US2685497A

US2685497A - Treatment of polymeric materials

Info

Publication number: US2685497A
Application number: US89807A
Authority: US
Inventors: Sammons Charles William; Fisher James Wotherspoon
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1948-05-12
Filing date: 1949-04-26
Publication date: 1954-08-03
Anticipated expiration: 1971-08-03

Description

1954 c. w. SAMMONS ETAL 2,685,497

TREATMENT OF POLYMERIC MATERIALS Filed April 26, 1949 4 j 2 H i A nmKA/Eys Patented Aug. 3, 1954 UNITED STATES RATENT OFFICE TREATMENT OF POLYMERIC MATERIALS.

Application April 26, 1949, Serial No. 89,807=

Claims priority, application Great Britain May 12, 1948 7 Claims. 1

This invention relates to improvements in the treatment of filaments or yarns of polymeric materials, and more particularly polymeric materials of the character described in U. S. Patents Nos. 2,512,627 and 2,512,632. Insaid U. S. patents there is described the production of nitrogencontaining copolymers by condensing polyaminotria zoles obtained according to U. S. Pat. Nos. 2,512,600 and 2,512,667 with polycarboxylic amides, and particularly polycarboxylic amides with terminal amino groups, and there is further described the production of such nitrogencontaining copolymers from a pre-iormed polycarboxylic amide with the constituents necessary to form a polyaminotriazole, or from a preformed polyaminotriazole and the constituents necessary to form a polycarboxylic amide. In all cases the reaction to produce the final copolymer is carried out with the reagents in a mobile state and is stopped while the polymer'is still linear.

Generally these polymers are capable of undergoing reaction With formaldehyde, glyoxal or. other aldehydes, for example acetaldehyde, to render the polymers insoluble. or less soluble in organic solvents such as formic acid or phenols, and substantially infusible.

We have now found that such treatments of filaments and yarns with aldehydes may be so applied and combined with a mechanical treatment as to produce a crimped yarn. The mechanical treatment consists in an alternate tensioning and relaxation of the filaments or yarns. Preferably the treatment is applied to filaments or yarns whichv have not been cold drawn but it may be applied to filaments and yarns which have been incompletely cold drawn. For example, if a polymer of the type produced according to the prior patents referred to by condensing a preformed poly-t-amino-1.2.4-triazole with a diamine-stabilised polyamide is spun into filaments and the filaments, before cold drawing, are treated with aqueous formaldehyde, the formaldehyde allowed to dry on the filaments until nearly all the water is evaporated, and the filaments are then subjected to alternate tensioning and relaxation, with each repeated removal of thetension a more and more crimped effect is produced.

This crimped chest is not produced either with a yarn composed or" a simple polyaminotriazole produced according to U. S. Pat. Nos. 2,512,600 and 2,512,667, or with yarns made of a simple polyamida, The formaldehyde can react, with both these types of'yarns, but on tensioning and 2. relaxation no crimping or substantially no crimp"- ing is produced. The maximumcrimping isobtained by using a yarn in which the weight of polyamide components in the copolymer is roughly twice the weight of polyaminotriazol'e or polyaminotriazole components. in the yarn. However, quite good crimping is obtained with other proportions of the components. For example, the proportions mayv be from 2 of polyamide to I of polyaminotriazole up to 1 of polyamide to 2 of polyaminotriazole, andfurthermore the crimping effect is observed in a lower degree. in limits outside these, for example in co-poly mers containing proportions from 5 of polyarnide to 1 of polyaminotriazole up to lof polyamide to 3 or of polyaminotriazole'. However, we prefer to use copolymers of the typedescribecl in U. 8. Patent 2,512,627 where the total weight of aminotriazole in the co-polyamide/aminotriazole is less than 50%. It may be of the order of 20-45%. All these proportions are by weight.

Generally the invention therefore comprises the treatment of filaments or a yarn of a copolymer containing both aminotriazole and carboxylic amide units with formaldehyde or other aldehyde, followed by alternate tensioning and relaxation of the yarn until the crimping effect is produced.

