DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claims 1-18 are pending as amended on 12/30/2025. Claims 9-16 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
The rejections set forth below are substantially the same as the rejections previously set forth in the action mailed on 9/30/2025.
The rejections have been modified to include new claims 17 and 18. These modifications were necessitated by Applicant’s amendment.
The rejections over Shaofeng have additionally been modified to withdraw the rejection of the elected species. The rejection of the generically claimed subject matter over Shaofeng is the same as previously set forth in the action mailed on 9/30/2025, and therefore, this action is properly made final.
Any rejections and/or objections made in the previous Office action and not repeated below are hereby withdrawn. The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office Action.
Claim Rejections - 35 USC § 103
Claim(s) 1-5, 7, 8 and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gadda et al (US 2016/0060387).
As to claims 1, 3-5, 7, 8 and 17, Gadda teaches method for preparing polyglycolic acid polymers [0027-28] which preferably comprise at least 90 mol% of residues derived from glycolic acid [0047]. The molar ratio between residues derived from glycolic acid and residues derived from a comonomer is 1000:1 or less [0049], and Gadda teaches an embodiment wherein comonomers are exclusively hydroxy-terminated comonomers, naming propanediol, butanediol, hexanediol, pentaerythritol and combinations thereof as examples [0050]. See also examples 1-3 of a PGA formed from glycolic acid and 2, 3 or 4 mol% hexanediol [0111-3], and example 7 of a PGA formed from glycolic acid and 2 mol% pentaerythritol [0117].
Gadda teaches that the properties and molecular weight of the polyhydroxyacid material can be adjusted based on the ratio of the hydroxy acid and the α,ω-difunctional compound. An increased use of the difunctional compound results in a decreased molecular weight of the polyhydroxy acid material [0071]. Gadda further teaches that multiterminated polyhydroxyacids (which can yield thermosetting materials) are prepared by replacing difunctional compounds with an equivalent having three or more functionalities (such as glycerol, pentaerythritol and trimethylolpropane) [0074].
Considering Gadda’s disclosure in [0071] and [0074], one having ordinary skill in the art would have recognized the effect on molecular weight from using a difunctional hydroxy comonomer, and, the effect on thermosetting behavior/branching from using a multifunctional hydroxy comonomer. Therefore, especially given Gadda’s disclosure in [0050] to use combinations of hydroxy-terminated monomers, the person having ordinary skill in the art would have been motivated to utilize any appropriate combination of the hydroxy-terminated comonomers named by Gadda, including a combination of hexanediol (a diol which has a bp of 250 C, meeting instant claim 5) as a difunctional compound and pentaerythritol (a tetraol) or TMP (a triol) as multifunctional compound, in order to provide a polyhydroxyacid having a desired molecular weight and degree of branching. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed a polyglycolic acid (PGA) copolymer from polycondensation of glycolic acid (corresponding to instant “GA”) and a combination of hydroxy-terminated comonomers, as taught by Gadda, by utilizing hexanediol (corresponding to instant “AO”) in combination with pentaerythritol or TMP (corresponding to instant “H”) as the comonomers, thereby arriving at a glycolic acid polymer as presently recited. [Note that a PGA from glycolic acid, hexanediol, and pentaerythritol/TMP, as suggested by Gadda, meets instant claims 3, 7 and 8 even though Gadda suggests a PGA which does not contain a hydroxyacid or a monoacid or a polyacid: while claims 3, 7 and 8 further limit the hydroxyacid (A), monoacid (C) and polyacid (O), respectively, the components remain optional, as in independent claim 1.]
As to claim 2, as set forth above, Gadda teaches that the content of added difunctional compound is most preferably less than 10% [0071], and, teaches that the properties and molecular weight of the polyhydroxyacid material can be adjusted based on the ratio of the hydroxy acid and the α,ω-difunctional compound. An increased use of the difunctional compound results in a decreased molecular weight of the polyhydroxy acid material [0071]. Gadda further teaches that multiterminated polyhydroxyacids (which can yield thermosetting materials) are prepared by replacing difunctional compounds with an equivalent having three or more functionalities (such as glycerol, pentaerythritol and trimethylolpropane) [0074]. Considering Gadda’s disclosure, the person having ordinary skill in the art would have been motivated to select any appropriate amounts of difunctional and multifunctional comonomers totaling less than 10% in order to achieve a desired molecular weight and desired degree of branching/thermosetting behavior. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed a glycolic acid polymer from glycolic acid, difunctional comonomer (hexanediol) and multifunctional comonomer (pentaerythritol or TMP) utilizing any appropriate amounts of hexanediol and multifunctional comonomer which total less than 10%, including amounts corresponding to hydroxyl group percentages within the presently claimed ranges.
