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 .
Continued Examination Under 37 CFR 1.114
Applicant’s request for continued examination is acknowledged. Claim 1 is amended to require aromatic amine hardener and inner core of the core shell particle has to be crosslinked. Claim 7 is amended such that the range of the thermosetting resin is changed from 50-95 wt.% to 20-75 wt.%. The amine curing agent is aromatic amine, the multistage polymer comprises core A1 which is crosslinked and it is the innermost layer of the multilayered structure. Claim 9 has been amended to specify the aromatic amine hardener, its content as well as content of secondary hardener.
The amendment to claims 1 and 7 overcomes the 112-1st paragraph rejection. Claims 6 and 9 are also amended to overcome the 112-2nd paragraph rejection of record.
Response to Arguments
In their arguments dated 6/9/2026 applicants traversed rejection as follows:
With respect to rejection over Nguyen in view of Haji applicants argued that the rejection fails to teach crosslinked core A1 which is the innermost layer of the core shell particle.
Response:
Examiner disagrees. The core of the core-shell particles is crosslinked. Nguyen teaches using Kaneka MX series citing two EP references to teach about the properties of the particulate. EP 1 632 533 discloses the particles referred to in Nguyen. The EP patent in [0022], the particles of Kaneka MX series have to be crosslinked so that it can be swollen. In [0030] EP disclosure states that the degree of the crosslinking of the core is critical since it will affect the properties of the epoxy composition. Additionally, Haji further teaches that the core of the core shell particles can be crosslinked. The rejection will be restated to meet further clarify the nature of the core-shell particle.
Applicants further stated that the polymer of Haji is not equivalent to the presently claimed polymer A1.
Response
Examiner disagrees. Instant claims only require a multistage polymer, that comprises core A1 having glass transition temperature that is crosslinked, as well as shell having glass transition temperature. These are the only requirement of the multistage polymer is its glass transition temperature, which means that the core and shell themselves can be any monomer or polymer that is known for its use in core shell polymer. The instant invention only defines the most inner core and shell, leaving the core shell particle open to multiple layers. The innermost layer of the polymer of Haji has glass transition temperature that meets instant claims. Composite particle of Haji has middle layer with glass transition temperature of at least 60oC, which is encompassed by the broad limitation of the instant particle. Additionally, at least 60oC falls within the claimed range of at least 30oC. The outermost layer of Haji has glass transition temperature of at least 30oC, which is exactly the same temperature range as that of applicants.
In summary, under broadest reasonable interpretation, the applicants have not defined their multistage particle to distinguish it over the prior art of record.
Applicants argued that Meegan does not remedy the deficiencies of Nguyen and Haji.
Response:
Examiner disagrees. Nguyen teaches aromatic amines as hardeners. Meegan was utilized to provide another type of aromatic curing agent that is excellent for the same type of composition as that of Nguyen. Basically, the composition also comprises epoxy resins, core shell particles, polyether sulfones to make fibrous prepreg. The two compositions are in the same field of endeavor and choice of curing additives is prima facie obvious.
It is well settled that it is prima facie obvious to combine two ingredients, each of which is targeted by the prior art to be useful for the same purpose. In re Linder 457 F,2d 506,509, 173 USPQ 356, 359 (CCPA 1972).
The combination of two compositions, each of which is taught by the prior art to be useful for the same purpose, in order to for a third composition that is to be used for the very same purpose may be prima facie obvious. In re Susi, 440 F.2d 442, 445, 169 USPQ 423, 426 (CCPA 1971).
Selection of a known material based on its suitability for its intended use supports prima facie obviousness. Sinclair & Carroll Co vs. Interchemical Corp. 325 U.S. 327, 65 USPQ 297 (1945).
Having said that, it should be noted that Meegan discloses core-shell particles which have core shell having glass transition temperature of less than 0oC and outer shell having glass transition of at least 20oC [0060]. In a way, Meegan does teach the glass transition temperature of the multistage particles, while crosslinked core is included in the cited by Nguyen EP documents, which applicants did not dispute.
With respect to the rejection over Mizuki, the applicants also argue that the prior art does not teach the core that is crosslinked.
