Foam compositions, related articles, and processes comprising surface-modified nanoparticles

Abstract

The foam composition comprises a vehicle, surface-modified nanoparticles disposed in the vehicle, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane. Each individual nanoparticle has a particle size of less than about 100 nanometers. The vehicle can have voids therein. Also described are articles comprising the foam composition, and processes for making the foam composition and the articles.

Description

Background Art

[0001] [Cross - reference to Related Applications] This application claims the priority of U.S. Provisional Patent Application No. 63 / 348,393, filed on June 2, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] [Background Art] In a foam, the bubbles are separated from each other by thin liquid films. Typically, a surfactant functions by reducing the surface tension of a liquid so that bubbles introduced beneath the surface of the liquid can be maintained in the liquid. The surfactant can also adsorb at the interface between the bubble and the liquid film and stabilize the foam by providing a barrier to bubble coalescence. Typically, it is more difficult to form a foam in an organic liquid than in an aqueous liquid. Some fluorinated surfactants are known to produce stable foams in organic liquids. However, recently, there has been a trend in the industry away from using fluorinated surfactants.

[0003] Certain silicone surfactants have been reported to be useful for foaming organic liquids in U.S. Patent No. 4,415,615 (Esmay et al.). On the other hand, silicone MQ resins have been reported to be defoaming agents in U.S. Patent No. 6,207,722 (Juen et al.) and in the pamphlet "Your Technology - Siltech Chemistry" published by Siltech Corporation, Toronto, Canada in August 2016.

[0004] Inorganic particles are included in many foam compositions for various reasons. Some of these particles function as nucleating agents. Other particles act as fillers that change the physical properties of the composition, for example, changing the rheology of the composition. Still other particles, such as hydrophobic fumed silica, have been found to function as defoaming agents. Fumed silica, also known as pyrogenic silica, consists of primary particles that are irreversibly bonded to each other in the form of aggregates having an average size of 200 nm to 300 nm. U.S. Patent No. 6,586,483 (Kolb et al.) reports a foam composition containing surface-modified nanoparticles having a particle size of about 100 nanometers or less. U.S. Patent No. 7,141,612 (Baran, Jr. et al.) reports a foam composition containing surface-modified organic molecules such as fullerenes, dendrimers, organic polymer microspheres, and combinations thereof.

Summary of the Invention

[0005] We, the inventors, hereby report that a composition containing surface-modified nanoparticles has the ability to form a persistent foam in the presence of silicone MQ resin and / or poly(alkylene oxide)-modified polydimethylsiloxane. Surprisingly, a composition containing surface-modified nanoparticles and silicone MQ resin has the ability to form a persistent foam despite the fact that silicone MQ resin has been reported to be a defoaming agent. In some embodiments, a composition containing surface-modified nanoparticles and poly(alkylene oxide)-modified polydimethylsiloxane surprisingly has a higher ability to form a persistent foam than a composition containing surface-modified nanoparticles and other surfactants. In some embodiments, a composition containing surface-modified nanoparticles and poly(alkylene oxide)-modified polydimethylsiloxane surprisingly has a higher ability to form a persistent foam than a composition containing either surface-modified nanoparticles or poly(alkylene oxide)-modified polydimethylsiloxane alone.

[0006] In one aspect, the present disclosure provides a foam composition comprising a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane. In some embodiments, the foam composition has voids therein. The present disclosure provides the composition before foaming, during foaming, and after foaming.

[0007] In another aspect, the present disclosure provides a foam composition comprising a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and a silicone MQ resin. In some embodiments, the foam composition has voids therein. The present disclosure provides the composition before foaming, during foaming, and after foaming.

[0008] In another aspect, the present disclosure provides an adhesive tape (e.g., a pressure-sensitive adhesive tape) comprising the above-described foam composition.

[0009] In another aspect, the present disclosure provides an article comprising the above-described foam composition. The article can be, for example, a gasket or an automotive body molding.

[0010] In another aspect, the present disclosure provides a process for producing the above-described foam composition, the process comprising introducing a foaming agent into a composition comprising a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane to form voids in the composition.

[0011] In another aspect, the present disclosure provides a process for producing a tape, the process comprising foaming a composition comprising a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane, and subsequently applying the composition to a substrate.

[0012] As used herein, In this application, terms such as "a", "an", and "the" are not intended to refer only to singular entities, but include general classifications and specific examples thereof may be used for illustration. The terms "one (a)", "one (an)", and "the" are used interchangeably with the term "at least one". The phrases "at least one of" and "comprises at least one of" followed by a list refer to any one of the items in the list and any combination of two or more of the items in the list. All numerical ranges, unless otherwise stated, include their endpoints and non-integer values between the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5).

[0013] The term "acrylic" refers to polymers, oligomers, and monomers of both acrylic and methacrylic.

[0014] The term "(meth)acrylate" with respect to a monomer, oligomer, or polymer means a vinyl-functional alkyl ester formed as a reaction product of an alcohol and acrylic acid or methacrylic acid. "(Meth)acrylate" includes methacrylate and acrylate, individually and collectively.

[0015] Unless otherwise specified, the term "alkyl group" and the prefix "alk-" include both straight-chain and branched-chain groups having up to 30 carbons (in some embodiments, up to 20, 15, 12, 10, 8, 7, 6, or 5 carbons).

[0016] "Alkylene" is the polyvalent (e.g., divalent or trivalent) form of the "alkyl" group as defined above.

[0017] "Arylalkylene" refers to an "alkylene" moiety to which an aryl group is attached.

[0018] As used herein, "aryl" and "arylene" include, for example, carbocyclic aromatic rings or ring systems having one, two or three rings and containing, optionally, at least one heteroatom (e.g., O, S or N) in the ring, optionally substituted with up to five substituents including one or more alkyl groups having up to 4 carbon atoms (e.g., methyl or ethyl), alkoxy groups having up to 4 carbon atoms, halo groups (i.e., fluoro, chloro, bromo or iodo), hydroxy groups or nitro groups, examples of which include phenyl, naphthyl, biphenyl, fluorenyl, and furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl, tetrazolyl, imidazolyl, pyrazolyl, oxazolyl and thiazolyl.

[0019] The term "polymer" refers to a molecule having a structure that includes a plurality of repetitions of units derived, actually or conceptually, from one or more monomers. The term "monomer" refers to a molecule of low relative molecular weight that can combine with other monomers to form a polymer. The term "polymer" includes homopolymers and copolymers, as well as homopolymers or copolymers that can be formed in miscible blends, for example, by coextrusion or reaction. The term "polymer" includes random polymers, block polymers, graft polymers and star polymers. The term "copolymer" includes oligomers.

[0020] A "monomer unit" of a polymer or oligomer is a segment of the polymer or oligomer that is derived from a single monomer.

[0021] The term "crosslinking" generally refers to the formation of a network polymer in which polymer chains are connected to each other by chemical covalent bonds, usually through crosslinkable molecules or groups. Crosslinked polymers are generally characterized by insolubility, but can be swellable in the presence of a suitable solvent. The term "crosslinked" includes being partially crosslinked. Thermosetting polymers are crosslinked.

[0022] The term "surface-modified nanoparticles" refers to particles that include surface groups bonded to the surface of the particles. The surface groups modify the properties of the particles.

[0023] The term "persistent foam" refers to the presence of gas voids in the composition for at least 5 minutes after the composition has foamed.

[0024] The terms "particle size" and "particle diameter" refer to the maximum cross-sectional dimension of the particles. When the particles exist in the form of aggregates, the terms "particle size" and "particle diameter" refer to the maximum cross-sectional dimension of the aggregates.

[0025] The term "ceramic" refers to glass, crystalline ceramics, glass ceramics, and combinations thereof.

[0026] The above summary of the disclosure is not intended to describe each and every implementation of the disclosed embodiments or all implementations of the disclosure. The following description illustrates exemplary embodiments in more detail. Accordingly, it should be understood that the drawings and the following description are for illustrative purposes only and should not be construed as unduly limiting the scope of the disclosure.

Best Mode for Carrying Out the Invention

[0027] The foam compositions of the present disclosure and / or foam compositions useful in the processes of the present disclosure include surface-modified nanoparticles having a particle size of less than 100 nanometers disposed in a vehicle. In some embodiments, the foam composition includes voids in the vehicle, which may be present on the surface of the composition, dispersed throughout the composition, or a combination thereof. In some applications, the voids are uniformly dispersed throughout the composition. The voids generally contain at least one gas and, therefore, may be referred to as gas voids or air bubbles. In some embodiments, the foam composition includes a cellular structure in which the voids are in the form of closed cells. In some embodiments, the foam composition is an open-cell foam.

[0028] The surface-modified nanoparticles useful in the foam compositions and processes disclosed herein are individual non-associated (i.e., non-aggregated) nanoparticles dispersed throughout the vehicle and do not irreversibly associate with each other. The terms "associating" or "associated" include, for example, covalent bonds, hydrogen bonds, electrostatic attractions, London forces, and hydrophobic interactions. The surface-modified nanoparticles are selected such that the foam composition does not contain particle agglomerates or aggregates to the extent that they interfere with the desired properties of the composition, such as the ability of the composition to foam.

[0029] The surface-modified nanoparticles useful in the foam compositions and processes of the present disclosure may be selected to be compatible with the vehicle being foamed. For a vehicle containing various components, the surface-modified nanoparticles may be selected to be compatible with at least one component of the vehicle. In the case of a transparent vehicle, one useful way to evaluate the compatibility of the surface-modified nanoparticles with the transparent vehicle is to combine the surface-modified nanoparticles with the vehicle and observe whether the surface-modified nanoparticles appear to be dissolved in the vehicle such that the resulting composition is transparent. The nature of the inorganic particle component of the surface-modified particles prevents the surface-modified particles from actually dissolving in the vehicle, i.e., the surface-modified nanoparticles are dispersed in the vehicle, but the compatibility of the surface groups with the vehicle gives the surface-modified nanoparticles the appearance of being dissolved in the vehicle. As the size of the surface-modified nanoparticles increases, the degree of cloudiness of the vehicle generally increases. The surface-modified nanoparticles can be selected so as not to settle out of the vehicle.

[0030] The surface-modified nanoparticles useful in the foam compositions and processes of the present disclosure have surface groups that modify the dissolution characteristics of the nanoparticles. The surface groups are selected to render the particles compatible with the vehicle or at least a component of the vehicle, and the particles are arranged such that the resulting composition forms a persistent foam upon foaming. If the composition is polymerizable, for example, the surface groups can be selected to associate or react with at least one component of the vehicle to become part of the polymer network of the composition.

[0031] Suitable surface groups can also be selected based on the solubility parameters of the surface groups and the vehicle. The surface group, or the agent from which the surface group is derived, can be selected to have a solubility parameter similar to that of the vehicle to be foamed. For example, if the vehicle to be foamed is hydrophobic, one of ordinary skill in the art can select from among various hydrophobic surface groups to obtain surface-modified particles that are compatible with the hydrophobic vehicle. Similarly, if the vehicle to be foamed is hydrophilic, one of ordinary skill in the art can select from hydrophilic surface groups. The particles can also include at least two different surface groups that bind to provide nanoparticles having a solubility parameter similar to that of the vehicle.

[0032] The surface groups can be selected to provide statistically averaged, randomly surface-modified nanoparticles. The surface groups are present on the surface of the nanoparticles in an amount sufficient to provide surface-modified nanoparticles capable of being dispersed in the vehicle without later aggregating. The surface groups can be present in an amount sufficient to form a monolayer, in some embodiments a continuous monolayer, on the surface of the nanoparticles.

