EP1551896A1

EP1551896A1 - Coating material which is thermally curable and curable by means of actinic radiation and method for coating microporous surfaces

Info

Publication number: EP1551896A1
Application number: EP03757894A
Authority: EP
Inventors: Yvonne Lichte; Heinrich Wonnemann
Original assignee: BASF Coatings GmbH
Current assignee: BASF Coatings GmbH
Priority date: 2002-10-17
Filing date: 2003-09-29
Publication date: 2005-07-13
Also published as: AU2003273927A1; US20070021553A1; WO2004035651A1; DE10248324A1; JP2006503131A

Abstract

A coating material which is thermally curable and curable by means of actinic radiation, comprising (a1) at least one component consisting of (a11) at least two functional groups per molecule, on a statistical average, which contain at least one bond which can be activated with actinic radiation and which is used for cross-linking with actinic radiation, and optionally (a12) at least one isocyanate-reactive group, (a2) at least one thermally curable component with at least two isocyanate-reactive groups and (a3) at least one aromatic polyisocyanate devoid of functional groups (a11) or a mixture of at least one aromatic polyisocyanate which is devoid of functional groups (a11) and at least one (cyclo)aliphatic polyisocyanate devoid of functional groups (a11). The invention also relates to the use thereof in order to coat microporous surfaces, especially SMC and BMC's.

Description

Coating material curable thermally and with actinic radiation and method for coating microporous surfaces

Field of the Invention

The present invention relates to a new coating material which is curable thermally and with actinic radiation. In addition, the present invention relates to a new method for coating, in particular for sealing, microporous surfaces of all kinds, especially the microporous surfaces of moldings made of wood, glass, leather, plastics, metals, minerals, in particular fired and unfired clay, ceramics, nature - and artificial stone or cement; Fiber materials, in particular glass fibers, ceramic fibers, carbon fibers, textile fibers, plastic fibers or metal fibers and composites of these fibers; or fiber-reinforced materials, in particular plastics reinforced with the fibers mentioned above, especially the porous surfaces of SMC (Sheet Molded Compounds) and BMC (Bulk Molded Compounds).

State of the art

When coating porous surfaces, in particular microporous surfaces that have pores with a width of 10 to 1,500 nm, with thermally curable coating materials, at the temperatures used for baking the applied coating materials, volatile constituents are often outgassed from the molded parts. This leads to undesirable surface defects, such as microbubbling (blistering). These problems are particularly unpleasant for SMC and BMC.

SMC and BMC have long been used for the production of complex shaped sanitary articles, household appliances and components, in particular for the automotive industry, such as mudguards, fenders, doors or reflectors of lamps. Due to their structure and material composition based on glass fibers, the SMC and BMC are highly temperature-resistant and can withstand temperatures of 190 to 200 ° C. They show only a slight deformation. In addition, the complex articles can be manufactured more easily and with greater accuracy with this technology than with reinforced thermoplastic materials.

A disadvantage of the SMC and BMC is that their surface is microporous and therefore cannot be coated directly, because microbubbles are formed in the coating at 70 to 80 ° C by outgassing monomers such as styrene.

The coating material known from German patent application DE 199 20 799 A1 has made an important contribution to solving these problems.

The coating material known from the German patent application and curable with actinic radiation contains

(a1) at least one constituent, for example a urethane (meth) acrylate, with (a11) at least two functional groups, for example acrylate groups, which are used for crosslinking with actinic radiation, and if appropriate

(a12) at least one functional group, in particular hydroxyl groups, which can undergo thermal crosslinking reactions with a complementary functional group (a22) in component (a2),

and

(a2) at least one component, for example an isocyanatoacrylate, with

(a21) at least two functional groups, for example

Acrylate groups, which are used for crosslinking with actinic radiation, and

(a22) at least one functional group, in particular an isocyanate group, which can undergo thermal crosslinking reactions with a complementary functional group (a12) in component (a1),

and if necessary

(a3) at least one photoinitiator,

(a4) at least one initiator of the thermal crosslinking,

(a5) at least one reactive diluent curable with actinic radiation and / or thermally curable, (a6) at least one paint additive and / or

(a7) at least one thermally curable constituent,

with the proviso that the coating material contains at least one thermally curable component (a7) if the component (a1) has no functional group (a12).

It is therefore essential for the known coating material that it contains a constituent (a2), in particular an isocyanatoacrylate.

The known coating material may contain, as constituents (a7), thermally curable binders and / or crosslinking agents, for example blocked polyisocyanates. Unblocked polyisocyanates are not used as components (a7).

In addition, the known coating material can contain electrically conductive pigments as a paint additive (a6).

The well-known coating material provides coatings and seals that effectively suppress the formation of microbubbles without great effort and have a smooth surface free of surface structures such as orange peel, which does not require post-treatment, and can be easily and safely overpainted without problems of interlayer adhesion thereafter result. The ability to be overpainted is retained even if the seal or primer layer on electrically conductive surfaces is overpainted with an electrocoat. This enables the corresponding SMC or BMC to be directly coated in, for example, uncoated Install car bodies and coat them electrophoretically in the same way as the metal parts.

However, the known coating material and the coatings produced from it have to be further improved by means of electrostatic high-rotation processes (ESTA) or by means of electrophoretic dip coating, despite the high technological level already achieved with regard to sandability and polishability, mechanical flexibility, adhesion, interlayer adhesion and overpaintability. to meet the increased demands of the market.

With all the advantages that the known coating process has, the coating of complex shaped molded parts does not yet fully meet the increasing demands of the market. The hardening of the coatings in the shadow zones of the molded parts is often not sufficient to ensure good sandability and polishability of the coatings, in particular the seals. However, this is particularly disadvantageous in the production of particularly high-quality SMC and BMC.

Coating materials curable thermally and with actinic radiation are known from German patent applications DE 199 30 665 A1, DE 199 30 067 A1 and DE 199 30 664 A1 or DE 199 24 674 A1 which contain at least one thermally curable constituent with at least two Isocyanate-reactive groups, which are necessarily copolymers of olefinically unsaturated monomers with 1, 1-diphenylethylene and its derivatives. Problems associated with the coating of a microporous surface and possible solutions for this are not addressed. In addition, a wet-on-wet process is known from international patent application WO 98/40170, in which a layer of a basecoat is overlaid with a clearcoat as topcoat, after which the resulting clearcoat layer is irradiated with actinic radiation before being baked together , Whether the known clear coat is able to solve problems with. The coating of microporous surfaces or whether it is suitable as a seal for SMC and BMC at all cannot be found in the international patent application.

In the unpublished German patent application DE 10113884.9 describes a method for coating microporous surfaces which have pores with a width of 10 to 1,500 nm, in which the surfaces in question are coated with at least one thermally and with actinic radiation coating material, after which the resulting layer (s) cures thermally and with actinic radiation, the coating material or at least one of the coating materials

(a1) at least one component with

(a11) on average at least two functional groups per molecule which contain at least one bond which can be activated with actinic radiation and which is used for crosslinking with actinic radiation, and if appropriate

(a12) at least one isocyanate-reactive group,

(a2) at least one thermally curable component with at least two isocyanate-reactive groups and

(a3) at least one (cyclo) aliphatic polyisocyanate

contains. The coating material can contain an electrically conductive pigment, such as a pigment based on mica (Minatec® 40th CM from Merck). The use of saturated aromatic polyisocyanates is not described, but it is specifically only emphasized on the (cyclo) aliphatic polyisocyanates.

Object of the invention

It is an object of the present invention to provide a new coating material which is curable thermally and with actinic radiation and which no longer has the disadvantages of the prior art, but instead maintains the technological level achieved hitherto, with an improved processing window and improved curing properties, in particular in the Shadow zones of complex shaped three-dimensional moldings, leads and supplies coatings, especially seals, on a wide variety of microporous surfaces, which have excellent sandability and polishability. In addition, the new coating material should allow thermal curing to be carried out at temperatures of <120 ° C. Furthermore, the new coatings and seals should be of high mechanical flexibility and have very good adhesion to a wide variety of substrates. In addition, they should be easy to paint over. They should also be able to be set to be electrically conductive in a simple manner, so that they can also be overpainted using electrostatic high-rotation processes (ESTA) or electrophoretic dip-coating processes. The new coatings and seals should also have particularly good interlayer adhesion.

