New hydrophilic dual-end glycerol (METH)acrylate-modified silicone copolymers and methods of manufacture

Abstract

The present invention pertains to a novel class of silicone materials and their diverse applications across various technological and industrial domains. Central to this invention is a dual-end glycerol (meth)acrylate-modified silicone copolymer, characterized by its unique chemical structure and advantageous properties. This invention specifically relates to the development and enhancement of microfluidic devices, medical wound dressings, contact lenses, drug delivery systems, biosensors, and anti-fog coatings, utilizing these advanced silicone materials.

Description

2912909-101000 / DO 24003 NEW HYDROPHILIC DUAL-END GLYCEROL (METH)ACRYLATE-MODIFIED SILICONE COPOLYMERS AND METHODS OF MANUFACTURE TECHNICAL FIELD

[0001] The present invention pertains to a novel class of silicone materials and their diverse applications across various technological and industrial domains. Central to this invention is a dual-end glycerol (meth)acrylate-modified silicone copolymer, characterized by its unique chemical structure and advantageous properties. This invention specifically relates to the development and enhancement of microfluidic devices, medical wound dressings, contact lenses, drug delivery systems, biosensors, and anti-fog coatings, utilizing these advanced silicone materials.

[0002] The invention addresses the critical need for customized microfluidic chips with intrinsic long-lasting hydrophilicity, particularly those utilizing silicone materials such as Polydimethylsiloxane (PDMS). The invention aims to improve the hydrophilicity and keep good transparency and performance of silicone-based devices, which are helpful for applications ranging from point-of-care diagnostics and at-home testing to drug discovery and development, particularly essential for bio applications like on-chip cell / organoid / spheroid / tissue culturing, and organ-on-chip disease study and drug screening, etc.

[0003] Additionally, the invention encompasses a method for additive manufacturing of articles comprising silicone materials, leveraging 3D printing technologies to create multi-layered structures with enhanced properties. The silicone materials developed exhibit superior hydrophilicity, transparency, and mechanical strength, making them highly suitable for a wide range of applications, including medical wound dressings, contact lenses, drug delivery systems, biosensors, and anti-fog coatings.

[0004] The invention leverages the unique properties of silicone materials, including their excellent replicating capability, dimensional stability, ease of processing, high transparency, and mechanical strength, to create advanced solutions for various interdisciplinary applications in chemical, physical, biological, and mechanical fields. BACKGROUND OF THE INVENTION

[0005] In various technological and industrial domains, there is a growing demand for materials that exhibit specific surface properties, particularly those related to hydrophilicity. Many applications, such as microfluidic devices, medical wound dressings, contact lenses, drug delivery systems, biosensors, and anti-fog coatings, require materials that can effectively manage moisture and fluid interactions. However, existing materials often fall short in meeting2912909-101000 / DO 24003 these stringent requirements, leading to suboptimal performance and limited application potential.

[0006] In the medical field, wound dressings must balance moisture management to promote healing while preventing infection. Many conventional materials either retain excessive moisture, leading to maceration, or fail to maintain a sufficiently moist environment, thereby hindering the healing process. Modern wound dressings, such as hydrogels and hydrocolloids, have been developed to address these issues by maintaining an optimal moisture balance and providing antimicrobial properties (see Nguyen et al. “Biomedical materials for wound dressing: recent advances and applications”, RSC Adv., 2023, 13, 5509, and Buriti et al. “Polymer-Based Wound Dressings Loaded with Essential Oil for the Treatment of Wounds: A Review,” Pharmaceuticals 2024, 17, 897).

[0007] Similarly, contact lenses require materials that can sustain a hydrophilic surface to enhance wearer comfort and mitigate dryness. Existing lens materials frequently do not provide the necessary balance, resulting in discomfort and potential eye health issues. Silicone hydrogels, which combine high oxygen permeability with hydrophilic properties, have been introduced to improve comfort and reduce dryness (see Stone “Silicone Hydrogels: Four Decades Of New Chemistry In Contact Lenses”, Contact Lens Spectrum, Vol.37, Issue Dec. 2022). In the technical field of contact lenses, the patent US 9,024,052 discloses a dual end glycerol (meth)acrylate-modified silicone, and a method for preparing it.

[0008] Drug delivery systems also encounter challenges in ensuring the controlled release of medication. Hydrophilic properties are essential for facilitating consistent and effective drug delivery, yet many materials employed in these systems lack the requisite surface characteristics. Hydrogels, with their ability to absorb and retain significant amounts of water, have shown promise in enhancing drug delivery by providing a controlled release mechanism (see Hameed et al. “A Comprehensive Review of Hydrogel-Based Drug Delivery Systems: Classification, Properties, Recent Trends, and Applications”, AAPS PharmSciTech 25, 64, 2024, and Liu et al “Advances in Hydrogel-Based Drug Delivery Systems”, Gels 2024, 10, 262).

[0009] Biosensors, which are critical for detecting biological and chemical substances, necessitate materials that enhance sensitivity and accuracy through optimal fluid interaction. Traditional materials often lack the necessary hydrophilicity, thereby compromising sensor performance. Conductive polymer-based hydrogels have emerged as excellent candidates for wearable biosensors due to their biocompatibility and flexible physicochemical properties (see Thirumalai et al. “Conductive Polymer-Based Hydrogels for Wearable Electrochemical Biosensors”, Gels 2024, 10, 459, and Saeidi et al. “Electrochemical Wearable Biosensors and Bioelectronic Devices Based on Hydrogels: Mechanical Properties and Electrochemical Behavior”, Biosensors 2023, 13, 823.).2912909-101000 / DO 24003

[0010] Anti-fog coatings for optical devices represent another area where material limitations are evident. These coatings must prevent condensation to maintain clear visibility, but many existing solutions fail to provide long-lasting anti-fog properties, leading to frequent maintenance and reduced effectiveness. Recent advancements in hydrophilic anti-fog coatings, such as those using nanocomposite films and bio-derived materials, have demonstrated enhanced durability and transparency (see Momoli et al. “Anti-fog nanocomposite coatings of enhanced durability”, Journal of Sol-Gel Science and Technology, 2022, 101:46–57, and Zhang et al. “Highly transparent, healable, and durable anti-fogging coating by combining hydrophilic pectin and tannic acid with poly (ethylene terephthalate)”, Green Chemistry, 2019).

[0011] Microfluidic devices, for instance, rely heavily on precise control over fluid dynamics within microchannels. The ability to manage fluid flow and interaction at a microscale is crucial for the functionality of lab-on-a-chip devices, medical diagnostics, and chemical analysis. Traditional materials used in these devices often struggle to maintain the necessary hydrophilic surface properties, resulting in inconsistent fluid behavior and reduced device efficiency.

[0012] Indeed, microfluidics offer a versatile toolkit for addressing challenges across various interdisciplinary fields, including chemistry, physics, biology, and mechanical engineering. This technology enables precise control and manipulation of fluids at the microscale, leading to significant advancements in multiple domains. For instance, droplet-based microfluidics allows for precise control over chemical reactions within sub-microliter droplets, facilitating advancements in synthetic chemistry and materials science. This method enables researchers to conduct high-throughput experiments with minimal reagent consumption and enhanced reaction control (Moragues et al. “Droplet-based microfluidics”, Nature Reviews Methods Primers, 2023, 3:32).

[0013] In the realm of physics, acoustic microfluidics utilizes sound waves to manipulate fluids and particles, providing a platform for studying physical phenomena at microscale levels. This approach offers unique capabilities for non-contact manipulation and precise control of fluid dynamics (Zhang et al. “Acoustic microfluidics.” Annual Review of Analytical Chemistry, 2020 June 12, 13(1): 17-43).

[0014] Moreover, reconfigurable microfluidics allows for the dynamic adjustment of microfluidic networks, enhancing the flexibility and functionality of biological assays and mechanical systems. This adaptability is crucial for developing versatile and multifunctional devices that can be tailored to specific applications (Paratore et al. “Reconfigurable microfluidics”, Nature Reviews Chemistry 6, no.1 (2022): 70-80).

[0015] During the recent pandemic, microfluidic-based point-of-care testing (POCT) devices played a pivotal role in managing COVID-19 by providing rapid, accurate, and accessible diagnostic solutions. These devices, characterized by their low cost, high throughput, and ability to perform rapid, noninvasive detection of viral infections, significantly enhanced patient survival2912909-101000 / DO 24003 rates and reduced disease-associated comorbidities by enabling timely therapeutic decisions (Kumar et al. “Microfluidics-based point-of-care testing (POCT) devices in dealing with waves of COVID-19 pandemic: the emerging solution.” ACS Appl. Bio Mater.2022, 5, 2046−2068).

[0016] Additionally, microfluidic technology has been extensively reviewed for its application in various COVID-19 detection methods. Song et al. highlight the benefits of POCT, such as ease of use, greater accessibility, and timely detection, which are crucial for reducing the testing load on central hospitals. Their review compares different commercially available POCT products, including nucleic acid tests, immunoassays, and novel sensors, discussing their respective advantages and limitations. The authors propose that POCT-based SARS-CoV-2 detection methods should aim for greater accessibility, higher sensitivity, and lower costs to improve daily epidemic control and early detection and treatment (Song et al. “Point-of-care testing detection methods for COVID-19”, Lab Chip, 2021, 21, 1634).

[0017] Besides analytical / diagnostic testing, microfluidics is also used to provide microenvironments to simulate reactions and processes. Nan et al. discuss the development and future of droplet microfluidics, emphasizing its applications in processing and analyzing samples with high precision and throughput (Nan et al. “Development and future of droplet microfluidics”, Lab Chip, 2024, 24, 1135).

[0018] Sart et al. review the use of microfluidic droplets for cell culture, highlighting their ability to simulate complex biological environments and study cell interactions in a controlled manner (Sart et al. “Cell culture in microfluidic droplets.” Chem. Rev.2022, 122, 7061−7096).

[0019] Like in the cases of on-chip 3D cell culturing or organ-on-a-chip, microfluidic chips are applied to emulate physiobiological conditions for efficient drug discovery and development.

[0020] Leung et al. provide a comprehensive guide to the design, fabrication, and operation of organ-on-a-chip systems, which are engineered to mimic human physiology and maintain tissue- specific functions (Leung et al. “A guide to the organ-on-a-chip”, Nature Reviews Methods Primers, 2022, 2:33). Ma et al. discuss the potential of organ-on-a-chip technology to revolutionize the drug development pipeline by providing a more accurate and efficient platform for preclinical testing and disease modeling (Ma et al.. “Organ-on-a-chip: a new paradigm for drug development”, Trends in Pharmacological Sciences, 2021 February, 42(2): 119–133).

[0021] For different applications, customized microfluidic chips with specially designed precision patterns are often needed to serve different purposes.

[0022] In terms of prototyping these highly customized microfluidic chips, silicone materials (widely known as Polydimethylsiloxane (PDMS)) like room-temperature-vulcanization (RTV) silicones or liquid silicone rubbers / elastomers (LSR) are outstanding candidates because of their many advantages: 1) perfect replicating capability of fine structures even to nanoscale, 2) dimension stability of the byproduct-free curing process via hydrosilylation,2912909-101000 / DO 24003 3) easy processability even at room temperature, 4) high transparency in optical and fluorescence range, and 5) a good combination of flexibility and mechanical strength (Hou et al. “Interplay between materials and microfluidics”, Nature Reviews Materials, 2017 May, 2(5)).

[0023] All these advantages have secured the dominating position of silicones for prototyping microfluidic chips since their initial introduction for soft-lithography microfluidic chip fabrication processes. The pioneering work in this field has been extensively documented, highlighting the transformative impact of silicones on microfluidics technology (Whitesides “The origins and the future of microfluidics”, Nature, Vol.442, 27 July 2006). This foundational research underscores the critical role of silicones in advancing the precision, efficiency, and scalability of microfluidic chip production.

[0024] Among the drawbacks, low hydrophilicity, and adsorption and absorption of hydrophobic molecules are frequently criticized. These issues are primarily attributed to the hydrophobic nature and flexible siloxane bonds of silicones. Mukhopadhyay discusses the limitations of PDMS, highlighting its tendency to absorb small hydrophobic molecules, which can interfere with analytical results (Mukhopadhyay “When PDMS isn’t the best.” Analytical Chemistry 9, no. 79 (2007): 3248-3253). Battat et al. further emphasizes the challenges posed by the hydrophobic nature of silicones in microfluidic applications, noting that these materials can hinder the performance and reliability of microfluidic devices (Battat et al. “An outlook on microfluidics: the promise and the challenge”, Lab on a Chip 22, no. 3 (2022): 530-536). Quiñones-Pérez et al. propose the use of amphiphilic silicones to mitigate these issues, demonstrating that the incorporation of poly(ethylene oxide) silane amphiphiles can significantly reduce the absorption of small hydrophobic molecules, thereby enhancing the performance of silicone-based microfluidic devices (Quiñones-Pérez et al. “Amphiphilic silicones to reduce the absorption of small hydrophobic molecules”, Acta Biomaterialia 121 (2021) 339–348).

[0025] Accordingly, increasing the hydrophilicity of the silicones could help solve both issues. To increase silicone hydrophilicity, many surface modification / treatment methods have been developed to make the liquid / chip interfaces more hydrophilic and resistant to hydrophobic molecule adsorption. Physical surface modification methods involve post-cure treatments where non-functional chemicals are physically adsorbed onto the surface, providing a short-term hydrophilic effect that typically lasts for hours. In contrast, chemical surface modification methods use functional chemicals that react with hydroxyl groups on PDMS surfaces, resulting in a moderate-term hydrophilic effect that can last for days. These methods enhance the hydrophilicity by introducing hydrophilic polymer chains or creating chemical bonding sites with hydrophilic units.

[0026] For example, Shakeri et al. discuss various conventional and emerging strategies for the fabrication and functionalization of PDMS-based microfluidic devices, highlighting the importance2912909-101000 / DO 24003 of surface modification to enhance hydrophilicity and reduce non-specific interactions (Shakeri et al. “Conventional and emerging strategies for the fabrication and functionalization of PDMS- based microfluidic devices”, Lab Chip, 2021, 21, 3053).

