WO1997031952A1

WO1997031952A1 - Sterically stabilized non-aqueous dispersion and coating material made from it

Info

Publication number: WO1997031952A1
Application number: PCT/EP1997/000833
Authority: WO
Inventors: Lazaros Vogdanis; Arno Schmitz
Original assignee: Ppg Industries, Inc.
Priority date: 1996-02-28
Filing date: 1997-02-21
Publication date: 1997-09-04
Also published as: AU1793697A; CN1213392A; CA2247140A1; AU706657B2; EP0883656A1; DE19607435A1; TR199801711T2; JPH11512780A

Abstract

The invention concerns a coating material containing: a) a sterically stabilized non-aqueous dispersion produced by reacting, in an organic solvent in the presence of a dispersion stabilizer, at least one epoxy resin (A) containing an average of at least two epoxy groups per molecule with at least one diol (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D-Ph- (II) in which Ph- is a phenylene group and D a methylene or propylene group, and optionally with a further reagent (C) containing groups which react with epoxy or hydroxy groups, and b) at least one cross-linking agent and, optionally, solvents, pigments, fillers and other auxiliaries and additives, the diol (I) being in the form of a non-aqueous dispersion which is sterically stabilized by a stabilizer containing isoprene or a compound derived from polyisoprene.

Description

Sterically stabilized, non-aqueous dispersion, and coating compositions based thereon

The present application relates to a sterically stabilized, non-aqueous dispersion and a coating agent based on this dispersion.

The present application also relates to a process for the preparation of the dispersion mentioned, the coating composition and its use for the coating of packaging.

To produce a can for use as packaging material, in particular for packaging foodstuffs, sheets of tinplate, chromated steel and aluminum are coated in the form of sheets or strips. The lacquer layer acts as a protective layer, on the one hand to protect the metal against attack by the filling material and the resulting corrosion, and on the other hand to prevent the filling material from being influenced by corrosion products of the metal. Of course, the lacquer layer itself, for example by detached lacquer components, must not influence or impair the contents, neither in the case of food packaging after filling performed sterilization of the contents during the subsequent storage of the packed goods. In the case of technical packaging, it is often a matter of chemically reactive or aggressive filling goods, against which the lacquer layers should also be resistant. Furthermore, the lacquers must be constructed in such a way that they withstand the mechanical stresses which arise during the further processing of the coated metal sheets into cans, for example during the shaping, stamping, flanging and beading of the metal sheets.

Typically, the so-called gold lacquers based on one or more epoxy resins and one or more phenolic resins are used as internal protective coatings for sheet metal packaging. A disadvantage of these coating agents usually used, however, is the low solids content of generally 30 to 40% by weight.

Furthermore, EP-A-321 088 discloses a process for producing a sterically stabilized, non-aqueous dispersion of a polyepoxide, in which polybutadiene is used as the dispersion stabilizer. A disadvantage of this method is the limited production of dispersions with a defined structure. The need for improvement in this process is the incorporation of additional resins. In addition, various properties of the coatings produced using the dispersions, such as flexibility, porosity and resistance to acidic test solutions, such as 1% lactic acid or 3% acetic acid, are in need of improvement. Finally, the layer thicknesses of the applied coating agent are too high. Adequate sterilization resistance and freedom from pores, especially in acidic media can only be achieved with at least 7-8 g / m ² , while the requirements for can coating today are less than 5 g / m ² .

Furthermore, from German patent application P 44 23 309.4 a process for the production of a sterically stabilized, non-aqueous dispersion of a polyepoxy resin and its use in coating compositions for the interior coating of packaging are known. However, the addition of phenolic resins to the coating compositions is not described in this application.

Finally, German patent application P 44 41 684 discloses a coating agent based on a sterically stabilized, non-aqueous dispersion and phenolic resins. Polybutadiene serves as the dispersion stabilizer. The same disadvantages occur here as with the product according to EP-A-321088.

The present invention is therefore based on the object of a coating composition comprising a) a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule in an organic solvent in the presence of a dispersion stabilizer with at least one diol (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D- Ph- (II), in which - Ph- is a phenylene and D is a methylene or a propylene group, and optionally reacted with a further component (C) which has groups which are reactive toward epoxy or hydroxyl groups, and b) the coating agent contains at least one crosslinking agent. The coating composition should have as high a solids content as possible and the requirements that are usually imposed on the interior painting of cans coating agents used are met. These coating compositions should therefore have, for example, good application properties and ensure good adhesion, good flexibility and good sterilization resistance and freedom from pores in the resulting coatings. In addition, the coating agent should be simple and inexpensive to manufacture.

