Filled polyisobutene-based pressure sensitive adhesives and methods for preparing same and uses thereof - Patents.com

Abstract

A filled polyisobutene-based (PIB) pressure sensitive adhesive (PSA) containing a crosslinked structure therein. The composition for preparing the PSA includes a PIB resin, a surface-treated and / or untreated filler, where the surface treatment includes a silane, a silazane, or a combination thereof, and a SiH, SH, or isocyanate functional crosslinker. Related embodiments include methods for preparing the filled PSA and for using the filled PSA, e.g., a barrier adhesive, as a component of an adhesive tape.

Description

[Technical field]

[0001] The present invention relates generally to filled polyisobutene-based (PIB) pressure sensitive adhesives (PSA). [Prior art documents] [Patent documents]

[0002] [Patent Document 1] U.S. Pat. No. 5,602,221 Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention is directed to a composition for providing a filled PIB PSA (filled polyisobutene-based pressure sensitive adhesive) having a crosslinked structure, and related methods for preparing same and uses. [Means for solving the problem]

[0004] The compositions of the present invention comprise, consist essentially of, or consist only of PIB resin; non-surface-treated (NST) and / or surface-treated (ST) fillers, where the surface treatment comprises, consists essentially of, or consists of a silane, a silazane, or a combination thereof; a crosslinker comprising at least two moieties that react with at least the ST and / or NST fillers; and, where necessary based on the particular crosslinker selected, a crosslinking catalyst and / or a catalyst inhibitor.

[0005] In one embodiment, the invention is directed to a composition for providing a filled PIB PSAs utilizing a SiH crosslinker. In this embodiment, the composition comprises, consists essentially of, or consists of a PIB resin; a surface treated (ST) filler, where the surface treatment comprises, consists essentially of, or consists of a silane, a silazane, or a combination thereof; a SiH functional crosslinker; a crosslinking catalyst; and a catalyst inhibitor. Related embodiments include the resulting filled PIB PSAs after the crosslinking reaction is complete, methods of using these filled PIB PSAs, and methods for preparing filled PIB PSAs. A method for preparing a filled PIB PSA comprises, consists essentially of, or consists of: (a) providing a pre-reaction composition comprising, consisting essentially of, or consisting of a PIB resin; a surface treated filler, the surface treatment comprising, consisting essentially of, or consisting of a silane, silazane, or combination thereof; a SiH functional crosslinker, and a catalyst inhibitor; and (b) adding to the pre-reaction composition a type and amount of catalyst sufficient to initiate a crosslinking reaction of at least the silane, silazane, or combination thereof on the surface treated filler with the SiH functional crosslinker, thereby obtaining a filled PIB PSA.

[0006] In another embodiment, the present invention is directed to a composition for providing a filled PIB PSA utilizing an SH-functional crosslinker. In this embodiment, the composition comprises, consists essentially of, or consists of a PIB resin; a ST filler, the surface treatment of which comprises, consists essentially of, or consists of a silane, a silazane, or a combination thereof; and an SH-functional crosslinker; and optionally, in certain embodiments, it is desirable to use a radical initiator. Related embodiments include the resulting PIB PSAs after the crosslinking reaction is complete, methods of using these filled PIB PSAs, and methods for preparing filled PIB PSAs. A method for preparing a filled PIB PSA comprises, consists essentially of, or consists of: (a) providing a pre-reaction composition comprising, consisting essentially of, or consisting of: a PIB resin; an ST filler, the surface treatment of which comprises, consists essentially of, or consists of a silane, silazane, or combination thereof; an SH-functional crosslinker; and optionally, in certain embodiments, a radical initiator; and (b) in embodiments where the optional radical initiator is included, exposing the pre-reaction composition to a type and amount of (i) heat or (ii) electromagnetic radiation sufficient to initiate a crosslinking reaction of at least the silane, silazane, or combination thereof on the ST filler with the SH-functional crosslinker, thereby obtaining a filled PIB PSA.

[0007] In yet another embodiment, the present invention provides a composition for providing a filled PIB PSA utilizing an isocyanate crosslinker. In this embodiment, the composition comprises, consists essentially of, or consists only of a PIB resin; (i) NST (non-surface treated) silica and / or (ii) ST (surface treated) silica or ST (surface treated) alumina, where the surface of the ST silica comprises a silane or silazane; an isocyanate functional crosslinker; and optionally, in certain embodiments, a catalyst. Related embodiments include the resulting filled PIB PSAs after crosslinking is complete, methods of using these filled PIB PSAs, and methods for preparing filled PIB PSAs. A method for preparing a filled PIB PSA comprises, consists essentially of, or consists of a composition comprising, consisting essentially of, or consisting of (a) a PIB resin; (i) a filler comprising, consisting essentially of, or consisting of NST silica and / or (ii) ST silica or ST alumina, where the surface treatment of the silica comprises a silane or silazane; an isocyanate-functional crosslinker; and optionally, in certain embodiments, a catalyst, thereby obtaining a filled PIB PSA. Desirably, in embodiments that include an isocyanate-functional crosslinker, the filler comprises, consists essentially of, or consists of ST silica, more desirably ST silica without methacryloyl or amino groups.

[0008] The PSAs of the present invention provide at least one, preferably several advantages over existing PSAs. By way of illustration and not limitation, embodiments of the present invention provide filled PIB PSAs prepared using relatively low concentrations of NST silica fillers or ST fillers that exhibit improved static shear strength at higher temperatures, relatively low creep (sometimes referred to as creep resistance) compared to the same adhesive composition in the absence of crosslinking, and related embodiments also provide the aforementioned improved static shear strength while also exhibiting at least one, preferably several additional beneficial properties, including adhesion to polar surfaces (such as stainless steel and / or glass), tight liner release, water vapor transmission rate (WVTR), and, when acetylene black is used as an optional filler, a desirable level of electrical conductivity.

[0009] The PSAs of the present invention described herein may be used, among other applications, as components in adhesive tapes or as barrier adhesives, the latter generally recognized as limiting water and oxygen permeation therethrough and providing some degree of electrical conduction insulation.Embodiments containing at least acetylene black provide PSAs with conductive paths through the adhesive and may be used in applications requiring electrical conductivity as described above.Additional applications of the PSAs of the present invention will be apparent to those skilled in the art upon reading the disclosure provided herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Various embodiments of the present invention include at least one PIB resin. A PIB resin is generally a resin having a PIB resin backbone in the main chain or in a side chain. In some embodiments, the PIB resin is substantially a homopolymer of isobutylene.

[0011] PIB resins that are useful in certain embodiments may also be devoid of functional groups (such as reactive double bonds), contain functional groups (such as PIB containing at least about 60 mol % terminal double bonds), or mixtures of these resins. However, it should be recognized that unfunctionalized PIBs may have very low concentrations of reactive double bonds or other functional groups remaining from their preparation, typically less than about 5, 4, 3, or 2 mol % reactive double bonds or other functional groups.

[0012] Examples of suitable non-functionalized commercially available PIB resins include those in the OPPANOL® B and N series (BASF), such as OPPANOL B10 (about 40,000 g / mol, viscosity average molecular weight (vMW)), B11 (about 47,000 vMW), B12 (about 55,000 vMW), B13 (about 65,000 vMW), B14 (about 73,000 vMW), B15 (about 85,000 vMW), N50 (about 425,000 vMW), N80 (about 800,000 vMW), N100 (about 1,100,000 vMW), and N150 (about 2,600,000 vMW), each of which may contain from about 1 to about 500 ppm of a stabilizer such as BHT. Examples of suitable commercially available functional PIBs include those in the GLISSOPAL® series (BASF), such as 1000, 1300, and 2300, and those in the V-series, such as V190, V230, V430, V500, V640, V700, V800, V950, and V1500.

[0013] In some embodiments, the PIB resin may include copolymers of isobutylene, such as synthetic rubbers in which isobutylene is copolymerized with another monomer. Synthetic rubbers include copolymers of mostly isobutylene with small amounts of isoprene, such as butyl rubber. Examples of such suitable commercially available synthetic rubbers include those available under the trade names VISTANEX® (Exxon Chemical Co.) and JSR Butyl® (Japan Butyl Corporation).

[0014] The aforementioned synthetic rubbers may also include copolymers with styrene, n-butene, or butadiene, with a majority of isobutylene. In some embodiments, a mixture of isobutylene homopolymer and butyl rubber may be used. Other useful copolymers include styrene-isobutylene diblock copolymers (SIB) and styrene-isobutylene-styrene triblock copolymers (SIBS) available under the trade name SIBSTAR® (Kaneka Corporation).

