BACKGROUND

There continues to be a need for container labelling adhesives, especially for adhering labels to beverage bottles, that have good resistance to cold and/or ice water and at the same time are easily washed off under alkali conditions to enable easy removal of the label prior to reuse or recycling of the bottle.

SUMMARY

In one aspect the invention features an aqueous adhesive composition including a saponified alkali soluble acrylic copolymer, a polyethylene imine, and a silane adhesion promoter. In one embodiment, the silane adhesion promoter is a functionalized silane oligomer adhesion promoter.

In one embodiment, the saponified alkali soluble acrylic copolymer comprises ammonia. In another embodiment, the silane adhesion promoter is selected from the group including an epoxy silane and an amino silane, or even an epoxy functional silane oligomer.

In one embodiment, the aqueous adhesive composition includes from 0.02% by weight to 5% by weight of the silane adhesion promoter.

In one embodiment, the polyethylene imine is an aqueous solution that is multifunctional and cationic. In another embodiment, the aqueous solution of polyethylene amine has a pH of greater than 8.

In another embodiment, the polyethylene imine is selected from the group consisting of linear, branched and hyper-branched. In a different embodiment, when in aqueous solution the polyethylene imine has a molecular weight (Ms) as measured by GPC (Gel Permeation Chromatography ) of from 500 to 1,000,000.

In another embodiment, the aqueous adhesive composition includes from 0,02% by weight to 5% by weight of the polyethylene imine.

In one embodiment, the aqueous adhesive composition further includes a natural polymer. In another embodiment, the natural polymer is selected from the group consisting of starch, dextrin, rosin, casein and cellulose. In a different embodiment, the aqueous adhesive composition includes from 10% by weight to 99.5% by weight of the saponified alkali soluble acrylic copolymer, from 0.02% by weight to 5% by weight of the polyethylene inline, and from 0.02% by weight to 5% by weight of the silane adhesion promoter. In another embodiment, the polyethylene imine is an aqueous solution and has a molecular weight (Mw) as measured by GPC (Gel Permeation Chromatography) and reported by the supplier of from 500 g/mol to 2,000,000 g/mol and the functionalized silane oligomer adhesion promoter is an epoxy silane.

In another embodiment, the invention features a container including a label and the dried aqueous adhesive composition, wherein the dried aqueous adhesive composition is present between the label and the container thereby adhering the label to the container. In another embodiment, the container is selected from the group consisting of glass and poly ethylene terephthalate. In a different embodiment, the label is a paper label i.e. has a paper backing. In one embodiment, the container is a beverage container. In another embodiment, the container is a glass beverage container and the label is paper. In a different embodiment, the glass beverage container comprises coated glass.

In another aspect, the invention features a container including a label and a dried aqueous adhesive composition including a saponified alkali soluble acrylic copolymer and an aqueous solution of a cationic polymer based on a hyperbranched polyethylene imine, wherein the dried aqueous adhesive composition is present between the label and the container thereby adhering the label to the container.

In another aspect, the invention features a container including a label and a dried aqueous adhesive composition including a saponified alkali soluble acrylic copolymer, a polyethylene imine, and a functionalized silane oligomer adhesion promoter, wherein the dried aqueous adhesive composition is present between the label and the container thereby adhering the label to the container.

In one embodiment, the polyethylene imine has a molecular weight (Mw) as measured by GPC (Gel Permeation Chromatography) and reported by the supplier of from 100,000 g/mol to 1,000,000 g/mol and the functionalized silane oligomer adhesion promoter is an epoxy silane.

In recent years, glass bottles often used for beverages have been modified to include a coating on the outside of the bottle. The coating can serve to protect the bottle, improve the brilliance of the bottle, improve scuffing/sliding of the bottle, or adjust any other property of the glass on the outside of the bottle. The coating can make it more difficult for the bottle labeling adhesive to strongly adhere a label to the bottle and further to maintain adhesion of the label to the bottle when the bottle is exposed to cold and/or ice water.