This object is surprisingly achieved by a coating agent which is characterized in that the compound (I) is in the form of a non-aqueous dispersion which is sterically stabilized by a stabilizer which contains isoprene or a component derived from polyisoprene.

The present application also relates to a process for the preparation of the coating compositions based on a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups in an organic solvent in the presence of a dispersion stabilizer per molecule with at least one diol (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D-Ph- (II), in which - Ph- is a phenylene and D is a methylene or a propylene group and, if appropriate, is reacted with a further component (C) which has groups which are reactive toward epoxy or hydroxyl groups, and the coating composition contains at least one crosslinking agent.

This process is characterized in that the reaction of the diol (B) and possibly component (C) with the epoxy resin component (A) in A steric dispersion stabilizer is present, which comprises isoprene or a component derived from polyisoprene.

The invention further relates to a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol (B) of the formula HOROH in an organic solvent in the presence of a dispersion stabilizer (I) in which R is a group of the formula -Ph-D- Ph- (II), in which - Ph- is a phenylene and D is a methylene or a propylene group, and optionally with a further component (C) which has groups reactive towards epoxy or hydroxyl groups is reacted, characterized in that the compound (I) is in the form of a non-aqueous dispersion which is sterically stabilized by a stabilizer which contains isoprene or a component derived from polyisoprene.

The invention accordingly also relates to a process for the preparation of a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol in an organic solvent in the presence of a dispersion stabilizer (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D-Ph- (II), in which - Ph- is a phenylene and D is a methylene or a propylene group, and optionally with a further component (C) which has groups which are reactive toward epoxy or hydroxyl groups is reacted, characterized in that the reaction of the diol (B) and possibly component (C) with the epoxy resin component (A) in the presence of a steric Dispersion stabilizer takes place, which contains isoprene or a component derived from polyisoprene.

The sterically stabilized, non-aqueous dispersion is preferably prepared in a one-step process. Alternatively, the dispersion can also be produced in a two-stage process.

In the first stage of the process, the epoxy resin component (A) with at least one diol (B) and optionally component (C) is converted into a reaction product containing phenolic hydroxyl groups as end groups with a phenoxy equivalent weight of at least 246, preferably at least 642, particularly preferably of 642 to 26,500. The amounts of epoxy resin component (A) and diol (B) are preferably chosen so that 1 equivalent of epoxy resin component (A) is reacted with 3 to 1.001 equivalents, preferably 1.5 to 1.01 equivalents, of at least one diol (B), up to 100% by weight of component (B) can be replaced by component (C). 0 to 20% by weight of component (C) is preferably present in component (B).

The reaction of the epoxy resin component (A) with the diol (s) (B) and optionally (C) in the first stage of the process preferably takes place in that the epoxy resin (s), the diol (s) and (C) optionally Dispersion stabilizer and the solvent are combined and slowly heated with stirring. It is preferably heated to temperatures between 80 and 140 ° C. At this slightly elevated temperature, it is preferred to disperse for some time first. Thereafter, the catalyst is added if necessary and heated to the desired reaction temperature. The reaction of the epoxy resin with the diol and possibly (C) usually takes place at a temperature between 120 and 250 ° C., preferably at a temperature between 160 and 180 ° C.

In addition, however, in the first stage of the process it is also possible to initially introduce the epoxy resin component (A) with the solvent and the dispersion stabilizer and to disperse the epoxy resin component by stirring and, if appropriate, gentle heating, preferably to temperatures between 80 and 140 ° C. The dispersion can then be heated to the desired reaction temperature and the diol (B) and optionally (C) added.

In a second stage, 50 to 100, preferably 80 to 100% of the phenolic hydroxyl groups contained in the reaction product obtained in stage (1) are then reacted with further epoxy resin component (A) and / or component (C). In the second stage, 50 to 100, preferably 80 to 100% of the phenolic hydroxyl groups contained in the reaction product obtained in stage (1) are preferably reacted with further epoxy resin component (A).

The reaction with the epoxy resin component and / or possibly further modifying components (C) is preferably carried out by slowly adding the epoxy resin and possibly the further modifying components slowly at an elevated temperature, preferably at a temperature of 60 to 120 ° C. It is also possible to add the epoxy resin component in step (2) of the process all at once. After the end of the epoxy resin addition or addition of the modifying components, catalyst is preferably added again and the temperature is increased, preferably to values between 160 and 180 ° C. Then the reaction is continued until the desired degree of conversion is reached.

