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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on January 2, 2026, has been entered.
Detailed Action
This office action is a response to applicant’s communication submitted January 2, 2026 wherein claim 1 is amended. This application is a national stage application of PCT/FI2022/050817, filed December 4, 2020, which claims benefit of foreign application FI20196060, filed December 5, 2019.
Claims 1-13 are pending in this application.
Claims 1-13 as amended are examined on the merits herein.
The following rejections of record in the previous action are maintained:
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-13 are rejected under 35 U.S.C. 103 as being unpatentable over Gas Guangzhou Chemistry Co, LTD (Foreign patent publication CN102268096, Reference and English machine translation included with 4/20/2023 PTO-1449, herein referred to as Gas Guangzhou, all citations herein are to the English translation included by Applicant) in view of Sun et al. (US patent 5858021, of record in previous action)
Independent claim 1 claims a method comprising preparing a slurry of a cellulosic starting material in an alkaline organic liquid, performing mercerization of the cellulosic material, adding a cationizing agent, and allowing the mixture to react and form a cationized product. In this claim, the term “mercerization,” is interpreted as including treatment of cellulose in an organic or aqueous solvent with alkali. As amended this claim further requires that the reaction contain specific amounts of cellulose, water, organic solvent, alkali, and cationizing agent.
Gas Guangzhou discloses a process for producing cationic cellulose, comprising steps of activation of cellulose, cationization, purification, and drying. (p. 3 paragraph 15) The activation step comprises mixing cellulose with isopropanol, sodium hydroxide, and water, and carrying out pretreatment at 10-30C for 40-80 minutes. (p. 3 paragraph 16) The cationization step comprises adding additional isopropanol and an etherification reagent, and reacting at 20-40C for 2-4 hours. (p. 3 paragraph 17) The amount of isopropanol in the activating step is preferably added at a ratio of about 6-14:1 with respect to cellulose, and 30% sodium hydroxide is preferably added at a mass ratio of 0.71-1.08. (p. 4 paragraphs 21-23)The activation step weakens the hydrogen bonds of the cellulose and renders it more accessible for subsequent reaction. (p. 5 paragraph 34) This is reasonably considered to be a description of a mercerization step. According to example 1 (see table 1) for example 1 part cellulose, 3.13 parts 30% aqueous NaOH, and 8 parts IPA are used in the activation step and an additional 6 parts IPA and 6 parts of 50% aqueous CTA (3-chloro-2-hydroxypropyltrimentylammonium chloride) are added. This reaction method meets all of the limitations of present claims 1, 2, 5, 7, 8, 10, and 12, with the exception that the proportion of cellulose is only about 10%, rather than 20% or greater. Furthermore the disclosure of Gas Guangzhou specifically describes a preferred ratio of IPA to cellulose of at least 6 parts IPA to one part cellulose.
However, Sun et al. discloses that mercerization is a process of alkali treatment of cellulose that disrupts its crystal structure and renders it more accessible to further chemical treatment reagents. (column 1 lines 15-24) This description of the term “mercerization” is clearly applicable to the activation step described by Gas Guangzhou above. Additionally, Sun et al. discloses that the use of large quantities of solvent and alkali during mercerization is undesirable because of the cost and environmental impact of these chemicals. (column 1 lines 25-42) Sun et al. further describes that in order to minimize the amount of solvent and alkali used, mercerization can be carried out under conditions wherein the cellulosic fibers are present at 27-90% of the total weight of the composition. (column 1 lines 58 – column 2 line 16) While Sun et al. discloses the use of fully aqueous solutions as being preferred, other solvents such as isopropanol can be included so long as the solvent is at least 30% water, or 7 parts alcohol to 3 parts water. (column 3 lines 44-55)
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the activation step of the process described by Gas Guangzhou to increase the concentration of cellulose in the activation (i.e. mercerization) step, for example to 20% or more. One of ordinary skill in the art would have found this modification to be obvious based on a rationale of applying a known improvement to a prior art process ready for improvement, and would have reasonably expected this modification to improve the cost and environmental impact of Gas Guangzhou’s process by reducing the amount of solvent and alkali required.
Regarding the limitation requiring that the cationization reagent be added after at least 90% of the crystalline regions in the cellulose have disappeared, p. 5 paragraph 34 of Guangzhou describes hydrogen bonding between cellulose molecules as inhibiting their reaction with cationization reagents and the swelling in isopropanol and water as improving accessibility by breaking hydrogen bonds. One of ordinary skill in the art would have understood this as referring to crystalline regions in the cellulose which are disrupted by the swelling treatment. Furthermore column 5 lines 38-54 of Sun describes mercerization, which one of ordinary skill in the art would understand as the same process described by Guangzhou. Sun specifically describes mercerization as converting cellulose from crystalline to amorphous form and states that the degree of mercerization can be measured by Tappi test method T 401 om-93. From these disclosures it would be evident that the degree of mercerization, and the resulting disappearance of crystalline regions, is a desirable property and that the degree of residual crystallinity is a result-effective variable that could be affected by mercerization and additionally measured by one of ordinary skill in the art. Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to optimize the process described by Guangzhou by carrying out mercerization to a point wherein the maximum amount of crystallinity has been disrupted, rendering achieving a value of 90% as described in claim 1 to be obvious.