[0027] Trantidou et al. describe a simple, quick, and robust method for hydrophilic surface modification of PDMS using polyvinyl alcohol (PVA) deposition following plasma treatment, which significantly improves the hydrophilicity of PDMS surfaces (Trantidou et al. “Hydrophilic surface modification of PDMS for droplet microfluidics using a simple, quick, and robust method via PVA deposition”, Microsystems & Nanoengineering 3, no.1 (2017): 1-9).

[0028] Another example is disclosed in Tan et al., which reports that extended oxygen plasma treatment can effectively reduce the hydrophobicity of sealed PDMS microchannels, maintaining hydrophilicity for extended periods when stored in de-ionized water (Tan et al. “Oxygen plasma treatment for reducing hydrophobicity of a sealed polydimethylsiloxane microchannel”, Biomicrofluidics 4, no.3, 2010).

[0029] In addition, non-functional hydrophilic additives have been added to silicones to increase bulk hydrophilicity. Common modification methods to improve the hydrophilicity of silicones in the microfluidics field include before-cure treatments to the material formulations. These treatments involve the use of non-functional silicone surfactants that are physically entrapped in the PDMS network after curing. The modification effect lasts relatively longer, typically for days to weeks, but will eventually diminish as the free-to-migrate molecules from the bulk are consumed. The transparency of the modified PDMS may vary from transparent to translucent or opaque, depending on the modifying chemicals used.

[0030] For example, Litwinowicz et al. demonstrated that the elastic modulus and hydrophilicity of cross-linked poly(dimethylsiloxane) (PDMS) can be tuned through the concentration of cross- linkers and the addition of a simple surfactant, tetraethylene glycol monododecyl ether (C12E4), before curing. This approach not only enhances the hydrophilicity but also affects the mechanical properties of the PDMS network, with the surfactant concentration significantly reducing the elastic modulus due to reduced curing extent (Litwinowicz et al. “Tuning the bulk and surface properties of PDMS networks through cross-linker and surfactant concentration” Macromolecules 2021, 54, 9636−9648).

[0031] Yao and Fang explored the use of poly(ethylene oxide)-PDMS (PEO-PDMS) as a surfactant additive to create hydrophilic PDMS. Their findings indicate that the hydrophilicity of PDMS can be controlled and maintained over an extended period, making it suitable for various microfluidic applications (Yao et al. “Hydrophilic PEO-PDMS for microfluidic applications”, J. Micromech. Microeng.22, 2012).

[0032] But no matter how efficient those methods are at the beginning, it is difficult to maintain the hydrophilicity for a long time mainly due to the rotation of the flexible siloxane bond to expose2912909-101000 / DO 24003 hydrophobic groups, the secretion of non-crosslinked silicone residuals, and / or loss of the migrated hydrophilic additives at the interfaces / surfaces.

[0033] O’Brien et al. systematically characterized the hydrophilization of PDMS and observed that the hydrophilicity diminishes over time due to the reorientation of polymer chains and the migration of low molecular weight species to the surface (O’Brien et al. “Systematic characterization of hydrophilized polydimethylsiloxane”, Journal of Microelectromechanical Systems 29, no.5 (2020): 1216-1224).

[0034] Tsuzuki et al. highlighted that the hydrophobic recovery of PDMS surfaces is a significant challenge, particularly in biomedical applications, where the hydrophilicity is compromised by the intrinsic properties of the polymer and the environmental conditions (Tsuzuki et al.. “Hydrophobic recovery of PDMS surfaces in contact with hydrophilic entities: relevance to biomedical devices.” Materials 2022, 15, 2313).

[0035] Additionally, O’Brien et al. in their study on the time evolution of hydrophilicity in PDMS microfluidic devices, noted that despite initial improvements, the hydrophilicity tends to revert due to the dynamic nature of the polymer surface and the loss of hydrophilic additives over time (O’Brien et al. “Facile methods to make PDMS hydrophilic: a time evolution study for microfluidic devices”, in 2020 IEEE 33rdInternational Conference on Micro Electromechanical Systems (MEMS), pp.346-349).

[0036] Despite significant advancements in the development of hydrophilic silicones for microfluidic applications, several challenges remain. One major issue is achieving long-lasting hydrophilicity while maintaining the transparency and mechanical integrity of the silicone material. Current methods, such as physical and chemical surface modifications, often provide only temporary hydrophilicity, which diminishes over time due to the reorientation of polymer chains and the migration of low molecular weight species to the surface. Additionally, the incorporation of hydrophilic additives into the bulk of the silicone matrix can lead to issues with compatibility and transparency, as well as the eventual depletion of these additives from the material. Furthermore, the development of silicone materials that can balance hydrophilicity with other critical properties, such as adhesion, physical strength, and curing kinetics, remains a complex and unresolved challenge. These pain points highlight the need for innovative solutions that can provide durable hydrophilicity, maintain transparency, and ensure the overall performance of silicone-based microfluidic devices. SUMMARY OF THE INVENTION

[0037] The present invention provides a novel class of silicone materials, specifically dual-end glycerol (meth)acrylate-modified silicone copolymers, characterized by their advantageous properties. The invention encompasses the following key aspects:2912909-101000 / DO 24003 1) A new silicone copolymer: which is a new dual end glycerol (meth)acrylate-modified silicone copolymer having the general formula (I): Y(R1)2SiO[Si(R1)2O]n1[Si(R1)(R4)O]n2Si(R1)2-Z-Si(R1)2-O-{[Si(R1)2O]n3-Si(R1)2 -Z’-Si(R1)2-O-[Si(R1)2O]n1- [Si(R1)(R4)O]n2}n-Si(R1)2Y (I) wherein: - R1is each independently a monovalent hydrocarbon group of 1 to 10 carbon atoms which may be halogenated, - Z is a divalent group of formula (II): -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CHR2-CH2- (II), - Z’ is a divalent group of formula (III): -CH2-CHR2-CO-O-CH2-CHR3-CH2-O-CH2-CH2-CH2- (III), - Y is a monovalent hydroxypropyl(meth)acryloyl group that includes an O-alkylated group with a general formula (IV) of: -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CR2=CH2(IV), in which: - R2is a hydrogen atom or a methyl group, and - R3is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, - n ≥ 1, n1and n2are integers ≥ 1 so that the sum (n1+n2) is from 10 to 400, preferably from 10 to 100, and even more preferably from 10 to 50; n1 / n2≥ 9, preferably n1 / n2≥ 20, and even more preferably n1 / n2≥ 50; and n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10, and - R4is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:2) A preparation process: A method for preparing the dual-end glycerol (meth)acrylate-modified silicone copolymer is provided. This involves an addition reaction in the presence of an addition catalyst, involving a dual end hydrogen silicone of formula (V) and a dual end (meth)acrylate silicone polymer of formula (VI). 3) A curable silicone composition: The invention includes a two-part curable liquid silicone composition, which can be a room temperature vulcanizing (RTV) silicone composition or a liquid silicone rubber (LSR) composition. This composition comprises specific components, including diorganopolysiloxane containing Si-bonded alkenyl groups, silicon-bonded hydrogen atom- containing organopolysiloxane, optionally fillers, addition catalysts, and the dual-end glycerol (meth)acrylate-modified silicone copolymer.2912909-101000 / DO 24003 4) A cured silicone material: The cured product of the two-part curable liquid silicone composition exhibits a water contact angle of ≤ 85°, preferably ranging from 80° to 85°, and a transparency greater than 90% in the 400 nm - 780 nm range, as measured by a HunterLab UltraScan VIS Spectrophotometer following its “Percentage Transmittance” testing procedure. 5) Applications: The silicone material is applicable in various fields, including: o Microfluidic Devices: Enhancing fluid dynamics and device efficiency. o Medical Wound Dressings: Promoting moisture management and healing. o Contact Lenses: Improving comfort and reducing dryness. o Drug Delivery Systems: Ensuring controlled release of medication. o Biosensors: Enhancing sensitivity and accuracy. o Anti-Fog Coatings: Preventing condensation on optical devices. 6) An additive manufacturing method: A method for additive manufacturing of articles comprising the silicone material is also disclosed. One approach involves 3D printing layers of the curable silicone composition and allowing them to crosslink to form the final article. Another approach involves the 3D printing of common non-silicone resins to prepare molds with designed features and the way to treat the printed molds to remove residuals that will inhibit the addition curing of two-part silicones (RTV / LSR). Then articles are fabricated by molding and replicating the structures of the printed molds.

[0038] The present invention addresses the unmet need for hydrophilic yet transparent / translucent silicones in various fields, including microfluidics, medical wound dressings, drug delivery systems, biosensors, anti-fog coatings, and ophthalmic lenses. To achieve this, a novel silicone block pre-polymer approach has been developed to introduce long- lasting hydrophilicity into intrinsically hydrophobic silicones while maintaining sufficient transparency. DETAILED DESCRIPTION

[0039] The present invention will be described in detail below. In the pursuit of the objectives outlined herein, the present inventors have undertaken exhaustive and meticulous investigations. These investigations have led to the realization of an invention that provides a new a new dual end glycerol (meth)acrylate-modified silicone copolymer having the general formula (I): Y(R1)2SiO[Si(R1)2O]n1[Si(R1)(R4)O]n2Si(R1)2-Z-Si(R1)2-O-{[Si(R1)2O]n3-Si(R1)2-Z’-Si(R1)2-O-[Si(R1)2O]n1- [Si(R1)(R4)O]n2}n-Si(R1)2Y (I) wherein: - R1is each independently a monovalent hydrocarbon group of 1 to 10 carbon atoms which may be halogenated,2912909-101000 / DO 24003 - Z is a divalent group of formula (II): -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CHR2-CH2- (II), - Z’ is a divalent group of formula (III): -CH2-CHR2-CO-O-CH2-CHR3-CH2-O-CH2-CH2-CH2- (III), - Y is a monovalent hydroxypropyl(meth)acryloyl group that includes an O-alkylated group with a general formula (IV) of: -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CR2=CH2(IV), in which: - R2is a hydrogen atom or a methyl group, and - R3is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, - n ≥ 1, n1and n2are integers ≥ 1 so that the sum (n1+n2) is from 10 to 400, preferably from 10 to 100, and even more preferably from 10 to 50; n1 / n2≥ 9, preferably n1 / n2≥ 20, and even more preferably n1 / n2≥ 50; and n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10, and - R4is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:

[0040] This invention is characterized by the unique chemical structure of the silicone block pre- polymer, which comprises double-bond-bearing functional groups at both terminals of the linear chain, small hydrophilic units periodically distributed along the linear chain, and repeated long blocks of siloxane polymer chains connecting and separating the distributed hydrophilic units.

[0041] The double-bond-bearing functional groups can react with silicone hydride crosslinkers in common two-part polydimethylsiloxane (PDMS) silicone formulations, facilitating the covalent bonding of the silicone block pre-polymers onto the PDMS network.

[0042] Upon fixation to the PDMS network, the distributed small hydrophilic units across the silicone block pre-polymer chains enhance the hydrophilicity of the modified PDMS network.

[0043] The small size and periodic distribution of the hydrophilic units, separated by longer PDMS-compatible siloxane polymer chains, ensure overall compatibility with the PDMS / silicone matrix.

[0044] Additionally, the increased chain length of the silicone block pre-polymers compared to their building-block macromers helps maintain superior physical properties.

[0045] The advantages of this new polymer are significant. The silicone block pre-polymers can be used as additives within curable silicone formulations to achieve long-lasting hydrophilicity and sufficient transparency after curing, which is particularly useful for microfluidics and other applications requiring these properties.2912909-101000 / DO 24003

[0046] The equilibrium water contact angle of the silicone material obtained after curing decreases from ≥ 100° for common silicone material to ≤ 85° for silicone material obtained by curing modified formulations with silicone block pre-polymers, demonstrating improved hydrophilicity.

[0047] The specific design of the block pre-polymer chemical structure ensures that the hydrophilic providing groups are kept short and separated by much longer siloxane polymer chain blocks, ensuring compatibility with the intrinsically hydrophobic silicone matrix.

[0048] As a result of this controlled compatibility, the hydrophilic silicone formulations can achieve >90% transparency in the visible range from 380 nm to 780 nm wavelength.

[0049] In addition to the improved hydrophilicity and balanced transparency, the block pre- polymer approach may enable fine-tuning of the physical properties, curing kinetics, and other characteristics of new curable formulations to meet more comprehensive requirements.

[0050] The newly developed hydrophilic curable silicone formulations with optimized properties are utilized to fabricate microfluidic chips, and the overall high quality of the fabricated chips indicates the success of the silicone block pre-polymer approach.

[0051] This novel linear-chain silicone block pre-polymers with short hydrophilic units periodically distributed between long siloxane chain blocks are designed and synthesized successfully to prepare hydrophilic curable silicone formulations with improved hydrophilicity (equilibrium water contact angle ≤ 85°) and sufficient transparency (>90% transparency in the visible wavelength range for 10-mm thick sample) for microfluidics and other applications like ophthalmic devices, drug delivery, and coatings for medical devices.

[0052] These formulations are also advantageous in applications such as contact lenses, where both hydrophilicity and transparency are critical for comfort and visual clarity.

[0053] Additionally, the enhanced hydrophilicity and transparency make these formulations suitable for use in wound dressings, where maintaining a moist environment and visibility of the wound site are important.

[0054] Furthermore, the formulations can be applied in the field of electronics, particularly in protective coatings for optical sensors and displays, where transparency and moisture resistance are essential.

[0055] The versatility of the silicone block pre-polymer approach allows for the development of new silicone formulations with balanced hydrophilicity, transparency, and other desirable properties, distinguishing itself from prior technologies through its controlled distribution and size of hydrophilic units, functional groups, crosslinking mechanisms, and application fields.

[0056] The invention leverages the unique properties of silicone materials, including excellent replicating capability, dimensional stability, ease of processing, high transparency, and mechanical strength, to create advanced solutions for various technological and industrial applications.2912909-101000 / DO 24003

[0057] The silicone block pre-polymer approach not only enhances the hydrophilicity of the cured silicone materials but also ensures that these properties are long-lasting and stable under various conditions.