[0033] The surface modifying group may be derived from a surface modifier. Generally, the surface modifier can be represented by the formula A-B, where the A group has the ability to bind to the surface of the nanoparticle, and the B group is a compatibilizing group that may or may not be reactive with other components of the vehicle or composition. The compatibilizing group can be selected to make the nanoparticle relatively more polar, relatively less polar, or relatively non-polar compared to the nanoparticle before treatment. In some embodiments, B is alkyl, alkenyl, arylalkylenyl, alkylarylenyl, or aryl, and alkyl, alkenyl, arylalkylenyl, alkylarylenyl, and aryl are optionally interrupted by at least one ether, thioether, amine, amide, ester, thioester, carbonate, thiocarbonate, carbamate, thiocarbamate, urea, thiourea, or combinations thereof, and are optionally terminated by acrylate, methacrylate, acrylamide, methacrylamide, styrenyl, or a terminal alkenyl group (e.g., vinyl). In some embodiments, A is hydroxyl (e.g., -OH), sulfonic acid group (i.e., -SO3M), phosphonic acid group (i.e., -PO3M), carboxylic acid group (-CO 2 M), amino (-NH2 or -N(H)alkyl), epoxy, or silane (-Si(Y) x (Z) 3-x ). For any of the embodiments where W is an acid group (e.g., carboxylic acid, sulfonic acid, or phosphonic acid), M is hydrogen, a free anion, or a counter cation. Examples of useful counter cations include alkali metal ions (e.g., sodium, potassium, and lithium), alkaline earth metal ions (e.g., calcium and magnesium), ammonium, and alkylammonium (e.g., dialkylammonium, trialkylammonium, and tetraalkylammonium, where alkyl is optionally substituted with hydroxyl, fluoride, or aryl). The free anion on the acid group is possible, for example, when the acid has an ionic interaction with the surface of the nanoparticle, as described in more detail below. When A is silane (-Si(Y)x (Z) 3-x For any of the embodiments that are (Z), each Y is independently a non-hydrolyzable group (e.g., any of the R groups described below), and each Z is independently a halide (i.e., fluoride, chloride, bromide, or iodide), hydroxyl (i.e., -OH), alkoxy (e.g., -O-alkyl), aryloxy (e.g., -O-aryl), or acyloxy (e.g., -O-C(O)-alkyl), amino (e.g., -N(R A )(R B ), polyalkyleneoxy; and oxime (e.g., -O-N=C-(R A )(R B ), where each R A. or R B is independently hydrogen or alkyl), and alkoxy and acyloxy are optionally substituted by halogen, aryloxy is optionally substituted by halogen, alkyl (e.g., having up to 4 carbon atoms), or haloalkyl, and x is 0 or 1. In some embodiments, alkoxy and acyloxy have up to 6 (or up to 4) carbon atoms. In some embodiments, aryloxy has 6 to 12 (or 6 to 10) carbon atoms. In some embodiments, Z can also be -O- covalently bonded to the surface of the nanoparticle.

[0034] Examples of suitable classes of surface modifiers include silanes, organic acids, organic bases, and alcohols.Examples of useful silanes include alkylchlorosilanes, alkoxysilanes (e.g., methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, n-octyltriethoxysilane, isooctyltrimethoxysilane, phenyltriethoxysilane, poly(triethoxysilane), vinyltrimethoxysilane, vinyldimethylethoxysilane, vinylmethyldiacetoxysilane, vinylmethyldiethoxysilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltriphenoxysilane, vinyltri(t-butoxy)silane, vinyltris(isobutoxy)silane, vinyltris(isopropenoxy)silane, and vinyltris(2-methoxyethoxy)silane); N-(3-triethoxysilylpropyl)methoxyethoxyethoxyethylcarbamate; N-(3-triethoxysilylpropyl)methoxyethoxyethoxyethylcarbamate; silane-functional (meth)acrylates (e.g., 3-(methacryloyloxy)propyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-(methacryloyloxy)propyltriethoxysilane, 3-(methacryloyloxy)propylmethyldimethoxysilane, 3-(acryloyloxypropyl)methyldimethoxysilane, 3-(methacryloyloxy)propylmethyldiethoxysilane, methacryloyloxymethyltriethoxysilane, methacryloyloxymethyltrimethoxysilane, 3-(methacryloyloxy)propylmethyldiethoxysilane, and 3-(methacryloyloxy)propenyltrimethoxysilane) and other organosilanes; polydialkylsiloxanes such as polydimethylsiloxane, arylsilanes such as substituted and unsubstituted arylsilanes, alkylsilanes such as substituted and unsubstituted alkylsilanes such as methoxy and hydroxy-substituted alkylsilanes, and combinations thereof.Methods for surface modification of silica using silane-functional (meth)acrylates are described, for example, in U.S. Patent Nos. 4,491,508 (Olsen et al.), 4,455,205 (Olsen et al.), 4,478,876 (Chung), 4,486,504 (Chung), and 5,258,225 (Katsamberis).

[0035] Useful organic acid surface modifiers include acids of carbon (e.g., carboxylic acids), sulfur, and phosphorus, and combinations thereof. Examples of polar surface modifiers having carboxylic acid functional groups include CH3O(CH2CH2O)2CH2COOH (hereinafter, MEEAA) and 2-(2-methoxyethoxy)acetic acid (hereinafter, MEAA) having the chemical structure CH3OCH2CH2OCH2COOH, and mono(polyethylene glycol) succinate. Examples of nonpolar surface modifiers having carboxylic acid functional groups include octanoic acid, dodecanoic acid, and oleic acid. Examples of suitable phosphorus-containing acids include phosphonic acids (e.g., octylphosphonic acid, laurylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, and octadecylphosphonic acid). Useful organic base surface modifiers include alkylamines (e.g., octylamine, decylamine, dodecylamine, and octadecylamine). Examples of suitable surface-modifying alcohols include aliphatic alcohols (e.g., octadecyl, dodecyl, lauryl, and furfuryl alcohol), alicyclic alcohols such as cyclohexanol, and aromatic alcohols (e.g., phenol, benzyl alcohol, and combinations thereof). Examples of other useful non-silane surface modifiers include acrylic acid, methacrylic acid, beta-carboxyethyl acrylate, mono-2-(methacryloyloxyethyl) succinate, and combinations thereof. A useful surface modifier that imparts both polarity and reactivity to nanoparticles is mono(methacryloyloxypolyethylene glycol) succinate.

[0036] When the vehicle contains an aromatic ring-containing epoxy resin, useful surface modifying groups can include an aromatic ring. Examples of surface modifying groups particularly suitable for epoxy resin compositions are disclosed in U.S. Patent No. 5,648,407 (Goetz et al.).

[0037] To modify the surface of the nanoparticles, there are various methods such as adding a surface modifier to the nanoparticles (e.g., in the form of a powder or a colloidal dispersion) and reacting the surface modifier with the nanoparticles. Other useful surface modification processes are described, for example, in U.S. Patent Nos. 2,801,185 (Iler) and 4,522,958 (Das et al.).

[0038] In some embodiments, the nanoparticles useful in the practice of the present disclosure are inorganic particles. Examples of suitable inorganic nanoparticles include silica, as well as metal oxide nanoparticles including zirconia, titania, ceria, alumina, iron oxide, vanadia, antimony oxide, tin oxide, alumina / silica, and combinations thereof. The nanoparticles have an average particle size of 100 nm or less, in some embodiments 50 nm or less, and in some embodiments 3 nm to 100 nm, 3 nm to 50 nm, 3 nm to 20 nm, or 5 nm to 10 nm. When the nanoparticles are aggregated, the maximum cross-sectional dimension of the aggregated particles is within any of these ranges.

[0039] In some embodiments, the surface-modified zirconia nanoparticles include a combination of oleic acid and acrylic acid adsorbed on the surface of the particles. Useful surface-modified silica nanoparticles include silica nanoparticles surface-modified with silane surface modifiers such as 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, n-octyltrimethoxysilane, isooctyltrimethoxysilane, and combinations thereof. The silica nanoparticles can be treated with many surface modifiers such as alcohols, organosilanes such as those described above, and combinations thereof, as well as organotitanates and mixtures of these.

[0040] The nanoparticles may be in the form of a colloidal dispersion. Examples of useful commercially available unmodified silica starting materials include nano-sized colloidal silica available as NALCO 1040, 1050, 1060, 2326, 2327, and 2329 colloidal silica from Nalco Chemical Co., Naperville, IL. Useful metal oxide colloidal dispersions include colloidal zirconium oxide (preferred examples of which are described in U.S. Patent No. 5,037,579 (Matchett)), and colloidal titanium oxide (useful examples of which are described in U.S. Patent No. 6,329,058 (Arney et al.)).

[0041] In some embodiments, the nanoparticles useful in the practice of the present disclosure are organic particles. Specific examples of useful surface-modified organic molecules include alkylated buckminsterfullerene (fullerene) and alkylated polyamidoamine (PAMAM) dendrimers. Specific examples of fullerenes include C 60 、C 70 、C 82 、and C 84 . Specific examples of PAMAM dendrimers include those of Generations 2 - 10 (G2 - G10) available from Millipore Sigma, St. Louis, Missouri. PAMAM dendrimers are currently commercially available and have primary amine, hydroxyl, sodium carboxylate salt, mixed amine / hydroxyl, and C 12 surface functional groups. The alkyl groups on the organic molecules may be linear or branched and may be in the range of at least C3 - C 30 or any size or range between C3 - C 30 . For example, the range may be C3 - C 22 、C3 - C 18 、C3 - C 12 、C3 - C8, and any combination or integer therebetween.

[0042] Another example of suitable organic nanoparticles are polymer microspheres. Specific examples of useful organic polymer microspheres include microspheres containing polystyrene, available as a powder or dispersion from Bangs Laboratories, Inc., Fishers, Ind. The average particle size of the polystyrene microspheres ranges from at least 20 nm to 60 nm or less. Currently commercially available average particle sizes are 20, 30, 50, and 60 nm.

[0043] Various methods can be used to combine the surface-modified nanoparticles with the vehicle. For example, a colloidal dispersion of the surface-modified nanoparticles can be combined with the vehicle. The solvent present in the composition is then removed, leaving the surface-modified nanoparticles dispersed in the vehicle. The solvent can be removed by evaporation (e.g., distillation, rotary evaporation, or oven drying). Optionally, for some colloidal dispersions such as aqueous colloidal dispersions, a co-solvent (e.g., methoxy-2-propanol or N-methylpyrrolidone) can be added to the colloidal dispersion prior to addition of the vehicle to assist in the removal of water. After addition of the vehicle, the water and co-solvent are removed.

[0044] Another method for incorporating a colloidal dispersion of surface-modified nanoparticles into a vehicle involves drying the colloidal dispersion of surface-modified nanoparticles to a powder and subsequently adding the vehicle or at least one component of the vehicle in which the nanoparticles are dispersed. The drying step can be accomplished by conventional means such as oven drying or spray drying. The surface-modified nanoparticles can be designed to have a sufficient amount of surface groups to prevent irreversible agglomeration or irreversible aggregation upon drying. The drying time and drying temperature can be minimized for nanoparticles having a surface coverage of less than 100%.

[0045] The surface-modified nanoparticles can be added to the vehicle in any amount sufficient to provide a composition that is capable of foaming, and in some embodiments, in any amount sufficient to provide a composition that is capable of forming a sustainable foam. In some embodiments, the surface-modified nanoparticles are present in the foam composition in the range of 0.1 weight percent to 10 weight percent, based on the total weight of the foam composition. In some embodiments, the surface-modified nanoparticles are present in the foam composition in the range of 0.1 weight percent to 5 weight percent, or in the range of 0.5 weight percent to 3 weight percent, based on the total weight of the foam composition. The surface-modified nanoparticles may be present in the foam composition in an amount of at least 0.1, 0.2, 0.3, 0.4, or 0.5 weight percent and at most 10, 5, 4, or 3 weight percent, based on the total weight of the foam composition. In some embodiments, the surface-modified nanoparticles are dispersed throughout the vehicle, and in some embodiments, are homogeneously dispersed throughout the vehicle.