In addition, however, it is also possible to add the epoxy resin component and / or the further modifying components (C) at room temperature to the phenoxy-terminated product obtained in stage (1) of the process, then to heat them to a temperature of from 120 to 180 ° C., to disperse them and continue the reaction until the desired degree of conversion is reached.

Finally, the invention is directed to use for coating packaging.

It is surprising and was not foreseeable that the coating compositions produced using the new dispersion stabilizer have good application properties despite a very high solids content and at the same time also meet the other requirements which are normally placed on coating compositions for the interior coating of packaging. The coatings produced from the coating compositions according to the invention have good adhesion and good flexibility, good resistance to sterilization and freedom from pores. In particular, these coating compositions can be used to produce films with a lower layer thickness than those produced using polybutadiene dispersion stabilizers in accordance with EP-A-321088, and are resistant to sterilization and non-porous. This can easily be achieved with layer thicknesses of <5 g / m ² . It is also advantageous that the coating compositions are simple and inexpensive to produce. Finally, it is advantageous that the coatings have a high degree of non-pores. The components used to produce the coating compositions of the invention are now explained in more detail below:

Epoxy resins (A) suitable for producing the non-aqueous dispersion of the polyepoxide used according to the invention are epoxides with an average of at least 2 epoxy groups per molecule. Epoxy resins which are liquid at room temperature are preferably used as component (A). Epoxy resins with a

Epoxide equivalent weight of 150 to 450, preferably from 170 to 192, used.

Aromatic epoxy resins (A) are particularly suitable for use, but aliphatic and araliphatic epoxy resins (A) are also suitable. As

Examples are diglycidyl ethers of polyphenols, diglycidyl ethers of

Dialcohols and diglycidyl esters of dicarboxylic acids called. Diglycidyl ethers of polyphenols, in particular diglycidyl ethers of

Bisphenol A, and epoxidized novolak resins, particularly preferably epoxy resins based on bisphenol A, are used. Mixtures of different epoxy resins can of course also be used. Furthermore, it is also possible - provided that there are two stages - in the

Stage (1) and stage (2) use different epoxy resins (A).

In particular, it is possible to use epoxy resins (A) with a functionality <2, that is to say for example also monoepoxides, in stage (2).

Suitable epoxy resins (A) are, for example, the products commercially available under the following names Bisphenol A base:

Epikote ^R 828 from Shell-Chemie; DER ^R 330 and 333 from Dow Chemicals; GY ^R 250 from Ciba-Geigy.

Also suitable are, for example, the products commercially available under the following names based on epoxidized novolak resins: XPY 307 and EPN 1139 from Ciba-Geigy and DEN ^R 438 from Dow Chemicals.

The polyepoxides of the formula (4) are also suitable.

A'θBO (A ² OBO) _a A '(4).

where a is a number such that the epoxy equivalent weight is in the range from 350 to infinity, B is a group of the formula (2) and A is hydrogen or a group of the formula (6),

wherein n is 1 to 4 and A ^{2 is} a group of the formula (7),

wherein n has the same meaning as in formula (6), or A ^{1 represents} hydrogen or a group of formula (9),

^{y χ ό} and A "is a group of the formula (10),

or A represents hydrogen or a group of the formula (12),

^Ö

where D is a methylene group or a propane-2,2-diyl group and b is 0 to 2, and A ^{2 is} a group of the formula (13), -CH (13)

where D and b have the same meaning as in formula (12).

In further embodiments, A ^{1 is} hydrogen or a group of the formula (12), A ^{2 is} a group of the formula (13) and D is the group propane-2,2-diyl and b is 0.1 to 1. Furthermore A ¹ can be hydrogen or a group of the formula (6), A ^{2 can be} a group of the formula (7) and n can be 4. The compound having at least two epoxy groups is preferably an epoxy novolak compound.

The epoxy equivalent weight is in the range from 350 to 50 (). () () (), Preferably in the range from 350 to 250,000, very particularly preferably in the range from 350 to 25,000.

Other suitable compounds are the epoxides described in Karsten, Lackrohstoffabatten, 9th edition, chapter 31, sections 31.1 and 31.2.

To prepare the non-aqueous dispersion of the polyepoxide, diols (B) of the formula HOROH (I) are used, in which R is a group of the formula - Ph-D-Ph- (II), in which Ph is a phenylene and D a Is methylene or a propylene group.

