Toagosei Annual R&D Report “TREND” – Issue No. 10

“ARON OXETANE” is a compound that has an oxetane ring, a four-membered cyclic ether, as the cation-curable functional group.
Polymerization of cation-curable materials is initiated by photo-latent or thermally latent initiators. Compared to radical curing materials currently used as UV curing resins, cation-curable materials have the following characteristics.

・Thin-film curing is possible even in air because there is no polymerization inhibition by oxygen.
・Curing by dark reaction (post-polymerization) proceeds even after light irradiation is completed.
・The use of ring-opening polymerization monomers can reduce curing shrinkage.
・Many oxetane compounds are safe materials even at low molecular weights and can be used to reduce the viscosity in composition systems.

We have already launched four types of “ARON OXETANE” products, and are carrying out market development for them domestically and overseas (Fig. 1).

However, there are not sufficient choices of cation-curable materials on the market. We have been developing distinctive monofunctional monomers to meet the market’s demand for new materials (Fig. 2). In the process, we discovered that cured products of “OXT-211 (POX)” and “OXT-213 (CHOX)” have excellent toughness, and we brought them to market after establishing manufacturing capabilities and securing compliance with the Act on the Regulation of Manufacture and Evaluation of Chemical Substances (low production volume). This article introduces the monofunctional oxetanes with excellent toughness (“OXT-211 (POX)” and “OXT-213 (CHOX)”).

Building sealants are materials that are used to fill seams and gaps in exterior walls to prevent moisture from entering the indoor areas and to maintain airtightness1). Non-solvent-type curable liquid compositions (amorphous sealants) consisting of a base resin (curable resin), a plasticizer, inorganic components, etc. are commonly used, and among these, demand for sealants using modified silicone resin (Fig. 1) as the base resin has increased1).

In recent years, with the enforcement of the Act on the Promotion of Housing Quality Assurance, “a 10-year period of warranty against defects regarding prevention of water leakage in housing” has become mandatory, and demand for highly weather-resistant and highly durable sealants has been growing2).

We market acrylic oligomers obtained by the Uniform Functional Oligomer (UFO) process under the trade name “ARUFON.” The UFO process enables molecular weight control through high-temperature continuous polymerization without the use of chain transfer agents, allowing efficient and cost-effective production of solvent-free acrylic oligomers with high weather resistance. We have already launched the non-functional type acrylic oligomers “UP Series” as highly weather-resistant plasticizers for sealants3)-7). We recently developed the “US Series,” reactive plasticizers containing alkoxysilyl groups (moisture-curing crosslinking groups), in response to growing market demand for higher weather resistance and functionality.

Formaldehyde, acetaldehyde, etc. are considered to be causative agents of sick building syndrome. Reduction of aldehyde gas in living spaces is being pursued through approaches such as switching to aldehyde-free materials and using aldehyde deodorants. In addition, aldehyde deodorants have been attracting more attention recently as the reduction of aldehyde gases in automobile cabins has come under consideration.

We have developed the KESMON series of deodorants for various odors in living spaces, which are already used in a wide range of fields. We have recently developed a deodorant with much higher aldehyde deodorization performance than conventional KESMON. This article introduces the characteristics and applications of KESMON, the newly developed aldehyde deodorant.