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ABSTRACT

The invention relates to a process for ennobling, i.e., finishing, fabrics, in particular fabrics comprising cellulose, preferably regenerated cellulose.

STATE OF THE ART

The term "ennobling" refers, in general, to finishing treatments designed to improve the characteristics of the fabrics. They include finishing treatments carried out to improve characteristics such as, for example, the appearance, softness and hand, or to give the fabric new properties, for example anti-bacterial or anti-wrinkle properties. The processes of ennobling, or finishing, are, in general terms, the production steps in which the fabric is made suitable for sale and its subsequent use.

The fabrics that comprise cellulose, particularly regenerated cellulose, are used to produce a wide variety of items, among which not only clothing items, including pajamas and robes, but also sheets, pillowcases, tablecloths, napkins and the like. Therefore, it is necessary that the fabrics have a pleasing appearance and hand.

Several ennobling, or finishing, processes are known that are useful to give fabrics a pleasing appearance and hand. For example, fabrics have been known to be treated with softeners. However, such treatments do not allow obtaining a fabric that is not only pleasing in the appearance and hand, but also resistant and adapted for the production of items of daily use. Also known are processes in which the fabric is treated with resins, particularly resins comprising a crosslinking agent, for example formaldehyde or its derivative compounds.

However, the known resin treatments do not allow for treated fabrics to have a fully satisfactory appearance and hand.

SUMMARY OF THE INVENTION

Object of the present invention is to provide a process which allows making a fabric that has a particularly pleasing appearance and hand. Another object of the present invention is to provide a process which allows making a fabric that is antipilling and anti -wrinkle. Further object of the present invention is to provide a process which allows making a fabric that has a silky hand and that may be used in the production of a wide range of items.

These and other objects, which will be even better clarified by the description below, are achieved by the process according to claim 1. Preferred embodiments are the subject of the dependent claims 2-19. The process according to the present invention allows making a fabric treated according to claim 20, which may be, in turn, used for the production of items, for example household goods or clothing items, according to claim 23.

DESCRIPTION OF THE INVENTION

The present document refers to an ennobling process of fabrics which comprise regenerated cellulose fibers, comprising the following steps: a. providing a fabric comprising regenerated cellulose fibers; b. treating at least part of said fabric with an aqueous composition comprising at least one crosslinking resin, preferably in an amount in the range from 30 to 90 g/1, preferably from 40 g/1 or 70 g/1 to 90 g/1, more preferably from 70 g/1 or 75 g/1 to 85 g/1, at least one catalyst adapted to activate the polymerization of the resin, preferably in an amount in the range from 5 g/1 to 25 g/1, preferably from 7 g/1 or 10 g/1 to 25 g/1, more preferably from 15 g/1 to 20 g/1, at least one silicone softening agent, preferably in an amount in the range from 7 g/1 to 30 g/1, for example from 15 g/1 to 30 g/1, more preferably from 20 g/1 to 25 g/1, and at least one non-silicone softening agent, preferably in an amount in the range from 10 g/1 to 40 g/1, for example from 20 g/1 to 40 g/1, more preferably from 30 g/1 to 35 g/1.

The process according to the invention allows fabrics comprising regenerated cellulose fibers to be given a particularly pleasing appearance and a particularly silky hand. The treated fabric is, moreover, particularly resistant and has anti-wrinkle characteristics.

In embodiments, the crosslinking resin comprises at least one of dimethylol dihydroxy ethylene urea (DMDHEU) and/or derivatives thereof. For example, commercial products adapted for use as resins in the process of the invention are the currently commercially available products called "Fixapret", sold by BASF. For example, the commercial product "Fixapret® AP", currently commercially available and sold by BASF, is particularly adapted for use in the process of the invention in the specified amount, i.e., in the range from 70 g/1 to 90 g/1, more preferably from 75 g/1 to 85 g/1.