Solution according to the invention

Accordingly, the new thermally and actinic radiation-curable coating material has been found to contain

(a1) at least one component with

(a12) at least one isocyanate-reactive group,

(a2) at least one thermally curable component with at least two isocyanate-reactive groups

and

(a3) at least one aromatic polyisocyanate free of functional groups (a11) or a mixture of at least one aromatic polyfunctional free of functional groups (a11)

Polyisocyanate and at least one of functional groups

(a11) free, (cyclo) aliphatic polyisocyanate.

In the following, the new coating material curable thermally and with actinic radiation is referred to as “coating material according to the invention”. In addition, the new process for coating microporous surfaces has been found, in which the surfaces in question are coated with at least one thermally and actinic radiation-curable coating material, after which the resulting layer (s) are thermally cured and with actinic radiation, where as Coating material at least one coating material according to the invention is used.

The new process for coating microporous surfaces is referred to below as the “process according to the invention”.

The new coated, in particular sealed, molded parts are referred to below as "molded parts according to the invention" and the corresponding SMC and BMC as "compounds according to the invention".

Further objects according to the invention result from the description.

Advantages of the invention

In view of the prior art, it was surprising and unforeseeable for the person skilled in the art that the object on which the invention was based could be achieved with the aid of the coating material according to the invention, the method according to the invention, the moldings according to the invention and the compounds according to the invention.

It was particularly surprising that due to the coating material according to the invention and the method according to the invention without major Effort resulted in a sealing of microporous surfaces that was free of microbubbles (blistering), had a smooth surface that was free of surface structures such as orange peel, required no post-treatment and could be easily and safely overpainted without problems of interlayer adhesion and the adhesion to the substrate.

The processes and coating materials according to the invention and the seals produced therefrom could surprisingly be adjusted to be very electrically conductive. This made it possible to coat seals on non-electrically conductive substrates with the help of electrostatic high-rotation processes (ESTA) or electrophoretic dip coating processes.

This made it possible, among other things, to incorporate the molded parts and compounds according to the invention directly into uncoated, electrically conductive metal parts, such as automobile bodies, and to coat them electrophoretically in the same way as the metal parts.

However, it was particularly surprising that the coating material according to the invention had a particularly wide processing window and therefore can be carried out without problems even under difficult technical and climatic conditions with technologically outdated devices and systems and / or at comparatively high or low temperatures and / or comparatively low or high air humidity caused improved curing properties, especially in the shadow zones of complex shaped three-dimensional moldings, and provided coatings, in particular seals, on a wide variety of microporous surfaces that had excellent sandability and polishability. In addition, the coatings and seals of the invention were high mechanical flexibility and had excellent adhesion to a wide variety of substrates and excellent interlayer adhesion.

Detailed description of the invention

The coating material of the invention is curable thermally and with actinic radiation.

In the context of the present invention, the term “thermal hardening” means the heat-initiated hardening of a layer of a coating material, in which a crosslinking agent that is usually present is used. Usually this is referred to by experts as external crosslinking.

In the context of the present invention, actinic radiation means electromagnetic radiation such as near infrared (NIR), visible light, UV radiation or X-rays, in particular UV radiation, or corpuscular radiation such as electron beams.

If thermal and curing with actinic light are used together in one coating material, this is also referred to as "dual cure".

The coating material of the invention contains at least one constituent (a1) with a statistical average of at least two, in particular at least three, functional groups (a11) per molecule which contain at least one, in particular one, bond which can be activated with actinic radiation and which serves for crosslinking with actinic radiation , and optionally at least one, in particular at least two, isocyanate-reactive group (s) (a12). It is preferred that the radiation-curable binders are UV-curable. It is further preferred if component (a1) contains essentially no, particularly preferably none, groups (a12).

Component (a1) preferably contains on average no more than six, in particular no more than five functional groups (a11) per molecule.

Examples of suitable bonds which can be activated with actinic radiation are carbon-hydrogen single bonds or carbon-carbon, carbon-oxygen, carbon-nitrogen, carbon-phosphorus or carbon-silicon single bonds or double bonds. Of these, the double bonds, in particular the carbon-carbon double bonds, are preferably used.

Suitable carbon-carbon double bonds are, for example, in (meth) acrylate, ethacrylate, crotonate, cinnamate, vinyl ether, vinyl ester, ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isoprenyl, isopropenyl, allyl - or butenyl groups; Ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl or butenyl ether groups or ethenylarylene, dicyclopentadienyl, norbornenyl, isoprenyl, isopropenyl, allyl or butenyl ester groups. Of these, (meth) acrylate groups, in particular acrylate groups, are of particular advantage and are therefore used with very particular preference in accordance with the invention.

Examples of suitable isocyanate-reactive groups (a12) are thiol, primary or secondary amino, imino or hydroxyl groups, especially hydroxyl groups. The component (a1) is oligomeric or polymeric.

In the context of the present invention, an oligomer is understood to mean a compound which generally has on average 2 to 15 basic structures or monomer units. By contrast, a polymer is understood to mean a compound which generally has on average at least 10 basic structures or monomer units. Compounds of this type are also referred to by experts as binders or resins.

In contrast to this, in the context of the present invention, a low-molecular compound is to be understood as a compound which essentially derives only from a basic structure or a monomer unit. Compounds of this type are generally referred to by the experts as reactive thinners.

The polymers or oligomers used as binders (a1) usually have a number average molecular weight of 500 to 50,000, preferably 1,000 to 5,000. They preferably have a double bond equivalent weight of 400 to 2,000, particularly preferably 500 to 900. In addition, they preferably have a viscosity of 250 to 11,000 mPas at 23 ° C.

Examples of suitable binders or resins (a1) come from the oligomer and / or polymer classes of the (meth) acrylic-functional (meth) acrylic copolymers, polyether acrylates, polyester acrylates, polyesters, epoxy acrylates, urethane acrylates, amino acrylates, melamine acrylates, silicone acrylates and phosphazene acrylates and the corresponding methacrylates. Binders (a1) which are free from aromatic structural units are preferably used. Urethane (meth) acrylates, phosphazene (meth) acrylates are therefore preferred and / or polyester (meth) acrylates, particularly preferred

Urethane (meth) acrylates, in particular aliphatic urethane (meth) acrylates, are used.

The urethane (meth) acrylates (a1) are obtained by reacting a di- or polyisocyanate with a chain extender from the group consisting of diols / polyols and / or diamines / polyamines and / or dithiols / polythiols and / or alkanolamines and then reacting the remaining free ones Isocyanate groups with at least one hydroxyalkyl (meth) acrylate or hydroxyalkyl ester of other ethylenically unsaturated carboxylic acids.

The amounts of chain extenders, di- or polyisocyanates 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) is between 3: 1 and 1: 2, preferably 2: 1, and

2.) the OH groups of the hydroxyalkyl esters of the ethylenically unsaturated carboxylic acids are present in a stoichiometric amount with respect to the free isocyanate groups of the prepolymer of isocyanate and chain extender.

It is also possible to prepare the urethane (meth) acrylates by first reacting part of the isocyanate groups of a di- or polyisocyanate with at least one hydroxyalkyl ester and then reacting the remaining isocyanate groups with a chain extender. In this case too, the amounts of chain extender, isocyanate and hydroxyalkyl ester become so selected that the equivalent ratio of the NCO groups to the reactive groups of the chain extender is between 3: 1 and 1: 2, preferably 2: 1 and the equivalent ratio of the remaining NCO groups to the OH groups of the hydroxyalkyl ester is 1: 1. Of course, all intermediate forms of these two processes are also possible. For example, part of the isocyanate groups of a diisocyanate can first be reacted with a diol, then another part of the isocyanate groups can be reacted with the hydroxyalkyl ester and then the remaining isocyanate groups can be reacted with a diamine.

The urethane (meth) acrylates (a1) can be made more flexible, for example, by reacting corresponding isocyanate-functional prepolymers or oligomers with longer-chain, aliphatic diols and / or diamines, in particular aliphatic diols and / or diamines with at least 6 C atoms , This flexibilization reaction can be carried out before or after the addition of acrylic or methacrylic acid to the oligomers or prepolymers.

