Patent Description:
A label is often the primary resource for evaluating wine or beverages before making a purchase. Moreover, wineries place great importance on label design as appearance of label is known to influence wine buying choices. A majority of wine and beverage bottles use paper as label facestock because of its perceived superior aesthetic appearance and shelf appeal. Paper facestocks are however, susceptible to losing opacity when exposed to moisture, humidity and water during cooling or storing. During the period of cooling, liquid infuses into such facestocks and causes the appearance of the paper to change unacceptably. Additionally, the facestock might pucker, further reducing appearance.

It is also observed in certain cases that irrespective of the nature of the facestock being used in the label, moisture and related components can adversely affect the adhesive holding the label to the bottle and the label may become detached which causes identification even more difficult.

Attempts have been made or solutions have been proposed in the past to provide or improve general opacity of labels. These attempts, however either failed to recognize the opacity problem of labels in wet conditions, and were ineffective or expensive or both.

In addition to the past attempts to devise a solution to improve opacity in labels, the conventional art provides general solutions to dry opacity. The solutions include addition of pigments, such as titanium dioxide, calcium carbonate, aluminium silicate, calcined clay, kaolin clay, and zinc oxide. The pigments can be added to the paper facestock layer during the paper making process. The pigments can also be added as a coating layer such as an undercoat or topcoat on the paper facestock and the coat can be placed between the facestock and a pressure sensitive adhesive layer.

A significant limitation with those pigments is that many of those pigments such as calcium carbonate, aluminium silicate, calcined clay, kaolin clay, and zinc oxide show good dry opacity but exhibit poor wet opacity. Titanium dioxide even though showing better wet opacity, cannot be used in the suggested way because titanium dioxide is significantly expensive. Also manufacturers of labels do not have control on paper manufacturing so as to be able to incorporate desired levels of pigment into the paper. Moreover, use of pigments in coating layers involves multiple steps that are often complex requiring special processing requirement and thus adding further to cost of manufacturing. Thus utilization of the pigments, while attractive, has not been general.

Accordingly, a need exists for a new strategy for labelling articles so that the labels maintain a relatively high level of opacity when in a wet condition, while also maintaining adhesive properties.

<CIT> describes multilayer composite PSA constructions.

<CIT> describes a method of improving an adhesive article.

<CIT> describes reconfigurable multilayer laminates and methods.

<CIT> describes a label having effect pigments.

The difficulties and drawbacks associated with previous approaches are addressed by the present invention.

In one aspect, the present invention provides an opacifying adhesive composition adapted to remain opaque in wet condition for pressure sensitive label application, said opacifying adhesive comprising an adhesive component and a pigment component, said pigment component comprising surface coated TiO<NUM> and being present in a weight range of <NUM>% to <NUM>% of said adhesive component, which is a proportionate amount sufficient to maintain opacity when exposed to an aqueous environment for at least <NUM> hour and a peel adhesion of at least <NUM> N/cm (<NUM> N/inch) and a loop tack of at least <NUM> N/cm (<NUM> N/inch) in said pressure sensitive application, as measured in accordance with the methods specified herein.

In another aspect, the present invention provides a method of preparation of an opacifying adhesive composition which is adapted to remain opaque in wet condition for pressure sensitive label application, said method comprising the step of: mixing an adhesive component and a pigment component with agitation, said pigment component comprising surface coated TiO<NUM> and being present in a weight range of <NUM>% to <NUM>% of said adhesive component, which is a proportionate amount such that the loss of peel adhesion or tack is less than <NUM>% compared to the nonpigmented adhesive under dry conditions, i.e. said opacifying adhesive does not cause any unacceptable loss of peel adhesion or tack of the adhesive component in pressure sensitive application.

As will be realized, the drawings and the description are to be regarded as illustrative and not restrictive. That is, the present invention is only limited by the appended claims.

The present invention is not limited to the particular embodiments described herein. As mentioned above, the present invention is only limited by the appended claims. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also encompassed, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, a limited number of the exemplary methods and materials are described herein.

It must be noted that as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

The embodiments described herein will be better understood in terms of their components, structure and effectiveness from the following detailed description with reference to the figures and data depicting various results. Various objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description of various embodiments along with accompanying drawings.

The present invention results from the unexpected discovery that when a particular adhesive is proportionally mixed with surface coated TiO<NUM> as a pigment, an opacifying adhesive results which can be used in a pressure sensitive adhesive application that maintains opacity in wet condition without compromising required adhesive properties.

