5 to 1.

The melting point of the inventively provided epoxy / sulfonamide resins is generally from 50 to 18O ⁰ C and the weight average molecular weight Mw is generally from 500 to 10,000.

In the above-described mixture, various other ingredients may be incorporated, such as fillers, pigments, additives such as sacking agents, reducing agents, antioxidants, etc.

Examples of fillers for the composition of the invention are talc, calcium and manganese carbonates and potassium and Aluminum silicates. Examples of pigments are titanium dioxide, strontium chromate, zinc phosphate, Blelsllicochromat, carbon black, and the like. 'Iron oxides

called.

The mixture consisting of polyamide and / or polyesteramide and epoxy / sulfonamide resins may be different

add other components, as selected from those described above and their respective proportions are within the limits as they are for potting on polyamide or polyester amide basis for coating

Metal substrates are common. In general, up to 100% by weight of these further components can be incorporated. The invention likewise relates to a plurality of processes according to which the above-defined thermoplastic powder compositions are obtained

become/

The first method developed according to the invention provides:

Dissolving the epoxy / sulfonamide resin (s), in short, the epoxy / sulfonamide resin in a suitable solvent,

The resulting solution is mixed with the polyamide and / or polyester amide powder, in short with the polyamide powder,

- And finally drying and sieving of the resulting mixture to obtain a powdery mass having the desired particle size distribution.

All these steps can be performed at room temperature. The solvent in which the epoxy / sulfonamide resin is dissolved can be conveniently used among ketones, such as acetone, esters

or any other solvent in which the resin dissolves very well and can be easily removed by the known, commonly used procedures.

The second process for the preparation of the powder compositions according to the invention provides that the epoxy / sulfonamide resin with the Polyamide is kneaded in a knotter of suitable type. The temperature for the kneading or mixing can be in the range of 150 to 300 ⁰ C, preferably in the range of 170 to

23O ⁰ C lie. The mixture obtained in this way is generally present in granules which are prepared in a manner known per se according to the

conventional operations will be ground to the desired particle size distribution for coating metal substrates.

The third method developed according to the invention provides that the previously finely ground epoxy / sulfonamide resin with Polyamide powder is dry mixed. This dry mixture l ·, · w. (Trousers crumb (dry-blend) does not require special Apparatus; it can be produced at room temperature and thus economically and quickly. The fourth method by which the powder compositions of the invention are obtained provides that the polyamide monomers

in the presence of the epoxy / sulfonamide resin (co) -poly as defined above. It generally works at a temperature in the range of 150 to 300 ⁰ C, preferably in the range of 190 to 25O ⁰ C.

Any type of device used for the polycondensation of polyamides can be used to advantage

Find. As an example, mention may be made of a reactor equipped with a stirrer for about 50 rpm and capable of withstanding a pressure of 20 bar.

The duration of the polycondensation may be 5 to 15 hours, preferably 4 to 8 hours. When the operations of polycondensation are completed, the mixture is obtained in the form of granules, which are based on the

desired grain size distribution is milled. In general, the particle size distribution of the invention

Powder in the range of 5 pm to 1 mm. The invention also relates to the use of the above-described thermoplastic powder compositions for coating Metal substrates. The metal substrate can be selected from a variety of products. It can be workpieces of ordinary

or galvanized steel, of aluminum or aluminum alloys. The thickness of the metal substrate may be arbitrary (for example, on the order of '/ tomm up to the order of several 10cm).

According to a known per se, which in itself is not the subject of the invention, the Metal substrate, especially if it consists of ordinary steel, aluminum or an aluminum alloy and the in

present in the materials of the invention have undergone one or more of the following surface treatments, this list not being restrictive:

- degrease roughly

- alkaline degreasing

- brush out

- degrease finely

- rinse hot

- phosphating degreasing

- Iron or zinc phosphating

- Chromating

- rinse cold

- rinse in the presence of chromium compounds.

Examples of metal substrates which can be coated with a composition according to the invention are:

- degreased steel, smooth or steel blasted

- degreased steel phosphated

- Steel, iron or zinc phosphated

- Steel, galvanized according to Sendzimir

- Steel, electrically galvanized

- Steel, badgalvanized

- cataphoresis steel

- chromated steel

- anodised steel

- Steel, sandblasted with corundum

- Aluminum, degreased

- Aluminum smooth or steel blasted

- Aluminum Alodine 1200.