The following commercially available polyfunctional aliphatic urethane acrylates may also be mentioned as examples of suitable urethane (meth) acrylates (a1):

Crodamer® UVU 300 from Croda Resins Ltd., Kent, Great Britain;

Genomer® 4302, 4235, 4297 or 4316 from Rahn Chemie, Switzerland;

Ebecryl® 284, 294, 8210, 5129 or 1290 or Radcure® IRR 351 from UCB, Arzneimittelbos, Belgium; - Roskydal® LS 2989 or LS 2545 or V94-504 from Bayer

AG, Germany; Viaktin® VTE 6160 from Vianova, Austria; or Laromer® 8861 from BASF AG as well as test products developed from it.

Urethane (meth) acrylates (a1) containing hydroxyl groups are known, for example, from US Pat. Nos. 4,634,602 A or 4,424,252 A.

An example of a suitable polyphosphazene (meth) acrylate (a1) is the phosphazene dimethacrylate from Idemitsu, Japan.

Ebecryl® 8210, Laromer® LR8987 and Laromer® UA19T are particularly preferably used.

Preferably with component (a1) in an amount of 5 to 50% by weight, preferably 6 to 45% by weight, particularly preferably 7 to 40% by weight, very particularly preferably 8 to 35% by weight and in particular 9 up to 30 wt .-%, each based on the solid of the coating material of the invention applied.

Furthermore, the coating material contains at least one thermally curable component (a2) with at least two, in particular at least three, isocyanate-reactive groups. Examples of suitable isocyanate-reactive groups are those described above, especially hydroxyl groups.

The component (a2) is oligomeric or polymeric.

Examples of suitable constituents (a2) are linear and / or branched and / or block-like, comb-like and / or randomly constructed oligomers or polymers, such as (meth) acrylate (co) polymers, polyesters, alkyds,

Aminoplast resins, polyurethanes, polylactones, polycarbonates, polyethers, Epoxy resin-amine adducts, (meth) acrylate diols, partially saponified polyvinyl esters or polyureas, of which the (meth) acrylate copolymers, the polyesters, the polyurethanes, the polyethers and the epoxy resin-amine adducts, but especially the polyesters, are advantageous.

Suitable binders (a2) are, for example, under the trade names Desmophen® 650, 2089, 1100, 670, 1200 or 2017 from Bayer, under the trade names Priplas or Pripol® from Uniqema, under the trade names Chempol® polyester or polyacrylate polyol from the company CCP, under the trade names Crodapol® 0-25, 0-85 or 0-86 from the company Croda, Setal® 1615 or 1715 from the company Akzo, under the trade name Dobeckan ® IU 080014 from the company Schenectady-Beck Elektroisoliersysteme or sold by Witco under the trade name Formrez® ER417.

The binders (a2) preferably have a mass-average molecular weight of 500 to 10,000 daitons, preferably 1000 to 5000 daltons, and a hydroxyl number of 80 to 160 mg KOH / g. Setal® 1615, Setal® 1715, Desmophen® 650 and Desmophen® 670 are preferably used as binders (a2).

The proportion of constituents (a2) in the coating materials can vary widely and depends on the requirements of the individual case. They are preferably used in an amount of 5 to 90% by weight, preferably 6 to 80% by weight, particularly preferably 7 to 70% by weight, very particularly preferably 8 to 60% by weight and in particular 9 to 50% by weight. %, each based on the solids of the coating material, applied.

The coating material further contains at least one aromatic polyisocyanate (a3) free of functional groups (a11). The aromatic polyisocyanates (a3) contain on average at least 2.0, preferably more than 2.0 and in particular more than 3.0 isocyanate groups per molecule. There is basically no upper limit to the number of isocyanate groups; According to the invention however, it is advantageous if the number of 15, preferably 12 _^ more preferably 10, most preferably 8.0, and especially does not exceed 6.0.

Examples of suitable aromatic polyisocyanates (a3) are polyurethane prepolymers containing isocyanate groups, which can be prepared by reacting polyols with an excess of aromatic diisocyanates and are preferably of low viscosity.

Examples of suitable aromatic diisocyanates are 1, 2- 1, 3- and 1, 4-benzene diisocyanate, 2,4- and 2,6-toyulenediisocyanate, 4,4 ^' -

Biphenylene diisocyanate, bis (4 ~ isocyanatophenyl) methane, 2,2-bis (4-isocyanatophenyl) propane and the positional isomers

Naphthalene diisocyanates, in particular the technical mixtures of 2,4- and 2,6-tolylene diisocyanate.

It is also possible to use aromatic polyisocyanates (a3) which contain isocyanurate, biuret, allophanate, iminooxadiazinedione, urethane, urea, carbodiimide and / or uretdione groups and are prepared in a customary and known manner from the aromatic diisocyanates described above , Example more suitable

Manufacturing processes are known from the patents CA 2,163,591 A, US 4,419,513 A, US 4,454,317 A, EP 0 646 608 A, US 4,801,675 A, EP 0 183 976 A 1, DE 40 15 155 A 1, EP 0 303 150 A 1, EP 0 496 208 A 1, EP 0 524 500 A 1, EP 0 566 037 A 1, US 5,258,482 A 1, US 5,290,902 A 1, EP 0 649 806 A 1, DE 42 29 183 A 1, EP 0 531 820 A 1 or DE 100 05 228 A 1 known. In addition, there are highly viscous aromatic polyisocyanates (a3), as described in German patent application DE 198 28 935 A 1, or the aromatic polyisocyanate particles deactivated on their surface by urea formation and / or blocking according to European patent applications EP 0 922 720 A 1, EP 1 013 690 A1 and EP 1 029 879 A1.

Furthermore, the adducts of aromatic polyisocyanates described in German patent application DE 196 09 617 A1 with aromatic isocyanate-reactive functional groups containing dioxanes, dioxolanes and oxazolidines, which still contain free isocyanate groups, are suitable as aromatic polyisocyanates (a3).

The aromatic polyisocyanates (a3) can be used together with cycloaliphatic and / or aliphatic polyisocyanates free of functional groups (a11), resulting in the mixture (a3).

The cycloaliphatic and aliphatic polyisocyanates free of functional groups (a11) also contain on average at least 2.0, preferably more than 2.0 and in particular more than 3.0 isocyanate groups per molecule. There is basically no upper limit to the number of isocyanate groups; According to the invention, however, it is advantageous if the number does not exceed 15, preferably 12, particularly preferably 10, very particularly preferably 8.0 and in particular 6.0.

Examples of suitable aliphatic and cycloaliphatic polyisocyanates are isocyanate-containing polyurethane prepolymers which are obtained by reacting polyols with an excess of aliphatic and Cycloaliphatic diisocyanates can be prepared and are preferably low viscosity.

Examples of suitable aliphatic and cycloaliphatic diisocyanates are isophorone diisocyanate (= 5-isocyanato-1-isocyanatomethyl-1, 3,3-trimethyl-cyclohexane), 5-isocyanato-1- (2-isocyanatoeth-1-yl) -1,3,3 trimethyl-cyclohexane, 5-isocyanato-1- (3-isocyanatoprop-1-yl) -1,3,3-trimethyl-cyclohexane, 5-isocyanato- (4-isocyanatobut-1-yl) -1,3,3 -trimethyl-cyclohexane, 1-isocyanato-2- (3-isocyanatoprop-1-yl) -cyclohexane, 1- isocyanato-2- (3-isocyanatoeth-1-yl) cyclohexane, 1-isocyanato-2- (4-isocyanatobut -1-yl) -cyclohexane, 1, 2-diisocyanatocyclobutane, 1, 3-

Diisocyanatocyclobutane, 1, 2-diisocyanatocyciopentane, 1, 3-

Diisocyanatocyclopentane, 1, 2-diisocyanatocyclohexane, 1, 3-

Diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-2,4'-diisocyanate, trimethylene diisocyanate,

Tetramethylene diisocyanate, pentamethylene diisocyanate,

Hexamethylene diisocyanate (HDI), ethyl ethylene diisocyanate, trimethyl hexane diisocyanate, heptamethylene diisocyanate, methyl pentyl diisocyanate (MPDI), nonane triisocyanate (NTI) or diisocyanates, derived from dimer fatty acids, such as those sold by the Henkel company under the trade name DDI 1410 and in the patent specifications WO45 and WO47 / 977 WO 97/49747 can be described, in particular 2-heptyl-3,4-bis (9-isocyanatononyl) -1-pentylcyclohexane, or 1, 2-, 1, 4- or 1,3-bis (isocyanatomethyl) cyclohexane, 1,2-, 1, 4- or 1,3-bis (2-isocyanatoeth-1-yl) cyclohexane, 1, 3-bis (3-isocyanatoprop-1-yl) cyclohexane, 1, 2-, 1, 4 - or 1,3-bis (4-isocyanatobut-1-yl) cyclohexane or liquid bis (4-isocyanatocyclohexyl) methane having a trans / trans content of up to 30% by weight, preferably 25% by weight and in particular 20 % By weight as described in patent applications DE 44 14 032 A1, GB 1220717 A1, DE 16 18 795 A1 or DE 17 93 785 A1, preferably isophorone diisocyanate, 5-isocyanato-1 - (2-isocyanatoeth -1 -yl) -1,3,3-trimethyl- cyclohexane, 5-isocyanato-1- (3-isocyanatoprop-1-yl) -1,3,3-trimethylcyclohexane, 5-isocyanator (4-isocyanatobut-1-yl) -1,3,3-trimethylcyclohexane , 1-isocyanato-2- (3-isocyanatoprop-1-yl) cyclohexane, 1-isocyanato-2- (3-isocyanatoeth-1-yl) cyclohexane, 1-isocyanato-2- (4-isocyanatobut-1-yl ) -cyclohexane or HDI, especially HDI.

