Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Claims 1-10 of G. Fremy et al., US 18/18/567,183 (Jul. 17, 2025) are pending and under examination on the merits. Claims 1-10 are rejected.
Rejections 35 U.S.C. 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. — The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Pursuant to 35 U.S.C. 112(b), the claim must apprise one of ordinary skill in the art of its scope so as to provide clear warning to others as to what constitutes infringement. MPEP 2173.02(II); Solomon v. Kimberly-Clark Corp., 216 F.3d 1372, 1379, 55 USPQ2d 1279, 1283 (Fed. Cir. 2000). A claim is indefinite when it contains words or phrases whose meaning is unclear. MPEP § 2173.05(e) (citing In re Packard, 751 F.3d 1307, 1314, 110 USPQ2d 1785, 1789 (Fed. Cir. 2014)).
Improper Preferences
Claims 3, 4, 6, 7 and 8 are rejected under 35 U.S.C. 112(b) as being indefinite for recitation of exemplary claim language “preferably” or “preferentially”. MPEP § 2173.05(d). For example, claim 7 recites “preferably” in the following context:
Claim 7. The preparation process according to claim 1, in which step F) is performed in the presence of a catalyst chosen from promoted or nonpromoted catalysts based on zeolites, alumina (Al2O3), silica (SiO2), titanium dioxide (TiO2), aluminosilicate, bentonite or zirconia (ZrO2); preferably, the catalyst is a zeolite.
This claim 7 recitation of “preferably”, in this context, improperly provide for preferences and thereby renders confusion over the intended scope of claim 7. See, MPEP § 2173.05(d). The same issue is present in claims 3, 4, 6, and 8, which are rejected under § 112(b) for the same reasons.
Non-Statutory Double Patenting
The non-statutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A non-statutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
Provisional Non-statutory Double Patenting Rejection over H. Salembier et al., US 18/566,958 (2020), published as US 2024/0286997 (2024)
Claims 1-10 are rejected on the ground of non-statutory double patenting as being unpatentable over conflicting claims 9, 2 and 7 of H. Salembier et al., US 18/566,958 (2020), published as US 2024/0286997 (2024). The rejection is provisional because the conflicting claims have not been patented. However, the instant and conflicting application have the same patent term filing date. Conflicting claim 9 recites:
Conflicting claim 9. A process for preparing at least one mercaptan, preferably continuously, comprising the following steps:
A) H2S and at least one alcohol are introduced into a first reactor;
B) the H2S and said at least one alcohol are reacted to obtain an outlet stream comprising at least one mercaptan and at least one dialkyl sulfide and possibly H2S;
C) the stream comprising at least one mercaptan, at least one dialkyl sulfide and possibly H2S is separated into:
-a stream F1 comprising the mercaptan(s),
-a stream F2 comprising the dialkyl sulfide(s), and
-optionally a stream F3 comprising H2S;
D) optionally, stream F2 is purified to obtain a stream F2' enriched in dialkyl sulfide(s);
E) stream F2 or F2' is introduced with H2S into a second reactor, said reactor comprising a catalyst treated according to the treatment of step i) as claimed in claim 1;
F) a sulfhydrolysis reaction of the dialkyl sulfide(s) with H2S is performed to obtain an outlet stream F4 comprising said mercaptan(s) and possibly H2S;
G) optionally, stream F4 obtained from step F) is recycled into step A).
Conflicting claim 9 differs from instant claim 1 in that it does not specifically recite that stream F2 comprises DADS(s) (i.e., dialklyldisulfides). However, the conflicting specification teaches that:1
[0150] Furthermore, it has been observed that the preparation of mercaptan(s) from at least one alcohol and H2S can lead to the formation of dialkyl disulfide impurities (noted DADS and of the type R-S-S-R).
. . .
[0152] These DADS end up with the dialkyl sulfide(s) and then in the reactor in which the sulfhydrolysis is performed.
. . .