[0015] The PIB resin may desirably have a vMW ranging from about 40,000 to about 3,000,000 g / mol.

[0016] Desirably, and in some embodiments, two PIB resins having different vMWs may be used, which are desirably non-reactive. In these embodiments, the resins will include at least one relatively low vMW resin and at least one relatively high vMW resin. Low vMW resins useful in embodiments of the present invention may have a vMW ranging from about 35,000 to about 100,000 g / mol, desirably from about 40,000 to about 75,000 g / mol, more desirably from about 45,000 to about 65,000 g / mol, and even more desirably from about 50,000 to about 60,000 g / mol. High vMW resins useful in embodiments of the present invention may have an average vMW ranging from about 300,000 to about 3,000,000 g / mol, desirably from about 400,000 to about 2,500,000 g / mol, more desirably from about 500,000 to about 2,000,000 g / mol, and even more desirably from about 700,000 to about 1,500,000 g / mol. Preferably, high vMW resins may have a vMW ranging from about 800,000 to about 1,300,000 g / mol, more preferably from about 900,000 to about 1,200,000 g / mol, and even more preferably from about 900,000 to about 1,100,000 g / mol.

[0017] Desirably, another resin may be optionally included in certain embodiments of the present invention. In embodiments that include a SiH- or SH-functional crosslinker, this optional resin contains at least two vinyl functional groups, and is desirably a PIB resin, such as a poly(acrylic / methacryloyl) resin. It is believed that the vinyl groups in this optional resin are reactive with the crosslinker (as described herein), and thus further aid in providing the desired crosslinked structure in the finished adhesive. When an embodiment includes an isocyanate-functional crosslinker, the optional resin may be a polyol, polyamine, or polythiol resin that is reactive with the isocyanate-functional crosslinker.

[0018] For example, and without intending to limit the scope of the invention, it has been found that the inclusion of this optional resin has a positive effect on certain properties of the resulting PSA. More specifically, and in some embodiments (e.g., those including a SiH-functional crosslinker), it has been found that the inclusion of this resin helps to increase the static shear strength compared to adhesives prepared without this optional resin, thereby helping to provide increased, desirable static shear strength.

[0019] In absolute amounts, this optional resin may be included in any suitable amount, with such amounts desirably ranging from about 0.1 wt % (weight percent) to about 15 wt %, more desirably from about 0.5 wt % to about 10 wt %, even more desirably from about 1 wt % to about 7 wt %, preferably from about 1 wt % to about 5 wt %, and more preferably from about 1 wt % to about 3 wt %, all weight percentages being based on the total weight of non-volatile components in the composition.

[0020] The compositions of the present invention useful for preparing filled PIB PSAs may comprise, consist essentially of, or consist only of ST fillers, and the surface treatment may comprise, consist essentially of, or consist only of silanes, silazanes, or combinations thereof. The inclusion of silanes, silazanes, or combinations thereof on the filler surface is believed to be important to the structure and performance of the resulting PSA, as they improve the hydrophobicity of the filler, thus helping to provide relatively high moisture barrier properties (e.g., lower WVTR compared to PSAs prepared using NST silica), and in certain embodiments, contain functional groups that are believed to react with at least the crosslinking agent, thereby providing a desirable crosslinking structure within the PSA. The functional groups contained in the silanes and silazanes may include alkyl acryloyl groups, such as methacryloyl groups, amino groups, such as aminopropyl silanes. ST fillers containing (non-functional) alkyl groups, such as dimethylsiloxane or polydimethylsiloxane, also provide desirable crosslinked structures in the resulting PSAs, believed to be due to reaction of at least the crosslinker with the SiOH groups on the ST filler.

[0021] The ST fillers may include silica and alumina and are desirably fumed, and the surface treatment preferably comprises, consists essentially of, or consists of organosilanes (including organohalosilanes and aminosilanes), organosiloxanes, organosilazanes, or mixtures thereof, and in some embodiments mixtures of organosilanes and organosilazanes.

[0022] More preferably, the organosilane may be one or more of methacryloyloxypropyltrialkoxysilane, aminopropylsilane, octylsilane (e.g., octyltrialkoxysilane such as octyltrimethoxysilane (OCTMO)), hexadecyltrialkoxysilane, dimethyldialkoxysilane, dimethyldichlorosilane, and trimethylalkoxysilane, while the organosiloxane may be polydimethylsiloxane and the organosilazane may be hexamethyldisilazane (HMDS). One combination of surface treatments useful in certain embodiments of the present invention is a filler surface treated with HMDS and aminopropylsilane.

[0023] ST fumed silica and alumina contain a hydrophobic surface which is attributable at least in part to the surface treatment described above.

[0024] ST fumed silica has a BET specific surface area which may vary, but is preferably from about 80 to about 400 m 2 / g, more preferably from about 100 to about 350 m 2 / gram, and more preferably from about 125 to about 300 m 2 / gram. ST fumed alumina also has a BET specific surface area, which can vary but is preferably from about 50 to about 150 m 2 / g, more preferably from about 75 to about 110 m 2 / gram.

[0025] Examples of commercially available ST silicas include, but are not limited to, AEROSIL® and CAB-O-SIL® ST fumed silicas, such as AEROSIL® R711, AEROSIL® R805, AEROSIL® R974, and AEROSIL® RA200HS (Evonik, Germany), while illustrative commercially available ST aluminas include, but are not limited to, AEROXIDE® surface-treated fumed aluminas, such as AEROXIDE® Alu C805 (Evonik, Germany). In general, the "R" series AEROSIL® and CAB-O-SIL® ST fumed silicas do not contain methacryloyl or amino groups, with the exception of R711, which contains methacryloyl groups, and RA200HS, which contains amino groups.

[0026] Certain embodiments of the present invention may include, desirably as the only filler, NST silica and / or NST alumina. These silicas and / or aluminas, preferably fumed, are well known to those skilled in the art and are generally considered to be hydrophilic in the relevant technical field. Such fumed silicas have a hydrophilicity of about 50 to about 400 μm. 2 / g, more preferably from about 150 to about 300 m 2 / gram. Examples of commercially available NST fumed silicas include, but are not limited to, hydrophilic silicas sold under the AEROSIL trademark (Evonik, Germany), and hydrophilic silicas sold under the CAB-O-SIL and CAB-O-SPERSE trademarks (Cabot, Boston, Massachusetts), while commercially available fumed aluminas include, but are not limited to, AEROXIDE Alu C (Evonik, Germany).

[0027] The compositions of the present invention may also optionally include one or more optional non-reactive fillers. Illustrative examples of such fillers are titanium dioxide, talc, zirconia, zinc oxide, calcium carbonate, barium sulfate, graphene, graphene-based particles, and combinations thereof. These other fillers, if included, should be in the form of particles and generally range from about 35 to about 400 μm. 2 The nanoparticles may have a BET specific surface area ranging from 0.1 to 1.0 μm / g.

[0028] Acetylene black (e.g., carbon black) may be useful as an additional filler in various embodiments of the present invention, particularly when a conductive PSA is desired. Acetylene black is well known to those skilled in the art and is not surface treated. Desirably, the acetylene black has the following attributes: 2 / gram and an average particle size in the range of about 30 to about 50 nm, and preferably more than one of the following:

[0029] Commercially available examples of acetylene black include, but are not limited to, AB 50%-01, AB 50%-03, AB 75%-01, AB 100%-01, and ABHC-01 (Soltex Corporation, Houston, Texas), DENKA BLACK (Denka Company, Tokyo, Japan), and Y50A (Orion Engineered Carbons, Houston, Texas).

[0030] Desirably, the crosslinking of the surface-treated filler is completed by including at least one crosslinking agent in the composition used to prepare the finished PSA. As described in more detail herein, various crosslinking agents may be used in the compositions of the present invention. Without wishing to be bound by any particular theory, it is believed that each functional group in the crosslinking agent described herein reacts with the functional groups present in one or more of the ST filler (e.g., silane and / or silazane), NST silica, and in embodiments containing optional resins, with the vinyl and / or divinyl functional groups therein, as further described herein, thereby providing the desired crosslinked structure in the finished PSA.

