DETAILED ACTION
Response to Amendment
Applicant's amendment filed June 11th, 2026 has been entered. Claims 13-14, 16, and 19 have been amended. Claim 21 has been cancelled. Claim 22 has been added.
The Section 112, 2nd paragraph rejections made in the Office action mailed January 8th, 2026 have been withdrawn due to Applicant’s amendment.
The Section 102/103 rejections over Gao (as a primary reference) made in the Office action mailed January 8th, 2026 have been withdrawn due to Applicant’s amendment. However, upon further search and consideration, a new ground(s) of rejection has been made.
The Section 102/103 rejections over Naik (as a primary reference) made in the Office action mailed January 8th, 2026 have been maintained due to Applicant’s arguments being unpersuasive. The rejections have been reapplied and updated to reflect Applicant’s amendment.
The Section 102/103 rejections over Ye (as a primary reference) made in the Office action mailed January 8th, 2026 have been somewhat maintained/withdrawn due to Applicant’s arguments being unpersuasive. The rejections have been reapplied and updated to reflect Applicant’s amendment.
The Section 102 rejections over Loth (as a primary reference) made in the Office action mailed January 8th, 2026 have been withdrawn due to Applicant’s amendment. However, upon further search and consideration, a new ground(s) of rejection has been made.
The Section 103 rejections over Loth (as a primary reference) made in the Office action mailed January 8th, 2026 have been maintained due to Applicant’s arguments being unpersuasive. The rejections have been reapplied and updated to reflect Applicant’s amendment.
Response to Arguments
Applicant's arguments filed June 11th, 2026 have been fully considered but they are not persuasive.
Applicant argues that Naik and Ye do not teach the claimed coatings as being applied to “technical products” or as a “technical product” having the protective coating disposed thereon.
First, regarding claim 13, the technical product is only set forth in a functional/intended use type clause (i.e. “for sensitive surfaces of technical products”), wherein a recitation of the intended use of the claimed invention must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. Furthermore, it has been held that the recitation that an element is “adapted to” perform a function is not a positive limitation but only requires the ability to so perform. It does not constitute a limitation in any patentable sense. In re Hutchinson, 69 USPQ 138.
The coatings of Naik and Ye are capable of being applied to any surface, regardless of their intended use, and thus would function as a “protective” coating for the “sensitive” surface as claimed.
Regarding newly added claim 22, while there is no disclosure that a human body or food packaging is a technical product as presently claimed, MPEP 2111.02 states that “if the body of a claim fully and intrinsically sets forth all the limitations of the claimed invention, and the preamble merely states, for example, the purpose or intended use of the invention, rather than any distinct definition of any of the claimed invention’s limitations, then the preamble is not considered a limitation and is of no significance to claim construction”.
Further, MPEP 2111.02 states that statements in the preamble reciting the purpose or intended use of the claimed invention must be evaluated to determine whether the purpose or intended use results in a structural difference between the claimed invention and the prior art. Only if such structural difference exists, does the recitation serve to limit the claim. If the prior art structure is capable of performing the intended use, then it meets the claim
The preamble does not state any distinct definition of any of the claimed invention’s limitations or further that the purpose or intended use that would result in a structural difference between the presently claimed invention and the prior art and further that the prior art structure which is a coated object wherein the coating is identical to that set forth in the present claims is therefore capable of performing the recited purpose or intended use.
Lastly, and to clarify the above point, the definition of a “technical product” is nebulous at best. The term technical product is not clearly set forth in the specification, especially in the manner as argued by Applicant. The only two instances of the term technical product (that do not just simply restate the term) are as follows: “It is common industrial practice to coat sensitive technical surfaces with a film or sheeting to protect them against corrosion and damage. In this case, plastic film is widely employed for this purpose which is removed and disposed of when the relevant products are delivered or sold. The surfaces to be protected are frequently paint coated surfaces, for example motor vehicles.” [PGPub, 0002]; and “Alginate has hitherto been used in the foodstuff industry, in the pharmaceutical field (capsules, in the textile industry, in photographic paper manufacture, and for molding purpose. Alginate protective films for technical products have been described, as indicated above” [PGPub, 0014].
