DE1669245A1 - Process and aqueous dispersion for anodic coating of phosphated metals - Google Patents

Description

EGG. DU PONT DE STEMOURS AND COMPANY 10th and Market Streets, Wilmington, Delaware 19 898,

Process and aqueous dispersion for anodic coating of phosphated metals

The invention relates to an improved aqueous polymer dispersion for the anodic coating of surface- treated metal products and an improved anodic coating process using these new polymer dispersions. In particular, the invention relates to improved aqueous polymer dispersions for coating phosphated steel products in which the film-forming polymer has a low acid number.

The anodic coating of products with pilm formers is known to have decided advantages compared to the usual Methods of spraying, painting, dipping and the like, as the anodic coating is quick and effective

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runs, is easy to control and smooth covers on the whole product. Anodic coating makes it possible to create film formers evenly on recessed surfaces to deposit which are difficult to coat in a uniform manner using other known processes »such as e.g. on the inside of "rocker panels" of motor vehicle bodies.

In the previously known electrical coating processes, e.g. that according to Belgian patent specification 624 488, the film-forming polymer must have a high acid number, i.e. above 30; however, they are preferred Polymers with acid numbers from 60 to 100 and even up to 300. The acid number is the amount of potassium hydroxide in mg that is required is »to neutralize 1 g of polymer. Those with these known polymeric coating agents on electrical However, path-coated products have a poorer corrosion resistance than those with the same coating agents products coated by other conventional processes with a high acid number.

The purpose of the invention is therefore to provide a new coating agent for anodic coating available as Film former contains a polymer with a low acid number, which can be easily dispersed in an aqueous solution, and that after the anodic deposition on a pre-

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treated metal surface a coating with good corrosion resistance educates

The aqueous dispersion according to the invention has a solid content of about 3 to 30 #, a pH of about 7 to 9 »5 -and contains

1) an evenly dispersed film-forming polymer, which consists essentially of a carboxylic acid polymer with an acid number of 6 to 25 and with ammonia « water soluble primary amines, secondary amines * tertiary Amines, polyamines and or · or hydroxyamines is neutralized »and

. ", A water-miscible solvent for the film-forming Polymer in amounts of 2 to 10 percent by weight of the dispersion.

lae preferred film-forming polymer consists of one Carboxylic acid polymer with an acid number of 6 to 25 in amounts of about 95 to 50 wt .- # and from a water-dispersible, thermosetting, nitrogen-containing resin which at least partially reacted with the carboxylic acid polymer is, 5-n amounts of about 5 to 50 wt .- #. There is a goal in part reads out the forming polymer to about 75 to 95% by weight a carboxylic acid polymer with an acid number of about 15 ois 24 and about 5 to 25 wt .- # of the thermosetting, nitrogen-containing resins

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The aqueous dispersion preferably has a Peststoffgehalt from 7 "to 20 fi and contains Pigmentteilciien in a concentration up to 30 vol .- # au. Pigment volume concentrations of 5 Ms 15 i> are preferred.

The pigment volume concentration is the ratio of the volume of the pigment to the total volume, expressed as a percentage of pigment and film-forming substances in the composition. The "volume of pigment" is the volume of the vehicle, which is displaced by the pigment moistened with the carrier.

The coating compound according to the invention is produced by mixing a film-forming polymer with a water-miscible solvent for the polymer. These Solution of polymer in solvent is then dispersed in water. The film-forming polymer in the dispersion is then aminated with a compound such as ammonia or an amine, forming a dispersion bit of negatively charged polyamide particles arises. Can be used for most purposes pigment particles are also preferably added to the aqueous dispersion dispersed "

This new dispersion is called an anodic bath in an anodic bath Sealing cell of conventional type user, in fig the metal ore to be coated is connected as an anoda.

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When electrical current is applied to the cell, divorce the anionic, negatively charged polymer particles are deposited on the positively charged metal anode.

There can be many different Cerbonsäurepolymerisate as sinsiges film-forming polymer can be used according to the invention, provided they have an acid number between 6 and 25 and are dispersible in an aqueous medium. Suitable for this e.g. alkyd resins, epoxy resins, acrylic resins and reaction product from dicarboxylic acid anhydrides and drying oils.

Many alkyd resins, i.e. from the condensation product of a polyvalent one Polymeric Εε-ter produced from alcohol and a polybasic acid are suitable as film-forming polymers. To the The usual fatty acids are suitable for the production of alkyd resins, such as linoleic acid, linolenic acid, elaostearic acid., ricinoloic acid and dehydrated small acid. These fatty acids come from commonly found in tung oil, linseed oil, and soyabi; the preferred tone drying oils are dehydrated picinus oil and resin-free Tall oil.

Together with the fatty acids mentioned above, you can use it to produce of the alkyd resins which can be used according to the invention also include others ffiehrbae: · see acids or their A.ihydrida used verden how Phthalic acid, maleic acid, sebacic acid and adipic acid. Tri-mellitic anhydride is one of you advised

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A wide variety of polyhydric alcohols can be used to produce the alkyd resins, such as glycerol, pentaerythritol, ethylene glycol, propylene glycol, diethylene glycol and the like. However, pentanediol-1 _f 5 and hydrogenated bisphenol A (4,4-isopropylidenedicyclohexanol) are preferred.

