DE2035615A1 - Water-thinnable coating agents for electrocoating - Google Patents

Description

relates to water-thinnable coating agents for electrocoating the end

2. a water-tolerant solvent that preferably does not contain any primary hydroxyl groups,

5 «in such water-tolerant solvents and / or water-soluble ammonia and / or amine soaps of condensation products from hydroxy! Free drying and / or semi-drying fatty acid esters or mixed esters of these fatty acids with alphabetically ethylenically unsaturated dicarboxylic acids or, if they exist, their anhydrides, which are characterized are that the condensation product for 3 is an adduct with 10-25% by weight, preferably 15-20% by weight of the dienophilic compound and 75-90% by weight, preferably 80-85% by weight of one of the 3 - JO times the value of the initial viscosity of prepolymerized hydroxyl-free drying and / or semi-drying fatty acid esters or mixed esters of these fatty acids with resin acids.

109887/1564

As stated in the registration, the binders stand out among other things by an excellent throwing power (throwing pbwer) the end ·

Due to the wide application that the electrocoating process for priming complicated 'hollow body constructions in the metalworking industry (e.g. car bodies) found in recent years, the claims are on the The binding agent's spreading power has increased continuously. The required Reducing or avoiding the workload for additional auxiliary electrodes also requires binding agents, whose scattering power is so great that hollow bodies without additional electrons which are still sufficiently coated and a satisfactory one Corrosion protection is guaranteed. . · ■ "'.'

It has now been found that, in a modification of the Ausftihrungsform according to Hätipifeanmeldung binders with significantly increased scattering power can be produced if the reaction ¹ between alpha-beta ethylenically unsaturated dicarboxylic acid or its anhydride with the 3-30 fold fatty ¥ ert the initial viscosity prepolymerized hydroxyl-free drying and / or semi-drying fatty acid esters or mixed esters of these fatty acids with resin acids in the presence of a separately prepared reaction product between an alkyl, aryl and / or aralkylphenol resol and an unsaturated fatty acid and / or resin acid and / or their esters -and polyhydric alcohols is made. The remaining. Features ,, such as elasticity, hardness _s corrosion resistance; ,, among others remain counter '· on the .Produkten of H ^ o-gitipafcesTfees maintained or improved as "j part

Suitable phenol resols are obtained by adding aldehydes, preferably ₉ formaldehyde, to alkyl ₉ aryl or aralkyl phenols _B, preferably p-tertiary butylphsnol, p-nonylphenol _, pP & enylphenol, in an aqueous 'solution' in an alkaline medium in a known manner You can, ψοτρ the reaction with the unsaturated fatty acid and / or es ^ ssäur © and / or their esters

are subjected to a partial self-condensation at temperatures between 50 and 15O ^o C »The water formed is advantageously removed in vacuo. ■

As unsaturated fatty acids for the reaction with the phenol resol are the natural drying and / or semi-drying Suitable for fatty acids that build up oils. They are found in linseed oil, soybean oil, safflower oil, perilla oil, wood oil, Castor oil, fish oil, as well as in their isomerized, dehydrated or polymerized derived products. Suitable resin acids are present in rosin. Suitable mixtures of fatty acids and resin acids are present in the different refining stages of tall oil, the alkaline one Decomposition of coniferous wood occurs.

Just like the fatty acids and / or resin acids, their esters can be used with monohydric and polyhydric alcohols. As examples are mentioned: the corresponding methyl esters, butyl esters, Ethylene glycol diesters, glycerol triesters, pentaerythritol tetraesters, or those produced by complete esterification of the existing ones , Esters formed by hydroxyl groups with epoxy compounds, hydroxyl group-containing polymers and hydroxyl group-containing Urethanes that are formed by the reaction of isocyanates with excess polyol. Preferably used epoxy compounds are made from 4, ^ - dihydroxy-2,2-diphenylpropane ' and epichlorohydrin obtained, preferably used hydroxyl-containing Polymers are obtained by copolymerizing allyl alcohol with styrene. ,,

The reaction between the phenolic resole and the unsaturated fatty acids and / or resin acids and / or esters thereof is effected at temperatures between 120 and 250 ⁰ C until the desired viscosity, with removal of the forming Wassers.-The resulting products are dark, at room temperature to bore hard, brittle resins that can still be melted

and have no gelled portions.