It is typically understood by those having ordinary skill in the art that mixing pigments with adhesive is undesirable as addition of pigment is known to reduce adhesive strength and tack of adhesive. Specifically, it is reported that an addition of <NUM>% TiO<NUM> in pressure sensitive adhesive (PSA) reduces tack by more than <NUM>% and peel by <NUM>%.

Pressure sensitive adhesives (PSA's) are typically characterized by the ability of the adhesive to withstand creep or shear deformation, while exhibiting adequate tack and peel adhesion properties. This balance of properties is derived from the structure of the main polymer bulk which makes up the PSA. It is characterized by a high molecular weight, which provides the necessary cohesive strength and resistance to shear deformation, and by a low modulus of the polymer backbone, which allows the polymer to conform to a substrate surface upon contact. It is also important that PSA's should perform in wide range of substrates to which the adhesive may be attached and such substrates include glass, plastics such as high density polyethylene (HDPE), wood, and metal. Accordingly, any adverse effect on adhesive property such as peel adhesion and tack typically results from mixing of additive into the adhesive, and significantly limits applicability of the adhesive in pressure sensitive constructions, particularly for label applications which are intended to withstand wet environments.

An embodiment of a pressure sensitive construction of a label laminate (which does not form part of the present invention) is shown in <FIG>. The label of laminate <NUM> is adapted to remain opaque in wet condition/environment. The laminate <NUM> includes an outer layer of facestock <NUM>, an opacifying adhesive layer <NUM> and a liner <NUM>. The facestock <NUM> has a first surface <NUM> and a second surface <NUM>. The first surface <NUM> of the facestock is meant to receive indicia such as printed indicia or other text or symbols. The opacifying adhesive layer <NUM> underlies the second surface <NUM> of the facestock <NUM>. The liner <NUM> underlies the opacifying adhesive layer <NUM>.

The opacifying adhesive layer includes an adhesive component and a pigment component in a proportion sufficient to cause/maintain opacity when wet, while maintaining peel adhesion and loop tack of the adhesive component in pressure sensitive applications. That is, there is no unacceptable loss in peel adhesion and/or loop tack. The opacity of the label in wet condition may be in range of from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%. All opacity values noted herein are overall opacity values taken across a thickness of a label assembly as described herein, unless noted otherwise. Opacity is measured as described herein in the description of various examples of the present disclosure.

The expression "while maintaining peel adhesion and tack of the adhesive component" as used herein refers to a comparison of such properties of an adhesive without any pigment (fillers) and an adhesive with pigments.

The term "no unacceptable loss of peel adhesion" refers to a loss in peel adhesion of less than <NUM>%, e.g. less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, or less than <NUM>% when the pigment is added compared to the nonpigmented adhesive under dry conditions.

The term "no unacceptable loss of loop tack" refers to a loss in loop tack of less than <NUM>%, e.g. less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, less than <NUM>%, or less than <NUM>% when the pigment is added compared to the nonpigmented adhesive under dry conditions.

The adhesive component is a pressure sensitive adhesive and the pressure sensitive adhesive component may be selected from the group consisting of emulsion adhesives, hot-melt adhesives, solvent adhesives, and/or combinations thereof.

Various commercially available adhesive formulations can be used as the adhesive component of the opacifying adhesive composition according to the present invention. Nonlimiting examples of such adhesive formulations include but are not limited to S2000N, S692N, AT20N all available from Avery Dennison; H9232 available from BASF; and XPE1045 available from Avery Dennison. It will be appreciated that the present invention is not limited to any particular adhesive component, and includes a wide array of such components.

The pigment component in the opacifying adhesive layer is selected such that the pigment exhibits acceptable wet opacity when present along with the noted adhesive component. The pigment component is present in a weight range of <NUM>% to <NUM>% of the adhesive component, e.g. in a range of <NUM>% to <NUM>% or in a range from <NUM>% to <NUM>%.

According to the present invention, the opacifying adhesive composition utilizes surface coated TiO<NUM> in the pigment component. The surface coated TiO<NUM> maintains a relatively high dispersal level within the opacifying adhesive in addition to exhibiting other benefits and/or advantages.

The pressure sensitive construction may further comprise an adhesive layer underlying the opacifying adhesive layer which is detailed hereinafter in reference to <FIG>.