At the same time, the bottle labeling adhesive needs to be easily washed off under alkali conditions to enable easy removal of the label prior to reuse or recycling of the bottle. Easy removal as used herein corresponds to label carryover of 0.5 to 2% based on the total bottles washed.

The inventors have surprisingly found that an aqueous adhesive composition comprising an alkali soluble acrylic copolymer, and specific additive/s has an excellence balance of adhesion, ease of removal and stability.

DEFINITIONS

As used herein, the term “alkali soluble acrylic copolymer” means that the acrylic copolymer may be dissolved, preferably fully dissolved, in an aqueous medium comprising an alkali.

As used herein, the term “copolymer” refers to a copolymer formed from the copolymerization of at least two different types of monomers. This term includes bipolymers, terpolymers, quaterpolymers, etc. according to the number of used monomer species. This term also includes different types of copolymers, such as alternating copolymers, periodic copolymers, random copolymers, block copolymers, linear copolymers and branched copolymers.

As used herein, the term “acrylic copolymer” refers to a general term for a copolymer formed from the copolymerization of at least two acrylic monomers, such as (meth)acrylic acids and their esters.

As used herein, the term “monomer” refers to any chemical compound that can form a covalent bond with itself, another monomer or another chemical compound in a repetitive manner.

DETAILED DESCRIPTION The invention includes an aqueous adhesive composition comprising a saponified alkali soluble acrylic copolymer, a polyethylene imine, and a silane adhesion promoter.

The invention further includes an aqueous adhesive composition comprising a saponified alkali soluble acrylic copolymer, a polyethylene imine, and a functionalized oligomer silane adhesion promoter. The invention also includes an aqueous adhesive composition comprising a saponified alkali soluble acrylic copolymer, an aqueous solution of cationic polymer based on polyethylene imine and a functionalized silane oligomer adhesion promoter that is an epoxy silane.

The invention also includes a container including a label and a dried aqueous adhesive composition including a saponified alkali soluble acrylic copolymer, a polyethylene inline, and a functionalized silane oligomer adhesion promoter, wherein the dried aqueous adhesive composition is present between the label and the container thereby adhering the label to the container. The polyethylene imine can have a molecular w-eight (Mw) as measured by GPC (Gel Permeation Chromatography) and reported by the supplier of from 100,000 g/inol to 1,000,000 g/mol and the functionalized silane oligomer adhesion promoter is an epoxy silane.

The invention further includes an aqueous adhesive composition comprising a saponified alkali soluble acrylic copolymer and an aqueous solution of cationic polymer based on polyethylene imine

The saponified alkali soluble acrylic copolymer, the polyethylene imine and the silane adhesion promoter can make up at least 15% by weight, at least 20% by weight, at least 30% by weight, at least 40% by weight, at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, from 15% by weight to 100% by weight, from 30% by weight to 100% by weight, from 30% by weight to 95% by weight, from 60% by weight to 100% by weight, or even from 80% by weight to 100% by weight of the solid portion of the aqueous adhesive composition.

The aqueous adhesive composition can be soluble under alkali conditions. The aqueous adhesive composition can be soluble in a solution having an alkaline concentration of between 1% by weight and 3 % by weight and at a temperature of from 60°C to 90°C, or even 65°C to 85 °C.

The aqueous adhesive composition can have a viscosity of from 3,000 cP to 500,000 cP, 3,000 cP to 300,000 cP, from 10,000 cP to 300,000 cP, or even from 30,000 cP to 180,000 cP at 26°C using a Brookfield Viscometer.

The aqueous adhesive composition can have a solids content (as measured after 2 hours @ 105°C) of from 5% by weight to 80% by weight, 10% by weight to 80% by weight, 5% by weight to 50%, or even from 30% by weight to 50% by weight.

The inventors have found that the compositions of the invention are stable and are particularly useful for bonding paper labels (i.e. paper backed labels) to hard to bond containers (e.g. glass or plastic bottles) - where the label needs to remain firmly bonded in cold/ice-water yet be easily removed prior to reuse or recycling of the bottle. SAPONIFIED ALKALI SOLUBLE ACRYLIC COPOLYMER

The adhesive composition includes a saponified alkali soluble acrylic copolymer, in particular a fully or partially saponified acrylic copolymer, preferably a fully saponified acrylic copolymer. The saponified alkali soluble acrylic copolymer is in solution with water. The saponified alkali soluble acrylic copolymer is formed by neutralizing an alkali soluble acrylic copolymer.