[0046] In some embodiments, the foam composition of the present disclosure or the foam composition produced by the process of the present disclosure comprises a silicone MQ resin. The silicone MQ resin is an organosilicon polymer made from a structural unit called an M unit represented by the formula (R)3SiO 1 / 2 and a Q unit represented by the formula SiO 4 / 2 , wherein Si is silicon, O is oxygen, and R is either hydrogen or an aliphatic or aromatic organic group. Thus, the silicone MQ resin contains a silicon atom bonded to one oxygen atom and a silicon atom bonded to four oxygen atoms. A representative structure of the silicone MQ resin is shown in Formula I below.

Chemical Formula

[0047] Suitable R substituents include hydrogen, alkyl, aryl, alkylene, at least one of which is interrupted or terminated by arylene or heterocyclylene, and alkyl and alkylene, at least one of which is interrupted or terminated by arylene or heterocyclylene, which are unsubstituted or substituted by halogen and optionally interrupted by at least one chain-linked -O-, -NH-, -N(alkyl)-, -S-, -Si-, or combinations thereof. Aryls, arylenes, and heterocyclylenes are unsubstituted or substituted by at least one alkyl, alkoxy, halogen, or combinations thereof. The R groups can be selected independently of each other. In some embodiments, each R group is the same. In some embodiments, R is not fluorinated. In some embodiments, R is not halogenated. In some embodiments, R is not hydrogen. In some embodiments, each R is independently hydrogen, alkyl, aryl, or alkyl, at least one of which is interrupted by at least one chain-linked -O- group or arylene or terminated by aryl. Suitable alkyl groups for R typically have 1 to 20, 1 to 18, 1 to 12, 1 to 10, 1 to 6, or 1 to 4 carbon atoms. Examples of useful alkyl groups include methyl, ethyl, isopropyl, n-propyl, n-butyl, iso-butyl, and octadecyl. In some embodiments, each R is independently alkyl, phenyl, benzyl, or C6H5C2H4- having up to 18 (in some embodiments, up to 4, 3, or 2) carbon atoms. In some embodiments, each R is independently methyl, phenyl, C6F 13C2H4- or octadecyl. In some embodiments, each R is independently alkyl. In some embodiments, each R is independently methyl or phenyl. In some embodiments, each R is methyl, and in these embodiments, the silicone MQ resin contains methyl groups. In some embodiments, the silicone MQ resin is not fluorinated. In some embodiments, the silicone MQ resin is not halogenated.

[0048] The ratio of M units to Q units affects the properties of the silicone MQ resin. A silicone MQ resin having an M:Q ratio greater than 1 is typically liquid at room temperature. A silicone MQ resin having an M:Q ratio of 1 or less is typically solid at room temperature. In some embodiments, the silicone MQ resin has an M:Q ratio of at least 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, or 1.5:1. In some embodiments, the silicone MQ resin has an M:Q ratio of at least 0.8:1, 0.9:1, 1:1, 1.1:1, or 1.2:1. The maximum M:Q ratio is 4:1. For silicone MQ resins, the M:Q ratio is typically 3:1 or less, and in some embodiments, 2.9:1, 2.8:1, 2.7:1, 2.6:1, 2.5:1, 2.4:1, 2.3:1, 2.2:1, 2.1:1, or 2:1 or less. For the purposes of the present disclosure, the M:Q ratio is determined by NMR spectroscopy using the method described in the Examples section below.

[0049] The silicone MQ resin is represented by the formula (R)3-Si-R 1 with one or more compounds represented by the formula (R 1 )4Si, where R is as defined above in any of its embodiments, and R 1is a hydrolyzable group. The term "hydrolyzable group" refers to a group that can react with water under atmospheric pressure conditions. The reaction with water can optionally be catalyzed by an acid or a base. Suitable hydrolyzable groups include halogen (e.g., iodine, bromo, chloro), alkoxy (e.g., -O-alkyl), aryloxy (e.g., -O-aryl), acyloxy (e.g., -O-C(O)-alkyl), amino (e.g., -NR A )(R B ), polyalkyleneoxy; and oxime (e.g., -O-N=C-(R A )(R B ), wherein each R A or R B is independently hydrogen or alkyl). In some embodiments, each R 1 is independently halogen, or alkoxy optionally substituted with halogen. In some embodiments, each R 1 is independently chloro, or alkoxy having up to 12 (or up to 6 or 4) carbon atoms. In some embodiments, each R is independently methoxy or ethoxy. When compounds of the formula (R)3-Si-R 1 and (R 1 )4Si react, R 1 is converted to a hydrolyzed group such as -OH during hydrolysis. The Si-OH groups react with each other to form silicone-oxygen bonds. Hydrolysis and condensation can be carried out by conventional methods, for example, by heating compounds of the formula R-Si(R 1 )3 and optionally R 2 -Si(R 1 )3 in water in the presence of an acid or a base, optionally.

[0050] After hydrolysis and condensation, typically -OH groups are present in the silicone MQ resin. The -OH groups can be further reacted with an end-capping agent to be converted to a hydrolyzed group, for example, -OH can be converted to -OSi(R)3. Suitable end-capping agents include, for example, those having the formula R 1 -Si(R)3 and O[Si(R)3]2, wherein R1 is as defined above in any of its embodiments. Suitable end-capping agents include those having the formula H-Si(R)3 that can react with hydroxyl groups in the presence of a transition metal catalyst (e.g., a palladium catalyst and a platinum catalyst). The silicone MQ resin contains a further group having the formula -Si(R)3 after end-capping, where R is, independently of the other R groups in the silicone MQ resin, as defined above in any of its embodiments. In some embodiments, the silicone MQ resin has a hydroxyl content in the range of 185 to 1840 milliequivalents per kilogram (meq / kg). In some embodiments, the silicone MQ resin has a hydroxyl content in the range of 500 to 1000 milliequivalents per kilogram (meq / kg). For the purposes of the present disclosure, the hydroxyl content is determined by NMR spectroscopy using the method described in the following examples to determine the MQ ratio.

[0051] Depending on the M:Q stoichiometry, synthetic preparation, and end-capping, the silicone MQ resin can adopt various polycyclic structures and can have various properties such as solubility in an organic vehicle. Although Formula I is shown as having a structured organization at least in the central part, it should be understood that the silicone MQ resin can have a more random structure. Accordingly, silicone MQ resins useful for practicing the present disclosure include three-dimensional and branched random copolymers.

[0052] Silicone MQ resins can be obtained from various commercial suppliers, for example, from Siltech, Corporation, Toronto, Ontario, Canada under the trade name "SILMER Q"; from Dow Chemical Company, Midland, Michigan under the trade name "DOWSIL"; from Wacker Chemie, Munich, Germany, from Momentive Performance Materials, Waterford, New York under the trade name "SILGRIP"; from BYK-Chemie, Wesel, Germany, and from Gelest, Inc., Morrisville, Pennsylvania. Silicone MQ resins have been reported to provide release properties, lubricity, adhesiveness, flexibility, and / or water repellency. Further, MQ resins have been explicitly reported as "defoamers" and "antifoaming agents". Silicone MQ resins are generally not known as surfactants. In some embodiments, the silicone MQ resin does not include an alkyloxy group, for example, one represented by the formula -(OR 2 ) n -OR 3 wherein n, R 2 , and R 3 are as defined below in any of those embodiments.

[0053] In some embodiments, the foam composition of the present disclosure or the foam composition made by the process of the present disclosure includes a poly(alkylene oxide) modified polydimethylsiloxane. Polydimethylsiloxane is an organosilicon polymer composed of structural units called D units represented by the formula (R)2SiO 2 / 2 , wherein Si is silicon, O is oxygen, and R is a methyl group. In some embodiments, the poly(alkylene oxide) modified polydimethylsiloxane is not fluorinated. In some embodiments, the poly(alkylene oxide) modified polydimethylsiloxane is not halogenated. Polydimethylsiloxane includes a repeating divalent unit represented by Formula II:

Chemical formula

Chemical formula

[0054] In some embodiments, the poly(alkylene oxide) modified polydimethylsiloxane useful in the foam compositions of the present disclosure can be represented by Formula IV:

Chemical formula

[0055] The number of repeating units and the molecular weight of the polysiloxane can be determined, for example, by nuclear magnetic resonance (NMR) spectroscopy using techniques known to those skilled in the art. Molecular weights, particularly for high molecular weight materials such as number average molecular weight and weight average molecular weight, can also be measured, for example, by gel permeation chromatography (i.e., size exclusion chromatography) using techniques known to those skilled in the art. For the purposes of the present disclosure, the number average molecular weight of the poly(alkylene oxide) modified polydimethylsiloxane is determined by NMR spectroscopy using the method described in the following examples.

[0056] In some embodiments, the silicone MQ resin, poly(alkylene oxide) modified polydimethylsiloxane, or a combination thereof is present in the foam composition in the range of 0.1 weight percent to 10 weight percent, based on the total weight of the foam composition. In some embodiments, the silicone MQ resin, poly(alkylene oxide) modified polydimethylsiloxane, or a combination thereof is present in the foam composition in the range of 0.1 weight percent to 5 weight percent, or in the range of 0.5 weight percent to 3 weight percent, based on the total weight of the foam composition. The silicone MQ resin, poly(alkylene oxide) modified polydimethylsiloxane, or a combination thereof may be present in the foam composition in an amount of at least 0.1, 0.2, 0.3, 0.4 weight percent, or 0.5 weight percent, and at most 10, 5, 4 weight percent, or 3 weight percent, based on the total weight of the foam composition. Advantageously, when the silicone MQ resin, poly(alkylene oxide) modified polydimethylsiloxane, or a combination thereof is used in combination with the surface-modified nanoparticles, a smaller amount of the silicone MQ resin, poly(alkylene oxide) modified polydimethylsiloxane, or a combination thereof may be useful for increasing the foam height and / or stabilizing the foam composition. In some embodiments, the foam composition does not contain a fluorinated surfactant.

[0057] The vehicle of the foam composition can include various components and can be in the form of a solid, a liquid, or a combination thereof. The vehicle can be selected based on the desired properties of the foam composition (e.g., adhesiveness, rigidity, hardness, density, volume, transparency, flexibility, conformity, resilience, creep, strength, elastic modulus, elongation, chemical resistance, temperature resistance, environmental resistance, and compressibility). In some embodiments, during foaming, the vehicle is a liquid and can be, for example, a solution, an emulsion, a suspension, a dispersion, a syrup, or a melt. In some embodiments, the vehicle is an organic liquid. Useful examples of organic liquids include acids, alcohols, ketones, aldehydes, amines, ethers, hydrocarbons, halocarbons, monomers, oligomers, and polymers.

[0058] In some embodiments, the vehicle includes water. In some embodiments, the vehicle is water-free. In some embodiments, the foam composition includes 50, 40, 30, 20, 10, 5 weight percent or less, or 1 weight percent or less of water.

