In re Schwarze

536 F.2d 1373, 190 U.S.P.Q. (BNA) 294, 1976 CCPA LEXIS 151
CourtCourt of Customs and Patent Appeals
DecidedJune 30, 1976
DocketPatent Appeal No. 76-534
StatusPublished
Cited by1 cases

This text of 536 F.2d 1373 (In re Schwarze) 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 Schwarze, 536 F.2d 1373, 190 U.S.P.Q. (BNA) 294, 1976 CCPA LEXIS 151 (ccpa 1976).

Opinion

BALDWIN, Judge.

This appeal is from the decision of the Patent and Trademark Office Board of Appeals (board) affirming the examiner’s rejection of claims 4, 5, 8, 11, and 12 in application serial No. 53,984, filed July 10, 1970, entitled “Process for Making Isothiocyanates.” We affirm.

The Invention

The rejected claims are directed to a process for preparing isothiocyanates. In the first step, a triazine compound is reacted with a dithiocarbamate to form the dithiocarbamate of the triazine. In the second step, the dithiocarbamate of the triazine is decomposed into a mixture of mercaptotriazine and an isothioeyanate. The isothiocyanate is then isolated from the decomposition mass. Claim 12, the only independent claim, is illustrative:

12. The process of making isothiocyanatcs of the formula

[1375]*1375

wherein R is alkyl of 1 to 6 carbon atoms, cyclohexyl phenyl, benzyl or phenyl ethyl and Me is an alkali metal atom, in a first stage exothermic reaction within the temperature range of about 0 to 50° in the presence of water as solvent or of a homogeneous or heterogeneous mixture of water and an inert organic solvent, whereby the bis- or tris-dithiocarbamate of the triazine is formed, whereupon, thereafter, in a second reaction stage, for. a period of at least one hour, the latter product is maintained at about the temperature previously reached or further heat is applied within the temperature range of about 0 to 100°C until the product is decomposed into a mixture of mercaptotriazinc and the isotKtocyanate of formula (1), followed by isolation of the isothiocyanate of formula (1) from the decomposition mass after or upon separation of the mercapatotriazine.

Claims 4, 5, 8, and 11 are each individually dependent upon claim 12. Claim 4 specifies the use of steam distillation or extraction to separate the mercaptotriazine and isothiocyanate. Claim 5 recites certain specific triazine compounds, namely cyanuric chloride, 2-methylmercapto-4,6-dichlorotriaz-ine,n-butoxy-4,6-dichlorotriazine, and 2-ethylamino-4,6-dichlorotriazine. Claim 8 further limits the second stage of the process to a temperature above the temperature of the reaction between the triazine and dithiocarbamate. Claim 11 further defines the dithiocarbamate reaction component.

The Rejections

The following references were relied upon:

Claudin 2,338,902 Jan. 11, 1944

Yalenzin 3,139,350 June 30, 1964

Cometti' et al. 3,288,831. Nov. 29, 1966

Werres 3,406,191 Oct. 15, 1968

Higson (British) 857,166 Dec. 29, 1960

Toyama Chem. (Jap.) 42-10,498 June 7, 1967

The board sustained the examiner’s rejection of claims 5, 8, 11, and 12 as obvious under 35 U.S.C. § 103 over Valenzin and Higson in view of Cometti et al., Claudin, or. Toyama Chem. (hereinafter Toyama). The board also sustained the rejection of claim 4 [1376]*1376over the above-cited combination, further in view of Werres.

The board noted that Valenzin discloses the first stage of the claimed process, albeit at a higher temperature (60 to 90 °C.) than that of the claimed reaction (0 to 50 °C.), but considered this difference in temperature to be an obvious variation. Moreover, the board stated that Higson suggests that a lower temperature range (30 to 60 °C.) would be operable in this first stage and, furthermore, that condensates of cyanuric chloride with bis-dithiocarbamate salts decompose upon heating at about 180 °C. Since Valenzin discloses that the bis-dithiocarbamate compounds react in the same manner as the alkyl dithiocarbamates, the board reasoned that it would be expected that thermal decomposition would also take place with the condensates containing alkyl dithiocarbamate residues.

The board found that each of the secondary references to Toyama, Cometti et al., and Claudin suggests that isothiocyanates may be obtained from the decomposition mass resulting from the thermal treatment of the condensates since, although the particular compounds decomposed in these secondary references are not the same as those decomposed in appellants’ thermal treatment of their condensates, the reaction mechanism appears to be the same and an isothiocyanate is obtained in each instance. Therefore, the board held that one skilled in this art would expect that other dithiocarbamate compounds, i. e., those of Higson and Valenzin, would likewise decompose to produce the corresponding isothiocyanates.

With respect to claim 4, the board found that Werres discloses the use of steam distillation to isolate methyl isothiocyanate from a reaction product containing it.

Furthermore, the board found that claim 8, which limits the second stage of the process to a temperature “above the temperature of the reaction between the triazine compound and the dithiocarbamate,” is also obvious since the increase in temperature would depend upon the stability of the compounds to be decomposed. Thus, the board stated, the use of higher temperatures would involve no more than the routine ability of a chemist in this field. Finally, the board noted that Higson discloses that his compounds may be prepared at 30 to 60 °C. and decompose at 180 °C., thus suggesting that the second stage of appellants’ reaction be carried out at a “higher” temperature.

Solicitor’s Arguments Concerning “Reasons of Appeal”

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Related

In re Toma
575 F.2d 872 (Customs and Patent Appeals, 1978)

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Bluebook (online)
536 F.2d 1373, 190 U.S.P.Q. (BNA) 294, 1976 CCPA LEXIS 151, Counsel Stack Legal Research, https://law.counselstack.com/opinion/in-re-schwarze-ccpa-1976.