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 .
Claims 1-5 and 7-18 are pending as amended on March 12, 2026. Support for amended claim 1 is found in original claim 6. Support for amended claims 3 and 4 is found in claims 1, 3, and 4. Claim 6 is cancelled. Claims 9-18 stand withdrawn from consideration.
The new grounds of rejection set forth below were not necessitated by Applicant’s amendment. This action is non-final.
Any objections and/or rejections made in the previous Office action and not repeated below are hereby withdrawn.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 the action can be found in a prior Office action.
Response to Arguments
Applicant’s arguments, see page 7-8, filed March 12, 2026, with respect to the rejections of claims 1-8 under 35 U.S.C. 103 over Osada (JP 2005186613 A) in view of Liu (US 2016/0176165 A1) and evidenced by Nakai (US 2015/0013766 A1) and Jabrin (Optical properties of thermally crystallized poly(ethylene terephthalate), Polymer Engineering and Science, 1982, 22 (13), 815-820) have been fully considered and are persuasive. The examiner agrees that sufficient evidence of crystalline content was not provided because biaxial stretching is known to increase crystallinity and is influenced by the specific polyester chemistry. Jabrin deals with non-oriented polyester that does not comprise cyclohexane dimethanol residues and would therefore not be expected to represent the crystallization behavior of Osada. Therefore, the rejection has been withdrawn.
Applicant’s arguments, see page 11, filed March 12, 2026, with respect to the rejections of claims 1-7 under 35 U.S.C. 103 over Liu and evidenced by Nakai and Jabrin have been fully considered and are persuasive. The examiner agrees that sufficient evidence of crystalline content was not provided because biaxial stretching is known to increase crystallinity and is influenced by the specific polyester chemistry. Jabrin deals with non-oriented polyester that does not comprise cyclohexane dimethanol residues and would therefore not be expected to represent the crystallization behavior of Liu. Therefore, the rejection has been withdrawn.
Upon further consideration, a new ground of rejection is made in view of Osada in view of Liu and evidenced by Rao (The relationship between microstructures and toughness of biaxially oriented semicrystalline polyester films, Polymer, 2008, 49, 2507-2514). A new ground of rejection is also made in view of Rao in view of Buchbinder (US 2014/0079894 A1)
Applicant argues (page 8-10) that Osada does not provide motivation to use the method of Liu to measure tear strength and that one would not have a reasonable expectation of success in doing so. Applicant argues that Liu teaches a different material than Osada with a low CHDM content. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case, one would have been motivated to form a film according to Osada having MD and TD tear strengths of Liu because Liu demonstrates this range as being suitable for similar layered, biaxially stretched films used in laminated glass applications.
Claim Rejections - 35 USC § 103
Claims 1-5 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Osada (JP 2005186613 A, Cite No. b on 5/31/2023 IDS, English translation provided) in view of Liu (US 2016/0176165 A1) and evidenced by Rao (The relationship between microstructures and toughness of biaxially oriented semicrystalline polyester films, Polymer, 2008, 49, 2507-2514).
Regarding claims 1, 3-4 and 7, Osada teaches a polyester film (biaxially stretched laminated film including at least a layer formed of a polyester A and a layer formed of a polyester B, Osada, [0006]). The film comprises a layer containing poly(ethylene terephthalate) (PET) as a main component and a layer containing PET copolymerized with 15-45 mol% of 1,4-cyclohexanedimethanol (CHDM) as a main component (Osada, [0016]). PET copolymerized with 15-45 mol% of CHDM reads on a polycyclohexylenedimethylene terephthalate resin comprising a first repeating unit derived from a dicarboxylic acid-based compound (terephthalic acid) and a second repeating unit derived from a diol-based compound (CHDM and ethylene glycol). The first repeating unit comprises 100 mol% of a terephthalic acid residue (claim 7).
Osada is silent as to the film crystallinity.
However, Rao teaches the crystallinity of biaxially stretched PET-CHDM copolymer films with a range of monomer ratios (Rao, page 2509, Figure 1). Rao teaches that CHDM is more rigid and bulky than ethylene glycol and does not fit in the unit cell of a PET crystal, causing a decrease in crystallinity (Rao, page 2509, col. 1, last paragraph). Rao demonstrates this decrease in crystallinity for biaxially stretched films where PET with no CHDM has a crystallinity of about 41%, but all of the examples comprising CHDM have lower crystallinity (Rao, page 2509, Figure 1). Rao’s figure 1 includes an example with about 20 mol% CHDM and an example with about 31 mol% CHDM. These examples have about 15% and 5% crystallinity, respectively. Rao also teaches examples with about 10 mol% CHDM and 62 mol% CHDM. These examples have at most about 26% crystallinity. All films are processed with biaxial stretching and the crystalline content is determined by DSC (Rao, page 2508, col. 2, sections 2.2.1 and 2.3.2). Rao therefore demonstrates that biaxially stretched PET-CHDM films where CHDM is included in an amount of 10-62 mol% have a maximum crystallinity of about 26%. Similarly, Liu teaches that a higher concentration of PETG results in reduced strain induced crystallinity (Liu, [0017]).