It is also possible to use aliphatic and cycloaliphatic polyisocyanates which contain isocyanurate, biuret, allophanate, iminooxadiazinedione, urethane, urea, carbodiimide and / or uretdione groups and which are prepared in a customary and known manner from the aliphatic and cycloaliphatic diisocyanates described above become. Examples of suitable production processes are also from the patent specifications CA 2,163,591 A, US 4,419,513, US 4,454,317 A, EP 0 646 608 A, US 4,801, 675 A, EP 0 183 976 A1, DE 40 15 155 A1, EP 0 303 150 A. 1, EP 0 496 208 A1, EP 0 524 500 A1, EP 0 566 037 A1, US 5,258,482 A1, US 5,290,902 A1, EP 0 649 806 A1, DE 42 29 183 A1, EP 0 531 820 A 1 or DE 100 05 228 A 1 known.

In addition, there are the highly viscous aliphatic and cycloaliphatic polyisocyanates, as are described in German patent application DE 198 28 935 A1, or the surface of deactivated aliphatic and cycloaliphatic polyisocyanate particles according to European patent applications EP 0 922 720 A1, due to urea formation and / or blocking , EP 1 013 690 A1 and EP 1 029 879 A1.

Furthermore, there are those in German patent application DE 196 09

617 A 1 described adducts of aliphatic and cycloaliphatic

Polyisocyanates with isocyanate-reactive functional groups containing dioxanes, dioxolanes and oxazolidines, which are still free Contain isocyanate groups as aliphatic and cycloaliphatic polyisocyanates.

The aromatic polyisocyanates (a3) are preferably selected from the group of polyisocyanates based on the technical mixtures of 2,4- and 2,6-toluenediisocyanate.

The (cyclo) aliphatic polyisocyanates are preferably selected from the group consisting of polyisocyanates based on hexamethylene diisocyanate and based on isophorone diisocyanate.

A minor part of the aromatic polyisocyanates (a3) and / or the (cyclo) aliphatic polyisocyanates can be blocked with customary and known blocking agents. A subordinate part is to be understood as meaning amounts which vary the technological profile of properties of the polyisocyanates (a3) in an advantageous manner, but do not characterize them. 5 to 80 mol%, in particular 20 to 45 mol%, of the aromatic polyisocyanates (a3) and / or the (cyclo) aliphatic polyisocyanates are preferably blocked.

The (cyclo) aliphatic polyisocyanate hardeners preferably have an NCO content of 15 to 25%. The aromatic polyisocyanate hardeners preferably have an NCO content of 10 to 15%.

The content of aromatic polyisocyanates (a3) or of the mixture (a3) of at least one aromatic polyisocyanate (a3) and at least one aliphatic and / or cycloaliphatic polyisocyanate in the coating materials according to the invention can vary very widely and depends on the requirements of the individual case, in particular the content of components (a2) and optionally (a1) in isocyanate-reactive groups. The content is preferably 5 to 60 % By weight, preferably 5 to 55% by weight, particularly preferably 5 to 50% by weight, very particularly preferably 5 to 45% by weight and in particular 5 to 40% by weight, in each case based on the solids content of the coating material of the invention.

The quantitative ratio of aromatic polyisocyanate (a3) to (cyclo) aliphatic polyisocyanate in the mixture (a3) is 95: 5 to 5:95, preferably 85:15 to 15:85 and in particular 80:20 to 20:80.

The coating material of the invention can also contain at least one pigment and / or a filler. These can be coloring and / or effect-giving, fluorescent, electrically conductive and / or magnetically shielding pigments, metal powder, scratch-resistant pigments, organic dyes, organic and inorganic, transparent or opaque fillers and / or nanoparticles.

If the coating material of the invention is used to produce electrically conductive seals, it preferably contains at least one electrically conductive pigment and / or at least one electrically conductive filler.

Examples of suitable effect pigments are platelet pigments such as commercially available aluminum bronzes, aluminum bronzes chromated according to DE 36 36 183 A1, and commercially available stainless steel bronzes and non-metallic effect pigments, such as pearlescent or interference pigments, platelet-shaped effect pigments based on iron oxide and brown, a shade of pink has or liquid crystalline effect pigments. In addition, Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 176, "Effect pigments" and pages 380 and 381 "metal oxide mica pigments" to "metal pigments", and the patent applications and patents DE 36 36 156 A1, DE 37 18 446 A1, DE 37 19 804 A1, DE 39 30 601 A 1, EP 0 068 311 A 1, EP 0 264 843 A 1, EP 0 265 820 A 1, EP 0 283 852 A 1, EP 0 293 746 A 1, EP 0 417 567 A 1, US 4,828,826 A or US 5,244,649 A.

Examples of suitable inorganic color pigments are white pigments such as titanium dioxide, zinc white, zinc sulfide or lithopone; Black pigments such as carbon black, iron-manganese black or spinel black; Colored pigments such as chromium oxide, chromium oxide hydrate green, cobalt green or ultramarine green, cobalt blue, ultramarine blue or manganese blue, ultramarine violet or cobalt and manganese violet, iron oxide red, cadmium sulfoselenide, molybdate red or ultramarine red; Iron oxide brown, mixed brown, spinel and corundum phases or chrome orange; or iron oxide yellow, nickel titanium yellow, chrome titanium yellow, cadmium sulfide, cadmium zinc sulfide, chrome yellow or bismuth vanadate.

Examples of suitable organic coloring pigments are monoazo pigments, bisazo pigments, anthraquinone pigments,

Benzimidazole pigments, quinacridone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, dioxazine pigments, indanthrone pigments, isoindoline pigments, isoindolinone pigments, azomethine pigments,

Thioindigo pigments, metal complex pigments, perinone pigments, perylene pigments, phthalocyanine pigments or aniline black.

In addition, Römpp Lexikon Lacquers and Printing Inks, Georg Thieme Verlag, 1998, pages 180 and 181, "Iron Blue Pigments" to "Iron Oxide Black", Pages 451 to 453 "Pigments" to "Pigment Volume Concentration", page 563 "Thioindigo Pigments", Page 567 »Titanium dioxide pigments«, Pages 400 and 467, »Naturally occurring pigments «, page 459» Polycyclic pigments «, page 52,» Azomethine pigments «,» Azo pigments «, and page 379,» Metal complex pigments «.

Examples of fluorescent pigments (daylight pigments) are bis (azomethine) pigments.

Examples of suitable electrically conductive pigments are e.g. Pigments with a pigment content of 20 to 25 wt .-%, based on the total solids of the composition, from one

Dry film layer thickness of 60μm cause opacity to black / white contrast. These pigments are preferably transparent to actinic radiation, in particular UV radiation.

Particularly suitable electrically conductive pigments of this type are pigments based on mica or mica, which are coated with metal oxide layers, in particular antimony-tin mixed oxide layers. Particularly suitable conductive mica pigments are marketed by Merck under the brand Minatec ® 40 CM, 31 CM or 30 CM ("Conductive Mica").

Examples of magnetically shielding pigments are pigments based on iron oxides or chromium dioxide.

Examples of suitable metal powders are powders made of metals and metal alloys such as aluminum, zinc, copper, bronze or brass.

