WO2022167953A1 - Primer layer for flexographic plate mounting tape - Google Patents

Abstract

Articles that include a foam layer, having a first and a second opposing surface. The articles also include a first primer layer, the first primer layer including thermoplastic polymeric binder and inorganic nanoparticles having a bound organic surface coating. The articles also include a first pressure sensitive adhesive layer, having a first and a second opposing layer. The first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer. Assemblies including such articles and a flexographic printing plate are also included herein.

Description

PRIMER LAYER FOR FLEXOGRAPHIC PLATE MOUNTING TAPE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 63/144,702, filed February 2, 2021, the disclosure of which is incorporated by reference in its entirety herein.

FIELD OF THE DISCLOSURE

This disclosure relates to primers for bonding a pressure sensitive adhesive (PSA) to a foam layer, such as may be used in a flexographic plate mounting tape, as well as flexographic plate mounting tapes incorporating this primer and methods of making and using such tapes.

BACKGROUND

Flexographic plate mounting tapes are used to mount flexographic printing plates to plate cylinders in a flexographic printing press. Novel, more advantageous mounting tapes for such uses are always in need.

SUMMARY OF THE DISCLOSURE

Disclosed herein are articles that comprise a foam layer, having a first and a second opposing surface. The articles also comprise a first primer layer, the first primer layer comprising thermoplastic polymeric binder, and inorganic nanoparticles having a bound organic surface coating. The articles also comprise first pressure sensitive adhesive layer, having a first and a second opposing layer. The first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer.

Such articles can further comprise a second primer layer and a second pressure sensitive adhesive layer, wherein the second primer layer is positioned between the second surface of the foam layer and the second pressure sensitive pressure adhesive layer.

Such articles can further comprise a first release liner positioned on the first surface of the first pressure sensitive adhesive layer. Such articles or assemblies can further comprise a second release liner positioned on the second surface of the second pressure sensitive adhesive layer.

Such articles can further comprise a first skin layer positioned between the first surface of the foam layer and the first primer layer. Such articles or assemblies can further comprise a second skin layer positioned between the second surface of the foam layer and the second primer layer.

Disclosed herein are assemblies that comprise a flexographic printing plate and any of the articles disclosed herein, enumerated immediately above, or any combination thereof, which can be referred to as a mounting tape. The mounting tape may comprise a foam layer, having a first and a second opposing surface; a first primer layer; and a first pressure sensitive adhesive layer, having a first and a second opposing layer, wherein the first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer, wherein the first surface of the first pressure sensitive adhesive layer is attached to the flexographic printing plate.

Such assemblies can further comprise a second primer layer and a second pressure sensitive adhesive layer having a first and a second opposing surface, wherein the second primer layer is positioned between the second surface of the foam layer and the first surface of the second pressure sensitive pressure adhesive layer.

Such assemblies can further comprise a plate cylinder, wherein the plate cylinder is attached to the mounting tape via the second surface of the second pressure sensitive adhesive layer.

Such articles and assemblies can have the first primer layer, the second primer layer, or both independently with thicknesses of at least 1 micrometer (pm), 3pm or 5 pm; of less than 50 pm, 25 pm, or 8 pm; or combinations thereof.

Such articles and assemblies can have the foam layer, exclusive of an optional skin layer, having a thickness of at least 200 pm, 300 pm, or 400 pm; of less than 2500 pm, 2000 pm, or 1500 pm; or combinations thereof.

In such articles and assemblies, the inorganic particles in the first primer layer can comprise silica, zirconia, alumina, ceria, tin oxide, or titanium dioxide. In such articles and assemblies, the organic surface coating can provide active binding sites comprising an epoxy group, amine group, alkynyl group, (meth) acrylate group, mercapto group, or combinations thereof. In such articles and assemblies, the organic surface coating can provide active binding sites comprising an epoxy group, an amine group, or combinations thereof. In such articles and assemblies, the organic surface coating can provide active binding sites derived from an amine silane selected from the group 3-aminopropyltrimethoxysilane, 3- aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- aminoethylamino)propyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2- aminoethyl)-3 -aminopropylmethyldiethoxysilane, 4-aminobutyltrimethoxysilane, 4- aminobutyltriethoxy silane , 3 -aminopropylmethyldiethoxy silane , 3 -aminopropylmethyldimethoxy silane , 3-aminopropyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane, and any combinations or mixtures thereof. In such articles and assemblies, the organic surface coating can provide active binding sites derived from 3-aminopropyltrimethoxysilane. In such articles and assemblies, the organic surface coating can provide an aliphatic or aromatic structure. In such articles and assemblies, the organic surface coating can provide active bonding sites derived from an epoxy silane selected from the group 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, (3- glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, and any combinations or mixtures thereof. In such articles and assemblies, the organic surface coating can provide active binding sites comprising amine groups present on the surface of the inorganic nanoparticles in an amount equivalent to at least 3 mole-%, at least 5 mole-%, at least 10 mole-%, or at least 25 mole-% of the total molar functional groups on said surface. Such articles and assemblies, wherein the organic surface coating provides active binding sites comprising amine groups present on the particle surface in an amount of not more than 150 mole-% of the total molar functional groups on said surface.

In such articles and assemblies, the thermoplastic polymeric binder can be a thermoplastic polymeric binder of an ethylenic polymer.

In such articles and assemblies, the first primer layer can further comprise non-fimctionalized fillers.

In such articles and assemblies, the first primer layer can have a solvent resistance that is higher than that of the second primer layer. In such articles and assemblies, the first primer layer can have a solvent resistance that is higher than that of the second primer layer as measured according to the Rub Resistance Test.

In such articles and assemblies, the first pressure sensitive adhesive layer, the second pressure sensitive adhesive layer, or both can independently comprise a polyacrylate polymer comprising units derived from an acrylate, acrylic acid, or combinations thereof.

In such articles and assemblies, the first primer layer can be laminated to the foam layer using heat and pressure.

The preceding summary of the present disclosure is not intended to describe each embodiment of the present invention. The details of one or more embodiments of the invention are also set forth in the description below. Other features, objects, and advantages of the invention will be apparent from the description and from the claims.

In this application:

The term “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. Such terms will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements. “Consisting of’ means including, and limited to, whatever follows the phrase “consisting of.” Thus, the phrase “consisting of’ indicates that the listed elements are required or mandatory, and that no other elements may be present. “Consisting essentially of’ means including any elements listed after the phrase and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase “consisting essentially of’ indicates that the listed elements are required or mandatory but that other elements are optional and may or may not be present depending upon whether or not they materially affect the activity or action of the listed elements. Any of the elements or combinations of elements that are recited in this specification in open-ended language (e.g., comprising and derivatives thereof), are considered to additionally be recited in closed-ended language (e.g., consisting of and derivatives thereof) and in partially closed-ended language (e.g., consisting essentially of, and derivatives thereof).

The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other claims are not useful and is not intended to exclude other embodiments from the scope of the disclosure.

Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity but include the general class of which a specific example may be used for illustration. The terms “a,” “an,” and “the” are used interchangeably with the term “at least one.” The phrases “at least one of’ and “comprises at least one of’ followed by a list refers to any one of the items in the list and any combination of two or more items in the list.

The term “or” is generally employed in its usual sense including “and/or” unless the content clearly dictates otherwise.

The term “and/or” means one or all of the listed elements or a combination of any two or more of the listed elements.