Based on the disclosures of Rao and Liu, it is reasonable to expect biaxially stretched PET-CHDM films where CHDM is included in an about of about 15-45 mol%, as taught by Osada, to necessarily have a crystallinity less than about 26% crystallinity. Based on Rao, one would expect the crystallinity of Osada’s PET layers to be about 41% (0% CHDM example in Rao figure 1). Given that Osada teaches alternating between the PET and PET-CHDM layers (Rao, [0016]), it is reasonable to expect the overall crystallinity of the film to be about the average of the two layer types. The crystallinity of Osada is therefore necessarily less than about 33.5% ((26+41)/2=33.5) (claim 1) for the film with alternating PET and PET-CHDM layers taught by Osada.
Osada further teaches that by having a high tear strength, the interlayer film for a laminated glass is very difficult to tear (Osada, [0018]). Specifically, Osada teaches a tear strength of 80 N/mm to 1,000 N/mm in both the longitudinal direction and the transverse direction of the film (Osada, [0018]). In the working examples, Osada demonstrates measuring tear strength according to the Elmendorf method (Osada, [0039]). This method is different than the instantly claimed ASTM D1004 method because the Elmendorf method measures the force to propagate a tear while ASTM D1004 measures the force required to initiate a tear. Based on the disclosure of Osada, one of ordinary skill would have recognized that high tear strength is desirable, but would not have known the tear strength as measured by ASTM D1004.
However, Liu teaches a tear resistant multilayer film that can be used in shatter resistant glass (Liu, [0001]). Liu teaches a tear resistance measured according to ASTM D1004 in each of a first direction and a second direction, reading on a machine direction (MD) tear strength and transverse direction (TD) tear strength measured in accordance with ASTM D1004 (Liu, [0029]). Liu teaches a range of 100-300 N in both the first and second direction (Liu, [0029]). Liu further teaches a film thickness of 150-500 µm (Liu, [0035]). Liu therefore suggests a tear strength range of 2,000 N/cm (100N/500µm* 10000 µm/cm = 2000) to 20,000 N/cm (300N/150µm* 10000 µm/cm = 20,000). This range is related to the claimed units of kg/cm by a factor of 9.8 kg/s2 and corresponds to a range of about 204-2,040 kg/cm. It would have been obvious to one of ordinary skill in the art at the time of the invention to form a film according to Osada having MD and TD tear strengths of 204-2,040 kg/cm, as Liu demonstrates this range as being suitable for similar films. This represents the use of a suitable range of MD and TD tear strengths in a similar laminated glass application. "The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416-21 (2007). See MPEP 2141.
It would have further been obvious to one of ordinary skill to have selected any MD tear strength and any TD tear strength in the range of 204-2,040 kg/cm because Osada in view of Liu teaches a tear strength of 204-2,040 kg/cm. A range of 204-2,040 kg/cm overlaps with the claimed ranges of a MD tear strength of 240-350 kg/cm (claim 1) and 280-350 kg/cm (claim 3). A range of 204-2,040 kg/cm overlaps with the claimed ranges of a TD tear strength of 280-400 kg/cm (claim 1) and 307-400 kg/cm (claim 4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Regarding claim 2, Osada teaches the polyester film of claim 1 where the crystallinity is less than about 33.5%, as discussed above for claim 1. Rao and Liu teach that crystallinity decreases with CHDM content. The lowest CHDM content taught by Osada is 15 mol%, but Rao does not demonstrate a 15 mol% CHDM sample.
However, one would expect the crystallinity of a film with 15 mol% to be within the range of about 20% based on figure 1 of Rao. This would lead Osada’s layered film crystallinity to be about 30.5% ((20+41)/2=30.5) when the PET-CHDM polymer has 15 mol% CHDM. Because Osada teaches 15-45 mol% CHDM and crystallinity decreases with CHDM content, the crystallinity for the layered films produced using a PET-CHDM polymer 15-45 mol% CHDM range taught by Osada would necessarily have crystallinities less than about 30.5%.
Regarding claim 5, Osada teaches the polyester film of claim 1. Osada further teaches a preferred thickness range of 75 µm to 450 µm (Osada, [0021]).
Claims 1-5 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Rao (The relationship between microstructures and toughness of biaxially oriented semicrystalline polyester films, Polymer, 2008, 49, 2507-2514) in view of Buchbinder (US 2014/0079894 A1).
Rao teaches optically transparent films prepared by biaxial stretching of sheets of copolyesters derived from ethylene glycol (EG), cyclohexane dimethanol (CHDM), and terephthalic acid (Rao, abstract). These films read on a polyester film comprising a polycyclohexylenedimethylene terephthalate resin comprising a first repeating unit derived from a dicarboxylic acid-based compound (terephthalic acid) and a second repeating unit derived from a diol-based compound (CHDM and ethylene glycol). The first repeating unit comprises 100 mol% of a terephthalic acid residue (claim 7).
