Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D193/00—Coating compositions based on natural resins; Coating compositions based on derivatives thereof
  • C09D193/04—Rosin
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
• • 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
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
• • 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
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
  • Y10T428/139—Open-ended, self-supporting conduit, cylinder, or tube-type article
  • Y10T428/1393—Multilayer [continuous layer]

Definitions

• This invention relates to articles of manufacture comprising polyamide/low density polyethylene blends and the process for producing such articles.
• One specific aspect of this invention relates to extruded articles of manufacture including a polyamide, an unfunctionalized low density polyethylene, and a functionalized polyethylene.
• compositions comprising nylon 6, functionalized high density polyethylene (“HDPE”), and unfunctionalized linear low density polyethylene (“LLDPE”) as well as compositions comprising nylon 6, 6 and functionalized low density polyethylene have been made as indicated in Padwa, 32 (22) Poly Eng Sci 1703 - 10 (1992) and Hobbs, et al, 23(7) Poly Eng Sci 380 (1983), respectively. Because these references are directed to modifying the impact properties of polyethylene/polyamide compositions, their teachings are restricted to blended compositions employing functionalized low density polyethylene at low concentrations per se without addressing the composition's flexibility, chemical and solvent resistance, or suitability for tubing, jacketing or sheathing applications.
• HDPE functionalized high density polyethylene
• LLDPE unfunctionalized linear low density polyethylene
• high heat resistance is denoted by properties, such as a high softening temperature, i.e. VICAT softening temperature greater than about 200 °C.
• High solvent resistance refers to a solvent resistance imparted to the composition which is proportional to that of the polyamide present. More specifically, we have found that by adjusting the ratios of the three above- mentioned components accordingly, a polyamide-low density polyethylene blend composition of suitable viscosity can be extruded into various articles of manufacture having high chemical resistance and heat stability as well as superior flexibility.
• FIG. 1 is a graph illustrating the Vicat Softening Temperature of nylon 6/LDPE blends (° C) versus LDPE content.
• FIG 2 is a graph illustrating the flexural modulus (MPa) and notched izod (J/M) versus LDPE content.
• FIG 3 is a TEM of a composition containing 40% by weight of nylon 6 and 60% by weight of maleated LDPE.
• FIG 4 is a TEM of a composition containing 60% by weight of nylon 6 and 40% by weight of maleated LDPE.
• melt index reported herein are in units of g/10 minutes at 235 °C and under a load of 1 kg, unless otherwise indicated.
• the polyamides of component (a) are formed by the reaction of diamines and diacids such as poly(hexamethylene adipamide) (nylon 6,6), pol (hexamethylene sebacamide) (nylon 6,10), poly(heptamethylene pimelamide) (nylon 7,7), poly(octamethylene suberamide) (nylon 8,8), poly(nonamethylene azelamide) (nylon 9,9), poly(decamethylene azelamide) (nylon 10,9), and the like.
• diamines and diacids such as poly(hexamethylene adipamide) (nylon 6,6), pol (hexamethylene sebacamide) (nylon 6,10), poly(heptamethylene pimelamide) (nylon 7,7), poly(octamethylene suberamide) (nylon 8,8), poly(nonamethylene azelamide) (nylon 9,9), poly(decamethylene azelamide) (nylon 10,9), and the like.
• poly(4- aminobutyric acid) (nylon 4), poly(6-aminohexanoic acid) (nylon 6, also known as poly(caprolactam) ) , poly(7-aminoheptanoic acid) (nylon 7), poly(8- aminoocatanoic acid) (nylon 8), poly(9-aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid) (nylon 10), poly(11-aminoundecanoic acid) (nylon 11), poly(12-aminododecanoic acid) (nylon 12) and the like. Blends of two or more aliphatic polyamides may also be employed.
• Copolymers formed from recurring units of the above referenced aliphatic polyamides can also be used.