[0153] In particular, when methyl mercaptan is formed from methanol and H2S, dimethyl disulfide (DMDS) may be formed secondarily. When this DMDS is present during the sulfhydrolysis reaction, it has been observed that the facilities (in the reactor and downstream of the sulfhydrolysis reactor) are clogged with sulfur impurities
US 2024/0286997 at page 6, [0150]-[0153] (emphasis added). Thus, the conflicting specification teaches that DADS(s) (i.e., dialklyldisulfides) are inherently present in conflicting claim 1’s stream “stream F2 comprising the dialkyl sulfide(s)”. Thus, practice of conflicting claim 9, and including the following optional step:
Conflicting claim 9 . . . D) optionally, stream F2 is purified to obtain a stream F2' enriched in dialkyl sulfide(s);
necessarily teaches each and every limitation of instant claim 1. Conflicting claim 9 is therefore patentably indistinct from instant claim 1.
Instant claims 2 and 3 are obvious over conflicting claim 9 in further view of R. Khankal et al., US 2018/0050986 (2018) (“Khankal”). Khankal teaches that processes for producing MeSH by reacting hydrogen sulfide and methanol can include the desired methyl mercaptan and other compounds which can include dimethyl sulfide (DMS) and dimethyl disulfide (DMDS). Khankal at page 1, [0003]; Id. at page 7, [0065]. This teaching of Khankal is summarized by the Examiner as follows.
H2S+ MeOH [Symbol font/0xAE] CH3SH + CH3-S-CH3 + CH3-S-S-CH3 + [others]
Khankal teaches that the desired methyl mercaptan (CH3SH) can be separated from the other components by distillation. Khankal at page 6, [0062]. Khankal taches that, for example, one or more of the separation stages in the methyl mercaptan production plant 210 can recover at least a portion of the dimethyl sulfide from the MeSH reactor effluent to yield recovered DMS in the DMS stream 102. Khankal at page7, [0066]. Instant claims 2 and 3 are obvious because one of ordinary skill taught by conflicting claim 9 that the “stream F2' enriched in dialkyl sulfide(s)” is desirable is motivated by Khankal’s teaching of distillation to perform the instant claim 1 step D using (per instant claims 2 and 3) at least one distillation step.
Instant claims 4-6 are obvious as above because one of ordinary skill can readily arrive at the distillation conditions, including temperatures and pressures (as falling within the instant claims) by routine experimentation. MPEP § 2144.05(II). The instant specification indicates no criticality is associated with the instantly claimed distillation. Specification at pages 6-7.
Instant claim 7 is patentably indistinct from conflicting claim 9 is view of conflicting claim 2 because conflicting claim 2 teaches the catalyst may be Y-type zeolite.
Instant claim 8 is patentably indistinct over conflicting claim 9 in view of conflicting claim 7, where conflicting claim 7 recites the same H2S/dialkyl sulfide ranges as recited in instant claim 8.
Instant claim 9 is obvious over conflicting claim 9 because conflicting claim 9 specifically recites “G) optionally, stream F4 obtained from step F) is recycled into step A)”.
Instant claim 10 is obvious over conflicting claim 9 in view of Khankal because Khankal teaches methanol as a reactant with H2S give the commercially important methyl mercaptan. Khankal at page 1, [0003]; Id. at page 7, [0065].
Terminal Disclaimer
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Subject Matter Free of the Art of Record
Subject to the double patenting and § 112(b) rejections, claims 1-10 are free of the art of record. The independent claim 1 limitation that distinguishes the claims from the art is the following steps D and E.
Claim 1 . . . D) a purification step is performed on stream F2 in order to separate:
- a stream F2' comprising the dialkyl sulfide(s); and
- the DADS(s);
E) stream F2' is introduced with H2S into a second reactor . . .