The pressure sensitive application may be performed on nearly any substrate that may include but not limited to glass, plastic, metal substrate, high density polyethylene (HDPE), wood, metal, plastic or any other substrate related to bottling and packaging commonly known in the art and useful as containers.

The facestock may comprise paper facestock, plastic facestock, a multilayer laminated facestock including both paper and plastic layers, or any other materials that are commonly used in the industry.

The pressure sensitive construction of labels may have loop tack which is greater than <NUM> N/cm (<NUM> N/inch), greater than <NUM> N/cm (<NUM> N/inch), greater than <NUM> N/cm (<NUM> N/inch), and more particularly greater than <NUM> N/cm (<NUM> Newtons per inch (N/inch)) when the facestock being used is paper, and when the pressure sensitive application being is performed on a glass substrate. The label may have loop tack which is greater than <NUM> N/cm (<NUM> N/inch), greater than <NUM> N/cm (<NUM> N/inch), and more particularly greater than <NUM> N/cm (<NUM> Newtons per inch (N/inch)) when the facestock is paper, and when the pressure sensitive application is performed on a high density polyethylene (HDPE) substrate. Herin, for many combinations of substrates and facestocks, the labels exhibit loop tack values greater than <NUM> N/cm (<NUM> N/inch) and typically at least <NUM> N/cm (<NUM> N/inch). Loop tack values as described herein are measured using Finat test method FTM-<NUM> using a pull rate of <NUM>/min at room temperature.

The pressure sensitive construction of labels exhibits a peel adhesion of at least <NUM> N/cm (<NUM> N/inch), such as at least <NUM> N/cm (<NUM> N/inch) after <NUM> hours bond time. The labels may exhibit a peel adhesion of at least <NUM> N/cm (<NUM> N/inch), such as at least <NUM> N/cm (<NUM> N/inch), at least <NUM> N/cm (<NUM> N/inch), or at least <NUM> N/cm (<NUM> N/inch). Peel adhesion <NUM>° values are measured using Finat test method FTM-<NUM> using a pull rate of <NUM>/min at room temperature.

The coat weight of the opacifying adhesive may be from <NUM> to <NUM> grams per square meter (gsm). The opacifying adhesive layer can have a coat weight of from <NUM> to <NUM> grams per square meter (gsm). The opacifying adhesive layer may have a coat weight, more particularly from <NUM> to <NUM> grams per square meter (gsm).

Another embodiment of a pressure sensitive construction of a label laminate (which does not form part of the present invention) which is adapted to remain opaque in wet environment is shown in <FIG>. The label laminate <NUM> includes an outer layer of facestock <NUM>, an opacifying adhesive layer <NUM>, an adhesive layer <NUM>, and a liner <NUM>. The facestock <NUM> has a first surface <NUM> and a second surface <NUM>. The first surface <NUM> of the facestock is meant to receive indicia such as printed or others text or symbols. The opacifying adhesive layer <NUM> underlies the second surface <NUM> of the facestock <NUM>. The adhesive layer <NUM> underlies the opacifying layer <NUM>. The liner <NUM> underlies the adhesive layer <NUM>.

The opacity of the label laminate <NUM> may be similar to the laminate <NUM> and the composition/content of the opacifying adhesive layer <NUM> may be similar to opacifying adhesive layer <NUM>. The pigment component of the opacifying adhesive layer <NUM> can be more than <NUM>% or more than <NUM>% of the adhesive component.

The adhesive layer <NUM> may be selected from the group consisting of emulsion adhesives, hot-melt adhesives, solvent adhesives, and/or combinations thereof.

The adhesive component may include acrylic adhesive.

The adhesive layer <NUM> may have a coat weight of <NUM> to <NUM> gsm.

The label <NUM> may have loop tack which is greater than <NUM> N/cm (<NUM> Newtons per inch (N/inch)) when the facestock being used is paper, and when the pressure sensitive application is performed on a glass substrate. The label <NUM> may have loop tack which is greater than <NUM> N/cm (<NUM> Newtons per inch (N/inch)) when the facestock being used is paper, and when the pressure sensitive application is performed on a high density polyethylene (HDPE) substrate.