The types of alkali soluble acrylic copolymers that can be used to form the saponified alkali soluble acrylic copolymer in the present invention is not limited to the following examples.

The alkali soluble acrylic copolymer of the invention may be obtained by selecting one or more features from a single or a separate list of constituents defined below. The alkali soluble acrylic copolymer of the invention is obtained from the copolymerization of at least two esters of (meth) acrylic acids.

The main components of the alkali soluble acrylic copolymer can be alkyl acrylates and alkyl methacrylates. The alkali soluble acrylic copolymer can be formed from at least one alkyl (meth)acrylate monomer.

As used herein, the term “(meth)acrylate” refers either to the acrylate or to the methacrylate or to a mixture of both the acrylate and methacrylate. Similarly, the term “alkyl (meth)acrylate” refers either to the alkyl acrylate or to the alkyl methacrylate or to a mixture of both the alkyl acrylate and alkyl methacrylate.

As used herein, the term "alkyl" includes linear and branched alkyl groups.

The alkyl group of the alkyl (meth)acrylate monomer can be a linear or branched alkyl group having 1 to 20 carbon atoms.

Examples of a linear or branched alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a n-propyi group, an isopropyl group, a n-butyi group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyi group, a sec-pentyl group, a 3 -pentyl group, a n-hexy! group, an isohexyl group, a n-heptyi group, a n-octyl group, an iso-octyl group, a 2-ethylhexyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, an undecyl group, a dodecy! group, a tri decyl group, a tetradecy! group, a pentadecyf group, a hexadecyl group, a heptadecyl group, an octadecyi (stearyl) group, a nonadecyl group, and an eicosyi group. The linear or branched alkyl group having 1 to 20 carbon atoms can be selected from the group consisting of a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a n-pentyl group, a n- hexyl group, a n-heptyl group, a n-octyl group, a nonyl group, a decy! group, an undecy! group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyi (stearyl) group, a nonadecyl group and an eicosy! group.

Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acryiate, sec-butyl (meth)aerylate, tert-butyl (meth)acrydate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acry _' late, tert-pentyl (meth)acrylate, sec-pentyl (meth)acrylate, 3 -pentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acryiate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, iso-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)aerylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyi (meth)acrylate, nonadecyl (meih)acryiate and eicosyl (meth)acryiate.

The alkyl (meth)acrylate can be selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acryiaie, propyl (meth)acrylate, butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

More than one type of alkyl (meth)acrylate as previously defined can be used to prepare the acrylic copolymer.

The alkali soluble acrylic copolymer can be formed from a plurality of monomers including at least one alkyl (meth)acrylate monomer as previously defined and at least one another monomer that is able to copolymerize with said alkyl (meth) acrylate.

Said at least one another monomer that is able to copolymerize with said alkyl (meth)acrylate may be selected from the group consisting of aromatic vinyl compounds of the styrene-type, vinyl acetate, butyl methacrylate, hydroxypropyl methacrylate, lauryl (meth)acrylate, hydroxy alkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acry!ate and hydroxybutyl (meth)acry!ate, and N-vinyl lactames such as N-vinyl pyrrolidone.

Said at least one another monomer that is able to copolymerize with said alkyl (meth)acry!ate may comprise some functional groups enhancing the solubility of the alkali soluble acrylic copolymer in water. The alkali soluble acrylic copolymer can be formed from at least one alkyl (meth)acrylate monomer as previously defined and at least one further monomer comprising acid functionality, preferably carboxylic acid functionality.

