TRENDS IN MOLDED FOAM TECHNOLOGY AND MARKETS
While the patent literature is notably poor at providing insight into fundamental science, it is the clearest way to understand the future of a technology and market [38, 39]. This is because the patent literature represents a sizable investment by a company or individual on what is believed will be desirable by customers and market competitors in the next-generation product. Furthermore, defense of a patent asset requires that the technology on which a patent is based be protected by patent prior to its commercial introduction.
While a single patent may not be instructive as to the direction of future innovation, a clear trend in industrial patent activity can be unmistakable. Figure 7.11 shows the patent activity of several large multinational polyurethane feedstock providers over the years 2000-2013. In this analysis, the patents filed in the Chinese language represent the activity within the sizable Chinese market by Chinese companies. For perspective, the total number of issued patents found within the search parameters was 1033, so it is clear that there are a large number of patents not accounted for by this analysis. Despite this, it is likely that the preponderance of unaccounted for patents will reflect the activity of these highly experienced and influential participants (i.e., Dow, BASF, and Bayer) within the polyurethane market. Figure 7.11 shows that the majority of issued patents reflect the attempt to protect novel flexible foam properties and processes for a specific formulation or range of formulations. Arguably, this is suggestive of the richness of polyurethane chemistry and the fact that creative scientists are still finding new ways to achieve continuous improvements. However, it can also be argued that these patents cannot be considered as part of a more general future-oriented strategy since they reflect the properties found in pursuit of current applications. However, within this category, there are also industrial trends.
Relative to foam properties, innovation is being pursued to provide thinner/lighter seat foams with identical support properties achieved by thicker/heavier foams. Some of this activity is being motivated by the desire of automobile manufacturers to provide lower-profile automobiles for improved wind resistance without sacrifice of occupant headspace. The advent of hybrid and electric vehicles also has created a premium for space that can otherwise be utilized to hold batteries.
FIGURE 7.11 Patent activities within flexible polyurethane foam category of several large polyurethane market servicers and the patents filed in the Chinese language for the years 2000-2013 over the years 2000-2013. (See insert for color representation of the figure.)
Another foam property trend is the desire to provide foam that maintains a high level of support and comfort and at the same time dissipates vibrational energy that may otherwise be transmitted through the seat and degrade the perception of comfort. The balance is that many support and durability factors are highly correlated with low hysteresis. Low hysteresis, a result of network connectivity and phase separation, which results in low energy loss upon compression, works against vibration damping. Foam innovation has resulted from the identification of those vibrational frequencies that are perceived to result in passenger discomfort. It has been established that discomfort is perceived at vibrational frequencies less than 6 Hz [34,40-42]. Thus, foam innovation has focused on development of foams that under compression dampen frequencies below 6Hz.
We can understand the innovations of tailored foam vibrational damping by consideration of the equations relating mechanical properties to vibration transmissivity (Eq. 7.2) [43^15]. In Equation 7.2, K is the dynamic spring constant or stiffness (units of N/m), g is the gravitational constant (m/s2), Wis the applied load (N), and C is the damping factor (N-s/m). From the perspective of designing a polyurethane foam to achieve a desired result, it is simplified at least to the extent that the only variable that can be impacted by formulation is K, the foam stiffness. The foam stiffness is a function of many possible design variables and would have to be optimized within the boundaries of all of the other critical foam performance criteria. From the processing perspective, the damping factor can be influenced by foam structural properties like pneumatic damping, suggesting that optimization of airflow resistivity can help to increase vibrational damping. Alternatively, the tan delta spectrum can be optimized such that certain relaxation modes are inhibited at typical driving temperatures to retard energy return of certain frequencies (i.e., under 6 Hz) to the driver. This technique would have to be balanced with the comfort perception that highly resilient foams are closely associated with passenger comfort in the absence of vibrations:
Figure 7.12 provides the same information subtracting the patents protecting a specific foam property but instead focusing on a general field of application or composition of matter. This analysis shows that the most active fields of patent activity are those guided by regulatory pressures associated with supplemental blowing agents and flame retardants. A somewhat hidden patent field is the catalyst category. The import of this activity is apparent by the fact that all companies are engaged, in spite of the fact that these companies are not specifically catalyst manufacturers. Their presence in this field may point to anticipated regulation by occupational safety and health agencies of certain catalysts like those based on tin and mercury [46, 47].
Across the rest of the spectrum of activity, it is apparent that an individual company may pursue a specific intellectual asset strategy independent of the activity of its peers. Activity by a few companies in the use of soybean oil is a reflection of a strategy of pursuit of that agricultural oil as an alternative feedstock. However, the fact that not all companies are active in that area may suggest that not all companies share a soy-based-alternative-feedstock-for-polyurethane vision or may be taking a strategy of waiting to see if alternative feedstocks come to commercial fruition before developing a market follower technology response. Several companies, including Bayer and BASF, have also pursued an alternative feedstock vision employing ricinoleic acid (from castor beans; see Chapter 2), which has intrinsic secondary hydroxyl groups along the triglyceride chains. While ricinoleic acid has a process advantage by not requiring industrial introduction of hydroxyl groups onto the backbone, there is at least one serious disadvantage associated with a ricinoleic acid strategy for feedstocks (except for very small applications). Specifically, it relates to the limited volume of castor oil (the source of ricinoleic acid) in the world. Difficulty in growing and harvesting castor oil has narrowed the number of producing countries to primarily India and secondarily Brazil. The annual volume of produced castor oil is less than 2 billion pounds . While this sounds like a lot, available volume is relatively in short supply compared to alternative agricultural oils like soya or canola.
FIGURE 7.12 Data of Figure 7.9 with "Foam property" category removed to improve visualization of more specific subjects. (See insert for color representation of the figure.)
Acreage devoted to production is controlled by governmental agencies, and there is approximate balance between current supply and demand at relatively elevated prices. Accessing ricinoleic acid volumes required to satisfy an alternative feedstock strategy would distort the market for castor oil and raise prices—probably sufficiently to make the product economically untenable even with the lower capital cost allowed by an "isocyanate ready" triglyceride or source of fatty acid.
Lastly, over the years 2000-2013, it would appear that patent activity is relatively muted for such a large industrial segment and that BASF has been the most active company.