Response:
Mizuki discloses multistage particles having the same tradename Kane MX416. In [0085] Mizuki states that the rubber particles having core-shell structure is formed by growing dissimilar polymer on the surface of the crosslinked rubber particles. This is an explicit recitation of rubber core being crosslinked before the shell is formed. The tradenames listed in [0087] include Kane Ace where in the evidentiary reference clearly states the core is crosslinked, and the degree of crosslinking of the core influences the properties of the epoxy resins. The rejection further provided glass transition temperatures for Polaroid EXL-2611, which under broadest reasonable interpretation meet the only limitation that describes instant multistage particles, which is their glass transition temperature.
For the particle Stafiloid AC-3355 see [0087]. For crosslinked core, please refer to the tradenames or [0085] where crosslinked core is explicitly disclosed. Furthermore, the office action clearly disclosed this paragraph of Mizuki, explicitly stating that the particle core is crosslinked. So no, the claims are not patentable over the prior art of record as currently presented before the office.
The examiner would like to note, that crosslinking the core of core-shell particles is well established in the art and anyone practicing instant invention or disclosures applied in the rejection would know how the properties of the final product will be influenced if the degree of crosslinking is too low. Crosslinking enhances structural stability, mechanical integrity and functional performance. Swelling of the particle core that was disclosed in an evidentiary EP reference (see above), such swelling allows the particulates to resist deformation, which is important when such particles are used as tougheners or impact modifiers. There is no deficiency to be cured in any of the primary rejections.
Submitted by the applicant’s IDS has been considered. Rejections of record will be restated to clearly address the all limitations; new references will be applied as well. The examiner would like to further stress that under broadest reasonable interpretation, the only requirement of the multi-stage particles is the glass transition temperature of crosslinked core and shell. That’s it. No structural or chemical or any other limitations are present that would distinguish the multistage particles of the instant invention from the particles of the prior art.
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chen (WO 2020/003122 cited by the applicants) in view of evidence in Yamaguchi (EP 1 632 533) and Kaneka brochure.
With respect to claim 1, Chen discloses composition comprising thermosetting resin, aromatic amine as curing agent, polyethersulfone and multistage particles (Table 1 – list of materials), wherein polyethersulfone and multistage particles meet the limitation of toughener.
The core shell particles are defined starting p. 11 of Chen. On p. 11, l. 21 Chen states that the core of the particles is crosslinked or phase separated. The examiner relies on first embodiment out of 2, which is crosslinked in view of exemplified Kaneka particles, which as evidenced in Yamaguchi, the core of the Kaneka core shell particles is crosslinked so that swelling of the particle can resist deformation and serve the purpose of the toughener or impact modifier.
Chen further teaches that the core of the particle has glass transition temperature of less than 0oC (p. 12, l. 24-29) which enables rubbery behavior.
Shell of the particle has glass transition temperature that is greater than 25oC (p. 13, l. 1-4).
Core-Shell particles are utilized in amount of 1-25 wt.%, preferably 5-15 wt.% (p. 13, l. 16-20), which is the same range as that of instant claim 1.
Polyethersulfone, which is a thermoplastic polymer is utilized in amount of 0.1-20 wt.%, preferably 0.3-10 wt.% (p. 5, l. 18-21).
With respect to claim 2, thermoset resin is epoxy (p. 5, starting l. 24), wherein epoxies are polyepoxy compounds.
With respect to claim 3, polyepoxy compounds include diepoxies which have two or more oxirane rings (p. 6, l. 12-13) such as bis (di) epoxies, diglycidyls. Exemplified compounds in Table 1 include tetraglycidyl compound. See also, p. 6, l. 25 for diepoxides.
With respect to claim 5, the thermoplastic resin as it was mentioned in rejection of claim 1 is polyethersulfone.
With respect to claim 10, the epoxies of Chen are those that are utilized to make fiber reinforces composites (p. 5) such as pre-pregs (p. 14, l. 25) for use in aerospace.
With respect to claim 11, 12 and 15, fibers disclosed in Chen include carbon fibers and glass fibers (p. 13, l. 36), which would meet the requirements for the composites made for aerospace industry. The content of such filler is 0.5-40 wt.% (p. 14, l. 2).
With respect to claims 13 and 14, specifically for use in prepregs and aeronautical industry, the substrate would be fiber structure (glass fiber or carbon fiber as mentioned above). The composition is applied as unsupported film onto a substrate and then reticulated onto honeycomb prepreg. In this art reticulation means applying the curable composition to either honeycomb or fibers. The temperature of the composition is kept low to avoid premature cure. Curing of the composition is achieved at a temperature of 60-130oC (p. 15).
Claims 7 and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Chen (WO 2020/003122) in view of evidence in Yamaguchi (EP 1 632 533).