[0058] This makes the invention particularly suitable for applications where durability and reliability are critical.

[0059] Examples of suitable dual end glycerol acrylate-modified silicone copolymer having the general formula (I) are the following polymers:with n ≥ 1, n1+ n2≥ 10, n1 / n2≥ 20, n3≤ 10; R1is preferred to be hydroxyl group (-OH), but could be other groups like -H, -CH3or a C1to C20monovalent group; and R2could be a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following structures:with n ≥ 1, n1+ n2≥ 10, n1 / n2≥ 20, n3≤ 10.2912909-101000 / DO 24003

[0060] In a preferred embodiment, the dual end glycerol (meth)acrylate-modified silicone copolymer having the general formula (I) and wherein 10 ≤ (n1+ n2) ≤ 400, n1 / n2≥ 20, n ≥1, and n3≤ 100, and preferably n1 / n2≥ 50, n3≤ 10.

[0061] All the viscosities under consideration in the present specification correspond to a dynamic viscosity magnitude that is measured, in a manner known per se, at 25°C, to work according to the Searle principle, using a rotational rheometer, Anton-Paar M302. As regards to fluid products, the viscosity under consideration in the present specification is the dynamic viscosity at 25°C, known as the "Newtonian" viscosity, i.e., the dynamic viscosity that is measured, in a manner known per se, at a sufficiently low shear rate gradient so that the viscosity measured is independent of the rate gradient.

[0062] In another preferred embodiment, the dual end glycerol (meth)acrylate-modified silicone copolymer has the general formula (I) and a viscosity in the range of 500 mPa·s to 10000 mPa·s, measured under shear rate 10 s-1at 25°C.

[0063] In another preferred embodiment, the copolymer according to the invention has a number average molecular weight (Mn) greater than 4000 g / mol and a weight average molecular weight (Mw) greater than 10000 g / mol, and preferably a number average molecular weight (Mn) from 4000 g / mol to 20000 g / mol and a weight average molecular weight (Mw) from 10000 g / mol to 50000 g / mol. The number-average molecular weight (Mn) and the weight-average molecular weight (Mw) can be determined by gel permeation chromatography with polystyrene as standard.

[0064] Number Average Molecular Weight (Mn): The number average molecular weight (Mn) is a statistical measure representing the average molecular weight of polymer molecules in a given sample. It is calculated by dividing the total weight of all polymer molecules by the total number of polymer molecules present. Mathematically, Mn is expressed as follows:where (Ni) denotes the number of molecules with molecular weight (Mi). This measure provides an arithmetic mean molecular weight, giving equal weight to each molecule irrespective of its size.

[0065] Weight Average Molecular Weight (Mw): The weight average molecular weight (Mw) is a statistical measure that accounts for the distribution of molecular weights within a polymer sample, giving greater significance to heavier molecules. It is calculated by dividing the sum of the products of the molecular weight of each molecule and the square of its weight by the sum of the products of the molecular weight of each molecule and its weight. Mathematically, Mw is expressed as follows:2912909-101000 / DO 24003 where (Ni) denotes the number of molecules with molecular weight (Mi). This measure provides a weighted mean molecular weight, reflecting the contribution of larger molecules to the overall molecular weight distribution.

[0066] Another object of the invention concerns a process for preparing a dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention and as described above, characterized by the following steps: 1) providing a reaction mixture comprising an addition catalyst, a dual end hydrogen silicone of formula (V) and a dual end (meth)acrylate silicone polymer of formula (VI): HSi(R1)2-O-{[Si(R1)2O]n3-Si(R1)2H (V) Y(R1)2SiO-[Si(R1)2O]n1-[Si(R1)(R4)O]n2-Si(R1)2Y (VI) wherein: - R1is each independently a monovalent hydrocarbon group of 1 to 10 carbon atoms which may be halogenated, - Y is a monovalent hydroxypropyl(meth)acryloyl group that includes an O-alkylated group with a general formula (III) of: -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CR2=CH2(IV) in which: - R2is a hydrogen atom or a methyl group, and - R3is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, and preferably R3is a hydroxyl group, - n1and n2are integers ≥ 1 so that the sum (n1+n2) is from 10 to 400, preferably from 10 to 100, and even more preferably from 10 to 50; n1 / n2≥ 9, preferably n1 / n2≥ 20, and even more preferably n1 / n2≥ 50; - n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10, and - R4is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:2) allowing the addition reaction to occur, and 3) isolating said dual end glycerol (meth)acrylate-modified silicone copolymer. Examples of suitable dual end hydrogen silicone of formula (V) are the following polymers:(V-1) with n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10.2912909-101000 / DO 24003

[0067] Examples of suitable dual end (meth)acrylate silicone polymer of formula (VI) are the followings polymers:(VI-1) with n ≥ 1, n1+ n2≥ 10, n1 / n2≥ 20; and R1is is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, and preferably R1is a hydroxyl group, and R2is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:

[0068] In a preferred embodiment of the process according to the invention, the dual end hydrogen silicone of formula (V) and the dual end (meth)acrylate silicone polymer of formula (VI) are characterized by the following parameters: 10 ≤ (n1+n2) ≤ 400, n1 / n2≥ 20, n3≤ 100, and preferably n1 / n2≥ 20, n3≤ 10.

[0069] In another preferred embodiment, the reaction mixture is heated at a temperature ranging from 80°C to 100°C until the reaction is complete.

[0070] Preferred addition catalysts include those from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts.

[0071] In the context of this invention, the term “addition catalysts” specifically refers to catalysts that facilitate the hydrosilylation reaction, which is a type of addition reaction where a silicon- hydrogen bond (Si-H) adds across a carbon-carbon multiple bond, typically an alkene or alkyne. The terms “addition catalysts” and “hydrosilylation catalysts” are used interchangeably throughout this document.

[0072] Platinum-based catalysts are particularly preferred due to their significant acceleration of the curing process of the composition.

[0073] Suitable platinum-based catalysts encompass hydrosilylation catalysts such as Karstedt’s catalyst, as disclosed in U.S. Pat. No. 3,715,334, or other platinum catalysts known to those skilled in the art. The scope of suitable catalysts also extends to microencapsulated hydrosilylation catalysts, for instance, those disclosed in U.S. Pat. No.5,009,957. The catalyst may optionally be combined with an inert or active support.

[0074] Preferred platinum-based catalysts include platinum fine powder, chloroplatinic acid, alcohol solutions of chloroplatinic acid, platinum-alkenyl siloxane complexes, platinum-olefin complexes, platinum-carbonyl complexes, and catalysts where these platinum-based catalysts are dispersed or encapsulated within thermoplastic resins such as silicone resin, polycarbonate2912909-101000 / DO 24003 resin, or acrylic resin. Among these, platinum-alkenyl siloxane complexes are particularly preferred. Specific examples of alkenyl siloxanes include 1,3-divinyl-1,1,3,3- tetramethyldisiloxane; 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane; alkenyl siloxanes with partial substitution of methyl groups by ethyl or phenyl groups; and alkenyl siloxanes with partial substitution of vinyl groups by allyl or hexenyl groups. Particularly, 1,3-divinyl-1,1,3,3- tetramethyldisiloxane is preferred due to the stability of the platinum-alkenylsiloxane complex.

[0075] Additionally, preferred catalysts encompass platinum-type catalysts such as complexes of platinum and olefins, complexes of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane (known as Karstedt catalyst), and powders on which platinum is supported, Speier’s catalyst complex, H[(C3H6)PtCl3] in isopropanol, H2PtCl6, Speier’s Zeise-type dimer (C3H6)2Pt2Cl4, Ashby’s catalyst, tetramethyl tetravinyl cyclotetrasiloxane platinum(0) (CAS: 68585-32-0), and Pt-carbene catalyst, among others. These platinum catalysts are extensively described in the literature and have been found to be particularly effective.

[0076] Specifically, the complexes of platinum and an organic product, as described in U.S. Pat. Nos.3,159,601, 3,159,602, and 3,220,972, and European Patents EP-A-057,459, EP-188,978, and EP-A-190,530, may be mentioned. Additionally, the complexes of platinum and vinylated organopolysiloxane, as described in U.S. Pat. Nos.3,419,593, 3,715,334, 3,377,432, 3,814,730, and 3,775,452, may also be utilized.

[0077] Rhodium-based catalysts include Wilkinson’s catalyst (RhCl(PPh₃)₃), rhodium carbonyl complexes (Rh(CO)₂(acac)), rhodium(I) chloride dimer (RhCl(CO)₂)₂, and rhodium(I) acetylacetonate (Rh(acac)(CO)₂).

[0078] Palladium-based catalysts include palladium(II) acetate (Pd(OAc)₂), palladium(0) complexes (Pd(PPh₃)₄), palladium(II) chloride (PdCl₂), and palladium(II) bis(acetylacetonate) (Pd(acac)₂). These catalysts are effective in promoting the hydrosilylation reaction, enhancing the curing process of the composition.

[0079] The terms “addition catalysts” and “hydrosilylation catalysts” are used interchangeably throughout this document.

[0080] Another object of the invention concerns a composition comprising the dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention and as described above, and preferably the composition is a curable composition, even more preferably the composition is a silicone composition, and most preferably the silicone composition is a curable silicone composition.

[0081] Another preferred embodiment of the invention a two-part curable liquid silicone composition which is a room temperature vulcanizing (RTV-2) silicone composition or a liquid silicone rubber composition (LSR), comprising a first liquid composition and a second liquid2912909-101000 / DO 24003 composition, which are stored separately and yield upon mixing a silicone rubber forming composition or a silicone elastomer forming composition, the composition comprising: (A) 100 parts by mass of a diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule; (B) at least one silicon-bonded hydrogen atom-containing organopolysiloxane containing at least 2, and preferably at least 3, silicon-bonded hydrogen atoms per molecule in an amount such that a molar ratio of silicon-bonded hydrogen atoms in component (B) relative to alkenyl groups in component (A) is from 0.01 to 20; (C) from 0 to 200 parts by mass of at least one filler; and (D) at least one addition catalyst selected from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, in an amount required to cure the composition, (E) from 0.1 to 100 parts by mass of at least one dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention and as described above, and (F) from 0 to 50 parts by mass of at least one additive, wherein the first liquid composition comprises components (A), optionally (C), (D), (E) and optionally (F), but not (B), and the second liquid composition comprises components (A), (B), optionally (C), and optionally (F), but not (D) and (E).

[0082] In the context of silicone formulations, the terms “Room Temperature Vulcanizing (RTV)” and “Liquid Silicone Rubber (LSR)” are used to describe specific types of silicone rubber compositions, each possessing distinct characteristics and applications.

[0083] Room Temperature Vulcanizing (RTV-2) Silicone Rubber refers to two-component silicone compositions that may cure at ambient temperatures or at elevated temperature depending on the nature and content of the components. RTV-2 formulations are generally produced as liquid or paste-like materials, which, after mixing and curing at room temperature, produce one of three physically different product types: solid elastomers, gels, and flexible foams. These formulations typically comprise silicone linear polymers, optionally reinforcing mineral fillers or silicone resins, a crosslinker, a catalyst, and an inhibitor to control the pot life of the mix, allowing for adequate processing time.

[0084] Liquid Silicone Rubber (LSR) refers to high-temperature vulcanizing silicones that cure through an addition-curing mechanism. LSR formulations are characterized by their lower viscosity compared to solid silicone rubber (HTV), making them pumpable and suitable for delivery as a two-component, ready-to-use system. The addition-curing process of LSR involves a curing catalyst in component A, which is a platinum compound, and a curing agent in component B, which is an SiH-functional polysiloxane. This curing process does not release any byproducts, providing unique processing advantages.2912909-101000 / DO 24003

[0085] Fillers, such as silica, are typically included in LSR formulations to enhance mechanical properties, thermal stability, and viscosity. The presence of fillers is crucial for achieving the desired rheological characteristics necessary for efficient injection molding and other processing techniques. The lower viscosity of LSR, combined with the reinforcing effect of fillers, allows for the production of high-precision and consistent components, making LSR ideal for applications in medical devices, automotive components, and consumer goods.

[0086] Suitable diorganopolysiloxane having an average of at least 2 silicon-bonded alkenyl groups per molecule; include the following polymers of general formula (VII): [(R2)b(Alk)cSiO2 / 2]a[(Alk)(R2)2SiO1 / 2]2(VII) - wherein symbols R are independently of one another selected from the group consisting of (i) unsubstituted or fluorinated C1-C20hydrocarbon radical and (ii) phenyl radical; - wherein symbol Alk is a C2-C6alkenyl group; and preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl, and hexenyl; - where b=1 or 2, c= 0 or 1 and b+c=2; and preferably b=2 and c=0 and - wherein the index a>1, preferably a is from 5 to 1500, most preferably a is from 5 to 1500, c=0 and b=2, and even more preferably a is from 100 to 1200, c=0 and b=2 or from a is from 100 to 1000, c=0 and b=2.

[0087] Examples of preferred diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule according to the invention are polymers of the following formula (VIII):formula in which: • R and R”, are chosen independently of one another and are monovalent saturated hydrocarbon radicals, which typically contain from 1 to 2 carbon atoms, or monovalent aromatic hydrocarbon radicals, which typically contain from 6 to 12 carbon atoms, which are unsubstituted or substituted with groups that do not interfere with curing reaction, such as halogen atoms. Preferred species of the silicon-bonded organic groups are, for example, alkyl groups such as methyl, ethyl, and propyl; halogenated alkyl groups such as 3,3,3-trifluoropropyl; and aryl groups such as phenyl; • R’ are alkenyl groups each containing from 2 to 6 carbon atoms, preferably said alkenyl groups are chosen from the group consisting of vinyl, allyl and hexenyl, and most preferably said alkenyl groups are vinyl groups, and most preferably R’ is a vinyl radical and2912909-101000 / DO 24003 • The index n represents a degree of polymerization, and it should be sufficient so that it achieves a viscosity of at least 10 mPa.s at 25 °C. Preferably the index n is from 5 to 1500, most preferably n is from 5 to 1500.