Suitable soluble organic dyes are lightfast organic

Dyes with little or no tendency to migrate from the coating material and those produced from it

Coatings. The specialist can determine the tendency to migrate assess his general specialist knowledge and / or determine it with the help of simple preliminary tests, for example in the context of tinting tests.

Examples of suitable organic and inorganic fillers are chalk, calcium sulfates, barium sulfate, silicates such as talc, mica or kaolin, silicas, oxides such as aluminum hydroxide or magnesium hydroxide or organic fillers such as plastic powder, in particular made of polyamide or polyacrylonitrile. In addition, reference is made to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 250 ff., »Fillers«.

Examples of suitable transparent fillers are those based on silicon dioxide, aluminum oxide or zirconium oxide, but in particular nanoparticles based on this.

Fillers which are transparent to actinic radiation, in particular UV radiation, such as Mircavor® 20, Mistron® Monomix and Blancfix® N or F are particularly preferably used.

The electrically conductive coating materials according to the invention very particularly preferably comprise at least one of the electrically conductive mica pigments described above and at least one of the fillers described above which are transparent to UV radiation.

The content of the pigments and / or fillers described above in the coating material according to the invention can vary very widely and depends on the requirements of the individual case. Based on the solids content of the coating material, it is preferably 5 to 50, more preferably 5 to 45, particularly preferably 5 to 40, very particularly preferably 5 to 35 and in particular 5 to 30% by weight.

Furthermore, the coating material of the invention can contain at least one tackifier. Tackifiers are polymeric additives for adhesives that increase their tack, i.e. their inherent stickiness or self-adhesion, so that they adhere firmly to surfaces after a short pressure (cf.Ullmann ^'s Encyclopedia of Industrial Chemistry, CD-ROM, Wiley VCH, Weinheim, 1997, "tackifier").

Examples of suitable tackifiers are highly flexible resins selected from the group consisting of

Homopolymers of alkyl (meth) acrylates, especially alkyl acrylates, such as poly (isobutyl acrylate) or poly (2-ethylhexyl acrylate), which are sold under the Acronal® brand by BASF Aktiengesellschaft, under the Elvacite® brand by Dupont, under the Brand Neocryl® from Avecia and Plexigum® from Roehm;

linear polyesters, as are used in the usual way for coil coating and are sold, for example, under the Dynapol® brand by Dynamit Nobel, under the Skybond® brand by SK Chemicals, Japan, or under the trade name LTW by Degussa ;

linear difunctional, curable with actinic radiation

Oligomers of number average molecular weight greater than

2,000, in particular 3,000 to 4,000, based on polycarbonate diol or polyester diol, which under the name CN 970 are marketed by Craynor or the Ebecryl® brand by UCB;

linear vinyl ether homopolymers and copolymers based on ethyl, propyl, isobutyl, butyl and / or 2-ethylhexyivinyl ether, which are sold under the Lutonal® brand by BASF Aktiengesellschaft; and

non-reactive urethane-urea oligomers made from bis (4,4-isocyanatophenyl) methane, N, N-dimethylethanolamine and diols such as propanediol, hexanediol or dimethylpentanediol and e.g. are marketed by Swift Reichold under the Swift Range® brand or Mictchem Chemicals under the Surkopack® or Surkofilm® brands.

The tackifiers are preferably used in an amount of 0.1 to 10% by weight, preferably 0.2 to 9% by weight, particularly preferably 0.3 to 8% by weight, very particularly preferably 0.4 to 7% by weight. % and in particular 0.56% by weight, based in each case on the solids of the coating material of the invention.

In addition, the coating material of the invention can contain at least one photoinitiator. If the coating material is to be crosslinked with UV radiation, the use of a photoinitiator is generally necessary. If they are also used, they are preferably in the coating material in proportions of 0.1 to 10% by weight, preferably 0.2 to 8% by weight, particularly preferably 0.3 to 7% by weight, very particularly preferred 0.4 to 6 wt .-% and in particular 0.5 to 5 wt .-%, each based on the solids of the coating material. Examples of suitable photoinitiators are those of the Norrish II type, the mechanism of which is based on an intramolecular variant of the hydrogen abstraction reactions, as occurs in a variety of ways in photochemical reactions (examples here are from Römpp Chemie Lexikon, 9th extended and revised edition, Georg Thieme Verlag Stuttgart, Vol. 4, 1991) or cationic photoinitiators (for example, refer to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag Stuttgart, 1998, pages 444 to 446), in particular benzophenones, benzoins or benzoin ethers or phosphine oxides. Products which are commercially available under the names Irgacure® 184, Irgacure® 1800 and Irgacure® 500 from Ciba Geigy, Grenocure® MBF from Rahn and Lucirin® TPO from BASF AG can also be used.

In addition to the photoinitiators, conventional sensitizers such as anthracene can be used in effective amounts.

Furthermore, the coating material of the invention can contain at least one initiator of the thermal crosslinking. From 80 to 120 ° C, these form radicals that start the crosslinking reaction. Examples of thermolabile free-radical initiators are organic peroxides, organic azo compounds or CC-cleaving initiators such as dialkyl peroxides, peroxocarboxylic acids, peroxodicarbonates, peroxide esters, hydroperoxides, ketone peroxides, azodinitriles or benzpinacol silyl ethers. CC-cleaving initiators are particularly preferred, since during their thermal cleavage no gaseous decomposition products are formed which could lead to disturbances in the sealing. If they are used, their amounts are generally between 0.1 to 10% by weight, preferably 0.5 to 8% by weight and in particular 1 to 5% by weight, in each case based on the solids content of the coating material. In addition, the coating material according to the invention can contain at least one reactive thinner that is curable with actinic radiation and / or thermally.

Examples of suitable thermally curable reactive diluents are positionally isomeric diethyloctanediols or hydroxyl group-containing hyperbranched compounds or dendrimers, as described in patent applications DE 198 09 643 A1, DE 198 40 605 A1 or DE 198 05421 A1.

Further examples of suitable reactive diluents are polycarbonate diols, polyester polyols, poly (meth) acrylate diols or polyadducts containing hydroxyl groups.

Examples of suitable reactive solvents which can be used as reactive diluents are butyl glycol, 2-methoxypropanol, n-butanol, methoxybutanol, n-propanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether,

Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether,

Trimethylolpropane, 2-hydroxypropionic acid ethyl ester or

3-methyl-3-methoxybutanol and derivatives based on propylene glycol, e.g. Called ethoxyethyl propionate, isoprpoxypropanol or methoxypropylacetate.

Reactive diluents which can be crosslinked with actinic radiation are, for example, (meth) acrylic acid and its esters, maleic acid and its esters or half esters, vinyl acetate, vinyl ether, vinyl ureas and others. Examples include alkylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, vinyl (meth) acrylate, allyl (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate,

Trimethylol propane di (meth) acrylate, styrene, vinyl toluene, divinyl benzene, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate,

Dipentaerythritol penta (meth) acrylate, dipropylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, ethoxyethoxyethyl acrylate, N-vinylpyrrolidone, phenoxyethyl acrylate, dimethylaminoethyl acrylate,

Hydroxyethyl (meth) acrylate, butoxyethyl acrylate, isobornyl (meth) acrylate, dimethylacrylamide and dicyclopentyl acrylate, the long-chain linear diacrylates described in EP 0 250 631 A1 with a molecular weight of 400 to 4000, preferably 600 to 2500, mentioned. For example, the two acrylate groups can be separated by a polyoxibutylene structure. It is also possible to use 1,12-dodecyl diacrylate and the reaction product of 2 moles of acrylic acid with one mole of a dimer fatty alcohol, which generally has 36 carbon atoms. Mixtures of the monomers mentioned are also suitable.

Further examples of suitable reactive thinners curable with actinic radiation are those described in Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, on page 491 under the keyword “reactive thinners”.

If they are used, the reactive diluents are used in an amount of preferably 2 to 70% by weight, particularly preferably 10 to 65% by weight and in particular 15 to 50% by weight, in each case based on the solids content of the coating material ,

The coating material of the invention can also contain at least one customary and known isocyanatoacrylate. Examples of suitable isocyanatoacrylates are described in European patent application EP 0

928 800 A1. These isocyanatoacrylates can also be used the blocking agents known from the American patents US 4,444,954 A or US 5,972,189 A may be blocked.