The composition of the invention on dot bases of polyamide or polyetheresteramide is thus in powder form on the Applied metal substrate. The application of the powder mass can be carried out according to the usual application method. The grinding of the powders can be carried out in cryogenically cooled devices or in devices with strong air absorption

(Granulators, hammer mills, disk mills, etc.) take place. The obtained powder particles were in geoigneten

Devices selected to the non-desired particle size ranges, for example, coarse grain and / or too fine Grain, weed out. Among the methods of application of the powder are electrostatic spraying and immersion in a Fluid bed or a fluidized bed, particularly preferred operations to the coating of To carry out metal substrates according to the invention. In electrostatic spraying, the powder is introduced into a spray gun in which it is compressed air

is transported and passed into a nozzle, which has been brought to an increased potential generally in the range of 10 to 10OkV.

The polarity of the applied voltage can be positive or negative. The discharge amount of the powder from the gun is in the general range of 10 to 200 g / minute and preferably between

501: id i20g / Mir; ite. On the way to the nozzle, the powder charges up with a certain amount of electricity, the powder particles transported by the compressed air move away on the metal surface to be coated, this surface in turn contacting the earth, i. is connected to an electrical potential = 0. The powder particles are retained on this surface due to their electrostatic charge, and the electrostatic forces of attraction are sufficient not only to powder coat the powdered article but also to place it elsewhere and heat it in an oven to a temperature sufficient to cause melting or melting

Crosslinking of the coating or Beschchtungspulver causes. The polarity of the electrostatic charging of the powder may be positive or negative, as stated above. General chooses

Depending on the nature of the powder, it should be coated with it, and that with a polarity of a particular character, it can give good results, while the results are of opposite polarity

Characters can be less good and even zero. Generally, positive polarity gives better results when applying powder based on polyamide-11 or -12

by means of electrostatic spraying.

According to the invention, however, it has been found that for the powder compositions of the invention based on polyamide and the Epoxy / sulfonamide resin, the results of adhesion and quality of the final coating

practically independent of polarity during application or coating and (practically) identical.

The electrostatic spraying of erfindungsgmäßen masses based on polyamide offers regardless of the

This is because of the inherent polarity used, in particular, because one can apply the existing standard commercial equipment developed for the electrostatic spraying of powder coatings in a single polarity.

In electrostatic spraying, the preferred weight ratio of epoxy / sulfonamide resin is in admixture with polyamide

advantageously in the range of 1.5 to 7.5%. In general, a powder with a mean particle size distribution in

Range to 100pm, preferably in the range of 5 to 65pm use. The coatings obtained by electrostatic spraying with any of the compositions of this invention have good properties Adhesive properties and a final appearance of high quality and this regardless of the layer density of the Order or coating in the range of 40 to 400pm. This is not the case for powdered polyamide only coatings; These coatings have numerous shortages of Appearance at low and thick film thicknesses. As low layer thicknesses, layer thicknesses of about 40 pm and as thick layer thicknesses are in the range of

400pm.

At low layer thicknesses, for example, a polyamide coating has deep, narrow holes. For thick layer thicknesses exists

a significant risk that the coating will peel off again and there will be numerous bubbles and other surface defects.

When immersed in a fluidized bed or a fluidized bed, the metal substrate is to be coated and handled carefully

has been prepared, for example, by one or more or the above surface treatments, preferably by steel blasting, in an oven to a predetermined temperature, especially the nature of the

Substrate heated its shape and the desired layer thickness of the coating. The substrate heated in this way then becomes

immersed in a powder composition according to the invention by means of a circulating in a container with porous soil

Gas stream is kept in suspension. The powder melts on contact with the hot metal surfaces and forms on them Make a precipitate, its layer thickness of the temperature of the substrate and the duration of immersion in the powder

depends. When immersed in a fluidized bed or fluidized bed, the preferred weight ratio of epoxy /

Sulfonamide resin to polyamide advantageously 1 to 5%. The particle size distribution of the fluidized bed or the fluidized bed

The powder used may be in the range of 10 to 1000 pm, preferably in the range of 80 to 200 pm.

