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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 7/29/2026 has been entered.
Claims 1-20 are pending in the application. Claims 12-20 have been withdrawn from consideration as being directed to a non-elected invention. Claims 1-11 are rejected.
The rejections over Kristy in view of Friedman, Harper and Wu; and further in view of Nicholson have been maintained.
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.
Claims 1-5, and 7-11 are rejected under 35 U.S.C. 103 as being unpatentable over US 2022/0294044 to Kristy et al. (hereinafter “Kristy”) in view of US 5,534,593 to Friedman (hereinafter “Friedman”), US 4,433,069 to Harper (hereinafter “Harper”), and US 2022/0169814 to Wu et al. (hereinafter “Wu”) as evidenced by PLASKOLITE UL 94 flame ratings.
Claim 1 is directed to a silicone foam layer comprising components A and B, not a composition for forming a silicone foam layer. Since the claim is not specific about a mixing ratio of A to B, the examiner interprets the mixing ratio of A to B is 1:1. Therefore, the silicone foam layer of the claimed invention contains 5-30 wt% of a first filler of alumina trihydrate (ATH), 1-15 wt% of a second filler of perlite, 1-20 wt% of third filler of calcium carbonate and 0.5-10 wt% of a fourth filler of zinc borate. The components A and B contain said fillers and these carry through to the final foam product. Therefore, the absence of the fillers in the component B does not add patentable weight with respect to the foam product claim. If the final product of the prior art silicone foam contains the fillers and their contents within the claimed ranges, the distinctions in the intermediate components A and B of the prior art silicone foam do not render the claim unobvious.
Kristy discloses a multilayer composite comprising: a silicone foam layer comprising components A and B, disposed between two release layers (paragraph 99). Component A contains 5-40 wt% of ATH and 5-40 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate, each based on the total weight of component A (paragraph 69). Kristy teaches that the ATH, the zinc borate, and the hydrous sodium silicate are “reactive” fillers because they can generate water upon exposure to fire. The generating water can absorb heat to prevent thermal runaway (paragraph 48). Additionally, the reactive fillers render the silicone foam flame retardant due to formation of a thermal barrier layer upon exposure to a heat source. The reactive fillers remain inert during curing and foaming of the silicone foam layer but become reactive upon exposure to fire. The ATH, the zinc borate, and the hydrous sodium silicate which are incorporated in the component A carry through to the final foam product.
Kristy does not disclose the component B comprising the fillers as presently claimed. However, the reactive fillers in the component A carry through to the final foam product. Therefore, lack of the reactive fillers in the intermediate component B is found irrelevant to determining patentability of the foam product claim. Since the silicone foam layer contains the fillers and their contents within the claimed ranges, the distinction in the intermediate component B will not affect the non-obviousness of the final foam product claim.
Given that a mixing ratio of A:B is 20:1 (paragraph 112), the silicone foam layer approximately includes 5-40 wt% of ATH, 5-30 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate. These overlap the claimed ranges.
Kristy teaches that the component A includes a thermally insulating fillers comprising calcium carbonate (paragraph 72).
According to PLASKOLITE UL 94 flame ratings, UL 94 5VA is a significantly higher and more stringent flame-retardant rating than UL 94 V-0.
PNG
media_image1.png
491
684
media_image1.png
Greyscale
As shown in tables 7 and 8, the silicone foam layer of Kristy passes the UL 94 5VA test (tables 7 and 8) as the highest and most flame-retardant level of the UL 94 ratings. The examiner takes the position that the silicone foam layer would inherently pass the UL 94 V-0.
As shown in figure 9 and table 2, the silicone foam layer has a cold side temperature of 200oC at 5 min when a 3 mm thickness of the silicone foam layer is exposed to a hot plate test at 650oC.
Kristy does not explicitly disclose (i) a first polymethylpentene liner; and (ii) component A and component B, each comprising 1-15 wt% of perlite, and 1 to 20 wt% of calcium carbonate.