109887/1564

To produce the water-thinnable coating media for electrocoating, the separately produced reaction products of phenol resols and unsaturated fatty acids and / or resin acids and / or their esters, according to the present invention, are based on the value of the initial ^viscosity "3 - 3O-i * acne i ^1" Pre-polymerized hydroxyl-free drying and / or semi-drying fatty acid esters or mixed esters are added, whereupon the reaction with the alpha-beta ethylenically unsaturated dicarboxylic acid or its anhydride takes place.

The implementation with the dienophiien components and the processing for water-soluble binders is carried out analogously to the Hi uptian registration.

The following examples illustrate the invention without it to restrict.

Example 1:

450 g of p-tertiary butylphenol resol, prepared in a known manner from 1 mole of p-tertiary butylphenol and 2 moles of formaldehyde in an alkaline medium, are heated to 120 ° C in a suitable reaction vessel under vacuum until a sample of the resin solidifies at room temperature, and is no longer sticky. Thereupon 250 g tall oil (with 20-23 # rosin acid content) are added and the mixture within 2 hours -on 23O ⁰ C

j. i, ι

heated. This temperature is held for one hour. That Resin is hard and brittle at room temperature.

A mix of 22? g linseed oil and 45 g wood oil, viscosity approx. 50 ep / 20 ⁰ C _f is heated to Z60 - 2? 0 ° C 'until the viscosity is' 600 cp / 20 ° C ο then 128 g des product 1a) and 100 g of maleic anhydride "added the mixture is maintained at 200 ° C at 5 $> the Mefeg® used geawak © until the content of maleic anhydride ®m FR® ± 2i. Then 20 g of wood oil are added, the temperature of 2OQ ⁰ C becomes like this

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held for a long time until a sample of the resin, 60% in xylene, has a viscosity of about 1000 cp / 20 ° C. · It is cooled and 30 s of distilled water, 5 g of diacetone alcohol and 1 g of triethylamine react 2 hours at 80 ° C with a mixture of '■. The resin is diluted to a solids content of 70 # with ethylene glycol monoethyl ether.

To investigate the electrophoretic coating behavior of the binder produced, 290 g of 70% resin are rubbed with 66 g of red iron oxide on a three-roller. The lacquer paste is neutralized with ammonia to a pH value of 6-6.8 (measured in a 10% aqueous solution) and diluted with distilled water to a resin solids content of 10%. Films are electrophoretically deposited in a known manner from the lacquer bath thus obtained and baked.

Testing the scattering force (wraparound) :

A plastic cylinder with a diameter of 6 cm and a volume of 2 liters is filled with the material to be examined. At the bottom of the cylinder there is a disc-shaped cathode made of sheet iron with the same diameter. When connected as an anode, a strip of sheet metal 5 cm wide is immersed in the paint bath. The end of the strip is 2 cm from the cathode. The electrical conditions for the deposition are chosen so that there is a ¹ layer thickness of 20 my at the lower end of the sheet metal strip. Along the strip, the layer thickness decreases with increasing distance from the cathode. The distance is measured between 20 my and 10 my in .cm. The longer this distance, the better the binding agent's grip.

The throwing power for the binders in the examples

'are summarized in Table I.

• i

ORIGINAL INSPECTED

109887/1564

Example 2 ^:;

300 g of p-tertiary Butylphenolresol (from 1 mole of p-tertiary butyl »phenol and 2 moles of formaldehyde) are mixed with 3OO g of rosin in 90 minutes at 23O ⁰ C heated This temperature is one hour" held, the resin is hard at room temperature and cracked.

