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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/28/2026 has been entered.
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:
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.
Claims 9-11 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Takao et al (JP 2018188610) in view of Hide et al (JP 2018024851), cited in the previous Office action.
Takao teaches a process of making polyarylene sulfide, which includes the preparation of first polyphenylene sulfide prepolymer using aqueous solution of sodium hydrosulfide, N-methyl-2-pyrrolidone (NMP) and p-dichlorobenzene (p-DCB) at 250C (see Reference Example 1).
Then the following method steps are used:
Step 1. The polar solvent is distilled off at 245 C, using the rectification column (see Reference Example 5). Alternatively, even though Takao does not teach distillation of organic polar solvent (i.e., NMP), the reference teaches an intensive stirring the reaction mixture at the temperature well above the boiling point of NMP for (boiling point is 204° C, while the reactor heated for 250° C, meeting the limitations of claim 10). Thus, at least part of NMP is evaporated (see Reference Example 1).
Step 2. The polymer is precipitated with water, filtered and then washed with water and vacuum dried at 80 ° C overnight to obtain a dry solid (see Reference Example 1). Note that even though Takao fails to teach water content at the finish of this step, the term ”dry solid” and drying conditions suggest that amount of water in the powder is less than 30% wt. (meeting the limitations of claim 11).
Note that a common vacuum dryer is also used by Applicant in the step above (see printed publication at 0087).
Step 3. The obtained solid was charged into a cylindrical filter paper, and Soxhlet extraction was performed for about 5 hours using chloroform as a solvent to separate low molecular weight components contained in the solid.
Note that even though Toray does not teach exact amount of chloroform extractables at the finish of the step above, it is clear that very low number of them left after intense Soxhlet extraction.
Note that in order to measure chloroform extractables, Applicant uses Soxhlet extraction for 3 hours (see printed publication at 0039), while Toray uses such extraction for 5 hours.
Therefore, it would have been obvious to a person of ordinary skills in the art before the effective filing date of the invention to expect the claimed value of chloroform extractables in Takao’s polymer, since the polymer underwent an extensive chloroform extraction using Soxhlet apparatus for an appropriate time period.
Step 4. After removing the solvent from the extract obtained by the chloroform extraction operation, about 5 g of chloroform was added to prepare a slurry, which was added dropwise to about 600 g of methanol while stirring. The precipitate thus obtained was collected by filtration and vacuum dried at 70 ° C for 5 hours to obtain a white powder (meeting the corresponding limitations of claim 14).
Note that Applicant is also used vacuum dryer for the distilling off of the organic solvent in Step 4 (see printed publication at 0112).
Takao fails to teach a solvent distillation step and heating under inert gas flow.
Hide teaches a method of making a polyarylene sulfide having a weight average molecular weight of
5,000 or more and 50,000 or less (see claim 1) comprising reacting a mixture containing a sulfidating
agent with p-dichlorobenzene (p-DCB) in N-methyl-2-pyrrolidone (NMP) at 200-250°C in autoclave
under Nitrogen blanket.
Then, after cooling to 230 °C over about 15 minutes, by gradually opening the high-pressure valve
installed at the top of the autoclave and the vapors mainly composed of NMP were discharged (meeting the limitations of claims 10 and 13).
In reference to claim 11, Hide teaches that the reaction started in the solution comprising more than
600 g of liquid and about 30 g of solids. During the distillation, 394 g of liquid components were
removed. Thus, total solid content in remaining composition constituted less than 30% wt. As a result
of GPC measurement, the number average molecular weight was 4,300, the weight average molecular
weight was 11,000, and molecular weight distribution was 2.6. The melt viscosity at 320 C was 0.7 Pa
S. The oligomer component content was 0.30% by weight (see Reference Example 1).
Regarding drying Step 4 of claim 9, Hide teaches a procedure, where 2 g of the polyphenylene sulfide
charged into a test tube and Nitrogen gas was purged at a flow rate of 100 ml / min for at 320 C for 1
hour (see Example 1). Thus, corresponding limitation of claim 9, requiring 200 ml/min of inert gas per
1000 g of the polymer is met.
