Transfer member for printing systems

Patent metadata

Field	Value
Publication number	US-10606191-B2
Application number	US-201916424712-A
Country	US
Kind code	B2
Filing date	May 29, 2019
Priority date	Nov 30, 2016
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

There is disclosed a layered article that can be used in indirect printing, in analog or digital processes. The layered article, when configured as a transfer member, may serve to receive an ink in any form, allow the ink to be treated so as to form an ink image, and permit the application of the ink image on a substrate. The transfer member comprises a support layer and an imaging layer, which may be formed of a silicon matrix including dispersed carbon black particles. Methods for preparing the same are also disclosed.

First claim

The invention claimed is:

1. A transfer member for receiving ink and transferring an ink image to a substrate, the transfer member comprising:
a) a support layer; and
b) an imaging layer, disposed on the support layer, the imaging layer comprising:
i) a cured hydrophobic silicone matrix comprising hydrophilic carbon black particles non-covalently dispersed therein; and
ii) a release surface distal to the support layer.

2. The transfer member according to claim 1 , wherein the release surface is integral to the imaging layer.

3. The transfer member according to claim 1 , wherein the hydrophobic silicone matrix of the imaging layer is a layer formed from silicone pre-polymers selected from liquid silicone resins (LSR), room temperature vulcanization (RTV) silicones, polydialkyl siloxanes (PDAS) or polydimethyl siloxanes (PDMS) silicones, and functionalised versions thereof, provided that the silicone pre-polymer is not a fluorosilicone.

4. The transfer member according to claim 1 , wherein the silicone matrix is an addition-cured silicone matrix.

5. The transfer member according to claim 1 , the hydrophilic carbon black particles having one or more properties selected from the list consisting of:
a) an I D /I G ratio of at least 0.8, or at least 1.0, or at least 1.2, wherein I D and I G represent the peak intensity maxima of D-band and G-band, respectively, as determined by Raman spectroscopy;
b) an average primary particle size (Dv50) of at most 100 nm;
c) a predominant secondary particle size (Dv90) of at most 5 μm, at most 4 μm, at most 3 μm, at most 2 μm or at most 1.5 μm;
d) a predominant secondary particle size (Dv90) of at most 1000 nm, at most 500 nm, at most 400 nm, at most 300 nm, at most 200 nm or at most 100 nm; and
e) contains at least one type of functional group selected from the group consisting of epoxy, hydroxy and carboxylic moieties, as detected by Fourier-transform infrared (FTIR) spectroscopy.

6. The transfer member according to claim 1 , wherein the concentration of carbon black in the silicone matrix on a weight per weight basis is at least 0.1% and at most 30%, at least 5% and at most 30%, at least 7.5% and at most 27.5%, at least 10% and at most 25%, at least 12.5% and at most 25%, at least 15% and at most 25%, or at least 15% and at most 20%.

7. The transfer member according to claim 1 , wherein the silicone matrix further comprises a dispersant having at least one carbon-black-affinic moiety.

8. The transfer member according to claim 7 , wherein said dispersant is miscible with the silicone matrix and has a branched molecule structure, the branched molecule having a backbone and at least one branching unit, wherein one of said backbone and branching unit is siloxane-based, or contains at least one siloxane unit.

9. The transfer member of claim 7 , wherein the dispersant is selected from the group consisting of: an amino-silicone dispersant, an epoxy-silicone dispersant and a silicone-acrylate dispersant.

10. The transfer member according to claim 1 , wherein the transfer member is opaque.

11. The transfer member according to claim 1 , wherein the transfer member or the support layer is substantially transparent.

12. The transfer member according to claim 1 , wherein the support layer is substantially transparent.

13. The transfer member according to claim 1 , wherein the support layer is flexible, so that the transfer member is suitable to form a blanket or an endless belt.

14. The transfer member according to claim 13 , further comprising, along lateral edges of the transfer member, protruding formations which are capable of engaging with lateral tracks in a printing system so as to (a) constrain the transfer member to follow a printing path in at least a segment of the path and/or to (b) place the transfer member under lateral tension, in at least a segment of the path.

15. The transfer member according to claim 1 , wherein the transfer member is a seamless transfer member.

16. The transfer member according to claim 1 , wherein at least 80% of the carbon black particles, are disposed at a distance of at least 0.01 μm, at least 0.02 μm, at least 0.03 μm, at least 0.04 μm, at least 0.05 μm, at least 0.1 μm, at least 0.2 μm, at least 0.3 μm, at least 0.5 μm, or at least 1.0 μm, from the release surface.

17. The transfer member according to claim 1 , dimensioned and configured for use in indirect printing, wherein the indirect printing is selected from offset printing, thermal printing, electrophotographic printing and radiation printing.

18. A transfer member for receiving ink and transferring an ink image to a substrate, the transfer member comprising:
a) a support layer; and
b) an imaging layer, disposed on the support layer, the imaging layer comprising:
i) a cured hydrophobic silicone matrix comprising dispersant-laden hydrophilic carbon black particles non-covalently dispersed therein; and
ii) a release surface distal to the support layer

wherein a dispersant of the dispersant-laden hydrophilic carbon black particles has at least one carbon-black-affinic moiety selected from an amino-moiety, an acrylate-moiety and an epoxy-moiety.

19. A method for preparing a transfer member, the transfer member comprising on a first side a release surface for receiving ink and transferring an ink image to a substrate, the method comprising:
a) providing a support layer adapted to form a rear side of the transfer member, the rear side being opposite the first side;
b) providing an imaging layer, the imaging layer including a hydrophobic silicone matrix comprising hydrophilic carbon black particles non-covalently dispersed therein;
c) optionally providing a release layer able to form the release surface;
d) contacting the support layer, the imaging layer and the optional release layer, when at least one of any two adjacent said layers is at least partially cured; and
e) fully curing the transfer member including said layers so that the surface distal to the support layer forms the release surface, said surface being part of the imaging layer or of the release layer.

Assignees

• Landa Labs 2012 Ltd

Inventors

• Landa Benzion
• Abramovich Sagi
• Haviv Amit

Classifications

• C08G77/04

  Polysiloxanes · CPC title

• B41M5/52

  Macromolecular coatings · CPC title

• C01P2004/04

  obtained by TEM, STEM, STM or AFM · CPC title

• B41M2205/06

  relating to melt (thermal) mass transfer · CPC title

• C08K2201/005

  Additives being defined by their particle size in general · CPC title