With respect to claims 7 and 8, Chen discloses composition comprising thermosetting resin, aromatic amine as curing agent, polyethersulfone and multistage particles (Table 1 – list of materials), wherein polyethersulfone and multistage particles meet the limitation of toughener.
The core shell particles are defined starting p. 11 of Chen. On p. 11, l. 21 Chen states that the core of the particles is crosslinked or phase separated. The examiner relies on first embodiment out of 2, which is crosslinked in view of exemplified Kaneka particles, which as evidenced in Yamaguchi, the core of the Kaneka core shell particles is crosslinked so that swelling of the particle can resist deformation and serve the purpose of the toughener or impact modifier.
Chen further teaches that the core of the particle has glass transition temperature of less than 0oC (p. 12, l. 24-29) which enables rubbery behavior.
Shell of the particle has glass transition temperature that is greater than 25oC (p. 13, l. 1-4).
Core-Shell particles are utilized in amount of 1-25 wt.%, preferably 5-15 wt.% (p. 13, l. 16-20), which is the same range as that of instant claim 7.
Polyethersulfone, which is a thermoplastic polymer is utilized in amount of 0.1-20 wt.%, preferably 0.3-10 wt.% (p. 5, l. 18-21).
Collective amount of thermosetting resin is 30-60 wt.% (p. 7, l. 24-29).
The amount of primary curing agent which is aromatic amine is in a range of 2-50 wt.% (p. 9, l. 35-37). Secondary curing agents are utilized in amount of less than 5 wt.% (p. 8, l. 16-18).
With respect to claim 2, thermoset resin is epoxy (p. 5, starting l. 24), wherein epoxies are polyepoxy compounds.
With respect to claim 3, polyepoxy compounds include diepoxies which have two or more oxirane rings (p. 6, l. 12-13) such as bis (di) epoxies, diglycidyls. Exemplified compounds in Table 1 include tetraglycidyl compound. See also, p. 6, l. 25 for diepoxides.
With respect to claim 5, the thermoplastic resin as it was mentioned in rejection of claim 1 is polyethersulfone.
Claims 1-3, 5, 6 and 10-17 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Meegan (US 2016/0176083) in view of evidence in Yamaguchi (EP 1 632 533) and Kaneka MX series brochure.
With respect to claim 1, claim 1 of Meegan discloses composition comprising up to 5 wt.% of thermoplastic polymer, up to 5 wt.% of core-shell particles, an epoxy resin and amine curing agent. Wherein thermoplastic polymer and core-shell particles meet the limitation of the toughener.
Core-shell particles of Meegan have an elastomeric (rubbery) core which has glass transition temperature of less than 0oC [0085] while shell has a glass transition temperature greater than 20oC [0086]. While Meegan does not explicitly state that the core of the particle is crosslinked, he discloses a tradename of Kaneka MX 660 and MX 411. Based on the manufacturer’s website the core of both core shell particles is crosslinked. In fact, the entire MX series by Kaneka has crosslinked core (See brochure). As it is further evidenced in Yamaguchi, the core has to be properly crosslinked, in order to allow swelling of the rubber core and resist deformation which an important property if core shell particles are used as tougheners of impact resistance type fillers. This is reflected in Meegan need for improvement of compression strength after impact [0010, 0031]
Amine curing agents are aromatic amines [0082].
With respect to claims 2 and 3, thermosetting resin can be epoxy [0063], which include epoxies that have at least two epoxide groups and polyfunctional epoxies that have at least 3 or 4 epoxy groups.
With respect to claim 5, the thermoplastic resin is polyethersulfone (claim 12 of Meegan).
With respect to claim 6, the preferred amine curing agent includes MCDEA (claim 17 of Meegan).
With respect to claim 10, the composition of Meegan is utilized to make fiber reinforced articles [0099-0100], wherein the composition will inherently comprise reinforcing fibers.
With respect to claim 11, fibers of Meegan include glass fibers, polymeric fibers (polyester), inorganic fibers made from alumina, zirconia, silicon carbide as well as carbon fibers [0100]. While [0100] discloses use of fibers in terms of volume, the content of the fiber is at least 20% by volume as such if the content of the entire chemical composition is 100% volume, the content of the fiber will meet the content of claim 12.
With respect to claim 13, the composition of Meegan was applied to carbon fibers and subjected to vacuum to impregnate the fiber substrate with the composition. The prepreg was cured in an oven at a temperature of 90-110oC [0147].
