Storage-stable two-component silicone kit

Abstract

A storage-stable, curable two-component kit comprising: a first component (A) comprising a first crosslinkable polysiloxane polymer, a curing catalyst, and glycerol, wherein the glycerol is in the form of separate droplets uniformly distributed within the first component; and a second component (B) comprising a crosslinking agent for the first polysiloxane polymer.

Description

[Technical Field]

[0001] This invention relates to a storage-stable, curable two-component kit capable of forming a cured silicone product. The kit allows for extended storage time before mixing / curing. [Background technology]

[0002] The materials industry is increasingly focusing on developing non-toxic, energy-saving, and biodegradable materials to mitigate the environmental impact caused by conventional elastomers. Naturally derived substrates have emerged as promising alternatives to traditional synthetic monomers. As an alternative, environmentally friendly additives such as glycerol can be used to impart improved properties to elastomers while reducing the environmental impact of silicone products, as a result of partially replacing energy-intensive silicones with glycerol, an "environmentally friendly" substitute. In this regard, extensive research has been conducted to investigate the properties obtained from glycerol-containing elastomers and adhesives, as well as the possibility of simple production of these silicone elastomer / adhesive products. The focus is mainly on how to formulate these emulsions so that the products may appear as classic elastomer premixes, commercially available for customers producing a wide range of products, as two-component systems that react upon mixing with or without an external energy source (heat, UV, etc.) and do not require changes to oven length, etc., due to curing times similar to the original elastomer / adhesive compared to reactive emulsions.

[0003] Silicone elastomers are highly versatile and widely used due to their flexibility, solvent and abrasion resistance, high hydrophobicity, high thermal stability, high gas permeability, low surface tension, and other desirable properties, including chemical and biological inertness. Thus, silicone elastomers, particularly polydimethylsiloxane (PDMS), find applications such as adhesives, transdermal films / patches, dielectric elastomers, and biomedical applications. Due to the many excellent properties of silicone elastomers, expanding their range of applications, such as identifying elastomers with improved water handling properties during skin contact and those with inherent drug delivery capabilities, is of great interest.

[0004] However, it is also interesting that, for example, when chemically functionalized by hydrophilic portions, the inherent properties of the silicone are not altered in the sense that some of the properties of the silicone matrix are lost. Silicone-glycerol technology allows for a silicone matrix whose initial mechanical properties are not compromised, but further functionalization is embedded in the system via embedded glycerol droplets in the sense that the glycerol-silicone elastomer has significantly improved water handling properties compared to the original silicone analog. This is counterintuitive, as the glycerol-silicone elastomer should become more liquid-like by adding more liquid glycerol to the system. However, the elastic energy arising from surface tension in the emulsion system is of a similar magnitude to the classical elastic contribution from the elastomer / adhesive.

[0005] Patent publications in this technical field include US2001 / 016609, CN101747630A, JP2007 / 106946A, CN112795196A, US2019 / 0060211A1, US2023 / 0090479, CN107868471B, and WO2016 / 189117.

[0006] Non-patent literature in this field includes the following: J.D. Eshelby:The force on an elastic singularity. Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1951, 244, 87. P. Mazurek, S. Hvilsted, A.L. Skov:Green silicone elastomer obtained from a counterintuitively stable mixture of glycerol and PDMS. Polymer, 2016, 87, 1. V. Chiuala, P. Mazurek, J.Eiler, A.C. Nielsen, A.L. Skov:Glycerol-silicone adhesives with excellent fluid handling and mechanical properties for advanced wound care applications. Int. J.Adhes. Adhes., 2020, 102, 102667. P. Mazurek, B.E.F. Ekbrant, F.B. Madsen, L. Yu, A.L. Skov:Glycerol-silicone foams - Tunable 3-phase elastomeric porous materials. Eur. Polym. J., 2019, 113, 107. P. Mazurek, M.A. Brook, A.L. Skov:Glycerol-silicone elastomers as active matrices with controllable release profiles. Langmuir, 2018, 34, 11559.

[0007] The kits used to form such products require long-term stability, and there is a need for continuous storage of the cured silicone products which have improved properties. [Overview of the project]

[0008] In this way, a storage-stable, curable two-component kit is provided. This kit is A first component (A) comprising a first crosslinkable polysiloxane polymer, a curing catalyst, and glycerol, wherein the glycerol is in the form of separate droplets uniformly distributed within the first component (A), The first polysiloxane polymer contains a second component (B), which contains a crosslinking agent for the first polysiloxane polymer.

[0009] When the first component and the second component are mixed, a curing reaction accelerated by the curing catalyst occurs between at least the first polysiloxane polymer and the crosslinking agent, forming a cured silicone product.

[0010] The kits mentioned earlier have an unexpectedly long shelf life, often several months.

[0011] A process for providing a cured silicone product is also provided, and this process is -To provide the first component (A) as described herein, -To provide a second component (B) as described herein, The method includes mixing the first component (A) and the second component (B), and curing the mixture.

[0012] Further aspects of this technology are presented in the following specification text, examples, figures, and claims. [Brief explanation of the drawing]