[0059] Examples of useful organic vehicles include organic polymers. Suitable organic polymers for the vehicle include natural and synthetic rubber resins such as thermoplastic rubbers and elastomers, as well as thermosetting rubbers, such as nitrile rubber (e.g., acrylonitrile-butadiene), polyisoprene rubber, polychloroprene rubber, polybutadiene rubber, butyl rubber, ethylene-propylene-diene monomer rubber (EPDM), Santoprene® polypropylene-EPDM elastomer, ethylene-propylene rubber, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber, styrene-ethylene-butylene-styrene rubber, styrene-ethylene-propylene-styrene rubber, polyisobutylene rubber, ethylene vinyl acetate rubber, silicone rubber (e.g., polysiloxane), polymethacrylate rubber, polyacrylate rubber (e.g., a copolymer of isooctyl acrylate and acrylic acid), polyester, polyether ester, polyvinyl ether, polyurethane, and blends and copolymers thereof. Useful copolymers include linear, radial, star-shaped, and tapered block copolymers and combinations thereof.

[0060] Other elastomers suitable for the vehicle include fluoroelastomers (e.g., polytetrafluoroethylene, polyvinylidene fluoride, hexafluoropropylene, and fluorinated ethylene-propylene copolymer), fluorosilicone, and chloroelastomers (e.g., chlorinated polyethylene), and combinations thereof.

[0061] As further examples of organic polymers suitable for vehicles, there are thermoplastic resins such as polyacrylonitrile, acrylonitrile-butadiene-styrene, styrene-acrylonitrile, cellulose, chlorinated polyether, ethylene vinyl acetate, fluorocarbons (e.g., polychlorotrifluoroethylene, polytetrafluoroethylene, fluorinated ethylene-propylene, and polyvinylidene fluoride), polyamides (e.g., polycaprolactam, polyhexamethylene adipamide, polyhexamethylene sebacamide, polyundecanamide, polylauramide, and polyacrylamide), polyimides (e.g., polyetherimide), polycarbonates, polyolefins (e.g., polyethylene, polypropylene, polybutene, and poly-4-methylpentene), polyalkylene terephthalates (e.g., polyethylene terephthalate), polyalkylene oxides (e.g., polyphenylene oxide), polystyrene, polyurethanes, polyisocyanurates, vinyl polymers (e.g., polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, polyvinylidene chloride), and combinations thereof.

[0062] Further examples of organic polymers suitable for the vehicle include thermosetting resins such as polyesters and polyurethanes, and their hybrids and copolymers such as acylated urethanes and acylated polyesters, amino resins (e.g., aminoplast resins, alkylated urea-formaldehyde resins, melamine-formaldehyde resins), acrylate resins (e.g., polyacrylates and polymethacrylates, vinyl acrylates, acrylated epoxies, acrylated urethanes, acrylated polyesters, acrylated acryl, acrylated polyethers, acrylated oils, and acrylated silicones), alkyd resins such as urethane alkyd resins, polyester resins, reactive urethane resins, phenolic resins (e.g., resol resins, novolac resins, and phenol-formaldehyde resins), phenol / latex resins, epoxy resins (e.g., bisphenol epoxy resins, aliphatic and alicyclic epoxy resins, epoxy / urethane resins, epoxy / acrylate resins, and epoxy / silicone resins), isocyanate resins, isocyanurate resins, polysiloxane resins such as alkylalkoxysilane resins, reactive vinyl resins, and mixtures thereof.

[0063] In some embodiments, the vehicle comprises at least one of isocyanate, polyurethane, or polyurea. A wide variety of isocyanates and polyols and polyurethanes made therefrom can be used in the foam compositions of the present disclosure. In some embodiments, the foam composition is a polyurethane foam, and the process for making the foam composition is a process for making a polyurethane foam.

[0064] In some embodiments, the vehicle is not a silicone polymer. In some embodiments, the vehicle comprises an organic polymer other than a silicone-containing polymer. In some embodiments, the vehicle comprises an organic polymer other than acrylated silicone, silicone-containing polyurethane, or epoxy / silicone resin.

[0065] The vehicle may be selected to provide an adhesive composition such as a pressure - sensitive adhesive composition, a hot - melt adhesive composition, a thermosetting adhesive composition, and a thermoplastic adhesive composition. The vehicle can include any pressure - sensitive adhesive composition such as a coatable adhesive, a hot - melt - coatable adhesive, a radiation - curable adhesive (e.g., by electron beam, actinic rays such as visible and UV, and heat), an aqueous adhesive (e.g., an emulsion), and combinations thereof. Suitable pressure - sensitive adhesive (PSA) compositions for the vehicle include tackifier - rubber adhesives (e.g., natural rubber, olefin, silicone, polyisoprene), polybutadiene, polyurethane, styrene - isoprene - styrene and styrene - butadiene - styrene block copolymers and other elastomers), as well as tackifier - containing adhesive compositions and non - tackifier - containing acrylic adhesive compositions. In some embodiments, the PSA composition does not contain and / or is free of silicone rubber.

[0066] In some embodiments, the vehicle includes at least one of an organic polymer or an organic monomer. In some embodiments, the vehicle includes an organic polymer and an organic monomer used to make the organic polymer.

[0067] In some embodiments, the vehicle includes an acrylic PSA or a precursor thereof (e.g., a first and optionally a second acrylic monomer). In some embodiments, the vehicle includes a copolymer of an alkyl ester of acrylic acid as a first monomer and optionally a small amount of a second monomer. Useful acrylic esters include acrylic or methacrylic esters of monohydric alcohols having 1 to 20 carbon atoms. Suitable acrylic or methacrylic esters of monohydric alcohols include those represented by Formula V:

Chemical formula

[0068] The second monomer unit can be more polar than the first monomer unit. Examples of suitable second monomers useful for preparing acrylic PSAs include acrylic acids (e.g., acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid), acrylamides (e.g., acrylamide, methacrylamide, N-ethylacrylamide, N-hydroxyethylacrylamide, N-octylacrylamide, N-t-butylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-ethyl-N-dihydroxyethylacrylamide, and methacrylamides of the aforementioned acrylamides), hydroxyl or amino-substituted acrylates (e.g., 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 6-hydroxyhexyl acrylate, 8-hydroxyoctyl acrylate, 10-hydroxydecyl acrylate, 12-hydroxylauryl acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, dimethylaminoethyl acrylate, t-butylaminoethyl acrylate, aminoethyl acrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropyl acrylate, and methacrylates of the aforementioned acrylates), N-vinylpyrrolidone, N-vinylcaprolactam, alpha-olefins, vinyl ethers, vinyl esters (vinyl acetate, vinyl benzoate, vinyl 4-tert-butylbenzoate, vinyl cinnamate, vinyl decanoate, vinyl neodecanoate, vinyl neononanoate, vinyl pivalate, vinyl propionate, vinyl stearate, and vinyl valerate), allyl ethers, styrene monomers (e.g., 4-tert-butoxystyrene, 4-(tert-butyl)styrene, 4-chloromethylstyrene, chloromethylstyrene, 3-chlorostyrene, 2(diethylamino)ethylstyrene, 2-methylstyrene, 4-methylstyrene, 4-nitrostyrene, and 4-vinylbenzoic acid), maleates, and combinations thereof.In some embodiments, the acrylic polymer comprises at least one second monomer unit of acrylic acid, methacrylic acid, acrylamide, acrylonitrile, methacrylonitrile, N-substituted acrylamide, N,N-disubstituted acrylamide, hydroxyalkyl acrylate, N-vinylcaprolactam, N-vinylpyrrolidone, maleic anhydride or itaconic acid. Other useful monomers that may be present in the acrylate-based adhesive composition include ethylenically unsaturated monomers such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and combinations thereof.

[0069] The crosslinked acrylic PSA can be prepared, for example, by including one or more polyfunctional crosslinkable monomers in the formulation. Suitable polyfunctional monomers include diacrylate esters of diols such as ethylene glycol diacrylate, diethylene glycol diacrylate, propanediol diacrylate, butanediol diacrylate, butane-1,3-diyl diacrylate, pentanediol diacrylate, hexanediol diacrylate (including 1,6-hexanediol diacrylate), heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate, decanediol diacrylate, and dimethacrylates of any of the foregoing diacrylates. Further suitable polyfunctional monomers include polyacrylate esters of polyols such as glycerol triacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, neopentyl glycol diacrylate, dipentaerythritol pentaacrylate, methacrylates of any of the foregoing acrylates, and combinations thereof. Further suitable polyfunctional crosslinkable monomers include polyfunctional acrylate oligomers containing two or more acrylate groups. The polyfunctional acrylate oligomer may be a urethane acrylate oligomer, an epoxy acrylate oligomer, a polyester acrylate, a polyether acrylate, a polyacrylic acrylate, a methacrylate of any of the foregoing acrylates, or a combination thereof. Crosslinking can also be achieved without a crosslinking agent by using high energy radiation such as gamma rays or electron beam radiation.

[0070] Typically, the alkyl ester of acrylic acid (e.g., the first monomer is used in an amount of 75 wt% to 100 wt% based on the total weight of the monomers for making the acrylic polymer, and the second monomer above is used in an amount of 0 wt% to 25 wt% based on the total weight of the monomers for making the acrylic polymer. In some embodiments, the first monomer is used in an amount of at least 80, 85, 90, 92, 95, 97, 98 wt%, or 99 wt% based on the total weight of the monomers, and the second monomer is used in an amount of at most 20, 15, 10, 8, 5, 3, 2 wt%, or 1 wt% based on the total weight of the monomers. These percentages also reflect the percentages of the various monomer units in the acrylic polymer. When present, the polyfunctional crosslinkable monomer can be used in an amount of 0.002 parts to 2 parts per 100 parts of the monofunctional monomer, e.g., about 0.01 part to about 0.5 part or about 0.05 part to 0.15 part per 100 parts of the monofunctional monomer.

[0071] The vehicle can include any of these monomers, a polymer made from any of these monomers, or a combination thereof.

[0072] When the vehicle contains monomers, the polymerization of the monomers can be achieved by various conventional free radical polymerization methods (e.g., solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization), which can be initiated chemically, thermally, and / or by radiation. The polymerization can be initiated by actinic rays (e.g., visible light or ultraviolet light), electron beam rays, and combinations thereof.

[0073] The vehicle can also include free radical initiators such as thermal initiators and photoinitiators. Certain photoinitiators, when used, can also be consumed during the reaction with light and may not need to be present in the foam composition of the present disclosure. In some embodiments, the foam composition further includes a photoinitiator or a fragment thereof. Any suitable photoinitiator can be useful in a foam composition comprising at least one acrylic monomer, for example, the first and second acrylic monomers as described above in any of those embodiments. Suitable photoinitiators include type I or type II photoinitiators. Suitable photoinitiators can also include acetophenone, benzyl ketal, alkylaminoacetophenone, benzoylphosphine oxide, benzoin ether, benzophenone, and benzoyl formate ester. In some embodiments, the free radical photoinitiator is a type I (cleavage type) photoinitiator. Cleavage type photoinitiators include acetophenone, alpha-aminoalkylphenone, benzoin ether, benzoyloxime, acyl (e.g., benzoyl) phosphine oxide, acyl (e.g., benzoyl) phosphinate, and mixtures thereof.

[0074] Examples of useful benzoin ethers include benzoin methyl ether and benzoin butyl ether. Examples of suitable acetophenone compounds include 4 - diethylaminoacetophenone, 1 - hydroxycyclohexyl phenyl ketone, 2 - benzyl - 2 - dimethylamino - 4'- morpholinobutyrophenone, 2 - hydroxy - 2 - methyl - 1 - phenylpropan - 1 - one, and 2,2 - dimethoxy - 1,2 - diphenylethane - 1 - one. Examples of suitable acylphosphine oxides, acylphosphinates, and acylphosphonates include bis(2,6 - dimethoxybenzoyl) - 2,4,4 - trimethylpentylphosphine oxide, phenylbis(2,4,6 - trimethylbenzoyl)phosphine oxide, ethylphenyl(2,4,6 - trimethylbenzoyl)phosphinate, (2,4,6 - trimethylbenzoyl)diphenylphosphine oxide, dimethylpivaloylphosphonate, and poly(oxy - 1,2 - ethanediyl), α,α',α'' - 1,2,3 - propanetriyltris[ω - [[phenyl(2,4,6 - trimethylbenzoyl)phosphinyl]oxy]]. Many photoinitiators are available, for example, from BASF (Vandalia, Ill.) under the trade name "IRGACURE", and from IGM Resins (Waalwijk, Netherlands) under the trade names "OMNIRAD" and "ESACURE". Two or more of any of these photoinitiators may be used in combination in any desired combination. The photoinitiator can be selected, for example, based on the desired curing wavelength and compatibility with the composition.

