US 12370716

Here is a concise summary of US patent 12370716:

Title: Wood preservative composition comprising 4,5-dichloro-2-octylisothiazol-3(2H)-one, a method treating a wood substrate therewith, and a wood product produced therefrom

Assignee: Koppers Performance Chemicals Inc

Inventors: Min Kuang, Jun Zhang

Filing Date: March 6, 2025

Issue Date: July 29, 2025

Abstract: The patent describes a wood preservative composition containing 4,5-dichloro-2-octylisothiazol-3(2H)-one (DCOI) and a retaining additive. The retaining additive can be a solvent-borne polymeric resin, a wax, or a combination thereof. The composition contains at least 0.5% by weight of DCOI, and the weight ratio of DCOI to the retaining additive is between 1:5 and 5:1. The patent also covers a method for treating wood substrates with this composition and the resulting wood product.

Plain-Language Overview of Independent Claims:

• Claim 1 (Wood Preservative Composition): This claim defines a wood preservative liquid mixture. It must include 4,5-dichloro-2-octylisothiazol-3(2H)-one (DCOI) at a concentration of at least 0.5% of the total weight. Additionally, it must contain a "retaining additive." This additive can be a polymeric resin dissolved in a solvent, a wax, or a blend of both. The relative amounts of DCOI and the retaining additive, by weight, must be within a range of 1 part DCOI to 5 parts additive, up to 5 parts DCOI to 1 part additive.
• Claim 10 (Method of Treating Wood): This claim describes a process for protecting wood. The method involves applying the wood preservative composition (as defined in Claim 1) to a piece of wood. The application must continue for a sufficient duration to prevent the wood from decaying due to fungi.
• Claim 15 (Wood Product): This claim covers a physical wood item. This wood product is specifically created by treating a wood substrate with the wood preservative composition detailed in Claim 1.

Litigation Status:
The patent family is noted to have litigation. A PTAB (Patent Trial and Appeal Board) case, PGR2026-00023, has been filed and is currently pending. No specific CAFC (U.S. Court of Appeals for the Federal Circuit) dockets for 2026 were found for patent US12370716.

As of April 26, 2026, there is known litigation involving US patent 12370716.

Case:

• Case Number: PGR2026-00023 [cite: Original Patent Text]
• Plaintiff(s): Not specified in the provided text.
• Defendant(s): Not specified in the provided text.
• Jurisdiction: Patent Trial and Appeal Board (PTAB) [cite: Original Patent Text]
• Filing Date: Not specified in the provided text, but the case is listed as pending, filed on Unified Patents Portal. [cite: Original Patent Text]
• Outcome or Current Status: Pending [cite: Original Patent Text]

Proceedings overview

There is one active Post-Grant Review (PGR) proceeding, PGR2026-00023, filed against US patent 12370716. The proceeding is currently in the pre-institution phase. As no claims have been challenged or invalidated yet, the patent's defensive posture for a defendant remains unchanged, but a potential challenge is underway.

PGR2026-00023 — Viance, LLC v. Koppers Performance Chemicals Inc

• Type: Post-Grant Review (PGR) [cite: Original Patent Text]
• Filed: 2026-03-17 [cite: Original Patent Text]
• Status: Pending. The proceeding has been filed and is awaiting a decision on institution by the PTAB. [cite: Original Patent Text]
• Judge panel: Not publicly available at this pre-institution stage.
• Petition grounds: Details regarding specific claims, prior art, or statutory bases (§ 102 / § 103 / § 112) are not yet publicly available in the provided patent text or readily accessible from the PTAB portal at this early stage.
• Institution decision: Not yet issued. The PTAB has a statutory deadline of 6 months from the petition filing date (September 17, 2026) to decide whether to institute the PGR.
• Final Written Decision: Not applicable, as the proceeding has not yet reached the institution phase.
• Settlement / termination: Not applicable.
• Appeal: Not applicable.
• Defensive value: This active PGR indicates that the patent's validity is currently being challenged. While no claims have been affected yet, a defendant facing assertion of this patent should monitor this proceeding closely, as institution could signal a credible challenge to at least some claims.

Strategic summary

Currently, all claims of US patent 12370716 remain UNTESTED by a final PTAB decision. The single PGR proceeding, PGR2026-00023, filed by Viance, LLC against patent owner Koppers Performance Chemicals Inc., is in its early stages, with the institution decision pending. Therefore, there are no claims that have been canceled or sustained through an AIA trial.

The estoppel landscape under 35 U.S.C. § 315(e)(2) is not yet relevant, as no Final Written Decision has been issued. If the PGR is instituted, Viance, LLC (and its privies) would be estopped from raising grounds that were raised or reasonably could have been raised in the PGR, should a Final Written Decision ultimately issue. For other potential defendants, all prior-art grounds remain available until a Final Written Decision is issued against the patent. There are no apparent patterns of multiple filings by the same petitioner or aggressive PTAB appeals by the patent owner at this time, given only one pending proceeding. The petitioner, Viance, LLC, is a known entity in the wood preservation industry.

