MXPA01003500A - Uv stabilized spunbond fabrics with enhanced trapezoidal tear - Google Patents

Abstract

A nonwoven fabric with UV stability having a spunbonded fabric layer (2) comprising a base resin selected from the group consisting of polypropylene and polyethylene;combined with melt processable additives;wherein said melt processable additives are a mixture of (i) at least two hindered amine light stabilizers;(ii) a processing aid selected from the group consisting of hydroxyl amines and phosphites;and (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene. Other melt processable additives include pigments which are added to provide the desired color in the resulting fabric layer.

Description

UNITED THREADED FABRICS STABILIZED AGAINST ULTRAVIOLET LIGHT WITH IMPROVED TRAPEZOIDAL SCRATCH Field of the Invention The invention relates to spin-bonded non-woven fabrics having photostability, particularly to ultraviolet, suitable for substrates used to manufacture exterior covers. In particular, the invention relates to non-woven fabrics made using a combination of at least two hindered amine photostabilizers, and the hydroxylamine and phosphite processing aid; and a carrier resin of polypropylene, polyethylene, or a mixture of both. The resulting spunbond fabric layer has improved trapezoidal tear in both of the MD and CD directions.

BACKGROUND OF THE INVENTION Non-woven fabrics possessing photostability (particularly ultraviolet) are desirable to be used as substrates for manufacturing outer covers. The outer covers include marine, automobile, bicycle and recreational vehicle covers. Such covers include vehicle protection against wear and tear caused by wind, rain and light Ref: 128756 solar. Non-woven fabrics and composite non-woven fabrics for such covers are available in the market. However, it has not been possible until now to incorporate stability against UV and still maintain a high strength fabric, particularly trapezoidal tear strengths necessary for downstream ultrasonic transformation. To overcome these problems the invention provides a non-woven product and a process for producing such a fabric, having improved trapezoidal tear, suitable for further ultrasonic lamination. In general, hindered amine photostabilizers (HALS) are known in the art. For example, published European patent application EP 0792911 A2 of Tennesen discloses a phosphate-based flame retardant combined with a functional hindered amine-amine photostabilizer (NOR-HALS) used to achieve flame-retardant properties that are better than those with phosphates. alone U.S. Patent No. 5,393,812 to Haley discloses fibers and fabrics, such as those used in clothing, upholstery and carpeting which contain from about 0.1 to 3% (preferably from 0.2 to 1.0%) by weight of the composition, a light stabilizer. This patent discloses a polyolefin, a NOR HALS (functional alkoxy amine hindered amine photostabilizers) and a phosphorus flame retardant (column 2, lines 33-40, column 4, lines 62-64). The HALS (regular hindered amine photostabilizers) can be used additionally or instead of the NOR HALS. U.S. Patent No. 5,096,950 to Galbo describes numerous photostabilizers of hindered amine, alkoxy-N-ORl. U.S. Patent No. 5,200,443 to Hudson discloses a non-woven polypropylene polymer network containing an acetylated hindered amine photostabilizer and a siloxane > substituted with hindered amine. U.S. Patent No. 5,004,770 of Cortolano; U.S. Patent No. 5,124,378 to Bahrens; U.S. Patent No. 5,939.41 to Brown and U.S. Patent No. 5,300,647 to Malherber describe all formulations of particular hindered amine photostabilizers. None of the known prior art discloses a spun bonded nonwoven fabric with UV stability having improved durability. In addition, the known art has not described the synergistic defect of combining at least two hindered amine photostabilizers to produce a spunbonded nonwoven fabric having improved trapezoidal tear properties.

Thus, a broad object of the invention is to provide a spin-bonded non-woven fabric with UV-photostability. Specifically, the fabric layer is made of a base (or virgin) resin polypropylene which is combined with melt processing additives. These additives are a mixture of (i) at least two hindered amine photostabilizers (HALS); (ii) processing aids which are hydroxylamines or phosphites or a combination of both; and (iii) a carrier resin of polypropylene or polyethylene or a mixture of both. Pigments are also included in the formulation to impart the desired color properties to the resulting fabrics. The additives are incorporated into a base polyolefin resin to form a homogeneous mixture which is then spun-bonded to form the fabric layer. Another object of the invention is to provide a spunbonded fabric structure having at least two layers of spunbonded webs (SB) to which additives processed by melting the virgin resin prior to melt spinning have been incorporated. A specific object of the invention is to provide substrates for spunbonded roofs having spun-bonded spin-linked (SS), spunbonded-spun-bonded-spun-bonded (SSS) and spunbonded-bonded composite structures. yarn-linked by spinning-linked by spinning (SS-SS) all possessing improved trapezoidal tear strength. Another more specific object of the invention is to provide spun-bonded structures that have a useful service life of six to sixty months, depending on the desired end use. Another specific object of the invention is to provide a spunbonded fabric having superior initial physical properties as measured by the hook / strip test and trapezoidal tear tests. A further object of the invention is to provide a spunbonded web that does not suffer a loss of more than 50% of its MD, CD initial and MD trapezoidal tear values, CD initials at the end of its useful service life. A further specific object of the invention is to provide a spunbonded fabric where the color deviation is maintained within tolerances throughout the service life.

Brief Description of the Invention The present invention provides a spunbonded fabric having UV stability to be used as a substrate for manufacturing outer covers.

