Digital printing methods

Abstract

An aqueous treatment composition for an ITM (intermediate transfer member) of a printing system and a printing method, the printing method comprising the step of applying the treatment composition to a surface of the ITM, wherein the treatment composition comprises: at least 3 wt% quaternary ammonium salt, at least 1 wt% water-soluble polymer and at least 65 wt% water. A printing system is also disclosed, comprising an ITM and a treatment station to form a thin layer of a liquid treatment formulation on the surface of the ITM.

Description

[0001] This application is a divisional application of the Chinese national phase patent application with international application number PCT / IL2017 / 050616, international application date June 1, 2017, and invention name “Digital Printing Method”, which entered the Chinese national phase on January 25, 2019 and has application number 201780046259.1.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present disclosure claims priority to U.S. Patent Application Serial No. 62 / 343,123 filed on May 30, 2016 and U.S. Patent Application Serial No. 62 / 343,108 filed on May 30, 2016, both of which are incorporated herein by reference in their entirety. Technical Field

[0004] The present disclosure relates to a digital printing method, aqueous treatment formulations, and related kits and systems. Background Art

[0005] The following patent publications provide potentially relevant background material and are incorporated herein by reference in their entirety:

[0006] WO / 2017 / 009722 (published as PCT / IB2016 / 053049 filed May 25, 2016);

[0007] WO / 2016 / 166690 (published as PCT / IB2016 / 052120 filed April 4, 2016);

[0008] WO / 2016 / 151462 (published as PCT / IB2016 / 051560 filed on March 20, 2016);

[0009] WO / 2016 / 113698 (published as PCT / IB2016 / 050170 filed January 14, 2016);

[0010] WO / 2015 / 110988 (published as PCT / IB2015 / 050501 filed on January 22, 2015);

[0011] WO / 2015 / 036812 (published as PCT / IB2013 / 002571 filed September 12, 2013);

[0012] WO / 2015 / 036864 (published as PCT / IB2014 / 002366 filed September 11, 2014);

[0013] WO / 2015 / 036865 (published as PCT / IB2014 / 002395 filed September 11, 2014);

[0014] WO / 2015 / 036906 (published as PCT / IB2014 / 064277 filed on September 12, 2014);

[0015] WO / 2013 / 136220 (published as PCT / IB2013 / 051719 filed on March 5, 2013);

[0016] WO / 2013 / 132419 (published as PCT / IB2013 / 051717 filed on March 5, 2013);

[0017] WO / 2013 / 132424 (published as PCT / IB2013 / 051727 filed on March 5, 2013);

[0018] WO / 2013 / 132420 (published as PCT / IB2013 / 051718 filed on March 5, 2013);

[0019] WO / 2013 / 132439 (published as PCT / IB2013 / 051755 filed on March 5, 2013);

[0020] WO / 2013 / 132438 (published as PCT / IB2013 / 051751 filed on March 5, 2013);

[0021] WO / 2013 / 132418 (published as PCT / IB2013 / 051716 filed on March 5, 2013);

[0022] WO / 2013 / 132356 (published as PCT / IB2013 / 050245 filed January 10, 2013);

[0023] WO / 2013 / 132345 (published as PCT / IB2013 / 000840 filed on March 5, 2013);

[0024] WO / 2013 / 132339 (published as PCT / IB2013 / 000757 filed on March 5, 2013);

[0025] WO / 2013 / 132343 (published as PCT / IB2013 / 000822 filed on March 5, 2013);

[0026] WO / 2013 / 132340 (published as PCT / IB2013 / 000782 filed on March 5, 2013);

[0027] WO / 2013 / 132432 (published as PCT / IB2013 / 051743 filed on March 5, 2013);

[0028] Figure 1 1 is a flow chart of a conventional printing method, wherein an intermediate transfer member (ITM) is pretreated before an ink image is deposited thereon. In step S1, a treatment solution is applied to the surface of a hydrophobic ITM to pretreat the ITM surface. In step S9, droplets of an aqueous ink are jetted onto the pretreated ITM surface to form an ink image thereon. In step S13, the ink image on the ITM surface is dried. In step S17, the dried ink image is transferred to a substrate.

[0029] Embodiments of the present invention are directed to improved printing methods, improved ITMs (or portions thereof), and improved compositions for pre-treating ITMs prior to depositing droplets of aqueous ink. Summary of the invention

[0030] Aspects of the present invention relate to a printing method comprising: a. providing an intermediate transfer member (ITM) comprising a silicone-based release layer surface, the surface being sufficiently hydrophilic to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the silicone-based release layer surface is at most 60°; and (ii) a 10-second dynamic contact angle (DCA) of a distilled water droplet deposited on the silicone-based release layer surface is at most 108°; b. providing an aqueous treatment formulation comprising: i. at least 3 wt. % of a quaternary ammonium salt having a solubility in water of at least 5% at 25°C; ii. at least 1 wt. % of at least one water-soluble polymer having a solubility in water of at least 5% at 25°C; and iii. an aqueous carrier fluid, the water comprising at least 65 wt. % of the aqueous treatment formulation; the aqueous treatment formulation having the following properties: i. a static surface tension at 25°C in the range of 20 dynes / cm and 40 dynes / cm; ii. a 25°C dynamic viscosity of at least 10 cP; and iii. a 60°C evaporation load of at most 8:1 by weight; c. applying the aqueous treatment formulation to the surface of the silicone-based release layer of the ITM to form a wet treatment layer having a thickness of at most 0.8 μm thereon; d. subjecting the wet treatment layer to a drying treatment to form a dry treatment film from the wet treatment layer on the surface of the silicone-based release layer; e. depositing droplets of an aqueous ink onto the dry treatment film to form an ink image on the release layer surface of the silicone-based release layer; f. drying the ink image to leave an ink image residue on the surface of the silicone-based release layer; and g. transferring the ink image residue to the printing substrate by pressure contact between the ITM and the printing substrate.

[0031] Aspects of the present invention relate to a printing method comprising: a. providing an intermediate transfer member (ITM) comprising a silicone-based release layer surface, the surface being sufficiently hydrophilic to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the silicone-based release layer surface is at most 60°; and (ii) a 10-second dynamic contact angle (DCA) of a distilled water droplet deposited on the silicone-based release layer surface is at most 108°; b. providing an aqueous treatment formulation comprising: i. at least 3 wt. % of a quaternary ammonium salt having a solubility in water of at least 5% at 25°C; ii. at least 1 wt. % of at least one water-soluble polymer having a solubility in water of at least 5% at 25°C; and iii. an aqueous carrier fluid, the water comprising at least 65 wt. % of the aqueous treatment formulation; the aqueous treatment formulation having the following properties: i. a static surface tension at 25°C in the range of 20 dynes / cm and 40 dynes / cm; ii. a 25°C dynamic viscosity of at least 10 cP; and iii. a 60°C evaporation load of at most 8:1 by weight; c. applying an aqueous treatment formulation to the surface of the silicone-based release layer of the ITM to form a wet treatment layer thereon; d. subjecting the wet treatment layer to a drying treatment to form a dry treatment film from the wet treatment layer on the surface of the silicone-based release layer; e. depositing droplets of an aqueous ink onto the dry treatment film to form an ink image on the release layer surface of the silicone-based release layer; f. drying the ink image to leave an ink image residue on the surface of the silicone-based release layer; and g. transferring the ink image residue to the printing substrate by pressure contact between the ITM and the printing substrate.

[0032] Aspects of the present invention relate to a printing kit comprising: a. an intermediate transfer member (ITM) comprising a silicone-based release layer surface, the surface being sufficiently hydrophilic to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the silicone-based release layer surface is at most 60°; and (ii) a 10-second dynamic contact angle (DCA) of a distilled water droplet deposited on the silicone-based release layer surface is at most 108°; and b. an amount of an aqueous treatment formulation comprising: i. at least 3 weight percent of a quaternary ammonium salt having a solubility in water of at least 5% at 25°C; ii. at least 1 weight percent of at least one water-soluble polymer having a solubility in water of at least 5% at 25°C; and iii. an aqueous carrier fluid, The water comprises at least 65 wt % of the aqueous treatment formulation; the aqueous treatment formulation has the following properties: i. a static surface tension at 25°C in the range of 20 dynes / cm and 40 dynes / cm; ii. a dynamic viscosity at 25°C of at least 10 cP; and iii. a 60°C evaporative load of at most 8:1 by weight.

[0033] In some embodiments, provided aqueous treatment formulations have a 60°C evaporative loading of at most 6:1, at most 5:1, at most 4:1, at most 3.5:1, or at most 3:1, and optionally, at least 2:1, at least 2.2:1, or at least 2.5:1.

[0034] In some embodiments, the concentration of the quaternary ammonium salt in the provided aqueous treatment formulation is in the range of 3% to 15%; the concentration of the water-soluble polymer is in the range of 2.5% to 10%, or 2.5% to 8%, the 60°C evaporation load is in the range of 2.5:1 to 4:1, and the viscosity is at least 12 cP, and optionally, at least 14 cP or at least 16 cP.

[0035] In some embodiments, the aqueous treatment formulations provided have a total surfactant concentration of at least 6%, at least 7%, at least 8%, at least 9%, or at least 10%, and optionally, in the range of 6% to 40%, 6% to 30%, 6% to 20%, 7% to 30%, 7% to 20%, 7% to 15%, 8% to 25%, 8% to 20%, 8% to 15%, or 8% to 13%.

[0036] In some embodiments, the total concentration of organic solvents in provided aqueous treatment formulations is at most 3 wt%, at most 2 wt%, at most 1 wt%, or at most 0.5 wt%, or wherein the formulations are free of organic solvents.

[0037] In some embodiments, the total concentration of liquid hygroscopic agent in the provided aqueous treatment formulation is at most 1.5 wt%, at most 1 wt%, at most 0.5 wt%, at most 0.3 wt%, or at most 0.1 wt%, or wherein the aqueous treatment formulation contains no liquid hygroscopic agent.

[0038] In some embodiments, the quaternary ammonium salt of provided aqueous treatment formulations is an organic quaternary ammonium salt.

[0039] In some embodiments, the first carbon chain of the organic quaternary ammonium salt has at least 6 carbon atoms, and optionally, a length ranging from 6 to 20, 6 to 18, 8 to 20, or 8 to 18 carbon atoms.

[0040] In some embodiments, the second carbon chain of the organic quaternary ammonium salt has a length of at most 3 carbon atoms or at most 2 carbon atoms.

[0041] In some embodiments, the third carbon chain of the organic quaternary ammonium salt has a length of at most 3 carbon atoms, at most 2 carbon atoms, or 1 carbon atom.

[0042] In some embodiments, the organic quaternary ammonium salt is a cationic organic quaternary ammonium salt optionally having a sulfate or phosphate anion.

[0043] In some embodiments, the surface of the silicone-based release layer is sufficiently hydrophilic to satisfy at least one of the following properties: the receding contact angle of a drop of distilled water deposited on the surface of the silicone-based release layer is at most 60°.

[0044] In some embodiments, the surface of the silicone-based release layer is sufficiently hydrophilic that the 10-second dynamic contact angle (DCA) of a drop of distilled water deposited on the surface of the silicone-based release layer is at most 108°.

[0045] In some embodiments, the provided ITM includes a support layer and a release layer having the silicone-based release layer surface and a second surface, wherein the second surface is (i) opposite to the silicone-based release layer surface and (ii) attached to the support layer, the release layer is formed of an addition-cured silicone material, and the thickness of the release layer is at most 500 microns (μm).

[0046] In some embodiments, the release layer of the provided ITM consists essentially of, or contains at least 95% by weight, addition-cured silicone.

[0047] In some embodiments, the functional groups within the surface of the silicone-based release layer of the provided ITM comprise up to 3 weight percent of the addition-cured silicone material.

[0048] In some embodiments, a polyether glycol functionalized polydimethyl silicone is impregnated into the addition-cured silicone material of the provided ITM.

[0049] In some embodiments, the release layer of the provided ITM is adapted such that the polar groups of the ink receiving surface are oriented away from or opposite to the second surface.

[0050] In some embodiments, the surface hydrophobicity of the silicone-based release layer surface of the provided ITM is less than the bulk hydrophobicity of the cured silicone material within the release layer, the surface hydrophobicity being characterized by a receding contact angle of a distilled water droplet on the ink receiving surface, and the bulk hydrophobicity being characterized by a receding contact angle of a distilled water droplet disposed on an inner surface formed by exposing an area of ​​the cured silicone material within the release layer to form an exposed area.

[0051] In some embodiments, the aqueous treatment formulation is applied to the surface of the silicone-based release layer such that the thickness of the wet treatment layer is at most 0.6 μm, at most 0.5 μm, or at most 0.4 μm.

[0052] In some embodiments, the wet-processed layer is formed and / or thinned by pushing a circular surface toward the ITM, or vice versa, wherein: i. the circular surface has a radius of curvature of at most 2 mm, or at most 1.5 mm, or at most 1.25 mm, or at most 1 mm, and / or ii. the pushing is performed in the cross-printing direction at a force density of at least 250 g / cm, or at least 350 g / cm, or at least 400 gm / cm and / or at most 1 kg / cm, or at most 750 g / cm, or at most 600 g / cm, and / or iii. the pushing is performed by applying a pressure between and the ITM, the pressure being at least 0.1 bar, or at least 0.25 bar, or at least 0.35 bar, or at least 0.5 bar, and optionally, at most 2 bar, or at most 1.5 bar, or at most 1 bar.

[0053] In some embodiments, the wet treatment layer is formed and / or thinned by a fixed applicator and / or a circular surface that directly or indirectly applies force to the running ITM to (i) deform the ITM to induce depressions therein; and (ii) establish a velocity gradient of the flowing aqueous treatment formulation that is formed in the normal direction of the ITM and in the gap region between the ITM and the fixed applicator.

[0054] In some embodiments, the magnitude of the velocity gradient is at least 10 6 sec -1 , or at least 2×10 6 sec -1 .

[0055] In some embodiments, the aqueous treatment formulation is applied to at least one or more portions of the ITM traveling at a speed of at least 1 m / s, or at least 1.5 m / s, or at least 2 m / s to form a wet treatment layer thereon.

[0056] In some embodiments, the formation of the wet treatment layer or the thinning thereof comprises forcing the aqueous treatment formulation to flow, thereby establishing a velocity gradient in the normal direction of the ITM, the velocity gradient having a magnitude of at least 10 6 sec -1 or at least 2×10 6 sec -1 .

[0057] In some embodiments, the release surface of the ITM has a Shore A hardness of at most 50, or at most 45, or at most 40, or at most 35, or at most 30, or at most 25, or at most 20, or at most 15.

[0058] In some embodiments, the drying process of the wet treatment layer is rapid enough so that the viscosity of the aqueous treatment formulation increases rapidly enough to inhibit surface tension driven beading, thereby resulting in a dry treatment film having a smooth upper surface.

[0059] In some embodiments, the smooth upper surface of the dried treated film is characterized by an average roughness R a It is at most 12 nanometers, or at most 10 nanometers, or at most 9 nanometers, or at most 8 nanometers, or at most 7 nanometers, or at most 5 nanometers.

[0060] In some embodiments, drying of the treatment solution is performed quickly enough to prevent beading, and leaves a continuous hydrophilic and cohesive polymer treatment film having a thickness of at most 200 nm, or at most 150 nm, or at most 120 nm, or at most 100 nm, or at most 80 nm, or at most 70 nm, or at most 60 nm, or at most 50 nm, or at most 40 nm, or at most 30 nm.

[0061] In some embodiments, the thickness of the dried process film of the deposited aqueous ink droplets is at most 200 nm, or at most 120 nm, or at most 100 nm, or at most 80 nm.

[0062] In some embodiments, the thickness of the dried process film of the deposited aqueous ink droplets is at least 15 nm, or at least 20 nm, or at least 30 nm.

[0063] In some embodiments, the dry process film is continuous across a rectangle of the release surface of the ITM, wherein the rectangle has a width of at least 10 cm and a length of at least 10 m.

[0064] In some embodiments, the dried process film occupies at least 50%, or at least 75%, or at least 90%, or at least 95%, at least 95%, or at least 99%, or 100% of the area of ​​the rectangle, and the thickness of the dried process film deviates from the average thickness value within the rectangle by no more than 50%, or no more than 40%, or no more than 30%.

[0065] In some embodiments, during the drying process of the wet-process layer, its dynamic viscosity increases at least 1000-fold within a time period of up to 250 milliseconds.

[0066] In some embodiments, the liquid content of the dried process membrane is at most 10 wt%, or at most 7.5 wt%, or at most 5 wt%, or at most 2.5 wt%, or at most 1.5 wt%, or at most 1 wt%.

[0067] In some embodiments, droplets of aqueous ink are deposited onto the dry process membrane by inkjetting.

[0068] In some embodiments, ink image residues are transferred to the printed substrate along with non-printed areas of the dried treatment film.

[0069] In some embodiments, the thickness of the dried processed film is at most 120 nm.

[0070] In some embodiments, the dry treat film has sufficient cohesion such that during transfer of the ink image residue, the dry treat film completely separates from the ITM and transfers to the printed substrate along with the dried ink image in both printed and non-printed areas.

[0071] In some embodiments, the transfer of the ink image residue is performed at a transfer temperature of at most 100°C or at most 90°C.

[0072] In some embodiments, solids (eg, nanopigments and / or resins) of the aqueous ink migrate into the bulk of the dried process film to interact with (eg, bind to) the quaternary ammonium salt residing within the dried process film (eg, to facilitate droplet spreading).

[0073] In some embodiments, the solids of the aqueous ink migrate into the bulk of the dry process membrane to interact with the quaternary ammonium salt resident within the dry process membrane to facilitate droplet spreading.

[0074] In some embodiments, the method is performed so that: i. an ink dot set IDS of ink substrate-resident ink dots is formed; ii. a plurality of droplets DP of the aqueous ink droplets deposited onto the ITM-resident dry treatment film form an ink dot set IDS of ink substrate-resident ink dots, thereby making a corresponding relationship between: A. each given droplet of the plurality of droplets DP and B. each given substrate-resident ink droplet of the ink dot set, so that the given droplet is generated and / or evolves into the given substrate-resident ink dot; iii. during deposition, whenever a droplet of the plurality of droplets collides with the dry treatment film on the ITM, the kinetic energy of the colliding droplet deforms the droplet; iv. the maximum impact radius of each of the deformed droplets on the surface of the ITM has a maximum impact radius value R 最大冲击 v. After the impact, the physical and chemical forces spread the deformed droplet, thereby making each ink dot of the substrate-residing ink dot set IDS have a dry dot radius R 在基材上的干点 ; vi. For each droplet in the plurality of droplets and the corresponding ink dot of the ink dot set IDS, at A. the substrate stationary dry dot radius R 基材上的干点 ; and B. the maximum impact radius value R of the deformed droplet 最大冲击 The ratio between them is at least 1.1.

[0075] In some embodiments, the method is performed so that: i. the plurality of droplets DP deposited onto the ITM resident dry treatment film produces a set of substrate resident ink dots IDS (i.e., fixedly adhered to the top substrate surface), each droplet of the plurality of droplets DP corresponds to a different respective substrate resident ink dot of the ink dot set IDS; ii. each ink droplet of the plurality of droplets DP is deposited onto the substrate according to the ejection parameters; iii. the ejection parameters together with the physicochemical properties of the ink droplets of the plurality of droplets DP jointly define the inkjet paper dot radius R 直接喷射到喷墨纸上 , theoretically, it is the radius of the ink dot obtained by directly jetting the ink droplet onto the inkjet paper instead of jetting onto the drying treatment film; and iv. (A) the dry dot radius R of the ink dot of the ink dot set IDS 在基材上的干点 and (B) inkjet paper dot radius R 直接喷射到喷墨纸上，理论 The ratio between them is at least 1.1.

[0076] In some embodiments, the cardinality of the set of dots is at least 5, or at least 10, or at least 20, or at least 50, or at least 100, and each dot of the set of dots is different on the substrate.

[0077] In some embodiments, the ink dots of the ink dot set are contained within a square geometric projection projected onto the printing substrate, each ink dot of the ink dot set is fixedly adhered to the surface of the printing substrate, and all of the ink dots within the square geometric projection are counted as separate members of the ink dot set IDS.

[0078] In some embodiments, the method is performed so that: i. an ink dot set IDS of ink substrate-resident ink dots is formed; ii. the cardinality of the ink dot set is at least 5, or at least 10, or at least 20, or at least 50, or at least 100, and each ink dot of the ink dot set is different on the substrate; iii. the ink dots of the ink dot set are contained within a square geometric projection projected onto the printing substrate, each ink dot of the ink dot set is fixedly adhered to the surface of the printing substrate, and all the ink dots within the square geometric projection are counted as separate members of the ink dot set IDS; iv. each of the ink dots contains at least one colorant dispersed in an organic polymer resin, and each of the dots has an average thickness of less than 2,000 nm and a diameter of 5 to 300 microns; v. each of the ink dots has a substantially convex shape, wherein the deviation from convexity (DC 点 ) is defined by the following formula: DC 点= 1-AA / CSA, AA is the calculated projected area of ​​the dot, the area being disposed approximately parallel to the printing substrate; and CSA is the surface area of ​​the convex shape that minimally defines the contour of the projected area; and vi. the average deviation of the convexity from the set of dots (DC 点平均值 ) is at most 0.05, at most 0.04, at most 0.03, at most 0.025, at most 0.022, at most 0.02, at most 0.018, at most 0.017, at most 0.016, at most 0.015, or at most 0.014.

[0079] In some embodiments, the aqueous treatment formulation is applied to at least one or more portions of the ITM traveling at a speed of at least 1 m / s, or at least 1.5 m / s, or at least 2 m / s to form a wet treatment layer thereon.

[0080] In some embodiments, the method is performed such that the water-soluble polymer concentration of the water-soluble polymer in the aqueous treatment formulation is at most 10 wt%, or at most 8 wt%, or at most 6 wt%, or at most 5 wt%.

[0081] An aqueous treatment formulation for use with an intermediate transfer member of a printing system, the aqueous treatment formulation comprising: (a) a first surfactant composition comprising a first surfactant, the first surfactant comprising a quaternary ammonium salt having a solubility in water of at least 5% at 25°C; (b) at least 1 weight percent of a water-soluble polymer having a solubility in water of at least 5% at 25°C; and (c) an aqueous carrier liquid, the water comprising at least 65 weight percent of the treatment formulation; wherein the concentration of the quaternary ammonium salt in the aqueous treatment formulation is at least 3 weight percent; and wherein the treatment formulation has (i) a static surface tension at 25°C in the range of 20 dynes / cm and 40 dynes / cm, (ii) a 60°C evaporative load of up to 8:1 by weight and (iii) a 25°C viscosity in the range of 10 cP to 100 cP.

[0082] In some embodiments, the solubility of the quaternary ammonium salt is at least 7%, at least 10%, at least 15%, or at least 20%, optionally, at most 50%, at most 40%, or at most 35%, or further optionally, in the range of 5% to 40%, 5% to 30%, 5% to 25%, 7% to 35%, 10% to 35%, 12% to 35%, or 15% to 35%.

[0083] In some embodiments, the concentration of the quaternary ammonium salt in the aqueous treatment formulation is at least 4%, at least 5%, at least 6%, or at least 7%, optionally, up to 30%, up to 25%, or up to 20%, or further optionally, in the range of 2% to 30%, 3% to 30%, 4% to 30%, 4% to 20%, 5% to 25%, 6% to 25%, 6% to 20%, or 7% to 20%.

[0084] In some embodiments, the concentration of the water-soluble polymer in the aqueous treatment formulation is at least 1.5 wt%, or at least 2 wt%, at least 2.5 wt%, at least 3 wt%, or at least 3.5 wt%, optionally, up to 10 wt%, or up to 9 wt%, or up to 8 wt%, or up to 7 wt%, or up to 6 wt%, or further optionally, between 1.5 wt% and 20 wt%, or between 2 wt% and 10 wt%, between 2 wt% and 8 wt%, between 2 wt% and 7 wt%, between 2.5 wt% and 10 wt%, between 2.5 wt% and 8 wt%, between 2.5 wt% and 7 wt%, between 2.5 wt% and 6 wt%, or between 3.5 wt% and 3.5 wt%. wt %, 3.5 wt % to 6 wt %, or 4 wt % to 6 wt %.

[0085] In some embodiments, the solubility of the water-soluble polymer in water is at least 7%, at least 10%, at least 12%, or at least 15%.

[0086] In some embodiments, the water-soluble polymer is selected from the group consisting of polyvinyl alcohol, water-soluble cellulose, polyvinyl pyrrolidone (PVP), polyethylene oxide, polyethylene imine, and water-soluble acrylate.

[0087] In some embodiments, wherein the 60°C evaporative duty is at most 6:1, or at most 5:1, at most 4:1, at most 3.5:1, or at most 3:1, and optionally, at least 2:1, at least 2.2:1, or at least 2.5:1.

[0088] In some embodiments, a second surfactant selected to reduce the static surface tension of the aqueous treatment formulation is also included, wherein the second surfactant is optionally a silicone polyether, and the second surfactant optionally has a concentration in the formulation of at least 1 wt%, at least 1.5 wt%, at least 2 wt%, at least 2.5 wt%, or at least 3 wt%, optionally, at most 15 wt%, at most 12 wt%, at most 10 wt%, at most 8 wt%, or at most 7 wt%, or further optionally, in the range of 1.5 wt% to 13 wt%, 1.5 wt% to 10 wt%, 2 wt% to 13 wt%, 2 wt% to 10 wt%, 2.5 wt% to 13 wt%, 2.5 wt% to 10 wt%, or 3 wt% to 10 wt%.

[0089] In some embodiments, the treatment formulation further comprises a water absorbent disposed within the carrier liquid at least within the range of 25°C to 60°C; thus, the water absorbent acts as a water absorbent when the aqueous treatment solution is evaporated to form a solid film.

[0090] In some embodiments, a water absorbent is further included in the carrier liquid, the water absorbent being solid in a pure state at least in the range of 25°C to 60°C; therefore, when the aqueous treatment solution is evaporated to form a solid film, the water absorbent acts as a water absorbent.

[0091] In some embodiments, the water absorbent has a concentration of 1% to 25%, 1% to 15%, 1% to 10%, 2.5% to 20%, 2.5% to 12%, 3% to 15%, 3% to 12%, 3% to 10%, or 3.5% to 12%.

[0092] In some embodiments, the concentration of the quaternary ammonium salt is in the range of 3% to 15%; the concentration of the water-soluble polymer is in the range of 2.5% to 10%, or 2.5% to 8%, or 2.5% to 7%, or 2.5% to 6%, the 60°C evaporation load is in the range of 2.5:1 to 4:1, and the viscosity is at least 12 cP, and optionally, at least 14 cP or at least 16 cP.

[0093] In some embodiments, the static surface tension is in a range of 25 dynes / cm to 36 dynes / cm.

[0094] In some embodiments, the water absorbing agent has a concentration of 2.5% to 10%.

[0095] In some embodiments, the aqueous treatment formulation has a total surfactant concentration of at least 6%, at least 7%, at least 8%, at least 9%, or at least 10%, and optionally, in the range of 6% to 40%, 6% to 30%, 6% to 20%, 7% to 30%, 7% to 20%, 7% to 15%, 8% to 25%, 8% to 20%, 8% to 15%, or 8% to 13%.

[0096] In some embodiments, all components of the aqueous treatment formulation are completely dissolved.

