CN108084929B

CN108084929B - Hot melt pressure sensitive adhesive for clear to clear labels

Info

Publication number: CN108084929B
Application number: CN201810076821.1A
Authority: CN
Inventors: X·潘; H·王; X·邢; S·王
Original assignee: Avery Dennison Corp
Current assignee: Avery Dennison Corp
Priority date: 2017-02-08
Filing date: 2018-01-26
Publication date: 2020-02-28
Anticipated expiration: 2038-01-26
Also published as: KR102263275B1; TW201837150A; WO2018145257A1; CN108084929A; KR20190115028A; JP2020510715A; TWI659083B; JP6807463B2

Abstract

The present invention provides a hot melt pressure sensitive adhesive comprising a low block fraction SIS as a base polymer, a low viscosity and low molecular weight hydrogenated alicyclic hydrocarbon resin as a tackifier, a high viscosity and high molecular weight paraffin oil as a plasticizer, and a polyethylene wax. The adhesive may achieve performance characteristics including: clear to clear beverage bottle labeling, clarity, resistance to water whitening, repositionability within the first 4-8 hours after label application, low swelling of film facestock, low viscosity for processability for compounding and coating, low odor and low color.

Description

Hot melt pressure sensitive adhesive for clear to clear labels

Technical Field

The present invention relates generally to compositions for pressure sensitive adhesives, and in particular to improved adhesives that provide higher quality labels while maintaining good processability in processes that include compounding and coating the improved adhesives.

Background

Adhesive labels and tapes are well known. In a typical label construction, one or more layers of adhesive are coated or otherwise applied to a release liner and then laminated to a facestock such as paper, polymeric film or other ink receptive flexible material. In a typical tape construction, a polymeric film or woven paper is coated with adhesive on one surface and then wound upon itself. Adhesives used in tapes and labels include rubber-based and acrylic-based Pressure Sensitive Adhesives (PSAs). The PSA may be applied to the release liner or facestock from an organic solvent, aqueous dispersion or hot melt.

Hot melt psa (hmpsa) can provide convenient and economical labeling of consumer and industrial goods such as glass, metal and plastic containers. HMPSAs are easy to handle in solid form, they form adhesive bonds rapidly without any secondary treatment, and they generally have a long shelf life. Also, since HMPSA does not contain solvents, it is generally environmentally friendly and cost effective.

An example of a HMPSA can be found in U.S. patent No. 5,942,569, which describes a polymeric composition in pellet form comprising a tacky hot melt composition comprising a) from about 5% to about 90% by weight of a thermoplastic polymer, b) from about 0% to about 65% by weight of a tackifying resin, c) from about 0% to about 50% by weight of a plasticizer, d) up to about 2% by weight of an antioxidant, and a pelletizing aid, wherein the tacky hot melt composition has some minimum amount of tackifier or plasticizer and has a storage modulus G' at about 25 ℃ of less than about 5 x 10⁶Dyne/cm²And each pellet has a substantially tack-free surface. The disclosure further includes a polymer composition in the form of pellets suitable for molding articles. The composition comprises a viscous hot melt composition comprising at least one high molecular weight triblock copolymer of general configuration a-B-a and a plasticizer and a granulation aid. The pelletizing aid substantially surrounds the tacky composition such that the molded article is substantially free of surface tackiness. A method of forming the pellets is also disclosed.

The HMPSA of U.S. patent No. 7,595,365 discloses the use of a poly α -olefin oil or a combination of poly α -olefin oils to modify the softening point characteristics of a tackifier this disclosure also includes compositions containing a tackifier and a poly α -olefin oil.

U.S. Pat. No. 8,076,422A hot-melt adhesive for resealable packaging, comprising 30 to 90% by weight of at least one ethylene-and/or propylene-based polymer and C₄-C₁₂α -copolymers of olefins obtainable by metallocene-catalyzed polymerization having a melt index of from 5 to 100 g/10 min (DIN ISO 1133.) the adhesive further comprises from 5 to 50% by weight of a tackifying resin having a softening point of from 80 to 140 ℃, from 0 to 15% by weight of a wax having a melting point of from 120-170 ℃ and from 0.1 to 20% by weight of additives and auxiliaries the adhesive has a viscosity of from 25,000-250,000mPas, measured at a temperature of from 170-190 ℃.

Other HMPSA compositions are also described by U.S. patent nos. 9,242,437; U.S. patent application publication Nos. US2005/0013996, US2006/0251890, US2010/0193127, and US 2016/0272856; and international patent application publication nos. WO2002/074837 and WO 2006/107763.

Even in view of these references, there is a need for high performance HMPSAs that provide improved performance characteristics (e.g., resistance to water whitening, repositionability, and/or optical clarity).

Summary of The Invention

In one embodiment, the present invention relates to a hot melt pressure sensitive adhesive. The adhesive comprises a base polymer, wherein the base polymer comprises a styrene-isoprene copolymer. The base polymer preferably has a diblock fraction of less than 30 wt%. The adhesive also comprises a tackifier, wherein the tackifier comprises a hydrogenated cycloaliphatic hydrocarbon resin. Preferably, the tackifier has a weight average molecular weight in the range of 300-. The adhesive further comprises a plasticizer, wherein the plasticizer comprises a kinematic viscosity of 400-1000mm at 40 ℃²Paraffin oil per second. The plasticizer preferably has a number average molecular weight of 400-1000 and a kinematic viscosity at 40 ℃ of 400-700mm²In seconds. The adhesive may further comprise a polyethylene wax. Preferably, the polyethylene wax has a dynamic viscosity of 150-500 centipoise at 140 ℃ and a pour point greater than 100 ℃.

In another embodiment, the present invention relates to a label. The label includes a facestock layer for receiving printed indicia. According to one embodiment, the label further comprises a hot melt pressure sensitive adhesive layer.

In another embodiment, the present invention relates to a labeled container. The labeled container includes a container defining an outer surface. The labeled container further includes a label according to one embodiment adhered to an outer surface of the container.

In another embodiment, the present invention is directed to a method of applying a label to a container. The method includes providing a container defining an exterior surface. The method also includes providing a label according to an embodiment. The method further includes adhering the label to an outer surface of the container, thereby applying the label to the container.

