DE19720292C1 - Radiation-cured coating material, especially for cans - Google Patents

Abstract

The present invention provides a radiation-curable coating material comprising at least one radiation-curable binder having at least two acrylic ester and/or methacrylic ester groups, which comprises (a) as binder (a) a mixture of (a1) at least one binder (a1) having at least two acrylic ester and/or methacrylic ester groups and having an elongation at break of at least 20 %, preferably at least 40 %, and (a2) at least one further binder (a2) which is different from (a1) and has at least two acrylic ester and/or methacrylic ester groups, (b1) at least one silicone-containing lubricant (b1) and (b2) at least one halogen-containing polyolefin wax (b2). The invention also provides for the use of this coating material for producing multicoat paint systems, especially as a clearcoat or as a topcoat, and to its use for coating glass metal substrates, especially for coating packaging containers.

Description

The present invention relates to a radiation curable coating composition containing at least one radiation-curable binder with at least two Acrylic acid ester and / or methacrylic acid ester groups.

The invention also relates to the use this coating agent for the production of more layer coatings, in particular as a clear coat or as Top coat, as well as the use for coating Glass and metal substrates, especially for coating processing of packaging containers.

As a packaging container (hereinafter also called a container called) come in particular glass bottles and Glasbe containers and metal containers, such as. B. two and three partial beverage cans and cans, for use. Such packaging containers are outside with a decorative coating. This coating has on the one hand the task of ge packaging containers to protect against the mechanical stresses the packaging containers both in their manufacture as also during the filling process of the filling goods as well during transportation and distribution of the filled Packaging containers are exposed. So rub the ver packaging containers, for example on the conveyor belts to each other and come with the guide rails at Transport in touch. The outside coating of packaging made of both glass and metal coating agents used in containers therefore have the highest possible scratch resistance in order to so the packaging containers in front of these strong mechani  strain, z. B. on the conveyor belts, protect effectively.

On the other hand, there is also high gliding ability the coated packaging container necessary to a smooth process in the high speed to ensure ongoing filling equipment.

This required lubricity of the Be layers, for example by measuring the so-called simulated mobility of the coatings. The measurement mobility is measured by measuring the glide resistance via a ball bearing. Be measured relative values from 0 to 0.25. The smaller the value is the better the gliding ability. Mobi are welcome lities of less than 0.09.

The measurement of scratch resistance is carried out in the laboratory for example with a so-called Dur-O tester leads. A metal pin is used with a spring a certain force pressed onto the coating and then passed over the coated surface. Is measured the spring force that is needed to damage it to achieve the paint surface. The higher these measured values the better the scratch resistance. He wishes are values of at least 7 N.

In the case of packaging containers made of metal The applied coatings must be applied at the same time a high level of flexibility and high scratch resistance lity. Metal packaging containers are named Lich usually made by first Metal sheets or strips with the desired coating tion and the already coated banks the or sheets to the appropriate containers be prepared. During these deformation steps but no damage to the coating occurs because  otherwise the protective function of the coatings mentioned above is no longer given.

Nowadays, very high throughput speeds are achieved on modern coating systems for metal containers. Belt speeds of more than 100 m / min require highly reactive paints, which, for. B. must be curable in UV applications with a dose of 200 mJ / cm ² to 280 mJ / cm ² .

In addition to the protective function, the coating agents have but also an increasingly important decorative function to fulfill. Many are coated in white beforehand Containers printed with printing ink and then with Overcoated clear coats. The used Clear varnishes not only meet the required chemical stocks abilities, e.g. B. in the sterilization of the filled Ver packaging container, meet, but also by good ver running surfaces with precisely adjusted gloss convey drawn brilliance. Self-coloring or ver Yellowing of the clear coats must be excluded.

Glass bottles as well as metal Packaging containers with plastic coatings too provided, also describing the need such plastic coatings on-line immediately to apply after the production of the glass bottles. In international patent applications WO 90/05 031 and WO 90/05 088 is the production of transparent Coatings on glass containers described one high gloss and abrasion resistance. Before the The transparent coatings can be applied to the Glass containers as well as metal packaging containers Inscriptions and labels to be attached protected by the coatings. As a coating agent become solvent-based, through ultraviolet radiation  curable lacquers used on acrylic basis. These paints are sprayed on, and the solvent is evaporated off and the remaining coating by ultraviolet light is hardened.

From DE-A-41 30 682 is the coating of glass body known with radiation-curable paints. Likewise mentions the adhesion-improving effect of silanes. The application process uses formulations used where the necessary for spraying low viscosity over acrylic acid derivatives and low molecular compounds with hexanediol diacrylate or TMP-Tri acrylate is set. These substances are toxic logically questionable and therefore undesirable.

Finally, laminates are from DE-A-195 27 667.1 known for the production of coated glass products, at an adhesive to the glass surface layer of silane and at least one layer of applied a radiation-curable coating agent and then hardened both layers together will. Radiation-curable coating agents with a required for the coating of metal containers however, there is great flexibility in this application not described.

The present invention is therefore the object reasons to provide coating agents, which is suitable for the coating of glass as well as me talluntergrund are suitable and those of such Coating agents usually made requirements gene. In particular, this coating should means lead to coatings that have a high scratch strength and good gliding at the same time high flexibility, the subsequent deformation of the enables coated substrates. About that  In addition, the coating agents should be as possible possess high reactivity to get them off painting lines to be able to use high process speed.