[0097] In some embodiments, the total concentration of organic solvents in the aqueous treatment formulation is at most 3 wt%, at most 2 wt%, at most 1 wt%, or at most 0.5 wt%, or wherein the formulation contains no organic solvents.

[0098] In some embodiments, the total concentration of liquid hygroscopic agent in the aqueous treatment formulation is at most 1.5 wt%, at most 1 wt%, at most 0.5 wt%, at most 0.3 wt%, or at most 0.1 wt%, or wherein the aqueous treatment formulation contains no liquid hygroscopic agent.

[0099] In some embodiments, the quaternary ammonium salt is an organic quaternary ammonium salt.

[0100] In some embodiments, the first carbon chain of the organic quaternary ammonium salt has at least 6 carbon atoms, and optionally, a length ranging from 6 to 20, 6 to 18, 8 to 20, or 8 to 18 carbon atoms.

[0101] In some embodiments, the second carbon chain of the organic quaternary ammonium salt has a length of at most 3 carbon atoms or at most 2 carbon atoms.

[0102] In some embodiments, the third carbon chain of the organic quaternary ammonium salt has a length of at most 3 carbon atoms, at most 2 carbon atoms, or 1 carbon atom.

[0103] In some embodiments, the organic quaternary ammonium salt is a cationic organic quaternary ammonium salt optionally having a sulfate or phosphate anion.

[0104] In some embodiments, the polyethyleneimine comprises at most 0.8%, 0.6%, 0.4%, or 0.3%, or 0.2%, or 0.1% by weight of the formulation, or wherein the polyethyleneimine comprises at most 30%, at most 20%, at most 15%, at most 10%, or at most 5% of the water-soluble polymer.

[0105] In some embodiments, the viscosity is at least 12 cP, at least 14 cP, or at least 16 cP, optionally, at most 90 cP, at most 80 cP, at most 70 cP, at most 60 cP, at most 55 cP, or at most 50 cP, and further optionally, in the range of 10 cP to 80 cP, 12 cP to 80 cP, 12 cP to 60 cP, 12 cP to 55 cP, or 14 cP to 60 cP.

[0106] In some embodiments, the water-soluble polymer is present in the aqueous treatment formulation at a concentration of at most 10 wt%, or at most 8 wt%, or at most 6 wt%, or at most 5 wt%.

[0107] In some embodiments, an ITM is provided that includes: (a) a support layer; and (b) a release layer having an ink receiving surface for receiving an ink image, and a second surface opposite the ink receiving surface, the second surface being attached to the support layer, the release layer being formed from an addition-cured silicone material, the release layer having a thickness of up to 500 micrometers (μm); and the ITM satisfies at least one of the following structural properties: (1) the total surface energy of the ink receiving surface is at least 2 mN / m, at least 3 mN / m, at least 4 mN / m, at least 5 mN / m, at least 6 mN / m, at least 8 mN / m, or at least 10 mN / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of the corresponding release layer to a standard aging process; (2) the total surface energy of the ink receiving surface is at least 4 mN / m, at least 6 mN / m, at least 8 mN / m, or at least 10 mN / m higher than the total surface energy of a hydrophobic ink receiving surface of a corresponding release layer prepared by standard air curing of a silicone precursor of the cured silicone material. The invention relates to a method for preparing a silicone material having a thermal conductivity of at least 10 mN / m, at least 12 mN / m, at least 14 mN / m, or at least 16 mN / m; (3) a receding contact angle of a distilled water droplet on the ink receiving surface that is at least 7°, at least 8°, at least 10°, at least 12°, at least 14°, at least 16°, at least 18°, or at least 20° lower than the receding contact angle of a distilled water droplet on the ink receiving surface of a corresponding release layer prepared by standard air curing of a silicone precursor of the cured silicone material; (4) a receding contact angle of a distilled water droplet on the ink receiving surface that is at least 5°, at least 6°, at least 7°, or at least 8° lower than the receding contact angle of a distilled water droplet on an aged surface produced by subjecting the ink receiving surface to a standard aging procedure; (5) the surface hydrophobicity of the ink receiving surface is less than the bulk hydrophobicity of the cured silicone material in the release layer, the surface hydrophobicity being characterized by a receding contact angle of a distilled water droplet on the ink receiving surface, the bulk hydrophobicity being characterized by a receding contact angle of a distilled water droplet disposed on an inner surface formed by exposing an area of ​​the cured silicone material in the release layer to form an exposed area; wherein the receding contact angle measured on the ink receiving surface is at least 7°, at least 8°, at least 10°, at least 12°, at least 14°, at least 15°, at least 16°, at least 17°, at least 18°, at least 19°, at least 20°, at least 21°, at least 22°, at least 23°, at least 24°, at least 25°, at least 26°, at least 27°, at least 28°, at least 29°, at least 30°, at least 31°, at least 32°, at least 33°, at least 34°, at least 35°, at least 36°, at least 37°, at least 38°, at least 39°, at least 40°, at least 41°, at least 42°, at least 43°, at least 44°, at least 45°, at least 46°, at least 47°, at least 48°, at least 49°, at least 50°, at least 51°, at least 52°, at least 53°, at least 54°, at least 55°, at least 56°, at least 57°, at least 58°, at least 59°, at least 60°, at least 61°, at least 62°, at least 63°, at least 64° at least 14°, at least 16°, at least 18°, or at least 20°; and (6) a receding contact angle of a distilled water drop on the ink receiving surface of at most 60°, at most 58°, at most 56°, at most 54°, at most 52°, at most 50°, at most 48°, at most 46°, at most 44°, at most 42°, at most 40°, at most 38°, or at most 36°.

[0108] In some embodiments, the addition-cured silicone material consists essentially of, or contains at least 95% by weight of, the addition-cured silicone.

[0109] In some embodiments, functional groups constitute at most 5 weight percent, at most 3 weight percent, at most 2 weight percent, or at most 1 weight percent of the addition-cured silicone material, or wherein the addition-cured silicone material is substantially free of the functional groups.

[0110] In some embodiments, a polyether glycol functionalized polydimethylsiloxane is impregnated in the addition-cured silicone material.

[0111] In some embodiments, the polyether glycol functional siloxane is impregnated into the addition-cured silicone material but does not form part of the covalent structure of the addition-cured silicone material.

[0112] An intermediate transfer member (ITM) for use with a printing system (for example, this can be an ITM of the 'provided ITM'), the ITM comprising: (a) a support layer; and (b) a release layer having an ink receiving surface for receiving an ink image, and a second surface opposite the ink receiving surface, the second surface being attached to the support layer, the release layer being formed of an addition-cured silicone material, the release layer having a thickness of up to 500 micrometers (μm); the ink receiving surface being adapted to satisfy at least one of the following structural properties: (i) a receding contact angle of a distilled water drop on the ink receiving surface of up to 60°; (ii) a 10 second dynamic contact angle (DCA) of up to 108° for a distilled water drop deposited on the ink receiving surface; and wherein the release layer has at least one of the following structural properties: (1) the addition-cured silicone material is essentially composed of, or contains at least 95% by weight of, the addition-cured silicone; and (2) functional groups constitute up to 3% by weight of the addition-cured silicone material.

[0113] In some embodiments, the receding contact angle is at most 58°, at most 56°, at most 54°, at most 52°, at most 50°, at most 48°, at most 46°, at most 44°, at most 42°, at most 40°, at most 38°, or at most 37°.

[0114] In some embodiments, in the provided ITM (i.e., printing method), functional groups constitute at most 2 wt%, at most 1 wt%, at most 0.5 wt%, at most 0.2 wt%, or at most 0.1 wt% of the addition-cured silicone material or the release layer surface, or the addition-cured silicone material (or the release layer surface) is substantially free of such functional groups. In some embodiments, a polyether glycol-functionalized polydimethylsiloxane is impregnated in the addition-cured silicone material.

[0115] In some embodiments, provided ITMs (ie, printing methods) have the following features: The polyether glycol functionalized siloxane is impregnated in the addition-cured silicone material but does not form part of the covalent structure of the addition-cured silicone material.

[0116] In some embodiments, a provided ITM (ie, printing method) has the following features: the thickness of the release layer is at most 500 μm, at most 100 μm, at most 50 μm, at most 25 μm, or at most 15 μm.

[0117] In some embodiments, provided ITMs (ie, printing methods) have the following features: The thickness of the release layer ranges from 1 μm to 100 μm, 5 μm to 100 μm, 8 μm to 100 μm, 10 μm to 100 μm, or 10 μm to 80 μm.

[0118] In some embodiments, provided ITMs (ie, printing methods) have the following features: The thickness of the support layer ranges from about 50 micrometers (μ) to 1000μ, 100μ to 1000μ, 100μ to 800μ, or 100μ to 500μ.

[0119] In some embodiments, the provided ITM (i.e., printing method) has the following features: The total surface energy of the ink-receiving surface is at least 2 J / m higher than the total surface energy of the modified ink-receiving surface produced by subjecting the ink-receiving surface of the corresponding release layer to a standard aging procedure. 2 , at least 3J / m 2 , at least 4J / m 2 , at least 5J / m 2 , at least 6J / m 2 , at least 8J / m 2 , or at least 10 J / m 2 .

[0120] In some embodiments, the provided ITM (i.e., printing method) has the following features: The total surface energy of the ink-receiving surface is at least 4 J / m greater than the total surface energy of the hydrophobic ink-receiving surface of the corresponding release layer prepared by standard air curing of the silicone precursor of the cured silicone material. 2 , at least 6J / m 2 , at least 8J / m 2 , at least 10J / m 2 , at least 12J / m 2 , at least 14J / m 2 , or at least 16 J / m 2 .

[0121] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: wherein the receding contact angle of a distilled water droplet on the ink receiving surface is at least 7°, at least 8°, at least 10°, at least 12°, at least 15°, at least 18°, or at least 20° lower than the receding contact angle of a distilled water droplet on the ink receiving surface of a corresponding release layer prepared by standard air curing of a silicone precursor of a cured silicone material.

[0122] In some embodiments, the receding contact angle of a distilled water drop on the ink-receiving surface is at least 5°, at least 6°, at least 7°, or at least 8° lower than the receding contact angle of a distilled water drop on an aged surface generated by subjecting the ink-receiving surface to a standard aging procedure.

[0123] In some embodiments, the surface hydrophobicity of the ink receiving surface is less than the bulk hydrophobicity of the cured silicone material within the release layer, the surface hydrophobicity being characterized by a receding contact angle of a distilled water drop on the ink receiving surface, and the bulk hydrophobicity being characterized by a receding contact angle of a distilled water drop disposed on an inner surface formed by exposing an area of ​​the cured silicone material within the release layer to form an exposed area.

[0124] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: the receding contact angle measured on the ink-receiving surface is at least 7°, at least 8°, at least 10°, at least 12°, at least 14°, at least 16°, at least 18°, or at least 20° lower than the receding contact angle measured on the exposed area.

[0125] In some embodiments, the receding contact angle of the distilled water drop on the ink receiving surface is at least 25°, at least 28°, at least 30°, at least 32°, at least 34°, or at least 36°, and further optionally, in the range of 25° to 60°, 28° to 60°, 30° to 60°, 30° to 60°, 30° to 55°, 30° to 50°, 32° to 60°, 32° to 55°, 32° to 44°, 35° to 60°, 35° to 55°, 36° to 44°, or 38° to 50°.

[0126] In some embodiments, the release layer is adapted such that the polar groups of the ink receiving surface are oriented away from or opposite to the second surface.

[0127] In some embodiments, the release layer is adapted such that when the ITM is in an operating mode, the ink receiving surface is exposed to a surrounding environment, and the polar groups of the ink receiving surface have an orientation toward or facing the surrounding environment.

[0128] In some embodiments, an ITM (ie, printing method) is provided having the following features: The ITM forms a component in a digital printing system.

[0129] In some embodiments, an ITM (ie, printing method) is provided having the following features: the support layer includes an elastomeric compliant layer attached to the second surface of the release layer, the elastomeric compliant layer adapted to closely follow the surface contour of the printing substrate onto which the ink image is impressed.

[0130] In some embodiments, an ITM (ie, printing method) is provided having the following features: The support layer includes a reinforcement layer attached to the compliant layer.

[0131] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: the release layer contains a total amount of functional groups in its silicone polymer matrix of up to 3 wt%, up to 2 wt%, up to 1 wt%, up to 0.5 wt%, up to 0.2 wt%, or essentially 0 wt%.

[0132] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: The release layer contains a total amount of up to 3 wt%, up to 2 wt%, up to 1 wt%, up to 0.5 wt%, up to 0.2 wt%, or essentially 0 wt% of functional groups selected from the group consisting of C=O, S=O, OH and COO in its silicone polymer matrix.

[0133] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: the release layer contains a total amount of up to 3 weight percent, up to 2 weight percent, up to 1 weight percent, up to 0.5 weight percent, up to 0.2 weight percent, or essentially 0 weight percent of functional groups selected from the group consisting of silane, alkoxy, amido and amido-alkoxy moieties in its silicone polymer matrix.

[0134] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: the release layer contains a total amount of up to 3 weight %, up to 2 weight %, up to 1 weight %, up to 0.5 weight %, up to 0.2 weight %, or essentially 0 weight % of functional groups selected from the group consisting of amines, ammonium, aldehydes, SO2, SO3, SO4, PO3, PO4 and COC in its silicone polymer matrix.

[0135] In some embodiments, an ITM (ie, printing method) is provided having the following features: The addition-cured silicone material has a structure composed of vinyl-functional silicone.

[0136] In some embodiments, an ITM (ie, printing method) is provided having the following features: The addition-cured silicone material comprises polar groups of the "MQ" type.

[0137] In some embodiments, provided ITMs (ie, printing methods) have the following characteristics: The total surface energy of the ink receiving surface is evaluated using the Owens-Wendt surface energy model.

[0138] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: The 10 second DCA is at most 108°, at most 106°, at most 103°, at most 100°, at most 96°, at most 92°, or at most 88°, optionally, at least 60°, at least 65°, at least 70°, at least 75°, at least 78°, at least 80°, at least 82°, at least 84°, or at least 86°, and further optionally, in the range of 60° to 108°, 65° to 105°, 70° to 105°, 70° to 100°, 70° to 96°, 70° to 92°, 75° to 105°, 75° to 100°, 80° to 105°, 80° to 100°, 85° to 105°, or 85° to 100°.

[0139] In some embodiments, the provided ITM (i.e., printing method) has the following characteristics: the ink receiving surface is suitable for, for the distilled water droplet deposited on the ink receiving surface, the difference between the 70 second dynamic contact angle (DCA) and the 10 second DCA is at least 7°, at least 8°, at least 10°, or at least 12°, optionally, at most 25°, at most 22°, at most 20°, at most 18°, or at most 17°, and further optionally, between 6° and 25°, 6° and 22°, 6° and 20°, 6° and 18°, 6° and 17°, 7° and 25°, 7° and 20°, 7° and 17°, 8° and 25°, 8° and 22°, 18° and 20°, 8° and 18°, 8° and 17°, 10° and 15°, 11° and 12°, 12° and 15°, 13° and 15°, 14° and 15°, 15° and 16°, 16° and 17°, 17° and 18°, 18° and 19°, 19° and 20°, 21° and 22°, 23° and 24°, 25° and 26°, 27° and 28°, 29° and 30°, 29° and 31°, 29° and 32°, 20° and 21°, 21° and 25°, 22° and 25°, 23° and 25°, 24° and 28°, 29° and 31°, 21° and 29°, 29° and 31°, 2 to 25°, 10° to 22°, 10° to 20°, 10° to 18°, or 10° to 17°.

[0140] In some embodiments, the ink receiving surface is suitable for the 70 second DCA of at most 92°, at most 90°, at most 88°, at most 85°, at most 82°, at most 80°, at most 78°, at most 76°, at most 74°, or at most 72°, optionally, at least 55°, at least 60°, at least 65°, or at least 68°, and further optionally, in the range of 55° to 92°, 55° to 90°, 55° to 85°, 55° to 80°, 65° to 92°, 65° to 90°, 65° to 85°, 65° to 80°, 68° to 85°, 68° to 80°, 70° to 92°, 70° to 90°, 70° to 85°, or 70° to 80°.

[0141] According to various aspects of the present invention, a printing system is provided, comprising: a. an intermediate transfer member (ITM) comprising a flexible endless belt mounted on a plurality of guide rollers; b. an image forming station configured to form an ink image on a surface of the ITM, wherein a first guide roller and a second guide roller are arranged upstream and downstream of the image forming station to define an upper stroke and a lower stroke through the image forming station; b. an imprinting station through which the lower stroke of the ITM passes, the imprinting station being arranged downstream of the image forming station and configured to transfer the ink image from the surface of the ITM to a substrate; and d. a treatment station disposed downstream of the imprinting station and upstream of the image forming station for forming a uniform thin layer of a liquid treatment formulation on the surface of the ITM during its lower stroke, the treatment station comprising: i. a coater for coating the ITM with the liquid treatment formulation; and ii. a coating thickness adjustment assembly for removing excess liquid to leave only a desired uniform thin layer of the treatment formulation, the coating thickness adjustment assembly comprising a rounded tip facing the surface of the ITM during the lower stroke.

[0142] In some embodiments, the rounded tip is the tip of a spatula.

[0143] In some embodiments, the scraper is oriented normal to the ITM surface.

[0144] In some embodiments, the rounded tip is pushed toward the ITM surface and / or vice versa.

[0145] In some embodiments, the rounded tip is pushed toward the ITM surface by a backing roller having a soft outer surface and / or vice versa.

[0146] In some embodiments, (i) a backing roller is disposed inside the closed loop of the endless belt and positioned opposite the blade and / or (ii) the backing roller and rounded tip are disposed on opposite sides of the lower stroke of the ITM.

[0147] In some embodiments, the outer surface of the backing roll has one or more of the following properties: (i) elastic; (ii) zero memory; (iii) maintains its soft outer surface over a range of temperatures; (iv) is constructed of polyurethane.

[0148] In some embodiments, the difference between the maximum and minimum of the temperature range is at least 10°C, or at least 20°C, or at least 50°C and / or the average of the temperature range is between 50°C and 120°C.

[0149] In some embodiments, the backing roll has a compressible surface that is compressed when the rounded tip is pushed toward the ITM surface and / or vice versa, thereby causing the rounded tip along with the ITM to penetrate into the compressible surface of the backing roll at a predetermined penetration depth.

[0150] In some embodiments, the penetration depth is at least 1 mm, or at least 2 mm and / or at most 5 mm, or at most 4 mm, or at most 3 mm in magnitude.

[0151] In some embodiments, the scraper extends across substantially the entire width of the ITM.

[0152] In some embodiments, the length of the scraper (measured in the cross-printing direction) is at least 10 cm or at least 30 cm, and optionally, at least 50 cm, at least 70 cm, or at least 100 cm, and optionally at most 250 cm, at most 200 cm, or at most 150 cm.

[0153] In some embodiments, the length of the doctor blade (measured in the cross-print direction) ranges from 50 to 250 cm, 70 to 250 cm, 100 to 250 cm, 70 to 200 cm, 70 to 150 cm, or 100 to 200 cm.

[0154] In some embodiments, when the round tip is pushed toward the ITM surface and / or vice versa, the round tip is thereby caused to penetrate into the ITM at a specific penetration depth.

[0155] In some embodiments, the rounded tip is pushed toward the ITM and / or vice versa against a liquid solution disposed in a gap between the rounded tip and a portion of the ITM surface facing the rounded tip, in a force balance, thereby keeping the gap constant.

[0156] In some embodiments, the size of the gap regulates the thickness of the desired uniform thin layer of treatment formulation.

[0157] In some embodiments, the ratio between the gap and the thickness of the desired uniform thin layer is at least 0.1, or at least 0.25, or at least 0.5, and / or at most 10, or at most 4, or at most 2.

[0158] In some embodiments, (i) the size of the gap is at most 2 microns, or at most 1 micron, or at most 0.8 microns, or at most 0.6 microns, and / or (ii) the ratio between the size of the gap and the penetration depth of the round tip through the ITM surface is at most 0.01, or at most 0.005, or at most 0.001, or at most 0.0005.

[0159] In some embodiments, the penetration depth is set to a set point value, and the magnitude of the pushing force is adjusted to maintain the penetration depth at the set point value.

[0160] In some embodiments, the radius of curvature of the rounded scraper tip is at most 2 mm, or at most 1.5 mm, or at most 1.25 mm, or at most 1 mm.

[0161] In some embodiments, the coating machine used to coat the ITM is selected from (i) a spray device and (ii) a wet tray positioned below the lower stroke of the ITM in which a quantity of liquid treatment formulation is placed.

[0162] In some embodiments, the system includes a cleaning station positioned downstream of the imprinting station and upstream of the conditioning station for removing residual material remaining on the surface of the ITM after the ink image has been transferred to the substrate.

[0163] In some embodiments, the scraper blade is one of a plurality of scrapers mounted on a circumference of a turret that is rotatable to facilitate replacement of the scraper blade that is urged toward the surface.

[0164] In some embodiments, the spacing of the blades on the circumference of the turret is such that during rotation of the turret to change a doctor blade, the blade being replaced does not cease operation before the replacement blade becomes operational.

[0165] In some embodiments, a blade cleaning device is provided adjacent to the turret to remove any deposits adhering to the currently inactive blade.

[0166] In some embodiments, a blade cleaning device is provided adjacent to the turret to remove any deposits adhering to the currently inactive blade.

[0167] In some embodiments, the cleaning device is a rotating brush.

[0168] According to various aspects of the present invention, a printing method is provided, which includes: a. providing an aqueous ink, an aqueous treatment formulation, and an intermediate transfer member (ITM) having a release surface; b. applying the aqueous treatment formulation to the release surface of the ITM to form a wet treatment layer thereon; c. subjecting the wet treatment layer to a drying process to form a dry treatment film from the wet treatment layer and on the ITM; d. depositing aqueous ink droplets onto the dry treatment film to form an ink image thereon; e. drying the ink image to leave an ink image residue on the release surface of the ITM; and f. transferring the ink image residue to a printed substrate through pressure contact between the ITM and the substrate.

[0169] In some embodiments, ink image residues are transferred to the printed substrate along with non-printed areas of the dried treatment film.

[0170] In some embodiments, during and / or immediately after transfer, the drying process film mechanically connects and / or bonds the non-printed areas to the ink image residue.

[0171] In some embodiments, the dry process film is continued over a plurality of different substrate-residual ink dots immediately following the ink image residue.

[0172] In some embodiments, at least the release surface of the ITM has a Shore A hardness of at most 50, or at most 45, or at most 40, or at most 35, or at most 30, or at most 25, or at most 20, or at most 15.

[0173] In some embodiments, the ITM is in the form of an endless belt mounted on a plurality of rollers, and the wet treatment layer is formed by applying pressure (eg, in a normal direction) to the surface of the ITM at an inter-roll location between upstream and downstream rollers.

[0174] In some embodiments, (i) the aqueous treatment formulation is applied to the ITM while the ITM is in operation, whereby at least a portion or portions thereof are applied at a speed of at least 0.5, or at least 1, or at least 1.5, or at least 2, or at least 2.5, or at least 3 m / s, optionally at most 5.5 m / s, at most 5.0 m / s, at most 4.5 m / s, at most 4.0 m / s, or at most 3.8 m / s, and typically at a speed of between 0.5 and 5 m / s, 1 and 5 m / s, 1 and 4.5 m / s, 1 and 4 m / s, 1.5 and 5 m / s, 1.5 and 4.5 m / s, 1.5 and 4 m / s, 2 and 5 m / s, or at least 3.8 m / s. sec, 2 to 4.5 m / sec, 2.5 to 4.5 m / sec, or 3 to 4.5 m / sec, and (ii) applying an aqueous treatment formulation to one or more moving portions of the ITM to form a wet treatment layer thereon.

[0175] In some embodiments, the wet processing layer is formed by applying force to the ITM from a highly rounded surface having a radius of curvature of at most 5 mm, or at most 3 mm, or at most 2.5 mm, or at most 2 mm, or at most 1.75 mm, or at most 1.5 mm, or at most 1.25 mm, or at most 1 mm.

[0176] In some embodiments, the highly rounded surface is the surface of a scraper.

[0177] In some embodiments, the scraper is oriented in the cross-print direction and pushes against the ITM with a force density of at least 250 g / cm, or at least 350 g / cm, or at least 400 gm / cm, and / or at most 1 kg / cm, or at most 750 g / cm, or at most 600 g / cm in the cross-print direction.

[0178] In some embodiments, the scraper blade is formed of a wear resistant material having a Brinell hardness exceeding 100.

[0179] In some embodiments, the scraper is smooth and / or has a regular cylindrical surface.

[0180] In some embodiments, the surface roughness RA of the scraper is at most a few micrometers, or at most 1 micrometer, or at most 0.5 micrometer.

[0181] In some embodiments, the scraper blade is one of a plurality of scrapers mounted on a turret that is rotatable to allow for rapid replacement of the scraper blade that interacts with the surface of the ITM.

[0182] In some embodiments, the spacing of the blades on the turret is such that during rotation of the turret to change a doctor blade, the blade being replaced does not cease interacting with the ITM before the replacement blade begins interacting with the ITM.

[0183] In some embodiments, a cleaning device such as a rotating brush is disposed adjacent to the turret to the circular edge of at least one scraper that is not currently interacting with the ITM.

[0184] In some embodiments, prior to applying the aqueous treatment solution to the release surface of the ITM, the release surface of the ITM is washed to remove any treatment film remaining on the release surface after completion of a previous printing cycle.

[0185] In some embodiments, washing of the release surface of the ITM is performed using an aqueous treatment solution to dissolve any dried treatment film on the release layer.

[0186] In some embodiments, the thickness of the wet-processing layer is at most 2μ, or at most 1.5μ, or at most 1μ, or at most 0.9μ, or at most 0.8μ, or at most 0.7μ, or at most 0.6μ, or at most 0.5μ, or at most 0.5μ, or at most 0.4μ, or at most 0.3μ, or at most 0.2μ, or at most 0.15μ.

[0187] In some embodiments, the wet-process layer has a uniform thickness.

[0188] In some embodiments, in a rectangle having a width of at least w cm and a length of at least 1 cm, the entire rectangle is covered by a wet-processed film, such that the thickness of the wet-processed film deviates by no more than 50%, or no more than 40%, or no more than 30%, or no more than 20%, or no more than 10%, or no more than 5%, or no more than 2.5%, or no more than 1% from the average thickness value within the rectangle, wherein (i) the value of w is at least 10, or at least 20, or at least 30, and / or at most 100, or at most 80, or at most 60, and (ii) the value of l is at least 50, or at least 100, or at least 250, or at least 500, or at least 1000.

[0189] In some embodiments, the formation of the thin wet treatment layer comprises generating a velocity gradient of the aqueous treatment solution at a location of strong velocity gradient (IVG) that is (A) generally displaced from the exfoliation surface of the ITM (e.g., at most 3 microns, or at most 2 microns, or at most 1 micron) and / or (B) between the applicator and the exfoliation surface of the applicator; and ii. at the IVG location, the magnitude of the velocity gradient is equal to or exceeds a VG value that is at least 10 6 sec -1 , or at least 2×10 6 sec -1 , or at least 4×10 6 sec -1 , or at least 5×10 6 sec-1, or at least 7.5×10 6 sec -1 , or at least 10 7 sec -1 , or at least 2×10 7 sec -1 , or at least 4×10 7 sec -1 , or at least 5×10 7 sec -1 , or at least 7.5×10 7 sec -1 .

