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The Role of NSF's Support of Engineering in Enabling Technological Innovation

II. REACTION INJECTION MOLDING

RELATIONSHIPS BETWEEN FUNDAMENTAL RESEARCH AND TECHNOLOGY DEVELOPMENT IN RIM

In the evolution of RIM, technology appears to have preceded research; industrial practice led scholarly research and understanding. As Alberino (1982: 2) put it, "As in so many other areas, large scale commercial use of RIM preceded a full understanding of the technology from a theoretical point of view." We have already presented some evidence of this relationship in the RIM chronology and in our interview material. Analysis of RIM patents provides additional support for this conclusion, as well as offering details of the relationship between academic research and industrial development in this important process innovation.

With a search using the keywords "reaction injection molding," the U.S. Patents Database shows a total of 264 RIM patents dating from 1973 to the present, and 30 RRIM patents (these data were the basis for Figure 1, above). One means of determining the significance of patents is to count the number of times a patent is cited in subsequent patents, under the assumption that frequently cited patents are more significant than less frequently cited ones. A straightforward search of the reference sections of the 264 RIM patents shows that 1,924 patents were cited. The number of citations ranges from 29 (a 1980 patent issued to Bayer for a process for producing elastic moldings) to 1; 64 patents are cited 5 or more times. A check of the patents that have been cited 7 or more times (there were 27) shows, first, that virtually all are related to RIM and, second, that all but one were issued to private firms.[23] Prominently represented are RIM material suppliers: Bayer, Dow Chemical, Union Carbide, Texaco, Mobay, Hercules.

A crude indicator of a technology's dependence on research is to examine the "other references" sections of patents, which typically cite scholarly literature relevant to the patent. The use of "other references" is neither required of patent applicants nor invariably related to the role of research in the patent, but previous research (e.g., Albert et al., 1991) has indicated that, with appropriate caveats, citations in patents to research literature can be used as an indicator of the strength of the research-technology link in particular fields of technology or industry. In the case of RIM patents, 107 (40.5%) have entries in the "other references" field; in the case of the 30 RRIM patents, 16 (53.3%) have entries. A visual scan of a sample of these sections shows that, with only a few exceptions, these entries are actually citations to scholarly literature.[24] These percentages compare favorably (from the point of view of the strength of the research-technology link) with data from other fields. Narin[25] has calculated the percentage of U.S. patents in different industries that cite at least one public, private, or foreign research paper, with the following results:

Allowing for possible differences in the way Narin's and our percentages were derived, it still seems apparent that in RIM and RRIM the research-technology linkage is relatively strong, at least according to this measure.

THE ROLE OF NSF

According to Macosko, NSF funded work in the RIM area (mainly his work) after industry developed the technology. His initial awards in 1979 and 1982 were from the Industry-University Cooperative Research Projects program. Industry was supportive of NSF funding and wrote letters to NSF encouraging funding at universities (SRI interview with Macosko, June 3, 1996).[26] John Kardos, Director of the Materials Research Laboratory at Washington University, considers the Defense Department's role in composites to be significantly greater than NSF's; "for a long time, it was very difficult to get funds for research on composites from NSF." Kardos noted, however, that there are now NSF-supported centers at VPI (a Science and Technology Center) and Case Western Reserve (an Industry-University Cooperative Research Center). Critchfield, formerly of Union Carbide, could recall no academics other than Macosko who were involved in RIM R&D, although he identified a number of Macosko's students (who were supported by NSF) now engaged in research on RRIM and/or SRIM: James Lee and Jose Castro. The latter worked at Union Carbide during his summers in graduate school.

Andrew Bastone, President of ISARCO (an organization founded by former Owens-Corning employees to promote work in the field of composite materials, which they believe have high potential), says that current research on the manufacture of preforms for SRIM is being done primarily by industry (SRI interview with Bastone, September 13, 1996). Bastone was unable to say whether NSF had funded any academic work in the SRIM field. He said that ISARCO largely serves the needs of its industrial clients and does not have time to work with universities.

