Method of forming aqueous dispersion of copolymer, adhesive composition comprising copolymer, film or article comprising same, and method of coating substrate

Abstract

A method of forming an aqueous dispersion of a copolymer includes providing a copolymerizable composition in water. The copolymerizable composition comprises (5) to 95% by weight of an ethylenically functionalized siloxane polymer or silane based on the total weight of the copolymerizable composition, and 5% or more by weight of an organic acrylic monomer based on the total weight of the copolymerizable composition. The method further includes providing 0.1 to 10 wt% of a surfactant based on the total weight of the ethylenically functionalized siloxane polymer or silane and the organoacrylic monomer. The ethylenically functionalized siloxane polymer or silane is polymerized with the organoacrylic monomer to form an aqueous dispersion of a copolymer. The copolymer exhibits a glass transition temperature (Tg) of from 0 to-100 DEG C. Tg is determined by differential scanning calorimetry according to DIN 53765 using a perforated crucible at a heating rate of 10 DEG K / min.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an aqueous dispersion of a copolymer, an adhesive comprising such a copolymer, and a method of coating a substrate with such materials.

[0002] When pressure is applied to cause the adhesive to bond to the substrate, the adhesive, such as a pressure-sensitive adhesive (PSA), will adhere to the substrate.

[0003] Conventional PSAs contain organic solvents. Recently, due to environmental, resource conservation, and safety considerations, water has been used as a solvent for PSAs.

[0004] Water-based PSAs mainly comprise a dispersion of an acrylic polymer or copolymer. Advantages of acrylic PSAs include the ability to control the glass transition temperature (Tg), molecular structure, crosslink density, and the competitive cost of such systems. A PSA having excellent tack and peel strength can be achieved by incorporating an acrylic resin, and such a PSA has good environmental stability and antioxidant properties.

[0005] However, a disadvantage of acrylic PSAs is the difficulty encountered in bonding to low surface energy surfaces, such as those comprising, for example, siloxanes, polyethylene, or polypropylene. In addition, acrylic PSAs cause adhesion buildup on the surfaces to which they are applied over time and can be challenging to clean off the surface. Further, when used in applications on the skin, acrylic PSAs may cause skin trauma during removal from the skin and have limited repositionability.

[0006] PSAs comprising acrylate systems have the same disadvantages and generally also have poor high and low temperature performance.

[0007] Accordingly, there is a desire to provide materials that can be used in adhesives and enable the adhesives to overcome the above deficiencies. Methods for forming such materials, along with their attendant embodiments, would also be desirable. SUMMARY OF THE INVENTION

[0008] Embodiments of a method for forming an aqueous dispersion of a copolymer are provided. In one embodiment, the method includes providing a copolymerizable composition in water. Based on the total weight of the copolymerizable composition, the copolymerizable composition comprises 5% to 95% by weight of an ethylenically functionalized siloxane polymer or silane. Based on the total weight of the copolymerizable composition, the copolymerizable composition further comprises 5% or more by weight of an organic acrylic monomer. The method includes providing 0.1 to 10 wt% of a surfactant, based on the total weight of the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer. The ethylenically functionalized siloxane polymer or silane is polymerized with the organic acrylic monomer to form an aqueous dispersion of the copolymer. The copolymer exhibits a glass transition temperature (Tg) of 0 to -100 °C. The Tg is determined by differential scanning calorimetry using a pierced crucible at a heating rate of 10 °K per minute according to DIN 53765.

[0009] In certain embodiments, the method further includes forming a miniemulsion. The miniemulsion comprises an ethylenically functionalized siloxane polymer or silane, an organic acrylic monomer, and a surfactant. A radical initiator is also introduced. The organic acrylic monomer comprises one or more acrylates or acrylic monomers. The ethylenically functionalized siloxane polymer or silane is polymerized with the organic acrylic monomer in the presence of the surfactant and water.

[0010] In some embodiments, the miniemulsion comprises organic droplets. The organic droplets comprise an ethylenically functionalized siloxane polymer or silane and an organic acrylic monomer, and are formed prior to polymerizing the ethylenically functionalized siloxane polymer or silane with the organic acrylic monomer.

[0011] In other embodiments, the method further includes curing the aqueous dispersion of the copolymer by heating the aqueous dispersion to evaporate water therefrom.

[0012] Preferably, the aqueous dispersion of the copolymer comprises a solids content of 40 wt% or higher based on the total weight of the aqueous dispersion. More preferably, based on the total weight of the aqueous dispersion, the solids content of the aqueous dispersion of the copolymer is 40 wt% to 70 wt%.

[0013] In some embodiments, these copolymers exhibit a Tg of -10 °C to -60 °C. In other embodiments, when measured by dynamic light scattering, these copolymers have a z-average particle size of 1000 nanometers or less.

[0014] In one embodiment, the aqueous dispersion of the copolymer exhibits a viscosity of 1 to 20,000 mPa·s at 25 °C.

[0015] In other embodiments, an adhesive composition is provided. In one embodiment, the adhesive composition comprises a copolymer formed by a method for forming an aqueous dispersion of a copolymer.

[0016] In some embodiments, the film of the adhesive composition has a wet thickness of 381 microns and exhibits a peak tack of 100 grams-force or greater after curing when measured by a TA.XT Plus texture analyzer using a TA-57R probe and a TA-303 device. Preferably, the film exhibits a peak tack of 100 to 1,000 grams-force.

[0017] In other embodiments, the adhesive composition comprises an active compound that can be released from a matrix formed by these copolymers at a controlled rate. In other examples, the adhesive composition is stable against phase separation at 25 °C, as measured by the absence of any observable phase separation within 180 days.

[0018] Preferably, according to EPA test method 24, the adhesive composition has a volatile organic content of 2.5% or less. In certain embodiments, the adhesive composition is stable against phase separation at 25 °C, as measured by no more than a 20% change in the z-average particle size. In other embodiments, the adhesive composition is a pressure-sensitive adhesive.

[0019] In other embodiments, a film comprising the adhesive composition is provided. The film does not exhibit residue transfer upon contact.

[0020] Embodiments of articles are also provided. In one embodiment, the article comprises an adhesive composition on a substrate. The adhesive composition forms a film. The film has a wet thickness of 381 microns, and after curing at 60 °C for 15 minutes, a stainless steel plate is attached to the outer surface of the film, allowed to stand for 30 minutes and then the stainless steel plate is removed at a rate of 300 mm / min (12 inches / min), and the film exhibits a 180-degree peel strength of 1.5 N / inch or greater, as measured by an adhesion / peel tester at a rate of 12 inches / min.

[0021] Embodiments of methods of coating a substrate are also provided. In an embodiment, the method comprises applying the adhesive composition to a substrate and curing the composition. In some examples, the adhesive composition is applied by spraying, knife coating, roll coating, casting, slot die coating, dipping, and combinations thereof or by a transfer coating method. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 show a release profile of the active substance from the binder composition according to the invention over time; and

[0024] Figure 2 is a release profile showing the release of the active substance from the binder composition according to the invention over time. DETAILED DESCRIPTION

[0025] It should be understood that, unless expressly specified to the contrary, the present invention may assume various alternative orientations and step sequences. It should also be understood that the specific processes, compositions, articles, and methods described in the following specification are merely exemplary embodiments of the inventive concept. Accordingly, specific characteristics, conditions, or other physical properties associated with the disclosed embodiments are not to be considered limiting, unless expressly stated otherwise.

[0026] Furthermore, as used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a method, article, or composition that comprises a list of features is not necessarily limited to those features, but may include other features not expressly listed or inherent to such method, article, or composition. In addition, unless expressly stated to the contrary, "or" means an inclusive or and not an exclusive or. For example, condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0027] Also, the use of "a" or "an" is for describing elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. The description should be understood to include one or at least one, and the singular also includes the plural, and vice versa, unless expressly stated otherwise. For example, when a single item is described herein, more than one item may be used in place of the single item. Similarly, where more than one item is described herein, a single item may be used in place of the more than one item.

[0028] In some embodiments, a method for forming an aqueous dispersion of a copolymer is provided. These copolymers are suitable for use in adhesive compositions. For example, the copolymer can be used in pressure-sensitive adhesives. Such adhesives exhibit good tack, adhesion, and shear resistance properties and can be used on the skin and / or in medical applications in such articles as surgical tapes, dressings, drapes, bandages, and wearable devices. However, the adhesive composition is not limited to medical applications and can be used in other applications where a tacky, cohesive, and low-traumatic adhesive is required. For example, the adhesive composition can be used in non-medical wearable device applications such as headphone devices, or in other applications such as industrial tapes, surface protection films for electronic devices, other instruments, and automotive parts.

[0029] In an embodiment, the method for forming an aqueous dispersion of a copolymer comprises providing a copolymerizable composition in water. The copolymerizable composition comprises 5 to 95% by weight of an ethylenically functionalized siloxane polymer or silane (based on the total weight of the copolymerizable compounds) and 5% or more by weight of an organic acrylic monomer (based on the total weight of the copolymerizable compounds). A surfactant is provided at 0.1 to 10 wt%, based on the total weight of the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer. The ethylenically functionalized siloxane polymer or silane is polymerized with the organic acrylic monomer to form an aqueous dispersion of the copolymer. The copolymer exhibits a glass transition temperature (Tg) of 0 to -100 °C, determined by differential scanning calorimetry at a heating rate of 10 °K per minute using a perforated crucible according to DIN 53765.

[0030] In some embodiments, the weight ratio between the ethylenically functionalized siloxane polymer or silane and the ethylenically unsaturated organic acrylic monomer can vary between 0.05 and 99.

[0031] Organic acrylic monomers suitable for use in the copolymerizable composition are acrylic acid or methacrylic acid and esters thereof. Suitable monomers forming the group of acrylate or methacrylate esters are esters of straight-chain or branched-chain alcohols having 1 to 20 carbon atoms. Preferred methacrylate or acrylate esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, stearyl acrylate, phenyl acrylate, and norbornyl acrylate. Particularly preferred are methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and norbornene acrylate. Preferably, the organic acrylic monomers include one or more acrylate esters, methacrylic acid, or acrylic acid monomers. In some embodiments, it may be preferred that these organic acrylic monomers include a combination of one or more acrylate esters, one or more methacrylic acids, and / or one or more acrylic acid monomers.

[0032] Additional monomers are also suitable for inclusion in the copolymerizable composition. In some embodiments, such monomers are ethylenically unsaturated monomers, including vinyl esters, preferably those of carboxylic acids having 1 to 15 carbon atoms. Preferred are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate, and vinyl esters of α-branched monocarboxylic acids having 9 to 11 carbon atoms, such as or (trade name of Resolution). Particularly preferred is vinyl acetate.

[0033] Additional monomers may also include vinyl aromatic compounds, vinyl halide compounds, vinyl ethers, and olefins. Preferred vinyl aromatic compounds are styrene, α-methylstyrene, isomeric vinyl toluenes and vinyl xylenes, and divinylbenzene. Particularly preferred is styrene. Preferred vinyl halide compounds include vinyl chloride, vinylidene chloride, and tetrafluoroethylene, vinylidene fluoride, hexyl perfluoroethylene, 3,3,3-trifluoropropene, perfluoropropyl vinyl ether, hexafluoropropene, chlorotrifluoroethylene, and vinyl fluoride. Particularly preferred is vinyl chloride. Examples of preferred vinyl ethers are methyl vinyl ether. Preferred olefins are ethylene, propylene, 1-alkenylene, and also polyunsaturated olefins, and preferred dienes are 1,3-butadiene and isoprene. Particularly preferred are ethylene and 1,3-butadiene.

[0034] Optionally, based on the total weight of the copolymerizable components, it is further possible to copolymerize 0.1 to 5 wt% of comonomers. Preferably, 0.5 wt% to 2.5 wt% of comonomers are used. Examples of comonomers are fumaric acid and maleic acid; ethylenically unsaturated carboxamides and nitriles, preferably acrylamides such as N-methylacrylamide, N,N-dimethylacrylamide, tert-octylacrylamide, diacetoneacrylamide (DAAM) and acrylonitrile; mono- and diesters of fumaric acid and maleic acid such as diethyl ester and diisopropyl ester and maleic anhydride, ethylenically unsaturated sulfonic acids and their salts, preferably vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid. Further examples are pre-crosslinked comonomers, such as polyethylenically unsaturated comonomers, examples being divinyl adipate, diallyl maleate, allyl methacrylate or triallyl cyanurate, or post-crosslinked comonomers, examples being acrylamide glycolic acid (AGA), methyl acrylamide glycolate methyl ester (MAGME), N-hydroxymethylacrylamide (NMA), N-hydroxymethylmethylacrylamide, N-hydroxymethylallylcarbamate, alkyl ethers, such as isobutoxy ether or esters of N-hydroxymethylacrylamide, N-hydroxymethylmethylacrylamide and N-hydroxymethylallylcarbamate. Also suitable are vinylamides having 1 to about 8 carbon atoms, including vinylpyrrolidone and the like. Comonomers having epoxy functionality are also suitable, for example glycidyl methacrylate and glycidyl acrylate. Also mentionable are monomers having a hydroxyl or CO group, examples being hydroxyalkyl esters of acrylic acid and methacrylic acid, such as hydroxyethyl ester, hydroxypropyl ester or hydroxybutyl ester of acrylic acid or methacrylic acid, and also compounds such as diacetoneacrylamide and acetoacetoxyethyl ester of acrylic acid or methacrylic acid.

