Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N5/00—Roofing materials comprising a fibrous web coated with bitumen or another polymer, e.g. pitch
• • 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
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/447—Yarns or threads for specific use in general industrial applications, e.g. as filters or reinforcement
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/04—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyesters, e.g. polyethylene terephthalate [PET]
• • 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
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/20—Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
  • Y10T442/2738—Coating or impregnation intended to function as an adhesive to solid surfaces subsequently associated therewith

Definitions

• This invention relates to reinforcing fibrillary material, e.g., fibers, threads, yarns or like threadlike products, of a polymer substantially made up of ethylene terephthalate units and more particularly to polyethylene terephthalate fibers having a combination of properties especially suitable for the reinforcing of bitumen-containing materials, to a process for producing such fibers and products reinforced thereby.
• fibers as used throughout this specification is meant to include continuous monofilaments, nontwisted or entangled multifilament yarns, staple yarns and spun yarns. Such fibers may be used to form woven fabrics, knitted fabrics, fibrous webs, or any other fiber-containing structures.
• a polymersubstantially made up of ethylene terephthalate units is meant to define polyethylene terephthalate and copolymers which have in their polymer chains not more than mole percent of units other than the ethylene terephthalate units.
• the polymer may be prepared from a reaction mixture which in addition to terephthalic acid or derivatives thereof contains isophthalic acid or other dicarboxylic acid or derivatives thereof.
• the reaction mixture may in addition to ethylene glycol contain one or more other diols such as propylene glycol.
• Reinforcing fibers of polyethylene terephthalate are known. These fibers are used, inter alia, for reinforcing rubber articles such as pneumatic tires and conveyor belts, as well as sheet material and layered material having a base of bitumen or asphalt. In these applications the fibers absorb part of the strain acting on the reinforced product. The higher the force which is required to elongate the fibers to a given extent, the smaller will be the deformation at a given force. Products such as automobile tires and road surfaces are subject to varying dynamic forces. The smaller the deformations as a result of these forces, the longer will be the service life, because the creep and fatigue properties of such products are to a high degree negatively influenced by deformation.
• Fibers that conform to this requirement are known, inter alia, from the disclosure of the British Pat. specification No. 848,81 1.
• the known polyethylene terephthalate fibers are in many respects very suitable for reinforcing sheet material and layered material having a base of bitumen, these fibers have the following shortcoming.
• bitumen, or bitumen-containing materials having a high softening point.
• the application of such a material must be carried out in a liquid or molten state at temperatures up to 160 C. or higher. It has been found that at 160 C. the known polyethylene terephthalate fibers show a relatively high degree of shrinkage, which often gives rise to undue deformation in the reinforced product.
• the present invention provides a polyethylene terephthalate fiber having a unique combination of properties including low shrinkage at elevated temperatures.
• this invention contemplates a reinforcing fiber which comprises a fiber of polyethylene terephthalate that has a tenacity of at least about 7.5 grams per denier, an elongation at break of at least about 9 percent and an elongation of not more than about 5 percent at a load of 5 grams per denier and that shrinks less than 4 percent when kept under a tension of 0.05 grams per denier for 4 minutes at a temperature of about 160 C. (The tenacity and elongation of the fibers are determined at a temperature of 20 C., a relative humidity of 65 percent and at a constant rate of extension of 30 centimeters per minute.)
• the fiber of this invention is thus distinct from all known polyester fibers in that it satisfies a combination of requirements regarding tenacity, elongation at break, elongation at a load of 5 grams per denier, and low shrinkage at about 160 C.
• the fiber of the invention is particularly suitable for reinforcing layered material and sheeted material having a base of bitumen. It is preferred that the fiber should be employed in the form of a continuous multifilament yarn. This yarn may be twisted or nontwisted. Alternatively, if a higher coherency of the filaments is required, use may be made of a tangled yarn. In such case, the filaments have been interlaced by turbulent air streams.
• the fiber of this invention may be obtained by subjecting an undrawn fiber of polyethylene terephthalate having a relative viscosity of about 1.50 to 1.70 to a two-stage drawing procedure, the drawing in the first stage taking place at a temperature of about 70 to 100 C., and at a draw ratio in the range of about 3.8 to 4.2, and the drawing in the second stage taking place in the presence of superheated steam at a temperature of about 210 to 250 C. and at such a draw ratio that the total draw ratio is in the range of about 5.6 to 6.0.
• relative viscosity it is meant the ratio of the rate of flow through a capillary of a 1 percent solution of the polymer in metacresol to the rate of flow of the pure solvent, measured at a temperature of 30 C.
