DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
A request for continued examination under 37 CFR 1.114 was filed in this application after a decision by the Patent Trial and Appeal Board, but before the filing of a Notice of Appeal to the Court of Appeals for the Federal Circuit or the commencement of a civil action. 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examination under 37 CFR 1.114 and the fee set forth in 37 CFR 1.17(e) has been timely paid, the appeal has been withdrawn pursuant to 37 CFR 1.114 and prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant’s submission filed on 11/5/2025 has been entered.
Claims 1, 6, 7, 9 and 21-25 are pending as amended on 11/5/2025. Claim 9 stands withdrawn from consideration as being drawn to a nonelected invention, and newly presented claims 22, 24 and 25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, there being no allowable generic or linking claim.
Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claim Rejections - 35 USC § 103
Claim(s) 1, 6, 7, 21 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Moriuchi et al (US 2010/0140557) in view of Kondo et al (US 2019/0153158) and Tanaka et al (JP 2012040836A; included machine translation cited herein).
As to claims 1, 21 and 23, Moriuchi discloses a polyimide film that is substantially colorless and transparent, and useful as a coating film for liquid crystals, touch panels, solar cells and the like (abstract), [0003]. The film is formed by casting polyamic acid on a plate and converting to polyimide by heating [0040]. The process disclosed by Moriuchi in [0040] comprises a step wherein, after casting a solution of polyamic acid (i.e., polyimide precursor), heating is the only action carried out on a polyamic acid film.
As to the presently recited BPDA and second compound BPADA (dianhydride) monomers:
Moriuchi discloses using BPADA as a dianhydride monomer to maintain higher transparency [0030], and specifically teaches utilizing a combination of BPDA and BPADA in a range of BPDA:BPADA of 9:1 to 5:5 in order to increase toughness while maintaining high transparency [0031]. See also the films exemplified by Moriuchi (Table 5) wherein the dianhydride component of the polyimide consists of BPDA and BPADA. Therefore, Moriuchi discloses a polyimide wherein the dianhydride component consists of monomers according to the presently recited first compound (BPDA) and second compound (BPADA).
The preferred range (9:1 to 5:5 ratio of BPDA:BPADA) disclosed by Moriuchi corresponds to a mole fraction of BPDA to a total of (BPDA+BPADA) from 50 to 90 mol%, and a total of second compound (BPADA) to a total of (BPDA+BPADA) from 10-50 mol%. Moriuchi teaches that when BPADA is used, it is possible to maintain an even higher transparency [0030], and that using BPDA in an amount within the preferred ratio range makes it possible to increase toughness while maintaining high transparency [0031]. The person having ordinary skill in the art would have been motivated, therefore, to select any appropriate ratio of BPDA:BPADA within Moriuchi’s disclosed range in order to achieve a desired balance between toughness and transparency. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed Moriuchi’s polyimide film utilizing any mixing ratio of BPDA:BPADA within Moriuchi’s preferred range, including a ratio corresponding to molar fractions of BPDA and BPADA (second compound) within the presently claimed ranges of 70-99 mol% and 1-30 mol%, respectively. Case law has established that a prima facie case of obviousness is established where the claimed ranges overlap the ranges disclosed by the prior art. See MPEP 2144.05.
As to the presently recited TFMB and DDS (fourth compound) diamine monomers:
Moriuchi discloses a preferred embodiment wherein the aromatic diamine is DDS in the meta- or para- form (i.e., 3,3’-DDS or 4,4’-DDS) [0027], which corresponds to the presently recited fourth compound. Moriuchi further teaches that it is preferable to use a second diamine monomer for the purpose of diluting color of the obtained polyimide [0029].
However, Moriuchi fails to name TFMB as an example of a second diamine monomer.
Like Moriuchi, Kondo discloses a polyimide film which can be used as a glass substitute material [0001], in view of increasing demands for reduction in thickness and increase in flexibility of devices such as liquid crystal displays, solar cells and touch panels [0002]. Kondo teaches that the polyimide resin contains a structure derived from a sulfonyl group-containing diamine in order to obtain a polyimide having high transparency and mechanical strength, and solubility for film formation [0014-15]. Kondo teaches that the content of sulfonyl diamine is preferably 10-80 mol%, and more preferably 20-50 mol%, of the diamine component; if the amount of sulfonyl diamine is too small, solubility decreases, while if the amount is too large, the resin is colored and transparency decreases [0016]. Kondo further teaches that by using a fluorine-containing diamine in addition to a sulfonyl group-containing diamine, the transparency and solubility of the polyimide resin tend to be improved. Kondo names two preferred fluorine-containing diamines, including TFMB [0017]. Kondo teaches that the amount of diamine containing benzidine skeleton (e.g., TFMB) is preferably 50-80 mol% [0018].
