Application of Barrett

182 F.2d 626, 37 C.C.P.A. 1073
Court of Customs and Patent Appeals·Decided May 9, 1950·No. Patent Appeal 5671·Published·Cited by 1 cases

Opinion

JOHNSON, Judge.

Appellants are dissatisfied with the decision of the Patent Office Board of Appeals affirming the Primary Examiner’s rejection of claims 24 through 28 of their application, filed November 2, 1942, for a patent on a process for preparing color composition usable as a coating material, and a novel apparatus for preparing the composition. They appeal from that decision, as provided by R.S. 4911, 35 U.S.C. 59a, 35 U.S.C.A. § 59a.

The application was examined in the Patent Office under the “dual prosecution” procedure in effect prior to November 1948 [present practice is governed by par. *627 705, 705.1, 705.1a through f, Manual of Patent Examining Procedure, U. S. Patent Office, November 1949], claims 24 and 25 being acted upon in Division 32 of the Patent Office while claims 26 through 28 were handled by Division 64. Under the practice then followed in the Patent Office, the examiner of each Division filed a separate statement of the grounds of the final rejection affecting the claims examined in his division. One process claim, 14, was allowed. The process claims, 26 through 28, were rejected in Division 64 as lacking invention over references cited. Claims 24 and 25, drawn to the apparatus, were rejected as reciting an aggregation, and not a patentable combination.

The board in affirming the rejections cited as references two patents and a publication which had been cited by the examiner of Division 64 in his statement, viz:

Hughes et al., 2,351,638, June 20, 1944*
(* — filed October 12, 1940).
Coleman, 2,185,110, Dec. 26, 1939.
Paint Manufacture, July 1935, pp. 202-207,
“Paint Making Machinery,” by N.N. Maas (English).

The board cited also three patents which it states had been cited during the prosecution of the case. Two of them are cited in the early actions appearing of record. The third, Calcott et al. is not elsewhere mentioned in the printed record.

Auspitzer, 1,577,052, Mar. 16, 1926.

McGougan et al., 1,671,868, May 29, 1928.

Calcott et al., 2,021,143, Noy. 19, 1935.

The application refers to a method and apparatus for preparing an aqueous suspension of pigment and adhesive known as a coating composition to be applied to the web or raw paper stock in the manufacture of colored paper for printing uses. An objective of those preparing coating compositions is to secure a homogeneous composition wherein each particle of pigment is surrounded by the adhesive, such as starch, and the resulting coating composition free of agglomerates. The application describes prior art methods of preparing coating compositions as requiring “cutting” the adhesive material (such as casein, alpha protein, starch, etc.) in a steam jacketed tank equipped with slow speed paddle agitators for stirring. The pigments are dispersed in water in a second tank similarly provided with paddle agitators. Such mixing is stated by the appellants to depend on the shearing action of the pigment particles over each other. The low rate of shear obtained does not achieve rapid mixing or a full disintegration of agglomerates. The adhesive is mixed into the pigment alurry in a third mixing unit. “In all coating preparation systems of this type,” state the appellants in their application, “auxiliary screening and/or filtering equipment are [sic] required for the mixed coatings, and even with these, small agglomerates of pigment and/or adhesive often appears [sic] on the coated paper.”

Appellants’ apparatus consists of a mixing chamber with funnel-shaped sides and a submerged high-speed stirring unit. The material to comprise the coating composition is placed in the mixing chamber, drawn off through a conduit at the bottom into a high speed dispersion unit, and forced from that unit in small pipes through a rapid heat transfer unit where the adhesive is cooked as the composition passes through the unit. The material may either be drawn off for use or returned through the continuous conduit system to the mixing chamber to repeat the processing Cycle. The high speed dispersion unit consists of a circularly shaped channel or circular cross-section with a high speed rotor positioned so that its notched or pocketed periphery encroaches within the inner circumference of the circular channel. As the rotor spins, the mixture is drawn from the mixing chamber and as it courses through the narrow restricted passage of the circular channel it is subjected to centrifugal force which thrusts the particles of pigment and adhesive in the mixture against the circular sides of the channel. Simultaneously, the edge of the rotor impels particles of matter striking its whirling surface in a direction variant to the line of:, centrifugal force. This is believed by the appellants to impart a whirling effect to those particles and they return in their trajectory to the rotor surface where they are again impelled forward to repeat the cycle. The peripheral speed of the impeller *628 is of the • order- of 3500-3600 feet per minute. The material is thus subjected to high shearing and centrifugal forces. The composition is forced from the dispersion unit through a- conduit which coils through a steam chamber. This is the heat exchanger where-the composition is “cooked.” The appellants assert that very high solid-content - compositions may be secured by their process and apparatus, as high as 75% solid-content having 'been obtained. The compositions prepared by their process and apparatus are stated to be “free of any agglomerates of pigment or adhesive.” Whereas a mixing time of from two to three hours is 'said to have been required by prior art methods, a dispersion time of 10 minutes with a like time for cooking yielded by one formula an agglomerate-free mixture of 65% solid-content. By another formula, the enzyme conversion of starches in the presence of pigments and other materials was made in 40 minutes to yield a 65% solid-content coating composition.

The following claims are illustrative:

“24. An apparatus for preparing coating composition comprising, a mixing vessel; •a heat exchanger; and a high speed dispersion means for withdrawing the material from the mixing vessel, dispersing the material and forcing the material through the heat exchanger, said dispersion means including a substantially circular channel of rotor with a periphery extending into the said channel.”
“26. A process of preparing mineral coating composition comprising, introducing into a container a selected quantity of starch, protein, pigment, and water; continuously withdrawing the material from the container; applying high shearing and centrifugal force to the mixed material at the same time while the material 'is passing through a restricted passage, and then heating the moving material to a cooking temperature.”

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Application of Barrett, 182 F.2d 626, 37 C.C.P.A. 1073 (ccpa 1950).

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