EP1844119A2

EP1844119A2 - Copolymer comprising monoethylenically unsaturated dicarboxylic acid derivatives

Info

Publication number: EP1844119A2
Application number: EP06704244A
Authority: EP
Inventors: Alexander Göthlich; Guido Vandermeulen; Helmut Witteler; Monica Fernandez Gonzalez
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2005-01-28
Filing date: 2006-01-24
Publication date: 2007-10-17
Also published as: WO2006079630A3; US20080139770A1; WO2006079630A2; BRPI0607070A2; CA2595970A1; JP2008528747A; MX2007008900A; KR20070107724A

Abstract

The invention relates to copolymers comprising dicarboxylic acid units modified by -SR, -CSNR2 and/or -CN-units and at least one other type of copolymer. A method for producing said copolymers by a polymer-analogous reaction and the use of said copolymers in the form of a corrosion inhibitor are also disclosed.

Description

Copolymer comprising derivatives of monoethylenically unsaturated dicarboxylic acids

description

The present invention relates to copolymers which comprise modified dicarboxylic acid units and at least one further comonomer. It further relates to a process for their preparation by polymer-analogous reaction and their use as a corrosion inhibitor.

Copolymers of modified maleic acid units and other comonomers are known in principle.

EP-A 244 584 discloses copolymers of modified maleic acid units and styrene or sulfonated styrene, alkyl vinyl ethers, C 2 - to C 6 -olefins and (meth) acrylamide. The modified maleic acid units have spacer groups attached to functional groups such as -OH, -OR, -PO ₃ H ₂ , -OPO ₃ H ₂ , -COOH or preferably -SO ₃ H.

EP-A 1 288 232 and EP-A 1 288 228 disclose copolymers of modified maleic acid units and other monomers such as, for example, acrylates, vinyl ethers or olefins. The modified maleic acid units are N-substituted maleic acid amides and / or imides. The N-substituents are heterocyclic compounds attached via spacers.

WO 99/29790 discloses copolymers of N-substituted maleimide units and styrene or 1-octene. The maleimide units are substituted with a piperazine unit attached via a spacer.

In conventional corrosion protection methods, several different layers are usually applied to the metallic surface. In the area of coil coating, pretreatment, for example phosphating, is usually first carried out and then overcoated with a primer varnish. One or more intermediate or topcoat layers can be applied thereon. In the case of atmospheric corrosion protection with anticorrosive coatings, a base coat, intermediate coat and top coat are usually applied.

In modern corrosion protection increasingly chromium-free corrosion protection systems are used. Furthermore, there is a requirement to simplify the layer structure described above. For this example, integrated corrosion protective layers can be used, which at least the properties of pretreatment and primer in the case of coil coating and at least the properties of base and intermediate coating in the case of atmospheric corrosion protection combine so that only one layer instead of two layers must be applied.

The object of the invention was to provide improved corrosion inhibitors, in particular for the described applications. These should be able to be used in particular for the production of integrated corrosion protection layers.

Accordingly, copolymers were found which are composed of the following structural units:

(I) 1 to 99 mol% of at least one structural unit (I) of derivatives of monoethylenically unsaturated dicarboxylic acids selected from the group of structural units (Ia), (Ib), (Ic), (Id), (Ie) and (If )

(Ia) (Ib) (Ic)

(Id) (Ie) (If) (II) 99 to 1 mol% of at least one further, of (I) different structural unit (II) from monoethylenically unsaturated monomers, and

(IM) optionally 0 to 30 mol% of at least one further structural unit (III) of other, different from (I) and (M) ethylenically unsaturated monomers,

are constructed, wherein the amounts of the monomers are each based on the total amount of all monomer units in the copolymer and the abbreviations have the following meaning:

R ¹ : (n + 1) -valent hydrocarbon group having 1 to 40 C atoms, in which non-adjacent C atoms may also be substituted by O and / or N, R ² , R ³ : independently of one another H, methyl, C2 to Cβ-alkyl, or R ² and R ³ together 1, 3-propylene or 1, 4-butylene R ⁴ : H, Cr to Cio hydrocarbon group or - (R ¹ -X ¹ _n ) M: H or a cation,

wherein X ¹ is a functional group selected from the group of -SR ⁵ , -CSNR ⁵ 2 or -CN and R ^{5 is} H or a hydrocarbon group having 1 to 6 C atoms, and wherein n is 1 , 2 or 3 stands.

In a second aspect of the invention, a process for preparing such a copolymer by polymer-analogous reaction has been found.

In a third aspect of the invention, the use of the copolymers as corrosion inhibitors has been found.

More specifically, the following is to be accomplished for the invention:

According to the invention, the copolymer is composed of 1 to 99 mol% of at least one structural unit (I), 99 mol% to 1 mol% of at least one structural unit (M) and optionally 0 to 30 mol% of structural units (IM), the quantities given in each case refers to the total amount of all incorporated into the copolymer structural units. Apart from the structural units (I), (M) and (IM), there are no further structural units. Structural units (I)

The structural units (I) are derivatives of monoethylenically unsaturated dicarboxylic acids selected from the group of structural units (Ia), (Ib), (Ic), (Id), (Ie) and (If)

(Ia) (Ib) (Ic)

(Id) (Ie) (If)

X ¹ is a functional group selected from the group of -SR ⁵ , -CSNR ⁵ 2 or -CN. R ⁵ here stands for H or a hydrocarbon group having 1 to 6 C atoms, in particular a straight-chain or branched alkyl group having 1 to 6 C atoms. It may, for example, be a methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 1-pentyl or 1-hexyl group. Preferably, R ⁵ is H or methyl, and more preferably H. Preferably, it is - CSNR 2 or -CN, and more preferably -CSNhfe. If a structural unit has several functional groups X ¹ , these may be identical or different groups X ¹ . The number n of the functional groups X ¹ is generally 1, 2 or 3, preferably 1 or 2 and more preferably 1. The group R ¹ is a spacer which connects the functional group (s) X ¹ with the remaining part of the structural unit (I). Here, R ^{1 is} an (n + 1) -valent hydrocarbon group having 1 to 40 carbon atoms, in which non-adjacent C atoms may also be substituted by O and / or N. Preference is given to hydrocarbon groups having 1 to 20 C atoms, more preferably 2 to 10 atoms, and very particularly preferably 2 to 6 C atoms. The hydrocarbon groups may be branched or preferably linear. It is preferably a 1 / »functional group.