As to claim 17, a PGA from glycolic acid, hexanediol, and pentaerythritol/TMP, as suggested by Gadda, meets instant claim 17 (which has the transitional phrase “consisting of”) because the monomers utilized to form the PGA do not include any monomers which are not recited in claim 17.
Claim(s) 1-8, 17 and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shaofeng (WO 2008/036049).
As to claims 1, 3-5, 7, 8, Shaofeng discloses a polyhydroxy acid produced from the reaction of a monomer mixture comprising a hydroxy acid with a functionalizing agent (p 3, lines 25-29; p 11, lines 18-22; p 14, lines 7-10).
Shaofeng names several examples of hydroxy acids, including glycolic acid (p 5, line 23, p 11, line 27). Shaofeng further teaches a functionalizing agent which comprises a polyalcohol and a diol (p 15, line 32; p 16, lines 6-7). Shaofeng defines “polyalcohol” as an alcohol having at least three hydroxyl groups, and names several examples of such compounds on p 6, lines 6-29, which are free from carboxylic acid groups (and which therefore correspond to instant polyol (H)). Shaofeng defines “diol” as a molecule which has at least two alcohol functionalities, and names several examples of alcohols comprising two hydroxyl groups on p 7, line 16 to p 8, line 9, which are free from carboxylic acid groups (and which therefore correspond to instant alcohol (AO)). Shaofeng exemplifies several polyhydroxy acid polymers formed from a monomer mixture wherein the functionalizing agent is a polyol having three or four hydroxyl groups and free from carboxylic acid groups (i.e., glycerin or pentaerythritol) and an alcohol comprising two hydroxyl groups and free from carboxylic acid groups (i.e., butanediol, which has a boiling point of 235 C, and therefore meets instant claim 5). See, e.g., example 4 on p 21, example 10 on p 24, example 20 on p 19.
All of Shaofeng’s exemplified polyhydroxy acids are formed from lactic acid as the hydroxy acid monomer. Shaofeng does not exemplify a polyhydroxy acid wherein the hydroxy acid monomer is glycolic acid.
However, glycolic acid is clearly contemplated by Shaofeng, along with lactic acid, as a hydroxy acid monomer for producing a polyhydroxy acid (see p 5, lines 21-26 and p 11, line 27: both lactic acid and glycolic acid are named in a list of exemplary aliphatic hydroxy acids). Considering Shaofeng’s disclosure, it was known in the art to produce polyhydroxy acid from a hydroxy acid monomer, and, lactic acid and glycolic acid were both known in the art as suitable hydroxy acid monomers for producing a polyhydroxy acid. One having ordinary skill in the art would have further recognized that the properties of a polyhydroxy acid depend on its structure. Therefore, one would have been motivated to select any appropriate hydroxyacid monomer from Shaofeng’s disclosed list of suitable options in order to produce a polyhydroxy acid having a desired set of properties. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed a polyhydroxy acid from a mixture of hydroxy acid monomer, a diol (e.g., butanediol as exemplified) and a polyol having three or four hydroxyl groups (e.g., glycerin or pentaerythritol as exemplified), as taught by Shaofeng, by selecting any appropriate hydroxy acid monomer from Shaofeng’s disclosed list of exemplary hydroxy acids, including glycolic acid, thereby arriving at a glycolic acid polymer (PGA) as presently recited.
[Note that a PGA from glycolic acid, butanediol, and pentaerythritol/glycerin, as suggested by Shaofeng, meets instant claims 3, 7 and 8 even though Shaofeng suggests a PGA which does not contain a hydroxyacid or a monoacid or a polyacid: while claims 3, 7 and 8 further limit the hydroxyacid (A), monoacid (C) and polyacid (O), respectively, the components remain optional, as in independent claim 1. A PGA prepolymer from glycolic acid, butanediol, and pentaerythritol/glycerin, as suggested by Shaofeng, meets instant claim 17 (which has the transitional phrase “consisting of”) because the monomers utilized to form the PGA do not include any monomers which are not recited in claim 17.]
As to claim 2, Shaofeng discloses that the prepolymer is formed by hydroxy acid and 25 to 0.001% of the prepolymer is formed by functionalizing agent containing at least three functional end groups, and/or 50 to 0.001% of diol monomers (p 16, lines 15-20), which encompasses the presently claimed ranges. See also Shaofeng’s example 20, which is a polyhydroxyacid prepolymer formed from a mixture of hydroxy acid, polyol, and alcohol (and no monomers corresponding to the optional components A, C or O recited in claim 1) wherein:
the amount of polyol (pentaerythritol) is such that the number of hydroxyl groups is 0.30% with respect to the overall number of carboxyl groups of the hydroxy acid (which falls within the instant range of 0.050 and 1.200%), and
the amount of diol (butanediol) is such that the number of hydroxyl groups is 0.49% with respect to the overall number of carboxylic groups of the hydroxy acid (which falls within the instant range of 0.010 and 0.750%).
