US3069218A

US3069218A - Dyed acrylonitrile containing textile having controlled shrinkage and processes for forming same

Info

Publication number: US3069218A
Application number: US823851A
Authority: US
Inventors: Hermes Julius
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-06-30
Filing date: 1959-06-30
Publication date: 1962-12-18
Anticipated expiration: 1979-12-18

Description

United States Patent Ofifice 3,069,218 Patented Dec. 18, 1962 3,069,218 DYED ACRYLONITRILE CONTAINING TEXTILE HAVING CONTROLLED PROCESSES FOR FORMING SAME Julius Hermes, Martinsville, Va. N Drawing. Filed June 30, 1959, Ser. No. 823,851 1 11 Claims. (Cl. 817) This invention relates to acrylonitrile containing polymeric yarn or filaments having deep dye penetration and high shrinkage characteristics. More particularly, it relates to arapidly efiective dyeing of the yarn or filaments with a high, controlled shrinkage by first dyeing and shrinking the acrylonitrile container polymeric yarn or filaments in a heated aqueous bath containing alkylene carbonate and then drawing to improve their physical properties whereby subsequent heat treatment after knitting or weaving shrinks the dyed yarn or filaments to substantially their original length.

In the manufacturing of high bulk yarn, pile fabrics, made by weaving or knitting, and the like where the filaments must undergo a controlled shrinkage to produce various effects such as bulking of the yarn or thickening of the pile, it is necessary that the filaments or a part of the filaments used be capable of a high controlled shrinkage after the filaments have been drawn to improve their physical properties. Also, it is necessary to have stable coloration of the filaments before usage. Acrylonitrile containing polymeric yarn or filaments used in the manufacture of bulk yarns or pile fabrics exhibit only limited shrinkage after being drawn. This lack of high filament shrinkage decreases the quality of the bulk yarn, pile fabric and like material made from the drawn filaments. 7

Commercial drawing of the filaments is accomplished by heating the filaments to a temperature of 220 F. to 320 F. and then mechanically stretching the filaments while in heated condition. Substantially oriented acrylonitrile containing filaments, such as Orlon 42 (DuPont), can be elfectively drawn up to about 30 percent and when heated in a relaxed state will shrink to their original length, If the filaments are drawn beyond 30 percent, subsequent relaxation and heating will produce only a Shrinkage of about 30 percent. Thus, by using conventional methods of drawing and shrinking a 30 percent shrinkage is all that can be achieved regardless of the amount of drawing of the filaments. Where un'oriented acrylonitrile containing polymeric filaments such as Orlon L-7 (DuPont) are drawn, the filaments become brittle and at high point of stretch (less than 30 percent) break thus making it diflicult to obtain a high shrinkage.

These and other disadvantages are. overcome by first immersing acrylonitrile containing polymeric filaments in a heated aqueous bath containing alkylene carbonates and a dye stuflf where initial shrinkage and drying takes place and then drawing the filaments either in the bath or immediatelythereaften: Filaments treated by the process of this invention produce dyedfilarnents having a high, controlled shrinkage which will shrink when heated in a relaxed condition to substantially the degree drawn. Thus, by con-trolling the degree of drawing, a predeter mined controlled shrinkage can be produced.

By the use of the process of this invention, substantially oriented acrylic filaments, such as Orlon type 42, can be drawn beyond 50 percent anddyed and: then, shrunk to their original length when heat treated in a relaxed condition. Orlon L-7, which is difiicult to draw under normal conditions because of its brittle structure can be successfully drawnbeyond 60 percent and dyed, with subsequent shrinkage to original length when heated in a relaxed condition.

SHRINKAGE AND I when the solution is neutral or close thereto.

Also, unoriented acrylic filaments, such as Typical of the polymeric material which may be treated by the process of this invention are .the well-known acrylonitrile type polymeric filaments both oriented and unoriented which include those containing at least 50 percent by weight acrylonitrile units in the polymer chain; for example, po-lyacrylonitrile and its copolymers and interpolymers of acrylonitrile with other polymerizable monomers. These monomers include, among others, vinyl acetate, vinyl chloride, acrylic and methacrylic acids or derivatives and homologues thereof, styrene, methyl vinyl ketone, vinyl pyridines, such as 2-vinyl, 4- vinyl, 5-ethyl-2-vinyl or 2-methyl-5-vinyl pyridine and isobu-tylene or other similar polymerizable hydrocarbons.

