FI78490B - GENOM STRAOLNING HAERDBARA BINDEMEDELSSYSTEM, FOERFARANDE FOER FRAMSTAELLNING AV DEKORATIONSBELAEGGNINGAR GENOM DEM OCH PAO SAO SAETT FRAMSTAELLDA BELAEGGNINGAR. - Google Patents

Abstract

1. Radiation-curable binder systems containing one or more unsaturated monomers and/or prepolymers curable by polymerisation and/or crosslinking, optionally an initiator which initiates the curing, as well as pigments, and, optionally, dyestuffs, fillers and additives, characterised in that the pigment contained therein is a pearlescent pigment.

Description

The invention relates to irradiable curable binder systems comprising one or more polymerizable and / or crosslinkable curable monomers and / or prepolymers and optionally initiators, optionally initiating , fillers 10 and additives. Such binder systems are used in the manufacture of decorative coatings, especially for planar materials such as paper, metal and the like. They are used in printing technology as light-curable inks or for coating labels, record cases 15 or book covers with a colorless lacquer coating and for coating tubes, boxes or bottles or also for ceramic tiles and covers, such as roof tiles used especially in Japan.

20 In order to create a decorative metallic effect, so-called aluminum, copper and the like are added to these systems. pronsseja. The surface of these metal flakes, called bronzes, is treated in a certain way to prevent interaction with the other components of the binder system. Despite these measures, binder systems containing such metal bronzes are poorly resistant to dark contrast. It has been found that despite the absence of radiation that initiates curing, the system gels in a relatively short time and thus becomes unusable.

Thus, the task has been to invent a binder system for the production of metallic coatings with improved storage stability. The goal of Li-35 has been to invent binder systems with a reduced cure time of 2,78490.

This object is solved by providing binder systems which contain pearlescent pigments instead of metal bronzes.

The invention therefore relates to irradiated curable binder systems comprising one or more polymerizable and / or crosslinkable curable monomers and / or prepolymers, optionally a curing initiator and pigments 10 and optionally dyes, fillers and additives, and characterized by: they contain a pearlescent pigment as a pigment.

The invention also relates to a method for forming decorative cured coatings by applying an irradiating curable binder system and then initiating curing by UV or electron irradiation using a binder system containing a pearlescent gloss pigment.

Finally, the invention also relates to radiation-curable metallic coatings thus prepared which contain a pearlescent pigment.

The main advantage of the binder systems according to the invention is their considerably improved storage stability, which allows the systems according to the invention to be stored for a long time without the systems becoming unusable due to premature curing, slow viscosity increase, gelation and finally complete stiffening.

With the exception of the pearlescent pigment, the composition of the binder systems of the invention is conventional. The main components of these systems are polymerizable or crosslinkable compounds which are monomers or oligomers. Such compounds include, for example, ethylenically unsaturated monomers such as esters of acrylic or methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, and N- and C-substituted acrylamides, vinyl esters and corresponding vinyl compounds, and such vinyl compounds, allyl compounds. Also important are unsaturated oligomers or poly-5 polymers and mixtures thereof with unsaturated monomers. These include thermoplastic resins containing unsaturated groups, e.g. fumaric acid esters, allyl groups or acrylate and methacrylate groups. Examples of oligomers which can be used singly or multiply with unsaturated monomers are unsaturated polyesters, unsaturated acrylic resins and isocyanate or acrylamide acryloidylated acrylate oligomers, especially uriconipers, urethanes, siletates, acrylated urethanes, acrylated polyamides, acrylated soybean oil, acrylated epoxy resin and acrylated acrylic resin.

In addition to binder systems based solely on organic monomers and oligomers, there are also aqueous binder systems in which the oligomer is either as an aqueous emulsion or, in the case of water-dilutable oligomers, as a colloidal solution. The viscosity of these aqueous systems is not controlled by the amount of organic monomers, but by the amount of water, which in many cases is advantageous due to the potential hazard associated with volatile monomers.

One skilled in the art is familiar with all of these base materials and also knows how the choice and mixing of these materials can vary both the consistency of the unpolymerized mixture and the properties of the cured resin.

Binder systems can be cured, e.g., by irradiation with electrons, in which case no initiator initiating polymerization (curing) is required. But most often, however, curing is initiated by irradiation with this UV light. For this purpose, photoinitiators are added. These are, for example, benzoin derivatives, in particular benzoin ethers, diakoxyacetophenones and hydroxyalkylphenones known from DOS publications 2,711,264 and 2,808,459, which are added to the monomers and prepolymers in an amount of about 0.05 to 15% by weight. In addition, curing can be accelerated by the addition of co-initiators, e.g. amines, phosphines or reducing agents. Such co-initiators are known, for example, from DOS Publication 2,251,048.

