SU1668374A1 - Composition for manufacture of slate-pencils - Google Patents

Abstract

The invention relates to the preparation of pencil leads intended for inscription on a light smooth surface (paper, plastics). The invention allows for the introduction (in wt.%) Of a composition comprising suspension polystyrene (mol. M. 75,000 - 140,000) 30 to 40 wt.%, Diisododecylphthalate 3 to 6 wt.%, Kaolin 10 to 13, graphite 28 - 36, paraffin 6 - 10, calcium stearate 3 - 6 and monoethanolamide synthetic fatty acids fraction C ₁₀ - C ₁₆ 3 - 6 significantly improve the quality of writing and reduce the output of defective leads. 2 tab.

Description

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The invention relates to the preparation of pencil leads intended for inscription on the light smooth surface of various materials (paper, plastics, etc.).

The purpose of the invention is to improve the quality of the letter and reduce the yield of rejected leads.

The composition is prepared as follows.

Polystyrene and a plasticizer are loaded into a 2-roll mixer with Z-shaped blades and mixed at 0.25-0.5 hours at 150-155 ° C. Paraffin, calcium stearate, mono-ethanolamide are added to the mixture. synthetic fatty acids and mixed for 0.5-0.8 h at the same temperature. After that, the mixture consisting of graphite and kaolin is poured into the mixer and again mixed at 150-155 ° C until a homogeneous mass is obtained (usually 5-8 hours),

The finished composition is removed from the blend and, when cooled to room temperature, plates with a length of 50–80 mm, a width of 30–50 mm, and a thickness of 3-5 mm are formed. The resulting plates are ground in a 2-roll mixer to a particle size of 0.5-3.0 mm. Extrusion of the obtained granules is formed into pencil slate (temperature by zones: I 70 ° C; II 110 ° C; IV 150 C, head temperature 170 ° C)

As polystyrene, suspension polystyrene grade PS-500 mol.m. 75000-140000. Paraffin, kaolin, diisododecyl phthalate are also used in the composition. calcium stearate and monoethanolON 00 00 CO

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Claims (1)

Claim Composition for the manufacture of pencil leads, including polystyrene, plasticizer, kaolin and a color-forming component, characterized in that, in order to improve the quality of writing and reduce the yield of defective leads, it contains polystyrene / mol.m suspension as polystyrene. 75000-140000, as a plasticizer - diisododecyl phthalate, as a color-forming component - graphite and, in addition, paraffin, calcium stearate and monoethanolamide of synthetic fatty acids of the Siu-Siu fraction in the following ratio, wt.%: . Suspension polystyrene with mol.m. 10 75000-140000 .30-40 Paraffin 6-10 Calcium Stearate 3-6 Diisododecylphthalate 3-6 Monoethanolamide 15 synthetic fatty acids of the CioCie fraction; 3-6 Graphite * '28 -36 Kaolin .10-13 Ta | Xiang, 1 1 Component X X X X X. I .4 ___ 1 ______! .......... 4-Content of components, ND, as part of _ Proposed -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------- 1 Control I 2 3 4 5 6 7 8 9 10 eleven 12 thirteen R Suspension polystyrene · (mol. 75000- 35 35 140,000) thirty 35 40 27 44 '- - 35 * - * Paraffin b 8 - 10 4 12 ' 8 9 9 9 9 6 6 6 8 ^ν Lniernolnetslftalat 3 4 6 1 9 . 4 5 5 4 4 3 4 6 5 Monoethanolamide Synthetic Fatty acid fraction · 0 <* 6 5 3 7 1 5 5 - - - -. - - Graphite 36 32 28 39 25 thirty 33 33 31 32 34 and 36 34 Kaolin thirteen AND | 0 fifteen 8 eleven eleven 12 . eleven eleven 12 eleven eleven . * 2 Calcium stearate 6 5 3 7. •1 5 5 6 ‘ 5 5 5 5 5 4 Suspension polystyrene (mol.m. 50000) - - - - 37 - - - - 37 37 - - Suspension polystyrene (mol.m. 170000) -  - - - - - 32 - - - - - 33 33 Moioethanpla ^ poison si '' fatty fat Acids Freight Cr-Cj - - - “· “· * · Monoethanolamide synthetic fatty acid fraction ^with p ~ ^c p 4 - 5  - 4 • T a blitz 2 Performance indicators for the composition. ' & Famous 1 2 3 4 5 6 7 8 9 10 thirteen 14 The number of lines satisfying ryuyinh requirements of TU 12-25 49 40 42 32 thirty 35 37 20 33 thirty 28 thirty 3 * 31 Writing effort, on, and 3.8-5.0 yo 2.7 3.0 4.0 4,5 ZL 4,5 3.7 4.0 3.6 ♦ .3 3.9 5 5.2 Erasable “nstnrayutspkh’ ’” movements 15-18 8 9 AND fifteen thirteen 20 19 21 ^x * 25 fifteen 20 24 18 25 The force "11, necessary for the adjacent lead, glued - go to the village "shell karay- 30 42 45 40 35 35 thirty 28 thirty 23 32 25 29th 25 33 maid ed AND ED ED _z Exit defective them of pencil lead, X 35-45 5 3 4 8 9 eleven g * 10 14 8 8 10 8 eleven Bending stress, MPa - 16.6 18.7 20.3 14.5 16.0 17.5 15.0 14.8 16.0 (6.2 13.1 fifteen thirteen 16 Deflection, ridges 0.5-2.0 8.1 9.9 6.0 8.2 8.0 7.5 5,6 7.2 AT 4 8.0 7.7 9 IN 9 Impact sluggishness, kJ / m * 2-4 zo 4.1 4.1 2.0 3,5 3.2 s oh 3,1 2,8 3.0 9,4 3 3 2 ’The numerator is the native value, the denominator is after 15 days of storage under normal conditions. ** All tests were carried out 24 hours after receipt of the lead. • “Ha breaks in the stylus are observed and homogenized with high pressure” (polystyrene, kaolin, etc.).