Section 3: Bioplastics
Development & application
Plastic production started at the beginning of the last century. Since then, it is estimated that around 8.3bn tonnes of plastic have been produced, nine percent has been recycled, and twelve percent has been incinerated. The remaining seventy-nine percent is in circulation, in landfill, or has transitioned into other parts of the natural environment. The latest update from the Geneva Environment Network (GEN), a cooperative partnership of more than one hundred environmental and sustainable development organizations, describes the impact of plastic: “The world is facing a plastic crisis, the status quo is not an option. Plastic pollution is a serious issue of global concern which requires an urgent and international response…” The half-life of common plastic items such as plastic bottles made of HDPE (high-density polyethylene) or PET (polyethylene terephthalate) is not thoroughly researched as scientific knowledge related to the conditions of breakdown is incomplete. It is clear, however, that without optimal environmental conditions such as UV exposure and heat, breakdown likely takes more than one hundred years. Even with optimal conditions, the half-life of such materials can be several decades.
Finding alternative packaging that can perform similarly, is inexpensive, and impacts the environment less, is a challenge. Before the world shifts to using bioplastic or bio-based/bio-derived plastics, the functionality of these materials must approach that of existing plastics.
Replacing current polymers with so-called bioplastics is a challenge. There is no agreed definition of bioplastics. These can include plastics made from renewable biological feedstocks (bio-based plastics, or BBP) and biodegradable plastics made from renewable or non-renewable feedstocks. BBP is not necessarily biodegradable and in fact, more than half the BBP produced today is not. For the purposes of this report, bioplastic means a plastic that is biodegradable. Today, most drinks and food are sold in single-use plastic packaging made from petrochemical feedstocks, such as HDPE, PP, and PET. Plastic packaging made from petrochemical resources can be strong, light, versatile, clear, and inexpensive – hence its popularity. Several types of bioplastics are in production today. These include:
Starch blends: readily available and cheap compared to other natural polymers, with additional biodegradability. However, when used, its poor water resistance and low strength mean starch is typically blended with other polymers. Novamont (IT) is currently the world leader in producing bioplastics based on starch blends and has an annual production capacity of 150,000 tonnes.
Polylactic acid (PLA): made from sugar found in crops like corn and sugarcane, PLA is relatively inexpensive and has several attractive mechanical properties compared to other biodegradable polymers, which makes it popular. However, it is not as easily broken down in the natural environment as would be ideal, requiring industrial composting. NatureWorks (U.S.) and Total Corbion (NL) are the global leaders in PLA production, having a combined annual production capacity of 175,000 tonnes.
Polyhydroxyalkanoates (PHAs): made from sugars grown from algae, high production costs are a hurdle to global use. Current PHA production capacity is twenty-five tonnes.
Polybutylene based polymers: include polybutylene succinate (PBS) and polybutylene adipate terephthalate (PBAT), which are petrochemically-derived, biodegradable plastics. BASF (DE) is the leading global producer of PBS/PBAT-based bioplastics with an annual production capacity of 74,000 tonnes.
Global patent activity Looking at global patent filings relating to the development of bioplastics and products containing bioplastics, on first impression there appears to have been a consistent, significant year-on-year rise.
Figure 3.1a Priority filing trend - bioplastics Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
However, if we try to filter out filings more likely driven by state monetary incentives (in particular, China-originating filings that do not extend patent protection beyond China) we see a different and more accurate global view of trends in bioplastic innovation over the past fifty years.
Figure 3.1b Priority filing trend - not including filings driven by state monetary incentives - bioplastics Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
The trend in filings shows that innovation in this technology took off after 1989 and peaked in 2003, after which activity declined. Interestingly, recently filings have risen, suggesting a renewed focus on this area. The complete dataset for priority filings in 2020 will not be available until mid-2022, but the number of filings in 2020 to-date reinforces this apparent upsurge in activity. Geographically, for the first decade of the 21st century, Japan-originating filings far exceeded those from the rest of the world and indeed, Japan was at the heart of innovation in bioplastics technology between the late 1980s and 2003. Since 2010, territories including the U.S., Europe and South Korea have pulled ahead, while Japan’s numbers have significantly fallen year-on-year. That said, it is Europe, South Korea and Japan who are leading the recent uptick in filing activity.