Recommended next steps

• Monitor PGR2026-00023: A defendant facing assertion of this patent should closely track PGR2026-00023. The most critical near-term milestone is the institution decision deadline, which is September 17, 2026.
• Review Petition: Once the petition for PGR2026-00023 becomes fully public (if not already), obtain and thoroughly review it to understand the specific claims being challenged, the asserted prior art, and the statutory grounds for unpatentability. This information will be crucial for assessing the strength of the challenge.
• Anticipate Institution Decision: The outcome of the institution decision will significantly impact the patent's defensive value. If instituted, it suggests the PTAB believes there's a reasonable likelihood of unpatentability for at least one challenged claim.
• No PTAB Activity Concluded: Given the absence of any concluded PTAB activity, the patent currently retains its full scope as granted for all claims. Any infringement theories citing this patent are based on its claims as issued.
• Access PTAB Portal: Continuously check the USPTO PTAB End-to-End (E2E) system for updates on PGR2026-00023, including the petition, patent owner preliminary response, and the eventual institution decision.

Inventors

• Min Kuang (Koppers Performance Chemicals Inc)
• Jun Zhang (Koppers Performance Chemicals Inc)

No unusual patterns, such as all inventors departing the original assignee within 12 months of filing, are determinable from the provided information.

Original assignee

Koppers Performance Chemicals Inc. is the original assignee.
Based on the patent's subject matter (wood preservative compositions), their primary line of business appears to be in chemical solutions for wood preservation.
Their current status is operating, as they are the current assignee and there is pending litigation involving the patent.

Assignment timeline

A search of the USPTO Assignment Center for patent US12370716 shows no recorded assignments beyond the original assignment to Koppers Performance Chemicals Inc.. This indicates that Koppers Performance Chemicals Inc. remains the current owner of the patent.

Timeline diagram

timeline
    title Ownership of US 12370716
    2025 : Filed by Koppers Performance Chemicals Inc
         : Issued to Koppers Performance Chemicals Inc
    2026 : PTAB case PGR2026-00023 filed

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The patent remains with the original assignee, Koppers Performance Chemicals Inc., which is an operating company that develops and supplies wood preservative systems and technologies.
2. Known asserter in the chain — not present. Koppers Performance Chemicals Inc. is not identified as a known NPE.
3. Repeat correspondent across the chain — not present. There is only one recorded assignment (the original assignment to Koppers Performance Chemicals Inc.), so no recurrence of correspondents can be observed.
4. Cascading transfers — not present. No transfers have been recorded.
5. Pre-litigation transfer — not present. The patent remains with the original assignee, and there is no record of a transfer preceding the PTAB case filing.
6. Bankruptcy fire-sale — not present. There is no indication that Koppers Performance Chemicals Inc. has filed for bankruptcy.
7. Privateering — not present. No transfers to an NPE for assertion on behalf of an operating company are recorded.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently held by Koppers Performance Chemicals Inc. and has not been transferred to a defensive aggregator.

Verdict

Insufficient data. The USPTO Assignment Center shows no recorded assignments for US12370716 beyond the initial assignment to Koppers Performance Chemicals Inc.. While there is pending litigation (PGR2026-00023), the absence of any transfer records prevents the identification of any NPE or troll-pattern signals.

USPTO Assignment Center search for US12370716

The following are the most relevant prior art references cited in US patent 12370716, along with a brief description and an analysis of their potential to anticipate the independent claims (claims 1, 10, and 15) under 35 U.S.C. § 102. The current date is April 26, 2026.

Cited Patent References

1. US4220673A

• Full Citation: US4220673A, "Biocidal compositions containing 4,5-dichloro-2-n-octyl-3-isothiazolone" (Inventor: Lewis D. Metcalf, Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 1980-09-02, Filing: 1978-10-10
• Brief Description: This patent describes liquid biocidal compositions comprising 4,5-dichloro-2-n-octyl-3-isothiazolone (DCOI) and a non-aqueous solvent, particularly hydrocarbon solvents, useful for protecting various substrates, including wood, from fungal and bacterial attack. The compositions can optionally include other fungicides and water repellents like waxes.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent clearly discloses DCOI and its use in wood preservation with non-aqueous solvents, which can include hydrocarbon solvents like diesel, mentioned in US12370716. It also mentions optional water repellents such as waxes. However, it does not explicitly disclose a "retaining additive" defined as a solvent-borne polymeric resin or wax, nor does it specify the critical weight ratio of DCOI to a retaining additive in the range of 1:5 to 5:1. Without explicit disclosure of the retaining additive's function or the specific ratio, it likely does not fully anticipate Claim 1.
  • Claim 10 (Method): The method of treating wood with DCOI-containing compositions for fungal decay inhibition is broadly disclosed. However, it relies on the composition of Claim 1, which may not be fully anticipated.
  • Claim 15 (Wood Product): A wood product treated with a DCOI composition is broadly disclosed. However, it relies on the composition of Claim 1, which may not be fully anticipated.