Bisphenol A is preferably used as diol (B). Possibly. Small amounts, preferably less than 20% by weight, particularly preferably from 1 to 15% by weight, of the diol (B) and / or the epoxy resin component (A) can be replaced by other components (C) which have the epoxy resin component (A) or - if working in two stages - are reacted with the reaction product obtained in stage (1). In particular, difunctional compounds are used as component (C). By using these further compounds (C), the physical properties of the resulting polyepoxide resins can be specifically improved.

For example, adipic acid, sebacin or dimer fatty acid or other flexibilizing components can be incorporated as component (C) for the reaction with the epoxy resin. Polyester, polyacrylates, diamines and fatty acid amides can also be used for this. If the two-stage process is used, component (C) is preferably implemented in stage (1).

The reaction of the diol (B) and possibly the component (C) with the epoxy resin component (A) takes place in the presence of a steric dispersion stabilizer.

A steric dispersion stabilizer is a compound having a part associated with the epoxy resin to be stabilized (commonly referred to as an anchor component) and a part associated with the solvent (usually referred to as a solvated component).

Suitable dispersion stabilizers are (co) polymers of isoprene or components derived therefrom. Accordingly, too Copolymers of isoprene and butadiene can be used. The stabilizer is preferably present as a solvated component.

The proportions of the isoprene are 1 to 99% by weight, preferably 10 to 70% by weight, and those of the polybutadiene 1 to 99% by weight, preferably 30 to 90% by weight.

The dispersion stabilizers can be used in such a way that the anchor component is based on an acrylic polymer. Suitable acrylate polymers are homopolymers and copolymers of (meth) acrylic acid alkyl esters (e.g. polymethyl methacrylate,

Polyethyl methacrylate, polymethyl acrylate, polyethyl acrylate,

Polyethylacrylate / Polyethylmethacrylat u.a.) and copolymers of (meth) acrylic acid alkyl esters and methacrylic and / or acrylic acid, the proportion of copolymerized (meth) acrylic acid usually being less than 10% by weight. Small proportions of other ethylenically unsaturated monomers may also be polymerized into the copolymers, for example small amounts of crotonic acid, isocrotonic acid, maleic acid and / or alkyl esters of these acids.

The dispersion stabilizers can be prepared by the methods usually used, for example by reacting the polymer desired as the anchor component with the polymer desired as the solvated component (e.g. derived from the polyisoprene).

Solvents which do not dissolve the resulting polyepoxide are used in particular to prepare the non-aqueous dispersion, for example non-polar organic solvents. Aliphatic hydrocarbons which may contain up to 20% by weight of other solvents, for example aromatic hydrocarbons, such as xylene and Solvesso ^R 150, are preferably used as solvents.

High-boiling aliphatic hydrocarbons, in particular those with a boiling point between 120 and 280 ° C., are preferably used as solvents. Examples of suitable solvents are Hydrosol ^R P 230 EA from Deutsche Hydrocarbures GmbH, Exxold 240 to 270, Norpar ^R 12 and Isopar ^R M from Deutsche Exxon Chemical GmbH.

When using the two-stage process, the amount of solvent is preferably chosen so that the reaction of the diol (B) with the epoxy resin component (A) (stage (1)) with a dispersion solids content of 20 to 80 wt .-%, preferably from 50 to 70% by weight and the reaction of the reaction product from stage (1) with the diol (B) (stage (2)) at a dispersion solids content of 25 to 85% by weight, preferably 55 to 75% by weight becomes.

The reaction of the diol (B) with the epoxy resin component (A) is preferably carried out in the presence of a catalyst. Suitable catalysts are, for example, alkali metal carbonates, such as potassium and sodium carbonate, alkali metal hydroxides, such as sodium and potassium hydroxide, quaternary ammonium salts, amines, such as dibenzylamine, and trialkylphosphonium salts, such as e.g. Triphenylethylphosphonium iodide and triphenylethylphosphonium acetate. Is preferred as a catalyst

Triphenylethylphosphonium iodide used. The non-aqueous dispersions obtained in the manner described above are combined with a phenolic resin or a mixture of phenolic resins as crosslinking agents in order to produce the coating compositions according to the invention.

Phenolic resins which are preferably used are reaction products of phenol, substituted phenols and bisphenol-A with formaldehyde, which have preferably been prepared under alkaline conditions. Under such conditions, the methylol group is linked to the aromatic ring either ortho or para.

Lower alcohols, for example ethanol, propanol, butanol and isobutanol, are used as etherification alcohol for the methylolic hydroxyl groups, n-butanol preferably being used as etherification alcohol.

Low-viscosity phenolic resins are particularly preferably used to prepare the coating compositions. In particular, phenolic resins are used whose 50 to 70% solutions have a viscosity at 20 C of less than 1000 mPas, preferably from 300 to 900 mPas.