[0035] As comonomers, one or more monomers from the group consisting of vinyl acetate, vinyl esters of α-branched monocarboxylic acids having 9 to 11 carbon atoms, vinyl chloride, ethylene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, styrene, and 1,3-butadiene are particularly preferred. A mixture of vinyl acetate and ethylene as comonomers is also particularly preferred; a mixture of vinyl acetate, ethylene, and vinyl esters of α-branched monocarboxylic acids having 9 to 11 carbon atoms; a mixture of n-butyl acrylate and 2-ethylhexyl acrylate and / or methyl methacrylate; a mixture of styrene and one or more monomers from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; a mixture of vinyl acetate and one or more monomers from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and optionally ethylene; and a mixture of 1,3-butadiene and styrene and / or methyl methacrylate; the mixture may optionally further comprise one or more of the above-mentioned auxiliary monomers.

[0036] In certain embodiments, these organic acrylic monomers may include combinations of acrylic monomers. One preferred combination of organic acrylic monomers includes soft monomers and hard monomers. As used herein, a "soft monomer" is a monomer that will have a glass transition temperature of less than 0 °C when homopolymerized. Exemplary acrylic soft monomers include alkyl acrylates such as butyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isodecyl acrylate, etc. Other soft monomers such as dialkyl fumarates may also be present. As used herein, a "hard monomer" is a monomer that will have a glass transition temperature above 0 °C if homopolymerized. Preferred hard monomers include methyl acrylate, ethyl acrylate, alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, vinyl acetate, etc., which are used to modify the adhesion properties. The hard monomer may also be one or more unsaturated carboxylic acids containing from 3 to about 5, preferably 3 to about 4 carbon atoms, such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and the like. These monomers are used to improve the adhesion strength and promote the adhesion of the resulting adhesive composition.

[0037] The copolymerizable composition comprises at least one ethylenically functionalized siloxane polymer or silane. When, for example, the copolymer is used in an adhesive, the use of a siloxane polymer or silane in forming the copolymer improves certain properties such as water resistance, skin-friendliness, breathability, and heat resistance.

[0038] The siloxane polymer is preferably a siloxane resin, which is functionalized with an ethylenically unsaturated free-radically polymerizable group and consists of siloxane units of the following general formula:

[0039] [R 1 p (OR 2 ) z SiO (4-p-z) / 2 (I),

[0040] wherein R 1 is the same or different each time it appears and is the group R * or E, where R * is the same or different each time it appears and is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms without aliphatic multiple C-C bonds, preferably a C1-C18 alkyl group, a C6-C18 cycloalkyl group or a C6-C18 aryl group, and may be optionally substituted, and

[0041] E is an ethylenically unsaturated group having the chemical formula -(CR 5 2) m -X, preferably -(CH2)3-X, where m is an integer from 1 to 10, preferably 3, R 2 is the same or different each time it appears and is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a C1-C18 alkyl group or a C6-C18 cycloalkyl group, R 5 is a hydrogen atom, a C1-C12 alkyl group or a C6-C18 aryl group, preferably a hydrogen atom, and X is an ethylenically unsaturated organic group,

[0042] and at least 1 mol% and at most 50 mol% of R1 in all the siloxane units (I) of the siloxane polymer are ethylenically unsaturated groups E,

[0043] p is 0, 1, 2 or 3, and

[0044] z is 0, 1, 2 or 3, 15

[0045] where the sum of p + z has a value of 0, 1, 2 or 3,

[0046] provided that for at least 20 mol% of all the siloxane units of formula (I) in the siloxane polymer, the sum of p + z is 1 or 0, where p is 1 or 0 and z is 0.

[0047] The polymerizable silanes include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldipropoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltripropoxysilane, 7-methacryloxy dimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropylmethyldipropoxysilane, γ-methacryloxymethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-methacryloxymethyltriethoxysilane, (methacryloxymethyl)methyldimethoxysilane, (methacryloxymethyl)-methyldiethoxysilane, γ-methacryloxypropyltriacetoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-methacryloxymethyldiethoxysilane, γ-acryloxypropyltripropoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropylmethyldiethoxysilane, acryloxypropylmethyldipropoxysilane, methacryloxypropyltris(trimethylsiloxysilane), etc. Preferably, the silane is methacryloxypropyltris(trimethylsiloxysilane).

[0048] The method includes providing a surfactant. Preferably, the surfactant is provided at 0.1 to 10 wt%, in each case based on the total weight of the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer. In some embodiments, the surfactant is an emulsifier. In one embodiment, the surfactant is a polymerizable surfactant, which may also be referred to as a reactive surfactant or a copolymerizable surfactant. These surfactants are preferred when the copolymer is intended for use in aqueous medical adhesives with no or minimal surfactant leaching. Suitable embodiments of the surfactant include allyl- or vinyl-substituted alkylphenol ethoxylates and their sulfates, block copolymers of polyethylene oxide, propylene oxide, or butylene oxide with polymerizable end groups, allyl- or vinyl-substituted ethoxylated alcohols and their sulfates, maleic acid semiesters of fatty alcohols, monoethanolamide ethoxylates of unsaturated fatty acids capable of autoxidative polymerization, allyl- or vinyl-polyalkylene glycol ethers, alkyl polyalkylene glycol ether sulfates, functionalized monomers and surfactants, and combinations thereof. Examples of polymerizable surfactants include those sold under the trade name HITENOL, such as the HITENOL AR series and the HITENOL KH series, which are commercially available from Montello Inc.

[0049] As described above, combinations of organic acrylic monomers can be used in the method. For example, the organic acrylic monomers can include one or more acrylate esters and acrylic monomers. In one such embodiment, based on the total weight of the copolymerizable composition, the copolymerizable composition includes 67 wt% of methacryloxypropyl tris(trimethylsiloxysilane), 19 wt% of 2-ethylhexyl acrylate, 6.6 wt% of methyl acrylate, 2.8 wt% of acrylic acid, and 4.6 wt% of a polymerizable surfactant. In this embodiment, the polymerizable surfactant can be, for example, HITENOL KH-10.

[0050] In certain embodiments, the aqueous dispersion of the copolymer can be prepared by a multiphase method. In one embodiment, the multiphase method is mini-emulsion polymerization. In such an embodiment, the mini-emulsion can be free-radically initiated and includes the polymerization of an olefinically functionalized siloxane polymer or silane with 5% or more by weight of an organic acrylic monomer.

[0051] As will be understood by those skilled in the art, mini-emulsion polymerization differs in many characteristics from emulsion polymerization. For example, in contrast to emulsion polymerization, in which the size of the polymer latex particles is determined substantially by kinetic processes and the stability of the latex, mini-emulsion polymerization is based on the complete presence of these monomers within the micelles prior to polymerization. Thus, in mini-emulsion polymerization, less time is required because these monomers do not require additional time to diffuse from the monomer droplets into the micelles during the polymerization process. In other words, the copolymer particles formed can be considered to be polymerization copies of the micelles or organic droplets present at the start of the polymerization. The result of this is that the size of the copolymer particles is determined only by the dispersion process and the stability of the micelles. Since it is not necessary to transport these monomers (such as olefinically functionalized siloxane polymers, silanes, or organic acrylic monomers) through the continuous phase, it is possible in this way to use monomers that are absolutely insoluble in the continuous phase. To increase the stability of the organic droplets, Ostwald ripening that may occur needs to be inhibited. During mini-emulsion polymerization, a hydrophobe is added, or in the case of inverse mini-emulsion, a lipophobe is added. Among the substances that can be used as hydrophobes, optionally, are hydrophobic monomers suitable for this purpose, such as, for example, silicon-containing components. In one such embodiment, the silicon-containing component is an olefinically functionalized siloxane polymer or silane.

[0052] Mini-emulsion polymerization differs from suspension polymerization in that the resulting copolymer particles are much smaller (50 to 500 nm) than those of suspension polymerization (1 μm to 1 mm), and the number of free radicals per growing copolymer particle in suspension polymerization is 10, much higher than those in mini-emulsion polymerization, where statistically, 0.5 free radicals are present per growing particle during the reaction.

[0053] For radical miniemulsion polymerization, it is first necessary to form a miniemulsion of the monomer in a continuous phase immiscible with the vinyl monomer. In certain embodiments, the vinyl monomer can be an organic acrylic monomer. For this purpose, the monomer is dispersed in water together with an emulsifier and a hydrophobe by inputting energy, for example, using a high-pressure homogenizer or by means of ultrasound. In certain embodiments, the combination of the emulsifier and the hydrophobe retards the occurrence of Ostwald ripening and coalescence of the organic droplets. In the second stage, the organic droplets thus formed are polymerized. This can be initiated by a water-soluble initiator added after the preparation of the stable miniemulsion, or by an oil-soluble initiator, which can be present in the monomer phase from the beginning, or by a combination of both.

[0054] In certain embodiments, the organic droplets formed in the miniemulsion have a size of about 50 to 500 nm. As used herein and in certain embodiments, the organic droplets formed in the miniemulsion may also be referred to as particles herein. The size of the organic droplets is the result of the homogenization of the miniemulsion, which is achieved by inputting a large amount of energy. Preferably, the transfer of these monomers between these individual organic droplets is inhibited by a specific type of stabilization.

[0055] In addition, in parallel with the formation of small organic droplets, there are no free micelles present in the miniemulsion. Thus, contrary to conventional emulsion polymerization, mainly the droplets are the sites of nucleation (droplet nucleation). Therefore, during miniemulsion polymerization, only a slight diffusion of the monomer is observed. Thus, in miniemulsion polymerization, each dispersed organic droplet can be described as an individual reactor operating at the nanoscale level. Thus, contrary to conventional emulsion and suspension polymerization, the use of miniemulsion polymerization in the method for forming an aqueous dispersion of a copolymer has many advantages, which are mentioned below.

[0056] For example, since these monomers do not have to be transported through the continuous phase (usually the aqueous phase), it is even possible to polymerize monomers that are absolutely insoluble in water in this method. In addition, the size of the copolymer particles can correspond to the size of the pre-formed organic droplets and can be adjusted quite precisely by the nature and amount of the emulsifier used. In addition, each organic droplet is homogeneous in its composition. Thus, specifically for copolymerization reactions, the monomer ratio in each droplet is the same and is not affected by differences in monomer diffusion. In addition, the amount of emulsifier used is small because the miniemulsion is only kinetically stable, not thermodynamically stable.

[0057] To prepare a miniemulsion for forming an aqueous dispersion of a copolymer, the following steps are carried out:

[0058] In a first step, an ethylenically functionalized siloxane polymer or silane is dissolved in one or more of the organic acrylic monomers described herein, forming a siloxane or silane monomer solution. It should be noted that the siloxane polymer or silane is soluble in the corresponding organic acrylic monomer. In certain embodiments, insoluble components are separated by filtration when appropriate. Preferably, the siloxane or silane monomer solution exhibits a viscosity of 2 to 20,000 mPa·s at 25 °C, preferably 5 to 15,000 mPa·s at 25 °C, more specifically 7 to 10,000 mPa·s at 25 °C.

[0059] The siloxane or silane monomer solution is optionally mixed with a hydrophobic co-emulsifier. Examples of hydrophobic co-emulsifiers are known in the art and are suitable for forming an aqueous dispersion of the copolymer.

[0060] In a second step, the siloxane or silane monomer solution is emulsified with water and at least one surfactant, and optionally with an auxiliary agent (such as a polymerization inhibitor to prevent premature free radical emulsion polymerization reaction) in such a way that, preferably, a high shear force is applied to obtain an emulsion having a droplet size of 350 nm or less, and these emulsions are called miniemulsions. In this context, the high shear force can be generated by means of a suitable emulsifying device (such as a conventional rotor-stator system) or in other ways known in the art, for example by a high-pressure homogenizer, a dissolver disk, an ultrasonic device or a similar emulsifying technique that allows the application of a high shear force, which allows the generation of small particles not exceeding 200 nm, thus forming a miniemulsion having a droplet size not exceeding 350 nm. When using a commercial rotor-stator system, rotational speeds of 4000 to 12,000 rpm, preferably 5000 to 11,000 rpm, more specifically 6000 to 10,000 rpm have proven to be particularly advantageous. Both continuous and discontinuous embodiments are suitable. When using a high-pressure homogenizer, pressures of preferably 300 bar to 1000 bar, more preferably 350 bar to 900 bar, more particularly 400 bar to 800 bar have proven to be advantageous. Since these formulations are polymerizable, it is preferred to implement an effective temperature monitoring strategy. In some embodiments, it is preferred that the temperature of the miniemulsion does not exceed 60 °C, preferably 55 °C, more preferably 50 °C. In embodiments where the temperature of the miniemulsion does not exceed 50 - 60 °C, the method may include rapidly cooling the miniemulsion to below the above temperature.

[0061] The miniemulsion comprises a continuous aqueous phase and a dispersed organic phase. The amount of water in the miniemulsion is 20 - 80% by weight (wt%), preferably 20 - 75, more preferably 25 - 70% by weight, in each case based on the total weight of the miniemulsion. Furthermore, the miniemulsion according to the invention has a viscosity at 25 °C of 2 - 5000 mPa·s, in particular a viscosity at 25 °C of 3 - 4500 mPa·s, more particularly a viscosity at 25 °C of 5 - 4000 mPa·s. A viscosity within the above ranges is desirable because of processing advantages and ease of handling.