[0013] [Figure 1] Component A immediately after preparation with a droplet size of 3.0 ± 0.8 μm (Example 1). [Figure 2] Component A 7 months after preparation, with a droplet size of 3.2±0.9μm (from Figure 1). [Figure 3] Component A immediately after preparation, with a droplet size of 2.0±0.3μm (Example 2). [Figure 4] Component A 6 months after preparation, with a droplet size of 2.1±0.4μm (from Figure 3). [Figure 5] Component A immediately after preparation, with a droplet size of 2.0±0.3μm (Example 3). [Figure 6] Component A 2 months after preparation, with a droplet size of 2.4±0.6μm (from Figure 5). [Figure 7] Curing plots of the mixture of Example 1 immediately after preparation and 7 months after preparation, cured at 100°C for 30 minutes. [Figure 8] Curing plots of the mixture of Example 2 immediately after preparation and 6 months after preparation, cured at 120°C for 30 minutes. [Figure 9] Curing plots of the mixture of Example 3 immediately after preparation and 2 months after preparation, cured at 100°C for 30 minutes. [Figure 10] Droplet size of the emulsion of S4642A_40phr glycerol_1phrSQO299 immediately after preparation according to Example 5. [Figure 11] Droplet size of the emulsion of S4642B_40phr glycerol_1phrSQO299 immediately after preparation according to Example 5. [Figure 12] Droplet size of the emulsion of S4645A_40phr glycerol_1phrSQO299 immediately after preparation according to Example 5. [Figure 13] Droplet size of the emulsion of S4645B_40phr glycerol_1phrSQO299 immediately after preparation according to Example 5. [Figure 14] Cured S4642A and B, S4642A and B_40phr glycerol_1phrSQO299, S4645A and B, and S4645A and B_40phr glycerol_1phrSQO299 adhesives after curing at 120°C for 30 minutes (with a 200μm casting gap). [Figure 15] Cure plots of S4642A and B, and a mixture of S4642A and B_40phr glycerol_1phr SQO299 at 120°C for 30 minutes according to Example 5. [Figure 16] Cure plots of S4645A and B, and a mixture of S4645A and B_40phr glycerol_1phr SQO299 at 120°C for 30 minutes according to Example 5. [Figure 17] LVE plots at room temperature of cured S4642A and B adhesives, and cured S4642A and B_40phr glycerol_1phr SQO299 adhesives after curing at 120°C for 30 minutes according to Example 5. [Figure 18] LVE plots at room temperature of cured S4645A and B adhesives, and cured S4645A and B_40phr glycerol_1phr SQO299 adhesives after curing at 120°C for 30 minutes according to Example 5. [Figure 19] Droplet size of S4950A_40phr glycerol_1phr SQO299 emulsion immediately after preparation according to Example 5. [Figure 20] Droplet size of S4950A_40phr glycerol_1phr SQO299 emulsion on day 1 after preparation according to Example 5. [Figure 21] Droplet size of S4950B_40phr glycerol_1phr SQO299 emulsion immediately after preparation according to Example 5. [Figure 22] Droplet size of S4950B_40phr glycerol_1phr SQO299 emulsion on day 1 after preparation according to Example 5. [Figure 23] Cured S4950A and B adhesives, and cured S4950A and B_40phr glycerol_1phr SQO299 adhesives after curing at 120°C for 30 minutes (200 µm casting gap). [Figure 24] Cure plots of S4950A and B, and a mixture of S4950A and B_40phr glycerol_1phr SQO299 at 120°C for 30 minutes according to Example 5. [Figure 25]LVE plots at room temperature for cured S4950A and B, and S4950A and B_40phrglycerol_1phrSQO299 adhesives after curing at 120°C for 30 minutes according to Example 5. [Figure 26] Viscosity (Pa·s) of glycerol, glycerol + PEG-200, and glycerol + HAc at a shear rate of 1 sec⁻¹, according to Examples 7 and 8. [Figure 27] Viscosity (Pa.s) of S184+glycerol and S184+(glycerol+PEG-200) at a shear rate of 1 sec⁻¹ according to Example 7. [Figure 28] Viscosity (Pa·s) of S184+ glycerol and S184+ (glycerol + HAc) at a shear rate of 1 sec⁻¹ according to Example 8. [Figure 29] Droplet size of S4410A_15phr emulsion immediately after preparation according to Example 10. [Figure 30] Droplet size of S4410B_15phr emulsion immediately after preparation according to Example 10. [Modes for carrying out the invention]

[0014] definition In the present context of this invention, the term “silicone product” refers to a product formed by crosslinking / curing a polysiloxane polymer. Examples of “silicon products” include gels, adhesives, elastomers, and rubbers. “Silicone elastomer” is a silicone product according to the IUPAC definition of a polymer exhibiting rubber-like elasticity.

[0015] In this context, the term “polysiloxane” refers to compounds of the form [RR'SiO]n, where R and R' are identical or different hydrocarbon groups, and n is the number of repeating units. The term “polysiloxane” also refers to compounds of the form [RR'SiO]n that can be partially functionalized in the sense that some R groups, R' groups are replaced or substituted by substituents. Non-limiting examples of such substituents include Cl, CN, F, S, NH2, OH, phenyl, benzo derivatives, alkenyls, and alkynyls, which are either directly bonded to the Si atoms on the silicone backbone or connected to the Si atoms via short aliphatic chains (1 to 4 carbon atoms).

[0016] In addition, the silicone compounds or silicone prepolymers or additives used for crosslinking may contain functional groups known in the art, including compounds containing SiH, SiOR, Si-vinyl, Si-allyl, Si-oxime, and Si-carboxylate functional groups.

[0017] In this context, the term "polydimethylsiloxane," abbreviated as "PDMS," refers to the formula CH3[Si(CH3)2O] n The term refers to a compound of Si(CH3)3, where n is the number of repeating units. The term "polydimethylsiloxane" encompasses its derivatives in which one or more methyl groups in PDMS are replaced, for example, by hydro, hydroxyl, vinyl, or allyl groups at the pendant or terminal positions.

[0018] In this context, the term "curing" refers to the crosslinking process of polymer chains. Curing can be thermal or photo-induced, or it can simply occur at room temperature due to the mixing of the two components of the kit. Curing refers to the transition of an elastomer mixture from a viscoelastic molten material to a silicone material with solid-like properties. This is described by G''>G' after the initial mixing of the molten materials, where G'' is the loss modulus and G' is the storage modulus. After curing, G'>G''. The time to reach gelation is an important measure indicating the time it takes to reach the transition from primarily liquid-like properties to primarily solid-like behavior (i.e., G'=G'' in the transition). It is measured via a curing profile where the temperature is kept constant (e.g., 100°C), and then the development of G' and G'' is measured over time. Another measurement is the time required to reach a plateau in G', indicating when curing is complete, and is often also referred to as the curing time.

[0019] The storage modulus and loss modulus, i.e., G' and G'', are measured using a rheometer. For example, G' and G'' can be measured using an AR2000 rotational rheometer (TA Instrument, UK) with a conical plate rotor shape (diameter D=25 mm, cone angle α=1). The temperature was maintained at 20°C using a Peltier system.

[0020] In this context, the terms “crosslinker” and “crosslinking agent” are used interchangeably and refer to chemical compounds or compounds that facilitate the crosslinking of polymer chains, particularly silicone polymer chains. No specific limitations on the actual composition of a crosslinker or crosslinking agent are inferred or intended by the chosen language. Examples of crosslinkers or crosslinking agents may include, for example, metals, small molecules, polymeric crosslinkers (e.g., polysiloxane-based), or crosslinking compositions further comprising two or more active crosslinkers or crosslinking agents involved in the crosslinking process.

[0021] In this context, the term "phr" is an abbreviation for "parts per 100 parts polysiloxane," used to indicate the glycerol content in a composition, corresponding to the weight of glycerol per 100 parts by weight of polysiloxane.

[0022] In this context, the term "phg" is an abbreviation for "parts per 100 parts glycerol," used to indicate the content of excipients, or components such as water and / or hydrophilic alcohols and / or esters, and / or surfactants, in a composition, and corresponds to the weight of such components per 100 parts by weight of glycerol.

[0023] In this context, homogeneity means, for example, that when viewing a 100 μm × 100 μm microscope image, glycerol is evenly distributed within the silicone, and the composition determined from such an image should correspond to the overall composition resulting from a mixture of the two components.

[0024] In this context, the term "film" has a typical thickness range of approximately 0.02 mm to 10.0 mm, for example, approximately 0.05 mm to 10 mm, for example, approximately 0.05 mm to 1 mm, for example, approximately 0.1 mm to 5 mm, for example, approximately 0.1 mm to 1 mm, for example, approximately 0.1 mm.

[0025] In this context, the term excipient is used to mean a substance added to either the silicone phase or the glycerol phase of the present invention. Therefore, in the context of this disclosure, an excipient is a substance included in the composition of the present invention, in addition to either glycerol or silicone. Excipients may be selected from the group consisting, for example, active substances, particularly active substances for human or animal use, especially pharmaceuticals, and / or catalysts, inhibitors, fluids, silicone oils, solvents, fillers, foaming agents, reinforcing agents, and plasticizers. Other examples of excipients are given below.