The mechanical working, involving successive tensioning and relaxation, may be carried out as a continuous process by passing yarns containing thetreated filamentsover a series of devices designed successively to. apply tension and. to relax tension. Such devices may, for example, be a series of eccentrically mounted. rollers, the phase of the eccentricity of successive pairs of rollers being so arranged. as to. apply tension in a run between two pairs of rollers and to relax that tension in the run between the next two pairs of rollers. Alternatively the rollers may be alternately eccentrically mounted and concentrically mounted. Furthermore, instead of using eccentrically mounted rollers in either of the above arrangements, other mechanical: def vices, such as eccentrically mounted bladesmay be used, the blades having the. advantage that they permit a higher degree of drawin and hence a higher degree of relaxation. Apparatus oi the general character described in U. S. Patents Nos. 1,898,085 and 2,033,722 maybe used for thispurpose.

Apparatus that. may be employed in carrying outgthe. process of. this, invention is shown. diagrammatically in the. accompanying drawing wherein Fig. 1 is a side elevation of the apparatus for applying formaldehyde,

Fig. 2 is a side elevation of a device for tensioning and relaxing the yarns, and

Fig. 3 is a side elevation of another form of device for tensioning and relaxing the yarns.

The following example illustrates the invention:

Example An unoriented yarn was melt spun from a copolymer prepared by condensation of 10-12 parts of a diamine-stabilized polyamide of intrinsic viscosity about O.2O.3, produced from hexamethylene diamine and adipic acid, with about 6 parts of a polyaminotriazole produced from sebacic dihydrazide and hydrazine and also condensed to an intrinsic viscosity of the order of 0.2-0.3. The details, apart from the proportions, for producing such a copolymer are described in example 12 of U. S. Patent No. 2,512,627. The melt spun yarn was then processed as follows on the apparatus illustrated in the drawing. The yarn l was unwound from a cheese or bobbin 2 and carried at a speed of 39 feet per minute into a 3-ft. trough 3 continuously supplied with 40% aqueous formaldehyde at C. by means of an inlet 4 and overflow 5 so that the time of immersion was approximately seconds. The yarn was then carried out of the trough and given a vertical run over a pulley 6 and thence down toa hank winding machine 2', the total air run being 30-40 feet. The slightly damp hank was then allowed to stand at room temperature for 5 minutes or more, and then subjected to alternate stretching and relaxation until the desired crimp had been produced. On stretching the yarn exhibited a rubber-like elasticity but with each repeated removal of tension a more and more crinkled effect was produced until finally the yarn was highly crimped.

One form of device for carrying out this step is shown in Fig. 2 and comprises three driven rollers 3, 9 and It that are mounted eccentrically out of phase so that as the yarn l passes around said rollers it will be alternately tensioned and relaxed. Another form of device for carrying out this step is shown in Fig. 3 and comprises three driven rollers ll, i2 and it, around which the yarn l passes and of which rollers 5i and iii are mounted eccentrically and roller i2 is mounted concentrically.

In a similar way, other co-polyamide/aminotriazoles of the type described in U. S. Pats. Nos. 2,512,827 and 2,512,632 may be subjected to a treatment with formaldehyde in the unoriented state, or alternatively the yarns may previously be partly but not completely drawn, the degree of crimp produced being dependent to some extent on the degree of cold. drawing before the formaldehyde treatment. The period of treatment with the formaldehyde may be reduced by raising the temperature. In a similar manner, other aldehydes, particularly glyoxal, may be used. Furthermore, other aldehydes, such as acetaldehyde, may be employed, but generally these other aldehydes are much less reactive than formaldehyde and therefore do not give the crimp effect so readily.

The treatment according to the present invention may be applied to yarns, twisted or untwisted, of filaments of relatively low filament denier, e. g. of the order of 2 to 5, 10 or filament denier, or filaments of relatively large denier, e. g. up to filaments of bristle dimensions.

Further, the treatment may be applied to yarns, which will of course be twisted, containing staple fibres made of the polymers. Special effects may be obtained by treatment of mixed yarns containing staple fibres of the polymer together with staple fibres of other materials, for exampl of cellulose acetate or other cellulose derivative or of the nylon type of polyamide, or containing continuous filaments of the polymer and continuous filaments or another fibre-forming material. In the case of treating a product, particularly a continuous filament product, containing undrawn filaments of the triazole polymer together with undrawn filaments of a nylon type of polymer, tensioning produces elongation in both types of filament, while during the relaxation period the triazole filaments shorten in length and produce the crimp whereas the nylon type of filament retains its stretched length and thus appears in loops along the yarn. By this means a very voluminous yarn may be produced.

