KR20040007500A - Coating compostion capable of absorbing uv radiation - Google Patents

Abstract

Coating compositions capable of absorbing UV or UV and visible light are disclosed. The coating composition comprises a carrier and a pigment dispersed therein. The pigment may comprise nanoparticles of a UV light absorber such that the coating composition may absorb UV light of 360 nm or less, or nanoparticles of UV and visible light absorber such that the coating composition may absorb UV and visible light of 550 nm or less. Particles, and absorbents include inorganic materials.

Description

코팅 Coating composition which can absorb radiation {COATING COMPOSTION CAPABLE OF ABSORBING UV RADIATION}

Transparent containers that are not colored are known to fail to protect the photosensitive content in the container from the harmful effects of UV light or UV and visible light.

According to the prior art, only completely opaque containers (eg metal cans and cardboard containers) and translucent containers (eg amber glass or plastic containers) can block UV and visible light.

Fully opaque or dark amber colored containers have a less favorable preference than transparent containers in situations where the consumer would like to see the contents of the container.

According to market research, consumers are particularly favored because transparent blue or green containers provide high quality images. It is commonly believed that blue or green transparent containers can provide protection from UV light or UV and visible light. In practice, however, the degree of protection of such a container is equally low as that provided by an uncolored transparent container.

A particular harmful effect of UV and visible light on beverages such as beer or wine is the formation of off-flavors called "lightstrikes." The human sense of smell is particularly sensitive to these off-flavors, so it is important to use UV and visible light blocking containers for these products.

One solution to the "light strike" problem in beer was to use chemically modified hops to remove the chemical precursors of the molecules causing off-flavor. However, these molecules are also chemicals that contribute to the bitter taste found by beer drinkers. Thus, many consumers' appetite for beer made this way falls significantly.

Typically, beer products are packaged in amber or green glass containers. A comparison of the UV and visible light shielding properties of amber glass and green glass is shown in FIGS. 1 (absorbance) and 2 (transmittance). As shown in FIG. 1, amber glass exhibits significant UV absorbance over the entire UV and substantial portion of the visible light spectrum, ie, generally in the wavelength range below 500 nm. On the other hand, green glass strongly absorbs wavelengths in the region below 320 nm but absorbs less in the 320-500 nm region. Because the light rays of these wavelengths are believed to be necessary for the formation of the "light strike" flavor, the results presented in Figures 1 and 2 are important.

Thus, while it can be seen that traditional green glass does not prevent the transmission of harmful harmful UV and visible wavelengths like amber glass, many brewers who produce these products nevertheless use green glass, and in fact consumer acceptance Is wide.

The requirement to increase the UV and visible light blocking capability of glass has been solved in the past by applying organic UV and visible light absorbing materials to the glass surface. Generally, these materials are sacrificial materials that absorb and decompose UV and visible light. Such materials are expensive and are not suitable for products with long shelf life due to the whitening action.

It is known that the selected metal oxide can strongly absorb the light spectrum of the UV and visible light region. However, such metal oxides lack the clarity and transparency suitable for use as an additive to the coating to be applied to the container in the context of being able to see the contents of the container.

It is an object of the present invention to provide a coating composition capable of protecting from UV or harmful wavelengths of UV and visible light.

The present invention relates to coating compositions that can prevent exposure to ultraviolet (“UV”) light or UV and visible light having wavelengths of less than 200 nm up to 500 or 550 nm.

In particular, the present invention relates to coating compositions that can be applied to containers used for the storage of photosensitive products. Non-limiting examples of such products include foods, beverages and pharmaceuticals.

1 compares the UV / Vis shielding properties of clear glass, green glass and amber glass used in beer bottles, expressed as UV / Vis absorbance.

FIG. 2 compares the UV / Vis shielding properties of clear glass, green glass and amber glass used in beer bottles, expressed as UV / Vis transmittance.

