Application of Cole

• Decision Date: 23 January 1964
• Docket Number: Patent Appeal No. 7033.
• Citation: 326 F.2d 769,140 USPQ 230
• Parties: Application of Robert M. COLE.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

140 USPQ 230, 326 F.2d 769 (1964)

Application of Robert M. COLE.

Patent Appeal No. 7033.

United States Court of Customs and Patent Appeals.

January 23, 1964.

Andrew R. Klein, Synnestvedt & Lechner, William P. Cole, Philadelphia, Pa., for appellant.

Clarence W. Moore, Washington, D. C. (J. F. Nakamura, Washington, D. C., of counsel), for Commissioner of Patents.

Before WORLEY, Chief Judge, and RICH, MARTIN, SMITH and ALMOND, Judges.

SMITH, Judge.

The Board of Appeals affirmed the examiner's rejection of claims in appellant's application¹ for a patent on a method and composition in which a low volatility insecticide, such as a pyrethrin, is propelled into the air by the subliming action of a highly volatile solid, such as paradichlorobenzene, a common moth-proofing material.

Claims, 4, 7, 9 and 10, all the claims remaining in the application, were finally rejected as "unpatentable over" Electrolux British Patent in view of either Chuck U. S. Patent or Algard British Patent. The issue thus presented arises under 35 U.S.C. § 103 and requires for its resolution a determination of whether the differences between the prior art and the invention as claimed were such that the claimed subject matter as a whole would have been obvious to one of ordinary skill in the insecticide art at the time appellant's invention was made.

Rejected claims 4, 7 and 10 are drawn to a solid insecticide. Claim 4 is representative of this group of claims and is as follows:

"4. A solid insecticide comprising in admixture a first ingredient comprising a 20% mixture of a pyrethrin and petroleum solvent and a second ingredient comprising crystal-line para-di-chloro-benzene, the first ingredient comprising from .01% to .02% of the total."

Claim 7 differs from claim 4 in specifying .5 gram of a 20% pyrethrum, 80% petroleum solvent mixture and paradichlorobenzene to make up 500 grams.

Claim 9 is a method claim as follows:

"9. The method of establishing and maintaining, in the atmosphere of an enclosed space, a concentration, effective against insects in flight, of a low volatility insecticide material selected from the class consisting of allethrin and pyrethrins, which method comprises forming a solid mass of a mixture consisting essentially of such material and a solid material selected from the class consisting of paradichlorobenzene, camphor and naphthalene, and exposing said mass to the atmosphere in said space."

Claim 10 covers the "mixture of claim 9."

Appellant has pointed out that the problem faced by the art in using pyrethrin type insecticides is that while they are extremely effective in "knocking down" flying insects, they have very low volatility. This has required their general use in inert solvents in spray guns, or in combination with inert fluid propellants of the halogenated hydrocarbon type to produce aerosols, as in the familiar aerosol insecticide bomb.

As appellant points out, aerosols are fugitive by nature, and the aerosol bomb does not provide an effective means of establishing and maintaining over a substantial period of time an effective concentration of the insecticide in the atmosphere, even in an enclosed space.

In his brief appellant states:

"The present invention involves the discovery that a mixture of a low volatility insecticide of the pyrethrin type with a subliming solid such as paradichlorobenzene will sublime as a mixture and establish in the atmosphere a concentration of vapors including both pyrethrins and the carrier material * * *.

"Such a combination is particularly effective in protecting clothing in a closet against moths. The paradichlorobenzene is effective against larvae and eggs, but ineffective against moths themselves; the pyrethrins in the air are effective against flying moths but ineffective against larvae and eggs * * *."

Appellant's specification discloses certain limits to the amount of pyrethrins which can be completely vaporized by a given amount of the subliming solid used as the carrier material and points out that in using such amounts the concentration of pyrethrins established and maintained in the atmosphere is as great as the temporary concentration achieved by the use of aerosols.

The prior art relied on by the Patent Office is as follows:

                  Chuck                   2,376,327     May  22, 1945
                  Algard (British)          440,536     Jan.  1, 1936
                  Electrolux (British)      639,937     July 12, 1950
                

Chuck discloses a composition for use in demothing a closet, or like confined space, which comprises cedar sawdust impregnated with a solution containing paradichlorobenzene and ethylene dichloride as the volatile ingredients for producing a vapor lethal to moths, moth eggs and larvae, and a pyrethrum extract for killing moths by contact. Glycerin and carbitol are added for lengthening the effective life of the composition by retarding vaporization of the paradichlorobenzene and ethylene dichloride.