[0031] In embodiments that include a SiH functional crosslinker, it is believed that the SiH functional group in the crosslinker reacts (and crosslinks) with reactive groups (e.g., methacryloyl groups on a silane) in the ST filler (e.g., ST fumed silica, where the surface treatment includes a silane with an unsaturated double bond) via a hydrosilylation reaction. In general, the hydrosilylation reaction proceeds by the addition of a silicon-hydrogen (Si-H) bond to an unsaturated carbon-carbon double bond (C=C) of another molecule to form a silicon-carbon (Si-C) bond. In these embodiments, the aforementioned reaction is catalyzed, as discussed further herein.

[0032] Suitable SiH functional crosslinkers for use in this embodiment of the invention include silanes, siloxanes (including hydrosiloxanes), and more desirably polymers of methylsiloxanes and di-, tri-, and / or octylmethylsiloxanes, where the crosslinker has at least two SiH functional groups. Examples of SiH functional crosslinkers suitable for use in the present invention include, but are not limited to, Gelest HMS-301 (25-35% methylhydrosiloxane-dimethylsiloxane copolymer, trimethylsiloxy terminated, 25-35 cSt), available from Gelest, Inc. (Morrisville, PA), Gelest HMS-501 (50-55% (methylhydrosiloxane) 45-50% (dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-151 (15-18% (methylhydrosiloxane) 82-85% (dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-082 (7-9% methylhydrosiloxane)-(91-3% dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-152 (15-18% (methylhydrosiloxane) 82-85% (dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-082 (7-9% methylhydrosiloxane)-(91-3% dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-151 (15-18% (methylhydrosiloxane) 82-85% (dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-082 (7-9% methylhydrosiloxane)-(91-3% dimethylsiloxane) copolymer, trimethylsiloxy terminated), Gelest HMS-152 (15-18% ( ... HMS-991 (poly(methylhydrosiloxane), trimethyl terminated, 15-25 cSt), and Gelest HAM-3012 (25-30% methylhydrosiloxane)-(30-35% octylmethylsiloxane) dimethylsiloxane terpolymer, 20-60 cSt), as well as Silmer HQ-20 available from Siltech, Inc. (Toronto, Canada).

[0033] In embodiments including SH-functional crosslinkers, the SH-functional groups are believed to react (and crosslink) with reactive groups (e.g., methacryloyl groups on the silanes) in the ST filler (e.g., ST fumed silica, where the surface treatment includes silanes and / or silazanes that may contain double bonds). While the crosslinking reaction may be initiated by application of heat, the reaction may also be initiated by UV light with the inclusion of an appropriate initiator in the composition.

[0034] Suitable SH-functional crosslinkers for use in this embodiment of the invention include thiols having at least two SH functional groups. Examples of suitable SH-functional crosslinkers for use in the present invention include, without limitation, pentaerythritol tetrakis(3-mercaptopropionate (PEMP) and trimethylolpropane tris(3-mercaptopropionate (TMMP) available from Kowa American, Inc. (New York, NY).

[0035] In embodiments that include an isocyanate-functional crosslinker, the isocyanate groups are believed to react (and crosslink) with reactive groups in the ST filler (e.g., ST fumed silica, whose surface treatment includes a silane with an amino group) and with the SiOH on the surface of the ST and / or NST silica. Thus, the isocyanate functional groups are believed to react with the SiOH groups on the ST or NST silica, although there should be more SiOH groups available to react with the isocyanate functional groups on the NST silica. It has been found that the use of this combination of an isocyanate-functional crosslinker with NST and / or ST (even in the absence of amino groups) silica provides various advantages, including, without limitation, desirable static shear strength and relatively low cost, as compared to embodiments of the present invention that include ST fillers whose surface treatment includes methacryloyl or amino groups.

[0036] Suitable isocyanate-functional crosslinkers for use in embodiments of the present invention include amines having at least two isocyanate substituents. Examples of suitable isocyanate-functional crosslinkers for use in the present invention include, without limitation, Desmodur® E28, Desmodur® XP2847, Desmodur® Ultra N3300, Desmodur® N100, Desmodur® N3400, and Desmodur® E1361 available from Covestro (Leverkusen, Germany).

[0037] Generally, embodiments including isocyanate-functional crosslinkers do not require a catalyst, but tin (e.g., dibutyltin dilaurate) or base (e.g., 1,4-diazabicyclo[2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) catalysts may be included if desired.

[0038] The amount of the second crosslinker can vary, and desirably may be included in an amount ranging from about 0.3 to about 3 wt%, more desirably from about 0.7 to about 2.5 wt%, and even more desirably from about 1 to about 2 wt%, all weight percentages being based on the total weight of nonvolatile components in the composition.

[0039] The embodiment including the SiH functional crosslinker also requires a catalyst. While the catalyst may be selected depending on the crosslinkable groups included on the filler and the crosslinker, platinum-containing catalysts are preferred because they are believed to promote the hydrosilylation reaction. Examples of suitable platinum catalysts that may be used include, but are not limited to, platinum complexes of unsaturated siloxanes (Karstedt's catalyst), with preferred catalysts including platinum-divinyltetramethyldisiloxane complex, platinum-cyclovinylmethyl-siloxane complex, and platinum-[N-methyl-N'-(trimethoxysilylpropyl)imidazol-2-ylidene][divinyltetramethyldisiloxane] complex.

[0040] The amount of catalyst used in the foregoing embodiments can vary, but should be sufficient to aid in substantially complete crosslinking of the functional groups on the filler, crosslinker, and, if present, optional vinyl-containing resin. In this regard, the catalyst may desirably be included in an amount ranging from about 0.001 to about 0.1 wt%, desirably from about 0.002 to about 0.05 wt%, more desirably from about 0.005 to about 0.02 wt%, all weight percentages being based on the total weight of nonvolatile components in the composition.

[0041] In embodiments of the present invention that include a SiH-functional crosslinker and a catalyst, it has been found that the crosslinking reaction as described herein, particularly in hydrosilylation reactions, can occur at room temperature within a matter of minutes after the introduction of the catalyst. Thus, desirably, these embodiments may include a catalyst inhibitor that provides some control over the rate of the crosslinking reaction, for example, to help increase the time from the addition of the catalyst to substantial completion of crosslinking.

[0042] While a variety of catalyst inhibitors may be used, preferably dimethyl fumarate, dimethyl maleate, and / or 3,5-dimethyl-1-hexyn-3-ol are used. The inhibitors may be used in any amount suitable to provide the desired period of time from addition of the catalyst to substantial completion of crosslinking, but are typically added in amounts ranging from about 0.1 to about 1 wt%, preferably from about 0.15 to about 0.75 wt%, and more preferably from about 0.2 to about 0.5 wt%, all weight percentages being based on the total amount of nonvolatile components in the composition.

[0043] The embodiment of the present invention that includes an SH-functional crosslinker may be initiated by application of heat to provide a PIB PSA, and does not require a catalyst, as it is believed, and at least as related to the increase in temperature that catalyzes the crosslinking reaction between the surface treatment composition and the reactive functional groups on the SH-functional crosslinker. However, if desired, a radical initiator may be included that can help catalyze the crosslinking reaction when exposed to heat or electromagnetic radiation. Illustrative and non-limiting examples of radical initiators that catalyze the crosslinking reaction when exposed to heat include VAZO™ free radical initiators, such as 52, 64, 67, 88 (Chemours™, Wilmington, Del.), and those that catalyze the crosslinking reaction when exposed to UV include photoinitiators such as the SpeedCure series available from Lambson (Wetherby, UK), or the Darocure series available from BASF (Florham Park, NJ).

[0044] The amount of radical initiator used in these compositions can vary, but should be sufficient to aid in substantially complete crosslinking of the surface-treated filler with the SH-functional crosslinker. In this regard, the initiator may desirably be included in an amount ranging from about 0.001 to about 2 wt%, desirably from about 0.01 to about 1 wt%, more desirably from about 0.1 to about 0.5 wt%, all weight percentages being based on the total weight of nonvolatile components in the composition.

[0045] In embodiments in which the radical initiator is initiated by exposure to electromagnetic radiation, electromagnetic radiation useful for initiating the crosslinking reaction includes UV radiation, desirably UV-A and UV-B radiation (from about 280 to about 400 nm).

[0046] In certain embodiments of the present invention, a tackifier comprises an optional ingredient (optionally desirable ingredient). Generally speaking, a tackifier is a substance that increases the tack of a PIB PSA compared to a PIB PSA without the tackifier. Tack may be described as a measure of how quickly an adhesive bond is formed when two surfaces are brought together using low pressure. The faster the two surfaces bond, the higher the tack. The inclusion of a tackifier may also allow for the use of relatively low amounts of PIB resin to prepare a PIB PSA that exhibits acceptable adhesion to polar surfaces. In general, the inclusion of a tackifier in the PSA compositions of the present invention described herein has been observed to have limited effect on the static shear strength of the composition.