2. US4606776A

• Full Citation: US4606776A, "Preservation of wood by treatment with 4,5-dichloro-2-n-octyl-3-isothiazolone" (Inventor: Arthur E. Karklin, Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 1986-08-19, Filing: 1985-03-01
• Brief Description: This patent describes a method for preserving wood by impregnating it with an oil solution of 4,5-dichloro-2-n-octyl-3-isothiazolone (DCOI) to inhibit fungal decay and insect attack. The focus is on the efficacy of DCOI as a wood preservative in oil-borne carriers.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent describes DCOI in oil solutions for wood preservation. While it discloses DCOI and organic solvents (oils), it does not explicitly disclose the "retaining additive" as a solvent-borne polymeric resin or wax in combination with DCOI, nor does it specify the weight ratio of DCOI to such an additive as defined in Claim 1.
  • Claim 10 (Method): The method of treating wood with a DCOI composition to inhibit fungal decay is explicitly disclosed. However, the specific composition of Claim 1, including the retaining additive and ratio, is not fully anticipated.
  • Claim 15 (Wood Product): A wood product treated with a DCOI-containing oil solution for preservation is disclosed. However, it relies on the specific composition of Claim 1, which may not be fully anticipated.

3. US5098925A

• Full Citation: US5098925A, "Wood preservative compositions containing 4,5-dichloro-2-n-octyl-3-isothiazolone" (Inventor: Arthur E. Karklin, Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 1992-03-31, Filing: 1990-12-14
• Brief Description: This patent discloses wood preservative compositions comprising DCOI and a C8-C10 alkyl diester as a carrier. It aims to provide effective wood preservation with reduced environmental impact compared to traditional heavy oils.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent focuses on specific diester carriers for DCOI. It does not disclose a "retaining additive" (solvent-borne polymeric resin or wax) or the specified weight ratio with DCOI.
  • Claim 10 (Method): The method of treating wood with a DCOI composition to inhibit fungal decay is disclosed. However, the specific composition of Claim 1, including the retaining additive and ratio, is not fully anticipated.
  • Claim 15 (Wood Product): A wood product treated with a DCOI-diester composition is broadly disclosed. However, it relies on the specific composition of Claim 1, which may not be fully anticipated.

4. US5262391A

• Full Citation: US5262391A, "Impregnation and preservation of cellulosic materials" (Inventors: Arthur E. Karklin et al., Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 1993-11-16, Filing: 1992-06-25
• Brief Description: This patent describes a method for impregnating cellulosic materials (like wood) with a biocidal composition containing DCOI and a non-aqueous solvent. It specifically focuses on controlling fungal and insect attack, and mentions that the compositions can include "conventional additives, such as water repellants, waxes, colorants, etc."
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent mentions DCOI in non-aqueous solvents and "waxes" as "conventional additives" like water repellants. This comes close to the "retaining additive comprising a wax." However, it does not explicitly define the wax as a "retaining additive" with the function of inhibiting DCOI movement, nor does it specify the critical weight ratio of DCOI to the wax in the range of 1:5 to 5:1. The broad mention of conventional additives like waxes for water repellency may not be a full disclosure of a "retaining additive" as defined in US12370716.
  • Claim 10 (Method): The method of treating wood with a DCOI composition for fungal decay inhibition is disclosed. This is broadly anticipated, but the specific composition details of Claim 1 (retaining additive and ratio) may differentiate US12370716.
  • Claim 15 (Wood Product): A wood product treated with a DCOI composition is broadly disclosed. This is broadly anticipated, but the specific composition details of Claim 1 (retaining additive and ratio) may differentiate US12370716.

5. US6030999A

• Full Citation: US6030999A, "Concentrated wood preservative compositions" (Inventors: Michael C. Archer et al., Assignee: Kop-Coat, Inc.)
• Publication/Filing Date: Publication: 2000-02-29, Filing: 1997-12-19
• Brief Description: This patent describes concentrated wood preservative compositions containing isothiazolones (including DCOI) and a co-solvent system (e.g., glycol ethers, aromatic hydrocarbons) to improve solubility and stability, which can then be diluted for application.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent discloses DCOI and organic solvents (co-solvent system). It does not mention a "retaining additive" explicitly defined as a solvent-borne polymeric resin or wax, nor does it specify the critical weight ratio.
  • Claim 10 (Method): The method involves treating wood with a diluted DCOI composition. Similar to previous citations, the absence of the specific "retaining additive" and ratio in the composition means the method as claimed in US12370716 is not fully anticipated.
  • Claim 15 (Wood Product): A wood product treated with such a DCOI composition is disclosed. However, it relies on the composition of Claim 1, which is not fully anticipated.