FIG. 3 shows the UV / UV of the amber glass used in (i) the coating composition according to the invention (compound A), (ii) transparent glass, and (iii) beer bottles, as described in UV / Vis absorbance. It is a figure comparing Vis shielding property.

FIG. 4 is a diagram comparing UV / Vis absorbance of the composition used in FIG. 3 with respect to UV / Vis absorbance of commercial glass products.

5 and 6 are comparisons of UV / Vis absorbances of a 1 micron film of a coating composition (compound B) according to the invention as disclosed in Example 1 with commercial glass products.

FIG. 7 is a comparison of the UV / Vis absorbances of 0.5 micron film and amber glass of the coating composition according to the present invention as described in Example 4 (compound RH503).

FIG. 8 is a comparison of the UV / Vis absorbances of amber glass with a 0.6 micron film of the coating composition according to the present invention as disclosed in Example 4 (brands RH502, RH504, RH505).

FIG. 9 is a view comparing UV / Vis absorbances of the membrane and the control coating of the ZnO-based coating composition according to the present invention as disclosed in Example 5. FIG.

Summary of the Invention

According to the present invention, there is provided a coating composition comprising a carrier and a pigment dispersed therein. The pigment may comprise nanoparticles of a UV ultraviolet absorber such that the coating composition may absorb a significant amount of incident UV light of 360 nm or less, or the coating composition may absorb a significant amount of incident UV and visible light of 550 nm or less. Nanoparticles of UV and visible light absorbers, and the absorber comprises inorganic materials.

The term “nanoparticle” herein is understood to mean that the particle is small enough to appear transparent without showing cloudiness in visible light.

With regard to the problem of accurately measuring the size of small particles, Applicants are not intended to be limited to the definition of the term “nanoparticle” based on the specific size range of the particles.

Preferred nanoparticles, however, are particles having an equivalent spherical diameter of less than 100 nm (0.1 micron).

More preferably, the nanoparticles do not contain significant concentrations of particles greater than 100 nm (as measured by transmission electron microscopy), and as a liquid coating composition and as a coating of the coating composition an agglomerate, lump or aggregate of individual particles No colloidal stabilizing effect.

More preferably, the nanoparticles are particles having an equivalent spherical diameter of less than 50 nm (0.05 micron).

A suitable kind of inorganic material for the absorbent is iron oxide.

Iron oxide based absorbents are particularly suitable for forming transparent colored coatings of coating compositions.

Iron oxide based absorbents are also particularly suitable for absorbing the UV and visible light spectrums.

Another suitable kind of absorbent inorganic material, though not unique, is zinc oxide.

Zinc oxide based absorbents are particularly suitable for forming colorless transparent coatings of coating compositions.

Zinc oxide based absorbers are also particularly suitable for absorbing the light spectrum of the UV region.

The pigment may contain one or more kinds of absorbents.

The pigment preferably further comprises pigment nanoparticles which provide the color of or cause the color of the coating composition.

By way of example, the pigment may comprise a blue or green pigment, or a combination of pigments yielding a blue or green pigment.

More preferably, the pigment further comprises nanoparticles of a blue or green pigment such that the coating composition is of a transparent blue or green color.

More preferably, the pigments comprise nanoparticles of blue or green pigments and yellow or red iron oxide absorbent pigments which surprisingly render the coating composition a transparent blue or green color.

The combination of a pale yellow or red iron oxide absorbent pigment and a blue or green pigment forms a coating composition with good UV and visible light absorption properties while exhibiting a transparent blue or green appearance which is a property useful in commercial terms.

The carrier is preferably capable of acting as a dispersant for (i) pigment particles and (ii) a film-forming agent.

Preferably the carrier is a polymeric material.

The carrier may be a composite of a plurality of materials having a range of properties.

For example, the material may include a material having mainly dispersion characteristics, a material having mainly deposition characteristics, and a material having dispersion characteristics and deposition characteristics.

Preferably, the deposition material is selected from the group comprising polyurethanes, polyesters, polyolefins, polyvinyl chlorides (eg polyvinyl chloride) and polyacryl.

