Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D4/00—Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
  • C09D4/06—Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D123/00—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers
  • C09D123/02—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers not modified by chemical after-treatment
  • C09D123/04—Homopolymers or copolymers of ethene
  • C09D123/08—Copolymers of ethene
  • C09D123/0846—Copolymers of ethene with unsaturated hydrocarbons containing other atoms than carbon or hydrogen atoms

Definitions

• the present invention relates to methods for coating metallic surfaces in which the metallic surface is brought into contact with aqueous copolymer dispersions. Furthermore, the invention relates to copolymers coated with metallic surfaces and the use of aqueous copolymer dispersions for coating metallic surfaces.
• WO 2004/108601 A1 describes the use of aqueous dispersions comprising at least one at least partially neutralized ethylene copolymer wax selected from those ethylene copolymer waxes incorporated in copolymerized form as comonomers (A) from 26.1 to 39% by weight of at least one ethylenically unsaturated carboxylic acid and (B ) 61 to 73.9 wt .-% of ethylene, and such ethylene copolymer waxes containing polymerized ( ⁇ ') 20.5 to 38.9 wt .-% of at least one ethylenically unsaturated carboxylic acid, ( ⁇ ') 60 to 79.4 wt % Of ethylene and (C) 0.1 to 15% by weight of at least one ethylenically unsaturated carboxylic acid ester, as auxiliaries for wastewater treatment.
• the partially neutralized ethylene copolymer waxes are at least partially neutralized with a basic substance, preferably an
• WO 2008/092853 A1 describes a process for coating surfaces by treatment with a substantially paraffin-free formulation which comprises an at least partially neutralized with an alkali metal copolymer of ethylene and 25.5 to 35 wt .-% of a contains ethylenically unsaturated carboxylic acid.
• the formulation also contains at least at least one nonionic or anionic surfactant, at least one defoamer and optionally other components.
• the basic component may also be a carbonate and / or bicarbonate of an alkali metal.
• WO 2007/137963 A1 describes a process for coating plastic or metal surfaces with an aqueous dispersion of ethylene copolymers having a molecular weight in the range from 2,000 to 20,000 g / mol, and the 15.5 to 19.9% by weight of an ethylenically unsaturated carboxylic acid copolymerized and containing at least one base, wherein the coated surfaces are provided with at least one further layer.
• the selected base are alkali metal salts and more preferably amines.
• WO 2006/066824 A1 describes a process for coating metallic surfaces with a copolymer of olefins and / or dienes, acidic monomers and optionally further monomers, the metal surfaces being contaminated with oil and / or grease and the contamination not being coated before coating Will get removed.
• the polymers used are neutralized by a base; preferred metal cations are also named Mg 2+ ions.
• preferred metal cations are also named Mg 2+ ions.
• the use of phosphates and especially of magnesium phosphate is not mentioned.
• WO 98/10023 describes the use of aqueous polymer dispersions of a polymer of an olefin and an acid comonomer, at least one colorant and / or a corrosion inhibitor for the protection of metallic surfaces from corrosion.
• the corrosion inhibitors used in the water phase are insoluble pigments which limit the transparency and surface properties of the films.
• the above-described dispersions are still in need of improvement with regard to the corrosion protection of metallic surfaces, in particular with regard to the passivation of surfaces containing steel and / or zinc or zinc-containing alloys.
• the object of the invention was to provide an improved process for the treatment of metallic surfaces, which can be used particularly advantageously in the passivation of surfaces containing steel and / or zinc or zinc-containing alloys.
• An object of the invention is therefore a process for coating metallic surfaces in which the metallic surface is brought into contact with an aqueous copolymer dispersion, characterized in that the aqueous copolymer dispersion comprises an effective amount of magnesium ions and phosphate or phosphonate ions or mixtures Contains phosphate and phosphonate ions, and wherein the copolymers contained in the dispersion are composed of the following components:
• (B) from 5 to 80% by weight of monoethylenically unsaturated monomers which contain acid groups and / or their anhydrides or salts.