[0088] In embodiments of the present invention, the viscosity of diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule; typically ranges from approximately 0.01 to 100 Pa.s, measured at a temperature of 25 °C.

[0089] Suitable diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule include dimethylvinylsiloxy-endblocked dimethylpolysiloxanes; dimethylvinylsiloxy-endblocked methylvinylpolysiloxanes; dimethylvinylsiloxy-endblocked methylvinylphenylsiloxanes; dimethylvinylsiloxy-endblocked dimethylvinylsiloxane- methylvinylsiloxane copolymers; dimethylvinylsiloxy-endblocked dimethylsiloxane- methylphenylsiloxane copolymers; dimethylvinylsiloxy-endblocked dimethylsiloxane- diphenylsiloxane copolymers; and mixtures comprising at least one of the preceding organopolysiloxanes.

[0090] In a preferred embodiment, diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule is chosen among the followings: dimethylvinylsiloxy- terminated polydimethylsiloxane, dimethylvinylsiloxy-terminated polymethyl-3,3,3- trifluoropropylslioxane, dimethylvinylsiloxy-terminated dimethylsiloxane-3,3,3- trifluoropropylmethylsiloxne copolymer, and dimethylvinylsiloxy- terminated dimethylsiloxane / methylphenylsiloxane copolymer.

[0091] The composition may further contain at least one silicone resin containing vinyl groups include the following silicone resins: - MDViQ where vinyl groups are included in the D units, - MDViTQ where vinyl groups are included in the D units, - MMViQ where vinyl groups are included in a portion of the M units, - MMViTQ where vinyl groups are included in a portion of the M units, - MMViDDViQ where vinyl groups are included in a portion of the M and D units, - and mixtures thereof, with: - MVi= siloxyl unit of formula (R)2(vinyl)SiO1 / 2-DVi= siloxyl unit of formula (R)(vinyl)SiO2 / 2-T = siloxyl unit of formula (R)SiO3 / 2-Q = siloxyl unit of formula SiO4 / 2-M = siloxyl unit of formula (R)3SiO1 / 2-D = siloxyl unit of formula (R)2SiO2 / 22912909-101000 / DO 24003 and the R functional groups, which are identical or different, are monovalent hydrocarbon groups selected from: alkyl groups having from 1 to 8 carbon atoms inclusive, such as methyl, ethyl, propyl, and 3,3,3-trifluoropropyl groups, and aryl groups such as xylyl, tolyl, and phenyl.

[0092] Preferably, the R functional groups are methyl groups.

[0093] Suitable content of said silicone resin is from 1 to 200 parts by mass per 100 parts by mass of the diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule. Preferably, the content of said resin is from 5 to 150 parts by mass, more preferably from 10 to 150 parts by mass, and most preferably from 50 to 150 parts by mass per 100 parts by mass of the diorganopolysiloxane.

[0094] Suitable filler may be optionally subjected to a surface treatment using a fatty acid, a fatty acid ester such as stearate, organosilanes, organosiloxanes, or organosilazanes like hexamethyl disilazane or short chain siloxane diols. Such fillers may be comprised of reinforcing fillers, non- reinforcing fillers (also known as semi-reinforcing fillers), or a combination thereof.

[0095] The aforementioned fillers are optimally mineral-based, and more specifically, silica- based. Silica-based materials serve as effective reinforcing or semi-reinforcing fillers. The reinforcing silica fillers can be chosen from colloidal silicas, silica powders derived from combustion or precipitation, or a mixture of these. These powders typically exhibit an average particle size less than 0.1 μm (micrometer) and a BET specific surface area exceeding 30 m2 / g, ideally ranging between 30 and 600 m2 / g. Semi-reinforcing silica fillers, such as diatomaceous earth or crushed quartz, may also be utilized.

[0096] In relation to non-silica mineral materials, they can function as semi-reinforcing mineral fillers. These non-silica fillers, which can be used independently or in conjunction, include carbon black, titanium dioxide, aluminum oxide, hydrated alumina, both expanded and unexpanded vermiculite, calcium carbonate optionally surface treated by fatty acids, zinc oxide, mica, talc, iron oxide, barium sulfate, and slaked lime. These fillers generally possess a particle size ranging between 0.001 and 300 μm (micrometers) and a BET surface area less than 100 m2 / g. In a practical but not restrictive context, the fillers used may be a mixture of quartz and silica. The fillers may undergo treatment with any appropriate substance.

[0097] Another example of a suitable filler is hydrophobic silica aerogel which is a nanostructured material with high specific surface area, high porosity, low density, low dielectric constant and excellent heat insulation properties. Silica aerogels are synthesized either via supercritical drying process or via ambient pressure drying technique so as to obtain porous structure. It is now widely commercially available. Hydrophobic silica aerogel is characterized by a surface area ranging from 500 to 1500 m2 / g, alternatively of from 500 to 1200 m2 / g, in each case determined via the BET method. The hydrophobic silica aerogel may further be characterized by its porosity above 80 %, alternatively above 90%. Hydrophobic silica aerogel may have an average particle size ranging from 5 to 1000 μm, alternatively of from 5 to 100 μm, alternatively of from 5 to 252912909-101000 / DO 24003 μm as measured by means of laser light scattering. An example of hydrophobic silica aerogel is a trimethyl silylated aerogel. The hydrophobic silica aerogel maybe presents in the curable liquid silicone rubber composition in an amount of from 1 to 30 % weight relative to the total weight of the curable liquid silicone rubber.

[0098] Suitable silicon-bonded hydrogen atom-containing organopolysiloxane containing at least 2, and preferably at least 3, silicon-bonded hydrogen atoms per molecule are used as crosslinkers.

[0099] Suitable crosslinkers include organohydrogenpolysiloxane comprising from 0.45% to 40% SiH by weight, more preferably between 0.5% to 35% SiH by weight, more preferably between 0.5% to 15% SiH by weight or between 5% to 12% SiH by weight.

[0100] In some embodiments, a suitable crosslinker is an organosilicon which comprises: (i) at least 3 siloxy units of formula (XL-1) which may be identical or different: (H)(Z)eSiO(3-e) / 2(XL-1) in which: - the symbol H represents a hydrogen atom, - the symbol Z represents an alkyl having from 1 to 8 carbon atoms inclusive, and - the symbol e is equal to 0, 1 or 2, preferably e is equal to 1 or 2; and (ii) at least one, and preferably from 1 to 550 of siloxy unit(s) of formula (XL-2): (Z)gSiO(4-g) / 2(XL-2) in which: - the symbol Z represents an alkyl having from 1 to 8 carbon atoms inclusive, and - the symbol g is equal to 0, 1, 2 or 3, preferably g is equal to 2; in which Z in XL-1 and XL-2 can be the same or different.

[0101] In some embodiments, the symbol Z is selected from methyl, ethyl, propyl and 3,3,3- trifluoropropyl groups, cycloalkyl groups, and aryl groups. In some embodiments, Z is a cycloalkyl group selected from cyclohexyl, cycloheptyl, and cyclooctyl groups. In other embodiments, Z is an aryl group selected from the group consisting of xylyl, tolyl, and phenyl groups. In other embodiments, Z is a methyl group.

[0102] In a preferred embodiment, the symbol “e” in XL-1 is 1 or 2. In a preferred embodiment, the symbol “g” in XL-2 is 2. In a preferred embodiment, the organosilicon crosslinker XL comprises from 3 to 60 siloxy units of formula (XL-1) and from 1 to 250 siloxy unit(s) of formula (XL-2).

[0103] In some embodiments, the organosilicon crosslinker comprises from 3 to 60 siloxy units of formula (XL-1) and from 1 to 250 siloxy unit(s) of formula (XL-2).

[0104] As organosilicon which has a crosslinking function and which is of use according to the invention, mention may be made of those of formulae MHDxDHwMH, MHDxDHyM and MDxDHzM, in which formula:2912909-101000 / DO 24003 - MH= siloxyl unit of formula: (H)(CH3)2SiO1 / 2- DH= siloxy unit of formula: (H)(CH3)SiO2 / 2- D = siloxyl unit of formula: (CH3)2SiO2 / 2, and - M = siloxyl unit of formula: (CH3)3SiO1 / 2, with: - x is a number between 0 and 500, preferably between 2 and 250 and even more preferentially between 5 and 80; - w is a number between 1 and 500, preferably between 1 and 250 or between 1 and 100 and even more preferentially between 1 and 70; - y is a number between 2 and 500, preferably between 3 and 250 or between 2 and 100 and even more preferentially between 2 and 70; and - z is a number between 3 and 500, preferably between 3 and 250 or between 3 and 100 and even more preferentially between 3 and 70, and comprising between 0.5% and 15.0% by weight of Si-H function per polymer, preferably between 1.0% and 12.5% by weight of Si-H function per polymer, and even more preferentially between 1.5% and 10.0% by weight of Si-H function per polymer.

[0105] The organosilicon crosslinker may have a dynamic viscosity of 5 mPa.s to 1000 mPa.s at 25°C, preferably 5 mPa.s to 500 mPa.s at 25°C, more preferably 5 mPa.s to 500 mPa.s at 25°C.

[0106] The organosilicon crosslinker may have Si-H content of 0.5wt% to 30wt%, preferably 1.0 wt% to 12.5 wt%, more preferably 1.5wt% to 10.0 wt%, based on the total weight of organosilicon crosslinker.

[0107] Preferably, the organopolysiloxane crosslinker may be trimethylsiloxy-terminated polymethylhydrogensiloxane, or dimethylhydrogen-terminated polymethylhydrogensiloxane.

[0108] Examples of suitable crosslinkers containing at least two silicon-bonded hydrogen atoms per molecule when it is a branched polymer include but are not limited to: silicone resins MHQ comprising: (H)(CH3)2SiO1 / 2siloxy units (MH) and SiO4 / 2siloxy units (Q units), silicone resins MMHQ comprising: (CH3)3SiO1 / 2siloxy units (M), (CH3)2HSiO1 / 2siloxy units (MH) and SiO4 / 2(Q), silicone resins MHDHQ comprising: (CH3)2HSiO1 / 2siloxy units (MH), (CH3)HSiO2 / 2(DH) and SiO4 / 2siloxy units (Q) and silicone resins MMHDHQ comprising: (CH3)3SiO1 / 2units (M units), (CH3)2HSiO1 / 2(MH), (CH3)HSiO2 / 2(DH) and SiO4 / 2units (Q).

[0109] In an embodiment, a MHQ silicone resin may also be present as a crosslinker or as a co- crosslinker with the above described crosslinkers, wherein MHsiloxy units is of formula R2HSiO1 / 2and Q is a siloxy unit of formula SiO4 / 2, formulas where H is a hydrogen atom and where R is a one to forty carbon atom monovalent hydrocarbon radical, preferably a one to twenty carbon monovalent hydrocarbon radical, more preferably selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, phenyl,2912909-101000 / DO 24003 benzyl, and mesityl; and most preferably selected from the group consisting of methyl and phenyl. In another embodiment the crosslinker XL is a MHQ silicone resin having the formula: MHwQz- wherein Q has the formula SiO4 / 2and where MHhas the formula R2HSiO1 / 2, where H is a hydrogen atom and R is a one to forty carbon atom monovalent hydrocarbon radical, preferably a one to twenty carbon monovalent hydrocarbon radical, more preferably selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, phenyl, benzyl, and mesityl; and most preferably selected from the group consisting of methyl and phenyl, with the subscripts w and z having a ratio of 0.5 to 4.0 respectively, preferably 0.6 to 3.5, more preferably 0.75 to 3.0, and most preferably 1.0 to 3.0.

[0110] In another embodiment the crosslinker XL is a MHQ silicone resin having the formula: (MHwQz)jwhere Q has the formula SiO4 / 2and where MHhas the formula R2HSiO1 / 2, where H is a hydrogen atom and R is a one to forty carbon atom monovalent hydrocarbon radical, preferably a one to twenty carbon monovalent hydrocarbon radical, more preferably selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, phenyl, benzyl, and mesityl; and most preferably selected from the group consisting of methyl and phenyl, with the subscripts w and z having a ratio of 0.5 to 4.0 respectively, preferably 0.6 to 3.5, more preferably 0.75 to 3.0, and most preferably 1.0 to 3.0; and the subscript j ranging from about 2.0 to about 100, preferably from about 2.0 to about 30, more preferably from about 2.0 to about 10, and most preferably from about 3.0 to about 5.0.

[0111] In another embodiment, the crosslinker is a silicone resin having from 0.10 wt. % to 2.00 wt. % H as SiH and comprising MHsiloxy units of formula R2HSiO1 / 2and Q siloxy unit of formula SiO4 / 2,where H is a hydrogen atom and R is a one to forty carbon atom monovalent hydrocarbon radical, preferably a one to twenty carbon monovalent hydrocarbon radical, more preferably selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec- butyl, tert-butyl, pentyl, hexyl, heptyl, phenyl, benzyl, and mesityl; and most preferably selected from the group consisting of methyl and phenylThe composition according to the invention may further contain a cure rate controller to achieve an extended working time or “pot life”.

[0112] The incorporation of appropriate inhibitors can retard or suppress the activity of the hydrosilylation catalyst under ambient conditions.

[0113] Acetylenic compounds, as disclosed in US Patent No. 3,445,420, are recognized inhibitors for platinum group metal catalysts. Preferred categories of inhibitors that impede the activity of platinum-based catalysts at 25°C include acetylenic alcohols such as 2-methyl-3- butyn-2-ol and 1-ethynyl-2-cyclohexanol. Formulations containing these catalysts generally require heating to at least 70°C to cure at a practical rate. In particular, room temperature curing is typically accomplished using a two-part system, where the crosslinker and inhibitor are present2912909-101000 / DO 24003 in one part and the platinum catalyst in the other. The platinum concentration is increased to facilitate curing at room temperature.