When using the coating agent for the coating The packaging should be used for packaging containers medium also the rack usually in this area meet requirements. Furthermore, the resul coatings have good chemical resistance speed, especially a good sterilization and pasteu resistance to risk.

Surprisingly, this object is achieved by a coating agent of the type mentioned, which is characterized in that it

• (a) as a binder (a) a mixture of
  • (a1) at least one binder (a1) with at least two acrylic acid ester and / or meth acrylic acid ester groups and with an elongation at break of at least 20%, preferably of at least 40%, and
  • (a2) at least one further binder (a2) which is different from (a1) and has at least two acrylic acid ester and / or methacrylic acid groups,
• (b1) at least one silicone-containing lubricant (b1) and
• (b2) at least one halogen-containing polyolefin wax (b2)

contains.

The invention also relates to the use this coating agent for the production of more layer coatings, in particular as a clear coat or as  Top coat, and their use for coating Glass and metal substrates, especially for coating processing of packaging containers.

It is surprising and was not foreseeable that the Coating agents have a high reactivity and to coatings with good scratch resistance and Lead mobility with high flexibility at the same time that the coating compositions of the invention both for the coating of glass containers as well as for the loading Layering of metal sheets or metal plates that finally processed into packaging containers, can be used. It is also advantageous that the resulting coatings are good chemicals resistance, especially a good sterilization and Resistance to pasteurization. Finally stand out the non-aqueous Be invention layering agent by a high non-volatile Portion, preferably a non-volatile portion of more than 90 wt .-%, based on the total weight of the Coating agent.

In the following, the individual stocks are now first parts of the coating agent according to the invention closer explained.

It is essential to the invention that the coating compositions at least one binder (component (a1)) with at least at least 2 acrylic esters and / or methacrylic esters groups and with an elongation at break of at least 20%, preferably of at least 40%.

The elongation at break is defined as the elongation (Elongation) of a test specimen (here free film) to to the appearance of cracks. The stretch will be for example using the Zwick OPM 1425 tester  Zwick GmbH & Co., Ulm, measured. The measurement is based on DIN 53 457 and DIN 53 455.

The free films used to measure the elongation at break are produced in a manner known to the person skilled in the art by first, for example, a glass plate (size 10 cm × 15 cm) or another substrate on which the coating agent does not adhere, such as, for. B. Polypro pylene or Teflon, taped on the left and right edge with Tesa film strips (type 4104) and the binder to be tested is knife-coated in the form of a solution with a wet film thickness of approx. 40 µm. The film is then cured by means of UV radiation using a mercury vapor lamp (incident energy generally 400-800 mJ / cm ² ) and stored at 23 ° C. for 1 day. Then the Tesa film strips are removed and z. B. with a Cuttermes serklinge 4 strips (1.5 cm wide and 13-14 cm long) cut out. The layer thickness of the hardened strips is then measured using a fine probe. The measurement of the elongation at break (elongation in% of the specimen up to the appearance of cracks, based on the original length) takes place, for. B. with the test device Zwick OPM 1425 from Zwick GmbH & Co., Ulm at a train speed of 12.5 mm / min and a force before 0.05 N. The average of at least 6 measurements is given in each case.

Component (a1) includes, for example, polyether acrylic latex, polyester acrylates, epoxy acrylates, urethane acrylates and the corresponding methacrylates. The ge required high elongation at break of at least 20% before pulls at least 40%, is in these binders in the person skilled in the art by appropriate selection of the structural components of the binder.  

Polyester (meth) acrylates are known to the person skilled in the art and can be produced by various methods. For example can directly use acrylic acid and / or methacrylic acid Acid component used in the construction of the polyester will. There is also the option of hydroxyalkyl ester of (meth) acrylic acid as alcohol component directly to use in the construction of the polyester. To be favoured the polyester (meth) acrylates but by acrylating Polyesters made. For example, first hydroxyl-containing polyesters are built up then reacted with acrylic and / or methacrylic acid the. It can also initially contain carboxyl groups Polyester are built up, which is then with a hydroxy alkyl ester of acrylic and / or methacrylic acid implemented will. Unreacted (meth) acrylic acid can pass through Wash out, distill, or preferably by reacting with an equivalent amount of a mono- or diepoxide connection using suitable catalysts, such as B. triphenylphosphine, from the reaction mixture be removed. For more details on Production of the polyester acrylates is particularly on DE-A-33 16 593 and DE-A-38 36 370 as well to EP-A-54 105, DE-B-20 03 579 and EP-B-2866.

Polyether (meth) acrylates are also known to the person skilled in the art knows. They are made by different methods bar. For example, hydroxyl-containing poly ether esterified with acrylic acid and / or methacrylic acid will. The polyethers containing hydroxyl groups can by reacting di- and / or polyhydric alcohol len with different amounts of ethylene oxide and / or Propylene oxide by well known methods (see e.g. Houben-Weyl, Volume XIV, 2, Macromolecular Substances II, (1963)) can be obtained. Polymers can also be used tion products of tetrahydrofuran or butylene oxide.  