[0047] When included, the tackifier may be included in any amount, but is preferably included in an amount ranging from about 1 to about 30 wt%, more preferably from about 5 to about 25 wt%, and even more preferably from about 10 to about 20 wt%, based on the non-volatile components in the filled PIB PSA. Examples of tackifiers that may be useful in various embodiments of the present invention include terpenes, such as terpene phenol esters, aliphatic or aromatic modified C5-C9 hydrocarbons, rosin esters, coumarin-indene resin PIBs having relatively low vMW (from about 500 vMW to about 5,000 vMW), and mixtures thereof. Examples of suitable commercially available tackifiers include, but are not limited to, Arkon P and M series hydrogenated hydrocarbon resins (Arakawa Chemical Industries, Ltd., Japan) and Indopol® H series polybutenes (Palmer Holland, Inc., USA).

[0048] The following table provides exemplary compositions contemplated by the present invention, which may be suitable for use in one or more of the methods described herein. All weight percentages in the table are based on the total weight of non-volatile components in each composition. It should be recognized that other optional components may be included in these compositions if desired.

[0049] Table A sets forth the ingredients and their amounts to provide PSAs useful in the various methods contemplated by the present invention, the compositions of which include a SiH functional crosslinker.

[0050] [Table 1]

[0051] Table B sets forth the ingredients and their amounts to provide PSAs useful in the various methods contemplated by the present invention, the compositions of which include an SH-functional crosslinker.

[0052] [Table 2]

[0053] Tables C and D set forth the ingredients and their amounts to provide PSAs useful in the various methods contemplated by the present invention, the compositions of which include an isocyanate crosslinker.

[0054] [Table 3]

[0055] [Table 4]

[0056] Certain embodiments of the invention are directed to a composition comprising: (a) about 10 to about 40, about 10 to about 30, or about 15 to about 25 wt % of a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol; (b) about 20 to about 70, about 25 to about 65, or about 30 to about 60 wt % of a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol; and (c) about 5 to about 30, about 10 to about 25, or about 15 to about 20 wt % of a ST filler, wherein the surface treatment desirably comprises, consists essentially of, or comprises a silane, a silazane, or a combination thereof, each having an unsaturated double bond. % of a crosslinking catalyst, and optionally, in some cases, may further comprise about 0.1 to about 20, 0.1 to about 15, or 0.1 to about 10 wt % of a functional resin, about 0.05 to about 5, about 0.1 to about 2, or about 0.1 to about 1 wt % of a catalyst inhibitor, and / or about 1 to about 30 wt %, about 5 to about 25, or about 10 to about 20 wt % of a tackifier. The foregoing embodiments may also, if desired, include a weight ratio of resin (a) to resin (b) ranging from about 1:1 to about 1:5, desirably from about 1:1 to about 1:4, and more desirably from about 1:2 to about 1:3. The foregoing weight percentages and ratios are relative to the non-volatile components in the composition.

[0057] Another embodiment of the invention is a composition comprising: (a) about 10 to about 40, about 10 to about 30, or about 15 to about 25 wt % of a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol; (b) about 20 to about 70, about 25 to about 65, or about 30 to about 60 wt % of a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol; and (c) about 5 to about 30, about 10 to about 25, or about 15 to about 20 wt % of a ST filler, wherein the surface treatment desirably comprises a silane, silazane, or combination thereof having unsaturated double bonds. and (d) about 0.1 to about 15, about 0.1 to about 10, or about 0.1 to about 5 wt % of an SH-functional crosslinker, optionally further comprising about 0.1 to about 20, 0.1 to about 15, or 0.1 to about 10 wt % of an SH-functional resin, about 0.001 to about 5, about 0.01 to about 2.5, or about 0.01 to about 1 wt % of a radical initiator, and / or about 1 to about 30 wt. %, about 5 to about 25, or about 10 to about 20 wt % of a tackifier. The foregoing embodiments may also, if desired, include a weight ratio of resin (a) to resin (b) ranging from about 1:1 to about 1:5, desirably from about 1:1 to about 1:4, and more desirably from about 1:2 to about 1:3. The foregoing weight percentages and ratios are relative to the non-volatile components in the composition.

[0058] Yet another embodiment of the present invention is a composition comprising: (a) about 10 to about 40, about 10 to about 30, or about 15 to about 25 wt % of a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol; (b) about 20 to about 70, about 25 to about 65, or about 30 to about 60 wt % of a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol; and (c) about 5 to about 30, about 10 to about 25, or about 15 to about 20 wt % of a ST filler, wherein the surface treatment is preferably a silane, silazane or a combination thereof, having or replacing an amino group, or (ii) a methacryloyl or non-amino group-containing silane, silazane or a combination thereof. and (d) from about 0.1 to about 20, from about 0.1 to about 15, or from about 0.1 to about 10 wt % of an isocyanate-functional crosslinker, optionally optionally further comprising from about 0.1 to about 20, from about 0.1 to about 15, or from about 0.1 to about 10 wt % of a functional polyol, polyamine, and / or polythiol resin, from about 0.01 to about 5, from about 0.01 to about 2.5, or from about 0.01 to about 1 wt % of a catalyst, and / or from about 1 to about 30 wt %, from about 5 to about 25, or from about 10 to about 20 wt % of a tackifier. The foregoing embodiments may also, if desired, include a weight ratio of resin (a) to resin (b) ranging from about 1:1 to about 1:5, desirably from about 1:1 to about 1:4, and more desirably from about 1:2 to about 1:3. The foregoing weight percentages and ratios are relative to the non-volatile components in the composition.

[0059] Another embodiment of the present invention is a polymeric cellulose ester resin comprising: (a) about 10 to about 40, about 10 to about 30, or about 15 to about 25 wt % of a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol; (b) about 20 to about 70, about 25 to about 65, or about 30 to about 60 wt % of a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol; (c) about 5 to about 30, about 8 to about 25, or about 15 to about 20 wt % of an NST filler; and (d) about 0.1 to about 20, about 0.1 % of an isocyanate crosslinker, and optionally may further comprise about 0.1 to about 20, 0.1 to about 15, or 0.1 to about 10 wt % of a functional polyol resin, about 0.01 to about 5, about 0.01 to about 2.5, or about 0.01 to about 1 wt % of a catalyst, and / or about 1 to about 30 wt %, about 5 to about 25, or about 10 to about 20 wt % of a tackifier. The foregoing embodiments may also include, if desired, a weight ratio of resin (a) to resin (b) ranging from about 1:1 to about 1:5, desirably from about 1:1 to about 1:4, and more desirably from about 1:2 to about 1:3. The foregoing weight percentages and weight ratios are relative to the non-volatile components in the composition.

[0060] The PSAs described herein are not intended to include clay as a filler, and therefore the amount of any clay is limited. For example, in certain embodiments, clay fillers, if present, comprise no more than about 1 wt. % of the PSA of the invention, more desirably no more than about 0.5 wt. %, even more desirably no more than about 0.1 wt. %, and most desirably are not detectable in the PSA of the invention.

[0061] The PSAs of the present invention may be prepared according to any standard mixing method known in the art with regard to equipment and conditions (eg, temperature, humidity).

[0062] The amounts of ingredients used to prepare the embodiments of the present invention are based on the weight of the non-volatile components in the filled PIB PSA, i.e., the amount used to prepare the composition before dilution. In this regard, and as is well understood by those skilled in the art, the filled PIB PSA may be diluted with a volatile component (e.g., toluene, heptane) to a solids concentration of between about 10 and about 20 wt % and mixed until a homogeneous composition is provided. This dilution, which reduces the viscosity of the filled PIB PSA, is desirable because it allows the filled PIB PSA to be coated onto a surface to provide a substantially homogeneous coating layer. After coating, the diluent is volatilized, leaving the filled PIB PSA as a film ready for use. Alternatively, the composition may be applied in the absence of any volatile components.

[0063] The order of addition of certain components is important to obtain the desired properties in the finished adhesive. In this regard, crosslinking of the crosslinkable filler (and vinyl or divinyl-containing PIB resin, if included) is to be completed after the filler is mixed with at least the PIB resin and preferably with each of the other components (with the exception of the catalyst and, if included, the isocyanate crosslinker, each of which should be added in a final mixing step). To achieve this, it is desirable to thoroughly mix the PIB resin with the filler (at which time optional components, e.g., colorants, may also be added). In embodiments that include a catalyst (and, in certain embodiments, a catalyst inhibitor), the inhibitor (if any) may be introduced (by mixing) into the resin / filler mixture, followed by the addition of the crosslinking catalyst by mixing.