The coating material of the invention can also contain at least one crosslinking agent, as is usually used for thermal crosslinking in one-component systems.

Examples of suitable crosslinking agents are aminoplast resins, as described, for example, in Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, page 29, "Aminoharze", the textbook "Lackadditive" by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, pages 242 ff., The book "Paints, Coatings and Solvents", second completely revised edition, Edit. D. Stoye and W. Freitag, Wiley-VCH, Weinheim, New York, 1998, pages 80 ff., The patents US 4,710,542 A1 or EP-B-0 245 700 A1 as well as in the article by B. Singh and co-workers "Carbamylmethylated Melamines, Novel Crosslinkers for the Coatings Industry", in Advanced Organic Coatings Science and Technology Series, 1991, Volume 13, pages 193 to 207, are described, compounds or resins containing carboxyl groups, as described, for example, in patent specification DE 196 52 813 A 1, epoxy group-containing compounds or resins, as described, for example, in the patents EP 0 299 420 A 1, DE 22 14 650 B1, DE 27 49 576 B1, US 4,091,048 A1 or US 3,781, 379 A1 can be described.

The coating material of the invention may further contain water and / or at least one inert inorganic or organic solvent.

Examples of inorganic solvents are liquid nitrogen and supercritical carbon dioxide. Examples of suitable organic solvents are the low-boiling solvents or high-boiling ("long") solvents usually used in the paint field, such as ketones such as methyl ethyl ketone, methyl isoamyl ketone or methyl isobutyl ketone, esters such as ethyl acetate, butyl acetate, ethyl ethoxypropionate, methoxypropyl acetate or butyl glycol acetate, ethers or ethylene dibutyl acetate, ethers such as dibutyl glycol acetate, Diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol or dibutylene glycol dimethyl, diethyl or dibutyl ether, N-methylpyrrolidone or xylenes or mixtures of aromatic and / or aliphatic hydrocarbons such as solvent naphtha®, gasoline 135/180, Dipentene (see Sol . also “Paints, Coatings and Solvents”, Dieter Stoye and Werner Freitag (editors), Wiley-VCH, 2nd edition, 1998, pages 327 to 349).

In addition, the coating material of the invention can contain at least one customary and known paint additive in effective amounts, i.e. in amounts of preferably up to 40% by weight, particularly preferably up to 30% by weight and in particular up to 20% by weight, in each case based on the solids content of the coating material.

Examples of suitable paint additives are UV absorbers, light stabilizers, free radical scavengers, catalysts for crosslinking such as dibutyltin dilaurate or lithium decanoate, slip additives, polymerization inhibitors, defoamers, emulsifiers, wetting agents, adhesion promoters, flow control agents, film-forming aids such as cellulose derivatives, flame retardants, sag control. rheology-controlling additives or matting agents.

The coating material of the invention can be in various forms. With a corresponding choice of its components (a1), (a2) and (a3) described above and any other components that may be present, it can be present as a liquid coating material which is essentially free of organic solvents and / or water (100% system ). However, the coating material can be a solution or dispersion of the components described above in water and / or organic solvents. A further advantage of the aqueous and the conventional coating material is that solids contents of up to 80% by weight, based on the coating material, can be set.

Furthermore, the coating material according to the invention can be a powder clearcoat if the components described above are selected accordingly. This powder clearcoat can optionally be dispersed in water, resulting in a powder slurry clearcoat.

If the reactivity of its constituents (a1) and (a2) on the one hand and (a3) on the other hand allows the coating material of the invention to be a one-component system. However, if there is a risk that the constituents mentioned will thermally crosslink prematurely, it is advisable to design the coating material of the invention as a two- or multicomponent system in which at least constituent (a3) is stored separately from the other constituents and only shortly before use in the process according to the invention is added.

The production of the coating material according to the invention does not offer any special features in terms of method, but instead takes place in a customary and known manner by mixing the components described above in suitable mixing units, such as stirred kettles, dissolvers, Ultraturrax, inline dissolvers, gear rim dispersing units. Pressure relief homogenizers, microfluidizers, agitator mills or extruders. It is important to ensure that there is no premature crosslinking induced by visible light or other actinic radiation.

The process according to the invention is used for coating, in particular sealing, microporous surfaces which generally have pores with a width of 10 to 1,500, preferably 20 to 1,200 and in particular 50 to 1,000 nm. The surfaces can be electrically conductive or electrically insulating.

The electrically conductive surfaces are metallic or non-metallic. Non-metallic conductive surfaces consist, for example, of electrically conductive ceramic materials, in particular oxides and chalcogenides, or electrically conductive polymers.

The microporous surfaces are preferably the surfaces of molded parts made of materials selected from the group consisting of wood, glass, leather, plastics, minerals, foams, fiber materials and fiber-reinforced materials, metals and metallized materials.

Foams i. S. of DIN 7726: 1982-05 are materials with open and / or closed cells distributed over their entire mass and a bulk density that is lower than that of the framework substance. Preferably elastic and soft elastic foams i. S. of DIN 53580 (see also Römpp Lexikon Chemie, CD-ROM: Version 2.0, Georg Thieme Verlag, Stuttgart, New York, 1999, "Foams"). The metallized materials are preferably wood, glass, leather, plastics, minerals, foams, fiber materials and fiber-reinforced materials.

The minerals are preferably fired and unfired clay, ceramics, natural or artificial stone or cement, the fiber materials are glass fibers, ceramic fibers, carbon fibers, textile fibers, plastic fibers or metal fibers and composites of these fibers, and the fiber-reinforced materials are plastics that are reinforced with the above fibers.

The metals are preferably reactive consumer metals, in particular iron, steel, zinc, aluminum, magnesium, titanium and the alloys of at least two of these metals.

The molded parts are preferred

Components for motor vehicle construction, in particular parts of motor vehicle bodies, such as mudguards, fenders, spoilers, bonnets, doors or reflectors of lamps,

sanitary articles and household appliances,

Components for buildings indoors and outdoors,

Components for doors, windows and furniture,

industrial components, including coils, containers and radiators, as well electrotechnical components, including winding goods, such as coils of electric motors.

In particular, however, the molded parts are SMC (sheet molded compounds) or BMC (bulk molded compounds). Depending on the manufacturer, the SMC and BMC can have a wide variety of technological properties and a wide variety of properties. "Semi-finished products" (ie the mixture that has not yet been processed in the mold) SMC and BMC contain unsaturated polyesters, fillers of all kinds, glass fibers and additives such as inhibitors to improve storage stability and initiators to start the polymerization as well as mold release agents. About the choice of SMC / BMC pigments can also be made conductive. Due to the fillers, SMC / BMC can draw moisture. Depending on requirements, the processing of the semifinished product into the molded part sets the viscosity, density, strength and other factors via the exact composition of possible porosity, additive concentration on the surface of the molded part and structure, these features generally having a negative effect on the adhesion of coatings. It is a particular merit of the coating materials according to the invention and the method according to the invention that the seals and Beschic attachments to a wide variety of SMC and BMC.

According to the methods of the invention, for the purpose of producing the moldings and compounds according to the invention, the coating material to be used according to the invention is applied to the surface of the moldings, in particular the BMC and SMC.

One or more layers of the coating material according to the invention can be used in the process according to the invention be applied. If several layers are applied, coating materials of different material composition according to the invention can be used. In most cases, however, the desired property profile of the molded parts and compounds according to the invention is achieved with a coating made of a coating material.

The layer of the coating material is applied in a wet layer thickness that results in a dry layer thickness of the seal of 10 to 100, preferably 10 to 75, particularly preferably 10 to 55 and in particular 10 to 50 μm after curing in the finished molded part or compound according to the invention.

The application of the coating material according to the invention can be carried out by all customary application methods, e.g. Spraying, knife coating, painting,

Pour, dip or roll. Preferably be

Spray application methods applied, such as

Pneumatic spraying, airless spraying, high rotation, electrostatic

Spray application (ESTA), possibly combined with hot spray application such as hot air hot spraying. The application can be used for

Temperatures of max. 70 to 80 ° C are carried out so that suitable application viscosities are achieved without a change in the short-term thermal load or

Damage to the coating material and any overspray that may need to be reprocessed. For example, hot spraying can be designed in such a way that the coating material is only heated very briefly in or shortly before the spray nozzle.