[0190] In some embodiments, the speed gradient is positioned along the printing direction such that: i. at an upstream position upstream of the IVG position, the maximum speed gradient is at most x% of the speed gradient value at the IVG position; ii. at a downstream position downstream of the IVG position, the maximum speed gradient is at most x% of the speed gradient value at the IVG position; iii. the value of x is at most 50, or at most 30, or at most 20, or at most 10; and / or iv. the upstream position and the downstream position are each displaced from the IVG position along the printing direction by at most 2 cm, or at most 1.5 cm, or at most 1.25 cm, or at most 1 cm, or at most 9 mm, or at most 8 mm, or at most 7.5 mm, or at most 7 mm, or at most 6 mm, or at most 5 mm.

[0191] In some embodiments, drying of the treatment solution is performed quickly enough to prevent beading and leave a continuous hydrophilic and cohesive polymer treatment film having a thickness (e.g., substantially uniform thickness) of at most 200 nm, or at most 150 nm, or at most 120 nm, or at most 100 nm, or at most 80 nm, or at most 70 nm, or at most 60 nm, or at most 50 nm, or at most 40 nm, or at most 30 nm.

[0192] However, in various embodiments, even if the dry process film is extremely thin, it is thicker than a single layer or a single layer type structure. Thus, in various embodiments, the thickness of the dry process layer can be at least 20 nanometers, or at least 30 nanometers, or at least 40 nanometers, or at least 50 nanometers. In some embodiments, providing such a 'body' (i.e., a minimum thickness feature - for example, together with one or more other features described below) helps to form a dry process film with cohesiveness and / or elasticity - this can be used in step S117, where it is desired that the dry process film (i.e., at that stage, carrying the dried ink image thereon) maintains its structural integrity when transferred from the ITM to the substrate.

[0193] In some embodiments, the thickness of the dried process film on which the ink droplets are deposited is at most 200 nm, or at most 100 nm, or at most 50 nm, or at most 30 nm.

[0194] In some embodiments, the thickness of the dried process film on which the ink droplets are deposited is at least 15 nm, or at least 20 nm, or at least 30 nm, or at least 50 nm, or at least 75 nm.

[0195] In some embodiments, the dried process film is continuous across a rectangle of the release surface of the ITM, wherein the rectangle has a width of at least w cm and a length of at least 1 cm, wherein (i) the value of w is at least 10, or at least 20, or at least 30, and / or at most 100, or at most 80, or at most 60, and (ii) the value of l is at least 50, or at least 100, or at least 250, or at least 500, or at least 1000.

[0196] In some embodiments, the dried process film is continuous such that for at least 50%, or at least 75%, or at least 90%, or at least 95%, or at least 99%, or 100% of the area of ​​the rectangle, the thickness of the dried process film deviates from the average thickness value within the rectangle by no more than 50%, or no more than 40%, or no more than 30%, or no more than 20%, or no more than 10%, or no more than 5%, or no more than 2.5%, or no more than 1%.

[0197] In some embodiments, during the drying process of the wet-processed layer, its dynamic viscosity increases by at least 100 times, or at least 500 times, or at least 1000 times, or at least 2500 times, or at least 5000 times, or at least 10,000 times, or at least 25,000 times within a time period of at most 1 second, or at most 500 milliseconds, or at most 250 milliseconds, or at most 150 milliseconds, or at most 100 milliseconds, or at most 75 milliseconds, or at most 50 milliseconds, or at most 25 milliseconds, or at most 15 milliseconds, or at most 10 milliseconds.

[0198] In some embodiments, the liquid content of the dried process membrane is at most 10 wt%, or at most 7.5 wt%, or at most 5 wt%, or at most 2.5 wt%, or at most 1.5 wt%, or at most 1 wt%.

[0199] In some embodiments, the drying process removes at least 80 weight percent, or at least 90 weight percent, or at least 95 weight percent of the water in the wet-process layer (e.g., within a time period of at most 1 second, or at most 0.5 seconds, or at most 100 milliseconds, or at most 50 milliseconds, or at most 25 milliseconds, or at most 10 milliseconds) to form a dried process film.

[0200] In some embodiments, the drying process removes at least 80 weight percent, or at least 90 weight percent, or at least 95 weight percent of the 60 degrees Celsius / 1 atmosphere liquid of the wet process layer to form a dried process film.

[0201] In some embodiments, the surface (eg, the upper surface) of the dried process film on which the aqueous ink droplets are deposited is characterized by an average roughness R a(commonly used one-dimensional average roughness parameter) is at most 30 nanometers, or at most 25 nanometers, or at most 20 nanometers, or at most 18 nanometers, or at most 16 nanometers, or at most 15 nanometers, or at most 14 nanometers, or at most 12 nanometers, or at most 10 nanometers, or at most 9 nanometers, or at most 8 nanometers, or at most 7 nanometers, or at most 5 nanometers, and / or at least 3 nanometers, or at least 5 nanometers.

[0202] In some embodiments, the dry treatment film on which the aqueous ink droplets are deposited and the surface (eg, the upper surface) of the dry treatment film are characterized by (i) the average roughness R of the dry treatment layer. a and (ii) a dimensionless ratio of thickness, wherein the dimensionless ratio is at least 0.02, or at least 0.03, or at least 0.04, or at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08, or at least 0.09, or at least 0.10, or at least 0.11, or at least 0.12, or at least 0.13, or at least 0.14, or at least 0.15, or at least 0.16, or at least 0.17, or at least 0.18, or at least 0.19, or at least 0.2.

[0203] In some embodiments, the dry treatment film on which the aqueous ink droplets are deposited and the surface (eg, the upper surface) of the dry treatment film are characterized by (i) the average roughness R of the dry treatment layer. a and (ii) a dimensionless ratio between a thickness of at most 0.5, at most 0.4, at most 0.3, at most 0.25, at most 0.2, at most 0.15, or at most 0.1, and optionally, at least 0.02, or at least 0.03, or at least 0.04, or at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08.

[0204] In some embodiments, when dried, the drying process film is continuous.

[0205] In some embodiments, the aqueous treatment formulation is provided in the form of a solution.

[0206] In some embodiments, the aqueous treatment formulation is provided in the form of a dispersion.

[0207] In some embodiments, solids (e.g., nanopigments and / or resins) of the aqueous ink migrate into the bulk of the dried process film to interact with (e.g., bind to) the quaternary ammonium salt residing within the dried process film (e.g., to facilitate droplet spreading).

[0208] In some embodiments, the substrate is selected from the group consisting of an uncoated fibrous printing substrate, a commodity coated fibrous printing substrate, and a plastic printing substrate.

[0209] In some embodiments, the printing substrate is paper, optionally selected from the group consisting of bond paper, uncoated offset paper, coated offset paper, copy paper, groundwood paper, coated groundwood paper, wood-free paper, coated wood-free paper, and laser paper.

[0210] In some embodiments, the transfer is performed at a transfer temperature of at most 120°C, or at most 120°C, or at most 100°C, or at most 90°C, or at most 80°C.

[0211] In some embodiments, solids (eg, nanopigments and / or resins) of the aqueous ink migrate into the bulk of the dried process film to interact with (eg, bind to) the quaternary ammonium salt residing within the dried process film.

[0212] In some embodiments, the method is performed such that an ink dot set IDS of ink-substrate-resident ink dots is formed.

[0213] In some embodiments, the method is performed so that a plurality of droplets DP of aqueous ink droplets deposited onto the ITM-residence dried processing film form an ink dot set IDS of ink-substrate-residence ink dots, thereby causing a correspondence between (i) each given droplet of the plurality of droplets DP and (ii) a corresponding given substrate-residence ink dot of the ink dot set, thereby causing a given droplet to be generated and / or evolved into a given substrate-residence ink dot.

[0214] In some embodiments, the method is performed such that during deposition, each time a droplet in the plurality of droplets collides with the dried process film on the ITM, the kinetic energy of the colliding droplet deforms the droplet.

[0215] In some embodiments, the method is performed such that: (i) the maximum impact radius of each deformed droplet on the ITM surface has a maximum impact radius value R 最大冲击 and (ii) after impact and / or during transfer and / or after transfer, physicochemical forces cause the deformed droplet or the resulting dot to spread, so that each ink dot of the ink dot set IDS residing on the substrate has a dry dot radius R 基材上的干点 ;

[0216] (iii) for each droplet in the plurality of droplets and a corresponding ink dot in the ink dot set IDS,

[0217] i. The substrate residence dry point radius R 基材上的干点 ;and

[0218] ii. The maximum impact radius value R of the deformed droplet 最大冲击

[0219] The ratio between is at least 1, or at least 1.01, or at least 1.02, or at least 1.03, or at least 1.04, or at least 1.05, or at least 1.1, or at least 1.15, or at least 1.2, or at least 1.25, or at least 1.3, or at least 1.35, or at least 1.4, or at least 1.45, or at least 1.5, and optionally, at most 2, at most 1.8, at most 1.7, at most 1.6, or at most 1.55.

[0220] In some embodiments, the method is performed so that: i. the plurality of droplets DP deposited onto the ITM resident dry treatment film produces a set of substrate resident ink dots IDS (i.e., fixedly adhered to the top substrate surface), each droplet of the plurality of droplets DP corresponds to a different respective substrate resident ink dot of the ink dot set IDS; ii. each ink droplet of the plurality of droplets DP is deposited onto the substrate according to the jetting parameters; iii. the jetting parameters together with the physicochemical properties of the ink droplets of the plurality of droplets DP jointly define the inkjet paper dot radius R 直接喷射到喷墨纸上 , theoretically, it is the radius of the ink dot obtained by directly jetting the ink droplet onto the inkjet paper instead of jetting onto the drying treatment film; and iv. (A) the dry dot radius R of the ink dot of the ink dot set IDS 在基材上的干点 and (B) inkjet paper dot radius R 直接喷射到喷墨纸上 , 理论 The ratio between is at least 1, or at least 1.01, or at least 1.02, or at least 1.03, or at least 1.04, or at least 1.05, or at least 1.1, or at least 1.15, or at least 1.2, or at least 1.25, or at least 1.3, or at least 1.35, or at least 1.4, or at least 1.45, or at least 1.5, and optionally, at most 2, at most 1.8, at most 1.7, at most 1.6, or at most 1.55.

[0221] In some embodiments, the cardinality of the set of dots is at least 5, or at least 10, or at least 20, or at least 50, or at least 100, and each dot of the set of dots is different on the substrate.

[0222] In some embodiments, the method is performed so that the ink dots of the ink dot set are contained within a square geometric projection projected onto the printing substrate, each ink dot of the ink dot set is fixedly adhered to the surface of the printing substrate, and all of the ink dots within the square geometric projection are counted as separate members of the ink dot set IDS.

[0223] In some embodiments, the method is performed such that each of the ink dots comprises at least one colorant dispersed in an organic polymer resin, each of the dots has an average thickness of less than 2,000 nm and a diameter of 5 to 300 microns.

[0224] In some embodiments, the method is performed such that: each of the ink dots has a substantially convex shape, wherein the deviation from convexity (DC 点 ) is defined by the following formula: DC dot = 1-AA / CSA, AA is the calculated projected area of ​​the dot, the area being disposed approximately parallel to the printing substrate; and CSA is the surface area of ​​a convex shape that minimally defines the contour of the projected area; wherein the average deviation of convexity from the set of dots (DC 点平均值 ) is at most 0.05, at most 0.04, at most 0.03, at most 0.025, at most 0.022, at most 0.02, at most 0.018, at most 0.017, at most 0.016, at most 0.015, or at most 0.014.

[0225] In some embodiments, the method is performed such that: wherein each ink dot contains at least one colorant dispersed in an organic polymer resin, each of the ink dots covers a continuous area of ​​the top surface of the substrate; each of the ink dots is completely disposed above the continuous area, such that (i) a projected vertical line extending downward toward the top substrate surface first encounters the ink dot at each point in the continuous area before encountering the top substrate surface; and / or (ii) each of the ink dots has a diameter of 15 microns to 300 microns; and / or (iii) each of the ink dots has an average thickness of at most 1,800 nm; each of the ink dots is characterized by a dimensionless aspect ratio (R) defined by the following formula: 纵横 ): R 纵横 =D 点 / H 点 , where D 点 is the diameter; and H 点 is the average thickness; and / or (iv) the aspect ratio is at least 50, or at least 60, or at least 75, or at least 95, or at least 110, or at least 120, or at least 135, or at least 150, or at least 170, or at least 180, or at least 190, or at least 200, or at least 220, or at least 240, or at least 260, or at least 280, or at least 300.

[0226] In some embodiments, the method is performed such that: the aspect ratio is at most 400, at most 350, or at most 325.

[0227] In some embodiments, the method is performed such that: each ink dot contains at least one colorant dispersed in an organic polymer resin, each of the ink dots covers a continuous area of ​​the top surface of the substrate; each of the ink dots is completely disposed above the continuous area, such that (i) a projected vertical line extending downward toward the top substrate surface first encounters the ink dot at each point in the continuous area before encountering the top substrate surface; and / or (ii) each of the ink dots has a diameter of 15 microns to 300 microns; and / or (iii) each of the ink dots has an average thickness of at most 1,800 nm; each of the ink dots is characterized by a dimensionless aspect ratio (R) defined by the following formula: 纵横 ): R 纵横 =D 点 / H 点 , where D 点 is the diameter; and H 点 is the average thickness; and / or (iv) the aspect ratio is in the range of 140 to 400, 150 to 300, 160 to 300, 180 to 300, 200 to 300, 210 to 300, 220 to 300, 230 to 300, or 240 to 300.

[0228] In some embodiments, the method is performed such that at least one (or at least most or all) of the ink dots of the droplet set IDS contains less than 2% charge director.

[0229] In some embodiments, the method is performed such that at least one (or at least a majority or all) of the ink dots of the ink drop set IDS are free of a charge director.

[0230] In some embodiments, the method is performed so that at least one (or at least most or all) of the ink dots of the ink dot set IDS has a thickness of at most 1,500 nm, or at most 1000 nm, or at most 800 nm, or at most 600 nm, or at most 400 nm, or at most 350 nm, or at most 300 nm, or at most 250 nm.

[0231] In some embodiments, the method is performed such that at least one (or at least most or all) of the ink dots of the ink drop set IDS contains at least 1.2% by weight of the colorant.

[0232] In some embodiments, the method is performed such that at least one (or at least most or all) of the ink dots of the ink drop set IDS contains at least 5% by weight of the resin.

[0233] In some embodiments, the method is performed such that at least one (or at least most or all) of the ink dots of the ink dot set IDS has a total concentration of the colorant and the resin within the ink dot of at least 40%.

[0234] In some embodiments, the method is performed such that the weight ratio of the resin to the colorant in the ink dot is at least 1:1.

[0235] In some embodiments, the method is performed such that: the ink dots of the ink dot set IDS result in no adhesion failure when subjected to a standard tape test.

[0236] In some embodiments, the method is performed such that: the surface concentration of nitrogen at the film upper surface of each of the ink dots exceeds the bulk concentration of nitrogen within the film, the bulk concentration being measured at a depth of at least 30 nanometers below the film upper surface, and wherein the ratio of the surface concentration to the bulk concentration is at least 1.1 to 1.

[0237] In some embodiments, the method is performed such that the upper surface of each ink dot exhibits an X-ray photoelectron spectroscopy (XPS) peak at 402.0±0.4 eV.

[0238] In some embodiments, the method is performed so that: the ink dots of the ink droplet set have a temperature within a range of 10°C to 195°C. 6 cP to 3.10 8 The first dynamic viscosity is in the range of cP.

[0239] In some embodiments, the method is performed such that: the first dynamic viscosity is at most 7.10 7 cP.

[0240] In some embodiments, the method is performed such that: the first dynamic viscosity is between 10 6 cP to 10 8 within the range of cP.

[0241] In some embodiments, the method is performed such that: the first dynamic viscosity is at least 4.10 6 cP.

[0242] In some embodiments, the method is performed such that at least one ink dot (or at least most or all of the ink dots) is a plurality of continuous ink dots.

[0243] In some embodiments, the method is performed so that: for at least one ink dot (or at least most or all ink dots), the dot thickness is at most 1,200nm, or at most 1,000nm, or at most 800nm, or at most 650nm, or at most 500nm, or at most 450nm, or at most 400nm.

[0244] In some embodiments, the method is performed such that the ITM is any ITM disclosed herein and / or the aqueous treatment solution is any aqueous treatment solution disclosed herein.

[0245] In some embodiments, the aqueous ink comprises a pigment, a binder, a dispersant, and at least one additive. BRIEF DESCRIPTION OF THE DRAWINGS

[0246] Some embodiments of the printing system are described herein with reference to the accompanying drawings. By way of non-limiting example, this description together with the accompanying drawings enables one of ordinary skill in the art to understand how to implement the teachings of the present disclosure. These figures are for the purpose of illustrative discussion and are not intended to show structural details of the embodiments in more detail than is necessary for a basic understanding of the present disclosure. For the sake of clarity and simplicity, some objects depicted in the drawings are not drawn to scale.

[0247] In the figure:

[0248] Figure 1 is a flow chart of a prior art printing method;

[0249] Figure 2 and 12 is a flow chart of a printing process according to some embodiments of the present invention;

[0250] Figures 3A-3D , 4A-4B, 5, 6-9, 10A-10C and 11A-11C illustrate printing systems or components thereof;

[0251] Fig.11D shows the shear strength as a function of position;

[0252] Figures 13A-13E Schematically describing the process of ink droplet deposition on an ITM (e.g., its release surface);

[0253] Figures 14A-14B Providing an instrumentally drawn topographical feature map of a drying treated film produced according to the present invention;

[0254] Figures 15A-15D Some examples of ink dots on a paper substrate are shown;

[0255] Fig.16 A cross section through a carrier is schematically shown;

[0256] Figures 17 to 21 Schematically showing the different stages of manufacturing an ITM according to the method of the present invention;

[0257] Fig. 22 is a cross-sectional view through the completed ITM after installation in a printing system;

[0258] 23A and 23B schematically show a cross section through a release layer prepared according to the prior art;

[0259] Fig.23C Schematically shows a cross section through a release layer prepared according to the method of the present invention;

[0260] Figures 24A to 24D Schematically illustrates an apparatus in which some embodiments of the method of the invention can be implemented, showing different stages of manufacture;

[0261] Figures 25A-25C are images of various ink patterns printed onto the release layer of the ITM of the present invention, wherein the release layer is cured relative to the PET carrier surface; and

[0262] Figures 26A-26C are images of various ink patterns printed onto the release layer of a prior art ITM, where the release layer is air cured. DETAILED DESCRIPTION

[0263] The present invention is described herein by way of example only and with reference to the accompanying drawings. With specific reference now to the accompanying drawings in detail, it should be emphasized that the details shown are by way of example only and for the purpose of illustrative discussion of the preferred embodiments of the present invention only, and that the details are presented in order to provide what is believed to be the most applicable and most understandable description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show the structural details of the present invention in more detail than is necessary for a basic understanding of the present invention, and the description made with reference to the accompanying drawings enables those skilled in the art to understand how several forms of the present invention can be implemented in practice. Throughout the drawings, the same reference characters are generally used to represent the same elements.

[0264] definition

[0265] In this application, the following terms shall be understood to have the following meanings:

[0266] a) The term "receding contact angle" or "RCA" refers to the receding contact angle measured using the drop shape method using a Dataphysics OCA15 Pro contact angle measurement device or a similar video-based optical contact angle measurement system. The similar "advancing contact angle" or "ACA" refers to the advancing contact angle measured in essentially the same manner.

[0267] b) The term "standard aging procedure" refers to an accelerated aging protocol performed on each release ply tested at 160°C for 2 hours in a standard convection oven.

[0268] c) The term "standard air cure" refers to conventional curing methods for curing release layers, wherein the release layer surface (or "ink receiving surface") is exposed to air during the curing of the release layer.

[0269] d) The term "bulk hydrophobicity" is characterized by the receding contact angle of a distilled water droplet disposed on the inner surface of the release layer, the inner surface being formed by exposing areas of cured silicone material within the release layer.

[0270] e) The term "image transfer member" or "intermediate transfer member" or "transfer member" refers to the component of a printing system to which ink is initially applied by a print head, such as by an inkjet head, and to which the jetted image is subsequently transferred to another substrate or substrates, typically the final printed substrate.

[0271] f) The term "blanket" refers to a flexible transfer member that can be mounted within a printing apparatus to form a belt-like structure on two or more rollers, at least one of which is capable of rotating and moving the blanket (eg, by moving its belt) to travel around the rollers.

[0272] g) The term "on the release surface" with respect to an object such as an ink image or ink residue means supported by and / or above the release surface. The term "on the release surface" does not necessarily mean direct contact between the ink image or ink residue and the release surface.

[0273] h) The term "having a static surface tension sufficiently high to increase the static surface tension of the aqueous treatment formulation" and the like with respect to a specific surfactant within an aqueous treatment formulation is evaluated by adding additional amounts or aliquots of the specific surfactant to the formulation and comparing the resulting static surface tension of the formulation to the static surface tension of the formulation prior to the addition of those aliquots.

[0274] i) The term "liquid hygroscopic agent" refers to a hygroscopic agent that is liquid at at least one temperature in the range of 25° C. to 90° C. and has a vapor pressure of at most 0.05 ata, and more typically at most 0.02 ata, at most 0.01 ata, or at most 0.003 ata in the neat state and at 90° C. The term "liquid hygroscopic agent" specifically refers to materials such as glycerol.

[0275] j) The terms "hydrophobic" and "hydrophilic" and the like may be used in a relative sense and not in an absolute sense.

[0276] k) The term '(treatment) formulation' means a solution or a dispersion.

[0277] l) Now define the evaporative load at x degrees Celsius, where x is a positive number. When the solution is y% solids by weight and z% liquid by weight at x degrees Celsius, the 'evaporative load at x-degrees Celsius' of a solution is the ratio z / y. The units of 'evaporative load' are "weight of solvent / weight of total solutes". For this disclosure, the evaporative load is always defined at atmospheric pressure. For this disclosure, the default value for 'x' is 60 degrees Celsius - the term 'evaporative load' without a prefix specifying a temperature refers to the evaporative load at 60 degrees Celsius at atmospheric pressure.

[0278] m) When a portion of the ITM is moving at a speed of v m / s, this means that a portion of the blanket ITM is moving in a direction parallel to its local surface / plane at a speed of at least v m / s - for example relative to a fixed applicator.

[0279] n) The term 'static surface tension' refers to the static surface tension at 25°C and atmospheric pressure.

[0280] o) The term 'thickness' of a wet layer is defined as follows: When a volume vol of material covers the surface area of ​​a surface having an area SA with a wet layer, the thickness of the wet layer is assumed to be vol / SA.

[0281] p) The term 'thickness' of a dry film is defined as follows. When a certain volume vol of material having x weight % of liquid wets or covers the surface area SA of a surface, and all the liquid is evaporated to convert the wet layer into a dry film, the thickness of the dry film is assumed to be

[0282] vol / ρ 湿层 (100-x) / ()SA·ρ 干层 )

[0283] where ρ 湿层 is the specific gravity of the wet layer and ρ 干层 is the specific gravity of the dry layer.

[0284] q) The term 'continuous wet layer' refers to a continuous wet layer covering the convex area without any exposed sub-areas within the perimeter of the convex area.

[0285] r) The term 'continuous thin dry film' refers to a continuous dry film covering a convex area without any discontinuity within the perimeter of the convex area.

[0286] s) The term 'cohesive film / tensile strength' refers to a construct that holds together when peeled from a surface to which it is adhered - ie when peeled from a surface, the 'cohesive film' retains its structural integrity and peels away as a skin, rather than breaking into small pieces.

[0287] t) The term 'normally applied force' refers to a force having at least one component in the normal direction - and optionally a 'normally applied' force may have additional components in other directions (eg along the surface to which the force is applied).

[0288] u) Unless otherwise stated, physical properties of liquids (eg, treatment formulations) such as viscosity and surface tension refer to properties at 25°C.

[0289] v) Unless otherwise stated, 'concentration' refers to weight - ie weight of formulation component / total formulation weight.

[0290] Figure 2 Discussion

[0291] Figure 2 is a flow chart of a method for indirectly printing onto a silicone-based release post-surface of an intermediate transfer member (ITM) via aqueous ink. In some embodiments, Figure 2 The method (or any combination of its steps) may be used Figure 3A-3B , 4A-4B, 5-9, 10A-10C and 11A-11C (or one or more components thereof). In particular, and as will be discussed below, embodiments of the present invention relate to methods and apparatus that can be used to generate a uniform submicron thickness wet-processed layer over a large area of ​​an ITM and / or at a high printing speed.

[0292] In various implementations, the Figure 2 To produce an ink image characterized by any combination of the following features: uniform and controlled dot gain, good and uniform print gloss, and good image quality due to high quality dots with consistent dot convexity and / or well-defined boundaries.

[0293] Steps S201-S205 involve Figure 2 The components or consumables used in the printing process, while steps S209-S225 relate to the process itself.

[0294] in short, Figure 2The steps of the method are as follows: In steps S201 and S205, an ITM (i.e., including a silicone-based release layer surface) and an aqueous treatment formulation (e.g., a solution) are provided, each of which has specific properties discussed below. In step S209, the aqueous treatment formulation is applied to the release layer surface of the ITM to form a wet treatment layer thereon. In step S213, the wet treatment layer is subjected to a drying process, thereby forming a dry treatment film on the ITM. In step S217, droplets of aqueous ink are deposited onto the dry treatment film to form an ink image on the ITM surface. In step S221, the ink image is dried to leave an ink image residue on the ITM surface, and in step S225, the ink image residue is transferred to a printing substrate.

[0295] Embodiments of the present invention are directed to methods, apparatus and kits for achieving the potentially competing goals of dot gain, image gloss and dot quality, preferably in a production environment where high printing speeds are critical. According to some embodiments, the inventors have discovered that performing Figure 2 The method is useful, whereby the dried treated film formed in step S213 is very thin (e.g., at most 150 nm, or at most 120 nm, or at most 100 nm, or at most 80 nm, or at most 70 nm, or at most 60 nm, or at most 50 nm, and optionally, at least 20 nm or at least 30 nm) and / or continuous over a large area and / or characterized by a very smooth upper surface and / or rich in quaternary ammonium salts (e.g., to promote dot gain) and / or having properties that promote good transfer from the ITM to the substrate (i.e., properties of the film itself or the film relative to the ITM surface).

[0296] For example, a thicker treatment film may negatively affect its gloss or uniformity because dried ink residues may reside under the treatment film and on the substrate surface after transfer. Therefore, it may be preferred to produce a very thin treatment film.

[0297] For example, discontinuities in the treatment film and / or treatment films of varying thickness may produce an image of uneven gloss on the substrate, or may generate ink image residues that lose their mechanical integrity when transferred to the substrate (in step S113). Therefore, it may be preferred to generate a treatment film that is continuous over a large area - preferably cohesive enough to maintain structural integrity on the printed substrate and / or has thermo-rheological properties so that the treatment film is tacky at a transfer temperature between 75 degrees Celsius and 150 degrees Celsius.

[0298] For example, the presence of a quaternary ammonium salt in a dry process film can promote the spreading of ink droplets, but not necessarily uniform droplet spreading. However, the combination of (i) a high concentration of quaternary ammonium salt in the dry process film and (ii) a process film of uniform thickness with a very smooth upper surface can promote uniform droplet spreading.

[0299] Embodiments of the present invention are directed to techniques for achieving these results simultaneously, even though they require potentially competing goals. For example, the requirement for the process film to be very thin makes it more challenging to form a process film that is continuous over a large area and / or cohesive enough to transfer well to a substrate and / or has a very smooth and uniform upper surface.

