In re Krodel

223 F.2d 285, 42 C.C.P.A. 993, 106 U.S.P.Q. (BNA) 195, 1955 CCPA LEXIS 178
CourtCourt of Customs and Patent Appeals
DecidedJune 15, 1955
DocketNo. 6140
StatusPublished
Cited by4 cases

This text of 223 F.2d 285 (In re Krodel) is published on Counsel Stack Legal Research, covering Court of Customs and Patent Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
In re Krodel, 223 F.2d 285, 42 C.C.P.A. 993, 106 U.S.P.Q. (BNA) 195, 1955 CCPA LEXIS 178 (ccpa 1955).

Opinion

Johnson, Judge,

delivered the opinion of the court:

This is an appeal from the decision of the Board of Appeals of the United States Patent Office affirming the holding of the Primary-Examiner rejecting, as unpatentable over the prior art and as functional, claims 18 and 19, the only remaining claims in appellants’ application for a patent for a “Process for De-inlring Printed Waste Paper.”

The appealed claims read as follows:

18. The process of de-inking printed material which comprises forming an aqueous slurry of printed and shredded waste newsprint stock material, [then adding to the slurry a water soluble salt yielding an ion having a valency of at least 4,] to thereby induce a zeta potential of the same charged sign as the ink particles and which differs from that of similarly charged particles of the material by a factor of at least 4i to thereby effect a substantial separation of the ink particles from, the material particles; then adding to the resultant mass a detergent of a suitable type to emulsify the separated ink particles and retain them in suspension and separated from the material particles; then subjecting such mass to a temperature of 150-190° F. for a period of %-2 hours and agitating the mass during said period; and then removing the separated ink particles from the slurry and mass with the water (Brackets and italics added.)
19. The process of de-inking printed material which comprises forming an aqueous slurry of printed and shredded waste newsprint stock material, then adding to the slurry a water soluble salt yielding an ion having a valency of at least 4, to thereby induce a zeta potential of the same charged sign as the ink particles and which differs from that of similarly charged particles of the material by a factor of at least 4, to thereby effect a substantial separation of the ink particles from the material particles, then adding to the resultant mass a detergent of a suitable type to emulsify the separated ink particles and retain them in suspension and separated from the material particles; then subjecting such mass to a temperature of 150-190° F. for a period of %-2 hours and agitating the mass during said period; then applying to electrodes in contact with such mass an imposed electric potential difference approximating 1.8 to 2.4 volts per inch of linear distance between said electrodes, and without permitting electrolysis, and to substantially complete the separation of the ink particles from the material fibers; and then removing the separated ink particles from the slurry and mass with the water.

[995]*995As can be seen from the above claims, the process recites a series of steps for cle-inking printed paper. All of the recited steps, except -as hereafter noted, seem to be self-explanatory, and adequately describe appellants’ process. Therefore, it is believed that only the italicized portion of claim 18 and the bracketed subject matter relating to this italicized portion need be further explained. It appears to be the theory of operation of appellants’ process that by adding a water soluble salt having a valence of at least 4 that a charge of the same sign is placed on both the ink particles and on the paper. Since particles having charges of like sign will repel each other, the placing of charges of like sign on the particles to be separated will aid in their separation. The specification states, insofar as pertinent here, that the water soluble salt may be tetrasodium pyrophosphate (JSra4P207). It appears from the specification, relative to the above italicized portion of claim 18, that the zeta potential, in effect, is proportional to the rate of movement of a charged particle in an electrolyte, and can be determined according to a given formula after making certain physical measurements. It is stated in the specification that “it is desirable that the salt and its concentration which is used give the greatest possible difference between the zeta potentials, as this will effect a more rapid and more thorough separation between the ink particles and the cellulose fibers.” It is further stated in the specification “To obtain satisfactory results from a practical standpoint, zeta potential of the one [the ink particles] should be at least four times greater than the zeta potential of the other [the paper], and there appears to be no maximum difference.” This is brought out in different terminology in the italicized portion of claim 18. It is further shown in the disclosure that an optimum concentration of the salt will give the greatest difference in zeta potentials, but if the concentration is greater or less than the optimum value this desirable difference between zeta potentials is not obtained.

The references relied on are:

Bonser- 1, 008, 779 Nov. 14, 1911
Darling- 1, 925, 372 Sept. 5, 1933
Snyder et al- 1, 933, 228 Oct. 31, 1933
Rassow (Br.)- 506, 472 May 30, 1938
Ellis, “Printing Inks” pp. 480-483, 1940.
West, “Deinking of Paper”, April 1943, pp. 5 to 9.

Relative to claim 18, the Board of Appeals felt that West, Darling, and Rassow references were the most pertinent, the patents to Ellis and Snyder et al. being merely cumulative. We will therefore only set forth the teachings of the former, the latter being unnecessary to our decision. The Bonser reference was relied on with respect to [996]*996claim 19;-therefore, the substance of this reference will also be' set forth hereafter.

The West publication relates to de-inking of paper. Insofar as pertinent here, it teaches that shredded printed paper may be cooked at a temperature of 140° F. to the boiling point for 2y2 to 48 hours. It is further stated that a de-inking formula is used which, among other things, consists of: (-1) “An alkali to saponify the varnish or vehicle of • the ink — sodium hydroxide, sodium carbonate, calcium hydroxide,- sodium silicate or metasilicate, trisodium phosphate, soaps,'and other chemicals, either separately or in various combinations;” (2) “a detergent * * *-sodium silicate, or bentonite in the presence of- an alkali and trisodium phosphate or tetrasodium pyro-phosphate;” (3) “a base exchange chemical — such as tetrasodium pyrophosphate or hexasodium metaphosphate to prevent formation of-calcium .soaps where the water used: for washing is too hard.”

" The Darling patent relates to a process for de-inking printed paper. - .Claim 1 of the- patent succinctly sets forth the patented process and is therefore quoted in its entirety as follows :

. 1. The process oí separating the eellulosic fibers of filled and printed paper from the printing ink arid fillers therein contained which comprises beating the paper in a solution containing an alkaline reacting compound selected from the group consisting of sodium hydroxide, sodium metasilicate and trisodium phosphate in such proportions as to render said solution alkaline to the extent of having a hydrogen ion concentration of from pH 9.0 to pH' 12.6 until the paper has been substantially disintegrated, and thereupon adding to the suspension thus formed a small amount of an emulsifying agent, continuing the beating for a short period of time, and thereupon filtering the suspension through a sieve fine enough to retain the eellulosic fibers but coarse enough to pass the fillers and ink particles.

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223 F.2d 285, 42 C.C.P.A. 993, 106 U.S.P.Q. (BNA) 195, 1955 CCPA LEXIS 178, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-krodel-ccpa-1955.