Fluorosilicone acrylate composition and application thereof

Abstract

The invention specifically discloses a fluorosilicone acrylate composition and application thereof, and relates to the technical field of macromolecules. The optical element prepared from the fluorosilicone acrylate composition provided by the invention has the advantages of low body absorption and clear threshold response at 405nm, high Dk required by an OK mirror, 1.0-1.6 GPa modulus, low shrinkage, high light transmission and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer technology, and in particular to a fluorosilicone acrylate composition and its application. BACKGROUND

[0002] Three-dimensional printing, also known as additive manufacturing process, is a method of printing three-dimensional objects. These objects can be obtained from photosensitive powders, liquids or molten starting materials. In particular, they can be obtained from resins such as monomers (photo-polymerizable at room temperature).

[0003] The PCT application WO 2018 / 208378 published on November 15, 2018, the article entitled "Volumetric 3D printing of elastomers by tomographic back-projection" (2018) by D. Loterie and the article entitled "Volumetric additive manufacturing via tomographic reconstruction" (2019) by B. E. Kelly et al. published in Science, describe a method called "Computed Axial Lithography" (CAL) based on volumetric continuous printing. In the CAL method, the standard resin is contained in a rotatable, optically transparent tank. It can include a free-radical polymerizable liquid resin and a free-radical stabilizer including oxygen, which acts as an inhibitor of photopolymerization. Any and all stabilizers are already present in the resin and are not supplied continuously. Light projections from one side of the tank are directed simultaneously at multiple angles. The superposition of exposures from different angles creates a 3D energy dose sufficient to cause photopolymerization of the resin in the desired geometry.

[0004] Continuous 3D printing methods are advantageous over layer-by-layer based methods, particularly due to their article formation speed and quality of printed parts. Many of these methods rely on the use of inhibitors of photopolymerization, particularly for free-radically polymerizable liquid resins, such as oxygen or air. In fact, regardless of the type of polymerizable liquid resin used, for example, in the CLIP method, including polyurethanes, epoxies, cyanate esters, and silicones, it relies on oxygen-inhibited acrylate curing. Alternative resin systems have not been demonstrated. However, the use of such liquid resins is associated with several drawbacks. First, these liquid resins need to be fine-tuned for their sensitivity to free-radical photopolymerization during continuous printing, which in turn creates issues with product shelf stability, and often need to be packaged and sold as two-part formulations, and mixed prior to use. Second, these liquid resins need to be further fine-tuned to function when balancing inhibition by controlling the diffusion of supplied oxygen. Third, oxygen diffusion varies with resin viscosity, thus requiring adjustment depending on the resin type and its pot life. Fourth, expensive specialized films with high air / oxygen permeability and transparency are required to form optically transparent parts.

[0005] Different liquid resins are conventionally used for 3D printing methods. For example, in theory, the liquid resin can include polymerizable monomers selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, styrene, olefin, halogenated olefin, cyclic olefin, maleic anhydride, alkenes, alkynes, carbon monoxide, functionalized oligomers, multifunctional cure site monomers, functionalized PEG, and combinations thereof. See, for example, WO 2015 / 164234 A1, WO 2015 / 164234 A1, and the article by D. Loterie (2018). In practice, however, the vast majority of photopolymerized 3D objects are obtained from radically polymerizable monomers, in particular from (meth)acrylates and their derivatives, which are typically inhibited by oxygen or air, as disclosed in the article by V. A. Bhanu et al. in Chemical Reviews (vol. 91, No. 2, 1991) entitled "Role of Oxygen in polymerization reactions". Control inhibition by oxygen or air can be advantageously used to create a polymerization dead zone during 3D printing, for example in conventional CLIP methods. However, oxygen inhibition is also disadvantageous because the surface of the object provided with (meth)acrylate resins is in contact with the ambient air (oxygen) and thus remains partially uncured and tacky. In order to obtain a tack-free surface, the 3D printed object should therefore be post-processed (see, for example, WO 2019 / 043529 A1). Post-processing to complete the curing of the 3D printed object can require additional hardware and is currently a time-consuming process that can also involve heating.