Friedman, however, discloses a release film obtained from a composition comprising polymethylpentene (TPX) and polypropylene and having an improved tensile strength, elongation and release properties (abstract).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use a polymethylpentene/ polypropylene release film disclosed in Friedman for the release layer disclosed in Kristy motivated by the desire to provide a multilayer composite having an improved tensile strength, elongation and release properties.
Harper, however, discloses a silicone foam exhibiting superior flame-retardant properties, comprising 2.5 wt% of glass fibers and 5.0 wt% of perlite and at least 5 ppm of platinum catalyst (abstract; and table 2, sample I).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to include perlite and glass fibers disclosed in Harper in the silicone foam layer disclosed in Kristy motivated by the desire to enhance flame retardant properties for the multilayer composite.
Wu, however, discloses a silicone foam comprising components A and B wherein component A comprises at least one polyorganosiloxane having at least one vinyl group, at least one chemical blowing agent; and at least one catalyst; wherein component B comprises at least one polyorganosiloxane having at least one vinyl group, at least one polyorganosiloxane having at least one SiH group, and at least one expandable graphite (paragraphs 11-18). The silicone foam further includes 2-40 wt% of additional filler including calcium carbonate, based on the total weight of the component A (paragraph 93). This overlaps the claimed range.
In the case, where the claimed ranges overlap or touch the range disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257,191 USPQ90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
The claim is not rendered unobvious because discovering the optimum or workable ranges involves only routine skill in the art. Difference in a content of the calcium carbonate will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such a content of the calcium carbonate is critical or provides unexpected results.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to add the calcium carbonate of Kristy in the component A in an amount as disclosed in Wu, motivated by the desire to enhance flame retardant properties for the multilayer composite.
Alternatively, even if assuming that Kristy does not teach the silicone foam layer having (i) a V-0 flammability rating; and (ii) a cold side temperature of not greater than 300oC as measured at 5 mins when a 3 mm thickness of the silicone-based foam layer is exposed to a hot plate test, which the examiner does not agree for the reasons discussed above, the claim is not rendered unobvious in view of the combination of Kristy, Friedman, Harper and Wu.
It appears that the combined disclosures of Kristy, Friedman, Harper and Wu result in a multilayer composite meeting all structural limitations and chemistry required by the claims.
It appears that the combined disclosures of Kristy, Friedman, Harper and Wu result in a multilayer composite meeting all structural limitations and chemistry required by the claims.
The resulting multilayer composite comprises: a polymethylpentene release liner, and a silicone foam layer comprising components A and B. Component A contains 5-40 wt% of ATH, 5-40 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate, each based on the total weight of component A. Given that a mixing ratio of A:B is 20:1, the silicone foam layer approximately includes 5-40 wt% of ATH, 5-30 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate.
The resulting component A also includes 2-40 wt% of the calcium carbonate, 2.5 wt% of the glass fibers, and 5 wt% of the perlite.
Therefore, the examiner takes the position that the V0 flammability rating as measured according to ASTM D3801; and the cold side temperature of not greater than 300oC would be inherent to the silicone foam layer as like material has like property.
As to claims 2 and 3, Kristy discloses that the component A comprises a pigment (paragraph 72). However, Kristy does not explicitly disclose the amount of the pigment being incorporated in the component A.
Wu, however, discloses a silicone foam comprising components A and component B wherein component A comprises at least one polyorganosiloxane having at least one vinyl group, at least one chemical blowing agent; and at least one catalyst; wherein component B comprises at least one polyorganosiloxane having at least one vinyl group, at least one polyorganosiloxane having at least one SiH group, and at least one expandable graphite (paragraphs 11-18). The silicone foam further includes 2-40 wt% of additional filler including a pigment, based on the total weight of the component A (paragraph 93). This overlaps the claimed range.
In the case, where the claimed ranges overlap or touch the range disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257,191 USPQ90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
The claim is not rendered unobvious because discovering the optimum or workable ranges involves only routine skill in the art. Difference in a content of the pigment will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such a content of the pigment is critical or provides unexpected results.