• Such copolyamides can be aliphatic/aliphatic type or aliphatic/aromatic (semi-aromatic) type compounds.
• such aliphatic polyamide copolymers include caprolactam/hexamethylene adipamide copolymer (nylon 6/6,6), hexamethylene adipamide/caprolactam copolymer (nylon 6,6/6), hexamethylene adipamide/ hexamethylene terephthalamide copolymer (nylon 6,6/6T , hexamethylene terephthalamide /isophthalamide (nylon 6T/6I), hexamethylene terephthalamide/caprolactam copolymer (nylon 6T/6) and the like.
• Nylon 6 is most preferred.
• Polyamides suitable for use in this invention have a formic acid viscosity ("FAV") of about 30 to about 150, preferably about 40 to about 100, and most preferably about 45 to about 75, as well as a number average molecule weight, as measured by end group titration, of about 15,000 to 40,000.
• FAV formic acid viscosity
• the polyamide preferably has a FAV between about 55 to about 70.
• Polyamides may be obtained from commercial sources or prepared in accordance with known preparatory techniques.
• nylon .6 can be obtained from AlliedSignal Inc., Morristown, New Jersey.
• nylon 6 contains about 10 weight % caprolacta .
• the lactam content of the nylon may vary between about 0 to about 10 weight % through selective extraction of the nylon or by the blending of washed and unwashed nylon.
• Unwashed polycaprolactam is preferred due to its low modulus.
• Component (b) is a polyethylene containing a carboxylic acid or anhydride moiety. More specifically the polyethylene is functionalized with a compound selected from the group consisting of maleic anhydride, fumaric acid, methacrylic acid, acrylic acid, and the like and having a melt index of about 0.001 to about 20 at 190 °C and under a load of 2.16 kg, preferably about 0.01 to about 5, and most preferably about 0.04 to about 3.
• Other functionalizing compounds include maleic acid, itaconic acid, citric acid, itaconic anhydride, citraconic anhydride, and the like.
• the term "functionalized” as used herein means reactively attaching the functionalized compound to the polymer, i.e. polyethylene, backbone.
• component (b) is selected from the group consisting of high density polyethylene, low density polyethylene, and linear low density polyethylene.
• component (b) is a low density or linear low density polyethylene functionalized with maleic anhydride.
• Component (b) may be synthesized by methods generally known in the art for the functionalization of polyolefins. While not being limited to any theory, it is believed that the maleic anhydride reacts with the polyethylene backbone via radical addition mechanism and thus becomes grafted thereto as a pendant succinic anhydride moiety. See United States Patent 3,862,265 to Steinkamp, et al.
• unfunctionalized low density polyethylene is commercially available from Dow Chemical Co.
• unfunctionalized as used herein means a conventional unmodified polymer.
• low density as used herein means having a density between about .85 and about .95 g/cm? .
• Low density polyethylene suitable for use in this invention has a melt index of about 0.5 to about 50 at 190 °C and under a load of 2.16 kg, preferably from about 1 to about 10, and most preferably from about 2 to about 5.
• the unfunctionalized low density polyethylene preferably has a melt index of about 2.
• the polyamide is present in the polymeric blend in an amount of from about 50 to about 80%, preferably from about 65 to about 80%, and most preferably about 70 to about 80%, based upon the total weight of the polymeric blend.
• the unfunctionalized low density polyethylene is present in an amount of from about 0 to about 49%, preferably from about 0 to about 30%, and most preferably from about 20 to about 30%, based upon the total weight of the polymeric blend.
• the functionalized polyethylene is present in an amount of from about 1 to about 50%, preferably from about 1 to about 30%, and most preferably from about 1 to about 10%, based upon the total weight of the polymeric blend.
• the amount of functionalized moiety in component (b) is about 0.1 to about 3%, preferably about 0.4 to about 2%, and most preferably about 0.8 to about 1.5%, based upon the total weight of the functionalized polyethylene.