Flexibilization of the polyether (meth) acrylates and the polyester (meth) acrylate is for example possible that corresponding OH-functional prepolymers or oligomers (polether or polyester base) with longer-chain, aliphatic dicarboxylic acids, in particular their aliphatic dicarboxylic acids with at least 6 C-ato such as adipic acid, sebacic acid, Dodecanedioic acid and / or dimer fatty acids, who implemented the. This flexibility reaction can be done before or after the addition of acrylic or methacrylic acid to the Oligomers or prepolymers are carried out.

Furthermore, epoxy (meth) acrylates are also known to the person skilled in the art known and therefore do not need to be explained in more detail the. They are usually made by Accumulation of acrylic acid on epoxy resins, for example on epoxy resins based on bisphenol A or others standard epoxy resins.

The epoxy (meth) acrylates are made more flexible for example analogously possible in that corresponding epoxy-functional prepolymers or oligomers with longer-chain, aliphatic dicarboxylic acids, in particular their aliphatic dicarboxylic acids with at least 6 C-ato such as adipic acid, sebacic acid, Dodecanedioic acid and / or dimer fatty acids implemented will. This flexibility reaction can occur or after the addition of acrylic or methacrylic acid the oligomers or prepolymers are carried out.

Urethane (meth) acrylates are also well known to those skilled in the art known. They can be obtained through implementation a di- or polyisocyanate with a chain ver extenders from the group of the diols / polyols and / or Diamines / polyamines and / or dithiols / polythiols  and / or alkanolamines and subsequent implementation of remaining free isocyanate groups with at least one Hydroxyalkyl (meth) acrylate or hydroxyalkyl esters and others rer ethylenically unsaturated carboxylic acids.

The amounts of chain extender, di- or poly isocyanate and hydroxyalkyl esters are preferably chosen so that

• 1.) the equivalent ratio of the NCO groups to the reactive groups of the chain extender (Hydroxyl, amino or mercaptyl groups) between 3: 1 and 1: 2, preferably 2: 1, is and
• 2.) the OH groups of the hydroxyalkyl esters in stoichio metric quantity in relation to the still free ones Isocyanate groups of the prepolymer from isocyanate and Chain extenders are present.

It is also possible to manufacture the polyurethane acrylates deliver by first part of the isocyanate groups a di- or polyisocyanate with at least one Hydroxyalkyl ester is implemented and the rest Isocyanate groups then with a chain extension resources are implemented. In this case, too the the amounts of chain extender, isocyanate and hydroxyalkyl esters are chosen so that the equivalent ratio of the NCO groups to the reactive groups of the Chain extender between 3: 1 and 1: 2, is preferably 2: 1 and the equivalent ratio the remaining NCO groups to the OH groups of the Hy hydroxyalkyl ester is 1: 1. Of course also all intermediate forms of these two processes possible. For example, part of the isocyanate groups of a diisocyanate first with a diol can be implemented, then another part  the isocyanate groups with the hydroxyalkyl ester and im The remaining isocyanate groups can be connected to this be implemented with a diamine.

These different manufacturing processes of polyurethane Acrylates are known (see, for example, EP-A-204 161) and therefore do not require a more detailed description.

The urethane (meth) acrylates are more flexible possible, for example, that corresponding iso cyanate-functional prepolymers or oligomers with longer-chain, aliphatic diols and / or diamines, in particular with aliphatic diols and / or diamines at least 4 carbon atoms, such as butanediol, hexanediol and the like or the corresponding amines. This Flexibility reaction can be done before or after Addition of acrylic or methacrylic acid to the oligomers or prepolymers are carried out.

The following commercially available products may also be mentioned as examples of suitable binders (a1):
Epoxy acrylate Crodamer UVE 150 from Croda Resins Ltd., Kent, GB;
Urethane acrylate Crodomer UVU 300 from Croda Resins Ltd., Kent, GB;
Silicone-modified polyester acrylate Crodomer UVS 500 from Croda Resins Ltd., Kent, GB;
Actilane 20/20 urethane acrylate from Akcros Chemicals Ltd., GB;
Actilane 2030 PEA urethane acrylate from Akcros Chemicals Ltd., GB;
Polyester acrylate genomer D900 from Rahn Chemie;
Polyester acrylate Genomer T1200 from Rahn Chemie;
Polyester acrylate genomer T1200 PP from Rahn Chemie;
Ebecryl 210 urethane acrylate from UCB, Drugsbos, Belgium;
Ebecryl 211 urethane acrylate from UCB, Drugsbos, Belgium;
Ebecryl 230 urethane acrylate from UCB, Arzneimittelbos, Belgium;
Ebecryl 265 urethane acrylate from UCB, Drugsbos, Belgium;
Ebecryl 270 urethane acrylate from UCB, Drugsbos, Belgium;
Poly-acrylate Ebecryl 754 from UCB, Drugsbos, Belgium;
Urethane acrylate / methacrylate Ebecryl 1265 from UCB, Arzneimittelbos, Belgium;
Urethane acrylate / methacrylate Ebecryl 1259 from UCB, Arzneimittelbos, Belgium;
Urethane acrylate Ebecryl 4833 from UCB, Arzneimittelbos, Belgium;
Urethane acrylate Ebecryl 5264 from UCB, Arzneimittelbos, Belgium.