[0064] Using conventional coating methods, the PSAs of the present invention may be applied to a variety of flexible and non-flexible backing materials to produce adhesive-coated materials. Flexible substrates are defined herein as any material conventionally utilized as tape backings, or may be of any other flexible material. Examples include, but are not limited to, plastic films such as polypropylene, polyethylene, ethylene vinyl acetate (EVA), polyvinyl chloride, polyester (polyethylene terephthalate), polycarbonate, polymethyl (meth)acrylate (PMMA), cellulose acetate, cellulose triacetate, and ethyl cellulose. Foam backings may also be used. Examples of non-flexible substrates include, but are not limited to, metal, metallized polymeric films, indium tin oxide coated glass and polyester, PMMA plates, polycarbonate plates, glass, or ceramic sheet materials. Adhesive-coated sheet materials may take the form of any article conventionally known to be utilized with adhesive compositions, such as, for example, labels, tapes, signs, covers, marking indexes, display components, and touch panels. Flexible backing materials having a microreplicated surface are also contemplated.

[0065] The PSAs may also be used as components of pressure-sensitive adhesive transfer tapes, in which at least one layer of adhesive is disposed on a release liner for subsequent application to a secondary substrate. The PSAs may also be provided as single- or double-coated tapes, in which the adhesive is disposed on a stationary backing. The backing may be made from plastics (e.g., polypropylene, including biaxially oriented polypropylene, vinyl, polyethylene, ethylene vinyl acetate (EVA), polyesters such as poly(ethylene terephthalate), nonwovens (e.g., paper, cloth, nonwoven scrims), metal foils, and foams (e.g., polyacrylic, polyethylene, polyurethane, neoprene), and the like.

[0066] Foams are commercially available from a variety of sources, such as 3M, Voltek, Sekisui, and others. The foam may be formed as a coextruded sheet with the adhesive on one or both sides of the foam, or the adhesive may be laminated to it. If an adhesive is laminated to the foam, it may be desirable to treat the surface to improve adhesion of the adhesive to the foam, or any other type of backing. Such treatments are typically selected based on the properties of the adhesive and the foam or backing material, and include primers and surface modifications (e.g., corona treatment, surface abrasion). Additional tape constructions include those described in U.S. Patent No. 5,602,221 (Bennett et al.). Those skilled in the art will also recognize that other additives, such as antioxidants, stabilizers, and colorants, may be blended with the adhesive to provide additional beneficial properties.

[0067] For single-sided tapes, the side of the backing surface opposite the side on which the adhesive is disposed is typically coated with a suitable release material. Release materials are known and include materials such as silicone, polyethylene, polycarbamate, and polyacrylic. For double-sided coated tapes, another layer of adhesive is disposed on the backing surface opposite the side on which the adhesive of the present invention is disposed. The other layer of adhesive may be different from the adhesive of the present invention, for example, a conventional acrylic PSA, or it may be the same adhesive with the same or different composition. Double-sided coated tapes are typically supported on a release liner.

[0068] The PSA (diluted) compositions described above may be applied to a substrate using conventional coating methods, appropriately modified for the particular substrate. For example, these compositions can be applied to a variety of solid substrates by methods such as roller coating, flow coating, dip coating, spin coating, spray coating, knife coating, and die coating. These various coating methods allow the composition to be deposited on the substrate at an adjustable thickness, thus allowing the use of a wider range of compositions. Coating thicknesses can vary, but coating thicknesses of 0.1 to about 10 mils (dry thickness), preferably about 0.1 to 3 mils, and more preferably about 0.1 to about 1 mil (dry thickness) are contemplated.

[0069] PSAs contemplated by the present invention provide one or more advantageous properties including, without limitation, desirable static shear strength, relatively low creep resistance, peel strength, liner releasability, and WVTR values.

[0070] Preparation of Adhesive for Testing The filled PIB PSAs used in the tests described herein were prepared by introducing the specified amount of each component (as described in the Tables) except for the crosslinker (and catalyst and inhibitor, if desired) into a vessel, diluting the contents with toluene or heptane to a solids concentration of about 14 to about 20%, and mixing the diluted contents using a disperser blade (3500 rpm) at room temperature for 15 minutes. The crosslinker (and catalyst and inhibitor, if desired) was then added, if desired, and mixed at 3000 rpm for 2 minutes, thereby providing a liquid composition. The resulting liquid composition was coated onto a silicone release liner using a knife-over roll-down coater (e.g., Chemlnstruments Laboratory Drawdown Coater) at a thickness that provided a dry film thickness of 1 mil (or 0.2 mil for coatings containing acetylene (carbon) black) after the diluent had been volatilized. Volatilization was then proceeded by baking the liquid composition at 65° C. for 3 minutes, then at 150° C. for 5 minutes. The resulting exposed PSA adhesive is then covered with a second release liner (eg, a silicone release liner or a polyethylene terephthalate (eg, PET) release liner) to provide a PSA test strip.

[0071] <Static shear strength> The static shear strength of the PSA is determined as follows:

[0072] Pressure Sensitive Tape Council (PSTC) stainless steel (SS) panels to which the adhesive will be applied are cleaned with high purity urethane grade 2-butanone. Using a 4.5 lb, 80 durometer hardness roller, a 0.5 in. by 3 in. PSA test specimen (prepared as described above) is laminated to a 0.5 in. by 0.5 in. (12.7 mm by 12.7 mm) area of ​​the PSTC stainless steel panel.

[0073] After the 30 minute dwell period, the SS panel with the specimen attached is assembled vertically in a chamber preheated to 70°C (and maintained at 70°C for the duration of the test) and the static shear test is initiated by hanging a 500 gram weight from the portion of the PSA specimen not attached to the SS panel. The time (in minutes) that elapses before the weight falls is recorded as the static shear strength of the PSA.

[0074] The static shear strength of various embodiments of the PSAs of the present invention according to this test method are described herein, but may generally be at least about 10, 20, 50, 100, 200, 500, 1,000, 2,000, 5,000, or 10,000 minutes. For practical reasons, the test was terminated when 10,000 minutes (approximately 7 days) was reached, and therefore, 10,000 minutes may serve as an acceptable upper limit for static shear strength for purposes of describing the present invention. However, it should be understood that various embodiments of the present invention would be expected to provide a static shear strength in excess of 10,000 minutes, since they remained attached at 10,000 minutes.

[0075] <Peel strength> The peel strength of the PSA is determined as follows.

[0076] The PSA to be tested was prepared as previously described.

[0077] Pressure Sensitive Tape Council (PSTC) stainless steel (SS) panels to which the adhesive will be applied are cleaned with high purity urethane grade 2-butanone. Using a 4.5 lb, 80 durometer hardness roller, a 1 in x 10 in PSA test specimen (prepared as described above) is laminated to the PSTC SS panel.

[0078] After a 15 minute dwell period, the peel test is initiated by pulling the tape from the PSTC SS plate at an angle of 180 degrees at a rate of 12 inches / minute (with the specimen at room temperature and ambient humidity). The load and displacement are typically increased to a maximum over the first inch of the test and then remain constant until the test is completed. The peel strength is determined by averaging the load (oz) observed between 1 inch and 5 inches of displacement on the panel (based on a 1 inch sample width), giving an oz / in value that is the PSA peel strength.

[0079] The peel strengths of various embodiments of the PSAs of the invention according to this test method are described herein, but generally may be at least about 10, 20, 30, 40, 50, 60, 70, 100, 150, or 200 oz / inch, with 200 oz / inch generally serving as the upper peel strength limit for purposes of describing the invention.

[0080] <Water vapor permeability> Testing for water vapor transmission rate (WVTR) of PSAs using a Mocon Permatran-W3 / 33 MA (Ametek Mocon, Brooklyn Park, Minn.) is performed as follows.

[0081] The PSA to be tested was prepared as previously described. Prior to initiating testing in the Mocon Permatran device, the liner covering the PSA was removed, the PSA was placed on a Celgard® sheet, and the PSA sample was placed on a Mocon 032-076 aluminum foil sheet and inflated 1 cm. 2 The holes in the sheet are then covered and subjected to testing. The WVTR value of a PSA may be considered to be the same as the plateau value, which is usually reached at or after about 12-36 hours. The WVTR of various embodiments of the PSA of the invention according to this test method are described herein, but generally are about 100, 80, 70, 50, 40, 30, 25, or 10 g-mils / m 2 / day or less, and may have a WVTR of 0.1 g-mil / m 2 / day may generally serve as a lower limit for the WVTR for purposes of describing the present invention.