Depending on the application, radiation-curable binder systems further contain conventional additives, e.g. fillers such as silicic acid, talc or gypsum, pigments, dyes, fibers, thixotropic agents, flow aids, naphthenes and, optionally, substances to protect the mixture from premature hydration, premature polymerization, -stylamines, to improve storage stability and prevent the effect of oxygen in the air. All of these additives are known and are used in a known manner.

But crucial to the improvement of the binder systems of the invention is the use of pearlescent pigments instead of the known metal bronzes. Suitable pearlescent gloss pigments are in principle all pearlescent gloss pigments such as natural fish silver, basic lead carbonate, bismuth oxychloride, mica flakes coated with metal oxides or also scaly metal oxides without carrier. Due to their low cost, low toxicity, high mechanical stability and general applicability, metal oxides, especially titanium oxide and coated mica flakes, which are described, for example, in German patents and patent applications 14 67 468, 20 09 566, 22 14 545, 22, are particularly preferred. 15 191, 22 44 298, 23 13 331, 24 29 762 35 and 25 22 572.

The particle size of the pigments used is generally from about 1 to 200 [mu] m, preferably from about 5 to 80 [mu] m and in particular from about 10 to 50 [mu] m. However, it may be advantageous to use very large or very small particles for special purposes. In this case, it must be taken into account that very large particles, i.e. about 200 .mu.m in size, have a very strong metallic luster, while small particles in the range of about 1-5 .mu.m have a silkier luster. Of course, the thickness of the coatings to be produced must also be taken into account when selecting pearlescent pigments for a given 10 cases.

The binder systems of the invention generally contain about 0.2 to 50% by weight, preferably about 0.5 to 30% by weight of pearlescent pigments, and in most cases the content is in the range of about 0.5 to 20% by weight.

The binder systems according to the invention, like the known binder systems, are prepared simply by mixing the components and are immediately ready for use. The use is effected by applying the mixture as a thin coating to the material to be coated and then irradiating the coating with a radiation source, in particular a light source emitting high shortwave light such as mercury, low or medium pressure lamps or superactive fluorescent tubes or electron beam.

Light curing is another advantage of the binder systems of the invention. Curing of systems pigmented with conventional metal bronzes requires relatively high radiation doses, with the required exposure time still increasing sharply as the pigment content increases, but only a small dose is required to cure the systems of the invention, which does not depend much on the amount of pigment added. In comparison, where either the radiant energy or the radiation time is kept the same, the applied coating is harder when using the systems according to the invention or, if the hardness is predetermined, can be operated with considerably less radiant energy. The method according to the invention can thus be used to produce, in a very advantageous manner, qualitatively high-quality coatings with an excellent metal gloss.

Example 1 To prepare a UV-curable varnish, to 184 g of a mixture of 80 parts by weight of hexanediol acrylate-10 and 120 parts by weight of polyester acrylate resin (R) (Laromer LR 8549, fima BASF) was added 10 g of 2-hydroxy-2- methyl 1-phenylpropan-1-one (Daro (r) (Darocur 1173, E. Merck film) and 6 g of N-methyldiethanolamine as a co-theatrifier and mixed into a homo-15 gene mixture. By mixing 10 g of silver mica / titanium dioxide pigment with 90 g of this the mixture was obtained as a varnish very durable.

To obtain a cured coating, this varnish was applied in a 120 μm thick layer to glass sheets which were fed at a belt speed of 20 m / min through an irradiator and cured by irradiation with two mercury-medium pressure lamps with a combined power of 120 W / cm. Viewed against a black background, the cured coatings looked very metallic and resembled 25 varnishes pigmented with metal bronze in this respect.

Example 2 For a UV-curable binder system with 130 g Reaktivharz VP S 1748 from Degussa (= reaction resin based on acrylated polyurethane), 30 g of pentaerythritol (tetra) acrylate and 40 g of hexanediol diacrylate (R) were dispersed with stirring in 60 g of Iri Goldsatin, E. Merck (mica / TiO 2 based pearlescent pigment, particle size approx. 5-20 μm). To initiate photopolymerization, 20 g of Darocur 1664, E. Merck (a combination of photoinitiators of aryl ketones) and 10 g of N-methylethanolamine as a co-initiator were added to the non-agglomerated dispersion and mixed until uniform.