The spunbonded fabric comprises a base resin selected from the group consisting of polypropylene and polyethylene combined with melt-processable additives. The melt-processable additives are a mixture of (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxylamines and phosphites; and (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene. Pigments are also included in the formulations to impart the desired color properties to the resulting fabrics. The base resin and melt-processable additives combine to form a homogeneous mixture, which is then spun-bonded to form a non-woven fabric layer. The nonwoven fabric of the invention may comprise multiple layers of fabric. The fabric structures encompassed by the invention include non-woven fabrics spun-bonded (SB), spunbonded-spun-bonded (SS), spun-bonded > by spunbond-spinning (SSS), spunbonded-spunbonded-spunbond-spunbonded (SS-SS). Other objects, features and advantages of the present invention will be apparent when the detailed description of the preferred embodiments of the invention will be considered with reference to the drawings, which should be constituted in an illustrative and non-limiting sense as follows: BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a schematic diagram showing the basic components of a system for producing the non-woven fabric according to the process of the invention.

Detailed Description of the Preferred Modes As used herein, the terms "non-woven web" or "non-woven web" are interchangeable and refer to a network / web having a structure of individual fibers or filaments which are interspersed but not an identifiable repeated pattern. As used herein, the term "spunbonded fibers" refers to fibers which are formed by extruding molten thermoplastic material as filaments of a plurality of thin, usually circular, capillaries of a row. Cooling air is fed to a cooling chamber where the filaments are cooled. The cooling air is then sucked through a nozzle, which accelerates the flow of air. The friction between the flowing air and the filaments creates a force which stretches the filaments, that is, attenuates the filaments to a smaller diameter. The stretched filaments are then passed through a diffuser and deposited on a transformer strip to form a non-woven web. A conventional spin bonding technique is described in U.S. Patent No. 4,340,563 to Appel. In general, the invention provides a non-woven fabric with UV stability having a spunbond fabric layer comprising a base resin selected from the group consisting of polypropylene and polyethylene combined with melt-processable additives. The melt-processable additives are a mixture of (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxylamines and phosphites; and (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene. Pigments are also included in the formulations to impart the desired color properties to the resulting fabrics. The base resin is an olefinic material preferably polypropylene or polyethylene. In the preparation of the spunbonded networks of the invention, the base resin is typically present in amounts ranging from 80 to 99% by weight. The base resin used must be compatible with the carrier resins in the formulations for the homogeneous combination of the base resin with the melt-processable additives. In this way, if the base resin is polypropylene the carrier resin is preferably polypropylene or a combination of polypropylene and polyethylene. A preferred base resin used in the invention is a polypropylene having a melt flow rate of commercially available as Montel PH805 from Montel Polyolefins, Montel USA, Wilmington, Delaware. The preferred hindered amine photostabilizers used in this invention are 1, 3, 5-Triazine-2,4,6-triamine, N, N "'- [1,2-ethanediylbis [(4,6-bis- [butyl] (1,2,2,6,6-pentamethyl-4-piperidinyl) amino] -1,3,4-triazin-2-yl] imino] -3,1-propandiyl]] bis [N ', N "- dibutyl-N ', N "-bis (1,2,2,6,6-penta-met? l-4-piperidinyl) commercially available as Chimassorb MR119 from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada; Dimethyl succinate polymer with 4-hydroxy-2, 2, 6, 6-tetramethyl-1-piperidinetanol commercially available as Tinuvin ™ R622 from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada; Poly [[6- [(1, 1, 3,3-tetramethyl-butyl) amino] -l, 3,5-triazin-2,4-diyl] [2, 2,6,6-tetramethyl-piperidyl] imino] hexamethylene [2,2,6,6-tetra-methyl-4-piperidyl) imino]] commercially available as ChimassorbMR944 from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada; and 1, 6-Hexandiamine, polymer of N, N'-bis (2,2,6,6-tetramethyl-4-piperidinyl) with 2,4,6-trichloro-1,3,5-triazine, the products of reaction with N-butyl-1-butanamide and N-butyl-2,2,6,6-tetramethyl-4-piperidinylamine commercially available as Chimassorb MR2020 from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada. The data sheets for the ChimassorbMR119, 944 and 2020 and the TinuvinMR622 are all incorporated here for reference. At least two hindered amine photostabilizers (HALS) are combined in the formulations of the invention and are preferably combined in a ratio of 9: 1 to 1: 9. The total hindered amine photostabilizers are present in the resulting fabric layer in amounts ranging from 1000 ppm to 25,000 ppm. The combination of the use of two HALS provides an increase in the loading of UV stabilizing materials in the bonded product by final spinning. In addition, the synergic effect of the two HALS results in a product with greater durability and product life. Preferred processing aids used in the invention are hydroxyl amine (bis (alkyl hydrogenated bait) amines, oxidized and Tris (2,4-di-tert-butylphenyl) phosphite .These materials are used in the formulations separately or in combination. The processing aids are present in the fabric layer in amounts ranging from 100 ppm to 10,000 ppm.The preferred carrier resins are polyethylenes with a melt index of 1 to 20 and polypropylenes with a melt flow rate between 2 and 60. The carrier resin can also be a mixture of polypropylene and polyethylene, which are combined in a ratio of 9.5: 1 to 1: 9.5 As discussed in more detail here the fabric layer can also include color pigments added to levels up to 10% by weight to concentrated color formulations before spun bonding.Fusion-processable additives are combined together before mixing with the base resin (v. irgen.) Melt-processable additive formulations preferably have a melt flow rate of less than 35 to help produce a homogeneous mixture. Typically, between 1 to 20% by weight of the melt-processable additive formulations are mixed with 80 to 99% of the base resin. This mixture is then formed into a network connected by spinning. The invention also provides a method for manufacturing a non-woven fabric with UV stability having a spunbond fabric layer by combining a base resin selected from the group consisting of polypropylene and polyethylene with melt-processable additives to form a homogeneous blend. The melt-processable