Generally, the layer thickness of the coating may be 150 to 1000pm, preferably 200 to 700pm. In the following examples, the invention is explained in more detail. example 1 A - Preparation of the powder mass: In 100 parts by weight of acetone, 6 parts of epoxy resin / aromatic sulfonamide compound having Mw = 1200 and Glass transition temperature Tg = 54 ° C dissolved. The epoxy compound was a resin obtained by reacting bisphenol A with epichlorohydrin. The Epoxy equivalent weight of this resin was 172g and its hydroxyl content was 0.11 hydroxy equivalents per kg of resin.

The sulfonamide precursor was p-toluenesulfonamide. Subsequently, 200 parts by weight of polyamide-11 powders having an intrinsic viscosity of 0.9 containing 13% of various additives, of which 9.6 fillers, 1.8% of dyes and 1.6% of antioxidants, deep hole preventing agents and reducing agents were added , The mixture was stirred continuously at room temperature to give a paste which was oven-dried at 40 ° C for 5 hours to remove the acetone.

The dry residue was powdered and passed through a 100μ mesh screen to remove the coarse particles which did not conform to the particle size distribution of the electrostatic powders.

B-use:

The powder mass obtained according to A was at room temperature by means of electrostatic spraying, negative (a) or negative

(b) deposited at 3OkV on a steel plate which had previously been greased and then steel blasted, the

Metal surface potential exceeded. The thus coated substrate was then placed in an oven included in

220 ± 20 ° C and remained there for 5 to 15 minutes; then it was taken out and cooled in air.

C - Property or characteristics of the material:

1) The material is a composite comprising in sequence:

- a degreased and steel-blasted steel plate (thickness 1.5mm)

- A layer of the powder mass as described under A in a thickness of 100pm

2) The material described under C was subjected to the following adhesion test developed according to the invention:

- with a cutting tool in the coating and up to the metal two parallel notches spaced 10mm apart. Subsequently, another notch was applied perpendicular to the first two and this intersecting.

The same tool, whose cutting width was 10mm, was set in the last notch and exposed between the two parallel notches at the level of the metal / groove interface, a tongue of the 10mm wrap. At this tongue was pulled to try to separate the coating from the metal. The results were then classified as follows:

- Class 4: the film can not be separated from the metal,

Class 3: the film separates irregularly, the separation is complete on at least 50% of the surface,

Class 2: the film separates on a regular basis, the force necessary for tearing is increased and is at the limit of the strength of the coating,

- Class 1: the film separates slightly from the surface, the connection is weak,

- Class 0: the coating has no connection with the surface.

3) It was evaluated visually, the spreading of the distribution of the powder mass to a steel plate 100mm 100mm χ χ 1mm upon melting at 22O ⁰ C, the plate was vertically inserted into the furnace. A classification from 0 to 4 was made according to the following observations:

- Class 0: no more coating on the plate. The entire molten coating had fallen into the oven.

- Class 1: At least half of the coating had dropped off on melting, leaving about half of the surface of the metal plate bare.

- Clause 2: In some places (generally at the edges and at the corners of the plates) the coating had come off.

- K'asse 3: no detachment. Deficiency attributable to poor wetting: bubbles, large deep needle-like holes (craters).

- Class 4: The coating is stretched and shows no defects in terms of wetting or spreading.

The results with respect to adhesion and propagation obtained with the material described under C1) are summarized in Table I.

P. S The half values or fractional values for the classification correspond to the properties lying between the adjacent classes. Example: Class 1.5 corresponds to properties that are between those of class 1 and those of class 2 or are to be evaluated.

Example 2 Example 1 repeated with a mixture containing by weight:

- 100 parts of acetone

6 parts of epoxy / sulfonamide resin having the same characteristics as described in Example 1 A),

- 200 parts of polyamide-12 and copolyamide ^e / u powder of intrinsic viscosity 0.96 containing 12% of various additives, of which 11.3% filler, 0.7 antioxidant and reducing agent.

A composite was produced which comprises successively the following layers:

- a sheet of zinc-phosphated steel 1.5mm thick,

- A layer of polyamide-12, ^e / i2 in a layer thickness of 120 pm. This material was subjected to an adhesion test as described in 1 C), and an evaluation of the propagation as described under 1 C 3). The results are summarized on the table.

Example 3 A - Preparation of the powder mass:

30 parts by weight of epoxy / sulfonamide resin having the same characteristics as in Example 1 A) previously ground to a mean particle size distribution of 5 to 40 μm became 1000 parts of PA-11 having intrinsic viscosity 0.90 containing 13.8% of additives , of which 11.3 fillers, given. The whole was mixed at a temperature in the range of 200 ⁰ C to 22O ⁰ C or kneaded and homogenized. The residence time in the kneader was on the order of 45 s.

