DETAILED ACTION
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 .
Election/Restrictions
Applicant’s election of Group I, claims 1-8, in the reply filed on Jan. 6, 2026 is acknowledged. Because Applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claims 9-12 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on Jan. 6, 2026.
Claim Interpretation
Independent claim 1 recites a polyvinyl alcohol having a specified “degree of hydration”. The specification states that “the degree of hydration is defined as the degree of substitution of an acetate with an alcohol” (p. 9, ¶ [34] of the clean specification submitted on Apr. 7, 2023).
Claim Rejections – 35 U.S.C. § 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 of this title, 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 1-5 and 8 are rejected under 35 U.S.C. § 103 as being unpatentable over CN 108467450 A (herein “Liu”) in view of GB 2 078 237 A (herein “Okuno”) or CN 111393548 A (herein “Zhao”). The attached computer-generated English translations of Liu and Zhao are referred to herein.
As to claims 1 and 5: Liu describes a method of preparing a vinyl chloride-based polymer (see Example 5 in ¶¶ [0051]-[0053] of the translation) comprising adding polyvinyl alcohol and hydroxypropyl methylcellulose dispersants and sodium carbonate into a polymerization reactor (see ¶ [0052] of the translation) and polymerizing vinyl chloride in their presence. The dispersants include 50 wt% of a polyvinyl alcohol having a degree of hydrolysis of 82% (see ¶ [0052] of the translation).
Liu does not disclose a step of injecting a mixed dispersant and a metal carbonate.
Okuno describes methods of preparing a vinyl chloride-based polymer (see the abstract and Example 2 on p. 4). Okuno discloses a step of injecting an aqueous solution of dispersants into a polymerization reactor (see p. 4, ll. 11-13).
Zhao discloses methods of preparing a vinyl chloride-based polymer in which dispersants are injected into the polymerization reactor (see ¶ [0043] of the translation).
Case law has established that it is prima facie obvious to use a known technique to improve a similar method. KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398 (2007). MPEP 2143, rationale (C). MPEP 2144(IV)(C). In KSR, the Supreme Court required an analysis that takes account of “the background knowledge possessed by a person having ordinary skill in the art” and “the inferences and creative steps that a person of ordinary skill in the art would employ.” KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398, 418 (2007).
In the present case, Liu describes a “base” method upon which the presently claimed method including an injecting step can be seen as an “improvement”. Each of Okuno and Zhao describes “comparable” methods which have been improved by the introduction of ingredients into a reactor by means of injection. One of ordinary skill and creativity in the art would have recognized that the transfer of ingredients by means of injection is a known alternative method of introducing ingredients into a reaction. One of ordinary skill and creativity in the art could have applied this “improvement” technique to the method described in Liu by injecting the dispersants and sodium carbonate, and the results (an alternative manner of introducing ingredients into the reactor) would have been predictable to one of ordinary skill in the art.
In light of this discussion, it is apparent that the presently claimed invention is arrived at by using a known technique to improve a similar method. Therefore, it would have been obvious to a person of ordinary skill in the art at the time of the present invention to have introduced the dispersants and sodium carbonate into the reactor in Liu’s method by means of injection, thereby arriving at the presently claimed invention.
As to claim 2: As set forth above, Liu and Okuno or Zhao suggest a method according to base claim 1. The presently claimed method differs from Liu’s method by the order in which the dispersants and metal carbonate mixed.
Case law has established that it is prima facie obvious to select any order of mixing ingredients. MPEP 2144(IV)(C). In KSR, the Supreme Court required an analysis that takes account of “the background knowledge possessed by a person having ordinary skill in the art” and “the inferences and creative steps that a person of ordinary skill in the art would employ.” KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398, 418 (2007).
One of ordinary skill in the art would have had a reasonable expectation that this order of mixing the dispersants and sodium carbonate would not influence the resulting polymer produced by the method of Liu. One of ordinary skill would merely exercise ordinary creativity by adding these ingredients in another order. It would have been obvious to a person of ordinary skill in the art at the time of the present invention to have added the ingredients of Liu’s method in any order, including adding the dispersants and metal carbonate by mixing them prior to their injection into the reactor.
As to claims 3-4: Liu’s dispersants further include a polyvinyl alcohol having a degree of hydrolysis of 50% and a hydroxypropyl methylcellulose (see ¶ [0052] of the translation).
As to claim 8: Liu’s polymerization is performed at 50 °C (see ¶ [0052] of the translation).
Allowable Subject Matter
Claims 6-7 are objected to as being dependent upon a rejected base claim, but they would be allowable if written in independent form.
Conclusion
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/RICHARD A. HUHN/Primary Examiner, Art Unit 1764