Divalent linking groups R ¹ may preferably be linear 1, ω-alkylene radicals having from 1 to 20, preferably from 2 to 6, carbon atoms. Particular preference is 1, 2-ethylene, 1, 3-propylene, 1, 4-butylene, 1, 5-pentylene or 1, 6-hexylene. Further preferably, they may be O-atom-containing groups, for example -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ - or polyalkoxy groups of the general formula -CH ₂ -CH ₂ - [- O-CH ₂ -CH ₂ -] _m -, where m is a natural number from 2 to 13.

If the radical R ^{1 is to} bind a plurality of functional groups, in principle a plurality of functional groups can be bonded to the terminal carbon atom. In this case, however, R ¹ preferably has one or more branches in the carbon skeleton and the functional groups X ¹ are each attached terminally to the respective branches. The branching may be a C atom or, preferably, an N atom. An example of such a linking group R ¹ comprises -CH ₂ -CH ₂ -N (CH ₂ -) - ₂ .

R ² and R ³ are each independently H, methyl or C ₂ - to Ce-alkyl, in particular straight-chain alkyl chains such as ethyl, 1-propyl, 1-butyl, 1-pentyl or 1-hexyl groups. Furthermore, R ² and R ^{3 may} also be linked together; this may in particular be a 1, 3-propylene or 1,4-butylene radical. R ² and R ³ are preferably H or methyl independently of one another, and R ² and R ³ are more preferably H.

R ⁴ is H or C ¹ to C 6 alkyl or for a group -R ¹ -X ¹ _n where R ¹ and X ¹ n are as defined above. R ⁴ is preferably a group selected from H, methyl or ethyl, preferably H or methyl, and very particularly preferably H.

M is H or a cation, preferably a monovalent cation. Examples of such cations include in particular alkali metal cations such as Li ⁺ , Na ⁺ or K ⁺ . Furthermore, it may be in particular NH ₄ ⁺ and organic ammonium salts. Organic ammonium salts may be the ammonium salts of primary, secondary or tertiary amines. The organic groups in such amines may be alkyl, aralkyl, aryl or alkylaryl groups. Preference is given to straight-chain or branched alkyl groups. They may also have other functional groups. In such functional

Groups are preferably OH groups and / or ether groups. The amines can also be ethoxylated. Examples of suitable amines include linear, cyclic and / or branched C 1 -C 6 -mono-, di- and trialkylamines, linear or branched C 1 -C 6 -mono-, di- or trialkanolamines, in particular mono-, di- or trialkanolamines , linear or branched C 1 -C 6 -alkyl ethers of linear or branched C 1 -C 8 -mono-, di- or trialkanolamines, oligo- and polyamines, such as, for example, diethylenetriamine. The amines may also be heterocyclic amines such as morpholine, piperazine, imidazole, pyrazole, triazoles, tetrazoles, piperidine. It is particularly advantageous to use those heterocycles which have corrosion-inhibiting properties. Examples include benzotriazole and / or tolyltriazole.

Of course, several different structural units (Ia) to (If) may be present in a copolymer. Preference is given to either the structural units (Ia), (Ib) and (Ic) containing the amide or imide groups or the structural units (Id) and (Ie) having the ester groups.

The structural units of a kind (Ia) to (If) may each have similar functional groups X ¹ ; but they can also be different groups X ¹ . In particular, CSNhfe and CN groups can be used in combination with each other.

The amount of all structural units (I) together is preferably 10 to 90 mol%, particularly preferably 20 to 80 mol%, very particularly preferably 30 to 70 mol% and for example 40 to 60 mol%, in each case based on the total amount of all copolymerized in the copolymer structural units.

Structural units (II)

The structural units (II) are one or more of (I) different structural units (II) from monoethylenically unsaturated monomers.

In principle, these may be any monoethylenically unsaturated monomers, provided that they can be copolymerized with the monoethylenically unsaturated dicarboxylic acids or derivatives thereof based on the structural units (I). The person skilled in the art makes a suitable choice depending on the desired properties of the polymer. The monoethylenically unsaturated monomers (II) may be at least one monoethylenically unsaturated hydrocarbon (IIa) and / or one monoethylenically unsaturated hydrocarbon (IIb) modified with functional groups X ² .

(IIa)

In principle, (IIa) may be all hydrocarbons which have an ethylenically unsaturated group. It may be straight-chain or branched aliphatic hydrocarbons (alkenes) and / or alicyclic hydrocarbons (cycloalkenes). They may also be hydrocarbons which, in addition to the ethylenically unsaturated group, have aromatic radicals, in particular vinylaromatic compounds. They are preferably ethylenically unsaturated hydrocarbons in which the double bond is arranged in the α position. As a rule, at least 80% of the monomers (IIa) used should have the double bond in the α-position.

The term "hydrocarbons" is intended to also oligomers of propene or unbranched, or, preferably, branched C ₄ -. Contain up Cio-olefins which have an ethylenically un- saturated group in the Oligomers employed generally have a number average molecular weight M _n of not more than 2300 g M _n is preferably from 300 to 1300 g / mol and more preferably from 400 to 1200 g / mol Preferred oligomers are isobutene, which may optionally comprise comonomers with further C 3 - to C 10 -olefins as oligomers Based on isobutene, the general usage is to be referred to as "polyisobutene" in the following. Polyisobutenes used should preferably have a content of double bonds in the α-position of at least 70%, more preferably at least 80%. Such polyisobutenes, also referred to as reactive polyisobutenes, are known to the person skilled in the art and are commercially available.

