PBT Engineering Resins Patents: Top Filers & Trends 2026
- Filing has cooled since 2020. activity peaked at 81 records that year and has declined toward 4 in the most recent (partial) year, with the 2022 midpoint of 57 confirming a flattening trend rather than a temporary dip.
- The top 5 hold 42.3% of the field. 380 of 898 records sit with five assignees, and the top 10 combined reach 56.7% — concentrated enough that a newcomer's freedom-to-operate work should start with those portfolios, not a broad landscape scan.
- Additives and condensation chemistry dominate the classing. C08K (additives) appears on 57.1% of records and C08G (condensation polymers) on 26.9%, showing that flame-retardant and hydrolysis-stabilising additive packages, not new backbone chemistry, are where most claims sit.
What this landscape covers
This landscape tracks 898 published records at the intersection of polybutylene terephthalate resin compositions and four performance problems that recur across the automotive, electronics and connector markets: hydrolysis resistance, warpage control in molded parts, flame retardant grades, and laser weldability for connectors, alongside crystallization rate claims that affect all four. The search combines PBT-specific text terms with IPC classes for condensation polymers (C08G63), polymer compositions (C08L67) and glass or fibre additive use (C08K7), so the corpus is deliberately narrow to formulation and processing claims rather than the wider polyester family.
Coverage runs from 2015 through the 2026-07-31 cut-off. Because publication typically lags filing by around 18 months, the most recent one or two years in any trend chart will understate real filing activity and should be read as provisional.
Filing trend and technology composition
Two views of the same 898 records: how filing volume has moved year over year, and which IPC subclasses carry the claims.
A decade of rise and cooling
Filings rose from 31 in 2017 to a peak of 81 in 2020, held near the 2022 midpoint of 57, then declined toward 4 in the latest partial year. Read the tail end cautiously given publication lag, but the multi-year decline from the 2020 peak predates that lag and looks real.
Where the claims sit
C08L (polymer compositions) touches 86.2% of records and C08K (additives) 57.1%, confirming this is primarily a formulation field. C08G (condensation polymers, base resin chemistry) appears on only 26.9% of records, and shaping/processing classes like B29C and B32B sit further back still — most competitive activity is in what gets blended into the resin, not how the resin itself is made or shaped.
Shares are the percentage of the 898 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on PBT Engineering Resins with Eureka
This page is one run against one query. Ask Eureka your own question about pbt engineering resins and every answer comes back with the patent numbers behind it.
Try EurekaRepresentative filing and most-cited prior art
Polybutylene terephthalate resin composition having excellent flame retardancy and hydrolysis resistance and molded article produced therefrom
The present invention relates to a polybutylene terephthalate resin composition having excellent flame retardancy and hydrolysis resistance and a molded article produced therefrom and, more specifically, to a polybutylene terephthalate resin composition and a molded article produced therefrom, the polybutylene terephthalate resin composition having hydrolysis resistance and heat resistance that are improved by melt-processing a polybutylene terephthalate resin by using polycyclohexylenedimethylene terephthalate resin, and simultaneously having flame retardancy and impact resistance that are improved by using a phosphorus-based flame retardant and a compatibilizer.Filed by Samyang Corporation, published 2023-04-06. Notable for combining a PCT-modified blend route to hydrolysis resistance with a phosphorus-based flame retardant package in a single composition claim.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4632869A | Resin composition, opaque film and method of preparing same | 399 |
| 2 | JP1996073719A | Thermoplastic resin composition | 79 |
| 3 | EP0685509A1 | Transparent film for lamination coating of metallic can | 72 |
| 4 | US20070129475A1 | Resin composition for laser welding and molded article | 71 |
| 5 | US4536531A | Polyester resin composition | 71 |
| 6 | US6359106B1 | Production process and production apparatus for polybutylene terephthalate | 70 |
| 7 | US6465067B1 | Composition and process for manufacturing PBT catheter balloons | 58 |
| 8 | JP2006056997A | Polybutylene terephthalate resin composition and molded product | 51 |
| 9 | US6723826B2 | Production process and production apparatus for polybutylene terephthalate | 51 |
| 10 | US6458916B1 | Production process and production apparatus for polybutylene terephthalate | 50 |
Citation counts accumulate over time, so older records such as US4632869A and US4536531A lead the table by virtue of age as much as influence. Treat citation rank as a signal of historical influence on the field, not of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once volume, concentration and classing are read together.
The field is concentrated but not closed
The top 5 assignees hold 380 of 898 records (42.3%), and the top 10 reach 509 (56.7%). That leaves a long tail below tenth place holding roughly 43% of the corpus between them, which is where smaller entrants and single-filing companies operate around the edges of established formulation claims.
Volume has been declining since 2020
The peak year of 81 filings in 2020 gave way to a midpoint of 57 in 2022 and a sharp fall toward the most recent partial year. Even allowing for publication lag understating the last one to two years, the multi-year direction from 2020 onward points to a maturing, not expanding, claim space.
