It has been reported that the sorption of water by vulcanized rubber is proportional to the surface area and varies as the square root of immersion time, and can not observe the saturated point experimentally. This is very interesting phenomenon, but there is little report which explain this sorption mechanism.
The author discovered that the rubber vulcanizates do not saturate in pure water, but saturate in salt water solution, and explained the sorption mechanism by thermodynamical treatment.
In this Part 1, the author reports the preliminary experiments which are observed by chloroprene rubber compounds, and the presumed osmotic mechanism theory of sorption.

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The osmotic mechanism of sorption by rubber could not be shown in the Part 1 sufficiently, because, the quantitative analysis of soluble materials in rubber was impossible.
Hence, we observe the sorption by butyl rubber which contained constant weight of electrolyte. On this experiment, the saturated values of sorption are shown as a function of electrolyte concentration in rubber and in solution. By the temperature, the sorption velocity varies, but the saturated value does not vary. And the same phenomena are recognised in the case of natural rubber and many synthetic rubber vulcanizates which do not contain fillers.

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When a mixed dispersion of reactive acrylic polymers and melamine formaldehyde resins was used as a binder of nonwoven fabrics, a study was made as to what effects the melamine formaldehyde resins had upon the physical properties of nonwoven fabrics. And then the following results were obtained:
1. Because of increased adhesion strength caused by the addition of melamine-formaldehydes into the binder, inter-fibre bonding force was remarkably increased. In consequence, the more is the amount of added melamine-formaldehydes added, the larger the number of fibers to show the resistance against pull-stress at the same time. In this way, I think, the increase of the dry tensile strength of nonwoven fabrics has been ensured.
2. If melamine formaldehyde resins were combined with acrylic binders, the binding force of acrylic polymers was strengthened depending on the amount of melamines added, and besides, the water resistance of this binding power increased with the increased content of melamines.
Thus the wet strength of nonwoven fabrics has been ensured.
3. Many cross linkages was generated in binders on account of the reaction between functional groups in acrylic polymers and methylol radicals of melamine-formaldehydes and in consequence, solvent resistance, that is, dry cleaning resistance of nonwoven fabrics was successfully obtained. The cross linking reaction between acrylics and melamines played a significant role in case of the 3rd but in the 1st and the 2nd played very little.

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Electron spin resonance of three kinds of carbon blacks, i.e. channel black (EP), furnace black (HAF) and thermal black (FT) have been studied in connection with the mechanism of the strengthen effect on rubber.
1) Each carbon black has a different line width and forms. The result shows that the structure of the free radical are different from each other. The concentration of the free radicals is ordered as follows:
EPC<FT<HAF
3) When they were heated in vacuo, the form of the absorption of HAF and FT were not varied, but that of EPC became very sharp and asymmetry.
4) In order to increase the free radicals of carbon black, Co-60 gamma-rays was irradiated on them, but little effect was observed.

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