Apart from the oligomers mentioned, particularly suitable monoethylenically unsaturated hydrocarbons having 6 to 30 carbon atoms are suitable for carrying out the present invention. Examples of such hydrocarbons include hexene, heptene, octene, nonene, decene, undecene, dodecene, tetradecene, hexadecene, octadecene, eicosane, docosane, in each case preferably the 1-alkenes, or styrene.

Preference is given to using monoethylenically unsaturated hydrocarbons having 9 to 27, particularly preferably 12 to 24, carbon atoms and, for example, 18 to 24 carbon atoms. Of course, mixtures of different hydrocarbons can be used. These may also be technical mixtures of various hydrocarbons, for example technical C2o-24 mixtures. The monoethylenically unsaturated hydrocarbons used are preferably linear or at least substantially linear. "Substantially linear" is intended to mean that any side groups are only methyl or ethyl groups, preferably only methyl groups.

Also particularly suitable are the said oligomers, preferably polyisobutene. Surprisingly, it is precisely this that can improve the processability in aqueous systems. However, the oligomers are preferably not used as the sole monomer, but in admixture with other monomers (IIa). It has proven useful not to exceed an oligomer content of 60 mol% with respect to the buzzer of all monomers (II). If present, the content of oligomers is usually 1 to 60 mol%, preferably 10 to 55 and particularly preferably 20 to 50 mol%.

(IN THE

The monoethylenically unsaturated hydrocarbons (IIb) modified with functional groups X ² may in principle be all hydrocarbons which have an ethylenically unsaturated group and in which one or more H atoms of the hydrocarbon are substituted by functional groups X ² .

It may be alkenes, cycloalkenes or aromatic alkenes. They are preferably ethylenically unsaturated hydrocarbons in which the double bond is arranged in the α position. In general, the monomers (IIb) have 3 to 30 C atoms, preferably 6 to 24 C atoms and more preferably 8 to 18 C atoms. They usually have a functional group X ² . The monomers (IIb) are preferably linear or substantially linear α-unsaturated-ω-functionalized alkenes having 3 to 30 carbon atoms and / or 4-substituted styrene.

The functional groups X ² can advantageously be used to modify the properties of the copolymer, such as, for example, its solubility in certain formulations or the adhesion to certain surfaces. The functional groups X ² are preferably at least one selected from the group of -OR ⁷ , -SR ⁷ , -NR ⁷ _2l -NH (C =O) R ⁷ , COOR ⁷ , - (C =O) R ⁷ , -COCH ₂ COOR ⁷ , - (C =NR ⁷ ) R ⁷ , - (C =N-NR ⁷ ₂ ) R ⁷ , - (C =N-NR ⁷ - (C =O) -NR ⁷ ₂ ) R ⁷ , - (C = N-OR ⁷ ) R ⁷ , -O- (C = O) NR ⁷ ,

-NR ⁷ (C = O) NR ⁷ ₂ , -NR ⁷ (C = NR ⁷ ) NR ⁷ , -CSNR ⁷ ₂ , -CN, -PO ₂ R ⁷ ₂ , -PO ₃ R ⁷ ₂ , -OPO ₃ R ⁷ ₂ , -SO 3 R ⁷ or -Si (OR ⁸ ) 3, where R ^{7 is} here in each case H, a cation, preferably a monovalent cation, or a hydrocarbon radical having 1 to 10 C atoms, preferably a C 1 to C 6 alkyl radical , R ⁸ is a d- to Cβ-Alkvlrest. X ² is particularly preferably -COOH. Examples of suitable monomers (IIb) include C ₄ to C 20 (α, ω) ethenylcarboxylic acids such as vinylacetic acid or 10-undecenecarboxylic acid, C ₂ to C ₂ o- (α, ω) -ethenylphosphonic acids such as vinylphosphonic acid , their mono- or diesters or salts, C3- to C2o-ethenylcarboxylic acid nitriles such as acrylonitrile, allylnitrile, 1-butenenitrile, 2-methyl-3-butenenitrile, 2-methyl-2-butenenitrile, 1-, 2-, 3- or 4 Pentenenitrile or 1-hexenenitrile, 4-substituted styrenes such as 4-hydroxystyrene or 4-carboxystyrene. Of course, mixtures of several different monomers (d b ') can be used. Preferably (d b ') is 10-undecenecarboxylic acid.

(Nc)

As structural units (II), it is also possible to use other monoethylenically unsaturated monomers (Mc) in addition to or instead of the monomers (IIa) and (IIb). Suitable monomers (Mc) include (meth) acrylic compounds such as (meth) acrylic acid, (meth) acrylic esters or (meth) acrylamides, in particular (meth) acrylic esters with straight-chain or branched C ₁ - to C 20, preferably C ₂ - to Ci- Alkyl radicals such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate or 2-Etyhlhexyl (meth) acrylate. They may also be (meth) acrylic esters which have additional functional groups, in particular OH-functional monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate. Examples of further monomers (Mc) include alkyl vinyl ethers such as 1,4-dimethylolcyclohexane monovinyl ether, ethylene glycol monovinyl ether, diethylene glycol monovinyl ether, hydroxybutyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether or t-butyl vinyl ether or vinyl esters such as vinyl acetate or vinyl propionate.