According to the invention, a substrate having a coating of the coating composition is also provided.

The substrate can be made of any suitable material.

Examples of suitable materials are glass and plastic materials.

Preferably the substrate forms the wall of the container, such as a bottle, and the coating is on the outer surface of the container.

Preferably, the coating thickness is 100 microns or less.

More preferably, the coating thickness is 50 microns or less.

Coating thickness is related to the required degree of barrier and the concentration of UV light or UV and visible light (“UV / Vis”) absorbers in the pigment of the coating composition. Specifically, different combinations of (i) the concentration of UV / Vis absorbent and (ii) a range of coating thicknesses can provide a certain level of blocking.

The coating thickness can be made relatively small while the concentration of the UV / Vis absorber is biased relatively high at one extreme, and the coating thickness can be made relatively large while the concentration of the UV / Vis absorbent is relatively low biased by the other extreme.

This is important because it means that the concentration of UV / Vis absorbent and / or coating thickness can be varied to provide the desired physical properties of the coating, such as wear resistance, scuffing resistance, unit cost and transparency.

Depending on the situation (e.g., the substrate being coated, the end use of the substrate, and the coating apparatus for applying the coating), the degree of barrier may be varied by varying the concentration of the UV / Vis absorber and coating thickness between the two extreme examples. It is preferable to provide.

For example, cold end coated containers, such as beer bottles, preferably have a coating thickness in the range of 0.1 to 2 microns.

The coating thickness is more preferably 0.1 to 1.5 microns, more preferably 0.3 to 1.5 microns.

It is a surprising aspect of the present invention that a blue, smooth, absorbing UV and visible light coating can be applied as a cold end coating with a coating thickness of 0.3 to 1 micron.

According to the present invention, a coating composition capable of absorbing UV light up to 360 nm or UV and visible light up to 550 nm, comprising wet milling the carrier and the pigment to form a granular dispersion of the pigment in the carrier. Provided is a method of forming a pigment, wherein the pigment comprises nanoparticles of an absorbent capable of absorbing UV up to 550 nm and visible or UV light.

It is particularly preferred that the carrier comprises a dispersant to prevent the formation of aggregates in the wet milling step.

Preferred dispersants are

(a) polycarboxylates for aqueous media; And

(b) entropic ("Solsperse") superdispersants for non-aqueous media

It includes.

The wet grinding step is preferably carried out at low solids content.

It is preferable that solid content is 5-30 weight%.

The solid content is more preferably 15 to 25% by weight.

Preferably, the wet grinding step is batchwise, continuously passed or continuously recycled using small beads (<0.7 mm diameter) inputting at least 0.5 kW per liter of shell volume for a long time until the required transparency is obtained. Grinding (bead grinding) the wet stirred medium.

The wet grinding step is described in M J Bos Consultants Pty. As disclosed in International Application WO 9717406, filed under the name of Ltd.

According to the invention,

(a) forming a coating composition as described above; And

(b) applying a coating composition to a substrate to form a continuous coating on the substrate, a method of forming a coating of the coating composition capable of absorbing UV and visible light of 550 nm or less on a substrate is provided. .

The coating composition may be applied to the substrate by any means, such as by spraying or roller coating the coating composition onto the substrate.

Preferably, the method comprises adding an additional carrier to the coating composition formed in step (a), diluting the coating composition to the required pigment volume concentration before applying it to the substrate in step (b).

Preferably, the further carrier is a film forming material.

The pigment volume concentration is preferably 25 to 45%.

The pigment volume concentration is more preferably 30 to 40%.

Preferably the substrate is a wall of the container and step (b) is part of the container preparation.

The container is preferably a glass container.

Glass container manufacturing, such as glass bottle manufacturing, typically involves two steps in the process of coating being applied to the bottle surface.

