Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
  • D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
  • D01F8/14—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyester as constituent
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
  • Y10S264/26—Composite fibers made of two or more materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S8/00—Bleaching and dyeing; fluid treatment and chemical modification of textiles and fibers
  • Y10S8/04—Polyester fibers

Definitions

• Textile yarns made from filaments of these aromatic polyesters such as polyethylene terephthalate are more difiicult' to dye than yarns made from natural fibres or regenerated cellulose or protein fibres.
• This difliculty is associated with the highly oriented and crystalline structure of the polyester fibre. This structure is not easily permeable by molecules of water and molecules of dyestuffs during conventional dyeing procedures. It is known, however, that dyeing polyethylene terephthalate fibres at elevated temperatures improves the rate of dyeing It is desirable, therefore, that a polyester staple fibre,
• parts of the fibre change from a rigid or glassy nature, to a mobile or rubbery nature and this transition is known as the glass-rubber transition, occurring at the glass-rubber transition temperature (Tg).
• washing temperatures because a garment made from polyester fibre with a lowered Tg will lose some of its permanent pleats if washed, or otherwise heat treated repeatedly at temperatures close to or above the transition temperature.
• Tg transition temperature
• filaments and like shaped structures made from polyesters derived from terephthalic acid, particularly those made from polyethylene terephthalate, characterized in that the 7 structure consists of a core portion and a physically modified skin or outer layer portion, the proportion of the cross-sectional area of the fibre skin portion may be as high as 70% and as low as 45%, preferably 50-60%.
• the modified skin portion is characterized by a transition temperature (Tg) l545 C. lower than that of the core portion, preferably 2040 C. lower than that of the core portion. This confers on the fibre various improved properties, particularly dyeability.'
• the glass-rubber transition temperature is defined as the temperature at which the properties of the fibre change from those of a glass-like solid to those similar to a rub- It can be determined by measurements of dynamic modulus, expansion coeflicient, specific heat, etc. over a range of temperatures. For dynamic methods, the value is dependent on the frequency of measurement.
• the glass-rubber temperature obtained from tensile or torsion measurements will be identical.
• the glass-rubber transition temperature of such a fibre measured by tensile modulus is not greatly diiterent from that of the core, whereas the torsional modulus shows a much reduced glass-rubber transition temperature. This is because the deformations of the fibre in torsion are much greater in the skin than in the core, whereas in tension comparabledeforrnation of skin and core are produced. 7
• the improved polyester filaments provided by our invention have much improved dyeing properties whilst retaining the full pleating properties of unmodified polyesters, particularly of polyethylene terephthalate.
• These modified polyester filaments are superior to uniform structures made from e.g. poly(hexa hydro-para-xylylene terephthalate) or copolyesters of polyethylene terephthalate/sebacate, terephthalate/adipate, terephthalate/ isophthalate, etc., in that whilst such filaments have improved dyeing properties, they also have inferior pleat (Tg) at least C. lower than that of the unaffected core portion. It will be appreciated that any liquid may be used for the treatment, which will bring about the desired modification of the structure.
• liquids for treatment are the poly- If on the other hand, more is modified and converted to a skin portion, certain desirable properties will be lost, such as pleat retention in garments containing the modified polyester fibre. In extreme cases, drawing of the undrawn and treated structures at least twice their length as spun may become impossible or at least very difficult.
• the structures after the treatment with the liquids should be capable of being drawn at least two and prefw erably up to six times their length as spun. This drawing may be carried out by heating the structures to between 75100 C., but we have found that if the treatment has been effective, drawing to the required extent without heating becomes possible under adiabatic conditions, at high speeds of drawing. Although the polyester structures may be treated in batches in their relaxed condition,
• the desired skin/core modification of the fibre can be produced with temperatures up to 150 C., treatment times up to one minute duration and polyethylene glycols and their equivalent nonyl phenyl ethers up to 6,000 molecular weight.
• Polyethylene glycols of molecular weights between 200 and 2,000, containing ethylene oxide condensate portions of similar molecular size, are preferred for use in the manufacture of our modified fibre because they have melting points below about C. and so can readily be washed oif the drawn treated fibre with warm water.
• the polyglycol ethers may be mixed and used together in the treatment bath. Immersion of a spun 'undrawn tow of polyethylene tercphthalate in these treating agents at these temperatures produces complex changes in the structure of the fibre and these changes can render the fibre undrawable unless the treatment temperatures are less than 150 C. and immersion times in the liquids are one minute or less, but more than one second.
• the final treated drawn product must have satisfactory tensile properties, i.e. a tenacity of 3.0-3.5 g.p.d. or more, and be substantially free of liquid used for the treatment e.g. the polyethylene glycol or the nonyl phenyl polyethylene glycol ether.
• tensile properties i.e. a tenacity of 3.0-3.5 g.p.d. or more
• liquid used for the treatment e.g. the polyethylene glycol or the nonyl phenyl polyethylene glycol ether.
• the final treated drawn set fibre has satisfactory tensile properties and can be washed free of treating agent at a stage between the drawing and the crimping operations.
• the treatment conditions must always be designed to produce the desired ratio of modified skin to inner unmodified core in the fibre.
