Scratch mixture

Typical scratch mixtures are the pair A) potassium chlorate 6, antimony sulfide 2, glue 1 and (B) powdered pyrolusite (Mn02) 8, red phosphorus 10, glue 3, recommended by Weingart and the pair (A) potassium chlorate 86, antimony sulfide 52, dextrin 35 and (B) red phosphorus 9, fine sand 5, dextrin 4, used with gum arabic as a binder, and recommended by A. F. Clark. 

Uses In scratch mixtures and other pyrotechnic compositions. 

If the solid does not dissolve in the cold solvent gently heat the mixture over a micro-Bunsen burner or in a small water-ba until the liquid boils. Continue to add o-i ml. portions of solvent until the solid dissolves. [If more than about i ml. of solvent is required, the solvent is considered unsatisfactory.] If a clear solution is obtained, cool the tube and scratch it below the surface of the solution with a very fine glass rod and proceed as suggested on p. 16. In general, the products from the choice of solvent investigation are not discarded but added to the main bulk of the crude product for recrystallisation. 

Naphthyl Acetate. CHgCOOCi H,. Dissolve 1 g. of pure 2-naphtnol in 5 ml. (r8 mols.) of 10% sodium hydroxide solution as before, add 10 g. of crushed ice, and i-i ml. (1-14 g., 1 5 mols.) of acetic anhydride. Shake the mixture vigorously for about 10-15 minutes the 2-naphthyl acetate separates as colourless crystals. Filter at the pump, wash with water, drain, and dry thoroughly. Yield of crude material, 1-4 g. (theoretical). Recrystallise from petroleum (b.p. 60-80 ), from which, on cooling and scratching, the 2-naphthyl acetate separates as colourless crystals, m.p, 71 yield, 10 g. 

Then add 3 drops of acetophenone (or about 0 3 g. of powdered benzo-phenone dissolved in 1 ml. of acetic acid) and shake the mixture. A precipitate of the phenylhydrazone is produced on scratching. 

Dissolve 1 g. of the ketomethylene compound and 1 1 g. or 2 2 g. of pure benzaldehyde (according as to whether the compound may be regarded as RCOCHjR or as RCHjCOCHjR ) in about 10 ml. of rectified (or methylated) spirit, add 0 5 ml. of 5.N -sodium hydroxide solution, shake and allow the mixture to stand for about an hour at room temperature. The benzylidene derivative usually crystallises out or will do so upon scratching the walls of the vessel with a glass rod. Filter off the solid, wash it with a little cold alcohol, and recrystallise it from absolute alcohol (or absolute industrial spirit). 

Add 0 -5 ml. of phenyl isothiocyanate to the distillate and shake the mixture vigorously for 3-4 minutes. If no derivative separates, crystallisation may be induced by cooling the flask in ice and scratching the walls with a glass rod. Filter off the crude product, wash it with a little 50 per nent. ethanol, and recrystaUise from hot dilute alcohol. (See Table 111,123 for melting points of phenylthiourea derivatives of amines.)... 

Dissolve equivalent quantities of the reagent and of the amine in a small amount of rectified spirit. K no reaction appears to take place in the cold, reflux the mixture for 5-15 minutes. Upon cooling (and scratching with a glass rod, if necessary) the crystaUiiie thiourea separates. RecrystaUise it from rectified spirit or from 60-b0 per cent, alcohol. 

Dissolve 0-2 g. of fructose in 10 ml. of water, add 0-6 g. of cw-methyl-phenylhydrazine and sufficient rectified spirit to give a clear solution. Since the fructose may not be quite pure, warm the mixture slightly, allow to stand, preferably overnight, so that any insoluble hydrazones may separate if present, remove them by filtration. Add 4 ml. of 50 per cent, acetic acid to the filtrate it will become yellow in colour. Heat the solution on a water bath for 5-10 minutes, and allow to stand in the dark until crystalUsation is complete it may be necessary to scratch the walls of the vessel to induce crystalUsation. Filter the crystals and wash with water, followed by a little ether. RecrystaUise the orange-coloured methylphenylosazone from benzene m.p. 152°. 

Allow a mixture of 0-5 g. of the tertiary amine and 0-5 ml. of colourless methyl iodide to stand for 5 minutes. If reaction has not occurred, warm under reflux for 5 minutes on a water bath and then cool in ice water. The mixture will generally set solid if it does not, scratch the sides of the tube with a glass rod. RecrystaUise the solid product from absolute alcohol, ethyl acetate, acetone, glacial acetic acid or alcohol-ether. 

Scratch resistance of polymer from DADC is improved by novel mixtures of peroxide initiators such as 5% isopropyl percarbonate with 3.5% benzoyl peroxide (16). In order to force completion of polymerization and attain the best scratch resistance in lenses, uv radiation is appHed (17). Eyeglass lenses can be made by prepolymerization in molds followed by removal for final thermal cross-linking (18). 

Hydraulic limes (84) may be used for mortar, stucco, or the scratch coat for plaster. They harden slowly under water, whereas high calcium limes, after slaking with water, harden in air to form the carbonate but not under water at ordinary temperatures. However, at elevated temperatures achieved with steam curing, lime—silica sand mixtures do react to produce durable products such as sand—lime bricks. 

A 250-mL, three-necked, round-bottomed flask is equipped with a mechanical stirrer, a reflux condenser fitted with a drying tube, and a stopper. The flask is charged with 14.3 g (0.1 mol) of 5-(2-hydroxyethyl)-4-methyl-1,3-thiazole, 12.7 g (0.1 mol) of freshly distilled benzyl chloride, and 50 mL of dry acetonitrile. The mixture is heated at reflux for 24 hr and cooled to room temperature. Crystallization is induced by scratching or... 

