Process for producing polyolefin microporous breathable film

Information

  • Patent Grant
  • 6706228
  • Patent Number
    6,706,228
  • Date Filed
    Monday, June 18, 2001
    23 years ago
  • Date Issued
    Tuesday, March 16, 2004
    20 years ago
Abstract
Polyolefin/filler breathable films may be produced by machine or transverse direction orientation using interdigitating grooved rollers. Biaxial orientation to similarly produce breathable films may be accomplished by the same method. By heating the rollers, the breathability of the film is increased without increasing the depth of engagement of the interdigitating rollers.
Description




BACKGROUND OF THE INVENTION




1. Field




This invention relates generally to an improved polyolefin microporous breathable film and method of making same. More specifically, this invention is directed toward a process by which increased Water Vapor Transmission Rate (WVTR) and enhanced film appearance can be realized with substantially the same film formulation and orientation.




2. Background




Preparation of films having good WVTR from highly filled polymers, usually polyolefins, is well known in the art. In the past, a combination of polyolefin, usually a polyethylene, with a filler, usually CaCO


3


, is widely used as a film with good WVTR, often, but not necessarily, in combination with non-woven polymers for use in diapers, adult incontinence devices, feminine hygiene articles, surgical garments, housewrap composites, protective apparel, roofing materials and the like.




The use of interdigitating rolls to orient films or non-wovens is also well known in the art. In some cases this process is referred to as cold stretching. To increase the WVTR of films, while employing interdigitating technology, it has been necessary to increase the level of filler in the polyolefin/filler blend, or to increase the depth of interengagement of the orienting rollers—both of which have technical limits, and which may have a serious negative impact on important physical properties of the resulting film. The technical limits of depth of engagement of the interdigitating rolls and CaCO


3


loading restrict film breathability level.




Also, it is desirable for many applications of breathable film, such as disposable diapers, adult incontinence products, and feminine hygiene devices, that some visual evidence of a difference between breathable and non-breathable films exist. It is thought that this product differentiation could be of benefit to the consumer, as well as the manufacturer of the disposable products.




SUMMARY




We have discovered that applying heat to interdigitating rollers results in a substantial improvement in orientation effectiveness (WVTR increases), and imparts a third dimensionality to the film which differentiates it from other breathable films. In addition, a new control is provided for the adjustment of film breathability, i.e., rather than require a formulation change, or adjustment to the depth of activation of the interdigitating rollers, to control WVTR levels, roller temperature may be adjusted. As can be seen from the following examples, with all other factors constant, an increase in the temperature of the interdigitating rolls from 70° F. to 140° F., increases WVTR from 1900 gm/sqm/day to 4100 gm/sqm/day.











BRIEF DESCRIPTION OF THE DRAWINGS




A better understanding of the Process for Producing Polyolefin Microporous Breathable Film may be obtained by reference to the following drawing figures together with the detailed description.





FIG. 1

shows the geometry of interdigitating rollers;





FIG. 2

shows a machine direction orientation roller;





FIG. 3

shows a transverse direction orientation roller; and





FIG. 4

shows a cross-section of a WVTR test cell.











DETAILED DESCRIPTION




Introduction




This invention concerns polyolefin/filler based breathable films. While initial work was executed on a polypropylene based product, it will be shown that the disclosed process is effective for all polyolefin materials.




This invention further includes certain polyolefins, their conversion into fabricated articles such as films, articles made from such films, and applications in which such articles having high WVTR combined with good physical properties are desirable. The resulting films, and film composites, (including coextruded and laminated films) have combinations of properties rendering them superior and unique to films or film composites previously available. The films disclosed herein are particularly well suited for use in producing certain classes of high WVTR films, consumer and industrial articles using the films in combination with, for instance, polymeric woven or non-woven materials. Such consumer articles include, but are not limited to diapers, adult incontinence devices, feminine hygiene articles, medial and surgical gowns, medical drapes, industrial apparel, building products such as “house-wrap”, roofing components, and the like made using one or more of the films disclosed herein. Additionally, the films of the present invention may also be used in metallized films with a high WVTR, according to the disclosure of U.S. Pat. No. 5,055,338, which is to be incorporated herein by reference in its entirety.




Production of the Films




Films contemplated by certain embodiments of the present invention may be made utilizing a polyolefin, by film processes including blown molding, casting, and cast melt embossing. The preferred process is a cast melt embossed film process. In extrusion processes, the films of the present invention can be formed into a single layer film, or may be one layer or more of a multi-layer film or film composite. Alternatively, the polyolefin films described in this disclosure can be formed or utilized in the form of a resin blend where the blend components can function to modify the WVTR, the physical properties, the draw-down, the sealing, the cost, or other parameters. Both blend components and the parameters provided thereby will be well known to those of ordinary skill in the art. The breathable films of the present invention may also be included in laminated structures. As long as a film, multi-layer film, or laminated structure includes one or more polyolefin/filler film layers having the WVTR, or draw-down, and the like of the film, such film, multi-layer film, or laminated structure will be understood to be contemplated as an embodiment of the present invention.




