Adhesive and tape including precipitated amorphous silica or silicate and related processes

Abstract

An adhesive includes a styrenic block copolymer having a styrenic block and a conjugated diene block that is hydrogenated or not hydrogenated, a tackifying resin, and at least one of precipitated amorphous silica or a precipitated amorphous silicate. The adhesive can further include at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin. The precipitated amorphous silica or precipitated amorphous silicate may be surface modified with hydrophobic groups. The adhesive can further include natural rubber. The adhesive may have not more than 4.5 weight percent polyisobutylene or a polyisobutylene copolymer, based on the total weight of the adhesive, or may be free of polyisobutylene and a polyisobutylene copolymer. A tape includes the adhesive disposed on a backing. Processes for making and using the tape are also provided.

Description

[0001] PA103295W003

[0002] ADHESIVE AND TAPE INCLUDING PRECIPITATED AMORPHOUS SILICA OR SILICATE

[0003] AND RELATED PROCESSES

[0004] Cross-Reference to Related Application

[0005] This application claims priority to U.S. Provisional Application No. 63 / 714,690, filed October 31, 2024, the disclosure of which is incorporated by reference in its entirety herein.

[0006] Background

[0007] Styrene-conjugated diene block copolymers have been formulated to produce adhesive compositions. For example, U.S. Pat. No. 3,239,478 (Harlan), shows combinations of these block copolymers with tackifying resins and paraffinic extending oils to produce various types of adhesives. U.S. SIR H1387 (Hansen et al.) and U.S. Pat. No. 4,104,323 (Hansen) propose using polyphenylene ether to improve the performance of styrene-conjugated diene block copolymer-based adhesives at relatively higher temperatures.

[0008] In unrelated disclosures, fumed silica has been used in acrylic pressure-sensitive adhesive formulations for various purposes as reported in U.S. Pat. Nos. 4,415,615 (Esmay et al.), 4,710,536 (Klingen et al.), and 11,578,162 (Seth et al.) and Int. Pat. Appl. Pub. No. WO 95 / 13331 (Bennett et al.). Furthermore, U.S. Pat. No. 3,565,247 (Brochman) reports fumed silica as a nucleating and reinforcing agent in a foamed pressure-sensitive adhesive.

[0009] The use of colloidal silica nanoparticles in emulsion-based (methjacrylate copolymer pressuresensitive adhesives that have high shear properties is disclosed in U.S. Pat. No. US 7,645,827 (Lewandowski et al.). A pressure-sensitive adhesive strip composed of a polymer matrix incorporating spherical fillers is disclosed in U.S. Pat. Appl. Pub. No. 2022-0195260 (Mayer et al.).

[0010] A binder composition for adhesives and sealants including poly(alpha-methylstyrene), polybutenes, and a styrene-elastomer copolymer for various applications is disclosed in U. S. Pat. No. 4,042,555 (Raimondi et al.). An adhesive composition for roofing membranes comprising a blend of thermoplastic block copolymers, polyisobutylene, a compatible tackifier, and optionally an amorphous polyolefin is described in U.S. Pat. Appl. Pub. No. 2005-0043468 (Fisher).

[0011] Summary

[0012] The present disclosure provides a styrenic block copolymer-based adhesive useful, for example, for tapes for a variety of applications. Typically, and advantageously, the adhesive of the present disclosure has unexpectedly better holding power than comparable adhesives that do not include filler or include another filler other than precipitated amorphous silica or a precipitated amorphous silicate. In one aspect, the present disclosure provides an adhesive. The adhesive includes a styrenic block copolymer including a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated, a first tackifying resin, at least one of precipitated amorphous silica or a precipitated amorphous silicate, and at least one of a plasticizer or a second tackifying resin having a lower glass transition temperature than the first tackifying resin. The adhesive has not more than 4.5 weight percent poly isobutylene or a poly isobutylene copolymer, based on the total weight of the adhesive, or is free of polyisobutylene and a polyisobutylene copolymer.

[0013] In another aspect, the present disclosure provides an adhesive. The adhesive includes a styrenic block copolymer including a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated, a first tackifying resin, and at least one of precipitated amorphous silica or a precipitated amorphous silicate. The at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified, or the adhesive further comprises a surface modifying agent, or the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified and the adhesive further comprises a surface modifying agent.

[0014] In another aspect, the present disclosure provides an adhesive. The adhesive includes a styrenic block copolymer including a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated, a first tackifying resin, at least one of precipitated amorphous silica or a precipitated amorphous silicate, and natural rubber.

[0015] In another aspect, the present disclosure provides a tape. The tape includes the adhesive disposed on a tape backing.

[0016] In another aspect, the present disclosure provides a process of making a tape. The process includes applying the adhesive described herein as a hot melt on a tape backing to provide the tape.

[0017] In this application:

[0018] 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".

[0019] The phrase "comprises at least one of followed by a list including the conjunction “or” refers to comprising any one of the items in the list and any combination of two or more items in the list. The phrase "at least one of followed by a list including the conjunction “or” refers to any one of the items in the list or any combination of two or more items in the list.

[0020] The term “styrenic” as used herein includes polymers and copolymers of substituted styrene monomers and / or unsubstituted styrene.

[0021] The term “crosslinking” refers to joining polymer chains together by covalent chemical bonds to form a network polymer. A crosslinked polymer is generally characterized by insolubility but may be swellable in the presence of an appropriate solvent. The term “crosslinked” includes partially crosslinked. The terms “thermoplastic elastomeric block copolymer”, “stryenic block copolymer”, and “thermoplastic elastomer” may be used interchangeably.

[0022] The term “bio-based” when referring to a material is an organic material in which the carbon derives from CO2 recently fixed (on a human scale) by photosynthesis from the atmosphere. On earth, this CO2 is captured or fixed by plants. At sea, CO2 is captured or fixed by bacteria or plankton carrying out photosynthesis. A biomaterial (100% carbon of natural origin) has a14C / 12C isotope ratio greater than 1 x 10'12, typically of approximately 1.2 x 10'12, while a fossil material has a zero ratio. Indeed, the isotope14C is formed in the atmosphere and is then integrated by photosynthesis, according to a time scale of a few decades at most. The half-life of14C is 5730 years. Thus, materials resulting from photosynthesis, namely plants in general, necessarily have a maximum14C isotope content.

[0023] Pressure-sensitive adhesives (PSAs) are generally known to possess the following desirable properties: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be cleanly removable from the adherend. Materials that have been found to function well as PSAs are polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power.

[0024] All numerical ranges are inclusive of their endpoints and nonintegral values between the endpoints unless otherwise stated (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0025] Detailed Description

[0026] The adhesive of the present disclosure includes a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated. The adhesive can include a single block copolymer or a mixture of two or more block copolymers. In some embodiments, at least one block copolymer in the adhesive is a block copolymer comprising a conjugated diene midblock and two or more polystyrene end blocks. The conjugated diene midblock is generally a rubbery block (or low-Tg block), and the polystyrene end blocks are sometimes referred to as glassy blocks or high-Tg blocks.

[0027] While the present disclosure is not to be bound by theory, it is believed that at the service temperature of some embodiments of the adhesive, the block copolymer microphase separates into ordered nanoscale domains that include rubbery block domains and glassy block domains. When microphase separated, these copolymers form elastic, dimensionally stable solids that display significant shear strength. Unlike chemically crosslinked rubbers, the block copolymers are capable of being reversibly melted and re-solidified with temperature; thus, they are known as thermoplastic elastomers. Thus, in some embodiments, the block copolymers as described herein are not covalently crosslinked.

[0028] In some embodiments, the block copolymer is a linear block copolymer of general formula (S-R)m-S where S is a polystyrene block, R is a rubbery block, and m is a value of at least 1. Variable m can be from 1 to 10, 1 to 5, 1 to 3, or in some embodiments, less than, equal to, or greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. In some embodiments, the linear block copolymer is a triblock copolymer wherein m is 1 and can also be represented by formula S-R-S.

[0029] In some embodiments, the block copolymer can be a star (also known as a radial or multi-arm) block copolymer of general formula (S-R)n-Y where each R and S are the same as defined above, n is an integer equal to at least 3, and Y is the residue of a multifunctional coupling agent used in the formation of the star block copolymer. The variable n represents the number of arms in the star block copolymer and can be from 3 to 10, from 3 to 8, from 3 to 6, or in some embodiments, less than, equal to, or greater than 3, 4, 5, 6, 7, 8, 9, or 10.

[0030] In the block copolymer, including any of those described above, the polystyrene blocks can have the same or different molecular weights. In some embodiments, each polystyrene block independently has a weight average molecular weight of 4,000 to 50,000 grams per mole. Similarly, if there is more than one midblock (e.g., rubbery block), the midblocks can have the same or different molecular weights. In some embodiments, each midblock independently has a weight average molecular weight of 5,000 to 500,000 grams per mole.

[0031] Generally, each conjugated diene block has a glass transition temperature (Tg) that is less than ambient temperature. For example, the glass transition temperature can be less than 20°C, less than 0°C, less than -10 °C, or less than -20 °C, less than -40 °C, less than -60 °C, or in some embodiments, less than, equal to, or greater than -60 °C, -55 °C, -50 °C, -45 °C, -40 °C, -35 °C, -30 °C, -25 °C, -20 °C, -15 °C, -10 °C, -5 °C, 0 °C, 5 °C, 10 °C, 15 °C, or 20 °C. The glass transition temperature can be determined using conventional methods known in the art, including Differential Scanning Calorimetry or Dynamic Mechanical Analysis.

[0032] In some embodiments, each midblock in the block copolymer is the polymerized product of a conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof. The conjugated diene often contains 4 to 12 carbon atoms. Examples of useful conjugated dienes include butadiene, isoprene, 2-ethylbutadiene, 1 -phenylbutadiene, 1,3 -pentadiene, 1,3 -hexadiene, 2,3-dimethyl- 1,3 -butadiene, 3 -ethyl- 1,3 -hexadiene and combinations thereof. Each midblock can be a homopolymer or copolymer. The midblock may be hydrogenated. In some embodiments, the midblock comprises at least one of poly(butadiene), poly(isoprene), poly(2-ethylbutadiene), poly(l-phenylbutadiene), poly(l,3- pentadiene), poly ( 1 ,3 -hexadiene), poly (2,3 -dimethyl- 1 ,3 -butadiene), poly (3 -ethyl- 1 ,3 -hexadiene), poly(ethylene / propylene), poly(ethylene / butylene), or poly(isoprene / butadiene). In some embodiments, the midblock comprises at least one of polybutadiene, polyisoprene, poly(isoprene / butadiene), poly(ethylene / butylene), or poly(ethylene / propylene). The glass transition temperature of each styrenic block is generally at least 50 °C, at least 60 °C, at least 70 °C, at least 80 °C, at least 90 °C, at least 100 °C, or in some embodiments, less than, equal to, or greater than 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, or 100 °C.

[0033] Styrene monomers useful for making the polystyrene blocks may be unsubstituted or substituted. Useful styrene monomers at least 8 carbon atoms and in some embodiments contain at least 10 carbon atoms or at least 12 carbon atoms and up to 18 carbon atoms, up to 16 carbon atoms, or up to 14 carbon atoms. Examples of suitable styrene monomers include styrene, vinyltoluene (e.g., 2, 3, or 4- vinyltoluene), alpha-methyl styrene, 2,4-dimethyl styrene, ethyl styrene, 2,4-diethyl styrene, 3,5-diethyl styrene, alpha-2-methyl styrene, 4-tert-butyl styrene, 4-isopropyl styrene, and combinations thereof. Each polystyrene block can be a homopolymer or a copolymer. In some embodiments, the polystyrene end blocks each comprise at least one of unsubstituted polystyrene, poly(vinyltoluene), poly(alpha- methylstyrene), poly(2,4-dimethylstyrene), poly(ethylstyrene), poly(2,4-diethylstyrene), poly(3,5- diethylstyrene), poly(4-tert-butylstyrene), or poly(4-isopropyl styrene). In some embodiments, the polystyrene blocks each comprise unsubstituted polystyrene. In some embodiments in which one or more polystyrene blocks comprises a copolymer, at least 50 weight percent (wt%) (in some embodiments, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt% or at least 99 wt%) of the monomeric units are derived from styrene.