• the ratio of component (a) to components (b) and (c) be about 60:40 to about
• the ratio of component (a) to components (b) and (c) is about 70:30 to about 80:20.
• the functionalized and unfunctionalized polyethylene is dispersed within the continuous polyamide phase. This is illustrated in FIG. 4, in which the low density polyethylene, as shown by the light areas, is dispersed within the continuous nylon phase for a 60:40 nylon 6-maleated low density polyethylene blend composition.
• nonconvoluted (straight) tubings, sheathings and jacketings permits a wider range of viscosity in the polyamide- polyethylene blend composition, i.e. acceptable melt index ranges between about 0.1 and about 20, we have found that by using polyamide having a FAV between about 50 to about 70 and a polyethylene having a melt flow index of about 2, and by increasing the polyamide ratio such that the polyethylene is dispersed within the continuous polyamide phase, we are able to create a polyamide-polyethylene blend composition having sufficient viscosity, i.e. a melt index between about 1 and about 5, and preferably between about 2 and about 3, which is extrudable into convoluted tubing articles.
• compositions containing less than about 50% nylon 6 are also unsuitable since at that amount the nylon 6 is dispersed within the low density polyethylene continuous phase, leading to low softening points and low chemical resistance. This is illustrated in FIG. 3, wherein the nylon, as shown by the dark areas, is dispersed within the continuous low density polyethylene phase for a 40:60 nylon 6- maleated low density polyethylene composition.
• polyolefins grafted with maleic anhydride may be dry-blended with polyamide, then extruded under vacuum at about 5 °C to about 100 °C above the melting point of the blended composition, preferably at 310 °C or below.
• the articles of manufacture of the present invention may be formed by initially combining a polyamide, an unfunctionalized polyethylene, and a functionalized polyethylene at the recommended ratios and viscosities.
• the combination may be formed into various articles of manufacture by methods, such as extrusion, which are well-known in the art.
• extrusion which are well-known in the art.
• the combination of the three components of the polymeric blend was known in the art, see, i.e., Padwa, the art did not elaborate upon the effects of each respective component's phase or viscosity on the overall blended composition's properties and stability.
• processing requirements i.e. amounts of each component
• the term "article” is broadly meant to encompass that which is formed, molded, extruded, blow-molded, coextruded, thermoformed, laminated, and the like from the melt blended composition as well as blends with other thermoplastics into any of a variety of sizes, shapes, thicknesses, and so forth, whether it be film, sheet, tubing, containers, bottles, cans, vessels, coextrusions, laminations, and the like.
• the articles of manufacture can be single or multi-layered constructions.
• Such constructions include extruded materials such as cylindrical, convoluted or corrugated tubings which have utility in industrial and automotive applications, for example, windshield wiper tubing, wire and cable jacketing, fuel lines, vapor return lines, paint spray hoses, ducts, and the like.
• these tubes have inner diameters ranging between about 0.04 mm to about 40 mm.
• an outer layer comprised of the polyamide-polyethylene blend of the present invention may be bonded to a thermoplastic resin inner layer, with an optional tie layer therebetween.
• the inner thermoplastic layer may possess high barrier properties to hydrocarbons, such as gasoline and "gasohol", a mixture of gasoline and alcohol.
• Resins which are suitable for forming such coextruded articles in conjunction with the compositions of this invention may include one or more of the following: polyamides, such as poly (11-aminoundecanoic acid) (“nylon 11”) and poly(laurolactam) (“nylon 12"), fluoroplastics, such as polyvinylidene fluoride and ethylene-tetrafluoroethylene copolymer, polyesters, such as polybutylene terephthalate and derivatives thereof, and the like and blends thereof. Preferred among these resins are fluoroplastics.
• Such multilayer coextruded tubings in which the fluoroplastics are used as the inner layer and the polyamide-polyethylene blend of this invention is used as the outer layer are particularly useful as fuel lines and vapor return lines in automobiles.