If the surface temperature of the vessel is 600 ° C. or higher, Hot End Coating (HEC) is applied to the glass using chemical vapor deposition techniques immediately after molding of the glass vessel. HEC is typically a ceramic material, such as tin oxide, and serves to prevent damage to the glass surface and to provide a substrate for cold end coating.

Cold end coating (CEC) is applied after the glass vessel is annealed at a surface temperature of 120-180 ° C. The CEC consists of an organic coating that provides the glass surface with the lubricity needed for high-speed passage through filling lines and automatic monitoring. Some coatings serve to prevent abrasion damage to the glass surface and to preserve the inherent strength of the glass. Cold end coatings may be based on silicone wax, polyethylene, polyvinyl alcohol, stearic acid, oleic acid, polyurethane, polyester, polyolefin and polyacrylic.

The coating composition of the present invention may be applied to a glass container in the cold end stage of bottle making.

The coating thickness is preferably 0.1 to 1.5 microns.

The carrier of the cold end coating is preferably a carrier of the coating composition of the present invention.

In a particularly preferred form of the invention, the carrier of the coating composition is an aqueous thermoplastic acrylic or polyurethane or polyester material and the coating composition is applied to the container surface in the CEC step.

Alternatively, solvent-based thermosetting curable acrylic or polyurethane or polyester materials may be used at certain application conditions independent of cold end coatings.

The invention is further illustrated with reference to the following examples and the accompanying drawings.

Example 1

Formulations A and B-Examples According to the Invention

Formulation A -Based on thermosetting acrylic carrier.

Based on solids / solids, the coating composition comprises the following components.

12% FeOOH (TOY-Pigment Yellow 42) Pigment

1.3% Fe ₂ 0 ₃ (TOR-Pigment Red 101) Pigment

0.5% Blue 5203 Pigment (Pigment Blue 15: 3)

20 pph solsperse 3000 pigment (super dispersant)

40 parts thermosetting acrylic solution

"TOY" is an iron oxide yellow pigment sold by Johnson Matty under the trade name Trans Oxide Yellow AC0500.

"TOR" is the trade name Trans Oxide Red AC1000 and is a commercially available iron oxide sold by Johnson Matthey.

Formulation B -Based on polyethylene emulsion as carrier.

The coating composition is similar to Formulation A, except that (i) aqueous and (ii) 20 pph of Orotan 731 pigment (polycarboxyl dispersant) pre-prepared as ammonium salt as a substitute for solsperse 3000; (iii) A commercially available polyethylene emulsion product (used as a cold end coating in the manufacture of glass bottles, sold under the trade name DURACOTE) as a substitute for the acrylic resin of Formulation A.

Properties of Formulations A and B

Applicants have found that the nanoparticles of the iron oxide pigments of Formulations A and B do not aggregate and the coating composition is green.

The color of the coating composition was indistinguishable from the green glass traditionally used in beer bottles.

Performance of Formulation A

Commercially available formulation A, which is a coating composition mainly composed of a thermosetting acrylic carrier, absorbs UV and visible light thinly on the glass plate of the composition by 2 microns, and its UV / Vis absorbance is used in untreated glass plates and beer bottles. Evaluation was made by comparing the absorbance of the amber glass article. The results are shown in FIG.

It can be seen from FIG. 3 that the coated glass has a significantly improved absorbance compared to the untreated glass and provides a protective effect similar to conventional amber glass products.

The blend used was applied as a coating onto a green bottle. As already observed, the UV absorbance of green bottles did not meet the standard specifications required by food manufacturers and brewers. The coating effect of the green bottle with the blend is shown in FIG. 4.

As can be seen from FIG. 4, the coating generally provided a good blocking effect against UV light at harmful wavelengths of 350 nm to 500 nm.

Performance of Formulation B

The UV / Vis absorbance of the 1 micron coating of Formulation B, a composition based primarily on polyethylene emulsion, was measured and compared to a standard amber bottle. The results are shown in FIG.

