Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2002-01-16
2003-07-15
Shoshu, Callie (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S400000, C523S414000, C523S424000, C524S548000, C528S087000, C528S097000
Reexamination Certificate
active
06593398
ABSTRACT:
RELATED PATENTS
Inks are illustrated in U.S. Pat. Nos. 5,931,995; 5,958,119; 5,902,390; 5,922,117; 6,110,265; 6,096,124; 6,071,333; 6,086,661; 6,096,125; 6,066,200; 6,106,601; 6,106,599, and U.S. Pat. No. 5,876,492, the disclosures of each being totally incorporated herein by reference.
The appropriate components of the above copending applications may be selected for the inks and processes of the present invention in embodiments thereof.
BACKGROUND OF THE INVENTION
The present invention is directed to robust, that is, for example, firm and rigid, phase change conductive inks, that is inks that change from a liquid state to solid state in a suitable period of time, for example from about 1 to about 100 milliseconds and preferably in less than about 10, such as from about 2 to about 7 milliseconds, and more specifically, the present invention relates to (1) inks containing solid polymeric additives with hardness values of, for example, from about 80 to about 95, and preferably from about 85 to about 95, hardness being, for example, a property of solids and plastics that is indicated by their solidity and firmness as measured by their resistance to indentation by an indenter of fixed shape and size under a static load; (2) inks that are conductive that is, for example, inks that possess the quality or capability of transmitting electrical signals generated by electric field assisted acoustic ink jet printing processes and apparatuses and which inks possess, for example, controlled jettability thereby permitting low edge raggedness images such as from about 1 to about 3 microns.
The hardness of the ink polymeric additive material can be measured with a Digital-Pencil style Durometer, Model 211B-00 PTC, obtained from Pacific Transducer Corporation, using ASTM Standard specifications for resistance to penetration with a conical [30 degrees included angle] indenter and applying 1 killigram load. The hardness range for elastomeric plastics as measured with this instrument is from about 1 to about 100, the latter being the highest measurable value. The conductivity of a material can be measured by the reciprocal of resistivity, which is the capacity for electrical resistance. The conductivity values of inks expressed as log (pico.mho/cm) and recited herein were measured under melt conditions at 150° C. by placing an aluminum electrode in the molten ink and reading the resistivity output on a GenRad 1689 precision RLC Digibridge at a frequency of 1 K.Hz. Conductivity expressed in terms of [log (pico.mho/cm)] is calculated from the reciprocal of resistivity. Generally, the invention inks possess conductivity values of, for example, from about 2 to about 8 log (pico.mho/cm) and preferably in the range of from about 6 to about 6.5 log (pico.mho/cm).
More specifically, the present invention relates to robust phase change conductive inks with a melting point of from about 60° C. to about 150° C., and preferably from about 70 to about 90° C., especially useful for electric field assisted acoustic ink jet printing with enhanced jettability, acoustic ink processes and apparatuses, reference, for example, U.S. Pat. No. 5,121,141, U.S. Pat. No. 5,111,220, U.S. Pat. No. 5,128,726, U.S. Pat. No. 5,371,531, the disclosures of which are totally incorporated herein by reference, including especially acoustic ink processes as illustrated in a number of the above recited copending applications such as an acoustic ink printer for printing images on a record medium.
The inks of the present invention in embodiments thereof are comprised of (1) a solid polymeric additive that has a hardness value of from about 80 to about 93 with a viscosity of from about 50 to about 2,000 cps and preferably from about 50 to about 500 cps at, for example, 150° C. such additive being, for example, poly(bisphenol A-co-epichlorohydrin), glycidyl end-capped; [M
n
=1075; hardness value of 93.5; Aldrich # 40,545-0]; poly[(o-cresyl glycidyl ether)-co-formaldehyde] [M
n
=870; Mp=70 to 75° C.; Aldrich #40,551-5; hardness value of 92], and which additives can, for example, substantially fill the pores of a substrate, such as paper, and which additive polymer possesses, for example, a melting point of lower than about 135° C. and preferably from about 60° C. to about 100° C.; (2) a viscosity modifying compound that, for example, can lower the viscosity of the ink to a value of, for example, from about 10 to about 20 centipoise and which additive compound is selected from the group consisting of aliphatic unsaturated acids of the general formula CH
3
(CH
2
)
m
(CH
2
CH═CH)
p
(CH
2
)
n
COOH(1) when m=0, p=1 and n=1; trans-3-hexenoic acid, CH
3
(CH
2
CH═CH)(CH
2
)COOH, (Aldrich #19,309-7); (2) when m=1, p=1 and n=0; trans-2-hexenoic acid, CH
3
(CH
2
)(CH
2
CH═CH)COOH (Aldrich #19,308-9); (3) when m=3, p=1 and n=0; 2-octenoic acid, CH
3
(CH
2
)
3
(CH
2
CH═CH)COOH (Aldrich #28,692-3), which acids are preferably liquids and possess, for example, a boiling point of equal to about, or higher than about 150° C. (Centigrade), and more specifically, with a boiling point of from about 150° C. to about 225° C., and which acids preferably possess a low acoustic loss, which enables a reduction, or minimization of energy consumption, and which acoustic loss is, for example, below, or about equal to 60 dB/mm; (3) a conductive phosphorous or sulfur compound, (4) a lightfastness antioxidant, (5) and a colorant such as a dye, a colorant, or mixtures thereof, and wherein there can be generated with such inks in embodiments excellent developed images on plain and coated papers with acceptable image permanence, excellent projection efficiency on transparencies without a post fusing step, and excellent crease resistance, and wherein the inks possess acceptable, and in embodiments superior lightfastness, for example from about 90 to about 100 percent and superior waterfastness, for example from about 95 to 100 percent. Moreover, in embodiments of the present invention there is enabled the elimination, or minimization of undesirable paper curl since water need not be present, and it is preferred in embodiments that there be an absence of water. When water is not present in the inks a dryer can be avoided thereby minimizing the cost of the acoustic ink jet apparatus and process.
PRIOR ART
In acoustic ink printing, the printhead produces approximately 2.2 picoliter droplets by an acoustic energy process. The ink under these conditions should preferably display a melt viscosity of about 6 to about 20 centipoise or less at the jetting temperature. Furthermore, once the ink is jetted onto the paper, the ink image should be of excellent crease property, and should be non-smearing waterfast, possesses excellent transparency and possesses excellent fix qualities. In selecting an ink for such applications, it is desirable that the ink vehicle display a low melt viscosity, such as from about 1 centipoise to about 25 centipoise in the acoustic head, while also displaying solid like properties after being jetted onto paper. Since the acoustic head can tolerate a temperature of, for example, up to about 180° C., and preferably up to a temperature of from about 140° C. to about 160° C., the vehicle for the ink should preferably display liquid like properties, such as a viscosity of 1 to about 10 centipoise at a temperature of from about 75° C. to about 165° C., and solidify or harden after jetting onto paper such that the ink displays a hardness value of from about 0.1 to about 0.5 millimeter measured by utilizing a penetrometer according to the ASTM penetration method D1321.
Ink jet printing processes that utilize inks that are solid at room temperature and liquid at elevated temperatures are known. For example, U.S. Pat. No. 4,490,731, the disclosure of which is totally incorporated herein by reference, discloses an apparatus for dispensing certain solid inks for printing on a substrate such as pape
Breton Marcel P.
Kovacs Gregory J.
Malhotra Shadi L.
Shoshu Callie
Thompson Robert
Xerox Corporation
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