[0062] The organic phase of the miniemulsion is polymerized by free-radical emulsion polymerization. In this case, in a third step, the dispersed organic droplets are subjected to free-radical polymerization. This free-radical emulsion polymerization is preferably carried out by metering the miniemulsion into an initial charge comprising water and a portion of the catalyst. Further metered feeds can comprise polymerization initiators, which can optionally cover a variety of components, and each component is metered in separately or comprised in the initial charge according to their interactions and functions in the polymerization procedure. Metering of the feeds can be carried out using commercially available equipment such as metering pumps or feed funnels.

[0063] The polymerization is initiated by a water-soluble initiator or a combination of redox initiators, preferably the latter. Examples of initiators are the sodium, potassium, and ammonium salts of peroxydisulfuric acid, hydrogen peroxide, tert-butyl peroxide, tert-butyl hydroperoxide, potassium peroxydiphosphate, tert-butyl peroxyneopentanoate, cumene hydroperoxide, cumene monohydroperoxide, and azobisisobutyronitrile. Based on the total weight of the monomers, the initiator is preferably used in an amount of 0.01 to 4.0 wt%. As a combination of redox initiators, the above initiators are used in combination with reducing agents. Suitable reducing agents are sulfites and bisulfites of monovalent cations, examples being sodium sulfite, or derivatives of sulfurous acid such as zinc or alkali metal formaldehyde sulfoxylates, for example sodium hydroxymethanesulfinate, ascorbic acid. A preferred class of reducing agents is sulfinic acid compounds such as disodium 2-hydroxy-2-sulfinoacetate. Such preferred reducing agents are, for example, sold under the trade names FF6 and FF6 M. The amount of the reducing agent is preferably 0.15 wt% to 3 wt% of the amount of monomers used. Furthermore, small amounts of metal compounds can be introduced, which are soluble in the polymerization medium and whose metal components are redox-active under the polymerization conditions, such compounds being based, for example, on iron or vanadium. A particularly preferred initiator system comprising the above components is tert-butyl hydroperoxide / sodium hydroxymethanesulfinate / Fe(EDTA) 2+ / 3+ system.

[0064] It is also possible to mainly use oil-soluble initiators such as cumene hydroperoxide, cumene monohydroperoxide, benzoyl peroxide or azobisisobutyronitrile. Preferred initiators for miniemulsion polymerization are potassium persulfate, ammonium persulfate, azobisisobutyronitrile and benzoyl peroxide.

[0065] After forming a miniemulsion comprising an ethylenically functionalized siloxane polymer or silane, an organic acrylic monomer and a surfactant, the initiator is introduced as described above.

[0066] After the addition of the initiator, the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer polymerize to form an aqueous dispersion of the copolymer. Thus, the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer polymerize in the presence of a surfactant and water. The polymerization can be carried out batchwise or continuously, with all or individual components of the reaction mixture included in the initial feed, with individual components of the reaction mixture partially included in the initial feed and subsequently metered in partially, or by a metering method without an initial feed. All metered feeds are preferably carried out at the consumption rate of the corresponding components. The polymerization can be carried out at a predetermined temperature. In certain embodiments, the reaction temperature in the miniemulsion polymerization reaction is from 0 °C to 100 °C. More preferably, the reaction temperature in the miniemulsion polymerization reaction is from 5 °C to 80 °C, and in some embodiments, the reaction temperature is from 30 °C to 70 °C.

[0067] When the miniemulsion polymerization is complete, the resulting aqueous dispersion of the copolymer is adjusted to the desired pH, optionally filtered, and then can be used for the corresponding applications. In certain embodiments, the pH of the dispersion medium is between 2 and 9, preferably between 4 and 8. In a preferred embodiment, the pH is between 4.5 and 7.5. The pH can be adjusted by adding aqueous hydrochloric acid or sodium hydroxide to the dispersion medium before the start of the reaction.

[0068] Advantageously, the method forms an aqueous dispersion of a copolymer having a high solids content. For example, the aqueous dispersion of the copolymer can contain 40 wt% or more solids based on the total weight of the aqueous dispersion. In some embodiments, the aqueous dispersion of the copolymer contains 40 wt% to 70 wt% solids based on the total weight of the aqueous dispersion. Preferably, the aqueous dispersion of the copolymer contains 40 to 65 wt% solids based on the total weight of the aqueous dispersion.

[0069] In some embodiments, the aqueous dispersion of the copolymer exhibits a viscosity of 1 to 20,000 mPa·s at 25 °C. Preferably, the aqueous dispersion of the copolymer exhibits a viscosity of 1 to 5,000 mPa·s at 25 °C. The viscosity of the aqueous copolymer dispersions reported herein is in each case at 25 °C and an atmospheric pressure of 1013 mbar and can be determined by measurement using rotational viscometry according to DIN EN ISO 3219 [rotor LV1, 10 rpm] with a Brookfield viscometer.

[0070] In addition, the copolymer formed by polymerization can exhibit certain advantageous properties.

[0071] For example, the copolymers exhibit a desired glass transition temperature (Tg) that makes them suitable for certain applications. By selecting these monomers and / or by selecting the weight fractions of these monomers, the Tg of these copolymers can be preselected. In an embodiment, the copolymer exhibits a Tg of 0 to -100 °C. In another embodiment, the copolymer exhibits a Tg of -10 to -60 °C. In these embodiments, the Tg is determined by differential scanning calorimetry using a perforated crucible at a heating rate of 10 °K / min according to DIN 53765. The Tg of the polymer can be determined in a known manner by differential scanning calorimetry (DSC) according to DIN 53765, using a perforated crucible and heating at 10 K / min. The Tg can also be approximately calculated in advance using the Fox equation. According to Fox T.G., Bull.Am.Physics Soc.1,3,page 123(1956): 1 / Tg = x1 / Tg1 + x2 / Tg2 +... + x n / Tg n , where x n is the mass fraction (wt% / 100) of monomer n, and Tg n is the glass transition temperature of the homopolymer of monomer n in Kelvin. The Tg values of the homopolymers can be found in many reference works and standard works on polymer technology and in tabular works retrievable on the Internet, for example, retrieved from Aldrich under the entry "Polymer Properties, Thermal Transitions of Homopolymers" (https: / / www.sigmaaldrich.com / content / dam / sigma-10aldrich / docs / Aldrich / General_Information / thermal_transitions_of_homopolymers.pdf). Having a Tg within the ranges mentioned above means that the copolymer is flexible but not overly viscous.

[0072] The tack exhibited by the adhesive composition is a function of factors such as the Tg exhibited by the copolymer. Thus, the tack exhibited by the adhesive composition can be predetermined by selecting the Tg exhibited by the copolymer. In some embodiments, when these copolymers are included in the adhesive composition, the adhesive composition is provided as a film. Prior to curing, the film of the adhesive composition has a wet thickness. In some embodiments, the film has a wet thickness of 381 microns. After curing the film from this thickness, the film exhibits a peak tack of 100 gram-force (gf) or greater. Preferably, at a wet thickness of 381 microns and after curing, the film exhibits a peak tack of 100 to 1,000 gram-force. The peak tack of the film can be measured using a TA.XT Plus texture analyzer with a TA-57R probe and a TA-303 device.

[0073] The resulting film can also be tacky and does not exhibit residue transfer upon contact, meaning that while the film can be tacky, it does not leave deposits when contacted and separated from it.

[0074] The copolymer also exhibits a desired particle size. In some embodiments, the Z-average particle size of the copolymer dispersion is 1000 nm or less, preferably not exceeding 350 nm, more preferably not exceeding 250 nm, very preferably not exceeding 200 nm, and at least 20 nm, preferably at least 30 nm, more preferably at least 50 nm. Preferably, the Z-average particle size of the copolymer dispersion is 50 to 300 nm. As described below, the Z-average particle size can be measured using a Malvern Zetasizer Nano ZS particle size analyzer by the method of dynamic light scattering (DLS). The polydispersity index (PDI) of the particle size indicates the width of the particle size distribution.

[0075] In some embodiments, the size of the siloxane or silane domains within the copolymer after the copolymerization reaction is preferably 5 nm - 150 nm, more particularly 10 nm - 140 nm, and particularly preferably 15 nm - 125 nm. The size can be determined, for example, by scanning electron microscopy or transmission electron microscopy on the copolymer dispersion or on the obtained film.

[0076] Due to the above properties, the copolymer is particularly suitable for certain applications. For example, in one embodiment, an adhesive composition comprising these copolymers is provided. The adhesive composition can be used to provide an adhesive of the PSA type. In these embodiments, the PSA includes the copolymer.

[0077] Surprisingly, in some embodiments, even when the amount of water is quite low (<50 wt%, based on the total weight of the aqueous dispersion of the copolymer), the aqueous dispersion of the copolymer has a low viscosity (<100 mPa·s). The low viscosity of the aqueous dispersion enables the dispersion to be suitable for application to a surface by spraying. In other embodiments, when the viscosity of the aqueous dispersion is higher, a film applicator can be used to draw a film containing the dispersion on the surface.

[0078] After or before applying the aqueous dispersion of the copolymer to a substrate, the copolymer dispersion can be cured. In the present application, curing refers to a method by which water is removed from the copolymer dispersion and can also be referred to herein as "drying". Preferably, water is removed by evaporation, which can be achieved by evaporating water therefrom (e.g., by heating the aqueous dispersion). The copolymer is considered cured when a dry film can be formed or when the copolymer does not show a weight change greater than 2% after being heated in an oven at 120 °C for 1 hour.

[0079] The aqueous dispersion of the copolymer can be applied to a substrate using conventional equipment and techniques. Suitable substrates include those commercially available, such as high surface energy substrates or low surface energy substrates, e.g., metal substrates or polymer substrates. The substrate can include stainless steel, paper, cardboard, glass, polyolefin, PET, PVC, PMMA, PC, polyurethane, composite materials, wood, textiles, various other types of plastics, and additional materials. Coating the substrate can be achieved by spraying, knife coating, roll coating, casting, drum coating, dipping, etc., and combinations thereof. Coating techniques can include, but are not limited to, gravure coating, reverse roll coating, Meyer rod coating, Dahlgren coating, knife over roll coating, slot die coating, dip coating, curtain coating, etc. It is also possible to apply it indirectly to the substrate using a transfer method, where the copolymer is first applied to a release liner rather than directly to the substrate (also called the face stock). After drying, the base layer is laminated to the adhesive-coated liner. When the liner and the face stock are separated, the adhesive is transferred from the release liner to the face stock.

[0080] A coated article can be formed by applying an adhesive composition to a substrate. The coated article includes the adhesive composition and a substrate, which is preferably a polymeric substrate. The adhesive composition forms a film on the substrate. The film adheres well to the substrate. In fact, the film exhibits a high peel strength. For example, in certain embodiments, a film having a wet thickness of 381 microns exhibits a 180-degree peel strength of 1.5 N / inch or greater after curing at 60 °C for 15 minutes. In one such embodiment, a film having a wet thickness of 381 microns exhibits a 180-degree peel strength of 1.5 N / inch to 60 N / inch after curing at 60 °C for 15 minutes. The peel strength can be measured by a bond / peel tester by attaching a stainless steel plate to the outer surface of the film, allowing it to stand for 30 minutes, and then removing the stainless steel plate at a rate of 300 mm / min (12 in / min). Suitable bond / peel testing machines for measuring peel strength include the Shimadzu AGS-X-10kNX tensile testing machine or the Chemisteriments AR-1000 bond / peel testing machine.

[0081] When these copolymers are used in PSA adhesive compositions, it has been found that the PSA retains many of its desired properties under a variety of conditions. For example, the PSA can maintain its adhesion properties in a humid environment, which means that the PSA can be used on or near sweating or wet skin. In this embodiment, the PSA may be insoluble in water after curing.

[0082] In other embodiments, the PSA containing the copolymer exhibits improved properties. For example, the PSA can exhibit improved moisture vapor transmission rate (MVTR). The MVTR can be controlled by changing the organic acrylic monomers. For example, according to WO2001042384A2, the use of hydroxyethyl acrylate (HEA) has an effect on the MVTR. In addition, the MVTR can be increased by increasing the acrylic acid content in the copolymer (according to the Journal of Applied Polymer Science, Vol. 59, No. 8, pp. 1243-1247). In an embodiment, when measured according to the above method using a fabric backing, the adhesive composition of this PSA type has a MVTR value of > 300 g / m 2 / day. In these embodiments, the MVTR can be measured according to ASTM D1653.

[0083] An adhesive composition comprising a copolymer can exhibit other advantageous properties. For example, the adhesive composition exhibits excellent stability. In certain embodiments, when the adhesive composition is of the PSA type, the composition is unexpectedly very storage stable. As used herein, storage stability refers to the degree of layer separation observed in the adhesive composition over a period of time at room temperature. In certain embodiments, the adhesive composition does not exhibit any layer separation at 25 °C, as measured by the absence of any observable phase separation over 180 days. In some embodiments, the adhesive composition does not exhibit any layer separation at 25 °C, as measured by the absence of any observable phase separation over 720 days or longer. Stability can also be measured by the absence of a change in the z-average particle size. In particular, in one embodiment, the adhesive composition is stable against layer separation at 25 °C, as measured by a change in the z-average particle size of no greater than 20%. In some embodiments, the adhesive composition does not show a change in the z-average particle size of more than 20% over at least a six-month period. The z-average particle size of these embodiments can be measured using a Malvern Zetasizer Nano ZS particle size analyzer by the method of dynamic light scattering (DLS).