[0034] Polystyrene blocks can represent from 5 wt% to 50 wt% of the block copolymer. With such an amount of polystyrene in the block copolymer, an excellent balance of cohesive strength and modulus may be achieved. The block copolymer can have a polystyrene block content of from 7 wt% to 40 wt%, 9 wt% to 33 wt%, 13 wt% to 25 wt%, or in some embodiments, less than, equal to, or greater than 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 27 wt%, 30 wt%, 32 wt%, 35 wt%, 37 wt%, or 40 wt%, based on the total weight of the block copolymer.

[0035] In addition to the styrenic blocks and the conjugated diene blocks, star block copolymers include a residue of a multifunctional coupling agent Y. The coupling agent often has multiple carbon-carbon double bonds, carbon-carbon triple bonds, or other groups that can react with carbanions of a living polymer that may be used to form the star block copolymers. The multifunctional coupling agents can be aliphatic, aromatic, heterocyclic, or a combination thereof. Examples of suitable coupling agents include polyvinyl acetylene, diacetylene, di(meth)acrylates (e.g., ethylene dimethacrylate), divinyl benzene, divinyl pyridine, and divinyl thiophene. Other useful coupling agents include multi-functional silyl halide (e.g., tetrafunctional silyl halide), polyepoxides, polyisocyanates, polyketones, polyanhydrides, polyalkenyls, and dicarboxylic acid esters.

[0036] The weight average molecular weight of the block copolymer is often not more than 1,200,000 grams per mole (g / mol). In some embodiments, the weight average molecular weight is not more than 1,050,000 g / mol, 900,000 g / mol, 800,000 g / mol, 600,000 g / mol, or 500,000 g / mol. In some embodiments, the weight average molecular weight of the block copolymer is at least 75,000 g / mol, at least 100,000 g / mol, at least 200,000 g / mol, at least 300,000 g / mol, or at least 400,000 g / mol. The weight average molecular weight of the block copolymer can be from 75,000 g / mol to 1,200,000 g / mol, from 100,000 to 1,000,000 g / mol, from 100,000 to 900,000 g / mol, or from 100,000 to 500,000 g / mol.

[0037] In some embodiments, the block copolymer comprises at least one of a polystyrene-containing triblock copolymer or a polystyrene-containing star block copolymer, wherein the polystyrene-containing triblock copolymer and polystyrene-containing star block copolymer independently comprise a block of at least one of polyisoprene, polybutadiene, poly(ethylene / propylene), poly(ethylene / butylene), or polyisobutylene. In some embodiments, the block copolymer comprises at least one of a polystyrene- containing triblock copolymer or a polystyrene-containing star block copolymer, wherein the polystyrene- containing triblock copolymer and polystyrene-containing star block copolymer independently comprise a block of at least one of polyisoprene or polybutadiene. In some embodiments, the block copolymer comprises at least one of a polystyrene-polyisoprene-polystyrene triblock copolymer or a polystyrene- polybutadiene-polystyrene triblock copolymer. In some embodiments, the block copolymer comprises at least one of a polystyrene-polyisoprene-polystyrene star block copolymer or a polystyrene-polybutadiene- polystyrene star block copolymer. In some embodiments, the block copolymer comprises at least one of a polystyrene-polyisoprene-polystyrene triblock copolymer or a polystyrene-polyisoprene-polystyrene star block copolymer.

[0038] The styrenic block copolymer can be present in any suitable amount in the adhesive. In some embodiments, the block copolymer is present in amount of from 5 wt% to 60 wt%, from 10 wt% to 60 wt%, from 15 wt% to 55 wt%, or 20 wt% to 50 wt%, based on the total weight of the adhesive.

[0039] In some embodiments, the adhesive of the present disclosure further includes a second block copolymer that is a diblock copolymer. The diblock copolymer generally has a single polystyrene block and a single rubbery block and can be represented here by the chemical structure S-R, wherein S and R are as defined above in any of their embodiments.

[0040] The polystyrene block content in the diblock copolymer can be from 10 wt% to 50 wt%, from 10 wt% to 40 wt%, from 15 wt% to 50 wt%, from 15 wt% to 40 wt%, from 20 wt% to 50 wt%, from 20 wt% to 40 wt%, or in some embodiments, less than, equal to, or greater than 10 wt%, 12 wt%, 15 wt%, 17 wt%, 20 wt%, 22 wt%, 25 wt%, 27 wt%, 30 wt%, 32 wt%, 35 wt%, 37 wt%, or 40 wt% relative to the overall weight of the diblock copolymer. The weight average molecular weight of the diblock copolymer can be from 75,000 g / mol to 250,000 g / mol, from 100,000 g / mol to 250,000 g / mol, from 125,000 g / mol to 250,000 g / mol, or from 125,000 g / mol to 200,000 g / mol. In some embodiments, the diblock copolymer is present in an amount of from 1 wt% to 25 wt%, from 3 wt% to 15 wt%, or from 5 wt% to 10 wt% based on the total weight of the block copolymer and the diblock copolymer.

[0041] Suitable materials for use as the block copolymer alone or in combination are commercially available, for example, under the trade designation “KRATON” (e.g., “KRATON DI 161”, “Dll 18”, “DI 119”, “DI 126”, and “A1535”) from Kraton Performance Polymers (Houston, TX, USA), under the trade designation “SOLPRENE” (e.g., “SOLPRENE S-1205”) from Dynasol (Houston, TX, USA), under the trade designation “QUINT AC” from Zeon Chemicals (Louisville, KY, USA), and under the trade designations “VECTOR” and “TAIPOL” from TSRC Corporation (New Orleans, LA, USA).

[0042] The adhesive of the present disclosure includes a first tackifying resin. Tackifying resins generally refer to materials that are compatible with the thermoplastic elastomeric block copolymer and have a number average molecular weight of up to 10,000 grams per mole. In some embodiments, the tackifying resin has a softening point of at least 70 °C as determined using a ring and ball apparatus and a glass transition temperature of at least 25 °C as measured by differential scanning calorimetry. In some embodiments, the tackifying resin has a softening point from 80 °C to 160 °C, from 100 °C to 150 °C, or from 115 °C to 145 °C. The tackifying resins are typically amorphous. In some embodiments, the number average molecular weight of the tackifying resin is up to about 5000 grams / mole, 4000 grams / mole, 2500 grams / mole, 2000 grams / mole, or 1500 grams / mole. In some embodiments, the number average molecular weight is in the range of 200 to 5000 gram / mole, in the range of 200 to 4000 grams / mole, in the range of 200 to 2000 grams / mole, or in the range of 200 to 1500 gram / mole. Number average molecular weights are determined using gel permeation chromatography according to methods known to a person skilled in the art.

[0043] In some embodiments, the first tackifying resin comprises at least one of a polyterpene (e.g., those based on a-pinene, p-pinene, or limonene), a terpene phenolic tackifier, an aromatic-modified terpene resin, a rosin acid, a rosin ester, a metal rosinate, a tall oil ester, an aliphatic hydrocarbon resin (e.g., those based on cis- or trans-piperylene, isoprene, 2-methyl-but-2-ene, cyclopentadiene, dicyclopentadiene, or combinations thereof), an aromatic resin (e.g. those based on styrene, a-methyl styrene, methyl indene, indene, coumarone, or combinations thereof), or a mixed aliphatic -aromatic hydrocarbon resin. The aromatic hydrocarbon resins may be C9-type petroleum resins obtained by copolymerizing a C9 fraction produced by thermal decomposition of petroleum naphtha, and aliphatic hydrocarbon resins may be C5-type petroleum resins obtained by copolymerizing a C5 fraction produced by thermal decomposition of petroleum naphtha. Mixed aliphatic / aromatic resins may be C5 / C9-type petroleum resins obtained by polymerizing a combination of a C5 fraction and C9 fraction produced by thermal decomposition of petroleum naphtha. Any of these tackifying resins may be hydrogenated (e.g., partially or completely).

[0044] In some embodiments, the first tackifying resin is a bio-based tackifying resin. Examples of biobased tackifying resins include at least one of a rosin acid, a rosin ester, a polyterpene, a terpene phenolic resin, or an aromatic-modified terpene resin, any of which may be hydrogenated (e.g., partially or completely). Any of these resins can be obtained from biological sources and can be bio-based. In some embodiments, the tackifying resin is a rosin acid, a rosin ester, tall oil ester, or a polyterpene, wherein the rosin acid, the rosin ester, the tall oil ester, or the polyterpene is hydrogenated or not hydrogenated. In some embodiments, the tackifying resin is a rosin acid, a rosin ester, or tall oil ester, wherein the rosin acid, the rosin ester, or the tall oil ester is hydrogenated or not hydrogenated.

[0045] The term rosin, as employed herein, includes natural rosin, refined or unrefined (refined rosin will usually contain, by weight, about 90% of rosin acids and about 10% of inert material), such as natural wood rosin, natural gum rosin, and tall oil rosin; modified rosin, refined or unrefined, such as disproportionated rosin, hydrogenated rosin, and polymerized rosin; and the pure or substantially pure acids, of which rosin is comprised, alone or in admixture. In some embodiments, the rosin includes the rosin acid C19H29COOH, in some embodiments, at least one of abietic acid, neoabietic acid, palustric acid, levopimaric acid, pimaric acid, or an isopimaric acid. In some embodiments, the rosin comprises dehydro- or hydrogenated rosin acids, for example, dehydroabietic acid, dihydroabietic acid, and tetrahydroabietic acid. Any of these acids can be esterified, for example, with methanol, triethylene glycol, glycerol, or pentaerythritol. In some embodiments, the tackifying resin is methyl abieate. The tackifying resin can also include a metal rosinate (sometimes referred to in the art as a metal resinate). The metal rosinate can be metal salt (e.g., zinc, calcium, or magnesium) of any of the rosins described above.

[0046] Terpene resins useful in the adhesive composition include polyterpene homopolymers, copolymers of more than one terpene monomer, copolymers of one or more terpene monomers and one or more additional monomers, and hydrogenated products of any of these polymers. Examples of terpene monomers useful for any of these terpene resins include a-pinene, P-pinene, dipentene, and limonene. Catalyzed cationic and anionic polymerizations of terpenes are known. Monomers suitable for copolymerization with terpenes include styrene, alpha-methylstyrene, vinyltoluene, and any of the other substituted styrene monomers listed above. Copolymers of terpenes with styrene and substituted styrene monomers are referred to herein as aromatic -modified terpene resins. Further monomers suitable for copolymerization with terpenes include phenols such as phenol, cresol, and bisphenol. Copolymers of terpenes with phenolic monomers are referred to herein as terpene phenolic resins. In some embodiments, the terpene resin is an aromatic-modified terpene resin. In some embodiments, the terpene resin is a copolymer of a terpene and at least one of styrene or a substituted styrene.

[0047] In some embodiments, the first tackying resin is selected to be compatible with the midblock of the thermoplastic elastomeric block copolymer. The compatibility of the tackifying resin with the midblock can be determined by measuring the effect of the tackifying resin on the glass transition temperature of the midblock. If a tackifying resin is compatible, it will generally increase the glass transition temperature of the midblock as measured by Differential Scanning calorimetry or Dynamic Mechanical Analysis.

[0048] Some suitable tackifying resins are commercially available under the trade designations "ARKON" from Arakawa Chemical Industries Co., Ltd. (Osaka, Japan); "ESCOREZ" from ExxonMobil Chemical Company (Spring, Texas); "REGALREZ" and "PICCOTAC" from Eastman Chemical (Kingsport, TN); "WINGTACK" from Cray Valley (Exton, PA); and others listed in the Examples, below. Examples of suitable terpene resins and hydrogenated terpene resins include those available under the trade designation CLEARON (e.g., CLEARON P150 and P135) from Yasuhara Chemical Company, Ltd. in Hiroshima, Japan. Further examples of terpene resins include those available from Pinova, Brunswick, GA, under the trade designation “PICCOLYTE” in grades “Al 15”, “A125”, and “A135” and corresponding grades from Foreverest Resources Ltd., Fujian, China. Examples of suitable terpene phenolic resins include those available under the trade designation YS POLYSTER (e.g., POLYSTER T115, T160, T130, S145, and G150) from Yasuhara Chemical Company, Ltd. Examples of suitable aromatic -modified terpene resins include those available under the trade designations "YS RESIN TO” and “YS RESIN TR" from Yasuhara Chemical Co., Ltd. Examples of suitable rosins include “GA90A”, “GA100A”, “GA85HS”, “GB-120”, “GA-AT”, “KK”, “D-125”, “D135”, and “D160” from Arakawa Chemical Industries, Co., Ltd. (Osaka, Japan) and similar resins from other suppliers.

