Inside Green Innovation: Progress Report - Fourth Edition highlights:
- Global bioplastic patent applications are at a historic high.
- South Korea continues to be the largest source of filings in bioplastics.
- Filing rates appear to reflect increasing research focus on polyhydroxyalkanoates (PHAs) compared to polylactic acid (PLA), butylene-based polymers or starch blends.
- There has been a decrease in the number of filings that progress into international patent families, possibly due to economic pressures.
Conventional, petrochemically-derived plastics are used in a wide variety of everyday items, such as food packaging and drinks bottles. They are typically cheap, strong, and lightweight and may be formed of polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET) amongst others. However, plastic pollution is becoming recognised as an increasingly pressing problem. Once single-use plastics find their way into the natural environment, they degrade very slowly and may remain there for decades. The very longevity that makes conventional plastics valuable materials is also one of their greatest downsides. Plastics produced from renewable biomass sources can offer additional end of life pathways to deal with the problems surrounding plastic pollution. There are various bioplastics in production today, including:
- Starch blends: readily available and cheap compared to other natural polymers, with good biodegradability. However, poor water resistance and low strength means that starch is typically blended with other polymers
- Polylactic acid (PLA): made from sugar found in crops like corn and sugar cane, PLA is relatively inexpensive and has several attractive mechanical properties compared to other biodegradable polymers, which makes it popular. However, it requires industrial composting to break down
- Polyhydroxyalkanoates (PHAs): made from sugars grown from algae, high production costs are a hurdle to global use
- Butylene-based polymers: include polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT), which are petrochemically-derived, biodegradable plastics.
There has been some criticism that bioplastics that only break down under industrial composting conditions, such as PLA, are not suitable for addressing plastic pollution in the natural environment. This highlights the challenge faced by researchers in the bioplastics field to find bioplastics with the right combination of biodegradability and mechanical properties.
Global patent activity
Global patent filings in bioplastics saw significant activity in the 1990s, peaking in 2003 and then steadily declining over the 2010s.
However, since 2018 there has been a year-on-year increase in patent filing activity (Figure 1). Each year since has been higher than the previous year and now the number of patent filings far surpasses the earlier peak in 2003. This global high for bioplastic patent filing reflects the level of innovation aimed at solving the plastics problem.
Figure 1: Sixty-year trend (1963-2022) - global priority filings – bioplastic innovations
(Priority filing = the first time a patent application for a unique invention has been filed (the first filing))
We have also looked at the filing numbers for patent applications which subsequently extend into other territories (Figure 2), which can be an indication of the commercial importance of the invention being patented internationally. The filing numbers of these ‘international patent families’ are similar to the total filing numbers of Figure 1, but the major activity peaking in 2003 is instead replaced with a more subdued number of peaks across 2002, 2006 and 2011.
Figure 2: Thirty-year trend (1993-2022) - global priority filings also filed in one or more additional territories – bioplastic innovations
Differences between total filing numbers and filing numbers for international patent families can be due to a variety of factors. One is the commercial promise of an invention. An application must typically be extended into other territories within twelve months of the initial filing. However, as this can involve considerable expense, the filing entity is more likely to decide to extend the application to other territories if it becomes clear during the period that an application may lead to a return on investment. Therefore, the initial promise of bioplastics may have led to a boom in research and a corresponding wave of total patent filings to protect the innovations. But, when commercial results failed to materialise, investment fell, and organisations did not progress the patents into international filings. Nevertheless, the filing numbers for international patent families relating to bioplastics saw a year-on-year increase between 2018 and 2021, culminating in a historic high and mirroring the trends in overall filing numbers seen in Figure 1. We observe that the number of filings for international patent families dropped in 2022, unlike the overall filing numbers. Possibly, the commercial prospects of the filings in 2022 were not sufficient to warrant extending into multiple territories. However, rather than reflecting poorly on the strength of the innovations themselves, a bigger factor may have been the global economic downturn in 2022 as extending a patent application into multiple territories requires higher expenditure. That said, the rise of overall filings numbers in 2022 suggests that research into bioplastics continues to attract investment.
Top filing territories
Splitting global patent filings by originating territory reveals some interesting differences between the respective countries (Figure 3) - the 2003 peak was almost entirely due to filings originating in Japan. Since the early 2000s, the filing numbers from Japan have dropped significantly and never reached the same heights, despite rebounding slightly since 2018. In fact, no individual territory has ever matched the filing numbers emerging from Japan in 2003. The fact that overall filing numbers are currently at a historic high is due to the combined contribution from multiple countries. In 2022, filing numbers were either stable or increased in South Korea, Europe, Japan, India, China, and Brazil compared to the previous year, together forming a general upward trend. A notable exception is the US, where filings have dropped since 2021. South Korea has been the global leader in filings relating to bioplastics since 2020, but significantly pulled ahead in 2021. This is possibly in response to the South Korean government setting targets for the reduction of plastic waste by 2025 and fossil-based plastics by 2050. South Korea’s stable filing numbers in 2022 show that the incentive to innovate has remained high.