Another embodiment of a pressure sensitive construction of a label laminate (which does not form part of the present invention) which is adapted to remain opaque in wet condition is shown in <FIG>. The label laminate <NUM> includes an outer layer of facestock <NUM>, a first opacifying adhesive layer <NUM>, a second opacifying adhesive layer <NUM>, and a liner <NUM>. The first opacifying adhesive layer <NUM> underlies the facestock <NUM>. The facestock <NUM> defines oppositely directed faces <NUM> and <NUM> as previously described. The liner <NUM> underlies the second opacifying adhesive layer <NUM>. The first opacifying adhesive layer <NUM> includes a first adhesive component and a first pigment component in a proportion sufficient to maintain opacity when wet with no unacceptable loss of peel adhesion or loop tack of the first opacifying adhesive layer <NUM> in the pressure sensitive application. The second opacifying adhesive layer <NUM> includes a second adhesive component and a second pigment component in a proportion sufficient to maintain opacity when wet with no unacceptable loss of peel adhesion or loop tack of the second opacifying adhesive layer <NUM> in the pressure sensitive application.

The first adhesive component and the second adhesive component may be selected from the group consisting of emulsion adhesives, hot-melt adhesives, solvent adhesives, and/or combinations thereof.

The first pigment and the second pigment have an acceptable wet opacity.

The first pigment and the second pigment may include TiO<NUM>.

The first pigment component may be present in a weight range of <NUM>% to <NUM>% of the first adhesive component, e.g. in a weight range of <NUM>% to <NUM>% of the first adhesive component or in a weight range of from <NUM>% to <NUM>% of the first adhesive component. The second pigment component may be present in a weight range of from <NUM>% to <NUM>% of the second adhesive component.

The opacity of the label laminate <NUM> in wet condition may be <NUM>% to <NUM>% and more particularly <NUM>%.

The first opacifying adhesive layer <NUM> may have coat weight of from <NUM> grams per square meter (gsm) to <NUM> grams per square meter (gsm).

The second opacifying adhesive layer <NUM> may have coat weight of <NUM> grams per square meter (gsm) to <NUM> grams per square meter (gsm).

The pressure sensitive application may be performed on a substrate that includes but is not limited to glass, plastic, metal or high density polyethylene (HDPE) or any other substrate and commonly known material substrate useful for containers.

The facestock <NUM> may include paper facestock, plastic facestock, multilayer laminate facestock include both paper and plastic layers, or any other face material known in the art. The multilayer laminate facestock may include a paper layer overlying a plastic layer. The plastic layer may be white or colorless, and in each condition may exhibit varying degrees of opacity. The plastic layer may be adhered to the paper by an adhesive. Alternatively, the plastic layer may be extruded or otherwise coated onto the paper layer. In the case of such multilayer laminate facestock, the opacity of the paper layer may reduce upon exposure to moisture or a liquid, while the opacity of the underlying plastic layer may not decrease upon exposure to moisture or liquid, or the change in opacity of the underlying plastic layer upon exposure to moisture or a liquid may be different than the change in opacity of the overlying paper layer subjected to the same moisture or liquid conditions. In such cases, the opacity change in the plastic layer may be less than the opacity change in the paper layer.

The pressure sensitive label laminate <NUM> exhibits loop tack which may be greater than <NUM> N/cm (<NUM> Newtons per inch (N/inch)) when the facestock being used is paper, and when the pressure sensitive application is performed on glass. The label may exhibit a loop tack which is greater than <NUM> N/cm (<NUM> N/inch) when the facestock is paper and the pressure sensitive application is performed on a high density polyethylene (HDPE) substrate.

According to the present invention, an opacifying adhesive composition adapted to remain opaque in wet condition for pressure sensitive label application is provided. The opacifying adhesive is stable under aging conditions. The opacifying adhesive includes a proportionate amount of adhesive component and a pigment component sufficient to maintain opacity when wet while maintaining peel adhesion and loop tack in a pressure sensitive application.

The adhesive component may be selected from the group consisting of emulsion adhesives, hot-melt adhesives, solvent adhesives, and/or combinations thereof. The pigment component is present in a weight range of <NUM>% to <NUM>% of the adhesive component, e.g. in a weight range from <NUM>% to <NUM>% of the adhesive component or from <NUM>% to <NUM>% of the adhesive component. The pigment component comprises surface coated TiO<NUM>. The opacity of the label in wet condition may be in range of from <NUM>% to <NUM>%, from <NUM>% to <NUM>%, or from <NUM>% to <NUM>%. The pigment component may have higher proportion or concentration depending upon its use in conjunction with other adhesive layer(s) when used for maintaining opacity of the label in wet conditions.