[0084] When the copolymer is used in an adhesive composition for PSA, the PSA can exhibit very low residual volatile organic carbon (VOC) or no VOC at all. For example, in one embodiment, the adhesive composition can exhibit a VOC of 2.5% or less. The VOC content of the adhesive composition can be measured according to EPA test method 24.

[0085] In other embodiments, the adhesive composition is biocompatible, which means that it does not have any observable adverse effects if used on the skin or when used near the human body. In these embodiments, the residual monomer reaction components, such as residual organic acrylic monomers, should be very low, preferably less than 0.5 wt%, based on the total weight of the cured adhesive composition.

[0086] As noted above, the adhesive composition can be used in medical applications, such as wound care and other healthcare applications, such as in medical tapes, adhesive patches, wound care dressings, ostomy care, drug delivery, cosmetic patches, wearables, and other applications. Such adhesive tapes can be of the PSA type and include copolymers formed by the method, which are useful in medical applications that require low-traumatic characteristics, which means that the adhesive adheres to the skin, but does not exhibit excessive adhesive buildup over time, which would result in difficult removal and thus pain.

[0087] Due to the diversity of potential medical applications, it may be important that compositions containing the copolymer be capable of exhibiting a wide range of physical properties. For example, such compositions comprising the copolymer can exhibit hydrophobicity / hydrophilicity that can be controlled by careful selection of appropriate monomers or combinations thereof. For instance, in certain embodiments, an adhesive composition, such as a PSA-type adhesive composition, can be provided that has relatively hydrophilic characteristics by incorporating hydrophilic monomers during polymerization, such monomers including 2-hydroxy methacrylate and acrylamide.

[0088] In certain embodiments, the adhesive composition may further include a drug or active compound, an adhesive resin, a penetration enhancer, a water-absorbing material, a softening agent, and / or a tackifier. Examples of suitable adhesive resins include polyacrylates, natural or synthetic rubbers, and the like. Suitable penetration enhancers include polar materials capable of forming strong hydrogen bonds, such as urea, which polarizes the skin molecules of the user and increases skin permeability through ionic forces. Another suitable polar agent for use in the adhesive composition is a solution of DMSO (dimethyl sulfoxide). Other examples of suitable agents include nonionic surfactants or solvents having a hydrophilic-lipophilic balance (HLB) value of from about 6 to 30. As used herein, the term "HLB" refers to a numerical representation of the ability to emulsify immiscible components in oil and water. These agents may be selected from the chemical groups of glycerol esters, polyglycerol esters, alkyl fatty acid esters, ethoxylated sorbitan esters, alcohol ethoxylates, lanolin ethoxylates, ethoxylated fatty acid methyl esters, and alkanolamides. Preferably, in these embodiments, the agent has an HLB value of from about 8 to 28. Examples of suitable agents having an HLB value of 8 to 10 include PEG 200 monolaurate, sorbitan monolaurate, POE myristyl ether, POE lauryl alcohol, POE lauryl ether, POE sorbitan monooleate, octylphenoxy poly(ethyleneoxy) ethanol, linear alcohol ethoxylate, monoglycerides and diglycerides with polysorbate 80, nonylphenol ethoxylate, alkylaryl polyether ethanol, N,N-dimethylamide. Examples of agents having an HLB value of 11 to 14 include PEG 400 monooleate, polyoxyarylether, POE oleyl alcohol, PEG 600 monooleate, POE sorbitan monooleate, PEG 400 monolaurate, POG lauryl alcohol, and nonylphenoxy poly(ethyleneoxy) ethanol. Examples of agents having an HLB value of 15 to 28 include nonylphenol ethoxylate, castor oil ethoxylate, ethoxylated coconut monoglyceride, oleyl alcohol condensed with ethylene oxide, modified ethoxylated linear alcohol, ethoxylated lanolin alcohol, nonylphenyl ethoxylate, polyethylene 100 stearyl ether, PEG 6000 monooleate, ethoxylated polyoxypropylene glycol, and ethoxylated polyoxypropylene glycol. Preferably, the agent is provided in an amount of from about 1 to 50 wt% based on the total weight of the adhesive composition prior to curing. Examples of water-absorbing materials may be selected from superabsorbent polymers, polyols, and water-absorbing inorganic materials. Examples of superabsorbent polymers may include mucopolysaccharides such as hyaluronic acid, chondroitin sulfate, dermatan sulfate, polymers having a large number of hydrophilic groups in the molecule such as chitin, chitin derivatives, starch, and carboxymethyl cellulose, and semi-synthetic and synthetic superabsorbent polymers such as polyacrylic acid, polyoxyethylene, polyvinyl alcohol, and polyacrylonitrile. Examples of water-absorbing inorganic materials that may be incorporated into the adhesive to adjust its water-absorbing ability may include powdered silica, zeolite, powdered ceramics, and the like. Examples of polyols may include propylene glycol, glycerol, sorbitol, and the like.Suitable tackifiers may be selected from hydrocarbon resins, hydrogenated hydrocarbon resins, fully hydrogenated hydrocarbon resins, hydrogenated rosin esters, fully hydrogenated rosin esters, and combinations thereof. Examples of suitable analgesics are α-bisabolol, chamomile oil, allantoin, and d-panthenol.

[0089] Although these copolymers are prepared in water, the adhesive compositions containing these copolymers are preferably dry, which means that it contains very little or no residual water when in use. Thus, in certain embodiments, it may be desirable for these copolymers to be hydrophobic and generally impart hydrophobic characteristics to the adhesive composition, which results in low water absorption and better adhesion characteristics.

[0090] The embodiments of the adhesive compositions described herein should provide good adhesion characteristics. However, these adhesive compositions can also be blended with other adhesives to obtain the best characteristics for specific applications. In addition, tackifiers can be added to the adhesive compositions to adjust the properties exhibited. Other additives suitable for use in the adhesive compositions can include wetting agents, defoamers, and / or coalescing agents.

[0091] Compositions containing the copolymer can also be used to provide a matrix containing one or more active ingredients. Advantageously, such active agents can be incorporated into such compositions and can be released from such compositions at a controlled rate. Such compositions can also have the adhesion properties described above. Thus, in certain embodiments, the adhesive compositions described above can be used for the controlled release of one or more active substances. The active substances suitable for use in the adhesive compositions can be simply referred to herein as "active agents" or "multiple active agents".

[0092] Preferably, the active agent used is compatible with the aqueous dispersion. Water-soluble or partially water-soluble active agents are more suitable. Non-limiting examples of such active agents include melamine, niacinamide, Benadryl, vitamin C, etc. Water-insoluble active agents can also be used, in which case the active agent can be added in an emulsified form to be compatible with the aqueous dispersion of the copolymer. For example, in some embodiments, water-insoluble active agents can be encapsulated, such as inside the cavity of cyclodextrin or other encapsulating agents, to make them compatible with the aqueous dispersion.

[0093] Before curing, it is preferred to incorporate the active agent into the adhesive composition, such as a PSA composition. The active agent can be a pharmacologically active substance. However, the active agent can also be suitable for use in cosmetic, wound care, health, or performance enhancement applications. The active agent suitable for use can be delivered topically or transdermally.

[0094] In some embodiments, suitable pharmacologically active agents include oxymorphone, caffeine, zidovudine, pilocarpine, ranitidine, lazabemide, thiopental, scopolamine, butabarbital, digoxin, thioindigo, pemoline, diclofenac, antipyrine, albuterol, oxycodone, terbutaline, ephedrine, pseudoephedrine, morphine, captopril, mescaline, naloxone, phenelzine, secobarbital, flumazenil, fluvastatin; sumatriptan, oxcarbazepine, modafinil, moclobemide, nadolol, aldosterone, pentaerythritol, prazosin, ramipril, guanfacine, physostigmine, phenobarbital, minoxidil, aprobarbital, naltrexone, leflunomide, terazosin, pindolol, fludrocortisone, mephobarbital, lofencoxine, methyldigoxin, tranylcypromine, prednisone, hydromorphone, dantrolene, hydrocortisone, risperidone, lidocaine, metoprolol, betamethasone, timolol, levosimendan, benzocaine, clobazam, colchicine, butalbital, prilocaine, atropine, mepivacaine, procaine, pentobarbital, amobarbital, chlordiazepoxide, yohimbine, temazepam, hydrocodone, benzoin, trimethobenzamide, warfarin, camazepam, nedocromil, buspirone, ketorolac, oxazepam, piribedil, pramipexole, secobarbital, hydrocortisone, lorazepam, clorazepate, quetiapine, enalapril, betamethasone acetate, tamsulosin, nifedipine, ergotamine, clonazepam, atorvastatin, tolmetin, bumetanide, piroxicam, perindopril, propranolol, methadone, chlorzoxazone, indapamide, diazepam, ciclopirox, ramipril, amphetamine, benztropine, methylphenidate, apomorphine, diltiazem, alprenolol, clozapine, ropivacaine, valproic acid, norethindrone, ketoprofen, tramadol, tetracaine, etorphine, flurazepam, pethidine, ropinirole, carvedilol, bupranolol, pravastatin, naproxen, diphenhydramine, ketamine, albendazole, idebenone, tacrine, finasteride, nabumetone, gestodene, testosterone, venlafaxine, eszopiclone, rimantadine, phenytoin, propafenone, levorphanol, bupivacaine, perindopril, droperidol, celecoxib, norgestrel, isradipine, risperidone, benazepril, loratadine, betamethasone, progesterone, butorphanol, quinapril, alprostadil, citalopram, ibuprofen, flurbiprofen, chlorpheniramine, zolpidem, alprazolam, fentanyl, nisoldipine, benztropine, betamethasone, etodolac, tibolone, estradiol, amantadine, chlorpromazine, oxybutynin, triazolam, doxepin, praziquantel, granisetron, frovatriptan and norethisterone acetate.

[0095] Other activities suitable for implementing the method include antioxidants, free radical scavengers, moisturizers, decolorizing agents, reflectants, humectants, antimicrobials (such as antibacterial agents), allergy inhibitors, anti-acne agents, anti-aging agents, anti-wrinkle agents, preservatives, analgesics, antitussives, antipruritics, local anesthetics, anti-hair loss agents, hair growth promoters, hair growth inhibitors, antihistamines, keratolytics, anti-inflammatory agents, fresheners, healing agents, anti-infective agents, inflammation inhibitors, anticholinergics, vasoconstrictors, vasodilators, wound healing promoters, peptides, polypeptides and proteins, deodorants and antiperspirants, skin emollients and skin moisturizers, hair conditioners, hair softeners, hair moisturizers, tanning agents, skin lightening agents, antifungal agents such as antifungal agents for foot preparations, depilatory agents, external analgesics, counterirritants, hemorrhoid medications, insecticides, poison ivy products, poison oak products, burn products, anti-diaper rash agents, prickly heat agents, cosmetic preparations, vitamins, amino acids and their derivatives, herbal extracts, retinoids, flavonoids, sensory markers (such as coolants, heating agents, etc.), skin conditioners, hair brighteners, chelating agents, cell transformation enhancers, colorants, sunscreens, anesthetics, immunomodulators and nutraceuticals, water absorbents, sebum absorbents, etc., and mixtures thereof. Local anesthetics, local antibiotics, preservatives, antifungal agents, antihistamines, and antipruritic drugs, keratolytics and caustic drugs, antiviral drugs, anti-scabies drugs, steroids, and different substances for treating acne, psoriasis, photosensitive dermatitis, or pre-cancerous conditions can all be used in skin treatment methods.

[0096] In certain embodiments, intradermal-directed active agents can be used. Active agents that can be applied via the intradermal route include, for example, steroids and non-steroidal anti-rheumatic drugs, local anesthetics, substances that stimulate blood flow, vasoprotective agents and vasoconstrictors for treating vascular diseases, and active substances that affect processes in subcutaneous adipose tissue.

[0097] Other suitable active agents include, for example, analgesics, antiarrhythmics, anesthetics and their antagonists, antipsychotics, hormones or hormone replacements, antidepressants, tranquilizers, hypnotics, psychostimulants, anti-Parkinson drugs, ganglionic blockers, sympathomimetics, alpha-sympathomimetics, beta-sympathomimetics, anti-sympathomimetics, anti-asthma drugs, antiemetics, appetite suppressants, diuretics, or active substances for weight loss, etc.