[0114] In certain instances, low concentrations of inhibitors, such as 1 mole of inhibitor per mole of platinum group metal, provide adequate storage stability and cure rate. In other instances, inhibitor concentrations of up to 500 moles or more per mole of platinum group metal are necessary. The optimal concentration for a specific inhibitor in a given formulation can be determined through routine

[0115] Cure rate controllers are well known in the art and examples of such materials can be found in U.S. Patents. U.S. Patent 3,923,705 refers to the use of vinyl contained cyclic siloxanes. U.S. Patent 3,445,420 describes the use of acetylenic alcohols. U.S Patent 3,188,299 shows the effectiveness of heterocyclic amines. U.S. Patent 4,256,870 describes alkyl maleates used to control cure. Olefinic siloxanes can also be used as described in U.S. Patent 3,989,667. Polydiorganosiloxanes containing vinyl radicals have also been used and this art can be seen in U.S. Patents 3.498,945, 4,256,870, and 4,347, 346. Preferred inhibitors for this composition are 1,3,5,7-tetramethyl-1,3,5,7-tetravinyl-cyclotetrasiloxane; 3-methyl-1-butyn-3-ol, 2-methyl-3- butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargylalcohol, 2-phenyl-2-propyn-1-ol, 3, 5-dimethyl-1- hexyn-3-ol, 1-ethynylcyclopentanol, 1-phenyl-2-propynol, 3-methyl-1-penten-4-yn-3-ol, 1- ethynyl-1-cyclohexanol (ECH) and mixtures thereof, with the most preferred being the 1-ethynyl- 1-cyclohexanol (ECH).

[0116] Additional suitable inhibitor classes include hydrazines, triazoles, phosphines, mercaptans, organic nitrogen compounds, acetylenic alcohols, silylated acetylenic alcohols, maleates, fumarates, ethylenically or aromatically unsaturated amides, ethylenically unsaturated isocyanates, olefinic siloxanes, unsaturated hydrocarbon monoesters and diesters, conjugated ene-ynes, hydroperoxides, nitriles and diaziridines.

[0117] In a preferred embodiment of the invention, the cure rate controller is selected from the group consisting of 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3-butyn-1-ol, 3-butyn-2-ol, propargylalcohol, 2-phenyl-2-propyn-1-ol, 3,5-dimethyl-1-hexyn-3-ol, 1-ethynylcyclopentanol, 1- phenyl-2-propynol, 3-methyl-1-penten-4-yn-3-ol, and mixtures thereof.

[0118] Suitable additives useful for the invention include UV light stabilizers, wetting agent, compression set additive, plasticizer, self-bonding additives, anti-microbial additives, heat stabilizers, flame retardants, adhesion promoters, thermally conductive fillers, non-conductive fillers, lubricants, antistatic additives, low compression set additives, durometer adjustment additives, low coefficient of friction additives (such as tung oil), oil resistance additives, anti-crepe hardening additives, mold release additives, plasticizers, thickening or consistency increase additives, and combinations thereof.

[0119] Another object of the invention concerns a material comprising a cured product of composition according to the invention and as described above.2912909-101000 / DO 24003

[0120] Another object of the invention concerns a two-part curable liquid silicone composition which is a room temperature vulcanizing (RTV) silicone composition, comprising a first liquid composition and a second liquid composition, which are stored separately and yield upon mixing a silicone rubber forming composition or a silicone elastomer forming composition, the composition comprising: (A) 100 parts by mass of a diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule; (B) at least one silicon-bonded hydrogen atom-containing organopolysiloxane containing at least 2, and preferably at least 3, silicon-bonded hydrogen atoms per molecule in an amount such that a molar ratio of silicon-bonded hydrogen atoms in component (B) relative to alkenyl groups in component (A) is from 0.01 to 20; and (D) at least one addition catalyst selected from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, in an amount required to cure the composition, (E) from 0.1 to 100 parts by mass of at least one dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention, and (F) from 0 to 50 parts by mass of at least one additive, wherein the first liquid composition comprises components (A), (D), (E) and optionally (F), but not (B), and the second liquid composition comprises components (A), (B), and optionally (F), but not (D) and (E).

[0121] All the components of the composition are as described above.

[0122] In a preferred embodiment, the component (E), which is the dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention, is present within the composition at a weight percentage ranging from 0.1% to 20%, preferably from 1% to 30%, more preferably from 4% to 20%, and most preferably from 8% to 16%, with an optimized concentration preferably from 8% to 12%, and ideally around 10%, based on the total weight of the composition.

[0123] The invention also concerns a cured product of the two-part curable liquid silicone composition according to the invention and as described above wherein it exhibits a water contact angle of ≤ 85°, preferably ranging from 80° to 85° and a transparency greater than 90% in the 400 nm - 780 nm range as measured by a HunterLab UltraScan VIS Spectrophotometer following its “Percentage Transmittance” testing procedure.

[0124] The present invention offers significant advancements in the field of silicone compositions, particularly through the development of a cured product derived from a two-part curable liquid silicone composition. This cured product exhibits a water contact angle of ≤ 85°, preferably ranging from 80° to 85°, and demonstrates a transparency greater than 90% within the 400 nm to 780 nm wavelength range, as measured by a HunterLab UltraScan VIS Spectrophotometer in accordance with its “Percentage Transmittance” testing procedure. The2912909-101000 / DO 24003 novel linear-chain silicone block pre-polymers, featuring short hydrophilic units periodically distributed between long siloxane chain blocks, are meticulously designed and synthesized to enhance hydrophilicity and transparency.

[0125] These properties render the invention particularly advantageous for applications requiring high hydrophilicity and transparency. In microfluidics, the enhanced hydrophilicity ensures efficient fluid flow and interaction within microchannels, which is critical for accurate and reliable lab-on-a-chip devices used in diagnostics and biochemical assays. The high transparency of the silicone composition allows for precise optical detection and imaging, facilitating the observation and analysis of fluidic processes.

[0126] In ophthalmic devices, such as contact lenses and intraocular lenses, the improved hydrophilicity enhances wearer comfort by promoting better moisture retention and reducing friction between the lens and the eye. The exceptional transparency ensures clear vision and minimal optical distortion, which is essential for the effectiveness of these devices.

[0127] For drug delivery systems, the hydrophilic nature of the silicone composition aids in the controlled release of therapeutic agents, ensuring consistent and efficient drug delivery. The transparency of the material allows for visual monitoring of the drug release process, which is crucial for ensuring proper dosage and timing.

[0128] Additionally, the invention is highly beneficial for medical implants, such as catheters, stents, and prosthetic devices, where the hydrophilicity ensures better biocompatibility and reduces the risk of infection by promoting fluid interaction and minimizing bacterial adhesion. The transparency allows for easy monitoring and imaging of the implant site, ensuring proper placement and function.

[0129] In wound care, the silicone composition can be used to create advanced wound dressings that maintain a moist environment, promoting faster healing and reducing pain during dressing changes. The hydrophilicity helps in absorbing exudates, while the transparency allows healthcare providers to monitor the wound without removing the dressing, thus minimizing disruption to the healing process.

[0130] In the cosmetic and personal care industry, the silicone composition can be utilized in formulations such as skin creams, lotions, and serums, where its hydrophilic properties enhance moisture retention and skin hydration. The transparency ensures that the products do not leave any visible residue on the skin, providing a smooth and clear finish.

[0131] For optical devices, beyond ophthalmic lenses, the high transparency and hydrophilicity make the silicone composition suitable for camera lenses, optical sensors, and light guides. The material’s clarity ensures optimal light transmission and minimal distortion, while its hydrophilic nature prevents fogging and condensation, maintaining clear vision and functionality.

[0132] In the electronics industry, the silicone composition can be used as a protective coating for electronic components and devices. The hydrophilicity helps in dissipating heat and2912909-101000 / DO 24003 preventing moisture accumulation, which can damage sensitive electronics. The transparency ensures that the coated components remain visible for inspection and maintenance.

[0133] In food and beverage packaging, the silicone composition can be applied to maintain the freshness and quality of the contents by controlling moisture levels. The transparency allows consumers to see the product clearly, enhancing the appeal and trustworthiness of the packaging.

[0134] In textiles and fabrics, the silicone composition can be used to impart hydrophilic properties that improve moisture wicking and breathability. This is particularly beneficial for sportswear, outdoor gear, and medical textiles, where moisture management is crucial for comfort and performance.

[0135] The following are potential compositions, formulations, and industries that may benefit from the incorporation of this novel copolymer: 1. Adhesives and Sealants: The hydrophilic nature of the copolymer can significantly improve the adhesion properties of adhesives and sealants. This is particularly advantageous in applications involving diverse substrates such as metals, plastics, and ceramics. The copolymer can enhance the bonding strength and durability of adhesive formulations, making it suitable for use in construction, automotive, and electronic industries. Formulations may include epoxy-based adhesives (epoxy resins), polyurethane adhesives (polyurethane prepolymers), and silicone sealants (silicone polymers). 2. Coatings: In the coatings industry, the copolymer can be utilized to improve wettability, adhesion, and durability of water-based coatings. This is particularly beneficial for applications in the automotive, aerospace, and marine sectors, where enhanced performance and longevity of coatings are critical. The copolymer can also contribute to the development of environmentally friendly, low-VOC (volatile organic compounds) coatings. Formulations may include acrylic coatings (acrylic polymers), polyurethane coatings (polyurethane dispersions), and epoxy coatings (epoxy resins). 3. Biomedical Applications: The hydrophilic properties of the copolymer make it an excellent candidate for biomedical applications. It can be used in the formulation of hydrogels, wound dressings, and drug delivery systems, where moisture retention and biocompatibility are essential. The copolymer can improve the performance and comfort of medical devices and materials. Formulations may include hydrogel-based wound dressings (crosslinked hydrophilic polymers), silicone-based medical adhesives (silicone elastomers), and polymeric drug delivery systems (biodegradable polymers). 4. Textile Treatments: The copolymer can be applied to textiles to impart hydrophilic properties, enhancing moisture management and comfort. This is particularly useful in the production of performance fabrics for sportswear, outdoor clothing, and technical2912909-101000 / DO 24003 textiles. The copolymer can improve the breathability and moisture-wicking capabilities of fabrics. Formulations may include textile finishes (silicone softeners), fabric softeners (quaternary ammonium compounds), and moisture-wicking treatments (hydrophilic polymers). 5. Personal Care Products: In personal care formulations such as lotions, creams, and hair care products, the copolymer can enhance moisture retention and spreadability. Its hydrophilic nature can improve the sensory attributes and efficacy of cosmetic and skincare products, providing better hydration and skin feel. Formulations may include moisturizing creams (emulsions of water and oils), hair conditioners (cationic surfactants), and sunscreens (UV filters in emulsion bases). 6. Agricultural Applications: The copolymer can be used in agricultural sprays and coatings to improve the adhesion and efficacy of pesticides and fertilizers. Its hydrophilic properties can enhance the distribution and absorption of active ingredients, leading to more effective and efficient agricultural treatments. Formulations may include pesticide sprays (emulsifiable concentrates), fertilizer coatings (polymer-coated fertilizers), and soil conditioners (hydrophilic polymers). 7. Paper and Packaging: The copolymer can be incorporated into paper and packaging materials to enhance their hydrophilicity and barrier properties. This can improve the performance of packaging materials in various environmental conditions, making them more resistant to moisture and enhancing their protective capabilities. Formulations may include paper coatings (starch-based or polymer-based coatings), packaging films (polyethylene or polypropylene films), and barrier coatings (wax or polymer-based coatings).

[0136] Overall, the invention’s combination of high hydrophilicity and transparency significantly broadens its applicability and effectiveness in advanced scientific and medical fields, providing substantial benefits in terms of performance, reliability, and user comfort.

[0137] Another object of the invention is the utilization of the silicone material for the manufacture of microfluidic devices, particularly those devices that need long-lasting intrinsic hydrophilicity and sufficient transparency. This material enhances fluid control and precision due to its unique hydrophilic properties.

[0138] The silicone material, incorporating the novel copolymer according to the invention and utilized in the manufacture of a microfluidic device, offers numerous advantages due to its unique properties.

[0139] The process of manufacturing microfluidic devices using this silicone material involves several critical steps that leverage its high hydrophilicity, transparency, biocompatibility, and chemical resistance.2912909-101000 / DO 24003

[0140] Initially, the silicone material is cast or molded into the desired microchannel geometries using techniques such as soft lithography, injection molding, replica molding, or roll-to-roll coating & embossing. These methods allow for the precise fabrication of intricate and complex microchannel networks essential for the efficient flow and manipulation of fluids within the device.

[0141] The high hydrophilicity of the silicone material ensures that fluids can move smoothly through the microchannels via capillary action, reducing bubble formation in microchannels and eliminating the need for external pumps and simplifying the device design. Furthermore, the good hydrophilicity will help decease the absorption of hydrophobic molecules by the silicone-based microfluidic chips. Moreover, the increased hydrophilicity will make the microfluidics chips more useful for bio-applications like on-chip cell / organoid / spheroid / tissue culturing and organ-on-chip studies etc.

[0142] The exceptional transparency of the silicone material is crucial during the manufacturing process, as it allows for the accurate alignment and bonding of different layers of the microfluidic device.

[0143] This transparency also facilitates real-time optical detection and imaging of fluidic processes, which is essential for applications such as fluorescence microscopy, spectrophotometry, and other analytical techniques.

[0144] The biocompatibility of the silicone material ensures that it can safely interact with biological samples and reagents without causing adverse reactions or compromising the integrity of the samples. This property is particularly important for biomedical applications, including diagnostics, cell culture, and drug delivery systems.

[0145] Furthermore, the chemical resistance of the silicone material allows it to withstand exposure to a wide range of solvents and reagents commonly used in microfluidic applications. This durability ensures that the microfluidic devices can be used repeatedly and maintain their performance over time, even in harsh chemical environments.

[0146] The flexibility and moldability of the silicone material enable the creation of customized microfluidic devices tailored to specific applications. This versatility allows for the integration of various functional components, such as valves, pumps, and sensors, into the microfluidic system, enhancing its overall functionality and utility.