• the amount of components (A) and (B) is based on the total amount of components (A) and (B).
• the total amount of components (A) and (B) is 100% by weight.
• the components (A) are in the range of 20 to 95 wt .-% and (B) in the range of 5 to 50 wt .-%.
• metal surfaces treated with the method according to the invention are significantly more resistant to corrosion than those according to the prior art.
• an aqueous copolymer dispersion is understood as meaning mixtures comprising water and copolymers.
• the water is in this case present in an aqueous solvent mixture; the aqueous solvent mixture preferably consists essentially, more preferably completely, of water.
• the copolymer can be dispersed in the aqueous solvent mixture, emulsified or molecularly dissolved.
• the aqueous solvent mixture preferably contains from 75% by weight to 100% by weight of water.
• the aqueous mixed solution may also contain organic solvents in addition to water.
• the organic solvents preferably contain compounds selected from the group of alcohols, ethers, esters, ketones, or amides. Such organic solvents are often used as a component of paints and are known in the art from the prior art.
• solvents examples include alcohols such as methanol, ethanol, propanol, butanol, phenoxypropanol, or ethylene glycol, ketones such as acetone, methyl ethyl ketone, cyclohexanone, oligomeric and optionally partially etherified alkylene glycol ethers such as diethylene glycol, triethylene glycol, tetraethylene glycol, butyl glycol, butyl diglycol, 2,2,4- Trimethyl 1, 3-pentanediol monoisobutyrate, dimerized butyl glycol, dipropylene glycol n-butyl ether, dipropylene glycol dimethyl ether, esters such as the dimethyl esters of adipic acid, succinic acid, glutaric acid and their mixtures, 2-ethylhexyl lactate, butyl phthalate, dibutyl phthalate, amides such as dimethyl acetoacetamide, N -Methyl
• the copolymers are preferably present in the aqueous solvent mixture in substantially molecularly disperse form or in the form of a very finely divided dispersion having an average particle size of less than 100 nm, determined by dynamic light scattering in accordance with DIN ISO 13321. That is, they do not lead to significant changes in the transparency of the aqueous solvent or even to the formation of a sediment.
• the copolymers preferably have molecular weights M w (weight average) of more than 20,000 g / mol, very preferably of more than 50,000 g / mol.
• M w weight average
• the molecular weights of the copolymers are in the range from 20 000 g / mol to 200 000 g / mol, very particularly preferably from 50 000 g / mol to 200 000 g / mol.
• the copolymers present in the dispersion contain, as a further component:
• (C) from 0 to 30% by weight of (A) and (B) different, ethylenically unsaturated monomers.
• the total amount of magnesium ions, phosphate and phosphonate ions in the range of 0.1 to 5 wt .-%, based on the amount of copolymers, preferably in the range of 0.2 to 3.5 wt .-%, more preferably in the range of 0.4 to 2 wt .-%, most preferably from 0.6 to 1, 6 wt .-%.
• the magnesium ions and phosphate or phosphonate ions in the form of a magnesium phosphate or magnesium phosphonate-containing salt are preferably added to the aqueous copolymer dispersion.
• Preferred salts here are magnesium phosphate, magnesium phosphonate, magnesium phosphate octahydrate or further hydrates of these salts.
• the compounds may also be partially protonated, for example as hydrogen phosphates or dihydrogen phosphates or the corresponding phosphonates. It is also possible to use mixed salts of magnesium phosphate or phosphonate with other salts, for example with ammonoim, alkali or alkaline earth compounds. Such compounds are, for example, ammonium magnesium phosphate or sodium magnesium phosphate.
• component (A) is at least one alkene selected from the group of ethene, propene, 1-butene, 2-butene, 1-pentene, 1-hexene, 1 -hepten or 1 octene.
• the acidic group in (B) is at least one group selected from the group of carboxyl groups, sulfonic acid groups or phosphonic acid groups.
• Component (A) is particularly preferably ethene and component (B) is (meth) acrylic acid.
• from 0.5 to 50 mol% of the acid groups present in the copolymer are present as neutralized groups.
• the neutralization is preferably carried out by dispersing the polymer in the solvent with addition of the base at elevated temperature.
• the bases used are usually one or more basic substances, for example hydroxides and / or carbonates and / or bicarbonates of alkali metals, or preferably amines such as ammonia and organic amines such as alkylamines, N-alkylethanolamines, alkanolamines and polyamines.