• This process makes it possible to obtain fibers of this invention having a tenacity in the range of about 7.5 to 9.5 grams per denier, an elongation at break of about 9 to 15 percent, an elongation of about 2 to 5 percent at a load of 5 grams per denier, (determined under the heretofore-described testing conditions) and a shrinkage of about 1 to 4 percent upon being heated for 4 minutes at about 160 C.
• the yarns designated as 1 SD" and 3 DD in Table VIII in column 12 have a particularly low shrinkage at 90 C. (dry) and 100 C. (wet). After these yarns were drawn, they were relaxed and upon being subjected to a load of 5 grams per denier show an elongation which is much higher than the maximum elongation of 5 percent exhibited by the fiber of the present invention.
• this invention also is directed to sheet materials and layered materials which have a base of bitumen and are reinforced with the fibers according to the invention.
• the polymer streams issuing from the spinnerette are cooled over a distance of 10 to 150 cm. from the spinnerette by directing a stream of cooling air on to them.
• the threads are wound at a speed of 500 meters per minute.
• the threads obtained are passed over a drawpin having a temperature of 80 C. and drawn to four times their original length. Subsequently, the threads are passed through a steam box 10 meters long in which the threads are drawn at a temperature of 230 C. and a speed of 150 meters per minute to a total draw ratio of 5.8.
• the threads obtained in this way is doubled by plying it into a cord having a denier of 1,000, a tenacity of 7.8 grams per denier, an elongation at break of 9.7 percent, a shrinkage of 3.9 percent after heating for 4 minutes at 160 C., and an elongation of4.5 percent at a load of5 grams per denier.
• the polymer streams issuing from the spinnerette are cooled over a distance of 10 to 150 cm. from the spinnerette by directing a stream of cooling air on to them.
• the threads are wound at a speed of 500 meters per minute.
• the threads obtained are passed over a drawpin having a temperature of C. and drawn to four times their original length. Subsequently, the threads are passed through a steam box 10 meters long in which the threads are drawn at a temperature of 210 C. and a speed of meters per minute to a total draw ratio of 5.8.
• the thread thus made has a denier of 990, a tenacity of 8.15 grams per denier, an elongation at break of l 1.0 percent, a shrinkage of 3.9 percent after being heated for 4 minutes at C., and an elongation of 4.5 percent at a load of 5 grams per denier.
• heat-relaxation causes the elongation at a load of 5 g.p.d. to increase, so that products are obtained which do not meet the requirements for a yarn according to the present invention.
• a fiber according to the invention may in the usual way be provided with a finish and with a coating of a substance which promotes adhesion to the material to be reinforced.
• certain adhesive promoting substances are considerably more effective than others.
• adhesive substances comprising resinous materials that have a softening point between 50 and 160 C., are miscible with bitumen, and in the molten state act as wetting agents on the reinforcing fiber.
• Exemplary of the resinous materials that may be used as adhesive promoting substances with the fibers of this invention are montan resin, tall resin, the coumarone and indene resins, maleic resins, phenol resins, rosin derivatives, and the like.
• EXAMPLE V This example illustrates the use of the fibers of this invention to reinforce a bitumen-containing road surface.
• a foundation layer of a mineral mixture of 50 percent by weight of gravel and filler and 50 percent by weight sand with asphalt bitumen having a high softening point is applied at a depth of about 7 cm. to a sub-layer of compacted sand.
• About 5 to 6 percent by weight of the foundation layer consists of bitumen.
• This layer is applied at a temperature of about 160 C. and rolled.
• an adhesive layer of an anionic 50 percent asphalt emulsion is provided over the foundation layer and a fabric made of the same type of polyethylene terephthalate fiber described in Example I is then rolled out over the adhesive layer.
• the fabric has a plain weave type and is charged with about 45 percent by weight of a montan resin having a solidifying point of 75 to 76 C., an acid number between 30 and 40 and a saponification number between 55 and 65.
• a second coating of the asphalt emulsion is applied by spraying and is allowed to break up.
• another asphalt layer having the same composition of gravel, sand, filler and asphalt bitumen as the foundation layer is applied at a temperature of about 160 C. and rolled to a thickness of about 7 cm.
• a fiber reinforced bitumen-containing material which comprises a bitumen-containing layer reinforced with a fiber of polyethylene terephthalate having a tenacity of at least about 7.5 grams per denier, an elongation at break of at least about 9 percent, an elongation of not more than 5 5 percent under a load of 5 grams per denier, and a shrinkage of less than 4 percent when kept under a tension of 0.05 grams per denier for 4 minutes at about C.
• the fiber reinforced bitumen-containing material of claim 9 in which said fiber has a tenacity in a range of from about 7.5 to 9.5 grams per denier, an elongation at break of from about 9 to 15 percent, an elongation of about 2 to 5 percent at a load of 5 grams per denier, and a shrinkage of from about 1 to 4 percent when being heated for 4 minutes at 160 C. under said tension.

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Citations (1)

• 1968
  • 1968-08-31 NL NL6812442A patent/NL6812442A/xx unknown
• 1969
  • 1969-08-25 US US3650879D patent/US3650879A/en not_active Expired - Lifetime
  • 1969-08-29 FR FR6929626A patent/FR2016607A1/fr not_active Withdrawn
  • 1969-08-29 DE DE19691944042 patent/DE1944042A1/de active Pending
  • 1969-08-29 GB GB4321469A patent/GB1266982A/en not_active Expired

Patent Citations (1)

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