Data on the amount and significance of NSF's support of RIM-related research was obtained in several ways. First, we searched titles in the NSF awards database using keywords related to RIM. This approach yielded approximately 100 awards, using the following list of keywords:

• reaction injection molding
• reinforced reaction injection molding
• RRIM
• SRIM
• RIM
• resin transfer molding
• impingement mixing
• polyurethane
• transport with polymer
• rheology
• viscous fluids with polymer
• continuous mixing system with polymer.

A second bibliometric approach involved use of the highly specialized Research Front Database, produced annually by the Institute of Scientific Information (ISI). The database organizes publications into clusters that, in validation studies, are seen as approximating the research specialties of working scientists. The clusters are based on the frequent association ("co-citation") of pairs of papers in the reference list of scientists publishing in journals indexed by ISI. These older, frequently cited and co-cited papers typically represent the important findings or methods that have shaped the specialty. As such, they represent the important contributions to the field.

The 1988 database was searched for RIM-related topics, and two highly relevant clusters were identified. The first was characterized by the frequent use of phrases such as REACTIVE EXTRUSION PROCESS, POLYURETHANE IONOMERS, and BLOCK COPOLYMERS in the titles of the papers indexed by ISI. The second was larger but less central to RIM, being characterized by title phrases such as POLYMER MIXTURES, EMULSION POLYMERIZATION, DYNAMICS OF POLYMER MELTS, and LINEAR VISCOELASTIC PROPERTIES.

In the first cluster, the contributory co-cited papers represented 70 authors, 40 of whom were associated with papers coming from U.S. institutions. Macosko's work appeared prominently among them, and of the 40 associated with U.S. institutions, 6 were identified as having received NSF support in the database of grantees compiled for this study.[29] In the less focused second cluster, the contributory co-cited papers represented 56 authors, 12 of whom were associated with papers coming from U.S. institutions. Half of the 12 were identified as having received NSF support.[30]

A third approach examined NSF's significance from industry's perspective. Industry led the initial development of RIM but acknowledged the need for greater understanding of the underlying phenomena (and, indeed, argued for NSF support of university research). What significance did NSF support have for industrial development of RIM? Our interviews did not reveal much useful information on this point, unfortunately. Thus we have had to rely more heavily on a less direct measure of NSF's role based on analysis of patent citations.

As described in the preceding section, a total of 64 names appeared in the "other references" section of the highly cited RIM patents. Twenty-seven names appeared in the "other references" section of the 93 patents cited at least once by other patents among the 264 RIM patents; 5 of these also appeared on the highly cited patent names list. Of the total of 86 names cited in relatively important RIM patents, 6 appear in the NSF awards database: Macosko, James Ly Lee (Ohio State, and one of Macosko's former students), Harry Frisch (SUNY Albany), Costas Gogos (Stevens Institute of Technology), Jiri Kresta (University of Detroit), and Fred Billmeyer (Rensselaer). To the extent that relatively important RIM patents refer to relevant scholarly work, NSF seems well represented among scholars cited in these patents (although we do not yet have a basis for comparison). This information, together with knowledge of the close ties that have existed between NSF awardees and industry representatives via the Industry-University Research Projects program, Industry/University Centers, Engineering Research Centers, and Science and Technology Centers, suggests that industry is increasing its use of academic research in the general area of RIM (now SRIM) in which NSF has been substantially involved.

CONCLUSIONS

Government, Industry, University Roles and Relationships

It is important to observe that RIM and, to a lesser extent, RRIM and SRIM owe their development in the 1970s and early 1980s to actions by the U.S. Congress. In the absence of automobile crash-resistance and fuel-economy legislation, it is unlikely that RIM would have developed as rapidly as it did, or that there would have been such considerable demand for RIM products. In addition to bringing substantial cost savings to auto owners through reduced repair and insurance costs, these products provided additional savings from reduced fuel consumption owing to the light weight of polyurethane. Public benefits accrued from reduced air pollution as well.