[0026] In the context of the present invention, an active substance is a substance that can be released from the composition of the present invention after zero-order or higher release rates as detailed herein. Primarily, an active substance is a substance that, when released from the composition of the present invention, is chemically and / or biologically active on a surface or in the human or animal body, such as a pharmacological active ingredient and / or drug.

[0027] In the context of the present invention, a sprayable composition is a formulation that can be sprayed by various conventional methods, such as simple laboratory spraying without additional pressure, or by pressurized systems such as aerosol generation or aerosol-containing systems. The sprayable composition is diluted by various means, for example, by using a solvent, oil, or other excipient to dilute the viscosity of the silicone phase.

[0028] In the context of this invention, droplet size and droplet dispersion refer to the average droplet size and standard deviation, respectively. The droplet size is ideally 0.05 to 10 μm, for example, 0.1 to 10 μm, 0.1 to 5 μm, 0.5 to 5 μm, 1 to 5 μm, or 2 to 3 μm. The dispersion is ideally less than 5 μm, preferably less than 2 μm, more preferably less than 1.5 μm, and most preferably less than 0.8 μm.

[0029] The average droplet size and associated standard deviation of the emulsion can be evaluated using an optical microscope. The average droplet size and standard deviation were detected and measured using ImageJ software (ImageJ, version 1.53e) with the "Analyze Particles" plugin installed.

[0030] In the context of this invention, viscosity refers to dynamic viscosity (in SI units of Pa·s) as typically measured by a rheometer in combination with curing studies, or by a special viscometer.

[0031] For example, dynamic viscosity (η) is measured using a rotational rheometer (such as the TA Instrument AR2000 rotational rheometer from the UK) with a conical plate rotor shape (diameter D=25mm, cone angle α=1). The temperature was maintained at 20°C using a Peltier system. The η value was determined by introducing flow curves with increasing shear rate. The dynamic viscosity is then given by η=f(γ). The shear rate (γ) sweep was 0.1 seconds. -1 ~1000 seconds -1 It will be executed.

[0032] For each silicone composition, the dynamic viscosity (η0) of a Newtonian fluid (i.e., a low shear rate plateau) was evaluated. η was determined from a given shear rate range (0.1 to 1000 sec⁻¹) to simulate different flow rates and shear oil stability. -1 In this case, a constant dynamic viscosity was found for the silicone oil, and for our purposes, the dynamic viscosity was described as a plateau value. This is consistent with the teachings of R. Mendichi et al. Comparative study of chemical composition, molecular and rheological properties of silicone oil medical devices, TVST2019,8,9.

[0033] In the context of the present invention, the diluent for the glycerol phase is a component that is miscible with glycerol and reduces the viscosity of high-purity glycerol, and may be water, ethanol, other low molecular weight water-soluble alcohols (e.g., C3-C5 water-soluble alcohols), or low molecular weight polyethylene glycol (PEG), or a mixture thereof.

[0034] In the context of the present invention, a surfactant is a component that has hydrophilic and hydrophobic components in its structure, thereby acting to reduce the interfacial tension between two immiscible components, such as glycerol and silicone. Surfactants can also facilitate the thermodynamic / kinetic preference of smaller droplets, so that the final silicone product also has a smaller droplet size. Thus, surfactants alter the interface between glycerol and silicone by having differences in the polarity of their two ends, for example, nonionic, anionic, cationic, or amphoteric surfactants. Common examples of preferred nonionic surfactants are short polymers of ethylene oxide or propylene oxide.

[0035] "Storage stability" means that the elastomer kit retains its original properties and form (particularly with respect to glycerol droplets) for at least three weeks, for example, at least six weeks, preferably at least twelve weeks.

[0036] In this way, the "storage-stable" elastomer kit exhibits a change of less than 10% in average droplet size, typically less than 5% in average droplet size, and even less than 3% in average droplet size, when stored at 25°C for a period of at least 3 weeks, for example, at least 6 weeks, preferably at least 12 weeks.

[0037] The term "two-component" kit is used to describe a kit containing two components that are stored in separate containers until they are mixed.

[0038] The inventors have found that an extremely stable silicone-glycerol emulsion can be achieved by following a specific mixing process, which further allows for subsequent curing. The resulting product provides a kit of two reactive emulsion / blend components, each containing at least one component of a silicone-glycerol emulsion.

[0039] By adding glycerol to one or both of the components, a stable two-component kit is provided, which can then be cured into an elastomer or adhesive without losing the microstructural characteristics of the emulsion (droplet size less than approximately 4 μm and low polydispersibility droplet size).

[0040] In this way, a storage-stable, curable two-component kit is provided, and this kit is A first component (A) comprising a first crosslinkable polysiloxane polymer, a curing catalyst, and glycerol, wherein the glycerol is in the form of separate droplets uniformly distributed within the first component (A), The first polysiloxane polymer contains a second component (B), which contains a crosslinking agent for the first polysiloxane polymer.

[0041] When the first component and the second component are mixed, a curing reaction accelerated by the curing catalyst occurs between at least the first polysiloxane polymer and the crosslinking agent, forming a cured silicone product. To avoid crosslinking of the first component (A) alone, the first component (A) should not contain a crosslinking agent for the first polysiloxane polymer.

[0042] The first component (A) of the two-component kit comprises a first crosslinkable polysiloxane polymer, preferably polydimethylsiloxane. The first component (A) further comprises a curing catalyst. The first component (A) further comprises glycerol, which is in the form of separate droplets uniformly distributed in the first component. Preferably, the concentration of glycerol in the first component (A) is 10 to 160 phr, for example 15 to 160 phr, of the total amount of polysiloxane polymer in the first component (A).

[0043] The second component (B) may also contain glycerol in the form of separate droplets uniformly distributed within the second component (B). The concentration of glycerol in the second component (B) is preferably 10 to 160 phr, for example, 15 to 160 phr, per 100 parts of the total amount of any polysiloxane polymer and crosslinking agent in the second component (B).

[0044] The good storage stability of the kit has been found to be achieved by the small, uniform droplet size of glycerol in component (A). The average droplet diameter of separate glycerol droplets in component (A) and / or component (B) is therefore less than 10 μm, for example, 0.05–10 μm, e.g., 0.1–10 μm, 0.1–5 μm, 0.5–5 μm, 1–5 μm, or 2–3 μm. Additionally, the standard deviation of the average droplet diameter of glycerol in component (A) and / or component (B) is less than 5 μm, preferably less than 2 μm, more preferably less than 1.5 μm, and most preferably less than 1.0 μm.

[0045] The concentration of glycerol in the cured silicone product is preferably 10 to 160 phr, more preferably 15 to 160 phr, of the cured silicone product.

[0046] In one embodiment, the cured silicone product is an adhesive, and the weight ratio of component A to component B (A:B) is in the range of 1:0.5 to 0.5:1, preferably 1:0.75 to 0.75:1, and more preferably about 1:1. In this embodiment, the silicone phase of component A can be stabilized at a concentration of 0.5 to 3 phr using a Q-type or MQ-type silicone resin, preferably a silanol-trimethylsilyl-modified Q-type resin. In this embodiment, the glycerol is typically filled with a gelling agent or active substance in an amount of preferably 5 to 50 phr g.