While one may draw the conclusion from the aforementioned two paragraphs that a technical product is for example “an automobile part or another manufactured good”, the disclosure as set forth in no way limits the term thereto. What is “other manufactured goods” even limited to? Packaging for food is manufactured, so are pharmaceutical/medical products, among others. Furthermore, wounds often contain devices in and around them (i.e. sutures/stitches, reinforcement meshes, tubing, stents, implants, drug delivery membranes, artificial tissues) and even the coating devices themselves (i.e. spray nozzles, rollers, blades, etc.) will incidentally get the coating layer(s) thereon. How can one differentiate a “manufactured good” from a manufactured coating device comprising the coating thereon as claimed? Furthermore, the second paragraph explicitly mentions that many industries use alginate coatings while failing to differentiate the development of their particular industry’s alginate coating in the “technical product” field. It’s unclear why Applicant assumes, after acknowledging effort in other fields, why one of ordinary skill would not look to the formation of a similar coating in said fields, especially in fields where one of ordinary skill in the art would know the technology is more thoroughly developed (i.e. the coating being natural, biodegradable, and edible/non-toxic/biocompatible has been of particular interest/assistance in the medical and food related industries for decades).
In conclusion, the intended use/adapted to type clause does not impart any significant structural limitation to the protective coating, and since the preamble for the newly added claim also does not impart any significant structural limitations other than the aforementioned functional limitations, it does not further define the coated product in any meaningful way. Therefore, broadest reasonable interpretation of a “sensitive surface of a technical product” in light of the disclosure is that any surface that can be protectively coated can be, or is, a “technical product” as claimed, which includes humans and/or animals as set for in Naik.
Regarding Loth, Applicant argues that since Loth teaches a polyelectrolytic coating, wherein the oppositely charged anionic alginate and cationic chitosan are already complexed that one would not and could not further modify the coating by solidification using bivalent ions because it would collapse the polyelectrolytic coating, wherein Sava is found to be analogous art due to the design of a capsule being different from a coating/film and Reichenwagen not teaching the inclusion of chitosan. The Examiner partially disagrees.
While the aim of forming a pharmaceutical capsule is indeed different from a temporary coating, Applicant has admitted that prior art coatings are known in the pharmaceutical field (capsules) [PgPub, 0014], which indicates that some basic analogousness does exist in related fields to the claimed coating. Furthermore, a degradable multilayered protective capsule and a removable multilayered protective coating are seen as relevant to each other, despite different environs through which their protectiveness must endure. That the desired stable polyelectrolytic complexing of Loth [0012] would be further enhanced/stabilized by the addition of calcium is made obvious and motivated by Sava [0005, 0032] which would be stabilized in a general acid environment but releasable in an increased acid environment [0032], wherein gelation/solidification of an alginate-based coating such that release of the sequestered Ca2+ ions can only be effected by the addition of a weak organic acid (EDTA/citrate) for subsequent removal by water is taught to be a desirable feature in temporary coatings [0012]. Therefore, in addition to the general increased strength/gelation due to the addition of the calcium [Sava], a modified removal technique of Loth/Sava/Reichenwagen requiring both high-pressure heated water or steam [Loth, 0018] in the presence of a weak organic acid [Reichenwagen, 0012] would provide Loth’s multilayer structure with additional durability/stability/environmental protection in generally acidic situations (such as acid rain or more highly corrosive situations such as industrial buildings and/or internal motor vehicle parts) without accidental release/removal, while retaining the same qualities of being removable and biodegradable, and is actually taught by Reichenwagen [0032].
Furthermore, the ternary aspect of alginate-chitosan-Ca2+ ion systems is well-known in the art of biopolymer/biodegradable coatings/films, wherein the addition of the Ca2+ ions at the correct ratios usually further increasing the mechanical strength and stability, acting as a cross-linker. While the presence of Ca2+ can decrease stability, it has been found it does not substantially displace the chitosan-alginate bonds so long it is used properly, i.e. in the correct amounts and during or shortly preceding film formation [Wang et al., Chitosan-alginate-CaCl2 system for membrane coat application, Abstract & pg. 1140]. This is reflected in the prior art (as both discovered and as set forth below) that usually adds the calcium source following or during the addition of the chitosan before (or in many cases to effect) film formation (curing and/or drying steps).