The spray booth used for the application can be operated, for example, with a circulation that can be tempered if necessary a suitable absorption medium for the overspray, e.g. B. the coating material of the invention itself is operated.

The application is preferably carried out when illuminated with visible light of a wavelength of over 550 μm or with exclusion of light. This avoids material changes or damage to the coating material according to the invention and the overspray.

Of course, the application methods described above can also be used for overpainting the coatings or seals of the invention.

According to the invention, the layer of the coating material according to the invention is cured thermally and with actinic radiation after its application, so that the sealing according to the invention results.

Curing can take place after a certain period of rest. It can have a duration of 30 s to 2 h, preferably 1 min to 1 h and in particular 1 min to 30 min. The idle time is used, for example, for the course and degassing of the layer from the coating material or for the evaporation of volatile constituents such as solvents, water or carbon dioxide if the coating material has been applied with supercritical carbon dioxide as a solvent. The drying that takes place during the rest period can be supported and / or shortened by using elevated temperatures of up to 80 ° C, provided that there is no damage or changes to the coating material layer, such as premature complete crosslinking. Curing is preferably carried out using UV radiation or electron beams. If necessary, it can be carried out or supplemented with actinic radiation from other radiation sources. In the case of electron beams, work is preferably carried out under an inert gas atmosphere or an oxygen-depleted atmosphere. This can be ensured, for example, by supplying carbon dioxide and / or nitrogen directly to the surface of the layer made of the coating material according to the invention. Even in the case of curing with UV radiation, in order to avoid the formation of ozone, work can be carried out under an inert gas or in an oxygen-depleted atmosphere.

The usual and known radiation sources and optical auxiliary measures are used for curing with actinic radiation. Examples of suitable radiation sources are high-pressure or low-pressure mercury lamps or electron beam sources. Their arrangement is known in principle and can be adapted to the conditions of the workpiece and the process parameters. In the case of workpieces of complex shape, such as those intended for automobile bodies, the areas which are not directly accessible to radiation (shadow areas), such as cavities, folds and other undercuts due to construction, can be combined with point, small area or all-round emitters with an automatic movement device for irradiating cavities or Edges are (partially) cured.

The facilities and conditions of these hardening methods are described, for example, in R. Holmes, UN. and EB Curing Formulations for Printing Inks, Coatings and Paints, SITA Technology, Academic Press, London, United Kingdom 1984, in German patent application DE 198 18 735 A1, column 10, line 31 to column 11, line 22, by R. Stephen Davidson in Exploring the Science, Technology and Applications of UN. and EB Curing «, Sita Technology Ltd., London, 1999, Chapter I,» An Overview «, page 16, Figure 10, or by Dipl.-Ing. Peter Klamann in "eltosch system competence, UV technology, guidelines for users", page 2, October 1998.

The curing can take place in stages, i. H. by multiple exposure or exposure to actinic radiation. This can also take place alternately, i. that is, curing alternately with UV radiation and electron radiation.

The thermal curing also has no special features in terms of method, but is carried out according to the customary and known methods, such as heating in a forced air oven or irradiation with IR lamps. As with actinic radiation curing, thermal curing can also be carried out in stages. The thermal curing is advantageously carried out at a temperature of up to 120 ° C., particularly preferably up to 110 ° C., very particularly preferably up to 100 ° C. and in particular up to 90 ° C., preferably for a time of 1 min to 2 h, preferably 2 min to 1 h and in particular 3 to 30 min.

Thermal curing and curing with actinic radiation can be used simultaneously or alternately. If the two curing methods are used alternately, thermal curing can be started, for example, and curing with actinic radiation can be ended. In other cases, it may prove advantageous to start with the end of curing with actinic radiation. The person skilled in the art can determine the hardening method which is most advantageous for the individual case on the basis of his general specialist knowledge, if necessary with the aid of simple preliminary tests. The layers of the coating materials according to the invention can also be cured excellently in the shadow zones of the molded parts.

It is a very special advantage of the process according to the invention that the moldings and SMC and BMC coated with the coating material according to the invention can be immediately overpainted after drying and irradiation with actinic radiation, preferably in a state which is not fully cured, which is important for the production of the inventive Molded parts and the SMC and BMC according to the invention means significant time, energy and cost savings.

In a particularly advantageous embodiment of the method according to the invention, an electrically non-conductive coating material according to the invention is applied to the SMC and BMC. The applied layers are partially hardened with actinic radiation, in particular UV radiation. The partially hardened layers are then coated with a customary and known electrically conductive two-component coating material (two-component guide primer), or with an electrically conductive coating material according to the invention, in particular a two-component guide primer, after which the two layers are thermally cured together.

On the other hand, the molded parts and SMC and BMC coated with the coating material according to the invention can be thermally post-cured after drying and irradiation with actinic radiation, for example for 20 minutes at 90 ° C., after which the molded parts according to the invention and the SMC and BMC according to the invention until further processing, in particular for overpainting, can be stored in stacks without problems of sticking or deforming. The electrically conductive coatings and seals according to the invention are outstandingly suitable for the application of further coating materials with the aid of electrostatic high rotation (ESTA) or with the aid of electrophoretic application processes such as anodic or cathodic electrocoating.

The molded parts and compounds according to the invention obtained in the procedure according to the invention show no signs of microbubbles (microbubbling or blistering). Their surface is smooth and free from interference. Their thermal stability is excellent: the surface is not damaged even after several hours of thermal stress at high temperatures. The molded parts and compounds according to the invention can therefore, for example, be installed directly in uncoated automobile bodies and, together with them in the line - also electrophoretically - painted.

The coatings and seals obtained in the process according to the invention have excellent flexibility and excellent adhesion to a wide variety of substrates, so that the moldings and compounds according to the invention can be easily deformed without the coatings thereon being mechanically damaged. They are also extremely easy to grind and polish, so that damaged areas can be repaired very easily.

The coatings and seals can be applied with all customary and known aqueous or conventional, liquid or solid, anhydrous and solvent-free, physically or thermally and / or with actinic radiation-primers, electrocoat materials, fillers or stone chip protection primers, color and / or effect uni-paint or basecoats as well as clear coats. The resulting multicoat paint systems have excellent intercoat adhesion.

Examples

Manufacturing Examples 1 and 2 ^• 5

The production of electrically conductive coating materials

For the production of the coating materials of preparation examples 1 and 2, a mixed lacquer was first prepared by mixing and homogenizing the following components in the order given:

32 parts by weight of a saturated polyester with an OH content of 4.4%, based on the solids, solids content of 71-73%, an acid number of 6.5 to 9.8, a viscosity of 4.0 to 5 5.8 Pas at 23 ° C and 100s ^"1 (Setal® 1715 from Akzo),

15 parts by weight of an acrylated aliphatic urethane oligomer with an OH number of 76-90, a solids content of 100%, a theoretical functionality of 3.9 and a Höppner viscosity of approx. 4500 mPas at 25 ° C. (Ebecryl® 8210 from the company

UCB)

0.47 part by weight of a rheology aid (Bentone® SD2 from Rheox), 5

0.24 part by weight of a dispersant (Antiterra® U from Byk),

4.03 parts by weight of xylene, 0

2 parts by weight of butyl acetate, 6.8 parts by weight of a commercially available filler (microcrystalline talc, Mistron® Monomix from Luzenac),

10.2 parts by weight of ethyl ethoxypropionate (EEP),

15.8 parts by weight of an electrically conductive micapigment (Minatec® 40 CM from Merck),

- 2 parts by weight of a tackifier (LTW polyester adhesive resin from the company

Degussa, 60% in xylene),

0.2 part by weight of a lithium salt catalyst (Nuodex® Ll from OMG),

0.96 part by weight of a photoinitiator (Lucirin® TPO from BASF Aktiengesellschaft) and

10.2 parts by weight of EEM.