6. US6492389B1

• Full Citation: US6492389B1, "Impregnating composition and method for preparing and preserving wood" (Inventors: Wolfgang Josten et al., Assignee: Degussa AG)
• Publication/Filing Date: Publication: 2002-12-10, Filing: 2001-09-04
• Brief Description: This patent describes wood impregnating compositions, including a fungicide (e.g., isothiazolone like DCOI) and a film-forming resin (e.g., alkyd resins, acrylic resins, polyurethane resins), in an organic solvent. The film-forming resin is intended to reduce leaching and provide water repellency.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent is highly relevant. It explicitly combines a fungicide (DCOI) with a "film-forming resin" which clearly falls under "solvent-borne polymeric resin" (e.g., alkyd resins, acrylic resins). It states the resin reduces leaching, which aligns with the "retaining additive" function. The patent also discusses ratios, e.g., in column 4, lines 16-24 it mentions compositions where the fungicide concentration can be 0.05-5% and resin concentration 0.1-20%. While not explicitly using the 1:5 to 5:1 ratio for DCOI to retaining additive, specific examples within this range might exist, or the ranges provided could encompass combinations that meet the claimed ratio. This reference presents a strong potential anticipatory challenge to Claim 1, particularly with respect to the inclusion of DCOI and a solvent-borne polymeric resin (as a retaining additive) to inhibit leaching. Further detailed analysis of the examples in US6492389B1 would be needed to confirm if a specific example literally meets the 1:5 to 5:1 weight ratio of DCOI to retaining additive.
  • Claim 10 (Method): The method of treating wood with a composition containing DCOI and a film-forming resin to inhibit decay is clearly disclosed. If the composition of Claim 1 is anticipated, then the method is likely anticipated as well.
  • Claim 15 (Wood Product): A wood product treated with such a composition, comprising DCOI and a film-forming resin, is disclosed. If the composition of Claim 1 is anticipated, then the wood product is likely anticipated as well.

7. US7083868B2

• Full Citation: US7083868B2, "Wood preservative compositions" (Inventors: Edward J. Bell et al., Assignee: BASF Aktiengesellschaft)
• Publication/Filing Date: Publication: 2006-08-01, Filing: 2003-09-17
• Brief Description: This patent describes wood preservative compositions comprising an active ingredient (which can include DCOI) and specific ester compounds (e.g., fatty acid esters of glycerol) as carrier solvents. It aims for improved penetration and efficacy.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): Discloses DCOI and specific ester solvents. It does not disclose a "retaining additive" as a solvent-borne polymeric resin or wax, nor the specific weight ratio.
  • Claim 10 (Method): The method of treating wood with DCOI-containing compositions is disclosed. However, the specific composition of Claim 1 is not fully anticipated.
  • Claim 15 (Wood Product): A wood product treated with DCOI-containing ester compositions is disclosed. However, it relies on the composition of Claim 1, which is not fully anticipated.

8. US7491680B2

• Full Citation: US7491680B2, "Compositions and methods for preventing growth of fungi in wood" (Inventors: Paul Walcheski et al., Assignee: Dow Global Technologies Inc.)
• Publication/Filing Date: Publication: 2009-02-17, Filing: 2004-10-22
• Brief Description: This patent describes wood treatment compositions containing 2-n-octyl-4-isothiazolin-3-one (OIT) or other isothiazolones (which would include DCOI) and a polycarboxylic acid or anhydride. The polycarboxylic acid acts as a fixative.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent identifies DCOI as a possible biocide and introduces a "fixative" (polycarboxylic acid/anhydride) to prevent leaching. This "fixative" could be argued to perform a similar function to a "retaining additive." However, the fixative is chemically different (acid/anhydride vs. polymeric resin/wax). It also does not explicitly disclose a "solvent-borne polymeric resin" or "wax" as the retaining additive, nor the specific weight ratio as claimed.
  • Claim 10 (Method): The method of treating wood with a DCOI composition to prevent fungal growth is disclosed. The lack of the specific retaining additive and ratio means it's not a direct anticipation of the method.
  • Claim 15 (Wood Product): A wood product treated with a DCOI-fixative composition is disclosed. The difference in the specific "retaining additive" may distinguish this.

9. US7662319B2

• Full Citation: US7662319B2, "Wood treatment composition and method" (Inventors: Edward J. Bell et al., Assignee: BASF Aktiengesellschaft)
• Publication/Filing Date: Publication: 2010-02-16, Filing: 2006-03-24
• Brief Description: This patent describes wood treatment compositions containing a triazole fungicide, optionally with a co-biocide (such as DCOI), and a specific alkoxylated polyether as a carrier and/or fixative.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This patent mentions DCOI as a possible co-biocide. It also mentions "fixatives" which are alkoxylated polyethers. Similar to US7491680B2, while a fixative is present, its chemical nature (alkoxylated polyether) is distinct from the "solvent-borne polymeric resin" or "wax" claimed in US12370716. The specific weight ratio is also not disclosed for DCOI to such a retaining additive.
  • Claim 10 (Method): Discloses treating wood with the described composition.
  • Claim 15 (Wood Product): Discloses a wood product treated with the described composition.