[0098] In some embodiments, suitable active agents can provide effects at very low concentrations. Examples of such active agents include steroids such as estradiol, estriol, progesterone, norethindrone, norethisterone, levonorgestrel, and their derivatives, as well as estradiol diacetate, progestogens, gestagens, desogestrel, dienogest, megestrol acetate, testosterone, hydrocortisone and its derivatives, nitro compounds such as amyl nitrite, nitroglycerin, isosorbide dinitrate, amine compounds such as nicotine, chlorpheniramine, terfenadine and tripelennamine, oxicam derivatives such as piroxicam, mucopolysaccharidases such as endothiapepsin, opioids such as buprenorphine, morphine, fentanyl and their salts, derivatives or analogs, naloxone, codeine, dihydroergotamine, lysergic acid derivatives, prazosin, salbutamol, terbutaline, prostaglandins such as the PGA, PGB, PGE and PGF series, for example misoprostol and enprostil, omeprazole, imipramine, benzamides such as metoclopramide and scopolamine, peptides and growth factors such as EGF, TGF, PDGF etc., somatostatin, clonidine, dihydropyridines such as nifedipine, nitrendipine, verapamil, diltiazem, ephedrine, propranolol, metoprolol, spironolactone, thiazides such as hydrochlorothiazide and flunarizine. Hemostatic or wound cleaning active agents such as enzymes, antiseptics, disinfectants and antibiotics, analgesic and anesthetic active agents, and active substances that promote wound healing to stimulate granulation formation, induce angiogenesis or promote epithelial formation can be used. In some embodiments, the active agent can be a steroid hormone, preferably estradiol, alone or in combination with other active agents.

[0099] Active agents derived from plant preparations, such as extracts or tinctures for the treatment of local skin diseases, are also suitable. Suitable extracts or tinctures include oak bark extract, walnut extract, arnica tincture, witch hazel extract, plantain extract, pansy extract, thyme or sage extract, St. John's wort tincture, echinacea tincture, chamomile extract, calendula tincture, birch leaf extract, nettle extract, hyssop extract, comfrey tincture, horsetail extract or aloe extract. Other suitable active agents for the treatment of diseases by intracutaneous administration include, for example, extracts of horse chestnut and butcher's broom in the case of venous diseases, or extracts and tinctures of arnica, calendula and capsicum in the case of contusions, sprains or bleeding. Suitable active agents from plant preparations can also be used for transdermal treatment, such as extracts of ginseng, valerianate, balm and hops, extracts of kola nut and tea or hawthorn extract.

[0100] Suitable effervescent active agents can be used, including sodium bicarbonate and sodium carbonate. Suitable amino acid active agents can be utilized, including amino acids and their salts, esters, and acyl derivatives derived from the hydrolysis of various proteins. Examples of such amino acid agents include amphoteric amino acids such as alkylamidopropylamine, stearoyl acetylglutamic acid, octanoyl serine, octanoyl collagen amino acid, octanoyl citrulline, octanoyl pea amino acid, cocoyl dimethyl ammonium hydroxypropyl serine, corn gluten amino acid, cysteine, glutamic acid, glycine, hair keratin amino acid, hair amino acids such as aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, cysteine, lysine, histidine, arginine, cysteine, tryptophan, citrulline, lysine, serine, wheat amino acid, and mixtures thereof.

[0101] Suitable peptides, polypeptides, and proteins can be used as active agents, including those polymers having long chains (e.g., at least about 10 carbon atoms) and high molecular weights (e.g., at least about 1000) and formed by self-condensation of amino acids. Examples of such proteins include collagen, deoxyribonuclease, zein iodide, keratin, milk protein, protease, serum protein, silk, sweet almond protein, wheat germ protein, wheat protein, alpha helix and beta helix of keratin, hair protein such as intermediate filament protein, high sulfur protein, ultra-high sulfur protein, intermediate filament-associated protein, high tyrosine protein, high glycine tyrosine protein, trichohyalin, and mixtures thereof.

[0102] Vitamins can be used as active agents in the method. Examples of suitable vitamins that can be used include vitamin B complex, including thiamine, niacin, biotin, pantothenic acid, choline, riboflavin, vitamin B6, vitamin B12, pyridoxol, inositol, carnitine, vitamins A, C, D, E, K, and their derivatives such as vitamin A palmitate and provitamins such as panthenol (provitamin B5) and panthenol triacetate, and mixtures thereof.

[0103] Antimicrobial agents can be used as active agents. Examples of suitable antimicrobial agents that can be used include bacitracin, erythromycin, neomycin, tetracycline, chlortetracycline, benzethonium chloride, phenol, and mixtures thereof.

[0104] Skin emollients and skin moisturizers can be used as active agents. Examples of suitable skin emollients and skin moisturizers that can be used include mineral oil, lanolin, vegetable oil, isostearyl isostearate, glyceryl laurate, methyl gluceth 10, methyl gluceth 20, chitosan, and mixtures thereof.

[0105] Hair conditioners can be used as active substances. Examples of suitable hair conditioner active substances include quaternized compounds such as behenamidopropyl PG-dimonium chloride, triethyl citrate, dehydrotallowamidoethyl hydroxyethyl methyl sulfate, and mixtures thereof, and lipophilic compounds such as cetyl alcohol, stearyl alcohol, hydrogenated polydecene, and mixtures thereof.

[0106] Sun protection agents can be used as active agents. Examples of sun protection agents that can be used as active agents include butyl methoxydibenzoylmethane, octyl methoxycinnamate, oxybenzone, octocrylene, octyl salicylate, phenylbenzimidazole sulfonic acid, ethylhexyl dimethyl PABA, menthyl anthranilate, aminobenzoic acid, cinoxate, diethanolamine methoxycinnamate, glyceryl PABA, titanium dioxide, zinc oxide, oxybenzone, octocrylene, red petrolatum, and mixtures thereof.

[0107] Self-tanning agents and skin-whitening agents can be used as active agents. Examples of suitable self-tanning agents that can be used as active agents are dihydroxyacetone. Examples of suitable skin-whitening brightening agents that can be used include hydroquinone, catechol and its derivatives, ascorbic acid and its derivatives, and mixtures thereof.

[0108] Insecticides can be used as active agents. Examples of suitable insecticides include permethrin, pyrethrin, piperonyl butoxide, imidacloprid, N,N-diethyl-m-toluamide, which refers to a substance mainly containing the meta isomer.

[0109] Antifungal agents for foot preparations that can be used as active agents include those having antifungal properties, such as tolnaftate.

[0110] Hair removers can be used as active agents. Examples of suitable hair removers include calcium thioglycolate, magnesium thioglycolate, potassium thioglycolate, strontium thioglycolate, and mixtures thereof.

[0111] Analgesics and local anesthetics can be used as active agents. Examples of suitable external analgesics and local anesthetics that can be used include benzocaine, dibucaine, benzyl alcohol, camphor, capsaicin, chili peppers, oleoresin capsicum, crude coal tar, menthol, methyl nicotinate, methyl salicylate, phenol, resorcinol, turpentine, and mixtures thereof.

[0112] Antiperspirants and deodorants that can be used as active agents. Examples of suitable antiperspirants and deodorants that can be used as active agents include aluminum chlorohydrate, zirconium aluminum chlorohydrate, and mixtures thereof.

[0113] In some embodiments, the active agent can be a counterirritant. Examples of suitable counterirritants that can be used include camphor, menthol, methyl salicylate, mint, and clove oil, fish oil, and mixtures thereof.

[0114] In some embodiments, the active agent can be an anti-inflammatory agent, such as hydrocortisone. In other embodiments, the active agent can be a hemorrhoid product. Examples of suitable hemorrhoid products include anesthetics such as benzocaine, propamocillin hydrochloride, and mixtures thereof; preservatives such as benzethonium chloride; astringents such as zinc oxide, bismuth subgallate, balsam of Peru, and mixtures thereof; skin protectants such as cod liver oil, vegetable oil, and mixtures thereof.

[0115] Beneficial agents are also suitable as active agents. Suitable beneficial agents include therapeutic agents effective in treating dandruff, seborrheic dermatitis, psoriasis, and related symptoms. Examples of such suitable therapeutic agents include zinc pyrithione, shale oil and its derivatives such as sulfonated shale oil, selenium sulfide, sulfur, salicylic acid, coal tar, povidone iodine, and imidazoles.

[0116] In some embodiments, the active agent can be an antimicrobial agent, a preservative, or a keratolytic agent. Antimicrobial agents that can be used for topical application are penicillins, cephalosporins, other β-lactam compounds, aminoglycosides, tetracyclines, erythromycin, antifungal agents, etc., and combinations thereof. Preservatives that can be used as active agents for topical application to acne skin are phenoxyisopropanol, resorcinol, chlorhexidine, povidone, and iodine. Keratolytic agents that can be used for topical application to acne skin are salicylic acid, benzoyl peroxide, sulfur, retinoic acid, and any of a variety of fruit acids and α-hydroxy acids.

[0117] In other embodiments, the active substance can be an anti-irritant. Suitable anti-irritants for topical application to acne-like skin are α-bisabolol, famesol, chamomile extract, and glycyrrhetinic acid.

[0118] In some embodiments, the active agent can be an anti-inflammatory agent. Examples of anti-inflammatory agents suitable for use in the method include acetaminophen, methyl salicylate, monoethylene glycol salicylate, aspirin, mefenamic acid, flufenamic acid, indomethacin, diclofenac, alclofenac, sodium diclofenac, ibuprofen, ketoprofen, naproxen, pranoprofen, fenoprofen, sulindac, fenclofenac, clidanac, flurbiprofen, fentiazac, bucolome, piroxicam, phenylbutazone, oxyphenbutazone, clofezone, pentazocine, mepiprazole, thenalidine hydrochloride, etc.

[0119] In certain embodiments, the active agent can be a steroidal anti-inflammatory agent. Examples of steroidal anti-inflammatory agents that can be used in the method include hydrocortisone, prednisolone, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, hydrocortisone acetate, prednisolone acetate, methylprednisolone, dexamethasone acetate, betamethasone, betamethasone valerate, flumethasone, fluorometholone, beclomethasone dipropionate, etc.

[0120] Antihistamines are also suitable for use as active agents. Examples of antihistamines include diphenhydramine hydrochloride, diphenhydramine salicylate, diphenhydramine, chlorpheniramine maleate, chlorpheniramine hydrochloride, isothipendyl hydrochloride, tripelennamine hydrochloride, promethazine hydrochloride, meclizine hydrochloride, etc.

[0121] In certain embodiments, the active agent can be a local anesthetic, including for example dibucaine hydrochloride, dibucaine, lidocaine hydrochloride, lidocaine, benzocaine, 2-(diethylamino)ethyl p-butylaminobenzoate hydrochloride, procaine hydrochloride, tetracaine, tetracaine hydrochloride, chloroprocaine hydrochloride, oxyprocaine hydrochloride, mepivacaine, cocaine hydrochloride, piridocaine hydrochloride, dyclonine, dyclonine hydrochloride, etc.

[0122] In other embodiments, the active agent can be a bactericide or a disinfectant. Bactericides and disinfectants that can be used include thimerosal, phenol, thymol, benzalkonium chloride, benzethonium chloride, chlorhexidine, povidone iodine, cetylpyridinium chloride, eugenol, trimethylammonium bromide, etc.

[0123] In other embodiments, the active agent can be a vasoconstrictor, a hemostatic agent, a chemotherapeutic agent or an antibiotic. Examples of suitable vasoconstrictors include naphazoline nitrate, tetrahydrozoline hydrochloride, oxymetazoline hydrochloride, phenylephrine hydrochloride, tramazoline hydrochloride, etc. Examples of suitable hemostatic agents include thrombin, phytomenadione, protamine sulfate, aminocaproic acid, vigabatrin, carbazochrome, carbazochrome sodium bisulfate, rutin, hesperidin, etc. Examples of chemotherapeutic agents that can be used include sulfanilamide, thiazole, sulfadiazine, sulfameter, sulfafurazole, sulfamidine, sulfamethizole, nitrofurazone, etc. Examples of antibiotics include penicillin, meticillin, oxacillin, cefalutin, cefadroxil, erythromycin, lincomycin, tetracycline, chlortetracycline, oxytetracycline, methacycline, chloramphenicol, kanamycin, streptomycin, gentamicin, bacitracin, cycloserine, etc.

[0124] Suitable active agents include antiviral drugs such as protease inhibitors, thymidine kinase inhibitors, sugar or glycoprotein synthesis inhibitors, structural protein synthesis inhibitors, attachment and adsorption inhibitors, and nucleoside analogs such as acyclovir, penciclovir, valacyclovir and ganciclovir.

[0125] Other suitable active agents include alpha-hydroxy acids (AHAs), lactates (such as sodium lactate) that can be used as exfoliants, humectants and emollients, and salicylic acid that can be used as a peeling agent. The moisturizing activity of AHAs and their ability to remove skin keratin and interfere with the cohesion between outer epidermal cells are well known. It has been shown that, unlike salicylic acid and other exfoliating agents, AHAs interfere with the cohesion in the granular layer.

[0126] In some embodiments, an active agent that acts on the skin may be used. Such active agents may be of a cosmetic type, such as melatonin or niacinamide. Another suitable active agent that affects the skin is vitamin C (ascorbic acid), which can be used to implement the method. In some embodiments, vitamin C may be provided as a mixture comprising vitamin E and other ingredients, such as humectants, collagen synthesis promoters, and exfoliants. In other embodiments, vitamin C may be provided together with vitamin E, and optionally α-hydroxy acids (such as lactic acid and glycolic acid) and other keratinocytes for treating or preventing wrinkles and skin dryness.