• basic substances for example hydroxides and / or carbonates and / or bicarbonates of alkali metals, or preferably amines such as ammonia and organic amines such as alkylamines, N-alkylethanolamines, alkanolamines and polyamines.
• alkylamines are: triethylamine, diethylamine, ethylamine, trimethylamine, dimethylamine, methylamine.
• Preferred amines are monoalkanolamines, N, N-dialkylalkanolamines, N-alkylalkanolamines, dialkanolamines, N-alkylalkanolamines and trialkanolamines having in each case 2 to 18 C atoms in the hydroxyalkyl radical and optionally in each case 1 to 6 C atoms in the alkyl radical, preferably 2 to 6 C atoms in the alkanol radical and optionally 1 or 2 C atoms in the alkyl radical.
• ethanolamine diethanolamine, triethanolamine, methyldiethanolamine, n-butyldiethanolamine, ⁇ , ⁇ -dimethylethanolamine and 2-amino-2-methylpropanol-1.
• ammonia and N, N-dimethylethanolamine.
• polyamines are: ethylenediamine, tetramethylethylenediamine (TMEDA), diethylenetriamine, triethylenetetramine.
• TEDA tetramethylethylenediamine
• the copolymers are prepared by methods known to those skilled in the art.
• the copolymers are prepared according to the methods described in WO 2004/108601 A1.
• the mixtures of copolymer and aqueous solvent mixture are prepared by methods known to those skilled in the art.
• the copolymer is dispersed in the solvent mixture previously produced by mixing.
• the copolymer is preferably used in the form of a formulation with water or an aqueous solvent mixture comprising at least 75% by weight of water. It is particularly preferred in this case that the copolymer is formulated only in water as solvent and the concentration of the copolymer is 0.5 to 50 wt .-% with respect to the sum of all components of the formulation.
• the aqueous copolymer dispersions are preferably applied in the process according to the invention by means of spraying, spraying, dipping, brushing or electrophoretic coating.
• the metallic surface preferably contains a metal selected from the group of Mg, Al, steel, Zn or steel coated with Zn, Al, Ni, Sn, Cr or their alloys, the metal surface particularly preferably containing the metal Zn.
• the aqueous copolymer dispersion is brought into contact with an intermediate layer, wherein the intermediate layer is in contact with the metallic surface.
• the intermediate layer is preferably a conversion layer which serves to passivate the metal surface.
• Such layers are, for example, Cr conversion layers, phosphatizations, polymer-based aftertreatments, passivations containing Ti or Zr compounds, metal oxide layers, layer-by-layer layers, silane-crosslinked layers or oils, in particular corrosion protection oils.
• the intermediate layer is preferably a Cr conversion layer.
• copolymer dispersions contain, as a further component, film-forming agents, crosslinking components, wetting agents or other anticorrosive agents which deviate from the copolymers.
• copolymer dispersions can, as described above, additionally film-forming agents are added.
• These may be solvents or solvent mixtures, in particular those having an evaporation number according to DIN 53170 in the range from 50 to 20,000, for example butylglycol or butyldiglycol.
• non-evaporating compounds in particular alcohols which have been reacted with alkylene oxides, in particular ethylene oxide and / or propylene oxide. These alcohols can be monovalent or polyvalent. These compounds can lead to a better spreading of the solution on the metal surface.
• alkoxylates of oligomeric or polymeric alcohols for example of silicone derivatives.
• wetting agents may additionally be added to the copolymer dispersions as described above.
• suitable wetting agents are nonionic, anionic or cationic surfactants, in particular ethoxylation and / or propoxylation products of fatty alcohols or propylene oxide-ethylene oxide block copolymers, ethoxylated or propoxylated fatty or oxo alcohols, furthermore ethoxylates of oleic acid or alkylphenols, alkylphenol ether sulfates, alkylpolyglycosides, alkylphosphonates, alkylphenylphosphonates, Alkyl phosphates, or Alkylphe- nylphosphate.
• Low-foaming wetting agents are preferably used, for example end-capped ethoxylation and / or propoxylation products of fatty alcohols in which the alcoholic end group has been converted to an ether, for example methyl or ethyl ether.
• Particularly preferred wetting agents are alkoxylated fatty alcohols of the formula (I)