• Molded containers can also be made from the above-described polymeric blend by compression molding, blow molding, thermoforming, vacuum molding, or other such techniques, all of which are conventional techniques.
• Articles formed from the compositions of the invention are ideally suited for automotive and industrial applications which require the use of materials having a high heat resistance, high chemical or solvent resistance, and high flexibility.
• the resulting articles of manufacture are also imparted with great flexibility resulting from the blending of polyethylene.
• nylon and polyethylene are incompatible, use of the functionalized polyethylene component is essential.
• the blends of this invention may also contain one or more conventional additives such as stabilizers and inhibitors of oxidative, thermal, and ultraviolet light degradation, lubricants and mold release agents, colorants, including dyes and pigments, flame- retardants, fibrous and particulate fillers and reinforcements, plasticizers, and the like. These additives are commonly added at mixing.
• Representative oxidative and heat stabilizers which may be present in blends of the present invention include Group I metal halides, e.g., sodium, potassium lithium with cuprous halides, e.g. , chloride, bromide, iodide, ; hindered phenols. organophosphites, hydroquinones, and varieties of substituted members of those groups and combinations thereof.
• Group I metal halides e.g., sodium, potassium lithium with cuprous halides, e.g. , chloride, bromide, iodide, ; hindered phenols. organophosphites, hydroquinones, and varieties of substituted members of those groups and combinations thereof.
• Representative ultraviolet light stabilizers include various substituted resorcinols, salicylates, benzotriazoles, benzophenones, and the like.
• Representative lubricants and mold release agents include stearic acid, stearyl alcohol, and stearamides.
• Representative organic dyes include nigrosine, while representative pigments include titanium dioxide, cadmium sulfide, cadmium selenide, phthalocyanines, ultramarine blue, carbon black, and the like.
• Representative fillers include carbon fibers, glass fibers, amorphous silica, asbestos, calcium silicate, aluminum silicate, magnesium carbonate, kaolin, chalk, powdered quartz, mica, feldspar, and the like.
• Representative flame-retardants include organic halogenated compounds such as decabromodiphenyl ether and the like.
• plasticizers include lactams such as pyrrolidone, laurolactam, and caprolactam, sulfonamides such as o,p-toluenesulfonamide and N- ethyl, o,p—toluenesulfonamide and other plasticizers known in the art.
• extracted nylon 6 means nylon 6 containing essentially no monomers, i.e., less than 0.5 percent
• unextracted nylon 6 means nylon 6 containing approximately 8 - 10% of residual caprolactam monomer
• ASTM-D-256 Notched Izod at 23 °C, 3/16 inch (5 mm) thick sample; ASTM-D-790: Flexural Strength and Modulus; ASTM-D-638: Tensile Strength, Modulus and Elongation;
• Low Density Polyethylene Into the throat of the extruder, 100 parts of a low density polyethylene, 1 part of maleic anhydride produced by Aldrich Chemical Company, and 0.3 parts of a peroxide initiator, viz. 2, 5-Dimethyl-2,5(t-butyl peroxy)hexyne-3, produced by Atoche America under the tradename, "Luperco-130 LX" were fed at a rate of 100 pounds/hr (45.3 kg/hr) and melt-blended.
• a peroxide initiator viz. 2, 5-Dimethyl-2,5(t-butyl peroxy)hexyne-3
• the low density polyethylene had a density of about 0.92, and a melt index of 2.0, and was produced by Dow Chemical Company under the tradename, "DOW- 640".
• the temperature profile in the extruder was as follows: Zones 1 through 6 at 190 °C, and Zones 7 through 10 as well as the die at 200 °C.
• the operating conditions of the extruder included a screw speed of 100 rpm, a motor drive amperage of 90 amps, a melt temperature in the die of about 205 ° C to about 220 °C, and an extruder output of 100 pounds/hour (45.3 kg/hour) .