Polyolefin Precursor Film Component




The polyolefin precursor component can be any film forming polyolefin including polyethylene and polypropylene, ethylene polar comonomer polymers, ethylene α-olefin copolymers and combinations hereof.















Suitable Polyolefins and Relative Benefits



























Polypropylene




Impact




Tear




Softness




Drawdown









Metallocene




preferred




preferred




preferred




most






Homopolymers and







preferred






Copolymers






Random Copolymer




more




more




more




more






PP




preferred




preferred




preferred




preferred






Impact Copolymer




most




most




most




preferred






polypropylene




preferred




preferred




preferred






Homopolymer PP




preferred




preferred




preferred




preferred






Exxon LD 3003




preferred




preferred




preferred




preferred














It will be understood that, in general, we contemplate that a large number of polyolefins will be useful in the techniques and applications described herein. Also included in the group of polyolefins that are contemplated as embodiments of this invention are metallocene catalyzed polyethylenes, both linear low density and very low density (0.88 to 0.935 g/cm3), high density polyethylene (0.935-0.970 g/cm3), Ziegler-Natta catalyzed linear low density polyethylene, conventional high pressure low density polyethylene (LDPE), and combinations thereof. Various elastomers or other soft polymers may be blended with the majority polyolefin component, these include styrene-isoprene-styrene (styrenic block co-polymer), styrene-butadiene-styrene (styrenic block co-polymer), styrene-ethylene/butylene-styrene (styrenic block co-ploymer), ethylene-propylene (rubber), Ethylene-propylene-diene-modified (rubber), Ethylene-vinly-acetate, Ethylene-methacrylate, Ethylene-ethyl-acrylate, Ethylene-butyl-acrylate.




Filler




Fillers useful in this invention may be any inorganic or organic material having a low affinity for and a significantly lower elasticity than the film forming polyolefin component. Preferably a filler should be a rigid material having a non-smooth hydrophobic surface, or a material which is treated to render its surface hydrophobic. The preferred mean average particle size of the filler is between about 0.5-5.0 microns for films generally having a thickness of between about 1 to about 6 mils prior to stretching.




Examples of the inorganic fillers include calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, barium carbonate, magnesium, sulfate, barium sulfate, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, calcium oxide, magnesium oxide, titanium oxide, alumina, mica, glass powder, zeolite, silica clay, etc. Calcium carbonate (CaCO


3


) is particularly preferred for its low cost, its whiteness, its inertness, and its availability. The selected inorganic filler such as calcium carbonate is preferably surface treated to be hydrophobic so that the filler can repel water to reduce agglomeration. Also, the surface treatment of the filler should improve binding of the filler to the polyolefin precursor while allowing the filler to be pulled away from the precursor film under stress. A preferred coating for the filler is calcium stearate which is FDA compliant and readily available.




Organic fillers such as wood powder, and other cellulose type powders may be used. Polymer powders such as Teflon® powder and Kevlar® powder can also be used.




The amount of filler added to the polyolefin precursor depends on the desired properties of the film including dart impact strength, tear strength, WVTR, and stretchability. However, it is believed that a film with good WVTR generally cannot be produced as is taught herein with an amount of filler less than about twenty percent (20%) by weight of the polyolefin/filler blend.




The minimum amount of filler (about twenty percent by weight) is needed to assure the interconnection within the polyolefin precursor film of voids created at the situs of the filler—particularly by the stretching operation to be subsequently performed. Further, it is believed that useful films could not be made with an amount of the filler in excess of about seventy percent (70%) by weight of the polyolefin/filler composition. Higher amounts of filler may cause difficulty in compounding and significant losses in strength of the final breathable film. Preferred ranges include about 30% to about 70% by weight, more preferably from about 40% to about 60% by weight.




While a broad range of fillers has been described at a broad range of inclusion parameters based on weight percentages, still other embodiments of the present invention are contemplated. For instance, fillers with much higher or much lower specific gravity may be included with the polyolefin precursor at amounts outside the weight ranges disclosed. Such combinations will be understood to be contemplated as embodiments of our invention as long as the final film, after orientation, has WVTR, or draw down similar to that described herein.




Film Physical Property Modification




It was found that the addition of small amounts of low density polyethylene to the polyolefin/filler blend allowed film extrusion at higher throughput levels with some majority polymers. Low density polyethylene with a melt flow index of about 0.9 to 25.0 grams per ten minutes (12.0 grams per ten minutes being preferred), and a density of about 0.900 to 0.930 may be used.