[0006] and CAL requires "body penetration + threshold curing". Existing resins have too high absorption at 405 nm or no clear threshold, resulting in body fogging, ghosting and yellowing; also lack of material system to meet OK mirror high Dk, stable modulus, low shrinkage. SUMMARY

[0007] (1) Technical problems solved In view of this, one of the main purposes of the present application is to provide a fluorosilicone acrylate composition and its application. The optical element prepared by the fluorosilicone acrylate composition provided by the present application has low body absorption and clear threshold response at 405 nm, and also has the advantages of high Dk, 1.0-1.6 GPa modulus, low shrinkage and high light transmittance required by OK mirror.

[0008] (2) Technical solutions To achieve the above object, the present application provides a fluorosilicone acrylate composition, comprising the following components by total mass of the composition: fluorosilicone acrylate oligomer: 35-55, TRIS (3-[tris(trimethylsiloxy)silyl]propyl methacrylate): 20-35, IBOMA (isobornyl methacrylate): 2-12, TCDMDA (tricyclodecane dimethanol diacrylate): 5-12, UDMA (urethane dimethacrylate): 2-10, TPO-L (ethyl(2,4,6-trimethylbenzoyl) phenylphosphinate): 0.04-0.12, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical): 0.005-0.03, MEHQ (hydroquinone monomethyl ether): 100-300 ppm.

[0009] The OK mirror material must have the core physiological safety requirement of "high oxygen permeability (high Dk value)". The introduction of fluorine elements and siloxane segments is the key to achieving a high Dk value.

[0010] TPO-L with extremely low absorption at 405 nm is selected as the main initiator, and initiators such as BAPO with higher absorption in this waveband are explicitly prohibited or strictly limited. This ensures that the light can "body penetrate" the thick layer of resin, which is a prerequisite for precise CAL molding and avoiding surface over-curing and body fogging.

[0011] By introducing a very small amount of inhibitor TEMPO and cooperating with dissolved oxygen in the system, an "inhibition period" is artificially set at the initial stage of curing. Only when the cumulative exposure energy exceeds a critical value (D_c, curing threshold dose), the inhibitor is consumed, and the polymerization reaction can occur rapidly. This creates a "threshold curing" behavior with sharp boundaries and no ghosting on a macroscopic scale, which is the soul of the CAL process to achieve high precision.

[0012] In one embodiment, the fluorosilicone acrylate oligomer has a viscosity of 2-4.

[0013] In one embodiment, the fluorosilicone acrylate oligomer has a viscosity of 2.4.

[0014] In one embodiment, the fluorosilicone acrylate oligomer has a molecular weight of 800-2000.

[0015] In one embodiment, the fluorosilicone acrylate oligomer has a molecular weight of 1000-1200.

[0016] In one embodiment, the fluoro-silicone acrylate oligomer comprises fluoro- polysiloxane diacrylate capped oligomer, fluoro-polysiloxane triacrylate modified oligomer, fluoro-polyether-siloxane hybrid diacrylate; perfluoropolyether diacrylate (PFPE-DA), bis(methacryloyloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane (di-functional, Mn: 1000-1200) and / or PFPE-DA (di-functional, Mn: 900-1100).

[0017] In one embodiment, the fluoro-silicone acrylate oligomer is bis(methacryloyloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane.

[0018] In one embodiment, the fluoro-silicone acrylate composition comprises the following components by total mass of the composition: bis(methacryloyloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane: 35-55, TRIS: 20-35, IBOMA: 2-12, TCDMDA: 5-12, UDMA: 2-10, TPO-L: 0.04-0.12, TEMPO: 0.005-0.03, MEHQ: 100-300 ppm.