Drawings

The present invention is described in detail below with reference to the attached drawing figures, wherein like reference numerals represent like parts.

Fig. 1 is a schematic view of a labeled container (e.g., a bottle) according to one embodiment of the present invention.

Fig. 2 is a schematic representation of a cross-sectional view of a label having a facestock layer, a hot melt pressure sensitive adhesive layer, and a liner according to one embodiment of the present invention.

Detailed Description

The present invention relates generally to Hot Melt Pressure Sensitive Adhesives (HMPSAs) that provide an advantageous combination of performance characteristics while maintaining good processability when used in label applications. For example, for adhesives exposed to moisture or humid environments, it is beneficial to have a high level of resistance to water whitening. Such wet conditions are common for adhesive labels for glass or plastic bottles used to contain beverages, personal care products or other items. It is also useful that the label be removable and/or repositionable without leaving significant adhesive residue on the bottle or other container from which the label is removed. This feature is particularly important for containers that are to be reused or recycled. Additionally, optically clear (clear) or transparent adhesives may allow for visual attachment of labels through similarly clear or transparent containers (e.g., glass bottles). The ability of the adhesive to be easily processed is also a preferred characteristic, which enables the adhesive to better form a high quality coating on a label or other article.

However, HMPSA hardly exhibit all of the above properties at the same time. One reason for this is that components which improve one property often have an adverse effect on another property. For example, the desirable characteristics of low water whitening and repositionability may be associated with the use of adhesive components having high molecular weights and high viscosities. However, the use of an adhesive component having a high molecular weight and a high viscosity tends to adversely affect the ease of compounding and high-quality coating properties.

The present inventors have now found that a particular combination of components, optionally used in particular amounts, surprisingly provides a high performance HMPSA exhibiting a highly desirable combination of performance characteristics such as resistance to whitening by water, relocatability and/or optical clarity. Advantageously, these HMPSAs also exhibit improvements in processability during adhesive and label manufacture and application, as well as good adhesion and label quality in end-user products.

In particular, HMPSA compositions have been found comprising: a plasticizer comprising a paraffinic oil; and a tackifier comprising a hydrogenated cycloaliphatic hydrocarbon resin; each optionally having a molecular weight and viscosity within specific ranges, surprisingly provides HMPSAs having a combination of the above performance characteristics. For example, the adhesive can be used to produce labels that have good clarity, repositionability, and resistance to whitening, oil migration, swelling, or wrinkling, while still being easy to use in standard compounding and coating applications.

Without being bound by a particular theory, it is believed that the paraffin oil has good compatibility with the SIS block copolymer that is the basis of the HMPSA because both the paraffin oil and the SIS block copolymer have linear molecular structures. The internal interaction of these components of the adhesive layer may serve, for example, to limit oil migration and control swelling and wrinkling of the bonded polymeric structured film facestock. In addition, the low molecular weight of the hydrogenated cycloaliphatic hydrocarbon resin relative to the linear aliphatic hydrocarbon resin may allow the hydrogenated cycloaliphatic resin to increase the processability of the HMPSA without adversely affecting its softening point. Since the HMPSA composition is generally hydrophobic, water whitening of the adhesive is also minimized.

In one embodiment, the HMPSA comprises a base polymer, a tackifier, and a plasticizer. In some casesIn embodiments, the HMPSA further comprises a polyethylene wax. In some embodiments, the base polymer comprises a styrene-isoprene-styrene (SIS) copolymer, the tackifier comprises a hydrogenated cycloaliphatic hydrocarbon resin, and the plasticizer comprises a paraffinic oil. In a preferred embodiment, the plasticizer has a kinematic viscosity at 40 ℃ of 400-1000mm²In the range of/sec.

The base polymer of the HMPSA includes SIS block copolymers, where "S" represents a polymeric segment or "block" of styrene monomer and "I" represents a polymeric segment or "block" of isoprene monomer. The SIS block copolymer can be a pure triblock copolymer without SI diblock or can contain a percentage of SI diblock. It has been found that higher diblock content may be associated with increased stickiness of the SIS block copolymer and lower diblock content may be associated with increased elasticity of the copolymer. The diblock content of the HMPSA base polymer may be in the range of 0 to 50 wt%, such as 0 to 30 wt%, 5 to 35 wt%, 10 to 40 wt%, 15 to 45 wt%, or 20 to 50 wt%. As an upper limit, the diblock content may be less than 50 wt%, such as less than 45 wt%, less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, or less than 5 wt%. With respect to the lower limit, the diblock content may be at least 5 wt.%, at least 10 wt.%, at least 15 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, or at least 45 wt.%. In some embodiments, the base polymer has a diblock fraction of less than 30 wt%.

The styrene content of the SIS block copolymer can also affect the performance characteristics of the base polymer. It has been found that a specific styrene content, as well as a specific diblock content, can impart the desired properties of high melt flow index (greater than 20 grams per 10 minutes at 190 ℃) and low viscosity to the base polymer. Together, these properties make the polymer more suitable for compounding and coating processes. The styrene content of the base polymer may be in the range of 0 to 50 wt%, such as 0 to 30 wt%, 5 to 35 wt%, 10 to 40 wt%, 15 to 45 wt% or 20 to 50 wt%. As an upper limit, the styrene content may be less than 50 wt%, such as less than 45 wt%, less than 40 wt%, less than 35 wt%, less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, or less than 5 wt%. With respect to the lower limit, the styrene content may be at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, or at least 45 wt%. In some embodiments, the base polymer has a styrene content of less than 25 wt.%.

The amount of SIS block copolymer in the HMPSA composition can range from 15 to 65 weight percent, such as 15 to 45, 20 to 50, 25 to 55, 30 to 60, or 35 to 65 weight percent. The amount of SIS block copolymer in the HMPSA composition can range from 30 to 50 weight percent, such as 30 to 42, 32 to 44, 34 to 46, 36 to 48, or 38 to 50 weight percent. As an upper limit, the amount of SIS block copolymer in the HMPSA composition can be less than 70, less than 65, less than 60, less than 55, less than 50, less than 45, or less than 40 weight percent. For a lower limit, the amount of SIS block copolymer in the HMPSA composition can be at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent.