The amount of the structural units (M) is preferably 10 to 90 mol%, particularly preferably 20 to 80 mol%, very particularly preferably 30 to 70 mol% and for example 40 to 60 mol%, in each case based on the total amount of all structural units copolymerized in the copolymer ,

(Nd)

The structural units (M) can furthermore be structural units (Nd) from underivatized, monoethylenically unsaturated dicarboxylic acids or their anhydrides of the general formulas (I'g) and / or (I'h)

(i'g) (l'h)

be act, wherein R ² , R ³ and M have the meaning described above.

(Ne]

The structural units (II) can furthermore be structural units (Me) which correspond to the definition of the structural units (Ia) to (If) but which have X ¹ instead of the functional group and a functional group other than X ¹ X ³ acts. In particular, the functional group X ^{3 may} be one selected from the group of -OR ⁷ , -NR ⁷ ₂ , -NH (C = O) R ⁷ , COOR ⁷ , - (C = O) R ⁷ , -COCH ₂ COOR ⁷ , - (C =NR ⁷ ) R ⁷ , - (C =N-NR ⁷ ₂ ) R ⁷ , - (C =N-NR ⁷ - (C =O) -NR ⁷ ₂ ) R ⁷ ,

- (C = N-OR ⁷ ) R ⁷ , -O- (C = O) NR ⁷ , -NR ⁷ (C = O) NR ⁷ ₂ , -NR ⁷ (C = NR ⁷ ) NR ⁷ , -PO ₂ R ⁷ ₂ , -PO ₃ R ⁷ ₂ , -OPO ₃ R ⁷ ₂ , -SO ₃ R ⁷ or -Si (OR ⁸ ) ₃ , wherein R ⁷ and R ^{8 are} as defined above. Preferred as additional functional groups here are -OH, SO ₃ H or -PO ₃ H.

The structural units (II) are preferably the monomers (IIa) and / or (IIb), more preferably the monomers (IIa) or a mixture of (IIa) and other monomers (II). Preferred in a mixture are the monomers (IIb). If a mixture is present, the amount of the monomers (IIa) is preferably at least 40 mol% with respect to the sum of all monomers (II). Depending on the nature of the preparation of the polymer, monomers of the type (Md) are usually present as well.

Structural units (IM)

The copolymers according to the invention may additionally contain from 0 to 30 mol%, preferably from 0 to 10 mol%, particularly preferably from 0 to 5 mol% and very particularly preferably from 0 to 3 mol% of other ethylenically unsaturated monomers containing (I) and (M ) different but copolymerizable with (I) and (M) are included as building blocks. Such monomers may be used, if necessary, to fine tune the properties of the copolymer. Most preferably, no monomers (Ml) are included. Examples of monomers (IM) include compounds comprising multiple double bonds. These may be hydrocarbons having conjugated double bonds, such as butadiene or isoprene. Furthermore, it can also be crosslinking monomers having two or more isolated ethylenically unsaturated double bonds. However, the copolymers according to the invention should not be crosslinked too much. If crosslinking monomers are present, their amount should generally not exceed 5 mol% with respect to the sum of all monomers, preferably 3 mol% and particularly preferably 2 mol%.

Preparation of the copolymers

The preparation of the copolymers according to the invention can preferably be carried out by means of a polymer-analogous reaction.

In this process, a copolymer of unmodified, monoethylenically unsaturated dicarboxylic acids or salts thereof and the monomers (II) and optionally (IM) is provided in a first step. Instead of the dicarboxylic acids, it is also possible to use reactive derivatives of the dicarboxylic acids, for example the corresponding dicarboxylic acid halides or, in particular, dicarboxylic acid anhydrides. Preferably, the anhydrides of cis-dicarboxylic acids can be used, and particularly preferred is maleic anhydride. The copolymers used as starting material have structural units (Md1) and / or preferably (Md2). Such copolymers are also commercially available.

The preparation of unmodified polymers as starting material can be carried out in particular by means of radical polymerization. The implementation of a radical polymerization is known in principle to the person skilled in the art. The polymerization is preferably carried out using thermally decomposing polymerization initiators, but it can of course also be carried out photochemically. As solvents for the polymerization it is possible to use aprotic solvents such as toluene, xylene, aliphatics, alkanes, benzene or ketones. If long-chain monoethylenically unsaturated hydrocarbons are used as monomers, which have a higher boiling point, in particular those having a boiling point of more than about 150 ⁰ C, it is also possible to work without a solvent. The unsaturated hydrocarbons themselves act as solvents.

The radical polymerization with thermal initiators can be at 60-250 ⁰ C, preferably 80-200 ⁰ C, most preferably at 100- 180 ⁰ C and in particular at 130 to 170 ⁰ C are performed. The amount of initiator is from 0.1 to 10% by weight, based on the amount of monomers, preferably from 0.2 to 5% by weight and more preferably from 0.5 to 2% by weight. As a rule, an amount of about 1 wt.% Is recommended. The polymerization time is usually 1 to 12 hours, preferably 2 to 10 hours and more preferably 4 to 8 hours. The copolymers can be isolated from the solvent by methods known to those skilled in the art or, alternatively, are obtained directly without solvent.

After preparation of the unmodified copolymer as starting material, the copolymerized dicarboxylic acid units, preferably the corresponding dicarboxylic anhydride and more preferably the maleic anhydride in a polymer-analogous reaction with functional alcohols of the general formula HO-R ¹ -X ¹ _n (1) and / or functional amines of general formula HR ⁴ NR ¹ -X ¹ _n (2) are reacted, wherein R ¹ , R ⁴ , n and X ^{1 have} the meaning given above. These are preferably 1, ω-functional compounds where n = 1. Examples of compounds (1) and (2) include linear 1-amino-ω-nitriloalkanes of the general formula H ₂ N - (- CH ₂ -) k-CN, such as H ₂ N - (- CH ₂ -) ₆ -CN or H ₂ N - (- CH ₂ -) ₄ -CN, where k is 1 to 20, preferably 2 - 6. Further examples include HO - (- CH ₂ -) _k -CN, H ₂ N - (- CH ₂ -) _k -CSNH ₂ , HO - (- CH ₂ -) _k -CSNH ₂ , eg HO-CH ₂ -CH ₂ -CSNH ₂ , HO - (- CH ₂ -) _k -SH, eg HO-CH ₂ -CH ₂ -SH or H ₂ N - (- CH ₂ -) _k -SH.