[0019] In one embodiment, the fluoro-silicone acrylate composition comprises the following components by total mass of the composition: bis(methacryloyloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane: 40-50, TRIS: 25-33, IBOMA: 6-10, TCDMDA: 8-10, UDMA: 4-8, TPO-L: 0.01-0.02, TEMPO: 0.01-0.02, MEHQ: 100-300 ppm.

[0020] In one embodiment, the fluoro-silicone acrylate composition comprises the following components by total mass of the composition: bis(methacryloyloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane: 45, TRIS: 32.88, IBOMA: 6, TCDMDA: 8, UDMA: 8, TPO-L: 0.08, TEMPO: 0.02, MEHQ: 0.02.

[0021] In one embodiment, the fluoro-silicone acrylate composition further comprises PFPE-DA (perfluoropolyether diacrylate).

[0022] In one embodiment, the PFPE-DA is 0-15 wt% of the total mass of the composition.

[0023] In one embodiment, the PFPE-DA is 5-12 wt% of the total mass of the composition.

[0024] In one embodiment, the PFPE-DA accounts for 10 wt% of the total mass of the composition.

[0025] In one embodiment, the fluorosilicone acrylate composition comprises the following components by total mass of the composition: Bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane: 45, TRIS: 32.88, IBOMA: 6, TCDMDA: 8, UDMA: 8, TPO-L: 0.08, TEMPO: 0.02, MEHQ: 0.02, PFPE-DA: 10.

[0026] The present application provides, in another aspect, the use of the above-mentioned fluorosilicone acrylate composition in the preparation of an optical element.

[0027] The present application also provides, in another aspect, an optical element prepared from the above-mentioned fluorosilicone acrylate composition.

[0028] In one embodiment, the optical element comprises a convex lens, a concave lens, a right-angle prism, a light-splitting prism, a band-pass filter, a neutral density filter, a diffraction grating, and / or a hologram recording medium.

[0029] (III) Beneficial Effects The present application provides a fluorosilicone acrylate composition and its use. Compared with the prior art, the following beneficial effects are achieved: 1. Good body penetration at 405 nm, clear threshold, reduced ghosting and body fogging during curing.

[0030] 2. Low shrinkage and high Tg, stable curvature and geometry; high optical transmittance and low haze after post-curing. 3. Low initiator / inhibitor dosage, combined with deep extraction, reducing extractables and biological toxicity risk. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0032] Figure 1 is a curing work curve diagram.

[0033] Figure 2 is a dynamic mechanical property diagram of a cured sample.

[0034] Figure 3is a graph of the effect of depth extraction on key residual content. DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort should fall into the scope of protection of the present application.

[0036] Terms and definitions As used herein, the term "polymer" means a material formed by polymerization / crosslinking of one or more monomers or macromonomers or prepolymers or combinations thereof.

[0037] As used herein, the term "molecular weight" is number average molecular weight, unless specifically indicated otherwise or unless the test conditions dictate otherwise.

[0038] As used herein, the term "photoinitiator" refers to a chemical that initiates a free radical crosslinking / polymerization reaction by the use of light.

[0039] As used herein, the term "oxygen permeability", "Dk" is the rate of oxygen passing through a material. As used herein, the term "oxygen permeability (Dk)" with respect to a hydrogel (silicone or non-silicone) or contact lens means the corrected oxygen permeability (Dkc) measured at about 34°C to 35°C according to the procedure described in Example 1 of U.S. Patent Application Publication No. 2012-0026457 Al and corrected for surface resistance of oxygen flux resulting from boundary layer effects. Oxygen permeability is conventionally expressed in barrers, where "barrers" is defined as [(cm 3 oxygen)(mm) / (cm 2 )(s)(mmHg)] x 10 -10 .

[0040] As used herein, the term "oxygen transmissibility", "Dk / t" is the rate of oxygen passing through a specific lens or material of average thickness t [in mm] over the area measured. Oxygen transmissibility is conventionally expressed in barrers / mm, where "barrers / mm" is defined as [(cm 3 oxygen)(mm) / (cm 2 )(s)(mmHg)] x 10 -9 .