According to an aspect of the present invention, the crosslinking resin requires a catalyst, i.e., a compound adapted for activating and/or promoting the crosslinking, i.e., polymerization reaction, of the resin. In general, the use of a catalyst also allows for adjusting the course of the crosslinking reaction, for example adjusting the amount of resin to be crosslinked. For example, by varying reaction parameters such as, for example, the resin: catalyst ratio, the temperature at which the reaction takes place and/or the residence time at the reaction temperature, the progress of the polymerization reaction of the resin may be controlled.

According to embodiments, the catalyst may be selected from metal salts, ammonium salts and mixtures thereof. According to embodiments, the metal salt may be selected from magnesium chloride (MgCh), zinc nitrate (Zn(NO ₃ ) ₂ ), zinc chloride (ZnCl ₂ ), aluminum sulfate (Af/SO-Os), aluminum hydrochloride, and mixtures thereof. According to embodiments, the ammonium salt may be selected from ammonium chloride (NH4CI), ammonium sulfate ((NFU^SC ), ammonium nitrate (NH4NO3), and mixtures thereof. Preferably, the catalyst is magnesium chloride.

According to an aspect of the present invention, the amount of resin included in the composition is in the range from 70 g/1 to 90 g/1, preferably from 75 g/1 to 85 g/1, and more preferably from 75 g/1 to 80 g/1.

According to embodiments, the amount of catalyst, preferably magnesium chloride, is in the range from 10 g/1 to 25 g/1, preferably from 10 g/1 to 23 g/1, more preferably from 15 g/1 to 20 g/1, and even more preferably from 15 g/1 to 18 g/1. In general, in embodiments, the amount of catalyst with respect to the resin is in the range from 20% to 25% by weight, i.e., in a resin/catalyst ratio in the range from 4/1 to 5/1 w/w.

According to an aspect of the present invention, the composition comprises at least one silicone softening agent in an amount in the range from 7 g/1 to 30 g/1, for example from 15 g/1 to 30 g/1, preferably from 20 g/1 to 25 g/1. More preferably, the amount of silicone softening agent comprised in the composition is in the range from 20 g/1 to 22 g/1. In embodiments, the silicone softener is selected from polysiloxanes, the polysiloxanes containing amine groups, and mixtures thereof. Preferably, the silicone softener is a polysiloxane containing amine groups. Examples of polysiloxanes adapted for use in the present invention are polydimethylsiloxane, a, - dihydroxypolymethylsiloxane, and mixtures thereof. Examples of polysiloxanes containing amine groups suitable for use in the present invention are poly dimethyl siloxane containing amine groups, a,Q-dihydroxypolymethylsiloxane containing amine groups, and mixtures thereof. For example, a silicone softener adapted for use in the present invention is the product known by the trade name "Siligen SIO", currently commercially available and sold by BASF, usable in the amount in the range from 20 g/1 to 25 g/1, more preferably from 20 g/1 to 22 g/1.

According to an aspect of the present invention, the composition comprises at least one non-silicone softening agent in an amount in the range from 10 g/1 to 40 g/1, for example from 20 g/1 to 40 g/1, preferably from 30 g/1 to 35 g/1. Preferably, the amount of non-silicone softening agent comprised in the composition is in the range from 30 g/1 to 33 g/1.

In embodiments, the non-silicone softening agent is selected from polyethylene dispersions, fatty acid esters, stearyl-urea derivatives, and mixtures thereof. Preferably, the non-silicone softener is a polyethylene dispersion.

For example, a non-silicone softening agent adapted for use in the present invention is the product known by the trade name "Siligen PEP", currently commercially available and sold by BASF, usable in the amount in the range from 30 g/1 to 35 g/1, more preferably from 30 g/1 to 33 g/1.

According to embodiments of the present invention, the composition comprises at least one wetting agent in an amount in the range from 0.2 g/1 to 3.0 g/1, for example from 0.5 g/1 to 3 g/1, preferably from 1 g/1 to 2 g/1. More preferably, the amount of wetting agent comprised in the composition is in the range from 1 g/1 to 1.5 g/1.

In embodiments, the wetting agent is selected from non-silicone wetting agents. Preferably, the wetting agent comprises at least one non-silicone, preferably non-ionic, wetting agent. For example, a wetting agent adapted for use in the present invention is the product known by the trade name "Kieralon Jet", currently commercially available and sold by BASF, usable in the amount in the range from 1 g/1 to 2 g/1, more preferably from 1 g/1 to 1.5 g/1.

