Coated article and method of manufacturing the same

Abstract

A coated article includes a pressure-sensitive adhesive comprising copolymers that exhibit a glass transition temperature (Tg) of 0 to -100°C, the Tg being determined by differential scanning calorimetry with a heating rate of 10°K per minute according to DIN 53765, pierced crucible, and comprise certain structural units. The coated article also includes a release liner having a portion thereof in direct contact with the pressure-sensitive adhesive, wherein the portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine.

Description

[0001] WS12509

[0002] COATED ARTICLE AND METHOD OF MANUFACTURING THE SAME

[0003] BACKGROUND

[0004] The invention relates to a coated article. In particular, the invention relates to a coated article that includes a pressure-sensitive adhesive and a release liner. The invention also relates to a method of manufacturing the coated article.

[0005] Pressure-sensitive adhesives (PSAs) adhere to surfaces upon contact between the PSA and surface the application of pressure to the PSA.

[0006] Silicone adhesives are renowned fortheir biocompatibility, inertness, and high breathability, making them ideal for medical applications such as wound dressings. They are gentle on the skin, repositionable, and leave minimal residue, reducing the risk of skin trauma. Additionally, silicone PSAs exhibit exceptional adhesion across a wide range of substrates and offer remarkable temperature resistance, e.g. from -100°F to 500°F.

[0007] A release liner is a crucial component in products that include a PSA because the release liner serves as a protective backing that prevents premature adhesion. Typically made from paper, plastic film, or other materials coated with a release agent, the liner ensures the adhesive remains intact and uncontaminated until application. The design and material of the release liner are vital for maintaining adhesive integrity and ease of use. However, the liner must have a consistent and appropriate release force, allowing the adhesive to be easily removed without leaving residue or damaging the adhesive layer. This is typically achieved through coatings like silicone to provide a siliconized release liner.

[0008] Silicone release liners or siliconized release liners are generally avoided for use with silicone adhesives due to their similar surface properties, which can lead to strong adhesion and difficulties in liner removal. Additionally, using a silicone liner with silicone adhesive can lead to inconsistent release properties, where the adhesive may not detach smoothly or may leave residue on the liner, which can lead to adhesive transfer onto the liner compromising the adhesive's effectiveness and contamination.

[0009] To combat the issues associated with silicone release liners, fluorinated release liners have been utilized. Fluorinated release liners include materials that are intentionally provided with some fluorine content because the incorporation of fluorine enables the release liner to exhibit excellent release properties and chemical compatibility with silicone PSAs. However, growing concerns about the environmental and health impacts of fluorinated compounds, particularly PFAS, have prompted a search for safer and sustainable alternatives.WS12509

[0010] Thus, a coated article comprising a pressure-sensitive adhesive and a release liner that overcomes the deficiencies known in the art would be desirable. Methods of making such coated articles would also be desirable.

[0011] BRIEF SUMMARY

[0012] Embodiments of a coated article are provided. In an embodiment, the coated article comprises a pressure-sensitive adhesive. The pressure-sensitive adhesive comprises copolymers that exhibit a glass transition temperature (Tg) of 0 to -100°C, the Tg being determined by differential scanning calorimetry with a heating rate of 10°K per minute according to DIN 53765, pierced crucible, and comprise

[0013] organic monomer residue units of structure I:

[0014] - H2c - c -

[0015]

[0016] A1

[0017] I

[0018] and silicone polymer or silane residue units of structure II:

[0019] Y1Z or Z

[0020] - H2C - C -

[0021]

[0022] A2

[0023] II

[0024] wherein

[0025] A1 is an H or methyl group,

[0026] A2 is an H or methyl group,

[0027] wherein A1 and A2 may be the same or may be different. Y1 is a linker, and

[0028] Z is a siloxane or silane residue.WS12509

[0029] The coated article also comprises a release liner. The release liner has a portion thereof in direct contact with the pressure-sensitive adhesive. The portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine.

[0030] In some embodiments, the portion of the release liner in direct contact with the pressuresensitive adhesive is a backing layer or a release layer. In one such embodiment, the release liner further comprises the release layer. In this embodiment, the release layer is provided between the backing layer and the pressure-sensitive adhesive and the release layer is substantially free of organic fluorine. In another embodiment, the release liner further comprises the backing layer. In this embodiment, the backing layer is substantially free of organic fluorine.

[0031] In other embodiments, the copolymers comprise the reaction product of a free-radical copolymerizable composition comprising 5 to 95% by weight of ethylenically functionalized silicone polymers or silanes, which is based on the total weight of the copolymerizable compounds, and 5% or more by weight of free-radical copolymerizable ethylenically unsaturated organic monomers, which is based on the total weight of the copolymerizable compounds.

[0032] In some embodiments, the pressure-sensitive adhesive is free of any organic solvents. In other embodiments, the pressure-sensitive adhesive has a VOC of 10 g / L or less. In certain embodiments, the pressure-sensitive adhesive has peak tack of 100 to 1,000 grams of force when measured by a TA.XT Plus Texture Analyzer using a TA-57R probe and a TA-303 apparatus for a adhesive film of 25-75 microns dry thickness.

[0033] In other embodiments, the pressure-sensitive adhesive has a peel force from the release liner of 0.5 N / in or less when measured utilizing a Chemlnstruments adhesion / release tester for 180° peel at a rate of 12 in / min.

[0034] In some embodiments, the pressure-sensitive adhesive has a peel force from the release liner of 0.5 N / in or less after 28 days of aging at 50°C.

[0035] In other embodiments, the release liner has a thickness of 30 to 350 microns.

[0036] In still other embodiments, the release layer comprises a silicone matrix.