The absorbance of the coating on the quartz slide was compared with that of the amber bottle. However, the results should reflect that the quartz slide did not absorb at the measured wavelength and the film thickness was only 1 micron.

UV / Vis absorbance of Formulation B was compared to that of a green glass beer bottle as shown in FIG. 6. UV / Vis blocking by the coating formulation was very similar to, or better than, amber glass.

Example 2

The transparent coating formulations according to the invention tested in this example contained 5-100 nm diameter nanoparticles of iron oxide and other pigments dispersed in a carrier having dispersion and film formation properties.

Crushing Procedure

Coating formulations were formed according to the following standardized procedure.

A water-jacket for cooling was mounted in a 1 L stainless steel container with an internal diameter of 100 mm. The rotor was placed in a container with four flat, 6 mm thick, 90 mm diameter and holding circular disks made of ultra high molecular weight polyethylene. The net volume of the mill was 850 ml. 85% of the net volume was filled with 0.268 kg of partially stabilized zirconia beads (47% porosity) of 0.4-0.7 mm diameter. The lid was sealed with bolts on top of the grinder with a stirrer guide in the lid and a rotor passing through the hole. 400 ml of each mill base formulation disclosed below was charged to the mill. The actual amount of addition was determined by the density. For example, for a milling base formulation with a density of 2.2 kg / l, the amount of milling base added was 0.88 kg. The rotor was driven at a speed of 10 m / s around the disk, ie 2100 rpm for a 90 mm diameter disk. The grinding of each formulation continued for at least 2 hours when the room temperature water was passed through the cooling jackkit.

The pulverization of the nanoscales described above is very intensive compared to dispersible pulverization of pigments for paints and inks. In terms of the strength measured in liters per liter of bulk beads per hour for 1 hour, compared to the conventional 9 milling of pigments for inks and paints using beads of several millimeters in diameter, 9 millimeters of milling is calculated. 0.3 L or less is calculated.

By this intensive grinding the coating composition can obtain the protective absorbance and transparency reported below.

Formulation

As mentioned above, the transparent coating formulations comprised nanoparticles of 5-100 nm diameter of iron oxide and other pigments dispersed in a carrier having dispersion and film formation properties.

Colloidal stabilization of nanoparticles 5-100 nm in diameter and the corresponding high surface area (1000-50 m ² per ml) of nanoparticles,

(a) necessary to prevent reassembly and aggregation of the particles in the milling process;

(b) necessary to prevent agglomeration and loss of protective absorbance upon blending and dilution of the coating with the resin.

At the same time, the carrier requires film forming and mechanical pasteurization resistance in addition to its dispersing properties.

Dispersants used in formulations

(a) polyacrylic acid dispersants for aqueous media, such as a proportion of polyacrylic acid as ammonium salts; And

(b) It was an entropic ("Solsperse") superdispersant for non-aqueous media.

The coating formulation had a low viscosity of 5-10 cP, the rheological yield value was negligible, and was a Newtonian fluid.

The coating formulation has the following composition and properties.

Formulation 1 -Blue-Green Photoprotective Cold End Coating Additive-12% Fe ₂ 0 ₃ PR101-8% PY124-3% CuPc-PB15: 3 aq-18pph Joncryl 61HV-10p Dispex A40. Crush for 2.25 hours. Vivid and pure bottle green-transparent.

Formulation 2 -Amber Light Protective Coating Additive-18% Fe ₂ 0 ₃ PR101-4% PY124 1.5% CuPc-PB15: 3 aq-18pph Joncryl 61HV-10pph Dispex A40. Crush for 2 hours. Dark Amber-Transparent. Even if the film thickness changes during spraying, the color intensity does not change.

Formulation 3 -Blue-Green Photoprotective Cold End Coating Additive-12% Fe ₂ 0 ₃ PR101-2.3% PY124-8.8% CuPc-PB15: 3 aq. Crushed for 2 hours, vivid turquoise-very transparent. The color is more turquoise than in Formulation 1.