[0075] Examples of suitable thermal initiators include (e.g., benzoyl peroxide, dibenzoyl peroxide, dilauryl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide), hydroperoxides (e.g., butyl hydroperoxide and cumene hydroperoxide), dicyclohexyl peroxydicarbonate, t-butyl perbenzoate, and azo compounds such as 2,2,-azo-bis(isobutyronitrile) (AIBN), and combinations thereof. Examples of commercially available thermal initiators include initiators available under the trade name "VAZO" from The Chemours Company (Wilmington, DE), such as "VAZO 64" (2,2’-azobis(isobutyronitrile)), "VAZO 52", "VAZO 65" and "VAZO 68", and initiators available under the trade name "CELOGEN" from CelChem LLC, Naples, FL. Peroxides are available from various suppliers.

[0076] The initiator is used in an amount effective to promote the polymerization of the monomers present in the vehicle, and that amount varies depending on polymerization process factors such as, for example, the type of initiator, the molecular weight of the initiator, the intended use of the resulting adhesive composition, and temperature. The photoinitiator can be used in any amount effective to promote the polymerization of the monomers (e.g., from 0.1 part to about 5 parts, 0.2 part to about 2 parts, or about 0.1 part to about 1 part per 100 parts of monofunctional monomer used to make an acrylic polymer).

[0077] In some embodiments, the vehicle includes a photoinitiator that can be regarded as a photo-crosslinking agent. Examples of suitable photo-crosslinking agents include ethylenically unsaturated compounds having the ability to abstract hydrogen in the excited state (e.g., acrylated benzophenones, such as those described in U.S. Patent No. 4,737,559 (Kellen et al.)), p-acryloxybenzophenone available from Sartomer Company, Exton, PA, p-N-(methacryloyl-4-oxapentamethylene)-carbamoyloxybenzophenone, monomers such as N-(benzoyl-p-phenylene)-N'-(methacryloxy-methylene)-carbodiimide described in U.S. Patent No. 5,073,611 (Rehmer et al.), and p-acryloxy-benzophenone) and paraacryloxyethoxybenzophenone; monofunctional benzophenones (e.g., benzophenone, 4-phenylbenzophenone, 4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-dimethylbenzophenone, 4-methylbenzophenone, 4-(2-hydroxyethylthio)-benzophenone and 4-(4-tolylthio)-benzophenone); polyfunctional benzophenones (e.g., carboxymethoxy-benzophenone and the diester of polytetramethylene glycol 250); anthraquinone photo-crosslinking agents (e.g., anthraquinone, 2-methylanthraquinone, 2-t-butylanthraquinone, 2-ethylanthraquinone, 2-phenylanthraquinone, 1,4-dimethylanthraquinone, 2,3-dimethylanthraquinone, 1,2-dimethylanthraquinone, 1-methoxy-2-methylanthraquinone, 2-acetylanthraquinone and 2,6-di-t-butylanthraquinone);Thioxanthone photo-crosslinking agents (e.g., thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-dodecylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methylthioxanthone, 1-cyano-3-chlorothioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1-ethoxycarbonyl-3-ethoxythioxanthone, 1-ethoxycarbonyl-3-aminothioxanthone, 1-ethoxycarbonyl-3-phenylsulfurylthioxanthone, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone, 2-methyl-6-dimethoxymethylthioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)-thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, N-allylthioxanthone-3,4-dicarboximide, N-octylthioxanthone-3,4-dicarboximide, N-(1,1,3,3-tetramethylbutyl)-thioxanthone-3,4-dicarboximide, 6-ethoxycarbonyl-2-methoxythioxanthone; and 6-ethoxycarbonyl-2-methylthioxanthone); halomethyl-1,3,5-triazines (e.g., 2,4-bis(trichloromethyl)-6-(4-methoxy)phenyl)-s-triazine; 2,4-bis(trichloromethyl)-6-(3,4-dimethoxy)phenyl)-s-triazine; 2,4-bis(trichloromethyl)-6-(3,4,5-trimethoxy)phenyl)-s-triazine; 2,4-bis(trichloromethyl)-6-(2,4-dimethoxy)phenyl)-s-triazine; 2,4-bis(trichloromethyl)-6-(3-methoxy)phenyl)-s-triazine as described in U.S. Patent No. 4,330,590 (Vesley);Also included are 2,4-bis(trichloromethyl)-6-naphthylenyl-s-triazine and 2,4-bis(trichloromethyl)-6-(4-methoxy)naphthylenyl-s-triazine as described in U.S. Patent No. 4,329,384 (Vesley). The photo-crosslinking agent may be present in the acrylic polymer in any useful amount. For example, in a vehicle containing at least one acrylic monomer, such as a vehicle containing the above first and second acrylic monomers in any of their embodiments, an amount of from 0.001 part to 10 parts, from 0.001 part to 5 parts, from 0.001 part to 2 parts, from 0.001 part to 1 part, from 0.001 part to 0.5 part, or from 0.001 part to 0.1 part per 100 parts of the monofunctional monomer may be useful.;

[0078] The polymerizable vehicle may also contain a chain transfer agent. The chain transfer agent can be selected to be soluble in the monomer mixture to be polymerized. Examples of suitable chain transfer agents include triethylsilane and mercaptan.

[0079] In some embodiments of the foam composition of the present disclosure and / or the foam composition made by the method of the present disclosure, the vehicle is derived from a composition comprising at least one acrylic monomer, such as the above first and second acrylic monomers in any of their embodiments, and a polymer prepared from a partial polymerization of at least one acrylic monomer. The vehicle may be a solution of the polymer in at least one monomer, for example, it may be polymerized by about 3 percent to 15 percent. In some embodiments, the vehicle comprises at least 75 weight percent, 80 weight percent, 85 weight percent, 90 weight percent or 95 weight percent of monomer based on the total weight of the vehicle. In some embodiments, the vehicle is exposed to ultraviolet irradiation to provide a solution of the polymer in at least one acrylic monomer. A solution of the polymer in at least one acrylic monomer can also be prepared by partial free radical polymerization using a thermal initiator or other free radical source.

[0080] A useful solventless polymerization method is disclosed in U.S. Patent No. 4,379,201 (Heilmann et al.). First, a mixture of a first and a second monomer is exposed to UV irradiation in an inert environment for a time sufficient to form a coatable base syrup, together with a portion of a photoinitiator, and subsequently polymerized by adding a crosslinking agent and the remaining photoinitiator. The crosslinking can be, for example, any of the above-mentioned polyfunctional crosslinkable monomers in any of the above-mentioned amounts. This final syrup containing the crosslinking agent (e.g., having a Brookfield viscosity of about 500 centipoise (cps) to about 10,000 cps, about 100 cps to about 6,000 cps, or about 5,000 cps to about 7,500 cps at 23°C as measured at 60 revolutions per minute using a No. 4 LTV spindle) can be coated onto a substrate. After coating the syrup onto the substrate, further polymerization and crosslinking can be carried out in an inert environment (e.g., nitrogen, carbon dioxide, helium, and argon that does not contain oxygen). A sufficiently inert atmosphere can be obtained by covering the layer of the photoactive syrup with a polymer film that is permeable to UV irradiation or electron beam irradiation, such as a silicone-treated PET film.

[0081] Any suitable light source such as a fluorescent UV bulb, mercury lamp (e.g., low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp), xenon lamp, metal halide lamp, electrodeless lamp, incandescent lamp, LED, and laser can be used. In the case of a broadband light source (e.g., fluorescent UV bulb, mercury lamp, or incandescent lamp), a filter can be useful to narrow the wavelength range within or outside the wavelengths absorbed by the ultraviolet absorber and / or to modify the intensity of the light source.

[0082] The vehicle and / or foam composition can also include other components, such as curing agents, curing accelerators, catalysts, tackifiers, plasticizers, dyes, flame retardants, adhesion promoters (such as coupling agents like silane coupling agents), pigments, impact resistance improvers, flow regulators, foaming agents, fillers (such as talc, zinc oxide, and fused silica), glass and polymer microspheres and fine particles, conductive particles, heat conductive particles, fibers, antistatic agents, hindered phenols, amines, and antioxidants such as sulfur and phosphorus hydroperoxide decomposers, UV absorbers, stabilizers (such as hindered amine light stabilizers and heat stabilizers), and viscosity regulators such as fumed silica.

[0083] The foam composition of the present disclosure and / or the foam composition produced by the method of the present disclosure may contain hollow microspheres (e.g., hollow ceramic (e.g., glass) microspheres, or hollow polymer microspheres, such as elastomeric particles, e.g., those available under the trade name "EXPANCEL" from Akzo Nobel (Amsterdam, The Netherlands). Examples of hollow ceramic microspheres include alumina / silica microspheres ("FILLITE", Pluess-Stauffer International) having a particle size in the range of 5 microns to 300 microns and a specific gravity of 0.7, aluminum silicate microspheres ("Z-LIGHT") having a specific gravity of about 0.45 to about 0.7, calcium carbonate-coated polyvinylidene copolymer microspheres ("DUALITE 6001AE", Pierce & Stevens Corp.) having a specific gravity of 0.13, and glass bubbles commercially available as "3M GLASS BUBBLES" by 3M Company (Saint Paul, Minnesota) in grades K1, K15, K20, K25, K37, K46, S15, S22, S32, S35, S38, S38HS, S38XHS, S42HS, S42XHS, S60, S60HS, iM30K, iM16K, XLD3000, XLD6000, and G-65, and any of the HGS series of "3M GLASS BUBBLES". A foam containing hollow microspheres is called a syntactic foam. The foam adhesive may also contain a hydrocarbon elastomer as described in U.S. Patent No. 5,024,880 (Vesley et al.).

[0084] In some embodiments, the vehicle comprising the adhesive composition includes tackifiers useful for improving the tack of the surface of the PSA. In some embodiments, the foam composition does not include a tackifier. Useful tackifiers can have a number average molecular weight of up to 10,000 grams / mole, a softening point of at least 70 °C as determined using a ring and ball apparatus, and a glass transition temperature of at least -30 °C as measured by differential scanning calorimetry. Useful tackifiers are typically amorphous. In some embodiments, the tackifier is miscible with the PSA polymer, such that macrophase separation does not occur in the PSA. In some embodiments, there is no microphase separation in the PSA. In some embodiments, the tackifier includes at least one of rosin, rosin ester, ester of hydrogenated rosin, polyterpene (e.g., those based on α-pinene, β-pinene or limonene), aliphatic hydrocarbon resin (e.g., those based on cis- or trans-piperylene, isoprene, 2-methyl-but-2-ene, cyclopentadiene, dicyclopentadiene or combinations thereof), aromatic resin (e.g., those based on styrene, α-methylstyrene, methyl indene, indene, coumarone or combinations thereof), or mixed aliphatic-aromatic hydrocarbon resin. Any of these tackifying resins may be (e.g., partially or fully) hydrogenated.Examples of suitable tackifiers include those obtained from "FLORAL" such as "FORAL 85E" (glycerol ester of highly hydrogenated purified gum rosin), commercially available from Eastman, Middelburg, NL; "FORAL 3085" (glycerol ester of highly hydrogenated purified wood rosin), commercially available from Pinova, Brunswick, GA; "ESCOREZ" such as "ESCOREZ 2520" and "ESCOREZ 5615" (aliphatic / aromatic hydrocarbon resins), commercially available from ExxonMobil Corp., Houston, TX; "ARKON" such as the fully hydrogenated hydrocarbon resin "ARKON P125", commercially available from Arakawa Chemical Inc., Chicago, Illinois; and "REGALITE" such as "REGALITE 7100" (partially hydrogenated hydrocarbon resin), commercially available from Eastman, Kingsport, Tennessee.