Further improvements in film impact and tear strength are possible by the addition of plastomers, elastomers, styrenic block co-polymers (SIS, SBS, SEBS), or rubbers. Material grades included are:















Property Improvement Materials


















Melt Flow








Supplier




Grade




Index




Density




















Exxon Chemical




Exact 3139




7.5




.900







Exxon Chemical




Exact 4044




16.5




.895







Exxon Chemical




Exact 9095




2.2




.893







Exxon Chemical




Exact 3131




3.5




.900







Exxon Chemical




Paxon SLX 9106




2.0




.900







Exxon Chemical




Paxon SLX 9101




3.5




.900







Dexco




Vector 4211




13







Dexco




Vector 4411




40







Exxon




Vistalon 3708







Exxon




Vistalon 3030







Shell




Kraton G1657




8




SEBS







Union Carbide




UC 9042




5.1




.900







Union Carbide




UC 1085




0.8




.884















Stretching or Orienting




Final preparation of a breathable film is achieved by stretching the filled polyolefin precursor film to form interconnected voids. Stretching or “orientation” is achieved by incrementally orienting the polyolefin precursor in the machine direction, transverse direction, or both. Films can be incrementally oriented by a number of mechanical techniques, however, the preferred technique is to stretch the film through pairs of interdigitating rollers, as shown in FIG.


1


. Therein it may be seen that the film is contracted by the apex


18


of a plurality of teeth spaced a distance or pitch (W) apart. The apex


18


of each tooth extends into the open space


20


between the teeth on an opposing roller. The amount of interengagement depends both on the tooth depth (d) and the relative position of the rollers.




Machine direction orientation is accomplished by stretching the film through a gear like pair of rollers


16


as shown in FIG.


2


. Transverse direction orientation is accomplished by stretching the film through a pair of disk-like rollers as shown in FIG.


3


.




The preferred embodiment employs rollers with a tooth pitch, W=0.080″, however a pitch of about 0.040″ to 0.500″ is also acceptable. The tooth depth (d), is preferably 0.100″, however, a tooth depth of about 0.030″ to 0.500″ is also acceptable. For the transverse direction orientation rollers, as shown in

FIG. 3

, the depth may be up to about 1.000″ as mechanical interference is less of an issue with the transverse direction rollers. The preferred embodiment employs interdigitating rollers that can be temperature controlled from about 50° F. to about 210° F. More preferred is a temperature range of from about 70° F. to about 190° F. Even more preferred is a temperature range from about 85° F. to about 180° F. And most preferred is a temperature range from about 95° F. to about 160° F. Roll temperature may be maintained through the internal flow of a heated or cooled liquid, an electrical system, an external source of cooling/heating, combinations thereof, and other temperature control and maintenance methods which will be apparent to those of ordinary skill in the art. The preferred embodiment is internal flow of a heated or cooled liquid through the rollers.




The depth of interengagement of the roller teeth determines the amount of orientation imparted on the film. A balance must be drawn between the depth of engagement of the roller teeth and the level of filler in the film, as many physical properties of the film are affected as depicted in the following table.















Relationships between process and formulation factors




















Dart




Basis




CD








Adjust




WVTR




Impact




Weight




Tensile




MD Tear





















CaCO


3






Increase




Increase




Increase






decrease






MD Orientation




Increase




Increase




decrease




decrease





decrease






TD Orientation




Increase




Increase




decrease




decrease




Decrease






Roll




Increase




Increased





decrease






Temperature














Properties of Films Produced




WVTR




In an embodiment of the present invention, certain films and articles made therefrom have higher WVTR than previously thought possible. The WVTR of such films should be above about 100 g/m


2


/24 hr @37.8° C., 100% RH, preferably above about 1000 g/m


2


/24 hr @37.8° C., 100% RH, more preferably above about 2000 g/m


2


/24 hr @37.8° C., 100% RH. Some applications benefit from film with a WVTR at or above about 10,000 g/m


2


/24 hr @37.8° C., 100% RH.




Test Methods




Water Vapor Transmission Rate (WVTR)




Both a Mocon W1, and a Mocon W600 instrument are used to measure water evaporated from a sealed wet cell at 37.8° C. through the test film and into a stream of dry air or nitrogen. It is assumed that the relative humidity on the wet side of the film is near 100%, and the dry side is near 0%. The amount of water vapor in the air stream is precisely measured by a pulse modulated infra red (PMIR) cell. Following appropriate purging of residual air, and after reaching a steady state of water vapor transmission rate, a reading is taken. WVTR of the test films are reported at Grams of Water/Meter


2


/Day @37° C. The output of the unit has been calibrated to the results obtained with a film of known WVTR. The testing protocols are based on ASTM 1249-90 and the use of a reference film, such as Celgard 2400, which has a WVTR of 8700 g/m


2


/day @37.8° C. The diagram depicted in

FIG. 4

illustrates the basic operation of the Mocon units.




