Abstract: Self-adhesive reinforcing material comprisinga) a UV-transparent plastic film to whichb) a woven fabric impregnated with a partially acrylate-modified epoxy resin is applied which, on the side facing away from the film a), is coated withc) a layer of an epoxy resin which again is partially acrylate-modified, the resins of b) and c) being converted by UV irradiation to a gelled state which can be further cured by heat, and containing a heat-activatable hardener component, andd) a release paper applied to the side opposite the film a), is very suitable for reinforcing sheet metal.

Abstract: Apparatus comprising a solar collector, three heat exchangers operating at different temperature levels and connected in series on the service-water side, a latent-heat store, various lines and valves, a circulating pump and an electrical operation-control circuit responsive to the temperatures sensed by various temperature sensors located in the above mentioned components. The two heat-exchangers operating at the higher temperature levels are each by-passed by a mixing valve on the service-water side. Depending on the solar radiation or the temperature of the circulating medium, the heat exchangers at the higher or lower temperature level or combinations thereof are successively connected to the circulating medium.

Abstract: The invention relates to the use of crystalline resins as storage material in latent heat accumulators. Crystalline synthetic resins replace the crystalline inorganic salt of the known latent heat reservoirs. Preferably epoxide resins, polyurethane resins and polyester resins, which contain very specific long-chain polyester molecule moieties, are used. The crystalline synthetic resins have one or more, preferably two, crystallite melt temperatures.

Abstract: The invention relates to the manufacture of crystalline epoxide resins which have at least two crystallite melt temperatures. The cause of the crystallites are molecule blocks which are derived from aliphatic polyesterpolycarboxylic acids. According to the invention, at least two aliphatic polyester-polycarboxylic acids (D and E), which bear a special relation to each other in respect of the number of --CH.sub.2 groups in the primary chain member, are reacted under very specific quantitative conditions with epoxide compounds which contain at least 2 epoxide groups and optionally with curing agents. The synthetic resins thereby obtained are particularly suitable for use as storage material in latent heat accumulators.

Abstract: The invention relates to the manufacture of crystalline epoxide resins which exhibit a marked crystallite melt temperature. The formation of the crystallites is caused by molecule blocks which are derived from aliphatic polyester-polycarboxylic acids. According to the invention, two aliphatic polyester-polycarboxylic acids (A and B) are reacted under very specific quantitative conditions with epoxide compounds which contain at least 2 epoxide groups and optionally with curing agents. The polyester-polycarboxylic acids A are purely n-aliphatic in character, whereas the polyester-polycarboxylic acids B are not. They contain, for example, neopentyl radicals which are derived from neopentyl alcohol during the ester formation. These crystalline synthetic resins are particularly suitable for use as material for absorbing solar energy in solar energy collectors.

Abstract: The invention relates to the manufacture of crystalline epoxide resins which exhibit a marked crystallite melt temperature. The formation of the crystallites is caused by molecule blocks which are derived from polyester-polycarboxylic acids, which contain aliphatic radicals in the chain. According to the invention, two aliphatic polyester-polycarboxylic acids (A and B) are reacted under very specific quantitative conditions with epoxide compounds which contain at least 2 epoxide groups and optionally with curing agents. The polyester-polycarboxylic acids A are purely n-aliphatic in character, whereas the polyester-polycarboxylic acids B are not. They contain radicals which are derived from dimerized mono- unsaturated or di- unsaturated fatty acids during the ester formation. These crystalline synthetic resins are particularly suitable for use as material for absorbing solar energy in solar energy collectors.

Abstract: A heat accumulator is provided which has a heat exchanger embedded in a crystalline substance and has a maximum operating temperature greater than the melting point of the crystalline substance. The latter and the heat exchanger are integrated in a moulding bonded by means of crosslinked plastic. Preferably, the crosslinked plastic is crystalline and, at the same time, forms the crystalline substance. There is also provided an installation for the utilization of solar energy. The installation comprises a heat accumulator as described hereinbefore, a useful-heat exchanger and a solar energy absorber, which are connected together to form a heat transfer circuit. The installation is of particular use for the production of warm water.