Application of Sutton, Patent Appeals No. 6004.

• Decision Date: 23 March 1954
• Docket Number: Patent Appeals No. 6004.
• Parties: Application of SUTTON et al.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

41 CCPA 816, 211 F.2d 582 (1954)

Application of SUTTON et al.

Patent Appeals No. 6004.

United States Court of Customs and Patent Appeals.

March 23, 1954.

Cushman, Darby & Cushman, and William M. Cushman, Washington, D. C. (Andrew R. Klein, Philadelphia, Pa., of counsel), for appellants.

E. L. Reynolds, Washington, D. C. (J. Schimmel, Washington, D. C., of counsel), for the Commissioner of Patents.

Before GARRETT, Chief Judge, and O'CONNELL, JOHNSON, WORLEY, and COLE, Judges.

JOHNSON, Judge.

This is an appeal from the decision of the Board of Appeals of the United States Patent Office affirming the action of the Primary Examiner in finally rejecting claims 21 to 40, inclusive, which are all of the claims of appellants' application, Serial No. 54,363, for a patent on "Improvements in the Coloration of Cellulose Acetate." All of the appealed claims are process claims and no claims have been allowed.

Claims 23, 24, 28, 29, 33, 34, and 36-40, inclusive, have been rejected as drawn to nonelected species of appellants' alleged invention. There is no controversy over this rejection. Those claims will not be considered on their merits by this court. In re Jones, 162 F.2d 638, 34 C.C.P.A., Patents, 1168; In re Kirwan, 171 F.2d 326, 36 C.C.P.A., Patents, 772.

The claims rejected by the Patent Office as unpatentable over the prior art fall into three distinct categories. Claims 25, 26, and 35 are considered by us to be representative of these categories. These claims read as follows:

"25. Process for the coloration of textile material comprising cellulose acetate which process includes the step of contacting the material with a mixture consisting essentially of a vat dyestuff, a sulphoxylic reducing agent, and an alkaline pH regulator of insufficient alkalinity to cause substantial saponification of cellulose acetate under the conditions of the process, subjecting the material to temperatures of the order of 90°C.-100°C., and oxidizing the dyestuff, said process being characterized in the omission of addition agents having a pronounced swelling effect on cellulose acetate.

"26. Process for dyeing textile material comprising cellulose acetate which process includes the steps of immersing the material in a dyebath consisting essentially of water, a vat dyestuff, and a sulphoxylic reducing agent, at temperatures of the order of 90°C.-100°C., and for from 10 to 15 minutes, and subsequently oxidizing the dyestuff.

"35. Process for dyeing textile material comprising cellulose acetate which process includes the steps of mechanically impregnating the material with a liquor containing a vat dyestuff and a sulphoxylic agent, steaming the impregnated material under pressure, and then giving it an oxidizing treatment."

The rest of the claims to be considered on their merits are similar to one of the above claims. Claim 21 is similar to claim 25, differing therefrom in that it does not set out the pH regulator nor the omission of swelling agents, although it does state that there will be no addition of agents capable of affecting substantial saponification of the cellulose acetate. Claim 21 also specifies air oxidizing. Claim 31 is very similar to claim 35, except that it adds a drying step before the steaming step, and it does not require that the steaming be done under pressure. Claim 22 depends on claim 21, claim 27 depends on claim 26 and claim 32 depends on claim 31, each of the dependent claims adding to the parent claim that the sulphoxylic reducing agent used in sodium formaldehyde sulphoxylate. Claim 30 depends on claim 26 and adds that the dye bath also contains an alkaline pH regulator that will not cause substantial saponification of the cellulose acetate.

The reference relied on is: Scull 2,424,857, July 29, 1947.