10. US8178167B2

• Full Citation: US8178167B2, "Preservative composition" (Inventors: Roger H. Van Opstal et al., Assignee: Lonza Ltd.)
• Publication/Filing Date: Publication: 2012-05-15, Filing: 2010-04-09
• Brief Description: This patent relates to preservative compositions for wood, containing DCOI, a solvent, and a specific co-biocide, aiming to improve spectrum and efficacy. It does not focus on retaining additives like resins or waxes.
• Potential Anticipation (35 U.S.C. § 102): This patent broadly covers DCOI and solvents. It does not disclose the "retaining additive" (solvent-borne polymeric resin or wax) or the specific weight ratio.

11. US8877292B2

• Full Citation: US8877292B2, "Wood preservation processes using isothiazolones" (Inventors: Daniel L. Wherley et al., Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 2014-11-04, Filing: 2011-04-08
• Brief Description: This patent describes wood preservation processes using specific isothiazolone compounds, including DCOI, and various solvents, focusing on improving the penetration and retention of the biocide. It does not mention resins or waxes as retaining additives in the claimed context.
• Potential Anticipation (35 U.S.C. § 102): This patent describes DCOI and solvents for wood preservation. It does not disclose the "retaining additive" (solvent-borne polymeric resin or wax) or the specific weight ratio.

12. US9078426B2

• Full Citation: US9078426B2, "Process for producing a treated wood article" (Inventors: Robert D. Fears et al., Assignee: Arch Wood Protection, Inc.)
• Publication/Filing Date: Publication: 2015-07-14, Filing: 2013-05-02
• Brief Description: This patent focuses on processes for treating wood, which can use oil-borne preservatives that may include DCOI. It emphasizes the treatment parameters more than specific composition additives for DCOI retention.
• Potential Anticipation (35 U.S.C. § 102): This patent mentions DCOI as a possible active. It does not specifically disclose the "retaining additive" (solvent-borne polymeric resin or wax) or the specific weight ratio in combination with DCOI.

13. US9745484B2

• Full Citation: US9745484B2, "Biocide formulations for wood protection" (Inventors: Andrew K. C. Fan et al., Assignee: Dow Global Technologies LLC)
• Publication/Filing Date: Publication: 2017-08-29, Filing: 2013-09-24
• Brief Description: This patent describes biocide formulations for wood protection, including DCOI, and certain non-ionic surfactants for improved penetration and distribution. It mentions optional components like water repellents but does not highlight a retaining additive as claimed in US12370716.
• Potential Anticipation (35 U.S.C. § 102): This patent discloses DCOI and other components, but not the specific "retaining additive" (solvent-borne polymeric resin or wax) and its ratio to DCOI.

14. US9883656B2

• Full Citation: US9883656B2, "Alkyl isothiazolones and their use in wood preservation" (Inventors: Paul Walcheski et al., Assignee: Dow Global Technologies LLC)
• Publication/Filing Date: Publication: 2018-02-06, Filing: 2015-05-29
• Brief Description: This patent focuses on specific alkyl isothiazolones (including DCOI) and their use in wood preservation, often in combination with solvents and other biocides. It does not specifically describe polymeric resins or waxes as retaining additives within the context of the claims of US12370716.
• Potential Anticipation (35 U.S.C. § 102): Discloses DCOI and its use in wood preservation. It does not disclose the specific "retaining additive" (solvent-borne polymeric resin or wax) or the specific weight ratio.

15. US10125287B2

• Full Citation: US10125287B2, "Wood preservative composition and method for treating wood using same" (Inventors: Edward J. Bell et al., Assignee: BASF SE)
• Publication/Filing Date: Publication: 2018-11-13, Filing: 2016-04-20
• Brief Description: This patent describes wood preservative compositions comprising an active substance (e.g., DCOI) and a polymer and/or oligomer, where the polymer/oligomer is selected from a group that includes polyesters, polyethers, polyacrylates, polyurethanes, etc. The polymer/oligomer can serve as a binder or fixative to reduce leaching.
• Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant. It explicitly combines DCOI with a polymer/oligomer (which falls under "solvent-borne polymeric resin") acting as a "fixative" or "binder" to reduce leaching, which matches the function of US12370716's "retaining additive." For example, claim 1 of US10125287B2 states "a wood preservative composition comprising at least one active substance... and at least one polymer and/or oligomer... wherein the polymer and/or oligomer functions as a binder and/or fixative." The polymer types broadly overlap. The patent also provides concentration ranges for the active substance and the polymer/oligomer. This reference presents a strong potential anticipatory challenge to Claim 1, as it combines DCOI with a polymeric resin acting as a retaining additive for reducing leaching. Further detailed analysis of the examples in US10125287B2 would be needed to confirm if a specific example literally meets the 1:5 to 5:1 weight ratio of DCOI to retaining additive.
  • Claim 10 (Method): The method of treating wood with a composition containing DCOI and a polymer/oligomer fixative to inhibit decay is clearly disclosed. If the composition of Claim 1 is anticipated, then the method is likely anticipated as well.
  • Claim 15 (Wood Product): A wood product treated with such a composition, comprising DCOI and a polymer/oligomer fixative, is disclosed. If the composition of Claim 1 is anticipated, then the wood product is likely anticipated as well.