The Defense Department and NASA have supported considerable research on polymer chemistry, composites, and reinforced polymers. DOD's network of university-based Materials Research Laboratories, established in the early 1960s, was transferred to NSF in the 1970s. No doubt, research supported by these agencies contributed to greater understanding of polymer chemistry and composites, producing knowledge that benefited both the RIM industry and aerospace/defense firms. Yet our interviews revealed little evidence of interchange of knowledge between these industrial sectors; materials suppliers to RIM had problems to solve different from those of aerospace firms building high-performance polymer composites. To some extent, academic science and engineering researchers brought the disparate fields of application together, upstream, in fundamental studies of polymer chemistry.

The RIM-related research we have identified, supported by NSF and conducted by individual investigators as well as in centers, appears to be strongly tied to industry. Macosko was at the core of this work in the 1980s, and his research was shaped considerably by industry interests (recall that it was Union Carbide that first supported his RIM research). Macosko has coauthored numerous works with industrial researchers; his students have worked in industry while doing doctoral study, and many have joined industry after receiving their degrees; a considerable amount of his research was conducted in collaboration with RIM firms. Given NSF's support of a variety of centers conducting polymer processing research, there continue to be strong industry-university ties in the field. This view is supported by evidence from citations in RIM patents, which show much greater-than-average frequency of referrals to scholarly research.

Intellectual Property Rights

RIM is characterized by extensive patenting of key process components: premix materials, mold release agents, and mixheads. There is no evidence that this patenting has hampered development or diffusion of the technology, nor is there evidence of extensive cross-licensing, at least in materials. Apparently, in polymer chemistry, slightly different components can have similar applications but sufficiently different compositions (and, presumably, performance) to lead to extensive patenting that does not result in market dominance by one or a small number of firms. Key RIM patents-indeed, nearly all the industrially important patents-are held by large firms, mostly materials suppliers. Bayer, already a major player in chemicals, introduced RIM and patented a mixhead design very early, but this did not lead to market dominance. Bayer had one key patent on a urea-urethane mix, and Dow had a key patent on mold release agents, and the two traded licenses. Texaco patented an all-urea mix but could not lock up the market, and sold licenses to Bayer and others (Macosko, personal communication, October 1996).

Each supplier appears to have developed proprietary formulations that are different enough from those of their competitors for each to enjoy satisfactory market share. One explanation may be the diversity of RIM applications, each calling for somewhat different performance requirements and tradeoffs between materials costs and processing costs. Process equipment, on the other hand, is very difficult to protect. There was a highly focused market in automobile bumpers that is now declining. Patents in this narrow field were weak in that they were primarily mechanical rather than formulations.

Relationships between Fundamental Research and Technology Development

As recently as 1990, industrial RIM users were fine-tuning their systems by trial and error. A process that began with industrial practice is continuing to be led by experimental data, rather than predictive theory. RIM has peaked; both industrial and related scholarly research efforts are focusing on reinforced RIM and structural RIM. As demand for lighter replacements for structural steel increases, the contributions that research makes to applications in RRIM and, especially, SRIM may increase accordingly.

There was incomplete, even contradictory, evidence about research-technology relationships in RIM. On the one hand, industry representatives whom we interviewed could not say much one way or the other about the impact of fundamental or academic research on RIM development. Books on RIM by industrial researchers and engineers (e.g., Becker, Mallick and Newman) refer infrequently to scholarly research. Yet industry representatives also concluded that fundamental knowledge of RIM and RIM chemistry was needed but lacking. They supported, and continue to support, academic research with their own funds, while encouraging public support of research as well. Evidence from patent databases shows stronger-than-average ties between (presumably mostly academic) research and industry in RIM. Macosko and his students interacted closely with industry, reflecting the close ties that academic chemistry and chemical engineering traditionally have had with industry.

