Studies on Pitch Troubles, its Cause and its Measure to be taken for its Prevention (VII.)

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Abstract
Is pitch trouble caused simply by a particular quantitative ratio between the different components of the pitch, as was dealt with in the previous report (pitch-abietic acid 60 to 70 %, unsaturated fatty acid 10 to 20% an unsaponifiable substance 10 to 20%, and saturated fatty acid 1% or less) ? If so, how is pitch trouble produced by one particular composition of the pitch? For elucidation of these problems the authers prepared a sort of artificial pitch and measured the amount of the pitch attached to the wire, a part of an apparatus devised for the purpose. The substances used each as the 100% component of the artificial pitch were pitch itself, pitchabietic acid, its like substance, oleic acid, linolic acid, linolenic acid, palmitic acid, stearic acid, an oil containing the ester of one of the preceeding substances in large quantities, a-pinen, p-cymen, turpentine oil, and a resen-type substance.1) The wire-attached proportion of pitch was 95.82%.2) Pitchabietic acid, usually considered as the first and foremost producer of pitch trouble ; a substance resembling it, as saturated fatty acid; an oil, of which the main component is the ester of saturated fatty acid, asa-pinen, p-cymen, or turpentine oil, -none of these substances caused any pitch trouble by itself.3) The wire-attached proportion was 62 % or so for unsaturated fatty acid and for an oil containing its ester, and 56.60 % for a resen-type neutral substance. These were each a probable maker of pitch trouble.4) Pitchabietic acid and rosin, and saturated fatty and oil containing its ester, each pair used together as pitch, were not likely to cause any pitch trouble, the wire-attached proportion of each pair not exceeding 10% or in many cases 1 to 4%.5) A pitch composed pitchabietic acid anda-pinen. pcymen, turpentine oil or resen was likely to cause pitch trouble, the wire-attached proportion amounting to 50% or more, and, when combined in certain quantitative ratios, to 80 % or more. As has been stated, none of these substances became wire-attached when used by itself.6) Pitchabietic acid combined with unsaturated fatty acid or with an oil containing its ester-either a substance same 62% of which was wire-attached when used by itself-became wire-attached in an increased proportion-80% or more 95% according to the ratio in which the two substances were combined-as in the case of pitch. A pitch trouble caused such a pitch must no doubt be appalling.7) The wire-attached proportion was 56.60 % for resen used by itself ;roughly half as large for resen used along with unsaturated fatty acid or with an oil containing the ester of the acid, either substance dissolving resen ; equal for resen used together with saturated fatty acid or with an oil containing its ester and for unsaturated fatty acid used alone ; and equall for resin used together with a-pinen, p-cymen or turpentine oil and for pitchabietic acid used alone.8) Saturated fatty acid and an oil containing its ester are not likely to cause much pitch trouble when used by itself, but the wire-attached proportion of either substance was so much increased as to cause a pitch trouble when used together with unsaturated fatty acid.Unsaturated fatty acid is dissolved bya-pinen, p-cymen or turpentine oil, so that the wireattached proportion of the former substance was reduced when used with the latter, as in the case of resen.9) As a general rule, the number of double bonds in the chemical structure of a substance proved to have nothing to do with the pitch trouble it might produce, though the viscosity of a dissolved substance was intimately related to the pitch trouble.

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