The reaction can be carried out in bulk or preferably in a suitable aprotic solvent. Examples of suitable aprotic solvents include in particular polar aprotic solvents such as acetone, methyl ethyl ketone (MEK), dioxane or THF and, if appropriate, nonpolar hydrocarbons such as toluene or aliphatic hydrocarbons.

For the reaction, the unmodified copolymer may be initially introduced in the solvent, for example, and then the desired functional alcohol HO-R ¹ -X ¹ _n (1) and / or the desired functional amine HR ² NR ¹ -X ¹ _n (2) in the desired Men - be added ge. The reagents for functionalization may conveniently be previously dissolved in a suitable solvent. The derivatization is preferably carried out with heating. Temperatures have proven to be useful here from 30 to 150 ^° C., preferably from 40 to 130 ^° C., and more preferably from 60 to 120 ^° C. The reaction times are from 2 to 25 h. When using primary amines, the corresponding amides are preferably obtained at temperatures of up to 100 ⁰ C, while at higher temperatures increasingly imides are formed. At 130 to 140 ⁰ C already predominantly imides are obtained. Preferably, the formation of imide structures should be avoided.

The amounts of reagents used (1) and (2) for the functionalization depends on the desired degree of functionalization. An amount of from 0.5 to 1.5 equivalents per dicarboxylic acid unit, preferably from 0.6 to 1.2, more preferably from 0.8 to 1.1, and most preferably about 1 equivalent, has proven useful.

If the modified copolymer still has unreacted anhydride groups, these can be opened hydrolytically in a second step. This can be done, for example, by adding water and base to the organic solution, followed by vigorous stirring. For this purpose, a temperature of not more than 100 ^° C., for example 80 to 100 ^° C., has proven suitable.

Of course, it is also possible to use mixtures of a plurality of functional alcohols HO-R ¹ -X ¹ _n (1) and / or ammonia or the functional amines HR ² NR ¹ -X ¹ _n (2). Likewise, reaction sequences are possible in which first reacted with a functional alcohol or amine and after the reaction, a further functional amine or alcohol is added.

The obtained organic solutions of the modified copolymers can be used directly for the formulation of organic crosslinkable preparations. Of course, the polymer can be isolated from this but also by methods known in the art.

For incorporation into aqueous formulations, it is expedient to add water to the solution and to separate the organic solvent by means of methods known to the person skilled in the art, for example by distilling off.

The resulting copolymers can also be completely or partially neutralized. The pH of the copolymer solution should generally be at least 6, preferably at least 7, in order to ensure sufficient water solubility or dispersibility. Examples of suitable bases for neutralization include ammonia, alkali and alkaline earth hydroxides, zinc oxide, linear, cyclic and / or branched C 1 -C 6 -mono-, di- and trialkylamines, linear or branched C 1 -C 6 -mono-, di- or trialkanolamines, in particular Mono-, di- or trialkanolamines, linear or branched C 1 -C 6 -alkyl ethers of linear or branched C 1 -C 6 -mono-, di- or trialkanolamines, Oligo- and polyamines such as diethylenetriamine. The base can be used subsequently or advantageously even in the hydrolysis of anhydride groups.

The molecular weight M _{w of} the copolymer is selected by the person skilled in the art according to the desired use. A M _{w of} from 1000 to 100000 g / mol, preferably from 1500 to 50 000 g / mol, more preferably from 2000 to 20 000 g / mol, very particularly preferably from 3000 to 15 000 g / mol and, for example, from 8000 to 14000 g / mol, has proven useful.

The polymer-analogously functionalized base polymer generally has a plurality of structural units (Ia) to (Ic), (Id) and (Ie), (If) and optionally unfunctionalized groups (Ig ^' ) and (I ^' ) next to one another. The quantitative ratio of the structural units is determined by the type of difunctional compounds (1) or (2) used, the selected quantitative ratio of polymer to the difunctional compounds and the reaction conditions. Of course, imide units can only form when R ⁴ is H, with higher reaction temperatures generally favoring the formation of imide groups.

In an alternative synthetic route, ethylenically unsaturated, unmodified dicarboxylic acids or dicarboxylic acid derivatives, preferably dicarboxylic acid anhydrides and particularly preferably cis-dicarboxylic anhydrides and the functional alcohols HO-R ¹ -X ¹ _n (1) and / or or the functional amines HR ⁴ NR ¹ -X ¹ _n (2) derivatized, monomeric dicarboxylic acids are synthesized. Subsequently, these derivatized monomers can be polymerized together with the other monomers as described above.

Thioamidgruppen-containing copolymers can also be prepared by first producing nitrile polymers and after the polymerization, the nitrile groups in a manner known in the art with hfeS to thioamide groups. The reaction with the hfeS can advantageously be carried out in the presence of a base. It can be made, for example, using a pressure apparatus and methanol as a solvent. The degree of conversion can be determined, for example, by means of ¹³ C-NMR spectroscopy by comparing the intensity of the CN and CSNhfe signals.

Use of the polymers

The polymers according to the invention can be used for a wide variety of purposes, for example as corrosion inhibitors, incrustation inhibitors, adhesion promoters or dispersants. They are particularly suitable for use as corrosion inhibitors. In particular, the type and amount of the structural units (I) and (II) and optionally (IM) allow the properties of the polymer to be optimally adapted to the respective intended use. For example, polymers which are compatible with organic solvents or with water or aqueous solvents can be synthesized. For aqueous systems, a proportion of the structural units (I) of not less than 40 mol% is recommended. Furthermore, as monomers (IIb) hydrophilic modified monomers, such as hydroxystyrene or styrenesulfonic acid can be used for this purpose.