With respect to claims 14 and 15, the article produced is utilized in aeronautical industry. Examples of parts include primary parts such as fuselage, wings pressure bulkhead [0102-0103].
With respect to claim 16, the composition can be subject to resin infusion process [0113], wherein the process includes preparing fiber preform and laying it up within a mold, injecting the curable composition into a mold and curing the composition [0107-0113], wherein curing is conducted a t a temperature of up to 200oC [0116], wherein post curing operation is an optional step.
With respect to claim 17, the other method suitable for making prepregs of Meegan is vacuum assisted resin transfer molding [0106]. The general steps include laying up fibrous substrate, providing curable composition and injecting it into a mold, however impregnation of the resin between the fiber layup is achieved using vacuum back [0117]. See also rejection of instant claim 13 [0147] where after application of vacuum the prepreg is cured at a temperature range of 90-110oC.
Claims 7-9 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Meegan (US 2016/0176083) in view of evidence in Yamaguchi (EP 1 632 533) and Kaneka MX series brochure.
With respect to claims 7 and 8, claim 1 of Meegan discloses composition comprising up to 5 wt.% of thermoplastic polymer, up to 5 wt.% of core-shell particles, an epoxy resin and amine curing agent. Wherein thermoplastic polymer and core-shell particles meet the limitation of the toughener. Total content of the toughener is 10 wt.%.
Core-shell particles of Meegan have an elastomeric (rubbery) core which has glass transition temperature of less than 0oC [0085] while shell has a glass transition temperature greater than 20oC [0086]. While Meegan does not explicitly state that the core of the particle is crosslinked, he discloses a tradename of Kaneka MX 660 and MX 411. Based on the manufacturer’s website the core of both core shell particles is crosslinked. In fact, the entire MX series by Kaneka has crosslinked core (See brochure). As it is further evidenced in Yamaguchi, the core has to be properly crosslinked, in order to allow swelling of the rubber core and resist deformation which an important property if core shell particles are used as tougheners of impact resistance type fillers. This is reflected in Meegan need for improvement of compression strength after impact [0010, 0031]
Epoxy resin is utilized in an amount of up to 60 wt.% [0084].
Amine curing agents are aromatic amines [0082]. Curing agent is utilized in amount of up to 50 wt.% [0084].
With respect to claim 9, the preferred amine curing agent includes MCDEA (claim 17 of Meegan), utilized in an amount of 30-50 wt.% [0084], wherein content of secondary amine is zero.
Claim Rejections - 35 USC § 103
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 4 is rejected under 35 U.S.C. 103 as being unpatentable over Chen (WO 2020/003122) in view of Salinkov (US 2015/0218429) as evidenced by Yamaguchi (EP 1 632 533) and Kaneka brochure.
Discussion of Chen from paragraph 1 of this rejection is incorporated here by reference. As it was mentioned in paragraph 1, Chen discloses composition comprising epoxy, thermoplastic resin, core shell particles and aromatic amine curing agents to make prepregs suitable for aeronautic industry.
The difference between Chen and instant invention is use of benzoxazine as thermosetting resin.
Salinkov discloses composition comprising epoxy resins which includes polyepoxides just like those of Chen [0079]. Toughening agents include core-shell particles having crosslinked shell. Examples include Kaneka MX series and clearstrength series by Atofina [0058] as well as thermoplastic polymers [0054]. The composition is also cured with an amine [0106].
Salinkov teaches that benzoxazines have been utilized with epoxies for several reasons. These include imparting flame proof properties [0004]. Salinkov states also that epoxies when utilized in structural applications have noted deficiencies which include limited moisture stability, high moisture uptake, shrinkage and large exotherm on polymerization [0007]. Polybenzoxazines have been utilized to overcome many of these deficiencies because they have lower exotherms on curing, less shrinkage and higher thermal stability [0008].
Salinkov provides a composition comprising benzoxazine, with liquid epoxy and other components disclosed above to specifically overcome the short comings of epoxies [0011].
In the light of the above disclosure, it would have been obvious to one of ordinary skill in the art at the time instant invention was filed to utilize benzoxazine in addition to epoxy to form structural articles suitable in aerospace industry. The resulting composition will have good thermal stability and reduced exotherms and shrinkage [0011].
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Meegan (US 2016/0176083) in view of Salinkov (US 2015/0218429) as evidenced by Yamaguchi (EP 1 632 533) and Kaneka brochure.