The product obtained was ground after cooling at room temperature to give a powder particle size distribution of

10 to 80μπΊ to achieve.

B-use:

The powder mass obtained under A was described under the same conditions as in Example 1B, on a steel plate

applied.

C - Characteristics / properties of the material:

1) The material was a composite of sequentially:

- a steel plate degreased and stahlyösifbhlt (thickness 1.5mm),

a layer of powdered material as described under A, thickness lOOpm,

2) the material described under C1) was subjected to the adhesion and spreading tests described in Examples 1 C 2) and 1 C 3). The results are summarized in Table I.

Example 4 Example 3 was repeated using a mixture of the following composition:

30 parts by weight of epoxy / sulfonamide resin having the same properties as in Example 1 A) previously ground to a particle size distribution in the range from 5 to 40 μm, containing 1000 parts by weight of polyamide! 2 with intrinsic viscosity 0.95 were added.

The whole was kneaded and homogenized at a temperature range of 180 ° C to 230 ° C. The residence time in the kneading apparatus

was about 45s.

The product obtained was cryogenically ground after cooling by a particle size distribution of the powder in the range of

10 to 80pm.

Thus, a composite was fabricated comprising, sequentially:

- A steel plate degreased and steel blasted, in a thickness of 1.5mm.

- A layer of polyamide-12 in a thickness of 100μιη.

With the material thus described, the tests described under 1 C 2) and 1 C 3) with respect to adhesion and spreading

carried out.

The results are summarized in Table I. Example S A- Preparation of the powder mass: In a Henschel high speed mixer, contents 701, 20kg PA-11 powder 0.6kg epoxy / sulfonamide resin were ground to one

mean particle size of 10pm and 0.02 kg swirling agent given. The PA-11 used had an intrinsic viscosity of 0.90 and contained 13.8% additives, of which 11.3% were pigments and fillers and 2.5% antioxidant, anti-seize agents

Cratering and reducing agents. The epoxy / sulfonamide resin had a weight average molecular weight Mw = 1200 and

a glass transition temperature Tg = 54 ⁰ C on. The mixture was stirred for 100 s at a speed of 830 rpm. The obtained powder could be used as such.

B-use:

The powder mass obtained under A was electrostatically described under the same conditions as in Example 1 B)

sprayed on a steel plate.

C - Features / characteristics of the material:

1. The material was a composite of sequentially:

- a steel plate, degreased and steel-blasted (thickness 1.5mm),

- A layer of powdered material as described under A), strength 100pm.

2. The material described under C1) was subjected to the adhesion and spreading tests described in Examples 1 C 2) and 1 C 3). The results are summarized in Table I.

Example β

On a steel plate degreased and blasted under the same conditions as in Example 5 B) was electrostatically sprayed a powder composition consisting of Va polyamide-12 powder and ^2/3 copolyamide-612 powder, wherein the PA-12 encapsulated in the PA-612 and various additives, including 11.3% pigments, fillers and 0.7% antioxidants and reducing agents and 3% milled epoxy / sulfonamide resin according to the characteristics given in Example 5. This gave a composite material which had successively:

- a steel plate, degreased and steel-blasted, thickness 1,5mm,

a layer of polyamide-12 and -612 in a thickness of 100pm.

The material thus described was subjected to the adhesion and spreading tests described in Example 1 C 2) and 1 C 3). The results are summarized in Table I.

Example 7 (comparison)

1. On a smooth and degreased steel plate was under the same conditions as in Example 1 B) described a PA-11 powder having the same properties as in Example 5 A) and an average particle size distribution of 35 pm electrostatically sprayed.

2. The material obtained was a composite material which had successively:

- a smooth, degreased steel plate (thickness 1.5mm)

- A layer of PA-11 powder in a thickness of 100pm.

3. The material described under 2) was subjected to an adhesion test as described in Example 1 C 2). The results with regard to the adhesion are summarized in Table I.

Example 8 (comparison)

1. On a smooth and degreased steel plate was under the same conditions as in Example 1 B) electrostatically a powder mill on the basis of PA-11 described with the same characteristics or properties as in Example 5 A), the 13.5Gew.- % blocked phenolic resins, sprayed on.