As established in the above discussion, Moriuchi discloses a polyimide resin from BPADA and BPDA as dianhydrides, and from DDS as diamine, wherein a second diamine is included for the purpose of diluting the coloration caused by utilizing DDS. Moriuchi fails to name TFMB as a suitable second diamine. Considering Kondo’s disclosure, TFMB was known in the art as a diamine suitable for combining with DDS to improve polyimide transparency and reduce the coloring associated with utilizing DDS. Therefore, Moriuchi differs from the claimed invention by the substitution of one known element (a diamine comonomer known to dilute coloration of a polyimide caused by a DDS monomer) for another. It would have been obvious to the person having ordinary skill in the art, therefore, to have prepared a polyimide from BPDA and BPADA as dianhydrides, and from DDS (meta or para) and a second diamine for reducing color as diamines, as disclosed by Moriuchi, by utilizing TFMB (as disclosed in Kondo) as Moriuchi’s second diamine. Case law has established that it is prima facie obvious to substitute one known element for another to obtain predictable results. KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398 (2007). MPEP 2143, rationale (B). Moreover, considering Kondo’s disclosure, the person having ordinary skill in the art would have been motivated to utilize any appropriate amount of TFMB within Kondo’s preferred range of 50-80 mol% in order to achieve the desired reduction in color associated with use of DDS. It would have been obvious to the person having ordinary skill in the art, therefore, to have prepared a polyimide form BPDA, BPADA, TFMB and DDS, as suggested by modified Moriuchi, utilizing amounts of (meta or para) DDS and TFMB within Kondo’s preferred ranges of 20-50 mol% and 50-80 mol%, respectively, thereby arriving at the presently claimed subject matter.
As to the presently recited haze value recited in claim 1 and transmittance recited in claim 21:
Moriuchi discloses light transmittance measured at 420 nm [0043]. Moriuchi teaches polyimide coating films that are essentially colorless and transparent, and which are used, e.g., as films in display devices and protective covering films for solar cells [0002-3, 0009]. However, Moriuchi is silent as to total light transmittance and haze as presently recited.
Tanaka discloses a laminate of a polyimide which is excellent in transparency, and a member of a flat panel display and flexible device using the same [0001]. Tanaka discloses the same types of monomers taught by Moriuchi and Kondo: both BPDA and BPADA are named among five preferred dianhydride monomers ([0028], first and last structures) which can be used in combination of two or more [0026]; TFMB is named as one of two diamines which are preferred from the viewpoint of excellent transparency, heat resistance and availability [0030].
Tanaka teaches heating conditions for drying and imidization which are important in order to provide a polyimide film having a haze of less than 2% and a total light transmittance of 85% or more [0041], and discloses how to adjust heating conditions based on film thickness [0047]. Tanaka teaches that when haze is 2% or more, the white turbidity of the film becomes strong, so that the sharpness of image quality decreases [0052]. When the total light transmittance is less than 85%, the entire display tends to be dark, and increased power consumption is needed to increase brightness [0053].
Considering Tanaka’s disclosure, when forming a polyimide film to be used for display applications wherein high transparency and colorlessness is desired, the person having ordinary skill in the art would have been motivated to decrease haze (to a value at least below 2%) in order to improve image sharpness, and to increase total light transmittance (to a value at least greater than 85%) in order to decrease the power consumption needed to increase display brightness. It would have been obvious to the person having ordinary skill in the art, therefore, to have prepared a polyimide film, as suggested by modified Moriuchi, having any appropriately high transparency and colorlessness which meets the requirements of the intended application, including a transparency and colorlessness corresponding to a haze percentage and total light transmittance within the presently claimed ranges, in order to improve the suitability of the film for use, e.g., in a display device or solar cell covering.
As to the presently recited solvent resistance, as measured by tensile elongation when wetted with MEK:
The presently claimed tensile elongation when wetted with MEK is not limited to any particular duration of MEK exposure prior to measuring tensile elongation, nor to any particular temperature of the film and MEK solvent during exposure, nor to any particular thickness of film. Each of these variables affect the solvent resistance of a polymer film. Because these testing variables are not defined in either the claims or the instant specification, a film which, at some thickness, meets the presently recited tensile elongation after MEK exposure for any duration at any temperature is considered to be encompassed by the claims.