All numbers are assumed to be modified by the term “about” and in certain embodiments, preferably, by the term “exactly.” As used herein in connection with a measured quantity, the term “about” refers to that variation in the measured quantity as would be expected by the skilled artisan making the measurement and exercising a level of care commensurate with the objective of the measurement and the precision of the measuring equipment used. Herein, “up to” a number (e.g., up to 50) includes the number (e.g., 50).

The recitations of numerical ranges by endpoints include all numbers subsumed within that range as well as the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.) and any sub-ranges (e.g., 1 to 5 includes 1 to 4, 1 to 3, 2 to 4, etc.).

Past tense verbs such as “coated” and “oriented” are intended to represent structure, and not to limit the process used to obtain the recited structure, unless otherwise specified.

Terms such as “first”, “second”, “third”, etc. are used for the sake of convenience to distinguish similarly named components. Designation as “first” as opposed to “second” for example does not imply anything additional and is only used to distinguish one component from another similarly named component.

The term “adjacent” as used herein with regard to layers means that there may or may not be intervening layers between the two referred to layers.

The phrase “immediately adjacent” as used herein with regard to layers refers to the absence of any intervening layers.

The term “room temperature” refers to a temperature of 20 °C to 25 °C. The phrase “directly bound” or “bound to” “coupled” refers to two materials that are in direct contact with each other and bound together.

The phrase “(meth)acrylate” includes, separately and collectively, methacrylate and acrylate.

The phrase “pressure sensitive adhesive (PSA)” means materials having the following properties: a) tacky surface, b) the ability to adhere with no more than finger pressure, c) the ability to adhere without activation by any energy source, d) sufficient ability to hold onto the intended adherend, and e) sufficient cohesive strength to be removed cleanly from the adherend; which materials typically meet the Dahlquist criterion of having a storage modulus at 1 Hz and room temperature of less than 0.3MPa.

The term “in the range” or “within a range” (and similar statements) includes the endpoints of the stated range.

Reference throughout this specification to “one embodiment,” “an embodiment,” “certain embodiments,” or “some embodiments,” etc., means that a particular feature, configuration, composition, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of such phrases in various places throughout this specification are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.

The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples may be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list. Thus, the scope of the present disclosure should not be limited to the specific illustrative structures described herein, but rather extends at least to the structures described by the language of the claims, and the equivalents of those structures. Any of the elements that are positively recited in this specification as alternatives may be explicitly included in the claims or excluded from the claims, in any combination as desired. Although various theories and possible mechanisms may have been discussed herein, in no event should such discussions serve to limit the claimable subject matter.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows a schematic depiction of a disclosed article according to illustrative embodiments.

FIG. 2 shows a schematic depiction of a disclosed article according to illustrative embodiments that includes, relative to the article depicted in FIG. 1, an additional primer layer and an additional pressure sensitive adhesive layer.

FIG. 3 shows a schematic depiction of a disclosed article according to illustrative embodiments that includes, relative to the article depicted in FIG. 2, two additional release liners. FIG. 4 shows a schematic depiction of a disclosed article according to illustrative embodiments that includes, relative to the article depicted in FIG. 2, two additional skin layers.

FIG. 5 shows a schematic depiction of a disclosed assembly according to illustrative embodiments that includes, a mounting tape in accordance with the embodiment of FIG. 2 and a flexographic printing plate.

FIG. 6 shows a schematic depiction of a disclosed assembly according to illustrative embodiments that includes, a mounting tape in accordance with the embodiment of FIG. 2 and a plate cylinder.

FIG. 7 shows a schematic depiction of a disclosed assembly according to illustrative embodiments that includes, a mounting tape in accordance with the embodiment of FIG. 2, a flexographic printing plate and a plate cylinder.

DETAILED DESCRIPTION

The present disclosure provides articles that can also be referred to as tapes, or even more specifically mounting tapes. The present disclosure provides a primer layer (referred to herein as a “first primer layer” for the sake of convenience) for bonding pressure sensitive adhesive (PSA) to the foam layer in a flexographic plate mounting tape. The present disclosure additionally provides flexographic plate mounting tapes incorporating this primer layer, assemblies incorporating mounting tapes and flexographic printing plates, cylinders, or both.

Flexographic plate mounting tapes are used to mount flexographic printing plates to plate cylinders in a flexographic printing press. Mounted flexographic printing plates may require washing between printing runs. The washing process may cause free “nibs” of separated adhesive from the flexographic plate mounting tape to form. If free adhesive nibs produced during the plate washing process are deposited on the plate print surface, they can compromise print quality by creating spots or flaws in the printed articles. Use of first primer layers according to that disclosed herein provides reduced adhesive nib formation during such in-situ plate washing. Flexographic plate mounting tapes made with the subject primer may provide improved solvent rub resistance as measured by a greater number of strokes before a solvent-soaked adhesive layer of a disclosed article begins to yield or fracture under rubbing force causing initial nib formation. Further, disclosed articles may provide flexographic plate mounting tapes made with the subject primer that prevent the formation of freely detachable nibs after solvent soak and abrasion when tested as described herein. Such freely detached nibs can result in a failing result in the solvent resistance test.

Disclosed articles include at least a foam layer, a first primer layer, and a first pressure sensitive layer. FIG. 1 shows an article 100 that includes a foam layer 110, a first primer layer 120 and a first pressure sensitive adhesive layer 130. As seen in FIG. 1, the first primer layer 120 is generally placed between the foam layer 110 and the first pressure sensitive adhesive layer 130. Each of the foam layer 110, the first primer layer 120 and the first pressure sensitive adhesive layer 130 also have two opposing surfaces. The foam layer 110 has a first surface 111 and an opposing second surface 112; the first primer layer 120 has a first surface 121 and an opposing second surface 122; and the first pressure sensitive adhesive layer 130 has a first surface 131 and a second opposing surface 132. The first primer layer 120 can therefore be more specifically described as being positioned between the first surface 111 of the foam layer 110 and the second surface 132 of the first pressure sensitive adhesive layer 130. The first primer layer 120 can also be described as immediately adjacent the first pressure sensitive adhesive layer 130. The first primer layer 120 can also be described as directly bound to the first pressure sensitive adhesive layer 130. The first primer layer 120 can also be described as immediately adjacent and directly bound to the first pressure sensitive adhesive layer 130. The first primer layer 120 can also be described as immediately adjacent the foam layer 110. The first primer layer 120 can also be described as directly bound to the foam layer 110. The first primer layer 120 can also be described as immediately adjacent and directly bound to the foam layer 110. Articles such as those depicted in FIG. 1 can be utilized as a single sided tape, part of a plate mounting system or can have additional layers added to them so that they could function as a doubled-sided tape or a double-sided mounting tape.