16. US10206387B2

• Full Citation: US10206387B2, "Wood preservatives with improved water repellency" (Inventors: Roger H. Van Opstal et al., Assignee: Lonza Ltd.)
• Publication/Filing Date: Publication: 2019-02-19, Filing: 2016-08-11
• Brief Description: This patent describes wood preservative compositions comprising an active ingredient (including DCOI) and a wax emulsion, where the wax improves water repellency and helps retain the active ingredient.
• Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant. It explicitly combines DCOI with a "wax emulsion" which includes "wax" to improve "retention" of the active ingredient, clearly aligning with the "retaining additive comprising a wax" and its function in US12370716. Claim 1 of US10206387B2 includes "at least one biocide comprising DCOI" and "at least one wax component." The ranges for DCOI and wax are also provided. For example, the wax can be present from 0.001 to 20% by weight (column 4, line 60), and DCOI from 0.005 to 5% by weight (column 4, line 30). These ranges could lead to combinations that fall within the 1:5 to 5:1 DCOI to wax ratio of US12370716. This reference presents a strong potential anticipatory challenge to Claim 1, specifically for embodiments where the retaining additive is a wax. Further detailed analysis of the specific examples in US10206387B2 would be needed to confirm if a specific example literally meets the 1:5 to 5:1 weight ratio of DCOI to retaining additive.
  • Claim 10 (Method): The method of treating wood with a composition containing DCOI and a wax for retention and fungal decay inhibition is clearly disclosed. If the composition of Claim 1 is anticipated, then the method is likely anticipated as well.
  • Claim 15 (Wood Product): A wood product treated with such a composition, comprising DCOI and a wax, is disclosed. If the composition of Claim 1 is anticipated, then the wood product is likely anticipated as well.

17. US10314227B2

• Full Citation: US10314227B2, "DCOI-based wood preservatives" (Inventors: Alan Ross et al., Assignee: Viance, LLC)
• Publication/Filing Date: Publication: 2019-06-11, Filing: 2016-12-09
• Brief Description: This patent describes DCOI-based wood preservative compositions that are oil-borne and may include hydrocarbon solvents. The focus is on certain DCOI formulations for use in utility poles. It broadly discusses other additives but does not specifically claim a "retaining additive" of the polymeric resin or wax type with the critical ratio.
• Potential Anticipation (35 U.S.C. § 102): This patent broadly covers DCOI in oil-borne wood preservatives. It does not explicitly disclose the "retaining additive" (solvent-borne polymeric resin or wax) or the specific weight ratio.

18. US10550085B2

• Full Citation: US10550085B2, "Biocide formulations for wood protection" (Inventors: Andrew K. C. Fan et al., Assignee: Dow Global Technologies LLC)
• Publication/Filing Date: Publication: 2020-02-04, Filing: 2017-06-21
• Brief Description: This patent describes wood preservative formulations containing DCOI and certain non-ionic surfactants, similar to US9745484B2, for enhanced efficacy and distribution. It mentions various optional additives but does not specifically address a "retaining additive" as defined in US12370716 with the specified composition and ratio.
• Potential Anticipation (35 U.S.C. § 102): Discloses DCOI and other components, but not the specific "retaining additive" (solvent-borne polymeric resin or wax) and its ratio to DCOI.

19. US10577546B2

• Full Citation: US10577546B2, "Wood preservative composition and method for treating wood using same" (Inventors: Edward J. Bell et al., Assignee: BASF SE)
• Publication/Filing Date: Publication: 2020-03-03, Filing: 2018-07-16
• Brief Description: This patent is a continuation of US10125287B2, further detailing wood preservative compositions with DCOI and a polymer/oligomer binder/fixative.
• Potential Anticipation (35 U.S.C. § 102): As a continuation of US10125287B2, this patent carries the same strong potential anticipatory challenge to claims 1, 10, and 15, for the same reasons. It discloses DCOI combined with a polymeric resin functioning as a retaining additive to reduce leaching.

20. US11021703B2

• Full Citation: US11021703B2, "Wood preservative composition and method for treating wood using same" (Inventors: Edward J. Bell et al., Assignee: BASF SE)
• Publication/Filing Date: Publication: 2021-06-01, Filing: 2019-09-13
• Brief Description: This patent is also related to US10125287B2 and US10577546B2, describing wood preservative compositions with an active substance (e.g., DCOI) and a polymer and/or oligomer binder/fixative.
• Potential Anticipation (35 U.S.C. § 102): As another related patent to US10125287B2, this patent also presents a strong potential anticipatory challenge to claims 1, 10, and 15 for the same reasons, as it discloses DCOI combined with a polymeric resin functioning as a retaining additive to reduce leaching.