[0127] Further examples of cosmetic active agents include D-α-tocopherol, DL-α-tocopherol, D-α-tocopheryl acetate, DL-α-tocopheryl acetate, ascorbyl palmitate, vitamin F and vitamin F glycerides, vitamin D, retinol, retinol esters, retinol palmitate, retinol propionate, P-carotene, D-panthenol, farnesol, farnesyl acetate, jojoba oil and blackcurrant oil rich in essential fatty acids, 5-n-octanoyl salicylic acid and its esters, salicylic acid and its esters, alkyl esters of α-hydroxy acids, such as citric acid, lactic acid, glycolic acid, asiatic acid, madecassic acid, asiaticoside, total asiatic extract, β-glycyrrhetinic acid, α-bisabolol, ceramides, such as 2-oleoylamino-1,3-octadecane; phytantriol, marine phospholipids rich in polyunsaturated essential fatty acids, ethoxyquin, rosemary extract, lemon balm extract, quercetin, dried microalgae extract, anti-inflammatory agents such as steroidal anti-inflammatory agents, and biostimulants, such as hormones or compounds for synthesizing lipids and / or proteins.

[0128] Other examples of suitable active agents for use include vitamin D3, iron in any form, zinc in any form (such as zinc citrate), folic acid, melatonin, niacinamide, green tea or extract, ginseng, cinnamon, turmeric, curcumin, tea tree oil, clotrimazole, hyaluronic acid, α-hydroxy acids, resveratrol, valan oil, and CoQ10.

[0129] In some embodiments, the active agent may be delivered in its free base or acid form, or in the form of a salt, ester, or any other acceptable derivative, or as a component of a molecular complex. It should be understood that the above active agents may be delivered as a mixture of active agents even if not specifically mentioned.

[0130] Examples

[0131] The following examples are provided solely for the purpose of further illustrating and disclosing embodiments of methods for forming aqueous dispersions of copolymers and adhesive compositions comprising such copolymers. Examples within the scope of the present invention include Examples 1-9 described below. Two comparative examples that are not part of the present invention are also described below.

[0132] In addition, in this part, the following substances are characterized by reporting data obtained by means of instrumental analysis. The basic measurements are determined according to publicly available standards or using specially developed techniques. To ensure the clarity of the teachings imparted, the methods used are described in detail below.

[0133] In all examples, unless otherwise stated, all figures for parts and percentages are given by weight.

[0134] Viscosity:

[0135] Unless otherwise specified, viscosity is determined by measurement using rotational viscometry according to DIN EN ISO 3219 using a Brookfield viscometer [rotor LV1, 10 rpm]. Unless otherwise specified, all viscosity figures are at 25 °C and an atmospheric pressure of 1013 mbar.

[0136] Molecular composition:

[0137] The molecular composition is determined by nuclear magnetic resonance spectroscopy (for terms, see ASTM E 386:35 High-Resolution Nuclear Magnetic Resonance Spectroscopy (NMR): Terms and Symbols), where measurements are made 1 of the 29 H nuclei and

[0138] Description of 1H NMR measurements:

[0139] Solvent: CDCl3, 99.8% d

[0140] Sample concentration: approximately 50 mg / 1 ml CDCl3 in a 5 mm NMR tube

[0141] Measurement without addition of TMS, using the residual CHCl3 in CDCl3 as reference at 7.24 ppm in the spectrum

[0142] Spectrometer: Bruker Avance 400

[0143] Sample head: 5 mm BBO sample head or SMART sample head (from Bruker)

[0144] Measurement parameters: 10

[0145] Pulprog = zg30

[0146] TD = 64k

[0147] NS = 64 or 128 (depending on the sensitivity of the sample head)

[0148] SW = 20.6 ppm

[0149] AQ = 3.17 s 15

[0150] D1 = 5 s

[0151] SFO1 = 500.13 MHz

[0152] O1 = 6.175 ppm

[0153] Processing parameters:

[0154] SI = 32 k 20

[0155] WDW = EM

[0156] LB = 0.3 Hz

[0157] Depending on the type of spectrometer used, individual adjustments to the measurement parameters may be required.

[0158] 29 Description of Si NMR measurement

[0159] Solvent: C6D6 99.8% d / CCl4 1:1 v / v with 1 wt% Cr(acac)3 as relaxation reagent

[0160] Sample concentration: Approximately 2 g / 1.5 ml solvent in a 10 mm NMR 30 tube

[0161] Spectrometer: Bruker Avance 400

[0162] Sample head: 10 mm 1 H / 13 C / 15 N / 29 Si glass-free QNP sample head (from Bruker)

[0163] Measurement parameters:

[0164] Pulprog = zgig60

[0165] TD = 64 k

[0166] NS = 1024 (depending on the sensitivity of the sample head)

[0167] SW = 200 ppm

[0168] AQ = 2.75 s

[0169] D1 = 4 s

[0170] SFO1 = 300.13 MHz

[0171] O1 = -50 ppm 5

[0172] Processing parameters:

[0173] SI = 64k

[0174] WDW = EM

[0175] LB = 0.3 Hz

[0176] Depending on the type of spectrometer used, separate adjustment of the measurement parameters may be required.

[0177] Molecular weight distribution:

[0178] The molecular weight distribution was determined by gel permeation chromatography (GPC) or size exclusion chromatography (SEC) using polystyrene standards and a refractive index detector (RI detector) as the weight-average M w and number-average M n . Unless otherwise specified, THF was used as the eluent and DIN 55672-1 was adopted. The polydispersity is the ratio of M w / M n .

[0179] Glass transition temperature:

[0180] The glass transition temperature was determined by differential scanning calorimetry (DSC) according to DIN 53765, using a perforated crucible and a heating rate of 10 K / minute.

[0181] Determination of particle size:

[0182] The particle size (z-average particle size) was measured by dynamic light scattering (DLS) using a Malvern Zetasizer Nano ZS particle size analyzer. The polydispersity of the particle size (PDI) indicates the width of the particle size distribution.

[0183] Measurement of tack:

[0184] The tack was measured on an adhesive film with a wet thickness of 381 microns stretched on a MYLAR TM film. If necessary, the MYLAR TM film was corona treated. To measure the probe tack, a TA.XTPlus texture analyzer with a TA-57R probe and a TA-303 device was used for consistent placement of the test substrate. The peak tack was reported for each sample and expressed in grams-force (gf), which was generated by the probe head contacting the surface of the sample and then pulling away and leaving the sample. For each example, five samples were taken and tested. Unless otherwise indicated, the final peak tack value is the arithmetic mean of the corresponding five peak tack results.

[0185] Measurement of 180° peel stress:

[0186] A binder composition with a wet film thickness of 381 microns was coated on the film. If necessary, the MYLAR TM film was corona treated. After coating, the film was cured in an oven at 60 °C for 15 minutes. The sample with a backing was cooled and applied to a polished stainless steel test plate. The sample was allowed to stand on the steel plate for 30 minutes or 1 hour. The peel strength was measured using a Shimadzu AGS-X-10kNX tensile tester at a rate of 300 mm / min or a Chemistruments AR-1000 adhesion / peel tester at a rate of 12 inches / min.

[0187] Measurement of static shear stress:

[0188] A binder composition with an appropriate thickness was coated on the film. The film was dried in an oven at 60 °C for 15 minutes. The sample with a backing was cooled, cut, and applied on a polished stainless steel plate. Pressure was applied to the sample part on the steel plate using a 5-pound rubber roller for 4 strokes (two sets of back-and-forth strokes). The steel plate was placed in a vertical sample holder and a 1-kg weight was attached. The sample contact area was measured as 1 inch × 0.5 inch. The time taken for the weight to drop, i.e., the time when the binder failed, was measured.

[0189] Measurement of volatile organic carbon (VOC):

[0190] VOC was measured according to EPA test method 24.

[0191] Measurement of water contact angle:

[0192] Using a Mobile Surface analyzer, the water contact angle was measured on the dry binder film on an aluminum Q-panel

[0193] Measurement of moisture vapor transmission rate:

[0194] A binder composition with a wet film thickness of 203.2 microns was coated on a nonwoven fabric. The film was dried in an oven at 60 °C for 15 minutes. The sample with a nonwoven fabric backing was cooled, cut into a circular shape with a diameter of 5.6 cm, and mounted on a Perm cup pre-filled with 10.00 ± 0.05 g of deionized water. The water vapor transmission rate was measured using the "wet (Payne) cup method" of ASTM D1653.

[0195] Franz cell:

[0196] The examples provided below involving the release of melatonin or niacinamide were carried out using a Franz diffusion cell (Franz cell) through a cellulose acetate membrane disk. The Franz cell described in the examples is the DHC-6AT Dry Heat Transdermal Diffusion Cell Transdermal Systems sold by Logan Instruments Corp. The cellulose acetate membrane has a molecular weight cut-off of 12 - 14. Before use in the study, each cellulose acetate membrane was soaked in a 20% aqueous EtOH solution for 1 hour to remove any unbound chemicals.

[0197] To study the release of the active agents mentioned in Examples 7 and 8, gel samples were formed and punched into sections with a circular shape and a 1.5 cm diameter. These sections were mounted on the cellulose acetate membrane, and the release of melatonin or niacinamide was measured. In these examples, a 20% aqueous EtOH solution was used as the receptor cell fluid. The temperature of the receptor cell of the Franz cell was set at 37 °C, while the solution was stirred at a constant rate of approximately 600 rpm. Solution samples were collected at different time points throughout the study. After each collection of the solution sample, a 1.00 mL aliquot was removed and replaced with an equal fresh amount of the same fluid. In Examples 7 and 8, the concentrations of melatonin and niacinamide in the collected samples were determined by high-performance liquid chromatography.

[0198] The vinyl-functionalized silicone resin B1 was prepared by co-condensation of an ethoxy-functionalized silicone resin with methacryloxypropyltrimethoxysilane (CH3O)3Si(CH2)3OC(=O)C(CH3)=CH2

[0199] The methacryloxypropyl-functionalized organosilicon resin was prepared by condensing tetraethyl orthosilicate oligomers with an average degree of oligomerization of 9, hexamethyldisiloxane, 3-methacryloxypropyltrimethoxysilane, and a low-viscosity, OH-terminated polydimethylsiloxane with an average of 45 siloxane units together. The condensation reaction was carried out in the presence of water and a catalyst, hydrochloric acid. The detailed procedure is described in US2018 / 0305576. The resin was diluted with 25% butyl acrylate. The following are the characteristics of the methacryloxypropyl-functional silicone resin:

[0200] Molecular weight:

[0201] M w =4018 g / mol

[0202] M n =1557 g / mol

[0203] PD=2.58

[0204] From 1 1H NMR and 29 Si NMR molecular composition:

[0205] Me3SiO 1 / 2 : 23.18 mol%

[0206] Me2SiO 2 / 2 : 20.66 mol%

[0207] ((CH2)3OC(=O)C(CH3)=CH2)SiO 3 / 2 : 0.72 mol%

[0208] SiO 4 / 2 : 37.30 mol%

[0209] EtO-Si: 3.68 mol%

[0210] MeO-Si: 0.12 mol%

[0211] Example 1: Preparation of an aqueous dispersion of a copolymer from an ethylenically functionalized silicone resin B1 and an organic acrylic monomer (1:9 silicone:organic acrylic monomer)

[0212] Step 1: Preparation of the miniemulsion

[0213] The miniemulsion was prepared as follows: A mixture of the silicone resin B1 and the (meth)acrylic monomer was dissolved and then homogenized under high pressure. In this example, an HPH 2000 / 5 high-pressure homogenizer was used to prepare the miniemulsion.

[0214] The following components were added to a sealable container and mixed on an orbital shaker:

[0215] Component Weight (g) Resin B1 solution containing 25% butyl acrylate 104.74 2-Ethylhexyl acrylate 459.39 Methyl acrylate 207.15 Acrylic acid 14.18 Hexadecane 2.40

[0216] The resulting mixture was combined with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0217] Component Weight (g) Polymerizable surfactant Hitenol KH-10 25.27 Hydroquinone monomethyl ether (2% solution in water) 3.69 Reverse osmosis water 433.74

[0218] The pre-emulsion was passed through a high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 233 nm (PDI = 0.32).

[0219] Step 2: Polymerization

[0220] Add 236.11 g of deionized water and 68 g of the miniemulsion prepared in Step 1 as the initial feed to a 3 L polymerization vessel equipped with an anchor stirrer, reflux condenser, thermometer, and nitrogen inlet, and heat to 50 °C with stirring. In a sealable container, provide an aqueous solution of 6.26 g of 70 wt% tert-butyl hydroperoxide (TBHP) diluted with 40.38 g of deionized water (Feed 1). In a second sealable container, provide a solution of 2.19 g of formaldehyde-free reducing agent ( FF6M) in 42.42 g of reverse osmosis water (Feed 2). In a third container, provide 855.7 g of miniemulsion (Feed 3). Start feeding Feed 1 and 2 at a rate of 220 μL / min, and then start feeding Feed 3 at a rate of 5.0 mL / min. Meter all three feeds continuously over 165 minutes. After completion of Feed 3, continue feeding Feed 1 and 2 for an additional 30 minutes, and then hold the reaction at 50 °C for an additional 60 minutes. After cooling to room temperature, adjust the product to pH 8 by adding ammonia water. Add a biocide (Acticide BW20, 0.25 g), and filter the product through a 100 μm filter to give an aqueous dispersion of the copolymer with the following properties:

[0221] Specific gravity: 1.02;

[0222] Glass transition temperature: -41.9 °C;

[0223] Solid content: 41.4 wt%;

[0224] Total residual free monomer: < 300 ppm;

[0225] Z-average particle size immediately after preparation: 129 nm (PDI = 0.10);

[0226] Z-average particle size measured after standing at 25 °C for 840 days: 117 nm (PDI = 0.02);

[0227] Viscosity (Brookfield): 18.3 mPa.s)

[0228] Stability: The dispersion is stable at 25 °C > 720 days without any visible separation

[0229] VOC: 1.1 wt%

[0230] When the aqueous dispersion of the copolymer is applied to a substrate and cured to form a film, the adhesive composition has the following properties:

[0231] Peak tack: 492 ± 36.6 gf

[0232] 180 °Peeling stress: 1299 ± 100.6 mN / mm (33.0 ± 2.6 N / inch)

[0233] Shear strength: 4.3 ± 1.1 min

[0234] Water contact angle: 120.8 ± 0.5 °

[0235] The adhesive composition of Example 1 can be used as a PSA.