Disclosed articles can also include other optional components or layers. FIG. 2 shows such an illustrative article 200. The article 200 includes a foam layer 210, a first primer layer 220, a first pressure sensitive adhesive layer 230, where the first primer layer 220 is generally positioned between the foam layer 210 and the first pressure sensitive adhesive layer 230. The article 200 also includes a second primer layer 225 and a second pressure sensitive adhesive layer 235. The second primer layer 225 is generally positioned between the second surface 212 of the foam layer 210 and the second pressure sensitive adhesive layer 235. The second primer layer 225 has a first surface 221 and an opposing second surface 222; and the second pressure sensitive adhesive layer 235 has a first surface 231 and a second surface 232. The second primer layer 225 can also be described as immediately adjacent the second pressure sensitive adhesive layer 235. The second primer layer 225 can also be described as directly bound to the second pressure sensitive adhesive layer 235. The second primer layer 225 can also be described as immediately adjacent and directly bound to the second pressure sensitive adhesive layer 235. The second primer layer 225 can also be described as immediately adjacent the foam layer 210. The second primer layer 225 can also be described as directly bound to foam layer 210. The second primer layer 225 can also be described as immediately adjacent and directly bound to the foam layer 210. Articles such as those depicted in FIG. 2 can be utilized as a double-sided tape or a double-sided mounting tape.

Other optional components or layers that can be included in disclosed articles include release liners. FIG. 3 shows such an illustrative article 300. The article 300 includes a foam layer 310, a first primer layer 320 and a first pressure sensitive adhesive layer 330, where the first primer layer 320 is generally positioned between the foam layer 310 and the first pressure sensitive adhesive layer 330; and a second primer layer 325 and a second pressure sensitive adhesive layer 335, where the second primer layer 325 is generally positioned between the foam layer 310 and the second pressure sensitive adhesive layer 335. This disclosed article also includes a first release liner 340 and a second release liner 345. The first release liner 340 is generally positioned adjacent the first surface 331 of the first pressure sensitive adhesive layer 330. The second release liner 345 is generally positioned adjacent the second surface 332 of the second pressure sensitive adhesive layer 335. The release liners are releasably bound to the pressure sensitive adhesive layer that they are adjacent to. Articles such as those depicted in FIG. 3 can be utilized as a double-sided tape or a double-sided mounting tape.

Other optional components or layers that can be included in disclosed articles include skin layers. FIG. 4 shows such an illustrative article 400. The article 400 includes a foam layer 410, a first primer layer 420 and a first pressure sensitive adhesive layer 430, where the first primer layer 420 is generally positioned between the foam layer 410 and the first pressure sensitive adhesive layer 430; and a second primer layer 425 and a second pressure sensitive adhesive layer 435, where the second primer layer 425 is generally positioned between the foam layer 410 and the second pressure sensitive adhesive layer 435. This disclosed article also includes a first skin layer 450 and a second skin layer 455. The first skin layer 450 is generally positioned between a first surface 411 of the foam layer 410 and first primer layer 420. The first skin layer 450 can also be described as immediately adjacent the foam layer 410. The first skin layer 450 can also be described as directly bound to foam layer 410. The first skin layer 450 can also be described as immediately adjacent and directly bound to the foam layer 410. The second skin layer 455 is generally positioned between the second surface 412 of the foam layer 410 and the second primer layer 425. The second skin layer 455 can also be described as immediately adjacent the foam layer 410. The second skin layer 455 can also be described as directly bound foam layer 410. The second skin layer 455 can also be described as immediately adjacent and directly bound to the foam layer 410. Articles such as those depicted in FIG. 4 can be utilized as a double-sided tape or a double-sided mounting tape.

The present disclosure provides assemblies that can also be referred to as flexographic printing setups.

Disclosed assemblies can include a flexographic printing plate and a mounting tape such as those that are disclosed above. FIG. 5 shows such an illustrative assembly 500. The assembly 500 includes a flexographic printing plate 560 and mounting tape 505. The mounting tape 505 can include foam layer 510, a first primer layer 520, a first pressure sensitive adhesive layer 530, where the first primer layer 520 is generally positioned between the foam layer 510 and the first pressure sensitive adhesive layer 530. The mounting tape 500 can also include a second primer layer 525 and a second pressure sensitive adhesive layer 535, where the second primer layer 525 is generally positioned between the foam layer 510 and the second pressure sensitive adhesive layer 535. The first surface 531 of the first pressure sensitive adhesive layer 530 is adjacent (in some embodiments, immediately adjacent and/or directly bound) to the flexographic printing plate 560. Disclosed assemblies can include a plate cylinder and a mounting tape such as those that are disclosed above. FIG. 6 shows such an illustrative assembly 600. The assembly 600 includes a plate cylinder 670 and mounting tape 605. The mounting tape 605 can include foam layer 610, a first primer layer 620, a first pressure sensitive adhesive layer 630, where the first primer layer 620 is generally positioned between the foam layer 610 and the first pressure sensitive adhesive layer 630. The mounting tape 605 can also include a second primer layer 625 and a second pressure sensitive adhesive layer 635, where the second primer layer 625 is generally positioned between the foam layer 610 and the second pressure sensitive adhesive layer 635. The second surface 632 of the second pressure sensitive adhesive layer 635 is adjacent (in some embodiments, immediately adjacent and/or directly bound) to the plate cylinder 670.

Disclosed assemblies can also include both a flexographic printing plate and a plate cylinder. FIG. 7 shows such an illustrative assembly 700. The assembly 700 includes a flexographic printing plate 760 a plate cylinder 770 and mounting tape 705. The mounting tape 705 can include foam layer 710, a first primer layer 720, a first pressure sensitive adhesive layer 730, where the first primer layer 720 is generally positioned between the foam layer 710 and the first pressure sensitive adhesive layer 730. The mounting tape 705 can also include a second primer layer 725 and a second pressure sensitive adhesive layer 735, where the second primer layer 725 is generally positioned between the foam layer 710 and the second pressure sensitive adhesive layer 735. The first surface 731 of the first pressure sensitive adhesive layer 730 is adjacent (in some embodiments, immediately adjacent and/or directly bound) to the flexographic printing plate 760, and the second surface 732 of the second pressure sensitive adhesive layer 735 is adjacent (in some embodiments, immediately adjacent and/or directly bound) to the plate cylinder 770.

In some applications of disclosed flexographic plate mounting tape, a flexographic printing plate is adhesively coupled to a plate cylinder of a flexographic printing press (not shown) by use of disclosed flexographic plate mounting tapes. Typically, a flexographic plate mounting tape is coupled to flexographic printing plate through the first pressure sensitive adhesive layer and coupled to the plate cylinder through second pressure sensitive adhesive layer.

In some embodiments, the second surface of a foam layer is further bound to an optional internal adhesion layer, which is further coupled to an optional carrier layer, which is further coupled to the second pressure sensitive adhesive layer. In some embodiments, first primer layer is provided between an optional carrier layer and an optional internal adhesion layer. In some embodiments, a second optional primer layer is provided between carrier layer and the second pressure sensitive adhesive layer.

Disclosed articles and assemblies include a foam layer. The material of the foam layer is typically resilient and may possess rapid rebound and low compression set characteristics and may be crosslinked. In some embodiments, the foam layer may comprise any suitable polymeric material. In some embodiments, the foam layer comprises an olefinic polymer. In some embodiments, the foam layer comprises ethylenic polymer, wherein the ethylenic polymer may include polyethylene, ethylene/vinyl acetate (EVA) copolymer, ethylene acrylic acid copolymer, ethylene methyl acrylate copolymer, and ethylene propylene copolymer and combinations thereof. In some embodiments, the foam layer comprises ethylene/vinyl acetate (EVA) copolymer. In some embodiments, the foam layer comprises crosslinked ethylene/vinyl acetate (EVA) copolymer. In some embodiments, the foam layer comprises one or more polymers comprising a thermoplastic elastomer block isoprene copolymer, a thermoplastic elastomer block butadiene copolymer, a poly(meth)acrylate polymer, a polyurethane polymer, an olefin polymer, an ethylenic polymer, a polypropylene polymer, a polyester polymer, or a polycarbonate polymer. Foam layers may be foamed by use of chemical blowing agents, such as inert gasses, air, or chemical species that break down to release gasses upon heating; or physical blowing agents, such as expandable microspheres.