The crystallization is accelerated by scratching the walls of the jar or by seeding. Seed is obtained easily by pouring a small portion of the reaction mixture into a large amount of water the precipitate is separated, treated with alcohol, and dried at 40°. 

X-ray evidence shows the material to be completely amorphous as might be expected from such a complex mixture. The specific gravity ranges from 1.05 to 1.10. It is slightly harder than gypsum and therefore just not possible to scratch with a fingernail. Yellow in colour, it is less brittle than other hard natural resins and may therefore be carved or machined with little difficulty. The refractive index is 1.54. 

The mixture is decanted into an Erlenmeyer flask, the residual green salts are washed with two 15-ml portions of acetone, and the washings are added to the main acetone solution. Cautiously, sodium bicarbonate (approx. 13 g) is added to the solution with swirling until the pH of the reaction mixture is neutral. The suspension is filtered, and the residue is washed with 10-15 ml of acetone. The filtrate is transferred to a round-bottom flask and concentrated on a rotary evaporator under an aspirator while the flask temperature is maintained at about 50°. The flask is cooled and the residue transferred to a separatory funnel, (If solidification occurs, the residue may be dissolved in ether to effect the transfer.) To the funnel is added 100 ml of saturated sodium chloride solution, and the mixture is extracted with two 50-ml portions of ether. The ether extracts are combined, washed with several 5-ml portions of water, dried over anhydrous magnesium sulfate, and filtered into a round-bottom flask. The ether may be distilled away at atmospheric pressure (steam bath) or evaporated on a rotary evaporator. On cooling, the residue should crystallize. If it does not, it may be treated with 5 ml of 30-60° petroleum ether, and crystallization may be induced by cooling and scratching. The crystalline product is collected by filtration and recrystallized from aqueous methanol. 4-r-Butylcyclohexanone has mp 48-49° (yield 60-90 %). 

The N-[)3-(p-aminophenyl)ethyl]-4-phenyl-4-carboethoxypiperidine is dissolved in 50 cc of hot anhydrous ethanol, an excess (about 20 cc) of 20% alcoholic hydrochloric acid solution is added upon scratching the side of the container crystals form. One hundred cubic centimeters of ether are then added to the mixture, the ethereal mixture is cooled, and the crystalline material which precipitates is recovered by filtration, washed with ether, and dried to give 12.7 grams of N-[)3-(p-aminophenyl)ethyl]-4-phenyl-4-carboethoxypiperidine dihydrochloride which can be further purified by recrystallization from ethanol or methanol to give substantially pure material MP 275°-277°C. 

Hydroxy-3-naphthoic acid (1.BB grams) was dissolved in hot aqueous sodium hydroxide (0.5N 20 ml) and the resulting solution was slowly added to a solution of N-benzyl-N,N-dimethyl-N-2-phenoxyethylammonium chloride (2.9 grams) in water (5 ml). A gum separated at first but it solidified on scratching. After the addition was complete, the mixture was allowed to stand at room temperature for 2 hours and then filtered. The residue was washed with water and dried in vacuo to give N-benzyl-N,N-dimethyl-N-2-phenoxyethylammonium 2-hydroxy-3-naphthoate, MP 170°-171°C. 

The mixture was filtered, the ethyl acetate layer separated and washed with three 100 ml portions of water, dried over Na2S04, filtered and treated with 30 ml of sodium 2-ethyl-hexanoate in n-butanol (34 ml = 0.1 mol). The oil which settled out was scratched to induce crystallization. After stirring for 20 minutes the product, sodium 7-(a-bromoacet-amido)cephalosporanate, was scraped from the sides of the flask and collected. The filter cake was washed with several portions of acetone, air dried, and dried in vacuo over P Os. The yield was 22.5 g and decomposed at 193°C. 

A mixture of 5.0 g of 3-chloro-5-(3-chloropropyl)-10,11 -dihydro-5H-dibenz(b,f)azepine, 5.0 g of 4-carbamoyl-4-piperidinopiperidine and 50 mi of dimethylformamide is heated at 100°C for 10 hours. The solvent is distilled off. After the addition of a 2% sodium carbonate solution to the flask, the content is scratched to yield a semisolid, which is dissolved in 50 ml of isopropanol. A solution of 5 g of maleic acid in 50 ml of isopropanol is added, and the precipitate is collected by filtration and recrystallized from isopropanol to give 5.6 g of crystalline 3-chloro-5-[3-(4-carbamoyl-4-piperidino-piperidino)propy I] -10,1 l-dihydro-SH-dibenz-Ib.fjazepine dilhydrogen maleate) with 1/2 molecule of water of crystallization melting at 181°C to 183°C. 

To obtain the quaternary salt, furfuryl dimethyl amine so prepared is dissolved in dry benzene and to the solution is added slightly more than one equivalent of methyl iodide. Inducement of crystallization of the quaternary salt which separates may be effected as, for example, by scratching the side of the vessel containing the mixture or seeding with a small quantity of the crystalline quaternary salt. 

Add 2.0 g of salicylic acid, 5.0 mL of acetic anhydride, and 5 drops of 85% H3P04 to a 50-mL Erlenmeyer flask. Heat in a water bath at 75°C for 15 minutes. Add cautiously 20 mL of water and transfer to an ice bath at 0°C. Scratch the inside of the flask with a stirring rod to initiate crystallization. Separate aspirin from the solid-liquid mixture by filtering through a Buchner funnel 10 cm in diameter. 

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