additives are a mixture of (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxylamines and phosphites; and (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene. The homogeneous mixture is spun-bonded to form the non-woven fabric layer. The nonwoven fabric of the invention can be a single fabric layer but preferably comprises multiple layers of spin-linked fabric. The fabric structures encompassed by the invention include spunbonded (SB), spunbonded-spunbonded (SS), spunbonded-spunbond-spin-bonded (SSS), spunbond-bonded by yarn-linked by spinning-linked by spinning (SS-SS). In an embodiment of the invention, a nonwoven fabric is formed having at least two of the fabric layers formed by spunbonding the homogeneous mixture to form a first and second nonwoven fabric layers followed by the thermal bonding of the layers together. In another embodiment of the invention, a non-woven fabric having at least three of the fabric layers is spun-bonded into the homogeneous mixture to form a first, second and third layer of non-woven fabric followed by thermal bonding of the layers. together In another embodiment of the invention, a non-woven fabric having at least four of the fabric layers is spun-bonded into the homogeneous mixture to form a first, second, third and fourth layer of non-woven fabric followed by thermal bonding. the layers together. FIGURE 1 is a schematic diagram showing the basic components of a system for producing the non-woven fabric according to the process of the invention. As described above, the non-woven fabric of the invention has at least one layer of fabric made of a homogeneous mixture of a base resin and a combination of melt-processable additives. The mixture is spun-bonded to form the fabric layer. The spunbond fabric layer can be produced by continuously extruding the homogeneous mixture through a plurality of fine, usually circular, capillaries of a row. The pressurized cooling air is fed to a cooling chamber, where the filaments are cooled. The cooling air is then accelerated through a nozzle by means of a positive air pressure. The friction between the flowing air and the filaments creates a force which stretches the filaments, that is, attenuates the filaments to a smaller diameter. The filaments are stretched to achieve molecular orientation and tenacity. The continuous filaments are then deposited in a substantially random form to form a network of substantially continuous and randomly arranged, molecularly oriented filaments. The preferred base polyolefin resin used to manufacture layers of spin-bonded fabric is polyethylene, although nylon, polyethylene, polyester and copolymers and mixtures thereof can also be used. The nonwoven fabric of the invention has at least one layer. The multiple layers of fabric are encompassed by the invention, with numerous variations of possible spunbond fabric layers. Multiple layers of fabric are then joined together in one step by the application of heat and pressure to form the desired fabric composition. The layers of spunbond fabric can be pre-joined by hot press rolls that provide structural integrity to the fabric. For illustrative purposes, the production of a spunbond-linked spin-linked fabric structure (SSS) of the invention is described. The production line illustrated in FIGURE 1 can be operated at a speed in the range of 250 to 600 m / min, preferably to approximately 375 m / min. The equipment of the production line 10 consists of a band of endless laminar formation 12 wound around the rollers 14 and 16. The band 12 is driven in the direction shown by the arrows. The production line 10 includes a forming machine which has three stations: spunbonding station 18, spunbonding station 20 and spunbonding station 22. In other embodiments, depending on the structure of the desired fabric, not all those stations may be operating. For the SS structure, first, the spunbonding station 18 places a network 8 of spunbonded fibers 28 on the carrier web 12. Then the spunbonding station 20 places a network 4 of fibers joined by spinning 26 on the network connected by spinning 8. Finally, the spunbonding station 22 places a network 6 of spun fibers by joining 30 over the spunbonded network 4.. Spunbonding stations 18, 20 and 22 are conventional extruders with rows which form continuous filaments of a polymeric / molten additive and deposit those filaments on the forming band 12 in a randomly interlaced manner. Each spunbonding station can include one or more spinning heads depending on the speed of the process and the particular polymer that is being used. The formation of the spunbonded material is a conventional process well known in the art. Outside the forming machine, the web laminated net SSS 12 is then fed through the bonding rollers 32 and 34. The surfaces of the bonding rollers 32 and 34 are provided with a pattern of raised surfaces which apply heat and pressure to thermally bond the three layers together in a punctual manner. The bonding rolls are heated to a temperature which causes the polymer bonded by spinning to soften. When the spunbonded webs pass between the hot bonding rollers 32 and 34, the composite material is compressed and heated by the bonding rollers according to the pattern on the rollers to create a pattern of discrete bonding areas. Such bonding by discrete areas or dots is well known in the art and can be carried out by means of hot rolls or by ultrasonic bonding. The bonding pattern is selected to provide the desired fabric strength characteristics. The bonding area of the pattern is not limited according to the present invention, although bonding areas of the pattern in the range of 5-25%, preferably 14-19%, of the total area of the fabric are feasible. Alternatively, the sheet can be punctually bonded ultrasonically or hot melt bonded / laminated to a cement adhesive. As a further illustration of the process of the invention according to another embodiment, a spunbonded / spunbonded (SS) web sheet is formed by operating only the spunbonding stations 18 and 22, i.e. Twist bond 20 is interrupted. In this case, the bonding rollers 32 and 34 must be heated to a temperature that causes the polymer bonded by spinning to soften. Other fabric structures encompassed by the invention are formed as described by the above process and as illustrated in FIGURE 1 with the number of spinning stations, 18, 20 or 22 depending on the number of layers in the fabric desired end In contrast to the systems of the prior art, where each spin-linked network is formed separately and thermally bonded twice, first to form the layer and secondly to form the composition, the present invention provides a binding process one step thermal Specifically, the nets joined by spinning are placed, ie one, two, three, etc., and then thermally joined together in one step. The following examples are for illustration purposes only and this invention should not be considered limited by any recipe used here.