Suitable commercially available linear SIS block copolymers include, for example, SIS 1220 available from Ju Sage technology LTD, shandong, china; quintac 3433 and Quintac 3421, available from Nippon zeon company, Ltd. (Louisville, KY); vector DPX 559, Vector 4111 and Vector 4113, available from Dexco, partners of Exxon Chemical Co. (Houston, Texas) and Dow Chemical Co. (Midland Mich); and KRATON^TMRubbers such as Kraton 604x, Kraton D-1117, Kraton D-1107 and Kraton D-1113 available from Shell Chemical Co. (Houston, Texas).

In one embodiment, the plasticizer, such as a paraffinic oil plasticizer, is a high molecular weight paraffinic oil. The use of such high molecular weight plasticizers has been found to provide a number of advantages to adhesives not observed with conventional HMPSA compositions. For example, the resulting adhesive has improved repositionability after first application to a substrate. More specifically, in some embodiments, a label using the adhesive can be substantially completely removed, e.g., substantially completely removed from and reapplied to a substrate, e.g., polyethylene terephthalate (PET) or a glass bottle, within the first 12 hours (e.g., within the first 11 hours, 10 hours, 9 hours, 8 hours, 7 hours, 6 hours, 5 hours, or 4 hours) after the initial application at a temperature greater than 5 ℃. Fig. 1 shows an example of such a labelled bottle 100, wherein a label 101 is applied to the outer surface 102 of the bottle 100. Due to the specific HMPSA composition, such labels can also be cleanly removed over an extended period of time, thereby substantially completely removing the adhesive from the exterior surface of the glass or PET container. The term "substantially completely removed" is used herein to refer to at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96% at least 97%, at least 98%, or at least 99% of the adhesive remaining with the label and not with the outer surface of the container to which the label is affixed.

Another advantage of high molecular weight paraffin oil is that the adhesive can be used to make labels with greater structural integrity. For example, labels comprising the HMPSA can exhibit reduced wrinkling and swelling. The reduced swelling may indicate a dimensional change of less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% over the predetermined measurement period. The swelling and wrinkling measurement period may be greater than 3 days, greater than 4 days, greater than 5 days, greater than 6 days, greater than 7 days, greater than 8 days, greater than 9 days, or greater than 10 days. Reduced swelling and wrinkling may be observed during storage at temperatures above 45 ℃, above 50 ℃, above 55 ℃, above 60 ℃, above 65 ℃ or above 70 ℃. Reduced swelling and wrinkling may be observed during storage at relative humidities greater than 80%, greater than 82%, greater than 84%, greater than 86%, greater than 88%, or greater than 90%. In some embodiments, the label comprising HMPSA does not change in size or changes in dimensions (e.g., machine direction and transverse direction) by less than 2% after storage at greater than 65 ℃ for 4 days at 85% relative humidity or greater than 50 ℃ for 7 days.

Furthermore, it has been surprisingly found that these paraffinic oils can improve the stability of the label with less migration of the oil within and between the layers of the label and with less leakage of the adhesive beyond the original footprint of the adhered label. These improvements not only improve the effectiveness of the label in affixing items and anchoring and retaining printed instructions, but also increase the visual presentation of the label from the perspective of the end user. These improvements can significantly increase the value of the label, as labels are often used to present important information, or to increase the visibility or appeal of consumer products.

The amount of paraffinic oil plasticizer in the HMPSA composition may be in the range of 5 to 35 wt%, for example 5 to 23, 8 to 26, 11 to 29, 14 to 32, or 17 to 35 wt%. The amount of paraffinic oil plasticizer in the HMPSA composition may be in the range of 14 to 26 wt%, for example 14 to 21.2, 15.2 to 22.4, 16.4 to 23.6, 17.6 to 24.8 or 18.8 to 26 wt%. As an upper limit, the amount of paraffinic oil plasticizer in the HMPSA composition may be less than 38, less than 35, less than 32, less than 29, less than 26, less than 23, or less than 20 weight percent. As far as the lower limit is concerned, the amount of paraffinic oil plasticizer in the HMPSA composition may be at least 2, at least 5, at least 8, at least 11, at least 14, at least 17 or at least 20 wt.%.

The paraffin oil plasticizer can have the number average molecular weight of 400-1000, such as 400-700, 500-800, 600-900, 700-1000, 400-500, 500-600, 600-700, 700-800, 800-900 or 900-1000. As an upper limit, the plasticizer may have a number average molecular weight of less than 1000, such as less than 900, less than 800, less than 700, less than 600, or less than 500. With respect to the lower limit, the plasticizer may have a number average molecular weight of at least 400, such as at least 500, at least 600, at least 700, at least 800, or at least 900.

Paraffinic oil plasticizers may also have high viscosities. Kinematic viscosity can be measured, for example, using the procedure of Chinese Standard BG/T265-1988. The paraffinic oil plasticizer may have a kinematic viscosity at 40 ℃ as follows: 400mm-1000mm²Second, e.g. 400-²500-²600 and 900 mm/sec²700-²400-²500-²600-²Second, 700 and 800mm²800-²Second or 900-²In seconds. In terms of an upper limit, the plasticizer may have a thickness of less than 1000mm²Per second, e.g. less than 900mm²Per second, less than 800mm²Per second, less than 700mm²Per second, less than 600mm²Per second, or less than 500mm²Kinematic viscosity per second. With respect to the lower limit, the kinematic viscosity of the plasticizer may be greater than 400mm²Per second, e.g. greater than 500mm²Second, greater than 600mm²Second, greater than 700mm²Second, greater than 800mm²Per second, or greater than 900mm²In seconds.

It has been found that the use of tackifiers with low molecular weight and viscosity advantageously (partially) counteracts the high molecular weight and viscosity of the plasticizer. The inventors have found that the processability of the adhesive may be impaired if the overall viscosity of the HMPSA is too high. In particular, adhesives with higher viscosities may be more difficult to use in standard compounding and coating processes associated with the production of adhesive labels. Generally, as the viscosity of the adhesive decreases, the workability of the adhesive increases and the resulting adhesive coating is more uniform and consistent.