[0037] In another embodiment, the coated article comprises a pressure-sensitive adhesive. The pressure-sensitive adhesive comprises copolymers that exhibit a glass transition temperature (Tg) of 0 to -100°C, the Tg being determined by differential scanning calorimetry with a heating rate of 10°K per minute according to DIN 53765, pierced crucible. Also, the copolymers comprise structural units of structure I:WS12509

[0038] H2C

[0039]

[0040] A1

[0041] and structural units of structure II:

[0042]

[0043] In this embodiment, A1 is an H or methyl group and A2 is an H or methyl group. Further, A1 and A2 may be the same or may be different. X1 is an H or aliphatic or aromatic hydrocarbon group that may contain heteroatoms or

[0044] o

[0045] C - OA3

[0046] X1 =

[0047] or

[0048]

[0049] A3 is a hydrocarbon group having 1 to 20 carbon atoms, A4 is a hydrocarbon group having 1 to 15 carbon atoms, Z is a siloxane or silane residue comprising MaDbTcQd, M is R1R2R3SiO1 / 2, D is R4 R5 SiO2 / 2, T is R6R7 SiO3 / 2, and Q is SiO4 / 2. R1, R2, R3, R4, R5, R6, R7, R8 and R9 isWS12509

[0050] each independently a H, a hydroxyl group, an alkoxy group, or a hydrocarbyl group having up to 100 carbon atoms and optionally containing at least one heteroatom, whereas a+ b+ c+ d>1. Y1 is a linker comprising a group selected from -CH2- and hetero atoms. The coated article also comprises a release liner having a portion thereof in direct contact with the pressure-sensitive adhesive. The portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine.

[0051] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0052] The above, as well as other advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which:

[0053] FIG. 1 is a graph illustrating the peel force in newtons per inch overtime for an embodiment of the coated article in accordance with the invention and a comparative example;

[0054] FIG. 2 is a graph illustrating the peel force in newtons per inch overtime for comparative examples; and

[0055] FIG. 3 is a graph illustrating the peel force in newtons per inch for embodiments of coated articles in accordance with the invention.

[0056] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific materials, compositions, articles, and methods described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific properties, conditions, or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise.

[0058] Further, 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 only to those features but may include other features not expressly listed or inherent to such method, article, or composition. Further, unless expressly stated to the contrary, "or" refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0059] Also, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of theWS12509

[0060] invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.

[0061] In certain embodiments, a coated article is provided. The coated article includes a pressure-sensitive adhesive (PSA) and a release liner. In certain embodiments, the coated article may be utilized in medical applications. However, the coated article is not limited to use in medical applications and can be utilized in other applications where providing a ready-to-use adhesive coated article that can be affixed to a non-tacky surface is desired or in applications where the intentional incorporation of fluorinated compounds is not desired. For example, the coated article may have electronic, automotive, or construction applications. In other embodiments, the coated article may be used in a specialty application such as, for example, applications where an adhesive is exposed to high temperatures.

[0062] The PSA is preferably a silicone-acrylate hybrid copolymer, which is produced by forming a copolymer dispersion.

[0063] Preferred copolymers may comprise organic monomer residue units of the structure I:

[0064] - H2c - c -

[0065]

[0066] A1

[0067] I

[0068] and silicone polymer or silane residue units of the structure II:

[0069] Y1Z or Z

[0070] H2C - C

[0071]

[0072] A2WS12509

[0073] Preferably, in these embodiments, A1 is a hydrogen (H) or a methyl group and A2 is an H or a methyl group. In some embodiments, the organic monomer residue units of the structure I are bonded to another organic monomer residue. In certain embodiments, it may be preferred that A1 and A2 are the same. In other embodiments, A1 and A2 may be different. Preferably, Z is a siloxane or silane residue. In some embodiments, the siloxane or silane residue comprises MaDbTcQd, M is R1R2R3SiO1 / 2, D is R4R5 SiO2 / 2, T is R6R7SiO3 / 2, and Q is SiO4 / 2.

[0074] Preferably, Y1 is a linker. In some embodiments, Y1 comprises a group selected from -CH2- and hetero atoms

[0075] In some embodiments, the copolymers may comprise organic monomer residue units of the structure III:

[0076] X1

[0077] - H2C - c -

[0078]

[0079] A1

[0080] III

[0081] and / or units of the structure IV:

[0082]

[0083] In these embodiments, A1 may be an H or methyl group and A2 may be an H or methyl group. In certain embodiments, A1 and A2 may be the same or different. In these embodiments, X1 is an H or an aliphatic or aromatic hydrocarbon group that may contain heteroatoms. Alternatively, X1 may beWS12509

[0084]

[0085] In certain embodiments, A3 is a hydrocarbon group having 1 to 20 carbon atoms, A4 is a hydrocarbon group having 1 to 15 carbon atoms, and Z is a siloxane or silane residue comprising MaDbTcQd. When Z is a siloxane or silane residue comprising MaDbTcQd, M is R1R2R3SiO1 / 2, D is R4R5 SiO2 / 2, T is R6R7SiO3 / 2, and Q is SiO4 / 2. Also, it is preferred that R1, R2, R3, R4, R5, R6, R7, R8 and R9 each independently is hydrogen, a hydroxyl group, an alkoxy group, a hydrocarbyl group having up to 100 carbon atoms and optionally containing at least one heteroatom. In these embodiments, it is preferred that a+b+c+d>1.

[0086] Y1 is a linker comprising a group selected from -CH2- and hetero atoms.

[0087] In an embodiment, Y1 is

[0088] o

[0089] -

[0090]

[0091] -C- - - (CH2)n -wherein n is an integer between 1 and 6, more preferably between 1 and 3.

[0092] Preferably, the copolymer dispersion is produced by an aqueous miniemulsion radical polymerization. Suitable aqueous miniemulsion radical polymerization process for forming the copolymers are described in application serial no. PCT / EP2024 / 087765, the entire disclosure of which is hereby incorporated by reference.

[0093] The copolymers produced by the aqueous miniemulsion radical polymerization stay in the aqueous dispersion form until drying, which leads to the formation of the PSA. Utilizing an aqueous dispersion of copolymers to form the PSA has several advantages over PSA systems which utilize organic solvents. For example, utilizing an aqueous dispersion of copolymers to form the PSA enables the avoidance of handling flammable and hazardous solvents and the environmental concerns related to them. Also, the copolymers can be formed to have a higherWS12509

[0094] molecular weight and exhibit a lower viscosity than the copolymers formed utilizing an organic solvent-based polymerization process.