Therefore, in the absence of unexpected results, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to add the pigment of Kristy in the component A in an amount in the range disclosed in Wu, motivated by the desire to provide a desired color for the silicone foam layer. This is in line with In re Aller, 105 USPQ 233 which holds discovering the optimum or workable ranges involves only routine skill in the art.
As to claim 4, Kristy discloses that component A comprises 50 wt% of a vinyl-PDMS (tables 1 and 2).
As to claims 5, 8 and 9, Kristy discloses that component A comprises 90-20 wt% of a polysiloxane and 10-80 wt% of the reactive filler wherein the polysiloxane comprises a blend of a vinyl polysiloxane and a hydride polysiloxane (paragraphs 62 and 66). The hydride polysiloxane reads on the claimed resin solution. The contents of the vinyl polysiloxane and the hydride polysiloxane thus overlap the claimed ranges.
In the case, where the claimed ranges overlap or touch the range disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257,191 USPQ90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
The claim is not rendered unobvious because discovering the optimum or workable ranges involves only routine skill in the art. Differences in the contents of the vinyl polysiloxane and the hydride polysiloxane will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such the contents of these polysiloxane resins are critical or provide unexpected results.
Therefore, in the absence of unexpected results, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use the contents of the vinyl polysiloxane and the hydride polysiloxane in the ranges instantly claimed, motivated by the desire to allow ready incorporation of the reactive fillers in the foamable composition while producing the desired siloxane foam. This is in line with In re Aller, 105 USPQ 233 which holds discovering the optimum or workable ranges involves only routine skill in the art.
As to claim 7, Kristy discloses that the component A comprises 0.31 wt% of a benzyl alcohol as a foaming agent (paragraph 99 and table 2). This is within the claimed range.
As to claim 10, Kristy discloses that the component A comprises 0.008 wt% of a Pt catalyst (table 2). Kristy does not explicitly disclose component A comprising a Pt catalyst at a content of at least 0.02 wt%.
Wu, however, discloses a silicone foam comprising components A and B wherein component A comprises at least one polyorganosiloxane having at least one vinyl group, at least one chemical blowing agent; and at least one catalyst; wherein component B comprises at least one polyorganosiloxane having at least one vinyl group, at least one polyorganosiloxane having at least one SiH group, and at least one expandable graphite (paragraphs 11-18). The silicone foam further includes 2-40 wt% of additional filler including calcium carbonate and/or pigment based on the total weight of component A (paragraph 93). The silicone foam also includes 0.1 to 0.5 wt% of a Pt catalyst based on the total weight of the component A (paragraph 60).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to incorporate the component A Pt catalyst disclosed in Kristy in an amount in the range disclosed in Wu, motivated by the desire to promote the reaction of SiH groups with vinyl groups to provide hydrogen gas necessary for the foaming process.
As to claim 11, Kristy discloses that the component A comprises 0.008 wt% of a Pt catalyst (tables 1 and 2). This is within the claimed range.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Kristy in view of Friedman, Harper, Wu as applied to claim 1 above, further in view of US 6,084,002 to Nicholson et al. (hereinafter “Nicholson”).
Kristy discloses that the component A comprises 0.31 wt% of a benzyl alcohol as a foaming agent (paragraph 99 and table 2). However, Kristy does not explicitly disclose the silicone foam comprising an alcohol foaming agent in an amount of at least 1 wt% based on the total weight of component A.
Nicholson, however, discloses a flame-retardant silicone foam obtained from composition comprising vinyl polyorganosiloxane, hydride polyorganosiloxane, a benzyl alxohol foaming agent, a Pt catalyst and wollastonite (abstract, and example 2). In particular, the flame-retardant silicone foam comprises 0.4-3.8 wt% of the benzyl alcohol.
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to incorporate the component A benzyl alcohol foaming agent disclosed in Kristy in an amount in the range disclosed in Nicholson, motivated by the desire to achieve a desired foaming rate, thereby giving excellent cell structure.