Exemplary of alkylene carbonates used in the bath of this invention are the alkylene carbonates having 3 to 5 carbon atoms. Among the more important of these carbonates are ethylene carbonate, propylene carbonate, trimethylene carbonate, tetramethylene carbonate, 2,3- butylene carbonate, glycerine carbonate, and the like, ethylene and propylene carbonate being preferred.

Typical dyestuffs which can be used to effect the dyeing of acrylonitrile filaments include some of the acid dyes, basic dyes, disperse dyes and the like. It has been found that these dyes exhaust rapidly from the dye bath However, good dye exhaustion from the bath is provided when the pH ranges from 2 to about 8. Any acid may be used to provide the acid dye bath. For this purpose either an organic or an inorganic acid may be used.

The aqueous alkylene carbonate bath contains a small percentage of the dyestufi dispersed therethrough to effect dyeing of the filaments while preparing the structure for drawing. It has been found that the shade of color can be controlled by the concentration of the alkylene carbonate in the bath. For example, alkylene carbonate in the range of 2 to 20 percent by volume produces excellent dye exhaustion from the bath within short contact time. Where lighter shades are desired the lower portion of the range can be used, the percentage of the alkylene carbonate used depending on the shade of dyeing desired. It has also been found that after the upper portion of the range has been reached, the addition of more alkylene carbonate does not substantially affect dye exhaustion.

In carrying out the process of this invention the acrylonitrile containing filaments are passed through a heated aqueous bath containing the alkylene carbonate and a dyestuff. The filaments are quickly heated to the temperature of the bath which effects rapid penetration of the alkylene carbonate from the liquid and allowing penetration of the dyestuft throughout the filament structure. The penetration is deep and uniform, which is evidenced by the fact that a small amount of residual treating liquid remains imbedded in the filament even after thorough Washing and drying. It is believed that the small residual amount of alkylene carbonate in the filaments aids in the realignment of the molecule of the filaments as they are being drawn so thatthere is the greatest possible degree of elasticity within the filament structure to allow for the increased drawing strength. The substantially uninhibited realignment of the molecules produced by the shrinkage in the bath is increased. Excellent results have been obtained for filament tow when the alkylene carbonate concentration is from 6 to percent by volume.

Advantageously, the temperature of the bath may be maintained between 80 C. and its boiling point. Very good results are obtainable when the bath temperature is at the boiling point. The bath can be maintained at a pH of from 2 to 8. Excellent results have been obtained when the bath is about neutral. If a low pH is desired, organic or inorganic acids can be included in the bath to provide the desired pH.

The filaments can be drawn after shrinkage in the aqueous alkylene carbonate bath containing dyestuff or they can be drawn after removal from the bath. Also, the filaments can be passed through a washing bath to remove from the surface presence of alkylene carbonate before the drawing is accomplished. The washing bath may include a hydrolyzation agent for hydrolyzing the alkylene carbonate on the surface of the filaments. The filaments can be exposed in the aqueous alkylene carbonate bath from 2 to 20 seconds which allows for a rapid and economical continuous process for inducing into the filament structure a high degree of controlled shrinkage.

Where the filaments are drawn after passing through the aqueous alkylenc carbonate bath they may be maintained at a drawing temperature sufiicient to impart plasticity to the filament so that the filaments will not break during the drawing operation. It has been found that acrylic filaments of the Orlon type maintained at a temperature between 140 F. to 170 F. have the desired plasticity for such a drawing operation. This plasticity, coupled with the elasticity provided by the residual alkylene carbonate in the filament structure is believed to provide the high degree of uniform drawing without breakage or fracture of the filament, such as is evidenced in the drawing of Orlon L-7 as heretofore described.

The process can be carried out wtih the filament tow in a relaxed state being first passed through the aqueous alkylene carbonate bath where the filaments are initially shrunk and dyed. The shrunken filaments are then passed through a wash to remove excess bath liquid from the surface of the filaments. The filaments are then drawn while in a heated bath maintained at a temperatule of from 140 F. to 150 F. by passing the filaments over two sets of spaced rolls with the second set of rolls operating at an increased speed. The differential in speed between the two sets of rolls can be set so that the desired percentage of elongation is introduced into the filaments. Advantageously, the drawing can take place in the treating bath immediately after the initial shrinkage of the filaments and the filaments washed and dried while under tension, the produced filament having therein a predetermined shrinkage ratio.