In addition to the u.G. especially preferably used resins additionally Actilane 20/20; Crodamer UVS 500; Genomer D900, T1200 and T1200PP; Ebecryl 265, 270, 754, 5264 and 5284 and especially Crodamer UVE 150 and UVU are preferred 300; Actilane 2030PEA and Ebecryl 210, 211, 1259 and 4833.

The binder (a1) is in the Be layering agents preferably in an amount of 2.5 to 80, particularly preferably 10 to 50 wt .-%, based on the total weight of the coating agent used.

It is believed that the addition of the binder (a1) on the one hand to avoid spalling at mechani shear stress on the coatings and secondly  particularly preferred when using higher amounts at least 10 wt .-%, based on the total weight of the Coating agent, to the desired deformability of the Coatings (can production) contributes.

As a further binder component (a2) they contain Coating agents according to the invention preferably still 19.8 up to 97.3% by weight, particularly preferably 25 to 89.8% by weight, based on the total weight of the coating by means of at least one further component (a1) various binders with at least 2 acrylic acid ester and / or methacrylic acid ester groups.

If the coating agent for the coating of Substrates are used that are not very high Flexibility requirements of the resulting Coatings are made, but especially the Abrasion resistance / scratch resistance of the coatings in the foreground is how B. in the coating of Glass bottles, the binder (a1) is preferred in the smallest possible amount used and very special preferably in amounts of 2.5 to 15% by weight, based on the total weight of the coating agent used. In this case, the binder (a2) is particularly preferred preferably in an amount of 40 to 95 wt .-%, based on the total weight of the coating agent used.

If the coating agent is against the coating tion of substrates are used where very high demands on the flexibility of the result the coatings are made such. B. at Be layering of metal packaging containers, that's how it will be Binder (a1) preferably in the highest possible amounts used and very particularly preferably in amounts of 10 up to 50 wt .-%, based on the total weight of the Be layering agent. In this case the binder  (a2) particularly preferably in an amount of 40 to 80% by weight, based on the total weight of the coating medium, used. Of course, it can also this coating agent with a high proportion of (a1) for coating with respect to the Flexibi lity less demanding substrates, such as. B. glass bottles, are used.

As component (a2), for example, those in the international patent application WO93 / 21240 on the page 5, line 21, to page 10, line 18 amino group-containing binders and other amine modifi graced binders such. B. from EP-A-280 222, that of US-A-4,045,416, US-A-4,547,562 and the Known binders US-A-4,675,374 can be used.

Furthermore, others, usually in rays, can also be used binders used in curable coating materials can be used with (meth) acrylate groups. So come for example as component (a2) polyether acrylates, Epoxy acrylates, polyester acrylates, urethane acrylates and the corresponding methacrylates into consideration. This bin agents (a2) have a lower elongation at break as the binder used as component (a1) on. The binders (a2) therefore generally have a break elongation less than 20%, preferably less than 10% and particularly preferably less than 5%.

Examples are suitable components (a2) called the following binders: polyether acrylates, e.g. B. Laromer PO83 F, PO84 F, PO85 F and Laromer LR 8863 der BASF AG, Viaktin VTE 5978 from Hoechst, Sartomer 494 from Harcros, epoxy acrylates, for example Laromer LR 8765 from BASF AG, UVE 140 from Crocda Resins, or polyester acrylates, for example Laromer LR 8799 and Laromer LR PE 55 W from BASF AG, Viaktin VTE 5970 from  Hoechst and Setacure EPS 2553 from Akzo-Nobel as well as urethane acrylates, e.g. B. Viaktin 5960 and Viaktin VTE 1420 from Hoechst, Ebecryl 264 and 284 from the company UCB.

Optionally, oligomeric, ethylenically un saturated compounds, e.g. B. Tripropylene glycol diacry lat, dipropylene glycol diacrylate, hexanediol diacrylate and the like be used.

It is believed that the addition of the binder (a2) to improve scratch resistance (avoidance damage to the coating in mechanical loading stress on conveyor belts, etc.), which only by adding lubricants (components (b1) and (b2)) to this extent without generating other after parts would not be reachable.

Furthermore, it is essential to the invention that the coating at least one silicone-containing lubricant medium (b1), preferably in an amount of 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, in each case based on the total weight of the coating agent, contain.

As component (b1) are all commonly used suitable lubricant containing silicone. To be favoured but polyether-modified, silicone-containing lubricants used. These silicone-based lubricants are Known in principle specialist and therefore do not need to be explained in more detail. You are in one too Variety commercially available.

Examples of suitable compounds are those in Trade under the names Byk® 301, 306, 307 and 333 der  Byk-Chemie GmbH, Wesel, available products called.

The coating according to the invention also contains medium at least one halogen-containing polyolefin wax (component (b2)) as another, from the component (b1) various lubricants, preferably in an amount of 0.1 to 5 wt .-%, particularly preferred 0.2 to 3 wt .-%, each based on the solid hold of (b2) and the total weight of the coating by means of.

Especially for coating agents in the area of Coating of packaging containers (packaging) the component (b2) is used, for example regarding the abrasion resistance of the right resulting coatings, advantageous. Surprise therefore such waxes also increase the reactivity of the Coating agent considerably.