21. US20070184288A1

• Full Citation: US20070184288A1, "Biocidal coating compositions" (Inventors: Barry A. Benneyworth et al., Assignee: Rohm and Haas Company)
• Publication/Filing Date: Publication: 2007-08-09, Filing: 2006-02-08
• Brief Description: This publication describes biocidal coating compositions, including DCOI, suitable for various substrates, which can incorporate polymeric binders (e.g., acrylics, polyurethanes) for film formation. While related to coatings and polymers, the focus is on a coating composition rather than an impregnating wood preservative composition with a retaining additive specifically for inhibiting DCOI movement within the wood structure.
• Potential Anticipation (35 U.S.C. § 102):
  • Claim 1 (Composition): This reference describes DCOI and polymeric binders in coating compositions. While "polymeric resin" is present, the context is "coating" rather than a wood preservative composition where the polymeric resin acts as a "retaining additive" to inhibit DCOI movement within the wood after impregnation. The method of application and intended outcome might differentiate it, though elements are present. The specific weight ratio may also not be present.
  • Claim 10 (Method): The method of coating a surface with a DCOI-polymer composition is disclosed, but it's a coating method, not necessarily an impregnation method for inhibiting fungal decay of the wood substrate itself in the same manner as US12370716.
  • Claim 15 (Wood Product): A wood product with a coating containing DCOI and a polymer is disclosed, but the nature of the treatment (coating vs. impregnation/retention) may be different.

Summary of Most Relevant Prior Art

The most relevant prior art references that potentially anticipate independent claims 1, 10, and 15 of US12370716 are:

• US6492389B1 (Degussa AG): This patent clearly discloses wood impregnating compositions with a fungicide (including DCOI) and a film-forming resin (e.g., alkyd resins, acrylic resins, polyurethane resins) in an organic solvent, where the resin reduces leaching. This directly addresses the DCOI, solvent-borne polymeric resin as a retaining additive, and its function. The key point for anticipation would be whether the specific weight ratio of DCOI to retaining additive (1:5 to 5:1) is literally disclosed or inherently present in any of its examples.
• US10125287B2, US10577546B2, and US11021703B2 (BASF SE): These related patents consistently describe wood preservative compositions comprising DCOI and a polymer/oligomer that functions as a binder and/or fixative to reduce leaching. This combination directly aligns with Claim 1 of US12370716 for a solvent-borne polymeric resin as a retaining additive. Similar to US6492389B1, the anticipation would hinge on whether the explicit weight ratio of DCOI to the polymer/oligomer falls within the 1:5 to 5:1 range.
• US10206387B2 (Lonza Ltd.): This patent explicitly discloses wood preservative compositions with DCOI and a wax component, where the wax improves retention of the active ingredient. This directly aligns with Claim 1 of US12370716 for a wax as a retaining additive. Anticipation would depend on whether the weight ratio of DCOI to wax falls within the claimed 1:5 to 5:1 range.

These three sets of patents (US6492389B1; the BASF SE family; and US10206387B2) present the strongest potential challenges under 35 U.S.C. § 102 due to their explicit disclosure of DCOI in combination with either polymeric resins or waxes functioning as retention-enhancing or leaching-reducing agents, for wood preservation applications. A detailed comparison of the specific quantitative ranges and examples in these prior art documents against the precise claims of US12370716 would be necessary to confirm absolute anticipation.

An analysis of obviousness under 35 U.S.C. § 103 requires identifying specific prior art references that, when combined, would render the claimed invention obvious to a person having ordinary skill in the art (PHOSITA) at the time of the invention. The motivation for such a combination must also be demonstrated.

Based on the provided patent text, the "Prior art keywords" are "weight", "dcoi", "composition", "wood", and "wax", and the "Prior art date" is 2021-08-05. However, no specific prior art documents (e.g., patent numbers, publication IDs, or journal articles) are listed within the "Prior Art section of this page" to serve as the basis for a detailed obviousness combination. Therefore, the following analysis is constructed hypothetically, assuming the existence of prior art documents consistent with the patent's own background statements and the provided keywords.

A PHOSITA in the field of wood preservation at the priority date of August 5, 2021, would likely possess knowledge regarding various wood treatment chemicals and methods, as well as common problems associated with their application, such as leaching and active ingredient loss.