The invention will be more clearly understood by reference to the following examples which are given for purposes of illustration and are not to be construed in any sense as limitative of the invention.

Example I A sample of raw Orlon tow (type 42) 10 inches in length was immersed in a bath containing 440 cc. of water, 60 cc. of propylene carbonate and 2 grams of Latyl Violet R (DuPont) under relaxed tension. The tow was removed from the bath after 10 seconds and heated to a temperature of 160 F. and drawn to 15.4 inches and dried under tension. The tow in a relaxed state was then shrunk to 10 inches in boiling water. Upon examination the tow exhibited a deep reddish violet color with excellent fastness properties. The sample showed a shrinkage of 34.5 percent.

Example 11 Orlon tow was treated as set forth in Example I by immersing it in an aqueous bath containing 435 cc. of

water, 65 cc. of propylene carbonate and the same dyestuffs with the following results:

Original length inches 9.8

After dyeing and drawing do 14.8

After treatment in boiling water do 9.0

Shrinkage percent 39 Example lII Orlon tow was treated as set forth in Example I by immersing it in an aqueous bath containing 430 cc. of water, 70 cc. of propylene carbonate and the same dyestuffs with the following results:

Original length inches 10.0

After dyeing and drawing -do 16.0

After treatment in boiling water do 9.0

Shrinkage "percent" 43 Example IV Orlon two was treated as set forth in Example I by immersing it in an aqueous bath containing 425 cc. of water, cc. of propylene carbonate and the same dyestuffs with the following results:

Original length inches 9.25 After dyeing and drawing u-.. do 14.5 After treatment in boiling water do 7.5 Shrinkage percent 48 All of the tow processed as set forth in Examples 11 through IV were tested and found to have a deep reddish violet color with excellent fastness as well as improved physical properties.

Example V The treating bath, as described in Example I, was used except that ethylene carbonate and Sevron Red G (DuPont) was used. The dyed tow exhibited the same percentage shrinkage and a deep red coloration which was found to have excellent fastness.

Example VI Example VII Orlon tow (type L-7) was processed as described in Example I except that 475 cc. of water, 25 cc. of ropylene carbonate and Latyl Violet R (DuPont) was used with the following results:

Original length inches 10 After dyeing and drawing do 20 After treatment in boiling water do 10 Shrinkage percent-.. 50

The tow exhibited a deep reddish violet color.

Example VIII Orlon tow (type L-7) was processed as described in Example I except that 465 cc. of water, 35 cc. of propylene carbonate and 1 gram of Quinoline Yellow M (DuPont) was used with the following results:

Original length inches 10 After dyeing and drawing do 24 After treatment in boiling water do 10 Shrinkage percent 58 The tow showed a bright yellow coloration and excellent color fastness.

Example IX A sample of Orlon tow (type L-7) was processed as described in Example I except that 490 cc. of water and cc. of propylene carbonate was used with the same dyestutf with the following results:

Original length inches 10 After dyeing and drawing do 17 After treatment in boiling water do 10 Shrinkage percent 38 As set forth in Examples VII through IX, tow (L-7) was processed with ethylene and glycerine carbonate being used in place of propylene carbonate with the same final results.

Several tests were conducted in which acetic acid and phosphoric acid was used to maintain the pH of the bath below 7. The results of these tests show that good dyed tow was obtained at low pH and a high shrinkage was produced as set forth in the foregoing examples.

It will be appreciated that the process set forth above produces dyed filaments capable of a controlled amount of shrinkage. It has been found that the shrinkage is dependent on the concentration of the alkylene carbonate in the bath as well as the percentage of draw induced into the filament. Thusby varying the percentage of draw and the concentration of the alkylene carbonate filaments having predetermined percentage shrinkage characteristics can be obtained.

It will be further appreciated that the filaments processed in accordance with this, invention possess new and different physical characteristics as is apparent from the high degree of controlled shrinkage exhibited when the filaments are heated under relaxed tension. It is believed that the realignment of the molecules due to the high degree of drawing and the residual alkylene carbonate in the filament structure produces the new and improved physical characteristics with better color distribution throughout the filament structure.