[0095] Water-based PSAs predominantly have included dispersions of acrylic polymers or copolymers. Advantages of acrylic PSAs include the ability to control glass transition temperature, molecular architecture, crosslinking density, and competitive cost of such systems. PSAs with excellent tack and peel strength are achievable by incorporating acrylics and such PSAs have good environmental stability and resistance to oxidation. However, a disadvantage of an acrylic PSA is the difficulty encountered during bonding to low surface energy surfaces such as those containing, for example, silicone, polyethylene, or polypropylene. Also, acrylic PSAs cause adhesion build up on the surfaces they are applied to over time and can be challenging to cleanly remove from the surface. Furthermore, when utilized in an on-skin application, acrylic PSAs can cause skin trauma during removal from the skin and have limited repositionability. In addition, acrylic PSAs used for medical field produce skin irritation due to the presence of unreacted acrylic monomers. PSAs that include acrylate systems typically have poor high and low temperature performance.

[0096] In stark contrast to acrylic PSAs, silicone PSAs provide biocompatibility, inertness and high breathability. Further, silicone PSAs are repositionable on the skin and considered gentler and skin friendly because they do not cause skin-trauma and leave little or no residue on the skin. For certain applications such as, for example, use in a wound dressing these factors are critical. Another advantage to using a silicone PSA is the adhesive’s capability of adhering to a wide variety of substrates including surfaces that have a high or low surface energy. Such surfaces may comprise, for example, glass, paper, polyolefins, polytetrafluoroethylene, fluorohalocarbon films, and silicone release liners. Most acrylic PSAs will not bond or adhere poorly to many of these low energy surfaces. In contrast, silicone PSAs are effective bonding agents for these materials. Silicone PSA’s offer both high temperature resistance (up to 500°F) along with the ability to bond at extremely low temperatures (-100°F).

[0097] Silicone PSAs can be utilized in a wide variety of applications including use in medical applications such as transdermal drug delivery systems, medical devices, and also as general medical adhesives. Traditional silicone PSAs, however, have a number of disadvantages including, generally, low tack and limited adhesion build. Further, typical silicone PSAs, which are based on MQ resins, are solvent based. The solvents used are often flammable, toxic, and require special handling. With more stringent regulations being implemented or expected across the globe, there is a desire to replace traditional PSAs with water-borne PSAs, which offer a greener and potentially less expensive alternative.WS12509

[0098] Advantageously, the PSA of the coated article may include a combination of acrylic and silicone units to provide surprising effects. In these embodiments, the copolymers are formed by reacting acrylic and silicone components in an aqueous medium, which provides copolymer(s) of silicone and acrylics that exhibit the advantages of both types of traditional PSAs while retaining the beneficial features of traditional waterborne PSAs.

[0099] In certain embodiments, the process of making the copolymers comprises providing a copolymerizable composition in water. The copolymerizable composition includes 5 to 95% by weight of ethylenically functionalized silicone polymers or silanes, which is based on the total weight of the copolymerizable composition. The copolymerizable composition also includes 5% or more by weight of organic acrylic monomers, which is based on the total weight of the copolymerizable composition. The process comprises providing 0.1 to 10 wt% of a surfactant, more preferably 0.1 to 5 wt%, and most preferably, 0.1 to 3 wt% of surfactant which is based on the total weight of the ethylenically functionalized silicone polymers or silanes and organic acrylic monomers. In some embodiments the surfactant is a polymerizable surfactant.

[0100] The ethylenically functionalized silicone polymers or silanes and the organic acrylic monomers are polymerized to form an aqueous dispersion of copolymers. The copolymers exhibit a glass transition temperature (Tg) of 0 to -100°C, more specifically, from -10 to -80°C or -15 to -70°C. The Tgbeing determined by differential scanning calorimetry with a heating rate of 10 °K per minute according to DIN 53765, pierced crucible.

[0101] In certain embodiments, the process further comprises forming a miniemulsion. The miniemulsion comprises the ethylenically functionalized silicone polymers or silanes, organic acrylic monomers, and surfactant. A radical initiator is also introduced. The organic acrylic monomers comprise one or more acrylates or acrylic acid monomers. The ethylenically functionalized silicone polymers or silanes and the organic acrylic monomers are polymerized in the presence of the surfactant and water.

[0102] In some embodiments, the miniemulsion comprises organic droplets. The organic droplets comprise the ethylenically functionalized silicone polymers or silanes and the organic acrylic monomers and are formed prior to polymerizing the ethylenically functionalized silicone polymers or silanes and the organic acrylic monomers. Preferably, after polymerization, the aqueous dispersion of copolymers comprises a solids content of 40 wt% or more, based on the total weight of the aqueous dispersion. More preferably, the solids content of the aqueous dispersion of copolymers is 40 to 70 wt%, and most preferably 50-65 wt%, based on the total weight of the aqueous dispersion. In other embodiments, the process further comprises curing the aqueous dispersion of copolymers by heating the aqueous dispersion to evaporate the water therefrom.WS12509

[0103] In some embodiments, the copolymers copolymers exhibit a Tg of -10 to -60°C. In other embodiments, the copolymers copolymers have a z-average particle size of 1000 nanometers or less when measured by a dynamic light scattering method. In an embodiment, the aqueous dispersion of copolymers exhibits a viscosity of 1 to 20,000 mPa.s at 25°C. In other embodiments, an adhesive composition is provided. In an embodiment, the adhesive composition comprises the copolymers formed by the process for forming an aqueous dispersion of copolymers. In some embodiments, a film of the adhesive composition has a 381 microns wet thickness, and exhibits a peak tack of 100 grams of force or more after curing when measured by a TA.XT Plus Texture Analyzer using a TA-57R probe and a TA-303 apparatus. Preferably, the film exhibits a peak tack of 100 to 1,000 grams of force. In some other embodiments, a film of the adhesive composition has a 25-75 microns dry thickness, and exhibits a peak tack of 100 grams of force or more after curing when measured by a TA.XT Plus Texture Analyzer using a TA-57R probe and a TA-303 apparatus. Preferably, the film with such thickness exhibits a peak tack of 100 to 1,000 grams of force. In other embodiments, the adhesive composition comprises an active compound that can be released at a controlled rate from a matrix formed by the copolymers. Preferably, the adhesive composition has volatile organic content of 2.5% or less according to EPA test method 24.