• a vacuum was applied at Zone 9 to remove the unreacted maleic anhydride.
• the pressure in the other zones of the extruder was 1120 psi (7,720 KPa) .
• the maleated low density polyethylene produced was functionalized with an efficiency of greater than or equal to 70 percent.
• Examples 2 - 3 Preparation of Nylon 6- Maleated Low Density Polyethylene Blends
• the temperature profile in the extruder was as follows: Zone 1 at 200 °C, Zone 2 at 230 °C, Zones 3 through 10 at 260 °C, and the die at 260 °C.
• the operating conditions of the extruder included a screw speed of 225 rpm, a motor drive amperage of about 60 to about 90 amps, a melt temperature in the die of about 270 ° C to about 280 °C, and an extruder output of-90 pounds/hour (40.8 kg/hour).
• a vacuum of 200 mmHg was applied at Zone 4 for the purpose of removing the unreacted maleic anhydride.
• a vacuum of 200 mmHg was also applied at Zone 9 for the same purpose.
• the pressure in all other zones of the extruder was 700 psi (4,800 KPa).
• the nylon heat stabilizer is comprised of 74.8 % nylon, 23 % potassium bromide, and 2.2 % of a mixture further comprised of cuprous iodide and magnesium stearate in a ratio of about 98.5:1.5.
• the extracted and unextracted nylon 6 was obtained from AlliedSignal Inc.
• the blend of nylon 6, and maleated low density polyethylene had a melt flow index of about 0.1 to about 0.5 g per 10 minutes at a load of 2.16 kg at 245 °C.
• the temperature profile in the extruder was as follows: Zone 1 at 200 °C, Zone 2 at 230 °C, Zones 3 through 10 at 260 °C, and the die at 260 °C.
• the operating conditions of the extruder included a screw speed of 300 - 450 rpm, a motor drive amperage of 60 to 100 amps, a melt temperature in the die of about 270 ° C to about 300 °C, and an extruder output of 200 pounds/hour (90.6 kg/hour).
• the pressure in all zones of the extruder was about 500 to about 800 psi (about 3.5 to about 5.5 MPa).
• a mixture of unextracted nylon 6 having a formic acid viscosity of 70, extracted nylon 6 having a formic acid viscosity of 45, carbon black obtained from Southwest Chemical Services, and the nylon heat stabilizer of Examples 2 - 3 were added at Zone 6.
• the extracted and unextracted nylon 6 was obtained from AlliedSignal Inc.
• the blend of nylon 6, maleated low density polyethylene, and low density polyethylene had a melt flow index of about 2 to about 3.
• compositions prepared according to the procedures described above are set - 1 5 - forth in Table I. All parts were based upon the total amount of material fed to the throat of the extruder.
• Example 2 - 5 The blends of Examples 2 - 5 were injection molded on a 25 ton Arburg Injection Molder into test bars. Bars (flex bars) for testing flexural properties were 1/8 inches (3.175 mm) thick, tensile bars were 1/8 inch (3.175 mm) thick. Izod testing was conducted on the flex bars. Typical molding conditions follow: Zone temperatures 1 to 3 of about 260 °C; mold temperature of about 180 °C, with about 400 to about 1,000 psi (about 2.8 to about 6.9 MPa) psi pressures and cycle times of about 20 to about 40 seconds. Tables 2 - 5 below illustrate the mechanical properties of injection molded bars comprised of the blend compositions of Examples 2 - 5.
• the nylon 6-polyethylene- maleated low density polyethylene blend displays a high impact strength, i.e. notched Izod of greater than 2 ftlbs/in (107 J/m) , low flexural modulus, i.e. less than 200,000 psi (1,378 MPa), see FIG 2, high softening temperatures, i.e. less than 210 °C, see FIG 1, high melt strength, i.e. extruded tubes produced herein have uniform diameter and thickness, and good heat aging resistance, i.e. retention of high tensile elongations to break.