What is claimed is:

1. A process for simultaneously dyeing and inducing controlled shrinkage in polymeric filaments containing at least 50 percent by weight of acrylonitrile, after formation and during heat processing of the yarn after stretching, which comprises immersing said filaments in a heated aqueous bath maintained at a temperature above 80 C. for a period of from 5 to 20 seconds, said bath containing from 2 to about 20 percent by volume of an alkylene carbonate having from 3 to 5 carbon atoms and a dyestufl, and stretching said filaments from about 30 to 70 percent of their original length.

2. The process of claim 1 in which the temperature of said bath is at its boiling point.

3. The process of claim 1 in which the filaments are stretched in a water bath heated to a temperature of between 140 F. and 170 F after removal from said alkylene carbonate bath.

4. The process of claim 1 in which said stretched filaments in the form of textile are heated to shrink the filaments to substantially their original length.

5. A process for simultaneously dyeing and inducing controlled shrinkage in polymeric filaments containing at least 50 percent by Weight of acrylonitrile, after formation and during heat processing of the yarn after stretching, which comprises immersing the filaments in a heated aqueous bath at a temperature above 80 C. for a period of from 5 to '20 seconds, said bath having from 2 to about 20 percent by volume of propylene carbonate and a dyestuif and maintained at a pH of from 2 to about 8, and stretching said filaments from about 30 to percent 0 their original length.

-6. A process for simultaneously dyeing and inducing controlled shrinkage in polymeric filaments containing at least 50 percent by weight of acrylonitrile, after formation and during heat processing of the yarn after stretching, which comprises immersing the filaments in a heated aqueous bath at a temperature above C. for a period of from 5 to 20 seconds, said bath having from 2 to about 20 percent by volume of glycerine carbonate and a dyestuff and maintained at a pH of from 2 to about 8, and stretching said filaments from about 30 to 70 percent of their original length.

7. A dyed polymeric filament containing at least 50 percent by weight of acrylonitrile, said filament having a controlled shrinkage when heat treated and having its molecular structure aligned by drawing the filament after contact with an aqueous bath of an alkylene carbonate having from 3 to 5 carbon atoms and a dyestuff, and maintained at a temperature above 80 C., said filament being from about 30 to 70 percent of its original length after initial shrinkage and containing a small amount of said alkylene carbonate within the polymer structure.

8. The polymeric filament of claim 7 in which the filament is drawn in propylene carbonate bath.

9. The polymeric filament of claim 7 in which the filament is drawn in ethylene carbonate bath.

10. The polymeric filament of claim 7 in which the filament is drawn in glycerine carbonate bath.

11. The polymeric filament of claim 7 in which the filament containing a small amount of residual alkylene carbonate within the polymeric structure is shrunk to substantially its original length.

References Cited in the file of this patent UNITED STATES PATENTS 2,173,997 Burgeni Sept. 26, 1939 2,438,968 Field et al Apr. 6, 1948 2,569,470 Hagemeyer Oct. 2, 1951 2,716,586 Terpay Aug. 30, 1955 2,869,975 Hare Jan. 20, 1959 2,931,272 Haas Apr. 5, 1960 FOREIGN PATENTS 734,974 Great Britain Aug. 10, 1955

Claims

1. A PROCESS FOR SIMULTANEOUSLY DYEING AND INDUCING CONTROLLED SHRINKAGE IN POLYMERIC FILAMENTS CONTAINING AT LEAST 50 PERCENT BY WEIGHT OF ACEYLONITRILE, AFTER FORMATION AND DURING HEAT PROCESSING OF THE YARN AFTER STRETCHING WHICH COMPRISES IMMERSING SAID FILAMENTS IN A HEATED AQUEOUS BATH MAINTAINED AT A TEMPERATURE ABOVE 80*C. FOR A PERIOD OF FROM 5 TO 20 SECONDS, SAOD BATH CONTAINING FROM 2 TO ABOUT 20 PERCENT BY VOLUME OF AN ALKYLENE CARBONATE HAVING FROM 3 TO 5 CARBON ATOMS AND A DYESTUFF, AND STRETCHING SAID FILAMENTS FROM ABOUT 30 TO 70 PERCENT OF THEIR ORIGINAL LENGTH.