Response to Arguments
Applicant alleges that the claim is not rendered obvious in view of the combined disclosures of Kristy, Friedman, Harper and Wu because the combination of the cited references fails to teach or suggest the silicone foam layer comprising (i) a V-0 flammability rating; and (ii) a cold side temperature of less than 300oC as measured at 5 min when a 3 mm thickness of the silicone foam layer is exposed to a hot plate test at 650oC.
The examiner respectfully disagrees.
According to PLASKOLITE UL 94 flame ratings, UL 94 5VA is a significantly higher and more stringent flame-retardant rating than UL 94 V-0.
PNG
media_image1.png
491
684
media_image1.png
Greyscale
As shown in tables 7 and 8, the silicone foam layer of Kristy passes the UL 94 5VA test (tables 7 and 8) as the highest and most flame-retardant level of the UL 94 ratings. The examiner takes the position that the silicone foam layer would inherently pass the UL 94 V-0 test.
As shown in figure 9 and table 2, the silicone foam layer has a cold side temperature of less than 200oC at 5 min when a 3 mm thickness of the silicone foam layer is exposed to a hot plate test at 650oC.
Alternatively, even if assuming that Kristy does not teach the silicone foam layer having (i) a V-0 flammability rating; and (ii) a cold side temperature of not greater than 300oC as measured at 5 mins when a 3 mm thickness of the silicone-based foam layer is exposed to a hot plate test, which the examiner does not agree for the reasons discussed above, the claim is not rendered unobvious in view of the combination of Kristy, Friedman, Harper and Wu.
It appears that the combined disclosures of Kristy, Friedman, Harper and Wu result in a multilayer composite meeting all structural limitations and chemistry required by the claims.
The resulting multilayer composite comprises: a polymethylpentene release liner, and a silicone foam layer comprising components A and B. Component A contains 5-40 wt% of ATH, 5-40 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate, each based on the total weight of component A. Given that a mixing ratio of A:B is 20:1, the silicone foam layer approximately includes 5-40 wt% of ATH, 5-30 wt% of zinc borate, and 5-30 wt% of hydrous sodium silicate.
The resulting component A also includes 2-40 wt% of the calcium carbonate, 2.5 wt% of the glass fibers, and 5 wt% of the perlite.
Therefore, the examiner takes the position that the V0 flammability rating as measured according to ASTM D3801; and the cold side temperature of not greater than 300oC would be inherent to the silicone foam layer as like material has like property.
Applicant states that Kristy fails to teach component B independently comprising alumina trihydrate, perlite, calcium carbonate and zinc borate at the recited weight percentages.
The absence of the fillers in component B does not add patentable weight with respect to the foam product claim because claim 1 is not directed to a composition comprising A and B, but a silicone foam layer comprising A and B.
Since the claim is not specific about a mixing ratio of A to B, the examiner interprets the mixing ratio of A to B is 1:1. Therefore, the silicone foam layer of the claimed invention contains 5-30 wt% of a first filler of alumina trihydrate (ATH), 1-15 wt% of a second filler of perlite, 1-20 wt% of third filler of calcium carbonate and 0.5-10 wt% of a fourth filler of zinc borate. The fillers in both components A and B remain inert during foaming and curing of the foam layer, and carry through the final product of the foam layer. Therefore, the absence of the alumina trihydrate, perlite, calcium carbonate and zinc borate in component B does not add patentable weight with respect to the foam product claim. If the final product of the prior art silicone foam contains the fillers and their contents within the claimed ranges, the distinctions in the intermediate components A and B of the prior art silicone foam do not render the claim unobvious.
Accordingly, the rejection over Kristy in view of Friedman, Harper and Wu has been maintained.
Applicant has reiterated positions taken with respect to the other rejection: Kristy in view of Friedman, Harper and Wu, and Nicholson, the examiner’s comments set forth above are equally pertinent in support of this rejection as well.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Hai Vo whose telephone number is (571)272-1485. The examiner can normally be reached M-F: 9:00 am - 6:00 pm with every other Friday off.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Alicia Chevalier can be reached at 571-272-1490. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Hai Vo/
Primary Examiner
Art Unit 1788
Prosecution Insights