[0104] In another embodiment the PSA has improved moisture vapor transmission rate (MVTR). MVTR can be measured according to ASTM D1653. The PSA has an MVTR value of >300g / m2 / day when measured according to the above method by using a textile backing. The PSA used to form the coated article should, by itself, provide very good adhesion properties. However, the adhesive can also be blended with other adhesives to obtain optimum properties for a specific application. Also, tackifying agents can be added to the PSA to adjust the properties exhibited thereby. Other additives suitable for use in the PSA may include wetting agents, defoaming agents, and / or coalescing agents. In other embodiments, the PSA is biocompatible which means that it does not have any observable adverse effect if used on the skin or when used in proximity of human body. In these embodiments, the residual monomeric reaction components should be very low, preferably below 0.5%.

[0105] To form the coated article, the copolymer dispersion is applied on a facestock, cured and combined with a non-fluorinated release liner. As used herein, a non-fluorinated release liner refers to the portion of the of the release liner that is in direct contact with the PSA. The portion of the of the release liner that is in direct contact with the PSA is non-fluorinated when it is substantially free of organic fluorine. The thickness of the release liner is preferably between 30-350 microns, more preferably between 50-200 microns, most preferably between 60-160 microns.WS12509

[0106] In some embodiments, the copolymer dispersion is applied on the facestock by spraying, knife coating, roller coating, casting, drum coating, dipping and combinations thereof.

[0107] Alternatively, the copolymer dispersion is directly coated on a release liner, cured and laminated on a facestock immediately or at a later time. In such processes, the adhesive film is transferred from the release liner to the face stock during application (transfer coating).

[0108] After applying the copolymer dispersion on facestock, the dispersion is allowed to cure, which can also be referred to herein as “dry,” to form the PSA. After curing, the PSA defines a layer of the coated article that exhibits a desirable thickness. Preferably, the thickness of the PSA is substantially uniform and between 5 to 300 micron, or, 10 to 300 micron, or, 25 to 200 micron, or, 25 to 100 micron or 50 to 100 micron thick when dry. Most preferably, the thickness of the PSA is between 25 to 200 micron when dry.

[0109] The coated article also comprises the release liner. As mentioned above, a portion of the release liner is in direct contact with the PSA. However, the purpose of the release liner is to protect the PSA prior to use of the PSA / facestock portion in its intended application. Thus, just before use of the PSA / facestock portion, the release liner is separated therefrom. Therefore, the release liner should not form a strong bond with the PSA. The bond between the release liner and the PSA can be measured by measuring peel force, also called peel strength. The 180 degree peel force should not exceed 0.5 newtons per inch (N / in). Thus, in an embodiment, the peel force is less than 0.5 N / inch after 28 days of aging of the composite at 50°C. Most preferably the peel force should not exceed 0.2 N / inch. In one embodiment the peel force is less than 0.2 N / inch after 28 days of aging of the composite at 50°C. Peel force can be measured as described herein. In addition to a desired bond strength, the release liner should release from the PSA without removing adhesive upon peeling, which means that there should not be any visible adhesive residue on the release liner upon peel so that the PSA remains cohesive.

[0110] As mentioned above, a portion of the release liner is in direct contact with the PSA and the portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine. As used herein, substantially free of organic fluorine means that the concentration is less than 50 ppm organic fluorine content. In other embodiments, the portion of the release liner in direct contact with the pressure-sensitive adhesive is fluorine free. As used herein, “fluorine free” means devoid of any fluorine residue.

[0111] In certain embodiments, the release liner comprises a backing layer. In some of these embodiments, the backing layer is in direct contact with the PSA and a portion of the backing layer in direct contact with PSA is substantially free of organic fluorine. In other embodiments, the release liner comprises a release layer and the backing layer. In embodiments where the release liner comprises the release layer, the release layer is provided between the backingWS12509

[0112] layer and the PSA. In these embodiments, the release layer is in direct contact with the PSA and the portion of the release layer in direct contact with the PSA is substantially free of organic fluorine. Substantially free of organic fluorine has the same meaning as provided above.

[0113] Although there are no particular limitations on the thickness of the release layer, the coated thickness can be, for example, about 0.03 to 5 microns and preferably 0.05 to 3 microns.

[0114] It is preferred that the release layer comprises a release compound which provides a release effect against the surface of the PSA to which it is attached, thus aiding the removal of the release liner from the adhesive surface. The release compound may comprise one or more of a wax, for example microcrystalline wax, or a silicone for example poly(dimethyl siloxane). Preferably, the release compound comprises a silicone. More preferably, the release compound comprises poly(dimethyl siloxane), poly(dimethyl dichloro silane), poly(divinyl silane), poly{diphenyl siloxane), poly(phenylmethyl siloxane), 1,3-tetraphenyl-1,3-dimethyl disiloxane, and / or 1,3-diphenyl-1,2-tetramethyl disiloxane. Yet more preferably, the release compound comprises poly(dimethyl siloxane).

[0115] In one preferable embodiment, the release compound is formed by addition reaction between at least one SiH functional silicone and at least one vinyl functional silicone in presence of a catalyst. In one preferable embodiment the release compound is a crosslinked silicone structure formed from addition reaction between at least one pendant SiH functional siloxane and at least one mono(vinyl)terminated siloxane in presence of a catalyst.

[0116] In some embodiments, like those where the release compound comprises a silicone, the release compound comprises 300 parts per million (ppm) or less catalyst, based on the total weight of the release compound. For example, the release compound may comprise 50 to 300 ppm catalyst, based on the total weight of the release compound. Preferably, the release compound comprises 250 ppm or less catalyst, based on the total weight of the release compound. In one such embodiment, the release compound may comprise 50 to 250 ppm catalyst, based on the total weight of the release compound. Advantageously, the release compound is formed so that it can cure at low temperatures of, for example, 80°C or less with a catalyst concentration of 200 ppm or less. Thus, in some embodiments, the release compound comprises 200 ppm or less catalyst, based on the total weight of the release compound. In other embodiments, the release compound comprises 150 ppm or less catalyst, based on the total weight of the release compound. For example, in an embodiment, the concentration of catalyst for catalyzing curing may be in an amount between 50 and 150 ppm, 75 and 150 ppm, or 100 and 150 ppm of the catalyst, depending on the total weight of the release compound.