[0041] As used herein, the term "modulus" or "elastic modulus" means tensile modulus or Young's modulus as a measure of the stiffness of a contact lens or material. Those skilled in the art are well versed in how to determine the elastic modulus of a silicone hydrogel material or contact lens.

[0042] As used herein, the term "UVA" refers to radiation occurring at wavelengths between 315 and 380 nanometers.

[0043] As used herein, "containing," "having," or "including" encompasses "comprising," "consisting essentially of," "consisting of," and "made of"; "consisting essentially of," "consisting of," and "made of" are subsumed into "containing," "having," or "including."

[0044] The experimental methods used in the following examples are routine methods unless otherwise specified, and the reagents, methods and apparatus used are routine reagents, methods and apparatus in the art unless otherwise specified.

[0045] Example 1 Curing of photo-fluoro-silicone acrylate composition #1: 1. Composition formulation: Bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane 45.00 wt% (22.50 g), TRIS 32.88 wt% (16.44 g), IBOMA 6.00 wt% (3.00 g), TCDMDA 8.00 wt% (4.00 g), UDMA 8.00 wt% (4.00 g), TPO-L 0.08 wt% (0.040 g), TEMPO 0.02 wt% (0.010 g), MEHQ 0.02 wt% (0.010 g).

[0046] 2. Curing of the composition: 2.1. Preparation of the composition: The liquid monomer and oligomer components were added to a brown glass bottle with magnetic stirring bar under light protection, with yellow light as safety illumination. The magnetic stirring was turned on and the solution was stirred until a clear and homogeneous solution was formed. The solid photoinitiator (TPO-L), inhibitor (TEMPO) and stabilizer (MEHQ) were added. The stirring was continued until all the solid components were completely dissolved. The prepared resin composition was vacuum degassed at room temperature for 15-30 minutes to remove dissolved air and air bubbles introduced during stirring, and was ready for use.

[0047] 2.2. Curing procedure: Apparatus: Commercial CAL (Constrained Area Lithography) or DLP (Digital Light Processing) 3D printer equipped with 405 nm LED light source. The printing chamber needs to have the ability to control the oxygen concentration.

[0048] Environmental control: Before starting the printing, nitrogen gas is introduced into the printing chamber until the oxygen concentration is reduced to below 200 ppm to eliminate the influence of oxygen inhibition on threshold curing.

[0049] Printing parameters: Layer thickness: Set to 50 pm.

[0050] Exposure energy: According to the curing working curve of the resin of the present application (as shown in Figure 1 ), the single-layer exposure energy is set in the ideal working zone of 1.6 x D_c to 2.0 x D_c. If D_c is about 12.5 mJ / cm², the single-layer exposure energy can be set to 20-25 mJ / cm².

[0051] Printing execution: Pour the prepared resin composition into the resin tank of the printer, and start the printing process according to the preset CAD model (for example, OK mirror or performance test standard spline).

[0052] 2.3. Post-processing: IPA cleaning: After printing is completed, the formed part is removed from the building platform, and is cleaned with isopropyl alcohol (IPA) for 2-5 minutes to remove the surface residual uncured resin. (The influence of secondary curing and deep extraction on residual materials is shown in Figure 3 ). Secondary curing: The cleaned part is placed in a UV curing box with a nitrogen atmosphere, and is subjected to 10-20 minutes of supplemental exposure using a 405 nm light source to ensure complete curing of the resin and improve the final conversion rate.

[0053] Deep extraction: For samples that need to be subjected to biological toxicology evaluation, Soxhlet extraction in n-hexane or physiological saline for 24-72 hours is performed according to the ISO 10993 standard to reduce the extractable content to a safe level.

[0054] Example 2 Curing of photo-fluorosilicone acrylate composition #2: 1. Composition formulation: Bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane 45.00 wt% (22.50 g), TMPTA (trimethylolpropane triacrylate) 32.88 wt% (16.44 g), IBOMA 6.00 wt% (3.00 g), TCDMDA 8.00 wt% (4.00 g), UDMA 8.00 wt% (4.00 g), TPO-L 0.08 wt% (0.040 g), TEMPO 0.02 wt% (0.010 g), MEHQ 0.02 wt% (0.010 g).