Regarding the specific amounts of active ingredients recited by the limitations recited in claim 1 and the narrower ranges in claim 3, Gas Guangzhou’s process in example 1 includes the following percent of each component in the activation step:
Cellulose 9.9%
Isopropyl alcohol 59.2%
Water 21.6% (from 30% aqueous NaOH)
NaOH 9.3% (from 30% NaOH)
Based on the disclosure of Sun et al., one of ordinary skill in the art would have modified this reaction to increase the cellulosic material to 20% or more, and reduced the amount of isopropyl alcohol to less than the amount disclosed in Gas Guangzhou’s process, thereby arriving at the presently claimed amounts.
Regarding the ratio of water to organic liquid, Example 1 of Sun et al. discloses an IPA to water ratio of about 2.7, and using a solution with a 3:7 or higher ratio of water to IPA as suggested by Sun et al. would have reduced this ratio to 2.3 or lower.
Regarding claims 6 and 11, example 1 in table 1 of Gas Guangzhou discloses adding a further 6 parts of IPA and 6.42 parts of 50% aqueous CTA to the reaction for the cationization step. This would result in a composition of:
Cellulose 4.0%
Isopropyl alcohol 56.7%
Water 21.6%
Sodium hydroxide (alkali) 3.8%
CTA (cationization agent) 13.0%
Furthermore the ratio of IPA to water is about 2.6:1
As with claim 3, following the suggestions of Sun et al. during the mercerization step would have resulted in the cationization step having a higher amount of cellulose and water. Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the process described by Gas Guangzhou in such a way as to arrive at the ratio recited in claim 6 and the percent composition described in claim 11.
Regarding claim 9, as discussed above example 1 described by Gas Guangzhou discloses a mercerization step using 9.9% cellulose and 9.3% NaOH. Therefore using a molecular weight of about 40g/mol for NaOH, the ratio of NaOH to cellulose is 2.3 mol per kg of dry cellulose. However, Sun et al. discloses that the amount of alkali can be significantly higher. (column 5 lines 15-25) Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the amount of alkali in the activation step, resulting in a ratio falling within the scope of claim 9.
Regarding claim 13, Gas Guangzhou discloses that the cellulosic material used can be cotton. (p. 4 paragraph 20) As disclosed by Abidi, (Reference of record in previous action) cotton fibers are composed of about 95% cellulose. (p. 95 section 5.1) Therefore when cotton is used in the process of Gas Guangzhou, the limitations of this claim are met.
For these reasons the invention taken as a whole is prima facie obvious.
Double Patenting
The nonstatutory 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 nonstatutory 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).
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.
Claims 1-13 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 2, 6, 8, and 9-13 of copending Application No. 18/281067 (US pre-grant publication 2024/0141075, of record in previous action, herein referred to as ‘067) in view of Gas Guangzhou Chemistry Co, LTD (Foreign patent publication CN102268096, Reference and English machine translation included with 4/20/2023 PTO-1449, herein referred to as Gas Guangzhou, all citations herein are to the English translation included by Applicant) in view of Sun et al. (US patent 5858021, of record in previous action).
The claims of ‘067 and Sun et al. are as discussed above. Additionally while present claims 3, 6, 9, and 11-13 include limitations not specifically described in the claims of ‘067, one of ordinary skill in the art, seeing the disclosure of Gas Guangzhou, would have seen this reference as describing a similar process having these characteristics, as described under 35 USC 103. Therefore one of ordinary skill in the art would have found it to be obvious to incorporate these features, such as the specific concentrations of different reagents, into the process claimed by ‘067, in view of the similarity between the two processes, which would lead to the expectation that these define acceptable variations of the process of ‘067 as well.
Response to Arguments
Applicant’s arguments, submitted January 2, 2026, with respect to the above grounds of rejection, have been fully considered and not found to be persuasive to remove the rejections.