Useful foam layers may have a thickness of at least 200 micrometers, in some embodiments at least 300 micrometers, and in some embodiments at least 400 micrometers. In some embodiments foam layers may have a thickness of less than 2500 micrometers, in some less than 2000 micrometers, and in some less than 1500 micrometers.

Disclosed articles and assemblies also include at least a first pressure sensitive adhesive (PSA) layer and, in some embodiments, include a first and a second pressure sensitive adhesive layer. Any suitable PSA layers may be utilized herein. In some embodiments, the PSA may comprise a polyacrylate polymer. In some embodiments, the PSA may comprise a tackified polyacrylate. In some embodiments, the PSA comprises a polyacrylate polymer comprising units derived from polar monomer in an amount of 0.1-15 wt% of the total weight of the polyacrylate polymer, in some embodiments 0.5-15 wt%, and in some embodiments 3-12 wt% wherein the polar monomer is selected from the group consisting of acrylic acid, itaconic acid, N,N-dimethylacrylamide, N-vinyl-2 -pyrrolidone, N-vinyl caprolactam, acrylonitrile, tetrahydrofurfuryl acrylate, glycidyl acrylate, 2-phenoxyethylacrylate, benzylacrylate, and combinations thereof. In some embodiments, the PSA comprises a polyacrylate polymer comprising units derived from carboxylic acid functional monomer in an amount of 0.1-15 wt% of the total weight of the polyacrylate polymer, in some embodiments 0.5-15 wt%, and in some embodiments 3-12 wt%. In some embodiments, the PSA may comprise a polyacrylate polymer comprising units derived from acrylic acid monomer in an amount of 0. 1-15 wt% of the total weight of the polyacrylate polymer, in some embodiments 0.5-15 wt%, and in some embodiments 3-12 wt%. In some embodiments, the PSA may comprise a tackified rubber. In some embodiments, the PSA may comprise a tackified natural rubber. In some embodiments, the PSA may comprise a tackified synthetic rubber. In some embodiments comprising multiple PSA layers, all PSA layers are of the same composition. In some embodiments comprising multiple PSA layers, PSA layers differ in composition. In various embodiments, PSA layers comprise cross-linked polymers.

Useful PSA layers, independently including both first and second pressure sensitive adhesive layers as disclosed herein, may have a thickness of at least 15 micrometers, in some embodiments at least 20 micrometers, and in some embodiments at least 30 micrometers. In some embodiments, PSA layers may have a thickness of less than 200 micrometers, in some less than 100 micrometers, and in some less than 70 micrometers. In some embodiments, other adhesive layers, if included in disclosed articles and assemblies, may be subject to the same constraints on thickness.

Adhesive layers (such as first and second pressure sensitive adhesive layers, for example) may comprise relief features in their outer surface (not shown). In some such embodiments that also include one or more release liners the release liner may have an embossed surface facing the adhesive layer which imparts and/or matches relief features in the outer surface of the PSA layer.

Disclosed articles and assemblies include a first primer layer. The first primer layer, as designated herein is the primer layer, if more than one primer layer is included, that is closest to a flexographic printing plate when the article is utilized with a flexographic printing plate. The first primer layer includes a thermoplastic polymeric binder and inorganic nanoparticles having a bound organic surface coating.

The first primer layer comprises thermoplastic polymeric binders of ethylenic polymers. In some embodiments, the first primer layer comprises a thermoplastic polymeric binder of ethylene vinyl acetate copolymers. In some embodiments, the thermoplastic polymeric binders additionally comprise one or both of wax and resin. In some embodiments, the thermoplastic polymeric binders additionally comprise one or both of wax and resin comprising softening points below 150°C. In some embodiments, the thermoplastic polymeric binder components along with any additives such as waxes and resins are selected to provide hot adhesive tack of the first primer layer within the range 80°C to 150°C. In some embodiments, the thermoplastic polymeric binders comprise at least 30 wt%, in some at least 40 wt%, in some at least 50 wt%, in some at least 70 wt%, and in some at least 90 wt% of the total weight of the first primer layer.

The first primer layer comprises inorganic nanoparticles with a bound organic surface coating providing active bonding sites. In some embodiments, the first primer layer comprises inorganic nanoparticles with a covalently bound organic surface providing active bonding sites.

Inorganic nanoparticles comprise nanometer-sized particles. The term “nanometer-sized” refers to particles that are characterized by an average particle size (e.g., the average of the largest dimension of the particles, or the average particle diameter for spherical particles) in the nanometer range, often no greater than 200 nanometers (nm), and preferably no greater than 100 nm (prior to surface modification, i.e., functionalization).

Average particle size of the nanoparticles can be measured using any suitable technique, including for example transmission electron microscopy. Preferably, particle size refers to the number average particle size and is measured using an instrument that uses transmission electron microscopy or scanning electron microscopy. Another method to measure particle size is dynamic light scattering that measures weight average particle size. One example of such an instrument found to be suitable is the N4 PLUS SUB-MICRON PARTICLE ANALYZER available from Beckman Coulter Inc. of Fullerton, CA. In some embodiments the inorganic core nanoparticles comprise surface areas of at least 10 m²/gram, more preferably at least 20 m²/gram, and even more preferably at least 25 m²/gram. The nanoparticles preferably have a surface area of greater than 750 m²/gram. In some embodiments the inorganic core nanoparticles comprise porous or nonporous features.

In some embodiments the inorganic core nanoparticles originally (before reaction to form the active binding sites, see below) comprised a sol. Preferred sols contain from 15 wt % to 50 wt % of colloidal particles dispersed in a fluid medium. In some embodiments the inorganic core nanoparticles comprise a sol in fluid media including water, aqueous alcohol solutions, lower aliphatic alcohols, ethylene glycol, N,N-dimethyl acetamide, formamide, or combinations thereof. In some embodiments the inorganic core nanoparticles comprise a sol in water medium and optionally one or more alcohols.

In some embodiments, non-aqueous silica sols (also called silica organosols) may also be used and are silica sol dispersions wherein the liquid phase is an organic solvent, or an aqueous organic solvent. Useful silica sols include those where the liquid phase is compatible with the emulsion and is typically aqueous or an aqueous organic solvent. Silica particles may be spherical, generally spherical, or acicular. The term “acicular” refers to the general needle-like, elongated shape of the particles and may include other string-like, rod-like, chain-like shapes, as well as filamentary shapes. The acicular silica sol may also be prepared as described in U.S. Patent No. 5,597,512 or U.S. Patent No. 5,221,497, for example, the disclosures of which are incorporated herein by reference thereto to the extent that they do not contradict the instant specification.