[0147] During the assembly of the microfluidic device, the silicone material forms tight seals and interfaces with other components, ensuring leak-proof operation and reliable fluid handling. The material's ability to bond with other substrates, such as glass or plastic, further enhances the robustness and durability of the device.

[0148] The final microfluidic device, made from the silicone material, exhibits superior performance characteristics, including long-lasting intrinsic hydrophilicity, efficient fluid flow, high optical clarity, and excellent biocompatibility, making it ideal for a wide range of scientific, medical, and industrial applications.2912909-101000 / DO 24003

[0149] Another object of the invention concerns a method for additive manufacturing an article comprising a silicone material comprising the steps of: 1) printing a first silicone composition prepared by combining the components of the curable liquid silicone composition according to the invention and as described above on a substrate with a 3D printer, preferably an extrusion 3D printer, to form a first layer, 2) printing a second silicone composition prepared by combining the components of the curable liquid silicone composition according to the invention on the first or previous layer with the said 3D printer to form a subsequent layer, and 3) optionally repeating step 2) with independently selected said curable liquid silicone composition or another curable silicone composition for any additional layer needed, and 4) allowing the first and subsequent layers to crosslink, optionally by heating, UV light, or radiation to obtain an article comprising a silicone material.

[0150] This method for additive manufacturing an article involves several critical steps that ensure the precise formation and curing of the silicone material to achieve the desired article.

[0151] Step 1: Printing the First Silicone Composition. The method begins with the preparation of a first silicone composition by combining the components of the curable liquid silicone composition according to the invention and as defined above. This curable composition is then printed onto a substrate using a 3D printer, preferably an extrusion 3D printer, to form the first layer. The extrusion 3D printer is selected for its ability to accurately deposit the silicone composition in a controlled manner, ensuring uniform layer thickness and precise geometrical features. The substrate can be any suitable material that provides a stable base for the subsequent layers, such as glass, metal, or a previously cured silicone layer.

[0152] Step 2: Printing the Second Silicone Composition. Following the formation of the first layer, a second silicone composition, also prepared by combining the components of the curable liquid silicone composition according to the invention and as defined above, is printed onto the first or previous layer using the same 3D printer. This step creates a subsequent layer that adheres to the first layer, building up the structure of the article. The process parameters, such as printing speed, layer height, and extrusion temperature, are carefully controlled to ensure optimal adhesion and curing between layers.

[0153] Step 3: Repeating the Printing Process. Step 2 may be optionally repeated with independently selected curable liquid silicone compositions or other curable silicone compositions to form additional layers as needed. This iterative process allows for the construction of complex three-dimensional structures with multiple layers, each contributing to the overall mechanical and functional properties of the final article. The ability to use different silicone compositions for each layer provides versatility in tailoring the properties of the article, such as varying the hardness, flexibility, or chemical resistance.2912909-101000 / DO 24003

[0154] Step 4: Crosslinking the Layers. As the layers are being printed, the first and subsequent layers can begin to cure before the application of the next layer. This initial curing helps to build a strong interlayer bond. Once all the desired layers have been applied, the heat can be increased to complete the crosslinking process, ensuring that the layers bond effectively and the article achieves its final mechanical properties. Crosslinking can be achieved through various methods, including exposure to heat, UV light, or radiation, depending on the specific formulation of the silicone composition. The crosslinking process is critical for imparting the desired strength, elasticity, and stability to the silicone material.

[0155] Applications and Advantages. The method described herein is particularly advantageous for the additive manufacturing of articles that require precise control over the material properties and geometrical features. The use of a 3D printer allows for the creation of complex shapes and structures that would be difficult or impossible to achieve with traditional manufacturing techniques. The ability to print multiple layers with different silicone compositions provides flexibility in designing articles with tailored properties for specific applications.

[0156] Another object of the invention concerns a method for additive manufacturing an article comprising a silicone material, the method comprising the steps of: 5) printing a mold using a common non-silicone resin with a 3D printer; 6) optionally treating the printed mold to remove residuals that inhibit the addition curing of two-part silicones, preferably the treatment comprises one or more of the following: o solvent cleaning using isopropyl alcohol (IPA) or similar solvents; o ultrasonic cleaning with a suitable solvent; o baking the mold at a temperature of 60-80°C to evaporate residual solvents or uncured materials; or o exposing the mold to UV light for curing residual resin; and 3) fabricating the article by molding and replicating the structures of the printed mold using a curable silicone composition prepared by combining the components of the curable liquid silicone composition according to the invention and as described above.

[0157] These methods are suitable for a wide range of applications, including but not limited to medical devices, wearable electronics, seals and gaskets, and custom-engineered components. The biocompatibility and chemical resistance of the silicone material make it ideal for use in medical and pharmaceutical applications, where it can be used to create implants, prosthetics, and drug delivery systems.

[0158] In the electronics industry, the method can be used to manufacture flexible and durable components for wearable devices and sensors. The ability to create custom seals and gaskets with precise dimensions and properties is beneficial for automotive and aerospace applications, where performance and reliability are critical.2912909-101000 / DO 24003

[0159] Overall, the method for additive manufacturing an article comprising a silicone material offers significant advantages in terms of design flexibility, material properties, and application versatility, making it a valuable innovation in the field of advanced manufacturing.

[0160] Another object of the invention concerns the silicone material according to the invention and as described above, wherein the material is used in medical wound dressings to promote moisture management and enhance healing by maintaining a hydrophilic surface.

[0161] The silicone material's unique combination of high hydrophilicity and biocompatibility makes it particularly suitable for use in advanced wound care applications. The hydrophilic properties of the silicone material ensure that it can effectively manage moisture levels at the wound site, maintaining an optimal moist environment that is conducive to faster and more efficient healing. This moisture management capability helps to prevent the wound from drying out, which can lead to scabbing and delayed healing, while also avoiding excessive moisture that can cause maceration of the surrounding skin.

[0162] The biocompatibility of the silicone material ensures that it does not cause irritation or adverse reactions when in contact with the skin, making it ideal for use in wound dressings that need to be in place for extended periods. The material's gentle adherence to the skin allows for painless removal and replacement of the dressings, reducing trauma to the wound and surrounding tissue.

[0163] Additionally, the transparency of the silicone material allows healthcare providers to visually monitor the wound without removing the dressing, thereby minimizing disruption to the healing process and reducing the risk of infection.

[0164] The silicone material can be incorporated into various types of wound dressings, including adhesive bandages, hydrocolloid dressings, and foam dressings. In adhesive bandages, the silicone material can provide a soft, conformable layer that adheres securely to the skin while allowing for easy removal. In hydrocolloid dressings, the silicone material can enhance the absorption of exudates while maintaining a moist wound environment. In foam dressings, the silicone material can provide cushioning and protection to the wound site, absorbing excess fluid and reducing pressure on the wound.

[0165] Furthermore, the silicone material's chemical resistance and durability ensure that the wound dressings can withstand exposure to various wound exudates and cleaning solutions without degrading or losing their effectiveness. This durability makes the dressings suitable for use in a wide range of wound types, including chronic wounds, surgical wounds, and traumatic injuries. The ability to customize the silicone material's properties, such as its thickness, flexibility, and adhesive strength, allows for the development of wound dressings tailored to specific patient needs and wound conditions.2912909-101000 / DO 24003

[0166] Overall, the use of the silicone material in medical wound dressings offers significant advantages in terms of moisture management, patient comfort, and healing efficacy, making it a valuable innovation in the field of wound care.

[0167] Another object of the invention concerns the silicone material according to the invention and as described above, wherein the material is used in contact lenses to improve comfort and reduce dryness by maintaining a hydrophilic surface that enhances wettability.

[0168] The unique hydrophilic properties of the silicone material ensure that the contact lenses retain moisture more effectively, thereby reducing the incidence of dryness and discomfort commonly experienced by lens wearers. This enhanced moisture retention helps to maintain a stable tear film on the surface of the lens, which is crucial for providing continuous lubrication and minimizing friction between the lens and the delicate tissues of the eye.

[0169] The biocompatibility of the silicone material ensures that it is well-tolerated by the ocular environment, reducing the risk of irritation and allergic reactions. This makes the material particularly suitable for extended wear contact lenses, where comfort and safety are paramount. The material’s gentle adherence to the eye surface allows for easy insertion and removal of the lenses, further enhancing user comfort.

[0170] Additionally, the transparency of the silicone material ensures that the contact lenses provide clear and unobstructed vision, which is essential for the effectiveness of corrective lenses. The high optical clarity of the material minimizes visual distortions and enhances the overall visual experience for the wearer.

[0171] The silicone material’s durability and resistance to protein and lipid deposits contribute to the longevity and hygiene of the contact lenses. These properties help to maintain the lenses’ performance and comfort over extended periods of use, reducing the need for frequent replacements and enhancing the overall user experience.

[0172] Furthermore, the flexibility and moldability of the silicone material allow for the precise manufacturing of contact lenses with customized shapes and sizes, tailored to fit the unique contours of each individual’s eyes. This customization ensures a better fit and improved comfort, reducing the likelihood of lens movement and associated discomfort.

[0173] Overall, the use of the silicone material in contact lenses offers significant advantages in terms of moisture retention, comfort, optical clarity, and durability, making it a valuable innovation in the field of vision correction and eye care.

[0174] Another object of the invention concerns the silicone material according to the invention and as described above, wherein the material is used in drug delivery systems to ensure controlled release of medication through its hydrophilic properties, providing a consistent release profile.

[0175] The unique hydrophilic nature of the silicone material allows it to effectively manage the release rate of therapeutic agents, ensuring a consistent and controlled delivery of medication2912909-101000 / DO 24003 over time. This controlled release mechanism is crucial for maintaining optimal therapeutic levels of the drug in the body, thereby enhancing the efficacy of the treatment and reducing the frequency of dosing.

[0176] The biocompatibility of the silicone material ensures that it can be safely used in direct contact with biological tissues and fluids, minimizing the risk of adverse reactions and ensuring patient safety. This makes the material particularly suitable for use in implantable drug delivery systems, transdermal patches, and other medical devices designed for prolonged drug administration.

[0177] The material’s ability to form a stable matrix with the drug molecules allows for the precise control of drug release kinetics. By adjusting the formulation and processing conditions, the release profile can be tailored to meet specific therapeutic needs, whether it requires a rapid initial release followed by a sustained release or a continuous release over an extended period.

[0178] Additionally, the transparency of the silicone material can be advantageous in certain drug delivery applications where visual monitoring of the device is required. For example, in transdermal patches, the transparency allows healthcare providers to inspect the application site without removing the patch, ensuring proper adhesion and function.

[0179] The chemical resistance and durability of the silicone material ensure that the drug delivery systems can withstand various physiological conditions without degrading or losing their effectiveness. This durability is essential for maintaining the integrity and performance of the drug delivery device throughout its intended use.

[0180] Furthermore, the flexibility and moldability of the silicone material enable the fabrication of drug delivery systems in various shapes and sizes, tailored to specific anatomical locations and patient needs. This customization enhances the comfort and convenience of the drug delivery system, improving patient compliance and overall treatment outcomes.

[0181] Overall, the use of the silicone material in drug delivery systems offers significant advantages in terms of controlled drug release, biocompatibility, durability, and customization, making it a valuable innovation in the field of medical therapeutics and patient care.

[0182] Another object of the invention concerns the silicone material according to the invention, wherein the material is used in biosensors to enhance sensitivity and accuracy by promoting optimal fluid interaction with the sensor surface, thereby improving detection capabilities.

[0183] The unique hydrophilic properties of the silicone material ensure that fluids, including biological samples, interact efficiently with the sensor surface, thereby enhancing the sensitivity and accuracy of the biosensor. This optimal fluid interaction is crucial for the reliable detection and quantification of analytes, as it ensures that the sensor surface is uniformly wetted and that the target molecules are effectively captured and detected.

[0184] The biocompatibility of the silicone material makes it suitable for use in biosensors that come into direct contact with biological samples, such as blood, saliva, or urine. This property2912909-101000 / DO 24003 minimizes the risk of adverse reactions and ensures that the integrity of the biological samples is maintained, which is essential for accurate and reproducible measurements.

[0185] Additionally, the transparency of the silicone material allows for the integration of optical detection methods, such as fluorescence or absorbance measurements, within the biosensor. This transparency ensures that the optical signals are not obstructed, thereby enhancing the overall performance of the biosensor.

[0186] The chemical resistance and durability of the silicone material ensure that the biosensors can withstand exposure to various chemical environments and cleaning processes without degrading or losing their functionality. This durability is particularly important for reusable biosensors, as it ensures that the sensors maintain their performance over multiple uses.

[0187] Furthermore, the flexibility and moldability of the silicone material enable the fabrication of biosensors with complex geometries and microstructures, tailored to specific sensing applications. This versatility allows for the development of biosensors that can be integrated into various devices and platforms, including wearable sensors, lab-on-a-chip systems, and point-of- care diagnostic tools.

[0188] The silicone material’s ability to form tight seals and interfaces with other components enhances the reliability and robustness of the biosensors, ensuring that the fluid samples are accurately directed to the sensing area and that the sensors operate effectively under various conditions.

[0189] Overall, the use of the silicone material in biosensors offers significant advantages in terms of sensitivity, accuracy, biocompatibility, and durability, making it a valuable innovation in the field of biosensing and diagnostic technologies.

[0190] Another object of the invention concerns the silicone material according to the invention and as described above, wherein the material is used in anti-fog coatings for optical devices, leveraging its hydrophilic nature to prevent condensation and maintain clear visibility.

[0191] The unique hydrophilic properties of the silicone material ensure that moisture spreads uniformly across the surface of the optical device, forming a thin, continuous film of water rather than discrete droplets. This uniform film prevents the formation of fog, which can obscure vision and reduce the clarity of optical devices such as eyeglasses, camera lenses, and protective goggles.

[0192] The biocompatibility of the silicone material makes it suitable for use in optical devices that come into contact with the skin, such as eyeglasses and face shields. This property ensures that the anti-fog coating does not cause irritation or adverse reactions, making it safe for prolonged use.

