Thermal transfer printing

Abstract

Disclosed is a tool for driving a barbed staple into a workpiece, the tool includes a housing enclosing a power delivery source and a driver blade driven by the power delivery source and comprising an engagement portion configured for engagement with the staple. The tool further includes a nosepiece comprising an aperture providing access for loading a staple into the nosepiece and a passage configured for slidable mounting of the driver blade. In use, the driver blade may be driven along a longitudinal axis of the passage by the power delivery source to engage and drive a staple into a workpiece. Clearances are providing to allow for loading and passage of the barbed staples in the nosepiece and arrangements are provided to maintain the alignment of the staple in the nosepiece to compensate for those clearances.

Claims

1. A thermal transfer ribbon for use in dye diffusion thermal transfer printing, the thermal transfer ribbon comprising: a continuous strip of a substrate having a thermally transferable receiver layer on one side surface of the substrate, the thermally transferable receiver layer comprising: a release agent, and a swellable inorganic lamellar material that is at least partially in an exfoliated or intercalated state, wherein the thermally transferable receiver layer is positioned so that part of the thermally transferable receiver layer can be transferred from the substrate to a receiving substrate.

2. The thermal transfer ribbon of claim 1, wherein the swellable inorganic lamellar material is a clay.

3. The thermal transfer ribbon of claim 2, wherein the clay is at least partially in the exfoliated state.

4. The thermal transfer ribbon of claim 1, wherein the swellable inorganic lamellar material is organically modified.

5. The thermal transfer ribbon of claim 1, which comprises from 0.5 to 8.0 wt % of the swellable inorganic lamellar material.

6. The thermal transfer ribbon of claim 1, which comprises from 1.0 to 5.0 wt % of the swellable inorganic lamellar material.

7. The thermal transfer ribbon of claim 1, further comprising a polymer resin.

8. The thermal transfer ribbon of claim 7, which comprises from 70 to 99.5 wt % of the polymer resin.

9. The thermal transfer ribbon of claim 7, wherein the polymer resin comprises a polyester.

10. A ribbon set for use in dye diffusion thermal transfer printing, the ribbon set comprising: a thermal transfer ribbon comprising a continuous strip of a substrate having a thermally transferable receiver layer on one side surface of the substrate, the thermally transferable receiver layer comprising: a release agent, and a swellable inorganic lamellar material that is at least partially in an exfoliated or intercalated state, wherein the thermally transferable receiver layer is positioned so that part of the thermally transferable receiver layer can be transferred from the substrate to a receiving substrate; and one or more separate dye color ribbons each including one or more dyes that that can be transferred to the receiving substrate.

11. The ribbon set of claim 10, wherein the swellable inorganic lamellar material is a clay.

12. The ribbon set claim 11, wherein the clay is at least partially in the exfoliated state.

13. The ribbon set of claim 10, wherein the swellable inorganic lamellar material is organically modified.

14. The ribbon set of claim 13, which comprises from 0.5 to 8.0 wt % of the swellable inorganic lamellar material.

15. The ribbon set of claim 13, which comprises from 1.0 to 5.0 wt % of the swellable inorganic lamellar material.

16. The ribbon set of claim 10, wherein the thermal transfer ribbon further comprises a polymer resin.

17. The ribbon set of claim 16, which comprises from 70 to 99.5 wt % of the polymer resin.

18. The ribbon set of claim 16, wherein the polymer resin comprises a polyester.

19. A method of dye diffusion thermal transfer printing onto a receiving substrate, the method comprising the steps of: thermally transferring part of a thermally transferable receiver layer from a thermal transfer ribbon onto a receiving substrate, the thermal transfer ribbon comprising a continuous strip of a substrate having the thermally transferable receiver layer on one side surface of the substrate, the thermally transferable receiver layer comprising: a release agent, and a swellable inorganic lamellar material that is at least partially in an exfoliated or intercalated state; and subsequently transferring one or more dyes from one or more separate dye color ribbons onto the transferred receiver layer on the receiving substrate.

20. The method of claim 19, wherein the swellable inorganic lamellar material of the dye diffusion thermal transfer ribbon is a clay.

21. The method of claim 19, wherein the swellable inorganic lamellar material of the dye diffusion thermal transfer ribbon is organically modified.

22. The method of claim 19, wherein the thermal transfer ribbon further comprises a polymer resin.

23. The method of claim 22, wherein the polymer resin comprises a polyester.

24. The method of claim 22, wherein the receiver layer further comprises a polymer resin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be illustrated with reference to the following figures, in which:

(2) FIG. 1 is a schematic illustrating the structural differences between a traditional macrocomposite, an intercalated nanocomposite and an exfoliated nanocomposite.

(3) FIG. 2 is a chart showing the cyan peel force for receiver layers without clay (coatings B to E) and with clay (coatings G to K).

(4) FIG. 3 is a chart showing the cyan peel force as a function of number of previous cyan 255 prints for a receiver layer without clay (coating D) and with clay (coating I).