Useful acicular silica particles may be obtained as an aqueous suspension under the trade name SNOWTEX-UP by Nissan Chemical Industries (Tokyo, Japan). The mixture consists of 20-21 % (w/w) of acicular silica, less than 0.35% (w/w) of Na2O, and water. The particles are about 9 to 15 nanometers in diameter and have lengths of 40 to 300 nanometers. The suspension has a viscosity of <100 mPas at 25°C, a pH of about 9 to 10.5, and a specific gravity of about 1. 13 at 20°C. Other useful acicular silica particles may be obtained as an aqueous suspension under the trade name SNOWTEX-PS-S and SNOWTEX-PS-M by Nissan Chemical Industries, having a morphology of a string of pearls. The mixture consists of 20-21 % (w/w) of silica, less than 0.2% (w/w) ofNa2O, and water. The SNOWTEX- PS-M particles are about 18 to 25 nanometers in diameter and have lengths of 80 to 150 nanometers. The particle size is 80 to 150 by dynamic light scattering methods. The suspension has a viscosity of <100 mPas at 25°C, a pH of about 9 to 10.5, and a specific gravity of about 1.13 at 20°C. The SNOWTEX-PS- S has a particle diameter of 10-15 nm and a length of 80-120 nm.

In some embodiments, the bound organic surface coating providing active bonding sites comprises an epoxy group, amine group, alkynyl group, (meth) acrylate group, mercapto group, or combinations thereof. As used herein, “amine” excludes quaternary ammonium. In some embodiments, the bound organic surface coating providing active bonding sites comprises an epoxy group, an amine group, or combinations thereof. In some embodiments, the bound organic surface coating providing active bonding sites comprises an amine group wherein the amine groups are primary or secondary (i.e., nontertiary), and even more preferably primary amine groups.

In some embodiments, the bound organic surface coating providing active bonding sites is derived from an amine silane selected from the group of 3 -aminopropyltrimethoxy silane, 3- aminopropyltriethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2- aminoethylamino)propyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2- aminoethyl)-3 -aminopropylmethyldiethoxysilane, 4-aminobutyltrimethoxysilane, 4- aminobutyltriethoxy silane , 3 -aminopropylmethyldiethoxy silane , 3 -aminopropylmethyldimethoxy silane , 3-aminopropyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane, and any combinations or mixtures thereof. More preferably, an amino silane for use herein may be 3 -aminopropyltrimethoxy silane.

In some embodiments, the covalently bound organic surface coating may further comprise aliphatic or aromatic structures. In some embodiments, the bound organic surface coating providing active bonding sites is derived from epoxy silanes selected from the group of 2-(3,4-epoxy cyclohexyl) ethyltrimethoxy silane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, (3- glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, and any combinations or mixtures thereof. More preferably, an epoxy silane for use herein may be 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane.

In some preferred embodiments, the bound organic surface coating providing active bonding sites may be derived from amino (or any of the other possible functional groups noted, such as epoxy, alkynyls, (meth) acrylates, mercaptos, or combinations thereof) functional silanes. It should be noted that whenever further description of amine groups is provided below, the description could equally be applied to other functional groups as applicable. The amine groups can be protected if desired. Furthermore, combinations of protected amine groups and unprotected amine groups may be used if desired.

The amine groups may be covalently bonded to a preferred silica surface of individual nanoparticles, preferably through Si — O — Si bonds. In some embodiments, nanoparticles containing zirconia, alumina, ceria, tin oxide, or titanium dioxide, may similarly be attached to aminosiloxanes by the chemical bonds Zr — O — Si, Al — O — Si, Ce — O — Si, Sn — O — Si, and Ti — O — Si, respectively. These chemical bonds may not be as strong as the siloxane bond, Si — O — Si, however, their bond strength may be sufficient for the present application.

The level of coverage of the amine-functionalized nanoparticles herein can be reported in terms of the concentration of amine groups in the coating composition, assuming 100% of the amount of amine groups in the coating composition would be covalently bonded to surfaces of the silica particles. Preferably, the amine groups are present on a particle surface in the coating composition in an amount equivalent to at least 3 mole-% of the total molar functional groups on said surface. More preferably, the functional groups are present on a particle surface in an amount equivalent to at least 5 mole-%, even more preferably at least 10 mole-%, and even more preferably at least 25 mole-%, of total molar functional groups on said surface. Higher molar equivalents of functional groups can contribute to more bonds between particles, thereby forming a coating with a denser particle network. In certain situations, an excess of functional groups (i.e., greater than 100%) can be desirable; however, typically the amount of functional groups present on a particle surface in the coating composition is an amount equivalent to no more than 150 mole-% of the total molar functional groups on said particle surface. Due to the multifunctionality of the amine alkoxy silanes, when the coating composition includes more than 100 mole-% amine groups, more than a monolayer of the functional siloxane is created on the particle surface.

The nanoparticle functionalization can be accomplished using conventional techniques. In some embodiments, this is accomplished at a pH of at least 10.5, even more preferably at a pH of at least 11.0, even more preferably at a pH of at least 11.5. In some typical methods, the pH of an aqueous dispersion of silica nanoparticles is initially adjusted to an indicated pH to generate negatively charged silica particles. Then the functional alkoxysilane can be combined with the negatively charged silica nanoparticles and allowed to react for a time effective for the alkoxy silyl end of the functional alkoxysilane to preferentially react with the negatively charged silica surface. The indicated pH can be maintained for a time effective to cause reaction between the alkoxy silyl end of the functional alkoxysilane and the silica nanoparticles. Typically, this is at least 2 hours, preferably at least 8 hours, and more preferably at least 12 hours. Temperatures above room temperature (e.g., 60° C-80° C) can be used to reduce the reaction time. The desired pH and time of reaction are conditions that may enhance functionalization and enhance stability of the composition (e.g., reduce precipitation and/or agglomeration of the particles).

The functional groups include various chemical groups that allow for binding to the nanoparticles. Such groups are typically provided by functional compound represented by the formula A- L-Fl. The functional group Fl includes the amine groups (and others recited above). In this representation, the group A is the nanoparticle surface-bonding group, and L can be a bond or any of a variety of organic linker. Organic linkers L can include linear or branched alkylenes, arylenes, or a combination of alkylenes and arylene groups, optionally including heteroatoms. In some embodiments, the inorganic nanoparticles with a bound organic surface providing active bonding sites comprise a structure A-L-Fl where A is an alkoxy silane and Fl is an amine.

The first primer layer may also include non-functionalized fillers. Any suitable fillers may be used, including non-functionalized silica particles such as fumed silica and the like.

The composition that forms the first primer layer may be applied to the pressure sensitive adhesive on a release liner. The composition that forms the first primer layer may be applied to the carrier as, for example, as a solution or suspension in aqueous solvent. The composition that forms the first primer layer may be applied to the carrier by any suitable method, including spraying, coating, brushing, immersion, and the like. After application, the composition that forms the first primer layer may be heated to first evaporate any solvent and then promote thermal local intermixing and accelerate any crosslinking reaction between the pressure sensitive adhesive and the inorganic nanoparticles having a bound organic surface coating. In some embodiments, the first primer layer described above with reference to FIG. 1 may be laminated to a foam layer using heat and pressure.

In some embodiments, the materials of the first primer layers of the present invention can have a relatively long shelf-life, preferably up to several months even when stored in liquid form at normal storage conditions. In some embodiments, the first primer layer composition may be applied to a pressure sensitive adhesive coated on a release liner and stored for long periods before application to foam layers, rather than requiring prompt lamination of the first primer layer to the foam layer. This characteristic allows greater flexibility in manufacture. Furthermore, in some embodiments of the present disclosure, the pressure sensitive adhesive layer having the first primer layer thereon, as well as a release liner roll may be stored for a long period and still be reliably laminated to a foam layer with heat and pressure.