Mocon W1




As illustrated generally by reference to

FIG. 4

, the Mocon W1 has a single test cell and an analog chart recorder. Air is pumped through a desiccant dryer, then through the test cell, and then past the PMIR sensor. A five-minute purge of residual air is followed by a six-minute test cycle with controlled air flow. The result is a steady state value for WVTR. The purge and test cycles are controlled manually. The unit is calibrated to a film with a known WVTR every twelve hours. Calibration results are control charted and adjustments are made to the instrument calibration accordingly.




Mocon W600




The Mocon W600 has six measurement cells with PMIR data fed into a computer. Nitrogen is fed through a desiccant dryer, then through the active test cell, then past the PMIR sensor. In addition to data compilation, a computer controls test cycle sequencing. All cells are purged simultaneously for an eight-minute period. This is followed by an eight-minute test cycle for each of the six measurement cells. Total testing time is fifty-six minutes. Two of the six measurement cells always measure reference films with a known WVTR.




EXAMPLES




Example 1




Experimental Grade 400-6-1




A blend of 57% ECC FilmLink 400 CaCO


3


was combined with 33% Exxon PD 7623 Impact Copolymer, 2% Exxon LD-200.48, and 8% Exxon Exact 3131 oriented in interdigitating rolls of 0.80″ pitch. The MD depth of engagement was 0.020″, and the TD depth of engagement was 0.040″. The temperature of the interdigitating rolls was 140° F.




Example 2




Experimental Grade 400-6-2




A blend of 57% ECC FilmLink 400 CaCO


3


was combined with 33% Exxon PD 7623 Impact Copolymer, 2% Exxon LD-200.48, and 8″ Exxon Exact 3131 oriented in interdigitating rolls of 0.080″ pitch. The MD length of engagement was 0.020″, and the TD depth of engagement was 0.040″. The temperature of the interdigitating rolls was 110° F.




Example 3




Experimental Grade 400-6-3




A blend of 57% ECC FilmLink 400 CaCO


3


was combined with 33% Exxon PD 7623 Impact Copolymer, 2% Exxon LD-200.48, and 8% Exxon Exact 3131 oriented in interdigitating rolls of 0.080″ pitch. The MD depth of engagement was 0.020″, and the TD depth of engagement was 0.040″. The temperature of the interdigitating rolls was 70° F.




As can be seen from the following table, the WVTR rise from a roll temperature of 70° F. (considered ambient temperature) to 110° F., and then 140° F. is dramatic, unexpected and surprising.















Table of Example Film Properties















Example 1




Example 2




Example 3


















Grade Number




400-6-1




400-6-2




400-6-3






Roll Temperature (° F.)




140




110




70






Basis Weight (gm/sqm)




43




40




39






WVTR (gm/sqm/day)




4100




3000




1900






Dart Impact Strength (gm)




240




300




300






MD Ultimate (gm/in)




1585




1532




1453






MD Elongation (%)




408




431




442






TD @ 5% (gm/in)




457




389




388






TD Ultimate (gm/in)




785




1166




1049






TD Elongation (%)




351




358




357






MD Elmendorf Tear Strength (gm)




166




208




205














A linear regression analysis reveals that with the above fixed formulation, depth of activation water vapor transmission rate is predicted by the following equation:








WVTR=−


329.73+31.216*Roller Temperature (°


F


.)






Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.