All can usually be used as component (b2) halogen-containing polyolefin waxes are used, for example halogen-substituted polyethylene and / or Polypropylene waxes, especially polytetrafluor ethylene waxes. Fluorine-substituted poly are preferred olefin waxes, in particular polyfluor waxes, are used.

Examples of suitable waxes are the products commercially available under the following names:
Polyfluoro waxes such as "Polyfluo 190, 400, 540 and 635 VF" from Micro Powders, INC., New York;
"Cerafluor types", such as Cerafluor 900, 910 and 930, from Byk Chemie.

The coating according to the invention preferably contains medium at least one more, from the components (b1) and (b2) different lubricants (component (b3)). Halogen-free are preferred as component (b3) Waxes, for example polyethylene and / or poly propylene waxes, waxes based on esters and the like. Organic lubricants other than Component (b3) are used.

Examples of suitable polyolefin waxes (b3) are also the products commercially available under the following names:
"Ceramat types", such as. B. Ceramat 250 from Byk Chemie;
"Cerafac types", such as. B. Cerafac 59 by Byk.

Is particularly preferred in the Be layering agents a mixture of a polyfluor wax (commercial product Polyfluo 540 from Micro Powders) and a polyolefin wax (commercial product Cerafac 59 from Byk) used.

Component (b3) is preferred in an amount of 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight, each based on the solids content of (b3) and the total weight of the coating agent used.

The binder mixture may also contain still up to 5 wt .-%, preferably 0.5 to 2.5 wt .-%, be based on the total weight of the coating material, at least one silane (component (c)).

According to the invention, a low molecular weight is preferably used Silane used. In particular, silanes come with ethyl  niche unsaturated groups or condensation products of this into consideration.

Examples of such compounds are CH ₂ = C (CH ₃ ) - COO- (CH ₂ ) ₃ -Si (OCH ₃ ) ₃ , CH ₂ = CH-Si (OCH ₃ ) ₃ , CH ₂ = CH-Si (OC ₂ H ₅ ) ₃ , CH ₂ = CH-Si (OC ₂ H ₄ -OCH ₃ ) ₃ .

The coating compositions of the invention may contain as component (d) in proportions of 0 to 6% by weight, be preferably in preparations hardened by UV rays, preferably 2 to 5 wt .-%, based on the total weight of the coating agent, customary, in radiation-curable Photoinitiators used in coating compositions for example benzophenones, benzoins or benzoin ethers. It can also, for example, the ones under the name Irgacure® 184, Irgacure® 1800 and Irgacure® 500 der Ciba Geigy and Genocure® MBF from Rahn be set.

When choosing appropriate photoinitiators, the different curing mechanisms carry. For example, photoinitiators based on benzo are required phenon and based on benzophenone derivatives in the Rule amines as synergists while on the other hand straight these amines other photoinitiators such. B. the in Photo available under the name Genocure MBF initiator, inhibit.

The counter in the coating compositions of the invention optionally in amounts of up to 15% by weight, based on the total weight of the coating agent present Fillers and / or pigments (s) can be inorganic and / or organic materials.

Exemplary for inorganic fillers and / or pig mentions include: titanium dioxide, sulfates, as in  for example barium sulfate (heavy spar) or potassium sulfate fate (light spar) or silicates, such as Kaolin, mica or quartz flour. In the inorganic Fillers and / or pigments (e) is too considered that the conceptual distinction between "Filler" and "pigment" are often difficult is because substances such as barium sulfate or Titanium dioxide, both as filler and pigment Act.

Organic fillers and / or pigments are included called playful and representative for many: soot, Azo dye pigments or phthalocyanine dye Pigments.

The coating according to the invention also contains means, if necessary, also conventional aids and / or Additives (f), for example defoamers, leveling agents tel, light stabilizers and film-forming aids, e.g. B. cellulose derivatives. These usual tools and / or additives are usually used in an amount of up to 15 wt .-%, based on the total weight of the Coating agent used.

According to the invention, it is preferred to use monomer-free or use low-monomer coating agents. The Be Layering agents (non-aqueous) therefore contain preference have a non-volatile content of more than 90% by weight (Monomer content preferably <10%).

Depending on the viscosity of the used according to the invention The coating agents may also bind smaller amounts, preferably 0 to 4% by weight, based on the total weight of the coating agent, organic Solvent (component (g)).  

Finally, the coating according to the invention medium depending on the viscosity of the invention still contain water.

In the unpublished DE-A-195 45 125.2, a method is described with which radiation-hardenable coating compositions can be converted into the aqueous phase. This method can also be used for the coating compositions according to the invention. The process comprises the following successive stages:

• 1. Transfer a pre-formulated water-incompatible Praelacks A) with 0.2 to 5 wt .-%, preferably 1 to 3% by weight, based on the prelack A), of a di- and / or Polyamine B) with at least one primary and at least one tertiary amino group,
• 2. Neutralization of the amino groups of component B) with an acid, as well
• 3. Transfer of the manufactured in stages 1 and 2 water-soluble lacquers in the aqueous phase and a establish the desired application viscosity Adding water.

In a further embodiment, the 1st stage this procedure the water-incompatible Praelack A) formulated with simultaneous addition of 0.2 to 5% by weight, preferably 1 to 3% by weight, based on the prelack A), component B).