[0082] <High peelability of liner> Using a TMI Lab Master® Release & Adhesion Tester (New Castle, Del.), testing of the liner release properties of the PSAs is performed as follows.

[0083] The PSA to be tested was prepared as previously described.

[0084] The test is conducted in a controlled temperature (70° F.) and humidity (50% RH) environment. A 2 in. by 10 in. PSA specimen is subjected to testing in the device (300 in. / min. at 180° C.) and the peel of the adhesive from the liner (which may be referred to as the "tight" liner) onto which the PSA composition is deposited is determined based on the average load (oz.) between 1 inch and 5 inch displacement (keeping in mind the 2 inch sample width), thereby giving a value of grams / 2 inch, which is the liner peelability.

[0085] The liners used in this test, identified in the table, are: AR-W2: Adhesives Research W-5002 (silicone), AR-W4: Adhesives Research W-5004 (a silicone with heavier release properties compared to AR-W2), AR-R6: Mitsubishi 2PKRN 1.5 mil PET (coated silicone), and AR-R7: Mitsubishi 2PKRN 2.0 mil PET (coated silicone).

[0086] The heavy liner release properties of various embodiments of PSAs of the invention according to this test method are described herein, but may generally have a (heavy) liner release property that is less than about 100, 90, 80, 70, 50, 40, 30, or 20 grams / 2 inches, with about 5 grams / 2 inches generally serving as a lower limit for the (heavy) liner release property for purposes of describing the invention.

[0087] <Conductivity> The conductivity of the PSA was evaluated using a Keithley Micro-ohmmeter (Model 580) as follows.

[0088] The PSAs to be tested were prepared as previously described, then the adhesive was applied to a removable AR-W4 liner at an initial thickness of 5 or 25.4 μm (the latter also referred to as 1 mil thickness) and then covered with a second removable Mitsubishi 2PKRN2.0 mil PET liner to give the samples.

[0089] The test protocol begins by removing the second liner from the sample to expose one side of the PSA layer. A gold-plated stainless steel electrode measuring 1 in. by 1 in. is brought into contact with the newly exposed PSA adhesive layer and pressed firmly. While still firmly pressed, the PSA adhesive and AR-W4 liner are cut to the shape of the electrode and separated from the larger sample. The AR-W4 liner is then removed from the newly cut 1 in. 2 The PSA adhesive / AR-W4 liner is then separated from the second gold plated stainless steel electrode and a second gold plated stainless steel electrode is pressed onto the newly exposed PSA adhesive and both electrodes are aligned end to end and facing each other to give the assembled electrode.

[0090] The assembled electrodes were then placed in a fixture where equal pressure was applied to the electrodes while allowing space for the attachment of conductive alligator clips. A current of 100 mA was then applied to the electrodes and after waiting 30 seconds to allow the sample to equilibrate, resistivity values ​​(in milliohms) were obtained from the instrument with a force of 11 lbs. Lower resistivity values ​​correspond to higher conductivity of the sample, with higher conductivity values ​​being desirable for compositions containing acetylene black.

[0091] For various embodiments of the PSAs of the present invention, the conductive PSAs may have resistivity values ​​(as determined using the protocols described herein) of from about 0.25 to about 250 ohms.

[0092] Alternatively, the well-known four-point method may be used to evaluate the volume resistivity, surface resistivity, and electrical conductivity of the PSA. This method generally requires that a probe having four points of known diameter spaced apart from one another is contacted with the PSA film under test at points where a known current is applied to the two outer points and the remaining two inner points are in communication with a voltmeter. Resistivity is calculated according to the well-known equation: ρ=2πS(V / I) [where ρ = resistivity (ohm cm), S = needle spacing (cm), V = voltage between the inner probes (V), and I = current through the outer probe] It is further known that if the thickness of the film being tested is less than 5 times the spacing between the dots, a correction factor should be applied, and if the thickness of the film is 5 times or more the spacing between the dots, the correction factor applied to the formula is less than 0.1%.

[0093] Using the four-point method, the volume resistivity of the PSA may desirably range from about 1 to about 1000 ohm cm.

[0094] The following examples are offered to illustrate, but not to limit the scope of the invention. EXAMPLES

[0095] Several PIB PSA compositions (including OPPANOL® N100 as the high vMW PIB resin and OPPANOL® B12 as the low vMW PIB resin) were prepared with various amounts of surface-treated fumed silica (ST fumed silica), SiH crosslinker, platinum catalyst, and catalyst inhibitor, and tested against an adhesive (1-A) that did not contain a crosslinker. The ingredients used to prepare the adhesives are listed in Table 1, and the amount of each ingredient is listed as a weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparation of Adhesives for Testing."

[0096] After preparation, the adhesives were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), and some of the adhesives were further tested for their adhesion to stainless steel surfaces (peel strength) and moisture barrier (WVTR) properties according to the test protocols described herein, with the resulting values ​​being reported in Table 1.

[0097] [Table 5]

[0098] The data provided in this example demonstrates that the crosslinked composition provided increased static shear strength compared to the comparative adhesive (A) that did not contain a crosslinker (and was therefore not crosslinked), especially when a SiH-functional crosslinker was added to the composition. EXAMPLES

[0099] Several PIB PSA compositions, including OPPANOL® N100 as a high vMW PIB resin and OPPANOL® B12 as a low vMW PIB resin, were prepared with surface-treated fumed silica (ST fumed silica), where the surface-treated composition includes a methacrylic silane having an unsaturated double bond, an SH-functional crosslinker, a tackifier, and a thermally initiated free radical initiator, and tested against an adhesive (2-A) that does not contain a crosslinker. The ingredients used to prepare the adhesives are listed in Table 2, and the amount of each ingredient is listed as a weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparation of Adhesives for Testing."

[0100] After the adhesives were prepared, they were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), adhesion to stainless steel surface (peel strength), liner peel strength, and (for some adhesives) moisture barrier (WVTR) properties according to the test protocols described herein. The resulting values ​​are listed in Table 2.

[0101] This example demonstrates that compositions with crosslinked structures provide enhanced static shear strength compared to non-crosslinked adhesives (2-A), especially when SH-functional crosslinkers are included in amounts ranging from about 0.1 to about 5 wt%. Such compositions further exhibit acceptable peel strength, liner peelability, and WVTR. Surprisingly, it was found that including SH crosslinkers in amounts of 10 wt% did not provide any benefit in static shear strength or other properties compared to the comparative non-crosslinked adhesive (2-A).

[0102] [Table 6] EXAMPLES

[0103] Several PIB PSA compositions (including OPPANOL® N100 as the high vMW PIB resin and OPPANOL® B12 as the low vMW PIB resin) were prepared with various amounts of surface-treated fumed silica (ST fumed silica), where the surface treatment includes HDMS and aminosilane (amino groups), an isocyanate-functional crosslinker, and a tackifier, and were tested against adhesives that did not contain a crosslinker (3-A, 3-B, and 3-C). The ingredients used to prepare the adhesives are listed in Table 3, with the amount of each ingredient listed as a weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparation of Adhesives for Testing."

[0104] After the adhesives were prepared, they were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), adhesion to stainless steel surface (peel strength), liner peel strength, and (for some adhesives) moisture barrier (WVTR) properties according to the test protocols described herein. The resulting values ​​are listed in Table 3.

[0105] This example demonstrates that compositions with crosslinked structures provide enhanced static shear strength compared to non-crosslinked adhesives (3-A, 3-B, and 3-C), especially when the isocyanate crosslinker is included in an amount ranging from about 0.1 to about 10 wt%. Such compositions also exhibit acceptable peel strength, liner peel strength, and WVTR. Surprisingly, it was found that including an isocyanate crosslinker in an amount of 12 wt% provides a benefit in static shear strength, but not in liner peel strength or peel strength, while increasing the amount of this crosslinker to 21 wt% does not provide any benefit in static shear strength due to relatively low adhesion, and has relatively low liner peel strength (which may be beneficial in certain applications) and peel strength, all compared to the comparative benchmark non-crosslinked adhesive (3-A).