In embodiments, the composition further comprises at least one acid, preferably organic, more preferably selected from citric acid, acetic acid, lactic acid, formic acid, oxalic acid, uric acid, malic acid, tartaric acid, and mixtures thereof. In embodiments, the organic acid is the citric acid.

In embodiments, the organic acid is in an amount in the range from 0.2 g/1 to 3 g/1, preferably from 0.5 g/1 to 2 g/1, more preferably from 0.5 g/1 to 1 g/1.

As mentioned above, the present invention relates to an ennobling treatment of fabrics which comprise regenerated cellulose fibers.

In embodiments, the fabric may be selected from orthogonal fabric or knitted fabric.

The regenerated cellulose is, in itself, well-known in the art. In general, regenerated cellulose fibers are made by dissolving or chemically reacting the cellulose obtained, for example, from wood, so as to achieve a spinnable fluid, which is processed in order to make a cellulose fiber.

In embodiments, the fabric consists of regenerated cellulose fibers, comprises or preferably consists of fibers known as HWM (High Wet Modulus), such as for example Modal, Liocell, Tencel fibers, polynosic fibers or a mixture thereof. These fibers are known in the art and are for example described in Handbook of Textile Fibers, II Man-Made Fibers, 2001 Woodhead Publishing Limited, pages 52-55. The term Modal fiber refers to regenerated cellulose fibers provided with high tenacity and high modulus in wet conditions.

In embodiments, the regenerated cellulose fibers are selected from Modal, Liocell, Tencel, viscose fibers, and mixtures thereof.

In embodiments of the invention, the regenerated cellulose fibers are derived from wood. For example, the regenerated cellulose fibers, particularly Modal fibers, may be derived from beech wood.

When the fabric is an orthogonal fabric, it comprises warp yams and weft yarns. In embodiments, when the fabric is an orthogonal fabric, at least part of the warp yams or at least part of the weft yams or at least part of both yarns may comprise regenerated cellulose fibers. In embodiments, at least part of the warp yams or at least part of the weft yarns or at least part of both yams may consist of regenerated cellulose fibers.

In embodiments, particularly when the fabric is an orthogonal fabric, the thread count may vary, for example, in the range from 200 to 1000 threads (considering the total number of warp and weft threads) per square inch (i.e., in the range from 31 threads per cm ² to 155 threads per cm ² ). In embodiments, the thread count may be 200, 300, 400, 500, 600, 700, 800, 900 or 1000 yams per square inch (i.e., 31, 46.5, 62, 77.5, 93, 108.5, 124, 139.5 or 155 yams per cm ² ). In embodiments, the fabric has 200, 300, 400 or 1000 threads per square inch (i.e., 31, 46.5, 62 or 155 threads per cm ² ). 1 square inch corresponds to 6.4516 square centimeters (cm ² ).

In embodiments, the fabric may comprise yarns having a count, i.e., linear mass density, in the range from Ne 20 to Ne 80, preferably from Ne 40 to 60. For example, the fabric may comprise yarns having yam count of Ne 40, Ne 50, Ne 60, individually or in combination to each other.

In embodiments, the fabric consists of regenerated cellulose fibers, preferably consisting of Modal or Liocell or Tencel fibers or a mixture thereof.

In preferred embodiments, the fabric is an orthogonal fabric in which both weft and warp yarns consist of regenerated fibers, preferably Modal fibers. For example, the fabric may be 100% Modal, i.e., consisting essentially of only Modal fibers.

In embodiments, in addition to the regenerated cellulose fibers, the fabric may further comprise at least one natural fiber and/or at least one synthetic fiber.

In embodiments, the weft yams or warp yams, or both, may comprise one or more natural fibers and/or one or more synthetic fibers.

In embodiments, the weft yarns or warp yarns, or both, may consist of one or more natural fibers or one or more synthetic fibers.

In embodiments, the natural fiber is selected from cotton, wool, flax, kenaf, ramie, hemp, linen fiber and mixtures thereof.