In a preferred embodiment of the method the amino groups are neutralized (stage 2) and setting the desired application viscosity tity (level 3) in a level using a dilute aqueous acid.  

Preferred diamines and / or polyamines B) are diamines with a primary and tertiary amino group.

In stage 1 of the process for the preparation of the aqueous Coating agent is the addition of component B) for pre-formulated water-incompatible coating medium A) preferably in the liquid phase with stirring carried out at room temperature. The temperature can be there to rise to around 40 degrees C. By increasing the Temperature can include the incorporation of component B) be accelerated. Because of the reproducibility should the familiarization run as completely as possible, which at Temperatures above 40 degrees C within a few hours is achieved. The viscosity of the mixture obtained from A) and B) is then constant over time.

The reaction is generally carried out without solvents led, but solvents can also be used the, especially solid di- and / or polyamines B) as Add solution. The solvent can then Michael addition can be removed.

In the 2nd stage of the procedure, this becomes in the 1st stage prepared mixture of components A) and B) by Neutralization, especially of the tertiary amino groups, with at least one acid with stirring, preferably at room temperature, in a water-dilutable form transferred. The acid is preferred in its aqueous Solution used.

Acid suitable for neutralizing the basic groups Ren are, for example, organic acids such as milk acid, acetic acid or formic acid, or mineral Acids such as phosphoric acid or preferably hydrochloric acid.  

The third stage of the process involves the transfer of the water-soluble Be produced in stages 1 and 2 layering agent in the aqueous phase and the setting len the desired application viscosity with water with stirring, preferably at room temperature.

The application viscosities of the resul Tieren aqueous radiation-curable coating agent are generally dependent on the application pending. So low viscosities for sprayable Coating agents can be realized as well as higher ones Viscosities for the roller application of the coating means are needed. The water content of the invented Coating agent according to the invention depends on Viscosity to be set usually between 5 and 50% by weight, based on the total weight of the coating agent.

The coating compositions of the invention can Glass and a wide variety of metal substrates, such as e.g. B. aluminum, steel or various iron alloys be applied. Furthermore, they can for example as a clear or top coat in the area of the car mobile painting can be used. Of course can apply the coating agent in addition to the application the most diverse metals also on other sub strate, such as wood, paper or plastics be applied.

The coating compositions of the invention are before moves to the coating of packaging containers, such as for example glass bottles, glass containers, metal containers hold, such as two and three-piece Ge drinking cans and cans, used. The Her position of the metal container used metal sheets or metal plates or metal strips can from the un  Different materials exist, such as wise aluminum, black plate, tin plate and various iron alloys with the most varied Coating agents can be coated.

The packaging containers coated in this way can be used for a wide variety of applications are used, such as B. for packaging food and Ge soak, for example for beer, juices, lemonades, wine, sparkling wine, Soups, vegetables, meat dishes, fish dishes, however also animal feed. But you can also use it for technical Filling goods are used.

For the production of coatings on metal substrates are the coating compositions of the invention before applies to primed or with a basecoat metal sheets or metal strips applied. As Primers can be the commonly used ones Primers are used. Come as a basecoat both conventional and aqueous basecoats for Commitment.

For example, primers on epoxy and Phenolic resin base, polyester base or polyacrylate base used.

As a primer, for example, are also the commercial ones usual white lacquers for containers and the standard ones Primers for packaging containers as well as the commercial usual primers for the coating of metal boards or metal strips (so-called coil paints), like that Primer for the board painting EG 030823 and the Primer for the coil coating EG 03060D from the company Suitable for BASF Lacke + Farben AG, Münster. But it can also radiation-curable primers, for example be used.  

The commonly used conventional and aqueous basecoats, For example, based on polyurethanes, polyacrylics latex and polyester / cellulose acetobutyrates.

If the coating agent is applied to glass, so can before applying the coating according to the invention means an adhesion promoter layer, in particular be applied on the basis of a silane, as in is described for example in DE-A-195 27 667.

Before the silane is applied, the substrate is placed in a preferred embodiment of the invention heated. The Temperatures are 80 to 120 ° C, preferably approx. 80 ° C.

Mixtures in particular are used to apply the silane layer made of water and silane. The content of the silane is 0.2 to 4% by weight, preferably 0.5 to 2% by weight. The silane is used to produce this mixture Room temperature stirred with deionized water and for some time, preferably about 30 min. under strong homogenized by stirring.

This solution is at elevated pressure, preferably at 2 up to 6 bar, especially at 3 to 4 bar, with the smallest possible atomized droplet size. The spray mist should approximately aerosol-like, fan-shaped to be layered object can be applied.

In addition to this order form are of course also all other common order processes possible, e.g. B. Application, spreading, rolling, pouring. The order However, from an aerosol solution has become special proven, because here the preferred small  Let layer thicknesses reach. These are between 0.2 and 4 microns, preferably 1.5 and 2 microns.

As soon as the silane is applied, the water flow begins damping. This process can be caused by heat be accelerated. After completion of the evaporation the water-free silane layer remains.

A low molecular weight silane is preferably incorporated puts. In particular, silanes come with an ethylenically unsure saturate groups or condensation products thereof in Consideration.