Many common linear aliphatic hydrocarbon tackifiers have weight average molecular weights in the range of 1000-4000. The inventors have discovered that by using cycloaliphatic hydrocarbon tackifier resins in HMPSAs, high molecular weight linear aliphatic hydrocarbons can be advantageously avoided. The alicyclic hydrocarbon tackifier may have a lower weight average molecular weight within the range of 300-1000 or 300-800, such as 300-600, 400-700, 500-800, 300-400, 400-500, 500-600, 600-700 or 700-800. With respect to the upper limit, the tackifier may have a weight average molecular weight of less than 800, such as less than 700, less than 600, less than 500, or less than 400. With respect to the lower limit, the tackifier may have a weight average molecular weight of at least 300, such as at least 400, at least 500, at least 600, or at least 700. As an additional benefit, the relatively high polarity and steric effects of the alicyclic hydrocarbon chemical structure may also be used to reduce oil migration within and between the relevant tag layers. Moreover, hydrogenation of the resin produces an adhesive layer and label with reduced color, odor and coke particles.

The amount of cycloaliphatic hydrocarbon tackifier in the HMPSA composition may range from 15 to 65 weight percent, such as 15 to 45, 20 to 50, 25 to 55, 30 to 60, or 35 to 65 weight percent. The amount of cycloaliphatic hydrocarbon tackifier in the HMPSA composition may range from 30 to 50 weight percent, such as 30 to 42, 32 to 44, 34 to 46, 36 to 48, or 38 to 50 weight percent. As an upper limit, the amount of cycloaliphatic hydrocarbon tackifier in the HMPSA composition may be less than 70, less than 65, less than 60, less than 55, less than 50, less than 45, or less than 40 weight percent. With respect to the lower limit, the amount of cycloaliphatic hydrocarbon tackifier in the HMPSA composition may be at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent.

The HMPSA may optionally comprise polyethylene wax. The optional polyethylene wax of the HMPSA can serve to increase the hydrophobicity of the adhesive. This increased hydrophobicity may help improve the resistance of the adhesive to water whitening, as well as the ability of the adhesive to be cleanly removed or repositioned. The specific polyethylene wax may also be selected to further reduce the overall viscosity of the HMPSA with minimal impact on the clarity of the adhesive.

The polyethylene wax may be selected to have a particular hardness value. Hardness values can be measured using, for example, the penetration test in the American Society for Testing and Materials (ASTM) standard procedure ASTM D5. The hardness in this procedure is defined as the distance in tenths of a millimeter that a standard needle penetrates a sample of the material being tested. The polyethylene wax may have a hardness value in the range of 3 to 10, such as 3 to 6,4 to 7,5 to 8, 6 to 9, 7 to 10, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9 or 9 to 10. As far as the upper limit is concerned, the polyethylene wax may have a hardness value of less than 10, for example less than 9, less than 8, less than 7, less than 6, less than 5 or less than 4. With respect to the lower limit, the polyethylene wax may have a hardness value of at least 3, such as at least 4, at least 5, at least 6, at least 7, at least 8, or at least 9.

Polyethylene waxes can have relatively low viscosities, such as dynamic viscosity as measured by a Brookfield viscometer. The polyethylene wax can have a dynamic viscosity of 150-. In terms of an upper limit, the polyethylene wax can have a dynamic viscosity at 140 ℃ of less than 500cps, less than 450cps, less than 400cps, less than 350cps, less than 300cps, less than 250cps, or less than 200 cps. With respect to the lower limit, the polyethylene wax can have a dynamic viscosity of at least 150cps, such as at least 200cps, at least 250cps, at least 300cps, at least 350cps, at least 400cps, or at least 450cps at 140 ℃.

Polyethylene waxes may also be selected to have a particular pour point as measured by standard procedure ASTM D5949. Pour point is defined as the temperature at which a liquid becomes semi-solid and loses its flow characteristics. The polyethylene wax may have a pour point greater than 90 ℃, greater than 91 ℃, greater than 92 ℃, greater than 93 ℃, greater than 94 ℃, greater than 95 ℃, greater than 96 ℃, greater than 97 ℃, greater than 98 ℃, greater than 99 ℃, greater than 100 ℃, greater than 101 ℃, greater than 102 ℃, greater than 103 ℃, greater than 104 ℃, greater than 105 ℃, greater than 106 ℃, greater than 107 ℃, greater than 108 ℃, greater than 109 ℃ or greater than 110 ℃. In some embodiments, the polyethylene wax has a pour point greater than 100 ℃.

The amount of polyethylene wax in the HMPSA composition can range from 0 to 5 wt%, such as 0 to 3, 0.5 to 3.5, 1 to 4, 1.5 to 4.5, or 2 to 5 wt%. The amount of polyethylene wax in the HMPSA composition can be in the range of 0 to 2 wt%, such as 0 to 1.2, 0.2 to 1.4, 0.4 to 1.6, 0.6 to 1.8, or 0.8 to 2 wt%. As an upper limit, the amount of polyethylene wax in the HMPSA composition can be less than 5, less than 4, less than 3, less than 2, less than 1.5, less than 1, or less than 0.5 weight percent. With respect to the lower limit, the amount of polyethylene wax in the HMPSA composition can be zero or at least 0.5, at least 1, at least 1.5, at least 2, or at least 2.5 weight percent.

The overall viscosity of the HMPSA can be such that the dynamic viscosity of the adhesive at 140 ℃ as measured by a Brookfield viscometer is within a range of 10,000-20,000cps, e.g., 10,000-14,000cps, 12,000-16,000 cps, 14,000-18,000 cps, 16,000-20,000 cps, 10,000-12,000 cps, 12,000-14,000 cps, 14,000-16,000 cps, 16,000-18,000 cps, or 18,000-20,000 cps. As an upper limit, the HMPSA can have a dynamic viscosity at 140 ℃ of less than 20,000cps, e.g., less than 18,000cps, less than 16,000cps, less than 14,000cps, or less than 12,000 cps. With respect to the lower limit, the HMPSA can have a dynamic viscosity of at least 10,000, such as at least 12,000cps, at least 14,000cps, at least 16,000cps, or at least 18,000cps at 140 ℃.