In general, Hide teaches that flow rate of the gas flowing into the system per minute is preferably at
least 100% of the volume in the system from the viewpoint of the effect of removing components in the
gaseous state.
The position is taken that the distillation step and drying under nitrogen represent widely used
techniques. Along with vacuum drying it is a most commonly used procedure in the industry.
Therefore, it would have been obvious to a person of ordinary skills in the art to use distillation step
and drying under nitrogen in Takao's method, since they are commonly used in commercial
applications.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Takao in view of Hide as applied to claims 9-11 above as evidences Mizuno et al (JP 2775635), cited in the previous Office action.
Takao and Hide do not teach the specific surface area of the polyarylene sulfide.
Mizuno teaches a method of obtaining a polyarylene sulfide by a reaction of alkali metal sulfide with a
dichloro aromatic compound in an organic amide solvent such as N-methylpyrrolidone in the presence
of water.
The resulting polymer having a BET specific surface area of about 10 cm 2 by nitrogen adsorption / g
powder discharged (meeting the limitations of claim 12) was washed three times with acetone and then
washed five times with cold water to form a sheet.
The position is taken that since Takao and Hide has the identical or analogous conditions for polyarylene sulfide, the resulting polymer powder is expected to have the same morphology as Mizuno’s one.
The claiming of a new use, new function or unknown property, which is inherently present in the prior art, does not necessarily make the claim patentable. In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977).
Therefore, it would have been obvious to a person of ordinary skills in the art before the effective filing date of the invention to expect the same morphology from Takao’s, Hide’s and Mizuno’s polymer powders, since they obtained at the same or analogous conditions.
Note that Mizuno teaches that the method above obtained a PPS sheet of not more than 1.5% by weight or even 0.6 to 0.7% by weight of chloroform extractables.
Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Takao in view of
Hide as applied to claims 9-11 above, and further in view of Tsuchiya et al (JP 5423038), cited in
the previous Office Action.
Takao and Hide fail to teach molecular characteristic of claim 15 and particle size of the final polymer particles of claim 16.
Tsuchiya discloses a method of making a polyarylene sulfide having a weight average molecular weight
of 5,000 or more and 50,000 or less comprising reacting a mixture containing a sulfidating agent with p-
dichlorobenzene (p-DCB) in N-methyl-2-pyrrolidone (NMP) at 210 in autoclave under Nitrogen blanket.
After the reaction completion, solvent is distilled off at 235°C over about 3 hours while passing nitrogen
at normal pressure (see Reference Example 1).
After drying, polyarylene sulfide with particle size from 1 to 200 µm was obtained.
Tsuchiya teaches that the method above allows to produce a polyarylene sulfide with reduced impurity
content (see Abstract).
Therefore, it would have been obvious to a person of ordinary skills in the art to modify Takao's
polyarylene sulfide production method with Tsuchiya's distillation in order to obtain a polymer with low
amount of impurities.
Note that since modified Takao's and Applicant's method have the same process steps, the same
physical characteristics of the resulting polyarylene sulfide are expected.
Thus, it would have been obvious to a person of ordinary skills in the art to expect the physical
properties of claim 15 for polymer, obtained by modified Takao's procedure, since it has all the
essential steps of the claimed polymer synthesis, recited in instant claim 1.
Response to Arguments
Applicant arguments regarding Mizuno’s disclosure are moot, since rejection under 35 USC 103 over Mizuno in view of Hide is withdrawn as a result of Applicant’s arguments. . New rejection under 35 USC 103 over Takao et al (JP 2018188610) in view of Hide et al (JP 2018024851) is created.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to GREGORY LISTVOYB whose telephone number is (571)272-6105. The examiner can normally be reached 9am-5pm EST M-F.
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GL
/GREGORY LISTVOYB/Primary Examiner, Art Unit 1765
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