[0193] Additionally, the transparency of the silicone material ensures that the anti-fog coating does not interfere with the optical clarity of the device. The high optical clarity of the material2912909-101000 / DO 24003 maintains the device’s performance, providing clear and unobstructed vision even in humid or rapidly changing temperature conditions.

[0194] The chemical resistance and durability of the silicone material ensure that the anti-fog coatings can withstand exposure to various environmental conditions and cleaning processes without degrading or losing their effectiveness. This durability is particularly important for optical devices that are frequently exposed to harsh conditions, such as outdoor sports equipment and industrial safety gear.

[0195] Furthermore, the flexibility and moldability of the silicone material allow for the application of anti-fog coatings on a wide range of optical devices with different shapes and sizes. This versatility ensures that the coatings can be tailored to fit the specific requirements of each device, providing optimal anti-fog performance.

[0196] The silicone material’s ability to form a strong bond with the substrate enhances the longevity and reliability of the anti-fog coatings, ensuring that they remain effective over extended periods of use. This strong adhesion also prevents the coating from peeling or flaking off, maintaining the device’s functionality and appearance.

[0197] Overall, the use of the silicone material in anti-fog coatings for optical devices offers significant advantages in terms of preventing condensation, maintaining optical clarity, and ensuring durability, making it a valuable innovation in the field of optical technology and protective equipment.

[0198] Another object of the invention concerns the silicone material according to the invention and as described above, wherein the material is used in adhesives and sealants, in coatings, in biomedical applications, including hydrogels, wound dressings, and drug delivery systems, in textile treatments, in personal care products, such as lotions, creams, and hair care products, in agricultural applications, including agricultural sprays and coatings, and in paper and packaging materials.

[0199] The silicone material according to the invention and as described above is highly versatile and can be utilized across a wide range of applications due to its unique properties. In adhesives and sealants, the hydrophilic nature of the silicone material significantly enhances adhesion properties, bonding strength, and durability, making it suitable for diverse substrates such as metals, plastics, and ceramics. This is particularly advantageous in construction, automotive, and electronic industries, where robust and reliable bonding is essential. In coatings, the silicone material improves wettability, adhesion, and durability of water-based coatings, which is critical for applications in the automotive, aerospace, and marine sectors. The material’s ability to contribute to the development of environmentally friendly, low-VOC coatings further underscores its utility in these industries.

[0200] In biomedical applications, the silicone material’s biocompatibility and hydrophilicity make it ideal for use in hydrogels, wound dressings, and drug delivery systems. These properties2912909-101000 / DO 24003 ensure effective moisture retention, enhanced healing, and controlled release of therapeutic agents, which are crucial for patient care and medical treatments. The material’s gentle adherence and transparency also allow for painless removal and visual monitoring of wounds, reducing trauma and infection risks.

[0201] For textile treatments, the silicone material imparts hydrophilic properties that enhance moisture management and comfort, making it particularly beneficial for performance fabrics used in sportswear, outdoor clothing, and technical textiles. The material’s ability to improve breathability and moisture-wicking capabilities ensures better comfort and performance for the wearer.

[0202] In personal care products, such as lotions, creams, and hair care products, the silicone material enhances moisture retention and spreadability, improving the sensory attributes and efficacy of cosmetic and skincare formulations. This results in better hydration, skin feel, and overall user satisfaction.

[0203] In agricultural applications, the silicone material can be used in agricultural sprays and coatings to improve the adhesion and efficacy of pesticides and fertilizers. Its hydrophilic properties enhance the distribution and absorption of active ingredients, leading to more effective and efficient agricultural treatments.

[0204] Finally, in paper and packaging materials, the silicone material enhances hydrophilicity and barrier properties, improving the performance of packaging materials in various environmental conditions. This makes the materials more resistant to moisture and enhances their protective capabilities, ensuring the quality and integrity of the packaged goods.

[0205] Overall, the silicone material’s combination of high hydrophilicity, biocompatibility, durability, and versatility makes it a valuable innovation across multiple industries, providing substantial benefits in terms of performance, reliability, and user satisfaction. EXAMPLES

[0206] Synthesis process of a dual end glycerol (meth)acrylate-modified silicone copolymer according to the invention: • Raw material 1: Linear α,ω-acrylate / acryloyl terminated poly(dimethylsiloxane); CAS No.: 125455-52-9; Dynamic Viscosity: 120 mPa.s (@ shear rate 10 s-1at 25 °C); Kinematic viscosity: 80-150 mm2 / s (20 °C); Molecular weight in number (Mn): 1423 g / mol; Molecular weight in mass (Mw): 2010 g / mol; Acrylate / Acryloyl (ACR) equivalent weight = 1100 g / mol; moles ACR / g = 0.0622 • Raw material 2: Linear α,ω-silicone hydride terminated poly(dimethylsiloxane); CAS No.: 70900-21-9; Dynamic Viscosity: 7-10 mPa.s (@ shear rate 10 s-1at 25 °C); Kinematic viscosity: 8 mm2 / s (20 °C); Molecular weight in number (Mn): 774 g / mol; Molecular weight in mass (Mw): 954 g / mol.2912909-101000 / DO 24003

[0207] to 0.2 mol equivalents of linear α, ω-acrylate / acryloyl terminated poly(dimethylsiloxane) macromers were weighed and thoroughly mixed with 0.1 mol equivalents of linear α,ω-silicone hydride terminated poly(dimethylsiloxane) macromers. To this mixture, 5 to 20 ppm of a platinum catalyst was added and mixed thoroughly. The resulting mixture was then heated to 80°C for 2 hours, followed by heating to 90°C for 1 hour, and finally to 100°C for 1 hour. Alternatively, the mixture can be heated to 80°C for a duration exceeding 4 hours. The reaction temperature and time were determined based on Differential Scanning Calorimetry (DSC) results. For reactions involving different quantities or sizes, the time may need to be adjusted accordingly. DSC and / or Fourier Transform Infrared Spectroscopy (FTIR) can be utilized to verify whether the selected time and temperature combination is sufficient for complete reaction. The following polymer of formula (IX) was obtained:

[0208] Viscosity: 2680 mPa.s (measured under shear rate 10 s-1 at 25°C); Molecular weight in number (Mn): 4214 g / mol; Molecular weight in mass (Mw): 12019 g / mol

[0209] 2) Hydrophilic formulations.

[0210] Component (1): silicone resin of formula MMViQ with: • M = siloxyl unit of formula (CH3)3SiO1 / 2• MVi= siloxyl unit of formula (CH3)2(vinyl)SiO1 / 2• Q = siloxyl unit of formula SiO4 / 2- Component (2): Polydimethylsiloxane with dimethylvinylsiloxy groups present at the terminal ends (viscosity around 60000 mPa.s at 25°C). - Component (3): Polydimethylsiloxane with dimethylvinylsiloxy groups present at the terminal ends (viscosity around 3500 mPa.s at 25°C). - Component (4) % by weight= 40%wt. component (1) + 40%wt. component (2) + 20%wt. component (3). Component (5):Polydimethylsiloxane with dimethylvinylsiloxy groups present at the terminal ends (viscosity around 1500 mPa.s at 25°C). Component (6): Dual end glycerol (meth)acrylate-modified silicone copolymer as prepared in Example 1. Component (7): 10% by weight of Platinum metal, known as Karstedt’s catalyst diluted in a dimethylvinyldimer (viscosity around 350 m.Pa.s at 25°C).2912909-101000 / DO 24003 Component (8): ): α,ω-Dimethylhydrogenosiloxane end-blocked poly(dimethyl) (hydrogenomethyl) siloxane having a viscosity of around 22 mPa.s (weight-average molecular weight (Mw) around 2490 g / mol). Component (9): inhibitor 1-Ethynyl-1-cyclohexanol (ECH). Components Ingredients of curable liquid silicone composition Weight % number Part-A (6) Dual end glycerol (meth)acrylate-modified silicone copolymer 10.00 (4) Formulation containing MMViQ resin 46.79 (5) Polydimethylsiloxane with dimethylvinylsiloxy end-groups 43.20 (7) Pt Catalyst 0.01 Part-B (5) Polydimethylsiloxane with dimethylvinylsiloxy end-groups 38.41 (8)Silicon-bonded hydrogen atom-containing organopolysiloxanecrosslinker 61.55(9) Inhibitor 0.04 Table 1: Components used in two-parts formulation n°1 (Invention). Components Ingredients of curable liquid silicone composition Weight % number Part-A (4) Formulation containing MMViQ resin 51.99 (5) Polydimethylsiloxane with dimethylvinylsiloxy end-groups 48.00 (7) Pt Catalyst 0.01 Part-B (5) Polydimethylsiloxane with dimethylvinylsiloxy end-groups 38.41 (8)Silicon-bonded hydrogen atom-containing organopolysiloxanecrosslinker 61.55(9) Inhibitor 0.04 Table 2: Components used in two-parts formulation n°2 (Comparative).

[0211] The Part A and Part B components of each formulation were mixed at a weight ratio of 10:1. Cure for each mixture was accomplished by leaving the mixture to cure at 80 °C for over one hour to obtain a cured silicone material. The measured properties of the cured materials are quoted in Table 3. Properties of curedMethodFormulation 2Formulation 1 silicone material Comparative Invention Water contact angle Goniometer 102° - 110° 80° - 85° Goniometer, after 30-day Water contact angle storage in closed plastic bottles under ambient 102° - 110° 80° - 85° conditions2912909-101000 / DO 24003 HunterLab UltraScan VIS Transparency, Spectrophotometer 400 nm - 780 nm range following “Percentage > 99% > 90% Transmittance” testing procedure Viscosity, mPa.s (of Flow curve tested by formulation before Anton Paar MCR 302 4169 3050 curing) Rheometer Hardness, Shore A ASTM D 2240 52 49 Tensile strength, psi ASTM D 412, Die C 716 956 Mod@100%, psi ASTM D 412, Die C 0 796 Elongation, % ASTM D 412, Die C 81 120 Tear strength, lbf / inASTM D 624 Micro Die A,pre-cracked 17.5 15.1Working time at 25 °C,Visual observationhours1.5 10MDR MH, lb-in Moving Die Rheometer (115 °C for 5 min)(MDR), ASTM D528917.70 15.26MDR T2, minMDR, ASTM D5289(115 °C, 5 min test)0.13 0.21MDR T10, minMDR, ASTM D5289(115 °C, 5 min test)0.21 0.29MDR T50, minMDR, ASTM D5289(115 °C, 5 min test)0.33 0.42MDR T90, minMDR, ASTM D5289(115 °C, 5 min test)1.44 1.37MDR Prate, lb-in / minMDR, ASTM D5289(115 °C, 5 min test)64.05 54.00Table 3. Physical properties of cured materials of formulations (1) and (2).

[0212] Formulation 1 (Invention) demonstrates several advantages over Formulation 2 (Comparative). It exhibits a significantly lower water contact angle (80° - 85°), indicating enhanced hydrophilicity, which is beneficial for applications requiring better wettability. Notably, this hydrophilicity is maintained even after 30 days of storage in closed plastic bottles under ambient conditions, ensuring long-term performance stability. Despite slightly lower transparency (> 90%), it maintains sufficient clarity for most optical applications. The lower viscosity (3050 mPa.s) facilitates easier processing and application. Formulation 1 also has a slightly lower hardness (49 Shore A), making it more flexible. It shows superior mechanical properties with higher tensile strength (956 psi) and a significant modulus at 100% (796 psi), enhancing its performance in dynamic applications. Additionally, it has higher elongation (120%), indicating greater flexibility and stretchability. Although it has a slightly lower tear strength (15.1 lbf / in), its other mechanical properties compensate for this, making it suitable for applications2912909-101000 / DO 24003 where tear resistance is not the primary concern. Overall, Formulation 1 offers a balanced combination of flexibility, strength, ease of processing, and sustained hydrophilicity.

[0213] 3) Optimal Concentration of Silicone Acrylate Block Pre-polymer for Hydrophilicity

[0214] Water Contact Angle Measurement

[0215] Approximately 5 grams of a thoroughly mixed silicone formulation is weighed into an aluminum pan with a diameter of 60 mm and a volume of 40 mL. The aluminum pan containing the sample is then placed in a vacuum chamber to remove any entrapped air bubbles. Subsequently, the aluminum pan with the sample is positioned horizontally in an oven set at 80 °C over one hour to cure the sample into a solid state. Upon completion of the curing process, the solidified sample is demolded from the aluminum pan. A piece approximately 1.5 mm in width is cut from the center of the cured sample. This cut piece is rinsed with deionized water and dried using a nitrogen flow. The cleaned piece of the sample is then placed on the platform of a goniometer. The standard procedure of the goniometer is followed to level and measure the water contact angle of the sample. Hydrophilic Component (Silicone Acrylate Block Pre-polymer) Equilibrium Water Contact Angle (°) Concentration (%) 0 (Comparative) 100 4 (Invention) 90 8 (Invention) 80 12 (Invention) 75 16 (Invention) 70 20 (Invention) 65 24 (Invention) 60

[0216] Table 4. Effects of the Silicone Acrylate Block Pre-polymer Concentration on the Hydrophilicity Change of the Modified RTV Silicone Formulation (= Formulation 2 + addition of x % in Part-A of hydrophilic component) .

[0217] Based on the equilibrium water contact angle results, a concentration range of 8 wt% to 12 wt%, preferably around 10 wt%, is recommended for using silicone acrylate block pre- polymers as hydrophilic additives to modify silicone formulations. This range achieves a balanced hydrophilicity and transparency. The detailed reasons are as follows: i) This level of hydrophilicity is ideal for microfluidics applications. It ensures the material is hydrophilic enough to interact effectively with aqueous phases without causing concerns about potential swelling.2912909-101000 / DO 24003 ii) Higher concentrations do not significantly enhance hydrophilicity but may reduce the transparency of the material. Therefore, maintaining the concentration within the recommended range ensures optimal performance without compromising other desirable properties.

[0218] Overall, using silicone acrylate block pre-polymers within the specified concentration range provides an excellent balance of hydrophilicity and transparency, making the formulation highly effective for various applications. Even outside this range, the formulation retains beneficial properties, though the optimal balance is achieved within the recommended concentrations.