[0049] In some embodiments, the adhesive includes at least about 20 wt% and up to about 65 wt% of the first tackifying resin, based on the total weight of the adhesive. In some embodiments, the first tackifying resin is present in a range from 20 wt% to 60 wt%, 30 wt% to 60 wt%, 40 wt% to 60 wt%, 35 wt% to 65 wt%, or 35 wt% to 55 wt%, based on the total weight of the adhesive.

[0050] While aromatic tackifying resins may be useful, in some embodiments, in combination with other tackifying resins described above, in some embodiments, the adhesive of the present disclosure does not include a significant amount of aromatic resins reported to reinforce the styrene end blocks of the block copolymer. Such aromatic resins include coumarone-indene resins, poly alpha methyl styrene, polystyrene resins, vinyl toluene-a-methyl styrene copolymers, polyindene resins, and polyphenylene ether resins such as unsubstituted polyphenylene ether resins and substituted polyphenylene ether resins (e.g., poly(2,6-dimethyl-l,4-phenylene)ether). In some embodiments, the adhesive includes not more than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 wt% of any of these aromatic resins, except where any of these is part of a mixed aliphatic-aromatic hydrocarbon resin. In some embodiments, the adhesive is free of any one or more of these aromatic resins. In some embodiments, the adhesive includes not more than 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.1 wt% of poly(alpha-methylstyrene) that is not incorporated into the styrenic block copolymer. In some embodiments, the adhesive is free of poly (alpha-methylstyrene).

[0051] The adhesive of the present disclosure includes precipitated amorphous silica, a precipitated amorphous silicate, or a combination thereof. Precipitated amorphous silica and precipitated amorphous silicates have a bulk density typically in a range from 1.9 grams per cubic centimeter (g / cc) to 2.1 g / cc and a purity of less than 99, 98, 97, or 96 percent, in some embodiments, in a range from 90 to 95 percent. In some embodiments, the precipitated amorphous silica or precipitated amorphous silicate has a Brunauer, Emmett, and Teller (BET) specific surface area in a range from 35 square meters per gram (m2 / g) to 400 m2 / g, 55 m2 / g to 400 m2 / g, 50 m2 / g to 300 m2 / g, 100 m2 / g to 300 m2 / g, 50 m2 / g to 250 m2 / g, 150 m2 / g to 250 m2 / g, or about 180 m2 / g. BET surface areas can be determined by ISO 9277. The particles of precipitated amorphous silica and precipitated amorphous silicates are generally porous. In some embodiments, the precipitated amorphous silica or precipitated amorphous silicate is in the form of aggregated particles. Aggregates of precipitated amorphous silica or precipitated amorphous silicate particles can have a size in a range from one micrometer to 100 micrometers, and these aggregated particles can form agglomerates.

[0052] Precipitated amorphous silica is precipitated from a solution of sodium silicate using acid. Precipitated amorphous silica is known to have a structure that is somewhat branched and not spherical, and it is also porous. This process of producing amorphous silica results in different structure and properties of the silica than those produced by other methods. For example, fumed silica is also known as pyrogenic silica and is produced in by pyrolyzing silicon tetrachloride, for example, in an oxygenhydrogen flame. Fumed silica typically is a light fluffy solid with a bulk density of up to 0.19 g / cc. It forms branched aggregates with sizes in the range from 150 to 300 nanometers, which can form agglomerates. The purity of fumed silica is typically greater than 99 percent. Fumed silica requires high shear in order to be dispersed into elastomers, and such high shear can break down the elastomer and decrease its molecular weight. In comparison to fumed silica, precipitated amorphous silica typically has more surface hydroxy groups, higher density, higher moisture content, higher porosity within the particle, and lower impact on viscosity than equal weights of fumed silica. The difference between precipitated amorphous silica and fumed silica is understood by a person skilled in the art. Furthermore, precipitated amorphous silica is distinguished from colloidal silica in that the silica particles are not dispersed in water. Colloidal silica is stabilized to remain as primary particles (i.e., not aggregated particles) having a size of 1 nanometer to 100 nanometers.

[0053] Precipitated amorphous silicate is precipitated from a solution of sodium silicate using metal salts such as calcium chloride or aluminum sulfate. Acid may or may not be used in combination with these salts. In some embodiments, the precipitated amorphous silicate is calcium silicate or sodium aluminum silicate.

[0054] Suitable precipitated amorphous silica and precipitated amorphous silicates are commercially available from a variety of sources such as PPG Silica Products, Monroeville, PA, Evonik Corporation, Parsippany, NJ, and Hifull Corporation, Yichang City, China. Sodium silicate can be obtained from a variety of sources, including green sources such as rice husk ash.

[0055] In some embodiments, precipitated amorphous silica and precipitated amorphous silicates useful for practicing the present disclosure generally have a hydrophilic surface. In some embodiments, the precipitated amorphous silica is not chemically treated to install hydrophobic groups on the surface. As shown in the Examples below, non-treated precipitated amorphous silica can significantly increase the shear holding power of styrenic block copolymer-based adhesives while maintaining other adhesion properties despite the hydrophobic nature of styrenic block copolymer-based adhesives and hydrophilic nature of precipitated amorphous silica. In some embodiments, the precipitated amorphous silica and precipitated amorphous silicate useful for practicing the present disclosure is surface-modified to have hydrophobic groups on the surface. Examples of hydrophobic groups include alkyl groups (e.g., linear, branched, and / or cyclic alkyl groups), aromatic groups (e.g., phenyl), and polymeric groups. The precipitated amorphous silica and precipitated amorphous silicate may be surface modified by a variety of techniques and with a variety of known reagents including silane, zirconate, titanate, and aluminate coupling agents. Typically, such materials chemically react with the silica or silicate surface thereby decorating it with one or more types of organic groups. A wide variety of silanes are available commercially including those which have reactive functional groups and oligomeric and polymeric silanes. More than one type of silane or other surface-modifying agent may be used together to functionalize the surface as desired for a particular adhesive. Examples of suitable silanes for treating the precipitated amorphous silica and precipitated amorphous silicate are hydrocarbon-bearing silanes (e.g., alkyl trialkoxy silanes such as octyl trimethoxy silane, phenyl trialkoxy silanes, and cycloaliphatic trialkoxy silanes), epoxy-functional silanes, aminofunctional silanes, vinyl-functional silanes, and isocyanato-functional silanes. Polymers containing silanes and organofunctional silanes that are useful along with methods of treating particles are described further in U.S. Pat. No. 10,703,927 (Ali et al.).

[0056] The choice of coupling agent for any given formulation depends on the choice of styrenic block copolymer and the tackifying resin(s). For example, C5 hydrocarbon tackifying resins are nonpolar, and it may be advantageous to select nonpolar or lipophilic silanes (e.g., alkyl chain silanes, phenyl silanes, and silanes containing cycloaliphatic groups) to treat silica or silicates used in C5 hydrocarbon tackifying resins. The organic component of the silane chosen may be selected to have a solubility parameter similar to the tackifying resin that is used in the adhesive. Examples of useful silane coupling agents for treating the precipitated amorphous silica and precipitated amorphous silicate include those obtained from Wacker Chemie AG, under the trade designation “SILRES 1316” from Wacker Chemie AG; those obtained from Evonik Industries under the trade designations “SI 69”, “SI 363”, “DYNASYLAN DAMO”; and “DYNASYLAN 1189”; those obtained from Shin-Etsu Chemical Company under the trade designation “KBM-1003”; and those described in the Examples, below. Examples of useful commercially available precipitated silicas that are pre-reacted with silanes include those available from Evonik Industries under the trade designations “COUPSIL 8113” and “COUPSIL VP6411”.

[0057] Titanate and zirconate organometallic surface modifying agents are also useful for treating the precipitated amorphous silica and precipitated amorphous silicate and are commercially available from Kenrich Petrochemicals under the trade designation “KEN-REACT”. Examples of useful titanate and zirconates include monoalkoxy and neoalkoxy titanates and zirconates. These materials can be directly added to solvent borne or hot melt formulations, and advantageously, there is no hydrolysis step required to react these with a silica or silicate surface. Further examples of useful surface modifying agents for precipitated amorphous silica and precipitated amorphous silicate include certain functionalized oligomers and polymers. These include maleated olefin copolymers, maleated polybutadienes, maleated rubbers, maleic anhydride copolymers, sulfonated polymers, and maleated acrylonitrile copolymers. Maleated olefin copolymers such as those obtained on the trade designations “ROYALTUF 527” and “ROYALTUF 485” from SI Group Inc., Schenectady, NY, have olefinic polymer chains that are compatible with the non-aromatic portion of the sytrenic block copolymer. Furthermore, the maleic anhydride group of these polymers adhere to the surface of the precipitated amorphous silica or silicate. Another useful polymer class for surface treating the precipitated amorphous silica and silicates are polyhydroxyethers. These typically are produced by homopolymerization or copolymerization of bisphenol A based diepoxides. They are commercially available from Huntsman or the Gabriel company under the trade name Gabriel “PHENOXY PKHH”. It is believed that the polar hydroxy groups of the polymer can associate with the polar surface of the precipitated amorphous silica and silicates through noncovalent bonds. It is also believed that the hydroxyl group can chemically react with the surface silanols present on the precipitated amorphous silica and silicates at high temperatures. The phenoxy polymers can be directly added to the melt in an extrusion process or dissolved into a solvent such as toluene when formulating solvent borne adhesives. Alternatively, the hydroxy group on the polymer backbone can readily be reacted with an isocyanato silane such as 3 -isocyanatopropyltrimethoxy silane to form a silane functional polymer. In general, polyhydroxyethers polymers are useful in the adhesives of the present disclosure, because of their unique nature attributed to their composition. They are fairly hydrophobic due to the aromatic groups in the backbone, yet they have some polarity due to the oxygen groups and can also hydrogen bond due to the hydroxyl groups that are present. As a result, they improve the cohesive strength and Tg of the adhesive and can serve as a compatibilizer or interfacial modifier when use in small amounts in a formulation as well.

[0058] In addition to the above, the precipitated amorphous silica or silicate may be surface modified with aromatic acids such as benzoic acid, salicylic acid, picolinic acid, p-aminobenzoic acid, naphthoic acid, p-tolenesulfonic acid, mandelic acid, and / or derivatives thereof.

[0059] Different classes of surface modifying agents may be used in combination with one another. It is believed that the modifying the surface of the precipitated amorphous silica or silicate with a tethered “organic” layer provides several advantages including improved adhesive and cohesive properties, higher toughness, improved quality with better dispersion of the precipitated amorphous silica or silicate within the adhesive, and improved (lower) melt viscosity when the adhesive is manufactured by melt extrusion or melt processing.

[0060] In some embodiments, the precipitated amorphous silica, the precipitated amorphous silicate, or the combination thereof is present in an amount ranging from 1 wt% to 22 wt%, based on the total weight of the adhesive. In some embodiments, the precipitated amorphous silica and / or precipitated amorphous silicate is present in an amount ranging from 1 wt% to 20 wt%, 2 wt% to 18 wt%, 3 wt% to 17 wt%, 4 wt% to 16 wt%, or 5 wt% to 15 wt%, or 6 wt% to 15 wt%, based on the total weight of the adhesive. When both precipitated amorphous silica and silicates are present, these ranges reflect the combined amounts.