[0106] [Table 7] EXAMPLES

[0107] Several PIB PSA compositions (including OPPANOL® N100 as the high vMW PIB resin and OPPANOL® B12 as the low vMW PIB resin) were prepared with various amounts of NST fumed silica or surface-treated fumed silica (ST fumed silica), where the surface treatment does not contain unsaturated double bonds or amino groups, an isocyanate-functional crosslinker, and a tackifier, and were tested against adhesives that did not contain a crosslinker (4-A, 4-B, 4-C, and 4-D). The ingredients used to prepare the adhesives are listed in Table 4, and the amount of each ingredient is listed as a weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparation of Adhesives for Testing."

[0108] After the adhesives were prepared, they were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), adhesion to stainless steel surface (peel strength), liner peel strength, and moisture barrier (WVTR) properties according to the test protocols described herein. The values ​​obtained are listed in Table 4.

[0109] This example demonstrates that compositions with crosslinked structures, especially when an isocyanate-functional crosslinker is included, provide enhanced static shear strength compared to non-crosslinked adhesives (4-A, 4-B, 4-C, and 4-D). Such compositions also exhibit acceptable peel strength, liner peel strength, and in some compositions, acceptable WVTR. Surprisingly, it was found that including an isocyanate-functional crosslinker with ST silica that does not contain methacryloyl or amino groups, i.e., formulation 4-3 (which is significantly less expensive than ST silicas that contain such groups), provides excellent static shear strength with relatively low liner peel strength and WVTR compared to non-crosslinked adhesives. Furthermore, and surprisingly, it was found that adhesives containing ST silica (surface-treated with a composition containing DDS) exhibited orders of magnitude better static shear strength compared to the same adhesives that are not crosslinked (4-C) without affecting peel strength, liner peel strength, or WVTR. In comparison, the adhesive containing ST silica (surface treated with a composition containing OCTMO) showed a smaller increase in static shear strength and smaller changes to peel strength, liner peel strength, and WVTR compared to the benchmark non-crosslinked adhesive (4-D).

[0110] In addition, it was found that the inclusion of an isocyanate-functional crosslinker in a formulation containing about 13 wt% NST silica provided some improvement in static shear strength compared to a formulation without the crosslinker, but did not significantly affect peel strength, liner release, or WVTR. This result contrasts sharply with the properties provided by a similar formulation containing an isocyanate-functional crosslinker with about 17 wt% NST silica, which has significant static shear strength (>10,000 min), as well as desirable peel strength, liner release, and WVTR.

[0111] [Table 8] EXAMPLES

[0112] PIB PSA compositions (including OPPANOL® N100 as the high vMW PIB resin and OPPANOL® B12 as the low vMW PIB resin) were prepared and tested with ST fumed silica, acetylene black, and an isocyanate-functional crosslinker in one formulation. The ingredients used to prepare the adhesives are listed in Table 5, with the amount of each ingredient listed as weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparing Adhesives for Testing."

[0113] After the adhesives were prepared, they were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), adhesion to stainless steel surface (peel strength), liner peel strength, moisture barrier (WVTR), and resistivity properties according to the test protocols described herein. The values ​​obtained are listed in Table 5.

[0114] This example demonstrates that the use of a crosslinker enhances the increase in static shear strength while not adversely affecting peel strength, liner peelability, WVTR, and resistivity.

[0115] [Table 9] EXAMPLES

[0116] PIB PSA compositions (including OPPANOL® N100 as the high vMW PIB resin and OPPANOL® B12 as the low vMW PIB resin) were prepared and tested with NST fumed alumina and an isocyanate-functional crosslinker in one formulation. The ingredients used to prepare the adhesives are listed in Table 6, with the amount of each ingredient listed as weight percent based on the total weight of the nonvolatile components in the composition. The process used to prepare these adhesives is described in "Preparing Adhesives for Testing."

[0117] After the adhesives were prepared, they were tested as described herein and analyzed for static shear strength (70° C., 500 gram mass), adhesion to stainless steel surface (peel strength), and liner peel strength according to the test protocols described herein, with the resulting values ​​being reported in Table 6.

[0118] [Table 10]

[0119] This example demonstrates that the inclusion of a crosslinker increases the static shear strength while not adversely affecting the peel strength or liner peelability compared to compositions without the crosslinker.

[0120] All references cited in this specification, including publications, patent applications, and patents, are hereby incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference in its entirety and set forth herein.

[0121] The use of the terms "a" and "an" and "the" and "at least one" and similar referents in the context of describing the present invention (particularly in the context of the claims below) are to be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term "at least one" followed by a list of one or more items (e.g., "at least one of A and B") is to be construed to mean one item selected from the listed items (A or B), or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated herein as if it were individually set forth herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to better teach the invention, and does not limit the scope of the invention unless otherwise stated. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0122] References to weight percent herein should be understood to describe the amount of a component or ingredient on a nonvolatile basis in a filled PIB PSA composition, unless contradicted by express language or context.

[0123] Preferred embodiments of the present invention include the best mode for carrying out the invention described herein and known to the inventors. Variations of those preferred embodiments may become apparent to those skilled in the art upon reading the foregoing description. The inventors anticipate that those skilled in the art will adopt such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. In addition, any combination of the elements described above in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein or clearly contradicted by context.

Claims

1. A composition, (a) PIB (polyisobutylene-based) resin, (b) Untreated (NST) silica fillers and / or treated (ST) fillers, wherein the surface treatment includes a silane, silazane or a combination thereof, (c) A crosslinking agent comprising at least two portions that react with at least the ST filler and / or the NST filler, (d) optionally, a crosslinking catalyst and A composition containing the following:

2. A composition, (a) PIB (polyisobutylene-based) resin, (b) A surface-treated filler wherein the surface treatment comprises a silane, a silazane, or a combination thereof, and the silane and silazane each contain an unsaturated double bond, (c) SiH functional crosslinking agent, (d) Crosslinking catalyst and A composition containing the following:

3. The composition according to claim 2, further comprising a catalyst inhibitor.

4. The composition according to claim 3, further comprising a functional PIB (polyisobutylene-based) resin.

5. The composition according to any one of claims 1 to 3, wherein the SiH-functionalized crosslinking agent is a siloxane containing at least two SiH functional groups.

6. The composition according to any one of claims 1 to 3, wherein the PIB (polyisobutylene-based) resin comprises a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol, and a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol.

7. The composition according to any one of claims 1 to 4, further comprising a functional resin containing vinyl functional groups.

8. A composition, (a) A PIB (polyisobutylene-based) resin having a vMW in the range of approximately 10 to approximately 40, from 300,000 to approximately 3,000,000 g / mol, (b) A PIB resin having a vMW in the range of approximately 35,000 to approximately 100,000 g / mol, in an amount of approximately 20 to approximately 70% by mass, (c) A surface-treated filler comprising approximately 5 to approximately 30% by mass, wherein the surface treatment includes silane, silazane, or a combination thereof, and the silane and silazane each contain unsaturated double bonds. (d) Approximately 0.1 to approximately 15% by mass of SiH functional crosslinking agent, (e) Approximately 0.001 to approximately 5% by mass of the crosslinking catalyst and Includes, The material may optionally further contain (i) a functional resin containing vinyl functional groups in an amount of about 0.1 to about 20% by mass, (ii) a catalyst inhibitor in an amount of about 0.05 to about 5% by mass, and / or (iii) a tackifier in an amount of about 1 to about 30% by mass. The aforementioned mass percentage is the amount relative to the non-volatile component in the composition. composition.

9. The composition according to any one of claims 1 to 4 and 8, wherein the mass ratio of resin (a) to resin (b) is in the range of about 1:1 to about 1:5, and the mass ratio is based on the non-volatile components in the composition.

10. A composition, (a) PIB resin and (b) A surface-treated filler wherein the surface treatment comprises a silane, a silazane, or a combination thereof, and the silane and silazane each contain an unsaturated double bond, (c) SH functional crosslinking agent and A composition containing the following:

11. The composition according to claim 10, wherein the SH-functionalized crosslinking agent is a thiol containing at least two SH functional groups.

12. The composition according to claim 11, wherein the SH functional crosslinking agent is PEMP and / or TMMP.

13. The composition according to any one of claims 10 to 12, further comprising a radical initiator.

14. The composition according to any one of claims 10 to 12, further comprising a functional PIB resin.

15. The composition according to any one of claims 10 to 12, wherein the PIB resin comprises a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol, and a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol.