(5) FIG. 4 is a chart showing the cyan peel force as a function of number of previous cyan 255 prints for a receiver layer without clay (coating C) and with clay (coating H).

(6) FIG. 5 is a chart showing the cyan peel force as a function of number of previous cyan 255 prints for a receiver layer without clay (coating F) and with clay (coating K).

DETAILED DESCRIPTION

EXAMPLES

(7) Sample Preparation

(8) The solvent (or solution) method of nanocomposite preparation is used wherein a solvent is selected in which the polymer is soluble and the clay is swellable. The clay is first swollen in a suitable solvent. The swollen clay and polymer solution are then mixed and the polymer chains intercalate into the clay gallery displacing the solvent molecules. The solvent is then removed and a polymer-clay nanocomposite is formed. The solvent aids the exfoliation process as it acts as a swelling agent, increasing the spacing between the clay platelets prior to mixing with the polymer. There is a loss of entropy of the polymer chains as they intercalate into the clay galleries. The driving force for this to occur is the entropy gained by de-sorption of the solvent molecules.

(9) An increase in viscosity and a lack of opacity of the dispersed clay/solvent dispersion and a lack of any settling out of clay upon standing for 24 hours were used as signs of at least partial exfoliation of the clay. A release agent was added to the clay/solvent pre-dispersion followed by addition of a resin/solvent solution, form the coating solution. Again the samples were observed for any clay dropout over time. A lack of settling out of clay was used as an indication that the clay was remaining in an exfoliated state within the coating solution. A coating was applied by hand using a Meier bar to give a wet coat weight of ?12 ?m, onto a 6 ?m polyester base film. The base film was already coated with a heat resistant backcoat to provide protection from the thermal head during the printing process, and a cross-linked acrylic subcoat to provide release of the receiver during transfer. The coating was dried initially by a hair drier, then in an oven at 110? C. for 30 seconds.

Example 1

(10) Three organically modified clays (Cloisites) obtained from Southern clay products were tested. These were all montmorillonite smectite clays that differed in their organic modification. The organic modifiers of the three Cloisites are given below.

(11) ##STR00001##

(12) A coating solution A (comparative) was prepared from:

(13) TABLE-US-00001 Cloisite 15A? Toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Vylon 885 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.7% wrt total weight

(14) A coating solution B (comparative) was prepared from:

(15) TABLE-US-00002 Tegoglide A115? 2% wrt resin (0.32% wrt total weight) Vylon 885? 16% wrt total weight MEK/Toluene 50/50 wt/wt 83.7% wrt total weight

(16) A coating solution C (comparative) was prepared from:

(17) TABLE-US-00003 Tegoglide 410? 2% wrt resin (0.32% wrt total weight) Vylon 885? 16% wrt total weight MEK/Toluene 50/50 wt/wt 83.7% wrt total weight

(18) A coating solution D (comparative) was prepared from:

(19) TABLE-US-00004 Tegoprotect 5000? 2% wrt resin (0.32% wrt total weight) Vylon 885 16% wrt total weight MEK/Toluene 50/50 wt/wt 83.7% wrt total weight

(20) A coating solution E (comparative) was prepared from:

(21) TABLE-US-00005 Tegomer Csi2342? 2% wrt resin (0.32% wrt total weight) Vylon 885? 16% wrt total weight MEK/Toluene 50/50 wt/wt 83.7% wrt total weight

(22) A coating solution F (comparative) was prepared from:

(23) TABLE-US-00006 Tegoglide 450? 2% wrt resin (0.32% wrt total weight) Vylon 885? 16% wrt total weight MEK/Toluene 50/50 wt/wt 83.7% wrt total weight

(24) A coating solution G (according to the invention) was prepared from:

(25) TABLE-US-00007 Cloisite 15A/? toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoglide A115? 2% wrt resin (0.32% wrt total weight) Vylon 885? 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(26) A coating solution H (according to the invention) was prepared from:

(27) TABLE-US-00008 Cloisite 15A/toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoglide 410? 2% wrt resin (0.32% wrt total weight) Vylon 885? 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(28) A coating solution I (according to the invention) was prepared from:

(29) TABLE-US-00009 Cloisite 15A/toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoprotect 5000? 2% wrt resin (0.32% wrt total weight) Vylon 885 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(30) A coating solution J (according to the invention) was prepared from:

(31) TABLE-US-00010 Cloisite 15A/? toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegomer Csi 2342? 2% wrt resin (0.32% wrt total weight) Vylon 885? 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(32) A coating solution K (accordina to the invention) was prepared from:

(33) TABLE-US-00011 Cloisite 15A/toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoglide 450 Tegoglide 450 2% wrt resin (0.32% wrt total weight) Vylon 885 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(34) A coating solution L (comparative) was prepared from:

(35) TABLE-US-00012 Cloisite 93A/toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoglide A115 2% wrt resin (0.32% wrt total weight) Vylon 885 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(36) A coating solution M (comparative) was prepared from:

(37) TABLE-US-00013 Cloisite 30B/toluene 5% Cloisite wrt resin pre-dispersion (1.6% wrt total weight) Tegoglide A115 2% wrt resin (0.32% wrt total weight) Vylon 885 15.7% wrt total weight MEK/Toluene 50/50 wt/wt 82.4% wrt total weight

(38) Each of coatings B to F are for comparison with coatings G to K according to the invention.