[0047] In another embodiment, the cured silicone product is an elastomer, and the weight ratio of component A to component B (A:B) is in the range of 8:1 to 12:1, preferably 11:1 to 9:1, and more preferably about 10:1. In this embodiment, the two-component kit may further contain a non-reactive silicone oil in component A and / or component B, preferably in component A, at a concentration of preferably 5 to 10 phr.

[0048] In the two-component kits described herein, the dynamic viscosity of the first component (A) before the addition of glycerol is preferably higher than the dynamic viscosity of the second component (B) before the addition of glycerol to one or both components. Viscosity is measured by standard fluid dynamics measurements, in which the liquid components are placed between two parallel plates (10 or 25 mm in diameter) with a gap size of approximately 1 mm on a shear rheometer. A frequency sweep is performed, and the viscosity is provided by the rheometer. The rheometer can be any conventionally used measuring instrument such as the TA Instruments Discovery HR-1.

[0049] Those skilled in the art of formulations would typically aim to prepare formulations consisting of two components with similar viscosities to increase the ease and reliability with which a mixer can combine the two components. In the case of silicone elastomer / adhesive formulations, the crosslinking agent-containing component usually has a significantly lower viscosity because the crosslinking agent is almost always much lower in molecular weight than the polymer (the viscosity of a polymer is, as a rule of thumb, proportional to about 2.4 times the molecular weight). Therefore, including glycerol in the crosslinking agent-containing component is also a logical step, due to the ease with which glycerol in silicones emulsifies, but also due to the reduced difference between the resulting components A and B. However, it has been found that emulsions prepared by mixing glycerol with a high-viscosity silicone component are far more stable. Despite the significant viscosity difference between component A and component B, i.e., component A (containing glycerol) having a significantly higher viscosity than component B, the emulsified glycerol droplets remain stable when the final mixing of components A and B is performed.

[0050] In one embodiment, the first component (A) of the two-component kit has a dynamic viscosity in the range of 1 to 100 Pa·s, preferably 1 to 40 Pa·s, and more preferably 2 to 30 Pa·s.

[0051] In one embodiment, component A of the kit comprises a vinyl-functionalized polysiloxane polymer (e.g., a vinyl-functionalized PDMS polymer), while component B of the kit comprises a hydride-functionalized crosslinking agent. The hydride-functionalized crosslinking agent typically comprises two or more Si-H functional groups. The hydride-functionalized crosslinking agent may be a Si-H-functionalized polysiloxane polymer comprising two or more Si-H functional groups. Addition curing occurs between the vinyl-functionalized polysiloxane polymer and the hydride-functionalized crosslinking agent, and is typically catalyzed by a transition metal catalyst, such as a Pt catalyst. Those skilled in the art can select a crosslinkable polymer, a crosslinking agent, and a suitable catalyst to achieve a desired addition curing process and the desired properties of the cured silicone product.

[0052] Each of the kit components (A / B) may contain additional polysiloxane components, which may be incorporated into the polysiloxane matrix of the cured silicone product, provided that the additional polysiloxane components do not begin curing before components A and B are mixed. For example, the first component (A) may contain two or more crosslinkable polysiloxane polymer components. Commercially available elastomer compositions also typically involve silica fillers and resins, the exact composition and type of which are proprietary knowledge.

[0053] Additionally, the second component (B) may further comprise a second crosslinkable polysiloxane polymer, and as a result, when the first component and the second component are mixed, a curing reaction occurs between at least the first polysiloxane polymer, the second crosslinkable polysiloxane polymer, and the crosslinking agent, accelerated by the curing catalyst, to form the cured silicone product.

[0054] Preferably, the curing catalyst is a Pt curing catalyst, present in the two-component kit in an amount of 5 to 30 ppm, preferably 5 to 10 ppm.

[0055] Components A and B may include additional components such as solvents, reinforcing inorganic fillers such as silica, or resins (such as Vinyl Q resin from Gelest Inc.), preferably resins (e.g., Q-type or MQ-type silicone resins). Such additional components may be mixed with component A or component B, or both components A and B, or added to the kit during mixing. The amount of additional components required varies greatly depending on the composition, but is typically in the range of 0 to 40% by weight of the final cured silicone product, for example, 5 to 30% by weight, or for example, 10 to 25% by weight.

[0056] In one embodiment of the present invention, a resin (e.g., a Q-type or MQ-type silicone resin such as Gelest's SQO299 resin) is used to stabilize an otherwise unstable emulsion. It is used, for example, in component A at a concentration of 0.1 to 25 phr, or 0.1 to 10 phr, or 0.1 to 5 phr, for example, 0.2 to 4 phr, preferably 0.5 to 3 phr. Preferably, the resin may be added to component A in an amount of, for example, 0.2 to 2 phr for optimal performance. The structure of the resin is shown below: [ka]

[0057] For example, the addition of glycerol to either component A or component B of Silbione® RT Gel4642 and the MG7-9900 Soft Skin Adhesive kit typically does not result in the formation of a stable emulsion. Therefore, these products benefit from the addition of a stabilizing resin, such as Gelest's SQO299 resin.

[0058] In one embodiment of the present invention, the two-component kit includes at least one blowing agent. The at least one blowing agent is preferably present in an amount in the range of 1 to 10 phr, for example, 1 to 5 phr, for example, 2 to 4 phr, for example, about 3 phr. The blowing agent may be a base or an acid. Non-limiting examples include inorganic bases such as NaOH and KOH, strong acids such as HCl, or bicarbonates, or organic acids such as acetic acid or lactic acid.

[0059] In one embodiment, the two-component kit further comprises one or more additives, each containing a cosmetic surfactant or agent, which are either pre-mixed with the glycerol component(s) or directly mixed with a given component A or B when preparing a glycerol-silicone emulsion. This type of additive is released when the product comes into contact with water. Depending on the additive and its hydrophilic / hydrophobic properties, the additive may be present in either a solution or dispersion in a glycerol droplet, a silicone matrix, or both. Ideally, the surfactant is present entirely in the glycerol droplet. This is inherent to hydrophilic components, but in the case of hydrophobic components, this can be facilitated by mixing the surfactant with a surfactant before mixing with the glycerol phase.

[0060] One or more additives may be selected from the group consisting of colorants and previously defined active pharmaceutical substances. For example, one or more additives may be added to impart specific properties to the cured silicone product, such as to provide therapeutic properties or to enable controlled release of active pharmaceutical substances. When preparing a glycerol-silicone emulsion, the additives may be mixed directly with component A and / or component B; alternatively, the additives may be first mixed with the glycerol component(s) and then added to the glycerol-silicone emulsion. Preferably, the additives are present in the glycerol droplets. This occurs inherently with hydrophilic components, but in the case of hydrophobic components, this can be facilitated by mixing the additive(s) with a surfactant before mixing with the glycerol phase(s).