In embodiments, the synthetic fiber is selected from polyester, nylon, polyurethane, spandex (elastane), acrylic, modacrylic, acetate, polyolefin, vinyl fiber and mixtures thereof. According to embodiments, the fabric is colored, i.e., dyed. In other words, the fabric may be dyed before being treated with the aqueous composition comprising the crosslinking resin described above.

According to an aspect of the present invention, the fabric comprising regenerated cellulose fibers is treated with an aqueous composition which comprises at least one crosslinking resin, at least one catalyst, at least one silicone softening agent, and at least one non-silicone softening agent. Optionally, said composition may further comprise an organic acid, preferably citric acid, and a wetting agent. According to such aspect of the invention, the components cited hereinabove are each present in their own amount set forth above as being the most preferred and as such present in the claims.

After being treated, the fabric is preferably dried.

In embodiments the treated fabric, preferably dry, is calendered. The calendering may be performed according to techniques known, per se, in the art. In general, the calendering may be done by passing the fabric between two heated rollers that compress the fabric.

In embodiments the fabric, after the calendering, is heat treated at a temperature in the range from 160°C to 180°C, preferably from 170°C to 175°C, preferably for a time in the range from 1 minute to 3 minutes, more preferably from 1 minute to 1.5 minutes. The fabric is heat treated in order to obtain the polymerization i.e., the crosslinking of the resin on the fabric.

For example, the heat treatment adapted to obtain the polymerization of the resin may be carried out by dry step in a drying machine, for example a tentering machine.

In embodiments, after being heat treated, the fabric may be washed and dried.

In embodiments, when the resin contains formaldehyde, the fabric, after the heat treatment, is washed in order to neutralize and/or remove residual free formaldehyde from the fabric. Such washing may be performed using techniques known, per se, in the art; for example, the washing may be performed with water, at a temperature of about 40°C.

After being washed the fabric is dried, preferably at a temperature in the range from 100°C to 150°C, preferably from 110°C to 130°C.

According to preferred embodiments, the process of the invention comprises one or more fabric pre-treatment steps. In other words, in embodiments of the present invention, the fabric may be pre-treated prior to being treated with the aqueous composition comprising resin, at least one catalyst, at least one silicone softening agent and at least one non-silicone softening agent, as described above.

According to embodiments, the fabric may be pre-treated by performing one or more steps selected from desizing, singeing and bleaching.

In the present description, the term "desizing" refers to a process adapted to remove the size from the fabric at the end of the fabric manufacturing process, in particular, after the fabric is removed from the loom. The size is a liquid, typically oily and sticky, generally comprising starch and applied to the yams in the preparation step to the weaving.

In the present description, the term "singeing" refers to a process adapted to remove fluff protruding from the fabric. The singeing process may be carried out by techniques known, per se, in the art. Typically, the fabric is passed close to or perpendicular to a flame, so as to burn off the fluff that protrudes from the fabric surface.

In the present description, the term "bleaching" refers to a process adapted to remove any impurities, particularly colored impurities, so as to make the fabric as white as possible, for example to prepare the fabric for dyeing or printing, as well as to increase the luster of the fabric.

According to embodiments, the process of the invention comprises a bleaching step of the fabric, prior to the treatment with the aqueous composition comprising resin, at least one silicone softening agent and at least one non-silicone softening agent. In other words, in embodiments, the fabric may be bleached before being treated with the mentioned composition.

In embodiments, the bleaching is performed by treating the fabric with an aqueous bleaching composition comprising a bleaching agent, preferably also a strong base and optionally a stabilizing agent.

In embodiments the bleaching agent may be, for example, oxygenated water (hydrogen peroxide) or sodium hypochlorite. Preferably, the amount of bleaching agent is in the range from 10 ml/1 to 60 ml/1, more preferably from 20 ml/1 to 50 ml/1, even more preferably from 30 ml/1 to 40 ml/1.

For example, hydrogen peroxide at a concentration of 130 volumes may be used as a bleaching agent in an amount in the range from 20 ml/1 to 50 ml/1, more preferably from 30 ml/1 to 40 ml/1.