Calculations:
9 kg of 88% (i.e., 7920 g) lactic acid (MW 90.08 g/mol) corresponds to 87.9 mol lactic acid, and therefore 87.9 mol of COOH groups.
9.0 g pentaerythritol (MW 136.15) corresponds to 0.066 mol of pentaerythritol, and therefore, 0.26 mol OH groups (0.066*4). OH/COOH = 0.26/87.9 = 0.30%.
19.5 g of butanediol (MW 90.12) corresponds to 0.216 mol of butanediol, and therefore, 0.43 mol OH groups (0.216*2). OH/COOH = 0.43/87.9 = 0.49%.
As to claims 6 and 18, as set forth in the rejection of claims 1 and 17 above, Shaofeng suggests a polyhydroxy acid formed from a hydroxy acid, and from a polyol and diol as a functionalizing agent. Shaofeng does not exemplify a polyhydroxy acid wherein the hydroxy acid monomer is glycolic acid, wherein the diol is cyclohexanedimethanol.
However:
Glycolic acid is named by Shaofeng as an exemplary hydroxy acid monomer for producing a polyhydroxy acid (see p 5, lines 21-26 and p 11, line 27),
Cyclohexanedimethanol is named as an exemplary diol on p 7, line 30.
One having ordinary skill in the art would have recognized that the properties of a polyhydroxy acid depend on its structure. Therefore, when forming a polyhydroxyacid from a hydroxy acid and a mixture of diol and polyalcohol as functionalizing agent, as taught by Shaofeng, one would have been motivated to select any appropriate hydroxyacid monomer from Shaofeng’s disclosed list of suitable options, any appropriate diol from Shaofeng’s list of suitable options, and any appropriate polyalcohol from Shaofeng’s list of suitable options, in order to produce a polyhydroxy acid having a desired set of properties. It would have been obvious to the person having ordinary skill in the art, therefore, to have formed a polyhydroxy acid from a mixture of hydroxy acid monomer, a diol, and a polyol, as taught by Shaofeng, by selecting any appropriate hydroxy acid monomer from Shaofeng’s disclosed list of exemplary hydroxy acids, including glycolic acid, any appropriate diol from Shaofeng’s disclosed list of exemplary diols, including cyclohexanedimethanol, and any appropriate polyalcohol from Shaofeng’s disclosed list of exemplary polyalcohols, thereby arriving at a PGA according to instant claims 6 and 18. Case law has established that it is prima facie obvious to choose from a finite number of identified, predictable solutions with a reasonable expectation of success. KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398 (2007). MPEP 2143, rationale (E).
Claim(s) 1-8, 17 and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shaofeng (WO 2008/036049) in view of Gadda et al (US 2016/0060387).
The rejection of claims 1-8, 17 and 18 over Shaofeng is incorporated here by reference.
As set forth above, all of Shaofeng’s exemplified polyhydroxy acids are formed from lactic acid as the hydroxy acid monomer. While glycolic acid is clearly contemplated by Shaofeng, along with lactic acid, as a hydroxy acid monomer for producing a polyhydroxy acid (see p 5, lines 21-26 and p 11, line 27: both lactic acid and glycolic acid are named in a list of exemplary aliphatic hydroxy acids), Shaofeng does not exemplify a polyhydroxy acid wherein the hydroxy acid monomer is glycolic acid.
Gadda teaches a method for preparing a polyglycolic acid polymer [0027-28] comprising residues derived from glycolic acid and from comonomers which are exclusively hydroxy-terminated comonomers, naming propanediol, butanediol, hexanediol, pentaerythritol and combinations thereof as examples [0047-0050; 0057-61]. Gadda teaches that the method is useful for producing polyglycolic acid-based materials with high molecular weights [0028]. Gadda teaches that lactic acid is optically active, such that condensation polymerization leads to racemization of optically pure monomers, resulting in PLA polymers which are limited in use because they are not crystalline. Gadda teaches that the glycolic acid polymers are not impaired by such features [0029].