[0055] 2. Composition curing: consistent with Example 1.

[0056] Example 3 Curing of Photo Fluoro Silicone Acrylate Composition #3: 1. Composition formulation: Bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane 45.00 wt% (22.50 g), TRIS 32.88 wt% (16.44 g), IBOMA 6.00 wt% (3.00 g), HDDA (1,6-hexanediol diacrylate) 8.00 wt% (4.00 g), UDMA 8.00 wt% (4.00 g), TPO-L 0.08 wt% (0.040 g), TEMPO 0.02 wt% (0.010 g), MEHQ 0.02 wt% (0.010 g).

[0057] 2. Composition curing: consistent with Example 1.

[0058] The cured optical elements of Examples 1-3 were each measured for oxygen permeability coefficient (Dk), glass transition temperature (Tg), flexural modulus (GPa), percent shrinkage on curing, and alpha 405 (cm -1 ).

[0059] The results of the testing are shown in Table 1 and Figures 1-2 . Table 1

[0060] It is to be noted that, in the present text, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0061] The above examples are merely used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A fluoro-silicone acrylate composition characterized in that, The fluorosilicone acrylate composition comprises the following components by total mass of the composition: fluorosilicone acrylate oligomer: 35-55, TRIS: 20-35, IBOMA: 2-12, TCDMDA: 5-12, UDMA: 2-10, TPO-L: 0.04-0.12, TEMPO: 0.005-0.03, MEHQ: 100-300 ppm.

2. The fluoro-silicone acrylate composition according to claim 1, characterized in that, The fluorosilicone acrylate oligomer has a viscosity of 2-4.

3. The fluoro-silicone acrylate composition according to claim 2, characterized in that, The fluorosilicone acrylate oligomer has a viscosity of 2.

4.

4. The fluoro-silicone acrylate composition of claim 1, wherein, The fluorosilicone acrylate oligomer has a molecular weight of 800-2000.

5. The fluoro-silicone acrylate composition according to claim 4, characterized in that, The fluorosilicone acrylate oligomer has a molecular weight of 1000-1200.

6. The fluoro-silicone acrylate composition according to any one of claims 1 to 5, characterized in that, The fluorosilicone acrylate oligomer comprises fluorosilicone diacrylate capped oligomer, fluorosilicone triacrylate modified oligomer, fluorosilicone-ether hybrid diacrylate; perfluoro polyether diacrylate (PFPE-DA), bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane (difunctional, Mn: 1000-1200) and / or PFPE-DA (difunctional, Mn: 900-1100).

7. The fluoro-silicone acrylate composition according to claim 6, characterized in that, The fluorosilicone acrylate oligomer is bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane.

8. The fluoro-silicone acrylate composition according to claim 7, characterized in that, The fluorosilicone acrylate composition comprises the following components by total mass of the composition: bis(methacryloxypropyl) terminated poly(methyl / 3,3,3-trifluoropropyl)siloxane: 35-55, TRIS: 20-35, IBOMA: 2-12, TCDMDA: 5-12, UDMA: 2-10, TPO-L: 0.04-0.12, TEMPO: 0.005-0.03, MEHQ: 100-300 ppm.

9. The fluoro-silicone acrylate composition according to claim 1, characterized in that, The fluorosilicone acrylate composition further comprises PFPE-DA.

10. Use of the fluorosilicone acrylate composition according to any one of claims 1-9 for the preparation of an optical element.

11. An optical element, characterized by, Prepared from the fluorosilicone acrylate composition according to any one of claims 1-9.

12. The optical element of claim 11, wherein, The optical element comprises convex lens, concave lens, right-angle prism, beam-splitting prism, band-pass filter, neutral density filter, diffraction grating and / or hologram recording medium.

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