In embodiments, the strong base may be selected from NaOH, KOH, and mixtures thereof. Preferably, the amount of strong base is in the range from 5 ml/1 to 40 ml/1, more preferably from 10 ml/1 to 30 ml/1, even more preferably from 20 ml/1 to 25 ml/1.

For example, the strong base may be caustic soda at 48°Be (Baume degrees) in an amount in the range from 10 ml/1 to 30 ml/1, more preferably from 20 ml/1 to 25 ml/1.

The stabilizing agents allow adjusting the bleaching process and allow obtaining a better degree of whiteness, while limiting the degradation of the fabric fibers. They may be both organic and inorganic in nature. Stabilizing agents for the bleaching processes are, per se, known in the art. In embodiments, the stabilizing agent may be selected from phosphate, sulfonate stabilizers, and mixtures thereof. For example, a stabilizing agent adapted for use in the present invention is the product known by the trade name "Softstab TIG", currently commercially available and sold by Soft Chemicals S.r.l. Preferably, the amount of stabilizing agent is in the range from 2 ml/1 to 10 ml/1, more preferably from 4 ml/1 to 8 ml/1, more preferably from 5 ml/1 to 7 ml/1. When the commercial product used as stabilizing agent in the process of the invention is Softstab TIG, it is usable in an amount in the range from 4 ml/1 to 8 ml/1, more preferably from 5 ml/1 to 7 ml/1.

In embodiments, the fabric is impregnated with the bleaching composition and is incubated i.e., maintained in an impregnated state, preferably at room temperature, preferably for 24 hours. The fabric is then washed, preferably at a temperature in the range from 70°C to 90°C, and dried at a temperature in the range from 110°C to 150°C.

In embodiments, the invention process also comprises a singeing step, prior to the bleaching step. According to embodiments, the process of the invention further comprises a desizing step, prior to said singeing step.

In embodiments, the desizing is performed by treating the fabric with an aqueous desizing composition comprising at least one enzyme selected from amylase, cellulase, pectinase, and mixtures thereof.

Preferably, the amount of enzyme is in the range from 2 g/1 to 8 g/1, more preferably from 4 g/1 to 7 g/1, even more preferably from 5 g/1 to 6 g/1.

Optionally, the desizing composition may further comprise one or more sequestering agents and/or one or more wetting agents.

In embodiments, the wetting agent is selected from non-silicone wetting agents. Preferably, the wetting agent comprises at least one non-silicone, preferably non-ionic, wetting agent. For example, a wetting agent adapted for use in the present invention is the product known by the trade name "Kieralon Jet", currently commercially available and sold by BASF.

In embodiments, the sequestering agent may be selected from iron sequestrants, calcium and magnesium sequestrants, and mixtures thereof. Iron sequestrants and calcium and magnesium sequestrants adapted for use in desizing processes are, per se, known in the art. In embodiments, the sequestering agent may comprise a phosphonate sequestrant. For example, a suitable sequestering agent for use in the present invention is the product known by the trade name "Softquest SE", currently commercially available and sold by Soft Chemicals S.r.l., usable in an amount in the range from 3 g/1 to 6 g/1, more preferably from 4 g/1 to 5 g/1. Preferably, the amount of sequestering agent is in the range from 1 g/1 to 8 g/1, more preferably from 3 g/1 to 6 g/1, even more preferably from 4 g/1 to 5 g/1.

In embodiments, the wetting agent may be selected from the non-silicone surfactants and mixtures thereof. Preferably, the amount of wetting agent is in the range from 1 g/1 to 8 g/1, more preferably from 3 g/1 to 6 g/1, even more preferably from 4 g/1 to 5 g/1. When the commercial product used as wetting agent in the process of the invention is Kieralon Jet, it is usable in an amount in the range from 3 g/1 to 6 g/1, more preferably from 4 g/1 to 5 g/1.

In embodiments, the fabric is impregnated with the desizing composition and is incubated, preferably at a temperature in the range from 50°C to 70°C, preferably for 5 to 9 hours, more preferably for 6 to 8 hours. The fabric is then washed, preferably at a temperature in the range from 70°C to 90°C, and dried at a temperature in the range from 110°C to 150°C.