Considering Shaofeng’s and Gadda’s disclosures, it was known in the art to produce polyhydroxy acid from a hydroxy acid monomer, and, lactic acid and glycolic acid were both known in the art as suitable hydroxy acid monomers for producing a polyhydroxy acid. One having ordinary skill in the art would have further recognized that the properties of a polymer depend on its structure, and given Gadda’s disclosure, one having ordinary skill in the art would have further recognized that unlike lactic acid, glycolic acid is not optically active, and therefore not susceptible to racemization during polycondensation (which decreases polymer crystallinity). Therefore, when forming a polyhydroxy acid via polycondensation of a hydroxy acid monomer, a diol and a polyol, as taught by Shaofeng, it would have been obvious to the person having ordinary skill in the art to have selected glycolic acid from Shaofeng’s list of hydroxy acid monomers, in order to prepare a polyglycolic acid material which is useful as packaging, as a barrier material, or in medical applications (see Gadda [0008]; see also Shaofeng p 1, lines 17-27) and which is biodegradable and biocompatible like polylactic acid (see Gadda [0006]), but, which is not susceptible to a decrease in crystallinity resulting from racemization of monomer during polycondensation.
Response to Arguments
Applicant's arguments filed 12/30/2025 have been fully considered.
As to the rejection over Gadda:
Applicant argues (pp 8-9) that the data of the present application demonstrates that PGA polymers as presently claimed (Ex 1 and 2, formed from glycolic acid, TMP and CHDM) exhibit improved hydrolysis resistance (180 hrs at 38 C) over polymers comprised only of glycolic acid and TMP units (Ex 1C) or glycolic acid, TMP and isophthalic acid (Ex 2C). Applicant argues that it is not expected that inclusion of an alcohol AO would improve the resistance to hydrolysis as demonstrated. Applicant’s argument has been fully considered, however, Applicant has not established what difference in hydrolysis resistance would have been expected in view of the structural differences between the exemplified copolymers. For example, Applicant’s data shows that PGA formed using TMP and CHDM in combination has improved hydrolysis resistance over PGA formed using TMP with no CHDM. However, no data has been provided for PGA formed using CHDM and no TMP. Therefore, it is not possible to assess whether the hydrolysis resistance of PGA formed using both types of hydroxy-functional compounds merely follows a trend which would be expected when using the two compounds together in varying proportions ranging between 100% CHDM and 100% TMP.
Additionally, the present claims encompass a very large number of species, yet Applicant has shown an improved hydrolysis resistance for only one species within the scope of the claims. Specifically, the PGA of instant examples 1 and 2 is formed using a mixture of GA with TMP as polyol and CHDM as alcohol in specific amounts, and no further monomers. In contrast, instant claim 1 is not limited to any particular polyol, any particular alcohol, or any particular amounts of polyol, alcohol and GA. Moreover, the PGA of instant examples 1 and 2 is formed using a very specific process which includes specific melt and solid-state polymerization steps, while the PGA of instant claim 1 is not limited to any particular production method. Evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support. See MPEP 716.02(d). Therefore, if Applicant wishes to overcome the present rejection by showing unexpected results, Applicant must provide sufficient evidence to show that unexpected results would be obtained for all species encompassed by the present claims.
As to the rejection over Shaofeng:
Applicant argues (p 10) that Shaofeng does not disclose trimethylolpropane as alleged in the office action. The examiner agrees. As accurately pointed out by Applicant, Shaofeng discloses trimethylolpropane triglycidyl ether, not trimethylolpropane. Because Shaofeng does not name TMP as a polyol, Shaofeng does not render obvious the elected species (i.e., a species of PGA formed from GA, TMP and CHDM). The rejections above have been modified to remove the previous assertion that Shaofeng discloses trimethylolpropane and withdraw the finding that Shaofeng suggests the elected species. However, no claims are presently limited to the elected species. As established in the rejections previously made of record (and maintained in the rejections above), Shaofeng suggests PGA polymers encompassed by the broader generic claims (which are not limited to PGA formed from TMP as the polyol component).
Applicant’s arguments on p 11 with respect to unexpected results are the same as previously argued against the rejection over Gadda. The allegations of unexpected results fail to overcome the rejections over Shaofeng for the same reasons set forth above in the discussion of the Gadda rejection.
Applicant argues (pp 11-12) that Shaofeng does not teach or suggest a PGA polymer according to claim 17 because an isocyanate coupling agent is excluded by the “consisting of” transitional phrase in claim 17. However, the rejection of record establishes that the prepolymer suggested by Shaofeng (not Shaofeng’s final product resulting from reaction of prepolymer with isocyanate) is encompassed by present claim 17. The prepolymer taught by Shaofeng is formed without the use of any coupling agent (or any other unrecited components). Therefore, Applicant’s argument is not persuasive.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/RACHEL KAHN/ Primary Examiner, Art Unit 1766