[0236] Example 2: Preparation of an aqueous dispersion of a copolymer from a linear methacryloxypropyl-terminated polydimethylsiloxane (1:9 siloxane:organic acrylic monomer)

[0237] Step 1: Preparation of the miniemulsion:

[0238] A linear methacryloxypropyl-terminated polydimethylsiloxane containing approximately 333 siloxane units is used as the siloxane component.

[0239] The following components are added to a sealable container and mixed on an orbital shaker:

[0240] Component Weight (g) Methacryloxypropyl-terminated polydimethylsiloxane 77.6 2-Ethylhexyl acrylate 456.8 Methyl acrylate 249.4 Acrylic acid 14.0 Hexadecane 2.4

[0241] The resulting mixture is mixed with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0242] Component Weight (g) Polymerizable surfactant Hitenol KH-10 25.00 Hydroquinone monomethyl ether (2% solution in water) 3.70 Reverse osmosis water 428.7

[0243] The pre-emulsion is passed through an HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 405 nm (PDI = 0.5).

[0244] Step 2: Polymerization

[0245] 250 g of reverse osmosis water and 72 g of the miniemulsion prepared in Step 1 are added as an initial feed to a 3-liter polymerization vessel equipped with an anchor stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, and heated to 50 °C with stirring. In a sealable container, an aqueous solution of 6.61 g of 70 wt% tert-butyl hydroperoxide (TBHP) diluted with 39.56 g of deionized water (feed 1) is provided. In another sealable container, 2.32 g of a formaldehyde-free reducing agent ( Solution of FF6M) in 44.93 g of reverse osmosis water (feed 2). In a third container, 828 g of a fine emulsion (feed 3) was provided. Feeds 1 and 2 were started at a rate of 220 μL / min, and then feed 3 was started at a rate of 5.0 mL / min to continuously metered-feed over a period of 165 minutes. After completion of feed 3, feeds 1 and 2 were continued for an additional 30 minutes, and then the reaction was held at 50 °C for an additional 60 minutes. After cooling to room temperature, the product was adjusted to pH 8 by addition of ammonia. A biocide (Acticide BW 20, 0.25 g) was added, and the product was filtered through a 100 μm filter to give an aqueous dispersion of the copolymer having the following properties:

[0246] Specific gravity: 1.03;

[0247] Glass transition temperature: -48.3 °C;

[0248] Solid content: 47.9 wt%;

[0249] Total residual free monomer: 3300 ppm

[0250] Z-average particle size: 126 nm (PDI = 0.11)

[0251] Z-average particle size measured after standing at 25 °C for 860 days: 114 nm (PDI = 0.13)

[0252] Viscosity: 440 mPa.s

[0253] Stability: The dispersion is stable at 25 °C > 720 days without any visible separation

[0254] VOC: 1.6 wt%

[0255] When the aqueous dispersion of the copolymer is applied to a substrate and cured to form a film, the adhesive composition has the following properties:

[0256] Peak tack: 651 ± 254 gf

[0257] 180 ° Peel stress: 522.8 ± 93.23 mN / mm (13.3 ± 2.4 N / inch)

[0258] Shear strength: 28.8 ± 6.1 min

[0259] Water contact angle: 114.9 ± 2.3 °

[0260] The adhesive composition of Example 2 can be used as a PSA.

[0261] Example 3: Preparation of an aqueous dispersion of a copolymer from silicone resin B1 and organic acrylic monomers (1:9 silicone:organic acrylic monomers, with a slightly higher amount of polymerizable surfactant)

[0262] Step 1: Preparation of the miniemulsion:

[0263] The following components were added to a sealable container and mixed on an orbital shaker:

[0264] Component Weight (g) Resin B1 solution containing 25% butyl acrylate 104.7 2-Ethylhexyl acrylate 459.9 Methyl acrylate 207.1 Acrylic acid 14.3 Hexadecane 2.4

[0265] The resulting mixture was combined with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0266] Component Weight (g) Polymerizable surfactant Hitenol KH-10 38.00 Hydroquinone monomethyl ether (2% solution in water) 3.70 Reverse osmosis water 433.7

[0267] The pre-emulsion was passed through a HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 272 nm (PDI = 0.3).

[0268] Step 2: Polymerization

[0269] 250 g of reverse osmosis water and 75 g of the miniemulsion prepared in Step 1 were added as an initial charge to a 3 L polymerization vessel equipped with an anchor stirrer, reflux condenser, thermometer, and nitrogen inlet, and heated to 50 °C with stirring. In a sealable container, an aqueous solution of 6.61 g of 70 wt% tert-butyl hydroperoxide (TBHP) diluted with 39.54 g of deionized water (feed 1) was provided. In a second sealable container, a solution of 2.37 g of formaldehyde-free reducing agent FF6M in 44.94 g of reverse osmosis water (feed 2) was provided. In a third container, 825 g of miniemulsion (feed 3) was provided. Feeds 1 and 2 were started at a rate of 220 μL / min, followed by feed 3 at a rate of 5.0 mL / min to continuously meter in over a 165-minute period. After completion of feed 3, feeds 1 and 2 were continued for an additional 30 minutes, and then the reaction was held at 50 °C for an additional 60 minutes. After cooling to room temperature, the product was adjusted to pH 8 by adding ammonia. A biocide (Acticide BW 20, 0.24 g) was added, and the product was filtered through a 100 μm filter to give an aqueous dispersion with the following properties:

[0270] Specific gravity: 1.02;

[0271] Glass transition temperature: -42.2 °C;

[0272] Solid content: 46.5 wt%;

[0273] Total residual free monomer: 4050 ppm

[0274] Z-average particle size: 132 nm (PDI = 0.11)

[0275] Viscosity: 167 mPa.s

[0276] Stability: The dispersion is stable at 25 °C for >720 days without any visible separation

[0277] VOC: 1.9 wt%

[0278] When the aqueous dispersion of the copolymer is applied to a substrate and cured into a film, the adhesive composition has the following properties:

[0279] Peak tack: 989 ± 23.7 gf

[0280] 180 ° Peel stress: 1646 ± 63.25 mN / mm (41.8 ± 1.6 N / inch)

[0281] Shear strength: 8.3 ± 2.5 min

[0282] Water contact angle: 119.9 ± 1.0 °

[0283] Water vapor transmission rate: 780 g / m 2 / day

[0284] The adhesive composition of Example 3 can be used as a PSA.

[0285] Example 4: Preparation of an aqueous dispersion of a copolymer from silicone resin B1 and an organic acrylic monomer (1:1 silicone:organic acrylic monomer)

[0286] Step 1: Preparation of the miniemulsion:

[0287] The following components were added to a sealable container and mixed on an orbital shaker:

[0288] Component Weight (g) Resin B1 solution containing 25% butyl acrylate 497.40 2-Ethylhexyl acrylate 162.12 Methyl acrylate 73.20 Acrylic acid 13.44 Hexadecane 2.28

[0289] The resulting mixture was combined with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0290] Component Weight (g) Polymerizable surfactant Hitenol KH-10 36.12 Butylated hydroxytoluene (3.55% solution in water) 3.48 Reverse osmosis water 411.96

[0291] The pre-emulsion was passed through HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 227 nm (PDI = 0.2).

[0292] Step 2: Aggregation

[0293] Add 241.3 g of reverse osmosis water and 69.5 g of the fine emulsion prepared in Step 1 as the initial feed to a 3-L polymerization vessel equipped with an anchor stirrer, reflux condenser, thermometer, and nitrogen inlet, and heat to 50 °C with stirring. In a sealable container, provide an aqueous solution of 6.36 g of 70 wt% tert-butyl hydroperoxide (TBHP) diluted with 38.16 g of deionized water (Feed 1). In a second sealable container, provide a solution of 2.28 g of formaldehyde-free reducing agent ( FF6M) in 43.32 g of reverse osmosis water (Feed 2). In a third container, provide 799 g of fine emulsion (Feed 3). Start feeding Feed 1 and 2 at a rate of 220 μL / min, and then start feeding Feed 3 at a rate of 5.0 mL / min to continuously meter the feeds over a 165-minute period. After completion of Feed 3, continue feeding Feed 1 and 2 for an additional 30 minutes, and maintain the reaction at 50 °C for an additional 60 minutes. After cooling to room temperature, adjust the product to pH 8 by adding ammonia. Add a biocide (Acticide BW 20, 0.24 g), and filter the product through a 100-μm filter to give a dispersion with the following properties:

[0294] Specific gravity: 1.04;

[0295] Glass transition temperature: -40.3 °C;

[0296] Solid content: 45.9 wt%;

[0297] Total residual free monomer: 1381 ppm

[0298] Z-average particle size: 182 nm (PDI = 0.19)

[0299] Viscosity: 17 mPa·s

[0300] VOC: 1.51 wt%

[0301] When the aqueous dispersion of the copolymer is applied to a substrate and cured to form a film, the adhesive composition has the following properties:

[0302] Peak tack (381-μm wet thickness): 289 ± 49 gf

[0303] 180 ° Peel stress: 815 mN / mm (20.7 N / inch)

[0304] Water vapor transmission rate: 790 g / m 2 / day

[0305] The adhesive composition of Example 4 can be used as a PSA.

[0306] Example 5: Preparation of an aqueous dispersion of a copolymer from methacryloxypropyltris(trimethylsiloxysilane) and an organic acrylic monomer (7:3 silane:organic acrylic monomer) Step 1: Preparation of the miniemulsion:

[0307] The following components were added to a sealable container and mixed on an orbital shaker:

[0308] Component Weight (g) Methacryloxypropyl tris(trimethylsiloxysilane) 405.95 2-Ethylhexyl acrylate 115.92 Methyl acrylate 40.57 Acrylic acid 17.44 Hexadecane 1.77

[0309] The resulting mixture was combined with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0310] Component Weight (g) Polymerizable surfactant Hitenol KH-10 28.07 Hydroquinone monomethyl ether (2% solution in water) 2.70 Reverse osmosis water 320.15

[0311] The pre-emulsion was passed through a HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 936.5 nm (PDI = 0.3).

[0312] Step 2: Polymerization

[0313] 201.10 g of reverse osmosis water and 57.90 g of the miniemulsion prepared in Step 1 were added as an initial feed to a 3 L polymerization vessel equipped with an anchor stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, and heated to 50 °C with stirring. In a sealable container, 5.30 g of an aqueous solution of 70 wt% tert-butyl hydroperoxide (TBHP) was diluted with 31.80 g of deionized water (feed 1). In a second sealable container, a solution of 1.90 g of formaldehyde-free reducing agent FF6M) in 36.10 g of reverse osmosis water (feed 2) was prepared. 665.90 g of the miniemulsion (feed 3) was placed in a third container. Feeds 1 and 2 were started at a rate of 220 μL / min, followed by feed 3 at a rate of 5.0 mL / min, for continuous metered addition over a period of 165 minutes. After completion of feed 3, feeds 1 and 2 were continued for an additional 30 minutes, and then the reaction was maintained at 50 °C for a further 60 minutes. After cooling to room temperature, the product was adjusted to pH 8 by adding ammonia. A biocide (Acticide BW 20, 0.20 g) was added, and the product was filtered through a 100 μm filter to give a dispersion with the following properties:

[0314] Specific gravity: 1.00

[0315] Glass transition temperature: -47.6 °C

[0316] Solid content: 49.8 wt%

[0317] Total residual free monomer: 2961 ppm

[0318] Z-average particle size: 269 nm (PDI = 0.0.4)

[0319] Viscosity: 126 mPa.s

[0320] VOC: 1.46 wt%

[0321] When the aqueous dispersion of the copolymer is applied to a substrate and cured to form a film, the adhesive composition has the following properties:

[0322] Peak tack: 809 ± 168.9 gf

[0323] 180 ° Peel stress: 886 mN / mm (22.5 N / inch)

[0324] Water vapor transmission rate: 1160 g / m 2 / day

[0325] The adhesive composition of Example 5 can be used as a PSA.