Examples of phenolic resins suitable as crosslinking agents are the products commercially available under the following trade names:

Phenodur ^R resins, such as, for example, Phenodur ^R PR 285 from Hoechst AG

Epikure ^R resins, such as Epikure ^R DX-200-N-60, from Shell Chemicals Bakelite ^R resins, such as Bakelite ^R 7576 LB, from Rütgerswerke AG Uravar ^R resins, such as Uravar ^R FB 209, from DSM Varcum ^R resins, such as Varcum ^R 2890, from Reichold Chemie GmbH.

The products commercially available under the following names are very particularly preferably used to prepare the coating compositions according to the invention:

SFC 123 from Schenectady Europe S.A. SFC 112 from Schenectady Europe S.A.

The coating compositions according to the invention can also contain other binders, e.g. Contain epoxy resins, polyester resins, polyacrylate resins or polyurethane resins.

In addition to the solvent used to prepare the non-aqueous dispersion, the coating compositions according to the invention may also contain further solvents. Examples of suitable further solvents are aromatic, aliphatic and cycloaliphatic hydrocarbons, such as, for example, Solventnaphta ^R , various Solvesso ^R and Shellsol ^R types, deasol and various white spirits. These further solvents are used in such an amount that the total solvent content of the coating compositions (ie including the solvent content of the non-aqueous dispersion and possibly of the phenolic resin) is 30 to 50% by weight.

The further solvent can be used to set a viscosity which is favorable for the application of the coating compositions and / or to increase the phenolic resins and / or pigments or fillers. Organic and inorganic pigments, such as titanium dioxide, iron oxides and diarylides, are also suitable for use in the coating compositions according to the invention. However, the coating compositions are preferably used unpigmented.

Also suitable for use in the coating compositions according to the invention are customarily used fillers, such as, for example, talc, mica, kaolin, chalk, quartz powder, slate powder, barium sulfate, various silicas, silicates and the like. However, coating compositions which contain no or only transparent fillers are preferred.

In addition, the coating compositions of the invention can also contain customary auxiliaries and additives, such as e.g. Contain leveling agents, wetting agents, defoamers, PVC-free plasticizers (e.g. adipic acid esters), wax (e.g. polyolefin waxes, carnauba waxes, beeswax, lanolin wax) and crosslinking catalysts (e.g. acid catalysts such as phosphoric acid solutions and p-toluenesulfonic acid solutions).

The coating compositions according to the invention preferably contain

30 to 60% by weight, preferably 35 to 50% by weight, of one or more non-aqueous dispersions according to the invention and

5 to 30% by weight, preferably 15 to 20% by weight, of one or more phenolic resins, wherein the percentages by weight are based in each case on the total weight of the coating composition and the solids content of the non-aqueous dispersion and of the phenolic resin.

The coating compositions also contain, if appropriate, further solvents and, if appropriate, further binders, if appropriate pigments and / or fillers and, if appropriate, conventional auxiliaries and additives in customary amounts. In addition to the sterically stabilized, non-aqueous dispersion and the phenolic resin, the coating compositions according to the invention particularly preferably comprise 0 to 40% by weight of further binders, 30 to 50% by weight of solvent (including the solvent content of the non-aqueous dispersion), 0 to 50% by weight of pigments and / or fillers and 1 to 10% by weight of conventional auxiliaries and additives.

The coating compositions are usually prepared by first preparing the non-aqueous dispersion of a polyepoxy resin and then adding the phenolic resin and, if appropriate, solvents, optionally pigments, optionally fillers and, if appropriate, customary auxiliaries and additives, and if necessary by dispersing them the coating agent are processed.

The coating compositions are preferably used for coating packaging, in particular for coating food packaging. The packaging can consist of a wide variety of materials and have a wide variety of geometries. The materials in particular black plate, tin plate and various iron alloys, which may be provided with a passivation layer based on nickel, chromium and zinc compounds. The packaging can be in the form of, for example Half-can parts, i.e. hulls and lids, as 3-part cans and as 2-part, stretched deep-drawn or otherwise deep-drawn cans, such as beverages and food cans, are coated.

The coating compositions of the invention harden in

Object temperature range from 150 to 400 C over a period of 2 s to 15 min. They can be applied by rolling, knife coating, brushing, spraying, flooding or dipping by means of conventional devices, the film then being cured to form a permanent coating. The coating compositions are preferably applied by roller application.

The invention will now be explained in more detail on the basis of exemplary embodiments. All information on parts and percentages are weight information unless expressly stated otherwise.

