Polyurethanes are polymers containing urethane groups in a narrow sense, and are a polymer produced from isocyanate in the broad senses. 80 years have passed since this polyurethane was invented by the group of Otto Bayer et al. of I.G.Farben (later Bayer). Polyester-based foam production technology was introduced in Japan and it was put on the market and passed the 60th calendar. In this paper, we look at the history of polyurethane development and its introduction to Japan and overview the flow of development of polyurethane in Japan from 1970.
Polyurethane (PU) is defined as a polymer having urethane bond in the chemical structure, but most of PU are industrially composed not only of urethane but also chemical bonding having high molecular cohesion force such as urea.Therefore, in a broad sense, PU is defined as “polymer derived from isocyanate” that forms those bonds. Generally, the production method and productivity of PU are greatly influenced by the chemical structure of isocyanate. In addition, a wide variety of polyol in chemical structure are used in order to widely control the physical properties of PU. Therefore, the production process, molding process and application of PU are also diverse. While PU has versatility of mass products, on the other hand, there are aspects of fine chemicals that require high functions with small quantities of various type, so research and development for constantly improving functions and environmental issues are being carried out. In this paper, after outlining the chemistry of isocyanate and polyol, the features for production method and raw material of PU, and further their latest progress are introduced.
Polyurethane elastomers (PUEs) are one of the most popular polar polymers. The PUEs are usually composed of soft segment formed with polymer glycol and hard segment done with diisocyanate and curing agent. The properties of the PUEs are strongly dependent on chemical structure, molecular weight and polydispersity of soft segment or hard segment components, weight fraction of both components and so on. However, the quantitative contribution of physical cross linkages to rubber elasticity and the direct observation of micro phase separation have not been done yet. The molecular design factors for high performance PUEs and origin of rubber elasticity are discussed by chemical analysis of crosslinks and observation of the micro phase-separated structure of the PUEs using AFM.
There are an increasing number of next generation vehicles such as plug-in hybrid electric vehicle and electric vehicle (EV) since the world’s first mass production hybrid vehicle appeared on the market in 1997. This trend seems to be continuing from a viewpoint of greenhouse gas reduction and air pollution prevention. In this trend, effective use of battery is received a lot of attention for longer cruising distance. One of the main causes of drain on battery is energy consumption of air conditioner. In recent years, ‘heat management’ is highlighted as a measure of energy consumption reduction. It is a concept to quickly control vehicle interior temperature and keep it with less energy. This review reports the required performance of automotive interior parts, the attractiveness of polyurethane material compared to metal and other resin, and the trial calculation result of drain on battery of EV in winter season. From the aspect of heat management, this paper shows polyurethane interior parts can save drain on battery and extend cruising distance of EV.
Ricoh has been mainly developing toner using polyester resins which have superiority of fixing property and coloring property, and producing chemical toner so called PxP toner since 2003. The ester elongation polymerization method of PxP toner has numerous merits that are not found in the conventional production one. This report introduces merits of the ester elongation polymerization method of PxP toner and it’s reaction analysis.
Polyurethanes developed by Dr. Otto Bayer of Germany IG. Farben Company in 1937 has been widely used industrially since 1950 because of its excellent properties and ease of handling. In the field of architecture and construction, the newly developed polyurethane supports the evolution of the architectural style, especially the application for sealing, waterproofing and heat insulating materials has greatly expanded. Polyurethane for waterproof material that appeared in 1966 made waterproof material with thickness of 2 mm or more spread to the world instead of a thin film thickness paint, and greatly improved the reliability of paint waterproofing.1) As for polyurethane for heat insulating materials, improvement of heat insulating performance was a major issue, but in 1987 the problem of ozone layer destruction by chlorofluorocarbon (CFC) used as a blowing agent was shown. After that, consideration to the environment as well as improvement of heat insulating performance has become a big problem. Recently, in addition to performance improvement and environmental consideration, the issues of extending the life expectancy of social infrastructure is mentioned as a problem. In the field of architecture and constructions, product specifications tailored to the climate of each country are often applied, and this time, focusing on the Japanese market, the technical trends of polyurethane developed to respond to these issues are summarized.