The copolymers according to the invention can be used, for example, as corrosion inhibitors or incrustation inhibitors in aqueous systems, for example cooling water circuits.

They are particularly suitable for the production of formulations for corrosion protective coatings or coatings. These may be formulations for atmospheric corrosion protection as well as formulations for coil coating applications. They are formulated for this purpose with suitable binder systems, pigments or fillers and optionally solvents and other additives. In this case, an amount of 0.1 to 40 wt.%, Preferably 0.2 to 20 wt.% And particularly preferably 0.5 to 10 wt.%, Each based on the amount of all components of the formulation, has proven.

The described formulations can be applied to any metallic surfaces; but they are particularly suitable for the protection of iron, steel, zinc, Zinkegierungen, aluminum or aluminum alloys.

Suitable binder systems for coil coating applications are, for example, thermosetting systems based on epoxy resins, polyurethanes and acrylate dispersions, which cure at elevated temperatures, typically at temperatures above 100 ^° C. Furthermore, it is also possible to use photochemically crosslinkable systems. The formulations can be applied, for example, by dipping or rolling on metal strips and then cured by heating or irradiation.

Suitable binder systems for atmospheric corrosion protection are, for example, atmospheric-curing binder systems based on polyacrylates, styrene-acrylate copolymers, styrene-alkadiene polymers, polyurethanes or alkyd resins. For example, the formulations can be applied to the metallic surface, eg, the surface of steel structures, by brushing or spraying. The applied layers then cure in contact with the atmosphere.

The following examples are intended to explain the invention in more detail.

Part A - Synthesis of the copolymers used

Part I - Synthesis of starting materials Copolymers with anhydride groups

Copolymer A

Copolymer of MSA / Ci ₂ -olefin / C _20-2 4-olefin (molar ratio 1 / 0.6 / 0.4)

In a 1500L pressure reactor with anchor stirrer, temperature control and nitrogen inlet 36.96 kg of C _20-2 4-olefin are pumped in at 60 ⁰ C and sucked 31, 48 kg of n-dodecene-1. The original is heated to 150 ⁰ C. Then, feed 1, consisting of 1.03 kg of di-tert-butyl peroxide, and feed 2, consisting of 30.57 kg of molten maleic anhydride, are metered in over the course of 6 hours. After the end of feed 1 and 2 is stirred at 150 ⁰ C for 2 h. At 150-200 mbar then acetone and t-butanol are distilled off.

Copolymer B

Copolymer of maleic anhydride / C ₂ olefin / polyisobutene 1000 (molar ratio 1 / 0.8 / 0.2)

In a 2L pilot agitator with anchor stirrer and internal thermometer are 600.0 g

(0.6 mol) highly reactive polyisobutene (α-olefin content> 80%) with a M _n of

1000 g / mol (Glissopal ^® 1000, Fa. BASF) and 322.5 g (1, 92 mol) Ci ₂ olefin under Rüh- ren and nitrogen gassing at 150 ⁰ C heated. Then within 6 h, a feed 1, consisting of 294.0 g of maleic anhydride (80 ⁰ C, 3.0 mol), and feed 2, consisting of 13.0 g of di-t-butyl peroxide (1% based on monomers) and 80.6 g (0.48 mol) of Ci _2- olefin added. After the end of feed 1 and 2 are stirred at 150 ⁰ C for a further 2 h. A solid yellowish polymer is obtained. Part II Functionalization of Copolymers

General Test Procedure 11-1

In a 2I pilot agitator with anchor stirrer and internal thermometer, the respectively desired maleic anhydride-olefin copolymers A or B are initially charged in an organic solvent and sparged with nitrogen. Then, 1 equivalent of the respectively desired hydroxy- or amino-functional compound (1) or (2) are added dropwise at y ⁰ C within x hours.

Solvent Exchange:

Following the derivatization, an exchange of the organic solvent for water can be carried out. For this purpose, the product is mixed with water and base to the desired pH. Subsequently, the organic solvent is distilled off under reduced pressure.

General Test Procedure II-2:

The desired maleic anhydride / olefin copolymer A or B and 1 equivalent of the respectively desired hydroxy- or amino-functional compound (1) or (2) are introduced into a 2 l pilot stirrer with anchor stirrer and internal thermometer, are sparged with nitrogen, and for x Stirred at y ⁰ C for hours. Subsequently, the product is taken up in a suitable organic solvent.

Following derivatization, replacement of the organic solvent with water may be carried out as described.

Further details on the polymers used in each case, the hydroxy- or amino-functional compound (I) or (II) used and the properties of the derivatized copolymers obtained are listed in Table 2.

The derivatized products were each analyzed by NMR spectroscopy. The spectra show that in each case the OH or NH 2 groups reacted with the carboxyl functions.

Table 2: Copolymers derivatized with functionalized alcohols (1) or amines (2) DMEA: dimethylethanolamine, MEK: methyl ethyl ketone, BG: butyl glycol

Part B - Performance Tests

Performance tests were carried out with the non-derivatized and derivatized maleic acid-olefin copolymers obtained.

Tests were carried out in 3 different coil coating lacquers based on epoxides, acrylates and polyurethanes.

Basic formulation for Coil Coating (organic) based on epoxy binders

For the formulation for the preparation of an integrated pretreatment layer, the following components were used:

The components were mixed in a suitable mixing vessel in the order given and predispersed with a dissolver for ten minutes. The resulting mixture was transferred in a bead mill with cooling jacket and mixed with 1, 8-2.2 mm SAZ glass beads. The millbase was ground for 1h 30 'minutes. Subsequently, the ground material was separated from the glass beads.