Production of a dispersion stabilizer

In the inlet 1

8,961 parts of methyl methacrylate and

0.572 parts methacrylic acid

weighed in and mixed.

In the inlet 2

0.191 parts of tert-butyl per-2-ethylhexanoate weighed in and mixed

Then be

14.185 parts of xylene

9.445 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range C15-C17 with a boiling range between 230 and 265 ° C (commercial product Hydrosol ^R P 230 EA from Deutsche Hydrocarbures GmbH)

9.529 parts of a commercially available, solvent-free polymer

Based on polyisoprene with a weight average molecular weight of approx. 40,000 (commercial product Isolene 40 S from Hermann ter Hell 6 Co. GmbH, Hamburg)

mixed and heated to 125 ° C with stirring. Then feed 1 and feed 2 are metered in simultaneously but separately. The feed 1 is within 90 min. and inlet 2 within 100 min. added. The temperature is kept at 125 ° C. for 1 hour. Then 4.702 parts of xylene are distilled off under a slight vacuum. Then be

52.383 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range Cl 5-C 17 with a boiling range between 230 and 265 ° C (commercial product Hydrosol ^R P230 EA from Deutsche Hydrocarbures

GmbH) added dropwise within 30 min at a temperature of 125 ° C. Then it is cooled.

The dispersion obtained has a solids content (90 min. 180 ° C.) of 18.4% and an acid number of 22.2 mgKOH / g and a viscosity (ICI plate / cone viscometer, 23 ° C.) of 0.4 dPas .

Preparation of a non-aqueous dispersion

35, 554 parts of a commercially available liquid epoxy resin based

Bisphenol A with an epoxide equivalent of 186 and a molecular weight of 350-380 (commercial product Epikote ^R 880 from Shell Chemie) 19.321 parts of bisphenol A and 29.333 parts of the dispersion stabilizer described above and

15.682 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range C15-C17 with a boiling range between 230 and 265 ° C (commercial product Hydrosol ^R P230EA from Deutsche Hydrocarbures GmbH)

are weighed in a 4 1 steel reactor and heated to 120 ° C. with slow stirring (approx. 80 revolutions per minute). Then the stirring speed is increased to 300 revolutions per minute and dispersed for 1 hour. Then be

0.110 parts of phosphonium ethyl triphenyl iodide as a catalyst added and the temperature increased to 170 ° C. It is held at this temperature until the epoxy equivalent weight is 3700. It is then cooled and the product is filtered through a nylon mesh (mesh size 30 μ.m).

The dispersion obtained has a solids content (90 nm in 180 ° C.) of 60.0% and a viscosity (ICI plate / cone viscometer, 23 ° C.) of 1.6 dPas. The dispersion obtained in this way has a storage stability at 23 ° C. of more than 30 days.

Examples 1 to 4

The components listed in Table 1 are processed into homogeneous coating compositions by stirring.

The properties of the resulting coating compositions 1 to 4 are shown in Table 2.

These coating compositions 1 to 4 are now applied in one layer to tinplate E 2.8 / 2.8 and baked for 12 minutes at a circulating air temperature of 200 ° C. The properties of the resulting coating are shown in Table 3.

Table 1

1 2 3

NAD ^υ 73.5 66.5 69

SFC123 ²⁾ 26.5

SFC112 (65% in butanol) ²⁾ 26.2

Epicure DX X) ³ * 26.5

Hydrosol EA230 ⁴⁾ 7 4.5

Butyl titanate (10% in Solvesso 150) 0.3

Solids (15 min. 20 () ° C) 58% 56% 59% viscosity (DIN- 4mm / 20 ° C) 40 s 50 s 60 s

Wedgebend test 28mm 43mm 60mm

Color light gold gold light gold lacquer coating 5g / m ² 5g / m ² 5g / m ²

Explanations to Table 1:

1) Non-aqueous dispersion of a polyepoxy resin described above 2) Product from Schenectady Europe SA, phenolic resin based on butylphenol and formaldehyde. 3) Epikure ^R DX-200-N-60 from Shell Chemicals, a commercially available resol-phenol-formaldehyde resin, 60% in n-butanol, with a viscosity / Brookfield) at 25 ° C from 450 - 800 mPas 4) Hydrosol Table 2: Sterilization properties of the coated according to the examples

1 to 4 (assessment: water absorption / porosity)