The pressure sensitive application for the opacifying adhesive may be performed on substrates that include but are not limited to glass, plastic, metal, high density polyethylene (HDPE) substrate or any other substrate known in the art useful for containers.

<FIG> illustrates another embodiment of a pressure sensitive construction of a label laminate <NUM> (which does not form part of the present invention) which is adapted to remain opaque in wet environment or condition. The label laminate <NUM> includes an outer layer of facestock <NUM>, an opacifying adhesive layer <NUM>, a clear or generally transparent layer or thin metallic layer <NUM>, a pressure sensitive adhesive layer <NUM>, and a liner <NUM>. Details of these materials and/or layers are as previously described herein.

<FIG> illustrates another embodiment of a pressure sensitive construction of a label laminate <NUM> (which does not form part of the present invention) which is adapted to remain opaque in wet environment or condition. The label laminate <NUM> includes an outer layer of facestock <NUM>, a layer of a pressure sensitive adhesive or structural adhesive <NUM>, a clear or generally transparent layer <NUM>, an opacifying adhesive layer <NUM>, and a liner <NUM>. Details of these materials and/or layers are as previously described herein.

The present disclosure includes the incorporation of one or more clear or transparent layers in any of the label constructions described herein. The present disclosure also includes the incorporation of one or more metallic layers or metal foils in any of the label constructions described herein. It is also contemplated that the label constructions can also include combinations of one or more transparent layers and one or more metallic layers.

According to the present invention, a method of preparation of an opacifying adhesive composition which is adapted to remain opaque in wet condition for pressure sensitive label application is provided. The method may include the steps of mixing a proportionate amount of an adhesive component and pigment component, and particularly with constant agitation, and continuing the mixing for <NUM> minutes for an emulsion preparation for example. In many applications, mixing can be performed for a time period of from <NUM> minutes to <NUM> minutes. The opacifying adhesive thus obtained does not cause any unacceptable loss of peel adhesion or tack of the adhesive component in pressure sensitive application.

The adhesive component may include acrylic emulsion adhesive. The pigment component comprises Rutile grade aqueous TiO<NUM> slurry for example.

A labeled article is also described herein. The article includes one or more labels adhered to the article using any of the adhesives described herein and particularly the opacifying adhesives. The construction of the label may vary but is in many applications the same or similar to the labels depicted in <FIG>. <FIG> illustrates an example of a labeled article <NUM> such as a bottle <NUM> having a label <NUM> adhered thereto.

The following examples are provided to illustrate the present invention in greater detail without however limiting the scope thereto. In the examples, all parts are ratios or percentage by weight unless otherwise noted.

The following emulsion adhesives were taken as a starting material which includes:.

The following TiO<NUM> slurries were taken as a starting material which includes:.

About <NUM>% to <NUM>% of Rutile grade aqueous TiO<NUM> slurry was added into the noted acrylic emulsion adhesives with constant agitation. The mixing was continued for an additional <NUM> minutes before being used for coating of layers in the label laminate.

Table <NUM> sets forth different opacifying adhesives (OA) based upon proportions of different adhesives and pigments component. Adhesives free of pigment were used as controls, i.e., "CTR-<NUM>, -<NUM>, - <NUM>, and -<NUM>.

Each of the adhesives as noted above was coated onto a siliconized polyester/paper liner at a coat weight of <NUM> grams per square meter (g/m<NUM>), and then transferred onto a paper facestock (Classic White UPM).

Coating of one or more layer(s) of opacifying adhesive and/or adhesive layer as illustrated in different embodiments including embodiments of <FIG> and <FIG> can be performed by employing methods described in <CIT>.

The test samples prepared were subjected to a peel adhesion test at <NUM>° using an Instron tensile tester on glass and high density polyethylene (HDPE) panels using a standard test protocol. Testing on the glass and HDPE panels was conducted at dwell times of <NUM> minutes and <NUM> hours. Test results are presented in Table <NUM> and Table <NUM>.

The test samples prepared as previously described were subjected to a loop tack test using an Instron tensile tester on glass and high density polyethylene (HDPE) panels using the standard test protocol. Test results are depicted in Table <NUM> and Table <NUM>.

The wet opacity of the paper laminate was measured by using a STD test method known to those in the art. The opacity was measured after two hours ice bucket immersion of samples applied onto standard BYK <NUM> black-white opacity test cards. Results are listed in Table <NUM> and Table <NUM>.

