DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 July 21, 2026 has been entered.
Specification
The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
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.
Claims 1, 3-5, 7, 9, 12, 19-20, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942). Regarding claims 1 and 19, Nordberg teaches a method for producing a high silicate glass substrate comprising obtaining a glass precursor comprising SiO2, B2O3, Al2O3, and Na2O (section (3) on page 2), applying a first heat treatment to the glass precursor to cause phase separation so as to obtain a phase-separate glass, applying acid treatment to the phase separated glass to obtain a porous glass, drying the porous glass (section (1) on page 1), and applying a second heat treatment to sinter the porous glass so as to obtain a high silicate glass substrate, wherein the B2O3 content in the high silicate glass substrate is 3 wt.%, or about 21 mol% (section (3) on page 2). Regarding the drying step, Nordberg teaches the wet porous glass after phase separation has about 25wt% of water and retains about 3-6% water after drying (section (2) on page 1), which appears to suggest the percentage of change in mass is about 19-22 wt%, which is in the range of 10% to 50%.
Norberg teaches the glass is a borosilicate glass and the precursor composition should be selected to allow for phase separation while also leaving the glass substrate whole (bottom of (1) on page 1), but doesn’t suggest a glass precursor composition. Like Norberg, Takashima teaches a method for producing a high silicate glass, the method comprising obtaining a borosilicate glass precursor, applying a first heat treatment to the glass precursor to cause phase separation so as to obtain a phase-separate glass ([0026], [0032]), and applying acid treatment to the phase separated glass to obtain a porous glass ([0041], [0044]). Takashima teaches for a borosilicate glass used for phase separation, a borosilicate glass mainly containing silicon oxide, boron oxide, and an alkali metal oxide is generally used ([0003], [0026]), such as SiO2 - B2O3 - Na2O - Al2O3 - based glass and SiO2 - B2O3 -CaO - Na2O - Al2O3 - based glass ([0027]). Furthermore, Takashima provides specific examples, such as example (2) comprising the following, which falls within the claimed ranges.
wt%
mol%
claimed ranges
SiO2
63
66.4%
60%-75%
B2O3
27
24.6%
15% -30%
Na2O
7
7.2%
1%-10%
Al2O3
3
1.9%
1.5% - 15%
Takashima the teaches the glass precursor composition predictably provides for phase separation of the glass while leaving the glass substrate whole ([0079]). As can be seen, in the table, the glass precursor does not contain TiO2 or ZrO2. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have employed a similar glass precursor for the method of Nordberg as it predictably provides for a glass composition that can be successfully phase separated while leaving the glass substrate whole, as taught by Takashima.
As mentioned, Takashima teaches borosilicate glass mainly containing silicon oxide, boron oxide, and an alkali metal oxide is generally used, and exemplifies sodium oxide as the alkali metal, as seen above. Although not specified, potassium oxide is a well known alkali metal oxide in glass precursor compositions as well, as made evident by Borrelli. Borrelli also teaches a borosilicate glass composition that is used for phase separation to produce a porous glass ([0008]), wherein the main constituents comprises SiO2, B2O3, Al2O3, and an alkali metal oxide ([0056]). Borrelli teaches the addition of a phosphorus content in the glass precursor increases the chemical activity of the porous glass due to accessible surface hydroxyl groups ([0055]). Borrelli further teaches substituting potassium for sodium to increase the phosphorus content, as this discourages or prevents the formation of a sodium borate phase in the glass ([0059]). Borrelli shows in table 1 examples wherein the Na2O (examples OVH to OVR) was replace with K2O (examples OVS and 741II to 741IK), and the corresponding porosity data for the examples in table 3. As can be seen in table 3, the porosity of the glass is enhanced for example 741 II, the glass wherein Na2O was substituted with K2O, resulted in higher porosity. In essence, Borrelli teaches K2O is a known alternative for Na2O, and using K2O instead can promote higher porosity of the porous glass, and thereby increased chemical activity of the porous glass. Accordingly, for these reasons it would have been obvious to one of ordinary skill in the art at the time of the invention to have alternatively provided for K2O as the alkali metal oxide component of the glass precursor of Takashima. Naturally, in substituting Na2O with K2O in the borosilicate glass precursor composition of Takashima, the glass precursor would not contain Na2O.
Regarding claim 3, Takashima teaches an example for the glass precursor with a rectangular shape having an aspect ratio of 1090 (40mmX30mm/1.1mm), which falls within the claimed range of 500-36000 ([0054]).