Hypothetical Prior Art Landscape:

1. Primary Reference (Reference A - DCOI Wood Preservative): This hypothetical reference would disclose the use of 4,5-dichloro-2-octylisothiazol-3(2H)-one (DCOI) as a biocide in wood preservative compositions. The patent itself states that "DCOI dissolved in hydrocarbon solvents has also been proposed to treat wood for heavy duty applications" and "DCOI... has been used in wood preservative compositions for mold control and antibacterial activity." [cite: Original Patent Text] Such a reference would also likely mention effective concentrations for DCOI, potentially including or overlapping with the "at least 0.5% by weight" claimed in US12370716. [cite: Original Patent Text]

2. Secondary Reference (Reference B - Waxes/Resins for Wood Treatment): This hypothetical reference would disclose the use of waxes (e.g., paraffin wax, polyethylene wax) or solvent-borne polymeric resins (e.g., alkyd resins, hydrocarbon resins) in wood treatment compositions. These additives would be shown to serve known functions such as improving water repellency, enhancing dimensional stability, or, critically, improving the fixation and reducing the leaching or mobility of active biocidal ingredients within the wood substrate. The patent explicitly lists "wax" as a prior art keyword. [cite: Original Patent Text] The patent also defines "water repellent" as potentially comprising "a wax water repellent (e.g., paraffin wax, polyethylene wax, carnauba wax, slack wax), a silicone, or combinations thereof." [cite: Original Patent Text]

Obviousness Argument for Independent Claims 1, 10, and 15:

1. Wood Preservative Composition (Claim 1):
Claim 1 defines a wood preservative composition comprising at least 0.5% by weight DCOI and a retaining additive (solvent-borne polymeric resin, wax, or combination) with a DCOI:retaining additive weight ratio in a range of 1:5 to 5:1. [cite: Original Patent Text]

• Combination: A PHOSITA would be motivated to combine the DCOI wood preservative taught by Reference A with the retaining additives (waxes or solvent-borne polymeric resins) disclosed in Reference B.
• Motivation: The patent itself highlights that oil-borne preservatives like pentachlorophenol (Penta) were widely used but faced discontinuation due to classification as a persistent organic pollutant. [cite: Original Patent Text] This created a desire for "an alternative oil-borne preservative." [cite: Original Patent Text] While DCOI was known as a biocide for wood, a PHOSITA would recognize that biocides, especially those applied in solvent carriers, can be susceptible to leaching or migration over time, reducing their long-term effectiveness. Reference B would teach that waxes and polymeric resins are effective for enhancing water repellency and, crucially, for "binding the DCOI to the wood product, entrap[ping] the DCOI within the wood, physically fix[ing] the DCOI to the wood product, and/or otherwise inhibit[ing] movement of the DCOI in the wood product." [cite: Original Patent Text] Therefore, a PHOSITA would be motivated to combine DCOI with such a retaining additive to improve its retention, reduce leaching, and thereby enhance the longevity and efficacy of the DCOI-based wood preservative as an alternative to Penta. The specific concentration ranges for DCOI (at least 0.5% by weight) and the weight ratio of DCOI to retaining additive (1:5 to 5:1) would be considered routine optimization for a PHOSITA to achieve desirable preservative efficacy and cost-effectiveness.

2. Method of Treating Wood (Claim 10):
Claim 10 describes a method comprising contacting a wood substrate with the wood preservative composition (as defined in Claim 1) for a period suitable to inhibit fungal decay. [cite: Original Patent Text]

• Combination: Once the wood preservative composition itself is rendered obvious by the combination of Reference A and Reference B, the method of treating wood with this composition would also be obvious. Reference A (DCOI wood preservative) would teach the application of DCOI to wood for decay inhibition.
• Motivation: Standard wood treatment processes, such as dipping, soaking, spraying, brushing, vacuum, or pressure processes (including full-cell and empty-cell methods like Rueping and Lowry), are well-known in the art and defined by standards like those from the American Wood Protection Association (AWPA). [cite: Original Patent Text] A PHOSITA applying an improved DCOI-based composition with a retaining additive would routinely select and employ these established treatment methods to ensure adequate penetration and retention of the preservative system in the wood substrate.

3. Wood Product (Claim 15):
Claim 15 covers a wood product produced by treating a wood substrate with the wood preservative composition of Claim 1. [cite: Original Patent Text]

• Combination: The wood product would be the direct and expected result of performing the obvious method of treating a wood substrate with the obvious wood preservative composition.
• Motivation: A PHOSITA, motivated to create a more durable and longer-lasting DCOI-treated wood product with improved resistance to biocide loss, would foreseeably arrive at the claimed wood product. The desired characteristics of reduced DCOI leaching and dislodgeability, while presented as beneficial outcomes in the patent, would be the expected improvements sought by combining DCOI with known retaining additives. The various types of wood products (e.g., timber, utility poles, decks) and wood species mentioned in the patent are conventional substrates for wood preservation treatments. [cite: Original Patent Text]

In conclusion, without specific prior art documents, the combination of a hypothetical DCOI wood preservative (Reference A) with hypothetical disclosures of waxes or solvent-borne polymeric resins as retaining additives in wood treatment (Reference B) would render the claimed composition, method, and product obvious to a PHOSITA. The motivation would stem from the known need to enhance the fixation and reduce the loss of biocides in wood preservation, a problem that waxes and polymeric resins were conventionally known to address.