In an embodiment of the process of the invention, the fabric comprising regenerated cellulose fibers is pre-treated by performing a desizing step. The desized fabric is then subjected to a singeing and bleaching step. After the bleaching, the fabric may optionally be dyed according to techniques known, per se, in the art. The bleached fabric, optionally dyed, is then treated with the aqueous composition comprising at least one crosslinking resin, at least one catalyst, at least one silicone softening agent and at least one non-silicone softening agent, as described above. The so-treated fabric is subjected to calendering and heat treatment and finally, preferably, washed and dried.

Further object of the present invention is a fabric treated as obtained by the process according to the present invention.

In embodiments, the process according to the present invention allows obtaining a treated fabric comprising a coating including the polymerized resin. Such coating, which is preferably in the film form, may include at least the polymerized resin and the softeners used in the composition, in particular at least one silicone softener and one non-silicone softener.

In general, as discussed above, the present invention allows obtaining a treated fabric which has a particularly pleasing appearance and hand. In particular, the treatment with a composition comprising at least one crosslinking resin (and one catalyst), at least one silicone softener and at least one non-silicone softener, allows obtaining a treated fabric with a particularly bright appearance and a particularly silky hand. Furthermore, the treated fabric is able to maintain its aesthetic and functional characteristics substantially unchanged over time, even after repeated washing cycles. In fact, in addition to what has been discussed above, the treated fabric obtained by the process of the present invention is particularly resistant both to the formation of wrinkles and to pilling, i.e., to the formation of balls of fluff, which would compromise the aesthetic appearance of the fabric as well as its pleasantness to the touch. According to an aspect of the present invention, the treated fabric may be used in the production of a wide range of items.

A further object of the present invention is an item comprising a treated fabric obtained by the process of the invention.

In embodiments the item is preferably selected from household goods and clothing items. For example, household goods that may be produced from the fabric treated according to the present invention are items for the table, e.g., tablecloths and napkins; for the bed, e.g., sheets and pillowcases; or for the bathroom, e.g., wipes and towels. For example, clothing items that may be produced from the fabric treated according to the present invention are pajamas and robes.

Example

The present example, which is merely illustrative and not limiting, illustrates a possible embodiment of the process according to the present invention.

A fabric comprised of regenerated cellulose fibers, preferably Modal fibers, is treated with an aqueous composition, comprising: amylase enzyme 2-8 g/1 sequestering agent (Softquest SE) 1-8 g/1 wetting agent (Kieralon Jet) 1-8 g/1

The fabric impregnated with such a composition is incubated at 60°C for 6-8 hours. The fabric is then washed at 90°C and dried at 130°C.

Such treatment allows removing the size from the fabric.

The desized fabric is then subjected to a singeing treatment in a manner known in the art.

Next, the fabric is bleached. In particular, the fabric is treated with an aqueous composition comprising:

Oxygenated water 10-60 ml/1

Caustic soda 5-40 ml/1

Stabilizing agent (Softstab TIG) 2-10 ml/1

The fabric impregnated with such a composition is incubated at room temperature for 24 hours. The fabric is then washed at 90°C and dried at 130°C.

The bleached fabric is treated with an aqueous composition, comprising: Crosslinking resin (Fixapret AP) 70-90 g/1

Non-silicone softener (Siligen PEP) 20-40 g/1

Silicone softener (Siligen SIO) 15-30 g/1

Catalyst - Resin Activator (MgCh) 10-25 g/1 Citric acid 0.2-3 g/1

Wetting agent (Kieralon Jet) 0.5-3 g/1

In a preferred embodiment, the above components are provided in combination, each in the relative amount set forth as the most preferred in the description and claims. After being impregnated with such a composition, the fabric is dried at 120°C.

The dried fabric is subjected to hot calendering in a way known in the art.

The fabric is then heat-treated at 170°C for 1 minute to achieve the polymerization of the resin onto the fabric.

Then, the fabric is washed with water at about 40°C, in order to neutralize and remove the residual formaldehyde, and dried at 130°C.