Discussion of Meegan from paragraph 3 of this office action is incorporated here by reference. As it was disclosed in paragraph 3, Meegan discloses composition comprising epoxy, amine curing agent, thermoplastic toughening agent as well as core-shell toughening agent. The composition of Meegan is utilized to make primary parts in aeronautic industries.
The difference between Meegan and instant invention is use of benzoxazine as thermosetting resin.
Salinkov discloses composition comprising epoxy resins which includes polyepoxides just like those of Chen [0079]. Toughening agents include core-shell particles having crosslinked shell. Examples include Kaneka MX series and clearstrength series by Atofina [0058] as well as thermoplastic polymers [0054]. The composition is also cured with an amine [0106].
Salinkov teaches that benzoxazines have been utilized with epoxies for several reasons. These include imparting flame proof properties [0004]. Salinkov states also that epoxies when utilized in structural applications have noted deficiencies which include limited moisture stability, high moisture uptake, shrinkage and large exotherm on polymerization [0007]. Polybenzoxazines have been utilized to overcome many of these deficiencies because they have lower exotherms on curing, less shrinkage and higher thermal stability [0008].
Salinkov provides a composition comprising benzoxazine, with liquid epoxy and other components disclosed above to specifically overcome the short comings of epoxies [0011].
In the light of the above disclosure, it would have been obvious to one of ordinary skill in the art at the time instant invention was filed to utilize benzoxazine in addition to epoxy to form structural articles suitable in aerospace industry. The resulting composition will have good thermal stability and reduced exotherms and shrinkage [0011].
Claims 1-5, 7, 8, 10-17 are rejected under 35 U.S.C. 103 as being unpatentable over Nguyen (US 2015/0240042) in view of Hajji (WO 2019/012052) and evidence in Yamaguchi (EP Yamaguchi (EP 1 632 533) and Kaneka brochure.
Nguyen discloses high modulus fiber reinforced polymer composite. Nguyen teaches that the fiber reinforced composite has to have durable bonds because it can be subjected to environmental and/or hostile conditions [0003]. High modulus fibers are carbon fibers with high tensile modulus that are used in components under rotation, bending, torsion loads or various thermal conditions [0008]. The composition is utilized to make prepreg [0014].
With respect to claim 1, comprising thermosetting resin, thermoplastic resin and (polyether sulfone) and core shell rubber article [0090 Table]. Nguyen also teaches addition or toughening agents/fillers which include core-shell particles. The core shell particle of Nguyen is Kane Ace MX416 which as depicted by company’s website and further evidenced in [0057] pf cited EP document is in fact an impact modified particle with crosslinked rubber core.
With respect to the amounts of the toughener per examples 17 and 18 of Nguyen (page 14), core shell particle is utilized in amount of 5% by weight and thermoplastic polyethersulfone is utilized in 6% by weight. Overall content of toughener is 11% by weight.
While Nguyen does not explicitly state that the core of the particle is crosslinked, he discloses a tradename of Kaneka MX 416 and refers the reader to the reference of Yamaguchi, which is an evidentiary reference. Based on the manufacturer’s website the core of both core shell particles is crosslinked. In fact, the entire MX series by Kaneka has crosslinked core (See brochure). As it is further evidenced in Yamaguchi, the core has glass transition temperature as claimed and has to be properly crosslinked, in order to allow swelling of the rubber core and resist deformation which an important property if core shell particles are used as tougheners of impact resistance type fillers.
Nguyen discloses hardeners which include [0042] as well as aromatic amines.
Nguyen discloses core shell particles as additive to improve impact resistance but fails to disclose specifics regarding to glass transition temperatures.
Hajji discloses multistage particles that are utilized as tougheners and impact modifiers in an epoxy composition for prepreg [0010]. Hajji teaches that utilizing usual core-shell particles are not easy to disperse to obtain homogeneous particle distribution and good homogeneous dispersion is required to obtain satisfactory impact performance [0013-0015]. Hajji teaches that multistage polymers overcome these challenges.
Hajji discloses a multistage particle having three layers. First layer A has glass transition temperature of less than 10oC [0061], second stage B has a glass transition temperature of at least 60oC and third stage C has glass transition temperature of at least 30oC. In accordance with claim interpretation above Hajji discloses at least one (reads on two layers) layer be having temperature over 30oC. wherein, the core of the particle in Haji is crosslinked [0085]
Under broadest reasonable interpretation, the multistage particulates of the instant invention are open two more than two layers, wherein the most inner layer is the core. There is no limit on how many shells can be utilized as long as at least one has claimed glass transition temperature.