Figure 3: Twenty five-year trend (1998-2022) – global priority filings by territory - bioplastic innovations
South Korea was also the largest source of international patent families relating to bioplastics in 2022 (Figure 4). As discussed, filings of international patent families suggest inventions that are anticipated to find global success. The increase in international patent families filed in South Korea between 2021 and 2022, in light of overall filing numbers plateauing, suggests that the bioplastics research in South Korea is maturing and returning a greater proportion of commercially viable innovation for global application. No other territory saw a significant increase in the filings of international patent families in 2022, as might be expected from the global drop seen in Figure 2. The US in particular has experienced a sharp drop in such filings, which suggests the country has experienced a sizeable decline in bioplastics research.
Figure 4: Twenty five-year trend (1998-2022) – global priority filings by territory also filed in one or more additional territories – bioplastic innovations
Trends in different types of bioplastics
Are certain types of bioplastics seeing a greater proportion of research activity and are there any recent changes in this? Looking at the overall filing numbers for starch blends, PLA, PHAs and butylene-based polymers reveals that filings relating to PLA have consistently been much higher than for starch blends, PHAs, and butylene-based polymers for decades. However, from 2021 to 2022 PHA-related filings had the sharpest increase amongst these four types of bioplastics, whereas filings relating to butylene-based polymers fell slightly. This caused PHAs to overtake butylene-based polymers as the bioplastic with the second highest number of patent filings behind PLA. Despite being relatively low, filing numbers for starch blends also experienced a sharp increase and those relating to both PHAs and starch blends are now at historic highs.
Figure 5: Twenty five-year trend (1998-2022) – global priority filings by material – starch blends, PLA, PHAs, and butylene-based polymers
When looking at international patent families, filing numbers for starch blends, PLA, PHAs and butylene-based polymers dropped in 2022. For the first time in more than 20 years, PLA is no longer the bioplastic with the largest number of international patent family filings. This distinction now goes (albeit by a thin margin) to PHAs. Therefore, it seems that PHAs are attracting a greater proportion of serious innovation compared to other types of bioplastics. Could this shift in filing trends reflect concerns regarding the sustainability and environmental biodegradability of bioplastics? While PLA has attracted the most research to date, possibly due to advantageous physical properties and processability, it does not biodegrade in the natural environment and must be recycled or industrially composted. Meanwhile, butylene-based polymers are typically derived from petrochemicals and starch blends suffer from low strength and robustness. In contrast, PHAs seem to offer the promise of a bioplastic that can degrade in the natural environment without the need for composting, is obtainable from renewal sources and has acceptable physical properties for a variety of commercial uses. The high biodegradability of PHA is often cited in patent applications as a key motivation for research into this type of bioplastic.
Figure 6: Twenty five-year trend (1998-2022) – global priority filings also filed in one or more additional territories - by material (starch blends, PLA, PHAs, and butylene-based polymers)
Companies filing bioplastics patents
The continued increase in overall filing numbers for bioplastics appears to be in part because of new players attracted to this area of innovation. In 2022, the top filer of bioplastics-related patent applications was by far Bioreset Biotecnologia LTDA, a Brazilian startup with no previous history of filing patent applications (Figure 7). Bioreset was responsible for the majority of filings coming from Brazil in 2022, seen in Figure 3. However, none of Bioreset’s filings have extended beyond Brazil, suggesting that this company is focused on producing and protecting a high volume of early-stage innovation in Brazil only. The second and third most prolific filers of 2022, the LG Chemical group and CJ Cheiljedang, reflect the dominance of South Korea in bioplastics innovation, while interesting to note that filings from these two entities have declined slightly despite stable filing numbers from South Korea. It seems that a wider spread of entities in South Korea are taking on more of the research effort in bioplastics. Bioreset, LG Chemical, and CJ Cheiljedang have each been filing patent applications relating to PHAs. In fact, PHAs appear to be the subject of most of the bioplastic-related filings from Bioreset and CJ Cheiljedang, in keeping with the recent increased focus on this type of bioplastic. Bioreset’s filings describe methods of producing PHAs from various sources of industrial and agricultural waste. CJ Cheiljedang, meanwhile, has recently filed applications relating to a variety of aspects of PHAs, including improving their mechanical properties, recovering and using the byproducts of PHA manufacture and adapting PHA compositions for different processing methods, such as extrusion coating or nonwoven fabric production.
Figure 7: Ten-year overview (2013-2022) – top filers – bioplastics innovation
Implications for innovation and future patent filings
The state of the global economy will inevitably be a consideration when filing patent applications, as shown by the decline of international patent families filed in 2022. However, the continued rise of overall filings relating to bioplastics suggests only a temporary decline. Meanwhile, the search for bioplastics with the ideal combination of biodegradability, sustainability, and mechanical properties is shifting the focus of innovation from PLA and butylene-based polymers to PHAs. However, we expect that all three bioplastic types will continue to attract significant research efforts and, consequently, significant number of patent applications in the future.
Chris Mason
Partner
David Jasiewicz
Associate