The HMPSA can be formulated as above to have a slightly white or colorless appearance. HMPSAs can also be formulated to have high clarity and transparency. This may provide benefits to the adhesive or related label in applications where a clear or transparent adhesive or label is desired. For example, clear labels may be used with a variety of different attachment surfaces or materials to allow the color or texture of these attachment surfaces to remain visible through the label. Clear or transparent adhesives or labels may also be used for clear or transparent containers. For example, in the beverage industry where glass or plastic bottles are used, such a "clear on clear" label is common. In clear versus clear labels, any print on the label tends to appear as if printed directly on the container itself, due in part to the transparency and lack of color of the adhesive. To produce an adhesive with the desired lack of color, the tackifier resin, plasticizer oil, wax, filler and other ingredients are each selected to have light to no color and/or good solubility in the adhesive composition.

Clarity and transparency of HMPSA can be measured as haze value according to standard protocol ASTM D1003 or opacity contrast ratio according to standard protocol ASTM D2805. Haze values are defined as the percentage of transmitted light scattered by the sample that is the cause of the above reduction upon observation thereof. The HMPSA can have a haze value of, for example, less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, or less than 1. In some embodiments, the HMPSA has a haze value of less than 5. Opacity contrast ratio is defined as the ratio of the reflectance of a film on a black substrate to the same film on a white substrate. The opacity contrast ratio value of the HMPSA may be, for example, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, less than 10, or less than 5. In some embodiments, the HMPSA has an opacity contrast ratio of less than 20.

Another advantage of HMPSA formulations is that whitening, clarity and transparency are not significantly affected by changes in temperature or humidity. For example, the haze value and opacity contrast ratio may each independently change by less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, less than 14%, less than 12%, less than 10%, less than 8%, less than 6%, less than 4%, or less than 2% when the adhesive is heated to 65 ℃ and over 1 hour. Heating may include contacting the adhesive with water heated to 65 ℃. Heating may include immersing the adhesive in 65 ℃ water.

The components of the HMPSA composition may be selected to meet food contact requirements and are generally classified as food safe. For example, the use of hydrogenated tackifiers and food grade paraffin oils can make HMPSA a food safe adhesive.

The invention also relates to labels comprising the hot melt pressure sensitive adhesive of the invention. The label includes a facestock layer for receiving printed indicia and a hot melt pressure sensitive adhesive layer having a composition as described above. The label may also include one or more facestock layers, one or more optional print layers, one or more adhesive layers, and an optional liner layer. The present subject matter can be used in a label that is not printed, but in many embodiments the label includes one or more printed regions.

Fig. 2 illustrates a multilayer label according to one embodiment. The illustrated label 200 includes a facestock layer 201, an HMPSA layer 202, and a liner layer 203. The HMPSA layer is disposed on the face stock layer surface 204 closer to the backing layer. The opposite surface 205 of the facestock layer may be configured to receive printed indicia. The optional indicia may be printed directly onto the surface 205; embedded in any of

layers

201, 202, or 203; or printed on any other surface of the label 200. The layers shown in fig. 2 may be positioned directly adjacent to each other as shown, or may have one or more additional layers therebetween. Additional layers may include, for example, one or more coating layers, support layers, printed layers, reflective layers, laminated layers, and the like. Any one or more of the layers shown may also include two or more sub-layers, each having a different composition, configuration, and function.

The facestock may include, for example, a paper facestock, a cardboard facestock, a plastic facestock, a multi-layer laminate facestock including a paper layer and a plastic layer, or any other material commonly used in the industry. The multilayer laminate facestock may include a paper layer overlying a plastic layer. The plastic layer of the multilayer laminate facestock may be extruded or coated onto the paper layer. The paper layer may include, for example, glossy paper, semi-glossy paper, lithographic paper, or Electronic Data Processing (EDP) paper; and may be configured for multi-color printing, typewriter printing, or inkjet printing, for example. The plastic layer may comprise, for example, polyester, such as PET; polyolefins such as polypropylene (PP), ethylene-propylene copolymers, Polyethylene (PE); and other materials. Other polymeric film materials include polyurethane-based polymers, such as polyether polyurethanes and polyester polyurethanes; amide-based polymers including polyether polyamide copolymers; acrylic-based polymers including polyacrylates and ethylene/vinyl acetate copolymers; polyester-based polymers, including polyether polyesters; vinyl chloride; vinylidene chloride; polystyrene; polyacrylonitrile; a polycarbonate; a polyimide; or the like. The facestock may comprise a flexible facestock. The facestock may comprise a transparent polymeric film. In certain applications, it may be useful to utilize "shrink" or oriented films as facestock layers. The subject of the invention includes, for example, a biaxially oriented film such as PET as the facestock layer.

In some embodiments, the label further comprises printing disposed on the facestock layer. The printed matter may include layers or regions of ink, dye, pigment or similar materials. It is understood that "dye" and similar terms refer to a visible light absorbing compound that exists in a molecularly dispersed or dissolved form. "pigment" and like terms refer to a visible light absorbing material or compound that is present in a non-molecularly dispersed or particulate form. "ink" and like terms refer to coatable or printable formulations containing dyes and/or pigments. Although the present subject matter is primarily directed to labels that include visually perceptible printing, it is contemplated that the label may include only or primarily printing that indicates under UV light or other conditions.

The HMPSA layer can be applied directly to and in contact with the facestock. An intermediate layer may be present between the HMPSA layer and the facestock. The label may comprise two or more layers of HMPSA and/or facestock. The HMPSA layer of the label can be coated onto the facestock at a coat weight of, for example, 5 to 30 grams per square meter (gsm). The coat weight of the adhesive layer may be 6-20gsm, 8-20gsm, 22-30gsm, 16-40 gsm. In some embodiments, the adhesive layer coat weight is in the range of 5 to 40 gsm. In terms of an upper limit, the adhesive layer coat weight may be less than 40gsm, such as less than 35gsm, less than 30gsm, less than 25gsm, less than 20gsm, less than 15gsm, or less than 10 gsm. With respect to the lower limit, the adhesive layer coat weight may be at least 5gsm, such as at least 10gsm, at least 15gsm, at least 20gsm, at least 25gsm, at least 30gsm, or at least 35 gsm.