The UV-curable system was applied in a 60 μm thick layer to a hard PVC film and irradiated in a UV irradiator with a belt feed rate of 10 m / min, a lamp power of 120 W / cm and an exposure distance of about 10 cm.

Radiation hardening gave a through-hardened, co-10 Scientific, gold bronze (gold) colored and dry surface coating.

Example 3 In a UV-curable binder system with (R) 120 g of Laromer LR 8549, BASF (= monomer-free, unsaturated polyester acrylate resin) and 80 g of hexanediol diacrylate / R1 were dispersed with stirring 60 g of Biron 'Silver CO, film Rona ( paste with 70% BiOCl as a pearlescent pigment). To initiate photopolymerization, 15 g (R1) was added to the lump-free dispersion with stirring.

Darocur 1173 (1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one), E. Merck.

A sample of the UV-curable system was applied as a 24-μm-thick layer on black paper and irradiated in a UV irradiator with a belt feed rate of 5 m / min, a lamp power of 80 W / cm and an exposure distance of about 10 cm.

Radiation curing gave a through-cured, decorative, silver-gloss and dry-surfaced coating.

Example 4 For a UV-curable binder water system with 80 g of Laromer® LR 8576, BASF (= 50% aqueous emulsion of unsaturated acrylate resin) (R) 12 g aqueous solution with 7.5% Luvisko K 90 , company (R) 35 BASF (= polyvinylpyrrolidone) and 0.5% Tylose H 300, Farbwerke Hoechst (= hydroxyethylcellulose) 8 78490 2 g n-butanol [R) 1 g Marlopon AT 50 # Chemische Werke Carbon (= triethanolamine salt of dodecylbenzenesulfonic acid, 50% active ingredient) was dispersed with stirring 5 g of 100 Silberperl of Iriod, E. Merck (mica / TiO 2 based pearlescent pigment, particle size approx. 10-50). To initiate the photopolymerization, 5 g (R) of

Darocur 953 (1- (4-dodecylphenyl) -2-hydroxy-2-10 methylpropan-1-one), E. Merck.

A sample of the UV-curable aqueous system was applied in a 250 μm thick layer to black paper and dried for five minutes at 100 ° C. The anhydrous coating was then cured by UV irradiation so that the power of the lamps 15 was 80 W / min, the exposure distance was about 10 cm and the belt feed speed was 10 m / min.

Radiation hardening gave a through-cured, silver-gloss and dry-surfaced coating.

Example 5 In 120 g of PLEX '^ 6724-0, Rohm (= mixture of a certain methacrylate polymer, UV-curable acrylates and vinyl heterocycles) was dispersed with stirring (R) 6.3 g of Iriod 130 Glitzerperl, E.

Merck (= mica / T102 based pearlescent pigment, particle size approx. 15-130 μm). To initiate photopolymerization, 6.3 g of Darocur 1173, from E. Merck, was added to the non-agglomerated dispersion with stirring.

A white-stained, drilled polystyrene ball 30 (diameter 2 cm) was dipped in the pigmented, UV-curable system. The coated ball was then cured with UV radiation for five minutes under a suitable UV radiator with continuous rotation. The dipping and UV curing were suitably repeated once or twice.

In this way, a decorative, silver glitter-35 va ball was obtained, which can optionally be coated with a UV-curable clear lacquer.

»9 78490

Example 6

Proceed exactly as in Example 5, but did not use 6.3 g of Iriodin 130 Glitzperl, but (R) 6.3 g of Iriodin 300 Goldperl and instead of 5 polystyrene balls colored in white, a black-colored polystyrene ball of the same size was used. .

This system gave a decorative, gold-bronze (gold) colored ball with a dry surface.

Example 7 A UV-curable, pigmented system was prepared as described in Example 5, but without mixing 6.3 g of Iriod 130 Glitzperl but 7.9 g of (R)

Iriodin PO0 A 65, company E. Merck (= paste with 65% basic lead carbonate as pearlescent pigment-15 as tin).

About 10 g of a UV-curable, pigmented system was added to a degreased glass flask. The flask was equipped with a filling tube (glass ball diameter 6 cm, tube diameter 1.5 cm). The inner wall of the glass ball-20 was moistened by rotating it continuously. Excess varnish was poured off. The inner coating was then cured by UV irradiation by rotating the glass ball continuously (R) for 10 minutes under a Vitalux lamp, Osram. The coating and UV curing of the coating is repeated so many times as to obtain a silver-gloss glass sphere.

