DETAILED ACTION
The present application is being examined under the pre-AIA first to invent provisions.
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.
Election/Restrictions
Applicant’s election of the invention of Group I, claims 1-7, in the reply filed on 2/10/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claims 8-14 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Takahashi et al, EP0514071, in view of Minematsu et al, US4361684.
Takahashi discloses the production of a thermoplastic resin composition comprising a copolymer (A) (abstract), wherein said copolymer (A) comprises 10 to 60 wt% methyl methacrylate, corresponding to the claimed (meth)acrylate monomer (for claim 1); 5 to 35 wt% acrylonitrile, corresponding to the claimed vinyl cyanide monomer (for claim 1), and 10 to 75 wt% α-methylstyrene, corresponding to the claimed vinyl aromatic monomer (for claim 1) substituted with a C1 alkyl group (for claim 4) (page 2: lines 55-56; page 3: lines 25-43).
Takahashi exemplifies a process wherein the monomers are polymerized in the presence of water, corresponding to the claimed water-based solvent (for claim 1), and 1.5 parts sodium dodecylbenzenesulfonate, corresponding to the claimed stabilizer (for claim 1).
Regarding the ratio of aromatic monomer to (meth)acrylate monomer: The prior art copolymer (A) comprises 10 to 75 wt% α-methylstyrene and 10 to 60 wt% methyl methacrylate. The ratio of aromatic monomer to methacrylate monomer therefore ranges from 10:60 to 75:10-i.e., 1:6 to 7.5:1, overlapping the claimed range (for claim 3)
It has been held that in the case where the claimed ranges overlap or lie inside ranges disclosed in the prior art, a prima facie case of obviousness exists; see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages; see In re Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 (" (MPEP § 2144.05). The ranges for the amounts of methyl methacrylate, acrylonitrile, and α-methylstyrene in Takahashi’s copolymer (A) overlap the claimed ranges. Barring a showing of evidence demonstrating unexpected results, it therefore would have been obvious to prepare a copolymer comprising the required amounts of each monomer in view of the prior art (for claims 1, 3).
Takahashi is silent regarding the claimed process steps wherein some of the aromatic monomer is added prior to the start of polymerization, followed by continuous feeding of the remainder of aromatic monomer starting when the temperature reaches 90 to 110 °C.
Minematsu discloses a process for the production of copolymers comprising α-alkyl substituted styrene and unsaturated nitrile monomer(s) (title, abstract), wherein said process can be performed by regulating the proportion(s) of each monomer added such that the concentration of unsaturated nitrile monomer is 31 wt% or more at the completion of the monomer addition. Minematsu teaches that regulating the monomer composition in such a manner improves productivity, and reduces the amount of unreacted monomer in the final product to 1 wt% or less (Column 3: lines 3-16). As said manner of regulating the amount of nitrile monomer, Minematsu specifically exemplifies a process wherein a portion of the monomer mixture is added to the reactor prior to polymerization, followed by the continuous addition of the remaining monomer over a period of 5 hours (Column 4: Example 2). Note that both the initial portion of monomer added prior to polymerization and the monomer portion added continuously contained α-methylstyrene, corresponding to the requirement that a portion of aromatic monomer is added in an initial batch followed by continuous addition (for claim 1).1111
Regarding the claimed polymerization temperature (for claims 1, 5) amount of solvent (for claim 1), mixing rate (for claim 5), reaction time (for claim 5), ratio of monomers (for claim 2), and pH (for clam 6): Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation"; see In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (MPEP 2144.05(II)(A)).
It is known in the art that reaction rate is dependent on temperature, generally increasing as temperature increases. Similarly, varying the amount of solvent and mixing speed will affect the reaction rate, as both tend to increase the frequency with which reactive molecules in the reaction mixture encounter one another. Finally, it would be obvious to vary reaction time to adjust the molecular weight, as longer times allow more monomers to link together resulting in longer chains. Barring a showing of evidence demonstrating unexpected results, it therefore would have been obvious to vary the polymerization conditions through routine experimentation in order to optimize the polymerization reaction rate and molecular weight of the final polymer (for claims 1, 5).
With regards to the ratio of monomers, Minematsu teaches that the rate at which the α-alkylstyrene monomer is added can be changed to regulate concentration of unsaturated nitrile monomer (Column 3: lines 20-25 and 45-48). It therefore would have been obvious to adjust the ratio of initial addition to continuous addition through routine experimentation to maintain the required nitrile concentration in the reactor (for claim 2).
With regards to the pH, Takahashi teaches that the reaction system is neutralized after polymerization (page 7: lines 32-33); i.e., the pH is adjusted. It is known in the art to reduce the pH after an emulsion polymerization to break the emulsion and coagulate the polymer particles for isolation and purification. Barring a showing of evidence demonstrating unexpected results, it would have been obvious to vary the pH of the reaction mixture through routine experimentation in order to optimize the isolation of the final polymer from the other components of the reaction mixture (for claim 6).
Takahashi teaches that the prior art copolymer (A) can be added via addition of the monomer(s) in portions (page 3: lines 53-56). As taught by Minematsu, it was known in the art that copolymerizing alkylstyrene monomers and unsaturated nitrile monomers via a process wherein the vinyl nitrile concentration is controlled by first adding a batch of monomers comprising a portion of the α-alkylstyrene monomer followed by continuous addition of all monomers results in improved productivity and reduced presence of unreacted monomers in the final polymer. Barring a showing of evidence demonstrating unexpected results, it therefore would have been obvious to modify the process of Takahashi by adding a portion of the α-alkylstyrene monomer in the initial batch, followed by continuous addition of the remainder to control the nitrile monomer concentration and reduce the presence of unreacted monomers in the final polymer (for claim 1).
Claim(s) 7 is rejected under 35 U.S.C. 103 as being unpatentable over Takahashi et al, EP0514071, in view of Minematsu et al, US4361684, as applied to claims 1-6 above, and further in view of Jung, KR1020000003096.
A machine translation of Jung was used for the preparation of this Action.
As discussed above, Takahashi a process wherein the monomers are polymerized in the presence of water, corresponding to the claimed water-based solvent (for claim 1), and 1.5 parts sodium dodecylbenzenesulfonate as a stabilizer.
Takahashi is silent regarding the use of a phosphate salt stabilizer.
Jung discloses the production of a copolymer of styrenic monomer, nitrile monomer, and acrylate monomer (page 1: 5th paragraph). Jung teaches that it was known that such copolymers can be prepared via aqueous suspension polymerization using calcium phosphate (for claim 7) as a stabilizer (page 2: last two paragraphs).
Takahashi and Jung are both directed towards the copolymerization of aromatic monomers and vinyl nitrile monomers via aqueous methods. As taught by Jung, calcium phosphate was a known stabilizer for such systems. Barring a showing of evidence demonstrating unexpected results, it would have been obvious to one of ordinary skill in the art to modify the teachings of Takahashi by using calcium phosphate as the stabilizer during the polymerization reaction.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Uchida et al, EP0188814, discloses a process for preparing a copolymer of an α-alkyl substituted aromatic monomer and a vinyl cyanide monomer, wherein said process comprises the addition of a first batch of monomer to the reactor prior to initializing polymerization, followed by continuous addition of additional monomer. Note that Uchida specifies that all of the aromatic monomer used to prepare the copolymer is added to the reactor as part of the first batch of monomer (abstract).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JEFFREY S LENIHAN whose telephone number is (571)270-5452. The examiner can normally be reached Mon.-Fri. 5:30-2:00PM.
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/JEFFREY S LENIHAN/Primary Examiner, Art Unit 1765
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