DETAILED ACTION
This office action follows a reply filed on November 25, 2025. Claims 1-2, 6, 11 and 13 have been amended. Claims 1-2, 6-7, 11 and 13 are currently pending and under examination.
The texts of those sections of Title 35 U.S. Code are not included in this section and can be found in a prior Office action.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
Claims 1-2, 6, 8, 11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Dhruv (US 8,053,548) in view of Bandyopadhyay (US 2019/0153241), as evidenced by Letailleur (US 9,752,031).
Dhruv teaches preparing an elastomer by mixing the following (col. 3, ll. 34-66):
PDMS polymer base comprising 30-60 wt% dimethylvinylated and trimethylated silica, 1-5 wt% tetra(trimethylsiloxy)silane and balance of dimethylvinyl terminated dimethyl siloxane;
Curing agent comprising 40-70 wt% dimethyl methylhydrogen siloxane, 15-40 wt% dimethyl siloxane dimethylvinyl-terminated, 10-30 wt% dimethylvinylated and trimethylated silica and 1-5 wt% tetramethyl tetravinyl cyclotetrasiloxane; and
A polyethylene oxide polymeric surfactant additive having the formula
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534
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.
The PDMS base which includes vinyl terminated polydimethylsiloxane meets applicants’ component (A), the curing agent which includes a silicon-hydrogen containing polydimethylsiloxane meets applicants’ component (B), the combination of components (A) and (B) meets applicants’ liquid silicone rubber and the surfactant meets applicants’ polyethylene glycol derivative.
As to the weight ratio of component (A) to component (B), Dhruv teaches that mixing ratios of 10:1:(0.1-0.5) (PDMS base: curing agent: polymeric surfactant additive) have been successfully employed, but the ratio may be varied from 1-20 PDMS to achieve different degrees of elasticity.
This suggests a ratio of component A to component B of 1-20:1, which overlaps with the claimed range of (0.5-1):(0.5-1), which is the same as (0.3-3):1, and it has been held that overlapping ranges are sufficient to establish prima facie obviousness. See MPEP 2144.05.
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to have selected from the overlapping portion of the range taught by the reference because overlapping ranges have been held to establish prima facie obviousness.
Dhruv teaches that the surfactant is used to reduce the water contact angle of the surface of the PDMS, but does not teach or suggest the inclusion of silicone oil, as claimed.
Bandyopadhyay teaches non-stick siloxane compositions, teaching the polymer as comprising one or more silanizing agents to render the polymer more hydrophobic/oleophobic, reaching that there is an increased ability of the treated polymer to retain lubricating fluids applied to it and increased oleophobicity and/or hydrophobicity, as reflected in reduced contact angles for water. Bandyopadhyay teaches the lubricating fluids to include silicone oils (p. 5, [0036]-[0037]). Bandyopadhyay further teaches that the lubricating fluid can be added to the polymerizable monomers/oligomers used to prepare the silicone elastomers (p. 5, [0040]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have included a lubricating fluid in the polymerization of the composition of Dhruv, as Bandyopadhyay teaches that the use of such can further adjust the hydrophobicity of the surface of PDMS.
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have incorporated silicone oils as a lubricating fluid in the PDMS composition of Dhruv, as Bandyopadhyay teaches that the inclusion of such can be further used to control the hydrophilic/hydrophobic properties of the composition, which is desired by Dhruv.
As to the crosslinked structure of the elastomer, Dhruv teaches that the surfactant is combined with the PDMS base and curing agent during polymerization, disclosing that the van der Waals force and hydrophobic interactions between the PDMS monolith and PDMS segments in the polymeric surfactant additives stabilize the surfactant at the polymer surface, resulting in a hydrophilic coating, further disclosing that the surface fraction of PEO on the PDMS surface is controlled by the crosslinking density of the PDMS (col. 4, ll. 22-33). Therefore, the curing results in the permanent bonding of the surfactant to the PDMS polymer base, as well as crosslinking of the PDMS.
Letailleur teaches the following (col. 1, ll. 42-46) and cites Dhruv:
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Therefore, the composition of Dhruv inherently prevents fouling, meeting applicants’ germ-repellent limitation.
Dhruv in view of Bandyopadhyay is prima facie obvious over instant claims 1-2.
As to claim 6, Dhruv discloses using the PDMS to prepare electrical insulators and tubes, which are known in the art as being formed by way of extrusion.
As to claims 8 and 11, Dhruv teaches the weight ratio of the PDMS base:polymeric surfactant additive as 10:(0.1-0.5), or 100:1-5, which is sufficiently specific to anticipate the claimed range of 100:(2-3).
As to claim 13, Bandyopadhyay teaches the lubricating fluid in an amount of greater than 1-60 wt% of the total weight of the monomers, oligomers and polymers used to prepare the silicone elastomer (p. 17, [0150]). This range overlaps with the claimed range of 40-60 w%, and it has been held that overlapping ranges are sufficient to establish prima facie obviousness. See MPEP 2144.05.
Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to have selected from the overlapping portion of the range taught by the reference because overlapping ranges have been held to establish prima facie obviousness.
Response to Arguments
Applicant's arguments filed November 25, 2025 have been fully considered but they are not persuasive.
Applicants argue that Letailleur focuses on siloxane compositions with hydrophilic surface, not germ-repellency.
Letailleur specifically mentions Dhruv, and teaches that the PDMS-PEO prevents the adsorption of proteins and the fouling which ensues, and prevents bacterial proliferation. This in itself suggests bacterial repellency, as bacteria is a type of germ.
Additionally, please consider the following reference as additional evidence that PDMS-PEO is used to prevent biofoulant adsorption, where the word biofoulant is defined as microorganisms, like bacteria, which can accumulate on a surface, leading to degradation of the surface below. This suggests applicants’ germ-repellency: Zhao (Engineering amphiphilic membrane surfaces based on PEO and PDMS segments for improved antifouling performances, Journal of Membrane Science, 450, 2014, pp. 111-123).
Applicants argue that Bandyopadhyay relates to antistick coating, not germ repellent coatings.
While the examiner agrees, Bandyopadhyay teaches that silicone oil is added to control the hydrophilic/hydrophobic properties of the composition, which is responsible for preventing the biofoulant adsorption. Therefore, one of ordinary skill in the art would expect the inclusion of such to further improve the bacterial repellency of the coating.
Additionally, it is known to add silicone oil to polysiloxane fouling-release coatings to further enhance the fouling-release properties, as evidenced by Chisholm (US 2012/0255480, p. 2, [0025]).
Applicants have not provided evidence that the prevention of the adsorption of proteins and the fouling, and the prevention of bacterial proliferation does not meet the claimed limitation “germ-repellent”.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIEANN R JOHNSTON whose telephone number is (571)270-7344. The examiner can normally be reached Monday-Friday, 8:00 AM - 4:00 PM EST.
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/Brieann R Johnston/Primary Examiner, Art Unit 1766