[0061] Some molecules may be less desirable to include in a two-component kit. Examples of compounds that are preferably absent or present in amounts of 3% by weight or less, preferably 2% by weight or less, more preferably 1% by weight or less, and more preferably 0.5% by weight or less, based on the total weight of the first component (A) and the second component (B), include C 12 ~C 20Examples include saturated or unsaturated fatty acids, or glycerol adducts thereof, such as palmitic acid, oleic acid, α-linoleic acid, or glycerides made from them; cyclic oligosaccharides such as cyclodextrins; and optionally, terpene derivatives and terpene alcohol derivatives such as limonene or linalool. These latter components have been found to interfere with some crosslinking catalysts and are therefore optionally avoided as needed.

[0062] A process for providing a cured silicone product is described, and this process is -To provide a first component (A) as defined herein, - To provide a second component (B) as defined herein, - The process includes mixing the first component (A) and the second component (B), and curing the mixture.

[0063] The storage-stable, curable two-component kit of this disclosure may be stored in syringes. For example, component (A) may be stored in a first syringe and component (B) may be stored in a second syringe. Alternatively, a dual syringe system may be used. A dual syringe system means a two-compartment syringe in which the contents from both compartments are placed simultaneously, either directly or via an attached mixing head.

[0064] In one embodiment, the storage-stable, curable two-component kit of the present disclosure is applied directly to the skin to be cured. In this case, the two-component kit is typically provided in a syringe or a dual-syringe system. Alternatively or additionally, the two-component kit has a curing temperature of 20°C to 35°C. When the curable two-component kit of the present disclosure is applied directly to the skin, the subsequently cured silicone product may also be referred to as a skin cream.

[0065] In one aspect of the process, the cured silicone product is in the form of a thin film on a substrate, and the process includes an additional step of coating the substrate with a first component (A) and a second component (B) that are mixed on the substrate before curing.

[0066] This disclosure also relates to patches comprising a storage-stable, curable two-component kit.

[0067] Such patches may further include a backing and a release liner. The backing is a substrate on which a thin film is coated and then cured. For example, a polyurethane (PU) backing having a thickness of 10 μm to 50 μm, for example, 20 μm to 30 μm, may be used. The release liner is placed on top of the thin film after curing. It serves to protect the patch until it is applied to the skin, i.e., the release liner is removed before applying the patch. Any release liner known to those skilled in the art may be used, such as a polyethylene terephthalate (PET) release liner having a fluorosilicone-based coating on one side, having a thickness of 25 μm to 150 μm, for example, 30 μm to 100 μm, for example, 40 μm to 60 μm.

[0068] In one embodiment, the method for forming a patch is: a. Providing a first component (A) and a second component (B) as defined herein, b. The step of mixing the first component (A) and the second component (B) to form a mixture, c. A step of coating the mixture onto the backing material, d. A step of curing the mixture, e. The step of attaching a release liner to the cured product.

[0069] The curing conditions depend on the composition of the first component (A) and the second component (B). For example, curing may proceed in 2 to 10 minutes at 90 to 120°C, or in 1 to 2 hours at ambient temperature, or, in the case of special elastomers, as low as 5 to 10 minutes at skin temperature (32°C).

[0070] While the present invention has been described with reference to several embodiments and aspects, the overall scope of the invention is defined in the appended claims. Those skilled in the art may combine embodiments and aspects as needed within the scope of the invention. All documents referenced herein are incorporated by reference. [Examples]

[0071] 1.1 Material SILPURAN® 2130A / B (abbreviated as S2130) and SILPURAN® 2114A / B (abbreviated as S2114) are supplied by Wacker and are two-component additive-curable silicone compositions that cure into silicone adhesives. A platinum catalyst is contained in component A, and a crosslinking agent is contained in component B. The mass mixing ratio between component A and component B is 1:1, as recommended by the manufacturer.

[0072] SYLGARD® 184 (abbreviated as S184) and SYLGARD® 186 (abbreviated as S186) are supplied by DOW and are two-component additive-curable silicone compositions that cure into silicone elastomers. A platinum catalyst is contained in the component base, and a crosslinking agent is contained in the component curing agent. The mass mixing ratio of the base to the curing agent is 10:1, as recommended by the manufacturer.

[0073] Silbione® RT Gel 4642 (abbreviated as S4642), Silbione® RT Gel 4645 (abbreviated as S4645), and Silbione® RTV 4410 (abbreviated as S4410) are supplied by Elkem and are two-component additive curing silicone compositions that cure into adhesives. The recommended mixing ratio is 1:1, but other suitable ratios are also possible. These are high-tack silicone "adhesives" (often referred to as "gels") designed to bond firmly to polyurethane films without the use of any primers or surface treatments.

[0074] Silopren Gel4950 (abbreviated as S4950) is supplied by Momentive and is a two-component additive curing silicone composition that hardens into an adhesive. The mixing ratio is 1:1, as recommended by the manufacturer.

[0075] Glycerol (Glycerin Ph.Eur., USP, BP) was purchased from VWR. SQO299 resin was supplied by Gelest Inc. Poly(ethylene glycol) (PEG-200) was supplied by Sigma-Aldrich. Hyaluronic acid (Blanova® Active Sodium Hyaluronate (8-50kDa)) was supplied by Azelis.

[0076] All chemicals were used exactly as received.

[0077] 1.2 Equipment A dual asymmetric centrifugal speed mixer (DAC150.1 FVZ-K, Synergy Devices Ltd, UK) was used to mix all the compounds.

[0078] An optical microscope equipped with a Leica MC190HD camera (DM LB, Leica Microsystems GmbH, Germany) was used to investigate glycerol in the form of silicone emulsions.

[0079] A strain-controlled shear rheometer (Hybrid Rheometer, TA Instruments Discovery HR-1, USA) was used to observe the time-degradation dynamic-mechanical curing profiles of the silicone mixture, as well as to determine the viscosity of various components.

[0080] The materials and apparatus from Example 1 were used in subsequent experiments and in the following examples.

[0081] Example 1: Adhesive formulated as a two-component system 5 g of component A from SILPURAN® 2130 (S2130A) and 4 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until a homogeneous component A (abbreviated as S2130A_80phr (parts per 100 parts of rubber) glycerol) was obtained. 5 g of component B from SILPURAN® 2130 (S2130B) was weighed out as component B.

[0082] Figures 1 and 2 show component A immediately after preparation (Figure 1) with a droplet size of 3.0 ± 0.8 μm, and component A 7 months after preparation (Figure 2) with a droplet size of 3.2 ± 0.9 μm. The size distribution of all droplets in the microscope images was analyzed using the image processing tool ImageJ.

[0083] This procedure was repeated for compositions containing 10 g of component A and 1.5 or 1.0 g of glycerol to obtain compositions of 15 phr and 10 phr, respectively.

[0084] The droplet size obtained for a 15 phr solution was 4 ± 2 μm, and the droplet size obtained for a 10 phr solution was 5 ± 3 μm.

[0085] Example 2: Achievement of a stable emulsion by gradually adding a large amount of glycerol to a catalyst-containing component (component A). 5 g of SILPURAN® 2114 component A (S2114A) and 2 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a 13-speed mixer until a homogeneous emulsion was achieved. Subsequently, 1 g of glycerol was added to the emulsion, and the mixture was again manually mixed for 30 seconds, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until homogeneous component A (abbreviated as S2114A_80phr glycerol) was obtained. 5 g of S2114B was weighed out as component B. A stable emulsion could not be achieved without gradually adding glycerol.