The closet art of record is J. Barth et al., US 2008/0200730 (2008) (“Barth”)
Relevant Teachings in the Instant Specification
The specification teaches that reaction of H2S with alcohols is an art-known procedure for preparation of mercaptans, where dimethyl sulfide is a byproduct. Specification at page 1, ¶¶ 2-3. The specification further teaches that dialkyldisulfides (R-S-S-R, which the specification refers to as “DADS”) are also a side product. Specification at page 2, ¶ 3. Thus, in the art-known preparation of methyl mercaptan (CH3SH) by reaction of H2S with methanol can be summarized as follows:
CH3OH + H2S [Symbol font/0xAE] CH3SH + CH3-S-CH3 + CH3-S-S-CH3
The specification teaches that the dialkylsulfide side product (e.g., CH3-S-CH3) can be reacted with H2S to give the desired methyl mercaptan (CH3SH) in a sulfhydrolysis reaction, according to the reaction CH3-S-CH3 + H2S [Symbol font/0xAE] CH3SH. Specification at paragraph bridging pages 2-3. The specification teaches that thus a sulfhydrolysis unit may be integrated in the main unit (i.e., the CH3OH + H2S unit). Specification at page 2, ¶ 2. The Examiner notes that this is suggested by J. Barth et al., US 2008/0200730 (2008) (“Barth”) as discussed below. However, the specification teaches that such integration is disadvantageous because Applicant observed surprising clogging phenomena in the reactor or downstream of the sulfhydrolysis unit, in the case where the sulfhydrolysis unit is integrated into a main mercaptan production unit. Specification at page 2, ¶ 2. In this regard, the specification teaches:
The present inventors have determined that these DADS end up with the dialkyl sulfide(s) and then in the reactor in which the sulfhydrolysis is performed. Over time, they may lead to pressure losses on the catalyst and/or to clogging in this reactor or further downstream in the process.
This phenomenon might be explained by coking of the catalyst due to parasitic or secondary reactions of the sulfhydrolysis reaction with the DADS. The sulfur products or impurities formed by such reactions may accumulate and create blockages in industrial facilities, giving rise to obvious safety and production problems.
This may be all the more problematic when it comes to recycling the outlet stream from the sulfhydrolysis reactor into the main mercaptan production unit.
. . .
The present inventors have discovered, surprisingly, that when sulfhydrolysis is performed on a dialkyl sulfide previously separated from the DADS, these phenomena of pressure losses and/or clogging are no longer observed.
Specification at pages 2-3 (emphasis added).
The specification teaches that the claim 1 step of:
Claim 1 . . . D) a purification step is performed on stream F2 in order to separate:
- a stream F2' comprising the dialkyl sulfide(s); and
- the DADS(s);
may be accomplished by distillation or absorbing the DADS on a porous support. Specification at page 6.
The specification teaches a working Example 1 (Test A), where the following sulfhydrolysis reactions were performed using a Y-type zeolite catalyst. Specification at pages 11-12.
CH3-S-CH3 (DMS) + CH3-S-S-CH3 (DMDS, 0.2 wt. %) [Symbol font/0xAE] CH3SH
CH3-S-CH3 (DMS) + CH3-S-S-CH3 (DMDS, 14 wt. %) [Symbol font/0xAE] CH3SH
The specification reports the result as follows:
Result: With DMS comprising 14% by weight of DMDS, clogging was observed in the reactor after a few hours, whereas with DMS comprising 0.02% by weight of DMDS, no clogging was observed after 1000 hours. This test demonstrates the role of the DMDS impurity in the clogging phenomena.
Specification at page 12.
In Example 1, Test B, the same sulfhydrolysis reactions were performed on distilled DMS comprising 0.02 % DMDS or undistilled DMS comprising 0.53% DMDS. Specification at page 12.
The specification reports the result as follows:
Without prior distillation, clogging occurs after 100 h of running the sulfhydrolysis. With prior distillation, no clogging is observed after 1000 h.
Specification at page 12.
Thus, the instant specification demonstrates (at least with respect to the Y-type zeolite catalyst employed) that sulfhydrolysis of a mixture of CH3-S-CH3 and CH3-S-S-CH3 results in reactor clogging over time in a continuous process due to the presence of even small amounts of CH3-S-S-CH3.
J. Barth et al., US 2008/0200730 (2008) (“Barth”)
Barth discloses process for continuously preparing methyl mercaptan by reacting a reactant mixture which contains a dialkyl sulfide and a dialkyl polysulfide with hydrogen sulfide to give methyl mercaptan (sulfhydrolysis process). Barth at Abstract.
As background, Barth teaches (as discussed by the instant specification) that reaction of hydrogen sulfide with methanol is known to yield methyl mercaptan (CH3SH) and dimethylsulfide (DMS, CH3-S-CH3) as well as the side product polysulfides, e.g., dimethyldisulfide (CH3-S-S-CH3, DMDS, referred to as DADS by Applicant). Barth at page 1, [0003]. This reaction is summarized by the Examiner as follows.