Firstly, Applicant argues that the application of Sun’s teachings to the disclosure of Guangzhou is improper because of elements of Sun’s disclosure that would allegedly render this reference inapplicable to the process of Guangzhou. In particular, Applicant points to the ultimate use of the mercerized cellulose described by Sun is different than the use to which Guangzhou puts the mercerized cellulose in its disclosure. However, there is nothing in the disclosure of Sun that would lead one of ordinary skill in the art to this conclusion. Sun discloses methods of mercerization of cellulose (e.g. column 5 lines 38-64) which is a process whereby alkali is used to disrupt the crystallinity of native cellulose I and render it more accessible to further treatment. Sun additionally discloses that this mercerized cellulose can be used to produce absorbent products such as handsheets. (column 11 line 52 – column 12 line 31) However, this is not a disclosure that mercerized cellulose produced according to this method is only useful for this purpose. The two elements of this disclosure (methods for mercerization and methods of making handsheets) are disclosed as discreet, separate elements. Furthermore Guangzhou also describes mercerizing cellulose. (See the sixth paragraph on p. 3 of the English translation, “The degree to which the reagent can reach the cellulose hydroxyl group is called accessibility. The greater the accessibility, the easier the cellulose hydroxyl group participates in the reaction. In the present invention, boron compounds are used as activators , Break or weaken the intramolecular and intermolecular hydrogen bonds of cellulose, improve the accessibility, and promote the reaction.”) Therefore one of ordinary skill in the art would have very clearly understood that Guangzhou is describing mercerization of cellulose and would have understood any prior art teachings regarding mercerization as being applicable to this process. Additionally, the discussion of mercerization in column 5 lines 38-54 of Sun specifically describes accessibility for further chemical treatment as an effect of mercerization, a consideration that would be irrelevant if the only use for the disclosed mercerized cellulose were the production of absorbent articles without further chemical treatment. For these reasons one of ordinary skill in the art would have seen Sun’s discussion of mercerization, and particularly the motivation to use the minimum amount of solvent and alkali possible for economic and environmental reasons, as applicable to other disclosures of mercerization in references such as Guangzhou.
Furthermore, Applicant argues that the percentages of water used by Sun (30-100%) refer to the composition of the liquid phase as opposed to the total weight of all reagents in the composition. Looking to the composition of example 1 of Guangzhou described above, this composition contained 21.6% water and 59.2% isopropanol. Therefore the liquid phase would be considered to be about 27% aqueous. The ratio recited in present claim 1 is 5-30 parts water to 30-55 parts isopropanol, or otherwise 8.3-50% aqueous. However, while it is true that Sun’s mercerization process differs from both the disclosure of Guangzhou and of the present claims in that it uses less organic solvent and more water, the statement that reducing the amount of solvent and alkali used is beneficial would be expected to be true regardless of the specific ratio of water to organic solvent.
Finally, Applicant argues that claim 1 has been amended so as to introduce a new limitation requiring that the cationization agent be added only after at least 90% of the crystalline regions of the cellulosic starting material have disappeared. This allegedly differentiates the claimed process form prior art mercerization such as that described by Guangzhou. However, this limitation appears to merely be describing a feature of the process of mercerization. The previously cited portions of the disclosures of Guangzhou and Sun describing mercerization both mention this feature. For example Guangzhou states in the sixth paragraph of p. 3 of the English translation, “In the present invention, boron compounds are used as activators, Break or weaken the intramolecular and intermolecular hydrogen bonds of cellulose, improve the accessibility, and promote the reaction.” Breaking or weakening the intramolecular hydrogen bonds of cellulose is the same thing as disrupting its crystallinity. Furthermore Sun (column 5 lines 42-46) states “Because the chemically treated or mercerized cellulose is less crystalline and more amorphous, the chemically treated or mercerized cellulose is generally more accessible for further treatment with additional reagents.” Therefore both references disclose the crystallinity of cellulose as a result-effective variable for chemical modification of cellulose, and the reduction of crystallinity by mercerization as beneficially promoting further chemical modification of the cellulose. Still further, looking to the disclosure of the present specification, Applicant has not provided any new, improved method of reducing the crystalline regions of cellulose during mercerization or provided some result that cannot be attained by the prior art. In particular, the examples on pp. 13-18 do not directly report the decree of crystallinity of the mercerized cellulose. All that is reported is the degree of substitution of the cationized product. According to the last paragraph of p. 16, all of the experimental examples (1-10) which used isopropyl alcohol as the solvent with water only coming from the aqueous NaOH added, gave better results than the sample prepared using only water as the solvent. This is in line with Guangzhou’s discussion of the advantage of using both isopropanol and water in the reaction medium, and there is no reason to believe that Applicant has discovered an unexpected improvement beyond what would generally be arrived at by optimizing Guangzhou’s process to maximize the accessibility of the cellulose for cationization.
For these reasons the rejections are deemed proper and maintained.
Conclusion
No claims are allowed in this action.
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/ANDREA OLSON/ Primary Examiner, Art Unit 1693 2/4/2026