1 2 3 4

Water 0/0 0/0 0/0 0/0

3% NaCl 0 / 0-1 0 / 1-2 0 / 0- 1 0 / 0-1

3% acetic acid 0/1 0/3 0/2 0/2

2% NaCl, 3% acetic acid 0 / 0-1 0/1 -2 0 / 0- 1 0 / 0-1

2% lactic acid 0/1 0/2 0 / 1-2 1 / 1-2

0.5 g / 1 cysteine 0/0 0/2 0/0 0 / 0-1

Marbling 2 0-1 0-1 0-1

Explanations to Table 2:

The resistance to sterilization was determined by sterilizing the coated sheets (99 mm) in an autoclave at 129 ° C. for 60 minutes and exposure to water or 3% saline solution (3%

NaCl) or 3% acetic acid (3% HAc) or 2% acetic acid and 3% saline solution or 1% lactic acid (lactic acid) or cysteine solution

(0.5 g cysteine / 1 water). Following the sterilization, the test panels were loaded with copper sulfate solution (10% copper sulfate, 10% concentrated hydrochloric acid) during an exposure time of 3 minutes

Room temperature. The liability was then assessed in accordance with DIN 53

151, a visual assessment of water intake (number before

Slash) and the porosity (number after the slash) according to the following rating scale: 0 = very good 5 = very bad.

The assessment of the sulfur resistance (marbling) was carried out according to the regulation in the packaging circular 28 (1977), 7, techn.-wiss. Supplement, page 58.

Examples of the mixtures according to the invention using component (C)

Example 5

35.764 parts of a commercial epoxy resin based on bisphenol A with an epoxide equivalent of 186 and a molecular weight of 350-380 (commercial product Epikote 880 from Shell Chemie) 12.971 parts of bisphenol ol

29.606 parts of the dispersion stabilizer described above

5,751 parts of sebacic acid

15.794 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range C 15-C 17 with a boiling range between 230 and 265 ° C (commercial product hydrosol

P230EA from Deutsche Hydrocarbures GmbH) 0.1 1 1 parts of phosphonium ethyl triphenyl iodide as a catalyst

are weighed in a 41 steel reactor and heated to 120 ° C. with slow stirring (80 revolutions / min.). Then it becomes the

Stirring speed to 300 revolutions / min. increased and dispersed for 1 h. Increase the temperature further to 170 ° C. Hold at this temperature until an EEW of 3700g / mol is reached. It is then cooled and the product is filtered through a nylon mesh (30 m mesh). The dispersion obtained has a particle size (90 min 180 C) of 60% and a viscosity (ICI plate / cone viscometer 23 ° C) of 2.1 dPas

Example 6

29, 134 parts of a commercial epoxy resin based on bisphenol A with an epoxide equivalent of 186 and a molecular weight of 350-380 (commercial product Epikote 880 from Shell Chemie) 8.045 parts of Pripol 1013

are weighed in a steel reactor and heated with stirring. Then add

0.008 parts of phosphonium ethyl triphenyl iodide as a catalyst

and raised the temperature to 165 ° C. Maintain this temperature until an EEW of 290g / mol is reached. Then cool to 60 ° C and

12,642 parts of bisphenol A

27.057 parts of the dispersion stabilizer described above

23.032 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range C15-C 17 with a boiling range between 230 and 265 ⁿ C (commercial product Hydrosol P230EA from Deutsche Hydrocarbures GmbH 1) and

0.082 parts of phosphonium ethyl triphenyl iodide as a catalyst

add and raise the temperature to 120 ° C with slow stirring. (80

Revolutions / min) Then the Ruhr speed is reduced to 300 revolutions / min. increased and dispersed for 1 h. The temperature continued to 170 ^nC increase. Hold at this temperature until an EEW of 3700g / mol is reached. It is then cooled and the product is filtered through a nylon mesh (30 m mesh).

The dispersion obtained has a solids content (90min. 180 ° C.) of 55% and a viscosity (ICI plate / cone viscometer, 23 ° C.) of 1.5 dPas.

Example 7

In this example, component C is included with a 100% share:

38.384 parts of a commercial epoxy resin based on bisphenol A with an epoxide equivalent of 186 and a molecular weight of 350-380 (commercial product Epikote 880 from Shell Chemie) 29.076 parts of the dispersion stabilizer described above

13.373 parts of adipic acid

19.048 parts of a commercially available mixture of paraffinic and naphthenic hydrocarbons in the range C15-C17 with a boiling range between 230 and 265 ° C (commercial product Hydrosol P230EA from Deutsche Hydrocarbures GmbH)