The core of the multistage polymer of Hajji can be made from rubber such as isoprene or butadiene, which is also the type of the core disclosed in Nguyen (rubber) [0073]. Layers B and C of Hajji comprise acrylates [0078] which are compatible with epoxy and wherein Nguyen also discloses acrylate. Hajji teaches the core made of rubber such as polybutadiene and shell made of acrylic polymers which have functional groups and therefore affinity to epoxy matrix resin
In the light of the above disclosure, it would have been obvious to one having ordinary skill in the art to utilize multistage polymer of Hajji in the teachings of Nguyen. Using multistage polymer of Hajji would improve dispersion of the filler which in turn will provide better impact resistance, which is a property required by both references.
With respect to claims 2 and 3, Nguyen discloses in Table [0090] diepoxies and tetra-epoxy [0040] and include combination of the epoxides as well.
With respect to claim 4, Nguyen teaches that in order to achieve better modulus the thermosetting resin may be a combination of epoxy and benzoxazine [0040].
With respect to claim 5, Nguyen teaches using thermoplastic polymer, preferred being polyether sulfones and polyetherimides [0054] [Table 0090].
With respect to claims 7 and 8, thermoplastic additive (polyether sulfone) is utilized in the most preferred range of 5-35 wt.% [0052], impact modifiers (core shell) are utilized up to 30 wt.% [0062], thermosetting resin is used in 50-70 wt.% [0040], curing agents (hardeners) are used up to 75 wt.% [0045].
With respect to claim 10, Nguyen discloses fiber reinforced composite.
With respect to claim 11, Nguyen discloses reinforcing fibers. Fibers can be polymer fibers such as aramid, silicon carbide fibers, alumina fibers, boron fibers, glass fibers, carbon fibers and the like [0064].
With respect to claim 12, based on the amounts of all components combined, examples 5 and 10 as well as comparative example 6 disclose fiber content of 29 wt.% based on the amounts depicted in Tables. (Comparative examples can also be utilized as prior art because they constitute a published record, which does not have to be better. Instant invention has to be different).
With respect to claims 13, 14, 16 and 17, fibers were brought into contact with the composition which infuses in between the fibers [0076] and cured by using heat at a temperature of 180oC or less [0077]. Vacuum is applied using autoclave, vacuum bag or pressure press to facilitate infusion of the composition between fibers. Examples further disclose placing the composition on a substrate and transferring the composition onto a fiber which results in coating the fiber component. All these processes result in forming fiber reinforced composite. Without forming a prepreg the composition may be directly applied to reinforcing fibers in a mold, composition can be injected to infuse the fibers through application of vacuum [0080-0082]. Examples discloses mixing the composition and cooling it to 65oC at which point the curing agent and accelerator were added and composition would begin to cure. The mixture was agitated for 1 hour when discharged. Mixture was poured into a mold, heated to 180oC for final cure. The composition was allowed to dwell at 180oC for two hours which meets the post curing operation required by instant claim 17. Final cure of the adhesive occurs when partial cure reaches approximately 20% [0077] and is held int final cure condition until cure reaches 80%, then vacuum is applied.
With respect to claim 15, the composite of Nguyen is utilized as a structural material in spacecraft and aircraft which meet the limitation of aerospace.
Claims 6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Nguyen (US 2015/0240042) in view of Hajji (WO 2019/012052) as applied to claims 1-5, 7, 8, 10-17 above, and further in view of Meegan (US 2019/0127514).
Discussion of Nguyen from paragraph 1 of this office action is incorporated here by reference. Nguyen teaches the hardener in amount of up to 75 parts by weight, wherein hardener comprises a nitrogen bearing group and amine group such as aminobenzamide [0046]. Nguyen utilizes these hardeners to obtain high modulus composite, however, one of ordinary skill in the art would understand that other hardeners can also achieve the same purpose.
Meegan discloses fiber reinforced epoxy composite which comprises core shell rubber particles as for impact resistance (Abstract) which composites are obtained via RTM or VaRTM [0006]. The composition utilizes amine curing agent (Abstract).
With respect to claim 6, suitable curing agent is MCDEA or 4,4’methylene-bis-(3-chloro-2,6-diethylaniline).