Preferably, the alkyd resin has a molecular weight of about 1000 to 1500 and an acid number of about 15 to 24 · particular Valuable alkyd resins with a high degree of corrosion resistance are obtained from mixtures of esters of dehydrated Rioinus oil fatty acid and trimellitic anhydride with 1,5-pentanediol and hydrogenated bisphenol A. The preferred ratio of trimellitic acid ester to the ester of dehydrated rioinus oil fatty acid is 2: 1. Another suitable alkyd resin, which also has good corrosion resistance, is this Esterification product of trimellitic acid and resin-free tall oil fatty acid with a mixture of 1,5-pentanediol and hydrogenated Bisphenol Ao

Another particularly valuable film former is the reaction product of the anhydride of an unsaturated aliphatic Dicarboxylic acid and a conventional drying OiJ .. Typisohe suitable anhydrides are maleic, itaconic and pyrocinohonic anhydrides, of which maleic anhydride is preferred. For the production of this film-forming polymer

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> Can any drying oil be used? such as tung oil, linseed oil, dehydrated Castor oil and soybean oil are used, * A preferred one Polymer is the reaction product of maleic anhydride and resin-free tall oil »

Esterified epoxy resins are also suitable as according to the invention film maker. A preferred epoxy resin is an epoxy hydroxy polyether resin, which is formed by the condensation of a chlorohydrin and a bis (4-hydroxyphenyl) alkane, the chlorotiydrin Is epiohlorohydrin or glycerol chlorohydrin. That Epoxy resin has the structural formula

OH ^ CH -

0- / V ° * ~ \ V ⁰ - ^CH 2 " ^CH ^ 2

CH ₉

These epoxy resins can be prepared according to the methods of United States patents 2,456,408 and 2,503,726 * These epoxy resins are known under the trade name "Epon" and in the technical publication "SC: 60-63, Epon Resin Esters for Surface Coatings" from Shell Chemical Corporation described «

The esterification of these epoxy resins with the usual drying oil fatty acids can be carried out according to the method of the USA patent 2,843,554.

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The following drying fatty acids are suitable for the esterification of the epoxy resins: dehydrated ricinis oil fatty acids, dimeric fatty acids, linseed oil fatty acids, oitizika fatty acids »soybean oil fatty acids and tung oil fatty acids, these acids can, with it They acquire particularly advantageous properties »e.g. with Acetic acid, tung oil fatty acid or tung oil, coconut fatty acid or coconut oil, phenolic resin, lauric acid, dimeric acids, p-terto-butylbenzoic acid, styrene, oiticic acid or -61, natural resins and tall oil can be modified.

A particularly suitable epoxy ester is prepared by first partially esterifying an epoxy resin with one of the conventional drying oil fatty acids and then completely esterifying this esterification product with the reaction product of an anhydride of an unsaturated dioarboxylic acid and a conventional drying oil fatty acid. A preferred one? Epoxy resin of this type is produced by partially esterifying "Bpon 1004" with dehydrated ricinue oil fatty acid and then completely esterifying this epoxy resin with the reaction product of maleic anhydride and dehydrated Rioinus oil fatty acid of 1 ha of a monobasic acid) and a Gardner-Holdt viscosity of C ₁ -V *

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Acrylic polymers are "particularly valuable film forming agent. These polymers are cc, ß-unge fed temperate carboxylic acid, acrylic acid amide, a methacrylic ester and a Acrylsäureesters prepared by polymerizing a. In general, acrylic polymers are suitable, which for the most part of methacrylic acid esters of alkanols of 1 to 8 carbon atoms and to a lesser extent are made from acrylic esters of alkanols with 1 to 8 carbon atoms. The following esters are typical methacrylic and acrylic esters that can be used for this purpose: ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, hexacrylate, butyl acrylate, Ethylhexyl 2-ester, octyl aorylate, methyl methacrylate, propyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate and tert-butyl methacrylate. A particularly valuable polymer consists of methacrylic acid, acrylic acid amide, methacrylic acid methyl ester and aoryl acid-2-ethylhexyl ester.

Another group of valuable film formers are polyesters from a dicarboxylic acid and unites in polyol in combination with a thermosetting resin o Typifiohe saturated aliphatic Dicarboxylic acids or anhydrides of the same for the production of these polyesters have 2 to 10 carbon atoms in the molecule, such as oxalic

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acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. A preferred one Acid of this group is adipic acid. Aromatic dicarboxylic acids or anhydrides thereof can also be used to produce the Polyesters can be used, such as phthalic acid, 5-methylisophthalic acid and isopropylbenzoic acid. Also, polybasic aromatic carboxylic acids and anhydrides thereof such as trimellitic acid, pyromellitic acid and mellitic acid can be used.

Many different polyols can be converted into polyesters with the acids mentioned above. Particularly suitable diols are e.g. ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and trimethylene glycol, 1,3-pentanediol, 1,4-butanediol and the preferred 1,5-pentanediol. Auoh polyols with more than two hydroxyl groups in the molecule can be used, such as glycerol, sorbitol, pentaerythritol, tetramethyloloyolohexanol, dipentaerythritol, trinethylolethane and trimethylolpropane. A preferred polyester is the esterification product of trimellitic anhydride, adipic acid, phthalic anhydride, neopentyl glycol and trimethylolethane »

A thermosetting, nitrogen-containing resin in quantities of 5 to 50 is preferably used together with the abovementioned carboxylic acid polymer as a constituent of the film former Gewo- £ of the entire film-maker. The thermosetting, nitrogenous

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Cold resin is geeisoht with the carboxylic acid polymer and roped implemented. Any warning-hardening, nitrogen-containing iarz can be used as a melting agent, provided is only dispersible in water. The nitrogenous Resins can be condensation products of formaldehyde and Xelaniz Urea, benzoguanamine or melaain / toluene sulphide. Preferably used melanin derivatives such as Hexsjtetnöxjaethylnelamino Biese nitrogen-containing Harse. Are known and can be. using the procedures of U.S. Patent Nos . 2,197,357, 2,508,875, and 2,191,957. You nitrogenous)? Hare · not only give the warpage thermosetting properties, but also improve the corrosion resistance »hardness and resistance; , be used.