Claims
  • 1. A process for adjusting the WVTR of a breathable filled film manufactured using interdigitating grooved rollers, the process comprising:a) extruding a precursor film including: (i) a polyolefin resin having at least about 20% polypropylene by wt. % of the polyolefin resin, and (ii) a filler in the range of from about 20 to about 70 wt. % of the precursor film; b) heating at least one pair of interdigitating grooved rollers to a predetermined temperature in the range of from about 95° F. to about 140° F., the predetermined temperature of the rollers being determined by a desired WVTR for the breathable film; c) passing the precursor film between the interdigitating grooved rollers to heat and stretch the precursor film to produce the breathable film, having a WVTR greater than about 1000 g/m2/day at 38° C. and 90% relative humidity and having permanent elongation in a stretched direction.
  • 2. The process of claim 1, further including blending a polymer composition selected from the group consisting of plastomers, elastomers, styrenic block co-polymers (SIS, SBS SEBS), and rubbers with the polyolefin resin prior to extruding the precursor film.
  • 3. The process of claim 1, further including blending a polymer composition having a low density polyethylene with the polyolefin resin prior to extruding the precursor film.
  • 4. The process of claim 1, wherein the interdigitating grooved rollers are positioned in a direction selected from the group consisting of machine direction, transverse direction and combinations thereof.
  • 5. The process of claim 1, wherein the at least one pair of interdigitating grooved rollers are heated to the predetermined temperature in the range of from about 95° F. to about 110° F.
  • 6. The process of claim 5, further including blending a polymer composition selected from the group consisting of plastomers, elastomers, styrenic block co-polymers (SIS, SBS SEBS), and rubbers with the polyolefin resin prior to extruding the precursor film.
  • 7. The process of claim 5, further including blending a polymer composition having a low density polyethylene with the polyolefin resin prior to extruding the precursor film.
  • 8. The process of claim 5, wherein the interdigitating grooved rollers are positioned in a direction selected from the group consisting of machine direction, transverse direction and combinations thereof.
  • 9. A process for adjusting the WVTR of a breathable filled film manufactured using interdigitating grooved rollers, the process comprising:a) extruding a precursor film from a polyolefin blend including: (i) at least about 33 wt. % polypropylene, (ii) at least about 2 wt. % low density polyethylene, and (iii) at least about 57 wt. % calcium carbonate filler b) heating at least one pair of interdigitating grooved rollers to a predetermined temperature in the range of from about 95° to about 140° F., the predetermined temperature of the rollers being determined by a desired WVTR for the breathable film; c) passing the precursor film between the interdigitating grooved rollers to heat and stretch the precursor film to produce the breathable film, having a WVTR greater than about 1000 g/m2/day at 38° C. and 90% relative humidity and having permanent elongation in a stretched direction.
  • 10. The process of claim 9, wherein the at least one pair of interdigitating grooved rollers are heated to the predetermined temperature in the range of from about 95° F. to about 110° F.
  • 11. A process for adjusting the WVTR of a film composite, comprising:providing a film composite having at least a first layer and a second layer, the first layer comprising (i) a polyolefin resin having at least about 20% polypropylene by wt. % of the polyolefin resin and (ii) a filler in the range of from about 20 to about 70 wt. % of the first layer; and simultaneously passing the first layer and the second layer between at least one pair of interdigitating grooved rollers having a surface temperature of from about 95° F. to about 140° F. to produce a film composite having a WVTR greater than about 1000 g/m2/day at 38° C. and 90% relative humidity and having permanent elongation in a stretched direction.
  • 12. The process of claim 11, wherein the second layer comprises a material selected from the group consisting of woven fabric, non-woven fabric, knit fabric, and combinations thereof.
  • 13. The process of claim 11, wherein the second layer comprises a material selected from the group consisting of apertured film, three-dimensioned formed film, film laminates, a second polyolefin resin, and combinations thereof.
  • 14. The process of claim 11, wherein the first layer further comprises a polymer composition selected from the group consisting of plastomers, elastomers, styrenic block co-polymers (SIS, SBS SEBS), and rubbers.
  • 15. The process of claim 11, the first layer further comprises a polymer composition having a low density polyethylene.
  • 16. The process of claim 11, wherein the interdigitating grooved rollers are positioned in a direction selected from the group consisting of machine direction, transverse direction and combinations thereof.
  • 17. The process of claim 11, wherein at least the first layer has been embossed prior to passing the first layer and the second layer.
  • 18. The process of claim 11, wherein the at least one pair of interdigitating grooved rollers have the surface temperature from about 95° F. to about 110° F.
  • 19. A process for adjusting the WVTR of a film composite, comprising:providing a film composite having at least a first layer and a second layer, the first layer comprising a polyolefin blend comprising (i) at least about 33 wt. % polypropylene, (ii) at least about 2 wt. % low density polyethylene, and (iii) at least about 57 wt. % calcium carbonate filler; and simultaneously passing the first layer and the second layer between at least one pair of interdigitating grooved rollers having a surface temperature of from about 95° F. to about 140° F. to produce a film composite having a WVTR greater than about 1000 g/m2/day at 38° C. and 90% relative humidity and having permanent elongation in a stretched direction.
  • 20. The process of claim 19, wherein the second layer comprises a material selected from the group consisting of woven fabric, non-woven fabric, knit fabric, and combinations thereof.
  • 21. The process of claim 19, wherein the second layer comprises a material selected from the group consisting of apertured film, three-dimensioned formed film, film laminates, a second polyolefin resin, and combinations thereof.
  • 22. The process of claim 19, wherein the at least one pair of interdigitating grooved rollers have the surface temperature from about 95° F. to about 110° F.
Parent Case Info

This is a continuation of copending application(s) now U.S. Pat. No. 6,264,864, Serial No. 09/418,405 filed on Oct. 14, 1999, which claims the benefit of U.S. Provisional Patent Application Serial No. 60/104,452 filed Oct. 16, 1998 and U.S. Provisional Patent Application Serial No. 60/104,985 filed Oct. 20, 1998.