• the two-component composition is highly viscous, as illustrated by its melt index of less than about 0.2 g/10 min at 245 °C under a load of 2.16 kg/hr, which makes it suitable only for straight, nonconvolute applications.
• composition of Examples 4 and 5 possesses lower values overall for mechanical properties, it advantageously possesses a viscosity that is low enough for convoluted tubing extrusions but yet high enough to withstand the rigors associated with tubing extrusion processes, i.e. melt index of between 1.2 and 1.4. Therefore, if the polymeric blend does not contain unfunctionalized polyethylene, then the extrudate therefrom is too viscous for use in convolute tubing applications.
• Tables 2 - 5 report the mechanical properties of nylon 6-low density polyethylene blend samples which were injection molded.
• the claimed articles of the invention are preferably extruded. Because the reduced shear rates normally encountered during the extrusion process are likely to contribute to the more stable morphology of an extruded article in comparison to that of an injection molded article, we believe that the properties of the extruded articles of manufacture are superior to those of the injection molded articles as illustrated in Tables 2 - 5.
• Examples 6 through 9 were performed to identify the processing characteristics of extruding Nylon 6- Polyethylene blends into tubing. In these examples, all materials were processed on a Royal Extruder Model No. 2-W having a 2.5 inch (63.29 mm) screw, a length to diameter ratio of 24:1, a compression ratio of 4.0:1, and the following melt temperature profiles: Zone 10 - 430 °F, Zone 9 - 440 °F, Zone 8 - 450 °F,
• Zone 7 - 450 °F
• Zone 6 - 450 °F Rear Flange Zone 5 - 450 °F
• Front Flange Zone 4 - 460 °F Velocity Section Zone 3 - 460 °F.
• Head Zone 2 - 460 °F Die Zone 1 - 460 °F
• a melt temperature of 475 °F which corresponds to 221, 226, 232, 232, 232, 232, 237, 237, 237, 237 and 246 °C, respectively.
• Example 6 Process for Extruding
• Nylon 6-PE Blend into Tubing The nylon 6-polyethylene blend of Example 2, having a melt flow of about 0.15 - 0.2 g/10 minutes under a load of 2.16 kg and at 245 °C, was fed into the hopper of the extruder.
• the operating conditions of the extruder included a screw speed of about 10 to about 60 rpm, primarily about 20 rpm, a motor drive amperage of about 10 to about 20 amps, a load of about 10 to about 15 % , head pressure of about 1000 to about 3000 psi (about 6.90 to about 20.70 MPa), preferably about 2000 psi (13.80 MPa) and an extruder output of about 10 to about 45 feet per minute ( about 2.5 to about 15 meters per minute) .
• the tooling of the extruder included a die and a pin that provided a tube having a 0.312 inch (7.93 mm) outer diameter. Specifically, a pin having an outer diameter of .205 inches (5.2 mm) concentrically- surrounded by a die having an inner diameter of .375 inches (9.52 mm), an annular opening of .085 inches (2.17 mm), and a 20/40/60 screen pack therein was used.
• the material exited from the die After the material exited from the die, it entered a quench tank of about 20 to about 30 feet (about 6 to about 9 m) in length, which contained water at a quench temperature of about 75 °F (23.86 °C) , and remained therein for about 2 to about 3 minutes. While in the quench tank, the extruded tube passed around a sizing plate having a diameter of .330 inches (8.36 mm) . The extruded tubing product had an outer diameter of 0.312 inches (7.93 mm) and a wall thickness of 0.031 inches (0.79 mm).
• Example 7 Process for Extruding Nylon 6-PE Blend into Tubing The process as described in Example 6 was performed with the blend of Example 3, which had a melt flow of about 0.05 to about 0.1 g/10 minutes under a load of 2.16 kg and at 245 °C .