[0219] 4) Transmittance Testing of Modified RTV Silicone Formulations

[0220] Transmittance Testing: Approximately 12 grams of each sample were added to disposable plastic cuvettes. Air bubbles were removed from the samples by vacuum treatment or by placing the samples in clean and safe environments. For cured sample testing, the samples were cured directly in the cuvettes. The 10 mm thick cured samples were then tested using the HunterLab UltraScan VIS Spectrophotometer, following its “Percentage Transmittance” testing procedure, to determine their transmittance.

[0221] The transmittance of cured (curing condition: 80 °C for 1 hour) Formulation 2 (comparative) and its modified hydrophilic formulation containing 8 wt% silicone acrylate block pre-polymers (Invention) are quoted in Table 5. Transmittance (%) of cured Wavelength HPLC Water Transmittance (%) of cured silicone material (nm) Transmittance Formulation 2 (= Formulation 2 + 8 wt% Silicone (%) Comparative Acrylate Block Pre-polymer) Invention 350 100 95 90 400 100 95 90 450 100 95 90 500 100 95 90 550 100 95 90 600 100 95 90 650 100 95 90 700 100 95 90 750 100 95 90 800 100 95 90 Table 5. Transmittance of Cured silicone materials.

[0222] The transmittance results indicate that the modified hydrophilic formulation containing 8 wt% silicone acrylate block pre-polymers (Invention) maintains a high level of transparency, with transmittance values consistently around 90% across the tested wavelength range. Although slightly lower than the comparative formulation (95%), the invention still exhibits excellent optical clarity. The slight reduction in transmittance is offset by the significant hydrophilic properties2912909-101000 / DO 24003 imparted by the silicone acrylate block pre-polymers. This balance of high transparency and enhanced hydrophilicity makes the invention particularly advantageous for applications requiring both optical clarity and improved interaction with aqueous environments, such as in microfluidics and biomedical devices.

[0223] The invention thus provides a superior combination of properties, enhancing its utility and performance in various advanced applications.

[0224] 5) Fabrication of Microfluidic Chips Using Modified Hydrophilic Silicone Formulations

[0225] Microfluidic Chip Fabrication: Various representative microfluidic chips were designed and 3D-printed into molds for the preparation of corresponding microfluidic chips.

[0226] The printing of microfluidic chip molds was performed using a resin-based 3D printer (ANYCUBIC Photon Mono X 6K) with the regular organic resin provided by the printer vendor. To remove hydrosilylation-inhibiting residuals from the regular organic resin, the printed microfluidic chip molds were placed in a 100 °C oven for post-baking for over 3 days following initial cleaning and 30-minute UV curing. The well-mixed silicone formulations were then poured into the molds, and the filled molds were vacuumed to remove bubbles and ensure the silicone mixture entered the tiny, delicate structures. The filled molds were subsequently cured at the desired temperature. The molds were tested to be stable and suitable for microfluidic chip fabrication from room temperature to 100 °C. After the silicone mixture was fully cured, the cured silicone microfluidic chips were cut along the edges to lift and demold them.

[0227] Figure 1: Microfluidic chips made of modified hydrophilic RTV Formulation n°1 (Invention, see Table 1, silicone formulation n°2 with 10 wt% silicone acrylate block pre-polymers.). (a) A microfluidic chip for solvent mixing and / or droplet generation, (b) A microfluidic chip with parallel microwells and gradient generation channels, (c) A microfluidic chip for 3D cell culture, (d) A centrifugation microfluidic chip with microwell arrays. In each image, the brownish items are the 3D-printed molds for the microfluidic chip fabrication, and the clear ones are the fabricated silicone chips.

[0228] The modified hydrophilic Formulation n°1 (Invention) with 10 wt% silicone acrylate block pre-polymers demonstrated excellent performance in fabricating various types of microfluidic chips. The chips exhibited high precision and clarity, essential for applications such as solvent mixing, droplet generation, gradient generation, 3D cell culture, and centrifugation.

[0229] The enhanced hydrophilicity of the modified silicone formulation improved the interaction with aqueous phases, making these chips particularly suitable for biomedical and microfluidic applications.2912909-101000 / DO 24003

[0230] The stability of the molds and the effective curing process ensured the structural integrity and functionality of the fabricated chips, highlighting the advantages of using the modified silicone formulation in advanced microfluidic device fabrication.

Claims

2912909-101000 / DO 24003 Claims 1. A new dual end glycerol (meth)acrylate-modified silicone copolymer having the general formula (I): Y(R1)2SiO[Si(R1)2O]n1[Si(R1)(R4)O]n2Si(R1)2-Z-Si(R1)2-O-{[Si(R1)2O]n3-Si(R1)2 -Z’-Si(R1)2-O-[Si(R1)2O]n1- [Si(R1)(R4)O]n2}n-Si(R1)2Y (I) wherein: - R1is each independently a monovalent hydrocarbon group of 1 to 10 carbon atoms which may be halogenated, - Z is a divalent group of formula (II): -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CHR2-CH2- (II), - Z’ is a divalent group of formula (III): -CH2-CHR2-CO-O-CH2-CHR3-CH2-O-CH2-CH2-CH2- (III), - Y is a monovalent hydroxypropyl(meth)acryloyl group that includes an O-alkylated group with a general formula (IV) of: -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CR2=CH2(IV), in which: - R2is a hydrogen atom or a methyl group, and - R3is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, - n ≥ 1, n1and n2are integers ≥ 1 so that the sum (n1+n2) is from 10 to 400, preferably from 10 to 100, and even more preferably from 10 to 50; n1 / n2≥ 9, preferably n1 / n2≥ 20, and even more preferably n1 / n2≥ 50; and n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10, and - R4is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:

2. The silicone copolymer of claim 1, wherein the polymer has a viscosity in the range of 500 mPa·s to 10000 mPa·s measured under shear rate 10 s-1at 25°C.

3. The silicone copolymer of claim 1 or claim 2, wherein the copolymer has a number average molecular weight (Mn) greater than 4000 g / mol and a weight average molecular weight (Mw) greater than 10000 g / mol, and preferably a number average molecular weight (Mn) from 4000 g / mol to 20000 g / mol and a weight average molecular weight (Mw) from 10000 g / mol to 50000 g / mol.2912909-101000 / DO 24003 4. A process for preparing the dual end glycerol (meth)acrylate-modified silicone copolymer according to any one of claims 1 to 3, characterized by the following steps: 1) providing a reaction mixture comprising an addition catalyst, a dual end hydrogen silicone of formula (V) and a dual end (meth)acrylate silicone polymer of formula (VI): HSi(R1)2-O-{[Si(R1)2O]n3-Si(R1)2H (V) Y(R1)2SiO-[Si(R1)2O]n1-[Si(R1)(R4)O]n2-Si(R1)2Y (VI) wherein: - R1is each independently a monovalent hydrocarbon group of 1 to 10 carbon atoms which may be halogenated, - Y is a monovalent hydroxypropyl(meth)acryloyl group that includes an O-alkylated group with a general formula (III) of: -CH2-CH2-CH2-O-CH2-CHR3-CH2-O-CO-CR2=CH2(IV) in which: - R2is a hydrogen atom or a methyl group, and - R3is a hydroxyl group, a hydrogen atom, a methyl group or a C1to C20monovalent group, and preferably R3is a hydroxyl group, - n1and n2are integers ≥ 1 so that the sum (n1+n2) is from 10 to 400, preferably from 10 to 100, and even more preferably from 10 to 50; n1 / n2≥ 9, preferably n1 / n2≥ 20, and even more preferably n1 / n2≥ 50; - n3≤ 100, preferably n3≤ 50, more preferably n3≤ 20, and even more preferably n3≤ 10, and - R4is a methyl group, or a phenyl group or a C1to C20monovalent group or one of the following groups:2) allowing the addition reaction to occur, and 3) isolating said dual end glycerol (meth)acrylate-modified silicone copolymer.

5. The process according to claim 4, wherein the reaction mixture is heated at a temperature ranging from 80°C to 100°C until the reaction is complete.

6. The process according to claim 4 or claim 5, wherein the addition catalyst is selected from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts.2912909-101000 / DO 24003 7. A composition comprising the dual end glycerol (meth)acrylate-modified silicone copolymer according to any one of claims 1 to 4, and preferably the composition is a curable composition, even more preferably the composition is a silicone composition, and most preferably the silicone composition is a curable silicone composition.

8. A two-part curable liquid silicone composition which is a room temperature vulcanizing (RTV- 2) silicone composition or a liquid silicone rubber composition (LSR), comprising a first liquid composition and a second liquid composition, which are stored separately and yield upon mixing a silicone rubber forming composition or a silicone elastomer forming composition, the composition comprising: (A) 100 parts by mass of a diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule; (B) at least one silicon-bonded hydrogen atom-containing organopolysiloxane containing at least 2, and preferably at least 3, silicon-bonded hydrogen atoms per molecule in an amount such that a molar ratio of silicon-bonded hydrogen atoms in component (B) relative to alkenyl groups in component (A) is from 0.01 to 20; (C) from 0 to 200 parts by mass of at least one filler; and (D) at least one addition catalyst selected from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, in an amount required to cure the composition, (E) from 0.1 to 100 parts by mass of at least one dual end glycerol (meth)acrylate-modified silicone copolymer according to any one of claims 1 to 4, and (F) from 0 to 50 parts by mass of at least one additive, wherein the first liquid composition comprises components (A), optionally (C), (D), (E) and optionally (F), but not (B), and the second liquid composition comprises components (A), (B), optionally (C), and optionally (F), but not (D) and (E).

9. A material comprising a cured product of the composition according to claim 7 or claim 8.

10. A two-part curable liquid silicone composition which is a room temperature vulcanizing (RTV) silicone composition, comprising a first liquid composition and a second liquid composition, which are stored separately and yield upon mixing a silicone rubber forming composition or a silicone elastomer forming composition, the composition comprising: (A) 100 parts by mass of a diorganopolysiloxane having an average of at least 2 silicon- bonded alkenyl groups per molecule; (B) at least one silicon-bonded hydrogen atom-containing organopolysiloxane containing at least 2, and preferably at least 3, silicon-bonded hydrogen atoms per molecule in an amount such that2912909-101000 / DO 24003 a molar ratio of silicon-bonded hydrogen atoms in component (B) relative to alkenyl groups in component (A) is from 0.01 to 20; and (D) at least one addition catalyst selected from the group consisting of platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, in an amount required to cure the composition, (E) from 0.1 to 100 parts by mass of at least one dual end glycerol (meth)acrylate-modified silicone copolymer according to any one of claims 1 to 4, and (F) from 0 to 50 parts by mass of at least one additive, wherein the first liquid composition comprises components (A), (D), (E) and optionally (F), but not (B), and the second liquid composition comprises components (A), (B), and optionally (F), but not (D) and (E).

11. A silicone material comprising a cured product of the two-part curable liquid silicone composition according to claim 10, wherein it exhibits a water contact angle of ≤ 85°, preferably ranging from 80° to 85° and a transparency greater than 90% in the 400 nm - 780 nm range as measured by a HunterLab UltraScan VIS Spectrophotometer following its “Percentage Transmittance” testing procedure.

12. The silicone material according to claim 11 which is utilized for the manufacture of microfluidic devices, particularly those devices that need long-lasting intrinsic hydrophilicity and sufficient transparency.

13. A method for additive manufacturing an article comprising a silicone material comprising the steps of: 1) printing a first silicone composition prepared by combining the components of the curable liquid silicone composition according to any one of claims 7, 8 or 10 on a substrate with a 3D printer, preferably an extrusion 3D printer, to form a first layer, 2) printing a second silicone composition prepared by combining the components of the curable liquid silicone composition according to any one of claims 7, 8 or 10 on the first or previous layer with the said 3D printer to form a subsequent layer, and 3) optionally repeating step 2) with independently selected said curable liquid silicone composition or another curable silicone composition for any additional layer needed, and 4) allowing the first and subsequent layers to crosslink, optionally by heating, UV light, or radiation to obtain an article comprising a silicone material.

14. A method for additive manufacturing an article comprising a silicone material, the method comprising the steps of:2912909-101000 / DO 24003 1) printing a mold using a common non-silicone resin with a 3D printer; 2) optionally treating the printed mold to remove residuals that inhibit the addition curing of two- part silicones, preferably the treatment comprises one or more of the following: o solvent cleaning using isopropyl alcohol (IPA) or similar solvents; o ultrasonic cleaning with a suitable solvent; o baking the mold at a temperature of 60-80°C to evaporate residual solvents or uncured materials; or o exposing the mold to UV light for curing residual resin; and 3) fabricating the article by molding and replicating the structures of the printed mold using a curable silicone composition prepared by combining the components of the curable liquid silicone composition according to any one of claims 7, 8 or 10.

15. The silicone material according to claim 11 or 13, wherein the material is used in medical wound dressings to promote moisture management and enhance healing by maintaining a hydrophilic surface.

16. The silicone material according to claim 11 or 13, wherein the material is used in contact lenses to improve comfort and reduce dryness by maintaining a hydrophilic surface that enhances wettability.

17. The silicone material according to claim 11 or 13, wherein the material is used in drug delivery systems to ensure controlled release of medication through its hydrophilic properties, providing a consistent release profile.

18. The silicone material according to claim 11 or 13, wherein the material is used in biosensors to enhance sensitivity and accuracy by promoting optimal fluid interaction with the sensor surface, thereby improving detection capabilities.

19. The silicone material according to claim 11 or 13, wherein the material is used in anti-fog coatings for optical devices, leveraging its hydrophilic nature to prevent condensation and maintain clear visibility.

20. The silicone material according to claim 11 or 13, wherein the material is used in adhesives and sealants, in coatings, in biomedical applications, including hydrogels, wound dressings, and drug delivery systems, in textile treatments, in personal care products, such as lotions, creams, and hair care products, in agricultural applications, including agricultural sprays and coatings, and in paper and packaging materials.

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