As is apparent from the above quoted claims, appellants' alleged invention is for a process for dyeing or coloring a textile material that is wholly or partly of cellulose acetate, with vat dyestuffs. To insure an understanding of appellants' process and the reference patent we believe that some discussion of vat dyes will be helpful. As shown by the record, the use of vat dyes is desired because they are very fast, resisting fading from both light and extensive washing. However, vat dyes are insoluble and thus cannot be used directly. To use them it is first necessary to reduce them to their colorless or leuco form, in which form they are soluble in an alkaline solution and can be adsorbed by various types of material. There are two common methods used in applying vat dyes to the desired material. In one method the leuco form of the dye is mixed in an alkaline solution and the material is immersed in this solution to adsorb the leuco form of the dye. Then the material is removed and subjected to an oxidizing action which converts the leuco form in the material back to the insoluble dye. An alternate method is to form a dye bath of a suspension of the unreduced vat dye and an alkaline reducing agent that is inactive below a certain temperature. The material to be dyed is placed in the dye bath and then, with or without passing through rollers to remove some of the excess suspension, it is passed through a drying step to remove the volatile. It is then placed in a steam chamber where the reducing agent is activated and the dyestuff reduced to its leuco form and adsorbed by the material. Then the material is subjected to an oxidizing treatment to convert the leuco form in the material back to the insoluble dye. These methods are apparently used to dye textile material composed of cotton or regenerated cellulose. However, they have not been satisfactory for the dyeing of material composed of cellulose acetate because of excessive saponification of that material by the alkaline baths. This saponification destroys some of the desirable characteristics of the cellulose acetate, in effect, changing it to regenerated cellulose or viscose. The dyeing art has sought for some method of applying these dyes to cellulose acetate without destroying its desirable properties. This is the problem to which appellants' application is directed as is the patent to Scull, cited by the Patent Office.

Appellants' process is for the coloration of a textile material with the vat dyes. The textile material can be wholly cellulose acetate or it can be a combination of some other material and a percentage of cellulose acetate. The process requires that the material be contacted with a dyebath that consists of a vat dyestuff, a sulphoxylic reducing agent and water, and it may contain an alkaline pH regulator. At some stage of the process, either while being contacted with the dyebath (claim 26) or after having contacted the dyebath, the material is subjected to temperatures of the order of 90°C.-100°C. The material is then given an oxidizing treatment to oxidize the dyestuff. The specification states that this process is carried out with little or no saponification of the cellulose material, but this limitation is only included in three of the claims (claims 21, 25, and 30) in terms of lack of "substantial saponification" under the conditions of the process.

The patent to Scull is for a "Process for Dyeing Textile Materials comprising a Cellulose Carboxylic Ester with Vat Dyes." This patent discloses a process for dyeing a material containing cellulose acetate in any percentage from 1 to 100 percent with a vat dye without "altering the physical characteristics of the original fibers of the textile material." It is also disclosed that dyeing by this process maintains "the characteristic feel and hand of the original goods." In the Scull process the cellulose acetate material is padded with a mixture comprising a vat dye in its unreduced form, a stable alkaline reducing agent, an alkaline agent and a thickening agent. The material is padded with this mixture, then dried without smearing the dye mixture. Then the material is "aged," that is, treated with steam until the vat dye is substantially reduced and the surface of the fibers of the cellulose acetate is saponified to a greater or lesser degree. As Scull states, col. 3, ll. 15-22:

"The saponification obtained in this manner is not to be confused with the saponification which occurs in an alkaline vat. The saponification which obtains in practicing my invention is a surface saponification which, I have found, is essential in order to obtain dyeings with anthraquinone vat dyes."

After "aging" the material is treated with an oxidizing agent for the reduced vat dye to convert the dye to its insoluble form. The patentee discloses that the temperature used in the "aging" step is from 212°F.-270°F. (100°C.-133°C.) and the time from 3½ to 4 minutes. In the example given in Scull's specification sodium carbonate is disclosed as the alkaline agent and formaldehyde sodium sulfoxylate as the reducing agent. In all of the patentee's claims the use of the alkaline agent is "to convert the reduced anthraquinone vat dye to its salt form and to cause surface saponification of a small fraction of the depth of the ester fibers." It is also disclosed that one of the earlier proposals in dyeing cellulose acetate with vat dyes was to treat the material with the dyes in a vat of such low alkalinity that the cellulose acetate was not saponified. The patentee states that this method was of no utility whatsoever for anthraquinone dyes.

All of appellants' claims considered on their merits, were rejected as unpatentable over the process disclosed by Scull. The examiner held that there was no distinction between the fractional saponification of Scull and the insubstantial saponification of appellant...