DETAILED ACTION
Summary
Applicant’s amendment dated 27 February 2026 is acknowledged. Claims 1-21 are pending. Claims 1-10 and 19 are withdrawn from consideration.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
New grounds for rejection are necessitated by applicant’s amendment dated 27 February 2026. For this reason, this action is properly made final.
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 .
Claim Rejections - 35 USC § 103
Claims 11-18 and 20-21 are rejected under 35 U.S.C. 103 as being unpatentable over MITAMURA (CN-106479176-A) in view of JEON (KR-20170112329-A).
Regarding Claims 11, 18 and 21, MITAMURA teaches a polyimide film used in the production of a graphite sheet (p. 1, par. 3). MITAMURA teaches the inclusion of inorganic particles in an amount of 0.05-0.8 wt% (p. 3, par [1]; Claim 1). This encompasses the 0.05-0.3wt% that is recited by the claim. MITAMURA teaches an example where the inorganic particles are 0.05wt% (p. 12, Example 2), which is within the recited range for Claim 11, and another example where the inorganic particles are 0.1wt% (p. 11, Example 1), which is within the recited range for both Claim 11 and Claim 21.
MITAMURA teaches that the polyamic acid used to create its polyimide may be optionally formed from non-metal phosphorus-containing monomers such as bis- (4-aminophenyl) ethylphosphine oxide, bis-phenylphosphine oxide (p. 4, par. 7) and MITAMURA also teaches that the organic solvent used for forming its polyamic acid may optionally be hexamethylphosphoramide (p. 5, par. 5) which is a non-metal phosphorus compound, but MITAMURA does not teach a phosphorus-containing non-metal additive. JEON, in an invention of a manufacturing method for a graphite sheet from a polyimide film ([0012]) teaches adding a phosphorus compound to its polyamic acid ([0055]) which does not contain a metal component ([0059]). JEON teaches adding this compound in an amount of 0.05-0.5 parts per 100 parts polyamic acid or 0.05-0.5wt%. JEON teaches this phosphorus compound serves as a defoaming agent which is evenly dispersed in the polyimide film and imparts flexibility to the graphite sheet after graphitization ([0057]). It would be obvious to one of ordinary skill in the art at the time of the effective filing date of the current invention to modify the invention of MITAMURA with the teachings of JEON and include a non-metal phosphorus-containing additive for the purpose of a defoaming agent which is evenly distributed and imparting flexibility to the resultant graphite sheet.
For the total phosphorus content limitation, MITAMURA teaches 0.05-0.8 wt% of inorganic particles (p. 3, par [1]; Claim 1). MITAMURA teaches that its particles contain as a main component dicalcium phosphate, also known as calcium hydrogen phosphate, CaHPO3, MW=136.06, (p. 6, par 4) with a phosphorus content of 30.97/136.06 ≈ 22.76%. Applying this percentage to the range for the inorganic particle content calculates to 0.2276(0.05 to 0.8), or 0.0114-0.1821 wt% phosphorus in the composition from the particles. Applying this to the two examples cited above with a particle content within range (p. 11, Examples 1; p. 12, Example 2) calculates to 0.0114wt% and 0.0228wt%. JEON teaches that its non-metal phosphorus-containing additive can be an organophosphorus compound, a nonmetallic phosphate salt or a phosphorous acid ([0059]) and that its organophosphorous compound includes phosphines, phosphine oxides, phosphates, phosphinates, phosphinites or phosphites ([0061]). JEON teaches that its phosphorus-containing additive is present in amounts of 0.05-0.5wt%. JEON teaches examples containing different phosphorus additives, all of which contain one phosphorus atom, with molecular weights ranging from 99 to 773 g/mol (Table 1). This corresponds to phosphorous content in the additive of 30.97/773 to 30.97/99, or 4.0-31wt%, which when applied to the general 0.05-0.5wt% range for the additive calculates to a range of 0.002-0.175wt% of phosphorus content from the non-metallic phosphorus-containing additive. JEON teaches specific examples which have 0.2-0.3wt% of the additive (Table 1), and when using the phosphorus content