2. The material obtained was a composite material which had successively:

- a glazed degreased steel plate (thickness 1.5mm),

- A Schic ¹ It from powder mass, as under 1) defined in a thickness of 100pm.

3. The material described in ') was-described tests for the Haftun _u and spreading as in Examples 1 C 2) and 1 C 3); ¹ subjected.

The results r ^! nd summarized in Table I. Example 9

Example 5 was repeated under the same conditions using PA-11 powder having the same characteristics but containing other additives

 A - The original powder contained:

- 99.25 wt .-% PA-11

- 0.75 wt .-% additives (antioxidants, cratering prevention agents and fluidizing agents).

B- The powder used was white and contained 68.8% by weight of PA-11.29.5% by weight of filler and 1.7% by weight of additives (antioxidant

and means for preventing cratering).

C- The powder used was black and contained 58.6% by weight of PA-11.39% by weight of filler, 0.5% by weight of black dye,

2% by weight of additives (antioxidant, anticratering agent and adhesive).

D - The powder used was gray in color and contained 85.3% by weight of PA-11.13.5% by weight of pigment and filler and 1.5% by weight. Additives (antioxidant, anti-cratering agent). E - The powder used was dyed yellow and contained 67.4% by weight of PA-11.28.9% by weight of fillers, 1.7% by weight of dyes and

2% by weight of additives (antioxidant, anticratering agent and reducing agent).

The adhesion and spreading results obtained for experiments A to E are shown in Table II

summarized.

Example 10 Example 5 was repeated under the same operating conditions using gray-colored powder PA-11, which was 13% by weight. Additives, of which 11.4% by weight of pigments and dyes and 1.6% by weight of antioxidant, anti-cratering agents

and reducing agent (10.A).

The following compositions also contained epoxy / sulfonamide resin in an amount of 0.2 kg (10.B), 0.6 kg (10.C) and 1 kg, respectively

(10.D) to 20kg of the previously described PA-11 powder.

The effect of the amount of epoxy / sulfonamide resin on the performance of the polyamide compositions can be determined by the methods described in Table IM

be evaluated.

Example 11 A- The powder mass obtained in Example 10 (Sample 10.C) became electrostatically similar to various metal substrates Working conditions as described in Example 1 B applied. B - The powder composition obtained in Example 6 was applied electrostatically under the same conditions as in A. C- For comparison, electrostatic and under the same conditions PA-11 powder was applied with intrinsic viscosity 0.90. D - For comparison, a powder mass based on PA-11 was used electrostatically and under the same conditions Intrinsic viscosity 0.90 containing 13.5 wt% of blocked phenolic resins. The adhesion and spreading results obtained in experiments A to D are shown in Table IV

summarized.

Table I

Ex. Classification of liability Ausbreit. Epoxy / sulfonamide resin PA + additives% by weight Production of the powder Αι », and polarity hs applying 1a 3 4 3 resolution IT,-) 1b 3 4 3 resolution EX (+) 2a 3 4 3 resolution IT(-) 2 B 3 4 3 resolution ES (+) 3a 4 4 3 Kneading in the melted. State IT(-) 3b 3 4 3 Kneading in the melted. State ES (+) 4a 3 3 3 Kneading in the melted. State IT(-) 4b 3 3 3 Kneading in the melted. State ES (+) 5a 4 4 3 Dry-mixing IT(-) 5b 4 4 3 Dry-mixing ES (+) 6a 4 4 3 Dry mix IT(-)

Continuation Table I ES = electrostatic spraying

Boisp. Classification of liability Aujbreit. Epoxy / sulfonamide resin PA + additives% by weight Production of the powder Type and polarity of application 6b 4 4 3 Dry-mixing ESI +) 7a 0 1 0 IT(-) 7b 0 1 0 ES (+) 8a 2 3 13.5% phenolic resins Dry-mixing IT(-) 8b 2 4 13.5% phenolic resins Dry-mixing ES (+)

tables

Ex. Classification of liability Ausbreit. Epoxy / sulfonamide resin PA + additives% by weight Production of the powder Type and polarity of application 9A 4 4 3 0.75 IT I-) 9A 2 4 3 0.75 ES (+) 9B 4 4 3 31.2 IT(-) 9B 4 4 3 31.2 ES (+) 9C 4 4 3 41.5 IT(-) 9C 4 4 3 41.5 ES (+) 9D 3 4 3 14.7 IT(-) 9D 3 4 3 14.7 ES (+ J 9E 4 4 3 32.6 IT(-) 9E 4 4 3 32.6 ES (+) Table III Ex. Classification of liability spread Epoxy / sulfonamide resin PA + additives% by weight Type and polarity of application 1OA 0 1 0 IT(-) 10A 0 1 0 ES (+) 10B 3 3 1 IT(-) 10B 2 2 1 ES (+) 10C 4 4 3 IT(-) 10C 4 4 3 ES (+) 10D 4 4 5 IT(-) 10D 4 4 5 ES (+) Table IV