Said at least one further monomer comprising acid functionality may be selected from the group consisting of monomers comprising carboxylic acid, sulfonic acid and phosphonic acid functionalities. Examples of monomers comprising carboxylic acid functionality include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid and itaconic acid. Examples of monomers comprising sulfonic acid functionality include vinyl sulfonic acid and 2-acrylamido-2-methy!propanesulfonic acid. Examples of monomers comprising phosphonic acid functionality include vinyisulfonic acid. The alkali soluble acrylic copolymercan be formed in the presence of at least one constituent selected from the group consisting of a carboxylic acid protective colloid such as acrylic acid and methacrylic acid, an anionic surfactant such as phosphate esters, for example ethoxy lated phosphate branched 03 alcohol, dodecylbenzenosulfonate and dioctyl sulfosuccinate, a nonionic surfactant such as fatty alcohol polyglycol ether and PE/PQ block copolymers, and combinations thereof. In the present invention, the alkali soluble acrylic copolymer does not contain crosslinking grafted groups.

The alkali soluble acrylic copolymer can have an acid number ranging from 60 nig KOH/g polymer to 160 mg KOH/g polymer, preferably from 80 mg KOH/g polymer to 130 mg KOH/g polymer. The alkali soluble acrylic copolymer can have a solids content (as measured after 2 hours @

105°C) of from 20% by weight to 80% by weight, or even from 40% by weight to 60% by weight.

The alkali soluble acrylic copolymer can have a glass transition temperature (Tg) ranging from - 20°C to 40°C, preferably from -7°C to 40°C. The glass transition temperature (Tg) is measured by the classical Differential Scanning Calorimetric (DSC) method. Examples of useful commercially available alkali soluble acrylic polymers include PLEXTQL

A1819, available from Synthomer Deutschland GmbH (Germany) and MAKROVTL PAC 7137 available from Indulor Chemie GmbH (Germany).

The alkali soluble acrylic copolymer of the invention is produced by copolymerization methods well -known in the an. The alkali soluble acrylic copolymer of the invention is in the form of an aqueous emulsion or dispersion. The term “dispersed” means that said fine particles of the alkali soluble acrylic copolymer are distributed throughout the aqueous medium.

The alkali soluble acrylic copolymer can be formed by emulsion polymerization.

As used herein, the term “emulsion” refers to a stable two-phase system where line particles of the alkali soluble acrylic copolymer are dispersed in the aqueous medium. Emulsion polymerization is carried out according to standard procedures. Preferably, the emulsion polymerization is carried out in an aqueous medium in the presence of a surfactant and free-radical initiators. More preferably, the emulsion polymerization is carried out in the monomer droplets emulsified in an aqueous medium. The pH of the aqueous emulsion or dispersion can range from about 3 to about 6.

A saponification step can then be carried out to neutralize the alkali soluble acrylic copolymer of the invention and form the saponified alkali soluble acrylic copolymer

The saponification step can be carried out using any alkali base, preferably ammonia (M¾) or amine. Said alkali is added in an amount sufficient to neutralize the acrylic copolymer, i.e. to obtain a neutralized acrylic copolymer.

Following the addition of the alkali to the aqueous emulsion or dispersion comprising the alkali soluble acrylic copolymer of the invention, i.e. after the saponification step, is a solution, in particular a transparent, medium to highly viscous solution. As used herein, the term “solution” refers to a homogenous mixture where the alkali soluble acrylic copolymer is completely solubilized in the alkali medium.

After the saponification step, the pH of the solution comprising the saponified alkali soluble acrylic copolymer can range from 6 to 10.

The aqueous saponified alkali soluble acrylic copolymer can be present in the composition at from 10% by weight to 99.5% by weight, from 20% by weight to 99.5% by weight, from 30% by weight to 99.5% by weight, from 50% by weight to 99.5% by weight, or even from 80% by weight to 99.5% by weight of the aqueous adhesive composition

POLYETHYLENE IMINE

The aqueous adhesive composition includes a polyethylene imine. The polyethylene imine can be selected from the group consisting of a room temperature solid and an aqueous solution. When the polyethylene imine is an aqueous solution, it can be an aqueous solution of a cationic polymer based on polyethylene imine. It can further have a structure selected from the group consisting of linear, branched and hyperbranched. In one embodiment, the inventors have found that an aqueous solution of a cationic polymer based on polyethylene imine, that is hyperbranched and has a relatively higher cationic charge is preferred.

