Process for the treatment of tracing
US 2947640 A
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United 2,947,640 Patented Aug. 2., 1960 ice PROCESS FOR THE TREATMENT OF TRACING JAPERS TO MAKE THEM READILY ERASABLE PON Maurice J. B. Ladeuze, 28 Rue Pre-Genfil, Rosny-sur-Bois, France, and Pierre Toni, 6 Villa des Buissonets, Chemin du Buisson, Champigny, France The present invention has for its object the provision of a process for the treatment of tracing papers permitting the very rapid erasure of lines made with Chinese ink or greasy ink on the surface treated. This process has the advantage of permitting also the erasure of all traces of pencil (by means of a soft rubber, known as a pencil rubber) without attacking the ink lines and without altering the quality of the surface treated, on which the inlc lines can be rapidly erased in the dry without the employment of a scraper by the simple rubbing of a pad of metal wadding or similar material which is very slightly abrasive; on the surface thus erased upon, new lines can be made directly without rte-finishing or re sizing and the operation canbe carried out a number of times at the same place.
The process consists essentially in covering the surface to be treated with a solution, for filling the pores of the tracing paper, which is practically colourless, and in allowing it to dry; the said coating reduces the penetration of the ink to that necessary for a sufficient grip in practice. Moreover, this treatment gives to the surface of the tracing paper a greater regularity, permitting toobtain lines of greater clarity. It will be understood that this covering can be made either on finished tracing paper, or in the last stage of manufacture, and on one or both surfaces of the tracing paper.
The number of substances, of solvents, of piastifiers, of varnishes, which lend themselves to the composition of this filling solution is only limited in practice by the inconveniences which certain of them would present, either in application of the solution, its penetration and its drying, or in the adherence of pencils and inks used later on the surfaces treated.
The formulae indicated below are given only by way of non-limiting example, as having given satisfactory results on various samples of tracing paper commercially available:
Formula 1 V Parts by weight (a) Alcohol (ethyl or propyl) 43 (b) Sodium carbonate 4 Parts by weight (c) Stearine 4 (d) Benzene 26 (e) Ethylamine 9 (f) Ethanolamine 9 (g) Oleic acid Baum) 5 The products (a) (b) and (c) are heated on a water bath whilst being mixed. Then'the other products are added. There is obtained a liquid which can be made pasty or solid by the addition of stearic acid.
Formula 2 Parts by weight (a) Alcohol (ethyl or propyl) 35 (b) Benzene 35 (c) Morpholine (C H ON) 10 (d) Stearic acid Ba'um) 11 (e) Glycerine 6 (f) Borax 3 The mixture constitutes a gelatinous product which can he made more liquid or more solid. by respectively diminishing or increasing the proportion of stearic acid.
1. A preparation for treating tracing paper, so as to fill the pores thereof and reduce ink penetration, including the following constituents:
2. Tracing paper having a surface treated with the preparation claimed in claim 1.
References Cited in the fiie of this patent UNITED STATES PATENTS 149,449 Dean Apr. 7, 1874 1,073,129 Horn Sept. 16, 1913 1,872,662 Brathing Aug. 23, 1932 1,996,858 Davidson Apr. 9, 1935 2,005,113 Smiley June 18, 1935 2,018,638 Driessen Oct. 22, 1935 2,205,042 Lenher et a1. June 18, 1940 2,267,240 Kummel Dec. 23, 1941 OTHER REFERENCES Witham: Modern Pulp and Paper Making (1942), 71 and 76. a