EXAMPLE 1 A spin-bonded substrate was produced to an outer cover having anti-UV stability with improved trapezoidal tear properties. A UV color concentrate was prepared by mixing the following ingredients: (1) 15% by weight of a mixture of hindered amine photostabilizers which consisted of a 9: 1 ratio of 1, 3, 5-Triacin-2, 4, 6 triamine, N, N "'- [1,2-ethanedi-bis [[4,6-bis- [buty (1,2,2,6,6-pentamethyl-4-piperidin-nyl) amino] -1,3] 4-triazin-2-yl] imino] -3,1-propanediyl]] bis [N ', N "-dibutyl-N', N" -bis (1, 2, 2, 6, 6-pentamethyl- 4-piperidinyl) (commercially available as Chimassorb ™ 119) and dimethyl succinate polymer with 4-hydroxy-2, 2,6,6-tetramethyl-1-piperidinetanol (commercially available as Tinuvin® 622) Both Chimassorb ™ 119 and Tinuvin ® 622 are available from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada. (2) 5% by weight of a processing aid consisting of a 1: 1 ratio of hydroxyl amine (bis (alkyl hydrogenated bait) oxidized amines and Tris (2,4-di-tert-butylphenyl) phosphite (commercially available from FiberstabM system) R FS 301 by Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada). (3) The remaining amount of the concentrate consists of a polypropylene carrier resin which, in this example, includes a bright UV blue pigment commercially available from Standridge Color Corporation, Social Circle, Georgia. The polypropylene carrier resin used has a melt flow rate of 4 and is commercially available from Montel Canada, Varennes, Quebec, Canada. The amount of pigment in the UV color concentrate formulations was up to 40% by weight, preferably up to 10% by weight. 5% by weight of the UV color concentrate was then combined with 95% by weight of the base polypropylene resin to form a homogeneous mixture. The base polypropylene used was Montel PH805, available from Montel Polyolefins, Montel USA Inc., Wilmington, Delaware, and has a fluid flow rate of 35. This mixture was spun-bonded to form a non-woven fabric layer. Next, samples were made of a non-woven fabric having at least two of the fabric layers joined by spinning (SS structure). The homogeneous mixture was spun-bonded to form first and second non-woven fabric layers, which were then thermally bonded together. The SS sample sheets were made at 28.4 gsy and 56.7 gsy. The physical properties and measurements of these samples were taken and summarized, respectively in TABLES 1 and 2.a.

TABLE 1 UNITED BY YARN (SS) BLUE UV BRIGHT OF 28.4 gsy Table 2 UNIT BY YARN (SS) BRIGHT UV BLUE 56.7 gsy Table 2 (continued) UNIFIED BY YARN (SS) BRIGHT UV BLUE 56.7 gsy Various variations of the non-woven fabric made in this example are possible according to a process of the invention. Although the structure of the fabric is described in this example as a composite structure SS, other additional compositions are possible. Examples include SS, SSS, SSSS, or other combinations. Such compositions are made in a one-step process, where all the layers are eventually thermally bonded together. An advantage of this invention over prior practice in this area is the provision of spunbonded nonwoven fabrics having improved trapezoidal tear.

EXAMPLE 2 Samples 13 to 28, summarized in TABLE 3 below, show various formulations of melt-processable additives that are used to produce layers of spunbond fabric according to the process of the invention. The% by weight listed in TABLE 3 refer to the additive formulations. These formulations are combined in formulations ranging from 1 to 20% with a base polypropylene or polyethylene resin in amounts ranging from 80 to 99% by weight to form a mixture which is then spun into a fabric layer. The total amount of hindered amine photostabilizers (HALS) present in the spunbonded fabric layer resulting from each Sample is also indicated in TABLE 3. In general, in samples 13 to 28 the melt-processable additives contain: (1) a mixture of two hindered amine photostabilizers (HALS) consisting of HAL-1 which is 1,3,5-Triazin-2,, 6- triamine, N, N '' '- [1,2-ethanediylbis [[4,6-bis- [buti (1,2,2,6,6-pentamethyl-4-piperidinyl) amino] -1, 3, 4 -triazin-2-yl] imino] -3, l -propandiyl]] bis [N ', N "-dibutyl-N', N" -bis (1,2,2,6,6-pentamethyl- 4-piperidinyl) (commercially available as Chimassorb ™ 119); combined with HAL-2 which is a polymer of dimethyl succinate with 4-hydroxy-2, 2,6,6,6-tetramethyl-1-piperidinetanol (commercially available as Tinuvin 622). Both Chimassorb® 119 and Tinuvin® 622 are available from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada. (2) a processing aid ("Process Aid") consisting of a ratio of 1: 1 hydroxyl amine (bis (alkyl hydrogenated bait) oxidized amines and Tris (2,4-di-tert-butylphenyl) phosphite (commercially available from Fiberstab FS 301 system by Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada.) (3) The remaining melt-processable additives consist of either a polypropylene or polyethylene carrier resin in combination with a pigment. ("PP") used in the formulations has a melt flow rate of between 2 and 35. The polyethylene carrier ("PE") used in the sample formulations has a melt index of between 1 and 20.