[0086] Figures 3 and 4 show component A immediately after preparation (Figure 3) with a droplet size of 2.0 ± 0.3 μm, and component A 6 months after preparation (Figure 4) with a droplet size of 2.1 ± 0.4 μm, respectively. The size distribution of all droplets in the microscope images was analyzed using the image processing tool ImageJ.

[0087] Example 3: Elastomer compounded in a two-component system 10 g of Sylgaard 184 (S184) base and 4.4 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until a homogeneous component A (S184 base and 44 phr of glycerol) was obtained. 1 g of S184 curing agent was weighed out as component B.

[0088] Figures 5 and 6 show component A immediately after preparation (Figure 5) with a droplet size of 2.0 ± 0.3 μm, and component A two months after preparation (Figure 6) with a droplet size of 2.4 ± 0.6 μm. The size distribution of all droplets in the microscope images was analyzed using the image processing tool ImageJ.

[0089] Instead of adding 4.4 g of glycerol to component A, the procedure was repeated using 1.0 g of glycerol. This resulted in a droplet size of 3.0 ± 1 μm immediately after preparation.

[0090] Example 4: The curing profile of the mixtures of components A and B from Examples 1-3 is not affected after storage time. 5 g of SILPURAN® 2130 (S2130B (component B)) was added to component A prepared according to Example 1. The mixture was then mixed using a speed mixer at 3500 rpm for 2 minutes until homogeneous. The curing profile of the homogeneous mixture was tested using a rheometer with a constant frequency of 0.1 Hz, applying a 20 mm diameter parallel plate shape and a 0.8 mm gap at 100°C for 30 minutes.

[0091] As shown in Table 1, the time to reach the gelation point (defined as the point where the storage modulus G' is greater than the loss modulus G'', indicating that the fluid has transitioned from fluid-like behavior to solid / elastic behavior) and the time to reach the plateau are almost the same. The hardening curves shown in Figure 7 for the mixture immediately after preparation and 7 months after preparation are very similar, further demonstrating the excellent storage stability of the formulation. [Table 1]

[0092] 5 g of S2114B (component B) was added to component A (prepared according to Example 2). The mixture was then mixed using a speed mixer at 3500 rpm for 2 minutes until homogeneous. The curing profile of the homogeneous mixture was tested using a rheometer with a constant frequency of 0.1 Hz, applying a 20 mm diameter parallel plate shape and a 0.8 mm gap at 120°C for 30 minutes.

[0093] As shown in Table 2, the gelation point and the time to reach the plateau are similar. The hardening curves shown in Figure 8 for the mixtures measured immediately after preparation and 6 months after preparation are similar and can be considered identical considering the experimental uncertainties. [Table 2]

[0094] 1 g of S184 curing agent (component B) was added to component A (prepared according to Example 3). The mixture was then mixed using a speed mixer at 3500 rpm for 2 minutes until homogeneous. The curing profile of the homogeneous mixture was tested using a rheometer with a constant frequency of 0.1 Hz, applying a 20 mm diameter parallel plate shape and a 0.8 mm gap at 100°C for 30 minutes.

[0095] As shown in Table 3, the gelation point and time to plateau are almost the same. The hardening curves shown in Figure 9 for the mixture immediately after preparation and two months after preparation are identical within the experimental uncertainty. [Table 3]

[0096] Example 5: Stabilization of emulsions with resin: SQO299 resin Some emulsions do not readily form stable emulsions. For example, when either component A or component B of Silbione® RT Gel4642 (S4642A) is mixed with 40 phr of glycerol using the same procedure as described in Example 1, it is difficult to form a stable emulsion.

[0097] In the case of emulsions that are difficult to stabilize, emulsion stability can be achieved by adding a small amount of SQO299 resin (Gelest Inc.) to component A of the formulation. The structure of the resin is shown below: [ka]

[0098] Component A from Silbione® RT Gel4642 (S4642A) and 0.05 g of SQO299 resin were added together to a clean 25 mL speed mixing vessel, and the mixture was speed-mixed at 3500 rpm for 2 minutes until a clear, homogeneous mixture was achieved. Then, 2 g of glycerol was added to the mixture, and the mixture was first manually mixed for 30 seconds using a metal scraper, and then the mixture was speed-mixed at 3500 rpm for 2 minutes until a homogeneous component A (abbreviated as S4642A_40phrglycerol_1phrSQO299) was obtained.

[0099] Component B from Silbione® RT Gel4642 (S4642B) and 0.05 g of SQO299 resin were added together to a clean 25 mL speed mixing vessel, and the mixture was speed-mixed at 3500 rpm for 2 minutes until a clear, homogeneous mixture was achieved. Then, 2 g of glycerol was added to the mixture, and the mixture was first manually mixed for 30 seconds using a metal scraper, and then the mixture was speed-mixed at 3500 rpm for 2 minutes until a homogeneous component B (abbreviated as S4642B_40phrglycerol_1phrSQO299) was obtained.

[0100] Figures 10 and 11 show optical microscope images of S4642A_40phrglycerol_1phrSQO299 emulsion and S4642B_40phrglycerol_1phrSQO299 emulsion immediately after preparation.

[0101] The homogeneous components A and B described above were added together in a 1:1 mass ratio to a clean 25 mL speed mixing vessel, and the mixture was speed-mixed at 3500 rpm for 2 minutes until a homogeneous mixture (abbreviated as S4642A and B_40phrglycerol_1phrSQO299) was obtained.

[0102] 5g of S4642A and 5g of S4642B were added together to a clean 25mL speed mixing vessel, and the mixture (abbreviated as S4642A and B) was speed-mixed at 3500rpm for 2 minutes until a homogeneous mixture was obtained.

[0103] The preparation of S4645A and B_40phrglycerol_1phrSQO299, S4950A and B_40phrglycerol_1phrSQO299, and mixtures of S4645A and B and S4950A and B is the same as that of S4642A and B_40phrglycerol_1phrSQO299, and S4642A and B.

[0104] Figures 12 and 13 show optical microscope images of S4645A_40phrglycerol_1phrSQO299 emulsion and S4645B_40phrglycerol_1phrSQO299 emulsion immediately after preparation.

[0105] As can be seen in Figures 19-22, the emulsions in component A and component B (S4950A_40phrglycerol_1phrSQO299 and S4950B_40phrglycerol_1phrSQO299) are almost the same immediately after preparation and on day 1 after preparation.

[0106] The homogeneous mixture thus prepared was coated onto a polyethylene terephthalate (PET) backing (190 μm thick, HOSTAPHAN, Mitsubishi Polyester Film) using a film applicator (3540bird, Elcometer, Germany) with a 200 μm blade gap. The film was fully cured in an oven at 120°C for 30 minutes. Figures 14 and 23 show the cured adhesive on the PET backing coated with a PET release liner (50 μm thick, one surface with a fluorosilicone-based coating, Siliconature SPA). These figures demonstrate that the formulation can be coated with a uniform thickness, resulting in a homogeneous distribution of glycerol across a larger coating area. The film is identical whether prepared from a fresh emulsion or from an emulsion stored for several months prior to the coating process.