• R 1 is C 6 -C 24 alkyl, linear or branched
• R 2 , R 3 is H, C 1 -C 16 alkyl, linear or branched,
• R 4 is H, C 1 -C 8 alkyl, linear or branched,
• y integer from the range 0 to 80.
• the alkylene oxide units can be arranged in formula (I) in one or more blocks or randomly.
• Another object of the present invention is a coated with a copolymer metallic surface, obtainable according to an embodiment of the method according to the invention.
• the thickness of the copolymer-containing layer on the metallic surface of 0.1 to 30 ⁇ , preferably from 0.2 to 30 ⁇ , more preferably from 0.5 to 10 ⁇ , most preferably from 1 to 6 ⁇ .
• one or more coating layers applied one above the other are still present on the copolymer-containing layer.
• the coated metallic surfaces can take any shape.
• the metallic surfaces are preferably surfaces of shaped or flat bodies, particularly preferably the surface of coils, wires, tubes, sheets, workpieces, formed, joined and / or joined parts.
• the copolymer dispersions can be applied to flat or shaped metal surfaces, for example on coils, wires, tubes, or other shaped or flat bodies.
• the copolymer dispersions are preferably applied by dipping or spraying.
• the applied films after drying have a preferred average layer thickness in the range from 0.2 to 30 ⁇ m, in particular from 0.5 to 10 ⁇ m, very particularly preferably from 1 to 6 ⁇ m.
• the drying can be done by various methods. In many cases, a conventional drying at slightly elevated temperature ranges.
• the workpieces (shaped or flat bodies) are preferably stored in an oven at 80 ° C. for 5 to 20 minutes. However, higher temperatures and longer or shorter times can be set as required.
• a further subject of the present invention is the use of aqueous copolymer dispersions containing an effective amount of magnesium ions and phosphate or phosphonate ions or mixtures of phosphate and phosphonate ions, the copolymers contained in the dispersion being composed of the following components:
• the amount of components (A) and (B) is based on the total amount of components (A) and (B).
• the total amount of components (A) and (B) is 100% by weight.
• the components (A) are in the range of 20 to 95 wt .-% and (B) in the range of 5 to 50 wt .-%.
• the copolymers present in the dispersion contain as a further component:
• (C) from 0 to 30% by weight of (A) and (B) different, ethylenically unsaturated monomers.
• the total amount of magnesium ions, phosphate and phosphonate ions is in the range from 0.1 to 5 wt .-%, based on the amount of copolymers, preferably in the range of 0.2 to 3.5%, particularly preferably in the range of 0.4 to 2 wt .-%, most preferably from 0.6 to 1, 6 wt .-%.
• the aqueous copolymer dispersions are preferably brought into contact with an intermediate layer, with the intermediate layer being in contact with the metallic surface.
• the aqueous copolymer dispersions comprise further additives as additional component. Dispersants, dispersants and / or wetting agents are preferably used as further additives.
• dispersants are polyacrylic acids or polyacrylic acid copolymers. These polyacrylic acids or polyacrylic acid copolymers are preferably present in the form of their sodium salts. Also preferred are dispersants having a molecular weight M w (weight average) of from 1000 to 30 000 g / mol, in particular from 2000 g / mol to 10000 g / mol. The total amount of dispersant is from 0.01 to 1 wt .-% based on the amount of copolymers of the aqueous copolymer dispersion. Preference is given to using from 0.01 to 0.2 wt .-%.
• dispersing aids are surfactants.
• the total amount of dispersing assistant is from 0.01 to 0.1% by weight, based on the amount of copolymers of the aqueous copolymer dispersion.
• wetting agents are nonionic surfactants.
• the total amount of wetting agent is from 0.01 to 0.1 wt .-% based on the amount of copolymers of the aqueous copolymer dispersion.
• the coatings are particularly preferably used as so-called sealers, a Cr conversion layer acting as an intermediate layer.
• sealer leads to a significant improvement in the corrosion protection properties of the Cr conversion layer.
• the present invention provides improved processes for the treatment of metallic surfaces, which can be used to particular advantage in the passivation of surfaces containing steel and / or zinc or zinc-containing alloys.
• the invention is explained in more detail by the examples without the examples restricting the subject matter of the invention.
• the amount of the selected additive in% by weight refers to the amount of copolymer used.