Formulation 4 -Increased Fe ₂ 0 ₃ PR101 concentration for greater protection at thinner thicknesses-09F (506) 18% Fe ₂ 0 ₃ -PR101-4% PY124 1.5% CuPc-PB15: 3 aq.- 18pph Joncry 161 HV-10 pph Dispex. Crush for 1.75 hours. Tan-very transparent.

Formulation 5 - 04F (500) 12% Fe 2 0 3 - 8% PY124 - 3% CuPc aq. 18 p Joncryl 61 HV-10 pph Dispex. Crush for 5 hours. Vivid turquoise-transparent.

Formulation _{6 - 10% Fe 2 0 3} - 12% Pigment Green - 36 1% CuPc aq. 18 p Joncryl 61 HV-10 pph Dispex. Crush for 3 hours. Light green-transparent. Pigment Green 36 produces a more pure green than the combination of blue and yellow 03J (475).

Formulations _{7 - 10% Fe 2 0 3} - 14% PG36 aq.- 18 pph Joncryl 61HV-10pph Dispex. Crush for 2 hours. Light yellow-green-transparent. Pigment Green 36 produces a more pure green than the combination of blue and yellow 03J (474).

Formulation 8 - (468) 10.3% Fe 2 0 3 - 13.7% PG36 aq.- 18p Joncryl 61HV - 10 pph Dispex. 2 hours crushing. Yellow-green-transparent.

Absorbance Evaluation of Formulations 1-8

The absorbances of the coating formulations 1-8 were tested. Test procedures and results are discussed below.

The clear dispersion of the formulation produced by the grinding procedure was diluted to 35% pigment volume concentration using a suitable resin such as polyethylene aqueous emulsion for cold end coating or water based or solvent based acrylic or solvent based polyurethane resin.

The diluted formulation was applied to glass or transparent plastic to form a coating of about 1 micron thick, sometimes 0.5 micron or 0.3 micron thick, providing the necessary film properties and protection beyond that of amber glass.

The absorbance of UV and visible (blue) light by coating was measured by Varian Cary Model 1E UV-Visible Spectroscopy, and the absorbance for the coating of the formulation was above 2 (99%) below 450 nm and below 550 nm In excess of 1 (90%). That is, the absorbance exceeded the absorbance of the amber glass commonly used in beer bottles.

The turbidity of the 0.5-1 micron thick coating of the blend was less than 15% as measured on a Cary spectrophotometer.

Film thickness was measured on a Taylor Hobson Talysurf 10 Surface Profile Analyzer.

Low temperature sterilization resistance was tested by immersion in water at 65-70 ° C for 1 hour. The result was satisfactory.

The scuff resistance and lubricity of the coating were evaluated while the bottles were in contact with each other. The result was satisfactory.

Example 3

The following coating formulation components were added to the stirring vessel in parts by weight as set forth below to form a grinding base.

BASF Sico FR1363 PY124 0.78 parts by weight

BASF Heliogen Blue D7072 PB15: 3 0.309 parts by weight

Johnson Matthey AC1000 PR101 1.200 parts by weight

Rhodia Joncryl 61HD 35% 0.589 parts by weight

Ciba Dispex A40 40% 0.343 parts by weight

6.78 parts by weight of water

10 parts by weight in total

The grinding base was passed from a well stirred vessel into a 1.2 L Drais Double Chamber Process Bead Mill, recycled and ground.

A bead separation screen of 0.25 mm diameter was attached to a DCP grinder, but operated without a phase separation screen, and 3.7 kg of partially stabilized zirconia beads of 0.4-0.7 mm diameter were charged.

The rotor speed was at maximum speed and a pumping speed of 5-15 L / min was maintained for 16 hours using a propulsion cavity. At this point the grinding base was clearly transparent.

Two parts of the ground base and one part of the DIC Duracote 20% polyethylene coated emulsion were mixed in a homogenizer to test the resulting coating composition as a cold end coating.