of each specific additive, calculates to phosphorus-contents between 0.012wt% (Example 8) and 0.081wt% (Example 1). The combined phosphorus content from the inorganic particles of MITAMURA and the additive of JEON is generally 0.0114+0.002 to 0.1821+0.175, or 0.0134-0.357wt% phosphorus, which encompasses the 0.055-0.097wt% which is recited by Claim 11 and the 0.061-0.091wt% range recited by Claim 18. Using the exemplified ranges for each, that calculates to 0.0114+0.012 to 0.0228+0.081, or 0.0126-0.1038wt% of combined phosphorus content which also encompasses the 0.055-0.097wt% range recited by the Claim 11 and the 0.061-0.091wt% range recited by Claim 18. It would be obvious to use amounts of phosphorus that are within the ranges taught by MITAMURA and JEON that are also within the ranges recited by Claim 11 and Claim 18. It is well settled that where the prior art describes the components of a claimed compound or compositions in concentrations within or overlapping the claimed concentrations a prima facie case of obviousness is established. See In re Harris, 409 F.3d 1339, 1343, 74 USPQ2d 1951, 1953 (Fed. Cir 2005); In re Peterson, 315 F.3d 1325, 1329, 65 USPQ 2d 1379, 1382 (Fed. Cir. 1997); In re Woodruff, 919 F.2d 1575, 1578 16 USPQ2d 1934, 1936-37 (CCPA 1990); In re Malagari, 499 F.2d 1297, 1303, 182 USPQ 549, 553 (CCPA 1974). For more discussion see MPEP 2144.05-I.
Regarding Claim 12, modified MITAMURA teaches the invention of Claim 11 where MITAMURA teaches that its inorganic particles are selected from a group which contains both calcium phosphate (CaPO4) (p. 6, par 4) and dicalcium phosphate (CaHPO4), also known as calcium hydrogen phosphate (p. 6, par 4). MITAMURA exemplifies calcium hydrogen phosphate (p. 11, Example 1).
Regarding Claim 13, modified MITAMURA teaches the invention of Claim 11 where JEON teaches the phosphorus-containing non-metal additive. JEON teaches that its additive can be an organophosphorus compound ([0059], [0061]) and teaches and exemplifies many specific organic phosphorus compounds ([0089], [0091], Table 1).
Regarding Claim 14, modified MITAMURA teaches the invention of Claim 13 were JEON teaches the phosphorus-containing non-metal additive. JEON generally teaches that its additive can be a phosphine oxide ([0065]), phosphate ([0065]), phosphonate ([0069]) or phosphinate ([0069]) which all have a P-valence of 5 (see formulas in [0064], [0068]). JEON teaches and exemplifies many of these compounds ([0089], Table 1).
Regarding Claim 15, modified MITAMURA teaches the invention of Claim 11 where JEON teaches the phosphorus-containing non-metal additive. Generally, JEON teaches that its organophosphorous compound preferably has a boiling point of 200°C or more to avoid evaporation during the manufacturing process ([0079]). JEON further teaches that it for cases where the manufacturing process involves rapid heating, a boiling point of its additive exceeding 300°C is better in order to have little loss due to evaporation ([0079]). JEON teaches an embodiment where the additive has a boiling point of 300°C or higher and hardly any is lost by evaporation in the process of preparing the polyimide film ([0087]). JEON teaches many specific high-boiling-point additives ([0093][0095]). JEON does not measure the temperature at which its additives have a weight reduction rate of 5% in measurement by TG-DTA as is recited by the claim, but one would inherently expect that the compounds taught by JEON, which have boiling points of greater than 300°C, which exhibit hardly any evaporation during the polyamide film preparation process, would have a 5%-weight-reduction-rate temperature in measurement by TG-DTA of not lower than 200°C and would satisfy the claim. Also, JEON teaches two of the specific additives used in instant examples, the triphenyl-substituted phosphine oxide and phosphate ([0089]). Here, the specification of the current invention is used as evidence that the triphenyl phosphine oxide taught by JEON has a 5%-weight reduction temperature of 243°C (cur spec: Table 1) and the triphenyl phosphate taught by JEON has a 5%-weight reduction temperature of 220°C (cur spec: Table 1).