[0117] The catalyst promotes the addition of a Si-bonded hydrogen atom from the organosilicon crosslinker to an aliphatically unsaturated group of the organosilicon compound. Preferably, theWS12509

[0118] catalyst is of the hydrosilyation variety, which is understood as meaning a catalyst which promotes the addition of Si-bonded hydrogen onto an aliphatic multiple bond.

[0119] Hydrosilylation catalysts known in the art are suitable for use in the release coating composition. When the catalyst is of the hydrosilyation variety, the catalyst typically will comprise platinum, but other platinum-group metals such as, for example, rhodium may be utilized. In an embodiment, the catalyst may include metallic and finely divided platinum which can be present on supports such as silicon dioxide, aluminum oxide or activated carbon. In other embodiments, the catalyst may be a compound or complex of platinum. For example, suitable compounds and complexes include platinum halides, e.g. PtCI4, H2PtCI6'6H2O, Na2PtCI4 4H2O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alkoxide complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H2PtCl6'6H2O and cyclohexanone, platinum-vinylsiloxane complexes, in particular platinum-divinyltetramethyldisiloxane complexes with or without detectable inorganically bound halogen, bis(gamma-picoline)platinum dichloride, trimethylenedipyridineplatinum dichloride, dicyclopentadieneplatinum dichloride, (dimethyl sulfoxide)ethyleneplatinum(ll) dichloride and also reaction products of platinum tetrachloride with olefin(s) and primary amine or secondary amine, or primary and secondary amine, for example the reaction product of platinum tetrachloride dissolved in 1-octene with sec-butylamine, or ammonium-platinum complexes.

[0120] Preferably, the catalyst is a platinum complex comprising at least one unsaturated group. In such an embodiment, the catalyst may be the so-called Karstedt catalyst, i.e. a Pt(O) complex, in particular the platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of the formula Pt2[[(CH2=CH)(CH3)2Si]2O]3.

[0121] The backing layer may comprise a polyolefin, for example polyethylene, polypropylene, polybutylene, mixtures, blends or copolymers thereof; a polyester, for example polyethylene terephthalate; a polyamide, for example nylon; a polyurethane; a polyvinyl halide, for example polyvinyl chloride; an acetate and / or a biopolymer, for example cellulose and / or its derivatives, polylactic acid or polyhydroxyalkanoate; a polycarbonate. Preferably, the backing layer comprises polypropylene or polyethylene terephthalate. In one embodiment the backing layer could be kraft paper.

[0122] In use, the coated article may be used in on-skin and / or medical applications in such items like surgical tapes, dressings, drapes, bandages, and wearable devices. However, the coated article is not limited to medical applications and can be utilized in other applications where a tacky, cohesive, and low trauma adhesive is desired. For example, the coated article may be utilized in non-medical wearable device applications such as, for example, headset devices. Also, the coated article can be used in the manufacture of various other items, forWS12509

[0123] example, industrial tapes, surface protection films for electronics and other instruments, or automotive components.

[0124] The PSA portion of the coated article may also be utilized to provide a matrix for containing one or more active ingredients. Advantageously, such actives can be incorporated into such compositions and can be released at a controlled rate from the same.

[0125] In certain embodiments a coated article comprising a , offering a sustainable solution without compromising performance, is utilized.As noted above, the coated article can be utilized in medical applications such as, for example, 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. Another preferred application is use as a PSA tape formed from the coated article, which is useful in medical applications requiring a low trauma characteristic, which means that the adhesive adheres to skin but does not exhibit excessive adhesion build overtime which would result in a difficult, and thus painful, removal.

[0126] In certain embodiments a coated article comprising a fluorine-free PSA and a fluorine-free release liner is provided, which offers a sustainable solution without compromising performance. In other embodiments, the PSA comprises silicone-acrylate hybrid copolymers, produced through a waterborne miniemulsion radical polymerization process. This polymerization method provides several advantages, including the avoidance of flammable solvents and improved environmental sustainability. Such copolymers combine the benefits of both silicone and acrylic materials, resulting in a PSA with enhanced tack, peel strength, breathability and environmental stability. The innovative use of the embodiments of the release liner described above ensures clean and efficient removal, aligning with regulatory trends and sustainability goals.

[0127] It has been surprisingly found that the silicone-acrylic copolymers prepared as described herein, while providing excellent adhesive properties, can be used with the release liners described herein, especially with silicone release liners or siliconized release liners, to form the coated article. The coated article exhibits an easy and clean release, offering a safer, environmentally friendly solution for medical and other applications.

[0128] Examples

[0129] The following examples are presented solely for the purpose of further illustrating and disclosing the embodiments of the coated article and method of manufacturing the same.

[0130] Examples within the scope of the invention include Examples 1-4, which are described below. Three Comparative Examples, which are not part of the invention, are also described below.WS12509

[0131] In the present text, substances are characterized by reporting of data obtained by means of instrumental analysis. The underlying measurements are carried out either in accordance with publicly accessible standards or are determined using specially developed techniques. In order to ensure the clarity of the teaching imparted, the methods used are specified hereinbelow. In all examples, all figures for parts and percentages are given by weight, unless otherwise indicated.

[0132] Viscosity:

[0133] The viscosities, unless otherwise indicated, are determined by measurement using rotational viscometry in accordance with DIN EN ISO 3219 by using a Brookfield viscometer [spindle LV 1, 10 rpm]. Unless indicated otherwise, all viscosity figures are for25°C and atmospheric pressure of 1013 mbar.

[0134] Glass transition temperatures:

[0135] The glass transition temperature is determined by Differential Scanning Calorimetry (DSC) according to DIN 53765, pierced crucible, heating rate 10 K / min.