16. A composition, (a) A PIB resin having a vMW in the range of 300,000 to approximately 3,000,000 g / mol in an amount of approximately 10 to approximately 40% by mass, (b) A PIB resin having a vMW in the range of approximately 35,000 to approximately 100,000 g / mol, in an amount of approximately 20 to approximately 70% by mass, (c) A filler comprising approximately 5 to approximately 30% by mass of surface-treated material, wherein the surface treatment includes silane, silazane, or a combination thereof, and the silane and silazane each contain an unsaturated double bond. (d) Approximately 0.1 to approximately 15% by mass of an SH functional crosslinking agent Includes, The mixture may optionally further contain (i) about 0.1 to about 20% by mass of a functional resin, (ii) about 0.01 to about 5% by mass of a radical initiator, and / or (iii) about 1 to about 30% by mass of a tackifier. The aforementioned mass percentage is based on the non-volatile components in the composition. composition.

17. The composition according to claim 16, wherein the mass ratio of resin (a) to resin (b) is in the range of about 1:1 to about 1:5, and the mass ratio is based on the non-volatile components in the composition.

18. A composition, (a) PIB resin and (b) A surface-treated filler wherein the surface treatment comprises a filler containing silane, silazane or a combination thereof, (c) Isocyanate functional crosslinking agent and A composition containing the following:

19. The composition according to claim 18, wherein the surface-treated filler does not contain (meth)acryloyl and / or amino groups.

20. The composition according to claim 18, wherein the surface-treated filler contains an amino group.

21. (a) PIB resin and (b) Untreated filler, (c) Isocyanate functional crosslinking agent and A composition containing the following:

22. The composition according to any one of claims 18 to 21, further comprising a catalyst.

23. The composition according to any one of claims 18 to 21, further comprising a functional PIB resin.

24. The composition according to claim 18, wherein the isocyanate-functionalized crosslinking agent comprises two isocyanate functional groups.

25. The composition according to any one of claims 18 to 21, wherein the PIB resin comprises a PIB resin having a vMW in the range of 300,000 to about 3,000,000 g / mol, and a PIB resin having a vMW in the range of about 35,000 to about 100,000 g / mol.

26. A composition, (a) A PIB resin having a vMW in the range of 300,000 to approximately 3,000,000 g / mol in an amount of approximately 10 to approximately 40% by mass, (b) A PIB resin having a vMW in the range of approximately 35,000 to approximately 100,000 g / mol, in an amount of approximately 20 to approximately 70% by mass, (c) A surface-treated filler comprising approximately 5 to approximately 30% by mass, wherein the surface treatment includes a filler containing silane, silazane, or a combination thereof. (d) Approximately 0.1 to approximately 20% by mass of an isocyanate functional crosslinking agent and Includes, The material may optionally further contain (i) about 0.1 to about 20% by mass of a functional polyol, polyamine, and / or polythiol resin, (ii) about 0.01 to about 5% by mass of a catalyst, and / or (iii) about 1 to about 30% by mass of a tackifier. The aforementioned mass percentage is based on the non-volatile components in the composition. composition.

27. The composition according to claim 26, wherein the surface-treated filler does not contain (meth)acryloyl and / or amino groups.

28. The composition according to claim 26, wherein the surface-treated filler contains an amino group.

29. (a) A PIB resin having a vMW in the range of 300,000 to approximately 3,000,000 g / mol in an amount of approximately 10 to approximately 40% by mass, (b) A PIB resin having a vMW in the range of approximately 35,000 to approximately 100,000 g / mol, in an amount of approximately 20 to approximately 70% by mass, (c) Approximately 5 to approximately 30% by mass of untreated filler, (d) Approximately 0.1 to approximately 20% by mass of isocyanate crosslinking agent and A composition comprising, The material may optionally further contain (i) about 0.1 to about 20% by mass of a functional polyol, polyamine, and / or polythiol resin, (ii) about 0.01 to about 5% by mass of a catalyst, and / or (iii) about 1 to about 30% by mass of a tackifier. The aforementioned mass percentage is based on the non-volatile components in the composition. composition.

30. The composition according to claim 29, wherein the mass ratio of resin (a) to resin (b) is in the range of about 1:1 to about 1:5, and the mass ratio is based on the non-volatile components in the composition.

31. The composition according to any one of claims 21 or 29 to 30, wherein the untreated filler is fumed silica.

32. The composition according to any one of claims 21 or 29 to 30, wherein the untreated filler is fumed alumina.

33. A composition according to any one of claims 1 to 4, 8, 10 to 12, 16 to 21, 24, and 26 to 30, further comprising a tackifier.

34. A composition according to any one of claims 1 to 4, 8, 10 to 12, 16 to 21, 24, and 26 to 30, further comprising acetylene black.

35. A pressure-sensitive adhesive (PSA) comprising the composition according to any one of claims 1 to 4, 8, 10 to 12, 16 to 21, 24, and 26 to 30, further comprising acetylene black, having a resistivity of about 0.25 to about 250 ohms as determined using the protocol described herein.

36. A pressure-sensitive adhesive comprising a composition according to any one of claims 1 to 4, 8, 10 to 12, 16 to 21, 24, and 26 to 30, further comprising acetylene black, wherein the composition has a volume resistivity of PSA of about 1 to about 1000 ohms / cm as determined using the four-point method.

37. A pressure-sensitive adhesive comprising the composition according to any one of claims 1 to 4, 8, 10 to 12, 16 to 21, 24, and 26 to 30.

38. A PSA comprising the composition according to any one of claims 1 to 4 and 8, wherein the following properties are present: (a) Static shear strength (70°C, 500g) from about 50, 60, or 70 to about 100, 125, 150, or 200 minutes, as evaluated according to the test protocols described herein. (b) Peel strength from about 5 to about 30 oz / in as evaluated according to the test protocol described herein, (c) Evaluated according to the test protocol described herein, approximately 15 to approximately 45 g-mil / m² ２ WVTR up to / day A pressure-sensitive adhesive (PSA) comprising at least one, two, or preferably all three of the following.

39. A pressure-sensitive adhesive (PSA) comprising the composition according to any one of claims 10 to 12, 16, and 17, wherein the following properties are present: (a) Static shear strength (70°C, 500g) from about 50, 60, or 70 to about 100, 125, 150, or 200 minutes, as evaluated according to the test protocols described herein. (b) Peel strength of about 30 to about 60 oz / in, as evaluated according to the test protocol described herein. (c) Liner peelability from about 15 to about 30 g / 2 inch, as evaluated according to the test protocol described herein, (d) Evaluated according to the test protocol described herein, from about 1 to about 15 g-mil / m ２ WVTR up to / day A pressure-sensitive adhesive (PSA) having at least one, two, three, or preferably all four of the following.

40. A pressure-sensitive adhesive (PSA) comprising the composition according to any one of claims 18 to 20, 24, and 26 to 28, wherein the following properties are present: (a) Static shear strength (70°C, 500g) from about 50, 60, or 70 to about 100, 125, 150, or 200 minutes, as evaluated according to the test protocols described herein. (b) Peel strength of about 30 to about 60 oz / in, as evaluated according to the test protocol described herein. (c) Liner peelability from about 15 to about 30 g / 2 inch, as evaluated according to the test protocol described herein, (d) Evaluated according to the test protocol described herein, from about 1 to about 15 g-mil / m ２ WVTR up to / day A pressure-sensitive adhesive (PSA) having at least one, two, three, or preferably all four of the following.

41. A PSA (pressure-sensitive adhesive) comprising the composition according to any one of claims 21, 29, and 30, wherein the following properties are present: (a) Static shear strength (70°C, 500g) from about 50, 60, or 70 to about 100, 125, 150, or 200 minutes, as evaluated according to the test protocols described herein. (b) Peel strength of about 30 to about 60 oz / in, as evaluated according to the test protocol described herein. (c) Liner peelability from about 15 to about 30 g / 2 inch, as evaluated according to the test protocol described herein, (d) Evaluated according to the test protocol described herein, from about 1 to about 15 g-mil / m ２ WVTR up to / day A pressure-sensitive adhesive (PSA) having at least one, two, three, or preferably all four of the following.

42. A PSA (pressure-sensitive adhesive) comprising the composition described in claim 34, wherein the following properties are present: (a) Static shear strength (70°C, 500g) from about 20, 25, or 30 to about 45, 50, 55, or 60 minutes, as evaluated according to the test protocol described herein. (b) Peel strength of about 50 to about 70 oz / in, as evaluated according to the test protocol described herein, (c) Liner peelability from about 10 to about 30 g / 2 inch, as evaluated according to the test protocol described herein. A pressure-sensitive adhesive (PSA) comprising at least one, two, or preferably all three of the following.