Rao measures the film crystallinity using a differential scanning calorimeter (Rao, page 2508, col. 2, section 2.3.2). The films have a thickness of about 80 µm (claim 5) (Rao, page 2508, col. 2, section 2.2.1). In Rao’s figure 1, films where the diol components have about 5-62 mol% CHDM have crystallinities below 30%. These samples have a degree of crystallinity of 30% or less (claims 1-2).
Rao does not teach the claimed MD and TD tear strengths.
However, Rao teaches using polymer films as transparent substrates (Rao, page 2508, col. 1, lines 5-7) and Buchbinder teaches suitable tear strengths for substrates that overlap with the claimed range. Buchbinder teaches biaxially oriented polymer film substrates (Buchbinder, [0042]). Buchbinder further teaches that the tear resistance of substrates in accordance with ASTM D-1004 is 25-100 N for a specimen thickness of 100-300 µm (Buchbinder, [0043]). This converts to a range of about 85-1000 kg/cm (e.g. 25 N corresponds to 25 N/ 9.8 m/s2= 2.5 kg and 2.5 kg/300 µm = 85 kg/cm). It would have been obvious to one of ordinary skill in the art at the time of the invention to form a film according to Rao having MD and TD tear strengths of 85-1020 kg/cm, as Buchbinder demonstrates this range as being suitable for similar films. This represents the use of a suitable range of cross direction tear strengths in a similar substrate application. "The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 416-21 (2007). See MPEP 2141.
It would have further been obvious to one of ordinary skill in to have targeted any MD tear strength and any TD tear strength in the range of 85-1020 kg/cm because Rao in view of Buchbinder teaches a tear strength of 85-1020 kg/cm. A range of 85-1020 kg/cm overlaps with the claimed ranges of a MD tear strength of 240-350 kg/cm (claim 1) and 280-350 kg/cm (claim 3). A range of 85-1020 kg/cm overlaps with the claimed ranges of a TD tear strength of 280-400 kg/cm (claim 1) and 307-400 kg/cm (claim 4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have selected the overlapping portion of the ranges disclosed by the reference because selection of overlapping portion of ranges has been held to be a prima facie case of obviousness. See MPEP § 2144.05.I.
Allowable Subject Matter
Claim 8 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
As of the date of this office action, no prior art references, whether considered individually or in combination have been identified to anticipate or render obvious the claimed invention under 35 U.S.C. §102 or §103. The examiner is not aware of any reference or combination of references that teaches the claimed crystallinity and tear strength when the CHDM residue is present in an amount of 85-100 mol%.
The closes prior art of record is Rao (The relationship between microstructures and toughness of biaxially oriented semicrystalline polyester films, Polymer, 2008, 49, 2507-2514) in view of Buchbinder (US 2014/0079894 A1) and Osada (JP 2005186613 A, Cite No. b on 5/31/2023 IDS, English translation provided) in view of Liu (US 2016/0176165 A1) and evidenced by Rao.
As discussed above for claim 1, Rao teaches films with up to 62 mol% CHDM. This CHDM content is less than claim 8’s minimum of 85 mol%. Rao provides no suggestion or motivation to further increase the CHDM content.
As discussed above for claim 1, Osada teaches 15-45 mol% CHDM. Osada also teaches poly-1,4-cyclohexanedimethylene terephthalate homopolymers where the CHDM content is 100 mol%. However, the examiner does not have sufficient evidence that the layered films produced using this higher CHDM content would necessarily have the claimed crystallinity. Applicant has demonstrated with comparative example 1 (instant Table 1) that biaxially stretched films of poly-1,4-cyclohexanedimethylene terephthalate homopolymers can have crystallinities outside of the claimed range. In addition, Rao does not provide crystallinity measurements of a poly-1,4-cyclohexanedimethylene terephthalate homopolymer. Rao teaches that CHDM causes decreased crystallinity in PET-CHDM copolyesters because CHDM does not fit in the unit cell of a PET crystal (Rao, page 2509, last paragraph). Rao’s teachings about the decreased crystallinity of the CHDM containing co-polyesters are in the context of copolymers and do not necessarily reflect the crystallinity of CHDM homopolymers where the PET unit cell would not play a role in crystallization. Rao also teaches that cooling rate, stretching temperature, stretching ratio, and final heatset temperature can change crystallinity (Rao, page 2509, top of col. 2). Therefore, there is insufficient evidence that Osada’s films comprising poly-1,4-cyclohexanedimethylene terephthalate homopolymer layers necessarily satisfy the claimed crystallinity.
Conclusion
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/AUDRA J DESTEFANO/Examiner, Art Unit 1766
/RANDY P GULAKOWSKI/Supervisory Patent Examiner, Art Unit 1766
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