Regarding claim 4, Nordberg specifies the glass substrate produced goes by the brand of VYCOR®. However, Nordberg and Takashima are silent regarding a P2O5 content in the glass precursor. Borrelli teaches a porous glass, such as VYCOR® glass, made by phase separating a borosilicate glass and treating with acid ([0003]). Borrelli teaches VYCOR® glass has high porosity and typically comprises of P2O5 ([0006], [0011]), wherein the phosphorus content provides for increased chemical activity of the porous glass due to accessible surface hydroxyl groups ([0055]). Borrelli specifies the P2O5 can be added in place of silica, alumina, or borate in equivalent amounts, i.e. mole percent ([0056]). Borrelli suggest a P2O5 content in the range of 2-25 wt%. In the OVK example in Table 1, the P2O5 content is 7.63 wt%, which when converted is 1.7mol%, which falls within the claimed range of 0.1 mol%-3 mol%. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided (or expected) a similar amount of P2O5 content of 1.7 mol% in the glass precursor of Nordberg, to enhance the chemical activity of the glass, as P2O5 allows for accessible surface hydroxyl groups in the glass, as taught by Borrelli.
Regarding claim 5, Nordberg teaches melting the glass precursor and then shaping the molten glass to the desired shape (section (1) on page 1).
Regarding claim 7, Nordberg teaches drying is performed at room temperature, which is typically 20°-22°C.
Regarding claim 9, Nordberg is silent regarding the temperature for the acid treatment. Takashima further teaches the acid treatment is performed at a temperature in the range of room temperature to 95°C ([0045]), and exemplifies a solution at 80°C ([0061]). Takashima teaches this provided successful production of the porous glass ([0062]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for similar temperatures for the acid treatment step, as Takashima teaches it predictably provides for successful leaching of the boron oxide-rich phase and producing a porous glass.
Regarding claim 12, both Nordberg and Takashima teach the glass precursor comprises SiO2, B2O3, Na2O, and Al2O3, which suggests the glass precursor has no chlorine.
Regarding claim 19, in the example provide above, Takashima teaches the Al2O3 content is 1.9 mol%, which is close to 2 mol%. Takashima further teaches the metal oxides content can be 15 wt% or less ([0031]), which would provide for an Al2O3 content that overlaps with the claimed range of 2 mol% to 15 mol%.
Regarding claim 20, Nordberg teaches the high silicate glass substrate comprises about 0.4wt% of Al2O3 (section (3)), which provides for 0.19 mol% of Al2O3.
Regarding claim 22, both Nordberg and Takashima teach the glass precursor comprises SiO2, B2O3, Na2O, and Al2O3, which suggests the high silicate glass substrate has no amount of OH-groups.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of GCP (VYCOR® Pro Data Sheet, 2018). Nordberg specifies the glass substrate produced goes by the brand of VYCOR®. Commercial glass sheets used in the building industry, sold under the tradename of VYCOR®, comes in typical sizes that is greater than 300 cm2, such as 75 ft rolls that are 4 inches wide, as made evident by GCP. Accordingly, it would have been obvious to one ordinary skill in the art at the time of the invention to have provided for porous glass sheets with a base area of greater than 300cm2, as there is a demand for such sizes in the building industry.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 5 above, and further in view of Tanii et al. (KR 20190033442 machine translation provided). Nordberg teaches obtaining the glass precursor by melting, and shaping in known conventional manner, including tank melting and drawing (section (1) on page 1), which suggests performing the steps continuously in a refractory tank. Similarly, Tanii teaches an efficient means for producing glass plates comprising melting a borosilicate glass precursor, and shaping the molten glass on a float bath, thereby producing a glass ribbon that can be cut into a plate shape. Thus, the shaping of the glass precursor occurs after obtaining the precursor. Tanii teaches the float bath process is a continuous process taken place in a refractory furnace (first 3 passages in description section on page 2, bottom half of page 3), thus making it a very efficient process for producing glass plates. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a shaping step, such as float bath, as it provides for continuous shaping of the molten glass precursor, thereby providing for an efficient means for providing plate shape glass. In keeping with the efficiency of a continuous process, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for the further step of applying the first heat treatment in the continuous production in the refractory furnace, so as to provide for an efficient process.