[0136] Determination of the particle size:

[0137] The particle sizes (z-average particle size) were measured by the method of Dynamic Light Scattering (DLS) with a Malvern Zetasizer Nano ZS Particle Size Analyzer. The polydispersity (PDI) of the particle size indicates the width of the size distribution.

[0138] Measurement of probe tack:

[0139] Probe tack was measured on adhesive films of 5 mil wet thickness drawn on a MYLAR™ film. The MYLAR™ films were corona treated if necessary. To measure the probe tack, a TA. XT plus Texture Analyzer with a TA-57R probe and a TA-303 apparatus for consistent placement of the tested substrate was used. The peak tack is reported for each sample and expressed in grams of force (gf), which results from the probe head contacting the surface of the sample and then pulling away and off the sample. For each example, five samples were taken and tested. The final peak tack value is the arithmetic mean from the corresponding five peak tack results unless otherwise noted.WS12509

[0140] Measurement of 180°peel force:

[0141] An aqueous dispersion comprising copolymers of 5 mil wet film thickness was coated on a MYLAR® film. The MYLAR™ film was corona treated if necessary. After being coated, the film was dried in an oven at 60°C for 15 min. The sample with the Mylar® backing was cooled and applied to a polished stainless steel testing plate. The sample was allowed to rest on the steel plate for 24 h. The peel strength was measured using a Shimadzu AGS-X-10kNX tensile tester at a rate of 300 mm / min or a Cheminstruments AR-1000 adhesion / release tester at a rate of 12 in / min.

[0142] Measurement of static shear stress:

[0143] An aqueous dispersion of appropriate thickness was coated on a Mylar® film. The film was dried in an oven at 60°C for 15 min. The sample with the Mylar® backing was cooled, cut and applied on a polished stainless-steel panel. Pressure was applied on the sample portion of the steel panel using a 5 Ib-weighted rubber roller in four strokes (two sets of back-and-forth strokes). The steel plate was placed in a vertical sample holder and a weight of 1 Kg was attached. Sample contact area measured 1 in X 0.5 in. The time taken for the weight to drop, i.e. , the time taken for the adhesive to fail, was measured.

[0144] Measurement of moisture vapor transmission rate:

[0145] A PSA dispersion of 8 mil wet film thickness was coated on a nonwoven fabric. The film was dried in an oven at 60°C for 15 min. The sample with the nonwoven fabric backing was cooled, cut into a circular shape with a 5.6 cm diameter, and mounted on a GARDCO® Perm Cup prefilled with 10.00 ± 0.05 grams (g) of deionized water. Moisture vapor transmission rate was measured using the “Wet (Payne) Cup Method” for ASTM D1653.

[0146] Example 1 : Preparation of an aqueous copolymer dispersion from methacryloxypropyltris(trimethylsiloxysilane) and organic acrylic monomers (1:1 silane:organic acrylic monomers)

[0147] Step 1: Preparation of the miniemulsion

[0148] The following components were added to a sealable vessel and mixed on an orbital shaker in the amounts listed below:WS12509

[0149] Component Weight (g) Methacryloxypropyltris(trimethylsiloxysilane) 722.25

[0150] 2-Ethylhexyl acrylate 684.00

[0151] Acrylic acid 36.00

[0152] Hexadecane 6.75

[0153]

[0154] The resulting mixture was combined with a solution of the following components in the amounts listed below and mixed in an orbital shaker for approximately 1 hour:

[0155] Weight

[0156] Component (g)

[0157] Polymerizable surfactant Hitenol

[0158] KH-10 29.25

[0159] Hydroquinone Monomethylether

[0160] (2% solution in water) 6.75

[0161] Reverse osmosis water 765.00

[0162]

[0163] The resulting pre-emulsion was passed through an HST HL 1.2 high pressure homogenizer, using a flathead valve, without an impact ring, at a pressure of 200-300 bar to obtain a miniemulsion with a Z-average particle size of 240.6 nm (PDI = 0.187).

[0164] Step 2: Polymerization

[0165] A 2 L polymerization vessel, equipped with an anchor stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, was charged with 120.00 g of the miniemulsion prepared in Step 1 as the initial charge and heated to 50°C with stirring. In one sealable vessel, a 7.27 g of 70 wt % strength aqueous solution of tert-butyl hydroperoxide (TBHP) was diluted with 41.28 g deionized water (feed 1). In a second sealable vessel, a solution of 2.60 g of a formaldehyde-free reducing agent (Bruggolite®FF6 M) in 46.86 g of reverse osmosis water was prepared (feed 2). In a third vessel was placed 1080.00 g of the miniemulsion (feed 3). Feed 1 and 2 were started at a rate of 245 pL / min, followed by the start of feed 3 at a rate of 6.75 mL / min to be continuously metered over a period of 165 minutes. Feeds 1 and 2 are continued for an additional 30 minutes after the completion of feed 3, and the reaction was then held at 50 °C for 60 minutes further. After cooling to room temperature, the product was adjusted to a pH of 8 by the addition of aqueous ammonia. Biocide (Acticide BW 20, 0.26 g) was added, and the product was filtered through a 100 pm filter to give an aqueous dispersion of copolymers with the following properties:WS12509

[0166] Specific gravity: 0.993

[0167] Glass transition temperature of the copolymers: -51.0 °C

[0168] Solids content: 57.51%

[0169] Total remaining free monomer: 1760 ppm

[0170] Z-average particle size: 275.8 nm (PDI = 0.121)

[0171] Viscosity: 1960 mPa. s

[0172] VOC: 3.29 wt%

[0173] The aqueous dispersion of copolymers was dried and applied to a substrate to give the following adhesive film properties:

[0174] Peak tack (2.7 mil dry film thickness): 280.6 ± 10.4 gf

[0175] 180° peel force (2.7 mil dry film thickness): 448.8 ± 55.1 mN / mm (11.4 ± 1.4 N / in)

[0176] Example 2: Preparation of an aqueous dispersion of copolymers from methacryloxypropyltris(trimethylsiloxysilane) and organic acrylic monomers (1:1 silane:organic acrylic monomers)