The present subject matter may include the incorporation of one or more clear or transparent layers in any of the label constructions described herein. The present subject matter may also include the incorporation of one or more metal layers or metal foils in any of the label constructions described herein. It is also contemplated that the label structure may also include a combination of one or more transparent layers and one or more metal layers. In some embodiments, the label is a clear to clear label having a laminate composition comprising a transparent biaxially oriented polypropylene (BOPP) film, a transparent HMPSA layer, and a transparent PET liner.

In some embodiments, the label further comprises a liner disposed on the HMPSA layer. The releasable liner may be positioned adjacent to the adhesive layer such that the adhesive layer is disposed or sandwiched directly or indirectly between the bottom surface of the facestock and the releasable liner. The release liner may serve as a protective cover such that the release liner remains in place until the tag is ready to be attached to an object. If a liner or release liner is included in the label, various materials and structures may be used as the liner. In many embodiments, the liner is a paper or paper-based material. In many other embodiments, the liner is a polymeric film of one or more polymeric materials. Typically, at least one face of the liner is coated with a release material such as a silicone or silicone-based material. It will be appreciated that the release coated side of the liner is placed in contact with the otherwise exposed side of the adhesive layer. The liner is removed prior to applying the label to the surface of interest, thereby exposing the adhesive side of the label. The liner may be in the form of a single piece. Alternatively, the liner may be in the form of multiple sections or panels.

Other additives may be added to one or more of the HMPSA, facestock or liner layers to achieve certain desired properties. These additives may include, for example, one or more waxes, surfactants, talc, silicate powders, fillers, defoamers, colorants, antioxidants, uv stabilizers, luminescent agents, crosslinking agents, buffering agents, antiblocking agents, wetting agents, matting agents, antistatic agents, acid scavengers, flame retardants, processing aids, extrusion aids, and the like.

The invention also relates to a labeled container comprising the hot melt pressure sensitive adhesive of the invention. The labeled container includes a container defining an outer surface, and the label described above adhered to the outer surface of the container. In some embodiments, the container is a bottle. The outer surface to which the HMPSA is bonded can comprise a wide range of substrates. The outer surface may comprise glass, plastic, wood, metal, combinations of these, and other materials. In some embodiments, the outer surface of the container comprises glass.

In some embodiments, the outer surface of the container comprises plastic. The outer surface may comprise or be formed from any suitable polymer or mixture of polymers. The polymer or polymer blend may include, for example, PET, recycled polyethylene terephthalate (rPET), High Density Polyethylene (HDPE), polyvinyl chloride (PVC), polylactic acid (PLA), cellulose, biopolymer film, low density polyethylene LDPE), PP, Polystyrene (PS), polyester, or other types of polymers or plastics. In some embodiments, the plastic comprises PET.

While the label is typically removable from the container, the outer surface of the container may retain a portion of the adhesive used to adhere the label to the container. This adhesive residue may contaminate or interfere with subsequent container operations, such as later washing, re-labeling or container recycling. In some embodiments, the provided labels may be removed from the outer surface while substantially all of the adhesive remains placed and/or retained with the label, rather than remaining on the outer surface.

The invention also relates to a method of applying a label to a container. The method includes providing a container defining an exterior surface and a label according to an embodiment. The method further includes adhering the label to an outer surface of the container, thereby applying the label to the container.

The label may be adhered to one or more containers or articles in a batch, continuous or semi-continuous manner. Prior to use, one or more liners may be removed from the label, thereby exposing the adhesive side of the label. The adhesive side and label are then contacted with the container or article and the label is applied thereto. Bonding may also include one or more operations, i.e., pressing or otherwise applying pressure on the label to facilitate contact and/or bonding with the container; activating and/or curing the adhesive, for example by heating and/or exposure to UV light; and/or a drying operation.

The following embodiments are envisaged. All combinations of features and embodiments are also contemplated.

Embodiment 1: a hot melt pressure sensitive adhesive comprising: styrene-isoprene-styrene copolymers; a tackifier comprising a hydrogenated cycloaliphatic hydrocarbon resin; a plasticizer comprising a kinematic viscosity at 40 ℃ of 400-1000mm²Paraffin oil in the range of/sec; and less than 5 wt% polyethylene wax.

Embodiment 2: embodiment 1 wherein the tackifier has a weight average molecular weight in the range of 300-1000.

Embodiment 3: an embodiment of any of embodiments 1 or 2, wherein the plasticizer has a number average molecular weight in the range of 400-1000.

Embodiment 4: an embodiment of embodiment 3 wherein the tackifier has a weight average molecular weight within 10% of the number average molecular weight of the plasticizer.

Embodiment 5: embodiment 1-4 wherein the concentration of styrene-isoprene-styrene copolymer in the hot melt pressure sensitive adhesive is in the range of 15 to 65 wt.%, wherein the concentration of tackifier in the hot melt pressure sensitive adhesive is in the range of 15 to 65 wt.%, and wherein the concentration of plasticizer in the hot melt pressure sensitive adhesive is in the range of 5 to 35 wt.%.

Embodiment 6: embodiment 1-4 wherein the concentration of styrene-isoprene-styrene copolymer in the hot melt pressure sensitive adhesive is in the range of 25 to 55 wt.%, wherein the concentration of tackifier in the hot melt pressure sensitive adhesive is in the range of 25 to 55 wt.%, wherein the concentration of plasticizer in the hot melt pressure sensitive adhesive is in the range of 15 to 25 wt.%, and wherein the concentration of polyethylene wax in the hot melt pressure sensitive adhesive is less than 2 wt.%.

Embodiment 7: an embodiment of any of embodiments 1 to 6, wherein the styrene-isoprene-styrene copolymer has a diblock fraction of less than 30 wt.%.

