Application of Francis N. Apel, Louis B. Conte and Howard L. Bender , 342 F.2d 459 ( 1965 )

SMITH, Judge.

The issue here, as in companion appeal PA 7244, 342 F.2d 455, arises under 35 U.S.C. § 103 and requires us to determine whether the differences between appellants’ invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was madé tó a person having ordinary skill in this art.

The process disclosed in appellants’ application ¹ and claimed in appealed claims 1 through 6 reacts phenols and aldehydes to produce alkylidene bisphenols, the reaction being catalyzed by a cation exchanging resin. The cation exchanging resin is used as a condensation catalyst, in lieU' of the strong mineral acids previously so used in known commercial practice. Commercially available cation exchange resins such as “Amberlite XE-100” and “Dowex 50-X-4” are disclosed as effective catalysts. The resin, if wet, is dried, for example under a vacuum or in an oven, but preferably by displacement of the water with phenol. The molar ratio of phenol to aldehyde in the reaction mixture is disclosed as more than 2:1 and preferably from 6:1 to 12:1. The process is carried out at temperatures of from 65° to 98° C. in a continuous column operation, and at temperatures of from 40° to 98° C. in a batch operation.

The rejection of the appealed claims was affirmed by the Board of Appeals which found the invention to be obvious in view of the following references:

DeGroote et al. 2,499,861 Mar. 7, 1950

Jansen 2,468,982 May 3, 1949

“Amberlite Ion Exchange”, p. 10, Rohm and Haas Co., The Resinous Products Div., Philadelphia, Sept. 1953.

Appellants’ position as stated in their brief is:

“The process now provided by appellants’ invention, for the first time provides a system whereby high purity bisphenols can be secured in a rapid reaction without the concomitant problems of by-product formation, the separation of soluble acia catalysts and the use of corrosion resistant equipment. The invention also provides, for the first time, a system which is continuous by passing a reaction mixture of the alde-hydes and the phenols through a packed bed of the cation exchanging synthetic resin to secure a conversion of the reactants to the bisphen-ols.”

Appellants refer to claims 1, 4 and 6 as typical of those on appeal. These claims are as follows:

“1. A process for the production of bisphenols from a phenol reactive in the para position and a saturated aldehyde which comprises contacting a mixture comprising said phenol and an aldehyde in a molar ratio of more than 2 to 1 with catalytic quantities of a cation exchanging resin at a temperature of less than about 100° C.

“4. The process claimed in claim 3 wherein the cation exchanging resin is anhydrous.

“6. A continuous process for the production of bisphenols from a phenol and an aldehyde which comprises forming a mixture of a phenol having a reactive hydrogen in the ring position para to the phenolic hydroxyl and an aldehyde free of ole-finic unsaturation in a molar ratio of at least 3 to 1, contacting said mixture with a cation exchanging resin saturated with said phenol in a reaction zone maintained at a temperature between about 65° C. and 95° C., drawing off the bisphenol product and the unreacted phenol and aldehyde, separating the bisphenol therefrom, recharging the phenol aldehyde mixture with additional phenol and aldehyde, and again contacting said mixture with said cation exchanging resin.”

The rejection of the claims is based primarily on DeGroote in view of Amber-lite. The DeGroote patent relates to (1) the preparation of diphenylolmethanes from an aldehyde and a phenol, (2) the preparation of oxyalkylated derivatives of diphenylolmethanes. The patent discloses a process for preparing a dipheny-lolmethane from o-cresol and heptalde-hyde in a molar ratio of 2:1.05 by adding the aldehyde to the phenol and 4 pounds of sulfuric acid, refluxing for 1 hour at 100°-110° C. following a rapid drop in temperature from an initial rapid rise to 140° to 160° C., adding 100 pounds of xylene and distilling off the water of reaction. DeGroote points out that the phenol to aldehyde molar ratio of 2:1.05, rather than the theoretical 2:1 ratio, is “desirable” to yield the maximum amount of diphenylolmethane, and that a higher molar ratio (excess of phenol) “ * * * merely results in incomplete combination of the phenol.” The product in xylene solution is dark red and soft-to-fluid.

The Amberlite publication, under the heading “Catalysis by Acids and Bases,” discloses that “Amberlite” ion exchange resins are in the nature of “solid” acids and catalyze many reactions catalyzed by acids. A number of reactions are pointed out, including the reactions of formaldehyde and styrene to yield 4-phenyl-1,3-dioxan, and phenol and isobutylene to yield t-butyl phenol. The publication discloses the advantages of separating the resins from reactants or products by simple filtration or decantation, and of eliminating the requirement for neutralization, as with soluble acids, and the need for acid-resistant equipment.