[0177] Step 1: Preparation of miniemulsion

[0178] The following components are added to a sealable vessel and mixed in an orbital shaker:

[0179] Component Weight (g) Methacryloxypropyltris(trimethylsiloxysilane) 673.50

[0180] 2-Ethylhexyl acrylate 264.00

[0181] Acrylic acid 24.00

[0182] Hexadecane 4.50

[0183]

[0184] The resulting mixture was combined with a solution of the following components and mixed in an orbital shaker for approximately 1 hour:

[0185] Weight

[0186] Component (g)

[0187] Polymerizable surfactant Hitenol

[0188] KH-10 19.50

[0189] Hydroquinone Monomethylether

[0190] (2% solution in water) 4.50

[0191] Reverse osmosis water 510.00

[0192]

[0193] WS12509

[0194] The pre-emulsion is passed through an HST HL 1.2 high pressure homogenizer, using a flathead valve, without an impact ring, at a pressure of 200-300 bar to obtain a miniemulsion with a Z-average particle size of 246.2 nm (PDI = 0.182).

[0195] Step 2: Polymerization

[0196] A 1 L polymerization vessel, equipped with an anchor stirrer, a reflux condenser, a thermometer, and a nitrogen inlet, was charged with 70.00 g of the miniemulsion prepared in Step 1 as the initial charge and heated to 50°C with stirring. In one sealable vessel, a 4.24 g of 70 wt % strength aqueous solution of tert-butyl hydroperoxide (TBHP) was diluted with 24.08 g deionized water (feed 1). In a second sealable vessel, a solution of 1.51 g of a formaldehyde-free reducing agent (Bruggolite®FF6 M) in 27.33 g of reverse osmosis water was prepared (feed 2). In a third vessel was placed 630.00 g of the miniemulsion (feed 3). Feed 1 and 2 were started at a rate of 140 pL / min, followed by the start of feed 3 at a rate of 3.80 mL / min to be continuously metered over a period of 165 minutes. Feeds 1 and 2 are continued for an additional 30 minutes after the completion of feed 3, and the reaction was then held at 50 °C for 60 minutes further. After cooling to room temperature, the product was adjusted to a pH of 8 by the addition of aqueous ammonia. Biocide (Acticide BW 20, 0.15 g) was added, and the product was filtered through a 100 pm filter to give an aqueous dispersion of copolymers with the following properties:

[0197] Specific gravity: 0.947

[0198] Glass transition temperature of the copolymers: -46.9 °C

[0199] Solids content: 57.93%

[0200] Total remaining free monomer: 2280 ppm

[0201] Z-average particle size: 341.6 nm (PDI = 0.306)

[0202] Viscosity: 7420 mPa.s

[0203] VOC: 3.19 wt%

[0204] The aqueous dispersion of copolymers was dried and applied to a substrate to give the following adhesive film properties:

[0205] Peak tack (2.7 mil dry film thickness): 230.8 ± 8.1 gf

[0206] 180° peel force (2.7 mil dry film thickness): 389.8 ± 98.4 mN / mm (9.9 ± 2.5 N / in)

[0207] Example 3 and Comparative Example 1: Coated articles formed from aqueous dispersion of copolymers from Example 1 and release linersWS12509

[0208] The aqueous silicone-acrylate copolymer dispersions of Example 1 and Example 2 were applied to a MYLAR® facestock by using an automatic thick film coater and a set-gap film applicator. The wet thickness of each film was approximately 10 mils (254 micron). The films were cured by drying at 120°C in an oven for 30 minutes to get dry pressure-sensitive adhesive layers of approximately 5 mils (127 microns). After drying, release liners were applied to each adhesive layer and allowed to sit at 25°C and 50% relative humidity before being cut into 1”x6” strips for peel testing. The coated article of Example 3 comprised a pressure-sensitive adhesive comprising the copolymers of Example 1 on the MYLAR® facestock and a Dehesive 429 release liner. The Dehesive 429 release liner comprises a silicone release layer coated provided on a PET backing layer. The silicone release layer comprises of silicone release agent produced by hydrosilylation reaction between SiH crosslinkers and vinyl terminated silicones. The coated article of Comparative Example 1 comprised a pressure-sensitive adhesive comprising the copolymers of Example 1 on the MYLAR® facestock and a release liner sold under the tradename TTL-1406 liner by The Tape Lab Inc. The TTL-1406 release liner comprises a 2 mil (50 micron) clear polyester fluorsosilicone material.

[0209] The peel force required to remove the liners from the coated article of Example 3 and Comparative Example 1 was measured over time and before and after heat aging. The peel force required to separate each release liner from the pressure-sensitive adhesive was measured by a Chemlnstruments adhesion / release tester for 180° Peel at a rate of 12 in / min. To conduct the measurements, double-sided tape was placed onto the sled of the adhesion / release tester and each coated article was placed mylar-side down onto the tape. The release liner was secured into the force gauge and, when the sled was moved forward, the force gauge measured the associated peel force. The measurements were taken in N / in. The peel force of portions of the Examples was measured at different time intervals (1 week, 4 weeks, and 16 weeks) and separate samples from Example 3 and Comparative Example 1 were heat aged at 50°C and were tested after 1 week and 4 weeks of incubation.

[0210] The results of the measurements are illustrated in FIG. 1. As can been seen from the results shown in FIG. 1, only a low peel force is required to separate the release liner from the PSA. In particular, in Example 3, where the release liner comprises a fluorine-free silicone system, the peel force is very low even after heat aging.

[0211] Comparative Examples 2 and 3:

[0212] Two coated articles were formed and each comprised a commercially available silicone adhesive gel sold under the trade name SILPURAN 2124 and by Wacker Chemical Corporation. The coated article of Comparative Example 2 comprised a layer of SILPURAN 2124 applied toWS12509

[0213] and connected with a MYLAR® facestock. The layer of SILPURAN 2124 was contacted by siliconized release liner that included a silicone layer comprising a silicone material sold under the tradename DEH ESI VE 429 and by Wacker Chemical Corporation.