US Referenced Citations (201)
Number Name Date Kind
2896626 Voigtman Jul 1959 A
3233029 Rasmussen Feb 1966 A
3299174 Kuhre et al. Jan 1967 A
3378512 Hamed et al. Apr 1968 A
3407253 Yoshimura et al. Oct 1968 A
3424649 Nyberg et al. Jan 1969 A
3426754 Bierebaum et al. Feb 1969 A
3562356 Nyberg et al. Feb 1971 A
3642967 Doll Feb 1972 A
3654929 Nilsson et al. Apr 1972 A
3678134 Middlebrook Jul 1972 A
3683917 Comeford Aug 1972 A
3738904 Ikeda et al. Jun 1973 A
3832267 Liu Aug 1974 A
3837773 Raley Sep 1974 A
3840418 Sabee Oct 1974 A
3844865 Elton et al. Oct 1974 A
3860003 Buell Jan 1975 A
3870593 Elton et al. Mar 1975 A
3894827 Raley et al. Jul 1975 A
3903234 Ikeda et al. Sep 1975 A
RE28606 Ikeda et al. Nov 1975 E
RE28608 Dixon Nov 1975 E
3927144 Hayashi et al. Dec 1975 A
3941859 Batiuk et al. Mar 1976 A
3969562 Suzuki Jul 1976 A
4076698 Anderson et al. Feb 1978 A
4091164 Schwarz May 1978 A
4116892 Schwarz Sep 1978 A
4116914 Coran et al. Sep 1978 A
4131654 Herman et al. Dec 1978 A
4132698 Gessler et al. Jan 1979 A
4134951 Dow et al. Jan 1979 A
4135023 Lloyd et al. Jan 1979 A
4144008 Schwarz Mar 1979 A
4153664 Sabee May 1979 A
4153751 Schwarz May 1979 A
4171411 Ehrenfreund Oct 1979 A
4173612 Kelly Nov 1979 A
4205021 Morita et al. May 1980 A
4210709 Doi et al. Jul 1980 A
4212787 Matsuda et al. Jul 1980 A
4220579 Rinehart Sep 1980 A
4220879 Hoshimi et al. Sep 1980 A
4223059 Schwarz Sep 1980 A
4243576 Fischer et al. Jan 1981 A
4251585 Schwarz Feb 1981 A
4253461 Strickland et al. Mar 1981 A
4277578 Yoshimura et al. Jul 1981 A
4285100 Schwarz Aug 1981 A
4289832 Schwarz Sep 1981 A
4298647 Cancio et al. Nov 1981 A
4303571 Jansen et al. Dec 1981 A
4303712 Woodroof Dec 1981 A
4303714 Mercer Dec 1981 A
4318408 Korpman Mar 1982 A
4319950 Sznopek et al. Mar 1982 A
4329309 Kelly May 1982 A
4331622 Doi et al. May 1982 A
4335193 Doi et al. Jun 1982 A
4344999 Gohlke Aug 1982 A
4350655 Hoge Sep 1982 A
4351784 Thomas et al. Sep 1982 A
4352355 Mesek et al. Oct 1982 A
4353945 Sampson Oct 1982 A
4357439 Blumel et al. Nov 1982 A
4368565 Schwarz Jan 1983 A
4378067 Butler et al. Mar 1983 A
4380564 Cancio et al. Apr 1983 A
4402688 Julemont Sep 1983 A
4418112 Toyoda et al. Nov 1983 A
4425127 Suzuki et al. Jan 1984 A
4425129 Karami Jan 1984 A
4427737 Cilento Jan 1984 A
4435141 Weisner et al. Mar 1984 A
4436520 Lipko et al. Mar 1984 A
4438167 Schwarz Mar 1984 A
4440911 Inoue et al. Apr 1984 A
4449977 Korpman May 1984 A
4450026 Pieniak et al. May 1984 A
4460646 Inoue et al. Jul 1984 A
4465729 Cancio et al. Aug 1984 A
4472328 Sugitomo et al. Sep 1984 A
4476180 Wnuk Oct 1984 A
4479989 Mahal Oct 1984 A
4480061 Coughlin et al. Oct 1984 A
4485133 Ohtsuka et al. Nov 1984 A
4517714 Sneed et al. May 1985 A
4525531 Zukosky et al. Jun 1985 A
4527989 Karami Jul 1985 A
4534769 De Jonckheere et al. Aug 1985 A
4535020 Thomas et al. Aug 1985 A
4585447 Karami Apr 1986 A
4585604 Okuyama et al. Apr 1986 A
4590020 Itaba et al. May 1986 A
4590202 Remy May 1986 A
4626252 Nishizawa et al. Dec 1986 A
4636340 Itaba et al. Jan 1987 A
4639487 Hazelton et al. Jan 1987 A
4639949 Ales et al. Feb 1987 A