Examples of such compounds are CH ₂ = C (CH ₃ ) - COO- (CH ₂ ) ₃ -Si (OCH ₃ ) ₃ , CH ₂ = CH-Si (OCH ₃ ) ₃ , CH ₂ = CH-Si (OC ₂ H ₅ ) ₃ , CH ₂ = CH-Si (OC ₂ H ₄ -OCH ₃ ) ₃ .

Such silanes are characterized in that they are saponifiable. Has for the purposes of the invention It has been shown that these products are surprisingly good smooth surfaces, e.g. As glass or metal, stick.

The product is preferred only shortly before application expediently prepared as a mixture with water. Versei occurs immediately after mixing with water development process. But it doesn't hurt if the product is stored in water for up to 14 days. Because the in the number of oligomers produced during this time would be affected the product does not.

After the application of the silane layer is the fiction moderate coating agent applied.

The coating compositions according to the invention can in principle Whoever applies them using all of the methods known today by, for example, spraying, rolling, flooding,  Dipping, knife coating, brushing, pouring or by vacuum Application.

The lacquer films harden immediately after Apply or after evaporation of present Water using UV or electron beams. The facilities and conditions for these curing methods are from the Literature known (see e.g. R. Holmes, U.V. and E.B. Curing Formulations for Printing Inks, Coatings and Paints, SITA-Technology, Academic Press, London, United Kingdom 1984, pp. 79 to 111) and do not need any further description.

In the following the invention based on execution examples explained in more detail. All information about parts and Percentages are given by weight, if not from something else is determined.

example 1 1.1. Production of the coating agent 1

The coating composition 1 is produced from the following components from the following components with intensive stirring using a dissolver or a stirrer:
21.00 parts of Crodamer® UVE 150, commercially available epoxy acrylate from Croda Resins, with on average 2 acrylate groups per molecule and with an elongation at break (Zwick) of approx. 60%, 80% in tripropylene glycol diacrylate,
21.00 parts of Crodamer® UVP 210, commercially available polyester acrylate from Crodo Resins with an elongation at break of <10%,
20.00 parts of polyether acrylate 1 with an elongation at break of <5%, produced from ethoxylated pentaerythritol (Polyol PP 150 from Perstorp) and acrylic acid,
15.20 parts of polyether acrylate 2, commercially available polyether acrylate Sartomer 494 from Cray Valley with an elongation at break of <5%,
5.00 parts of tripropylene glycol diacrylate,
2.00 parts of commercially available silane of the formula

CH ₂ = C (CH ₃ ) -COO- (CH ₂ ) ₃ -Si (OCH ₃ ) ₃ ,

0.50 parts acrylic acid,
0.50 parts of wax Polyfluo 540, commercially available poly fluorine wax from Micro Powders,
3.00 parts of polyolefin wax dispersion, Cerafac 59 from Byk,
1.00 parts of Byk® 333, commercially available lubricant based on polyether-modified dimethyl polysiloxane from Byk,
3.25 parts of commercially available Genocure MBF photo initiator from Rahn,
2.00 parts methoxypropanol,
0.05 parts of commercial optical brightener Uvitex OB from Ciba Geigy.

The composition of the coating agent 1 is in Table 1 summarized.

1.2. Production and testing of the coating 1

The coating agent 1 is applied to tinplate which is coated with a commercially available white lacquer based on polyacrylics or polyesters (wet film thickness 18 microns). The curing takes place with an 80 watt Hg UV lamp. The irradiated dose is 300 mJ / cm ² . The resulting coating was subjected to various tests. The results are summarized in Table 2. The tests were carried out as follows:

viscosity

The viscosity at 23 ° C is given as the run-out time in a DIN 4 cup.

Course and yellowing

The course and yellowing are assessed visually:
Grade 1 = very good; Grade 5 = insufficient.

Reactivity

In order to achieve the high number of pieces required for the coating of the respective packaging container, quick-curing coating materials are necessary. Sufficient reactivities are indicated for curing by low doses of UV radiation. A sufficient reactivity is given when the irradiated dose is not more than 200 to a maximum of 280 mJ / cm ² , measured in each case with a light bag IL 390 A from International Light INC. The respective coating is sufficiently cured at the respective dose if no surface damage can be generated during a scratch test with a fingernail.

mobility

Mobility is measured by measuring the Sliding resistance via a ball bearing using the ALTEK device 9505A from ALTEK using a 2 kg weight. Relative are measured Values from 0 to 0.25. The smaller the value, the more the glide is better. Mobility is desirable less than 0.09.

Scratch resistance

The measurement of scratch resistance is done with the Dur-O tester by the company Byk-Gardner. Doing so a metal pin over a spring with a certain Press force on the coating and then over the coated surface led. The spring is measured force needed to damage the paint to achieve surface. The higher these measured values are, um the better the scratch resistance. Are desired Values of at least 7 N.

Resistance to sterilization

The sterilization resistance was determined by the coated sheet for 30 min. is sterilized at 120 ° C with a 0.1% Na ₂ CO ₃ solution. The tape tear and water absorption are then tested.

flexibility

The flexibility is assessed (examination based on the so-called T-Bend test) by a coated Sheet bent and for cracks at the bending point is assessed visually: grade 1 = very good; Note 5 = insufficient.