In one embodiment, the polyethylene imine is an aqueous solution having a pH as reported by the supplier of greater than 8, from 9 to 13, or even from 9 to 12.

The polyethylene imine can have a structure expressed by the following general formula:

-(CH2-CH2-NH) n - where n is ^:; = between 10 to 10,000, 10 to 5,000, or even 10 to 1000.

If in an aqueous solution, the polyethylene imine can have a molecular weight (Mw) as measured by GPC (Gel Permeation Chromatography) and reported by the supplier of < 2,000,000 grams/mole (g/mol) < 1,500,000 g/mol, < 1,000,000 g/mol, from 500 g/mol to 2,000,000 g/mol, from 500 g/mol to 1,000,000 g/mol, from 100,000 g/mol to 1,500,000 g/mol, from 500 g/mol to 800,000 g/mol, from 100,000 g/mol to 1,000,000 g/mol, or even from 400,000 to 1,000,000 g/mol.

If in an aqueous solution, the aqueous solution of polyethylene imine can have a solids content of from 15% by weight to 70% by weight, or even from 20% by weight to 70% by weight (ISO 3251) as reported by the supplier.

Useful polyethylene imines include those available under the LOXANOL trade designation including, LOXANOL MI-6732 (Mw=2,000,000 g/mole), LOXANOL MI-6730 (Mw=750,000 g/mole) a dendritic hyperbranched polyethyleneimines available from BASF Co., Ltd. (Germany), those available under the LUPASOL trade designation including, LUPASOL PS (750,000 g/mole) and LUPASOL G-20 (Mw ^::: l,300 g/mole) also available from BASF Co., Ltd. (Germany), those available under the EPOMIN trade designation including, EPOMIN P-1050 available from Nippon Shokubai Co., Ltd. (Japan), and those available under the NEQADD PAX trade designation including, NEOADD PAX-521 AND NEOADD PAX-523 available from Covestro Coating Resin B.V. (The Netherlands)

The aqueous adhesive composition can include from 0.02% by weight to 5% by weight, from 0.02% by weight to 3% by weight, from 0.05% to 2.5% of the polyethylene imine, or even from .5% by weight to 3% by weight of the polyethylene imine. SILANE ADHESION PROMOTER

The aqueous adhesive composition can include a silane adhesion promoter. A silane adhesion promoter is a silicon based chemical that includes organic and inorganic groups in the same molecule. The silane adhesive promoter is often in a 100% solids form. Silane adhesion promoters can be helpful in increasing the adhesion of the aqueous adhesive composition to substrates such as e.g. glass.

The silane adhesion promoter is not limited and can include any type of composition useful in promoting the adhesion of the aqueous adhesive composition to substrates such as e.g. glass.

The silane adhesion promoter can be selected from the group consisting of silane, amino silane, epoxy silane, isocyanurate silane and any other silane. In an embodiment, the silane adhesion promoter is a functionalized silane oligomer adhesion promoter. The functional group can be selected from the group consisting of amine, methoxy, epoxy and isocyanurate.

In a preferred embodiment, the silane adhesion promoter is an epoxy silane oligomer. In addition to improving adhesion to glass, the epoxy silane oligomer also helps to improve adhesion to paper, Useful silane adhesion promoters include COATOSIL MP200, an epoxy functional silane oligomer and COATOSIL 2287, a 3-glycidoxypropylmethyldiethoxy silane both available from Momentive Performance Materials Inc (Waterford, NY) and CGOP2QO, an epoxy functional silane oligomer available from Qufu Chenguang Chemical Co., Ltd. (Qufu City, China).

The aqueous adhesive composition can include from 0.02% by weight to 5% by weight, from 0.02% to 3% by weight, from 0.05% to 2.5% by weight of the silane adhesion promoter.

The aqueous adhesive composition can include from 0,6% by weight to 5% by weight, or even from 0,6% to 2,5% by weight of the silane adhesion promoter.