The film-forming polyaerates, namely the carbonic acid polymers or the carboxylic acid polymers, some of which are made up of a nitrogen-containing, hardening resin! often relatively insoluble in water and difficult to disperse. Therefore, water-soluble solutions are used for the polymer in amounts * of 2 to 10 wt. ft of the total Dispersion used to bring the polymer into solution.

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This solution of the film-forming polymer in the water-miscible solvent can easily be achieved in water the new dispersions according to the invention. Some of the many solvents that can be used are the following: diacetone alcohol, ethyl alcohol denatured with acetone, acetone, Methyl alcohol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, Cyclohexanol, diethylene glycol monobutyl ether, the acetic acid ester of diethylene glycol monoethyl ether, tetrahydrofuran, tert-butyl alcohol and isopropyl alcoholo

Water-soluble compounds, which are particularly suitable for the formation of an anionic polymer and for adjusting the pH of the coating agent to 7.5 to 9 *, preferably 7,8 to 8, are ammonia, primary amines, secondary Amines, tertiary amines, polyamines and hydroxyamines «These compounds include monoethanolamine, diethanolamine,! Diethanolamine, N-methylethanolamine, N-aminoethylethenolamine, If-methyl diethanolamine, monoisop ^ opanolamine, diisopropanolamine, Triisopropanolamine, hydroxylamine, butanolamine, ftexanolamine, Methyl diethanolamine, octanolamine and the reaction products of an alkylene oxide with mono- and polyamines, such as the urasetting product from ethylene diamine and ethylene oxide or propylene oxide, the reaction product of laurylamine and ethylene oxide, Ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, Tetraethylene pentamine, propylene diamine,

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1 j3-diaminopropane, imino-bis-propylamine, the lower mono-, Di- and trialkylamines (with alkyl groups with 1 to 8 carbon atoms), such as mono-, di- and triethylamine. A preferred compound is Ν, ΙΤ-Diinethyläthanolainin.

]? for most uses, e.g. for making (S-rim coatings are used in the coating agent according to the invention preferably dispersed pigment particles. Iron oxide is a preferred figment. Barium chromate is suitable because of its anti-rust effect, especially for primer coatings for motor vehicle bodies and the like «Others Usable pigments are titanium dioxide, basic lead silicate acid mate, Chromium phosphate, strontium chromate and lead chromate.

It may be useful to add the coating agents Dispersants, such as non-ionic or cationic surfactants, are added to the film-forming agent and the pigments to disperse uniformly. All known cationic and non-ionic surface-active ITittsl 'can be used.

So that the coating agent according to the invention is anodic deposited coating has the degree of corrosion resistance required for most purposes; receives the must be besuhicihteade Metal surface, especially if it is made of steel, first treated with an x'OstrjohUtzenden compound

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will. Preferably, the Me taller certificate has a phosphated th surface, i.e. a surface of the metal is with one aqueous solution of phosphoric acid or a phosphoric acid Salt has been treated. Commercially available rust inhibitors such as "Bonderite" can be used for this purpose Product of the Parker Rust Proofing Company, or "Granodine", a product of Arnchem Products »Ino. Preferred rust inhibitors that contain dilute phosphoric acid react with the metal surface with the formation of a surface coating on the metal. When these preferred means are used " in order to treat steel, a coating called iron phoephate is used a strength of preferably 0.27 to 0.81 g / a produces »Ea other rust inhibitors containing diluted phosphoric acid and zinc phoapnate can also be used «

In a typical process for coating treated Metal products will convert the product into a conventional one Introduced electric cell in which the coating bath according to the invention is located. Bas metal product forms the anode of the cell. Electric current is passed through the cell and the negatively charged film former and pigment particles simultaneously deposit on the steel product. When the coating has reached the desired thickness, the product is taken out of the bath, washed with water and heated to about 200 to 500 ° C.

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Me current density in the anodic coating cell is intended

4.63 A / dm of anode surface immersed in the bath is not exceed and is preferably less. One can work bit voltages τοη about 50 to 500 V; Tensions yon however, up to 300 V are preferred.

In the following examples, the quantities “if nothing else is indicated on amounts by weight. · *

3 example 1

A polymerization vessel comes with the following components "sent *

Gewiohtsteile Srimellitic anhydride 238 Dehydrated castor oil fatty acid 229

? entanediol-1,5 149

Hydrogenated bisphenol A 344

(4,4 * -Isopropylidenedicyclohexanol)

Methyl isobutyl ketone 40

A total of 1000

The reaction mixture is made under nitrogen and with stirring heated to 60 ° C. Then the approach is slow to 82 bis Heated to 35 ° C and held at this temperature for 8 to 9 hours until the acid number has reached 21. The batch is then cooled to room temperature.