With respect to claim 9, Nguyen discloses use of curing agents in amount of up to 75 parts by weight. Since aromatic amine can be used in 0 wt.% its amount is viewed as optional.
In the light of the above disclosure, it would have been obvious to one having ordinary skill in the art at the time instant invention was filed to utilize curing agent of Meegan in the teachings Nguyen and still obtain the claimed invention because Nguyen teaches curing agents that contain amine group. One of ordinary skill in the art would also know that there are advantages associated with use MCDEA. Specifically, MCDEA as a highly effective curing agent for epoxies will enhance both mechanical and dynamic properties of the composition. MCDEA is also easy to process because of its low melting point.
It should also be noted that Meegan discloses core shell particles where the core has glass transition temperature of less than 0oC [0060] and shell has glass transition temperature greater than 20oC. In the event applicants continue to argue Haji without distinguishing the actual make up of the article, Meegan also meets the glass transition requirements of the core shell particles as required by instant invention.
Claims 1-5, 7, 8, 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Mizuki (US 2013/0202873) in view of evidence in Yamaguchi (EP 1 632 533) and Kaneka brochure.
With respect to claims 1 and 2, Mizuki discloses epoxy resin composition for fiber reinforced composite comprising (see examples 32 and 33 Table 5):
Epoxy resin A’ and B’
Core Shell rubber particles MX416 in amount of 6 %
Thermoplastic resin F’
Curing agent, which is multifunctional epoxy compound which include cycloaliphatic amines based on cyclohexane [0128]. Specifically, multifunctional compounds are utilized by Mizuki to crosslink (harden) the epoxy resin [0130]. Other curing agents include polyamines [0153
Wherein MX416 is Styrene-butadiene- methyl methacrylate rubber having particle size of 10 nm and produced by Kane Ace [0027]. As defined by Mizuki in [0085] core shell particles are produced by growing dissimilar polymer on the surface of crosslinked rubber particles. Consequently, Mizuki explicitly teaches that the core of CSR particles is crosslinked. Examples of other suitable core shell particles are listed in [0086-0088]. The CSR particles of Mizuki include Kane Ace MX series which as evidenced in Yamaguchi as well as the brochures, Kaneka core shell particles have crosslinked core and glass transition of the core is in fact less than 0oC. Other tradename in [0087] include Polaroid EXL-2611 which have polybutadiene core having glass transition temperature of -85oC and PMMA shell having glass transition temperature of 100oC. Stafiloid AC-3355 has acrylic rubber core having Tg below 0oC (as low ass -100oC) and shell Tg of approximately 90oC. All having PMMA core with Tg above required 30oC. See also [0163-0165].
In the light of the above disclosure, it would have been obvious to one having ordinary skill in the art at the time instant invention was filed to use CSR particles as the elastomeric component such as those mentioned above and thereby obtain the claimed invention which would meet the instant invention. Specifically, the glass transition temperature of crosslinked core has to be low enough to be suitable as impact modifier while shell enveloping the core has functionality that is compatible or reactive with the matrix epoxy resin.
With respect to claim 3, epoxy resin can be trifunctional resin A’ [0035] and difunctional resin B1[0036]. Epoxy of Mizuki is mixture of the two [0111] and monofunctional epoxy [01113-0114]. With respect to claim 4, Mizuki teaches use of benzoxazine resin which can be utilized in combination with the epoxy resin [0131].
With respect to claim 5, Mizuki discloses that thermoplastic resin can be dissolved in epoxy [0188] the preferred embodiment names polyether sulfone due to its excellent heat resistance [0189].
With respect to claims 7 and 8, based on the content of examples 32 and 33 (Table 5) for polymers and curing agents, normalizing the composition to 100%: total epoxy content is 56%, CSR rubber is 3%, PES is 11%, curing agent 1 is 5%, curing agent 2 is 22%. Please also note that in his specification, PES can be utilized in a range of 2-40% [0191], Epoxy resin is utilized in amount of 30-70% [0152].
With respect to claims 10 and 11, Mizuki discloses composition for fiber reinforced composites, wherein fiber, which include carbon fibers, glass fibers, graphite fibers, silicon carbide fibers, boron fibers, alumina fiber and the like [0096].