A mixture of 250 g linseed oil and 50 g wood oil with a viscosity of approx. 50 cp / 20 ° C is heated to 260 - 270 ° C until the viscosity is 400 cp / 20 ° C. 100 g of product 2a) and 100 g of maleic anhydride are then added. The mixture is "held 2Ö0®C, bis.der content of free, maleic anhydride is gesunkan 5 $ ^ ds amount used. Then, 20 g of tung oil was added and kept 200 ⁰ C until the viscosity of a 6" at 0 $ igen solution in xylene is 25OO cp / 20 ° C ο Mach cooling to 8O ⁰ C is 2 hours with a mixture of 30 S distilled water. -'5 S diacetone alcohol and 2 g of triethylamine Taei 8O ⁰ C _"o responding Dilute mitf ethylene glycol monoethyl 70 $ solids content =.

The processing to an.aqueous paint and the electrophoretically ^, deposition for PrüfuMig des-Umschlages takes place analogously Example 1.

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Example 3 * /

a) ^:

^ 00 g of p-tertiary butylphenol resol (from 1 mole of p-tertiary butylphenol and 2 moles of formaldehyde) and 250 g of a dinate fatty acid with an acid number of approx. · Viscosity of 4000 cp 25 ° C t ^ ground to 230 ⁰ C heated / Di · © temperature is maintained for one hour. "" This is Hafs boi / ZinoffleffteBnpera ^ tur · and brittle hard. <

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A mixture of 206 g of linseed oil and 102 g of dehydrated castor oil is heated to 20 ° C and held at this temperature until the viscosity is 500 cp / 20 ° C. After cooling to below 200 ^° C., 42 g of product 3a) and 100 g of maleic anhydride are added. Further processing is carried out in the same way as in Example 1.. ,

Example 4:. /

200 g of p-tertiary butylphenol resol (from T moles of p-tertiary butylphenol and 2 moles of formaldehyde) are precondensed as in Example 1. Then, 200 g of linseed oil and 100 g of rosin are added and the mixture to 23O ⁰ C heated. The temperature is held for one hour. The resin is hard and brittle at room temperature.

A mixture of 175 g of linseed oil and 175 g of dehydrated castor oil is heated to 260 ° C until the viscosity is 900 cp / 20 ° C. After cooling below 200 ^° C., 150 g of the product 4a) and 100 g of maleic anhydride are added. Further processing is carried out in the same way as in the example

Comparison of the throwing power of Examples 1-4 with the Examples of the Hstwpfrpatentes: ■

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Wrap in cm

Example 1 32

Example 2 '30

Example 3 _; 25th

Example 4. . 30th

Parent application example 1 18

Example 2 17 Example 3 17

^iÄ VA RESIN

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Example 5:

a) 300 g of p-phenylphenol resol, prepared in a known manner from 1 mole-ρ-pheny! phenol and 2 moles formaldehyde im alkaline medium, with 200 g tall oil fatty acid (with 20-23 # resin acid content) in 2 hours to 230 ° C heated. This temperature is held for one hour.

The resulting product has an 8Q solution in xylene a viscosity of 800 cP / 20 ° G and an acid number of 85 mg KOH / g solid resin.

b) A mixture of 250 g linseed oil and 50 g wood oil, viscosity 50 cP / 20 ° C, is heated to 26θ - 20 ° C until the viscosity is 600 cP / 20 ° C. Then 100 g of the product 5 &) are stirred in and 100 g of maleic anhydride are added. The temperature of the mixture is kept at 200 ^° C. until the content of free maleic anhydride has fallen to 5% of the amount used. Then, 20 g wood oil are added and a temperature of 200 - 210 ⁰ C maintained until the viscosity of a 60 $ solution in amounts Äthylenglykolmonoäthylätheracetat 500 cP / 20 ° C. Further processing is carried out in the same way as in Example 1. -

Example 6:

a) 160 g of a styrene-allyl alcohol copolymer with a molecular weight of 15.00 and a hydroxyl equivalent weight of 320 are heated to 240 ° with 350 g of oil fatty acid, the resulting water being removed azeotropically with iXylene. When the acid number of the mixture has fallen to 7 ^ 5 mg KOH / g, the temperature is lowered to 160 ° Q. In the course of 2 hours, 250 g of p-tert. Butylphenol resol (from 1 mole of p-tert-butylphenol and 2 moles of formaldehyde) was added dropwise. The temperature is kept out in one hour at 230 ⁰ C and 1 hour © rhöhfc ^first The resulting product has a viscosity of 550 cP / 20 ° C in a 70% solution in xylene. The acid number is 50 mg KOH / g solid