• the aqueous preparations were adjusted to a copolymer concentration of 20% by weight, based on the total amount of the preparation, by adding the appropriate amount of water.
• Oiled, galvanized sheets (dimensions about 220 mm * 10 mm * 0.5 mm, Zn support 100 g / m 2 ) were immersed for about 1 min in ethyl acetate and then rubbed off with a paper towel. They were then placed for 30 sec. At 60 ° C in a bath with an alkaline cleaning solution (SurTec® 133 Surtec mechanicalntechnik, Zwingenberg, Germany, 4%). Then they were 2 to 3 times immersed in a bath with 60 ° C warm tap water and then in a bath with demineralized water, drained and blown off with compressed air.
• the dry sheets were coated by applying the polymer solutions with a knife.
• the doctor blade was chosen so that a wet film thickness of 12 ⁇ was formed.
• the sheets were then dried in a circulating air drying oven (about 12 sec, PMT (peak metal temperature) 50 ° C) and then stored at 80 ° C for 10 min in a drying oven.
• the examples show the advantageous corrosion protection that results from the addition of magnesium phosphate.
• the amount of additive A is based on the amount of copolymer.
• magnesium ions or phosphates derived from other compounds of these ions the corrosion protection of the preparations can be increased in many cases.
• the increase in corrosion resistance is often slightly lower than when using magnesium phosphate (octahydrate).
• the above-mentioned copolymers can also be applied by means of dipping.
• the substrates used were both hot-dip galvanized and electrolytically galvanized test sheets.
• the galvanized sheets were pretreated as described above and then immersed in copolymer emulsions of different concentrations, whereby different dipping times and repeated dipping were investigated.
• Polymer B was diluted with water to a copolymer concentration of 12% by weight and dipped twice. Between the immersion steps, the dripping time was 1 min.
• the amount of additive A is based on the amount of copolymer.
• a very big advantage is that the copolymers can be formulated with a nonionic surfactant (eg Plurafac LF 300 - alkoxylated fatty alcohol), without the corrosion protection being greatly impaired.
• a nonionic surfactant eg Plurafac LF 300 - alkoxylated fatty alcohol
• the visual appearance (very uniform without edges) and the mechanical properties (thinner polymer layer about 3 g / m 2 with wetting agent vs. about 6 g / m 2 without wetting agent) of the sealing in the dipping application are also enormously improved.
• Polymer B was admixed with the wetting agent Plurafac LF 300 (alkoxylated fatty alcohol) and optionally with 1, 6 wt .-% (based on the amount of copolymer) of additive 1.
• Plurafac LF 300 alkoxylated fatty alcohol
• 1, 6 wt .-% based on the amount of copolymer
• the amount of additive 1 is based on the amount of copolymer.
• the amount of wetting agent is based on the amount of polymer B.
• Example 17 Tests were carried out with the solution from Example 7 for the storage stability of the aqueous copolymer solutions. The experiments were carried out over a period of 3 months at temperatures of 10, 20 or 60 ° C. The stability of the solutions was with the help a visual assessment. An unstable solution was seen by gelation surface of the solution.
• the polyacrylic acid used was the sodium salt of a low molecular weight polyacrylic acid having a weight average of 4000 g / mol (Sokalan® CP 10 from BASF SE).
• the concentration of the polyacrylic acid was 0.05% by weight based on the copolymers of Example 7.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Laminated Bodies (AREA)
• Chemical Treatment Of Metals (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (1)

Family

ID=47172478

Family Applications (1)

Country Status (8)

Families Citing this family (1)

Family Cites Families (12)

• 2013
  • 2013-11-04 JP JP2015541096A patent/JP2016505350A/ja active Pending
  • 2013-11-04 WO PCT/EP2013/072923 patent/WO2014072249A1/de active Application Filing
  • 2013-11-04 AU AU2013343699A patent/AU2013343699B2/en not_active Expired - Fee Related
  • 2013-11-04 EP EP13791765.4A patent/EP2917287A1/de not_active Withdrawn
  • 2013-11-04 BR BR112015009915A patent/BR112015009915A2/pt not_active IP Right Cessation
  • 2013-11-04 KR KR1020157014865A patent/KR20150083111A/ko not_active Application Discontinuation
  • 2013-11-04 RU RU2015121544A patent/RU2015121544A/ru not_active Application Discontinuation
  • 2013-11-04 CN CN201380057711.6A patent/CN104769047A/zh active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events