ADDITIONAL COMPONENTS The aqueous adhesive composition can include additional component such as urea, ammonia, surfactants, additional adhesion promoters, anti-foaming agents (i.e. defoamers), anti-fungals, thickening agents, extra water used to dilute/adjust the formula, natural polymers (e.g. starch, dextrin, rosin, casein, cellulose, etc.) or any other material or additive commonly used in aqueous adhesive compositions. CONTAINER LABELLING

The aqueous adhesive composition can be used to adhere labels to various items (e.g. containers). The invention includes a container including a label and the aqueous adhesive composition of this invention, wherein the aqueous adhesive composition is present between the label and the container thereby adhering the label to the container.

The aqueous adhesive composition can be applied to the back side of the label. The label can then be applied directly to the container, the aqueous adhesive composition gains strength as it dries over time, generally at room temperature to form the dried aqueous adhesive composition. The container can include a label and the dried aqueous adhesive composition, wherein the dried aqueous adhesive composition is present between the label and the container thereby adhering the label to the container.

The aqueous adhesive composition can be applied to the label substrate using any suitable technique including, e.g., intermittent, coating, continuous coating, air knife, trailing blade, spraying, brushing, dipping, doctor blade, roller coating (e.g., smooth roll), gravure coating (e.g., direct gravure, reverse gravure, offset gravure, and rotogravure), engraved roller coating, wheel coating, contacting coating, transfer coating (e.g., multi-roll transfer coating), flexographic coating, and combinations thereof

The container can be a bottle (e.g. beverage bottle (e.g. beer bottle, soda bottle, wine bottle, milk bottle, etc.), a jar (e.g. for food products), a vial, or any other type of container.

The container can be reusable. By reusable, it is meant that the container can be returned, cleaned and reused. The container can alternatively be recyclable.

The label preferably has a paper backing. The container can be glass, metal (e.g. aluminum or steel) or plastic (polyethylene terephthalate (PET), high density polyethylene (HOPE), polypropylene, etc. and surface treated versions thereof). In one embodiment, the container is a beverage container.

In a preferred embodiment, the container is glass and the backing is paper. Glass containers can be clear, amber, or any other color. Glass containers can be coated with any number of materials including e.g. metal, monostearate, wax (e.g. polyethylene, etc.), oleic acid, silane, silicon, etc.

The inventors have discovered that the compositions of this invention work particularly well in labeling containers comprising a coated glass. The label can be a spot label i.e. a label that does not extend completely around the container. Alternatively, the label can be a wraparound label i.e. a label that completely wraps around the entire container.

The following examples further illustrate the invention, but should not be construed to limit the scope of the invention in any way.

EXAMPLES

Stability - The aqueous adhesive composition sample is observed after mixing and a stability rating assigned to it. very good - adhesive sample is homogenous, and maintains good flow properties as it ages very bad - adhesive sample has separated, settled, gelled or sedimentation is present

The remaining of the tests were performed using coated glass bottles and paper labels.

Two type of labels were tested. The testing results encompass both types of labels unless otherwise noted

33 centilitre label - matte paper label, not metallized or embossed, having a paper weight of 82.4 g/m2, good wetting properties

66 centilitre label - matte paper label, not metallized, but embossed, having a paper weight of 80 g/m2, poor wetting properties

Mirror Bonding - The mirror bonding effect is a measure of how well the adhesive on a label transfers to a glass bottle. If the adhesive transfer is low, the bottle has a high mirror bonding effect, as there is no adhesive on the bottle and it is easy to see through the glass.

Before the test, the labels to be tested are stored for 16 to 24 hours at a temperature of 23 +/- 1°C and 50 +/- 5% relative humidity. On flat surface (e.g. glass plate), apply adhesive with a rod coater at a coat weight of 20-24 g/m ² .

1.) Immediately, pick up the adhesive with a rubber labelling pallet and transfer to reverse side of the label. Always apply the adhesive with the direction of the coating parallel to the label. Check coat weight to make sure it is in the correct range.

2.) Apply the label to the bottle and smooth it down by hand.

3.) After 1 minute, partially peel the label back from the bottle peel, peel back a bit more at

2min, 3 min, etc. until the label is off the bottle.