[0061] In some embodiments, the adhesive of the present disclosure includes at least one of a plasticizer or a second tackifying resin having a lower Tgthan the first tackifying resin. The second tackifying resin has a lower Tgrelative to the first tackifying resin as measured by any suitable method. Herein, a plasticizer is defined as an organic molecule that is miscible with the styrenic block copolymer and has a Tgless than - 30 °C as determined by Differential Scanning Calorimetry (DSC). The second tackifying resin behaves as a tackifier and, in some embodiments, has a Tgof -30 °C to 25 °C as determined by DSC. A glass transition was measured on a Differential Scanning Calorimeter (TA Instruments Model Q100, Ta Instruments, New Castle, DE, USA) as a shift in the profile upon heating at 5 °C per minute, where the heat profile after the transition was parallel but shifted lower compared to before the transition. The Tgis the inflection point of the shift in the heat flow profile. A plasticizer is not the same as a tackifying resin, which is understood by those skilled in the art. In general, the difference between a tackifying resin and a plasticizer is that the addition of a tackifying resin increases the Tgof the adhesive’s rubber phase while the addition of the plasticizer decreases the Tgof the adhesive’s rubber phase.

[0062] Examples of suitable plasticizers include those described in the Dictionary of Rubber, K. F. Heinisch, pp. 359, John Wiley & Sons, New York (1974); oils; elastomer oligomers; and waxes. Examples of suitable plasticizing oils include paraffinic oils, aromatic oils, and naphthene oils such as those available, for example, from Process Oils Inc., Houston, TX. The plasticizing oil may be selected based on viscosity, for example. In some embodiments, the adhesive of the present disclosure includes a vegetable oil, which is a composition comprising triple esters of fatty acids and glycerol (in other words, triglycerides). Examples of suitable vegetable oils include soybean oil, castor oil, linseed oil, sunflower oil, palm oil, coconut oil, olive oil, com oil, peanut oil, rapeseed oil, canola oil, and safflower oil. In some embodiments, the vegetable oil contains oleic acid as a fatty acid component of the triglyceride ester. In some embodiments, the vegetable oil comprises at least one of canola oil, castor oil, peanut oil, com oil, soybean oil, coconut oil, palm oil, sunflower oil, or safflower oil. In some embodiments, the plasticizer is a multifunctional ester synthetic oil comprising an ester of oleic acid.

[0063] Further examples of suitable plasticizers include esterified fatty acids and polymerized vegetable oil. Useful fatty acids may contain 6 to 30, 10 to 22, 14 to 22, or 16 to 18 carbon atoms and may be derived from a vegetable oil (e.g., sunflower oil, rapeseed oil, linseed oil, and soybean oil). Examples of suitable fatty acids include myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and ricinoleic acid. The fatty acid may be hydrogenated or not hydrogenated. Polymerized vegetable oils, including any of those described above, can be made by heating a vegetable oil in the absence of oxygen and at a temperature above 200 °C. There are a wide variety of ester plasticizers including aromatic esters with widely different characteristics including molecular weight, polarity, and viscosity. Vegetable oils such as canola oil and related ester plasticizers, in some embodiments, have advantages over hydrocarbon oils. First, vegetable oils, particularly those with some unsaturation, are a prime source of nutrient for fungi and some bacteria and are known to promote the degradation of compounded rubbers. Hence, they cause biodegradation of rubbers particularity in moist and warm areas such as tropics or industrial compost piles, which is desirable for biodegradable adhesives and tapes. In styrenic block copolymer adhesive formulations, the oil, tackifiers, and polymer midblock typically exist as one compatible phase, and the oil is essentially fully dissolved in the adhesive formulation. It is thus desirable to use a vegetable oil to promote biodegradation, and it is also desirable to use at least 4 wt% vegetable oil in an adhesive formulation to promote an acceptable rate of biodegradation. It is also desirable to optionally include natural rubber in the adhesive formulation to further promote consumption of the adhesive by microbes including fungi. In addition, other essential minerals and nutrients essential to microbial growth may compounded into the adhesive formulation as described in further detail below.

[0064] Vegetable oils are also good dispersants for precipitated silica. Furthermore, they are excellent lubricants and can help with reduction of the melt viscosity particularly with formulations that include natural rubber. Oils of vegetable origin can be used to offset the increased viscosity that comes with the added precipitated amorphous silica, especially at higher silica loadings. Other additives may be used alone or in conjunction with vegetable oils to optimize or improve the rheological properties of a hot melt processed adhesive including organozinc compounds, other oils including hydrocarbon oils, aromatic resins, low molecular weight tackifiers, ester plasticizers, titanates, carbon dioxide, and supercritical carbon dioxide. These additives may be further useful for the extrusion of a hot melt adhesive at high coating speeds or under higher shear conditions.

[0065] The second tackifying resin can be of any of the classes described above for the first tackifying resin. In some embodiments, the second tackifying resin comprises at least one of a polyterpene, a liquid C5 aliphatic hydrocarbon resin, or a rosin ester, for example, of an alkylene glycol (e.g., triethylene glycol or dipropylene glycol). Suitable liquid C5 aliphatic hydrocarbon resins include those obtained under the trade designation “WINGTACK 10” from Resin Solutions, LLC, Exton, PA, and "PICCOTAC 1020" from Eastman Chemical.

[0066] In some embodiments, the plasticizer and / or second tackifying resin is present in the adhesive in a range from 1 wt% to 25 wt%, 2 wt% to 25 wt%, 2 wt% to 20 wt%, 2 wt% to 15 wt%, or 1 wt% to 10 wt%, based on the total weight of the adhesive. When both the plasticizer and the second tackifying resin are present, these ranges reflect the combined amounts. Optionally, the adhesive may contain more than one tackifying resin and / or more than one plasticizer to optimize certain properties such as tack or peel strength. In some embodiments, the adhesives are readily biodegradable in an anaerobic or aerobic environment. For example, when the adhesive includes a vegetable oil as a plasticizer, biodegradability can be enhanced. In some embodiments, the adhesive further comprises other additives know to promote or support bacteria or fungal growth such as natural rubbers, starches, salts such as potassium phosphate, humectants, minerals, fatty acids and their salts, low molecular weight ester waxes (e.g., methyl 12- hydroxystearate), and salts of amino acids. Suitable starches include natural starches such as com, tapioca, rice, wheat, soybean, pea, potato, sweet potato, sago, or amaranth starch. Suitable humectants include polyethylene glycol) and derivatives thereof and glycerin and derivatives thereof. In some embodiments, the adhesive of the present disclosure comprises natural rubber. Natural rubber can be present in any suitable amount in the adhesive. In some embodiments, the block copolymer is present in amount of up to 70 wt%, from 5 wt% to 70 wt%, from 5 wt% to 60 wt%, from 10 wt% to 60 wt%, from 15 wt% to 55 wt%, or 20 wt% to 50 wt%, based on the total weight of the adhesive. To further promote the rate of biodegradation, the adhesive may contain discontinuous or continuous natural fibers that are known to be biodegradable such as cotton fibers, hemp, bamboo, and rayon fibers. Cotton fiber may readily be used in a tape as a reinforcement (in scrim or chopped fiber form) and have beneficial water absorbency, strength, wicking effect, biodegradability, and ease of handling. In some of these embodiments, the adhesive of the present disclosure can have superior biodegradability than conventional adhesives based on styrenic block copolymers that are largely of synthetic origin and very hydrophobic and therefore degrade very slowly in landfill or compost sites when disposed of.

[0067] A number of adjuvants may also be useful in the adhesive of the present disclosure. Examples of such adjuvants include antioxidants, such as hindered phenols, amines, sulfur and phosphorous hydroperoxide decomposers, and butylated hydroxytoluene (BHT), and other inorganic fillers such as talc, zinc oxide, titanium dioxide, and aluminum oxide. Useful commercially available antioxidants include those available from BASF, Florham Park, NJ, under the trade designations "IRGANOX" and "IRGAFOS" such as "IRGANOX 1010" and “IRGANOX 1076”, those available from Songwon Ind. Co, Ulsan, Korea, under the trade designations “SONGNOX”, and dilaurylthiodipropionate. Adhesives of the present disclosure can also include at least one of pigments, dyes, ultraviolet absorbers, hindered amine light stabilizers, antimicrobial agents, flame retardants, and heat stabilizers, if desired. When present, typically the antioxidant is present in the adhesive in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the styrenic block copolymer. In some embodiments, the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is present in an amount that exceeds any other inorganic filler that may be present in the adhesive. In some embodiments, the adhesive is free of any inorganic filler other than the precipitated amorphous silica or the precipitated amorphous silicate. In some embodiments, the adhesive is not foamed. In some embodiments, the adhesive does not contain a chemical blowing agent, in some embodiments, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, diazoaminobenzene, benzenesulfonyl-hydrazide, or toluene-(4)-sulfonyl hydrazide, or the decomposed reaction product thereof. Other rubbers such as acrylonitrile butadiene rubber, ethylene propylene diene monomer rubber, and polychloroprene may also be included in the adhesive in some embodiments.

[0068] In some embodiments, the adhesive of the present disclosure is disposed on a tape backing. Accordingly, in some embodiments, the present disclosure provides a tape comprising the adhesive of the present disclosure as described above in any of its embodiments. The tape backing can be any polymeric film material, paper, or a polymer-cloth laminate. Polymeric materials suitable for the backing include polyesters; polyolefins (e.g., polyethylene, polypropylene); ethyl cellulose film; cellulose esters (e.g., cellulose acetate, cellulose acetate butyrate, and cellulose propionate); poly lactide, polyvinylidene chloride-vinyl chloride and / or acrylonitrile polymers such as saran; vinyl chloride polymers (e.g., poly(vinyl chloride) and copolymers of vinyl chloride and vinyl acetate); polyfluoroethylenes (e.g., polytetrafluoroethylene and poly trifluorochloroethylene); polyvinyl alcohol; polyamides such as nylon; polystyrenes such as the copolymers of styrene and isobutylene; regenerated cellulose; benzyl cellulose; cellulose nitrate; gelatin; glycol cellulose; flexible acrylate and methacrylates; urea aldehyde films; polyvinyl acetal; polyvinyl butyral. In some embodiments, the tape backing is a polymeric film comprising at least one of a polyolefin, polyester, polylactide, or poly(vinyl chloride). In some embodiments, the backing comprises polyethylene-laminated cloth. In some embodiments, the tape backing comprises at least one of paper, a nonwoven, polyester, poly(vinyl chloride), polypropylene (e.g., monoaxially oriented polypropylene or biaxially oriented polypropylene), polyethylene laminated cloth, or polylactide. In some embodiments, the tape backing comprises at least one of paper, polylactide, or a biodegradable polymer.

[0069] The term "nonwoven" when referring to a sheet or web means having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs can be formed from various processes such as meltblowing processes, spunbonding processes, spunlacing processes, and bonded carded web processes. The fibers can be made from any of the polymers described above for tape backings.

[0070] In some embodiments, the polymer film tape backing of the tape is surface treated before the adhesive is applied. Useful surface treatments include electrical discharge in the presence of a suitable reactive or non-reactive atmosphere (e.g., plasma, glow discharge, corona discharge, dielectric barrier discharge or atmospheric pressure discharge), ultraviolet light exposure, electron beam exposure, flame discharge, and scuffing. The surface treatment can be applied as the polymer film backing is being made or in a separate process. In some embodiments, the polymer film backing is surface treated using corona discharge. An example of a useful corona discharge process is described in U.S. Pat. No. 5,972,176 (Kirk et al.).

[0071] In some embodiments, the tape includes optional low-adhesion backsize. Low-adhesion backsizes are known to one of ordinary skill in the art and can be made from a variety of materials (e.g., a silicone, fluorochemical, or carbamate). Some examples of low-adhesion backsizes are described, for example, in U.S. Pat. Nos. 2,532,011 (Dahlquist), 2,607,711 (Hendricks), and 3,318,852 (Dixon).