The resulting coating composition was sprayed onto hot glass bottles and hot glass panels in an 130 ° C. oven to have a dry film thickness of 0.1 micron as measured by a Talysurf Surface Profile Analyzer.

The "absorbance" of the film on the glass was measured with a Cary model 1E UV-visible spectrophotometer in transmission mode and compared to the "absorbance" of amber glass.

The absorbance of the coating composition exceeded that of amber glass.

The absorbance of the coating composition and the absorbance of the amber glass exceeded 1.0 (10% transmittance at 500 nm), and lowering 470 nm to 200 nm in the UV region exceeded 2.0 (1% transmittance).

Example 4

Experiments were carried out in four different iron oxide series formulations RH502, RH503, RH504, and RH505.

The composition of the formulation is disclosed below.

Formulation RH503-18 % Fe ₂ 0 ₃ PR101-4% PY124 1.5% CuPc, aq-18pph Joncryl 61-1O pph Dispex A40.

Formulations RH502, RH504, and RH505-18 % Fe ₂ 0 ₃ PR101-4% PY124 1.5% CuPc, aq-18pph Joncryl 61-1 Opph Dispex A40.

Formulation RH503 was prepared by grinding in a 1 L stainless steel grinder disclosed in Example 2 to produce a clear coating formulation. The grinding time was 6 hours. The formulation coating was formed and tested according to the procedure described in Example 2. The coating thickness was 0.5 micron. 7 illustrates the coating performance.

Formulations RH502, RH504 and RH505 were prepared by grinding in a glass vessel in a shake mill to yield a clear coating formulation. Grinding time was 48 hours. A coating of the blend blend was formed and tested according to the procedure described in Example 2. The coating thickness was 0.6 micron. 8 illustrates coating performance.

As can be seen in FIGS. 7 and 8, the blend had an absorbance of at least 1.5 at a wavelength of 500 nm and better absorbance than the amber glass standard in the wavelength range of interest.

Example 5

Experiments were carried out in zinc oxide based coating formulations according to the invention.

The formulation was prepared by adding 35% 20 nm ZnO (s) to 15 pph (based on solids) of Avecia Solsperse 24000 GR dispersant and 202 g propylene glycol monomethyl ether acetate, alpha isomer (PGMA) carrier. The blend was ground for 46 hours to yield a clear coating formulation. The resulting liquid was very clear and there was no evidence of aggregation. The coating formulation was added to the polyurethane to obtain 5%, 7.5%, 10% and 15% dispersions of ZnO, which were used to form a coating. The UV absorbing properties results of the coating are shown in FIG. 9.

It can be seen from FIG. 9 that the ZnO coating formulations have significantly better absorbance than the control coating formulations at 300-400 nm, and the absorbance increases with ZnO concentration.

The invention has been described by way of examples. However, the scope of the present invention is not limited to the examples in any way.

As will be apparent to those skilled in the art, modifications and variations of the present invention are considered to be within the scope of the present invention.

Claims (37)