Regarding Claim 16, modified MITAMURA teaches the invention of Claim 11. MITAMURA teaches film thickness of 25-80 µm (p. 3, par [5]; Claim 5) which overlaps the range of 37-160 µm. MITAMURA teaches changing the film thickness by adjusting the drum rotation speed and the gel film speed (p. 12, Example 7) and teaches in Example 7 (p. 12) a film thickness of 80 µm which is within the recited range. JEON teaches a minimum film thickness of 20 µm ([0117]) and a maximum thickness which is not limited but is generally less than 200 µm due to cost concerns ([0119]). JEON exemplifies a thickness of 50 µm ([0154], Table 1)
Regarding Claim 17, modified MITAMURA teaches the invention of Claim 11. MITAMURA teaches that its polyamic acid is formed from a diamine component (p. 4, par 6) and specifically teaches 4,4’-diaminodiphenyl ether (p. 4, par 7). MITAMURA exemplifies 4,4’-diaminodiphenyl ether (p. 11, [polyamic acid synthesis example] paragraph). JEON teaches and exemplifies 4,4’-oxydianiline (ODA) ([0043], [0151]). Here, the instant specification is used as evidence that the ODA taught by JEON is a synonym for 4,4’-diaminodiphenyl ether (cur spec: p. 36, line 17).
Regarding Claim 20, modified MITAMURA teaches the invention of Claim 12 where JEON teaches the phosphorus-containing non-metal additive. JEON teaches that its additive can be an organophosphorus compound ([0059], [0061]) and teaches and exemplifies many specific organic phosphorus compounds ([0089],[0091], Table 1).
Response to Arguments
Applicant's arguments filed 27 February 2026 have been fully considered but they are not persuasive.
Applicant argues that the claims recite weight percentages relative to the weight of the film while the prior art teaches weight percentages relative to the solid content of the film and that it is not proper to compare the recited ranges with the prior art taught ranges. In the response, the claims do not clarify what the basis for the weight percentages is. Comparison to the solid content of a resin is common in the prior art as the amount of solvent used is adjustable. The content relative to the solid content of the film would be the same as the content of the film following a drying step. Also, in instant example 1, the amount of CaHPO4 particles (0.16wt%) and phosphorus additive added (0.84wt%) are disclosed as being relative to the solid content (cur spec: [0080]). These match the values in Table 1 which suggests that all of the values in Table 1 are relative to the solid content. The examiner does not see a discrepancy between the weight percentage basis used in the prior art and in the instant specification.
Applicant argues unexpected results. Applicant argues that their films achieve excellent conveyability and thermal diffusivity when the inorganic particles are between 0.05-0.30 wt%. In response, MITAMURA teaches and exemplifies particles with 0.1 wt% (p. 11, Example 1) and 0.05wt% (p. 12, Example 2) which are both within the recited range of Claim 11 and MITAMURA teaches a large thermal diffusivity (p. 10, par. 1). Applicant argues they obtain excellent peelability, diffusivity and interlaminar strength when the phosphorus content is between 0.055-0.097 wt% and that comparative examples below this range show poor peelability. In response, the evidence does not support that these properties are commensurate with the scope of the claims. The independent claim recites inorganic particles, which do not necessarily contain phosphorus, and a phosphorus-containing non-metal additive, which includes a broad scope of compounds including red phosphorus (cur spec: [0033]), various phosphorus-containing acids and esters (cur spec: [0033]) and possibly ammonium salts which contain phosphorus-containing anions, while the evidence in the instant examples and comparative examples rely on a small group of aromatic phosphates and phosphine oxides. See MPEP 716.02(b) and 716.02(d).
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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/D.R.F./Examiner, Art Unit 1764
/KREGG T BROOKS/Primary Examiner, Art Unit 1764