Claims 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Cornejo et al. (2014/0349831). Nordberg doesn’t specify a drying time. Cornejo teaches a similar method for producing a porous glass substrate comprising providing for a precursor glass, applying a first heat treatment to cause a phase separation in the precursor glass, applying acid treatment to obtain a porous glass, drying and sintering to obtain the glass substrate (figure 1, [0009], [0027], [0034]). Cornejo further teaches the drying step functions primarily to remove water from the porous glass, and the drying conditions are dependent on the dimensions of the glass substrate and can be performed under a vacuum, which may affect drying time ([0037]). Regarding claims 7-8, Cornejo suggests drying at a temperature of at least 90°C by holding at the temperature for at least about 1 hour, up to 15 hours ([0037]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have controlled the drying conditions so as to remove the desired moisture level, i.e. drying for 1 hour or more, depending on the dimension of the glass substrate, as drying conditions are recognized result effective variables.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Fujino (TW 201422558 machine translation provided). Nordberg is silent regarding a sintering atmosphere. Fujino teaches a method for producing a porous glass substrate (abstract, figure 1, bottom half of page 3), the method comprising providing a porous glass structure (top three passages on page 8, page 9), drying the structure before sintering (top 2 passages on page 10), and sintering to produce a porous glass substrate (5th passage on page 10). Fujino further teaches sintering can be performed in different atmospheres, such as in air, or in an inert environment under an inert gas, wherein an inert gas/atmosphere is generally understood be a dry gas (top passage on page 11). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have tried sintering in an inert atmosphere in the process of Nordberg and , which would have a dewpoint of less than 60°, as there is a finite number of predictable potential options, with a reasonable expectation of success for the sintering of the porous glass.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Nakagawa et al. (JP 57205337, abstract provided for by applicant and machine translation provided). Nordberg teaches proper control of the sintering step to ensure no change in shape of the glass substrate, the evacuation of the pores and transparency of the glass substrate (section (3) on page 2), but is silent regarding a sintering rate. Like Nordberg, Nakagawa teaches a method for producing a high silicate glass substrate comprising obtaining a glass precursor comprising SiO2, B2O3, and Na2O, applying a first heat treatment to the glass precursor to cause phase separation so as to obtain a phase-separate glass, applying acid treatment to the phase separated glass to obtain a porous glass, drying the porous glass, and applying a second heat treatment to sinter the porous glass so as to obtain a high silicate glass substrate (abstract, example on pages 3-4). Nakagawa further teaches in the example (page 4), sintering is performed at a temperature rising rate of 60°C/hr, which is less than 100°C/hr. Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a similar drying rate in the drying process of Nordberg as Nakagawa teaches predictable success in sintering a porous glass substrate obtained from phase separation and acid treatment.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Borrelli et al. (CN 101484833 machine translation provided). Nordberg teaches the glass substrate is a Vycor glass, but fails to disclose a laser processing step for producing a hole. However, producing holes in glass substrate can serve many different purposes for the glass substrate. For example, Borrelli teaches providing for a glass substrate comprising high silica glass or Vycor, and performing laser drilling to form an array of holes in the glass substrate (2nd to last passage on page 6). Borrelli teaches such as substrate have polarizing properties (abstract). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have provided for a step of irradiating the glass substrate with a laser beam so as to form holes in the high silicate glass substrate, so as to provide for polarizing properties to the glass substrate, as taught by Borrelli.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Hammel (3,630,700). Norberg and Takashima doesn’t specify a chlorine content to the glass precursor. Like Norberg and Takashima, Hammel teaches a porous high silicate glass made by phase separating a borosilicate glass and treating with acid (abstract). Hammel teaches the glass precursor comprises the typical components, such as SiO2, B2O3, and Na2O (col. 1 lines 54-65). Hammel further teaches other glass-forming ingredients that are common include fluxes, such alumina and P2O5, and fining agents, such as NaCl (col. 1 lines 67-75). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have employed small quantities of a fining agent, such as NaCl, as it is a known ingredient for reducing bubbles in the glass. Hammel teaches the fining agents can be added in minor quantities without altering the characteristics of the glass. Note, the NaCl would be the source of Cl ions in the glass precursor. Although a small quantity of 0.1 mol% of NaCl is not specified, it would have been obvious to one of ordinary skill in the art at the time of the invention to have expected the minor quantity of NaCl to be at least 0.1 mol%.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Nordberg (Properties of some VYCOR-Brand Glasses, Journal of American Ceramic Society, Vol. 27, Issue 10, Nov. 1944) in view of Takashima et al. (2013/0074548) and Borrelli et al. (2008/0248942), as applied to claim 1 above, and further in view of Elmer (3,459,522). Nordberg teaches the glass substrate made is called “96%silica glass” (introduction paragraph), but doesn’t specify a OH content of the glass. Nordberg further teaches in another reference with Elmer, the “96% silica glass” is made from porous glass that has been further subjected to a drying step to remove hydroxyl ions and residual water (abstract, col. 1). Elmer further teaches residual water in the glass can have undesirable effects such as bubbling in the glass and decrease transmission of infrared radiation (col. 2 lines 12-19). Although a hydroxyl content in ppm is not recited, Elmer teaches the glass is water free (abstract). Accordingly, it would have been obvious to one of ordinary skill in the art at the time of the invention to have providing for a drying step to remove all residual water (hence OH group) from the glass substrate of Nordberg, so as to prevent bubbles in the glass substrate and decrease transmission of infrared radiation, as taught by Elmer.
Response to Arguments
Applicant’s arguments, filed July 21, 2026, with respect to the rejection(s) of claim 1 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Borrelli.
Conclusion
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/QUEENIE S DEHGHAN/Primary Examiner, Art Unit 1741