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The alkyd resin has a molecular weight of about 1300 Ms 1400, an acid number of 21 and has the following composition:

Esters of the dehydrated castor oil fatty acid 31 »6 f * Trimellitic acid ester 57.2 $>

Excess polyol $ 11.2>

Total 100.0 #

The Yiscosität of the polymer, after diluting it with ethylene glycol monobutyl on $ 60> solids determined · This polymer has a Gardner-Holdt viscosity of W,

The following ingredients are heated to 80 ° C and closed mixed with a heat-reactive resin mixture with about $ 60 pesticides,

Parts by weight

Alkyd resin solution (96 # pesticides) 100.0

Diacetone alcohol 63.7

Hexamethoxymethyl melamine 9.5

A total of 173.2

This is then turned into heat-reactive resin mixture the following coating agents are produced:

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Transfer agent A

A non-pigmented coating agent is produced, indQio the pH of the above-described, heat-reactive HarzgeiDisohes with Ν, ΙΙ-dimethylethanolamine 7.8 to 8 set and then the polymer solution with demineralized Water is diluted to 10 # pesticides.

Coating agent B

This coating agent is prepared by mixing a pigment in the reactive in the thermosetting resin mixture was dispersed and then diluting the dispersion with water to 10 $> solids and the pH is then adjusted with Ν, ΪΤ-Diniethyläthanolamin to be 7.8. 8

Pigment dispersion, manufacturing instruction 1 Parts by weight

Reactive in heat

Harag Mix ($ 60 Solids) 167

Barium earomat 19

A total of 186

The ingredients are pre-scooped and then ground in a ball mill for 43 hours to a unit of about 6.35 μ ". The pigment dispersion has a solids content of $ 64.

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The coating agent is then prepared by the following Components are mixed:

Weight parts 5 186 0 999, 3,

Pigment dispersion according to manufacturing instruction 1 (64 i » pesticides)

Demineralized water Ν, Ν-dimethylethanolamine

A total of 1188, 5.

The Ν, Ν-dimethylethanolamine is in the course of 15 minutes slowly added to the pigment dispersion with constant stirring. Then water preheated to 70 to 80 ° C is slowed down added to the mixture with constant stirring. When all the water has been added, the mixture is stirred for an additional hour. The pH value is finally increased with Ν, Ν-dimethylethanolamine 7.8 to 8 set ο

Coating agent G

A coating agent is prepared in the same way as the coating agent B, but instead of the barium earomat iron oxide is used as pigment.

Steel plates 5 cm 15.2 cm 0.8 mm are on both Pages treated with dilute aqueous phosphoric acid. The phosphoric acid etches the metal and it forms on the

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Staiilplatten © in iron phosphate covering of 0.54 g / m · The treated Steel plates are washed with water and dried.

Am second set of steel plates the same size will be treated on both sides with aqueous dilute phosphoric acid containing acid zinc phosphate. This arises on

the base plates have a zinc phosphate coating of 2.42 g / m 2. the treated steel plates are washed with water and dried

A galvanized steel vessel with a capacity of 700 ml is filled with coating agent A. In the middle of The barrel is treated with dilute phosphoric acid Steel plate arranged as an anode, while the vessel itself forms the cathode of the cell. A direct current voltage of 250 Y is applied to the cell for 3 minutes. This separates A 28 μ thick coating forms on both sides of the steel plate. The coating is somewhat tacky, but adheres well to the phosphated one Steel on. The coated steel plate is washed, dried and heated to 149 ° C. for 30 minutes. The so » haliene primer is smooth and free of imperfections, like sand holes. Other steel plates treated with dilute phosphoric acid and those containing acid zinc phosphate Steel plates treated with dilute phosphoric acid are coated using the same method.

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Both types of phosphated steel plates are coated with the coating agents ^ B and C under the same conditions. The coated steel plates are washed, dried and heated as described above. Receives in all cases one smooth, imperfect-free coatings.

B e i s ρ ie I 2

The polymer used in this example is made from the the same constituents and under the same polymerization conditions as that according to Example 1 the difference is that so much trimellitic anhydride is used wxx-d that the resulting polymer has an acid number of 45 has. The polymer has approximately the same molecular weight and the same composition as that according to Example 1 with the only difference that it has an acid number of 45.

The viscosity determination according to Example 1 results for this Polymer of a Gardner-Holdt-Yiscositäi; from V.

A reactive resin mixture in the heat with $ 60> solids is made of this polymer using diacetone alcohol and hexamethoxymethylmelamine in Example i stated amounts ·

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Intestines are made from the resin mixture, which is reactive in the heat the following coating agents are produced:

Coating agent D

A non-pigmented coating agent is made from the lubricants Ingredients and produced using the same process as the coating agent A of Example 1, where in this case the heat-reactive resin mixture from the Polymer with an acid number of 45 has been produced.

Coating agent E

This coating agent is made from the same components and prepared according to the same process as the coating agent B of Example 1, but again using the heat-resistant resin mixture according to Example 2 instead of that with the low acid number according to Example 1 is used.

Coating agent P

This coating agent is produced from the components and according to the process specified for the coating agent S, but using iron oxide instead of barium, chromate as a pigment.

According to Example 1 either with dilute phosphoric acid or with a dilute phosphorus containing acidic zinc phosphate

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acid-pretreated steel plates are made according to the process of Example 1 coated with the coating agent D. The so The primer coating obtained has a Di-oke of 28 μ and is after heating, smooth and free from imperfections.