[0085] In some embodiments, the vehicle comprises a tackifier in an amount of at least about 1 weight percent and up to about 50 weight percent, based on the total weight of the vehicle. In some embodiments, the tackifier is present in the range of 1 weight percent to 25 weight percent, 2 weight percent to 20 weight percent, 2 weight percent to 15 weight percent, 1 weight percent to 10 weight percent, or 3 weight percent to 10 weight percent, based on the total weight of the vehicle.

[0086] For example, in order to reduce the vitrification of the adhesive composition, a plasticizer may be added. Suitable plasticizers include various polyalkylene oxides (e.g., polyethylene oxide or propylene oxide), adipic acid esters, formic acid esters, phosphoric acid esters, benzoic acid esters, phthalic acid esters, polyisobutylene, polyolefins, and sulfonamides, naphthenic oils, plasticizing aids such as materials described as plasticizers in Dictionary of Rubber, K.F. Heinisch, pp. 359, John Wiley & Sons, New York (1974), oils, elastomer oligomers, and waxes. When using a plasticizer, the amount of the plasticizer used varies depending on the properties of the plasticizer and its compatibility with the vehicle.

[0087] In some embodiments, the foam composition of the present disclosure and / or the foam composition produced by the process of the present disclosure is substantially solvent-free. Common organic solvents include aliphatic and cycloaliphatic hydrocarbons (e.g., hexane, heptane, and cyclohexane), hydrocarbon solvents (e.g., benzene, toluene, xylene, 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., methyl chloroform, 1,1,2-trichloro-1,2,2-trifluoroethane, trichloroethylene, and trifluorotoluene), and alcohol solvents (e.g., propanol such as methanol, ethanol, or isopropanol). The foam composition may be substantially free of any of these solvents. The term "substantially free" means that the foam composition may contain up to 0.5, 0.1, 0.05 weight percent, or up to 0.01 weight percent of any of these solvents, or may contain none of these solvents. These percentages are based on the total weight of the foam composition.

[0088] In some embodiments, the vehicle comprises a silane coupling agent. Examples of useful silane coupling agents include many of the silanes listed above useful for treating nanoparticles, as well as epoxy silanes such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethoxydimethoxysilane and 3-glycidoxypropyltriethoxysilane; and aminosilanes such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. The silane coupling agent can be used in an amount of about 0.05 wt% or more or about 0.1 wt% or more and about 2 wt% or less or about 1 wt% or less based on the total weight of the vehicle.

[0089] In some embodiments, the foam composition of the present disclosure and / or the foam composition made by the process of the present disclosure further comprises a blowing agent. Useful blowing agents include physical blowing agents and chemical blowing agents, either of which may be an inorganic blowing agent or an organic blowing agent. Useful chemical blowing mechanisms include in-situ gas generation by chemical reaction; decomposition of components of the composition, such as decomposition of components that release gas upon thermal decomposition; evaporation of components of the composition, such as evaporation of a liquid gas; volatilization of gas in the composition due to a decrease in pressure in the composition or volatilization of gas in the composition due to heating of the composition; and combinations thereof.

[0090] Examples of chemical blowing agents include water and azo-based molecules, carbonate-based molecules, and hydrazide-based molecules such as 4,4'-oxybis(benzenesulfonyl)hydrazide, 4,4'-oxybenzenesulfonyl semicarbazide, azodicarbonamide, p-toluenesulfonyl semicarbazide, barium azodicarboxylate, azodiisobutyronitrile, benzenesulfonhydrazide, trihydrazinotriazine, metal salts of azodicarboxylic acid, oxalic acid hydrazide, hydrazocarboxylate, diphenyloxide-4,4'-disulfohydrazide, tetrazole compounds, sodium bicarbonate, ammonium bicarbonate, preparations of carbonate compounds and polycarbonates, mixtures of citric acid and sodium bicarbonate, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, N,N'-dinitrosopentamethylenetetramine, and combinations thereof. Water is a blowing agent useful for making polyurethane foams. Water reacts with isocyanate to ultimately form carbon dioxide, which foams the polyurethane.

[0091] Suitable inorganic physical blowing agents include, for example, nitrogen, argon, oxygen, water, air, helium, sulfur hexafluoride, and combinations thereof.

[0092] Useful organic physical blowing agents include carbon dioxide, aliphatic hydrocarbons, aliphatic alcohols, fully and partially halogenated aliphatic hydrocarbons such as methylene chloride, and combinations thereof. Examples of suitable aliphatic hydrocarbon blowing agents include members of the alkane series of hydrocarbons such as methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and blends thereof. Useful aliphatic alcohols include, for example, methanol, ethanol, n-propanol, and isopropanol, and combinations thereof. Suitable fully and partially halogenated aliphatic hydrocarbons include, for example, fluorocarbons, chlorocarbons, and chlorofluorocarbons, and combinations thereof.

[0093] Examples of suitable halogenated (in some embodiments, fluorinated) blowing agents include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1-trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane, pentafluoroethane (HFC-125), difluoromethane (HFC-32), perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane, methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-142b), chlorodifluoromethane (HCFC-22), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124), trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichloro-trifluoroethane (CFC-113), dichlorotetrafluoroethane (CFC-114), chloroheptafluoropropane, and dichlorohexafluoropropane, and combinations thereof. In some embodiments, the blowing agent is not halogenated. In some embodiments, the blowing agent is not fluorinated.

[0094] The blowing agents can be used as single components, as mixtures and combinations thereof, and as mixtures with other co-blowing agents. The blowing agents can be added to the composition in an amount sufficient to achieve the desired foam density.

[0095] In some embodiments, the foam compositions of the present disclosure and / or foam compositions made by the processes of the present disclosure further include a nucleating agent. The nucleating agent can be any conventional nucleating agent. The amount of nucleating agent added can be selected according to the desired cell size, the selected blowing agent, and the density of the vehicle. Examples of inorganic nucleating agents in particulate form include clay, talc, silica, and diatomaceous earth.

[0096] Organic nucleating agents can decompose or react at a given temperature. An example of an organic nucleating agent is a combination of an alkali metal salt of a polycarboxylic acid and a carbonate or bicarbonate. Examples of useful alkali metal salts of polycarboxylic acids include the monosodium salt of 2,3-dihydroxy-butanedioic acid (i.e., sodium hydrogen tartrate), the monopotassium salt of butanedioic acid (i.e., potassium hydrogen succinate), the trisodium and tripotassium salts of 2-hydroxy-1,2,3-propanetricarboxylic acid (i.e., sodium citrate and potassium citrate, respectively), and the disodium salt of ethanedioic acid (i.e., sodium oxalate), and polycarboxylic acids such as 2-hydroxy-1,2,3-propanetricarboxylic acid, and combinations thereof. Examples of carbonates and bicarbonates include sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium carbonate, calcium carbonate, and combinations thereof. One contemplated combination is a combination of a monoalkali metal salt of a polycarboxylic acid (e.g., sodium citrate or sodium hydrogen tartrate) and a carbonate or bicarbonate. It is contemplated that mixtures of different nucleating agents can be added to the vehicle. Other useful nucleating agents include a stoichiometric mixture of citric acid and sodium bicarbonate.

[0097] In some embodiments, the foam composition of the present disclosure has a foam half-life of at least 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 45 minutes, or 60 minutes at 22°C. In this application, the foam half-life is determined by placing approximately 30 grams of a 1 weight percent solution of a blend of surface-modified nanoparticles and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane in a 4 ounce glass jar in a vehicle, and bubbling nitrogen through the mixture for 5 minutes at 22°C while stirring the mixture with a magnetic stir bar set at a low setting using the apparatus described in the Example Syrup Bubbling Test. Stop bubbling and stop the magnetic stir bar. Measure the height of the foam with a ruler. Measure the time required for half of the liquid to drain from the foam (i.e., to provide half of the initial volume of the liquid) to provide the foam half-life.

[0098] As shown in the comparison of Examples 1 to 6 and Comparative Example 1 in the following examples, silicone MQ resin has been reported to be an antifoaming agent or a foam inhibitor and has no adverse effect on the foaming ability of surface-modified nanoparticles in the vehicle of acrylic monomers. In fact, silicone MQ resin was shown to enhance the foaming ability of surface-modified nanoparticles in Examples 1 to 3. Also, silicone MQ resin was found to be compatible with surface-modified nanoparticles and not to cause gelation or inhomogeneity when mixed together. As shown in the comparison of Examples 7, 8, and 10 and Comparative Examples 2 and 4 in the following examples, the composition containing surface-modified nanoparticles and poly(alkylene oxide)-modified polydimethylsiloxane is surprisingly synergistic, and the combination has a higher ability to form a foam that foams and persists than the composition containing either surface-modified nanoparticles or poly(alkylene oxide)-modified polydimethylsiloxane alone. Examples 7 and 8 foamed better and formed more persistent foams than Example 9. In addition to having a number average molecular weight of 10,000 grams / mole or less, the poly(alkylene oxide)-modified polydimethylsiloxane used in Examples 7 and 8 contained ethyleneoxy groups, while the poly(alkylene oxide)-modified polydimethylsiloxane used in Example 9 contained a combination of ethyleneoxy groups and propyleneoxy groups.

[0099] The present disclosure provides a process for making the foam composition of the present disclosure in any of its embodiments. This process involves introducing a blowing agent into a composition comprising a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane to form voids in the composition. The blowing agent may be any of the chemical or physical blowing agents described above. In some embodiments, the composition foams after the surface-modified nanoparticles are dispersed throughout the vehicle, and in some embodiments, after being homogeneously dispersed throughout the vehicle. The composition can be foamed according to various foaming methods such as those described in, for example, U.S. Patent Nos. 5,024,880 (Vesley et al.), 4,895,745 (Vesley et al.), and 4,748,061 (Vesley et al.).

[0100] The composition may be prepared by forming gas voids in the composition using various mechanisms such as mechanical mechanisms, chemical mechanisms, and combinations thereof. Useful mechanical foaming mechanisms include stirring the composition (e.g., shaking, agitating, and / or whipping the composition), injecting a gas into the composition, for example, inserting a nozzle beneath the surface of the composition and blowing a gas into the composition, and combinations thereof. In some embodiments, introducing the blowing agent includes at least one of stirring the composition or injecting a gas into the composition. In some embodiments, the blowing agent includes at least one of air, nitrogen, oxygen, carbon dioxide, helium, argon, or nitrous oxide.

[0101] The foam compositions of the present disclosure and / or foam compositions made by the processes of the present disclosure are suitable for use in a variety of applications. Representative examples of foam applications include adhesives, flotation, applications in the automotive industry such as automotive body moldings, applications related to automotive glazing such as gaskets and seals, applications in the construction industry such as structural parts (e.g., sized lumber, molded trim, posts, beams, and molded structural members), etc., cementitious materials and gypsum materials such as lightweight ceramics, landfill covers, odor barriers, dust covers, fire extinguishing and fireproof foams, liquid containment booms (e.g., booms for containing oil spills), and fillers for gaps and voids present in oil wells and tunnels and in soil. Other foam applications include packaging, commercial cleaning products such as cleaners for vertical cleaning applications, inks, deinking compositions, surface coatings such as foam coatings for paper and fabric treatment, etc.