This is theorized to be due to the alginate polymer structure comprising units of guluronic acid/guluronate (G-units) and mannuronic acid/mannuronate (M-units) in combination with the structural differences between the polymeric cation (chitosan) and divalent metal cation (Ca2+), such that the polymeric cation primary complexes with the M-units and the divalent metal cation primarily complexes with the G-units, wherein using a mixture of both chitosan and a Ca2+ salt allows for an increase in the diversity of sources of alginate having differing G/M ratios without significantly lowering gel strength and increasing the speed of reaction kinetics over that of CaCO3 (calcium carbonate) [Feng et al., Alginate gels with a combination of calcium and chitosan oligomer mixture as crosslinkers, pg. 491 & Scheme 1], which is the calcium source used by Reichenwagen. Thus, the addition of both provides the protonated amino groups of chitosan and the released/dissociated Ca2+ for a electrostatic complexing network and a covalent bonding/chelating network, respectively, produced independently (and in the case of at least Sava, Feng, and Tang, simultaneously) to a double-network solidified/gelled alginate [Tang et al., Construction of physically crosslinked chitosan/sodium alginate/calcium ion double-network hydrogel…, pg. 4, 1st paragraph].
Generally, this above finding holds true with alginate-chitosan polysaccharides usually providing the layered and/or blended complexed polyelectrolyte structure, with the more dominant polymer usually taking a film forming role and the other taking more of a reinforcing role, and the divalent metal ion acting as a curing/cross-linking agent that further strengthens the alginate (forming or reinforcing the film) within film as desired/required by additionally providing the egg-box structure [Tang et al., Construction of physically crosslinked chitosan/sodium alginate/calcium ion double-network hydrogel…, Fig. 1; Frank et al., U.S. Pub. No. 2024/0016147 A1, Fig. 1/0008-0009/0014/0061; Naik, 043/050/055/073, among many other less explicit sources].
Therefore, Applicant’s conclusion that the pharmaceutical multilayer coating system is entirely non-analogous to that of Loth and that Loth does not teach the addition of chitosan with the calcium ions are both moot with respect to the fact that the addition of calcium to the calcium-alginate system of Loth (or the system of Reichenwagen as made obvious/recited below) is well-known in the art of (protective) alginate coatings and would have been made obvious and have provided multiple motivated benefits, which are applicable within the context of the protective coatings of the applied prior art without any impermissible hindsight.
Claim Rejections - 35 USC § 102/103
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 13 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ye et al. (CN 109294001 A) (hereinafter “Ye”).
Regarding claim 13, Ye teaches a coated membrane/film, potentially applicable in the food and pharmaceutical industries (technical products) [0033], comprising a sodium alginate solution [0011-0012] and a chitosan/calcium complex solution [0013, 0026-0031], wherein the two solutions are blended and cross-linked (solidified) by the chitosan along with the divalent calcium (metal) ions, which are released with an organic acid [0005, 0033, 0054-0055].
Claims 14-19 & 22 are rejected under 35 U.S.C. 103 as being unpatentable over Ye, as applied to claim 13 above, in view of Berlin et al. (U.S. Patent No. 5,658,622) (hereinafter “Berlin”), wherein claim 16 is optionally further in view of Brown and claim 19 is further in view of Brown (U.S. Pub. No. 2022/0289999 A1) (hereinafter “Brown”).
Regarding claims 14-18 and 22, a particular use of the coating/film in food packaging as a substrate is not taught nor are any multilayer coating particulars.
Berlin teaches a food packaging laminate comprising a substrate having disposed on at least one surface a protective barrier coating or film of a water insoluble polysaccharide, wherein the water insoluble polysaccharide is formed of water-soluble cationic polysaccharide, such as chitosan, preferably a deacetylated chitin having protonatable amino groups, and a water soluble anionic polysaccharide, such as alginate (col. 2, lines 10-57), wherein the films are coated/laminated at a thickness of 5 to 15 µm (corresponding to a surface weight of 5 to 15 g/m2) (col. 4, lines 7-12 & 51-54), wherein the packaging laminate can be supplemented with additional layers of the same material (total film thickness being at least 10-30 µm), wherein the layers would have comprised a first of alginate (and chitosan) applied below a second of chitosan (and alginate).