Pre-treated steel plates according to Example 1 are coated with coating agents B and F in the same way. These primer coatings on the steel plates are also smooth and free from imperfections _{or the like}

The steel plates anodically coated according to Examples 1 and 2 are tested for their corrosion resistance in accordance with ASTM test standard D-1654-61. During this test, the The coating on each steel plate was scored in the same way using a tool with a tungsten carbide tip. The notch penetrates the covering down to the metal. These panels are then exposed to a corrosive atmosphere using the ASTM: B 117 salt spray test method.

After 125 hours, 213 hours and 336 hours, a representative number of flats are removed from the corrosive atmosphere. Each plate is scraped off with warm water gespül g and strong with a blunt blade edge. The mean distance between the scratch mark and the edge of the surface of the covering that has not been attacked indicates the reduction in the adhesive strength of the covering as a result of corrosion, rust and blistering.

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Me find results of this accelerated corrosion test in Table I.

The values in Table I show that those produced from the polymer with the low acid number according to Example 1 Coating agents have better corrosion resistance than those made from the polymer with the high acid number according to the example 2 produced coating agents.

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co
α>
κ>

Table I.

Results of the corrosion tests (ASgM D 1654-61) Mean distance from the scratch mark _t mm

Duration of exposure to the corrosive atmosphere, hours

Coating agent

(clear coating agent, polymer with a low acid number according to Example 1)

(clear coating agent, polymer with a high acid number according to Example 2)

(Barium chromate pigment, polymer with a low acid number according to Example 1)

(Barium chromate pigment, polymer with high acid number according to "Example 2)

125

336

Steel plates treated with dilute phosphoric acid containing zinc acid phosphate

1.778 3.81

03 *

CO

CD

GO

2.286 4.572 x 5.08

8.89

CO

125

213

336

Steel plates treated with dilute phosphoric acid

1.016 2.032 φ

7.112

0.254-1.016 1.778

Ti

-4 Φ V »

2.032 "3.81

- Continuation of table I see page 25 -

σ> to ro

Table

(Continuation)

Sour from the action of the cor » clearing atmosphere, hrs.

Coating agents

213

336

Steel plates treated with dilute phosphoric acid containing zinc acid phosphate

125 ·

336

Steel plates with diluted phosphoric acid treated

ο
co
co

ro

VJl

(Pigment iron oxide, polymer with a low acid number according to Example 1)

(Pigment iron oxide, polymer with high acid number according to Example 2) 2,794 5,588

00

co

0.508 1.27 2.54

5.334

co

co

* co β infinite, ie the whole coating can be easily removed «

CD CO (O

FFD-1783 »ι

Example 3

An alkyd resin is made by placing a polymerization vessel is charged with the following components:

Qewiohteteile

Trimellitic anhydride 208

Tall oil fatty acids (resin-free) 210

Pentanediol-1.5 128

Hydrogenated bisphenol A (4 »4'-iso-

propylidenedicyclohexanol) 296

Methyl isobutyl ketone 58

A total of 900

The alkyd resin is prepared according to the polymerization process of Example 1. The polymer has a molecular weight of about 1300 to 10000 and an acid number of 21. The approximate composition of the polymer is about 30 $ tall oil fatty acid ester, 60 # trimellitic acid ester and 10 $ 6 excess polyol.

A heat-reactive resin mixture with a solids content of 60 i ° is prepared from the ingredients specified in Example 1 in the amounts specified there, but the alkyd resin described above is mixed with the diacetone alcohol and the hexamethoxymethylmelamine.

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The coating agent G is prepared, however, _r according to the procedure given in Example 1 for the coating agent B method "using the heat-reactive in the resin mixture in accordance with the Torliegenden example.

A second alkyd resin is made from the same components in the same polymerization process, but with the difference produced that so much trimellitic anhydride is used that the resulting polymer has an acid number of 45. The molecular weight of this polymer "is also 1300 to 14-00,

Using the above ingredients, a reactive in the heat Harzgemiach is prepared by the process described in this alkyd resin. This resin mixture is used for the production of the coating agent H by the method described for the coating agent G, but in this case the above heat-reactive resin mixture produced from the alkyd polymer with an acid number of 45 is used _c

A row of steel plates, both surfaces of which have been treated with dilute phosphoric acid, is coated with the coating agent G according to the procedure of Example 1, and another row of the same steel plates is applied according to the same

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Method Coated with Coating Agent H The primer coats obtained in this way are the steel plates
25 μ thick and, after heating, smooth and free of flaws.

The coated steel plates are made according to the method of Examples 2 examined for their corrosion resistance. the Results can be found in Table II.

The values in Table II show that that from the polymer Coating agent produced with the low acid number of 21 has a better corrosion resistance than that from Coating agents produced from the polymer with the high acid number «

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Table II

Results of the corrosion tests (ASIM D 1654-61) Mean distance from the incised mark, mn

Acid of the action of the corrosive atmosphere, Std, 125 213 336

Steel plates treated with dilute phosphoric acid; Coating thickness 25 μ

Coating agents

(Barium chromate pigment, polymer with acid number 21) 0.508 1.016 1.778

(Barium chromate pigment, polymer with acid number 45) 2.286 4.318 β> *

* °° β infinite, d _o h _o of the entire coating can be easily removed.

Example 4

An epoxy ester polymer is made by using an epoxy resin partially reacted with dehydrated Rieinus oil fatty acid and dehydrate the reaction product with a maleic anhydride reacted oil fatty acid in Reaction is brewed.