[0072] A paper backing for the tape of the present disclosure can be any suitable paper, for example, crepe, paper kraft paper, or hemp paper. The paper may have any useful weight such as a weight of about 20 to 40 pounds per ream of 3000 square feet. The paper can be saturated with an aqueous emulsion of rubbers, for example, a mixture of carboxylated rubber latexes (e.g., carboxylated nitrile, styrene butadiene, and optionally acrylic rubber latexes) in a variety of ratios, optionally including polyethyleneglycol. Conventional additives such as pigments and antioxidants such as those described below can be included in the saturant. The aqueous saturant formulation may be 10% to 50% solids and may be applied to the paper at about 10% to 150% by weight, based on the weight of latex solids and dry paper weight. The saturated paper is typically then dried and cured at an elevated temperature up to about 180 °C. A conventional release coating is typically applied to one face of the impregnated paper backing. An example of a release coating formulation includes a 10:90 mixture of one acrylate (e.g., available from Dow Chemical Co., Midland, Mich., under the trade designation “RHOPLEX”) and a second acrylate (e.g., available from BASF, Florham Park, N.J., under the trade designation “ACRONAL S504”), which also contains some nitrile and butadiene rubbers. The mixture can be applied as an emulsion of about 15% to 50% solids, after which, the tape is again dried. Other suitable release coatings include waterbased polyurethane / acrylic dispersions such as those from Hitac Adhesives and Coatings, Santa Fe Springs, CA, under the trade designations “HITAC RA-13W”, “HITAC RA-15W”, and “HITAC RA- 42 W”.

[0073] In some embodiments, the adhesive is present on the tape backing in a range from 11 grams per square meter (gsm) to 150 gsm. Useful amounts of adhesive can be, for example, 11 gsm to 60 gsm, 20 gsm to 60 gsm, 20 gsm to 40 gsm, or 40 gsm to 60 gsm for paper and polymer film backings. For polymer / cloth laminates, useful amounts of adhesive can be, for example, 80 gsm to 150 gsm.

[0074] In some embodiments, the adhesive of the present disclosure can be prepared and applied to the tape backing out of organic solvent. Common organic solvents include aliphatic and alicyclic hydrocarbons (e.g., hexane, heptane, and cyclohexane), hydrocarbon solvents (e.g., benzene, toluene, xylenes, and d-limonene); acyclic and cyclic ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone, pentanone, hexanone, cyclopentanone, and cyclohexanone); ethers (e.g., diethyl ether, glyme, diglyme, diisopropyl ether, and tetrahydrofuran), esters (e.g., ethyl acetate and butyl acetate), sulfoxides (e.g., dimethyl sulfoxide), amides (e.g., N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone), halogenated solvents (e.g., methylchloroform, l,l,2-trichloro-l,2,2- trifluoroethane, trichloroethylene, and trifluorotoluene), and alcoholic solvents (e.g., methanol, ethanol, or propanol such as isopropanol). When the adhesive composition comprises solvent, the solvent is typically present in an amount of at least 50, 55, 60, 65, 70, or 75 percent by weight, based on the total weight of the adhesive composition. In some embodiments, the adhesive composition comprising solvent is applied to a tape backing as described above in any of their embodiments. The solvent is then typically removed by at least one of drying, evaporation, heating, or reduced pressure. If the adhesive of the present disclosure includes organic solvent, the weight percentages provided throughout this disclosure are based on the total weight of the adhesive, excluding any solvent that may be present.

[0075] In some embodiments, including embodiments in which the adhesive is prepared in solvent, the adhesive can include a crosslinker such as sulfur, a phenolic crosslinker, or an isocyanate crosslinker. Phenolic crosslinking of unsaturated elastomers has been reported to improve, for example, high temperature properties. See, for example, U.S. Pat. No. 5,439,963 (Korpman). Common phenolic curatives include alkyl phenolic resins, aryl phenolic resins, and halogenated (e.g., brominated) phenolic resins. Sulfur can be used in combination with vulcanization accelerators, if desired. These crosslinkers typically react to crosslink the adhesive when the adhesive is heated.

[0076] In some embodiments, the adhesive is prepared using a hot melt process. Useful hot melt processes include hot melt mixing and melt extruding. Various components of the adhesive may be added in various zones of an extruder, if desired. U.S. Pat. No. 5,539,033 (Bredahl et al.), for example, describes a continuous compounding device and hot melt processing techniques. The continuous compounding device has a sequence of alternating conveying and processing zones. An elastomer can be continuously conveyed from one zone to another by the device. The processing zones are capable of masticating an elastomer and of mixing additives into an elastomer. The adhesive can be applied to a moving web of a backing, for example, directly from the compounding device so as to provide a continuous method for the manufacture of an adhesive tape. The backing may be as described above in any of its embodiments. In some embodiments, hot melt processing of the adhesive, including applying the adhesive as a hot melt onto a tape backing to provide a tape, is carried out in a range from 150 °C to 210 °C, 160 °C to 200 °C, or 150 °C to 180 °C.

[0077] In some embodiments, including embodiments in which the adhesive is prepared using a hot melt process, the adhesive can be essentially free of volatile organic solvents. “Essentially free of volatile organic solvent” can mean that volatile organic solvent may be present (e.g., from a previous synthetic step or in a commercially available component) in an amount of up to 2.5 (in some embodiments, up to 2, 1, 0.5, 0.1, 0.05, or 0.01) wt%, based on the total weight of the adhesive. Volatile organic solvents are typically those have a boiling point of up to 150 °C at atmospheric pressure and include any of those described above.

[0078] In some embodiments of the tape and process of the present disclosure, the styrenic block copolymer and, in some embodiments, natural rubber or other component of the adhesive, is at least partially crosslinked by exposure to radiation, such as electron beam or ultraviolet radiation. Crosslinking may be carried out in-line with a continuous operation described above or may occur as a separate process. In some embodiments, crosslinking is carried out after the adhesive is disposed on a backing.

[0079] The degree of crosslinking achieved is a matter of choice and is dependent upon various factors such as the end product desired, the styrenic block copolymer used, and the thickness of the adhesive layer. Techniques for achieving crosslinking via exposure to radiation are known to those of skill in the art.

[0080] Radiation-crosslinking can enhance, for example, the cohesive strength of the composition. In some embodiments, the adhesive is crosslinked to the point where at least 20% by weight of the adhesive is insoluble by the following gel content evaluation. Gel content can be determined by soaking a sample of the crosslinked adhesive in toluene for 24 hours to extract the portion of the adhesive that is not crosslinked, determining the amount of gelled elastomer (e.g., styrenic block copolymer and natural rubber) in the extracted sample, and dividing the amount of gelled elastomer by the amount of elastomer in the adhesive formulation.

[0081] In embodiments in which the polymeric film backing is radiation degradable (e.g., vinyl films, cellulose films, polypropylene films, and polyfluoroethylene films, it may be useful to irradiate the composition on the polymeric film backing using a narrow voltage range as described in U.S. Pat. No. 5,266,400 (Yarusso et al.). Control of the voltage provides adequate uniformity of adhesive cure through the thickness thereof while limiting backing damage or degradation to acceptable levels.

[0082] A limitation of conventional formulations using block copolymers with tackifying resins and oils is their relatively low longer term shear performance or shear holding power at room temperature even when relatively small amounts of oils are used in these formulations. The detrimental effect of oils and related plasticizers is well known in the art and has been clearly shown in contour diagrams. Higher levels of tackifiers are also known to decrease the shear holding power of a pressure sensitive adhesive. It is also known that typical fillers when used at low levels have little effect on properties. Surprisingly, precipitated amorphous silica and precipitated amorphous silicates behave in a different manner than other known fillers. The Examples below illustrate the superior shear holding properties of the adhesives of the present disclosure.

[0083] Examples 2 to 5 have the same amount or a greater amount of soybean oil compared to Illustrative Example C, yet exhibit much greater shear holding power as measured using the Hang Shear to Fiberboard Test. Example 3 has the same organic composition as Illustrative Example D, but also contains precipitated amorphous silica. The shear holding power of Example 3 is greatly improved by a factor of 3.3. Example 6 demonstrates that it is possible to create novel formulations that have relatively high oil levels in combination with a tackifier that have exceptional shear holding power. This tape of Example 6 also has excellent tack with a mean rolling ball tack result of 53 mm. This adhesive composition has a soybean oil content of 8.7 wt% based on total organic solids. Because of the high oil content and lower level of tackifier, the Tgof the adhesive is expected to be relatively low making these adhesive compositions useful for a large variety of room temperature or low temperature applications including masking, packaging, constmction, and sustainable tapes. Soybean oil is known to be an excellent food source for various strains of fungi and bacteria. It is expected that formulations similar to those in Examples 4 to 6 would promote biodegradation via fungal or bacterial attack. Example 7 compared to Illustrative Example E shows a significant improvement in shear holding power. Example 10 contains a relatively large amount of tackifier and is useful as a sustainable stationary adhesive for paper notes and light duty packaging tapes. It has a biobased material content of 63.76 wt%. The main tackifier in the formula is a biodegradable glycerol ester that is not hydrogenated. The adhesives in Table 4 also contain a significant amount of soybean oil which is an excellent food source for a variety of bacteria and would promote microbial consumption of other components including the synthetic styrenic block copolymer. Example 12 can be useful as a high performance packaging tape, and has a better Hang Shear to Fiberboard performance than a commercially available packaging tape obtained under the trade designation “SCOTCH Performance Paper Box Sealing Tape 570”.

[0084] Advantageously, the precipitated amorphous silica and precipitated amorphous silicates in the adhesives of the present disclosure can enhance the cohesive strength of the adhesive without the need for radiation-crosslinking. In some embodiments, the adhesive is not crosslinked, for example, by electron beam or ultraviolet radiation. Radiation-crosslinking can enhance, for example, the cohesive strength of an adhesive. Example 11 demonstrated that the use of precipitated amorphous silica increased the shear properties of the tape, and a synergistic effect in shear increase was observed with combination of precipitated amorphous silica and E-beam crosslinking of the adhesive. In contrast, the use of calcium carbonate showed no improvement in shear properties of the tape as shown in Table 5. The unexpected superiority of adhesives of the present disclosure over comparable adhesives including calcium carbonate is also shown in Table 2.

[0085] From a comparison of Examples 15 and 16 to Illustrative Examples I and J, respectively, in Table 6, it is clear that Examples 15 and 16 had superior shear holding power compared to a similar formula without the precipitated silicate. Example 15 is useful, for example, as a permanent label adhesive and as an all-purpose packaging tape with a hang shear holding power of greater than 1,000 minutes. Illustrative Example I had lower shear holding power (less than 300 minutes), which is generally insufficient to be considered an all-purpose packaging tape. Example 19 had exceptional shear holding power (greater than 10,000 minutes) and had a precipitated silicate to liquid tackifier ratio of 9:8. Despite this relatively high ratio, the adhesive still exhibited thumb tack. Example 17 and Illustrative Example K were very similar in composition except for the precipitated silicate in Example 17 at 0.975 wt%. Examples 17 and 18 demonstrated that even a very small amount of precipitated silicate can be effective in an adhesive formulation for increasing holding power. Example 17 had more than twice the holding power compared to Illustrative Example K.

[0086] The paper tape of Example 16, for example, is expected to be biodegradable because the paper backing is composed of kraft pulp, which is known to be biodegradable, and the adhesive layer is primarily a combination of a polyisoprene based rubber, a low molecular weight C5 hydrocarbon tackifier, and soybean oil, which is an excellent food source for microorganisms as described above. The biodegradation rate is expected to be enhanced by soybean oil in the adhesive layer. Hence, tapes and related articles of the present disclosure can be useful as sustainable articles.

[0087] While this disclosure shall not be bound to any theory, it is believed that the precipitated amorphous silica or silicate acts as a reinforcing agent for the adhesive thereby increasing the shear strength, shear modulus and elastic modulus of the adhesive itself. This has a positive effect on an adhesive’s cohesive strength and its performance at higher temperatures and / or prolonged loads, i.e. creep or long-term shear holding power. This effect is the exact opposite effect of a plasticizer in a formulation, which reduces an adhesive’s shear strength. The improvement in shear properties created by the precipitated silica or silicate can counteract the detrimental effect that plasticizing oils have on shear holding power. It is also believed that because of its unique structure and large amount of surface area, the precipitated silica or silicate can also absorb significant amounts of plasticizer and prevent plasticizer migration or “bleeding out” to the adhesive interface. As a result, the overall amount of plasticizer that can be used in adhesives of the present disclosure is increased and the adhesive performance is improved as well.

[0088] Adhesives of the present disclosure can be used in a variety of tape and adhesive applications. Examples of these include high performance sustainable packaging tapes, biobased adhesives, lint roller sheets, label adhesives, light duty packaging tapes, double sided foam tapes, masking tapes, biodegradable tapes and sticky notes, and low temperature packaging tapes.