Figure 3.2 Priority filing trend - top five filing jurisdictions - bioplastics Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
Companies filing bioplastics patents Reflecting this geographical shift, once the top two filers, Japanese companies Toray Industries and Unitika Corporation have slid down the leader board over the last twenty years, replaced by higher filers from non-Japanese companies such as BASF and LG Chemical.
Figure 3.3a Top ten filers by priority filings within the last 20 years - bioplastics Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
Kingfa is notable as the highest, and only, China-based filing entity in our top ten despite the overwhelmingly larger number of China-originating patent filings (much more than the rest of the world) over the last five years. This is because most of these filings do not extend beyond China. it is also notable, that of the top ten filers in China, Kingfa is the only non-university entity.
Figure 3.3b Top ten filers by priority filings within the last 10 years - bioplastics Click graph to enlarge
Note: Due to an 18-month lag between patent application and full publication of patent data, data from 2021 has not been reported, and data from 2020 includes data through May 2020.
All of these indicators point to a shifting innovation and patent landscape, with a large number of different stakeholders vying to develop bioplastic technology and product lines that incorporate them. The subject matter covered by the top patent filers extends across the areas of innovation that we would expect to see in this field, ranging from the biopolymers themselves to blends of biopolymers, compositions that contain the biopolymers and end products in which the biopolymer compositions have been applied:
- Specifically, innovations in biopolymers focus on biopolymer composition and structure, for example, the biodegradable block-copolymer produced by Lotte for use in orthopaedic medical devices, and the biodegradable graft polymers made by BASF for use in washing and cleaning products
- LG chemicals have been working to produce new biodegradable polymer blends, including a new PLA and PHA blend that offers the often desirable combination of strength with flexibility
- From the perspective of new biopolymer compositions, Kingfa have developed polybutylene and polylactic acid-based polymer moulding compositions, uses for which includes plastics bags that satisfy real-world requirements such as combining biodegradability with easy bag opening
- End products containing biopolymer compositions as well as other components include such things as biodegradable paper packaging, where both OJI and Huhtamaki have been active; end products also include areas such as eco-friendly wallpaper, which LG have developed using a biodegradable polymer layer; another example would be a soil condition sensor, again developed by LG, which contains a PLA-based polymer component used to help measure soil temperature and humidity
- Innovators are also working to integrate biopolymer components with other components of complex products. Kaneka Corporation in particular is developing solutions to problems like poor adhesion of biopolymer to other non-plastic components
Implications for innovation and future patent filings Creating bioplastics that are functional, inexpensive to produce, and present a viable alternative to existing polymers, are major challenges for bioplastic innovators. Commercial production of some bioplastics is well-established. Patent filing data shows that activity predominantly still centres on innovations related to PLA and improving the mechanical properties of bioplastics for mass production (heat resistance in particular). This suggests refinements to production methods and performance/properties will continue. While there will no doubt be major breakthroughs to come, the bulk of patent filings will continue to be toward iterative and bespoke improvements. The ability of plastic to be adaptable for so many different uses is also a part of the problem. Each end use often requires adaptions to the polymers and moulding compositions to achieve the specific desired performance requirements. To replicate those performance requirements using bioplastics will likely also require similar levels of tweaking and bespoke production. The range of end-use areas covered in the patent filings reflects this challenge, whether it is food packaging, textiles, adhesives, or even the plastic parts of the multitude of different plastic-containing devices and tools that surround us in everyday life.
Trends in bioplastic patent filings indicate that innovation is thriving. Given legislative pressures to increase bioplastics use in consumer goods (especially short-life goods), innovation and patent filing activity is unlikely to slow down.
David Walsh Partner, BSc PhD CChem CSci MRSC CPA EPA MITMA
Chris Mason Partner, MSci (Hons), LLM, MRSC, CPA, EPA
Sarah Abou-Shehada Trainee Patent Attorney, MChem, MRes, PhD