Furthermore, Brown teaches a biodegradable material, usable in food packaging [0001], the biodegradable material comprising a coated film [0005] comprising at least an alginate polymer [0075], a second biomass-derived polymer, and an ionic metal linking agent such as calcium [0118-0119], the linking agent ionically bonding to the alginate polymer and the alginate polymer linking to the second polymer via any bonding mechanism including coordinate bonding [0117, 0120], wherein the biodegradable material may be applied in a single layer or as two or more layers, such as 2 to 12 layers, which can be correspondent first and second polymers such that a layer consisting essentially of first polymer links to the a layer consisting essentially of the second polymer [0012-0014, 0038] and comprising an overall thickness of 2 to 500 µm [0069]
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a multilayered alginate-chitosan based protective coating for food packaging substrates in blended layers or single-polysaccharide layer-by-layer basis, wherein the both the layer and total thickness ranges for a multilayered coating/film of 2 to 12 layers would have been prima facie obvious. One of ordinary skill in the art would have been motivated to look to the art for beneficial arrangements for a food industry based film/coating, wherein a thickness of 5 to 15 µm is sufficient but can be supplemented [Berlin].
Regarding claim 19, the addition of a preservative is not taught.
Brown further teaches the film/coating as comprising any preservative known for polysaccharide polymers [0138-0143], wherein the preservative may serve additional functionality such as being a crosslinker in the case of quaternary ammonium cation or a plasticizer in the case of an essential oil.
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a polysaccharide coating for food packaging with a preservation agent. One of ordinary skill in the art would have looked to the art for preservation agents known in the art for polysaccharides, specifically an essential oil, serving a missing functionality, such as a plasticizer supplement or replacement to the glycerol/glycerin in Ye [0009, 0012].
Claims 13-15, 17, 19, & 22 rejected under 35 U.S.C. 102(a)(2) as anticipated by Naik, or in the alternative, under 35 U.S.C. 103 as obvious over Naik, optionally in view of Melvik et al. (U.S. Pub. No. 2006/0159823 A1) (hereinafter “Melvik”).
Regarding claims 13-15, 17, and 19, Naik teaches a uniformly coated barrier film (protective coating) for a surface on a human or animal (technical product), which can be internal or external, such as post-surgical or post-traumatic wound sites [033-037, 070, 087] formed by a hydrogel of superposed layers [059-060, 064] of solution/composition B comprising an aqueous solution of alginate cross-linked by calcium or magnesium (ions) [050, claim 5] and solution/composition A comprising an aqueous solution of a non-alginate polymer, preferably chitosan, which contains the calcium salt cross-linker [040-043], wherein the chitosan reinforced alginate gelled (solidified) film leads to the formation of the barrier film [070, claim 12], wherein in an example solution/composition A is sprayed first followed by solution/composition B having a film thickness of about 1 mm [075-078], wherein in some embodiments solution/composition A can be sprayed over solution/composition B [071, 0125, 0128-0129], and wherein stabilizing/preserving agents can be added to ensure stability and antimicrobiality of the barrier film [051].
In the event that a human/animal surface is not a technical product as claimed: Melvik teaches a pourable or sprayable homogenous coating/film comprising a bivalent ion solidified alginate gel that may be further coated by chitosan or already mixed with chitosan [0092] applied to a wound site or post-surgical site [0064, 0068, 0106], wherein the coating/film may also be used to form a homogeneous alginate-based coating on implantable devices (technical product) [0018, 0071].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a coating/film used as a wound barrier as homogenously coating an implantable device. One of ordinary skill in the art would have used a known coating that applies homogenously/uniformly as providing an effective biodegradable/biocompatible coating for an implantable device regardless of shape complexity [0071].
Claims 16 & 18 are rejected under 35 U.S.C. 103 as being unpatentable over Naik, as applied to claims 13-14 above, in view of Melvik et al. (U.S. Pub. No. 2006/0159823 A1) (hereinafter “Melvik”) and Picart et al. (U.S. Pub. No. 2007/0129792 A1) (hereinafter “Picart”).
Regarding claims 16 and 18, while the coated thickness of at a possible wound site is taught to be about 1 mm (1000 µm), the coating thickness for an implantable device is not taught.
