Abstract: A refractory protective block protects heat exchange means connecting tubes to fins. The refractory protective block has an inside complementary shape corresponding to the surface shape of the heat exchange means and the refractory protective block is provided with recesses into which projections formed on the tubes are fitted and received. A pair of projections formed on the two adjacent tubes in the heat exchange means are arranged so as to confront each other. The refractory protective block has a high durability which does not break even when heat exchange means expand more than the refractory block at the time of the repetition of heating and cooling and which enable the dispersion of strain at the time of the repetition of expansion and contraction.

Abstract: A hardenable unsaturated polyester resin composition contains block copolymers and unsaturated polyester. The block copolymer includes both polyester blocks and a polydiene block as constituent segments.

Abstract: An antistatic resin composition with transparency contains 90-99.9 wt % of a synthetic resin selected from polycarbonate or polymethyl methacrylate and 0.1-10 wt % of a heat-resistant antistat containing phosphonium sulfonate shown by the general formula (I) below: ##STR1## where A is alkyl group with 1-36 carbon atoms, alkenyl group with 4-24 carbon atoms, phenyl group, phenyl group substituted by alkyl group with 1-18 carbon atoms, naphthyl group or naphthyl group substituted by alkyl group with 1-18 carbon atoms, R.sup.1, R.sup.2 and R.sup.3 are identical, each being an aliphatic hydrocarbon group with 1-8 carbon atoms or aromatic hydrocarbon group, and R.sup.4 is a hydrocarbon group with 1-18 carbon atoms.

Abstract: An additive for synthetic resins contains a block copolymer having as its constituent segments both polyester block obtainable by ring-opening polymerization of .epsilon.-aliphatic lactone and polydiene block. One or more of these polyester blocks are connected to the polydiene block through ester bond and at least one of these polyester blocks has at its end a reactive group such as vinyl group, epoxy group, isocyanate group or carboxyl group.

Abstract: An additive for synthetic resins includes a [liquid rubber]/[polyester] block copolymer comprising block liquid rubber compound parts and block polyester parts as constituent segments. One or more of these polyester blocks are connected to each one of the polydiene block parts through ester bond.