Jansen is directed to the soluble acid catalyzed condensation of phenols with ketones in the presence of a mercapto substituted aliphatic carboxylic acid. The examiner relied upon the showing in Example 10 of the use of formaldehyde and phenol in securing a product which the reference says contains methylene bisphenol.

The principal contribution to the art made -by Jansen appears to lie in the increased catalytic effects resulting from the use of the mercapto aliphatic acids as catalytic aids. It was applied against the appealed claims as showing the use of formaldehyde with a molar excess of phenol with an acidic catalyst.

While the subject matter of the present appeal is related to the subject matter of the companion appeal (PA 7244), we are here concerned with different claims to a different process and with different prior art. As pointed out by the Board of Appeals:

“ * * * The instant application differs from Appeal No. 422-37 [PA 7244] in that an aldehyde rather than a ketone is employed for condensation with a phenol in order to produce bisphenol. * * ”

While both the application here in issue and that in the companion appeal relate to processes for the production of bisphenols employing a cation exchange resin to catalyze the reaction, we agree with the position stated in appellants’ brief that “it was error to apply the same reasons of rejection here as in the companion docket D-7244 since [the] references are different and the reaction is different.”

It is apparent from the above that the examiner properly considered that the DeGroote reference alone is not an effective anticipation and that reliance on the Amberlite and Jansen references was necessary to supply some of the deficiencies of DeGroote. The question thus posed is whether the teachings of these combined references made the invention as a whole, as claimed in the appealed claims, obvious under section 103. We think they did not.

DeGroote does not teach the use of the molar ratios of phenol to aldehyde specified in the appealed claims. Thus, claim 1 requires a molar ratio of “more than 2:1,” and claims 2 and 6 specify a molar ratio of “at least 3:1” while claims 3, 4 and 5 call for ratios of “from 6:1 to 12:1.” DeGroote, on the other hand, makes the following statement:

“Use of an appreciably smaller ratio of aldehyde to phenol than 1 to 2 merely results in incomplete combination of the phenol, the amount remaining uncombined contributing little or nothing to the value of the product and at the same time raising its cost. Therefore, reactant proportions should be quite closely adhered to, and should be of the order of those just recited above.”

This passage would, if anything, tend to lead one skilled in the art away from appellants’ claimed molar ratios.

As to the importance of the molar ratios claimed, appellants’ specification states:

“It is necessary in the process of this invention to utilize more than stoichiometric amounts of phenol to aldehyde in the reaction zone. Generally at least 3 moles and up to about 20 moles of phenol per mole of aldehyde is suitable. It is preferred, in order to achieve higher conversions and greater efficiency, to employ mole ratios of phenol to aldehyde between about 6:1 and 12:1. The reaction of the phenol and aldehyde to the corresponding bis-phenol with the cationic exchange •resin catalysts hereinbefore described is preferably accomplished by contacting a mixture of a phenol and an aldehyde, containing 6 to 12 moles of phenol per mole of the aldehyde, with an amount of phenol modified-ion exchange resin catalyst sufficient to provide 1 mole equivalent of acid per mole of aldehyde at a temperature between 65° and 95° C., for a time sufficient to yield at least a 50% conversion of the reactants to bisphenol. The time during which the reactants are in contact with the catalyst, or the residence time, determines the per cent conversion for a given resin.”

The importance of the claimed temperature conditions is likewise set forth in the specification:

“The ion exchange resin of this invention is generally effective at moderate temperatures of about 40° to 100° C. Temperatures above 100° C. are not necessary or particularly advantageous since the rate of byproduct formation appears to increase rapidly above this temperature and no corresponding increase in rate of bisphenol production or total bisphenol yield occurs. At temperatures above 100° C., it is also possible that some of the polymeric catalysts could be degraded, significantly lowering their useful life.”

Nor do we think the Jansen reference suggests appellants’ claimed molar ratios. While it is true that Example X of Jansen shows a ratio of phenol to aldehyde which falls within the range claimed by appellants, it is also true that Jansen is directed to the use of a particular type of catalyst for this reaction, which catalyst is in no way related to appellants' cation exchanging resin. We think this difference in catalysts is highly significant and destroys much of the pertinence of Jansen’s teaching of molar ratios to appellants’ invention. Cf. Corona Cord Tire Co. v. Dovan Chem. Corp., 276 U.S. 358, 48 S.Ct. 380, 72 L.Ed. 610 (1928). And, we might add, the same reasoning applies with equal effect to the teachings of the DeGroote reference.

Thus, when the claimed subject matter as a whole is considered, including not only the particular catalyst used but the claimed temperature conditions and molar ratios as well, we think the cumulative differences over the prior art are such that appellants’ invention would not have been obvious to one of ordinary skill in this art.

The decision of the board is accordingly reversed.

Reversed.

1 . Serial No. 768,093, filed October 20, 1958.