The millbase was added with stirring in the order given, 5.9 parts by weight of a blocked hexamethylene diisocyanate (Desmodur ^® VP LS 2253 from. Bayer AG) and 0.4 parts by weight of a commercially available tin-free crosslinking catalyst (Borchi ^® VP 0245, Fa. Borchers GmbH) , Base formulation for coil coating paint (aqueous) based on acrylate binder

The crosslinkable binder used was an anionic amine-stabilized aqueous acrylate dispersion (solids content 30% by weight) of the following main monomers n-butyl acrylate, styrene, acrylic acid and hydroxypropyl methacrylate.

In a suitable stirred vessel 5 parts by weight of a leveling agent with defoamer, 5.5 parts by weight of a melamine resin as crosslinking agent (Luwipal 072 ^®, BASF AG) were mixed in the order given, 18.8 parts by weight of acrylate, 4.5 parts by weight of a dispersing additive, 1, , 0.2 parts by weight of a hydrophilic fumed silica (Aerosil® 200V from Degussa), 3.5 parts by weight of Finntalk M5 talc, 12.9 parts by weight of titanium rutile 2310 titanium pigment, 8.0 parts by weight of acrylate dispersion, 3.5 parts by weight of calcium ion-modified silica (Shieldex ^® from Grace Division), 4.9 parts by weight of zinc phosphate (Sicor ^® ZP-BS-M company Waardals Kjemiske factories), 1.2 parts by weight Black pigment (SICOMIX ^® Black from BASF AG) were mixed with a dissolver for ten Minutes predispersed. The resulting mixture was transferred in a bead mill with cooling jacket and mixed with 1, 8-2.2 mm SAZ glass beads. The millbase was ground for 45 minutes. Subsequently, the millbase was separated from the glass beads.

The millbase was added with stirring in the order given with 27 parts by weight of the acrylate dispersion, 1.0 parts by weight of a defoamer, 3.2 percent of a blocked sulfonic acid, 1, 5 parts by weight of a defoamer and 1.0 parts by weight of a flow control.

Basic formulation for Coil Coating (aqueous) based on polyurethane binders:

As crosslinkable binder, an aqueous polyurethane dispersion (solids content 44% by weight, acid number 25, M _n about 8000 g / mol, M _w about 21000 g / mol) based on polyester diols as soft segment (M _n about 2000 g / mol), 4,4'-

Bis (isocyanatocyclohexyl) methane and monomers with acidic groups and chain extenders used.

In a suitable stirred vessel 5 parts by weight of a leveling agent with defoamer, 5.5 parts by weight were in the order given, 18.8 parts by weight of the polyurethane dispersion, 4.5 parts by weight of a dispersing additive, 1, of a melamine resin as crosslinking agent (Luwipal ^® 072, BASF AG), 0 , 2 parts by weight of a hydrophilic fumed silica (Aerosil® 200V from Degussa), 3.5 parts by weight of Finntalk M5 talc, 12.9 parts by weight of titanium rutile 2310 white pigment,

8.0 parts by weight of the polyurethane dispersion, 3.5 parts by weight of calcium ion-modified silica (Shieldex® from Grace Division), 4.9 parts by weight of zinc oxide phosphate (Sicor® ZP-BS-M from Waardals Kjemiske factories), 1.2 parts by weight black pigment (Sicomix® Black from BASF AG) and predispersed with a dissolver for ten minutes. The resulting mixture was transferred into a bead mill with cooling jacket and mixed with 1.8-.2 mm SAZ glass beads. The millbase was ground for 45 minutes. Subsequently, the ground material was separated from the glass beads.

The millbase was added with stirring in the order given with 27 parts by weight of the polyurethane dispersion, 1, 0 parts by weight of a defoamer, 3.2 percent of an acidic catalyst (blocked p-toluenesulfonic acid, Nacure ^® 2500), 1, 5 parts by weight of a defoamer and 1, 0 Parts by weight of a flow aid offset.

Addition of the copolymers of the invention

In each case, 5% by weight of the above-described derivatized copolymers (calculated as solid copolymer with respect to the solid components of the formulation) were added to the described coil coating lacquers. For the organic paint based on epoxides, the abovementioned solutions of the copolymers in butyl glycol were used for this purpose, for the aqueous coatings based on acrylates or epoxides, the described aqueous solutions or emulsions used.

Coating of steel and aluminum sheets

For the coating trials, galvanized steel plates of grade Z (OEHDG 2, Chemetall) and aluminum plates AIMgSi (AA6016, Chemetall) were used. These were previously purified by known methods.

The coil coating paints described with the aid of bar knives applied in such a wet layer thickness that after curing in a continuous dryer at a circulating air temperature of 185 ⁰ C and an object temperature of 171 ⁰ C coatings resulted in a dry film thickness of 6 microns.

For comparative purposes, coatings were also prepared without the addition of the copolymers.

In order to test the corrosion-inhibiting effect of the coatings according to the invention, the galvanized steel plates were subjected to the VDA climate change test (VDA Prüfblatt 621-415 Feb 82) for 10 weeks.

In this test (see graph below), the samples are first subjected to a salt spray test for one day (5% NaCl solution, 35 ° C) and then (Rel 40 ⁰ C, 100%. Humidity) 3 x alternately moist air and dry air (22 ° C, 60% rel. Humidity) exposed. One cycle is completed by a 2-day dry kl imaphase. One cycle is shown schematically below.

Initial Condensation water test Room condition

Salt spray test

1 day 1 day 1 day 1 day 1 day 2 days (8h / 16h) (8h / 16h) (8h / 16h) (8h / 16h)

1 week = 1 cycle

A total of 10 such load cycles are performed sequentially.