[0102] The foam compositions can also be formulated for use in applications such as foam personal care products such as hair treatment compositions, shaving compositions, and skin treatment compositions; medical applications such as bandages and wound dressings; and household and industrial applications such as cups, plates, ear plugs, cushions, pillows, thermal insulators, e.g., dampers for suppressing sound and absorbing vibration (e.g., buffering the vibration of machine covers), and combinations thereof, and baffles.

[0103] In another embodiment, the foam composition is formulated to be useful, for example, as a gasket or seal for sealing an area from dust, moisture, organic vapors, and combinations thereof. Examples of sealing applications include sealing gaps between components within a computer printer, sealing of electronic devices, and sealing of a skylight assembly.

[0104] The foam composition can be formulated to provide a foam that is flexible and conformable, fills gaps, and bonds to irregular surfaces. The foam can also be formulated to provide a bond line that seals, cushions vibrations, dampens vibrations, resists shock, withstands a wide temperature range, or provides good thermal insulation, or a combination of these properties.

[0105] The foam composition can be in the form of a tape, such as a pressure-sensitive adhesive tape. Useful foam tape structures include a foam composition disposed on a substrate, such as a backing or release liner, and optionally wound in the form of a roll. In some embodiments, the foam tape structure includes an adhesive composition disposed on the surface of the foam tape, which forms a tape having an adhesive layer on one side of the foam tape, i.e., a single-coated adhesive foam tape. In another embodiment, the foam composition can be in the form of a tape having adhesive layers on two major surfaces of the foam tape, which is known as a double-coated foam tape.

[0106] The present disclosure provides a process for making an adhesive tape, the process including applying a foam composition to a substrate. Application of the foam composition to the substrate can be performed after foaming using any of the methods described above, i.e., after forming voids therein. The foam composition can be applied to the substrate using a variety of methods (e.g., dipping, spraying, brushing, roll coating, bar coating). In some embodiments, the composition can be coated onto a liner using a notch bar that sets a desired thickness of the gap, and another liner may be added to maintain the gap of the desired thickness. Any of the foam compositions described above in any of those embodiments can be applied to the substrate, but in some embodiments, the vehicle includes monomers and optionally polymers, and the process further includes polymerizing the monomers. In some embodiments, the process further includes crosslinking the foam composition. When polymerization or crosslinking using a UV light source such as any of the above is used, UV irradiation of any useful magnitude, e.g., from about 1,000 mJ / cm 2 to about 10,000 mJ / cm 2 , 1,000 mJ / cm 2 to about 5,000 mJ / cm 2 , or from about 1,000 mJ / cm 2 to about 3,000 mJ / cm 2 can be used.

[0107] Adhesive foams have a variety of useful applications, such as joining two substrates together, attachment applications using articles such as hooks, hangers, and holders, joining applications such as adhesively bonding two or more containers, e.g., boxes, together for later separation, joining an article to a surface, e.g., a wall, floor, ceiling, and counter, and replacing mechanical fasteners, mastics, or liquid adhesives. When joining a rough or irregular surface, the properties and formulation of the foam tape can be selected to provide a foam tape that distributes stress evenly across the joined area. Other adhesive foam applications include, for example, structural adhesives and in-situ foam adhesives.

[0108] In other embodiments, the foam composition includes other components such as scrims, films, tissues, and combinations thereof, which are dispersed in the foam, for example, in the form of alternating layers, interpenetrating layers, and combinations thereof, or are arranged in a layered structure with the foam composition. Other useful foam structures include multilayer foam structures that include layers of the foam, where these layers differ in at least one property such as, for example, density and composition.

[0109] The foam composition can also be subjected to post - processes such as, for example, die - cutting, cross - linking, and sterilization.

[0110] Some embodiments of the present disclosure In a first embodiment, the present disclosure provides a foam composition comprising a vehicle, surface - modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide) - modified polydimethylsiloxane. In a second embodiment, the present disclosure provides the foam composition according to the first embodiment, which comprises a silicone MQ resin. In a third embodiment, the present disclosure provides a foam composition comprising a vehicle, surface - modified nanoparticles having a particle size of 100 nanometers or less, and a silicone MQ resin. In a fourth embodiment, the present disclosure provides the foam composition according to any one of the first to third embodiments, wherein the silicone MQ resin has an M:Q ratio of at least 0.8:1, 0.9:1, 1:1, 1.1:1, or 1.2:1. In a fifth embodiment, the present disclosure provides the foam composition according to any one of the first to fourth embodiments, wherein the silicone MQ resin has an M:Q ratio of 2.5:1 or less than or equal to 2:1. In a sixth embodiment, the present disclosure provides that the silicone MQ resin is one or more compounds represented by the formula (R)3 - Si - R 1 and one or more compounds represented by the formula (R 1) Prepared by reaction with one or more compounds represented by 4Si, wherein each R is independently hydrogen, alkyl, aryl, arylene or heterocyclylene, at least one of which is interrupted or terminated by alkylene or heterocyclylene, and alkyl and arylene, at least one of which is interrupted or terminated by arylene or heterocyclylene, is unsubstituted or substituted with halogen and is optionally interrupted by at least one chain-linked -O-, -NR'-, -S-, -Si-, or combinations thereof, and aryl, arylene, and heterocyclylene are unsubstituted or substituted with at least one alkyl, alkoxy, halogen, or combinations thereof, each R 1 is independently a hydrolyzable group, and provides the foam composition according to any one of the first to fifth embodiments. R may be other than hydrogen. R is an alkyloxy group, for example, of the formula -(OR 2 ) n -OR 3 group, wherein n, R 2 , and R 3 are as defined below in any of those embodiments and does not include a group. In a seventh embodiment, the present disclosure provides the foam composition according to any one of the first to sixth embodiments, wherein the silicone MQ resin contains a methyl group. In an eighth embodiment, the present disclosure provides the foam composition according to any one of the first to seventh embodiments, wherein the silicone MQ resin has a hydroxyl content in the range of 185 to 1840 milliequivalents / kilogram. In a ninth embodiment, the present disclosure provides the foam composition according to any one of the first to eighth embodiments, wherein the foam composition contains or further contains poly(alkylene oxide) modified polydimethylsiloxane. In a tenth embodiment, the present disclosure provides that the poly(alkylene oxide) modified polydimethylsiloxane has a repeating divalent unit represented by formula II:

Chemical formula

[0111] In the 14th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 12th embodiments, wherein the vehicle contains at least one of a monomer, a polymer, or a combination thereof. In the 15th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 14th embodiments, wherein the vehicle is neither silicone nor a silicone-containing polymer. In the 16th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 15th embodiments, wherein the vehicle contains at least one of a thermoplastic polymer, a thermosetting polymer, or an elastomer. In the 17th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 16th embodiments, wherein the vehicle contains at least one of a polyester, a polyurethane, an amino resin, an alkyd resin, a phenolic resin, an epoxy resin, an isocyanate resin, an isocyanurate resin, or an acrylic polymer. In the 18th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 17th embodiments, wherein the vehicle contains a crosslinked polymer. In the 19th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 18th embodiments, wherein the vehicle contains at least one of an acrylate polymer or an acrylic polymer. In the 20th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 19th embodiments, wherein the vehicle is a mixture of at least two or at least three of isooctyl acrylate, 2-ethylhexyl acrylate, 2-propylheptyl acrylate, butyl acrylate, acrylic acid, or a structural isomer of a secondary alkyl (meth)acrylate of formula (VI): [Chemical formula] [wherein, R 7 and R 8 are each independently a C1-C 30 saturated straight-chain alkyl group, and the total number of carbon atoms in R 7 and R 8 is 7 to 31, and R 3Provided is the foam composition according to any one of the first to nineteenth embodiments, including at least one of polymers that are a hydrogen or methyl group, or contain any of these units. In the twenty-first embodiment, the present disclosure provides the foam composition according to any one of the first to twentieth embodiments, wherein the vehicle contains at least one of acrylic acid and at least one of isooctyl acrylate or 2-ethylhexyl acrylate. In the twenty-second embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-first embodiments, wherein the vehicle contains a polyolefin. In the twenty-third embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-second embodiments, wherein the vehicle contains at least one of a novolak resin, a resol resin, or a polyurea resin. In the twenty-fourth embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-third embodiments, wherein the vehicle contains at least one of isocyanate, polyurethane, or polyurea. In the twenty-fifth embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-fourth embodiments, wherein the vehicle contains at least one of an alcohol, an aldehyde, a ketone, an ester, an ether, an amine, an amide, or a hydrocarbon.

[0112] In the twenty-sixth embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-fifth embodiments, wherein the vehicle has voids therein. In the twenty-seventh embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-sixth embodiments, further including a foaming agent. In the twenty-eighth embodiment, the present disclosure provides the foam composition according to the twenty-seventh embodiment, wherein the foaming agent contains at least one of air, nitrogen, oxygen, carbon dioxide, helium, argon, or nitrous oxide. In the twenty-ninth embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-eighth embodiments, having a foam half-life of at least 10 minutes at 22°C. In the thirtieth embodiment, the present disclosure provides the foam composition according to any one of the first to twenty-ninth embodiments, further including at least one of fumed silica, hollow ceramic microspheres, or hollow polymer microspheres.

[0113] In the 31st embodiment, the present disclosure provides the foam composition according to any one of the 1st to 30th embodiments, wherein the surface-modified nanoparticles have a particle size of about 50 nanometers or less. In the 32nd embodiment, the present disclosure provides the foam composition according to any one of the 1st to 31st embodiments, wherein the surface-modified nanoparticles include inorganic nanoparticles. In the 33rd embodiment, the present disclosure provides the foam composition according to the 32nd embodiment, wherein the surface-modified nanoparticles include at least one of silica, titania, alumina, zirconia, vanadia, ceria, iron oxide, antimony oxide, tin oxide, or aluminum / silica. In the 34th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 31st embodiments, wherein the surface-modified nanoparticles include organic nanoparticles. In the 35th embodiment, the present disclosure provides the foam composition according to the 34th embodiment, wherein the surface-modified nanoparticles include at least one of alkylated buckminsterfullerene or alkylated polyamidoamine dendrimer. In the 36th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 35th embodiments, wherein the surface-modified nanoparticles have a hydrophobic surface group, a hydrophilic surface group, or a combination thereof. In the 37th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 36th embodiments, wherein the surface-modified nanoparticles have a surface group derived from organosilane, organic acid, organic base, or a combination thereof. In the 38th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 37th embodiments, wherein the surface-modified nanoparticles have a surface group derived from organosilane, carboxylic acid, sulfonic acid, phosphonic acid, or a combination thereof. In the 39th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 38th embodiments, wherein the surface-modified nanoparticles are present in the foam composition in an amount of 0.1 weight percent to 10 weight percent, 0.1 weight percent to 5 weight percent, or 0.5 weight percent to 3 weight percent based on the total weight of the foam composition. In the 40th embodiment, the present disclosure provides the foam composition according to any one of the 1st to 39th embodiments, wherein the foam composition does not contain a fluorinated surfactant.

[0114] In the 41st embodiment, the present disclosure provides the foam composition according to any one of the 1st to 40th embodiments, wherein the vehicle contains an adhesive composition. In the 42nd embodiment, the present disclosure provides the foam composition according to the 41st embodiment, wherein the vehicle contains a pressure-sensitive adhesive composition. In the 43rd embodiment, the present disclosure provides the foam composition according to the 41st embodiment, wherein the vehicle contains a hot-melt adhesive composition. In the 44th embodiment, the present disclosure provides an adhesive tape containing the foam composition according to any one of the 41st to 43rd embodiments. In the 45th embodiment, the present disclosure provides an article containing the foam composition according to any one of the 1st to 43rd embodiments.