(39) Vylon 885? is a polyester available from Toyubo. Tegoglide A115? is an organo-modified polysiloxane. Tegoglide 410? is a polyether siloxane copolymer. Tegoprotect 5000? is a modified polydimethyl siloxane resin. Tegomer Csi 2342? is a linear organo-functional polysiloxane. Tegoglide 450? is a polyether siloxane copolymer. All Tego additives are available from Degussa.

(40) Testing

(41) The organo-clay dispersions were observed as described in the sample preparation section above.

(42) TABLE-US-00014 TABLE 1 Appearance after addition of pre- dispersion to Appearance after polymer/solvent Organo-clay Appearance stirring in solvent solution Cloisite 15A Off-white solid Clear, yellow No drop out of any viscous fluid filler, clear fluid Cloisite 93A Off-white solid Murky, low Cloudy, some drop viscosity fluid out of solid material Cloisite 30B Off-white solid Murky, low Cloudy, large viscosity fluid amount of drop out of material

(43) From the observations contained in table 1 Cloisite 15A was assigned as being in at least a partially exfoliated state, whereas Cloisite 93A and 30B were assigned as being in a non-exfoliated state i.e. like a traditional clay filler. This is not to say that Cloisite 93A, Cloisite 30B or any swellable layered silicate (modified or not) could not be used in the application as disclosed herein provided that the appropriate conditions and formulation were used i.e. a solvent in which the clay is swellable, use of a polymer solution in which the clay remains in an exfoliated state or use of a different method of achieving exfoliation e.g. in situ polymerisation.

(44) The coatings were spliced into a dye-sheet and printed as a monochrome panel onto PVC and polycarbonate cards using a Pebble-3 printer (manufactured by Evolis). The receiver layer was visually assessed for transfer, looking for full coverage of the card and no flash (i.e. that the receiver layer gave a clean fracture along the edge of the printed area and there was no ragged torn edge to the panel). The receiver layer was print tested by printing a high-density coloured image (red lips image with black background) on a Pebble-3 printer using a standard YMCKO dye ribbon from ICI.

(45) Cyan peel forces were measured by first printing yellow 255 using a thermal print head set up that does not remove the dye-sheet after printing. The printed yellow dye-sheet was manually removed and then the same card was printed with magenta 255. The magenta dye-sheet was removed manually and a cyan image consisting of increasing density bars was printed. The cyan dye-sheet was not removed at this stage. The cyan dye-sheet was peeled apart from the card using an Instron 6021. The maximum peel force recorded during the removal of the dye-sheet was noted and reported as the cyan peel force for that sample.

(46) All examples above transferred well via heating with a thermal print head, there was complete transfer of all examples with no signs of flash. A table summarising the cyan peel force and print test results is given below. Using the methods as described in the sample preparation section described above it was concluded that the organo-clays contained within solutions L and M were not in an exfoliated state and therefore would not be expected to provide the beneficial barrier effect to reduce claw-back of the release agent. In the table TT stands for total transfer i.e. when parts of the ribbon have stuck to the card.

(47) TABLE-US-00015 TABLE 2 Coating solution Cyan peel force (N) Print test A (comparative) Ribbon stuck when printing cyan B (comparative) 3.46 Ribbon stuck at cyan C (comparative) 3.87 Ribbon stuck at cyan D (comparative) 3.22 Speckled cyan TT E (comparative) 3.13 Ribbon stuck at cyan F (comparative) Stuck at magenta so Ribbon stuck at couldn't measure cyan magenta peel force G 2.4 Good image, no TT H 1.79 Good image, no TT I 1.91 Good image, no TT J 2.44 Good image, no TT K 1.8 Good image, no TT L (comparative) Ribbon stuck at cyan M (comparative) Ribbon stuck at cyan

(48) The cyan peel force results comparing resin+release agent receiver layers with resin+release agent+organo-clay receiver layers for coating solutions B to K are summarised in FIG. 2. Coating solution F has not been included as no value could be obtained for this sample due to the magenta ribbon sticking (could not be removed by manual peeling) before printing cyan.

(49) It can be clearly seen that addition of an organo-clay to a receiver layer of a dyeable resin plus release agent reduces the cyan peel force and improves the dye diffusion print performance.

Example 2

(50) Thermally transferable receiver layers were prepared and transferred as described in the sample preparation section described above. A standard YMCKO ribbon from ICI was used to print three samples as described below: 1) Increasing density cyan bars with no preceding print 2) One print of cyan 255, dye-sheet removed manually, followed by increasing density cyan bars 3) Two prints of cyan 255, dye-sheet removed manually, followed by increasing density cyan bars

(51) The cyan peel forces were measured as described in the testing section as described above. FIGS. 3 to 5 show the increase in cyan peel force with increasing number of preceding prints.