• the extruded tubing product also had an outer diameter of 0.312 inches (7.93 mm) and a wall thickness of 0.031 inches (0.031 mm). It can be seen that compositions comprised of a polyamide and a maleated polyethylene can be extruded through dies having an appropriately-sized annular opening in order to produce tubing having an inner diameter suitable for straight tubing applications. It can also be seen that the head pressure within the extruder is within what we believe to be the preferred operating range, i.e. less than about 7000 psi (48.27 MPa) and more preferably less than 3000 psi (20.70 MPa), in the art of straight tubing applications.
• Example 8 Process for Extruding Nylon 6-PE-Maleated PE Blend into Tubing The process described in Example 6 was performed with the blend of Example 4, which had a melt flow of about 1.2. In place of the tooling having the dimensions as described in Example 6, the tooling included a die having an inner diameter of .457 inches (11.63 " mm) and an annular opening of .041 inches (1.06 mm) as well as a pin having an outer diameter of .375 inches (9.51 mm) were used.
• the extruded tubing product has an outer diameter of 0.312 inches (7.93 mm) and a wall thickness of 0.031 inches (0.79 mm).
• Example 6 Three additional runs of the process of Example 6 as modified above were also performed at different screw speeds: 60 rpm, 40 rpm, and 10 rpm, respectively. As the screw speeds -were reduced, the head pressure also decreased from 2300 psi (15.86 MPa), to 1800 psi (12.41 MPa), to 1080 psi (7.41 MPa). The final tubing product retained its outer diameter and wall thickness.
• Example 9 Process for Extruding Nylon 6-PE-Maleated PE Blend into Tubing The process described in Example 6 was performed with the blend of Example 5, which had a melt flow of about 1.4. In place of the tooling having the dimensions as described in Example 6, the tooling described in Example 8 was used.
• the extruded tubing product has an outer diameter of 0.312 inches (7.93 mm) and a wall thickness of 0.031 inches (0.79 mm).
• Example 6 Three additional runs of the process of Example 6 as modified above were also performed at different screw speeds: 60 rpm, 40 rpm, and 10 rpm, respectively. As the screw speeds were reduced, the head pressure also decreased from 2300 psi (15.86 MPa), to 2150 psi (14.78 MPa), to 1180 psi (8.135 MPa) . The final tubing product retained its outer diameter and wall thickness. It can be seen from Examples 8 and 9 that as a result of the lower melt viscosity of the three component polymeric blend, the blend can be extruded through a die having a smaller inner annular opening, i.e. 1.06 mm, than the inner annular opening of the die used with the two component composition in
• Examples 6 and 7 i.e. 2.17 mm, as well as at a head pressure within the range of what we believe to be acceptable for both straight and convolute tubing applications, i.e. less than about 7,000 psi (about 48.27 MPa), and more preferably less than about 3,000 psi ( about 20.70 MPa) .
• the smaller annular opening of the die used in Examples 8 and 9 enables the blend to be extruded into a tube having a diameter suitable for convolute tubing applications.

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• 1995
  • 1995-05-25 BR BR9508027A patent/BR9508027A/pt not_active IP Right Cessation
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  • 1995-05-25 CN CN95194516A patent/CN1157001A/zh active Pending
  • 1995-05-25 JP JP8502201A patent/JPH10501579A/ja active Pending
  • 1995-05-25 AT AT95921411T patent/ATE179738T1/de not_active IP Right Cessation
  • 1995-05-25 WO PCT/US1995/006644 patent/WO1995035347A1/en active IP Right Grant
  • 1995-05-25 MX MX9606273A patent/MX9606273A/es not_active IP Right Cessation
  • 1995-05-25 KR KR1019960706907A patent/KR970703393A/ko not_active Ceased
  • 1995-05-25 EP EP95921411A patent/EP0765364B1/en not_active Expired - Lifetime
• 1996
  • 1996-12-13 US US08/764,165 patent/US5814384A/en not_active Expired - Fee Related

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