A coating composition comprising a carrier and a pigment dispersed in the carrier, wherein the pigment comprises nanoparticles of a UV light absorber such that the coating composition can absorb up to 360 nm of UV light, or the coating composition comprises UV and 550 nm or less; A coating composition comprising nanoparticles of UV and visible light absorbers to absorb visible light, the absorbent comprising inorganic materials. The coating composition of claim 1, wherein the nanoparticles are particles having a diameter of 100 nm (0.1 micron) or less. The coating of claim 2, wherein the nanoparticles are particles having a diameter of 100 nm (0.1 micron) or less and the particle concentration above 100 nm is not significant and exhibits effective colloidal stabilization as a coating of liquid coating compositions and coating compositions. Composition. The coating composition of claim 2, wherein the nanoparticles are particles having a diameter of 50 nm (0.05 microns) or less. The coating composition of claim 1, wherein the inorganic material of the absorbent is iron oxide. 6. The coating composition of claim 1, wherein the inorganic material of the absorbent is zinc oxide. The coating composition of claim 1, wherein the pigment further comprises nanoparticles of the pigment that contribute to or contribute to the color of the coating composition. The coating composition of claim 1, wherein the pigment further comprises nanoparticles of a blue or green pigment such that the coating composition is transparent blue or green. 9. The coating composition of claim 1, wherein the pigment comprises blue or green pigments and nanoparticles of yellow or red iron oxide absorbent pigments such that the coating composition is transparent blue or green. 10. The coating composition of claim 1, wherein the carrier can act as a dispersant for (i) pigment particles and (ii) a film-forming agent. The coating composition of claim 1, wherein the carrier is a polymeric material. The coating composition of claim 1, wherein the carrier is a composite of a plurality of materials having a range of properties, including dispersing and film forming properties. The coating composition of claim 12, wherein the material is selected from (i) a material having primarily dispersion properties, (ii) a material having primarily deposition properties, and (iii) a material having dispersion and deposition properties. The coating composition of claim 13, wherein the deposition material is selected from the group consisting of polyurethanes, polyesters, polyolefins, polyvinyl chlorides (eg, polyvinyl chloride), and polyacrylics. The base material which has a coating of the coating composition of any one of Claims 1-14. The substrate of claim 15, wherein the substrate is made of a glass or plastics material. The substrate of claim 15, wherein the coating thickness is 100 microns or less. The substrate of claim 15, wherein the coating thickness is 50 microns or less. A container having a coating of the coating composition according to any one of claims 1 to 14. 20. The container of claim 19, wherein the container is made of glass or plastic material. 21. The container of claim 19 or 20, wherein the coating thickness is 100 microns or less. 21. The container of claim 19 or 20, wherein the coating thickness is 50 microns or less. 20. The container of claim 19, wherein the coating thickness is 0.1 to 2 microns when the container is a cold end coated container, such as a cold end coated beer bottle. A method of forming a coating composition capable of absorbing UV light up to 360 nm or UV and visible light up to 550 nm, comprising wet milling the carrier and pigment to form a granular dispersion of the pigment in the carrier. Wherein the pigment comprises nanoparticles of UV up to 550 nm and an absorbent capable of absorbing visible or UV light. The method of claim 24, wherein the carrier comprises a dispersant to prevent the formation of aggregates in the wet milling step. The method of claim 25 wherein the dispersant (a) polycarboxylates for aqueous media; And (b) entropic ("Solsperse") superdispersants for non-aqueous media Method comprising a. 27. The method of any one of claims 24 to 26, wherein the wet milling step is performed at a low solids content. 28. The process of claim 27 wherein the solids content is 5-30 weight percent. 28. The process of claim 27 wherein the solids content is 15-25 wt%. 30. The wet grinding step of any of claims 24 to 29, wherein the wet grinding step utilizes small beads (<0.7 mm diameter) while inputting at least 0.5 kW per liter of shell volume for a long time until the required transparency is obtained. Pulverizing the wet stirred medium in a batch, continuous or recycle manner. (a) forming a coating composition according to any one of claims 1 to 14; And (b) applying a coating composition to the substrate to form a continuous coating on the substrate, the coating of the coating composition capable of absorbing UV light up to 360 nm or UV and visible light up to 550 nm; How to form. 32. The method of claim 31 comprising adding an additional carrier to the coating composition formed in step (a), thereby diluting the coating composition to the required pigment volume concentration before applying the coating to the substrate in step (b). . 33. The method of claim 32, wherein the additional carrier is a deposition material. 34. The method of any one of claims 31-33, wherein the pigment volume concentration is 25-45%. 35. The method of any one of claims 31-34, wherein the substrate is a wall of the container and step (b) is part of the container preparation. 36. The method of claim 35, wherein the container is a glass container. 37. The method of claim 35 or 36, wherein step (b) comprises applying a coating composition to the container in a cold end coating step of the container preparation.