[0089] Some Embodiments of the Disclosure

[0090] In a first embodiment, the present disclosure provides an adhesive comprising: a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated; a first tackifying resin; at least one of precipitated amorphous silica or a precipitated amorphous silicate; and at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin, wherein the adhesive has not more than 4.5 weight percent poly isobutylene or a poly isobutylene copolymer, based on the total weight of the adhesive, or is free of polyisobutylene and a poly isobutylene copolymer. In a second embodiment, the present disclosure provides the adhesive of the first embodiment, further comprising natural rubber. In a third embodiment, the present disclosure provides the adhesive of the first or second embodiment, wherein at least one of the styrenic block copolymer or the natural rubber is crosslinked. In a fourth embodiment, the present disclosure provides the adhesive of any one of the first to third embodiments, wherein at least one of the styrenic block copolymer or the natural rubber is crosslinked with sulfur, a phenolic crosslinker, or an isocyanate crosslinker. In a fifth embodiment, the present disclosure provides the adhesive of any one of the first to fourth embodiments, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is hydrophilic. In a sixth embodiment, the present disclosure provides the adhesive of any one of the first to fourth embodiments, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified with hydrophobic groups. In a seventh embodiment, the present disclosure provides the adhesive of any one of the first to fourth or sixth embodiments, further comprising a surface-modifying agent comprising at least one of silane, a titanate, a zirconate, an aluminate, a maleated polymer, a polyhydroxyether, or an aromatic acid.

[0091] In an eighth embodiment, the present disclosure provides an adhesive comprising: a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated; a first tackifying resin; and at least one of precipitated amorphous silica or a precipitated amorphous silicate, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified with hydrophobic groups, or wherein the adhesive further comprises a surface modifying agent, or wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified and the adhesive further comprises a surface modifying agent. In a ninth embodiment, the present disclosure provides the adhesive of the eighth embodiment, further comprising at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin. In a tenth embodiment, the present disclosure provides the adhesive of any one of the seventh to ninth embodiments, wherein the surface modifying agent is at least one of silane, a titanate, a zirconate, an aluminate, a maleated polymer, a poly hydroxyether, or an aromatic acid. In an eleventh embodiment, the present disclosure provides the adhesive of any one of the eighth to tenth embodiments, further comprising natural mbber. In a twelfth embodiment, the present disclosure provides the adhesive of the eleventh embodiment, wherein at least one of the styrenic block copolymer or the natural mbber is crosslinked. In a thirteenth embodiment, the present disclosure provides the adhesive of the eleventh or twelfth embodiment, wherein at least one of the styrenic block copolymer or the natural rubber is crosslinked with sulfur, a phenolic crosslinker, or an isocyanate crosslinker. In a fourteenth embodiment, the present disclosure provides the adhesive of any one of the eighth to thirteenth embodiments, wherein the adhesive has not more than 4.5 weight percent polyisobutylene or a polyisobutylene copolymer, based on the total weight of the adhesive, or is free of polyisobutylene and a polyisobutylene copolymer.

[0092] In a fifteenth embodiment, the present disclosure provides an adhesive comprising: a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated; a first tackifying resin; at least one of precipitated amorphous silica or a precipitated amorphous silicate; and natural rubber. In a sixteenth embodiment, the present disclosure provides the adhesive of the fifteenth embodiment, wherein at least one of the styrenic block copolymer or the natural rubber is crosslinked. In a seventeenth embodiment, the present disclosure provides the adhesive of the fifteenth or sixteenth embodiment, wherein at least one of the styrenic block copolymer or the natural rubber is crosslinked with sulfur, a phenolic crosslinker, or an isocyanate crosslinker. In an eighteenth embodiment, the present disclosure provides the adhesive of any one of the fifteenth to seventeenth embodiments, further comprising at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin. In a nineteenth embodiment, the present disclosure provides the adhesive of any one of the fifteenth to eighteenth embodiments, wherein at least one of the precipitated amorphous silica or the precipitated amorphous silicate is hydrophilic. In a twentieth embodiment, the present disclosure provides the adhesive of any one of the fifteenth to eighteenth embodiments, wherein at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface-modified with hydrophobic groups. In a twenty -first embodiment, the present disclosure provides the adhesive of any one of the fifteenth to eighteenth or twentieth embodiments, further comprising a surface-modifying agent comprising at least one of silane, a titanate, a zirconate, an aluminate, a maleated polymer, a polyhydroxyether, or an aromatic acid.

[0093] In a twenty-second embodiment, the present disclosure provides the adhesive of any one of the first to twenty -first embodiments, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is present in the adhesive in a range from one weight percent (wt%) to 22 wt%, 1 wt% to twenty wt%, 1.5 wt% to 20 wt%, 2 wt% to 20 wt%, 2 wt% to 18 wt%, 3 wt% to 17 wt%, 4 wt% to 16 wt%, or 5 wt% to 15 wt%, or 4 wt% to 10 wt%, based on the total weight of the adhesive. In a twenty -third embodiment, the present disclosure provides the adhesive of any one of the first to twenty- second embodiments, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is present in an amount that exceeds any other inorganic filler that may be present in the adhesive. In a twenty -fourth embodiment, the present disclosure provides the adhesive of any one of the first to twenty -third embodiments, comprising the plasticizer, wherein the plasticizer comprises at least one of a vegetable oil, a fatty acid ester, or a polymerized vegetable oil. In a twenty -fifth embodiment, the present disclosure provides the adhesive of the twenty -fourth embodiment, wherein the plasticizer comprises at least one of canola oil, castor oil, peanut oil, com oil, soybean oil, coconut oil, palm oil, sunflower oil, or safflower oil. In a twenty-sixth embodiment, the present disclosure provides the adhesive of the twenty -fourth or twenty -fifth embodiment, wherein the plasticizer is present in a range from 1 wt% to 25 wt%, 2 wt% to 25 wt%, 2 wt% to 20 wt%, 2 wt% to 15 wt%, or 1 wt% to 10 wt%, based on the total weight of the adhesive. In a twenty-seventh embodiment, the present disclosure provides the adhesive of any one of the first to twenty-sixth embodiments, wherein the at least one of precipitated amorphous silica or the precipitated amorphous silicate has a BET specific surface area in a range from 35 square meters per gram to 400 square meters per gram (m2 / g), 50 m2 / g to 300 m2 / g, 100 m2 / g to 300 m2 / g, 50 m2 / g to 250 m2 / g, or 150 m2 / g to 250 m2 / g. In a twenty -eighth embodiment, the present disclosure provides the adhesive of any one of the first to twenty-seventh embodiments, wherein the adhesive has not more than 10 weight percent poly(alpha-methylstyrene), based on the total weight of the adhesive, or is free of poly(alpha-methylstyrene).

[0094] In a twenty -ninth embodiment, the present disclosure provides the adhesive of any one of the first to twenty -eighth embodiments, wherein the styrenic block copolymer comprises at least one of a polystyrene-containing triblock copolymer or a polystyrene-containing star block copolymer, wherein the polystyrene-containing triblock copolymer and polystyrene-containing star block copolymer independently comprise a block of at least one of polyisoprene, polybutadiene, or ethylene / butylene. In a thirtieth embodiment, the present disclosure provides the adhesive of the twenty-ninth embodiment, wherein the styrenic block copolymer comprises at least one of a styrene-isoprene-styrene triblock copolymer or a styrene-isoprene star block copolymer. In a thirty-first embodiment, the present disclosure provides the adhesive of any one of the first to thirtieth embodiments, wherein the tackifying resin comprises at least one of a polyterpene, a terpene phenolic resin, or an aromatic -modified terpene resin, a rosin acid, a rosin ester, a metal rosinate, a tall oil ester, a C5 aliphatic hydrocarbon resin, a C9 aromatic resin, or a mixed aliphatic -aromatic hydrocarbon resin, wherein the first tackifying resin is hydrogenated or not hydrogenated. In a thirty-second embodiment, the present disclosure provides the adhesive of the thirty -first embodiment, wherein the first tackifying resin comprises at least one of a rosin acid, a rosin ester, or a tall oil ester. In a thirty -third embodiment, the present disclosure provides the adhesive of any one of the first to thirty -second embodiments, comprising the second tackifying resin, wherein the second tackifying resin comprises at least one of a polyterpene, a liquid C5 aliphatic hydrocarbon resin, or a rosin ester.

[0095] In a thirty -fourth embodiment, the present disclosure provides the adhesive of any one of the first to thirty -third embodiments, wherein the styrenic block copolymer is present in an amount ranging from 5 weight percent to 60 weight percent, wherein the first tackifying resin is present in an amount ranging from 20 weight percent to 60 weight percent, wherein the at least one of the precipitated amorphous silica or precipitated amorphous silicate is present in an amount ranging from 1 weight percent to 22 weight percent, the at least one of the plasticizer or the second tackifying resin is present in an amount ranging from f weight percent to 25 weight percent, and wherein natural rubber is present in an amount of up to 70 weight percent, based on the total weight of the adhesive. In a thirty -fifth embodiment, the present disclosure provides the adhesive of any one of the first to thirty -fourth embodiments, further comprising at least one of starch, a humectant, a fatty acid, an amino acid salt, potassium phosphate, or natural or synthetic fibers.

[0096] In a thirty-sixth embodiment, the present disclosure provides the adhesive of any one of the first to thirty -fifth embodiment, wherein the precipitated amorphous silicate comprises at least one of calcium silicate or sodium aluminum silicate.

[0097] In a thirty-seventh embodiment, the present disclosure provides the adhesive of any one of the first to thirty -sixth embodiments, disposed on a tape backing. This can also be claimed as a tape comprising the adhesive of any one of the first to thirty-sixth embodiments disposed on a tape backing. In a thirty -eighth embodiment, the present disclosure provides the adhesive or tape of the thirty-seventh embodiment, wherein the tape backing comprises at least one of paper, a nonwoven, polyester, poly(vinyl chloride), polypropylene, polyethylene laminated cloth, or polylactide. In a thirty -ninth embodiment, the present disclosure provides the adhesive or tape of the thirty -eighth embodiment, wherein the tape backing comprises at least one of paper, polylactide, or a biodegradable polymer. In a fortieth embodiment, the present disclosure provides the adhesive or tape of any one of the thirty-seventh to thirty -ninth embodiments, wherein the adhesive is present in a range from 11 grams per square meter to 150 grams per square meter. In a forty -first embodiment, the present disclosure provides the adhesive or tape of any one of the thirty-seventh to fortieth embodiments, further comprising a low-adhesion backsize on a second face of the tape backing, opposite a surface on which the adhesive is disposed.

[0098] In a forty-second embodiment, the present disclosure provides a process of making a tape, the process comprising applying the adhesive of any one of the first to thirty-sixth embodiments as a hot melt on a tape backing to provide the tape. In a forty -third embodiment, the present disclosure provides the process of the forty-second embodiment, wherein applying the adhesive as a hot melt is carried out at a temperature in a range from 150 °C to 210 °C, 160 °C to 200 °C, or 150 °C to 180 °C. In a forty-fourth embodiment, the present disclosure provides the process of the forty-second or forty -third embodiment, wherein the tape backing comprises at least one of paper, a nonwoven, polyester, poly(vinyl chloride), polypropylene, polyethylene laminated cloth, or polylactide. In a forty -fifth embodiment, the present disclosure provides the process of the forty -fourth embodiment, wherein the tape backing comprises at least one of paper, polylactide, or a biodegradable polymer. In a forty-sixth embodiment, the present disclosure provides the process of any one of the forty-second to forty-fifth embodiments, further comprising crosslinking the adhesive by exposure to electron beam radiation.

[0099] Embodiments of the compositions and methods disclosed herein are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention.

[0100] EXAMPLES

[0101] Unless otherwise noted, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight. The following abbreviations are used in this section: kg = kilogram, cm = centimeter, mm = millimeter, m = meter, in = inch, mL = milliliter, °C = degrees Celsius, °F = degrees Fahrenheit, Hz = Hertz, RH = relative humidity, lb = pound, g = gram, kg = kilogram, s = second, oz = ounce, rpm = revolutions per minute, gsm = grams per square meter, W = watt, Phr = parts per hundred, Pa = Pascal, and min = minute.