The dehydrated castor oil fatty acid reacted with maleic anhydride is made by loading a reaction vessel with the following materials:

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Weight parts

Dehydrated castor oil 213.4

Maleic anhydride 74.4

Methyl isobutyl ketone 12 »2

A total of 300 _y 0

They reactants will slowly rise under carbon dioxide 200 ° C and heated at this temperature for 3 1/2 hours on The reflux condenser was allowed to boil.

The epoxy ester polymer is prepared by the following Reactants in a polymerization vessel a partially converted epoxy resin:

All in all Parts by weight "Bpon 1004" * 1446 Dehydrated castor oil fatty acid 1248 Me thyIi sobutylke ton 113 2807

* Epon 1004 is a commercially available epoxy resin with an epoxy equivalent of 875 to 1025 and a Gardner-Holdt viscosity from Q-U, which has the following structural formula:

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CHn CH- CHn - \ -0-CH ₂ -Oi CH, OH MM *
η i - / -

The reaction participants are reacted under carbon dioxide at 190 until an acid number of 5 is reached. The partially reacted epoxy resin is cooled to 100 ° C. and 193 parts of the dehydrated castor reacted with maleic anhydride are added with constant stirring. The epoxy ester polymer obtained in this way has an acid number of 24 and a pesticide content of $ 96.

Then a heat-reactive resin mixture is made made of the following components «

Proposed part

Epoxy ester polymer (96 Hexamethoxymethyl melamine Diaoetone alcohol

Solids)

83.5 20

All in all

200.0

The diacetone alcohol is added to the epoxy ester, which is at about 100 ° C., with constant stirring, and the Geaiach

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FED-1783 J.

cooled to 90 ° O and mixed with the hexamethozymethylmelamine. The Ifasse obtained in this way has a PET content of 50 *,

A coating agent is made by inserting a pigment in the dispersed in the heat-reactive resin mixture, the dispersion diluted with water to a pesticide content of 10 # and then with Ν, Ν-dimethylethanolamine to a pH value from 7 »8 to 8 is set.

The pigment dispersion is prepared according to procedure 1 for the pigment dispersion of Example 1, but using the heat-reactive resin mixture of Example 5 prepared from the epoxy ester. The pigment dispersion obtained in this way has a fineness of 6.3 μ and a solids content of 64 pounds

A coating agent is made by mixing the following ingredients * parts manufactured:

Parts by weight

Pigment dispersion genasβ Example 3

( $ 64 solids) 145

Demineralized water. 846

NfH-dimethylethanolamine 2

Cationic wetting agent (polyoxyethylene amine

a coconut oil fatty acid) 7

A total of 1000

- 32 -109823/1813

PPD-1783

The Ν, Ν-DimethyläthaaoXamin and the cationic wetting agent are added to the pigment dispersion with constant stirring. The water is preheated to 70 ° G and then slowly added to the pigment dispersion with constant stirring. The pH of the dispersion thus obtained, which has a pesticide content of 10 56, is increased with Ιί, ίΓ-dimethylethanolamine
7.8 Ms 8 © in set.

With dilute phosphoric acid irorbehandelte steel plates M NaOH ü.ew procedure of Example 1 are coated with this dispersion. The coated steel plates are washed, dried and heated to 300 ° C. The primer coating thus obtained on the panels is smooth, free from imperfections and corrosion-resistant.

Example 5

A polyester is made by reacting the following components: Λ

Parts by weight

Triraethylol ethane 118

Neopenyl Glycol 162

Adipic acid 113

Phthalic anhydride 222

Total 615 -

- 33 -109823/1813

These ingredients are under constant within an hour Stir slowly heated to 180 ° 0. Then the temperature of 180 ° O is maintained for a further hour, then followed gradually increased to 230 ° 0 and held at this level until "an acid number of 15. Then the Polyester cooled to 180 ° C

A heat-reactive resin mixture with a solids content of 55 $> is prepared by mixing the following ingredients and heating to 80 ° 0:

Polyester Solution ( $ 96> Solids) Diacetone Alcohol

Hexamethoxymethyl melamine

A total of 173.2

A coating agent is produced by adding a pigment in the in the heat-reactive polyester resin mixture diapered, the dispersion diluted with water to 10% solids and then with Ν, Ν-Diinethyläthanülamin to a pH value τοπ 7.β until 8 is set »

A pigment dispersion is made according to Voi ^ aohrift 1 according to the example 1, but using the heat-reactive polyester resin mixture of the present example

- 34 109823/1813

Parts by weight , 7 100 , 5 63 9

FS ¹ D-1785 . % S

The pigment dispersion thus obtained has a fineness of 6.3 μ and a solids content of 64 #

A coating agent is made by adding the following ingredients be mixed:

Parts by weight

Pigment dispersion according to Example 5

(64 fo pests) 186

Mineralized water 999 * 5

Total 1188.5

The K, N-dimethylethanolamine slowly becomes the pigment dispersion added «The water is preheated to 70 ° 0 and slowly added to the pigment dispersion with constant stirring. The pH of the dispersion is then adjusted with N, N-Diinethyläthanolamin set to 7.8 through 8.

Steel plates pretreated with dilute phosphoric acid are coated according to Example 1 with the above coating agent. The coated steel plates are washed, dried and heated to 300 ° C. The primer coating thus obtained is smooth, imperfect-free and corrosion-resistant.