Substrate

Classification of liability

Ex. 11.A

Ex. 11.B

Ex. 11.C

Ex. 11.D

Type and polarity of application

ES (+) IT(-) ES (+) IT(-) ES (+) IT(-) ES (+) IT(-) degreased steel CF ₂ = CHF 1.5 2.5 4 4 0 0 2 2 degreased steel steel blasted 4 3.5 4 4 1 1 2 2.5 phosphated steel, iron 3 3.5 4 4 0 0 1 1 phosphated steel, zinc 3 4 4 4 0 0 1 1 chromated aluminum 2 2.5 3.5 3.5 0 0 1 1

Bet game 12

In a tank for immersion application In the fluidized bed was powder with a mean particle size distribution of 80 to 200mm

given.

This powder was vortexed by supplying compressed gas through the perforated bottom of the tank. The steel-gray steel substrate to be coated was preheated in a ventilated oven to one-time Temperature of about 24O ⁰ C to 26O ⁰ C. Then, the substrate was immersed in the bath of fluidized powder for 4 to 6 seconds, pulled out thereon and at Allow room temperature to cool. Powders of PA-11, white colored PA-11 and PA-12 (Samples A, B and C) were used at 0% or 3% epoxy / Sulfonpmidharz having a weight average molecular weight Mw = 1200 and a glass transition temperature Tg = 54 ⁰ C.

contained.

The adhesion of the coatings obtained was measured after 15 days at ambient strength corresponding to those in Example 1 C 2).

described test. The results are summarized in Table V.

Table V

Epoxy / sulfonamide Example 12.A liability Example 12.C PA + additives% by weight class 1 Example 12.B 2nd grade 0 Class 3 class 1 Class 3 3 Class 3

Claims (10)

1. powder composition based on polyamide and / or polyetheresteramide, characterized in that it contains epoxy / sulfonamide resins. 2. Composition according to claim 1, characterized in that the weight ratio of the epoxy / sulfonamide resins to polyamide and / or polyetheresteramide in the range to 0.5 to 20%, preferably in the range of 2 to 7%. 3. Composition according to one of claims 1 or 2, characterized in that its base is polyamide-11, polyamide-12 alone, as a mixture or copolymerized. 4. A process for the preparation of a composition according to any one of claims 1 to 3, characterized in that it comprises the following steps: dissolving the epoxy / sulfonamide resins in a suitable solvent, adding the polyamide and / or polyetheresteramide powder, - Then the solvent is evaporated and sieves or mills the resulting mixture to the desired particle size distribution. 5. A process for preparing a composition according to any one of claims 1 to 3, characterized in that the components of the mass' n melted state kneaded and then ground to the desired particle size distribution. 6. A process for preparing a composition according to any one of claims 1 to 3, characterized in that the previously ground to powder components of the composition are dry mixed. 7. A process for preparing a composition according to any one of claims 1 to 3, characterized in that one simultaneously polymerized the polyamide and / or polyetheresteramide monomers in the presence of the epoxy / sulfonamide resins. 8. Use of a composition according to any one of claims 1 to 3, in a particle size distribution of preferably 5μιη up to 1 mm, for coating metal substrates according to one of the powder application procedures. 9. Use of a composition according to any one of claims 1 to 3, the weight ratio of epoxy / sulfonamide resins to polyamide and / or polyetheresteramide is preferably in the range of 1.5 to 7.5%, for coating metal substrates by means of electrostatic spraying. 10. Use of a composition according to any one of claims 1 to 3, wherein the weight ratio of epoxy / Stilfonamidharzen to polyamide and / or polyetheresteramide is preferably in the range of 1 to 5%, for coating Mstallsubstraten, preferably steel blasted, by immersion in a fluidized bed / fluidized bed.