0.119 parts of phosphonium ethyl triphenyl iodide as a catalyst

are weighed in a 41 steel reactor and heated to 120 ° C. with slow stirring (80 revolutions / min.). Then the stirring speed is increased to 300 revolutions / min. increased and dispersed lh. Increase the temperature further to 170 ° C. Hold at this temperature until an EEW of 3700g / mol is reached. It is then cooled and the product is filtered through a nylon mesh (30 m mesh). The dispersion obtained has a solids content (90 min. 180 ° C.) of 57%

Claims

Claims:

1. Coating composition comprising a) a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol (B) in an organic solvent in the presence of a dispersion stabilizer Formula HOROH (I), in which R is a

Group of the formula -Ph-D-Ph- (II), in which Ph- is a phenylene and D is a methylene or a propylene group, and optionally with a further component (C), the groups reactive towards epoxy or hydroxyl groups has, is implemented, and b) at least one crosslinking agent and, if appropriate. solvents, pigments,

Fillers and customary auxiliaries and additives such that compound (I) is in the form of a non-aqueous dispersion which is sterically stabilized by a stabilizer which contains isoprene or a component derived from polyisoprene.

2. A process for the preparation of a coating composition based on a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol in an organic solvent in the presence of a dispersion stabilizer (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D- Ph- (II), in which Ph- is phenylene and D is methylene or Is propylene group, and optionally reacted with a further component (C) which has groups which are reactive towards epoxy or hydroxyl groups, and at least one crosslinking agent and, if appropriate, solvents, pigments, fillers and customary auxiliaries and additives are added to the coating compositions thus obtained are characterized in that the reaction of the diol (B) and possibly the component (C) with the epoxy resin component (A) is carried out in the presence of a steric dispersion stabilizer which comprises isoprene or a component derived from polyisoprene.

3. Coating agent according to claim 1 or method according to claim 2, characterized in that the crosslinking agent contains one phenolic resin or more phenolic resins.

4. Coating agent or method according to one of claims 1 to 4, characterized in that the coating agent

30 to 60% by weight, preferably 35 to 50% by weight, of one or more non-aqueous dispersions according to Claims 1 to 4 and

- 5 to 30 wt .-%, preferably 15 to 20 wt .-%, of one or more phenolic resins, the percentages by weight in each case based on the total weight of the coating composition and the solids content of the non-aqueous dispersion and the phenolic resin.

5. Sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol in an organic solvent in the presence of a dispersion stabilizer (B) of the formula HOROH (I), in which R is a group of the formula -Ph-D- Ph- (II), in which Ph- is a phenylene and D is a methylene or a propylene group, and optionally with one further component (C), which has groups reactive towards epoxy or hydroxyl groups, is reacted, characterized in that the compound (I) is in the form of a non-aqueous dispersion which is sterically stabilized by a stabilizer, the isoprene or one of Polyisoprene derived component.

6. Process for the preparation of a sterically stabilized, non-aqueous dispersion which can be prepared by at least one epoxy resin (A) with an average of at least 2 epoxy groups per molecule with at least one diol (B) of the formula in an organic solvent in the presence of a dispersion stabilizer HOROH (I), in which R is a

Group of the formula -Ph-D-Ph- (II), in which Ph- is a phenylene and D is a methylene or a propylene group, and optionally with a further component (C), the groups reactive towards epoxy or hydroxyl groups has, is reacted, characterized in that the reaction of the diol (B) and optionally component (C) with the epoxy resin component (A) is carried out in the presence of a steric dispersion stabilizer which comprises isoprene or a component derived from polyisoprene.

7. coating agent or non-aqueous dispersion or method according to any one of claims 1 to 6, characterized in that the non-aqueous dispersion has been prepared in that 1) the epoxy resin component (A) is reacted in a first stage (stage (1)) with at least one diol (B) and / or component (C) to form a reaction product containing phenolic hydroxyl groups as end groups and having a phenoxy equivalent weight of at least 246 has been and

2) then in stage (2) 50 to 100% of the phenolic hydroxyl groups contained in the reaction product obtained in stage (1) have been reacted with further epoxy resin component (A) and / or component (C).

8. Coating agent or non-aqueous dispersion or process according to one of claims 1 to 7, characterized in that the stabilizer is a copolymer of butadiene and isoprene.

9. coating agent or non-aqueous dispersion or method according to claim 8, characterized in that the proportion of isoprene 1 to 99 wt .-%, preferably 10 to 70 wt .-% and that of polybutadiene 1 to 99 wt .-%, is preferably 30 to 90% by weight.

10. Use of the coating compositions according to one of claims 1,3,4,6,7 to 9 for coating packaging, in particular for coating food packaging containers.