• the polyester fibres should be modified so that they consist of at least by crosssectional area of skin portion. Otherwise, the improvement in dyeability will only be relatively small and, more importantly, the colour shade of a dyed fibre will not be stable to further heat treatments, viz. ironing at 180? C. A shade change may occur upon such heat treatment because the dye penetrates into the unmodified inner core of the fibre.
• the treatment is carried out by immersion in the presence of excess liquid, but other methods of treatment may be used, such as application by applicator rollers or by spraying, care being taken that at least 10%, pr ferably 20 to 40% of the liquid based on the dry weight of the structure is available at the selected treatment temperatures on the whole surface of the structure.
• various surface active agents- may be added in small amounts to ensure a homogeneous treatment'and care should be taken to reduce the risk of entrapping air between the liquid and the surface of the. structure during the treatment.
• liquids may be applied at low temperatures conveniently at room temperature, and that the structures may be subsequently heated to the required temperature for a sulficient time, providing the required amount of liquid is present during heating to effect a conversion of at least 45 of the structure to the modified constitution.
• the glass rubber transition temperature (Tg) was determined by measurement of dynamic tensile modulus and dynamic torsional modulus at various temperatures.
• the dynamic tensile modulus was measured by taking a bundle of fibres, of total denier about 500, and applying to this a sinusoidal by means of a Scotch-yoke mechanism, the resultant stress being determined by a strain gauge transducer attached to the other end of the bundle of fibres.
• the sinusoidal strain was monitored by using the Scotch yoke mechanism to strain simultaneously an elastic spring also attached to a strain gauge transducer.
• the amplitudes of the signals from the two strain gauges were compared electrically, and this gives a value for the tensile modulus.
• the bundle of fibres was enclosed in a thermal cryostat and the temperature controlled by a flow of air which could be heated.
• the fibre had taken up 15.8 mg. of dye/ g. fibre and microscopical examination of crosssections of this fibre showed that the dye had penetrated 50% of the cross- An untreated control fibre, dyed under the same conditions, had taken up 2.7 mg. of dye/g. fibre, and the dye had penetrated only 12% of'the cross-sectional area into the fibre.
• the treated fibre had taken up 20 mg. of dye/g. fibre and the penetration was 52%.
• the untreated control had taken up 5.3 mg. of dye/ g. fibre and the penetration had increased to about 15%.
• the treated fibre had taken up 24 mg. of dye/g. fibre and the penetration was 55%
• the untreated control had taken up 6.5 mg. of dye/ g. fibre and the penetration had increased to about 30%.
• Example 1 An undrawn tow of polyethylene terephthalate filaments (220 filaments, denier per filament) was passed through a bath containing polyethylene glycol (molecular weight 600) heated to 125 C. at such a speed that the tow was treated for five seconds.
• the undrawn tow, with polyethylene glycol 600 adhering to it then passed onto a set of feed rolls, through a hot water bath at 95 C. and onto a faster rotating set of draw rolls so that it was drawn to four times its original length.
• Sprays of warm Water on the firstthree draw rolls and a rubber covered roller pressing on the final draw roll removed excess polyethylene glycol and water.
• the drawn tow was then dried for five minutes at 95 C. and set (to have zero shrinkage in boiling water) at 140 C. for ten minutes, in a hot air oven.
• Example 2 A similar undrawn tow, as in Example 1, of polyethylene terephthalate was treated for five seconds in a bath containing polyethylene glycol 400 heated to 125 C.
• the dye uptake of this treated fibre was 14 mg. of dye/g. of fibre compared with a control fibre of 2.5 mg./g.
• Measurements of Tg gave a value of 93 C. for the skin portion (in the dry state) from the torsional method and 110 C. for Tg by the tensile modulus method.
• Example 3 Treatment as in Examples 1 and 2, but with Tergitol (R.T.M.) NF. 35 (a nonyl phenyl polyethylene glycol ether) gave a treated fibre with a dye uptake of 15.5 mg./ g. which had a skin portion, measured as before, of 51% having a Tg of C.
• R.T.M. Tergitol
• NF. 35 a nonyl phenyl polyethylene glycol ether
• Example 4 I Two undrawn threads each containing 336 undrawn 12 denier filaments of polyethylene terephthalate, were immersed in Carbow-ax 600 (polyethylene glycol of average molecular weight 600) at C. for 5 seconds and then mangled to leave a residue of about 35% Carbowax on the filaments.
• Carbow-ax 600 polyethylene glycol of average molecular weight 600
• One of the treated threads was drawn over a 2" diameter pin heated to 110 C.
• the drawn thread had a'dye uptake of 15 mg./gram.
• the other thread was drawn over a 2" diameter pin at room temperature, and the drawn thread had a dye uptake of 13 mg./ gram.
• the Tg from the torsional method of the treated threads was 95 C.' for the skin portion.
• Dye penetration indicated 50% of modified skin or outer layer portion of the filaments.
• a process for the manufacture of improved filaments, fibers and like shaped structures made from polyesters derived from terephthalic acid, having a core portion and a modified outer layer portion comprising treating the structures in their undrawn, as spun condition with a heated inert organic liquid selected from the group consisting of polyethylene glycols, nonyl phenyl polyethylene glycol ethers, and mixtures thereof, at a temperature up to 150 C. for 1 to 60 seconds and until 4570% of the structure ismodified and converted into said outer layer portion, said outer layer portion having a second order transition point (Tg), after drawing, 45 C. lower than said core portion, and then drawing said structures at least twice and up to six times their length as spun in a zone maintained at 75-100 C.
• Tg second order transition point

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Treatment Of Fiber Materials (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10133794

Family Applications (1)

Country Status (5)

Cited By (5)

Citations (15)

Family Cites Families (3)

• 0
  • NL NL265423D patent/NL265423A/xx unknown
  • BE BE604582D patent/BE604582A/xx unknown
• 1960
  • 1960-06-03 GB GB19703/60A patent/GB919860A/en not_active Expired
• 1961
  • 1961-05-31 DE DEJ20003A patent/DE1233533B/de active Pending
  • 1961-06-01 US US114021A patent/US3251913A/en not_active Expired - Lifetime

Patent Citations (15)

Also Published As

Similar Documents