The British patent to Algard discloses a liquid insecticide for killing insects such as moths and their larvae and eggs. The insecticide is a mixture containing 200 kg. paradichlorobenzene, 220 kg. Borneo naptha, 830 kg. trichloroethylene and 3 liters pyrethrum extract of 18 percent strength per 1,000 liters. The patent points out that the insecticide may be sprayed on an article or into a room to be protected, and that both the liquid and its vapor have a killing action, and further states that the insecticide "* * * does not leave any stains on textiles, furs or other delicate materials."

The British patent to Electrolux discloses combining a volatile, solid insecticidal carrier, such as paradichlorobenzene, with an insecticide, benzene hexachloride (Gammexane), having a low volatility, to form compositions in solid form for treating clothing in a closet to kill insects and their larvae and eggs. The compositions are asserted to be an improvement over similar compositions containing DDT as the insecticide of low volatility. The patent points out that for treating clothing the improved compositions may be effectively utilized in the spraying device of a vacuum cleaner arranged to operate as a blower to distribute the insecticidal composition in a closet. The quantity of benzene hexachloride is adjusted so that none of it remains as a residue in the spraying device after the carrier has vaporized. The preparation of a satisfactory composition is described in the patent. About 5 percent benzene hexachloride is dissolved in a melted carrier such as paradichlorobenzene. The mixture is allowed to cool and harden, and is then crushed or pulverized. The compositions are stated to be "harmless when applied to delicate objects, especially articles of clothing and the like."

Appellant has directed attention to certain differences between his invention and the prior art. Thus, as to the Chuck patent, appellant urges in his brief:

"The important points to note in connection with Chuck are:

"1. His composition is a liquid, absorbed in sawdust to be sure, but a liquid nevertheless. And he teaches that the vaporization of paradichlorobenzene and ethylene chloride is inhibited or reduced.

"2. Chuck also teaches that the pyrethrins do not vaporize, but rather remain on the objects to be protected, where they act as contact poisons."

As to the Algard patent, appellant points out:

"1. Algard\'s composition is liquid.

"2. Algard\'s pyrethrins are vaporized by spraying."

As to the Electrolux Limited patent, appellant says:

"1. When Electrolux talk about insecticide laden air, and vaporization of the mixture, they are talking about the spraying phase of their process, where they use heat and mechanical energy.

"2. When the paradichlorobenzene of Electrolux sublimes at normal temperatures, it leaves the `Gammexane\' behind."

The solicitor states in his brief:

"* * * Since the claims specify features of appellant\'s composition and method not found in Electrolux the question is whether those features would have been obvious."

It is the solicitor's position that since both Chuck and Algard show that pyrethrum extract is a known insecticide material,

"* * * The principal question, accordingly, is whether it would have been obvious to use pyrethrum extract, in lieu of benzene hexachloride, in the Electrolux mixture."

The board held that "it is within the skill of the art to substitute pyrethrin for the benzene hexachloride used by Electrolux, particularly in view of Chuck or Algard."

We agree with appellant that the prior art does not explicitly teach the use of a subliming solid as a propellant for a low volatility insecticide such as pyrethrin. Thus, Algard does not suggest the invention in issue, for when he used paradichlorobenzene and pyrethrum together, he retained the liquid form and the mechanical sprayer. Chuck does not suggest the invention in issue, since his combination of paradichlorobenzene and pyrethrum is liquid and he teaches explicitly that the pyrethrum is left behind when the volatile liquids evaporate.

Appellant has taken the position that the Electrolux patent would lead away from appellant's invention. The solicitor takes direct issue with this position.

Appellant's position in reference to the Electrolux teaching is stated in his brief as follows:

"* * * It teaches that, when a solid mixture of paradichlorobenzene and a low volatility insecticide is exposed to the atmosphere, the paradichlorobenzene sublimes, leaving the low volatility material behind."

It seems to us that the disclosure of the Electrolux patent as a whole does not support appellant's position. The patent states (col. 2, lines 71-82) that effective compositions are...