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the production of crimped yarns, which comprises reacting yarns, made from a linear co-polymer whose links consist of carboxylic amide and aminotriazole groups, containing lfi% by weight of polyaminotriazole constituents, which yarns are not completely drawn, with an aldehyde and repeatedly alternately tensioning and relaxing the materials until a crimp is produced.

2. Process for the production of crimped yarns, which comprises reacting yarns, made from a linear co-polyrner whose links consist of carboxylic amide and aminotriazole groups, containing 16%80% by weight of polyaminotriazole constituents, which yarns are not completely drawn, with aqueous formaldehyde and repeatedly alternately tensioning and relaxing the materials until a crimp is produced.

3. Process for the production of crimp-ed yarns, which comprises reacting yarns, made from a linear co-polymer whose links consist of carboxylio amide and aminotriazole groups, containing 16 7 -8094; by weight of polyaininotriaaole constituents, which yarns are not completely drawn, with aqueous formaldehyde, permitting the materials to dry until substantially all the Water is removed, and repeatedly alternately tensioning and relaxing the materials until a crimp is produced.

4. Process for the production of crimped yarns, which comprises reacting yarns, made from a linear co-polymer whose links consist of carboxylic amide and aminotriazole groups, containing l6%80% by wei ht of polyaminotriazole constituents, which yarns are not completely drawn, with aqueous formaldehyde at about 40 0., permitting the materials to dry until substantially all the water is removed, and repeatedly alternately tensicning and relaxing the materials until a crimp is produced.

5. Process for the production of crimped yarns, which comprises treating yarns, made from a linear co-polymer whose linlrs are carboxylic amide and aminotriazole, the polymer containing less than 50% but more than 16 /3 70 by weight of aminotriazole constituents and more than 50% by weight of amide constituents, which yarns are not completely drawn, with aqueous formaldehyde, permitting the materials to dry until substantially all the water is removed, and repeatedly alternately tensioning and relaxing the materials until a crimp effect is produced.

6. Process for the production of crimped yarns, which comprises treating yarns, made from a linear co-polymer Whose links are carboxylic amide and aminotriazole and which contains 20-45 of aminotriazole constituents and 80-55 of carboxylic amide constituents, which yarns are not completely drawn, with aqueous formaldehyde, permitting the materials to dry until substantially all the water is removed, and repeatedly alternately tensioning and relaxing the materials until a crimp efiect is produced.

'7. Process for the production of crimped yarns, which comprises treating yarns, made from a linear co-polymer whose links are carboxylic amide and aminotriazole and which contains 20-45% of aminotriazole constituents and 80-55% of carboxylic amide constituents, which yarns are not completely drawn, with aqueous formaldehyde at about 4G C., permitting the materials to dry until substantially all the Water is removed, and repeatedly alternately tensioning' and relaxing the materials until a crimp effect is produced.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Dreyfus et a1 Feb. 21, 1933 Dreyfus et a1 Apr. 28, 1936 Ewing June 30, 1942 Lely Aug. 25, 1942 Highberger et al. Apr. 24, 1945 Robbins June 5, 1945 Thomson Feb. 1, 1949 Waltz July 26, 1949 Fisher et a1. June 27, 1950 Fisher et al June 2'7, 1950 Fisher et a1 June 2'7, 1950 Moncrieff June 27, 1950 FOREIGN PATENTS Country Date Great Britain Mar. 14, 1941 Great Britain July 16, 1945

Claims

1. PROCESS FOR THE PRODUCTION OF CRIMPED YARNS, WHICH COMPRISES REACTING YARNS, MADE FROM A LINEAR CO-POLYMER WHOSE LINKS CONSIST OF CARBOXYLIC AMIDE AND AMINOTRIAZOLE GROUPS, CONTAINING 162/3-80% BY WEIGHT OF POLYAMINOTRIAZOLE CONSTITUENTS, WHICH YARNS ARE NOT COMPLETELY DRAWN, WITH AN ALDEHYDE AND REPEATEDLY ALTERNATELY TENSIONING AND RELAXING THE MATERIALS UNTIL A CRIMP IS PRODUCED.