TABLE 3 FUSION PROCESSABLE ADDITIVE FORMULATIONS In TABLE 3, Examples 27 and 28 have the highest amounts of UV HALS in the spin-bonded product, from 16,500 to 21,000 ppm, and provide a fabric that has a longer service life and greater durability. Examples 3 to 11 further illustrate non-woven fabrics with UV stability having a layer of spunbond fabric made in accordance with the invention. In general, the fabric layers of these examples include from 88 to 99.0% by weight of a polypropylene base resin; up to 10% by weight of an ultraviolet color concentrate and up to 10% by weight of an ultraviolet augmentation formulation. Both of the color concentrate and ultraviolet augmenting formulations have melt flow rates less than 35. The ultraviolet color concentrate has the following general formula: from 15.0 to 50.0%. by weight of a mixture of hindered amine photostabilizers; up to 10.0% by weight of a processing aid; up to 10.0% pigments; and and the remainder of the formulation comprising a polypropylene carrier resin.

The hindered amine photostabilizers in the color concentrate of Examples 3-10 are a mixture of Chimassorb ™ 119 and Tinuvin ™ 622, and Example 11 is a mixture of Chimassorb ™ 119 and 2020. Tinuvin ™ 622, Chimassorb ™ 119 and 2020 are found all commercially available from Ciba Specialty Canada, Mississauga, Ontario, Canada. The processing aid in the color concentrate of Examples 3-11 is the Fiberstab ™ FS 301 system commercially available from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada, which is a 1: 1 combination of hydroxyl amine hydroxyl amine (bis (hydrogenated alkyl bait) oxidized amines and Tris (2,4-di-tert-butylphenyl) phosphite The last component, Tris (2,4-di-tert-butylphenyl) phosphite is also available separately under the trademark Irgafos® 168 from Ciba Specialty Chemicals Canada The data sheet for the FS 301 system and the IrgafosMR168 is incorporated herein by reference.The processing aid performs the critical function of reducing the sudden increases in viscosity of the PP homopolymer, usually caused by the introduction of hindered amines in polypropylene Although such a function can be effected by traditional phenolic antioxidants, it is known that they also cause yellowing of the polypropylene fabric eno, unlike the processing aids used in the formulations of the invention. As mentioned, formulations incorporating the FS 301 processing system are added up to 10% by weight, preferably between 2-5% by weight. In the final spunbonded cloth layer the processing aid is present in amounts ranging from 100 to 10.00 ppm, preferably from 1000 to 3000 ppm. The pigments in the formulations are used to impart color. As illustrated in Examples 3-11, various pigments are incorporated into the formulations depending on the desired color of the resulting spunbond fabric. The pigments used include: Natural UV Brown, Dark Gray Seagull UV, Neutral UV Gray, UV Gray Lime, UV Carbon Gray # 1; Carbon Gray # 2, Blue UV Bright, Blue UV Brilliant, UV Gray Lime # 2, UV Desert Powder # 1-PP, UV Desert Powder # 2-PP, UV Desert Powder # 1-PE and UV Powder Desert # 2-PE all commercially available from Standridge Color Corporation, Social Circle, Georgia. The respective data sheets for each of the pigments are incorporated herein by reference. The pigments used include inorganic pigments, organic pigments, metal oxides, combinations of these pigments, as well as other materials. The pigments are typically added at levels of up to 40% by weight, preferably up to 10% by weight, in the UV color concentrate formulations. The selection of the carrier resin is very important to achieve the desired melt flow characteristics of the concentrate. It was found that both of the polypropylene and polyethylene carrier resins were suitable for incorporating UV stabilizer charges and processing aid systems. Nevertheless, since UV stabilizers typically have molecular weights significantly lower than those of the polypropylene homopolymer, only carriers of polypropylene and polyethylene with the correct viscosity can be used to produce the fabrics of the invention. Preferred polypropylene carrier resins that resulted in the highest melt stability in the formulations include the ProfilMR6301 from Montel and the ProfaxMR6501 from Montel, both in powder form, commercially available from Montell Canada, Varennes, Quebec, Canada. The ProfaxMR6301 has a melt flow rate of 11 and the ProfaxMR6501 has a melt flow rate of 4. The data sheets for Montel's ProfaxMR6301 and Montel's ProfaxMR6501 are incorporated herein by reference. Preferred polyethylene carrier resins used in the formulations include polyethylene resins having a melt index of less than 20, commercially available from Mobil Polymers, Edison, New Jersey. The ultraviolet augmentation formulations have the following general formula: From 15.0 to 50.0% by weight of a hindered amine photostabilizer; From 1.0 to 5.0% by weight of a phosphite processing aid; and the rest a carrier resin that is a mixture of polyethylene and polypropylene. The hindered amine photostabilizer used in the booster formulations of Examples 3 to 11 was Poly [6- [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2,4-diyl ] [2, 2, 6, 6-tetramethyl-4-piperidyl) imino] hexamethylene [2, 2, 6, 6, -tetramethyl-4-piperidyl) imino]] which is commercially available as Chimassorb 944 from Ciba Specialty Chemicals Canada, Mississauga, Ontario, Canada. The data sheet for ChimassorbMR 944 is incorporated herein by reference. The processing aid used in the augmentation formulations of Laos Examples was Tris (2,4-di-tert-butylphenyl) phosphite (commercially available as Irgafos MR168). The carrier resin was a combination of from 2 to 20% by weight of a low density polyethylene having a Melt Index of 2 and a polypropylene having a melt flow rate of 4 (commercially available as ProfaxMR6501 from Montel). Examples 3 to 11 below are only illustrative of some of the spunbonded fabrics encompassed by the invention and does not mean that they are limiting.