[0107] The curing profiles of the above homogeneous mixtures (A and B_40phr glycerol_1phr SQO299, and A and B) were tested using a rheometer with a constant frequency of 0.1 Hz, applying a 20 mm diameter parallel plate shape and a 0.8 mm gap at 120°C for 30 minutes.

[0108] As shown in Table 4, the gelation point and time to plateau for the original silicone and the silicone-glycerol-resin mixture are approximately the same. The curing curves are shown in Figures 15, 16, and 24. [Table 4]

[0109] The linear viscoelasticity (LVE) profile of the silicone (approximately 0.8 mm thick, fully cured at 120°C for 30 minutes) was tested using a rheometer at 23°C set to a controlled strain mode of 1% with a normal force of 0.2 N and a frequency range of 100–0.01 Hz.

[0110] As shown in Table 5, the linear viscoelastic properties of the original silicone and the silicone-glycerol-resin adhesive are very similar. The LVE curves are shown in Figures 17, 18, and 25. [Table 5]

[0111] A 180° peel force test was performed according to the ASTM D3330 standard for pressure-sensitive adhesives. The homogeneous mixtures A and B obtained above, as well as the mixtures of A and B_40phr glycerol_1phr SQO299, were coated onto polyethylene terephthalate (PET) backing material (75 μm thick, HOSTAPHAN, Mitsubishi Polyester Film) and cured at 120°C for 30 minutes. A sample approximately 100 μm thick was cut into a 25 mm × 120 mm rectangle, manually placed on a stainless steel plate, and then a 2 kg roller was used to ensure proper adhesion between the sample and the substrate and minimize air inclusion. The peel test was performed using an Instron 3340 (Instron, US) universal testing machine equipped with a 50 N load cell. The peel speed and peel angle were set to 5 mm·seconds, respectively. - The temperature was set to 1 and 180°. Three measurements were taken for each composition, and the results were averaged.

[0112] As shown in Table 6, the adhesive strength of the original silicone and the silicone-glycerol-resin adhesive are similar. [Table 6]

[0113] Example 6: Diluent for the glycerol phase: Water added to the glycerol phase The initial viscosity of glycerol was reduced by adding various amounts of deionized (DI) water to glycerol. The silicone used was S184 component-based. Glycerol and DI water were added to a 25 mL container and the mixture was speed-mixed at 3500 rpm for 2 minutes until a homogeneous mixture was obtained. Then, the S184 base was added to the above mixture and the mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes until a homogeneous mixture was obtained. The dynamic viscosity of the mixture was measured at 23°C for 1 second using a 20 mm diameter parallel plate shape and a 0.8 mm gap. -1 The test was performed using a rheometer with a shear rate of [value missing].

[0114] The viscosity of emulsions containing 0-30% water dissolved in glycerol and liquids (glycerol + water) with varying viscosity levels from 0-80 phr was measured and is shown in Table 7. When water is added, it is found that adding 30% (30 phr) of water to glycerol reduces the viscosity of the glycerol to approximately one-fifth. However, with 30 phr of water, the emulsion is only storage stable up to a maximum of 40 phr of glycerol, whereas high-purity glycerol in silicone emulsions operates beyond 80 phr. [Table 7]

[0115] Example 7: Various types of additives to the glycerol phase: low molecular weight polyethylene glycol (PEG). The shaded cells are a stable, homogeneous emulsion.

[0116] By adding different additives in varying amounts to glycerol, it becomes possible to change the initial viscosity of the glycerol, as shown in Figure 26.

[0117] Various amounts of PEG-200 were added to glycerol to change the initial viscosity of glycerol. The silicone used was based on the S184 component. Glycerol and PEG-200 were added into a 25 mL container, and the mixture was speed-mixed at 3500 rpm for 2 minutes until a uniform mixture was obtained. Thereafter, the S184 base was added to the above mixture, the mixture was first manually mixed for 30 seconds using a metal scraper, and then the mixture was speed-mixed at 3500 rpm for 2 minutes until a uniform mixture was obtained. The dynamic viscosity of the mixture was measured at 23°C with a shear rate of 1 s -1 using a rheometer with a parallel plate geometry of 20 mm diameter and a gap of 0.8 mm.

[0118] The viscosity of emulsions having 0 to 30% PEG-200 dissolved in glycerol and a liquid (glycerol + PEG-200) content varying from 0 to 80 phr was measured, shown in Table 8, and plotted in Figure 27. It can be seen that the addition of PEG-200 reduces the viscosity of the glycerol-PEG200 mixture. The resulting emulsion is stable even over 80 phr of liquid and up to 30 phg of PEG-200.

Table 8

[0119] Example 8: Various types of additives added to the glycerol phase: hyaluronic acid (abbreviated as HAc, Blanova® Active Sodium Hyaluronate (8 to 50 kDa)). Shaded cells indicate stable homogeneous emulsions.

[0120] The initial viscosity of glycerol was altered by adding varying amounts of HAc water to glycerol. The silicone used was S184 "base". Glycerol and HAc were added to a 25 mL container and the mixture was speed-mixed at 3500 rpm for 2 minutes until a homogeneous mixture was obtained. Then, S184 base was added to the above mixture, and the mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes until a homogeneous mixture was obtained. The dynamic viscosity of the mixture was measured at 23°C for 1 second using a 20 mm diameter parallel plate shape and a 0.8 mm gap. -1 The test was performed using a rheometer at the specified shear rate.

[0121] The viscosity of emulsions containing 0–1% HAc dissolved in glycerol and liquid (glycerol + HAc) content varying from 0–80 phr was measured and plotted in Table 9 and Figure 28. It was found that the viscosity of the glycerol-HAC mixture increased by up to 2.3 times with the addition of 1 phr of HAc. However, the viscosity of the resulting emulsions did not follow such a uniform pattern, and the final viscosity clearly increased with the amount of HAc only for the 80 phr formulation. All obtained emulsions were stable across 80 phr of liquid and up to 1 phr of HAc. [Table 9]

[0122] Example 9: Comparative Example: Mixing of glycerol into a phase containing a crosslinking agent (component B) Component B of SILPURAN® 2130 was mixed with 15, 10, 5, 1, 0.5, and 0.1 phr of glycerol, respectively. Component B from 10 g of SILPURAN® 2130 (S2130B) and glycerol (1.5 g, 1 g, 0.5 g, 0.1 g, 0.05 g, 0.01 g) were added to a 25 mL speed mixing vessel. No additives were added. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed using a speed mixer at 3500 rpm for 2 minutes. The emulsion was visually examined for its overall translucency and for the presence or absence of clear signs of phase separation. A well-dispersed emulsion is translucent and has homogeneous color / translucency throughout.

[0123] The 10 phr emulsion showed initial phase separation after approximately 1 minute, and the phase separation continued thereafter. The 5 phr emulsion remained stable for several minutes. Emulsions with lower phr appeared stable but were not homogeneous.

[0124] As the amount of glycerol in component B increased (20, 30, 40 phr), an immediate and clear distinction was made between the glycerol phase and the silicone phase after pouring from the speed mixer cup.

[0125] The same trend was observed with respect to the amount of glycerol and its effect on stability in the other two formulations, namely component B of SILPURAN® 2114 and SILPURAN® 2122. The emulsion is stable when mixed with component A, but not when mixed with component B.