Picart teaches a layer-by-layer electrostatic self-assembly of a biocompatible cross-linked polyelectrolyte coating for medical surfaces such as implants [0059-0061], comprising layers of anionic polyelectrolytes comprising free carboxylic groups such as alginic acid/alginate and cationic polyelectrolytes comprising free amino groups such as chitosan [0029-0031] and a crosslinker that enhances the stability of the film and also provides barrier properties, allowing for thick films to be formed [0006, 0016-0017, 0022], wherein the number of layers can vary from 1 to 1000, such as about 5 to 60, and overall thickness can vary from 1 to 150,000 nm, such as 20 nm to 150 µm [0066-0067], for possible layer thickness for a two-layer coating being about 10 nm to 75 µm, for a four layer coating being about 5 nm to 37.5 µm, for a six layer coating being about 3 nm to 17 µm, and so on, wherein a dip-coating method, spray coating method, or a hybrid thereof are taught as possible coating processes [0064-0070].
It would have been obvious to one of ordinary skill in the art at the time of invention to look to the art of coated implantable devices to provide a preferred number of bilayers greater than 1 to form a thick coating and comprising a prima facie obvious layer thickness range.
Claims 13-16, 19, & 22 are rejected under 35 U.S.C. 102 as being anticipated by Lv et al. (Layer-by-layer self-assembly of minocycline-loaded chitosan/alginate multilayer on titanium substrates to inhibit biofilm formation) (hereinafter “Lv”).
Regarding claims 13-16, 19, and 22, Lv teaches the application of a protective coating for a titanium-based implant (technical product) undergoing a series of layer-by-layer (dipped) coatings of a chitosan layer applied followed by (on top of) each alginate layer followed by treatment in a CaCl2 (calcium chloride solution) in order to crosslink (solidify) the alginate, the coating process performed for an experimental three cycles, forming a six-layer coating (pg. 1466, left col.), wherein the coating is additionally loaded by minocycline (a broad-spectrum antibiotic/preservative).
Claims 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Lv, as applied to claim 13 above, in view of Picart et al. (U.S. Pub. No. 2007/0129792 A1) (hereinafter “Picart”) and/or Wang et al. (Electrodeposition of alginate/chitosan layer-by-layer composite coatings on titanium substrates) (hereinafter “Wang”).
Regarding claims 17-18, a particular thickness of the coating and/or the layers are not taught.
Picart teaches a layer-by-layer electrostatic self-assembly of a biocompatible cross-linked polyelectrolyte coating for medical surfaces such as implants, which may be titanium [0059-0061], comprising layers of anionic polyelectrolytes comprising free carboxylic groups such as alginic acid/alginate and cationic polyelectrolytes comprising free amino groups such as chitosan [0029-0031] and a crosslinker that enhances the stability of the film and also provides barrier properties, allowing for thick films to be formed [0006, 0016-0017, 0022], wherein the number of layers can vary from 1 to 1000, such as 5 to 60, and overall thickness can vary from 1 to 150,000 nm, such as 20 nm to 150 µm [0066-0067], wherein a dip-coating method, the same method as Lv is taught [0064-0065], spray coating, or a hybrid thereof are taught as possible coating processes [0069-0070].
AND/OR
Wang teaches a layer-by-layer assembly electrodeposition technique of providing precisely controlled biocompatible alginate-chitosan stacked/multilayered coatings on titanium substrates, wherein a preferred thickness for the deposited chitosan layer is 20 µm and the deposited alginate layer is 10 µm [Conclusions, pg. 44], wherein the maximum number of layers for the disposed coatings is four [pg. 40, last paragraph – pg. 41, 1st paragraph].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide layer-by-layer alginate-chitosan coating comprising at least 4 layers and the thickness of the individual layers being obviously within or explicitly within the claimed range. One of ordinary skill in the art would have maximized the thickness of a thick coating for protection purposes [Picart], wherein the number of layers and thickness thereof can be optimized [Picart], based on a particular technique suitable for titanium implants [Wang].
Claims 13-15, 17, 19, & 22 are rejected under 35 U.S.C. 103 as being unpatentable over Gao in view of Zhuang et al. (Development and characterization of nano-bilayer films composed of polyvinyl alcohol, chitosan and alginate) (hereinafter “Zhuang”).