[0214] The coated article of Comparative Example 3 comprised a layer of SILPURAN 2124 applied to and connected with a MYLAR® facestock. The layer of SILPURAN 2124 was contacted by the TTL-1406 release liner available from The Tape Lab Inc.

[0215] The force required to remove the liners from the coated articles of Comparative Example 2 and Comparative Example 3 was measured as described above for Example 3.

[0216] The results of the measurements for Comparative Example 2 and 3 are illustrated in FIG.

[0217] 2. As can been seen from the results shown in FIG. 2, although the SILPURAN 2124 adhesive requires very low peel force to detach from the fluorinated release liner of Comparative Example 3, the adhesive requires high peel force to detach from the DEHESIVE 429 release liner of Comparative Example 2, which makes the combination of a traditional silicone adhesive (SILPURAN 2124) and a fluorine-free siliconized release liner not suitable for practical use. Also, after heat aging, the release force increases significantly for the coated article of Comparative Example 2.

[0218] Example 4:

[0219] A 4 mil (101.6 micron) thick wet PSA film was made from a copolymer dispersion prepared according a procedure similar to the one described for Example 1. The PSA film was formed on a silicone SILPURAN® 2030 film that had been pre-cured to a MYLAR® backing sheet, which served as the facestock. The PSA film was dried at 80°C for 30 minutes and cooled at room temperature for 15 minutes. To make a coated article, the PSA was then contacted by a static layer formed from either MYLAR® (PET), polypropylene, or polycarbonate and the articles were allowed to rest for 5 minutes. When MYLAR® was used as the static layer, it had to be fixed to a stainless-steel surface with a double-sided tape to prevent lateral movement and stretching. For measuring the peel force, the peel layer was slowly pulled at 180° angle from the static layer.

[0220] As can be seen from FIG. 3, the peel forces reported between the PSA-Mylar, PSA-polycarbonate, and PSA-polypropylene coated articles was low and allowed for easy

[0221] detachment.

Claims

WS12509CLAIMS1. A coated article, comprising:a pressure-sensitive adhesive comprising copolymers that exhibit a glass transition temperature (Tg) of 0 to -100°C, the Tg being determined by differential scanning calorimetry with a heating rate of 10°K per minute according to DIN 53765, pierced crucible, and compriseorganic monomer residue units of structure I:- H2c - c -A1Iand silicone polymer or silane residue units of structure II:Y1Z or Z- H2C - C -A2II,whereinA1 is an H or methyl group,A2 is an H or methyl group,wherein A1 and A2 may be the same or may be different, Y1 is a linker, andZ is a siloxane or silane residue; anda release liner having a portion thereof in direct contact with the pressure-sensitive adhesive, wherein the portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine.23WS125092. The coated article of claim 1 , wherein the portion of the release liner in direct contact with the pressure-sensitive adhesive is a backing layer or a release layer.

3. The coated article of claim 2, wherein the release liner further comprises the release layer, the release layer being provided between the backing layer and the pressure-sensitive adhesive and the release layer being substantially free of organic fluorine.

4. The coated article of claim 2, wherein the release liner further comprises the backing layer, the backing layer being substantially free of organic fluorine.

5. The coated article of claim 1 , wherein the copolymers comprise the reaction product of a free-radical copolymerizable composition comprising 5 to 95% by weight of ethylenically functionalized silicone polymers or silanes, which is based on the total weight of the copolymerizable compounds, and 5% or more by weight of free-radical copolymerizable ethylenically unsaturated organic monomers, which is based on the total weight of the copolymerizable compounds.

6. The coated article of claim 1 , wherein the pressure-sensitive adhesive is free of any organic solvents.

7. The coated article of claim 1 , wherein the pressure-sensitive adhesive has a VOC of 10 g / L or less.

8. The coated article of claim 1 , wherein the pressure-sensitive adhesive has peak tack of 100 to 1,000 grams of force when measured by a TA. XT Plus Texture Analyzer using a TA-57R probe and a TA-303 apparatus for a adhesive film of 25-75 microns dry thickness.

9. The coated article of claim 1 , wherein the pressure-sensitive adhesive has a peel force from the release liner of 0.5 N / in or less when measured utilizing a Chemlnstruments adhesion / release tester for 180° peel at a rate of 12 in / min.

10. The coated article of claim 1 , wherein the pressure-sensitive adhesive has a peel force from the release liner of 0.5 N / in or less after 28 days of aging at 50°C.WS1250911. The coated article of claim 1 , wherein the release liner has a thickness of 30 to 350 microns.

12. The coated article of claim 1 , wherein the release layer comprises silicone matrix.

13. A coated article, comprising:a pressure-sensitive adhesive comprising copolymers that exhibit a glass transition temperature (Tg) of 0 to -100°C, the Tg being determined by differential scanning calorimetry with a heating rate of 10°K per minute according to DIN 53765, pierced crucible, and comprisestructural units of structure I:X1- H2C - c -A1Iand structural units of structure II:zY1- H2C - c -A2II,whereinA1 is an H or methyl group,A2 is an H or methyl group,wherein A1 and A2 may be the same or may be different,X1 is an H or aliphatic or aromatic hydrocarbon group that may contain heteroatoms, or,WS12509O_ — C - OA3X1 =L Jor,r O -|_ _ _ O - f c-l -X1 = -A3 is a hydrocarbon group having 1 to 20 carbon atoms,A4 is a hydrocarbon group having 1 to 15 carbon atoms,Z is a siloxane or silane residue comprising MaDbTcQd,M is R1R2R3SiO1 / 2,D is R4 R5 SiO2 / 2,T is R6R7 SiO3 / 2,Q is SiO4 / 2,R1, R2, R3, R4, R5, R6, R7, R8 and R9 each independently is hydrogen, a hydroxyl group, an alkoxy group, a hydrocarbyl group having up to 100 carbon atoms and optionally containing at least one heteroatom, whereas a+ b+ c+ d>1,Y1 is a linker comprising a group selected from -CH2- and hetero atoms,anda release liner having a portion thereof in direct contact with the pressure-sensitive adhesive, wherein the portion of the release liner in direct contact with the pressure-sensitive adhesive is substantially free of organic fluorine.26

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