EXAMPLE 3 A spin-bonded fabric (28.4 gsy) was formed by combining the UV Color concentrate formulations, UV augmentation formulations and virgin polypropylene resin as described above. The pigment used in this example was UV Desert Powder. The two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 4. The total amount of hindered amine photostabilizers present in each fabric layer is 7500 ppm.

TABLE 4 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN TABLE 4 (continued) PROPERTIES OF FABRIC UNITED BY YARN-UNITED BY YARN EXAMPLE 4 A spin-bonded fabric (28.4 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was the. Green UV Cal. Two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 5. The total amount of hindered amine photostabilizers present in each fabric layer is 7500 ppm.

TABLE 5 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN EXAMPLE 5 A spin-bonded fabric (56.7 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was the Vde 'V Cal. Two layers of this fabric were thermally bonded together to form a spin-linked structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 6. The total amount of hindered amine photostabilizers present in each fabric layer is 7500 ppm.

TABLE 6 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN EXAMPLE 6 A spunbond fabric (28.4 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was UV Neutral Brown. Two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 7. The total amount of hindered amine photostabilizers present in each fabric layer is 7500 ppm.

TABLE 7 PROPERTIES OF FABRIC UNITED BY YARN-UNITED BY YARN EXAMPLE 7 I '»A spunbond fabric (28.4 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was the UV Desert Powder. Two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 8. The total amount of hindered amine photostabilizers present in each fabric layer is 13,500 ppm.

TABLE 8 PROPERTIES OF FABRIC UNITED BY YARN-UNITED BY YARN EXAMPLE 8 A fabric joined by. spinning (28.4 gsy) by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was UV Neutral Brown. Two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 9. The total amount of hindered amine photostabilizers present in each fabric layer is 13,500 ppm.

TABLE 9 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN EXAMPLE 9 A spunbond web (28.4 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was UV Gray Cal. Two layers of this fabric were thermally bonded together to form a spin-linked structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 10. The total amount of hindered amine photostabilizers present in each cloth layer is 13,500 ppm.

TABLE 10 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN EXAMPLE 10 A spin-bonded fabric (56.7 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was UV Gray Cal. Two layers of this fabric were thermally bonded together to form a spin-linked structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 11. The total amount of hindered amine photostabilizers present in each fabric layer is 13,500 ppm.

TABLE 11 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN EXAMPLE 11 A spunbond fabric (101.7 gsy) was formed by combining the UV color concentrate formulations, UV enhancer formulations and virgin polypropylene resin as described above. The pigment used in this example was the UV Gray Seagull Dark. Two layers of this fabric were thermally bonded together to form a spun-bonded structure by spinning. The physical properties and measurements of this cloth were taken and summarized in TABLE 12. The total amount of hindered amine photostabilizers present in each fabric layer is 14,000 ppm.