NSF Role

We have documented the amount of support NSF has provided for RIM-related research and traced the pattern of support over time. We also searched for evidence of NSF's impact in our questions to interview respondents, in citations to scholarly work in significant RIM patents, in contributions by researchers to the ENGINEERING database, and in clusters of RIM-related scholarly literature defined by using co-citation analysis. Interview respondents offered little information on the question of the influence of academic research on RIM development. Our impression from the remaining but limited sources of data is that NSF's role was significant. When evidence from the remaining nine case studies is available, we should be able to make such comparisons and draw more solid conclusions. Nonetheless, it is clear that RIM research supported by NSF was closely tied to industry, beginning with Macosko's 1980 award and continuing subsequently with substantial awards to several NSF-sponsored centers.. Industry benefited by hiring students already familiar with the process, and software based on Macosko's NSF-supported work is now proving commercially successful.

REFERENCES

Alberino, L. M. "Future of RIM Development in the U.S.A.," in Kresta (1982).

Albert, M. B., Avery, D., Narin, F., and McAllister, P. "Direct Validation of Citation Counts as Indicators of Industrially Important Patents," Research Policy, 20 (1991): 251-259.

Becker, W. E., ed. Reaction Injection Molding. New York: Van Nostrand Reinhold, 1979.

Boden, von Bonin, Kleimann, and Mergard. "Method of Molding Integral Skin Polyurethane Foams Having Mold Release Properties," U.S. Patent 3726952 (1973).

Castro, J. M., Macosko, C. W., Tackett, L. P., Steinle, E. C., and Critchfield, F. E. "Premature Gelling in RIM," Society of Plastics Engineering Technical Papers, 26 (1980): 423-427.

Coates, P. D., and Johnson, A. F. "An Introduction to Reinforced Reaction Injection Moulding," Plastics and Rubber Processing and Applications, 1, 3 (1981): 223-238.

Dominguez, R. J. G., Rice, D. M., and Lloyd, R. F. "Reaction Injection Molded Elastomer Containing an Internal Mold Release Made by a Two-stream System," U.S. Patent 4,396,729 (1983).

Ferrari, R. J. "Manufacturing Technology Using the RIM Process," in Becker (1979).

Harris, J. "Reaktionsguss: Ein neues Verfahren zum Herstellen Grosser Kunststoff-Formteile," Kunststoffe, 59 (1969): 398-402.

Kresta, Jiri E., ed. Reaction Injection Molding and Fast Polymerization Reactions. New York and London: Plenum Press, 1982. (Proceedings of the International Symposium on Reaction Injection Molding, sponsored by the American Chemical Society Division of Organic Coatings and Plastics Chemistry, March 31-April 1, 1981, Atlanta, GA.)

Kuerleber, R., and Pahl, F. W. "Device for Feeding Flowable Material to a Mold Cavity," U.S. Patent 3,706,518 (1972).

Lewis, G. D. "Reaction Injection Molding," in Modern Plastics Encyclopedia, 1986-1987 . Easton, PA: Breskin & Charlton Pub. Corp., 1987.

Macosko, C. RIM: Fundamentals of Reaction Injection Molding. New York: Hanser, 1989.

Mallick, P. K, and Newman, S., eds. Composite Materials Technology. New York: Hanser, 1990.

Mapleston, P. "PUR-RIM Technology Suppliers Concentrate on Reinforced Applications," Modern Plastics (June 1995): 54-62.

Newman, S. "Introduction to Composite Materials Technology: Mass Production Techniques," in Mallick and Newman (1990).

Slocum, Greg. "Reaction Injection Molding," in Mallick and Newman (1990).

Wirtz, Hans. "The Application of the RIM Process in Europe," in Becker (1979).

SRI INTERVIEWS

Christopher Macosko, University of Minnesota

John Kardos, Washington University

Frank Critchfield, Union Carbide (retired)

Michael Bogdan, Michigan State University

Douglas Barno, Composites Institute, formerly Owens Corning

Joel Barlow, University of Texas, Austin

Andrew Bastone, ISARCO, Owens Corning (retired)