The coating material of preparation example 1 was prepared shortly before application by mixing and homogenizing 100 parts by weight of the mixed lacquer and 10 parts by weight of a 75% by weight solution of a technical mixture of 2,4- and 2,6-tolylene diisocyanate in ethyl acetate (Desmodur® L 75 manufactured by Bayer AG (isocyanate content: 11.5 to 13%). The coating material of preparation example 2 was prepared shortly before application by mixing and homogenizing 100 parts by weight of the mixed lacquer, 5 parts by weight of a 75% by weight solution of a technical mixture of 2,4- and 2,6-tolylene diisocyanate in ethyl acetate (Desmodur® L 75 from Bayer AG (isocyanate content: 11.5 to 13%) and 5 parts by weight of a 90% by weight solution of the trimers of hexamethylene diisocyanate in solvent naphtha® (Desmodur® N3300 from Bayer diluted to a 90% solution) ,

Manufacturing Examples 3 and 4

The production of non-conductive coating materials

For the production of the coating materials of preparation examples 3 and 4, a mixed lacquer was first produced by mixing and homogenizing the following components in the order given:

35.2 parts by weight of a saturated polyester (Setal © 1715 from Akzo, 75% in solvent naphtha © / xylene - see Preparation Examples 1 and 2),

16, with parts by weight of an acrylated aliphatic urethane oligomer (Ebecryl® 8210 from UCB - see Preparation Examples 1 and 2),

0.51 part by weight of a rheology aid (Bentone ® SD2 from Rheox),

0.26 part by weight of a dispersant (Antiterra® U from Byk), 4.4 parts by weight of xylene,

5.6 parts by weight of EEP,

- 0.5 parts by weight of a leveling agent (Disparlon ® LC 900 der

Kusutomo Chemicals),

24.7 parts by weight of a white micapigment (Mircavor ® 20 from dam mineraux),

2.2 parts by weight of a tackifier (LTW polyester adhesive resin from Degussa, 60% in xylene),

0.22 part by weight of a lithium salt catalyst (Nuodex® Ll from OMG),

BASF Aktiengesellschaft),

5.72 parts by weight of EEM

- 3.427 parts by weight of butyl acetate.

The coating material of manufacturing example 3 was shortly before

Application by mixing and homogenizing 100

Parts by weight of the mixed lacquer and 10 parts by weight of a 75% by weight solution of a technical mixture of 2.4 and 2.6 Toluene diisocyanate in ethyl acetate (Desmodur © L 75 from Bayer AG (isocyanate content: 11.5 to 13%)).

The coating material of preparation example 4 was prepared shortly before application by mixing and homogenizing 100 parts by weight of the mixed lacquer, 5 parts by weight of a 75% by weight solution of a technical mixture of 2,4- and 2,6-tolylene diisocyanate in ethyl acetate (Desmodur © L 75 from Bayer AG (isocyanate content: 11.5 to 13%) 5 parts by weight of a 90% by weight solution of the trimers of hexamethylene diisocyanate in solvent naphtha® (Desmodur® N3300 from Bayer diluted to a 90% solution).

Examples 1 to 4

The production of seals on SMC and BMC

In Examples 1 to 4, the coating materials of preparation examples 1 to 4 were applied to a wide variety of porous surfaces, in particular SMC and BMC, using customary pneumatic or electrostatic methods.

After application, the resulting layers of the coating materials were flashed off and dried and then irradiated with UV radiation. This resulted in partially hardened, electrically conductive seals with a dry layer thickness between 10 and 50 μm. They were characterized by the complete absence of microbubbles. They had excellent flexibility and hardness and could be painted over immediately with commercially available primers or electro-dipping paints. After complete curing, the resulting primers and electrocoats adhered excellently to the Sealers. The seal in turn adhered excellently to the substrates.

According to a further variant, after application, the resulting layers of the coating materials of preparation examples 1 and 2 were flashed off and dried and then irradiated with UV radiation. They were then thermally hardened at 90 ° C. for 20 minutes. This resulted in hardened, electrically conductive (Examples 1 and 2) and non-conductive (Examples 3 and 4) seals with a dry layer thickness between 10 and 50 μm. They were characterized by the complete absence of microbubbles. They were also fully cured in the shadow zones of the molded parts, especially the SMC and BMC. They had excellent flexibility and hardness. The coated molded parts, in particular the SMC and BMC, could easily be stored in stacks until further processing without mechanical damage to the seals or their sticking. The paintability of the seals and the adhesion between them and the paintwork above were excellent. Like. the adhesion of the seals to the substrates was excellent: the adhesion was measured with the help of tests from Volvo and DaimlerChrysler known to the experts, test specification DBL5416. The adhesion in the cross cut test with tesa tear (DBL5416, 6.4 = DIN 53151) was excellent: in all cases grade GTO.

Claims

claims

1. Thermally and with actinic radiation curable coating material containing

(a1) at least one component with

(a11) a statistical average of at least two functional ones

Groups per molecule which contain at least one bond which can be activated with actinic radiation and which serves for crosslinking with actinic radiation, and if appropriate

(a12) at least one isocyanate-reactive group,

and

(a3) at least one aromatic polyisocyanate free of functional groups (a11) or a mixture of at least one aromatic polyisocyanate free of functional groups (a11) and at least one (cyclo) aliphatic free of functional groups (a11)

Polyisocyanate.

2. Coating material according to claim 1, characterized in that the isocyanate-reactive groups (a12) from the group consisting of hydroxyl, thiol, primary and secondary

Amino groups and imino groups can be selected.

3. Coating material according to claim 1 or 2, characterized in that the functional groups (a11) are carbon-carbon double bonds ("double bonds").

4. Coating material according to claim 3, characterized in that the double bonds are present in acrylate groups.

5. Coating material according to one of claims 1 to 4, characterized in that the functional groups (a12)

Are hydroxyl groups.

6. Coating material according to one of claims 1 to 5, characterized in that the oligomers and polymers (a2) from the group consisting of (meth) acrylate (co) polymers,

Polyesters, alkyds, aminoplast resins, polyurethanes, polylactones, polycarbonates, polyethers, epoxy resin-amine adducts, (meth) acrylate diols, partially saponified polyvinyl esters and polyureas can be selected.

7. Coating material according to one of claims 1 to 6, characterized in that in the mixture (a3) the weight ratio of aromatic polyisocyanate to (cyclo) aliphatic polyisocyanate is 95: 5 to 5: 95.

8. Coating material according to one of claims 1 to 7, characterized in that the aromatic polyisocyanates (a3) are selected from the group of polyisocyanates based on the technical mixtures of 2,4- and 2,6-tolylene diisocyanate.

9. Coating material according to one of claims 1 to 8, characterized in that the (cyclo) aliphatic polyisocyanates are selected from the group consisting of polyisocyanates based on hexamethylene diisocyanate and based on isophorone diisocyanate.

10. Coating material according to one of claims 1 to 9, characterized in that the coating material contains at least one electrically conductive pigment.

11. Coating material according to claim 10, characterized in that the electrically conductive pigment has a refractive index <....

12. Coating material according to claim 11, characterized in that the electrically conductive pigment is a mica pigment.

13. Coating material according to one of claims 1 to 13, characterized in that it contains a transparent filler.

14. Coating material according to claim 13, characterized in that the filler is transparent to UV radiation.

15. A method for coating microporous surfaces, in which the surfaces in question are coated with at least one thermally and with actinic radiation curable coating material, after which the resulting layer (s) are thermally hardened and with actinic radiation, characterized in that at least one coating material according to one of claims 1 to 14 used.

16. The method according to claim 15, characterized in that drying the layer of the coating material and, preferably in a not fully cured state, irradiated with actinic radiation and immediately overpainted.

5

17. The method according to claim 15, characterized in that the layer is dried from the applied coating material, irradiated with actinic radiation and thermally cured before the overcoating.

10

18. The method according to claim 17, characterized in that the coated moldings and compounds are stored before coating, preferably in stacks.

15 19. The method according to claim 10, characterized in that the relevant surfaces with

(1) at least one electrically non-conductive coating material according to one of claims 1 to 9

20 coated,

(2) the resulting layer (1) partially cures with actinic radiation and

25 (3) the partially hardened layer (2) with an electrically conductive two-component coating material or an electrically conductive coating material according to one of claims 10 to 14 overcoated, after which

30 (4) the resulting electrically conductive layer (3) and the partially hardened layer (2) together thermally harden. 56

20. The method according to any one of claims 15 to 19, characterized in that the pores have a width of 10 to 1,500 nm.

21. The method according to any one of claims 15 to 20, characterized in that the microporous surfaces are electrically conductive.

22. The method according to any one of claims 15 to 21, characterized in that it serves to coat components for motor vehicle construction.

23. The method according to claim 22, characterized in that the components SMC (sheet molded compounds) or BMC (bulk

Molded Compounds).

24. The method according to any one of claims 15 to 23, characterized in that the thermal curing takes place at temperatures up to 120 ° C.