[0126] Furthermore, even when SQ resin is added to component B, stable emulsions are not formed for SILPURAN® 2130, SILPURAN® 2114, and SILPURAN® 2122. Both 1 phr and 3 phr of SQ resin were tested but unsuccessful.

[0127] Example 10: Adhesive formulated as a two-component system Component A from 10 g of Silbione® 4410 (S4410A) and 1.5 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until a homogeneous component A (abbreviated as S4410A_15phr (parts per 100 parts of rubber) glycerol) was obtained.

[0128] Component B from 10 g of Silbione® 4410 (S4410B) and 1.5 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first mixed by hand for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until a homogeneous component A (abbreviated as S4410B_15phr (parts per 100 parts of rubber) glycerol) was obtained.

[0129] Figure 29 shows component A immediately after preparation with a droplet size of 5.0 ± 2 μm. Figure 30 shows component B immediately after preparation with a droplet size of 5.0 ± 2 μm. The size distribution of all droplets in the microscope image is analyzed using the image processing tool ImageJ.

[0130] This embodiment emphasizes that in some kits, glycerol may be added to component B.

[0131] Example 11: Adhesive formulated as a two-component system Example 10 was repeated, except that 1.0 g of glycerol was used instead of 1.5 g of glycerol, to obtain a final composition containing 10 phr of glycerol. The compositions may be referred to as S4410A_10phr and S4410B_10phr.

[0132] Immediately after preparation, component A had a droplet size of 6.0 ± 3 μm. Immediately after preparation, component B had a droplet size of 5.0 ± 3 μm. The size distribution of all droplets in the microscope image was analyzed using the image processing tool ImageJ.

[0133] This example highlights that, in some kits, glycerol may be added to component B. Additionally, this example emphasizes that a stable emulsion can be obtained even at low PHR.

[0134] Example 12: Elastomer compounded in a two-component system 10 g of Sylgaard 186 (S186) base and 1 g of glycerol were added together to a clean 25 mL speed mixing vessel. The mixture was first manually mixed for 30 seconds using a metal scraper, and then speed-mixed at 3500 rpm for 2 minutes using a speed mixer until a homogeneous component A (abbreviated as S186 base_10 phr glycerol) was obtained. 1 g of S184 curing agent was weighed out as component B.

[0135] Immediately after preparation, component A had a droplet size of 3.0 ± 1.0. The size distribution of all droplets in the microscope image was analyzed using the image processing tool ImageJ.

Claims

1. A storage-stable, curable two-component kit, - A first component (A) comprising a first crosslinkable polysiloxane polymer, a curing catalyst, and glycerol, wherein the glycerol is in the form of separate droplets uniformly distributed within the first component (A), A two-component kit comprising: a second component (B) containing the crosslinking agent for the first polysiloxane polymer; and

2. The two-component kit according to claim 1, wherein when the first component and the second component are mixed, a curing reaction accelerated by the curing catalyst occurs between at least the first polysiloxane polymer and the crosslinking agent, forming a cured silicone product.

3. A two-component kit according to any one of the prior claims, wherein the first component (A) does not contain a crosslinking agent for the first polysiloxane polymer.

4. A two-component kit according to any one of the prior claims, wherein the concentration of glycerol in the first component (A) is 10 to 160 phr of the total amount of polysiloxane polymer in the first component (A).

5. The two-component kit according to any one of the prior claims, wherein the second component (B) further comprises a second crosslinkable polysiloxane polymer, and as a result when the first component and the second component are mixed, a curing reaction occurs between at least the first polysiloxane polymer, the second crosslinkable polysiloxane polymer and the crosslinking agent, accelerated by the curing catalyst, to form the cured silicone product.

6. A two-component kit according to any one of the prior claims, wherein the first and / or second polysiloxane is PDMS.

7. The two-component kit according to claim 5 or 6, wherein the second component (B) further comprises glycerol in the form of separate droplets uniformly distributed within the second component (B).

8. The two-component kit according to any one of claims 5 to 7, wherein the concentration of glycerol in the second component (B) is 10 to 160 phr per 100 parts of the total amount of polysiloxane polymer and crosslinking agent in the second component (B).

9. A two-component kit according to any one of the prior claims, wherein the average droplet diameter of the separate droplets of glycerol in component (A) and / or component (B) is 0.05 to 10 μm, for example, 0.1 to 10 μm, 0.1 to 5 μm, 0.5 to 5 μm, 1 to 5 μm, or 2 to 3 μm.

10. A two-component kit according to any one of the prior claims, wherein the standard deviation of the average droplet diameter between the largest and smallest droplets of glycerol in component (A) and / or component (B) is less than 5 μm, preferably less than 2 μm, more preferably less than 1.5 μm, and most preferably less than 1.0 μm.

11. The two-component kit according to any one of claims 2 to 10, wherein the concentration of glycerol in the cured silicone product is 10 to 160 phr, preferably 15 to 160 phr, more preferably 15 to 100 phr, more preferably 30 to 100 phr, and most preferably 30 to 80 phr of the cured silicone product.

12. The two-component kit according to any one of the prior claims, wherein the cured silicone product is an adhesive, and the weight ratio of component A to component B (A:B) is in the range of 0.9:1 to 2.6:

1.

13. The two-component kit according to claim 12, wherein the polysiloxane phase of component A is stabilized at a concentration of 0.5 to 3 phr using a Q-type or MQ-type silicone resin, preferably a silanol-trimethylsilyl-modified Q-type resin.

14. The two-component kit according to claim 12 or 13, wherein the glycerol is preferably filled with a gelling agent or an active substance in an amount of 5 to 50 phg.

15. The two-component kit according to any one of claims 1 to 11, wherein the cured silicone product is an elastomer, and the weight ratio of component A to component B (A:B) is in the range of 8:1 to 31:

1.

16. The two-component kit according to claim 15, further comprising a non-reactive silicone oil in component A and / or component B, preferably in component A, preferably at a concentration of 5 to 10 phr.

17. The two-component kit according to claim 6, comprising a curing catalyst, preferably a Pt curing catalyst, in an amount of 5 to 30 ppm.

18. A two-component kit according to any one of the prior claims, wherein the dynamic viscosity of the first component (A) before the addition of glycerol is higher than the dynamic viscosity of the second component (B).

19. The two-component kit according to any one of the prior claims, wherein the dynamic viscosity of the first component (A) is in the range of 1 to 100 Pa·s, preferably 1 to 40 Pa·s, and more preferably 2 to 30 Pa·s.

20. The two-component kit according to any one of the prior claims, wherein the dynamic viscosity of the second component (B) is in the range of 1 to 30 Pa·s, preferably 1 to 20 Pa·s.

21. A process for providing a cured silicone product, - To provide the first component (A) described in any one of the prior claims, - To provide a second component (B) as described in any one of the prior claims, A process comprising: mixing the first component (A) and the second component (B), and curing the mixture.

22. The process according to claim 21, wherein the cured silicone product is in the form of a thin film on a substrate, and the process includes an additional step of coating the substrate with a mixture of a first component (A) and a second component (B) before curing.

Images