[0102] Table 1 : Materials List

[0103] TEST METHODS

[0104] Rollins Ball Test

[0105] Sample rolls were acclimated in a controlled temperature environment (73.4 + / - 3.6°F [23 + / - 2°C], 50 + / - 5% R.H) before starting the test. A TT100 Modified Chemlnstruments Inclined Ramp (obtained from Chemlnstruments, Fairfield, OH) and level platform were used to perform the test. The platform was leveled with an accompanying bubble level, which was set in the center of the platform. The four base screws were adjusted to align the bubble within the circle target. Both ends of the platform were secured with tape to prevent movement between tests.

[0106] A strip of 1-in (2.54-cm) wide double coated tape obtained under the trade designation “3M 410MYT Double Sided Masking Tape from 3M Company, St. Paul, MN, was applied at either end of the platform. The 7 / 16-in (1.1-cm), 5.6-g stainless-steel ball bearings were cleaned with one wash of technical grade diacetone alcohol of less than about 1 mL, using a “KIMWIPES” cleaning tissue (Kimberly-Clark Corp., Irving, TX) to remove the diacetone alcohol from ball bearing surface. This was followed by one dry wipe with an additional “KIMWIPES” cleaning tissue to remove any remaining diacetone alcohol from the ball bearing surface, followed by 3 washes of analytical grade ethanol and N- heptane of less than about 1 mL, using a “KIMWIPES” cleaning tissue to wipe off the remaining solvent from the ball bearing surface between each wash. After each ball bearing was cleaned, they were placed on an aluminum tray lined with “KIMWIPES” cleaning tissue. Nitrile rubber disposable gloves were used to place the ball bearing on the aluminum tray. After the cleaning procedure was completed, the ball bearings were allowed to sit and acclimate in a temperature-controlled environment at (73.4 + / - 3.6°F [23 + / - 2°C], 50 + / - 5% RH) for 15 minutes.

[0107] Tape samples were prepared by removing the outer 3 laps from a 1-in (2.54-cm) wide tape roll before cutting the roll to two 1-in (2.54-cm) by 24-in (61.0-cm) long strips. With adhesive side facing up, the tape sample was laid on the double-coated tape on the platform base. The tape sample was secured and centered in the middle of the 2-in (5.1-cm) wide double coated tape. It was ensured that the tape sample did not touch the tape adhesive surface but made sure it laid flat to the platform.

[0108] The TT100 Modified Chemlnstruments Inclined Ramp was placed on the left side of the level platform with the left edge of the ramp flush with the left edge of the platform with its rear touching the two guide pins located on the left side of the platform. The ramp was aligned so that it was centered on top of the surface of the 1-in (2.54-cm) wide tape sample. A McMaster Carr # 2056A23 300-mm graduated ruler was placed in the lengthwise direction of the platform along the bottom right edge of the ramp. A ball bearing, handled using the disposable gloves, was placed on top of the ramp. The ball bearing holding mechanism on the ramp was activated, allowing the ball bearing to roll freely down the ramp and on to the adhesive surface of the tape sample. The distance the ball bearing traveled was measured using the ruler. The distance to the center point of the ball bearing was measured in millimeters to determine the rolling ball tack value. The reported data was the average of three tests.

[0109] Hans Shear to Fiberboard Test

[0110] Hang Shear to Fiberboard Test followed ASTM D-3654. For test surface preparation, an approximately 10-inch (254 mm) long piece of fiberboard (Mosinee Specification 696-C) was removed from the roll and placed with the side of the paper that was toward the inside of the roll down on a clean surface. An approximately 12-inch (304.8 mm) long piece of double-coated obtained under the trade designation “3M FLEXOMOUNT” Plate Mounting Tape 411 from 3M Company was removed from the roll. The double-coated tape was positioned over the fiberboard so that more than 1 / 8 inch (3.2 mm) of one long edge of the paper was exposed. The double-coated tape was then applied to the paper, and the tape that extended beyond the paper on the two ends was trimmed. The paper / tape laminate was cut into approximately 2-inch (50.8 mm) long pieces. The liner from a laminate piece was removed, and the paper / tape laminate was positioned centered along one edge of a steel panel (3 -inch x 3 -inch (76 x 76 mm) , 45-65 mils (1.1-1.7 mm) thick so that the edges of the laminate with between 1 / 8 and 1 / 4-inch (3.2 and 6.4 mm) of double-coated tape visible were toward the center of the panel, and the paper extended 1 / 4-inch (6.4 mm) below the edge of the panel. The laminate was pressed to the panel using a razor blade only in areas that would not be occupied by the specimen. The laminate was then trimmed along the panel's edge.

[0111] Due to the nature of the fiberboard, the environment for the surface preparation and the testing was maintained at 73.4 + / - 3.6 °F (23 + / - 2 °C) and 50 + / - 5% relative humidity. An Example or Illustrative Example tape sample of 1 / 2 -inch (12.7 mm) width by approximately 10-inch (254 mm) in length (machine direction) was obtained. For the procedure, about 4 inches (102 mm) of one end of the tape specimen was applied to the fiberboard surface and the panel at a right angle to the paper-covered edge of the panel. A cut-off block with a razor blade was used to trim the specimen ! / 2inch (12.7 mm) from the panel edge. The specimen was rolled twice in each direction at 24-inch / min with a 4.5-pound [2.04-kg] rubber covered roller. The free end of the tape specimen was attached to a hook, folding the specimen end over the hook and onto itself. The sample was reinforced by wrapping the specimen from just above the hook and just below the fiberboard using filament tape, wrapping the specimen and filament tape around the hook and onto itself, and stapling through the specimen just above the hook.

[0112] The opposite end of the specimen was carefully peeled back to reduce fiber pulling to a minimum, leaving 0.50-inch (12.7 mm). The panel was then placed into the shear test stand, and a 1 kg mass was immediately hung. The adhesive area tested was !4 inch (12.7 mm) by !4 inch (12.7 mm). The time was recorded until the bond failed or terminated at a specified time.

[0113] Adhesive Rheology Measurements for Glass Transition Temperature

[0114] The instrument used for rheology testing of the adhesive was TA Instruments Ares G2 Rheometer (available from TA Instruments New Castle, Delaware). For measuring the tan delta peak of the adhesive, a temperature sweep test was performed from -20°C to 120°C at 1.0 % strain, at a frequency of 1 Hz., using an 8.0-mm parallel plate for the measurements. The temperature ramp rate used was 3.0°C per minute. The glass transition temperature is reported as the maximum tan delta.

[0115] Adhesion To Steel Test

[0116] Sample rolls were acclimated in a controlled temperature environment (73.4 + / - 3.6°F [23 + / - 2°C], 50 + / - 5% RH) before starting the test. The peel tester (INSTRON Model 3343Q8711, Norwood, MA) parameters were set to run at a crosshead speed of 12-in / min (30.5-cm / min), a jaw separation of 6 - in (15.2-cm), full-scale load of 100-oz (4.8-kg), a peel distance of 5-in (12.7-cm), and a peel force average distance set to measure between 2-in (5.1-cm) and 4-in (10.2-cm) of sample length. The peel tester was then calibrated.

[0117] A 2-in (5.1-cm) by 5-in (12.7-cm) stainless steel (Type 304) panel as prescribed in ASTM A666 with a bright annealed finish, 18-gauge (1.2-mm) thickness, and a polish finish on one side with a surface roughness height of 1.5 + / - 0.5 micro inches (0.038 + / 0.013 micrometers) (obtained from Chemlnstruments, Fairfield, OH) was cleaned with a quarter size quantity of diacetone alcohol and then wiped off with “KIMWIPES” cleaning tissue. An additional “KIMWIPES” cleaning tissue was used to wipe the stainless-steel panel panel again, removing any remaining diacetone alcohol making sure the surface looked clean. Finally, three N-heptane washes of less than about 1 mL were used, using a “KIMWIPES” cleaning tissue to wipe off the N-heptane from the stainless-steel plate inbetween each wash.

[0118] Tape samples were prepared by removing the outer 3 laps from a 1-in (2.54-cm) wide tape roll before cutting the roll to 1-in by 13-in (2.54-cm by 33-cm) long sample strips. The ends of the tape sample were then held in each hand. The sample was positioned above the stainless-steel panel so the long edge of the sample was parallel to the long side of the panel and so the specimen was centered in the middle of the vertical direction of the panel. The tape sample was then laid onto the stainless-steel panel, making sure there was 1-in (2.54-cm) of the tape sample extending from the top of the panel and that the remaining 7-in (17.8-cm) of the tape sample were extended from the bottom of the panel.

[0119] The tape sample was then rolled onto the stainless-steel panel using a 4.5-lb (2 -kg) rubber roller. The rubber roller was moved up and down the panel twice in each direction at approximately 24-in / min (61-cm / min) ensuring only to allow the weight of the roller to apply the force to the tape sample. A razor blade was used to cut, along the edge of the top of the panel, the 1-in (2.54 -cm) of the tape sample that was extended from the top of the panel. The extended 7-in (17.8-cm) tape sample was held from the bottom of the panel, and the tape sample was peeled back by hand 0.5-in (1.27-cm) from the bottom edge of the panel. The bottom end of the stainless-steel was clamped into the lower jaw of the peel tester. The top end of the 7-in (17.8-cm) tape sample extending from the bottom of the panel was clamped into the upper jaw of the peel tester. The crosshead peel test was carried out on the peel tester, and the average peel force value was recorded. The reported data was the average of three tests.

[0120] Shear to Steel Test

[0121] A stainless-steel panel 2-in (5.1-cm) by 3-in (7.6-cm) stainless steel (Type 304) as prescribed in ASTM A666 with a bright annealed finish, 18-gauge (1.2-mm) thickness, and a polish finish on one side with a surface roughness height of 1.5 + / - 0.5 micro inches (0.038 + / 0.013 micrometers) (obtained from Chemlnstruments, Fairfield, OH) was cleaned with a quarter size quantity of diacetone alcohol and then wiped off with “KIMWIPES” cleaning tissue. An additional “KIMWIPES” cleaning tissue was used to wipe the stainless-steel panel again, removing any remaining diacetone alcohol making sure the surface looked clean. Finally, three N-heptane washes of less than about 1 mL were used, using a “KIMWIPES” cleaning tissue to wipe off the N-heptane from the stainless-steel plate in between each wash.

[0122] Tape samples were prepared by cutting the roll to 0.5-in by 6.0-in (1.27-cm by 15.24-cm) long strips. The ends of the tape sample were then held in each hand. The test sample was positioned above the stainless-steel panel, so the tape sample was centered in the middle of the vertical direction of the panel. The tape sample was then laid onto the stainless-steel panel. The tape sample was then rolled onto the stainless-steel panel using a 4.5-lb (2 -kg) rubber roller. The rubber roller was moved up and down the panel twice in each direction at approximately 24-in / min (61-cm / min) ensuring only to allow the weight of the roller to apply the force to the tape sample. A razor blade was used to cut the adhered length of the tape sample to 0.5 in (1.27 cm), so that the tape sample adhered area was 0.5-in (1.27-cm) x 0.5-in (1.27- cm).

[0123] A clamp was placed on the free end of the tape sample, ensuring that the clamp extended completely across the width of the tape sample and was aligned to uniformly distribute the load. This was then placed in the test stand so that the free end of the tape sample was vertical, ensuring that no peel forces acted on the specimen. A 1000-g mass was applied to the clamp gently so as to cause no shear impact force on the tape sample. The samples were reinforced with filament tape as described for the Hang Shear to Fiberboard Test. Recorded was the time elapsed in which the test sample separated completely from the test panel. The reported data was the average of three tests.

[0124] Example 1 (Ex. 1) Illustrative Examples A and B (I.E. A and B)

[0125] The components in their weight percentages shown in Table 2, below, were melt blended in a twin screw extruder (Model Mega 40 from Steer America, Uniontown, OH) at 270 °F (132 °C) using 240 rpm. The molten adhesive was then coated at 325 °F (163 °C) onto a 42 gsm crepe paper backing obtained from Ahlstrom-Munksjo, Mosinee, WI, using a rotary rod die to make Example 1 and Illustrative Example A and B. For Illustrative Example B the backing also included a polyester scrim. The coating weight of the adhesive was as shown in Table 2, below. For Example 1 and Illustrative Example A, the adhesive was subjected to electron beam irradiation at 130 kilovolts and a dose of 4 megarads. For Illustrative Example B, the adhesive was subjected to electron beam irradiation at 145 kilovolts and a dose of 4 megarads. The natural rubber and the canola oil were biobased materials. The Hang Shear to Fiberboard Test was carried out, and the results are shown in Table 2, below.