[0300] Discussion of Step S201

[0301] Although the ITM provided in step S201 has a silicone-based release layer, its release surface may be less hydrophobic or significantly less hydrophobic than many conventional silicone-based release layers. The structural properties may be measured and characterized in various ways.

[0302] For example, Figure 2 As shown in step S201, the intermediate transfer member (ITM) includes a silicone-based peeling layer surface having sufficient hydrophilicity to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water drop deposited on the silicone-based peeling layer surface is at most 60°; (ii) a 10-second dynamic contact angle (DCA) of a distilled water drop deposited on the silicone-based peeling layer surface is at most 108°.

[0303] Any of a number of techniques for reducing the hydrophobicity of silicone-based release layers may be employed.

[0304] In some embodiments, polar functional groups are introduced into and / or generated in the silicone-based release layer. In one embodiment, the functional groups can be added to the prepolymer batch (e.g., monomers in solution) - these functional groups can become an integral part of the silicone polymer network when cured. Alternatively or additionally, the silicone-based release layer is pre-treated (e.g., by corona discharge, or by electron beam) to increase its surface energy.

[0305] Alternatively, the organosilicon-based release layer can be manufactured to have reduced hydrophobicity, even when substantially free of functional groups. In one embodiment, the organosilicon polymer backbone of the release layer can be configured such that its polar groups (e.g., O-Si-O) are oriented in a direction generally normal to the local plane of the ITM surface and facing 'upwards' toward the release layer surface.

[0306] To date, the present inventors believe that the technique of the preceding paragraph can provide excellent image transfer (step S225).

[0307] Figure 2 Discussion of Step S205

[0308] One feature of the aqueous treatment formulation provided in step S205 is that the static surface tension of the aqueous treatment formulation is in the range of 20 dynes / cm and 40 dynes / cm. For example, the aqueous treatment formulation comprises one or more surfactants.

[0309] Therefore, the aqueous treatment formulation of step S205 is less hydrophilic than many conventional treatment solutions, and is significantly less hydrophilic than water.

[0310] In some embodiments, the combination of (i) a silicone-based release layer having reduced hydrophobicity (step S201) and (ii) an aqueous treatment formulation having reduced hydrophilicity reduces (but does not necessarily eliminate) surface tension effects that promote beading of conventional aqueous treatment solutions.

[0311] In addition to a static surface tension in the range of 20 dynes / cm and 40 dynes / cm, the aqueous treatment formulation provided in step S205 has the following properties:

[0312] a. The aqueous treatment formulation contains at least 3 wt% of a quaternary ammonium salt. This can be used to ensure that the dried treatment film (i.e., generated in step S217) is rich in quaternary ammonium salt, which can be used to promote good dot gain;

[0313] b. The aqueous treatment formulation comprises at least 1 wt % (e.g., at least 1.5 wt %, or at least 2 wt %, or at least 3 wt %) of at least one water-soluble polymer having a solubility in water of at least 5% at 25° C. This can be used to promote the formation of a polymer film or matrix in the dried treatment film (generated in step S217) that has sufficient cohesiveness to achieve good transfer in step 225.

[0314] c. 25°C dynamic viscosity of at least 10 cP. As discussed below, it is believed that the elevated viscosity can serve to counteract any surface tension driven beading tendency.

[0315] d. A 60°C evaporation load of at most 8:1 (e.g., at most 7:1, or at most 6:1, or at most 5:1, or at most 4:1) by weight. Thus, the solution has a low specific heat capacity relative to conventional treatment formulations with higher evaporation loads. In addition, for a particular required residual thickness of the aqueous treatment solution, and for a given heat output delivered to the aqueous treatment solution, the viscosity of the aqueous treatment formulation will increase rapidly with evaporation to achieve a high absolute viscosity that effectively counteracts surface tension.

[0316] Physically, it is more difficult to induce flow of a fluid having a higher viscosity than a fluid having a lower viscosity - i.e., a greater driving force is required to induce flow of a fluid having a higher viscosity. The combination of at least a modest initial viscosity (i.e., a 25°C dynamic viscosity of at least 10 cP) and a rapid viscosity increase after evaporation on the ITM surface (e.g., due to a low evaporation load) ensures that the aqueous treatment formulation reaches a relatively 'high' (e.g., at least 10,000 cP) viscosity in a relatively short time (e.g., at most 1 second or at most 0.5 seconds). Thus, even if there is some thermodynamic tendency toward beading, actual beading can be suppressed or significantly mitigated, which can negatively affect the properties of the dried treatment film (i.e., formed in step S213).

[0317] In some embodiments, the 25°C dynamic viscosity of the initial aqueous treatment formulation may be at least 12 cP, or at least 14 cP - for example, in the range of 10 cP to 100 cP, 12 cP to 100 cP, 14 cP to 100 cP, 10 cP to 60 cP, or 12 cP to 40 cP.

[0318] In summary: The following combination: (A) the release layer is sufficiently hydrophilic to satisfy at least one of the following properties: (i) the receding contact angle of a distilled water droplet deposited on the surface of the silicone-based release layer is at most 60°; and (ii) the 10-second dynamic contact angle (DCA) of a distilled water droplet deposited on the surface of the silicone-based release layer is at most 108°; (B) the static surface tension of the aqueous treatment formulation is in the range of 20 dynes / cm to 40 dynes / cm can be used to minimize the magnitude of the thermodynamic driving force that will cause beading. In addition, the above-mentioned viscosity-related characteristics can be used to counteract such driving forces.

[0319] The reduction in the magnitude of the thermodynamic forces driving beading and the offsetting of the tendency ensure that any tendency to beading does not prevent the formation of a layer of the wet processing formulation in step S209 having a uniform thickness in step S209.

[0320] In embodiments of the invention, the aqueous treatment formulation comprises a carrier liquid comprising water, the water comprising at least 65% by weight (e.g., at least 70% by weight or at least 75% by weight) of the aqueous treatment formulation;

[0321] Discussion of Step S209

[0322] In step S209 , an aqueous treatment formulation is applied onto the silicone-based release layer surface of the ITM to form a wet treatment layer having a thickness of at most 0.8 μm (eg, at most 0.7 μm, or at most 0.6 μm, or at most 0.5 μm) thereon.

[0323] The "thickness of the wet layer" is defined as follows: when a certain volume vol of material covers the surface area of ​​a surface having an area SA with a wet layer, the thickness of the wet layer is assumed to be vol / SA.

[0324] Preferably, step S209 is performed such that the wet processed layer has a uniform thickness and is preferably defect-free over a large area, such as over the entire area of ​​the release layer. This may be particularly challenging when the wet processed layer has a sub-micron thickness.

[0325] As noted above, it is useful for the aqueous treatment formulation to have at least 'moderate viscosity' (eg, a 25°C dynamic viscosity of at least 10 cP) to counteract beading. However, at such viscosities, there may be challenges associated with obtaining a uniform layer of sub-micron thickness of the aqueous treatment formulation.

[0326] In step S209, an aqueous treatment formulation is applied onto the surface of the silicone-based release layer to form a wet treatment layer having a thickness of at most 0.8 μm.

[0327] Embodiments of the present invention are directed to apparatus and methods for applying the wet processing layer such that the thickness is preferably uniform over a large area of ​​the ITM.

[0328] In some embodiments, after coating the ITM surface with an initial coating of an aqueous treatment formulation, excess treatment formulation may be removed from the initial coating or a wet treatment layer having a uniform thickness of up to 0.8 μm may be obtained.

[0329] In some embodiments, this can be achieved by pushing a highly circular surface (eg, a highly circular surface of a scraper) toward the ITM, or vice versa. For example, the radius of curvature of the highly circular surface can be at most 1.5 mm, or at most 1.25 mm, or at most 1 mm.

[0330] At high printing speeds (e.g., where the surface velocity of the ITM is relatively large (e.g., at least 1 m / s, or at least 1.25 m / s, or at least 1.5 m / s)), removing excess liquid to form a treatment layer having a sub-micron thickness may require establishing a relatively large velocity gradient (i.e., shear) in the gap region between the elevation surface and the ITM (e.g., the velocity gradient is in the normal direction of the ITM surface) - e.g., at least 10 6 sec -1 or at least 2×10 6 sec -1 velocity gradient.

[0331] As described above, the 25°C dynamic viscosity of the treatment formulation can be at least 10 cP. Even if step S209 is performed at higher temperatures, the dynamic viscosity at these higher temperatures can be at least 3 cP, or at least 5 cP, or at least 10 cP. Therefore, in some embodiments of the present invention, a relatively large force is required (e.g., to push a highly rounded surface toward an ITM or vice versa) to achieve the desired uniform sub-0.8 μm (preferably) uniform thickness.

[0332] In some embodiments, the circular surface pushes toward the ITM or vice versa in the cross-print direction with a force density of at least 250 g / cm, or at least 350 g / cm, or at least 400 gm / cm, and / or at most 1 kg / cm, or at most 750 g / cm, or at most 600 g / cm.

[0333] In some embodiments, the wet processing layer is formed by applying a pressure between the applicator and the ITM, the pressure being at least 0.1 bar, or at least 0.25 bar, or at least 0.35 bar, or at least 0.5 bar, and optionally at most 2 bar, or at most 1.5 bar, or at most 1 bar.

[0334] Discussion of Step S213

[0335] In step S213, the wet-processed layer is subjected to a drying process, thereby forming a drying-processed film.

[0336] For example, during the drying process of the wet-processed layer, its dynamic viscosity increases at least 1000 times within a time period of at most 0.5 seconds or at most 0.25 seconds.

[0337] In some embodiments, the thickness of the dried process film (eg, cohesive polymer process film) is at most 150 nanometers, or at most 120 nanometers, or at most 100 nanometers, or at most 80 nanometers, or at most 60 nanometers.

[0338] In some embodiments, the dried treatment film has a smooth upper surface. For example, the drying process of the wet treatment layer is rapid enough so that the viscosity of the aqueous treatment formulation increases rapidly enough to inhibit surface tension driven beading, so that the dried treatment film has a smooth upper surface.

[0339] In some embodiments, the smooth upper surface of the dried treated film is characterized by an average roughness R a At most 12 nm, or at most 10 nm, or at most 9 nm, or at most 8 nm, or at most 7 nm, or at most 5 nm. The skilled person refers to Figure 13 and the accompanying discussion.

[0340] In some embodiments, the dry process film is continuous across a rectangle of the release surface of the ITM, wherein the rectangle has a width of at least 10 cm and a length of at least 10 m.

[0341] In some embodiments, the treatment film is transparent.

[0342] One of the purposes of the dry treatment film is to protect the ITM surface from direct contact with aqueous ink droplets deposited on the treatment film. However, aqueous ink droplets can 'erode' the thickness of the dry treatment film, especially when the dry treatment film is very thin (e.g., at most 150 nanometers, or at most 120 nanometers, or at most 100 nanometers, or at most 80 nanometers). Therefore, in some embodiments, provided aqueous treatment formulations (e.g., in Figure 2 In step S205 or Fig.12 In step S95), the concentration of the water-soluble polymer in the water-soluble polymer is at most 10 wt %, or at most 8 wt %, or at most 6 wt %, or at most 5 wt %.

[0343] Discussion of Steps S217-S221

[0344] In step S217, droplets of aqueous ink are deposited (eg, by ink drop deposition) onto the drying process film to form an ink image on the ITM surface. In step S221, the ink image is dried to leave an ink image residue on the ITM surface.

[0345] For example, the presence of a quaternary ammonium salt in the dry process film can be used to promote dot spreading and / or dot gain (e.g., uniform dot spreading and / or dot gain) during or immediately after droplet deposition - the skilled person refers to the following reference Figures 13A-13E As described above, the formation of a drying-processed film having a uniform thickness and / or being free of defects and / or having a very smooth upper surface (in step S213) can facilitate the uniform flow of aqueous ink on the upper surface of the film.

[0346] Discussion of Step S225

[0347] In step SS25, the ink image residue is transferred to the substrate. For example, the ink image residue can be transferred to the printed substrate together with the non-printing area of ​​the dried treatment film.

[0348] In embodiments, the dry treat film has sufficient cohesion such that during transfer of the ink image residue, the dry treat film completely separates from the ITM and is transferred to the printed substrate along with the dried ink image in both the printed and non-printed areas.

[0349] In some embodiments, the temperature of the ITM during transfer ranges between 80° C. and 120° C. In some embodiments, the ITM temperature is at most 100° C. or at most 90° C. In some embodiments, the ITM temperature is at least 100° C., or at least 110° C., or at least 120° C.

[0350] In some embodiments, the presence of a water-soluble polymer in the aqueous process solution provided in step S205 helps ensure (ie, by forming a polymer film or matrix) that the dried process film formed in step S213 has sufficient cohesion during transfer.

[0351] In some embodiments, the substrate of the ink image residue is a glossy paper, such as a glossy coated paper.

[0352] The transfer may be perfect (ie, the ink image residue and the dried process film are integrally transferred to the substrate). Alternatively, the transfer may not be perfect - for which a cleaning station may remove material remaining on the ITM surface after the transfer step at S225.

[0353] Figure 3A-3B Discussion

[0354] Figure 3A is a schematic diagram of a system for indirect printing according to some embodiments of the present invention. Figure 3A The system includes an intermediate transfer member (ITM) 210, which includes a flexible endless belt mounted on a plurality of guide rollers 232, 240, 250, 253, 242. In other embodiments (not shown), the ITM 220 is a drum or a belt wrapped on a drum.

[0355] exist Figure 3A In the embodiment of the present invention, the ITM 210 (i.e., its belt) moves in a clockwise direction. The direction of belt movement defines an upstream direction and a downstream direction. Rollers 242, 240 are positioned upstream and downstream of the image forming station 212, respectively - therefore, roller 242 can be referred to as an "upstream roller" and roller 240 can be referred to as a "downstream roller".

[0356] Figure 3A The system also includes:

[0357] (a) Image forming station 212 (e.g., including print bars 222A-222D, each of which includes one or more inkjet heads) is configured to form an ink image (not shown) on the surface of ITM 210 (e.g., by depositing droplets on a dry process film - see, e.g., Figure 2 Step S217 or Fig.12 Step S109);

[0358] (b) A drying station 214 for drying the ink image (see, e.g., Figure 2 Step S221 or Fig.12 Step S113)

[0359] (c) Imprinting station 216, where the ink image is transferred from the surface of ITM 210 to a sheet or web substrate (see, e.g., Figure 2 Step S225 or Fig.12 Step S117).

[0360] exist Figure 3A In a specific non-limiting embodiment of the present invention, the embossing station 216 includes an impression cylinder 220 and a blanket cylinder 218 carrying a compressible blanket 219. In some embodiments, a heater 231 may be provided just before the nip between the two cylinders 218 and 220 of the image transfer station to help make the ink film tacky to facilitate transfer to a substrate (e.g., a sheet substrate or a web substrate). The substrate feed is schematically shown.

[0361] (d) Cleaning station 258 (i.e. Figure 3A ), wherein residual material (e.g., a treatment film and / or ink image or portion thereof) is cleaned from the surface of the ITM 210 ( Figure 2 The cleaning step is not shown).

[0362] (e) Processing station 260 (i.e., Figure 3A ), wherein a layer (eg, having a uniform thickness) of a liquid treatment formulation (eg, an aqueous treatment formulation) is formed on the surface of the ITM (eg, see Figure 2 Step S209 or Fig.12 Step S101).

[0363] Those skilled in the art will appreciate that it is not necessary Figure 3A Each component shown in .

[0364] Figure 3B Shows multiple 'locations' fixed in space A -Loc J , Loc A Located at roller 242, Loc B Located at the 'start' of the image station 212, Loc C is located at the 'end' of the imaging station 212, and so on. Thus, at the imaging station 212 on the upper stroke of the ITM 210, at position Loc A and Loc B The ink image is formed in the region between Figure 2In step S217). At position Loc C and Loc E The ink image is dried in the region between Figure 2 Step S221 or Fig.12 Step S105) to form ink image residues - this can occur as the ink image moves (e.g., due to the clockwise rotation of the ITM) through the drying station 214. The ink image residues are formed at position Loc E and Loc F The transfer from the ITM surface to the substrate at the imprint station 216 between Figure 2 Step S225 or Fig.12 In step S117). The material remaining on the surface of the ITM 210 after transferring the ink image residue can be G and Loc H The surface of the ITM 210 is removed at the cleaning station 258 between the Figure 2 Step S209 (or Fig.12 In step S101) at position Loc I and Loc J A wet process layer is formed on the surface of the ITM 210 at the process station 260 between the Figure 2 Step S209 or Fig.12 The wet-processed layer is subjected to a drying process (ie, the wet-processed layer is converted into a dry-processed film) (eg, see Figure 2 Step S213 or Fig.12 Step S105) - This can be done on the right hand side at position Loc J and Loc A After the dry process film is transferred (eg, by counterclockwise rotation of the ITM 210) to the image forming station 212, an ink image may then be formed by droplet deposition onto the dry process film (eg, see Figure 2 Step S217 or Figure 2 Step S109).

[0365] like Figure 3A-3B As shown in the figure, at position Loc A and Loc D The portion of the ITM between is the upper stroke of the ITM 210 (i.e., its belt). Figure 3C The upper stroke passes through the image forming station 212.

[0366] The lower travel of the ITM is located at the ITM 210 position. D and Loc A 3D. The lower stroke passes through the imprinting station 216, the cleaning station 258 and the processing station 260.

[0367] An example of a processing station is Figure 4A shown.

[0368] exist Figure 4A In a specific non-limiting embodiment of the invention, the ITM 210 moves on a scraper, generally designated 2014, as viewed from right to left (as indicated by arrow 2012), and is suitably mounted within a tank 2016. Figure 4A In the embodiment, the scraper 2014 is of the scraper bar type and is formed by a rigid bar or support 2020 extending over the entire width of the ITM 210. In its upper surface facing the underside of the ITM 210, the bar 2020 is formed with a channel or groove 24, in which a rod 2022 made of fused quartz and having a smooth and regular cylindrical surface with a roughness of no more than a few micrometers, preferably less than 10 micrometers and in particular less than 0.5 micrometers is supported.

[0369] Prior to passing the scraper 2014, the underside of the ITM 210 (or lower stroke) is coated with an excess of treatment formulation (e.g., solution) 2030 (e.g., at Figure 2 Step S205 or Fig.12 ). Figure 5 The manner in which the excess treatment agent (e.g., solution) is applied to the ITM 210, particularly its underside in this illustration, is described, but is not critical to the invention. The ITM 210 may, for example, be simply immersed in a tank containing a liquid, passed through a fountain of treatment agent (e.g., solution), or as Figure 5 As shown, the spray is performed with an upwardly directed jet 1128.

[0370] In one embodiment of the invention, a liquid permeable cloth is placed over an upwardly directed spray head, thereby causing the liquid to penetrate the cloth and form a layer on the side of the cloth facing the surface to be coated. In this case, the spray head will act to push the cloth toward the surface, but will be prevented from contacting the surface by the liquid that penetrates it, the liquid acting in the same way as a hydrodynamic bearing.

[0371] As shown, when the ITM 210 approaches the doctor blade 2014 , it has a coating 2030 of liquid that is significantly greater than the desired thickness of the film to be applied to the ITM 210 .

[0372] The function of the doctor blade 2014 is to remove excess liquid 2030 from the ITM 210 and ensure that the remaining liquid is spread evenly and uniformly over the entire surface of the ITM 210. To achieve this, the ITM 210 is pushed toward the doctor blade 2014, for example by air pressure (not shown). Alternatively, the force pushing the ITM 210 toward the doctor blade 2014 can be a backing roller 1141, such as a compressible (e.g., sponge) roller in some embodiments, pressing down on the upper or opposite side of the web by its own weight or by its spring action. As another alternative, the doctor blade 2014 itself can be pushed toward the ITM 210 while the latter is held under tension.

[0373] The tip of the scraper 2014, which consists of a cylindrical smooth rod 2022, has a uniform radius across the width of the ITM 210, and its smoothness ensures laminar flow of liquid in the gap between it and the underside of the ITM 210. The nature of the flow may be similar to that of a liquid lubricant in a hydrodynamic bearing, and the liquid film 2030 that remains adhered to the underside of the ITM 210 (i.e., the surface of the 'down stroke' of the ITM) is reduced to a certain thickness depending on the force pushing the ITM against the scraper 2014 and the radius of curvature of the rod 2022. Since both the radius and the force are constant across the width of the web, the resulting film is uniform, and its thickness can be set by appropriate selection of the applied force and the rod diameter. Excess liquid removed by the scraper 2014 forms a small pool 2032 immediately upstream of the rod 2022 before falling into the tank 2016.

[0374] In an alternative embodiment of the invention, the surface of the ITM 210 to be coated with the liquid may face upward rather than downward. In this case, rather than applying excess liquid to the ITM 210 (i.e., the 'down-running' surface of the ITM), the liquid may be metered onto the surface to create and maintain a similar small pool of liquid upstream of the line of contact between the wiper blade and the upper surface of the web. In this case, an air knife may be provided to prevent the treatment formulation (e.g., solution) from overflowing the pool over the side edges of the ITM 210.

[0375] In an embodiment of the present invention, the pool 2032 provides a constant supply of treatment formulation (e.g., solution) across the width of the ITM 210, thereby allowing all areas of the ITM 210 to be coated even if the liquid is repelled from portions of the surface of the web before reaching the doctor blade 2014 for any reason (e.g., due to 'beading').

[0376] The tank 2016 into which the remaining treatment formulation (e.g., solution) falls can be the main storage tank from which liquid is drawn to coat the underside of the web with excess treatment formulation (e.g., solution), or it can be a separate tank that is drained into the main storage tank and / or emptied into a suitable waste system.

[0377] The rod 2022 is made of a hard material such as fused silica to resist wear. Small particles of grit or dust may be present in the liquid, which may damage the rounded edge over which the liquid flows. Materials other than fused silica may be used, but the material should preferably have a Brinell hardness of more than 100 (e.g., more than 200, or more than 500, or even more than 1000). In an embodiment of the present invention, the material should be able to form a smooth rod with a uniform diameter and a surface roughness of less than 10 microns, particularly less than 0.5 microns.

[0378] The rod 2022, which may have a radius of 6 mm but may only be 0.5 mm, is relatively fragile and may require a rod 2020 for support. In order to precisely hold the rod 2022 in place, a rod is formed with a groove 24 in which the rod 2022 rests. The rod may be held in the groove 24 in any suitable manner. For example, an adhesive may be used and the rod 2020 may be used to press the rod 2022 against a flat surface such as a sheet of glass until the adhesive sets. As another alternative, the groove may be precisely machined to be slightly narrower than the rod diameter, and heat shrink may be used to hold the rod in place within the groove.

[0379] Sometimes, when certain formulations (e.g., solutions) are applied using such a blade, a deposit 34 of solute accumulates on the downstream side of the blade 2014. While not wishing to be bound by theory, it is believed that this may be caused by a fixed film of formulation (e.g., solution) adhering to the downstream side of the blade and leaving behind solute as it dries. Regardless of the cause of the formation of such a deposit and its composition, if allowed to overgrow, it will eventually interfere with the layer of treatment formulation (e.g., solution) applied to the ITM 210.

[0380] Embodiments of the present invention relate to apparatus and methods for replacing a scraper blade 2014 when the scraper blade becomes dirty. Figure 4B An embodiment showing how a doctor blade can be easily replaced, and preferably without interrupting the web coating process, or requiring the application of conditioner to the printing system of its ITM.

[0381] exist Figure 4B In the embodiment, twelve scrapers 1122 are evenly mounted in recesses around the circumference of the cylindrical rotatable turret 1120. The axially extending scrapers 1122 are arranged in a manner similar to Figure 4AThe scraper bar 1122 in the embodiment of the present invention functions in the same manner as the scraper bar 1122 in the embodiment of the present invention, and the rotating frame 1120 serves the same purpose as the bar support 2020. Instead of using a bar of circular cross section, the scraper 1122 is constructed as a strip having a smoothly rounded and polished edge. The strip having a circular edge with a uniform radius of curvature can be made, for example, by flattening a bar of circular cross section. The scraper 1122 can be suitably made of stainless steel, but other hard materials that are resistant to wear can be used alternatively.

[0382] The manner in which the turret 1120 and the scraper 122 interact with the ITM 110 is described in detail below. Figure 5 It is shown in Figure 5 One embodiment of a cleaning station 258 and a processing station 260 (e.g., for applying a layer of a wet processing formulation—e.g., as in Figure 2 Step S209 or Figure 2 (in step S101 of FIG. 1 ).

[0383] exist Figure 5 In the embodiment of FIG. 1 , two separate tanks 1125, 1127 are shown. A certain amount of treatment solution (e.g., having Figure 2 Step S205 or Fig.12 The treatment solution (one or more properties of step S95) is stored in the tank 1125. For example, the treatment solution can be sprayed (ie, by the spraying device 774) onto the surface of the ITM 210. Figure 5 Also shown are brushes 1126A and 1126B for mechanically removing material from the surface of the ITM 210 to clean the ITM surface - for example, pressure may be applied between backing rollers 772A-772B disposed on opposing brushes 1126A-1126B, respectively.

[0384] In some embodiments, the material removed from the surface of the ITM includes a dry treatment film, which may be, for example, in a liquid treatment formulation (eg, having a Figure 2 Step S205 or Fig.12 The cleaning of the ITM surface can therefore be affected by the treatment solution itself.

[0385] Regardless of any mechanical properties of the system, in an embodiment of the present invention, Figure 2 Step S205 or Fig.12 The aqueous treatment formulation provided in step S95 may be fully soluble (eg, after drying, it may be fully soluble in the aqueous treatment formulation).

[0386] Treatment agent 1128 may be sprayed via spray device 1128. Figure 5In the embodiment, a scraper 1122 is active - this is marked as 1122 活动 A relatively thick layer of treatment formulation may be applied (e.g., by device 1128) and may be applied by scraper 1122. 活动 The excess treatment formulation is removed by the combination of the backing roller 1141, which is pushed toward the scraper 1122. 活动 .

[0387] Spray device 1128 is one example of a 'spreader' used to apply a coating of treatment formulation to the surface of ITM 210. Another example of a spreader is a bath 2032, where the liquid contents of the bath remain on the surface of the ITM.

[0388] In general, the scraper 1122 活动 (or its rounded tip) and backing roller 1141 (or alternatively, means for providing air pressure to rounded tip 1122) are generally a coating thickness adjustment assembly - thus, in Fig. 10A and 11A , the 'final thickness' of the treatment formulation can be adjusted depending on the amount of force that pushes the tip 1123 toward the opposing portion of the ITM 210 (eg, toward the backing roller 1141), or vice versa.

[0389] exist Figure 5 In the embodiment of FIG. 1 , only one scraper blade 122 interacts with the ITM 110 at any given time, but as the blade becomes dirty, the turret 120 rotates to bring the next adjacent scraper blade into an operational position where the blade is active, i.e., sufficiently close to the surface to remove excess liquid and allow only a desired thickness of film to adhere to the surface downstream of the device.

[0390] Before returning to the operating position, at some later stage in the turret rotation cycle, the dirty blade 1122 passes through a cleaning device, such as a brush 1130, which removes any deposits and cleans the blade, after which it becomes functional again.

[0391] Rotation of turret 1120 may be initiated by an operator as needed, or may be performed at regular intervals.