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b) A mixture of 500 g of linseed oil and 100 g of tung oil, viscosity 50 cP / 20 ° C is at 26o - heated 270 ⁰ C, until the viscosity of 450 cP / 20 C ^0. Then 200 g of the product 5 a) are added and a further 200 g of maleic anhydride. The temperature of the mixture is kept at 200 ° C. until the content of free maleic anhydride has fallen to 5% of the amount used. Then ½ g of wood oil are added and a temperature of 200-210 ° C. is maintained until the viscosity of a 60% solution in ethylene glycol monoethyl ether acetate is 600 cP / 20 ° C. Further processing is carried out as in Example 1

Example 7 J \

a) 130 g of a bisphenol polyglycidyl ether with an epoxy equivalent of 19CT are required. 400 g of linseed oil fatty acid and 0.7 S stannous octoate to 25O ⁰ C heated, wherein the Jleaktionswasser with xylene azeotropically removed. When the acid number of the mixture has fallen to 10 mg, KOH / g, the temperature is lowered to 160 ° C. In the course of 2 hours, 175 g of p-tert. Butylphenol resol (from 1 mole of p-tert, butylphenol and 2 moles of formaldehyde) was added dropwise. The temperature is then increased to 230 ° G in 1 hour and held for one hour. The resulting product has a viscosity of 100 cP / 20 ° C, ^ O ^ ig in xylene. The acid number is 8 mg KOH / g. ^; / '

b) A mixture of linseed oil and 3o8 g, 6Z g wood oil, viscosity 50 cP / 20 ° C, is 260 - heated 27O ⁰ C, until the viscosity reached 5.00 cP / 20 ° C \ has Then, 80 g of the product 7 β.) is added and 100 g of maleic anhydride are stirred in. The temperature is kept at 200 ° C. until the content of free maleic anhydride has fallen to 5% of the amount used. Then 20 g of wood oil are added and held at 200-210 ° C until the viscosity of a 60 # Lgen solution in xylene has reached 1000 cP / 20 ° C. Further processing takes place as in Example 1.

109887/1564 original inspected

Claims (3)

Claims 1. Water-thinnable coating agents for electrocoating according to the main patent Mr. ..... (Registration P 18 08 229.6 dated November 11, 1968) consisting of 1. Water 2. a water-tolerant solvent that preferably does not contain any primary hydroxyl groups, 3. Soluble in such solvents and / or water Ammonia and / or amine soaps of condensation products from 10-25% by weight of an alpha-beta ethylenically unsaturated Dicarboxylic acid or its anhydride, preferably 15-20% by weight, and 75-90% by weight, preferably 80 - 85 wt. ~ # One to 3 - 30 times the value of the initial viscosity pre-polymerized hydroxy! free drying and / or semi-drying fatty acid esters or mixed esters of these fatty acids with resin acids, characterized in that the condensation product according to 3 is an adduct of an alpha-beta ethylenically .unsaturated dicarboxylic acid or its anhydride and a mixture of a prepolymerized fatty acid ester with a reaction product between an alkyl and / or aryl and / or aralkyl benzene resol and one unsaturated fatty acid and / or resin acid and / or their esters with mono- or polyhydric alcohols. 2. Coating agent according to claim 1 _s, characterized in that the adduction achieved mixture of 50-90 wt .- ^, preferably 65-85 wt .- ^ of the prepolymerized fatty acid ester and 10-50 wt .- ^, preferably 15-35 wt .- $ of the reaction product consists of phenol resol and unsaturated fatty acid and / or resin acid and / or their esters. 3. Coating agent according to claims 1 or 2 ₉ daduroh characterized in that the phenol resol is preferably an alkylphenol resol. Coating agent according to claims 1 to 3, thereby ga-
_t denotes that the reaction product of 30-75 wt .- ^ alkylphenol resol, preferably p-tertiary Butylphenolresol, and 25 - 70 wt .- ^ unsaturated fatty acids and / or resin acids and / or their esters. ORIGINAL INSPECTED 10 98 8 7 / 1S6E