Representative loop tack performances of the labels with different opacifying adhesive formulations are shown in Table <NUM>. In Table <NUM>, "PT" refers paper tear.

Representative loop tack performances of the labels with different opacifying adhesive layer and/or adhesive layer are shown in Table <NUM>. In Table <NUM>, "PT" refers paper tear.

As described herein before, the opacifying adhesives maintain their stability under aging conditions and do not adversely affect the desired loop tack for PSA application. In Table <NUM> and Table <NUM>, changes in loop tack values are tabulated which are measured under various aging conditions. Coat weight used was about <NUM> gsm for glass substrates. For Table <NUM>, AVC <NUM> base polymer available from Avery Dennison was utilized as a control whereas for Table <NUM>, the base polymer was S692N which can be used as an adhesive component. In all adhesives, pigment from Slurry A was added. In Tables <NUM> and <NUM>, "RT" refers to room temperature. "Tropic" refers to a temperature of <NUM> and relative humidity of <NUM>%.

A comparison of loop tack values reported in Table <NUM> and Table <NUM> suggests that the opacifying adhesives have almost nil impact on aging and thus are stable.

Additional evaluations were performed to assess peel adhesion and loop-tack of opacifying adhesives after wetting.

XPE1045 is an acrylic emulsion adhesive internally developed by Avery Dennison. Face material used for the opacity measurement was Classic White paper UPM China.

Table <NUM> shows the impact of white pigment on the loop tack.

To exclude the impact of the face paper, a clear polypropylene film (PP60 available from Avery Dennison) was used. During aging tests materials from a paper face might migrate into the adhesive, which could have a negative impact. To exclude the possible effect of the face paper, a filmic polypropylene face was utilized. "RT" and "Tropic" have the same meanings as previously noted.

The use of different grades of TiO<NUM> was also investigated. The tested TiO<NUM> types differed in type, stabilization compound, percentage TiO<NUM> and oil absorption.

In this evaluation, the slurry was prepared by blending the noted TiO<NUM> powder with water under stirring. No additives such as dispersants were added. The prepared slurry was added to the adhesive under mixing.

Table <NUM> shows the formulations and loop tack results. Face material was polypropylene. No paper was used to exclude potential interaction with agents/components migrating out of the paper into the adhesive. The adhesive and pigments used are those described in conjunction with Tables <NUM> and <NUM>. In Table <NUM>, "RT" and "Tropic" have the same meanings as previously noted.

Table <NUM> shows there is substantially no difference in loop tack between the tested TiO<NUM> grades. These results demonstrate new and unexpected properties because it would be expected that uncoated TiO<NUM> and TiO<NUM> with a high oil absorption would have a negative impact on adhesive stability. Also the wet adhesive was stable and easy to coat using slot die techniques.

In still additional evaluations, the effect of coating paper with opacifying adhesive upon dry opacity and wet opacity was investigated. The paper used was Centaure Blanc from Arjo Wiggins. As shown below in Table <NUM>, when the paper is dry the opacity improvement because of the white adhesive is only <NUM> to <NUM> (delta opacity dry). When the paper is wet then this difference is <NUM> to <NUM>. This clearly shows the benefit of the white adhesive under wet conditions (delta opacity wet).

In yet another series of evaluations, peel adhesion was investigated. Table <NUM> summarizes peel adhesion values measured for samples using an opacifying adhesive including S692N and Slurry A as pigment. The samples were prepared using clear polypropylene film PP60.

Table <NUM> summarizes peel adhesion values measured for samples using an opacifying adhesive including XPE1045 and Slurry A as pigment. The samples were prepared using clear polypropylene film PP60.

Claim 1:
An opacifying adhesive composition adapted to remain opaque in wet condition for pressure sensitive label application, said opacifying adhesive comprising an adhesive component and a pigment component, said pigment component comprising surface coated TiO<NUM> and being present in a weight range of <NUM>% to <NUM>% of said adhesive component, which is a proportionate amount sufficient to maintain opacity when exposed to an aqueous environment for at least <NUM> hour and a peel adhesion of at least <NUM> N/cm (<NUM> N/inch) and a loop tack of at least <NUM> N/cm (<NUM> N/inch) in said pressure sensitive application, as measured in accordance with the methods specified in the description.