After completion of the corrosion load, steel plates were visually evaluated by comparison with given standards. Both the formation of corrosion products on the undamaged surface and the tendency to infiltrate edge and ritz were assessed.

The evaluation of the samples is based on a comparison with the comparative sample without the addition of the corrosion-inhibiting copolymers.

The corrosion-inhibiting effect of the steel plates was further carried out by a salt spray test according to DIN 50021.

The acetic acid salt spray test ESS (DIN 50021, Jun 88) was carried out on aluminum plates. After completion of the corrosion load, the panels were visually evaluated. The circular softening was evaluated over the entire paint surface.

For all tests, the paint layers were scored; in the case of steel plates through the zinc layer down to the steel layer.

The following grades were awarded for the evaluation of the samples:

0 Corrosion damage as in the blank sample + less corrosion damage than in the blank sample

++ much less corrosion damage than the blank sample more corrosion damage than the blank sample The results of the test are shown schematically in Tables 3 to 5.

Table 4: Corrosion tests with copolymers with derivatized dicarboxylic acid units

The examples show that with the novel polymers with derivatized dicarboxylic acid units, an improvement in the corrosion protection properties of the CoN coating paints can be achieved. The improvement occurs on at least one of the two substrates aluminum or steel, as a rule it is observed on both substrates.

Although the polymers modified in the comparative experiment with phosphonic acid groups (2 per dicarboxylic acid unit) lead to an improvement in the coating of galvanized steel, they lead to a deterioration of aluminum.

Claims

claims

1. Copolymer composed of the following structural units:

(Ia) (Ib) (Ic)

(Id) (Ie) (If)

(II) 99 to 1 mol% of at least one further, of (I) different structural unit (II) from monoethylenically unsaturated monomers, and

(IM) optionally 0 to 30 mol% of at least one further structural unit (IM) of other, different from (I) and (M) ethylenically unsaturated monomers, wherein the amounts of the monomers are each based on the total amount of all monomer units in the copolymer and the abbreviations have the following meaning:

R ¹ : (n + 1) -valent hydrocarbon group having 1 to 40 C atoms, in which non-adjacent C atoms may also be substituted by O and / or N, R ² , R ³ : independently of one another H, methyl, C ₂ to C 6 alkyl, or R ² and R ³ together 1, 3-propylene or 1, 4-butylene R ⁴ : H, Cr to Cio hydrocarbon group or - (R ¹ -X ¹ _n )

M: H or a cation,

characterized in that X ¹ is a functional group selected from the group of -SR ⁵ , -CSNR ⁵ ₂ or -CN and R ^{5 is} H or a hydrocarbon group having 1 to 6 C atoms, and wherein n is 1, 2 or 3.

2. A copolymer according to claim 1, characterized in that R ² and R ³ is H.

3. A copolymer according to claim 1 or 2, characterized in that X ¹ is -CSNH ₂ .

4. A copolymer according to claim 1 or 2, characterized in that X ¹ is -CN.

5. A copolymer according to claim 1 or 2, characterized in that X ¹ is -SH.

6. A copolymer according to any one of claims 1 to 5, characterized in that the copolymer comprises as monomer (II) at least one monoethylenically unsaturated hydrocarbon (IIa) and / or modified with functional groups X ² monoethylenically unsaturated hydrocarbon (IIb).

7. A copolymer according to claim 6, characterized in that the monoethylenically unsaturated hydrocarbon (IIa) and / or (IIb) has 6 to 30 carbon atoms.

8. A copolymer according to claim 6 or 7, characterized in that the copolymer further comprises 1 to 60 mol%, based on the amount of all monomers (II), of at least one reactive polyisobutene.

9. A copolymer according to any one of claims 1 to 8, characterized in that the amount of structural units (I) 30 to 70 mol% and the amount of structural units (II) is 70 to 30 mol%.

10. A process for the preparation of a copolymer in which the starting material is an unmodified copolymer composed of 1 to 99 mol% of structural units (I Id 1) and / or (I Id2) of unmodified monoethylenically unsaturated dicarboxylic acids, their salts or anhydrides,

(Ild1) (Ild2)

and 99 to 1 mol% of at least one further, different from (I) structural unit (II) of monoethylenically unsaturated monomers, and optionally 0 to

30 mol% of at least one further structural unit (IM) from other, different from (I) and (II) ethylenically unsaturated monomers, and the unmodified copolymer with difunctional alcohols HO-R ¹ -X ¹ _n (1) and / or difunctional amines HR ⁴ NR ¹ -X ¹ _n (2) to give a modified copolymer, the amounts of the monomers being based in each case on the total amount of all monomer units in the copolymer and the abbreviations having the following meanings:

characterized in that X ¹ is a functional group selected from the group of -SR ⁵ , -CSNR ⁵ 2 or -CN and R ^{5 is} H or a hydrocarbon group having 1 to 6 C atoms, and wherein n is 1, 2 or 3.

11. Process according to claim 10, characterized in that an unmodified copolymer is used in which the dicarboxylic acid units are present essentially as anhydride units (Ild2).

12. The method according to claim 10 or 11, characterized in that R ² and R ³ is H.

13. The method according to any one of claims 10 to 12, characterized in that the numerical ratio of the difunctional compounds (1) and / or (2) to the dicarboxylic acid or dicarboxylic anhydride 0.5 to 1.5.

14. A copolymer obtainable by a process according to any one of claims 10 to 13.

15. Use of copolymers according to any one of claims 1 to 9 and 14 as corrosion inhibitors.

16. Use according to claim 15, characterized in that the corrosion inhibitor is used as an additive to a coil coating lacquer.

17. Use according to claim 15, characterized in that the corrosion inhibitor is used as an additive to a paint or coating formulation for atmospheric corrosion protection.

18. Use of copolymers according to any one of claims 1 to 9 and 14 as an additive to aqueous systems.