[0392] The number of scrapers on the turret 1120 need not be twelve, but it is desirable that there be a sufficient number so that during conversion, such as Figure 8-9 As shown, there should be a time when both blades 1122 are active and interacting simultaneously with the ITM 110. As a result, blade replacement is substantially continuous, thereby not interrupting the film metering operation, which in turn allows blade changes without interrupting the printing system.

[0393] Figure 8-911 and 11. The turret 1120 and the scraper cleaning brush 1130 are shown in more detail in perspective and exploded cross-sectional views, respectively. Both are mounted on shafts rotatably supported in a metal frame 1140 in an immersion tank 1127. The shafts of the turret 1120 and the scraper cleaning brush 1130 are connected to respective drive motors 1412 and 1144 mounted outside the tank 1127. As shown in FIG. Figure 7 As can be seen in FIG. 1 , the rotating frame 1120 is made of a hollow cylinder, and its cylindrical surface may be perforated to reduce its weight and moment of inertia while still providing sufficient strength to support the scraper 1122 .

[0394] Although the scrapers 1122 supported by the turret 1120 have been shown as flat strips, it should be understood that they may alternatively be formed as rounded rods as described with reference to FIG. 4 .

[0395] It has been found that for some conditioners, vigorous stirring of the conditioner or treatment agent solution can lead to the formation of foam or foam. Ultrasonic waves can be used to break the foam, and such defoaming device can be incorporated in tank 1125.

[0396] like Fig. 10A and 10C As shown, when the scraper 1122 活动 When pushed toward the backing roller 1141, or vice versa, the scraper can penetrate into the lower stroke of the ITM 210. Fig. 10A As shown, the ITM 210 (i.e., its lower stroke) is disposed between the roller 1141 and the scraper 1122 活动 Therefore, when roller 1141 is pushed toward scraper 1122 活动 When the roller 1141 pushes on the ITM 210 (i.e., its lower stroke) and the ITM 210 is pushed toward the scraper 1122 活动 -vice versa.

[0397] exist Figures 10A-10B In the embodiment shown, the scraper 1122 活动 The central axis is 1188. Figures 10A-10B Middle, scraper 1122 活动 The round tip is marked 1123.

[0398] exist Fig. 10A In the embodiment of FIG. 1 , the tip 1123 faces the surface (i.e., the local normal) of the ITM 210. Fig. 10A In the embodiment, the scraper 1122 活动 It is oriented substantially in the normal direction of the local surface of the ITM 210 that faces the rounded tip 1123 .

[0399] exist Fig. 10AIn the embodiment of the present invention, a downward force can be applied by roller 1141 toward rounded tip 1123 (ie, via the ITM). Alternatively, air pressure can be used to bias ITM 210 toward rounded tip 1123. This causes scraper 1122 to move downwardly. 活动 All but thin liquid films (eg, less than typically less than 1 micron) are removed, the thickness of which is determined by the radius of curvature and the applied pressure.

[0400] All of the above also applies to Fig. 10C However, in Fig. 10C In an embodiment of the invention, the backing roller has a compressible surface that is compressed when the round tip is pushed toward the ITM surface and / or vice versa (i.e., any configuration in which the backing roller and the round tip are pushed toward each other), thereby causing the round tip along with the ITM to penetrate into the backing roller at a specific or desired penetration depth.

[0401] The spray device 1128 or a bath in which the ITM surface can be immersed or any other device for applying an initial coating can be considered as a 'coater' that coats the ITM with the liquid treatment formulation. In addition, the combination of (i) the circular surface 1123 (e.g., a circular tip) and the device for applying a reaction force (e.g., roller 1141) to push the circular surface 1112 in the opposite direction toward the ITM 210 (or vice versa) forms a thickness adjustment assembly for removing excess liquid so that only a desired uniform thin layer (e.g., sub-micron thickness) of the treatment formulation remains.

[0402] In embodiments of the present invention, even if rounded tip 1123 is out of contact with the opposing ITM surface (eg, to maintain a gap therebetween), the applicator can still apply pressure to the ITM indirectly via the treatment fluid.

[0403] In some embodiments, the rounded tip applies a pressure of at least 0.1 bar, or at least 0.25 bar, or at least 0.35 bar, or at least 0.5 bar, and optionally, at most 2 bar, or at most 1.5 bar, or at most 1 bar.

[0404] The pressure may be positioned in the printing direction. For example, a 'pressure stripe' (e.g., the stripe may be elongated in the cross-printing direction) (e.g., having a length in the cross-printing direction of at least 10 cm, at least 30 cm, at least 50 cm, at least 70 cm, or at least 100 cm, and typically at most 250 cm, at most 200 cm, or at most 150 cm) may be applied to the ITM by an applicator such that (i) the maximum pressure applied to the ITM within the stripe is Pstripemax, which has a value of at least 0.1 bar, or at least 0.25 bar, or at least 0.35 bar, or at least 0.5 bar, and optionally, at most 2 bar, or at most 1.5 bar, or at most 1 bar; (ii) at all locations within the strip, the local pressure applied by the applicator to the ITM is at least 0.5*PStripMaximum, and (iii) at all locations in the cross-printing direction on opposite sides of the strip (upstream and downstream of the strip - displaced from the strip by up to 2 cm, or up to 1 cm, or up to 5 mm, or up to 3 mm, or up to 2 mm, or up to 1 mm, or up to 0.5 mm), the maximum pressure is at most 0.2*PStripMaximum or at most 0.1*PStripMaximum.

[0405] like Fig.11A As shown, the presence (eg, holding stationary) of a rounded tip 1123 (eg, a scraper) can generate a shear field or velocity gradient - see, for example, Fig. 11B and Fig. 11C At locations on the ITM surface, the velocity of the treatment fluid may be non-zero (eg, substantially equal to the velocity of the ITM) due to inviscid boundary conditions with the ITM surface; at the applicator, the velocity of the treatment fluid may be zero.

[0406] In some embodiments, i. Formation of a thin wet handling layer (e.g., Figure 2 Step S209 or Fig.12 In step S101) the strong velocity gradient IVG position x=x IVG位置 The invention relates to a method for producing a velocity gradient of the aqueous treatment solution (e.g., in a direction normal to the surface of the ITM) at a location that is (i) generally displaced from the exfoliation surface of the ITM (e.g., at most 3 microns, or at most 2 microns, or at most 1 micron) and / or between the applicator and the exfoliation surface of the applicator; and ii. at the IVG location, the magnitude of the velocity gradient is equal to or exceeds the VG value, wherein the VG value is at least 10 6 sec -1 , or at least 2×10 6 sec -1 , or at least 4×10 6 sec -1 , or at least 5×10 6 sec-1 , or at least 7.5×10 6 sec -1 , or at least 10 7 sec -1 , or at least 2×10 7 sec -1 , or at least 4×10 7 sec -1 , or at least 5×10 7 sec -1 , or at least 7.5×10 7 sec -1 .

[0407] In some embodiments, the velocity gradient is positioned along the printing direction such that:

[0408] i. At an upstream position upstream of the IVG position, the maximum velocity gradient is at most x% of the velocity gradient value at the IVG position;

[0409] ii. at a downstream position downstream of the IVG position, the maximum velocity gradient is at most x% of the velocity gradient value at the IVG position;

[0410] iii. the value of x is at most 50, or at most 30, or at most 20, or at most 10; and / or

[0411] iv. The upstream position and the downstream position are each displaced from the IVG position by at most 2 cm, or at most 1.5 cm, or at most 1.25 cm, or at most 1 cm, or at most 9 mm, or at most 8 mm, or at most 7.5 mm, or at most 7 mm, or at most 6 mm, or at most 5 mm.

[0412] In some embodiments, the circular surface pushes toward the ITM or vice versa in the cross-print direction with a force density of at least 250 g / cm, or at least 350 g / cm, or at least 400 gm / cm, and / or at most 1 kg / cm, or at most 750 g / cm, or at most 600 g / cm.

[0413] Fig.12 Discussion

[0414] Embodiments of the present invention relate to Fig.12 In some non-limiting embodiments, the apparatus, system, and device described in FIGS. 3-11 may be used to perform Fig.12 method. Fig.12 The order of the steps in the embodiment is not limiting - in particular, steps S91-S99 may be performed in any order. In some embodiments, steps S101-S117 are performed in any order. Fig.12 Execute in the order shown in .

[0415] In some embodiments, step S91 may be performed to provide Figure 2 Any feature or combination of features of step S201.

[0416] In some embodiments, step S95 may be performed to provide Figure 2 Any feature or combination of features of step S205.

[0417] In some embodiments, step S101 may be performed to provide Figure 2 Any feature or combination of features of step S209.

[0418] In some embodiments, step S105 may be performed to provide Figure 2 Any feature or combination of features of step S213.

[0419] In some embodiments, step S109 may be performed to provide Figure 2 Any feature or combination of features of step S217.

[0420] In some embodiments, step S113 may be performed to provide Figure 2 Any feature or combination of features of step S221.

[0421] In some embodiments, step S117 may be performed to provide Figure 2 Any feature or combination of features of step S225.

[0422] Steps S91-99 involve Fig.12 In short, (i) in step S101, a thin treatment layer of a wet treatment formulation is applied to an intermediate transfer member (ITM) (e.g., having a release layer having hydrophobic properties), (ii) in step S105, such treatment layer is dried (e.g., flash dried) into a thin dry treatment film on the release surface of the ITM, (iii) in step S109, droplets of aqueous ink are deposited (e.g., by spraying) onto the thin dry treatment film, (iv) in step S113, the ink image is dried to leave the ink image on the dry treatment film on the ITM, and (v) in step S117, the ink image is transferred to a printing substrate (e.g., together with the dry treatment film).

[0423] The components of steps S91 - S99 and the details of process steps S101 - S117 are described below.

[0424] In an embodiment of the present invention, steps S91-S117 are performed as follows:

[0425] (A) in step S91, providing an ITM - for example, at most moderately hydrophobic and / or having hydrophobic properties and / or having a silicone-based release layer and / or only moderately hydrophobic and / or lacking functional groups;

[0426] (B) in step S95, providing an aqueous treatment solution (e.g., (i) having a low evaporation load, and / or (ii) rich in surfactant, and / or (ii) having only moderate hydrophilicity, and / or (iii) containing a water-soluble polymer, and / or (iv) containing a quaternary ammonium salt, and / or (v) having a viscosity low enough to allow the solution to be spread into a uniform thin layer, and / or (vi) containing a hygroscopic material, and / or (vii) being substantially free of organic solvents, and / or (viii) having at most a low concentration of a flocculant containing a multivalent cation;

[0427] (C) in step S99, providing aqueous ink;

[0428] (D) in step S101, applying an aqueous treatment formulation to a peeling surface of an ITM (e.g., an ITM in operation) to form a thin wet treatment layer (e.g., thickness ≤ 0.8 μ) thereon;

[0429] (E) In step S105, the wet thin processing layer is subjected to a drying process (e.g., rapid drying) on ​​the ITM release surface to leave a thin dry processing film (e.g., thickness ≤ 0.08 μ) of the water-soluble polymer on the ITM release surface. For example, the thin dry processing film can have one or both of the following properties: (i) For example, the processing film is a continuous and / or cohesive film; (ii) The upper surface of the dry processing film is characterized by very low roughness;

[0430] (F) in step S109, depositing (e.g., by inkjetting) aqueous ink droplets onto the thin dry processing film to form an ink image thereon;

[0431] (G) In step S119, the ink image leaves ink residue on the drying process film (e.g., to achieve good ink dot spreading)

[0432] (H) In step S119, the dried ink image (eg, at a relatively low temperature) (eg, together with the dried processing film) is transferred from the ITM surface to a printing substrate (eg, a paper substrate or a plastic substrate).

[0433] In some embodiments, executing Fig.12The process of step S101 is such that when the aqueous treatment solution is applied to the ITM, there is little or no beading, so that the resulting thin dried treatment film (i.e., obtained in step S105) is continuous and / or has a smooth (e.g., extremely smooth) upper surface. The smooth upper surface may be important for obtaining a high quality substrate-resident ink image.

[0434] One feature associated with conventional methods of pretreating an ITM and applying an ink image on top of the pretreated ITM is that, after transfer to the substrate, the dried treatment formulation (e.g., after drying) resides on top of the ink image and may add an undesirable gloss to the ink image. To overcome or minimize this potential undesirable effect, a thin dried treatment film (e.g., having a thickness of at most 400 nanometers, or at most 200 nanometers, or at most 100 nanometers, or even less) is obtained in step S105. Additionally, in some embodiments, this thin dried treatment film (i.e., obtained in step S105) is continuous, which may be beneficial, as discussed below.

[0435] Although not limiting, in some embodiments, executing Fig.12 process, whereby the image transfer of step S117 is performed at a low temperature (e.g., for an uncoated substrate) - for example, the temperature is at most 90°C, or at most 85°C, at most 80°C, or at most 75°C, at most 70°C, or at most 65°C, at most 60°C - for example, at about 60°C.

[0436] Fig.12 Discussion of Step S91

[0437] In various embodiments, the ITM (i.e., Fig.12 In step S91 or Figure 2 The ITM provided in step S201 of the embodiment of the present invention may provide one or more (i.e., any combination) of the following features A1-A5:

[0438] A1： In some embodiments, the release layer is formed from an organosilicon material (e.g., addition cured) - this provides the ITM with hydrophobic properties useful in step S117;

[0439] A2： In use Fig.12Prior to the methods of the present invention, silicone-based release layers have been generated in a manner that reduces their hydrophobicity. For example, rather than relying on the addition of functional reactive groups to render the release layer hydrophilic, the silicone release layer can be cured so that the polar atoms in the polar groups (e.g., the oxygen atoms in the polar Si-O-Si moieties) are aligned or otherwise facing outward relative to the release layer surface. In this embodiment, in step S117, the oxygen atoms of the "Si-O-Si" cannot chemically bond with materials within the processing solution, the dried ink image, and / or the dried processing film under typical process conditions. However, in steps S101-S105, the hydrophilicity of the polar "O" facing outward can be benefited.

[0440] A3： The release surface of the ITM may have a moderately hydrophobic nature, but not excessively hydrophobic. Thus, the release surface may have a surface energy (at 25° C.) of at least 23 dynes / cm, and more typically at least 25 dynes / cm, at least 28 dynes / cm, at least 30 dynes / cm, at least 32 dynes / cm, at least 34 dynes / cm, or at least 36 dynes / cm, and / or at most 48 dynes / cm, at most 46 dynes / cm, at most 44 dynes / cm, at most 42 dynes / cm, at most 40 dynes / cm, at most 38 dynes / cm, or at most 37 dynes / cm.

[0441] A4： The receding contact angle of a distilled water drop on the surface of the ink receiving or release layer is typically at least 30°, and more typically, 30° to 75°, 30° to 65°, 30° to 55°, or 35° to 55°;

[0442] A5 The release layer of the ITM may be free or substantially free of functional groups bonded within the cross-linked polymer structure; the inventors believe that these functional groups may increase or promote undesirable adhesion.

[0443] Fig.12 Discussion of Step S95

[0444] In step S95, an aqueous treatment formulation is provided. The treatment formulation comprises at least 50 wt%, or at least 55 wt%, or at least 60 wt%, or at least 65 wt% of an aqueous carrier fluid).

[0445] In various embodiments, the aqueous treatment formulation (i.e., Fig.12 The aqueous treatment formulation is in its initial state before step S101 or is applied Figure 1 The aqueous treatment formulation in its initial state before step S205 may provide one or more (i.e., any combination) of the following features:

[0446] B1. Low evaporation load -- In some embodiments, the initial aqueous treatment formulation has a low evaporation load and is relatively rich in materials that are solid at 60°C (and at atmospheric pressure). As will be discussed below, in some embodiments, this may be useful so that during step S105, the viscosity increases rapidly in a very short time, thereby counteracting any tendency of the aqueous treatment formulation to bead up on the peeling surface of the ITM, which has a hydrophobic nature. For example, the 60°C evaporation load may be at most 10:1, or at most 9:1, or at most 8:1, or at most 6:1, or at most 5:1, or at most 4:1. In some embodiments, this is useful for obtaining a continuously dried treatment film that lacks bald patches.

[0447] B2. Rich in surfactant - In some embodiments, the initial aqueous treatment formulation comprises at least 2 wt%, or at least 2.5 wt%, at least 3 wt%, or at least 4 wt%, or at least 5 wt%, or at least 6 wt%, or at least 7 wt%, or at least 8 wt%, or at least 9 wt%, or at least 10 wt% of one or more surfactants. For example, one or more surfactants present in the initial aqueous treatment formulation (e.g., at least 50 wt%, or at least 75 wt%, or at least 90 wt% of the surfactants in the treatment formulation) can be solid at 60°C, thus contributing to a low evaporation load. In some embodiments, a relatively high concentration of surfactants in the initial aqueous treatment formulation can be used to make the aqueous treatment formulation less hydrophilic, thereby reducing the tendency of the aqueous treatment formulation to bead up on the stripping surface of the ITM in steps S101 and / or S105. In some embodiments, because surfactants are wetting agents, relatively higher concentrations of surfactants can be used to spread the aqueous ink droplets on the dried ink film surface (or counteract any tendency of the ink droplets to shrink) during steps S109 and / or S113, thereby increasing the coverage of the resulting ink dots that ultimately reside on the substrate.

[0448] B3. The presence (e.g., relatively high concentration) of quaternary ammonium salts -- In some embodiments, the initial aqueous treatment formulation comprises at least 1.5 wt % (e.g., at least 2 wt %, at least 2.5 wt %, at least 3 wt %, at least 4 wt %, at least 5 wt %) of a quaternary ammonium salt. In some embodiments, the solubility of the quaternary ammonium salt in water is at least 5% at 25° C. In some embodiments, the ammonium quaternary ammonium salt contains an aliphatic substituent.

[0449] B4. Moderately hydrophilic initial aqueous treatment formulation- In some embodiments, the initial aqueous treatment formulation is only moderately hydrophilic - for example, a static surface tension at 25°C of at most 32 dynes / cm (e.g., between 20 dynes / cm and 32 dynes / cm), or at most 30 dynes / cm (e.g., between 20 dynes / cm and 32 dynes / cm), or at most 28 dynes / cm (e.g., between 20 dynes / cm and 32 dynes / cm). Because the release surface of the ITM has moderately hydrophobic (or moderately hydrophilic) properties, it may not be useful to employ an initial aqueous treatment formulation with high hydrophilicity, which would result in the aqueous treatment formulation beading up on the surface of the ITM in steps S101 and / or S105. This may be particularly important where the thickness of the wet treatment layer is thin, and it is desirable to avoid bald patches so that the resulting thin dried treatment film is continuous.

[0450] B5. The presence of a water-soluble polymer forming a polymer matrix (e.g., Fig.21 After drying in step S105 or Figure 2 After drying in step S213) - In some embodiments, the initial aqueous formulation comprises at least 1.5 wt% (e.g., at least 2 wt%, at least 2.5 wt%, or at least 3 wt%) of at least one water-soluble polymer, more particularly a matrix-forming polymer, whose solubility in water at 25°C is at least 5%. The one or more polymers include, but are not limited to, polyvinyl alcohol (PVA), water-soluble cellulose, including derivatives thereof, such as hydroxypropylmethylcellulose, PVP, polyethylene oxide, and acrylic acid. In some embodiments, the formation of a polymer matrix facilitates the formation of the film and / or gives the dried processed film the desired elasticity and / or cohesiveness or tensile strength, even when the dried processed film is quite thin.

[0451] B6. exist Fig.12 Before being applied to the ITM in step S101 (or Figure 2 before being applied to ITM in step S209) Relatively low viscosity --As will be discussed below, Fig.12 In step S101 (or in Figure 2 In step S209 of the present invention, the present inventors have found that it is desirable to apply a thin but relatively uniform layer of wet aqueous treatment formulation. To this end, the 25°C dynamic viscosity of the initial aqueous treatment formulation may be at most 100 cP, or at most 80 cP, or at most 40 cP, or at most 30 cP. Alternatively or additionally, the 25°C dynamic viscosity of the initial aqueous treatment formulation may be at least 8 cP, or at least 10 cP, or at least 12 cP, or at least 14 cP - for example, in the range of 8 cP to 100 cP, 10 cP to 100 cP, 12 cP to 100 cP, 14 cP to 100 cP, 10 cP to 60 cP, or 12 cP to 40 cP.

[0452] In some embodiments, this feature may be particularly useful when applying a treatment formulation to an ITM because the ITM is moving at high speeds (eg, through an applicator configuration - eg, a fixed applicator configuration).

[0453] B7. No organic solvents such as glycerin - In some embodiments, the presence of low vapor pressure organic solvents may delay the drying of the treatment formulation on the ITM surface in step S105 and / or produce a treatment film that lacks the desired elasticity and / or cohesiveness or tensile strength desired for transfer step S117. In some embodiments, the formulation is free of organic solvents, regardless of their vapor pressure in the pure state, and / or contains at most 3 wt%, at most 2 wt%, at most 1 wt%, or at most 0.5 wt%, or at most 0.25 wt%, or at most 0.1 wt% of organic solvent. Specifically, in some embodiments, the formulation is free of organic solvents and / or contains at most 3 wt%, at most 2 wt%, at most 1 wt%, or at most 0.5 wt%, or at most 0.25 wt%, or at most 0.1 wt% of glycerol. In some embodiments, the formulation is completely free of glycerol.

[0454] B8. Contains water-absorbing materials - In some embodiments, the initial aqueous treatment formulation comprises a solid water absorbent selected to absorb water from the ink when the water absorbent is disposed within the solid dry treatment film. For example, such a solid water absorbent may have a melting point of at most 60°C, or at most 50°C, or at most 40°C, or at most 30°C, or at most 25°C (i.e., in pure form) - for example, at least 1.5 wt%, or at least 2 wt%, or at least 2.5 wt%, or at least 3 wt%. Examples of such water absorbents include, but are not limited to, sucrose, urea, sorbitol, and isomalt.

[0455] B9. The presence of multiple types of surfactants, including at least one surfactant with a surface tension exceeding that of the overall formulation. Sexual Agents -In some embodiments, the initial aqueous treatment formulation comprises a first surfactant and a second surfactant, wherein the first surfactant is more hydrophobic (and has a lower surface tension) than the second surfactant (e.g., a quaternary ammonium salt). In one embodiment, the first surfactant comprises a silicon polyether and / or the second surfactant is a quaternary ammonium salt. For example, the absolute value of the surface tension difference between the first surfactant and the second surfactant can be at least 5 dynes / cm, or at least 7.5 dynes / cm, or at least 10 dynes / cm. For example, (i) the surface tension of the first surfactant is less than the surface tension of the initial aqueous treatment formulation (e.g., at least 1 dyne / cm, or at least 2 dynes / cm, or at least 3 dynes / cm, or at least 4 dynes / cm, or at least 5 dynes / cm, or at least 7 dynes / cm), and / or (ii) the surface tension of the second surfactant exceeds the surface tension of the initial aqueous treatment formulation (e.g., at least 1 dyne / cm, or at least 2 dynes / cm, or at least 3 dynes / cm, or at least 4 dynes / cm, or at least 5 dynes / cm, or at least 7 dynes / cm).

[0456] In some embodiments, the primary purpose of the first surfactant is to reduce the hydrophilicity of the initial aqueous treatment formulation (e.g., to the value described above in 'Feature A4') - for example, so that the treatment formulation does not bead up in steps S101 and / or S105. Alternatively or additionally, the primary purpose of the second surfactant is to provide any of the features described above in B3.

[0457] In various embodiments, the initial aqueous treatment formulation comprises at least 2 wt%, or at least 2.5% weight / weight, at least 3 wt%, or at least 4 wt%, or at least 5 wt% of the first surfactant and / or at least 2 wt%, or at least 2.5 wt%, or at least 3 wt%, or at least 4 wt%, or at least 5 wt% of the second surfactant. For example, the ratio between the weight concentration of the first surfactant and the weight concentration of the second surfactant is at least 0.1, or at least 0.2, or 0.25, or at least 0.33, or at least 0.5, or at least 0.75 and / or at most 10, or at most 4, or at most 3, at most 2, or at most 4 / 3.

[0458] B10. Flocculants with at most low concentrations containing multivalent cations such as calcium chloride - In some embodiments, these compounds are believed to be detrimental to image quality.

[0459] Fig.12 Discussion of Step S99

[0460] Potential characteristics of water-based inks:

[0461] Feature C1: In some embodiments (e.g., involving Figure 2 or Fig.12 The ink provides one or more features (any combination of features) disclosed in PCT / IB13 / 51755 or US2015 / 0025179, PCT / IB14 / 02395 or US14 / 917461, all of which are incorporated herein by reference.

[0462] Fig.12 Discussion of Step S105

[0463] Feature D1:The dry process layer formed in step S105 is thin, but not a monolayer (e.g., significantly thicker than a monolayer)-e.g., has a thickness of at most 100 nanometers. In some embodiments, the dry process layer is extremely thin, with a thickness of at most 80 nanometers, or at most 75 nanometers, or at most 70 nanometers, or at most 65 nanometers, or at most 60 nanometers, or at most 55 nanometers, or at most 50 nanometers. However, in different embodiments, even if the dry process film is extremely thin, it is thicker than a monolayer or monolayer type structure. Therefore, in different embodiments, the thickness of the dry process layer can be at least 20 nanometers, or at least 30 nanometers, or at least 40 nanometers, or at least 50 nanometers. In some embodiments, providing such a 'body' (i.e., minimum thickness feature-e.g., together with one or more other features described below) helps to form a dry process film with cohesion and / or elasticity-this can be used in step S117, wherein it is desired that the dry process film (i.e., at that stage, the ink image of the dryness is carried thereon) maintains its structural integrity when transferred from the ITM to the substrate.

[0464] In some embodiments, the dried treatment formulation can add undesirable gloss to the resulting ink image after transfer to the substrate - therefore, the ability to form a thin but cohesive layer of dried treatment can be useful. A thin layer also facilitates evaporation and drying of the layer into a film.

[0465] Feature D2--The drying process film formed on the ITM in step S105 is continuous and has no 'bald patches' thereon, although it is thin or extremely thin. As will be discussed below, in some embodiments, to achieve this (i.e., particularly for thin or very thin layers), it may be desirable that both: (i) the initially applied wet layer applied in step S101 is continuous and free of bald patches, even if the initially applied wet layer is relatively thin, having a thickness of at most about 1 μ (or at most 0.8 μ, or at most 0.6 μ, or at most 0.4 μ, and more typically at most 0.3 μ, at most 0.25 μ, or at most 0.2 μ and / or at least 0.1 μ), and (ii) the drying process of step S105 occurs very quickly, with the viscosity of the drying process formulation increasing very quickly (e.g., within at most 100 milliseconds, within at most 50 milliseconds, within at most 40 milliseconds, within at most 30 milliseconds, within at most 25 milliseconds, within at most 20 milliseconds, within at most 15 milliseconds, The aqueous treatment formulation may be subjected to beading when the aqueous treatment formulation is applied to the ITM peel layer. However, if the viscosity increases rapidly after the wet treatment layer is applied, the higher viscosity treatment formulation may resist beading better than the low viscosity formulation. In some embodiments and as discussed above in feature "B1", the aqueous treatment formulation may be rich in solids and / or include a low evaporative load - which may facilitate a rapid increase in viscosity.

[0466] Another anti-beading feature that can be used to obtain a continuous dry treatment film (i.e., anti-beading of the treatment formulation in steps S101-S105) can involve the relative properties of: (i) the release surface of the ITM, which in some embodiments has a hydrophobic nature but is not excessively hydrophobic (see feature (see feature "BA"); and (ii) the aqueous treatment formulation, which in some embodiments has a hydrophilic nature but is not excessively hydrophilic (see feature "B4"). When the static surface tension between the aqueous treatment formulation and the release layer of the ITM can be relatively small, the driving force for beading is small, and the viscosity formed by the aqueous treatment (for example, when it increases rapidly) can be sufficient to prevent beading.