[0115] In the 46th embodiment, the present disclosure provides a process for producing the adhesive tape according to the 44th embodiment, the process including applying the foam composition to a substrate. In the 47th embodiment, the present disclosure provides the process according to the 46th embodiment, wherein the vehicle contains a monomer and optionally a polymer, and the process further includes polymerizing the monomer. In the 48th embodiment, the present disclosure provides the process according to the 46th or 47th embodiment, the process further including crosslinking the foam composition. In the 49th embodiment, the present disclosure provides a process for producing the foam composition according to any one of the 1st to 43rd embodiments, the process including introducing a foaming agent into a composition containing a vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of a silicone MQ resin or a poly(alkylene oxide)-modified polydimethylsiloxane to form gaps in the composition. In the 50th embodiment, the present disclosure provides the process according to the 49th embodiment, wherein introducing the foaming agent includes at least one of stirring the composition or injecting gas into the composition. In the 51st embodiment, the present disclosure provides the process according to the 50th embodiment, wherein the foaming agent contains at least one of air, nitrogen, oxygen, carbon dioxide, helium, argon, or nitrous oxide.

[0116] The following specific but non-limiting examples will be useful in illustrating the present disclosure.

Example

[0117] Unless otherwise stated, all parts, percentages, ratios, etc. in the examples and elsewhere in this specification are by weight. The following abbreviations are used in this section: g = gram, cm = centimeter, Ga = gauge, LPM = liter / minute, mM = millimole, mm = millimeter, mL = milliliter, NMR = nuclear magnetic resonance, wt% = weight percent. The materials used in the examples and their suppliers are shown in Table 1 below.

Table 1

[0118] Determination of the M:Q ratio Approximately 150 mg of the sample was placed in a PTFE NMR tube and dissolved with 2 mL of 0.1 mM Cr(OAcAc)3 in CDCl3. S1 29 NMR data was collected on a 600 MHz JEOL NMR spectrometer equipped with a 10 mm JEOL silicon-free probe. The M:Q ratio was determined by integrating the M region of the Si 29 NMR spectrum from 17 to 5 ppm. Si 29 The Q region in the NMR spectrum, -90 to -115 ppm was also integrated. The M:Q ratio is the corresponding integration ratio. The data is shown in Table 4 below.

[0119] Molecular weight measurement of poly(alkylene oxide) modified polydimethylsiloxane Approximately 150 mg of the resin was placed in a PTFE NMR tube and dissolved with 2 mL of 0.1 mM Cr(OAcAc)3 in CDCl3. S1 29 NMR data was collected on a 600 MHz JEOL NMR spectrometer equipped with a 10 mm JEOL silicon-free probe and the number average molecular weight was determined. The data is shown in Table 4 below.

[0120] Preparation of surface-modified nanoparticles 350 g of the aqueous colloidal silica dispersion “NALCO 2326” was charged into a 1-liter three-necked round-bottom flask, and stirring was started. Next, 222 g of 2-propanol was slowly added. Slight exotherm was observed. After a mixing time of about 10 minutes, 25.6 g of n-octyltrimethoxysilane was added, followed by a rinse of 2.6 g of methyltrimethoxysilane and 19 g of 2-propanol. The mixture was heated to 82 °C. The mixture became a viscous slurry at about 80 °C. The mixture was held at 82 °C for 4 hours and then cooled to 25 °C. The mixture was transferred to a one-necked eggplant-shaped flask and rinsed with about 120 g of 2-propanol. The solvent was removed by rotary evaporation (bath temperature 50 °C, slowly reduced the vacuum to 80 mmHg). About 370 g of distillate was removed and the mixture was cooled to 25 °C. 80.0 g of 2-EHA and 0.02 g of phenothiazine were added to the mixture. This mixture was subjected to rotary evaporation (initial bath temperature was 35 °C, raised to 50 °C, slowly reduced the vacuum to 19 mmHg) to remove the remaining solvent and water. When the water was removed, the material transitioned from a turbid state to a clear state. The resulting 149.1 g of product (50 wt% surface-modified nanoparticles in 2-EHA) was transferred from the flask to a jar.

[0121] Examples 1 to 10 (EX1 to EX10) and Comparative Examples (CE1 to CE4) for the Foamed Column Screen Test Into a tall glass sample vial, for EX1 to EX10, 0.20 g of a 70:30 mixture of surface-modified nanoparticles (50 wt% in 2-EHA) and silicone MQ resin or poly(alkylene oxide)-modified polydimethylsiloxane (shown in Table 4 below) was weighed and added. For CE1, only 0.20 g of surface-modified nanoparticles (50 wt% in 2-EHA) was added. For CE2 to CE4, only 0.20 g of the poly(alkylene oxide)-modified polydimethylsiloxane shown in Table 4 below was added. For Examples 3 and 4, 0.1 g of 2-EHA was added. For Examples 7 to 9, since the sample gelled without adding 2-EHA, 0.06 g of 2-EHA was added. Next, 10.0 g of an acrylic monomer mixture (90 parts by weight of 2-EHA: 10 parts by weight of AA) was added to the sample vial. The sample vial was capped and evaluated using the foam column screening test described below. The data is shown in Table 4 below.

[0122] Foam Column Screening Test (Manual Stirring) The preparation samples of the acrylic monomer mixture containing Examples 1 to 10 and Comparative Examples CE1 to CE4 were thoroughly combined by shaking the sample vial vigorously for 15 seconds and allowing the contents to settle. Next, the sample vial was placed on a horizontal plane. Using a ruler, the height of the foam was visually measured. A photo was taken and the data was immediately recorded to record the height of the foam column. The time required for half of the liquid to be drained from the foam (i.e., to provide half of the initial volume of the liquid) was measured and the foam half-life was reported. The overall evaluation is further described in Table 2 below.

Table 2

[0123] Examples 1A to 10A (EX1A to EX10A) and Comparative Examples (CE1A to CE4A) for the Syrup Bubbling Test A coating-capable viscous syrup polymer was prepared by introducing 90 parts of 2-EHA, 10 parts of AA, and 0.04 part (per 100 parts of monomers) of “OMNIRAD 651” into a 1-quart jar and stirring until the photoinitiator was dissolved to obtain a homogeneous mixture. The mixture was degassed by introducing nitrogen gas through a tube inserted through the opening in the lid of the jar and bubbled vigorously for at least 5 minutes. While stirring, the mixture was exposed to UV-A light until a pre-adhesive syrup having a viscosity suitable for coating was formed. After UV exposure, air was introduced into the jar. The light source was an LED array having a peak emission wavelength of 365 nm.

[0124] 30.0 g of syrup was weighed into a 4-ounce glass jar equipped with a magnetic stir bar. For EX1A to EX10A, then, 0.30 g of a 70:30 mixture of surface-modified nanoparticles (50 wt% in 2-EHA) and silicone MQ resin or poly(alkylene oxide)-modified polydimethylsiloxane (shown in Table 4 below) was added to the glass jar. For CE1A, only 0.30 g of surface-modified nanoparticles (50 wt% in 2-EHA) was added. For CE2A to CE4A, only 0.30 g of the poly(alkylene oxide)-modified polydimethylsiloxane shown in Table 4 below was added. For Examples 3 and 4, 0.15 g of 2-EHA was added. For Examples 7 to 9, 0.09 g of 2-EHA was added. Then, the sample was capped. The sample was stirred on a magnetic stirring plate for 5 minutes and then subjected to the syrup bubbling test described below. The data are shown in Table 4 below.

[0125] Syrup Bubbling Test A bubbling device was installed. The house nitrogen line was connected to a Cole-Palmer 5 LPM flow meter. The flow meter was connected to a tube equipped with a long 18Ga needle. The lid of the prepared sample glass jar was replaced with a lid equipped with a glass adapter, which was a hollow tube attached through the hole of the standard jar lid. A septum was inserted into the glass adapter together with a 16Ga needle (for ventilation). Then, the long 18Ga needle was inserted into the septum. Then, nitrogen was released and the flow rate was adjusted to 4 LPM to confirm that the ventilation needle was functioning. Then, a magnetic stir bar was stirred on a magnetic stir plate at the "low" setting. Then, the long needle was pushed to the bottom of the jar. The device was bubbled for 5 minutes. Then, the needle was removed and the magnetic stir bar was stopped. Then, the closed glass jar lid was reapplied and the glass jar was left standing at the surface height.

[0126] Using a ruler, the height of the foam was visually measured. Photos were taken and the data was immediately recorded to record the height and persistence of the foam column. The time required for half of the liquid to be drained from the foam (i.e., to provide half of the initial volume of the liquid) was measured to report the foam half-life. The overall evaluation is shown in Table 3 below.

Table 3

Table 4

[0127] It should be understood that various modifications and changes to the present disclosure can be made by those skilled in the art without departing from the scope and spirit of the present disclosure, and that the present invention should not be overly limited to the exemplary embodiments described herein.

Claims

1. A foam composition, A vehicle with gaps inside, Surface-modified nanoparticles having a particle size of 100 nanometers or less, and At least one of silicone MQ resin or poly(alkylene oxide) modified polydimethylsiloxane, A foam composition containing the following:

2. The foam composition according to claim 1, wherein the foam composition comprises the silicone MQ resin.

3. The foam composition according to claim 2, wherein the silicone MQ resin has an M:Q ratio of at least 0.8:

1.

4. The foam composition according to claim 2, wherein the MQ resin contains methyl groups and has a hydroxyl content in the range of 185 to 1840 milliequivalents per kilogram.

5. The foam composition according to claim 1, wherein the foam composition comprises the poly(alkylene oxide)-modified polydimethylsiloxane, the poly(alkylene oxide)-modified polydimethylsiloxane having a number average molecular weight of 50,000 grams / mol or less, and the alkylene oxide comprises an ethylene oxy group, a propylene oxy group, or a combination thereof.

6. The foam composition according to claim 1, wherein the silicone MQ resin, the poly(alkylene oxide)-modified polydimethylsiloxane, or a combination thereof is present in the foam composition at a level of 0.1 to 10 weight percent based on the total weight of the foam composition.

7. The foam composition according to claim 1, wherein the vehicle comprises at least one of a polymer or a monomer.

8. The foam composition according to claim 1, wherein the vehicle is neither silicone nor a silicone-containing polymer.

9. The foam composition according to claim 1, wherein the vehicle comprises at least one of polyester, polyurethane, polyurea, amino resin, alkyd resin, phenolic resin, epoxy resin, isocyanate resin, isocyanurate resin, or acrylic polymer.

10. The foam composition according to claim 1, wherein the surface-modified nanoparticles include at least one of silica, titania, alumina, zirconia, vanadia, ceria, iron oxide, antimony oxide, tin oxide, or aluminum / silica.

11. The foam composition according to claim 1, wherein the surface-modified nanoparticles have surface groups derived from silane, organic acid, organic base, or a combination thereof.

12. The foam composition according to claim 1, wherein the surface-modified nanoparticles are present in the foam composition in an amount of 0.1 to 10 weight percent based on the total weight of the foam composition.

13. The foam composition according to any one of claims 1 to 12, wherein the vehicle comprises an adhesive composition.

14. An adhesive tape comprising the foam composition described in claim 13.

15. A process for producing the foam composition according to claim 13, comprising introducing a foaming agent into a composition comprising the vehicle, surface-modified nanoparticles having a particle size of 100 nanometers or less, and at least one of the silicone MQ resin or the poly(alkylene oxide)-modified polydimethylsiloxane, thereby forming voids in the composition.