TABLE 12 PROPERTIES OF THREAD UNITED BY YARN-UNITED BY YARN- UNITED BY YARN The properties of the polymer that has influences on the final properties of the fiber in the spunbonded cloth are the molecular weight, molecular weight distribution (MWD) and degree of crystallinity. In general, the higher the molecular weight and degree of crystallinity, the stronger the final fibers. The MWD determines how the fibers behave in the stages of stretching in the molten state of fiber formation. This distribution has significant effects on the resistances and processability of the resulting fibers. In view of these polymeric properties and due to the flow rates in this melt, the chemical reactions and processability factors of the melt-processable additives used here, it has not been possible so far a spunbond fabric that renders UV stability . An advantage of this invention over the prior art practice in this area is the production of spunbond nonwoven fabric which "stains UV stability and maintains high strength of the fiber, particularly improved trapezoidal strip resistance. invention have been described for manufacturing purposes The variations modifications of the described preferred modes falling within the concept of this invention have been described and will also be readily apparent to those skilled in the art, it is intended that all those variations and modifications they are encompassed by the claims set forth hereinafter.It is noted in relation to this date the best method * known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (33)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A nonwoven fabric with ultraviolet light stability having a layer of spunbonded fabric, characterized in that it comprises: a base resin selected from the group consisting of polypropylene and polyethylene; combined with melt-processable additives; wherein the melt-processable additives are a mixture of (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxyl amines and phosphites; and (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene.
2. 2. The non-woven fabric according to claim 1, characterized in that the hindered amine photostabilizers are selected from the group consisting of 1, 3, 5-Triazine-2,4,6-triamine, N, "'- [l , 2-ethanediylbis [(4,6-bis- [buti (1,2,2,6,6-pentamethyl-4-piperamethyl) amino] -1,3,4-triazin-2-yl] imino] -3,1-propandiyl]] bis [N ', N "-dibutyl-N', N" -bis (1,2,2,6,6-penta-methyl-4-piperidin-yl); succinate polymer of dimethyl with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidmethanol; Poly [[6- [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2 , 4-diyl] [2, 2, 6, 6-tetra-methyl-4-piperidyl) imino] hexamethylene [2,2,6,6-tetra-methyl-4-piperidyl) imino]]; and 1,6 -Hexandiamine, polymer of N, N'-bis (2, 2, 6, 6-tetramethyl-4-piperidinyl) with 2,4,6-trichloro-1,3,5-triazine, the products of the reaction with N -butyl-1-butanamide and N-butyl-2, 2, 6, 6-tetramethyl-4-piperidinamine 3. The non-woven fabric according to claim 2, characterized in that at least two of the hindered amine photostabilizers are combined in a ratio of 9: 1 to 1: 9. 4. The non-woven fabric according to claim 1, characterized in that the total hindered amine photostabilizers present in the fabric layer are in amounts ranging from 1000 ppm to 25,000 ppm. 5. The non-woven fabric according to claim 1, characterized in that the processing aids are hydroxyl amine (bis (alkyl hydrogenated bait) amines, oxidized and 'Tris (2,4-di-tert-butylphenyl) phosphite. 6. The non-woven fabric according to claim 1, characterized in that the processing aids are present in the fabric layer in amounts ranging from 100 ppm to 10,000 ppm. The non-woven fabric according to claim 1, characterized in that the carrier resin is polyethylene with a melt index of 1 to 20. The non-woven fabric according to claim 1, characterized in that the carrier resin is polypropylene with a flow rate in the molten state between 2 and 60. 9. The non-woven fabric according to claim 1, characterized in that the carrier resin is a mixture of polypropylene and polyethylene combined in a ratio of 9.5: 1 to 1: 9.5 The non-woven fabric according to claim 1, characterized in that the melt-processable additives have a combined melt flow rate of less than 35. 11. The non-woven fabric according to claim 1, characterized in that the The fabric layer further comprises color pigments added at levels of up to 10% by weight. The non-woven fabric according to claim 1, characterized in that it has at least two of the spunbonded fabric layers thermally bonded together. The non-woven fabric according to claim 1, characterized in that it has at least three of the spunbonded fabric layers thermally bonded together. The non-woven fabric according to claim 1, characterized in that it has at least four of the fabric layers joined by spinning. 15. A non-woven fabric with UV stability having a layer of spunbond fabric, characterized in that it comprises: (a) from 80 to 99.0% by weight of a base resin selected from the group consisting of polypropylene, polyethylene, polyester and polyamide; (b) up to 10% ultraviolet color concentrate comprising: (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxyl amines and phosphites; (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene; and (iv) pigments; and (c) up to 10% of an ultraviolet enhancer comprising: (i) a hindered amine photostabilizer; (ii) a processing aid selected from the group consisting of phosphites; and (iii) a carrier resin comprising a low density polyethylene having a melt melt index of less than 20 and polypropylene. 