Incremental printing of symbolic information – Ink jet – Medium and processing means
Reexamination Certificate
2001-05-07
2002-07-16
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Medium and processing means
C428S195100
Reexamination Certificate
active
06419356
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
Reference is made to commonly assigned, co-pending U.S. patent application Ser. No. 09/850,026 by Sadasivan et al., filed of even date herewith entitled “Ink Jet Recording Element”.
FIELD OF THE INVENTION
This invention relates to an ink jet printing method, more particularly to an ink jet printing method using a porous ink jet recording element.
BACKGROUND OF THE INVENTION
In a typical ink jet recording or printing system, ink droplets are ejected from a nozzle at high speed towards a recording element or medium to produce an image on the medium. The ink droplets, or recording liquid, generally comprise a recording agent, such as a dye or pigment, and a large amount of solvent. The solvent, or carrier liquid, typically is made up of water and an organic material such as a monohydric alcohol, a polyhydric alcohol or mixtures thereof
An ink jet recording element typically comprises a support having on at least one surface thereof an ink-receiving or image-receiving layer, and includes those intended for reflection viewing, which have an opaque support, and those intended for viewing by transmitted light, which have a transparent support.
An important characteristic of ink jet recording elements is their need to dry quickly after printing. To this end, porous recording elements have been developed which provide nearly instantaneous drying as long as they have sufficient thickness and pore volume to effectively contain the liquid ink. For example, a porous recording element can be manufactured by cast coating, in which a particulate-containing coating is applied to a support and is dried in contact with a polished smooth surface.
U.S. Pat. No. 5,932,355 relates to an ink-jet recording sheet wherein the ink-receptive composition contains a non-ionic silicone surfactant, from about 14 to about 93% by weight of a polymer and a small amount of particulates such that the coating is transparent. However, there is a problem with this element in that it is not porous, so that it has a poor dry time.
U.S. Pat. No. 5,919,559 relates to an ink jet recording sheet comprising an ink absorbing layer containing a predominant amount of water soluble resin or water dispersible resin and an nonionic surfactant having an HLB number of 11 or more. However, there is a problem with this element in that it is not porous, so that it will have a poor dry time.
It is an object of this invention to provide an ink jet printing method using a recording element that is porous. It is another object of the invention to provide an ink jet printing method using a recording element that has a fast dry time and good image quality.
SUMMARY OF THE INVENTION
These and other objects are achieved in accordance with the invention which comprise an ink jet printing method, comprising the steps of:
A) providing an ink jet printer that is responsive to digital data signals;
B) loading the printer with an ink jet recording element comprising a support having thereon a porous image-receiving layer comprising at least about 90% by weight of particles and less than about 10% by weight of a binder, the image-receiving layer also containing a nonionic surfactant having an HLB number of less than about 10 in an amount to substantially prevent foaming of the coating composition which is used to coat the support with the image-receiving layer,
C) loading the printer with an ink jet ink; and
D) printing on the porous image-receiving layer using the ink jet ink in response to the digital data signals.
By use of the method of the invention, a porous ink jet recording element is obtained which has a fast dry time and good image quality.
DETAILED DESCRIPTION OF THE INVENTION
The presence of a binder in an image-receiving layer coating solution increases its propensity to foam. The coating solution typically requires a large amount of agitation to minimize the concentration gradients of the ingredients and thereby reduce variability. This agitation, however, typically leads to entrainment of air, which leads to the formation of excessive foam.
In accordance with the invention, certain non-ionic surfactants have been found to be antifoaming agents. In addition, these materials do not themselves foam at low concentrations.
As noted above, the non-ionic surfactants which are used in this invention have an HLB number less than about 10. The HLB number of a surfactant is used to specify the nature of an oil/water dispersion that is formed in the presence of that surfactant. If the HLB number is less than 7, the dispersed (or drop) phase will be water. If the HLB number is above 12, the dispersed phase will be oil.
It has been found that the HLB number can also be used to predict the ability of a nonionic surfactant to eliminate foam in a coating solution. If a surfactant has an HLB number of 10 or greater, the surfactant may enhance the stability of the foam instead of eliminating it.
The HLB number of surfactants can be measured or calculated. There are several methods of measuring HLB, some of which are listed in “Nonionic Surfactants”, Ed. M. Schick, “Surfactant Science Series”, Vol. 1, Marcel Deker Inc., New York, 1967.
There are several kinds of nonionic surfactants that can be used in the present invention. There can be used, for example, ethoxylated alcohols having the formula R—O(CH
2
CH
2
O)
n
H where R can be alkyl, aryl or aralkyl having from about 2 to about 30 carbon atoms and n can vary from about 2 to about 20. The HLB number of an ethoxylated alcohol is related to the ratio of the number of ethylene oxide groups to the number of carbon atoms in the R group. Preferred ethoxylated alcohols useful in the invention include those where all or some of the hydrogen atoms in the R group are substituted by fluorine atoms.
Another class of nonionic surfactants useful in the invention is the block copolymers of ethylene oxide and propylene oxide. Examples of these are Pluronics® (poloxamers) which are triblock copolymers and Tetronics® (poloxamines), which are tetrafunctional block copolymers derived from the sequential addition of propylene oxide and ethylene oxide to ethylenediamine. The ratio of the amount of propylene oxide to ethylene oxide is directly related to the HLB number of the surfactant.
Another class of nonionic surfactants useful in the invention is alkoxylated poly(dimethylsiloxanes) (PDMS) or polyalkylene-modified PDMS materials, including those containing ethylene oxide as well as ethylene oxide and propylene oxide and having an HLB number as described above.
Another class of nonionic surfactants useful in the invention is based on derivatives of mono and disaccharides, including sorbitol esters such as Spans®, and alkyl glucosides and hydrophobic sucrose esters such as sucrose distearate.
Commercial examples of the above surfactants useful in the invention include:
S-1 Silwet® L7220 (Witco Corp.)
S-2 Silwet® L7210 (Witco Corp.)
S-3 Silwet® L7602 (Witco Corp.)
S-4 Pluronic® L61 (BASF Corp.)
S-5 Tetronic® 90R4 (BASF Corp.)
S-6 Tetronic® 701 (BASF Corp.)
S-7 Tetronic® 150R1 (BASF Corp.)
S-8 Fluorad® FC171 ( 3M Corp.)
S-9 Brij® 30 (ICI Chemicals)
S-10 Brij® 93 (ICI Chemicals)
The surfactants used in the present invention are typically used in relatively small amounts. Based on their HLB numbers, these surfactants have limited solubility in coating solutions. These surfactants have a cloud point, which is the highest temperature at which the surfactant is soluble in water. Coating operations typically take place between about 25 and 30° C. Therefore, these surfactants are usually used at levels below their solubility limit at the operating temperature. In general, the surfactants may be used in an amount of at least about 0.05% by weight of the coating solution, preferably from about 0.05% to about 1.0% by weight.
Examples of particles useful in the invention include alumina, boehmite, clay, calcium carbonate, titanium dioxide, calcined clay, aluminosilicates, silica, barium sulfate, or polymeric beads. The particles may be porous or nonporous. In a preferred embodiment of the inventi
Baier John M.
Lobo Lloyd A.
Sadasivan Sridhar
Barlow John
Cole Harold E.
Eastman Kodak Company
Shah Manish S.
LandOfFree
Ink jet printing method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ink jet printing method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ink jet printing method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2826222