[0326] Example 6 prepared an aqueous dispersion of a copolymer from siloxane resin B1, methacryloxypropyltris(trimethylsiloxysilane), and an organic acrylic monomer (14:1 (siloxane + silane): organic acrylic monomer)

[0327] Step 1: Preparation of the miniemulsion:

[0328] The following components were added to a sealable container and mixed on an orbital shaker:

[0329] Component Weight (g) Methacryloxypropyl tris(trimethylsiloxysilane) 300.00 Resin B1 solution containing 25% butyl acrylate 109.14 Hexadecane 1.25

[0330] The resulting mixture was mixed with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0331] Component Weight (g) Polymerizable surfactant Hitenol KH-10 19.81 Hydroquinone monomethyl ether (2% solution in water) 1.91 Reverse osmosis water 225.89

[0332] The pre-emulsion was passed through a HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a miniemulsion with a z-average particle size of 296 nm (PDI = 0.3).

[0333] Step 2: Polymerization

[0334] Into a 1-liter polymerization vessel equipped with an anchor stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, 152.81 grams of reverse osmosis water and 44.00 grams of the fine emulsion prepared in Step 1 were added as the initial feed, and the mixture was heated to 50 °C with stirring. In a sealable container, an aqueous solution of 1.35 grams of 70 wt% tert-butyl hydroperoxide (TBHP) was diluted with 25.36 grams of deionized water (Feed 1). In a second sealable container, a solution of 0.47 grams of formaldehyde-free reducing agent ( FF6M) in 26.23 g of reverse osmosis water (Feed 2) was provided. In a third container, 506.00 grams of fine emulsion (Feed 3) was provided. Feeds 1 and 2 were started at a rate of 220 μL / min, and then Feed 3 was started at a rate of 5.0 mL / min to continuously meter the feeds over a 165-minute period. After completion of Feed 3, Feeds 1 and 2 were continued for an additional 30 minutes, and then the reaction was maintained at 50 °C for an additional 60 minutes. After cooling to room temperature, the product was adjusted to pH 8 by adding ammonia water. A biocide (Acticide BW 20, 0.15 grams) was added, and the product was filtered through a 100 μm filter to give a dispersion having the following properties:

[0335] Specific gravity: 1.01

[0336] Glass transition temperature: -59.0 °C

[0337] Solid content: 47.4 wt%

[0338] Total residual free monomer: 2740 ppm

[0339] Z-average particle size: 292 nm (PDI = 0.4)

[0340] Viscosity: 50 mPa.s

[0341] VOC: 1.37 wt%

[0342] When the aqueous dispersion of the copolymer is applied to a substrate and cured to form a film, the adhesive composition has the following properties:

[0343] Peak tack (1 wt% wetting agent &L067 blended with the dispersion before film doctoring): 510 ± 50 gf

[0344] 180 ° 180° Peel stress (1 wt% wetting agent L067 used for film doctoring): 91 mN / mm (2.3 N / inch)

[0345] Water vapor transmission rate: 820 g / m 2 / day

[0346] The adhesive composition of Example 6 can be used as a PSA.

[0347] Example 7: Release of Melatonin

[0348] The controlled release of melatonin from the copolymer sample was determined by adding melatonin to the copolymer dispersion (Example 4, RH47), and the cumulative flux Q (μg / cm 2 ) was plotted against the reciprocal of time (min 1 / 2 ). A sample was prepared by mixing 0.069 g of melatonin with 10.000 g of the copolymer dispersion (melatonin with a solids content of about 1.5 wt%). A film was formed from this mixture. After stretching on a corona-treated MYLAR TM plate with a film applicator and curing in an oven at 80 °C for 10 minutes, the film had a thickness of 381 microns. After forming the film, the tack of the film was measured at 248 gf.

[0349] To measure the release of melatonin from the film, the sample was mounted on a Franz cell. As Figure 1 shown, after 24 hours, the release of melatonin from the sample was measured to be 79.2 μg / cm 2 . Figure 1 The release curve shown in

[0350] Example 8: Release of Niacinamide

[0351] The controlled release of niacinamide from the copolymer sample was determined by adding niacinamide to the copolymer dispersion (Example 4, RH47), and the cumulative flux Q (μg / cm 2 ) was plotted against the reciprocal of time (min 1 / 2 ). A sample was prepared by mixing 0.237 g of niacinamide with 10.00 g of the copolymer dispersion (melatonin with a solids content of about 5.0 wt%). A film was formed from this mixture. After stretching on a corona-treated MYLAR TM plate with a film applicator and curing in an oven at 80 °C for 10 minutes, the film had a thickness of 381 microns. After film formation, the tack of the film was measured at 825 gf.

[0352] To measure the release of niacinamide from the sample, the sample was mounted on a Franz cell. As Figure 2 shown, after 24 hours, the release of niacinamide from the sample was measured to be 256.5 μg / cm 2 . Figure 2 The release curve shown in

[0353] Example 9: Transfer Coating of Adhesive Composition

[0354] An aqueous dispersion of the copolymer from Example 5 was mixed with a wetting agent, WACKER Fluid L067 (1% by weight PSA dispersion). An adhesive film with a wet film thickness of 127 µm was formed on a strip of 3M TM Medical Release Liner 9955 (fluoropolymer-coated polypropylene), and cured in an oven at 60 °C for 15 minutes. The resulting adhesive-coated strip was then applied to target substrates (face stocks) (stainless steel, aluminum, polyurethane), and pressure was applied using a 5-pound rubber roller in four strokes (two sets of back-and-forth strokes). After a dwell time of 5 minutes, the adhesive-coated strip was removed from the substrate. The adhesive film was transferred to the substrate, and a continuous adhesive film with a thickness of approximately 25.4 to 38.1 µm was obtained on each substrate.

[0355] Comparative Example 1: Solvent-based Siloxane-Acrylic Hybrid Adhesive Prepared from Siloxane Resin B1 and Organic Acrylic Monomer

[0356] The following components were charged into a 250 mL four-neck round-bottom flask equipped with an anchor stirrer, reflux condenser, thermometer, and nitrogen inlet:

[0357]

[0358]

[0359] The components were stirred together until homogeneous. 10 g of the initiator azobisisobutyronitrile was added with stirring. The mixture was heated to 70 °C under nitrogen with continuous stirring. After stirring for 10 minutes, the reaction mixture became an unprocessable gel.

[0360] Comparative Example 2: Aqueous Siloxane-Acrylic Hybrid without Adhesive Properties Prepared According to US2018 / 0305576 A1

[0361] Step 1: Preparation of Miniemulsion

[0362] The following components were added to a sealable container and mixed on an orbital shaker:

[0363] Component Weight (g) Resin B1 solution containing 25% butyl acrylate 589.0 Butyl acrylate 890.0 Methyl methacrylate 756.9 Butyl methacrylate (BMA) 331.0 Styrene 188.4 Methacrylic acid (MAA) 52.3 Hexadecane 19.4

[0364] The resulting mixture was mixed with a solution of the following components and mixed on an orbital shaker for about 1 hour:

[0365] Component Weight (g) Sodium dodecyl sulfate 84.6 Hydroquinone monomethyl ether (2% solution in water) 13.1 Deionized water 1576.4

[0366] Pass the pre-emulsion through an HPH 2000 / 5 high-pressure homogenizer at a pressure of 400 - 800 bar to obtain a fine emulsion with a z-average particle size of 185.3 nm (PDI = 0.2).

[0367] Step 2: Polymerization

[0368] Add 1278 g of reverse osmosis water and 320 g of the fine emulsion prepared in Step 1 as the initial feed to a 10-liter polymerization vessel equipped with an anchor stirrer, reflux condenser, thermometer, and nitrogen inlet, and heat to 50 °C with stirring. In a sealable container, provide an aqueous solution of 29.32 g of 70 wt% tert-butyl hydroperoxide (TBHP) diluted with 96.65 g of deionized water (Feed 1). In a second sealable container, prepare a solution of 10.28 g of formaldehyde-free reducing agent FF6M in 107.21 g of reverse osmosis water (Feed 2). Prepare 3976.3 g of fine emulsion (Feed 3) in a third container. Start feeding 1 and 2, then start feeding 3, and continuously metering in over 165 minutes. After completion of Feed 3, continue feeding 1 and 2 for an additional 30 minutes, and then hold the reaction at 50 °C for an additional 60 minutes. After cooling to room temperature, adjust the product to pH 6.5 by adding ammonia water. Add a biocide (Acticide BW 20, 1.11 g), and filter the product through a 100 μm filter to give a dispersion with the following properties:

[0369] Specific gravity: 1.05;

[0370] Glass transition temperature: 13.7 °C;

[0371] Solid content: 45.8%;

[0372] Total residual free monomer: 1768 ppm

[0373] Z-average particle size: 119.5 nm (PDI = 0.19)

[0374] The film pulled from the copolymer dispersion showed no initial tack after curing.

[0375] From the foregoing detailed description, it will be apparent that various modifications, additions, and other alternative embodiments are possible without departing from the true scope and spirit. The embodiments and examples discussed herein are selected and described to provide the best illustration of the principles of the invention and its practical application, so that those of ordinary skill in the art can use the invention in different embodiments and with different modifications suitable for the particular uses contemplated. As should be understood, all such modifications and variations are within the scope of the invention.

Claims

1. A method for forming an aqueous dispersion of a copolymer, the method comprising: providing a copolymerizable composition in water, the copolymerizable composition comprising a) 5 to 95% by weight, based on the total weight of the copolymerizable composition, of an ethylenically functionalized siloxane polymer or silane, and b) 5% or more by weight, based on the total weight of the copolymerizable composition, of an organic acrylic monomer; providing 0.1 to 10 wt% of a surfactant, based on the total weight of the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer; polymerizing the ethylenically functionalized siloxane polymer or silane with the organic acrylic monomer to form an aqueous dispersion of a copolymer, wherein the copolymer exhibits a glass transition temperature (Tg) of 0 to -100 °C, and the Tg is determined by differential scanning calorimetry at a heating rate of 10 °K per minute using a pierced crucible in accordance with DIN 53765.

2. The method according to claim 1, further comprising forming a miniemulsion comprising the ethylenically functionalized siloxane polymer or silane, the organic acrylic monomer, and the surfactant, and introducing an initiator, wherein the organic acrylic monomer comprises one or more acrylate or acrylic monomers, and the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer are polymerized in the presence of the surfactant and water.

3. The method according to claim 1, further comprising forming a miniemulsion comprising organic droplets, wherein prior to polymerizing the ethylenically functionalized siloxane polymer or silane with the organic acrylic monomer, the organic droplets comprise the ethylenically functionalized siloxane polymer or silane and the organic acrylic monomer.

4. The method according to claim 1, further comprising curing the aqueous dispersion of the copolymer by heating the aqueous dispersion to evaporate water therefrom.

5. The method according to claim 1, wherein the aqueous dispersion of the copolymer comprises a solids content of 40 wt% or more based on the total weight of the aqueous dispersion.

6. The method according to claim 1, wherein the aqueous dispersion of the copolymer comprises a solids content of 40 wt% to 70 wt% based on the total weight of the aqueous dispersion.

7. The method according to claim 1, wherein the copolymer exhibits a Tg of -10 °C to -60 °C.

8. The method according to claim 1, wherein the copolymer has a z-average particle size of 1000 nanometers or less when measured by dynamic light scattering.

9. The method according to claim 1, wherein the aqueous dispersion of the copolymer exhibits a viscosity of 1 to 20,000 mPa·s at 25 °C.

10. An adhesive composition comprising: the copolymer formed by the method according to claim 1, Among them, When measured by a TA.XT Plus texture analyzer using a TA-57R probe and a TA-303 apparatus, the film of the adhesive composition having a wet thickness of 381 microns exhibits a peak tack of 100 grams-force or greater after curing.

11. The adhesive composition according to claim 10, further comprising an active compound capable of being released from the matrix formed by the copolymer at a controlled rate.

12. The adhesive composition according to claim 10, wherein the adhesive composition is stable against phase separation at 25 °C as measured by the absence of any observable phase separation over 180 days.

13. The adhesive composition according to claim 10, wherein the adhesive composition has a volatility with an organic content of 2.5% or less according to EPA test method 24.

14. The adhesive composition according to claim 10, wherein the film exhibits a peak tack of 100 to 1,000 grams-force.

15. The adhesive composition according to claim 10, wherein the composition is stable against phase separation at 25 °C as measured by no more than a 20% change in the z-average particle size.

16. The adhesive composition according to claim 10, wherein the adhesive composition is a pressure-sensitive adhesive.

17. A film comprising the adhesive composition according to claim 10, the film not exhibiting residue transfer upon contact.

18. An article, comprising: the adhesive composition according to claim 10; and a substrate having the adhesive composition disposed thereon, wherein the adhesive composition forms a film on the polymeric substrate, the film having a wet thickness of 381 microns, and after curing at 60 °C for 15 minutes, a stainless steel plate is attached to the outer surface of the film, allowed to stand for 30 minutes, and then the stainless steel plate is removed at a rate of 300 mm / min (12 inches / min), and the film exhibits a 180-degree peel strength of 1.5 N / inch or greater as measured by a peel / adhesion tester at a rate of 12 inches / min.

19. A method of coating a substrate, comprising: applying the adhesive composition according to claim 10 to the substrate; and curing the composition.

20. The method according to claim 19, wherein the adhesive composition is applied by spraying, knife coating, roll coating, casting, gravure coating, dipping, and combinations thereof or by a transfer coating method.

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