4640859 Hansen et al. Feb 1987 A
4657539 Hasse Apr 1987 A
4663220 Wisneski et al. May 1987 A
4673619 Itaba et al. Jun 1987 A
4681580 Reising et al. Jul 1987 A
4681781 Murray et al. Jul 1987 A
4684578 Inoue et al. Aug 1987 A
4704238 Okuyama et al. Nov 1987 A
4705812 Ito et al. Nov 1987 A
4713068 Wang et al. Dec 1987 A
4713069 Wang et al. Dec 1987 A
4714735 Hodgson, Jr. et al. Dec 1987 A
4716197 Seiss et al. Dec 1987 A
4719144 Kamat Jan 1988 A
4721592 Fruehauf et al. Jan 1988 A
4725481 Ostapchenko Feb 1988 A
4734324 Hill Mar 1988 A
4740258 Breitscheidel Apr 1988 A
4758297 Calligarich Jul 1988 A
4775375 Aledo Oct 1988 A
4777073 Sheth Oct 1988 A
4777703 Knox Oct 1988 A
4791144 Nagou et al. Dec 1988 A
4793956 Nogiwa et al. Dec 1988 A
4806300 Walton et al. Feb 1989 A
4808252 Lash Feb 1989 A
4814124 Aoyama et al. Mar 1989 A
4820590 Hodgson, Jr. et al. Apr 1989 A
4829096 Kitamura et al. May 1989 A
4833172 Schwarz et al. May 1989 A
4848564 Scheller et al. Jul 1989 A
4877679 Leatherman et al. Oct 1989 A
4878974 Kagawa Nov 1989 A
4891392 Abe et al. Jan 1990 A
4902553 Hwang et al. Feb 1990 A
4921653 Aoyama et al. May 1990 A
4923650 Antoon, Jr. et al. May 1990 A
4929303 Seth May 1990 A
4957943 McAllister et al. Sep 1990 A
4977014 Mitchell et al. Dec 1990 A
4995930 Merz et al. Feb 1991 A
5008204 Stehling Apr 1991 A
5008296 Antoon, Jr. et al. Apr 1991 A
5026798 Canich Jun 1991 A
5032450 Rechlicz et al. Jul 1991 A
5034078 Hodgson, Jr. et al. Jul 1991 A
5035338 Kaufhold et al. Jul 1991 A
5055338 Sheth et al. Oct 1991 A
5066526 German, Jr. Nov 1991 A
5126391 Yamamoto et al. Jun 1992 A
5145747 Jottier Sep 1992 A
5167652 Mueller Dec 1992 A
5169712 Tapp Dec 1992 A
5174231 White Dec 1992 A
5182069 Wick Jan 1993 A
5198401 Turner et al. Mar 1993 A
5206075 Hodgson, Jr. Apr 1993 A
5241031 Mehta Aug 1993 A
5272236 Lai et al. Dec 1993 A
5278272 Lai et al. Jan 1994 A
5296184 Wu et al. Mar 1994 A
5317035 Jacoby et al. May 1994 A
5328760 Gillberg-LaForce Jul 1994 A
5358792 Mehta et al. Oct 1994 A
5364695 Gurewitz Nov 1994 A
5376439 Hodgson et al. Dec 1994 A
5382461 Wu Jan 1995 A
5382630 Stehling et al. Jan 1995 A
5385972 Yamamoto et al. Jan 1995 A
5399396 Ohlsson et al. Mar 1995 A
5409761 Langley Apr 1995 A
5415905 Middlesworth et al. May 1995 A
5445862 Kaneko et al. Aug 1995 A
5447788 Rhim et al. Sep 1995 A
5451450 Erderly et al. Sep 1995 A
5470811 Jejelowo et al. Nov 1995 A
5472775 Obijeski et al. Dec 1995 A
5500260 Halle et al. Mar 1996 A
5500360 Ahlquist et al. Mar 1996 A
5525659 Falla et al. Jun 1996 A
5549777 Langdon et al. Aug 1996 A
5558930 DiPoto Sep 1996 A
5560974 Langley Oct 1996 A
5565250 Ohlsson et al. Oct 1996 A
5571619 McAlpin et al. Nov 1996 A
5575785 Gryskiewicz et al. Nov 1996 A
5580910 Isaac et al. Dec 1996 A
5580914 Falla et al. Dec 1996 A
5674944 Falla et al. Oct 1997 A
5690949 Weimer et al. Nov 1997 A
5695868 McCormack Dec 1997 A
5695871 Tallentire et al. Dec 1997 A
5738111 Weimer et al. Apr 1998 A
5800758 Topolkaraev et al. Sep 1998 A
5814569 Suzuki et al. Sep 1998 A
5865926 Wu et al. Feb 1999 A
6096014 Haffner et al. Aug 2000 A
H1955 Middlesworth et al. Apr 2001 H