The first primer layer may have a thickness of at least 1 micrometer, in some embodiments at least 3 micrometers, and in some embodiments at least 5 micrometers. In some embodiments first primer layers may have a thickness of less than 8 micrometers, in some less than 12 micrometers, in some less than 25 micrometers and in some less than 50 micrometers.

The second primer layer may be the same or different than the first primer layer. The second primer layer comprises thermoplastic polymeric binders of ethylenic polymers. In some embodiments, the second primer layer comprises a thermoplastic polymeric binder of ethylene vinyl acetate copolymers. In some embodiments, the thermoplastic polymeric binders additionally comprise one or both of wax and resin. In some embodiments, the thermoplastic polymeric binders additionally comprise one or both of wax and resin comprising softening points below 150°C. In some embodiments, the thermoplastic polymeric binder components along with any additives such as waxes and resins are selected to provide hot adhesive tack of the second primer layer within the range 80°C to 150°C. In some embodiments, the thermoplastic polymeric binders comprise at least 30 wt%, in some at least 40 wt%, in some at least 50 wt%, in some at least 70 wt%, and in some at least 90 wt% of the total weight of the first primer layer.

The second primer layer also comprises inorganic nanoparticles, which may be as described above with respect to the first primer layer in any of their embodiments.

In some embodiments one or both surfaces of the foam layer may be in contact with optional skin layer(s) which provide greater planar stiffness relative to that of an unskinned foam layer. In some embodiments the foam layer may have a skin layer on one surface or both surfaces, that has a lower (or in some cases, essentially no) void volume relative to the average void volume of the interior or bulk of the foam layer. In some embodiments, one or both skin layers may comprise a polymer composition providing an elastically extensible skin layer. In various embodiments, the foam layer with any optional skin layers comprises flexible materials selected to provide a layer that may be wrapped around a 100 centimeter diameter cylinder without layer creasing or buckling when each face is in-tum orientated to the surface of the cylinder. In some embodiments, a less extensible, greater stiffness elastic skin layer may be provided on one foam layer surface, with an optional lower stiffness extensible skin layer on the opposite foam layer surface, where layer compositions are selected to provide an entire foam layer that may be wrapped around a 10 centimeter diameter cylinder without causing creasing or buckling when the non- extensible skin layer face is orientated away from the surface of the cylinder.

In some embodiments the optional skin layer may comprise an olefinic polymer including ethylene vinyl acetate, low and medium density polyethylene, linear low-density polyethylene and the like. Such articles and assemblies can have skin layer(s) having a thickness of at least 1 pm, 5 pm, or 10 pm; of less than 15 pm, 125 pm, or 250 pm; or combinations thereof.

A composition for forming the first primer layer can be formed using known methods. In some embodiments, compositions for forming the first primer layer can include the steps of: a) mixing a functional silane and a waterborne silica sol, b) reacting the silane with the sol surface to create surface modified silica sol and c) mixing the surface modified silica sol with a waterborne polymeric dispersion of thermoplastic polymer.

Methods of making constructions such as disclosed articles herein that include a pressure sensitive adhesive layer bound to a foam layer can comprise steps of: a) providing a PSA layer coated on an release liner; b) coating the PSA layer with a primer layer coating mixture comprising a waterborne polymeric dispersion of thermoplastic polymer and surface modified silica sol; c) crosslinking the primer layer coating mixture to the PSA layer; d) laminating the primer layer to a foam layer at an elevated temperature to securely bond the primer layer to the foam; and e) optionally crosslinking the primer layer with the foam layer. In some embodiments, steps a)-e) are carried out in the order a), b), c), d), e).

Some assemblies disclosed herein can include flexographic printing plates. Useful flexographic printing plates may be of any suitable material. In some embodiments, flexographic printing plates comprise polymeric materials, which in some embodiments are one or more polyesters.

Some assemblies disclosed herein can include flexographic printing press plate cylinders, which are also referred to herein as plate cylinders. Useful plate cylinders may be of any suitable material. In some embodiments, plate cylinders comprise polymeric materials, which in some embodiments are one or more polyurethanes. In some embodiments, plate cylinders comprise metal materials, which in some embodiments are steel.

According to some aspects of the present disclosure:

Aspect 1 is an article that comprises a foam layer, having a first and a second opposing surface; a first primer layer, the first primer layer comprising thermoplastic polymeric binder, and inorganic nanoparticles having a bound organic surface coating; and a first pressure sensitive adhesive layer, having a first and a second opposing layer, wherein the first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer. Aspect 2 is an article according to aspect 1, further comprising a second primer layer and a second pressure sensitive adhesive layer, wherein the second primer layer is positioned between the second surface of the foam layer and the second pressure sensitive pressure adhesive layer.

Aspect 3 is an article according to either aspect 1 or 2 further comprising a first release liner positioned on the first surface of the first pressure sensitive adhesive layer.

Aspect 4 is an article according to any of aspects 2 or 3 further comprising a second release liner positioned on the second surface of the second pressure sensitive adhesive layer.

Aspect 5 is an article according to any of aspects 1 to 4 further comprising a first skin layer positioned between the first surface of the foam layer and the first primer layer.

Aspect 6 is an article according to any of aspects 2 to 5 further comprising a second skin layer positioned between the second surface of the foam layer and the second primer layer.

Aspect 7 is an assembly that comprises a flexographic printing plate; and a mounting tape comprising: a foam layer, having a first and a second opposing surface; a first primer layer; and a first pressure sensitive adhesive layer, having a first and a second opposing layer, wherein the first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer, wherein the first surface of the first pressure sensitive adhesive layer is attached to the flexographic printing plate. The mounting tape can be the article of any one of Aspects 1 to 6.

Aspect 8 is an assembly according to aspect 7, wherein the mounting tape further comprises a second primer layer and a second pressure sensitive adhesive layer having a first and a second opposing surface, wherein the second primer layer is positioned between the second surface of the foam layer and the first surface of the second pressure sensitive pressure adhesive layer.

Aspect 9 is an aspect according to either aspect 7 or 8, further comprising a plate cylinder, wherein the plate cylinder is attached to the mounting tape via the second surface of the second pressure sensitive adhesive layer.

Aspect 10 is an aspect according to any of aspects 1 to 9, wherein the first primer layer, the second primer layer, or both independently have thicknesses of at least 1 micrometer (pm), 3 pm or 5 pm; of less than 50 pm, 25 pm, or 8 pm; or combinations thereof.

Aspect 11 is an aspect according to any of aspects 1 to 10, wherein the foam layer has a thickness of at least 200 pm, 300 pm, or 400 pm; of less than 2500 pm, 2000 pm, or 1500 pm; or combinations thereof.

Aspect 12 is an aspect according to any of aspects 1 to 11, wherein the inorganic particles in the first primer layer comprise silica, zirconia, alumina, ceria, tin oxide, or titanium dioxide.

Aspect 13 is an aspect according to any of aspects 1 to 12, wherein the organic surface coating provides active binding sites comprising an epoxy group, amine group, alkynyl group, (meth) acrylate group, mercapto group, or combinations thereof. Aspect 14 is an aspect according to any of aspects 1 to 13, wherein the organic surface coating provides active binding sites comprising an epoxy group, an amine group, or combinations thereof.