Additive and blend claims outweigh backbone chemistry
C08L (polymer compositions) and C08K (additive use) together dominate the classing, at 86.2% and 57.1% of records respectively, while C08G (condensation polymer synthesis) sits at 26.9%. Most competitive filing effort goes into what is blended into PBT, not new routes to the polymer itself.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to pbt engineering resins, with the prior art for and against each one.
Who is filing, and where momentum has stalled
The ranked leaders are almost entirely Japanese material suppliers, with recent-year activity flat across the board.
A single leader well ahead of the field
The top-ranked assignee holds 114 records against a fifth-place figure of 36 and a tenth-place figure of 22 — a steep drop from first to fifth that flattens out further down the ranking.
Recent-year filing has gone quiet at the top
Several of the most active historical assignees show zero filings in the latest year, and the single leader tracked for year-over-year momentum shows just 1 filing at 0% YoY. This is consistent with the broader 2020-to-present decline rather than a company-specific pullback.
Co-filing is limited and mostly intra-market
Only 10 co-assignee pairs appear in the corpus, the strongest linking two entities with 6 joint records. This is a field of largely independent corporate filers rather than joint development programmes, at least as visible through co-assignment.
| Assignee | Recent year | YoY |
|---|---|---|
| Mitsubishi Chemical Corporation | 1 | 0% |
| Toray Industries, Inc. | 0 | — |
| Win Tech Polymer Ltd. | 0 | — |
| Polyplastics Co., Ltd. | 0 | — |
| Mitsubishi Engineering-Plastics Corporation | 0 | — |
| Toyobo Co., Ltd. | 0 | — |
| Teijin Limited | 0 | — |
| LG Chem Ltd. | 0 | — |
Using this landscape
The dataset points to where claim space is dense and where it has gone quiet — the next steps depend on whether you are filing, licensing or clearing a design.
Check freedom-to-operate against the concentrated top 10
With 56.7% of records held by ten assignees, a targeted clearance search against those portfolios will cover more risk than a broad keyword scan of the full 898-record field.
Run a clearance search in EurekaWatch for renewed filing after the 2020 peak
Volume has declined since 2020 toward the most recent partial year; whether that reverses will show once publication lag clears on 2025-2026 filings.
Track filing trends in EurekaExplore under-claimed branches before committing R&D
Sub-areas like laser-weldable connector housings and low-warpage thin-wall molding sit outside the dominant C08L/C08K claim density and may offer more open claim space.
Explore white space in EurekaCommon questions about PBT engineering resin patents
Filing in this space is concentrated among a small group of Japanese material suppliers, with the leading assignee holding 114 records compared with 36 at fifth place and 22 at tenth. The top 5 assignees together account for 42.3% of the 898 records in scope, and the top 10 reach 56.7%. Below that tenth position, the remaining share is spread across a long tail of the 100 ranked companies, so smaller or newer filers still have room to operate outside the concentrated core.
No — filing peaked at 81 records in 2020, held near a midpoint of 57 in 2022, and has declined toward 4 in the most recent partial year. Some of that recent drop reflects the roughly 18-month lag between filing and publication, which always understates the newest year in any trend. But the multi-year decline from the 2020 peak predates that lag window and points to a genuinely cooling filing environment rather than a data artefact.
Based on the IPC composition of this corpus, most claims fall under polymer compositions (C08L, 86.2% of records) and additive use (C08K, 57.1%), meaning the bulk of activity is about what gets blended into PBT — flame retardants, hydrolysis stabilisers, glass or fibre reinforcement — rather than new synthesis routes for the base polymer, which sits at 26.9% under C08G. Search terms in this dataset centre on hydrolysis resistance, warpage in molded parts, flame retardant grades, laser weldability for connectors and crystallization rate, which map directly onto that additive-heavy claim pattern.
In this dataset, Japan leads receiving offices with 272 records, followed by Europe (EPO) at 187, the United States at 163, China at 115, WIPO/PCT filings at 33, and Austria at 22. That distribution is consistent with a field led by Japanese material producers who also pursue protection across Europe and the US, with China representing a growing but still secondary filing venue.
US20230105770A1, filed by Samyang Corporation and published 2023-04-06, claims a PBT composition that pairs polycyclohexylenedimethylene terephthalate blending for hydrolysis and heat resistance with a phosphorus-based flame retardant and compatibilizer for flame retardancy and impact resistance. Anyone formulating a PBT blend that combines both hydrolysis-resistance and flame-retardancy improvements through a similar PCT-blend-plus-phosphorus-retardant route should review this filing's specific claim scope before finalising a formulation. It does not block hydrolysis-resistance or flame-retardancy improvements achieved through other mechanisms, such as different comonomers or non-phosphorus retardant chemistries.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.