[0467] As discussed above, even though the ITM's release layer is only moderately hydrophobic (see feature "A3"), the ITM release layer may have specific properties (see feature "A5") that limit adhesion between the ITM release layer and the dried processing film - thus, even if the processing surface is only moderately hydrophobic to avoid beading of the processing formulation thereon in steps S101 and / or S105, it is possible (e.g., at least in part due to feature "B2") to avoid paying the 'price' for the benefit in step S117 when it is desired to later minimize adhesion between the ITM's release layer and the dried processing film.

[0468] In some embodiments, this can be used to generate substrate-resident ink images with adequate image integrity (see, e.g., Figures 15A-15D ).

[0469] Feature D3 The dried treated film formed on the ITM in step S105 is characterized by an extremely low surface roughness - in some embodiments, the surface roughness may be characterized by a roughness average R of at most 20 nanometers, or at most 18 nanometers, or at most 16 nanometers, or at most 15 nanometers, or at most 14 nanometers, or at most 12 nanometers, or at most 10 nanometers, or at most 9 nanometers, or at most 8 nanometers, or at most 7 nanometers, or at most 6 nanometers. a The dry treated film formed on the ITM may have an R of at least 3 nm or at least 5 nm. a .

[0470] In some embodiments, such a low roughness average value R can be achieved even for a thin or extremely thin dry processed film formed in step S105. a - For example, even if the roughness average R a and the ratio between the thickness of the dried treatment layer is at least 0.02, or at least 0.03, or at least 0.04, or at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08, or at least 0.9, or at least 0.1, or at least 0.11, or at least 0.12, or at least 0.13, or at least 0.14, or at least 0.15, or at least 0.16, or at least 0.17, or at least 0.18, or at least 0.19, or at least 0.2.

[0471] In some embodiments, the dry treatment film on which the aqueous ink droplets are deposited and the surface (eg, the upper surface) of the dry treatment film are characterized by (i) the average roughness R of the dry treatment layer. aand (ii) a dimensionless ratio between a thickness of at most 0.5, at most 0.4, at most 0.3, at most 0.25, at most 0.2, at most 0.15, or at most 0.1, and optionally, at least 0.02, or at least 0.03, or at least 0.04, or at least 0.05, or at least 0.06, or at least 0.07, or at least 0.08.

[0472] Feature D4 - In some embodiments, a continuous dry film can be obtained covering an entire rectangle of at least 10 cm x 1 m, or an entire 1 m2, 3 m2 or 10 m2. The film can have a thickness or average thickness of at most 120 nm, at most 100 nm, at most 80 nm, at most 60 nm, at most 50 nm, or at most 40 nm, and typically at least 20 nm, at least 25 nm, or at least 30 nm.

[0473] Discussion of Steps S109-S117

[0474] In various embodiments, steps S109 and / or S113 and / or S117 may be performed to provide one or more of the following process-related features:

[0475] Feature E1 In some embodiments, step S117 is performed at a low transfer temperature (e.g., up to 90°C, or 80°C, or 75°C, or 70°C, or 65°C, or 60°C - due to thermoplastic properties and / or tensile strength) even when the image is transferred to an uncoated substrate. In some embodiments, providing a low temperature transfer step can be used to reduce or avoid clogging of the inkjet head, and / or can also be used to make the printing process overall more environmentally friendly.

[0476] In some embodiments, both the dried process film and the dried ink image are tacky at the transfer temperature and thus can be cleanly peeled off from the release layer even at relatively low temperatures. Such properties can be at least partially attributed to the chemical characteristics of the initial aqueous process solution. In some embodiments, the chemistry and structure of the release layer (see, e.g., feature 'A5') can also be used to provide a low temperature transfer process in step S117.

[0477] Feature E2-- Spreading -- the manner in which the droplet is deposited on the membrane (e.g., wetting angle) and the physical and / or chemical properties of the treated membrane [A2 and / or A3 and / or A8 - nanoparticles in the ink may also contribute] are such that upon impacting the dried treated membrane, the radius of the ink dot exceeds the radius of the precursor droplet - e.g., the size of each droplet increases beyond the size resulting from the spreading of the droplet caused by the impact energy of the droplet [Dmax = 2·Rmax, or Dimpactmax = 2·Rimpactmax].

[0478] Figures 13A-13E The process of ink droplet deposition on the ITM (eg, its peeling surface) is schematically described. Fig.13A In the process, the ink droplets move toward the ITM. Figures 13B-13C Describes the ink droplet immediately after collision between (i) the droplet and (ii) the ITM (or the dried process film on it). The kinetic energy of the droplet causes the droplet to deform - this is Figures 13B-13C In particular, the kinetic energy of the droplet causes it to expand outwards -- Fig. 13C The maximum radius of the droplet at impact is shown - i.e., the maximum increase in radius is due to the deformation caused by the kinetic energy of the droplet. After the droplet reaches the maximum radius ("R at impact" or "R max impact" are used interchangeably), for example, within 10 milliseconds of impact, due to the kinetic energy driven droplet deformation, the droplet (or its subsequent dots, as each droplet eventually becomes an ink dot after drying - the first dot resides on the ITM (e.g., by drying the treated membrane), as shown Fig.13D As shown, and after transfer, the ink droplets reside on the substrate, as Fig.13E As shown in Figure 2 ), the droplet or its subsequent points can further expand due to physicochemical forces or chemical interactions. This is achieved by comparing Fig. 13C or 13D with Fig. 13B Schematic illustration of the spreading phenomenon. Again, note that 13A-13E are schematic and do not require that the deformed droplet will have Figures 13A-13E The specific shape shown in .

[0479] Figures 14A-14B Instrumentally mapped topographic features of dried processed films produced according to embodiments of the present invention are provided.

[0480] about Figure 2 and 12 General comments - In some embodiments, it is possible to perform Figure 2 Step S201 is to provide Fig.12 In some embodiments, the step S91 may be performed Figure 2 Step S205 provides Fig.12 In some embodiments, the step S95 may be performed Figure 2Step S209 is to provide Fig.12 In some embodiments, the step S101 may be performed Figure 2 Step S213 provides Fig.12 In some embodiments, the step S105 may be performed Figure 2 Step S217 provides Fig.12 In some embodiments, the step S109 may be performed Figure 2 Step S221 provides Fig.12 In some embodiments, the step S113 may be performed Figure 2 Step S225 provides Fig.12 Any feature or combination of features of step S117.

[0481] Figures 14A-14B Provided are instrumental topographical features of dry, continuously processed films produced according to some embodiments of the present invention. The topographical features produced by the Zygo laser interferometer show that the Fig.14A ) and about 100 nanometers ( Fig. 14B ) average film thickness. The film surface is extremely smooth. Fig.14A The average roughness (R a ),exist Fig. 14B The average roughness (R a ). In other topographic feature images, an average film thickness of about 40 nm and an R of about 5 nm were observed. a .

[0482] Despite the film thinness (typically at most 120 nm, at most 100 nm, at most 80 nm, at most 70 nm, at most 60 nm, at most 50 nm, or at most 40 nm, more typically 30 nm to 100 nm, 40 nm to 100 nm, 40 nm to 80 nm, 40 nm to 70 nm, or 40 nm to 60 nm), the films are typically free of bare spots and defects, even at 20 cm 2 , 50cm 2 or 200cm 2 Or even larger areas.

[0483] Without wishing to be limited by theory, the inventors believe that the ultra-smooth surface of the dry process film enables the spreading of the ink dots to occur in a uniform and controlled manner, thereby significantly reducing or avoiding the formation of undesirable creeks and the like. The shape of the resulting ink dots is qualitatively very similar to the excellent shapes (convexity, roundness, edge definition) obtained in Application No. PCT / IB2013 / 000840 to Landa Corporation, which is incorporated by reference for all purposes as if fully set forth herein. This is particularly surprising considering the spreading mechanism utilized by the present disclosure, as compared to the surface tension-controlled droplet pinning and shrinkage disclosed in the said application.

[0484] Figures 15A-15D Some examples of ink dots on paper substrates are shown. In particular, Fig.15A Provides a top view of an enlarged image of a single ink dot adhered to a coated paper substrate (130 GSM) after inkjet onto and transfer from an ITM according to an embodiment of the present invention; Fig. 15B providing a top view of a magnified image of a plurality of inkjet ink dots within a field of view disposed on a coated paper substrate (130 GSM) in accordance with an embodiment of the present invention; Fig. 15C provides a top view of an enlarged image of a single ink dot adhered to an uncoated paper substrate after being jetted onto and transferred from an ITM in accordance with an embodiment of the present invention; Fig.15D A top view of a magnified image of a plurality of inkjet ink dots within a field of view disposed on an uncoated paper substrate according to an embodiment of the present invention is provided.

[0485] The point and convexity measurements are performed according to the procedure disclosed in PCT / IB2013 / 000840. In addition, the point and convexity measurements are performed substantially as follows:

[0486] Image acquisition method

[0487] The acquisition of the point images was performed using a LEXT (Olympus) OLS3000 microscope. The images were taken with X100 and X20 optical zoom. The color images were saved in an uncompressed format (Tiff) with a resolution of 640x640 pixels.

[0488] Furthermore, to measure the spot thickness and diameter, a ZYGO microscope with an X100 lens was used.

[0489] About Analysis

[0490] The basic parameters (and their units) included in this work are:

[0491] · Diameter - fit to ring [D point] [mic]

[0492] ·Perimeter [P] [mic]

[0493] ·Measured area [A] [pix^2]

[0494] Minimum convex surface area [CSA] [pix^2]

[0495] Optical uniformity [STD] [8-bit tone value]

[0496] Thickness [H point] [mic]

[0497] Based on these parameters, calculate the following:

[0498] Aspect ratio: R aspect ratio = D point / H point [dimensionless]

[0499] Point roundness: ER = P2 / (4π·A) [dimensionless]

[0500] DR point: ER-1 [dimensionless]

[0501] Convexity: CX = AA / CSA [dimensionless]

[0502] Non-convexity: Dc point = 1-CX [dimensionless]

[0503] Analysis was performed using MATLAB image processing tools, utilizing, where possible, the above analysis procedures applied in WO2013 / 132418.

[0504] blanket

[0505] ITM can Figure 17-22 The inventive method described and the manufacturing method described therewith. Such an ITM may be particularly suitable for Nanographic Printing TM technology.

[0506] Reference now Fig.16 , Fig.16 A cross section through a carrier 10 is shown schematically. In all the figures, the carrier 10 is shown as a solid black line in order to distinguish it from a layer forming part of a finished product. The carrier 10 has a carrier contact surface 12 .

[0507] In some embodiments, carrier contact surface 12 can be a well-polished flat surface having a roughness (Ra) of at most about 50 nm, at most 30 nm, at most 20 nm, at most 15 nm, at most 12 nm, or more typically, at most 10 nm, at most 7 nm, or at most 5 nm. In some embodiments, carrier contact surface 12 can be between 1 nm and 50 nm, between 3 nm and 25 nm, between 3 nm and 20 nm, or between 5 nm and 20 nm.

[0508] The hydrophilic nature of the carrier contact surface 12 is described below.

[0509] In some embodiments, carrier 10 may be inflexible, such as formed from a sheet of glass or a thick sheet of metal.

[0510] In some embodiments, the carrier 10 may advantageously be formed of a flexible foil, such as one consisting primarily of or comprising aluminum, nickel and / or chromium. In one embodiment, the foil is an aluminized PET (polyethylene terephthalate, polyester) sheet, such as PET coated with pyrolytic aluminum metal. The top coating of aluminum may be protected by a polymer coating, and the sheet typically has a thickness between 0.05 mm and 1.00 mm so as to remain flexible but difficult to bend through a small radius, thereby avoiding wrinkling.

[0511] In some embodiments, the carrier 10 may be advantageously formed of an antistatic polymer film such as a polyester film such as PET. The antistatic properties of the antistatic film may be achieved in various ways known to those skilled in the art, including adding various additives (such as ammonium salts) to the polymer composition.

[0512] In one step of the ITM manufacturing method of the present invention, the result is as follows Fig.17 As shown, a fluid first curable composition (in Fig. 24B 36 ) and forming therefrom a layer 16 on the carrier contact surface 12 , the layer 16 constituting an initial release layer having an outer ink transfer surface 14 .

[0513] The fluid first curable composition of layer 16 may include an elastomer, typically made from a silicone polymer, for example, polydimethylsiloxane, such as vinyl terminated polydimethylsiloxane.

[0514] In some embodiments, the fluid first curable material includes a vinyl-functional silicone polymer, such as a vinyl-silicone polymer comprising at least one pendant vinyl group in addition to a terminal vinyl group, such as a vinyl-functional polydimethylsiloxane.

[0515] In some exemplary embodiments, the fluid first curable material includes a vinyl terminated polydimethylsiloxane, a vinyl functional polydimethylsiloxane including at least one pendant vinyl group on the polysiloxane chain in addition to the terminal vinyl group, a crosslinker and an addition cure catalyst, and optionally further includes a cure retarder.

[0516] As is known in the art, the curable adhesive composition may contain any suitable amount of an addition cure catalyst, typically up to 0.01% per mole of prepolymer.

[0517] Exemplary formulations for the fluid first curable material are provided below in the Examples.

[0518] A layer 16 of a fluid first curable composition is applied to the carrier contact surface 12 and subsequently cured. The layer 16 can be spread to the desired thickness using, for example, a doctor blade (knife on a roller) without allowing the doctor blade to contact the surface of the ink transfer surface 14 that will ultimately serve as the ITM, thereby allowing defects in the doctor blade to not affect the quality of the finished product. After curing, the "peel" layer 16 can have a thickness between about 2 microns and about 200 microns. Fig.24A and 24B The device that can implement such steps and methods is schematically shown in FIG.

[0519] For example, the release layer formulation detailed above can be uniformly applied to a PET support, leveled to a thickness of 5-200 microns (μ), and cured at 120-130°C for about 2-10 minutes. Surprisingly, the hydrophobicity of the ink transfer surface of the release layer so prepared (assessed by its receding contact angle (RCA) of a 0.5-5 microliter (μl) drop of distilled water) can be about 60°, while the other side of the same release layer (which is used to approximate the hydrophobicity of a layer typically prepared with an air interface) can have a significantly higher RCA of typically about 90°. The PET support used to generate the ink transfer surface 14 can typically exhibit an RCA of about 40° or less. All contact angle measurements were performed using a contact angle analyzer - Krüss TM “Easy Drop” FM40Mk2 and / or Dataphysics OCA15 Pro (Particle and Surface Sciences Pty. Ltd., Gosford, NSW, Australia).

[0520] In the subsequent steps of the method, the results are as follows Fig.18As shown, on the side opposite to the ink transfer surface 14, an additional layer 18, referred to as a compliant layer, is applied to the layer 16. The compliant layer 18 is an elastomeric layer that allows the layer 16 and its outermost surface 14 to closely follow the surface contours of the substrate on which the ink image is impressed. The attachment of the compliant layer 18 to the side opposite to the ink transfer surface 14 may include applying an adhesive or bonding composition in addition to the material of the compliant layer 18. Typically, the compliant layer 18 may have a thickness between about 100 microns and about 300 microns or more.

[0521] Although the compliant layer 18 can have the same composition as the release layer 16, material and process economies may warrant the use of less expensive materials. In addition, the compliant layer 18 is typically selected to have different mechanical properties (e.g., greater stretch resistance) than the release layer 16. Such desired property differences may be achieved, for example, by utilizing a different composition relative to the release layer 16, by changing the ratios between the ingredients of the formulation used to prepare the release layer 16, and / or by adding additional ingredients to such formulation, and / or by selecting different curing conditions. For example, the addition of filler particles may advantageously increase the mechanical strength of the compliant layer 18 relative to the release layer 16.

[0522] In some embodiments, the compliant layer 18 may include various rubbers. Preferably, such rubbers are stable at a temperature of at least 100° C. and may include rubbers such as alkyl acrylate copolymer rubber (ACM), methyl vinyl silicone rubber (VMQ), ethylene propylene diene monomer rubber (EPDM), fluoroelastomer polymers, nitrile rubber (NBR), ethylene acrylic elastomer (EAM), and hydrogenated nitrile rubber (HNBR).

[0523] As a non-limiting example, LSR 2530 (Momentive Performance Materials Inc., Waterford NY) two-component liquid silicone rubber was applied to the aforementioned cured release layer 16, wherein the two components were mixed at a ratio of 1:1. The silicone rubber mixture was metered / leveled with a spatula to obtain an initial compliant layer 18 having a thickness of about 250 microns, and then cured at 150-160°C for about 5 minutes.

[0524] In the subsequent steps of the method, the results are as follows Fig.19As shown, a reinforcement or support layer 20 is constructed on the compliant layer 18. The support layer 20 generally includes a fiber reinforcement material in the form of a web or fabric to provide the support layer 20 with sufficient structural integrity to withstand stretching when the ITM is held taut in the printing system. The support layer 20 is formed by coating the fiber reinforcement material with a resin that is subsequently cured and retains flexibility after curing.

[0525] Alternatively, the support layer 20 can be formed as a reinforcement layer alone, including such fibers embedded and / or impregnated in a resin that is independently cured. In this case, the support layer 20 can be attached to the compliant layer 18 via an adhesive layer, optionally eliminating the need for in-situ curing of the support layer 20. Typically, the support layer 20, whether formed in-situ on the compliant layer 18 or formed separately, can have a thickness between about 100 microns and about 500 microns, a portion of which is attributed to the thickness of the fibers or fabrics, which typically varies between about 50 microns and about 300 microns. However, the support layer thickness is not restrictive. For heavy-duty applications, for example, the support layer can have a thickness greater than 200 microns, greater than 500 microns, or 1 mm or greater.

[0526] For example, for the multilayer ITM structure described herein, including the vinyl functionalized release coating 16 and the two-component silicone rubber compliant layer 18, a support layer 20 comprising a woven fabric of glass fibers is applied. The glass fiber fabric having a thickness of about 100 microns is a plain weave fabric having 16 yarns / cm in the vertical direction. The glass fiber fabric is embedded in a liquid silicone rubber layer containing the corresponding compliant layer. In a curable fluid of LSR 2530. In summary, the resulting support layer 20 has a thickness of about 200 microns and is cured at 150° C. for about 2-5 minutes. Preferably, a denser woven fabric (eg, having 24×23 yarns / cm) may be used.

[0527] After the support layer 20 is formed or attached in situ, additional layers may be constructed on its back side as desired. Fig. 20 An optional carpet 22 is shown secured to the reverse side of the support layer 20 (e.g., by a cured adhesive or resin), and Fig.21 A high friction layer 24 is shown applied to the reverse side of the blanket 22. As will be appreciated by those skilled in the art, a variety of relatively soft rubbers may be used to prepare a layer having high friction properties, silicone elastomer being only one example of such a rubber. In the absence of an intervening layer such as the blanket 22, the high friction layer 24 may be attached directly to the support layer 20.

[0528] As described above, all layers added to the release layer of the ITM (e.g., 18, 20, 22, 24 or any intervening adhesive or primer layers, etc.) together form the base of the structure, such as with respect to the Fig.23C As shown in the base 200.

[0529] Before using the ITM, the support 10 must be removed to expose the ink transfer surface 14 of the release layer 16, such as Fig. 22 Typically, the finished product can be simply peeled off from the carrier 10 .

[0530] If the carrier 10 is a flexible foil, it may be preferred to leave it in place on the ITM until the ITM is installed in the printing system. The foil will serve to protect the ink transfer surface 14 of the ITM during storage, transportation and installation. In addition, after the manufacturing process is completed, the carrier 10 can be replaced by a replacement foil suitable as a protective film.

[0531] Figures 24A to 24D An apparatus 90 is schematically shown in which an ITM may be manufactured. Fig.24A A schematic diagram of such an apparatus 90 is provided, the apparatus 90 having an unwinding roller 40 and a winding roller 42 that move a flexible endless conveyor 100. Along the path followed by the conveyor 100 can be located a dispensing station 52 capable of dispensing a curable fluid composition suitable for the desired ITM; a leveling station 54 capable of controlling the thickness of the curable layer as it moves downstream of the station; and a curing station 56 capable of at least partially curing the layer so that it can be used as an initial layer for subsequent steps (if any). The dispensing station 52, the leveling station 54, and the curing station 56 constitute a layer forming station 50a. As shown in 50b, the apparatus 90 can optionally include more than one layer forming station. In addition, the forming station 50 can include additional sub-stations, as shown by the dispensing roller 58 in the station 50a.

[0532] In some embodiments, the need for an endless conveyor 100 is avoided: the carrier 10 is tensioned directly between the rollers 40 and 42. The unprocessed carrier 10 is unwound from the unwinding roller 40 and, after passing through the stations 50a and 50b, is rewound onto the winding roller 42.

[0533] Although not shown in the figures, the apparatus may also include a "surface treatment" station upstream of the dispensing station, which facilitates the subsequent application of the curable composition, or its attachment to the carrier contact surface or initial layer as the case may be. As described with respect to the carrier, the optional surface treatment station (not shown) may be suitable for physical treatment (e.g., corona treatment, plasma treatment, ozonation, etc.).

[0534] Fig. 24BIt is schematically shown how a carrier 10 placed on a conveyor 100 is coated in a forming station 50 of an apparatus 90. At a dispensing station 52, a curable composition 36 of a release layer 16 is applied to the carrier contact surface 12. When the carrier 10 is driven in the direction of the arrow, the curable composition 36 is leveled to a desired thickness at a leveling station 54, for example by using a scraper. As the leveled layer travels downstream, it enters a curing station 56, which is configured to at least partially cure the curable composition 36, thereby enabling the formation of an initial layer 16 at the outlet side of the curing station. Fig.16 and 17 Such exemplary steps are described.

[0535] Fig.24C and 24D Schematically showing how the additional layers (forming the base) are applied. In FIG. 24C , the curable composition 38 is dispensed at a dispensing station 52 (which may be the same or different from the station used to coat the carrier with the release layer 16, e.g. Fig. 24B The curable composition 38 is leveled to a desired thickness at leveling station 54, then enters curing station 56, and leaves curing station 56 when sufficiently cured to be used as an initial layer 18 for subsequent steps, and so on. Fig.18 Such exemplary steps are described. Now referring to Fig.24C , Fig.24C Schematically depicted is a curable composition 39 applied at a dispensing station 52. A body of a support layer (e.g., fabric) may be conveyed by dispensing rollers 58. The exemplary fabric may be immersed in the curable composition at a station 60 before it enters a curing station 56. In this manner, a support layer 20 may be formed on the exit side of the curing station.

[0536] Figures 23A and 23B schematically illustrate how defects appear in the part of the outer layer 80 (e.g., peeling layer) prepared according to the above-mentioned method of the art. Figure 23A shows different phenomena related to bubbles, and if solidification occurs before such bubbles can be eliminated (e.g., by degassing), bubbles can be captured in any curable composition. As can be seen from the figure, when tiny bubbles 82 migrate toward the air interface, the orientation of layer 80 on the main body 800 during manufacture, so along the migration direction (indicated by arrows), they can merge into larger bubbles. Bubbles (regardless of their size) can remain captured in the body of the layer or on its surface, and the upper part of the bubble envelope forms a protrusion 84. When the bubbles adjacent to the surface break while the layer solidification is carried out, even if the envelope part of the bubble protruding from the surface disappears, the pit 86 can also be retained. Therefore, these phenomena generally provide a "gradient" of bubbles, and the upper part is generally filled with larger bubbles and / or has a higher bubble density per cross-sectional area or per volume compared to the lower part, and lower and higher are relative to the orientation during the layer manufacturing. The impact of bubble-derived defects on the surface is self-evident, and surface heterogeneity generally has a negative impact on any subsequent interaction, such as with an ink image. Over time, such ITMs are generally operated under tension and / or under pressure, and the pits can widen and merge to form more significant cracks. Therefore, this phenomenon may affect the structural integrity of the surface and any mechanical properties such as integrity will be imparted to the ITM.

[0537] Figure 23B schematically illustrates different phenomena related to solid contaminants such as dust. Although in the present invention illustration, dust is shown in addition to bubbles, this need not be the case, and each such surface or layer defect can occur independently. As can be seen from the figure, solid contaminants can remain on the surface. If sedimentation of contaminants occurs after the outer layer 80 is cured, these contaminants 92 can even be removed by properly cleaning the outer surface. Still, this phenomenon is undesirable because additional treatment is required before such ITM can be used. If such contamination occurs when the layer is still uncured, the contaminant can be captured on the surface of the layer 80 (e.g., contaminant 94, which appears to be "floating"), or can even be immersed in the peeling layer, (e.g., contaminant 96). As can be easily understood, larger / heavier contaminants can sink deeper than smaller / heavier contaminants.

[0538] Unlike methods known in the art, the methods disclosed herein include forming a layer of a fluid first curable material, wherein one side of the layer contacts a carrier contact surface, the layer constituting an initial peeling layer. The carrier contact surface serves to protect the initial peeling layer, imparting the desired properties to the ink transfer layer, while the carrier serves as a physically strong support structure upon which other layers are added to form the ITM until the ITM is complete. As a result, many potential sources of defects are avoided. Furthermore, the finish of the ink transfer surface is primarily, if not exclusively, determined by the carrier contact surface.

[0539] Fig.23C A cross section through an outer layer 16 (e.g., a peeling layer) prepared according to the method of the present invention is schematically shown. For comparison with the previous figures, the cross section is shown without a carrier and in the same orientation as Figures 23A and 23B, although the manufacturing is performed in a reversed orientation as shown by the arrows. As will be described in detail below, the base 200 is attached to the first outer layer 16 after the layer is at least partially cured and is therefore not equivalent to the body 800 that has been used as a support during the manufacturing process. For illustrative purposes only, the layer 16 is shown as including a significant number of bubbles 82, but this is not necessarily the case. However, if present, such bubbles would show a different pattern than previously described. First, since the now uppermost ink transfer surface 14 of the layer 16 was previously in contact with the carrier, no protrusions are observed, and therefore the peeling layer does not have phenomena such as previously shown by the surface protruding bubbles 84. Similarly, the pits previously shown as cavities 86 are very unlikely because they imply the use of incompatible curable layers and carriers. According to the method of the present invention, since the outer layer is formed and the curable material properly wets the support, it is believed that there are substantially no bubbles trapped between the support and the initial layer formed thereon. Therefore, if present, such bubbles will be arranged in the body of the layer. However, since the manufacturing is performed in a reversed orientation compared to conventional methods, the gradient of bubbles will be reversed for the same reason. Therefore, and as Fig.23C As depicted, tiny bubbles are closer to the outer surface than larger bubbles, which are closer to the base.

[0540] The inventive release layer structures of the present invention prepared from addition cure formulations may be substantially free of functional groups, or have insubstantial amounts of functional groups (eg, insubstantial amounts of OH groups), covalently attached within the polymer matrix. For example, these functional groups may include moieties such as C=O, S=O, and OH.

[0541] Because these release layer structures contain at most insubstantial amounts of such functional groups, it would be expected that their release layers would be highly hydrophobic. However, the inventors have surprisingly discovered that the release layer surface produced by the methods of the present invention can actually be slightly hydrophilic, and significantly more hydrophilic than a corresponding release layer having the same composition but produced using conventional curing techniques in which the release layer is exposed to air ("standard air cure"). Without wishing to be bound by theory, the inventors believe that the intimate contact between the support contact surface and the initial release layer surface induces in the release layer surface the slightly hydrophilic nature of the support contact surface.