Aspect 15 is an aspect according to any of aspects 1 to 14, wherein the organic surface coating provides active binding sites derived from an amine silane selected from the group 3- aminopropyltrimethoxysilane, 3 -aminopropyltriethoxy silane, 3 -(2 -aminoethylamino) propyltrimethoxy silane, 3-(2-aminoethylamino)propyltriethoxysilane, N-(2-aminoethyl)-3- aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyhnethyldiethoxysilane, 4- aminobutyltrimethoxysilane, 4-aminobutyltriethoxysilane, 3 -aminopropylmethyldiethoxy silane, 3- aminopropyhnethyldimethoxy silane , 3 -aminopropyldimethylmethoxy silane, 3 - aminopropyldimethylethoxysilane, and any combinations or mixtures thereof.

Aspect 16 is an aspect according to any of aspects 1 to 15, wherein the organic surface coating provides active binding sites derived from 3 -aminopropyltrimethoxy silane.

Aspect 17 is an aspect according to any of aspects 1 to 16, wherein the organic surface coating provides aliphatic or aromatic structure.

Aspect 18 is an aspect according to any of aspects 1 to 17, wherein the organic surface coating provides active bonding sites derived from an epoxy silane selected from the group 2-(3,4- epoxycyclohexyl) ethyltrimethoxysilane, 2-(3,4-epoxy cyclohexyl) ethyltriethoxy silane, (3- glycidoxypropyl) trimethoxy silane, (3-glycidoxypropyl) triethoxysilane, and any combinations or mixtures thereof.

Aspect 19 is an aspect according to any of aspects 1 to 18, wherein the first primer layer further comprises a curing agent or a co-curing agent.

Aspect 20 is an aspect according to any of aspects 1 to 19, wherein the curing agent or co-curing agent are selected from radical initiators, aliphatic amines, or polyamine or epoxy or multifunctional epoxy monomer/oligomers.

Aspect 21 is an aspect according to any of aspects 1 to 20, wherein the organic surface coating provides active binding sites comprising amine groups present on the particle surface in an amount equivalent to at least 3 mole-%, at least 5 mole-%, at least 10 mole-%, or at least 25 mole-% of the total molar functional groups on said surface.

Aspect 22 is an aspect according to any of aspects 1 to 21, wherein the organic surface coating provides active binding sites comprising amine groups present on the particle surface in an amount of not more than 150 mole-% of the total molar functional groups on said surface.

Aspect 23 is an aspect according to any of aspects 1 to 22, wherein the thermoplastic polymeric binder is a thermoplastic polymeric binder of an ethylenic polymer.

Aspect 24 is an aspect according to any of aspects 1 to 23, wherein the first primer layer further comprises non-functionalized fillers. Aspect 25 is an aspect according to any of aspects 1 to 24, wherein the first primer layer has a solvent resistance that is higher than that of the second primer layer.

Aspect 26 is an aspect according to any of aspects 1 to 25, wherein the first primer layer has a solvent resistance that is higher than that of the second primer layer as measured according to the Rub Resistance Test.

Aspect 27 is an aspect according to any of aspects 1 to 26, wherein the first pressure sensitive adhesive layer, the second pressure sensitive adhesive layer, or both independently comprise a polyacrylate polymer comprising units derived from an acrylate, acrylic acid, or combinations thereof.

Aspect 28 is an aspect according to any of aspects 1 to 27, wherein the first primer layer is laminated to the foam layer using heat and pressure.

EXAMPLES

These examples are merely for illustrative purposes and are not meant to be overly limiting on the scope of the appended claims. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding.

Unless otherwise noted, all chemicals used in the examples can be obtained from the noted suppliers.

Materials

Test Method

Rub Resistance Test

Rub resistance was tested per ASTM D7835/D7835M - 13: “Standard Test Method for Determining the Solvent Resistance of an Organic Coating using a Mechanical Rubbing Machine” with the following modifications. The mechanical finger was cylindrical with a 0.625 inch diameter, exerting a load of 30 +/-7 grams and a stroke length of two inches (5.1 centimeters), was covered with four layers of dry cheese cloth.

The test specimens were prepared as follows. Samples of double sided pressure sensitive adhesive tape constructions, measuring 1 inch wide by 5 inches long (2.54 centimeters by 12.7 centimeters) were adhered to a stainless steel plate measuring 2 inches wide by 6 inches long (5.1 centimeters by 15.2 centimeters), by removing the release liner from the supplementary adhesive face, and adhering the specimen to the panel, and then removing the primary release liner. A solvent combination of 80:20 (vol:vol) ethanol : ethyl acetate was then dripped onto the exposed adhesive surface in such a manner as to completely cover the adhesive surface area to be tested.

The adhesive surface with solvent thereon was then covered with a microscope slide to prevent solvent evaporation. After one minute, the slide was removed, and the adhesive surface was blotted dry using a tissue to remove any remaining free solvent. The test specimen panel was then held fast to the rubbing machine platform and immediately evaluated for its rub resistance using 15 rubs of the mechanical finger. One rub consisted of one complete forward and backward motion over the exposed solvent-soaked adhesive surface at a rate of 15 cycles per minute.

During the mechanical rubbing process the specimen surface was monitored to observe and record the stroke cycle number during which adhesive first began to form abraded nibs. After 15 rub cycles the test was stopped and the probe and adhesive surface inspected for free adhesive nibs. Free nibs are those that could easily be moved along the adhesive surface with finger contact or that were detected on the cheese cloth covered probe after careful inspection produced a failing rub resistance test result. In comparison, a test resulting in no nibs or nibs that remained well attached to the adhesive surface with none detected on the cheese cloth covered probe produced a passing rub resistance result.

Preparation of Primer Solution (A & B)

Example 1A

Primer solution 1 A Part 1 was prepared by mixing the following components in a glass eightounce jar in the following order using a magnetic mixer and stir bar at a moderate rate: First deionized water (41.8 grams (g)) was added to the jar followed by Ammonia (0.07 g), and a pH of 9.0 recorded. Next, Silica Sol (16.6 g) was added and mixed for one minute followed by dropwise addition of Silane (0.42 g) over a period of ~3 minutes into the vortex created by the stirring bar. The resulting 12% by weight blend was milky clear in appearance with a Brookfield viscosity of 110 centipoise. The jar was closed, and the Part 1 solution was allowed to set overnight (~18 hours) at ambient conditions to allow the silane to attach to the sol particle surface. The reported weights in grams are of the materials as listed in the Materials chart above, i.e., at the stated dilution or solids content.

Example IB

It was first observed that the Part 1 functionalized sol had formed a gel overnight, that could be broken by vigorous shaking or mixing. The Part 1 functionalized sol then retained a low viscosity for the time required to complete primer compounding. Primer solution IB was prepared by slowly adding the Thermoplastic Polymer Dispersion (41.2 g of the nominally 30 wt.% dispersion) to the Part 1 solution (58.8 g) while stirring with a magnetic mixer at moderate rate. The resulting primer had a Brookfield viscosity of 105 centipoise and solids content of 23.5% by weight.

Comparative Example 1A

Comparative Primer solution 1A was prepared by diluting the Thermoplastic Polymer Dispersion (56.3 g of the nominally 30 wt.% dispersion) with deionized water (18.8 g) and mixing in a glass four- ounce jar. The resulting primer had a Brookfield viscosity of 83 centipoise and solids content of 30.2% by weight.