Regarding claims 13 and 19, Gao teaches a protective film, such as against dust and paint [0002], and method of making and coating thereof, the coated film comprising an aqueous solution of polyvinyl alcohol, sodium (metal ion solidified) alginate, and an aqueous solution of chitosan blended together [0002-0003, 0022-0028], which forms a stable, biodegradable, human and environmentally friendly temporary film [0007, 0011] for technical surfaces in paint shops and for protection of painted surfaces [0006, 0008], wherein a 0.1 to 0.5% of a preservative, specifically calcium/sodium propionate, is added to the composition [0013, 0020], and the emulsifier is at least partially Tween-based [0015].
However, the use of a bivalent metal solidified alginate or a multilayer coating as claimed is not taught.
Zhuang teaches a biodegradable, human and environmentally-friendly film comprising polyvinyl alcohol, alginate, and chitosan, wherein nano-cellulose, surfactant (which is Tween-based), calcium chloride, and anti-bacterial agents (preservatives) can be added, wherein the addition of crosslinking calcium ions, in the correct amount (~0.5 wt%) so as to not adversely affect the performance of the film, specifically decreases film water solubility and enhances the strength and flexibility of the coated film [pg. 197, Section 3.2.4], wherein the film can be a single layer film comprising a blend of polyvinyl alcohol, sodium alginate, and chitosan or a bilayer film of an inner alginate layer and an outer chitosan-polyvinyl alcohol layer, wherein the bilayer film is improved in solubility resistance, water barrier properties, and mechanical properties compared to the single layer film [pg. 198, Section 4/Conclusions] and is formed in a layer-by-layer assembly based on electrostatic attraction between alginate and chitosan [pg. 192, left col., 3rd paragraph] such as a dip coating process [pg. 194, Section 2.12], wherein the film is formed at a thickness of about 0.1 mm (100 µm) [pg. 193, Section 2.6].
It would have been obvious to one of ordinary skill in the art at the time of invention to provide a biodegradable coating comprising polyvinyl alcohol, alginate, and chitosan as a multilayer film wherein the alginate is solidified/crosslinked by a Ca2+ (bivalent metal ion). One of ordinary skill in the art would have been motivated to improve the coated film in solubility resistance, water barrier properties, and mechanical properties compared to the single layer film of Gao, wherein the calcium ion crosslinking would enhance the electrostatic bonding of alginate and chitosan and further decrease the water solubility and enhance the strength and flexibility of the coated (single or multilayer) film.
Claims 16 & 18 are rejected under 35 U.S.C. 103 as being unpatentable over Gao in view of Zhuang, as applied to claims 13-14 above, in view of Picart et al. (U.S. Pub. No. 2007/0129792 A1) (hereinafter “Picart”).
Regarding claims 16 and 18, at a thickness of 0.1 mm as recited above, each layer in the bilayer assuming both layer have an approximately equal thickness would be 50 µm, while a four layer coating having a layer-based thickness within the range claimed is not taught.
Picart teaches a layer-by-layer electrostatic self-assembly of a biocompatible cross-linked polyelectrolyte coating comprising layers of anionic polyelectrolytes comprising free carboxylic groups such as alginic acid/alginate and cationic polyelectrolytes comprising free amino groups such as chitosan [0029-0031], and may further comprise neutral polymers such as polyvinyl alcohol [0035], and a crosslinker that enhances the stability of the film and also provides barrier properties, allowing for thick films to be formed [0006, 0016-0017, 0022], wherein the number of layers can vary from about 1 to 1000, such as about 5 to about 60, and overall thickness can vary from 1 to 150,000 nm, such as 20 nm to 150 µm [0066-0067], wherein a dip-coating method, the same method as Zhuang is taught [0064-0065], spray coating, or a hybrid thereof are taught as possible coating processes [0069-0070].
It would have been obvious to one of ordinary skill in the art at the time of invention to look to the art for possible ranges for a layer-by-layer formed polysaccharide coating having more than one bilayer, wherein a layer thickness for about 4 to about 60 layers at the same coating thickness would range from about 1.7 µm to about 25 µm.
Claims 13-19 & 22 are rejected under 35 U.S.C. 103 as being unpatentable over Loth et al. (EP 897964 A2) (hereinafter “Loth”) in view of Sava et al. (U.S. Pub. No. 2006/0228422 A1) (hereinafter “Sava”) and optionally Reichwagen (U.S. Pub. No. 2014/0245924 A1) (hereinafter “Reichwagen”).