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100823/1813

Example 6

An acrylic polymer is made by reacting the following ingredients produced in a polymerization vessel:

Parts by weight

Part 1 210.0 Methyl ethyl ketone Part 2 200.0 Methyl ethyl ketone 40.0 Aoryl acid amide 172.2 Methacrylic acid methyl ester 170.0 Acrylic acid-2-ethylhexyl ester 12.8 Acrylic acid 4 »0 Azodiisobutyronitrile

A total of 809.0

Part 1 is heated to 81 ° C. and kept at reflux temperature. Part 2 is premixed and then slowly added to Part 1 within 2 hours. The polymerization mixture is then held at reflux temperature for a further hour. The polymer solution thus obtained has a Peststoffgehalt of 60 i> and an acid value of 24o

The methyl ethyl ketone is removed from the polymer solution and mixed the remaining behind polymer having Ithylenglykolmonobutyläther to a solution containing 60 i »Peststoffen.

- 56 109823/1813

BAD ORiGi? 4AL

The pH of the solution is increased with Ν, Ν-dimethylethanolamine 7.8 to 8.0. Then a pigment dispersion using the above is prepared according to Procedure 1 of Example 1 Polymer solution produced.

A coating agent is produced by adding this pigment dispersion with demineralized water, which is 60 to 70 ° 0 has been preheated to a pesticide content of 10 # is diluted. Then the pH of the dispersion is adjusted to 7.8 to 8 with ίΤ, Ν-dimethylethanolamine.

Steel plates pretreated with dilute phosphoric acid are coated with this coating agent according to Example 1. the coated steel plates are washed, dried and heated to 300 ° C. The primer coating thus obtained is smooth, free of imperfections and corrosion-resistant

Example 7

A film-forming polymer made from maleic anhydride and dehydrated Castor oil is made by adding the following ingredients to a polymerization vessel:

Gewiohtsteile

Maleic anhydride 24

Dehydrated RiainusöX 1300

A total of 1324

- 37 109823/1813

PED-1783

The reactants are in the polymerization vessel heated to 300 ° C. under nitrogen, kept at this temperature for 3 hours and then cooled to room temperature The resulting polymer has an acid number of 21.

The polymer is mixed with ethylene glycol monobutyl ether to a solution containing 60 & Peststoffen. A pigment dispersion is then prepared according to instruction 1 of Example 1 using this polymer solution.

Sin coating agent is manufactured by using this pigment dispersion with demineralized water, which was previously to 60 has been heated to 70 ° 0, diluted to 10 μs of solids will. The pH of the dispersion is then adjusted with N, H-dimethylethanolamine set to 7 »8 to 8 *

Steel plates pretreated with dilute phosphoric acid are coated with this coating agent according to Example 1. the coated steel plates are washed, dried and heated to 300 ° C. The primer coating thus obtained is smooth, imperfect-free and corrosion-resistant.

- 38 -

109823/1813

Claims (1)