Comparative Example 2A

Comparative Primer solution 2A was prepared by mixing the following components in a glass four-ounce jar in the following order using a magnetic mixer and stir bar at a moderate rate: First the Thermoplastic Polymer Dispersion (30.8 g) was added to the jar followed deionized water (30.9 g) with mixing for one minute. Next, Silica Sol (13.2) was added and mixed for one minute. The resulting primer had a Brookfield viscosity of 93 centipoise and solids content of 23.5% by weight. The reported weights in grams are of the materials as listed in the Materials chart above, i.e., at the stated dilution or solids content.

Preparation of Pressure Sensitive Adhesive Transfer Tape (C)

Example 1C

An adhesive precursor syrup was prepared by mixing 90 parts by weight (pbw) IOA, 10 pbw AA, and 0.04 pbw Photoinitiator and partially polymerizing it under a nitrogen atmosphere by exposure to an ultraviolet radiation source having a spectral output from 300-400 nanometers with a maximum at 351 nanometers to provide a syrup having a viscosity of about 3 Pa*s (3000 centipoise) and a monomer conversion of about 8%. Next, 0.12 parts of Triazine, 0.375 parts of HDDA, and an additional 0.12 parts of Photoinitiator were added to the syrup and fully dissolved to give the final coatable adhesive precursor syrup. This syrup was then knife coated onto the embossed side of a release liner and exposed to ultraviolet radiation by means of a series of lamps having a spectral output from 300-400 nanometers with at maximum at 351 nanometers in a nitrogen-rich atmosphere for a time of 105 seconds to provide a total dose of 510 milliJoules/square centimeter as measured using a calibrated NIST radiometer. An adhesive transfer tape having pressure sensitive adhesive (PSA) layer, approximately 0.002 inches (51 micrometers) thick, on the embossed surface of the release liner was thereby obtained. The adhesive transfer tape was stored at ambient conditions prior to use. Preparation of Primed Pressure Sensitive Adhesive Transfer Tape (D)

Example ID

A wet layer of primer solution IB was applied to adhesive transfer tape 1C using a #18 wire round Mayer rod. The primer coating was dried and cured in a forced air convection oven for 120 seconds at 57°C resulting in dried prime layer coverage of 8.5 g/m².

Comparative Example ID and 2D

The same procedure to prepare primed pressure sensitive adhesive transfer tape ID was used to prepare Comparative Examples ID and 2D, except that the primer solution coated was Comparative Example 1C and 2C respectively.

Preparation of Adhesive Bonded Foam Laminates (E)

Examples IE and Comparative Examples IE and 2E

The Example ID and Comparative Example ID and 2D primed adhesive transfer tapes were laminated to a foam layer, by passing both through a heated rolling nip so that the interface between the foam and primer were bonded by maintaining a temperature between 126°C and 131°C for greater than two 2 seconds through a heated rolling nip. Using the same heated nip process, a supplemental primed adhesive transfer tape was bonded to the opposite foam face. The supplemental primed adhesive transfer tape thereby provided a means for bonding the adhesive bonded foam laminates to the stainless steel panel in order to complete Rub Resistance tests on each example. The number of strokes at which the first deformation of the adhesive surface was visually observed was recorded for Example IE and Comparative Example IE and 2E, as 14.5, 1.2, and 1.4 strokes to first nib creation, respectively. After 15 rub cycles the test was stopped and the probe and adhesive surface inspected for free adhesive nibs. For Example IE a few nibs were formed but each was well adhered to the adhesive surface and no nibs were detected on the cheese cloth covered probe, a passing result. For Comparative Example IE and 2E, numerous loose nibs were detected on both the adhesive surface and the cheese cloth covered probe, a failing result for both. The test was repeated six times for each example and the standard deviation for the number of strokes to first observed nib formations was 1.5, 0.2, and 0.5 respectively.

To the extent that there is any conflict or discrepancy between this specification as written and the disclosure in any document that is incorporated by reference herein, this specification as written will control. Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the disclosure intended to be limited only by the claims set forth herein as follows.

Claims

What Is Claimed Is:

1. An article comprising: a foam layer, having a first and a second opposing surface; a first primer layer, the first primer layer comprising a thermoplastic polymeric binder and inorganic nanoparticles having a bound organic surface coating; and a first pressure sensitive adhesive layer, having a first surface and a second opposing surface, wherein the first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer.

2. The article according to claim 1 further comprising a second primer layer and a second pressure sensitive adhesive layer, wherein the second primer layer is positioned between the second surface of the foam layer and the second pressure sensitive pressure adhesive layer.

3. The article according to any of claims 1 or 2 further comprising a first release liner positioned on the first surface of the first pressure sensitive adhesive layer.

4. The article according to any of claims 2 or 3 further comprising a second release liner positioned on the second surface of the second pressure sensitive adhesive layer.

5. The article according to any of claims 1 to 4 further comprising a first skin layer positioned between the first surface of the foam layer and the first primer layer.

6. The article according to any of claims 2 to 5 further comprising a second skin layer positioned between the second surface of the foam layer and the second primer layer.

7. An assembly comprising: a flexographic printing plate; and a mounting tape comprising: a foam layer, having a first and a second opposing surface; a first primer layer comprising a thermoplastic polymeric binder and inorganic nanoparticles having a bound organic surface coating; and a first pressure sensitive adhesive layer, having a first surface and a second opposing surface,

24 wherein the first primer layer is positioned between the first surface of the foam layer and the second surface of the first pressure sensitive adhesive layer, wherein the first surface of the first pressure sensitive adhesive layer is attached to the flexographic printing plate.

8. The assembly according to claim 7, wherein the mounting tape further comprises a second primer layer and a second pressure sensitive adhesive layer having a first surface and a second opposing surface, wherein the second primer layer is positioned between the second surface of the foam layer and the first surface of the second pressure sensitive pressure adhesive layer.

9. The assembly according to claim 8 further comprising a plate cylinder, wherein the plate cylinder is attached to the mounting tape via the second surface of the second pressure sensitive adhesive layer.

10. The article according to any of claims 1 to 6 or the assembly according to any of claims 7 to 9, wherein the inorganic nanoparticles in the first primer layer comprise silica, zirconia, alumina, ceria, tin oxide, or titanium dioxide.

11. The article according to any of claims 1 to 6 or 10 or the assembly according to any of claims 7 to 10, wherein the organic surface coating provides active binding sites comprising an epoxy group, an amine group, an alkynyl group, a (meth) acrylate group, a mercapto group, or combinations thereof.

12. The article according to any of claims 1 to 6, 10, or 11 or the assembly according to any of claims 7 to 11, wherein the thermoplastic polymeric binder comprises an ethylenic polymer.

13. The article according to any of claims 1 to 6 or 10 to 12 or the assembly according to any of claims 7 to 12, wherein the first primer layer further comprises non-functionalized fillers.

14. The article according to any of claims 2 to 6 or 10 to 13 or the assembly according to any of claims 8 to 13, wherein the first pressure sensitive adhesive layer, the second pressure sensitive adhesive layer, or both independently comprise a polyacrylate polymer comprising acidic polar monomer units.

15. The article according to any of claims 1 to 6 or 10 to 14 or the assembly according to any of claims 7 to 14, wherein the first primer layer is laminated to the foam layer using heat and pressure.