H2S+ MeOH [Symbol font/0xAE] CH3SH + CH3-S-CH3 + dialkylpolysulfides CH3-S-S-CH3 + [others]
Barth teaches that the above product mixture can be separated by various known procedures. Barth at page 2, [0026]. Barth teaches that uncovered dialkyl sulfide or dialkylpolysulfides are incinerated (page 3, [0041]) or alternatively can be recycled back to the main reactor. Barth at page 2, [0026]. This is in agreement with the specification teachings discussed above.
However, Barth teaches the inventive aspect that, rather than recycling back to a reactor or incinerated, the separated dialkyl sulfides/dialkylpolysulfides side products can be converted to the desired mercaptan (e.g., CH3SH) over aluminum oxide catalysts comprising an alkali metal. Barth at page 3, [0029]. In the working Example 2, Barth teaches overall selectivity for methyl mercaptan at 100%. Barth at page 3, [0038].
Barth teaches that preferably, the separated dialkyl sulfides/dialkylpolysulfides side products stem from processes for preparing methyl mercaptan from hydrogen sulfide and methanol. Barth at page 2, [0027].
Differences between Barth and the Claims
Barth does not teach either of the claim 1 steps D or E:
Claim 1 . . . D) a purification step is performed on stream F2 in order to separate:
- a stream F2' comprising the dialkyl sulfide(s); and
- the DADS(s);
E) stream F2' is introduced with H2S into a second reactor . . .
Rather, Barth teaches sulfhydrolysis combined stream of dialkylsulfide and dialkylpolysulfides (for example a CH3-S-CH3/CH3-S-S-CH3 side-product stream separated from the desired CH3SH product) with H2S to give the desired mercaptan.
The Claims Art Not Obvious over the Cited Art
It is first noted that as of the effective filing date, the art teaches that a number of catalysts are available for the reaction:
ROH + H2S [Symbol font/0xAE] RSH + R-S-CH3
M. Yu et al., Catalytic synthesis of methanethiol and its conversion to light olefins (2020). (see Yu at page 4). The art teaches (ostensibly In view of catalyst selectivity) that the amount of CH3-S-S-CH3 (DADS) contaminating the product stream is generally minor. See e.g., R. Khankai et al., WO 2018/035316 (2018); A. Pashigreva et al., 345 Journal of Catalysis, 308-318 (2017).
The claims are not obvious in view of Barth because neither Barth nor secondary art motivates one of ordinary skill to perform the claim 1 step of:
Claim 1 . . . D) a purification step is performed on stream F2 in order to separate:
- a stream F2' comprising the dialkyl sulfide(s); and
- the DADS(s) . . .
Rather, Barth teaches that a combined stream of dialkylsulfide (DMS) and dialkyldisulfide (DADS) is suitable for sulfhydrolysis.
On the other hand, the instant specification teaches (at least with respect to certain catalysts) that DADS (e.g., CH3-S-S-CH3) contamination results in reactor clogging over time in continuous sulfhydrolysis reactions. Absent the teachings of the instant specification, one of ordinary skill has no motivation to perform the extra step claim 1 step of separating the DADS (which are generally minor in amount) from the dialkylsulfide before sulfhydrolysis.
Conclusion
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ALEXANDER R. PAGANO
Examiner
Art Unit 1692
/ALEXANDER R PAGANO/Primary Examiner, Art Unit 1692
1 A reference specification may be reviewed to construe the conflicting claims. MPEP § 804(II)(B)(1). Further, those portions of the specification which provide support for the conflicting claims may also be examined and considered when addressing the issue of whether a claim in the application defines an obvious variation of an invention claimed in the reference patent or application. MPEP § 804(II)(B)(1) (citing In re Vogel, 422 F.2d 438, 441-42, 164 USPQ 619, 622 (CCPA 1970)). The court in Vogel recognized ‘that it is most difficult, if not meaningless, to try to say what is or is not an obvious variation of a claim,’ but that one can judge whether or not the invention claimed in an application is an obvious variation of an embodiment disclosed in the patent or application which provides support for the claim. MPEP § 804(II)(B)(1).
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