4.) Rank samples per following scale: very bad - high mirror bonding affect, no adhesive transfer medium - medium mirror bonding affect, partial adhesive transfer very good - no mirror bonding affect, complete adhesive transfer

Ice Water Resistance. Wet. Adhesion and Wet. Mirror Bonding of Labelled Bottles

Apply labels as described in the Mirror Bonding test method (through step 2), using the same amount of aqueous adhesive composition.

Let the labelled bottles dry' for 3 days at room temperature before starting the test. Test at least three bottles for each adhesive.

1.)Fill the labelled bottles with tap water 24 hours before the test and let stabilize at room temperature.

2.)Place a pail half full of fresh water in a fridge at 4-5° C for 24 hours before the test.

(Choose pail size and height/volume of the water; so as to cover completely the labels on the bottles to be tested).

3.) Start ice water resistance test:

- Measure and note the pH of the water inside of the pail

- Put the labelled bottles in the pail full of cool water at 4-5° C in the fridge. The labelled bottles should not touch each other.

- Every' day, rotate the bottles smoothly twice (one time to the left and one time to the right = rotation of 180° each). Rotation of the bottle should not be heavy, otherwise it will have an influence on the results.

Mirror Bonding Ice Water Resistance - As the bottles are rotated they are evaluated, when the label becomes dislodged, the adhesive adherence to the bottle is evaluated according to the mirror bonding scale above.

Label Wet Adhesion - As the bottles are rotated they are evaluated, if the label becomes dislodged, the adhesive adherence to the label is evaluated according to following scale, very' good - adhesive strongly adhered to label medium- adhesive partially adhered to label very bad- adhesive completely dislodged from label

- Cheek/measure the temperature of the cool water in the pail every day

- Note the day when labels start to flag - Note the day when labels are completely detached from the bottles, before or after rotation

- Note the following: If adhesive (traces) remains on the bottle, if adhesive is diluted by water or not.

- The test is regarded as positive if the labels adhere to the bottles for minimum 14 days in cool water. The test can be stopped when a positive result is obtained in excess of 21 days. The adhesive bonds are ranked according the following. very good - bond stays firmly intact medium - bond is partially intact very bad - bond is completely failed

Wash off Test

The labels were applied to the bottles as described in the Mirror Bonding test method (through step 2), using the same amount of aqueous adhesive composition.

The labelled bottles were allowed to dry for 24 hours at room temperature. The bottles were then aged for 7 days. The bottles were removed from climate chamber and allowed to sit at room temperature for 24 hours. The bottles were then tested according to the following.

Using a double jacketed reactor equipped with external circulation and a heating/cooling thermostat. The reactor is tilled with a soda hydroxide solution at a concentration of 1.5% by weight. The soda solution is held at a temperature of 75°C.

A bottle is attached to an electric stirrer by a stirring shaft equipped with a clamp that holds the bottle in place by clampi ng it between the inside and outside of the bottle.

The bottle is lowered into soda solution.

A stopwatch is started and the bottle is set to rotate. The rotation speed is set to at 25 rotations per minute in a clock wide direction.

Note the time when the label is completely detached from the bottle

Remove the bottle and observe if any glue residue remains

Rinse the bottle with tap water. Let dry and observe if any glue residue remains

Rank the bottles according to the following scale: very good - when label delaches fast and glue removal is complete good - when label detachment takes longer time but glue removal is complete medium - when label detaches and only slight glue remains very bad - when label does not detach; and all glue still remains on the bottle

Table 1

The amounts listed in tine table are in % by weight if the material in the table is aqueous, it is the % by weight of the aqueous material The remaining amount of the composition is made yp of a¾ aqueous alkali soluble acrylic copolymer saponified with ammonia. So, for example Coml is 100% aqueous alkali soluble acrylic copolymer saponified with ammonia. The aqueous alkali soluble acrylic copolymer has the following properties prior to saponification: pH = 3-5. solids content = 51- 53%, Brookfield Viscosity (cP) 100-3500 cP After saponification, the pH 8 The properties listed for the materials in the table tie. solids, pH, etc ) are as repotted by the supplier.