Response to Amendment
The amendment and response filed on April 14, 2026 has been entered. Claims 1-18, 20, and 21 are pending.
Claim Objections
Claim 13 is objected to because of the following informalities. Claim 13 has been amended to be dependent upon claim 1; thus, the terms “a gypsum core” (line 2), “a silicone oil” (line 4), “a hydride content” (line 4), and “a mass of the gypsum core” (lines 5 and 6) have antecedent basis from claim 1. Accordingly, the term “a” before these terms should be changed to “the”.
Claim Rejections - 35 USC § 112
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 20-21 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
In claim 20, line 4, and claim 21, line 5, the term “the silicone oil” lacks proper antecedent basis.
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 20 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Martin et al. (WO 2022/106419) in view of Blackburn et al. (US Pub 2008/0000392).
As set forth in the November 14, 2025 Office action, Martin discloses a method of producing a fire resistant gypsum board (pg 2, line 28) comprising the steps of providing a calcium sulfate slurry (pg 5, line 2) containing a silicone oil, such as dimethylpolysiloxane (PDMS, Example 6), in an amount of 0.2 to 2.5 wt% of the slurry (pg 3, line 5), allowing the slurry to set to form a set gypsum material, and drying the set gypsum material to provide the gypsum core (pg 7, lines 4-12). Example 6 of Martin is directed to an embodiment that uses 0.6 wt% of PDMS in the slurry. Since PDMS does not contain any Si-H bonds, the use of this polysiloxane meets the claim limitation of “a hydride content of no more than 0.01 equivalents per equivalent of silicone”.
Claims 20 and 21 set forth that the silicone oil is provided to the calcium sulfate in the form of an aqueous emulsion. Martin does not detail the process of adding the liquid polysiloxane to the slurry. Blackburn discloses that it is known in the gypsum slurry art to add a siloxane component to the slurry as an emulsion in order to obtain a slurry which can be thoroughly mixed [0046]. It would have been obvious to one of ordinary skill in the art to have provided the PDMS component to the slurry of Martin in an emulsion form, as taught in Blackburn, motivated by the desire to obtain a slurry that can be thoroughly mixed.
Allowable Subject Matter
Claims 1-12 and 14-18 are allowed.
Claim 13 be allowable if rewritten or amended to overcome the claim objections set forth in this Office action.
The argument that Martin does not disclose or suggest the claimed method of producing a fire-resistant gypsum board wherein the calcium sulfate slurry has no more than 1 wt% calcium carbonate relative to the mass of the stucco used to form the slurry, i.e., original claim 11, is persuasive. With respect to article claims 13-18, while a product-by-process claim is limited by the claimed process, patentability is based on the product itself (see MPEP 2113). In the present case, the above mentioned calcium carbonate content limitation would impart compositional limitations to the resulting product that are not disclosed or suggested in the prior art of record, i.e., Martin.
Response to Arguments
Applicant's arguments filed on April 14, 2026 have been fully considered but they are not persuasive. With respect to newly added claims 20 and 21, the present response argues the obviousness rejection of claim 4 and 5 with respect to Martin only. However, there were no arguments presented with respect to the combination of Martin with Blackburn. As set forth above, Blackburn provides motivation for providing the silicone oil to the calcium sulfate slurry in the form of an aqueous emulsion. The argument regarding unexpected results are not persuasive because the claims are not commensurate in scope with the showings set forth in Table 2. Further, Martin appears to exhibit similar shrinkage properties (see Tables 2 and 3).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/BLAINE COPENHEAVER/Primary Examiner, Art Unit 1781
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