Example 8 A UV-curable binder water system with 50 g of Purelast 145, Polymer System (= water-soluble urethane acrylate oligomer) and 50 g of water (R) was dispersed with stirring in 8.8 g of Iriodin '120 Glanzsatin, E. Merck ( mica / T1O2 based pearl wedge pigment, particle size about 5-20 .mu.m). To initiate photopolymerization, 2.6 g of Darocur '' 1173, E. Merck, was added to the non-lumpy dispersion and mixed until uniform.

A sample of 10,78490 UV-curable binder system was applied in a 60 μm thick layer to a glass plate (10 x 10 cm) fed through a UV irradiator at a belt speed of 0.5 m / min and cured so that the power of the lamps 5 was 120 W / cm and an exposure distance of about 10 cm.

A coating on the glass was obtained which, when viewed against a black background, looked silver and silky matt.

Example 9 By irradiation to a curable binder system with (R) 81.0 g of Actilane 18, SNPE, Paris (= oligomeric, aromatic polyurethane acrylate) 39.0 g of N-vinylpyrrolidone 22.5 g of ethyl diglycol acrylate 7.5 g of hexanediol ) 0.8 g of Dow Corning 193 surfactant, Dow Corning GmbH, Munich (= silicone-glycol copolymer as wetting agent) was dispersed with stirring 37.7 g of Iriod 500 bronze, E. Merck (= mica / TiO2 based pearl gloss pigment, particle size 10-50 μm). The binder system was applied in a 120 μm thick layer (= wet film thickness) to a hard PVC sheet and then cured by electron irradiation in a laboratory apparatus, type ESH 150-020, Polymer Physik, Tiibingen, under the following conditions:

Acceleration voltage: 150 kV

Electron current: 12 mA

30 Lateral deviation: 10 x 22 cm

Feed speed: 15.6 m / min Radiation dose: 10 megarads

Inerting: with nitrogen

A through-cured, decorative, gold-35 bronze-colored coating was obtained.

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Example 11 By irradiation into a curable binder water system with 160.0 g of Laromer® LR 8576, BASF (= about 50% aqueous emulsion of unsaturated acrylate resin, no organic solvents or monomers) 4.0 g of butanol (R) 4.0 g aqueous solution with 7.5% Luviskol K 90, BASF {= polyvinylpyrrolidone) and 0.5% (Dl 10 Tylose H 300, Farbwerke Hoechst (= hydroxyethylcellulose) 2.0 g Marlopon® AT 50, Chemische Werke Hvils (= triethanolamine salt of dodecylbenzenesulfonic acid, 50% active ingredient) (Rt 15 dispersed with stirring 30.0 g of Iriod 100

Silberperl, Merk (= mica / TiO 2 based pearlescent pigment, particle size 10-50 μm).

The binder system was applied in a 120 μm thick layer to a primed and sanded plywood board. Water 20 was removed from the applied coating by drying for five minutes at 100 ° C. The anhydrous coating was then cured by electron irradiation in a laboratory apparatus, type ESH 150-020, Polymer Physik, Tubingen, under the following conditions:

25 Acceleration voltage: 150 kV

Electron current: 12 mA

Side deviation: 10 x 22 cm

Feed speed: 15.6 m / min Radiation dose: 10 megarad 30 Inerting: with nitrogen

A through-cured, decorative silver-glossy and dry-surfaced coating was obtained.

Claims (7)

12 73490 Irradiation of curable binder systems useful in the manufacture of decorative coatings for particularly planar materials such as paper, wood, metal and the like and containing one or more polymerizable and / or crosslinkable curable monomer and / or prepolymer and an optional pigment initiator Dyes, fillers and additives, characterized in that they contain a pearlescent gloss pigment as a pigment. Radiation-curable binder systems according to Claim 1, characterized in that they contain about 0.2 to 50% by weight of pearlescent pigment. Radiation-curable binder systems according to Claim 1 or 2, characterized in that they contain a mica pigment coated with metal oxides as a pearlescent gloss pigment. A method of forming decorative, cured coatings by applying an irradiating curable binder system and then initiating curing by UV or electron irradiation, characterized in that a binder system according to claim 1 is used. Method according to Claim 4, characterized in that a binder system according to Claim 2 is used. Method according to Claim 4, characterized in that a binder system according to Claim 3 is used. Irradiation-curable, metallic coatings, characterized in that they are produced by the method according to claim 4.