Regarding claims 13-19 and 22, Loth teaches a protective polymer film/coating, usable on building walls or vehicles (technical products) [0001], comprising an aqueous solution of cationic chitosan which may include additional cationic components that may assist in mechanical stability of film formation and dissolve in water or dilute acids [0009, 0012, 0020, 0025] and aqueous solution of anionic alginate complexed (solidified) with sodium [0009, 0012, 0025, 0027], wherein the aqueous alginate primer solution is applied before the oppositely charged/cationic aqueous chitosan topcoat solution [0012, 0025, 0027], wherein while the anionic layer and cationic layer solutions are applied in repeatedly alternating stages such as at least two primer layers (four layer coating) forming a polyelectrolyte complex multilayer solidified/gelled coating having a total thickness of 5 to 200 µm, preferably 10 to 100 µm, with individual layers comprising a fractional thickness thereof [0014-0015], that is more mechanically stable in the environment [0014-0016] and the other chitosan layer providing additional antimicrobial and mechanical stability when it is provided as an outer layer [0037], wherein aqueous polysaccharide solutions additionally contain preservatives to suppress biological susceptibility [0005].
Further regarding claims 13 and 22, the alginate is not taught to be solidified by bivalent metal ions.
Sava teaches a multilayer protective coating, wherein alginate and chitosan are known to form gels with each other, wherein with alginate this gellification is further enhanced via divalent ions, calcium ions in particular [0005], wherein the combination of alginate and chitosan, especially with addition of the divalent metal ion has particular relevance for gellification and stability of the multilayer coating, wherein alginate is an inner layer and chitosan is an outer layer [0014-0015, 0018], wherein the stability can particularly assist in terms of providing a balance of strength in acidic environments, stable in lower acidic environments and decreased in increasingly acidic environments [0032].
Furthermore, Reichwagen teaches a metal ion solidified/gelled alginate coating for protection of surfaces, such as paint coated surfaces [0002], which is related to alginate coatings known in the foodstuff industry, medical industry (capsules), textile industry, etc. [0014], wherein the formation of a multilayer coating would be performed by applying the alginate solution followed by the calcium (metal) ion solution [0024, claim 5], wherein the calcium may be in the form of calcium chloride [0023] or calcium carbonate that can be subsequently released by the addition of a sequestrant/weak organic acid such as gluconic acid [0027], wherein the sequestrant/weak organic acid can be applied before high pressure and/or elevated temperature fluid for removing or washing off the coating [0012, 0032], wherein the aqueous polysaccharide solution can be provided with a biocide to protect or guard against the growth of bacteria or fungi, which are customary in nature [0030, claim 13]
It would have been obvious to one of ordinary skill in the art at the time of invention to provide at least the chitosan solution/layer with a divalent metal/calcium ion to further crosslink (solidify/gel) the alginate in addition to the chitosan. One of ordinary skill in the art would have been motivated to provide additional stabilization/strength [Sava], specifically in acidic environments [Sava], such that a non-sticky protective coating would have increased strength/resistance to water that could be easily overcome and then washed off with the addition of a weak acid and/or higher temperature/pressure water [Reichwagen; 0005-0006, 0012, 0032, 0036].
Claims 13-19 & 22 are rejected under 35 U.S.C. 103 as being unpatentable over Loth et al. (EP 897964 A2) (hereinafter “Loth”) in view of Jiang et al. (U.S. Patent No. 6,1150,581) (hereinafter “Jiang”) as evidenced by or further in view of Wang et al. (Chitosan-alginate-CaCl2 system for membrane coat application) (hereinafter “Wang”), and optionally (even) further in view of Reichwagen (U.S. Pub. No. 2014/0245924 A1) (hereinafter “Reichwagen”).
