Photo-functional polymers containing pendant phenacyl ester groups were synthesized by the reaction of poly (methacrylic acid) with various phenacyl bromides using 1, 8-diazabicyclo-[5.4.0]-undecane-7 (DBU) as a base. The esterification reaction proceeded very smoothly and quantitatively. The photochemical characteristics of the polymers thus obtained were measured by IR and UV spectroscopy in a film state, and photo-decomposition reactivity of these polymers was examined using various proton donors. It was found that 2, 3-butanediol (BDO) as a proton donor showed the highest activity for the decomposition reaction of pendant phenacyl moieties.

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A novel curing system having oxazolidine and phosphoric acid silyl ester for one-component moisture cure urethane was developed. Oxazolidine has been used for one-component moisture cure urethane and its hydrolysis is known to be accelerated by acid and tin-catalyst. But moisture cure urethane using oxazolidine and the catalysts was not good enough for storage stability. Control of curing time and storage stability was achieved by adding phosphoric acid trimethylsilyl ester in the moisture cure urethane system. Phosphoric acid trimethylsilyl ester acted as a moisture latent catalyst for activation of oxazolidine.

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There is a possibility to obtain organic-inorganic hybrid materials with high crosslinking density by reacting two functional groups of organically functional alkoxysilanes. In this work, photo-curing of acrylfunctional alkoxysilanes, i.e., 3-acryloxypropyl trimethoxysilane (APTMS) and 3-acryloxypropyl methyldimethoxysilane (APMDMS) was studied with benzoin sulfonate derivatives i.e., benzoin tosylate (BT) and benzoin 4-chlorobenzene sulfonate (B4CBS). In the presence of a small amount of benzoin sulfonate, APTMS and APMDMS were found to photo-crosslink readily. In those reactions, it was confirmed based on FT-IR and Raman spectroscopic analysis that radical polymerization of acryl group and condensation of methoxysilane group proceeded simultaneously. Benzoin sulfonates were furthermore recognized to be effective photo-acid. radical generators for crosslinking of acryl-functinal alkoxysilanes. Finally, the surface hardness of the crosslinked films and their adhesion to substrates were found to depend on the kind of photo-acid. radical generators.

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The phenolic compound behaves as a hardener of epoxy systems with the reaction between the OH group and the epoxy group. A new latent epoxy curing system was investigated using Claisen rearrangement of allyl ether of an aromatic compound derived from a phenolic. Synthesis of allyl ether, rearrangement reaction and cure behavior were studied. Allyl ethers synthesized in this study was liquefied state while the starting phenolic compound was solid state, therefore these compounds seemed to be useful for liquid epoxy systems. The rearrangement rate of allyl ether of 1,6-dinaphtol (DAEN) was much faster than that of mono cyclic phenolic compounds, and their curing behavior was studied as a hardener of epoxy compound. Rearrangement of DAEN and reaction with the epoxy compound were proceeded in several hours at 160°C. Cured resin from multifunctional epoxy compound and DAEN shows high glass transition temperature (Tg=150°C). Overall, our results in this study suggested that allyl ether of 1, 6-dinaphtol is useful for latent epoxy curing system.

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The curing behavior of bisphenol-A type epoxide oligomers (Ep) was evaluated by DSC in the presence of S-alkyldiphenylsulfonium salts as a thermal latent initiator. These initiators are soluble in Ep to obtain the homogeneous solutions and the curing reaction of the resulting mixtures occurred on heating. The initiation activity of these salts was controllable by the character of the S-alkyl group and of the substituents on the benzene ring. Namely, the stability of carbocation released from the sulfonium salts and the electron density on the sulfide affect the initiating temperature. A good correlation was obtained between the initiating temperature and the electron density of the sulfur atom of the corresponding sulfide estimated from ab initio molecular orbital calculation. It showed the initialing temperature becoming higher as the electron density of the sulfur atom increased.

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Polyhydric carboxylic acids, which have higher melting point, poor solubility and compatibility, were esterificated with alkyl vinyl ethers in the presence of acid as a catalyst to obtain the corresponding compounds having the hemiacetal ester moieties in excellent yield.
The obtained carboxylic acid derivatives protected with alkyl vinyl ethers showed lower melting point, better solubility and compatibility.
They could regenerate the corresponding carboxylic acids accompanied by the elimination of alkyl vinyl ethers by thermal dissociation and were stable under the storage condition (50°C×30days).
They may serve as a novel thermal latent hardener.

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A polymer having propargyl moieties was prepared by the reaction of commercial phenol resin with propargyl bromide and the possibility of control in the activity of the hydrosilylation catalyst was evaluated by a model reaction. In the presence of the polymer, a model hydrosilylation reaction of triethylsilane with trimethylvinylsilane was found to be inhibited effectively at an ambient temperature, while the activity of the catalyst sufficiently revealed on heating. Compared with other polymeric propargyl systems that the authors have examined, the phenol resin system was found to show a higher retardation effect. Besides polymer structure, the concentration of the added polymer affected catalytic activity. The crosslinking process of the silicone resin was also controlled effectively by the present latent system.

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Thermal latency of zinc 2-ethylhexanoate catalyst in the presence of triethanolamine and its application to hemiacetal ester / epoxide crosslinking system were examined. A novel crosslinking system consisting of oligomer having hemiacetal ester moiety and epoxy polymer could be constructed by zinc 2-ethylhexanoate-triethanolamine as a thermal latent initiator. Both thermal dissociation of the hemiacetal ester moiety and esterification of the generated carboxyl group with epoxy group were also accelerated in the presence of this initiator. The zinc 2-ethylhexanoate-triethanolamine served as an useful thermal latent initiator for hemiacetal ester / epoxide crosslinking system.

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