6258308 Brady et al. Jul 2001 B1
6264864 Mackay Jul 2001 B1
H2000 Middlesworth et al. Nov 2001 H
Foreign Referenced Citations (113)
Number Date Country
1615088 Apr 1988 AU
5039585 Sep 1988 AU
1296225 Feb 1992 CA
1311181 Dec 1992 CA
1322082 Sep 1993 CA
2144737 Mar 1994 CA
2130192 Feb 1998 CA
2 035 117 Jan 1971 DE
34 36 065 Apr 1986 DE
43 11 422 Oct 1994 DE
38 50 987 Dec 1994 DE
32 33 693 Jan 1995 DE
0 032 804 Jul 1981 EP
0 114 964 Aug 1984 EP
0 119 815 Sep 1984 EP
0 119 827 Sep 1984 EP
0 193 938 Sep 1986 EP
0 114 964 Nov 1986 EP
0 201 331 Nov 1986 EP
0 219 198 Apr 1987 EP
0 227 037 Jul 1987 EP
0 232 060 Aug 1987 EP
0 119 827 Jul 1988 EP
0 276 100 Jul 1988 EP
0 283 200 Sep 1988 EP
0 283 200 Sep 1988 EP
0 283 200 Sep 1988 EP
0 288 021 Oct 1988 EP
0 288 021 Oct 1988 EP
0 288 021 Oct 1988 EP
0 201 331 Dec 1989 EP
0 352 802 Jan 1990 EP
0 352 802 Jan 1990 EP
0 361 865 Apr 1990 EP
0 361 865 Apr 1990 EP
0 361 865 Apr 1990 EP
0 193 938 Jun 1990 EP
0 385 599 Sep 1990 EP
0 385 599 Sep 1990 EP
0 227 037 Jul 1991 EP
0 219 198 Oct 1991 EP
0 550 115 Jul 1993 EP
0 598 970 Jun 1994 EP
0691 203 Jan 1996 EP
0 598 970 May 1996 EP
0742 248 Nov 1996 EP
0 629 151 Dec 1996 EP
0 662 988 Feb 1997 EP
0 769 525 Apr 1997 EP
0 682 678 Dec 1998 EP
0 604 731 Jun 1999 EP
0 598 970 Apr 2000 EP
2.074.338 Sep 1971 FR
2.446.176 Aug 1980 FR
1 454 218 Nov 1976 GB
2 101 468 Jan 1983 GB
2 115 702 Sep 1983 GB
2 137 632 Oct 1984 GB
2 151 538 Jul 1985 GB
2 178 433 Feb 1987 GB
2 285 408 Jul 1995 GB
2 290 052 Dec 1995 GB
P9603548 Nov 1998 HU
48-60774 Aug 1973 JP
51-30856 Mar 1976 JP
54-120646 Sep 1979 JP
54-120658 Sep 1979 JP
55-110141 Aug 1980 JP
57-02350 Jan 1982 JP
57-117038 Jul 1982 JP
57-117039 Jul 1982 JP
58-129034 Jan 1983 JP
61-9448 Jan 1986 JP
61-284439 Dec 1986 JP
62-169642 Jul 1987 JP
62-176843 Aug 1987 JP
62-179543 Aug 1987 JP
62-282003 Dec 1987 JP
64-49619 Feb 1989 JP
64-79620 Mar 1989 JP
1-144431 Jun 1989 JP
1-235439 Sep 1989 JP
1-264031 Oct 1989 JP
1-266150 Oct 1989 JP
2-36938 Feb 1990 JP
2-179543 Jul 1990 JP
3-221540 Sep 1991 JP
6-29842 Feb 1994 JP
7-116429 Feb 1994 JP
7-118431 May 1995 JP
175038 Feb 1994 PL
9858799 Dec 1976 WO
9303093 Feb 1993 WO
9316863 Sep 1993 WO
9401276 Jan 1994 WO
9401376 Jan 1994 WO
9406857 Mar 1994 WO
9418263 Aug 1994 WO
9502630 Jan 1995 WO
9503765 Feb 1995 WO
9507314 Mar 1995 WO
9509199 Apr 1995 WO
9516562 Jun 1995 WO
9619346 Jun 1996 WO
9639032 Dec 1996 WO
9804397 Feb 1998 WO
9805502 Feb 1998 WO
9824834 Jun 1998 WO
9829247 Jul 1998 WO
9829481 Jul 1998 WO
9829504 Jul 1998 WO
9923139 May 1999 WO
WO 0023255 Apr 2000 WO
Non-Patent Literature Citations (4)
Entry
Search Report prepared by Hungarian Patent Office dated Jan. 23, 2002.
Japanese Kokai Patent Application No. Hei 2[1990]-276636; Examination not requested.
Van a. Wente; “Superfine Thermoplastic Fibers”; Industrial and Engineering Chemistry; Washington, D.C.; Aug. 1956; vol. 48, No. 8, pp. 1342-13466.
Abstract of HU P9303168 A (Nov. 28, 1997).
Provisional Applications (2)
Number Date Country
60/104452 Oct 1998 US
60/104985 Oct 1998 US
Continuations (1)
Number Date Country
Parent 09/418405 Oct 1999 US
Child 09/883747 US