[0542] As discussed above, an ITM peeling layer with low surface energy can be beneficial for transferring a dried ink image to a printed substrate. However, during the ink receiving stage, aqueous ink droplets ejected onto such a low energy hydrophobic peeling layer tend to bead up after initial impact, thereby impairing image quality. A peeling layer with higher energy and lower hydrophobicity can mitigate this effect, but is detrimental to image transfer quality. The inventors have found that the peeling layer structure of the present invention generally has a characteristic moderately hydrophobic peeling surface, as indicated by a receding contact angle of distilled water of at most 80°, or at most 70°, typically at most 60°, or at most 50°, and more typically, 30°-60°, 35°-60°, 30°-55°, 30°-50°, 30°-45°, or 35°-50°. However, surprisingly, both ink receiving and transfer of dried heated ink images can be of good quality. It must be emphasized that lower values ​​of receding contact angle (as well as dynamic contact angle discussed below) can be achieved by employing support surfaces with higher hydrophilicity (lower contact angle relative to a distilled water drop) and / or by corona (or similar) treatment.

[0543] Without wishing to be bound by theory, the inventors believe that the induced surface properties described above improve the interaction between polar groups (e.g., O-Si-O) on the release layer surface and corresponding polar moieties (e.g., OH groups in water) in the aqueous liquid (e.g., aqueous inkjet ink) deposited thereon, thereby facilitating the reception of jetted ink droplets. Subsequently, after drying the ink and heating the ink film to the transfer temperature, these interactions are weakened, enabling complete transfer of the dry or substantially dry ink image. Thus, the performance of the release layer structure of the present invention - both at the ink receiving stage and the ink film transfer stage - is significantly better than what would be expected from a release layer having moderate hydrophobicity but without the special surface structure and properties induced by the carrier contact surface.

[0544] Example

[0545] Reference is now made to the following examples, which together with the above descriptions illustrate the invention in a non limiting fashion.

[0546] List of Materials Used :

[0547]

[0548] Supports used as substrates in the preparation of release layer surfaces include (1) antistatic polyester films (Examples 1-7); (2) untreated polyester films, i.e., not antistatic (Example 11); and (3) aluminized polyester films (Example 10).

[0549] Example 1

[0550] The ITM peeling layer of Example 1 has the following composition (by weight):

[0551]

[0552] The release layer is prepared essentially as described in the blanket preparation procedure of the present invention, as follows.

[0553] Blanket preparation process (release layer for curing on carrier surface)

[0554] All components of the peel layer formulation are thoroughly mixed together. The initial peel layer of the desired thickness is applied to the PET sheet using a rod / knife (other coating methods may also be used) and then cured at 150°C for 3 minutes. Subsequently, Siloprene LSR 2530 is applied on top of the peel layer using a knife to obtain the desired thickness. Curing is then performed at 150°C for 3 minutes. Another layer of Siloprene LSR 2530 is then applied on top of the previous (cured) silicone layer, and the glass fiber fabric is bonded to this wet fresh layer, thereby allowing the wet silicone to penetrate into the fabric structure. Curing is then performed at 150°C for 3 minutes. The last layer of Siloprene LSR 2530 is then applied to the glass fiber fabric and cured again at 150°C for 3 minutes. The overall blanket structure is then cooled to room temperature and the PET is removed.

[0555] Example 2

[0556] The ITM peeling layer of Example 2 has the following composition:

[0557]

[0558]

[0559] Blankets were prepared essentially as described in Example 1.

[0560] Example 3

[0561] The ITM peeling layer of Example 3 has the following composition:

[0562] Component name Number of copies DMS-V35 70 XPRV-5000 30 VQM-146 40 Inhibitor 600 5 SIP6831.2 0.1 Crosslinker 100 6.5 Silsurf A010-D-UP 5

[0563] Blankets were prepared essentially as described in Example 1.

[0564] Example 4

[0565] The ITM peeling layer of Example 4 has the following composition:

[0566] Component name Number of copies DMS-V35 100 VQM-146 40 Inhibitor 600 3 SIP6831.2 0.1 Crosslinking agent HMS-301 5

[0567] Blankets were prepared essentially as described in Example 1.

[0568] Example 5

[0569] The ITM peeling layer of Example 5 is composed of LSR 2530 (Momentive Performance Materials Inc., Waterford, NY) two-component liquid silicone rubber was prepared in which the two components were mixed in a ratio of 1: 1. The blanket was prepared essentially as described in Example 1.

[0570] Example 6

[0571] The ITM peeling layer of Example 6 has substantially the same composition as Example 4, but contains a commercially available silicone-based resin SR545 (Momentive Performance Materials Inc., Waterford, NY) containing polar groups. These polar groups are of the "MQ" type, where "M" represents Me3SiO, and "Q" represents SiO4. The complete composition is as follows:

[0572] Component name Number of copies DMS-V35 100 VQM-146 40 SR545 5 Inhibitor 600 3 SIP6831.2 0.1 Crosslinking agent HMS-301 5

[0573] Blankets were prepared essentially as described in Example 1.

[0574] Example 7

[0575] The ITM release layer of Example 7 has substantially the same composition as Example 6, but contains polymer RV 5000, which includes a vinyl functional polydimethylsiloxane having a high density of vinyl groups, as described above. The complete composition is as follows:

[0576] Component name Number of copies DMS-V35 70 RV 5000 30 VQM-146 40 Inhibitor 600 5 SIP6831.2 0.1 Crosslinking agent HMS-301 12 SR545 5

[0577] Blankets were prepared essentially as described in Example 1.

[0578] Comparative Examples 1A-1F

[0579] The ITM release layer was prepared as the "corresponding release layer" or "reference release layer" of the composition of Examples 1-6, so that the corresponding release layers (referred to as Comparative Examples 1A-1F) had the same composition as Examples 1-6, respectively. However, during the curing of the release layer, the release layer surface (or "ink receiving surface") was exposed to air ("standard air curing") according to the general preparation procedure provided below.

[0580] Comparative Blanket Preparation Procedure (Peel Layer Exposed to Air During Curing)

[0581] The first layer of Siloprene LSR 2530 was coated on the PET sheet using a rod / knife, and then cured at 150°C for 3 minutes to obtain the desired thickness. Another layer of Siloprene LSR 2530 was then coated on top of the previous (cured) silicone layer, and the glass fiber fabric was bonded to this wet fresh layer, thereby allowing the wet silicone to penetrate into the fabric structure. Siloprene LSR 2530 was then coated on top of the glass fiber fabric and cured at 150°C for 3 minutes. Before forming the initial peel layer, all components of the peel layer formulation were thoroughly mixed together. The peel layer was coated on top of the cured Siloprene LSR 2530 to obtain the desired thickness, followed by curing at 150°C for 3 minutes while the peel layer surface was exposed to air.

[0582] Example 8

[0583] The procedure for performing receding contact angle (RCA) and advancing contact angle (ACA) measurements using a dedicated Dataphysics OCA15 Pro contact angle measurement apparatus (Particle and Surface Sciences Pty.) is a conventional technique described in detail by Dr. Roger P. Woodward (especially "Contact Angle Measurements Using the Drop Shape Method", www.firsttenangstroms.com / pdfdocs / CAPaper.pdf).

[0584] The results for Examples 1-6 are provided below, along with the results for release layers produced according to Comparative Examples 1A-1F.

[0585] In almost all cases, the resulting release surface exhibits a lower receding contact angle relative to the support surface than the same formulation cured in air. More typically, the resulting release surface exhibits a receding contact angle relative to the support surface that is at least 5°, at least 7°, at least 10°, at least 12°, or at least 15° lower, or 5°-30°, 7°-30°, 10°-30°, 5°-25°, 5°-22°, 7°-25°, or 10°-25° lower.

[0586] Example 9

[0587] The release surfaces generated in Examples 1-6 and the corresponding release surfaces generated in Comparative Examples 1A-1F were aged at 160° C. for 2 hours to simulate the aging of the release layer under extended operating conditions. The receding contact angle was measured and the results are as follows:

[0588]

[0589] With respect to the comparative examples, it is apparent that the receding contact angle is substantially maintained after the aging process is performed. However, with respect to Examples 1-6 of the present invention, it is apparent that the receding contact angle generally increases by 4°-15° after the aging process is performed. Without wishing to be bound by theory, the inventors believe that the increase in contact angle in the release layer structure of the present invention can be attributed to the loss of hydrophilic behavior (or increase in hydrophobic behavior) due to some change in the position of the polar groups (e.g., Si-O-Si) on the release layer surface.

[0590] Example 10

[0591] A blanket including a release layer of the composition of Example 2 was prepared essentially as described in Example 1, but for an aluminized PET carrier surface.

[0592] Embodiment 11

[0593] A release layer having the release layer composition of Example 2 was prepared essentially as described in Example 1, but on a commercially available PET carrier surface that had not been subjected to antistatic pretreatment.

[0594] Example 12

[0595] The peeling layers produced in Examples 2, 10 and 11 according to the present invention were subjected to contact angle measurements to determine both the advancing contact angle and the receding contact angle. The results are as follows:

[0596]

[0597] Examples 10 and 11 exhibited receding contact angles that were approximately 30° less than the receding contact angle of the same composition when the release layer was cured upon exposure to air. The release layer surface of Example 2, prepared for an antistatic PET carrier surface, exhibited a receding contact angle that was approximately 50° less than the receding contact angle of the same composition prepared upon exposure to air.

[0598] Example 13

[0599] The support surfaces utilized in Examples 2, 10, and 11 were subjected to contact angle measurements to determine both the advancing and receding contact angles. The results are as follows:

[0600]

[0601] From the obtained receding contact angles, it can be seen that the three support surfaces exhibit hydrophilic behavior, and the PET subjected to antistatic treatment exhibits the greatest degree of hydrophilic behavior (20° RCA vs. 40° RCA).

[0602] Significantly, the hydrophilic behavior of the carrier surface is at least partially induced in the corresponding release surface: the formulation cured upon exposure to air has an RCA of 65°; the same formulation prepared against an antistatic PET surface has an RCA of 45°; the antistatic PET carrier used exhibits an RCA of 20°. Thus, the release layer structure of the present invention has a release surface whose hydrophilic / hydrophobic properties are intermediate between those of the same formulation cured in air and the carrier surface itself.

[0603] Embodiment 14

[0604] The release layer surface energy was calculated for the ink receiving surfaces of the following examples: Example 1A, cured under exposure to air; Example 1, cured on an antistatic PET surface; and Example 1, cured on an antistatic PET surface and then subjected to a standard aging procedure at 160° C. for 2 hours. These three examples had the same chemical formulation.

[0605] For each of these examples, the total surface energy was calculated using the classical "harmonic mean" method (also known as the Owens-Wendt surface energy model, see, e.g., KRUSS Technical Note TN306e). The results are as follows:

[0606] Peel preparations <![CDATA[Total surface energy J / m 2 > Example 1A - Air Cured 20.9 Example 1 - Aged 22.6 Example 1 26.1

[0607] In Example 1A, cured under exposure to air, the release layer surface was extremely hydrophobic and, as expected, the total surface energy of the surface was low, 20.9 J / m 2For polydimethylsiloxane (PDMS), this is very close to the literature value for surface energy. Remarkably, Example 1 cured on an antistatic PET surface exhibited approximately 26 J / m 2 The total surface energy of the formulation was 26 J / m 2, which was moderately hydrophobic compared to the "air cured" sample. After the formulation was subjected to a standard aging procedure, the total surface energy increased from about 26 J / m 2 to about 10 J / m 2. 2 Reduced to 23 J / m 2 This result appears to confirm the RCA results obtained for various aged and unaged materials of this exemplary formulation.

[0608] Embodiment 15

[0609] The release layer surface energy was calculated for the ink receiving surfaces of the following examples: Example 2A, cured under exposure to air; Example 2, cured on an antistatic PET surface; and Example 2, cured on an antistatic PET surface followed by a standard aging procedure at 160° C. for 2 hours. These three examples had the same chemical formulation.

[0610] As in Example 14, the total surface energy was calculated using the classic "harmonic mean" method. The results are as follows:

[0611] Peel preparations <![CDATA[Total surface energy (J / m 2 )]]> Example 2A - Air Cured 34.6 Example 2 - Aged 39.9 Example 2 49.1

[0612] In Example 2A, cured under exposure to air, the surface of the release layer was less hydrophobic than the release layer of Example 1A, which had a total surface energy of about 35 J / m2. Significantly, Example 2 cured to an antistatic PET surface exhibited a total surface energy of about 49 J / m2, which had a significantly lower hydrophobicity than the "air cured" sample. After this formulation was subjected to a standard aging procedure, the total surface energy decreased from about 49 J / m2 to about 40 J / m2. This result appears to confirm the RCA results obtained for various aged and unaged materials of this exemplary formulation.

[0613] Example 16

[0614] The temperature of the blanket surface was maintained at 75°C. An image (typically a color gradient of 10-100%) was printed on the blanket at a speed of 1.7 m / s with a resolution of 1200 dpi. An uncoated paper (A4 Xerox Premium Copier Paper, 80 gsm) was set between the pressure roller and the blanket, and the roller was pressed against the blanket while the pressure was set to 3 bar. The roller moved over the paper, exerting pressure on the contact line between the blanket and the paper and facilitating the transfer process. In some cases, incomplete transfer could be observed, with ink residues remaining on the blanket surface. In order to evaluate the extent of ink residues, glossy paper (A4 Burgo glossy paper 130 gsm) was applied to the blanket, similar to the uncoated paper, and the transfer process was performed again. Any ink that remained on the blanket and was not transferred to the uncoated paper will be transferred to the glossy paper. Therefore, the ink residue of glossy paper (% of image surface area) can be evaluated according to the following ratio:

[0615] A-No visible residue

[0616] B-1-5% visible residue

[0617] C- Visible residue exceeding 5%

[0618] The results of the evaluation are as follows:

[0619] Peel preparations Transfer Level Example 4 B Example 1 B Example 2 A Example 3 A Example 6 C

[0620] Embodiment 17

[0621] Example 16 was repeated for the release surfaces of Examples 2 and 3, but the printing speed on the blanket was 3.4 m / sec. Transfer rating A was maintained for both release surfaces.

[0622] Embodiment 18

[0623] The ITM release layer compositions of Examples 2 and 3 were cured against a PET substrate according to the procedure provided in Example 1. The ITM release layer compositions of Examples 2 and 3 were cured against air according to the procedure provided in Comparative Examples 1B and 1C. The samples were then subjected to dynamic contact angle (DCA) measurements at 10 seconds and then at 70 seconds according to the following procedure:

[0624] The droplet is placed on a smooth PTFE membrane surface so that the droplet falls as little as possible, so that the kinetic energy does not spread the droplet. A pendant droplet is then formed. Subsequently, the sample is raised until it touches the bottom of the droplet. If the droplet is large enough, the adhesion forces of the surface will pull it off the needle tip. The needle tip is positioned above the surface at a height such that the growing pendant droplet will touch the surface and break away before it falls freely due to its own weight.

[0625] The dynamic contact angle was then measured at 10 seconds and 70 seconds. The results are as follows:

[0626]

[0627] It was observed that the initial measurement of the dynamic contact angle at 10 seconds provided a strong indication of the hydrophilicity of the release layer surface. Subsequent measurements at 70 seconds provided an indication of the extent to which any liquid (e.g., polyether glycol functionalized polydimethylsiloxane) disposed within the release layer had been incorporated into the droplet. This binding could further reduce the measured DCA.

[0628] Thus, the samples cured on PET exhibited significantly lower (more hydrophilic) initial DCA measurements (105°, 87°) relative to the hydrophilic initial DCA measurements (114°, 113°) for the corresponding samples cured on air. In addition to the demonstrated hydrophilicity, the samples cured on PET exhibited a DCA drop of 8° to 17° between the first and second measurements.

[0629] Figures 25A-25C Images of various ink patterns printed onto the release layer of the ITM of the present invention are provided, wherein the release layer of Example 2 was cured against a PET carrier surface. Figures 26A-26C is an image of the same ink pattern printed onto the release layer of Example 2, but where the release layer is cured to air. Fig.25A and 26A It is obvious that the release layer of the ITM of the present invention exhibits a higher optical density and more accurately reflects the ink image pattern. Fig.25C and 26C The comparison between the two yields the same conclusion. Fig.25B Compared with 26B, it is obvious Fig.25B Each ink dot in the Fig.26B The corresponding ink dots in .

[0630] As used in this specification and in the claims section that follows, the term "receding contact angle" or "RCA" refers to the receding contact angle measured at ambient temperature using a Dataphysics OCA15 Pro contact angle measurement device or a comparable video-based optical contact angle measurement system using the drop shape method described above. Similarly, "advancing contact angle" or "ACA" refers to the advancing contact angle measured in essentially the same manner.

[0631] As used in this specification and in the claims that follow, the term "dynamic contact angle" or "DCA" refers to the dynamic contact angle as measured at ambient temperature using a Dataphysics OCA15 Pro contact angle measurement apparatus or a comparable video-based optical contact angle measurement system using the method detailed by Dr. Roger P. Woodward in "Contact Angle Measurements Using the Drop Shape Method," supra, and as detailed above in Example 17.

[0632] As used in this specification and in the claims that follow, the term "standard aging procedure" refers to an accelerated aging regimen performed on each tested release layer at 160°C for 2 hours in a standard convection oven.

[0633] As used in this specification and the claims that follow, the term "standard air cure" refers to a conventional curing method for curing a release layer, such as described with respect to Comparative Examples 1A-1F, wherein the release layer surface (or "ink receiving surface") is exposed to air during the curing of the release layer.

[0634] As used in this specification and in the claims section that follows, the term "bulk hydrophobicity" is characterized by the receding contact angle of a distilled water droplet disposed on the inner surface of the release layer, the inner surface being formed by exposing areas of cured silicone material within the release layer.

[0635] For Examples C1-C12, the viscosity of each sample measured at room temperature is provided below (all values ​​are in cP):

[0636] C1=19.2

[0637] C2=18.15

[0638] C3=22.3

[0639] C4=36.2

[0640] C5=19.8

[0641] C6=21.2

[0642] C7=28.1

[0643] C8=18.0

[0644] C9=50.0

[0645] C10=48.2

[0646] C11=20.2

[0647] C12=20.7

[0648] For the 12 exemplary formulations, the surface tension of the aqueous treatment formulations was more uniform and generally ranged from 26 mN / m to 29 mN / m, or 26 mN / m to 28 mN / m at room temperature.

[0649] Examples C1-C12

[0650] Exemplary compositions of aqueous ITM treatment fluids of the present invention are provided in the following table:

[0651]

[0652]

[0653] Examples C13-C22

[0654] The compositions of ITM aqueous treatment fluids and their various properties are provided in the table below as example compositions C13 through C22.

[0655]

[0656] Example C23

[0657] In Example C23, an additional aqueous treatment formulation is provided. This formulation contains no surfactant except for a quaternary ammonium salt (Larostate 264A), which is present in a relatively high percentage (8 wt%) to sufficiently reduce the surface tension of the aqueous treatment formulation. The surface tension and viscosity at room temperature are 32.3 mN / m and 17.8 cP, respectively.

[0658]

[0659] Pigment preparation

[0660] The pigments used in the examples described below are generally supplied with an initial particle size of several microns. These pigments are ground to the submicron range in the presence of a dispersant, and the two materials are fed into the grinding device as an aqueous mixture. Unless otherwise stated, 30 g of pigment is mixed with a dispersant of a weight that satisfies the weight ratio shown in the following examples. Deionized water is added to a balance of 200 g. In the Attritor HDDM-01 / HD-01 of Union Process, In the presence of 4500 g of chrome steel balls (Glen Mills Inc., USA) with a diameter of 0.8 mm and under a certain energy input, the liquid slurry is reduced in size for a period of time sufficient to prepare a slurry containing particles having a diameter of 100 nm or less (D V50cmThe mill is typically operated at about 3000 rpm for at least 48 hours, the grinding duration also depending on the initial particle size.

[0661] The particle size and its distribution in the compositions thus prepared were determined using the DLS method (Malvern Zetasizer Nano ZS). Unless otherwise stated, an aliquot was removed from the composition under consideration and, if necessary, diluted in double distilled water (DDW) to obtain a sample with a solid concentration of about 1% by weight. Prior to the DLS measurement, the liquid sample was briefly sonicated (for about 7 seconds at 75% of the maximum power in a Sonics Vibracell VCX 750 (750 Watts)) to ensure proper dispersion of the pigment particles during the evaluation of the particle size and distribution. Results of the volume analysis based on the particles.

[0662] Once the pigment dispersant mixture has reached the desired particle size, 50 g of water is added to the chamber of the grinding apparatus and the resulting diluted dispersion is extracted therefrom. The diluted grind is filtered through a suitable screen to separate the beads. The pigment concentration at this stage is 12% by weight.

[0663] Sodium dodecanoate (SDD) and / or at least one additive from the following additives: potassium dodecanoate, sodium oleate, potassium oleate, sodium myristate, potassium myristate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, potassium octanoate, and sodium octanoate were added to the millbase containing the pigment dispersant. Water was added as needed to produce a composition with a pigment concentration of 10% by weight.

[0664] Example I1-Ink Composition

[0665] In this example, the preparation of the ink composition is described: Blue D7079 is used in the HDDM-01 / HD-01 mill as described above. 190 are ground together and the materials are mixed in the following proportions:

[0666]

[0667] The millbase concentrate, now having a DV50 of less than 100 nm, was further diluted with 50 g of water and extracted from the milling apparatus at a 12 wt% pigment concentration. The millbase concentrate was further processed as described below to prepare an ink composition.

[0668] In the first stage, 2.4 g of sodium dodecanoate were added to 200 g of millbase concentrate to produce the millbase. The mixture was stirred to homogeneity (5' magnetic stirrer, 50 rpm) and incubated at 60°C for 1 day. The mixture was then cooled to ambient temperature.

[0669] In the second stage, the ink ingredients are added to the mill grind as follows:

[0670]

[0671] The mixture was stirred at ambient temperature for 30 minutes to obtain an ink jettable ink composition having a viscosity of less than 10 cP.

[0672] Examples I2 to I5 - Ink Compositions

[0673] The ink of Example I1 was formulated, but 5 g, 10 g, 12 g and 15 g of TWEEN 20 were added respectively.

[0674] Point Gain

[0675] Dot gain refers to the increase in dot size relative to the initial spherical droplet diameter. Dot gain is determined by the ratio of the final dot diameter to the initial droplet diameter. It would be highly desirable to find a way to increase dot size without having to increase droplet volume.

[0676] Utilizing the inventive techniques disclosed herein, the inventors achieved a point gain of at least 1.5 or 1.6, and more typically at least 1.7, at least 1.8, at least 1.9, or at least 2.0, or in the range of 1.5 to 2.2, 1.5 to 2.1, 1.7 to 2.1, or 1.8 to 2.1.

[0677] For example, using a droplet volume of 6.3 picoliters (D = 22.9 microns), and using the aqueous treatment formulation of the present invention, a dried ink dot in the range of 40 to 48 microns in diameter was obtained.

[0678] As used herein in this specification and in the claims section that follows, the terms "hydrophobic" and "hydrophilic" and the like may be used in a relative sense, and not necessarily in an absolute sense.

[0679] As used herein in this specification and in the claims section that follows, the term "functional group" refers to a group or moiety that is attached to the polymer structure of the release layer and has a higher polarity than the O-Si-O group of a conventional addition-cured silicone. Various embodiments are provided herein. The inventors have observed that pure addition-cured polydimethylsiloxane polymers contain O-Si-O, SiO4, Si-CH3, and CC groups, and most other functional groups will have higher dipoles, thereby allowing them to be considered "functional". Those skilled in the art will understand that these functional groups may have a tendency or a strong tendency to react with components typically present in aqueous inks utilized in indirect inkjet printing at processing temperatures as high as 120°C.

[0680] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. In the event of a conflict, the present specification, including definitions, will take precedence.

[0681] In the description and claims of the present disclosure, each of the verbs "comprise", "include" and "have" and their conjugations are used to indicate that the subject(s) of the verb are not necessarily a complete list of members, components, elements, steps or parts of the subject(s) of the verb. These terms encompass the terms "consisting of" and "consisting essentially of".

[0682] Thus, as used herein, the singular forms "a," "an," and "the" include plural references and mean "at least one" or "one or more" unless the context clearly dictates otherwise.

[0683] Position or motion terms such as "upper", "lower", "right", "left", "bottom", "below", "low", "top", "above", "elevated", "high", "vertical", "horizontal", "backward", "forward", "upstream", and "downstream", and grammatical variations thereof, may be used herein for exemplary purposes only to illustrate the relative positioning, location, or displacement of certain components to indicate a first component and a second component or both in the current illustration. These terms do not necessarily indicate, for example, that a "bottom" component is below a "top" component, that the components or both may be flipped, rotated, moved, placed in a diagonal direction or position, placed horizontally or vertically, or similarly modified in space.

[0684] Unless otherwise stated, the use of the expression "and / or" between the last two members of a list of options for selection indicates that selection of one or more of the listed options is appropriate and can be made.

[0685] As used herein in the specification and in the claims section that follows, the term "%" refers to weight percent, unless expressly specified otherwise.

[0686] Similarly, the term "ratio" as used in this specification and the following claims section refers to a weight ratio, unless expressly specified otherwise.

[0687] In this disclosure, unless otherwise stated, adjectives such as "substantially" and "about" that modify conditions or relationship characteristics of one or more features of an embodiment of the present technology should be understood to mean that the condition or feature is limited to a tolerance range that is acceptable for the operation of the embodiment for the intended application.

[0688] Although the present disclosure is described in terms of certain embodiments and generally associated methods, variations and permutations of the embodiments and methods will be apparent to those skilled in the art. The present disclosure is to be understood not to be limited by the specific embodiments described herein, but only by the scope of the appended claims.

Claims

1. A printing system, comprising: a intermediate transfer member, comprising a flexible endless belt mounted on a plurality of guide rollers; b. an image forming station configured to form an ink image on a surface of the intermediate transfer member; c. an imprinting station through which the intermediate transfer member passes, the imprinting station being disposed downstream of the image forming station and being configured to transfer the ink image from the intermediate transfer member surface to a substrate; as well as d. a processing station disposed downstream of the imprinting station and upstream of the image forming station for forming a layer of a liquid treatment agent on the surface of the intermediate transfer member, the processing station comprising: i. A coater coating the intermediate transfer member with the liquid treatment formulation; and ii. a coating thickness adjustment assembly for removing excess liquid to leave only the desired layer of the treatment formulation, the coating thickness adjustment assembly comprising a rounded tip or a blade tip facing the surface of the intermediate transfer member; wherein the intermediate transfer member surface is pushed toward the rounded tip or the blade tip, wherein the system is configured such that at least one of a first feature and a second feature is true, the first feature and the second feature being defined as: A. According to the first feature, (i) the liquid treatment formulation is an aqueous treatment formulation, (ii) the printing system is configured to operate at a high printing speed so that the surface speed of the intermediate transfer member while in motion is at least 1 m / s, and (iii) the system is configured to subject the treatment formulation layer to a drying process that removes at least 80 wt % of the water from the treatment formulation layer; B. According to the second feature, the round tip penetrates the intermediate transfer member to a penetration depth, and the penetration depth is at least 1 mm.

