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
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters
• • 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
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/78—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products
  • D01F6/84—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products from copolyesters

Definitions

• the present invention relates to the manufacture of yarns by the melt-spinning of poly(ethylene-lz2- diphenoxyethane-4:4-dicarboxylate).
• a copolyester of poly( ethylene-l :2- diphenoxyethane-4-4'-dicarboxylate) we mean a copolyester of which at least 90 percent of the structural units are of the formula:
• Such copolyesters may contain in the chain minor amounts of other structural units derived from glycols other than ethylene glycol and/or from dicarboxylic acids other than bis-l:2-(paracarboxyphenoxy)ethane and/or from a hydroxycarboxylic acid.
• the poly( ethylene-l :2-diphenoxyethane-4:4- dicarboxylate) or its copolyester for use in accordance with our invention may be manufactured by known methods and may contain one or more additives, for example delustrants, pigments, optical brighteners or stabilizers.
• the yarns of our invention are of particular value when the poly(ethylene-l:2-diphenoxyethane-4:4'- dicarboxylate) or copolyester comprising them is of relative viscosity, as measured in orthochlorophenol at a concentration of l g. per 100 ml. of solvent and at a temperature of 25 C., greater than 2.0.
• the spun yarn produced is amorphous, while still having a high 'spun birefringence.
• the preference for amorphous yarn arises from the fact that crystallinity in the spun yarn results in lower extensibility in the drawn product.
• arnorphous we mean that examination by X-ray diffraction showed no crystallinity.
• the crystallinity of the spun yarn may be controlled by appropriate choice of relative viscosity of the poly(- ethylenel :2-diphenoxyethane-4:4-dicarboxylate) and of the parameters of the melt-spinning.
• crystallinity is favoured by increase in stress which is increased by increase in relative viscosity.
• increase in spinneret hole size for a given spun denier reduction in the temperature of the poly(ethylene-l:Z-diphenoxyethane- 4:4-dicarboxylate) at extrusion, increase in rate of cooling in the molten region of the threadline, and increase in draw-down during spinning.
• the ease of drawdown in forming the spun yarn will be, inversely related to the viscosity of the extrudate, and the desirable spinning temperature will increase with yarn relative viscosity.
• the desirable spinning temperature is in the range 295 to 335 C.
• it may be preferable to reduce the rate of filament cooling for example by the use of a heated threadline shroud as described in U.K. Pat. No. 1,052,067, rather than to use impracticably high extrusion temperatures.
• Spun yarns of poly(ethylene-l:2-diphenoxyethane- 4:4'-dicarboxylate) have the characteristic that when heated under low or zero tension they either shrink or increase in length spontaneously dependent on the initial spun yarn birefringence and on the temperature of heating.
• the spun yarn When the spun yarn expands spontaneously under zero tension as described above it also c'rystallises, the crystalline form (referred to as B crystallinity) has a monoclinic habit.
• the crystallisation which occurs under stress, as during spinning, is of a different crystalline form having an orthorhombic habit (referred to as the a form).
• the crystallisation under stress produces the a form; thus the crystallisation obtained under the spinning stress and during drawing using a pin only, for example as described in our U.K. Specification No. 1,047,978, is of the a form.
• An advantage of the process of our invention is that by the use of it drawn yarns may be produced having a tenacity of greater than 9.5 g. per denier and an extension to break greater than 7 percent.
• Such yarns are of particular advantage for the manufacture of ropes, and cords.
• the cords are of particular use in the manufacture of tyres and V-belts, in which high modulus, good hydrolytic stability and low shrinkage are desirable. ln the case of the use of the yarns in ropes, the good light stability is a further advantage.
• the orientation by extension may be carried out by known methods. Heated feed rolls or heated snubber pins may be used; we have 'found the latter to be preferable.
• Examples 1 10 are not according to the present inven- EXAMPLES 28 33 tion.
• EXAMPLES 21 27 The following Examples show how in the absence of external heating effects, for example a threadline These Examples show that inferior drawn yarns are shroud, the spinning extrusion temperature varies obtained from a-crystalline spun yarn. w1th relative viscosity for the processes found to Yarns of 48 filaments having relative viseosities of yield the best drawn tensile properties at a given 2.07 and 2.13 respectively were extruded at about 310 relative viscosity level. C. and wound up to give spun yarns of birefringence The results ar h wn in Tabl 3 about 130 X 10".
• EXAMPLE 34 This example shows how the dimensional stability of amorphous spun yarn varies as a function of spun birefringence and temperature of heat treatment.
• a 24 filament yarn was spun in a similar manner to that in case 11 to an RV of 2.08 at 312 C and collected at 3,500 fpm to give an amorphous spun yarn of birefringence 74 X 10
• the yarn was shown to be capable of drawing at optimum conditions to give a product having a filament tenacity in excess of 10.0 gm/denier.
• the minus sign indicates that shrinkage occurs.
• the plus sign indicates that elongation occurs.
• a 24 filament yarn of RV 2.08 was extruded at 312 C and collected at 3,500 fpm to give a spun yam which was amorphous and had a birefringence of 74 X b.
• a 24 filament yarn of RV 2.32 was extruded at 325 C and collected at 2,150 fpm to give a spun yarn which was partly a-crystalline and had a birefringence of 92 X 10*.
• the two spun yarns were drawn at 350 fpm and a heated pin and plate to the appropriate maximum draw ratio using a fixed pin temperature while the plate temperature was varied.
• the effects of plate temperature on the tensile properties and on the percentage of B-crystalline form in the crystalline regions of the drawn yarns are shown in Table 7.
• A (16.2 X 10 W (50 X 10 is in the range from 295 to 335 C.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (5)

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Citations (6)

• 1973
  • 1973-03-26 NL NL7304178A patent/NL7304178A/xx unknown
  • 1973-03-30 US US00346490A patent/US3832436A/en not_active Expired - Lifetime
  • 1973-04-03 CA CA167,839A patent/CA1067659A/en not_active Expired
  • 1973-04-05 FR FR7312302A patent/FR2179167B3/fr not_active Expired
  • 1973-04-06 JP JP48038826A patent/JPS497519A/ja active Pending
  • 1973-04-06 DE DE2317472A patent/DE2317472A1/de active Pending

Patent Citations (6)

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