Regarding claims 13-19 and 22, Loth teaches a protective polymer film/coating, usable on building walls or vehicles (technical products) [0001], comprising an aqueous solution of cationic chitosan which may include additional cationic components that may assist in mechanical stability of film formation and dissolve in water or dilute acids [0009, 0012, 0020, 0025] and aqueous solution of anionic alginate [0009, 0012, 0025, 0027], wherein the aqueous alginate primer solution is applied before the oppositely charged/cationic aqueous chitosan topcoat solution [0012, 0025, 0027], wherein while the anionic layer and cationic layer solutions are applied in repeatedly alternating stages such as at least two primer layers (four layer coating) forming a polyelectrolyte complex multilayer solidified/gelled coating that is semi-permeable in that it is non-greasy water-vapor permeable but impermeable to liquids/fluids [0008, 0012-0013, 0017] that can be removed with a high-pressure water jet or superheated steam [0018], with chitosan layer providing additional antimicrobial and mechanical stability when it is provided as an outer layer [0037], a total thickness of 5 to 200 µm, preferably 10 to 100 µm that is more mechanically stable in the environment [0014-0016], wherein individual layers each having a fractional thickness thereof [0014-0015], for instance a two-layer coating comprising an equal layer preferable thickness of 5 to 50 µm and a four-layer coating comprising an equal layer thickness of 2.5 to 25 µm, wherein aqueous polysaccharide solutions additionally contain preservatives to suppress biological susceptibility [0005].
Further regarding claims 13 and 22, the alginate is not taught to be solidified by bivalent metal ions.
Jiang teaches a chitosan/alginate anti-adhesion barrier (protective) coating/film comprising combining an aqueous solution of alginate with an aqueous solution of chitosan and a complexing agent, wherein the complexing agent is a calcium or magnesium salt, and optionally one or more medicinal agents (preservative) [abstract & col. 3, lines 47-60], wherein the anionic alginate and cationic chitosan react to form ionotropic gelation and the divalent cations react with alginate to also cause gelation such that alginate, chitosan, and divalent ions act together to form an especially durable biodegradable structure [col. 4, lines 13-22), wherein the solutions may be simultaneously (blend) or separately overlappingly (layered) applied by pouring or spraying at the application site (col. 4, lines 23-42 & col. 6, lines 30-54), wherein Wang evidences/further teaches that when calcium ions are added in the correct amount during or shortly preceding film formation that they do not substantially displace the chitosan-alginate bonds and moreover improve mechanical strength without increasing the thickness or eliminating water vapor permeability of the alginate-chitosan coating/film system [Wang et al., Chitosan-alginate-CaCl2 system for membrane coat application, Abstract & pg. 1140].
Furthermore, Reichwagen teaches a metal ion solidified/gelled alginate coating for protection of surfaces, such as paint coated surfaces [0002], which is related to alginate coatings known in the foodstuff industry, medical industry (capsules), textile industry, etc. [0014], wherein the formation of a multilayer coating would be performed by applying the alginate solution followed by the calcium (metal) ion solution [0024, claim 5], wherein the calcium may be in the form of calcium chloride [0023] or calcium carbonate that can be subsequently released by the addition of a sequestrant/weak organic acid such as gluconic acid [0027], wherein the sequestrant/weak organic acid can optionally be applied with high pressure and/or elevated temperature fluid for removing or washing off the coating [0012, 0032], wherein the aqueous polysaccharide solution can be provided with a biocide to protect or guard against the growth of bacteria or fungi, which are customary in nature [0030, claim 13]
It would have been obvious to one of ordinary skill in the art at the time of invention to provide at least the chitosan solution/layer with a divalent metal/calcium ion to further crosslink (solidify/gel) the alginate in addition to the chitosan. One of ordinary skill in the art would have been motivated to provide an especially durable biodegradable structure [Jiang] without eliminating the desired water vapor permeability [Wang], such the biodegradable coating could be easily overcome and then washed off by higher temperature/pressure water [Loth/Reichwagen] with an optional addition of a sequestrant/weak acid to release the calcium ions [Reichwagen].
Conclusion
The prior art made of record and not relied upon is considered pertinent to Applicant's disclosure:
Feng et al. (CN 107163305 A) and Dongfeng et al. (CN 102120514 A) teach multilayer coatings/films for food packaging comprising a trilayer chitosan-alginate-chitosan structure, wherein the alginate is solidified with the addition of calcium ions. Wang et al. (CN 107840981 A) teach a multilayer coating/film for food packaging comprising a bilayer alginate-chitosan structure, wherein the alginate is solidified with the addition of calcium ions.
Wu (CN 107298912 A) teaches a shell casing (i.e. mobile devices) coating comprising alginate, chitosan, wherein the alginate is solidified with the addition of calcium ions, and further including antibacterial and antifungal agents (preservatives).
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.
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/JEFFREY A VONCH/Primary Examiner, Art Unit 1781 August 28th, 2026
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