Embodiment 8: an embodiment of any of embodiments 1 to 7, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

Embodiment 9: embodiment 1 to 8 wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

Embodiment 10: an embodiment of any of embodiments 1-9, wherein the polyethylene wax has a dynamic viscosity of 150-500cps at 140 ℃.

Embodiment 11: an embodiment of any of embodiments 1 to 10, wherein the polyethylene wax has a pour point greater than 100 ℃.

Embodiment 12: embodiment of any of embodiments 1-11, wherein the hot melt pressure sensitive adhesive has a haze value of less than 5.

Embodiment 13: embodiment of any of embodiments 1-12 wherein the hot melt pressure sensitive adhesive has an opacity contrast ratio of less than 20.

Embodiment 14: embodiment 12 wherein the haze value changes by less than 20% after heating the hot melt pressure sensitive adhesive to 65 ℃ and over 1 hour.

Embodiment 15: the embodiment according to embodiment 13, wherein the opacity contrast ratio changes by less than 20% after heating the hot melt pressure sensitive adhesive to 65 ℃ and over 1 hour.

Embodiment 16: embodiment of any of embodiments 1-15 wherein the hot melt pressure sensitive adhesive has a dynamic viscosity in the range of 10,000 and 20,000 centipoise at 140 ℃.

Embodiment 17: a label comprising a facestock capable of receiving printed indicia; and the hot melt pressure sensitive adhesive of any of embodiments 1-16.

Embodiment 18: the embodiment of embodiment 17, further comprising a liner disposed on the hot melt pressure sensitive adhesive layer.

Embodiment 19: an embodiment of any of embodiments 17 or 18 wherein the label has a longitudinal length and a transverse length and wherein the longitudinal length and the transverse length each change by less than 2% when the label is stored for four days at greater than 65 ℃ and 85% relative humidity.

Embodiment 20: a labeled container comprising a container having an outer surface; and the label of any one of embodiments 17-19 adhered to the outer surface of the container.

Embodiment 21: an embodiment of embodiment 20 wherein the outer surface of the container comprises glass, polyethylene terephthalate, or other plastic.

Embodiment 22: an embodiment of any of the embodiments 20 or 21, wherein the container is a bottle.

Embodiment 23: an embodiment of any of embodiments 20-22 wherein the label can be substantially completely removed from the container by peeling.

Embodiment 24: a method of applying a label to a container, the method comprising providing a container defining an outer surface; providing a tag according to any one of embodiments 17 to 19; and adhering the label to the outer surface of the container to thereby apply the label to the container.

Embodiment 25: the embodiment of embodiment 24 wherein the outer surface of the container comprises glass, polyethylene terephthalate, or other plastic.

Embodiment 26: an embodiment of any of embodiments 24 or 25 wherein the label can be substantially completely removed from and reapplied to the container within the first 8 hours after bonding at a temperature greater than 5 ℃.

The invention will be better understood in view of the following non-limiting examples.

Examples

Eight HMPSA compositions were prepared according to the formulations listed in table 1 below. The HMPSA was tested for physical and performance characteristics such as swelling, dynamic viscosity and processability. The results are also provided in table 1.

Labels were prepared using the HMPSAs of comparative examples a and B and example 1 and tested for swelling. The labels using the HMPSA of example 1 (as well as those using comparative examples a and B) showed very good swelling results. As noted above, adhesives with reduced swelling have greater structural integrity and may also exhibit less oil migration than adhesives with greater tendency to swell. The labels using the HMPSA of example 1 also exhibit an excellent combination of performance characteristics, such as resistance to water whitening, re-orientation, and/or optical clarity. Importantly, the HMPSA of example 1 has a lower viscosity, is easier to process, and results in a high quality label. In contrast, the HMPSAs of comparative examples a and B exhibited much higher viscosities, which resulted in processing difficulties and poor quality labels.

As shown in Table 1, the formulations of examples 1 to 4 and 8 used a kinematic viscosity at 40 ℃ of 400-1000mm²Plasticizers in the range of/sec. These formulations provide, inter alia, hot melt PSAs with an advantageous combination of performance characteristics and excellent processability. These example adhesives had high levels of adhesionWhitening resistance, good removability, optical clarity and low swelling and oil migration. Importantly, examples 1-4 exhibit low dynamic viscosities, for example in the range of 10000-. In contrast, comparative examples a-D exhibited much higher dynamic viscosities (much higher than 20000 centipoise, and in some cases greater than 80000 centipoise). These comparative examples, at least in part due to the high viscosity plasticizer, exhibited poor processability.

In addition, as shown in table 1, the HMPSA formulations of examples 1-4 each included a tackifier having a molecular weight in the preferred range of 300-800. These relatively low tackifier molecular weights may be used to partially offset the number average molecular weight of the plasticizer, which further contributes to reducing the overall dynamic viscosity, for example, within the favorable range of 10000-. In contrast, the formulations of comparative examples A-D used tackifiers having number average molecular weights greater than 1000. The resulting HMPSA has a much higher dynamic viscosity, e.g. greater than 35000 centipoise, which makes processing steps such as compounding and coating difficult. Thus, examples 1-4 and comparative examples A-D demonstrate the importance of combining a low weight average molecular weight tackifier with a high number average molecular weight plasticizer to formulate an adhesive that meets the desired properties of low swell, low oil migration, and low viscosity simultaneously.

In summary, the data in table 1 shows that the formulation of the comparative example uses high viscosity plasticizers (and optionally plasticizers and/or tackifiers) outside the viscosity and/or molecular weight ranges discussed herein. These comparative examples have undesirable physical and/or performance characteristics. These data indicate the importance and criticality of the above combinations.

Although the present invention has been described in detail, modifications within the spirit and scope of the invention will be apparent to those skilled in the art. In view of the above discussion, relevant knowledge in the art, and references discussed above in connection with the background and detailed description, the disclosures of which are incorporated herein by reference in their entirety. Additionally, it should be understood that various aspects and portions of various embodiments of the present invention, as well as various features described below and/or in the appended claims, may be combined or interchanged either in whole or in part. In the foregoing description of various embodiments, those embodiments that refer to another embodiment may be suitably combined with other embodiments, as will be understood by those skilled in the art. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.