[0126] Table 2.

[0127] Examples 2 to 6 (Ex. 2 to 6) Illustrative Examples C and D (I.E. C and D)

[0128] The components in their weight percentages shown in Table 3, below were compounded on a 30- mm twin screw extruder (Coperion Model No. ZSK 30) (320 °F (160 °C) for all zones, 240 RPM) and cast as a hot melt pressure sensitive adhesive on a 1.38-mil (35 -micrometer) biaxially oriented polypropylene (BOPP) film using a rotary rod die with a coating weight of 6 grains / 24 square inches (25.1 gsm). All values Table 3 are in parts by weight. All Examples exhibited excellent tack at room temperature. The tape product was cooled and later tested in the Hang Shear to Fiberboard Test described above. The results are shown in Table 3, below.

[0129] Table 3.

[0130] Example 6 was also tested for tack using the Rolling Ball Test and provided a mean result of 53 mm.

[0131] Examples 7 to 10 (Ex. 7 to 10) Illustrative Examples E and F (I.E. E and F) Using the method of Examples 2 to 6, the adhesives of Examples 7 to 10 and Illustrative

[0132] Examples E and F were cast as hot melt pressure sensitive adhesives on a 1.38-mil (35 -micrometer) BOPP film at a coating weight of about 25 grams per square meter. The tapes were evaluated using the Hang Shear to Fiberboard Test. The components of each of Examples 7 to 10 and I.E. E and F in parts by weight, and the mean of the Hang Shear results are given in Table 4.

[0133] Table 4. Example 11 (Ex. 11) Illustrative Examples G and H (I.E. G and H)

[0134] The components in their weight percentages shown in Table 5, below, were melt blended in a twin screw extruder (Model Mega 40 from Steer America, Uniontown, OH) at 380 °F (193 °C) using 100 rpm. The molten adhesive from Example 11 and Illustrative Examples G and H was coated at 350 °F (177 °C) on to a 23x7 polyester scrim (23 threads per inch warp by 7 threads per inch weft) and Paper backing using a rotary rod die. The adhesive coat weight was 75 gsm. The coated tapes were tested for tape shear properties without and with E-beam curing. The coated webs were then exposed to electron beam radiation at 130 kV for a dose of 4.0 Mrad using a Comet AG, model EBLab-180 / 210, from Comet AG, Flamatt, Switzerland.

[0135] Table 5.

[0136] Example 12

[0137] SIS 1 (44.76 wt.%), AO 2 (0.95 wt.%), Tackifier 4 (38.10 wt%), Tackifier 5 (13.33 wt.%), and Silica (2.86 wt.%) were compounded in a 40-mm twin screw extruder (Model Mega 40) at 200 RPM and with a die temperature of 333 °F (167 °C). The adhesive was hot melt extruded onto the non-low adhesion backsize (LAB) side of a Mondi (Weybridge, UK) high strength plus paper backing with a siloxane-based LAB on the backside. The measured adhesive coat weight was 10.7 grains / 24 square inches (44.8 gsm). After manufacturing, the roll of 6-inch (15.24-cm) wide tape was slit into two separate rolls using a score slitter with one roll at 2 inches (5.08 cm) wide and the second roll at 3 inches (7.62 cm) wide. The final paper tape had excellent finger tack. The Tgof the adhesive was -7.68 °C (tan delta peak measured as described above). After heat aging the tape for 11 days at 120 °F (49 °C), the Hang Shear to Fiberboard Test was carried out, and a mean value of 9637 minutes was obtained. In comparison, a commercially available packaging tape obtained under the trade designation “SCOTCH Performance Paper Box Sealing Tape 570” had a mean hang shear value of 1926 minutes.

[0138] -a- Example 13

[0139] Step 1. In a glass vial, 7.4 grams of Fatty Alcohol was combined with 5.0 g Silane 1 and 0.1 g Catalyst. The vial was shaken vigorously for 3 minutes to form a solution, and the reaction was allowed to proceed at 20 °C for 1 week to provide a hydrophobic urethane silane.

[0140] Step 2. The urethane silane from Step 1 (0.8 g) was added dropwise to 5.0 g of Silica in an aluminum pan. The mixture was stirred thoroughly with a spatula and then covered with a piece of aluminum foil. The entire pan was then placed in a hot air Class A oven for 30 minutes at 110 °C to react the silane with precipitated amorphous silica.

[0141] Step 3: Toluene (35.7 g) of was added to a 100 mL glass container with a magnetic stir bar. 11.0 g of Tackifier 6 was added to the container and stirred for 10 minutes to completely dissolve the tackifier). The surface treated silica from Step 2 (0.7 g) was added to the glass vessel and stirred for 10 minutes to disperse the silica. Next, SIS 1 (10.0 g) was added to the vessel and stirred for 10 hours to completely dissolve the polymer. The calculated solids content of the solvent-borne adhesive formulation was 37.8 wt%.

[0142] Step 4: A six-inch-wide, 42 gsm crepe paper backing obtained from Ahlstrom-Munksjo, Mosinee, WI, was coated with the solvent-borne formulation of Step 3 with a notched bar aluminum coating station using a 5-mil (127 -micrometer) gap. The adhesive coating was dried for 10 minutes in a forced air oven at 73 °C to remove the solvent. The resulting paper tape had very good finger tack.

[0143] Example 14

[0144] Step 1: 5.0 g of Silica (5.0 g) was placed in a 3-inch x 5-inch (7.6-cm x 12.7-cm) aluminum pan. Silane 3 (0.2 g) and Silane 2 (0.3 g) were added dropwise to the precipitated silica. The mixture was thoroughly stirred for 5 minutes with a spatula resulting a dry uniform powder. The pan was covered with aluminum foil and baked in a forced air oven at 120 °C for 12 hours to react the silane with the silica.

[0145] Step 2: Toluene (38.8 g) and a magnetic stir bar were added to a 100-mL amber glass container. Next Tackifier 1 (9.0 g) was added and dissolved by stirring for 8 minutes. The pretreated silica from Step 1 (1.0 g) and Soybean Oil (1.0 g) were added and stirred in for 10 minutes. Next AO 2 (0.1 g) and SIS 1 (9.1 g) were added to the container, which was capped and stirred for 12 hours to create the adhesive formulation. A crepe paper tape was created in a similar manner to Example 13, Step 4 using a 5-mil (127-micrometer) gapped notch bar coater followed by drying in a heat air oven. The tape had excellent finger tack and good adhesion to cardboard. Examples 15 to 19 (Ex. 15 to 19) Illustrative Examples I to K (I.E. I to K)

[0146] The components in their weight percentages shown in Table 6, below, were compounded on a 30- mm twin screw extruder (Coperion Model No. ZSK 30) (320 °F (160 °C) for all zones, 240 RPM) and cast as a hot melt pressure sensitive adhesive on a 6-mil (152-micrometer) extensible kraft paper having no saturation using a rotary rod die with a coating weight of 12 grains / 24 square inches (50.2 gsm). For Examples 15 to 19, Silicate was fed into the first zone of the twin screw extmder furthest away from the die. All values Table 6 are in parts by weight. The tape product was laminated to a release liner layer, wound into rolls, and later tested in the Hang Shear to Fiberboard Test described above. All Examples exhibited good thumb tack at room temperature, with Examples 16 and 18 feeling more tacky than Examples 15 and 17, respectively. The results are shown in Table 6, below.

[0147] Table 6.

[0148] Example 20

[0149] The composition prepared as described for Example 16 was coated onto 1.37-mil (34.8- micrometer) thick polypropylene film with an adhesive coat weight of 6 grains / 24 square inches (25.1 gsm) followed by lamination with a white release liner. The adhesive had a tacky feeling. A 1-in by 3 -in (2.54-cm by 76.2-cm) strip was cut from the roll of tape and applied to a molded polycarbonate lens and removed after 5 minutes. The tape was removed cleanly and did not leave any residue. In a similar manner, a 1-in by 4-in (2.54-cm by 10.2-cm) strip of tape was applied to a plate glass window. After 10 minutes, it was removed, and there was no adhesive residue on the glass surface.

[0150] Various modifications and alterations of this disclosure may be made by those skilled the art without departing from the scope and spirit of the disclosure, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.

Claims

What is claimed is:

1. An adhesive comprising: a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated; a first tackifying resin; at least one of precipitated amorphous silica or a precipitated amorphous silicate; and at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin, wherein the adhesive has not more than 4.5 weight percent polyisobutylene or a polyisobutylene copolymer, based on the total weight of the adhesive, or is free of polyisobutylene and a polyisobutylene copolymer.

2. The adhesive of claim 1, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is hydrophilic.

3. An adhesive comprising: a styrenic block copolymer comprising a styrenic block and a conjugated diene block, wherein the conjugated diene block is hydrogenated or not hydrogenated; a first tackifying resin; and at least one of precipitated amorphous silica or a precipitated amorphous silicate, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface modified with hydrophobic groups, or wherein the adhesive further comprises a surface modifying agent, or wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is surface modified and the adhesive further comprises a surface modifying agent.

4. The adhesive of claim 3, further comprising at least one of a plasticizer or a second tackifying resin having a glass transition temperature lower than the first tackifying resin.

5. The adhesive of claim 3 or 4, wherein the surface modifying agent is at least one of silane, a titanate, a zirconate, an aluminate, a maleated polymer, a polyhydroxyether, or an aromatic acid.

6. The adhesive of any one of claims 3 to 5, wherein the adhesive has not more than 4.5 weight percent polyisobutylene or a polyisobutylene copolymer, based on the total weight of the adhesive, or is free of polyisobutylene and a polyisobutylene copolymer.

7. The adhesive of any one of claims 1 to 6, further comprising natural rubber.

8. The adhesive of any one of claims 1 to 7, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is present in an amount that exceeds any other inorganic filler that may be present in the adhesive.

9. The adhesive of any one of claims 1 to 8 comprising the plasticizer, wherein the plasticizer comprises at least one of a vegetable oil, a fatty acid ester, or a polymerized vegetable oil.

10. The adhesive of claim 9, wherein the plasticizer comprises at least one of canola oil, castor oil, peanut oil, com oil, soybean oil, coconut oil, palm oil, sunflower oil, or safflower oil.

11. The adhesive of any one of claims 1 to 10, wherein the tackifying resin comprises at least one of a polyterpene, a terpene phenolic resin, or an aromatic -modified terpene resin, a rosin acid, a rosin ester, a metal rosinate, a tall oil ester, a C5 aliphatic hydrocarbon resin, a C9 aromatic resin, or a mixed aliphatic- aromatic hydrocarbon resin, wherein the first tackifying resin is hydrogenated or not hydrogenated.

12. The adhesive of any one of claims 1 to 11 comprising the second tackifying resin, wherein the second tackifying resin comprises at least one of a polyterpene, a liquid C5 aliphatic hydrocarbon resin, or a rosin ester.

13. The adhesive of any one of claims 1 to 12, wherein the styrenic block copolymer is present in an amount ranging from to 5 weight percent to 60 weight percent, wherein the first tackifying resin is present in an amount ranging from 20 weight percent to 60 weight percent, wherein the at least one of the precipitated amorphous silica or the precipitated amorphous silicate is present in an amount ranging from 1 weight percent to 22 weight percent, the at least one of the plasticizer or the second tackifying resin is present in an amount ranging from 0 weight percent to 25 weight percent, and wherein natural mbber is present in a range from 0 weight percent to 70 weight percent, based on the total weight of the adhesive.

14. The adhesive of any one of claims 1 to 13, disposed on a tape backing.

15. The adhesive of claim 14, wherein the tape backing comprises at least one of paper, a nonwoven, polyester, poly(vinyl chloride), polypropylene, polyethylene laminated cloth, or polylactide.

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