The instant specification contains several examples of polyimides formed from BPDA, BPADA, DDS and TFMB, as summarized in Table 2. Only the instant comparative polyimides which do not have any BPDA (comparative example 2) or which have 6FDA in addition to BPDA and BPADA (comparative examples 4-7) have a tensile elongation when wetted with MEK which is below 3.5%. Given that modified Moriuchi suggests a polyimide formed from dianhydrides consisting of BPDA and BPADA, substantially similar in structure to the polyimides of instant working examples 1-9, 11 and 13-15, there is reasonable basis to conclude that modified Moriuchi suggests a polyimide film having properties, including tensile elongation and MEK resistance, which are substantially similar to the properties of the instant working example polyimides formed from dianhydrides consisting of BPDA and BPADA (which have properties within the presently recited ranges). There is reasonable basis to conclude, therefore, that modified Moriuchi suggests a polyimide formed from monomers consisting of BPDA, BPADA, DDS and TFMB which, when wetted on one side with MEK for some duration of time at some temperature, exhibits a tensile elongation within the presently claimed range.
As to claim 6, modified Moriuchi suggests a polyimide film according to claims 1, as set forth above. Moriuchi is silent as to the tensile strength of the film. However, every exemplified polyimide in instant table 2 (including both inventive and comparative) has a tensile strength within the presently claimed range of 100-500 MPa. Given that modified Moriuchi suggests a polyimide film formed from the same monomers as utilized to form the polyimide films of instant table 2, there is reasonable basis to conclude that modified Moriuchi suggests a polyimide film which has properties which are substantially like the properties of the instant polyimides, including a tensile strength within a range of 100-500 MPa.
As to claim 7, modified Moriuchi suggests a polyimide film according to claims 1, as set forth above. Moriuchi further teaches that the glass transition temperature is preferably 250 C or more [0044]. Therefore, when preparing a polyimide film for applications such as disclosed by Moriuchi, the person having ordinary skill in the art would have been motivated to select any appropriate Tg within Moriuchi’s disclosed range of 250 C or more in order to provide a film having sufficient heat resistance. It would have been obvious to the person having ordinary skill in the art, therefore, to have prepared the polyimide film of modified Moriuchi having any appropriate glass transition temperature within Moriuchi’s disclosed range of 250 C or more, including a glass transition temperature within the presently recited range. Case law has established that a prima facie case of obviousness is established where the claimed ranges overlap the ranges disclosed by the prior art. See MPEP 2144.05.
Response to Arguments
Applicant's arguments filed 11/5/2025 have been fully considered.
Applicant argues (p 8) that nothing in Kondo teaches or suggests TFMB as being advantageous when used in combination of BPDA and one or more of BPADA and ODPA. This argument was sufficiently addressed in the paragraph bridging pp 12-13 of the examiner’s answer dated 6/21/2024.
Applicant argues (p 8) that Moriuchi’s examples in Table 5 utilize at least 70% of the aromatic diamine 3,3’-DDS, 4,4’-DDS or NBDA as it’s diamine component, and therefore Moriuchi does not suggest a second diamine used in a molar fraction within a range from 40-98 mol%.
However, the “NBDA” in Moriuchi’s examples is norbornane diamine, which is not an aromatic diamine. Rather, NBDA (an alicyclic diamine) is named by Moriuchi in [0029] among the examples of “second” diamines to be used for the purpose of diluting color when using a diamine having an SO2 group, such as DDS. For at least the reason that Moriuchi’s Table 5 includes an example (Ex 17) wherein the diamine component is entirely a non-aromatic diamine named as an example of a second diamine for diluting color, Applicant’s argument that nothing in Moriuchi teaches or suggests utilizing a fraction of second diamine within the presently claimed range of 40-98 mol% is not persuasive. The examiner also notes that disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments (MPEP 2123).
Applicant argues (pp 8-10) that the Working Examples in the instant specification demonstrate that the claimed ranges are advantageous. Applicant cites instant Working Examples 1, 5, 14 and 15 as demonstrating advantageous haze and MEK tensile elongation values, while comparative examples 4-7 have MEK tensile elongation values below the claimed minimum, and comparative examples 4 and 7 have haze values greater than the claimed maximum. See paragraph bridging pp 8-9 of remarks. Applicant also argues (p 10, top) that comparative examples 4-7 have a total light transmission below the claimed minimum. Applicant’s arguments are not sufficient to overcome the rejection of record for at least the reason that none of comparative examples 4-7 are representative of the closest prior art because the cited instant comparative examples include 6FDA in the dianhydride component. Primary reference Moriuchi discloses and exemplifies a polyimide film wherein the dianhydride component consists of BPDA and BPADA (and does not include 6FDA).
Allegations of unexpected/advantageous properties were also previously addressed in the examiner’s answer dated 6/21/2024. The discussion on pages 13-24 of the examiner’s answer is relevant to the rejection set forth above, and is therefore incorporated here by reference.
Conclusion
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/RACHEL KAHN/ Primary Examiner, Art Unit 1766