2. The system of claim 1, wherein at least the first characteristic is true.

3. The system of claim 1, wherein both the first characteristic and the second characteristic are true. The system of claim 1 , wherein at least the second characteristic is true.

5. The system of claim 4, wherein the rounded tip or the blade tip faces the intermediate transfer member surface such that a gap between the rounded tip or the blade tip and the intermediate transfer member surface has a gap size, and a ratio between (i) the gap size and (ii) the size of the penetration depth is at most 0.

01. The system of claim 4 , wherein the penetration depth has a magnitude of at least 2 mm.

7. The system of claim 6, wherein the rounded tip or the blade tip faces the intermediate transfer member surface such that a gap between the rounded tip or the blade tip and the intermediate transfer member surface has a gap size, and a ratio between (i) the gap size and (ii) the size of the penetration depth is at most 0.

01.

8. The system of claim 4, configured to operate at high printing speeds such that the surface speed of the intermediate transfer member while in motion is at least 1 meter per second.

9. The system of any one of claims 1-8, wherein the coating thickness adjustment assembly is configured such that the treated thickness of the treatment agent layer is at most 1 μm.

10. The system of any one of claims 1-8, wherein the coating thickness adjustment assembly is configured such that the treated thickness of the treatment agent layer is at most 0.8 μm.

11. A printing system comprising: a intermediate transfer member, comprising a flexible endless belt mounted on a plurality of guide rollers; b. an image forming station configured to form an ink image on a surface of the intermediate transfer member; c. an imprinting station through which the intermediate transfer member passes, the imprinting station being disposed downstream of the image forming station and being configured to transfer the ink image from the intermediate transfer member surface to a substrate; as well as d. a processing station disposed downstream of the imprinting station and upstream of the image forming station for forming a layer of a liquid treatment agent on the surface of the intermediate transfer member, the processing station comprising: i. A coater coating the intermediate transfer member with the liquid treatment formulation; as well as ii. a coating thickness adjustment assembly for removing excess liquid to leave only a desired layer of treatment formulation, the coating thickness adjustment assembly comprising a rounded tip or a blade tip facing upwardly toward the surface of the intermediate transfer member on a horizontally oriented portion of the intermediate transfer member, the rounded tip or the blade tip being configured for removing the excess liquid, wherein the printing system is configured to operate at a high printing speed such that the surface speed of the intermediate transfer member when in motion is at least 1 meter per second.

12. The system of claim 11, wherein (i) the liquid treatment formulation is an aqueous treatment formulation, and (ii) the system is configured to subject the treatment formulation layer to a drying process that removes at least 80 wt% of the water from the treatment formulation layer.

13. The system of claim 12, wherein the rounded tip penetrates the intermediate transfer member to a penetration depth, and the penetration depth is at least 1 mm in magnitude.

14. The system of claim 12, wherein the rounded tip penetrates the intermediate transfer member to a penetration depth, and the penetration depth is at least 2 mm in magnitude.

15. The system of claim 11, wherein the rounded tip penetrates the intermediate transfer member to a penetration depth, and the penetration depth is at least 1 mm in magnitude.

16. The system of claim 11, wherein the rounded tip penetrates the intermediate transfer member to a penetration depth, and the penetration depth has a magnitude of at least 2 mm.

17. The system of any one of claims 11-16, wherein the coating thickness adjustment assembly is configured such that the treated thickness of the treatment agent layer is at most 1 μm.

18. The system of any one of claims 11-16, wherein the coating thickness adjustment assembly is configured such that the treated thickness of the treatment agent layer is at most 0.8 μm.

19. A printing system comprising: a. An intermediate transfer member having a hydrophobic release surface, the intermediate transfer member comprising a flexible endless belt mounted on a plurality of guide rollers, the printing system being configured to operate at a high printing speed such that the surface velocity of the intermediate transfer member when in motion is at least x m / s, wherein x is a positive number having a value of at least 1; b. a certain amount of aqueous ink, which includes nano-pigment; c. A certain amount of aqueous treatment preparation; d. an image forming station configured to deposit ink droplets comprising the nano-pigment on the surface of the intermediate transfer member to form an ink image thereon; e. an imprinting station through which the intermediate transfer member passes, the imprinting station being disposed downstream of the image forming station and being configured to transfer the ink image from the intermediate transfer member surface to a substrate; and f. a processing station disposed downstream of the imprinting station and upstream of the image forming station for forming an aqueous treatment formulation layer on the surface of the intermediate transfer member, the processing station comprising: i. A coater coating the intermediate transfer member with the aqueous treatment formulation having a surface speed of at least x m / s in motion; as well as ii. A rounded tip or blade tip facing the surface of the intermediate transfer member for removing excess aqueous treatment formulation to produce a uniform thin layer having a thickness of at most 0.8 µm.

20. The system of claim 19, wherein the system is configured such that the value of x is at least 1.25 m / s.

21. The system of claim 20, wherein the treatment station is configured to form a uniform layer of the aqueous treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform layer is at most 0.7 μm.

22. The system of claim 20, wherein the treatment station is configured to form a uniform layer of the aqueous treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform layer is at most 0.6 μm.

23. The system of claim 19, wherein the treatment station is configured to form a uniform layer of the aqueous treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform layer is at most 0.7 μm.

24. The system of claim 19, wherein the treatment station is configured to form a uniform layer of the aqueous treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform layer is at most 0.6 μm.

25. The system of any one of claims 19-24, wherein all components of the aqueous treatment formulation are completely dissolved.

26. A printing system comprising: a intermediate transfer member, comprising a flexible endless belt mounted on a plurality of guide rollers; b. an image forming station configured to form an ink image on a surface of the intermediate transfer member; c. an imprinting station through which the intermediate transfer member passes, the imprinting station being disposed downstream of the image forming station and being configured to transfer the ink image from the intermediate transfer member surface to a substrate; as well as d. a processing station disposed downstream of the imprinting station and upstream of the image forming station for forming a layer of a liquid treatment agent on the surface of the intermediate transfer member, the processing station comprising: i. A coater coating the intermediate transfer member with the liquid treatment formulation; and ii. a coating thickness adjustment assembly for removing excess liquid to leave only the desired layer of the treatment formulation, the coating thickness adjustment assembly comprising a rounded tip or a blade tip facing the surface of the intermediate transfer member, (i) the rounded tip or blade tip is the tip of a blade, the blade being one of a plurality of blades mounted on the circumference of a turret, the turret being rotatable to facilitate replacement of the blades being urged toward the surface; (ii) The spacing of the blades on the circumference of the turret is such that during rotation of the turret to change blades, the blade being replaced does not cease operation before the replacement blade becomes operational.

27. The system of claim 26 configured such that there is a period of time during said rotation wherein both scrapers mounted on said circumference of said turret are active and interacting simultaneously with said intermediate transfer member.

28. The system of claim 27, further comprising a scraper blade cleaning brush, wherein the rotation of the turret is effective to cause the scraper blade cleaning brush to clean a scraper blade mounted on the turret before the cleaned scraper blade is activated again.

29. The system of claim 26, further comprising a scraper blade cleaning brush, wherein rotation of the turret is effective to cause the scraper blade cleaning brush to clean a scraper blade mounted on the turret before the cleaned scraper blade is activated again.

30. The system of claim 26, wherein a tip of the scraper facing the intermediate transfer member surface faces upwardly toward the intermediate transfer member surface at a horizontally oriented portion of the intermediate transfer member.

31. The system of claim 26, wherein the printing system is configured to operate at a high printing speed such that the surface speed of the intermediate transfer member while moving is at least x meters per second, where x is a positive number having a value of at least 1.

32. The system of claim 31 , wherein the value of x is at least 1.

25.

33. The system of claim 31 , wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.8 μm.

34. The system of claim 32, wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.8 μm.

35. The system of claim 31 , wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.7 μm.

36. The system of claim 32, wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.7 μm.

37. The system of claim 32, wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.6 μm.

38. The system of claim 33, wherein the treatment station is configured to form a uniform thin layer of the liquid treatment formulation on the surface of the intermediate transfer member such that the thickness of the uniform thin layer is at most 0.6 μm.

39. The system of any one of claims 1-8, 11-16, 19-24, 26-38, wherein all components of the liquid treatment formulation are completely dissolved.

40. The system of any one of claims 1-8, 11-16, 19-24, 26-38, wherein the presence of the rounded tip or blade tip creates a velocity gradient of the aqueous treatment formulation at a location of strong velocity gradient, the location of strong velocity gradient being typically displaced by at most 1 micron from the stripping surface of the intermediate transfer member, such that at the location of strong velocity gradient, the magnitude of the velocity gradient is equal to or exceeds a value of at least 10 6 sec -1 The velocity gradient VG value.

41. The system of claim 40, wherein the VG value is at least 2×10 6 sec -1 .

42. The system of claim 40, wherein the VG value is at least 4×10 6 sec -1 .

43. The system of claim 40, wherein the VG value is at least 5×10 6 sec -1 .

44. The system of claim 40, wherein the VG value is at least 7.5×10 6 sec -1 .

45. The system of claim 40, wherein the VG value is at least 10 7 sec -1 .

46. ​​The system of claim 40, wherein the VG value is at least 2×10 7 sec -1 .

47. The system of claim 40, wherein the VG value is at least 4×10 7 sec -1 .

48. The system of claim 40, wherein the VG value is at least 5×10 7 sec -1 .

49. The system of claim 40, wherein the VG value is at least 7.5×10 7 sec -1 .

50. The system of claim 40, wherein the velocity gradient is positioned along the printing direction such that: i. at an upstream position upstream of the strong velocity gradient position, the maximum velocity gradient is at most x% ii. At a downstream position downstream of the strong velocity gradient position, the maximum velocity gradient is at most the velocity gradient value at the strong velocity gradient position x% ;iii. x The value of is at most 50; and iv. the upstream position and the downstream position are each displaced from the strong velocity gradient position by at most 2 cm.

51. The system of claim 50, wherein x The value of is at most 30.

52. The system of claim 50, wherein x The value of is at most 20.

53. The system of claim 50, wherein x The value of is at most 10.

54. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the location of the strong velocity gradient by at most 1.5 cm.

55. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the location of the strong velocity gradient by at most 1.25 cm.

56. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the location of the strong velocity gradient by at most 1 cm.

57. The system of claim 50, wherein the upstream location and the downstream location are each displaced by at most 9 mm from the location of the strong velocity gradient.

58. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the strong velocity gradient location by at most 8 mm.

59. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the strong velocity gradient location by at most 7.5 mm.

60. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the strong velocity gradient location by at most 7 mm.

61. The system of claim 50, wherein the upstream location and the downstream location are each displaced by at most 6 mm from the location of the strong velocity gradient.

62. The system of claim 50, wherein the upstream location and the downstream location are each displaced from the strong velocity gradient location by at most 5 mm.

63. The system of any one of claims 1-8, 11-16, 19-24, 26-38, wherein: (A) The intermediate transfer member includes a silicone-based release layer surface having sufficient hydrophilicity to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the surface of the silicone-based release layer is at most 60°; and (B) The dynamic contact angle of a distilled water drop deposited on the surface of the silicone-based release layer measured after 10 seconds is at most 108°.

64. A printing method comprising: a. Provide an aqueous ink comprising a nano-pigment, an aqueous treatment formulation and a printing system, the printing system comprising: i having a hydrophobic release surface intermediate transfer member, the intermediate transfer member comprising a flexible endless belt mounted on a plurality of guide rollers; ii. an image forming station configured to form an ink image on a surface of the intermediate transfer member, iii. an imprinting station disposed downstream of the image forming station and configured to transfer the ink image from the surface of the intermediate transfer member to a substrate; and iv. a rounded tip or a blade tip facing the surface of the intermediate transfer member; b. forming a wet treatment layer having a thickness of at most 0.8 μm on the surface of the intermediate transfer member by (A) applying the aqueous treatment formulation to the hydrophobic release surface and (B) removing excess liquid by pushing the surface of the intermediate transfer member toward and / or from the circular tip or the blade tip while the surface of the intermediate transfer member is moving at a speed of at least x meters per second, wherein x is a positive number having a value of at least 1; c. Subsequently and at the image forming station, depositing aqueous ink droplets comprising the nano-pigment on the surface of the intermediate transfer member to form an ink image thereon; and d. At the embossing station, the ink image is transferred to a printing substrate.

65. The method of claim 64, wherein the value of x is at least 1.

25.

66. The method of claim 65, wherein the wet-processed layer is formed to have a thickness of at most 0.7 μm.

67. The method of claim 65, wherein the wet-processed layer is formed to have a thickness of at most 0.6 μm.

68. A printing method comprising: a. providing an intermediate transfer member comprising a silicone-based release layer surface, the silicone-based release layer surface having sufficient hydrophilicity to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the silicone-based release layer surface is at most 60°; and (ii) a dynamic contact angle of a distilled water droplet deposited on the silicone-based release layer surface measured after 10 seconds is at most 108°; b. Providing an aqueous treatment formulation comprising: i. at least 1 wt% of at least one water-soluble polymer having a solubility in water of at least 5% at 25°C; and ii. an aqueous carrier liquid, said water comprising at least 50 wt% of said aqueous treatment formulation; c. applying the aqueous treatment formulation to the surface of the silicone-based release layer of the intermediate transfer member to form a wet treatment layer having a thickness of up to 0.8 μm thereon; d. subjecting the wet-processed layer to a drying process to remove at least 80 wt % of the water from the wet-processed layer on the surface of the silicone-based release layer of the intermediate transfer member, wherein: i. Drying of the treatment solution is performed quickly enough to prevent beading by removing at least 80 wt % of the water in at most 1 second; and ii. During the drying process of the wet process layer, the dynamic viscosity of the wet process layer increases by at least 500 times within a period of up to 1 second; e. depositing aqueous ink droplets on the dried treatment layer to form an ink image on the surface of the silicone-based release layer; f. drying the ink image to leave an ink image residue on the surface of the silicone-based release layer; and g. transferring the ink image residue to the printing substrate through pressure contact between the intermediate transfer member and the printing substrate.

69. The method of claim 68, wherein the aqueous treatment formulation provided has a 60°C evaporation load of at most 8:

1.

70. The method of claim 68, wherein during the drying process of the wet processing layer, its dynamic viscosity increases at least 1000 times within a time period of at most 250 milliseconds.

71. A printing system comprising: a. An intermediate transfer member comprising a silicone-based release layer surface having sufficient hydrophilicity to satisfy at least one of the following properties: (i) a receding contact angle of a distilled water droplet deposited on the silicone-based release layer surface is at most 60°; and (ii) a dynamic contact angle of a distilled water droplet deposited on the silicone-based release layer surface measured after 10 seconds is at most 108°; b. an amount of an aqueous treatment formulation comprising: i. at least 1 wt% of at least one water-soluble polymer having a solubility in water of at least 5% at 25°C; and ii. an aqueous carrier liquid, said water comprising at least 50 wt% of said aqueous treatment formulation; c. a treatment station configured to apply the aqueous treatment formulation to the surface of the silicone-based release layer of the intermediate transfer member to form a wet treatment layer having a thickness of at most 0.8 μm thereon; d. an image forming station disposed downstream of the processing station, the image forming station being configured to form an ink image on the surface of the silicone-based release layer of the intermediate transfer member; and e. an imprinting station at which the ink image is deposited from the surface of the intermediate transfer member to a substrate, wherein the system is configured such that: A. the wet processed layer is subjected to a drying process on the intermediate transfer member at a position downstream of the processing station and upstream of the image forming station; B. the drying process is effective to remove at least 80 wt % of the water of the wet-processed layer therefrom on the surface of the silicone-based release layer of the intermediate transfer member; C. drying of the treatment solution is performed quickly enough to prevent beading by removing at least 80 wt % of the water in at most 1 second; D. during the drying process of the wet-processed layer, the dynamic viscosity of the wet-processed layer increases by at least 500 times within a period of at most 1 second; E. At the image forming station, the ink image is formed by depositing aqueous ink droplets on a dried treatment film present on the surface of the silicone-based release layer of the intermediate transfer member.

72. The system of claim 71, wherein the aqueous treatment formulation has a static surface tension in the range of 25 dynes / cm and 40 dynes / cm at 25°C.

73. The system of claim 72, wherein: The aqueous treatment formulation has a 60°C evaporation loading of at most 8:1 by weight.

74. The system of claim 73, wherein the aqueous treatment formulation has a 25°C dynamic viscosity of at least 10 cP.

75. The system of claim 71, wherein during a drying process of the wet processing layer, the dynamic viscosity of the wet processing layer increases at least 2500 times within a time period of at most 1 second.

76. The system of claim 71, wherein during a drying process of the wet processing layer, the dynamic viscosity of the wet processing layer increases at least 5000 times within a time period of at most 1 second.

77. The system of claim 71, wherein during a drying process of the wet processing layer, the dynamic viscosity of the wet processing layer increases at least 25,000 times within a time period of at most 100 milliseconds.

78. An indirect printing system comprising: (a) a certain amount of water-based ink; (b) an intermediate transfer member having a release layer, the release layer having an ink receiving surface; (c) a printing station wherein an ink image is formed from aqueous ink droplets on the ink receiving surface of the intermediate transfer member, in: I. The ink printing system is configured to transfer the ink image from the ink receiving surface of the intermediate transfer member to a substrate; II. The release layer is formed of a silicone material; III. The ink receiving surface of the release layer is suitable for satisfying at least one of the following structural properties: (i) a receding contact angle of a distilled water drop on the ink receiving surface is at most 60°; and (ii) a dynamic contact angle of a distilled water droplet deposited on the ink receiving surface measured after 10 seconds is at most 108°; and IV. The peeling layer has at least one of the following structural properties: (1) the organosilicon material consists essentially of organosilicon, or contains at least 95 wt % of the organosilicon; and (2) The functional groups constitute no more than 5 wt % of the organosilicon material.

79. An indirect printing system according to claim 78, wherein the receding contact angle is at most 58°.

80. The indirect printing system of claim 79, wherein the receding contact angle is at most 56°.

81. The indirect printing system of claim 79, wherein the receding contact angle is at most 54°.

82. The indirect printing system of claim 79, wherein the receding contact angle is at most 52°.

83. The indirect printing system of claim 79, wherein the receding contact angle is at most 50°.

84. The indirect printing system of claim 79, wherein the receding contact angle is at most 48°.

85. The indirect printing system of claim 79, wherein the receding contact angle is at most 46°.

86. An indirect printing system according to claim 79, wherein the receding contact angle is at most 44°.

87. An indirect printing system according to claim 79, wherein the receding contact angle is at most 42°.

88. An indirect printing system according to claim 79, wherein the receding contact angle is at most 40°.

89. An indirect printing system according to claim 79, wherein the receding contact angle is at most 38°.

90. An indirect printing system according to claim 79, wherein the receding contact angle is at most 37°.

91. The indirect printing system of claim 78, wherein the functional groups comprise at most 3 wt% of the silicone material.

92. The indirect printing system of claim 91, wherein the functional groups comprise at most 2 wt% of the silicone material.

93. The indirect printing system of claim 91, wherein the functional groups comprise at most 1 wt% of the silicone material.

94. The indirect printing system of claim 91, wherein the functional groups comprise at most 0.5 wt% of the silicone material.

95. The indirect printing system of claim 91, wherein the functional groups comprise at most 0.2 wt% of the silicone material.

96. The indirect printing system of claim 91, wherein the functional groups comprise at most 0.1 wt% of the silicone material.

97. The indirect printing system of claim 91, wherein the silicone material is substantially free of the functional groups.

98. The indirect printing system of claim 78, wherein polyether glycol functionalized polydimethylsiloxane is impregnated in the silicone material.

99. The indirect printing system of claim 78, wherein the total surface energy of the ink receiving surface is at least 2 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

100. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 3 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

101. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 4 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

102. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 5 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

103. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 6 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

104. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 8 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

105. The indirect printing system of claim 99, wherein the total surface energy of the ink receiving surface is at least 10 J / m higher than the total surface energy of a modified ink receiving surface produced by subjecting the ink receiving surface of a corresponding release layer to a standard aging procedure at 160° C. for 2 hours. 2 .

106. The indirect printing system of claim 78, wherein the silicone material is a cured silicone material, and wherein the total surface energy of the ink-receiving surface is at least 4 J / m greater than the total surface energy of a hydrophobic ink-receiving surface of a corresponding release layer prepared by air exposure cure of an silicone precursor of the cured silicone material. 2 .

107. The indirect printing system of claim 106, wherein the total surface energy of the ink receiving surface is at least 6 J / m greater than the total surface energy of the hydrophobic ink receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

108. The indirect printing system of claim 106, wherein the total surface energy of the ink receiving surface is at least 8 J / m greater than the total surface energy of the hydrophobic ink receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

109. The indirect printing system of claim 106, wherein the total surface energy of the ink-receiving surface is at least 10 J / m greater than the total surface energy of the hydrophobic ink-receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

110. The indirect printing system of claim 106, wherein the total surface energy of the ink receiving surface is at least 12 J / m greater than the total surface energy of the hydrophobic ink receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

111. The indirect printing system of claim 106, wherein the total surface energy of the ink receiving surface is at least 14 J / m greater than the total surface energy of the hydrophobic ink receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

112. The indirect printing system of claim 106, wherein the total surface energy of the ink receiving surface is at least 16 J / m greater than the total surface energy of the hydrophobic ink receiving surface of a corresponding release layer prepared by air exposure cure of an organosilicon precursor of the cured organosilicon material. 2 .

113. An indirect printing system according to claim 78, wherein the silicone material is a cured silicone material, and wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 7º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

114. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 8º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

115. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 10º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

116. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 12º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

117. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 15º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

118. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 18º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

119. An indirect printing system according to claim 113, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 20º lower than the receding contact angle of a distilled water drop on the ink receiving surface of a corresponding peeling layer prepared by air exposure curing of a silicone precursor of the cured silicone material.

120. An indirect printing system according to claim 78, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 5° lower than the receding contact angle of a distilled water drop on an aged surface generated by subjecting the ink receiving surface to 160°C for 2 hours.

121. An indirect printing system according to claim 120, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 6° lower than the receding contact angle of a distilled water drop on an aged surface generated by subjecting the ink receiving surface to 160°C for 2 hours.

122. An indirect printing system according to claim 120, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 7° lower than the receding contact angle of a distilled water drop on an aged surface generated by subjecting the ink receiving surface to 160°C for 2 hours.

123. An indirect printing system according to claim 120, wherein the receding contact angle of a distilled water drop on the ink receiving surface is at least 8° lower than the receding contact angle of a distilled water drop on an aged surface generated by subjecting the ink receiving surface to 160°C for 2 hours.

124. An indirect printing system according to claim 78, wherein the silicone material is a cured silicone material, and wherein the surface hydrophobicity of the ink receiving surface is less than the bulk hydrophobicity of the cured silicone material within the peeling layer, the surface hydrophobicity being characterized by a receding contact angle of a distilled water drop on the ink receiving surface, and the bulk hydrophobicity being characterized by a receding contact angle of a distilled water drop on an inner surface formed by exposing an area of ​​the cured silicone material within the peeling layer to form an exposed area.

125. An indirect printing system according to claim 78, wherein the receding contact angle measured on the ink receiving surface is at least 7° lower than the receding contact angle measured on the exposed area.

126. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 8° lower than the receding contact angle measured on the exposed area.

127. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 10° lower than the receding contact angle measured on the exposed area.

128. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 12° lower than the receding contact angle measured on the exposed area.

129. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 14° lower than the receding contact angle measured on the exposed area.

130. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 16° lower than the receding contact angle measured on the exposed area.

131. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 18° lower than the receding contact angle measured on the exposed area.

132. An indirect printing system according to claim 125, wherein the receding contact angle measured on the ink receiving surface is at least 20° lower than the receding contact angle measured on the exposed area.

133. An indirect printing system according to claim 78, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 25°.

134. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 28°.

135. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 30°.

136. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 32°.

137. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 34°.

138. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is at least 36°.

139. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 25º to 60º.

140. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 28° to 60°.

141. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 30° to 60°.

142. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 30° to 55°.

143. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 30° to 50°.

144. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 32º to 60º.

145. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 32º to 55º.

146. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 32º to 44º.

147. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 35º to 60º.

148. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 35º to 55º.

149. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 36º to 44º.

150. An indirect printing system according to claim 133, wherein the receding contact angle of the distilled water droplet on the ink receiving surface is in the range of 38º to 50º.

151. The indirect printing system of claim 78, wherein: (i) the release layer of the intermediate transfer member further has a second surface opposite to the ink receiving surface, and (ii) the release layer is adapted to orient the polar groups of the ink receiving surface away from or opposite to the second surface.

152. An indirect printing system according to claim 78, wherein the release layer is adapted such that when the intermediate transfer member is in an operating mode, the ink receiving surface is exposed to the surrounding environment, and the polar groups of the ink receiving surface are oriented toward or facing the surrounding environment.

153. The indirect printing system of claim 78, wherein the silicone material forming the release layer is an addition-cured silicone material, and wherein at least one of the following statements is true: (1) the addition-cured silicone material consists essentially of addition-cured silicone, or contains at least 95 wt % of the addition-cured silicone; (2) The functional groups comprise no more than 5 wt % of the addition-curable silicone material.

154. The indirect printing system of claim 78, wherein the silicone material forming the release layer is a cured silicone material, and wherein at least one of the following statements is true: (1) The addition-cured silicone material consists essentially of cured silicone or contains at least 95 wt % of the addition-cured silicone; (2) The functional groups comprise no more than 5 wt % of the addition-curable silicone material.

155. An indirect printing method comprising: (a) providing a certain amount of aqueous ink and an intermediate transfer member having a release layer, the release layer having an ink receiving surface; (b) ejecting aqueous ink droplets onto the ink receiving surface of the intermediate transfer member to form an ink image on the ink receiving surface; as well as (c) transferring the ink image from the ink receiving surface of the intermediate transfer member to a substrate; in: I. the release layer of the intermediate transfer member is formed of an organic silicon material; II. The ink receiving surface of the release layer is adapted to satisfy at least one of the following structural properties: (i) a receding contact angle of a distilled water drop on the ink receiving surface is at most 60°; and (ii) a dynamic contact angle of a distilled water droplet deposited on the ink receiving surface measured after 10 seconds is at most 108°; and III. The release layer of the intermediate transfer member has at least one of the following structural properties: (1) the organosilicon material consists essentially of organosilicon, or contains at least 95 wt % of the organosilicon; and (2) The functional groups constitute no more than 5 wt % of the organosilicon material.

156. The method of claim 155, wherein the silicone material forming the release layer is an addition-cured silicone material, and wherein at least one of the following statements is true: (1) the addition-cured silicone material consists essentially of addition-cured silicone, or contains at least 95 wt % of the addition-cured silicone; (2) The functional groups comprise no more than 5 wt % of the addition-curable silicone material.

157. The method of claim 155, wherein the silicone material forming the release layer is a cured silicone material, and wherein at least one of the following statements is true: (1) The addition-cured silicone material consists essentially of cured silicone or contains at least 95 wt % of the addition-cured silicone; (2) The functional groups comprise no more than 5 wt % of the addition-curable silicone material.

158. The method of claim 155, wherein: (i) the release layer of the intermediate transfer member further has a second surface opposite to the ink receiving surface, and (ii) the release layer is adapted to orient the polar groups of the ink receiving surface away from or opposite to the second surface.

159. A method according to claim 155, wherein the release layer is adapted such that when the intermediate transfer member is in an operating mode, the ink receiving surface is exposed to the surrounding environment, and the polar groups of the ink receiving surface have an orientation toward or facing the surrounding environment.

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