With respect to claims 12-17, article of Mizuki is a prepreg. According to Mizuki’s claims 20-24 the prepreg comprises fiber and has industrial applicability in aerospace industry [0296] wherein fibers are impregnated with the epoxy composition [0221]. Mizuki teaches that when making prepreg the epoxy composition has to have appropriate viscosity at 80oC to properly impregnate the fiber [0090] and the content of the epoxy resin when making the prepreg has to be 30-50 parts to ensure proper adhesion between polymer and fiber can be utilized in amount of 25-50parts per 100 parts of epoxy resin [0124]. According to working example 13, prepregs are formed by impregnating the fiber with epoxy at 100oC [0290]. Curing temperatures include 150oC [0284] and 180oC [0286] depending on the method.
Claims 6, 9 are rejected under 35 U.S.C. 103 as being unpatentable over Mizuki (US 2013/0202873) as applied to claims 1-5, 7, 8, 10 and 11 above, and further in view of Meegan (US 2019/0127514).
Discussion of Mizuki from paragraph 9 of this office action is incorporated here by reference. Mizuki discloses aromatic amine containing curing agent in amount of 2-15 parts by weight [0030, 0039, 0089] in combination with another curing agent. Specific curing agent of Mizuki is lonzacure M-DEA, which has synthetic name of 4,4’-methylene bis(2,6-diethylaniline) [0054]
The difference between Mizuki and instant invention is use of other aromatic dianilines as curing agents for the epoxy compositions.
Meegan discloses fiber reinforced epoxy composite which comprises core shell rubber particles as for impact resistance (Abstract) which composites are obtained via RTM or VaRTM [0006] which also meet the limitations of claims 16 and 17. The composition utilizes amine curing agent (Abstract), wherein amine curing agents are also disclosed in Mizuki.
With respect to claim 6 and 9, suitable curing agent is MCDEA or 4,4’methylene-bis-(3-chloro-2,6-diethylaniline). MCDEA is an aliphatic amine curing agent and it can be utilized up to the amounts disclosed in Mizuki, who already teaches anilines that are also known as curing agents. Consequently, aniline or Meegan is a functional equivalent of the aniline of Mizuki.
In the light of the above disclosure, it would have been obvious to one having ordinary skill in the art at the time instant invention was filed to utilize curing agent of Meegan in the teachings Nguyen and still obtain the claimed invention because Mizuki teaches curing agents that contain amine group. One of ordinary skill in the art would also know that there are advantages associated with use MCDEA. Specifically, MCDEA as a highly effective curing agent for epoxies will enhance both mechanical and dynamic properties of the composition. MCDEA is also easy to process because of its low melting point.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claim 1-3, 5-9 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1-3, 5-10 of co-pending Application No. 18/021039 (‘039). Although the claims at issue are not identical, they are not patentably distinct from each other.
Claims 1 and 7 of copending application ‘039 discloses composition comprising:
50-95 wt.% of thermoset resin
1-15 wt.% of toughener comprising multistage polymer and a thermoplastic toughener
5-50 wt.% hardener
While claim 1 of ‘039 does not specify the glass transition temperature required by instant claims the double patenting rejection is still appropriate for two reasons: Reason 1, is that the multistage polymer of ‘039 is broader in scope and encompasses any glass transition temperature. Reason 2, per MPEP 804 specification can be used as a dictionary to learn the definition or a meaning of the term used in the claims. As such multistage polymer of ‘039 is the same as that of the instant invention. Additionally claim 1 of the instant invention is open to any hardener including that claim in ‘039. As such the limitations of instant claims 1 and 7 are met.
Claim 2 of ‘039 teaches that thermosetting resin is an epoxy which meets the limitation of instant claim 2.
Claim 3 of ‘039 teaches that epoxy resin includes difunctional epoxy resin, trifunctional epoxy resin, a tetrafunctional epoxy resin or mixtures thereof. This meets the limitations of instant claim 3.
Claim 4 of ‘039 teaches that the hardener is 4,4’methylene-bis-(3-chloro-2,6-diethylaniline), which meets the limitation of instant claim 6.
Claims 5 and 10 of ‘039 states that the thermoplastic toughener is polyether sulfone. This meets the limitation of instant claim 5.
Claims 6 and 9 of ‘039 discloses aromatic amine curing agent which meets the limitation of instant claim 9.
Claim 8 of ‘039 discloses amount of multistage polymer to be 5-10 wt. % and thermoplastic toughener in amount of 0.1-20 wt.% which encompasses amounts of instant claim 8.
This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented.
Correspondence
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/KATARZYNA I KOLB/Primary Examiner, Art Unit 1767 July 14, 2026
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