Examples 2 and 3

Analogously to Example 1 are given in Table 1 from the benen components with the coating agents 2 and 3 produced by stirrer or dissolver.

The application and curing of the coating agent 2 and 3 is carried out analogously to example 1. The test of resulting coatings are also carried out analogously to example 1. The test results are in table shown.

Comparative Examples 1 to 5

Analogously to Example 1 are given in Table 1 from the the components V1 to V5 made with a stirrer or dissolver.

The application and curing of the coating agents V1 up to V5 takes place analogously to example 1. The test of resulting coatings are also carried out analogously to Example 1. The test results are in Table 2 shown.  

Explanations to Table 1

UVE 150: epoxy acrylate Crodamer R UVE 150 described in Example 1,
UVP 210: polyester acrylate Crodomer R UVP 210 described in Example 1,
PEA 1: polyether acrylate 1 described in Example 1,
PEA 2: polyether acrylate 2 (Sartomer® 494) described in Example 1,
TPGDA: tripropylene glycol diacrylate,
Sil .: silane described in Example 1,
Acrylics: acrylic acid,
Init .: commercially available photo initiator Genocure MBF from Rahn,
F wax: polyfluor wax described in Example 1,
Wax 2: polyolefin wax dispersion described in Example 1,
Lubricant: Lubricant described in Example 1 based on polyether-modified dimethyl poly siloxane,
MP: methoxypropanol,
Add .: commercial optical brightener described in Example 1.

Explanations to Table 2

Viscous: measured as the expiry time in the DIN 4 cup,
Publ .: history, visually assessed,
React .: radiation dose required for sufficient curing,
Mobile: mobility, measured with the ALTEK test device,
Scratch: scratch resistance, measured in N with the Dur-O tester,
Flex .: flexibility, visual assessment of the occurrence of cracks after bending the coated sheet (see above),
Verg .: yellowing, visually assessed,
Sterile: resistance to sterilization; OK = OK.

Summary of test results

Meet the coating compositions of Examples 1 to 3 all requirements placed on them, whereby the Be Layering agent of Example 1 compared to the coating compositions of Examples 2 and 3 further improved reactivity and compared to the Be Layering agent of Example 3 in addition one more has improved scratch resistance and mobility.

The coating agent of comparative example V1 has in particular an insufficient reactivity and a bad course. The coating agent of Ver same example V2 shows above all an insufficient Flexibility on. The coating agent of Ver same example V3 has in particular an insufficient Mobility on. The coating agent of the comparison Examples V4 and V5 show insufficient reactivity on.

Claims (10)

1. Radiation-curable coating composition containing at least one radiation-curable binder with at least two acrylic acid ester and / or meth acrylic acid ester groups, characterized in that it

• (a) as a binder (a) a mixture of
  • (a1) at least one binder (a1) with at least two acrylic acid ester and / or meth acrylic acid ester groups and with an elongation at break of at least 20% and
  • (a2) at least one further binder (a2) which is different from (a1) and has at least two acrylic acid ester and / or methacrylic acid groups,
• (b1) at least one silicone-containing lubricant and
• (b2) at least one halogen-containing polyolefin wax

contains. 2. Coating composition according to claim 1, characterized ge indicates that it is at least as component (a1) a binder with an elongation at break of min contains at least 40%. 3. Coating agent according to claim 1 or 2, characterized in that it

• (a1) 2.5 to 80% by weight, preferably 10 to 50% by weight, of at least one binder (a1) and
• (a2) 19.8 to 97.3% by weight, preferably 25 to 89.8% by weight, of at least one binder (a2)

contains, the percentages by weight based on the total weight of the coating composition. 4. Coating agent according to one of claims 1 to 3, characterized in that there is at least one further components (b1) and (b2) contains various organic lubricants. 5. Coating agent according to one of claims 1 to 4, characterized in that it

• (b1) 0.1 to 3 wt .-%, preferably 0.2 to 2 wt .-%, based on the total weight of the coating agent, at least one silicone-containing lubricant (b1) and
• (b2) 0.1 to 5% by weight, preferably 0.2 to 3% by weight, based on the total weight of the coating composition, of at least one halogen-containing polyolefin wax (b2)

contains. 6. Coating agent according to one of claims 1 to 5, characterized in that it is up to 5 wt .-%, preferably 0.5 to 2.5 wt .-%, based on the Ge total weight of the coating agent, at least a silane (c), preferably at least one silane with ethylenically unsaturated groups. 7. Coating composition according to one of claims 1 to 6, characterized in that there is at least one silane selected from CH ₂ = C (CH ₃ ) -COO- (CH ₂ ) ₃ - Si (OCH ₃ ) ₃ , CH ₂ = CH- Si (OCH ₃ ) ₃ , CH ₂ = CH-Si (OC ₂ H ₅ ) ₃ and / or CH ₂ = CH-Si (OC ₂ H ₄ -OCH ₃ ) ₃ contains. 8. Use of the coating agent according to one of the Claims 1 to 7 for the production of a more layer coating, especially as a clear coat or as top coat. 9. Use of the coating agent according to one of the Claims 1 to 7 for coating metal sub straten. 10. Use of the coating agent according to one of the Claims 1 to 7 for coating packaging containers, especially glass containers and / or Metal containers, preferably of two or three parts leaden cans.