16. The non-woven fabric according to claim 15, acterized in that the hindered amine photostabilizers are selected from the group consisting of 1, 3, 5-Triazin-2, 6-triamine, N, N "'- [1 , 2-ethanediylbis [(4,6-bis- [buty (1,2,2,6,6-pentamethyl-piperidinyl) amino] -1,3,4-triazin-2-yl] imino] -3, 1-propandiyl]] bis [N ', N "-dibutyl-N', N" -bis (1, 2, 2, 6, 6-penta-methyl-4-piperidin-yl); polymer of dimethyl succinate with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinetanol; Poly [[6- [(1, 1, 3, 3-tetramethylbutyl) amino] -1,3,5-triazine-2, 4- diyl] [2,2,6,6-tetra-methyl-4-piperidyl) imino] hexamethylene [2,2,6,6-tetra-methyl-4-piperidyl) imino]] and 1,6-hexamideamine, polymer of N, N'-bis (2, 2, 6, 6-tetramethyl-4-piperidinyl) with 2,4,6-trichloro-1,3,5-triazine, the products of the reaction with N-butyl- 1-butanamide and N-butyl-2, 2, 6, 6-tetramethyl-4-piperidinamine 17. The non-woven fabric according to claim 16, acterized in that The ultraviolet color concentrate contains at least two of the hindered amine photostabilizers which are combined in a ratio of 9: 1 to 1: 9. The non-woven fabric according to claim 15, acterized in that the total hindered amine photostabilizers present in the fabric layer are in amounts ranging from 1000 ppm to 25,000 ppm. The non-woven fabric according to claim 15, acterized in that the processing aids are hydroxyl amine (bis (alkyl hydrogenated bait) amines, oxidized and Tris (2,4-di-tert-butylphenyl) phosphite. non-woven fabric according to claim 15, acterized in that the processing aids are present in the fabric layer in amounts ranging from 100 ppm to 10,000 ppm 21. The non-woven fabric according to claim 15, acterized in that the carrier resin is polypropylene with a melt flow rate between 2 and 60. 22. The non-woven fabric according to claim 15, acterized in that the carrier resin is a blend of polypropylene and polyethylene combined in a ratio of 9.5: 1 to 1: 9.5. 23. The non-woven fabric according to claim 1, characterized in that the ultraviolet color concentrate and the ultraviolet enhancer each have a melt flow rate of less than 35. The non-woven fabric according to claim 15, characterized in that the pigments are added at levels of up to 10% by weight. 25. The non-woven fabric according to claim 15, characterized in that it has at least two of the spunbonded fabric layers thermally bonded together. 26. The non-woven fabric according to claim 15, characterized in that it has at least three of the spunbonded fabric layers thermally bonded together. 27. The non-woven fabric according to claim 15, characterized in that it has at least four of the fabric layers joined by spinning. 28. A method for manufacturing a non-woven fabric with UV stability having a layer of spunbonded fabric, characterized in that it comprises the steps of: combining a base resin selected from the group consisting of polypropylene and polyethylene with melt-processable additives. to form a homogeneous mixture; wherein the melt-processable additives are a mixture of (i) at least two hindered amine photostabilizers; (ii) a processing aid selected from the group consisting of hydroxyl amines and phosphites; (iii) a carrier resin selected from the group consisting of polypropylene and polyethylene; and spinning the homogeneous mixture to form the non-woven fabric layer. 29. The method according to claim 28, characterized in that the hindered amine photostabilizers are selected from the group consisting of 1,3,5-Triazine-2,4,6-triamine, N, N "'- [1, 2-ethanedi-bis [(4,6-bis [buti (1,2,2,6,6-pentamethyl-4-piperamyrinyl) amino] -1,3,4-triazin-2-yl] imino] -3 , 1-propandiyl]] bis [N ', N "-dibutyl-N', N" -bis (1, 2, 2, 6, 6-penta-methyl-4-piperidin-yl); dimethyl succinate polymer with 4-hydroxy-2, 2,6,6-tetramethyl-1-piperidinetanol; Poly [[6 - [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2, 4 -diyl] [2, 2, 6, 6-tetra-methy1-4-piperidyl) imino] hexamethylene [2,2,6,6-tetra-methyl-4-piperidyl) imino]]; and 1,6-hexanoandiamine , polymer of N, N'-bis (2, 2, 6,6-tetramethyl-4-piperidinyl) with 2,4,6-trichloro-1,3,5-triazine, the products of the reaction with N-butyl -1-butanamide and N-butyl-2, 2, 6, 6-tetramethyl-4-piperidinamine. 30. The method according to claim 29, characterized in that at least two of the hindered amine photostabilizers are combined in a ratio of 9: 1 to 1: 9. 31. The method of compliance with the claim 28, characterized in that the hindered amine photostabilizers are aggregated to result in amounts ranging from 1000 ppm to 25,000 ppm in the fabric layer. 32. The method according to claim 28, characterized in that the processing aids are hydroxyl amine (bis (alkyl hydrogenated bait) amines, oxidized and Tris (2,4-di-tert-butylphenyl) phosphite. according to claim 28, characterized in that the processing aids are added to result in quantities ranging from 100 ppm to 10,000 ppm in the fabric layer 3. The method according to claim 28, characterized in that the carrier resin is polyethylene with a melt index of 1 to 20. 35. The method according to the claim 28, characterized in that the carrier resin is polypropylene with a melt flow rate of between 2 and 60. 36. The method according to the claim 28, characterized in that the carrier resin is a blend of polypropylene and polyethylene combined in a ratio of 9.5: 1 to 1: 9.5. 37. The method according to claim 28, characterized in that the melt-processable additives have a combined melt flow rate of less than 35. The method according to claim 28, characterized in that the additives are melt-processable. they also comprise color pigments aggregated at levels of up to 10% by weight. 39. The method according to claim 28, wherein the non-woven fabric has at least two of the fabric layers joined by spinning, characterized in that it comprises the steps of: spinning the homogeneous mixture to form the first and second layers of fabric. nonwoven; and thermally joining the first and second layers together. 40. The method according to claim 28, wherein the non-woven fabric has at least three of the fabric layers joined by spinning, characterized in that it comprises the steps of: spinning the homogeneous mixture to form the first, second and third layers of non-woven fabric; and thermally joining the first, second and third layers together. 41. The method according to claim 28, wherein the non-woven fabric has at least four of the fabric layers joined by spinning, characterized in that it comprises the steps of: spinning the homogeneous mixture to form the first, second, third and fourth layers of non-woven fabric; and thermally joining the first, second, third and fourth layers together. 42. The method according to claim 28, characterized in that the spunbond fabric layer has improved trapezoidal tear in both MD and CD directions.