Claims 1. Aqueous dispersion for anodic coating of phosphated metals, characterized in that it has a pesticide content of 3 to 30 fi and a pH of about 7 to 9y? has and (1) a uniformly dispersed, film-forming polymer, which consists essentially of a carboxylic acid polymer with an acid number of 6 to 25 and ammonia or a water-soluble primary amine, secondary amine, tertiary amine, polyamine or hydroxyamine has been, and (2) -9 contains a water-miscible solvent for the fumbildende polymer in amounts of from 2 to 10 percent by _e of the total amount of the dispersion. 2. Aqueous dispersion according to claim 1, characterized in that that the film-forming polymer to about 95 to 50 Gewo-jC from a Carbonsäurepolymerisat with an acid number of 6 to 25 and to about 5 to 50 Grev, ^r. ~? S from a thermosetting nitrogen-containing resin which partially with the carbon 109823/1813 166924b PED-1783 _ acid polymer has been implemented, "consists of pigment particles Contains less than £ 30 in volume concentration. 3 * Aqueous dispersion according to claim 2, characterized in that it has a solids content of 7 to 20 # and a volume concentration of pigment particles of 5 to 15 * f> , and the carboxylic acid polymer has an acid number of 15 to 24. 4. Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer is an alkyd resin and the thermosetting, nitrogen-containing resin is a Heiamine derivative " Aqueous dispersion according to Claim 2, characterized in that the carboxylic acid polymer consists essentially of units a mixture consisting of an ester of dehydrated castor oil fatty acid and a trimellitic acid ester Alkyd resin, the thermosetting nitrogen-containing resin, hexamethoxymethylmelamine and the pigment is iron oxide or barium chromate " 6. Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer is essentially composed of units of a mixture of a tall oil fatty acid ester and an alkyd resin consisting of a trimellitic acid ester, which is thermally - 2 - 109823/1813 FFD-1,783 mi curing, nitrogen-containing resin and hexamethoxymethylmelamine the pigment is iron oxide or barium chromate " 7 »Wassrx. e dispersion according to claim 2, characterized in that that the carboxylic acid polymer is a polyester made from a dicarboxylic acid and a polyol and the thermosetting, nitrogen-containing resin is a Heiamine derivative » 8. Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer consists essentially of a unit of a mixture of an adipic acid ester and a mixture Phthalic acid ester consisting of polyester, the thermosetting, nitrogen-containing resin is hexamethoxymethylmelamine and the pigment is iron oxide or barium chromate 9c Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer is an epoxy ester * 10 * Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer is the esterification product of (A) an esterifiable epoxy resin, (B) a drying ulcer acid and (C) a reaction product of maleic anhydride and a drying oil fatty acid. 1u Aqueous dispersion according to claim 2, characterized by that the carboxylic acid polymer consists essentially of units 109623/1813 166924b PKD-1783 h% a «, B-unsaturated carboxylic acid, acrylic acid amide and a mixture of esters of methacrylic acid and acrylic acid with saturated aliphatic monohydric primary alcohols having 1 to 8 carbon atoms . 12. Aqueous dispersion according to claim 2, characterized in »that the carboxylic acid polymer consists essentially of units of methacrylic acid, methyl methacrylate »2-ethylhexyl aorylate and acrylic acid amide 13 "Aqueous dispersion according to claim 2, characterized in that that the carboxylic acid polymer is the reaction product of a drying oil and an anhydride of an unsaturated one Is bicarboxylic acid with 4 to 8 carbon atoms 14 · Aqueous dispersion according to claim 13 »characterized in that that the drying oil is dehydrated castor oil and the anhydride Is maleic anhydride. 15. Aqueous dispersion for anodic coating of phosphated steel products, characterized * in that it has an esters content of 7 to 20 $ and a pH of 7 to 9 »5 and (1) a uniformly dispersed, film-forming polymer, which is about 95 to 50 wt. £ from a carboxylic acid polymer with an acid number of 15 to 24 and about - 4 109823/1113 5 "to 50 wt. (2) a water-miscible solvent for the film-forming Polymer in amounts of 2 to 10 wt .- # of the total Dispersion and (3) dispersed pigment particles in pigment volume concentration from 5 to 15 # holds. 16. StahlerZeugnis, characterized in that it is based on at least on one side a coating consisting essentially of iron phosphate in a thickness. 0.2 to 0.81 g / m which is coated with the coating agent according to claim 15. 17. A method for the anodic coating of metal products phosphated on at least one side, in which the metal product 3 in one a film-forming polymeric coating agent The cell is sounded as an anode and uses a Hindu sound Gaeiehetrom through the cell with the film forming lol / merisat is coated, before the coating duroh food £ * -n is converted into a coherent film., Dadiroh known that the coating agent used is an aqueous diaper « ^ w "Tl" tea 109823/1813 PFD-1783 l <f sion with a pesticide content of 3 to 30 i » and a pH of about 7 to 9» 5 is used, which (1) a uniformly dispersed film-forming polymer which consists essentially of a carboxylic acid polymer with an acid number of 6 to 25 and with ammonia or a water-soluble primary amine ,. secondary amine, tertiary amine, polyamine or hydroxyamine has been neutralized, and '2} a water-miscible solvent for the film-forming Polymer in amounts of 2 to 10 wt .- ^ of the total Contains dispersion. 18. The method according to claim 17, characterized in that a Coating agent is used in which the film-forming polymer the dispersion to about 95 to 50 wt .- £ from a carboxylic acid polymer with an acid number of 6 to 25 and about 5 to 50% by weight of a partially with the carboxylic acid polymer converted thermosetting, nitrogen-containing resin and the dispersion also pigment particles in contains a pigment volume concentration of less than £ 30. 19. \ experience according to claim 18, characterized in that a Vaseous dispersion with a particulate content of 7 to 20 pounds and a tolumen concentration of pigment parts of 5 to 15 # is used, in which the carboxylic acid polymer has a Has an acid number of 15 to 24. 109823/1813 PPD-1783 * 20. Terfahren naoh claim 18, characterized in that a aqueous dispersion is used in which the carboxylic acid »polymer is an alkyd resin and the thermosetting, nitrogen-containing resin is a melamine derivative. ο Terfahren naoh Anspruoh 18, daduroh marked * that one aqueous dispersion is used in which the carbonic acid polymer consists of a polyester made from a dioarboxylic acid and a Polyol and the thermosetting nitrogen-containing resin a melam. ^ is derivative. 22. The method according to claim 18, characterized in that a aqueous dispersion is used in which the carboxylic acid polymer is an epoxy ester. 23. Terfahren naoh Anspruoh 18, characterized by the fact that a Aqueous dispersion is used in which the carboxylic acid polymer consists essentially of units of an α ^ β-unsaturated carboxylic acid, aoryl acid amide and a mixture Udders of methacrylic acid and acrylic acid with saturated aliphatic monohydric primary alcohols bit from 1 to 8 carbon atoms. ? Λ · Method according to claim 18, characterized in that an aqueous dispersion is used in which the carboxylic acid polymer is the reaction product of a drying oil and 109fi23 / 1813 bad PPD-1783 hi an anhydride of an unsaturated dioarboxylic acid with 4 to 8 carbon atoms 25. The method according to claim 18, characterized in that a aqueous dispersion with a pest off content of 7 to 20 pounds and a pH of about 7 to 9 »5 is used, the (1) a uniformly dispersed, film-forming polymer, which consists of about 95 to 50 parts by weight of a carboxylic acid " polymer with an acid number of 15 to 24 and about 5 to 50% by weight consists of a thermosetting, nitrogen-containing resin partially reacted with the carboxylic acid polymer and with ammonia or a water-soluble primary amine, secondary amine, tertiary amine, Polyamine or hydroxyamine is neutralized, (2) a water-miscible solvent for the forming polymer in amounts of 2 to 10 wt .- ^ of the entire dispersion and ' (3) contains dispersed pigment parts in a pigment volume concentration of 5 to 15 # <, 109823/1113