Claims

1. A hot melt pressure sensitive adhesive comprising:

styrene-isoprene-styrene copolymers;

a tackifier comprising a hydrogenated cycloaliphatic hydrocarbon resin;

a plasticizer comprising a kinematic viscosity at 40 ℃ of 400-1000mm²Paraffin oil in the range of/sec; and

less than 5% by weight of polyethylene wax.

2. The hot melt pressure sensitive adhesive according to claim 1, wherein the tackifier has a weight average molecular weight in the range of 300-1000.

3. The hot melt pressure sensitive adhesive according to claim 1, wherein the plasticizer has a number average molecular weight in the range of 400-1000.

4. The hot melt pressure sensitive adhesive according to claim 2, wherein the plasticizer has a number average molecular weight in the range of 400-1000.

5. The hot melt pressure sensitive adhesive according to claim 3, wherein the weight average molecular weight of the tackifier is within 10% of the number average molecular weight of the plasticizer.

6. The hot melt pressure sensitive adhesive according to claim 4, wherein the weight average molecular weight of the tackifier is within 10% of the number average molecular weight of the plasticizer.

7. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the concentration of styrene-isoprene-styrene copolymer in the hot melt pressure sensitive adhesive is in the range of 15 to 65 wt. -%, wherein the concentration of tackifier in the hot melt pressure sensitive adhesive is in the range of 15 to 65 wt. -%, and wherein the concentration of plasticizer in the hot melt pressure sensitive adhesive is in the range of 5 to 35 wt. -%.

8. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the concentration of styrene-isoprene-styrene copolymer in the hot melt pressure sensitive adhesive is in the range of 25 to 55 wt. -%, wherein the concentration of tackifier in the hot melt pressure sensitive adhesive is in the range of 25 to 55 wt. -%, wherein the concentration of plasticizer in the hot melt pressure sensitive adhesive is in the range of 15 to 25 wt. -%, and wherein the concentration of polyethylene wax in the hot melt pressure sensitive adhesive is less than 2 wt. -%.

9. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the styrene-isoprene-styrene copolymer has a diblock fraction of less than 30 wt.%.

10. The hot melt pressure sensitive adhesive according to claim 7, wherein the styrene-isoprene-styrene copolymer has a diblock fraction of less than 30 wt.%.

11. The hot melt pressure sensitive adhesive according to claim 8, wherein the styrene-isoprene-styrene copolymer has a diblock fraction of less than 30 wt.%.

12. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

13. The hot melt pressure sensitive adhesive according to claim 7, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

14. The hot melt pressure sensitive adhesive according to claim 8, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

15. The hot melt pressure sensitive adhesive according to claim 9, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

16. The hot melt pressure sensitive adhesive according to claim 10, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

17. The hot melt pressure sensitive adhesive according to claim 11, wherein the styrene-isoprene-styrene copolymer has a styrene content of less than 25 wt.%.

18. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

19. The hot melt pressure sensitive adhesive according to claim 7, wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

20. The hot melt pressure sensitive adhesive according to claim 8, wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

21. The hot melt pressure sensitive adhesive according to claim 9, wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

22. The hot melt pressure sensitive adhesive according to claim 12, wherein the plasticizer has a kinematic viscosity at 40 ℃ of 400-700mm²In the range of/sec.

23. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the polyethylene wax has a dynamic viscosity of 150-500cps at 140 ℃.

24. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the polyethylene wax has a pour point of greater than 100 ℃.

25. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the hot melt pressure sensitive adhesive has a haze value of less than 5.

26. The hot melt pressure sensitive adhesive according to claim 25, wherein the haze value changes by less than 20% after heating the hot melt pressure sensitive adhesive to 65 ℃ for 1 hour.

27. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the hot melt pressure sensitive adhesive has an opacity contrast ratio of less than 20.

28. The hot melt pressure sensitive adhesive according to claim 27, wherein the opacity contrast ratio changes by less than 20% after heating the hot melt pressure sensitive adhesive to 65 ℃ and 1 hour.

29. The hot melt pressure sensitive adhesive according to any one of claims 1 to 6, wherein the dynamic viscosity of the hot melt pressure sensitive adhesive at 140 ℃ is in the range of 10,000 and 20,000 centipoise.

30. A label, comprising:

a face stock capable of receiving printed indicia; and

a hot melt pressure sensitive adhesive comprising the hot melt pressure sensitive adhesive of any one of claims 1 to 29.

31. The label of claim 30, further comprising:

a liner disposed on the hot melt pressure sensitive adhesive layer.

32. A label according to claim 30 or 31, wherein the label has a longitudinal length and a transverse length, and wherein the longitudinal length and the transverse length each change by less than 2% when the label is stored for four days at greater than 65 ℃ and 85% relative humidity.

33. A labeled container comprising:

a container having an outer surface; and

the label of any one of claims 30-32 adhered to an outer surface of a container.

34. A labeled container according to claim 33 wherein the outer surface of the container comprises glass, polyethylene terephthalate, or other plastic.

35. A labeled container according to claim 33 wherein the container is a bottle.

36. A labeled container according to claim 34 wherein the container is a bottle.

37. A labelled container according to any one of claims 33 to 36 wherein the label is substantially completely removable from the container by peeling, wherein "substantially completely removable from the container" is used to indicate that at least 90% of the adhesive remains with the label and not with the outer surface of the container to which the label is applied.

38. A method of applying a label to a container, the method comprising:

providing a container defining an outer surface;

providing the label of any one of claims 30-32; and

the label is applied to the container by adhering the label to the outer surface of the container.

39. The method of claim 38, wherein the outer surface of the container comprises glass, polyethylene terephthalate, or other plastic.

40. A method according to claim 38 or 39 wherein the label is substantially completely removable from the container and reapplied to the container within the first 8 hours after bonding at a temperature of greater than 5 ℃, wherein "substantially completely removable from the container" is used to indicate that at least 90% of the adhesive remains with the label and not with the outer surface of the container to which the label is affixed.