Патент USA US2404665код для вставки
Patented July 23, 1946 2,404,665 UNITED STATES PATENT OFFICE” METHODS OF HARDENING AND TANNING OF ARTIFICIAL FIBERS MADE OF PROTEIN Rudolf ‘Signer, Berne, Switzerland No Drawing. Application March '13, 1943, Serial No. 479,142. In Germany January 15, 1942 5 Claims. 1 This invention relates to methods ‘of hardening (C1. 18-475) 2 the second chemical condensing can be carried and tanning arti?cial ?bers made of protein sub out at different temperatures. Particularly, ‘it is stance. advisable to carry out the elongating at elevated temperature in connection with which the work ,Arti?cial ?bers made of protein substance, for ‘example of casein, have moderate physical proper ties such as for example a very small strength in ing can be considerably expedited and conse quently also be rendered continual. wet condition, due to swelling in water. Numerous methods for minimizing this draw back have already been proposed. Some of these operations can be chosen at will. The ?rst opera tion may consist in a treatment with organic sub The succession of the chemical condensing are based on chemical effects such as hardening 10 stances, such as aldehydes, chinone etc., the ‘with formaline and tanning with aluminium, second operation may consist in tanning with metal salts or vice versa. chromium, or other metal salts. Further methods are of physical nature such as stretching and Example 1 elongating methods which result in bringing about Fibers dry-spun from slightly alkaline caseinate a higher order of conditioning of the particles of 15 are exhaustively hardened with formaldehyde the ?ber. vapor. For eliminating the alkali the ?bers are It has also already been proposed to combine dipped in diluted acid for a short time at room chemical and physical effects by, for example, temperature. Thereupon the acid is washed out. ?rst stretching the spun ?ber and hardening same in elongated condition with formaline or sub 20 The ?bers are gathered into bundles in parallel . relation and the latter are then slowly elongated jecting the ?ber to an elongating process between in wet condition into double length at room a preliminary and a subsequent hardening with ' temperature. The elongated bundles are sub formaline. mersed during four days, at a temperature of 20°, It has now been discovered that extraordinarily great improvements on the strengths in wet and 25 in a bath containing 100 g. of chrome alum and 10.6 g. of calcined soda per litre. The bundles dry condition of the ?ber can be obtained if a are then washed and dried. previous chemical effect is followed by a vigorous mechanical elongation and the elongated ?ber Example 2 is then subjected to a second but different chem 30 A cord of long ?bres having been hardened ical condensation. , with formaldehyde is continuously unwound from The changing of the chemical condensing a spool at a velocity of 1 in. per min. and simul agent between the preliminary and the later elongation has a determinative in?uence as will taneously wound on a second spool at a velocity of 2 in. per min. The cord of long ?bers is thus A casein ?ber which has been preliminarily 35 elongated into double length between the two spools. During the elongating the ?bre is passed treated with formaldehyde has in wet condition through a bath of water of 40° and subsequently an elasticity similar to rubber. If this ?ber is introduced in a bath consisting in a chrome alum elongated to double length and exhaustively hard and calcined soda solution of the same composi ened with formaline in elongated condition at tion as speci?ed in Example 1. This bath moistens room or elevated temperature the ?ber shrinks the ?ber prior to being rolled up by the second on the cessation of the tension almost back into spool, whereby the penetration of the chrome bath the length which it has had prior to the elon into the ?ber is facilitated when the full spool gating. is submersed in said bath. Therefore, this treatment produces only a very The chrome solution is maintained at a temper small permanent elongation and a correspond 45 ature of 40°. The elongation is effected by the ingly small increase of the strength in wet and in two spools along a path of travel of about 6 m. dry condition. The same ?ber, having been pree The full spools are submersed in said chrome bath liminarily hardened with formaldehyde and elon for two days, whereupon the threads are washed gated in wet state into double length and then tanned with chromium salt in elongated condi 50 and dried. All temperatures are indicated in centigrades tion, shrinks on the cessation of the tension throughout the speci?cation. hardly any, while the strength in wet and in dry I claim: state is almost twice as great as before. 1. The method of increasing the strength of The three method steps, namely, the ?rst chem ical condensing, the mechanical elongation, and 55 arti?cial ?bers made from casein, which com-' be readily seen from the following comment. 2,404,665 T ~~ 3 prises dry-spinning arti?cial ?bers from an alka line casein mass, hardening the dry ?bers while - they are in alkaline condition by treating them with gaseous formaldehyde, freeing said ?bers of alkali by treating them with dilute acid, stretch ing the ?bers while they are wet, treating the ?bers while in‘wet stretched condition with a chromium salt solution, and then washing" and salt to render the solution basic, said solution serving to maintain therthreads stretched, and then washing and drying the permanently stretched threads. 4. The method of increasing the wet and dry strength of arti?cial threads made from casein , ,which ‘comprises dry-spinning arti?cial ?bers from an alkaline casein mass, hardening the fibers by treatment with gaseous formaldehyde 2. The method of increasing the wet and dry 10 while the ?bers are ‘alkaline, freeing said ?bers strength of arti?cial threads made from casein " of alkali by treating them with dilute acid, which comprises dry-spinning ‘threads from an‘ stretching the threads while they are in wet con alkaline casein mass, hardening the dry threads ' ' dition to approximately double their length, treat drying the ?bers. while they are still in alkaline condition by treat-_ , ing them while in stretched condition with a chro ing them with formaldehyde in gaseous form, re 15 mium salt bath at a temperature of approximately moving the alkali from the threads by treating 40° C., to substantially maintain the elongation, them with dilute acid, stretching the threads vand then washing and drying the fibers. While they are wet, and while they are still ‘in wet 5. The method of increasing the wet and dry stretched condition treating them with a solu-' strength of arti?cial threads made from casein tion of chrome alum to maintain them elongated, which comprises dry-spinning arti?cial ?bers and then washing and drying the threads. from an alkaline casein mass, hardening, the 3. The method of increasing the wet and dry ?bers by treatment with gaseous formaldehyde strength of arti?cial threads made from casein while} the ?bers are. alkaline, freeing said ?bers which comprises dry-spinning threads from an of alkali lby treating them withv dilute‘ acid, alkaline casein mass,_hardening the dry threads stretching the threads while they are in wet'con while they are‘ in alkaline'condition by treating them with gaseous formaldehyde, freeing said threads of alkali by the action of an acid, stretch ing the wet threads to approximately double their length and while they are in stretched condition ‘passing them through a chromium salt solution containing chrome alum and su?‘icient alkaline dition to approximately double their length, treat ing them while in stretched condition with a chro mium salt bath at atemperature of approxie mately 40° C., and for a period of at least two days to substantially maintain the elongation, and then washing and drying the elongated ?bers. RUDOLF ,SIGNEEt.